Library

Notes: The electron impact mass spectra of twenty acetates and methylates of spirostanol and related furostanol glycosides of high molecular weight (above 650) have been investigated, and the most probable fragmentation patterns of the glycoside derivatives are presented. High resolution mass spectrometry provides useful information concerning the structures of both aglycone and sugar moieties as well as the molecular size of the oligoglycosides.

Notes: The use of thin-layer chromatography has demonstrated that incubations of indoleamines with 5-methyl[14C]tetrahydrofolic acid and an enzyme previously described as an N-methyltransferase, do not yield Nω, N1 or O-methylated products. Further elucidation by thin-layer chromatography, gas chromatography, mass spectrometry and selected ion monitoring enabled us to identify the reaction products as tetrahydroisoquinolines and tetrahydro-β-carbolines in mixtures incubated respectively with catecholamines and indoleamines in the presence of 5-methyl[14C]tetrahydrofolic acid and enzyme. The alkaloids have been shown to originate from a spontaneous condensation of the corresponding amines with formaldehyde, this latter being formed in the first stage of the reaction by enzymatic conversion from 5-methyltetrahydrofolic acid.

Notes: N6-(2-succinyl)adenosine 5′-phosphate and N-(5-amino-1-ribosyl-4-imidazole carbonyl)-L-aspartic acid ′-phosphate were prepared enzymatically using adenylosuccinate lyase (EC 4.3.2.2) isolated from human erythrocytes. N6-(2-succinyl)adenosine 5′-phosphate, N-(5-amino-1-ribosyl-4-imidazole carbonyl)-L-aspartic acid 5′-phosphate and N-(5-amino-1-ribosyl-4-imidazole carboxamide) 5′-phosphate and the nucleoside and free base analogs of these nucleotides were converted to the trimethylsilyl derivatives and characterized by mass spectrometry. The extent of the trimethylsilylation was greater for adenine substituted compounds compared with those related to aminoimidazole carboxamide. Major mass spectral fragment ions correspond to the intact base plus portions of the sugar skeleton and to electron impact-induced decomposition products of the sugar moiety. Succinyl substitution at N6 of the adenine derivatives leads to characteristic loss of CO2 SiMe3 from the molecular ion. A combination of liquid chromatographic procedures and gas chromatography mass spectrometry gave rapid and unequivocal identification of succinyladenine from human urine.

Notes: We have used peak matching to accurately determine the molecular masses of field desorbed ions. A major advantage over high resolution photoplate recording is that it reduces analysis time without reducing accuracy or sensitivity. Molecular ions of nonvolatile and thermally labile compounds can be mass measured by this technique.

Notes: Five children deficient in growth hormone were treated with oxandrolone and human growth hormone. Average nitrogen retained was calculated from nine day balance data. During some balance periods, nitrogen retention was calculated by determination of 15N labeled glycine, as reported in this article. Twenty milligrams of 15N in excess of the natural abundance was administered orally. Urines were collected prior to, as well as after, administration of glycine-15 N and were analyzed for 15N by mass spectrometry. The percentage of 15N ranged up to 0.449% for collection over a 24 hour period, compared with 0.364% from control samples without excess 15N. These 15N data, like those from nitrogen balance, show the stimulating effects of oxandrolone and human growth hormone in the group as a whole.

Notes: A method is described for the micro-identification of both mono- and diesters of 12-deoxyphorbol based upon a combination of thin-layer chromatography and mass spectrometry. The technique may be used on as little as 5 ml of fresh plant latex. Nine thin-layer systems are described, six of which are adsorption systems based on silica gel or alumina as adsorbent, and three are partition systems using diethyleneglycol as stationary phase. The migration by means of thin-layer chromatography is dependent upon the chain length of the C-13 esterifying acid and on the presence or absence of a free primary hydroxyl group at C-20. By means of mass spectrometry it was possible to confirm the identity of the esterifying moiety at both the C-13 and C-20 positions of 12-deoxy-4βOH-phorbol.

Notes: The urinary excretion by rats of predominantly 2-ethyl-3-deuterohydracrylic acid is a consequence of the intraperitoneal injection of 2-trideuteromethylbutyric acid. A significant fraction of the loading acid also is excreted unchanged. These results support the proposal of an alternate minor pathway of isoleucine catabolism and suggest that the corresponding catabolites in the minor and major pathways, 2-ethylhydracrylic and 2-methyl-3-hydroxybutyric acids, respectively, have significantly different subsequent metabolism.

Notes: Field desorption mass spectra of a tripeptide Pro-Leu-Gly-NH2, a pentapeptide Cbz-Gly-Pro-Leu-Gly-Pro and a nonapeptide Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg are presented. In each case, a [M]+· or [M + 1]+ peak of the peptide is obtained. Sufficient fragmentation of the peptide backbone occurred to allow sequence determination of all three peptides. The pentapeptide produced [M]+·, [M + 1]+ and [M + 2]+· ions which also included molecules of ethylacetate, ethanol and/or water bound to the ion.

Notes: A method is described for continous mass range specific gas chromatographic detection using the β-slit of a reverse geometry double focusing mass spectrometer. The method has several advantages over total ion current detection, including elimination of the solvent peak from the detector trace and reduction of back ground noise due to column bleeding. The technique has been applied here to detect prostaglandins in biological samples.

Notes: The photodecomposition products of aldrin, dieldrin and endrin were investigated by means of gas chromatography mass spectrometry, nuclear magnetic resonance and infrared spectrophotometry. An alternate isomeric product of aldrin and four endrin analogs were encountered. The mass spectra of eight photoproducts are presented with direct inlet spectra of endrin aldehyde and endrin alcohol.

Notes: The mass spectroscopic behaviour of prostaglandin A1 and its methyl ester has been studied. Mechanisms are suggested for the majority of fragmentation processes occurring in the spectra of these compounds. The proposed mechanisms have been confirmed by low electron voltage spectra, measurements on metastable ion decompositions, high resolution mass measurements and deuterium labelling.

Notes: A mass fragmentographic method is described for the simultaneous assay of both the acidic and alcoholic metabolites of tyramine, octopamine, dopamine and norepinephrine. The method was successfully applied for the measurement of nanogram quantities of these metabolites in human ventricular and lumbar cerebrospinal fluids and in the rat brain. Mass fragmentography was carried out on the methyl ester/pentafluoroproprionyl derivatives of the acidic and the pentafluoropropionyl derivatives of the alcoholic metabolites, employing an 8 ft 3% SE-54 column. Chemical methods for the synthesis of a number of deuterated isomers (isotopomers) of the above metabolites are also described. These isotopomers were utilized as internal reference standards for the assay of the metabolites in biological materials. They were also used to study the fragmentation reactions of these metabolite derivatives.

Notes: A N-dealkylated metabolite, 1-phenylcyclohexylamine, was detected in a urine sample of a patient who had ingested phencyclidine. The identification was facilitated by a feeding experiment using a mouse administered a 1:1 mixture of unlabeled and phenyl-d5-labeled drug. A control experiment was also performed in which a mouse was fed only the unlabeled drug. Two hydroxylated metabolities were also identified in human urine samples. One of the hydroxylated metabolites has a hydroxy group located at the piperidine moiety of phencyclidine while the other has the hydroxy group located at the cyclohexane ring of the drug. It was also shown that 1-phenyl-cyclohexene detected in the human samples, was an artifact which arose from pyrolysis of phencyclidine during gas chromatography.

Notes: Interfering nonpolar lipid material was removed from the acetone extracts of several samples of benign hyperplastic prostate tissue. Endogenous steroids were separated by preparative thin-layer chromatography into fractions containing testosterone, 5α-dihydrotestosterone and the 5α-androstane-3, 17-diols, and concentrations of these steroids were measured by molecular ion monitoring of suitable derivatives at a resolution of 8500 to 10 000 during combined gas chromatography mass spectrometry. The sensitivity and specificity of this procedure allowed unequivocal detection of the steroids of interest at the femtomole level and the incorporation of epimers as internal standards enabled accurate quantitative measurements. The results indicated that 5α-dihydrotestosterone is usually the most predominant of the steroids measured, and that of the 5α-androstanediols, only the 3α, 17β and 3β, 17β isomers occur in measurable concentration, with the former usually predominant.

Notes: Ultraviolet irradiation of the methanoindene compounds chlordene, 1-hydroxychlordene cis- and trans-chlordane, trans-nonachlor and heptachlor using acetone as the sensitizing solvent yielded caged photoisomers. Electron impact spectra of twelve photoproducts are reported. Structural assignments based on nuclear magnetic resonance, infrared and gas chromatography data are reported for the major photoproducts.

Notes: The extent of C-methylation, an artifact of the permethylation procedure used to derivatize peptides for mass spectrometric sequencing, was investigated by mass spectrometry. Ten glycine-containing peptides were N-acetylated and then permethylated by the Hakomori method and analyzed by chemical ionization and, in some cases, by electron ionization mass spectrometry. A comparative study was made of the tripeptides Gly Pro Ala and Ala Pro Gly, derivatized by three permethylation procedures. The results show that while C-methylation occurs primarily at glycine, other amino acids (Gln, Glu, Met, Tyr) are also C-methylated, but to a lesser degree. The extent to which C-methylation occurs varies widely and depends on residue position and on the identity of neighboring residues. Such artifacts could lead to serious errors in peptide sequences determined by mass spectrometry, especially when mixtures of peptides are analyzed.

Notes: Incubation of four common cannabinoids with vegetative cultures of the fungus Syncephalastrum racemosum yielded a number of polar metabolites. Major metabolites of Δ9-tetrahydrocannabinol, Δ8-tetrahydrocannabinol, cannabidiol and cannabinol were eluted from preparative thin-layer chromatographic plates and analyzed by gas-liquid chromatography mass spectrometry. The mass spectrum of each of the compounds examined showed a molecular ion corresponding to a monohydroxylated derivative of the parent cannabinoid. Identification of the major metabolite of each cannabinoid as the product of hydroxylation in the penultimate (4′) position of the n-pentyl sidechain was made by analysis of the mass spectra of underivatized and TMS derivatized metabolites and by comparison with model compounds. A number of prominent fragment ions in the mass spectra were identified as arising through known fragmentation pathways of cannabinoids.

Notes: A pressure measuring probe has been built for the chemical ionization source of a Du Pont 21 490-B mass spectrometer. The probe fits exactly in the place of the solid sample probe and, when connected to a Baratron manometer, enables pressure measurement directly in the source. This can be used to calibrate an ionization gauge connected to the source housing or a manometer in the reagent gas inlet line. The probe has been used to determine the maximum source pressure attainable for various reagent gases in the Du Pont 21 490-B mass spectrometer.

Notes: A method employing gas-liquid chromatography and combined gas-liquid chromatography mass spectrometry was developed for the quantitative determination of α-D-mannopyranoside-(1 → 3)-β-D-mannopyranoside-(1 → 4)-2-acetamido-2-deoxy-D-glucose in urines. The concentration of this trisaccharide varied between 123 and 469 mg per litre of urine in the patients with mannosidosis but was not detected in twenty normals and two heterozygotes.

Notes: The identification of 6-methoxy 8-aminoquinoline as a metabolite of Primaquine, an important antimalarial drug, is described. The metabolite is present in urine, plasma and erythrocytes following drug ingestion. It was identified by mass fragmentography of its 1H and 2H acetate and the acetate produced from authentic material. No evidence of further metabolites was obtained.

Notes: The field desorption mass spectra of eight rifamycins were obtained and compared with their electron impact mass spectra. All the compounds gave abundant molecular or quasimolecular ions, while no significant fragmentation was observed in the low mass region of the spectra. Therefore, field desorption mass spectrometry has been shown to be of great importance for the determination of the molecular weight of these antibiotics.

Notes: Complex mixtures of O-trimethylsilylated polyamino alcohols, which have been generated by either acid or enzymatic hydrolysis of polypeptides and subsequent derivatization, are completely characterized by a gas chromatograph mass spectrometer computer system. These peptide derivatives possess excellent gas chromatographic properties; a wide range of derivatives from di- to hexapeptides may be separated in a single chromatographic experiment. The identification of these compounds, either manually or with the assistance of the computer, is based on three sets of data which are automatically generated after the g.c.m.s. computer experiment: (1) mass spectra, which exhibit sequence-determining ions of high abundance; (2) selected ion records, which allow efficient location of peptide derivatives in the gas chromatogram as well as resolution of incompletely separated fractions; (3) retention indices, which can be calculated from values which have been assigned to each amino acid residue.

Notes: A routine analysis for micro samples of plasma amino acids by a gas chromatography mass spectrometry computer system has been developed. Isotope ratio determination was used as the quantitating technique via multiple internal standards. The speed of the analysis is increased by omitting the ion exchange purification step and its flexibility is maximized by using repetitive scanning rather than selective ion monitoring. This procedure yields excellent precision and accuracy, as demonstrated by the analysis of a known amino acid mixture and of neonatal plasma.

Notes: An ion doublet chemical ionization mass spectrometry technique was utilized for the rapid detection and elucidation of the structure of a new hydroxylated metabolite of the oral anticoagulant warfarin. This technique involves the use of a 50:50 mixture of stable isotope labeled and unlabeled drug. With this procedure ions found in the mass spectrum which are associated with the administered drug can be identified unambiguously. The unknown metabolite from rat liver microsomal preparations was identified as benzylic hydroxywarfarin by reincubating the microsomes with warfarin specifically labeled in the benzylic position and observing the subsequent loss of label in the product. The ion doublet technique was also employed in a single human study, and benzylic hydroxywarfarin was detected and identified.

Notes: The electron impact mass spectra of permethyl ethers of twenty-five highly purified oligosaccharides, containing first, aldohexose units only and second, at least one fructose unit, have been determined. It is concluded that spectra of these derivatives can yield considerable structural information, especially in relation to the detection of fructose units, the pyranose/furanose ratio and the position of the glycosidic linkage, and are to be preferred from this point of view to the mass spectra of trimethylsilyl ethers.

Notes: Metabolism studies in the rat, dog and cat have demonstrated a definite species difference in biotransformation and elimination of α-1-trans-4-dimethylaminotetrahydro-3-furylcyclohexanephenylglycolate (Lilly 82537), an experimental anticholinergic agent. Separation and identification of urinary and biliary metabolites by gas chromatographic mass spectrometric analysis has shown three mechanisms to be involved in the metabolism of Lilly 82537 in these species; N-demethylation, aliphatic hydroxylation and ester hydrolysis. A major portion of the drug administered was eliminated unaltered in the cat and dog, while only trace quantities of parent drug were observed in the urine and bile of rats. These metabolic differences may be responsible for observed species differences in the pharmacologic activity of Lilly 82537.

Notes: A rapid, sensitive method of analysis for methylphenidate and ritalinic acid in blood and urine has been developed using gas chromatography mass spectrometry and selected ion monitoring for separation and detection. The methylphenidate is isolated by solvent extraction into chloroform and the ritalinic acid is isolated by salting out into isopropyl alcohol, followed by methylation and subsequent solvent extraction. The method has been applied to the study of methylphenidate metabolism and excretion in adults and hyperactive children under-going treatment with methylphenidate.

Notes: Identification of hydrazine monoamine oxidase inhibitor drugs such as isoniazid, iproniazid, nialamide, isocarboxazid and iproclozide is made by electron impact mass spectrometry using the direct insertion technique. The molecular ion itself, although of low relative abundance, is found in the mass spectra of all compounds studied. Relative intensities of the major fragments and data on metastable ions useful in the identification of these compounds are reported. With the aid of synthesized structurally related products, deuterium labelling of exchangeable hydrazidic and hydrazinic protons and by the use of hexadeuterated isopropylic analogues, detailed information about fragmentation patterns is obtained. Splitting processes are chiefly governed by the nature of the aromatic substituent at the hydrazidic end and the alkyl sidechain located at the second hydrazinic nitrogen. The major fragmentations occurring are loss of small neutral molecules, double rearrangement, cleavage of the N—N bond, amide bond rupture, β-cleavage to the hydrazinic nitrogen atom and McLafferty rearrangements.

Notes: The advantages and limitations which quadrupole mass filters afford to the field desorption technique with respect to use for routine work are discussed and experimentally confirmed by the analyses of some drugs using a field desorption quadrupole mass spectrometer. The possibility of fast identification of drug intoxication is demonstrated by the analysis of the chloroform extract of urine in a case of overdose of hypnotics.

Notes: Thin-layer chromatography and mass spectrometry were used to isolate and identify cyclophosphamide metabolites present in blood of mice. Blood was removed 5, 15, 30 and 45 minutes after intraperitoneal administration and extracted with chloroform followed by methanol. Thin-layer chromatography of the two extracts and the residual solid with or without prior methylation, collection of resulting alkylating components, determination of radioactivity and mass spectral analysis, served to identify cyclophosphamide, 4-ketocyclophosphamide, alcophosphamide, N-dechloroethylcyclophosphamide, carboxyphosphamide, phosphoramide mustard and nor-HN2. The absence of detectable levels of 4-hydroxycyclophosphamide or aldophosphamide in the blood of cyclophosphamide-treated mice suggests that cyclophosphamide is converted rapidly in the liver to carboxyphosphamide, 4-ketocyclophosphamide, phosphoramide mustard and nor-HN2. Direct administration of synthetic 4-hydroxycyclophosphamide to mice and extraction of blood with chloroform demonstrated the recovery of this metabolite in vivo. Analysis of extracts of blood from mice treated with phosphoramide mustard indicated the presence of nor-HN2, 3-(2-chloroethyl)-1,3-oxazolidin-2-one and unchanged drug. Consideration of blood levels, cytotoxicity and alkylating activity of metabolites identified in, or inferred from, this study, implicates phosphoramide mustard as a leading candidate for the biologically active form of cyclophosphamide.

Notes: Single and multiple ion monitoring is employed to evaluate whether deuteriomethylated allobarbitone or methylated quinalbarbitone is the better internal standard for quantifying methylated allobarbitone through a g.c.m.s. system based on a quadrupole mass spectrometer. It is shown that the coefficient of variation of the single ion monitoring method is substantially lower than that of the multiple ion monitoring method. Small quantities of a compound are therefore most accurately determined by adding a labelled version of the compound solely to act as a carrier, plus an internal standard giving an ion in common with the compound being measured. By this means 40 pg and 100 pg of methylated allobarbitone could be determined with coefficients of variation of 11.5 and 2.0%, respectively. Using only the labelled compound as internal standard, the corresponding values were 19.8 and 15.3% for the same quantities.

Notes: Mass spectra and fragmentation pathways of some achiral and a number of chiral 1,4-benzodiazepine-2-ones, and those of their in vitro biotransformation products are reported and discussed. Various derivatives substituted in position 3 are shown to be useful for the determination of fragmentation pathways from low resolution spectra.

Notes: The metabolism by rat liver microsomes of the 2,4,6-trideuterio derivative of aniline mustard [N, N-di-(2-chloroethyl)aniline] in admixture with unlabelled material, has been studied. The resulting p-hydroxy derivative was isolated and examined by mass spectrometry. The extent of migration of deuterium from the p- to the m-position, determined from the ratio of trideuteriated to dideuteriated product, was 46%, but the protium and deuterium forms were hydroxylated at the same rate (zero isotope effect).

Notes: Low molecular weight volatile organics extracted from the plasma of patients before and after hemodialysis were analyzed by high resolution capillary gas chomatographic mass spectrometric computer methods. The volatile components were collected on a polyphenyl ether solid adsorbent prior to analysis. Identification of components was achieved by mass spectrometry. Quantitaive changes were observed in both the plasma and dialysate composition with time. The method described provides a new means whereby the 100 or so low molecular weight organic volatiles of plasma can be monitored during the dialysis procedure.

Notes: Chemical ionization mass spectra of eleven biomedically significant quaternary amimes are reported. The samples are converted to volatile compounds by known thermal decompositions. Chemical ionization of the compounds gives simple, easily identifiable spectra which are useful for the analysis of the original samples.

Notes: The reported synthesis of N-hydroxyphenmetrazine from phenmetrazine by the action of m-chloroperbenzoic acid could not be repeated. When the synthetic procedure was modified N-hydroxyphenmetrazine was obtained in low yield. The product had different properties from those claimed previously, but was identical to metabolically produced N-hydroxyphenmetrazine. It was characterized by means of thin-layer chromatography, combined gas chromatography and mass spectrometry, preparation of a t-butyldimethylsilyl derivative and oxidation to a mixture of nitrones. Mass spectrometry was also used to characterize these derivatives.

Notes: Mass spectrometry has revealed the sugar sequence of a new saponoside isolated from the bark of Colubrina arborescens Mill (Rhamnaceae). The branched trisaccharide moiety if this saponoside is shown to be and O-β-L-arabinopyranosyl (1 → 2gal)-O-β-D-glucopyranosyl (1 → 3gal)-galactopyranose located on an as yet unknown genin. Mass spectra are presented for the permethylated saponoside, a permethylated trisaccharide and a partially methylated disaccharide, i.e. 3-β-D-glucopyranosylgalactose (C2 — OH), derived by partial hydrolysis. Further characterization of the mono-, di- and trisaccharides involved NaBH4 and NaBD4 reduction of the 4,6-dimethylgalactose reducing sugar moiety, followed by acetylation or trimethylsilylation.

Notes: The electron impact mass spectrum (70 eV) of 26-trimethylsilyloxy-4-cholesten-3-one shows a base peak at m/e 196, attributable to combination of the trimethylsilyl group with a fragment of m/e 123 produced by cleavage across ring B. 18O labelling confirms that the fragment of m/e 196 contains the 3-oxygen atom, and 2H labelling indicates retention of the trimethylsilyl moiety. Similar ions are observed from other Δ4-3-ketones with sidechain trimethylsilyloxy groups: abundances depend on the site of substitution. The corresponding enol trimethylsilyl ethers are readily separable from the keto forms by gas-liquid chromatography, and afford mass spectra in which the molecular ions are abundant, while ions of m/e 196 are of only moderate intensity.

Notes: A mass fragmentographic method for simultaneous measurement of unlabeled and deuterium labeled methadone in human plasma is described. This specific method has a lower sensitivity of about 16 pmol/ml with a coefficient of variation of less than 4%. The usefulness of the method was evaluated in studies on opiate dependent subjects undergoing methadone maintenance treatment. In one application methadone-d3 was given as a pulse dose during continuous treatment with unlabeled methadone and plasma levels of both species followed by mass fragmentography. The method will be of value in the study of methadone pharmacokinetics in the steady state and in other in vivo situations where multiple drug pools must exist.

Notes: High resolution photoplate mass spectrometry has been used to examine crude goat urine extracts to determine the fate of organochlorine xenobiotics in these animals. Using a direct introduction temperature controlled probe the crude urine extracts were analyzed and the presence of oxygenated metabolites of 4-chlorobiphenyl and 4,4′-dichlorobiphenyl were confirmed in goats; analyses of urine extracts from goats injected with the commercial Aroclor mixtures 1254 and 5460 confirmed the formation of oxygenated penta-, tetra- and monochlorobiphenyl metabolites and an oxygenated dichloroterphenyl metabolite, respectively. This technique was particularly useful in the analysis of complex mixtures of metabolites.

Notes: Several slightly volatile or nonvolatile organic compounds were transformed directly in the solid sample inlet system into more volatile compounds by addition of an appropriate reagent to the sample. In this way, in several instances free organic acids could be obtained from their salts. A similar method was used to transform some amino acids into derivatives of diketopiperazine or of phthalic acid.

Notes: A method has been developed for quantification of phencyclidine [1-(1-phenylcyclohexyl)piperidine] in body fluids using gas chromatography chemical ionization mass spectrometry with selected ion recording. Pentadeuterated phencyclidine was synthesized and used as the internal standard. In developing the method it was discovered that phencyclidine thermally fragments to 1-phenylcyclohexene at elevated temperatures. The sensitivity and specificity of the method permits determination of 1 ng of phencyclidine in 1 ml of body fluid. The concentrations of the drug in blood samples from five individuals, who ingested unknown quantities of phencyclidine, were found to range from 50 ng/ml to 2.7 μg/ml. Following intravenous administration of 1 mg of phencyclidine hydrochloride to a 12.5 kg dog, the blood concentration of the drug peaked at 17.6 ng/ml and exhibited a half-life of approximately one hour. Two metabolities of phencyclidine were detected in human and dog urine after enzymatic hydrolysis. The metabolities were tentatively identified as 4-phenyl-4-piperidinocyclohexanol and 1-(1-phenylcyclohexyl)-4-hydroxy-piperidine by electron impact and chemical ionization mass spectral analysis of the metabolites and their trimethylsilyl derivatives. Structural confirmation was achieved by synthesis of the metabolities. A third metabolite was found in urine from rhesus monkeys and was tentatively identified as 1-(1-phenyl-4-hydroxycyclohexyl)-4-hydroxypiperidine.

Notes: Publications from 1969 through 1974 reporting organic and spark source mass spectrometric studies on environmental samples have been compiled. Emphasis is placed on pollutants identified, but some methods and techniques are discussed. The 396 reports cited vary from those reporting hundreds of identified pollutants to those describing the analysis of only one sample containing one or a few pollutants. Reports concerning forensic, synthetic and standard samples, and analyses for drug residues, metabolites and degradation products are not included.

Notes: Pyrolysis gas chromatography mass spectrometry studies of the whole lyophilized microorganism Streptomyces longisporoflavus, an actinomycete, are reported. Identification of the pyrolysis products indicate that the vast majority arise from protein and carbohydrate origin. There is a paucity of lipid fragments evident. Some of the details of its biochemical composition evident in these results are compared with our previous similar studies on the bacteria Micrococcus luteus and Bacillus subtilis var. niger and suggest this actinomycete lies in biochemical complexity somewhere between the latter two organisms. Although the pyrolysis patterns of these three organisms possess considerable similarities, they are drastically different to that from the fungus Aspergillus niger.

Notes: Melatonin containing three deuterium atoms in the 5-methoxy position has been synthesized by methylation of N-acetylserotonin with dideuterodiazomethane. The deuterated product was characterized by mass spectrometry and found to contain 90.8% of maximum possible deuterium incorporation. The major fragmentation patterns of melatonin under electron impact ionization are discussed with the aid of high resolution, deuterium labelling and metastable transition data.

Notes: 2,3,7,8-Tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzo-p-dioxin-13C12 parent ion isotope cluster abundances are calculated on a multinomial probability basis for all possible isotope combinations. Parent negative ions \documentclass{article}\pagestyle{empty}\begin{document}$ \left[{\rm M} \right]^{\mathop - \limits_. } $\end{document} at m/e 322 and m/e 334 were selected for dual ion monitoring in the isotope dilution technique. Calculations, according to the Jaech's Method, are given for optimizing dual ion monitoring dwell time in the pulse counting mode at the femtogram level.

Notes: Methylphenidate undergoes partial thermal decomposition in the injection port of a gas chromatograph. This decomposition explains inconsistencies in some of the previously published mass spectra of the drug. The decomposition products were identified by gas chromatography mass spectrometry as methyl phenylacetate and a tetrahydropyridine. The extent of decomposition was found to be a function of the injector temperature and was also influenced by other factors, resulting in considerable variability. The ethyl ester analog behaved similarly. Derivatization with trifluoroacetic anhydride eliminates the thermal decomposition.

Notes: A sensitive analytical method involving isotope dilution analysis with multilabeled standards and using field ionization mass spectrometry has been developed for the determination of methaqualone and its metabolie, 6-hydroxymethaqualone, in urine. The limit of sensitivity measured with urine samples is 200 pg/ml for the two compounds. Analysis of urines collected over 11 days following ingestion of a single 250 mg tablet of Mandrax™ by a human subject indicates that the slow phase of excretion of the two compounds has a half-life approximately 50 h long.

Notes: Techniques are described for the computer reduction and identification of complex high resolution mass spectrometric data to yield qualitative and quantitative data for one hundred or more components in a complex mixture. The procedures described have been applied to direct insertion probe separations coupled with high resolution mass spectrometry. Two mass spectrometer computer systems are described in this paper. The basic techniques were developed at the University of Washington utilizing an A.E.I. MS-9 high resolution mass spectrometer, which was interfaced with a PDP-12 digital computer. The most recent system utilizes a Nova II computer interfaced to a Varian MAT 311 mass spectrometer. Programs were developed which were capable of determining the accurate mass (± 3 millimass) of up to 1000 ions per scan. High accuracy limited mass searches were first used to reduce the data. A correlation program was developed to resolve pure mass spectra from the composite mass spectral data using data obtained from the limited mass searches. A library search program was developed which used up to four major identifying masses and their relative abundances in addition to relative volatilization temperatures (probe) or relative retention times (gas chromatographic) for obtaining qualitative data. Quantitative data for each compound were obtained by comparing the total integrated ion current of one ion fragment to that of an internal standard. Instrumental and computer parameters are discussed with respect to the accuracy of the quantitative work. Final computer results gave compound identification and concentrations in μg/m3 or ppm. The use of this analytical technique for the analysis of complex mixtures of pollutants present in atmospheric aerosols is described.

Notes: A generally applicable strategy for polypeptide sequencing has been developed which involves cleavage of a large peptide (for example, primary degradation peptides obtained by tryptic or cyanogen bromide cleavage of a protein) to a mixture of small peptides whose individual amino acid sequences are then determined without their prior isolation. This is accomplished by conversion of the peptide mixture into the corresponding mixture of O-trimethylsilylated polyamino alcohols through reduction of the N-acetylated peptide esters with lithium aluminum deuteride, followed by treatment with trimethylsilyldiethylamine. The conditions for the enzymatic or chemical cleavage were optimized to yield mixtures of peptides best suited for this technique and which represented complete overlap. Limited acid hydrolysis combined with a second experimen utilizing either an enzyme with broad specificity, a set of enzymes, or dipeptidyl aminopeptidase I on the original and/or Edman-degraded molecule was found to be the best choice. This sequencing strategy was evaluated using 0.4 to 1.4 μmol of peptides with known structures (ribonuclease S-peptide, glucagon) and then applied to primary degradation peptides of rabbit skeletal muscle actin up to twenty amino acids long (0.4 to 1 μmol per experiment).

Notes: The brook stickleback, Culaea inconstans (Kirtland), in common with other bony fishes, lacks a germinal epithelium in the tubules of the testis, and the tubule wall is composed of a thin, discontinuous layer of myoid cells and collagenous fibers. Labelling of germ cells with tritiated thymidine has shown that the germ cells are derived from clumps of spermatogonia in the interstitial area. Large companion cells within the lumina of the tubules extend their processes to engulf spermatogonia from the interstitium which then enter the lumen of the tubule. Subsequent development of the germ cells takes place within individual compartments formed by folds of the plasma membrane of a companion cell. The companion cell, together with its complement of germ cells, constitutes a cyst. A companion cell may surround spermatogonia in the interstitium and at the same time encompass residual sperm of the previous season within the lumen. The plasma membranes of the germ cells and the companion cells remain discrete. Mature sperm are released into the lumen of the tubule and the companion cell again extends its processes into the interstitium and engulfs more spermatogonia for the following year.Companion cells may be homologous to the Sertoli cells of higher vertebrates although their processes penetrate the interstitium during the initial stages of spermatogenesis and they do not contain a permanent stock of spermatogonia.

Notes: The pulmonary veins of albino Wistar rats were studied by means of light and electron microscopy. The media of larger veins consists of cardiac muscle fibers which extend until the vessels attain about 100 μ in diameter. This coat consists of external longitudinal fibers and internal circular fibers. The vasa vasorum are well developed and the capillaries show pseudofenestrations. The numerous adrenergic and cholinergic nerve endings do not form typical motor end-plates as seen in skeletal muscles. The ultrastructure of these media muscle fibers is similar to that of rat hearts. The smooth muscle layer of larger pulmonary veins is not continuous as it is in smaller veins where it forms cushions. Comparisons of albino rats and other rodents reveal striking differences.Action potential shape and propagation velocity (0.5-1.2 m/s) along the myocardial coat of the pulmonary vein were similar to those observed in the left atrium and so was their sensitivity to locally applied acetylcholine. The physiological direction of propagation in rat pulmonary veins is toward the lung. This finding lends support to the hypothesis of a rhythmic, valve-like action of the striated musculature of the pulmonary venous wall during the systole and a possible role in the capacitance of the pulmonary circulation.

Notes: Freshwater sponges, Corvomeyenia carolinensis Harrison, were placed into tap water to induce degenerative reduction body formation. Reduction bodies were examined using light and electron microscopy in order to define their histochemical and ultrastructural characteristics. The reduction body of freshwater sponges is an extremely simple developmental system consisting primarily of an archeocyte reserve delimited by a simple squamous pinacoderm. The freshwater sponge reduction body displays many similarities to overwintering phases of marine sponges. The system presents an unusually straightforward vehicle for investigations of degeneration and regeneration as processes in developmental biology and may represent a reasonable vehicle in which to examine the process of the genesis of lysosomes.

Notes: The aquiferous systems of three common, coastal, marine Demospongiae, Halichondria panicea (Pallas), Haliclona permollis (Bowerbank) and Microciona Prolifera (Ellis and Solander), are analyzed by measurements of cross-sectional areas of conducting elements. The patterns in demosponges of extremely different organizational morphologies are found to be quantitatively similar. The porocyte nature of the ostia is established for all three species. Choanocyte chamber densities range from 1 to 1.8 × 107 chambers ml-1 with 57 to 95 choanocytes per chamber (means). Cross-sectional area of the intervillar space of the choanocyte collars is calculated to be 12 to 56 times the lateral surface area of the specimen. Velocities of water movement through specific elements of the aquiferous system are calculated from cross-sectional area data and measured oscular flow of Haliclona permollis. The calculated Reynolds numbers lie below the critical value and fluid flow is thus considered laminar throughout the aquiferous systems of these sponges.

Notes: A new pattern index, Ip, is introduced and used to compare patterns of wild type, burnsi, and kandiyohi chromatophores in the leopard frog, Rana pipiens. Wild type chromatophores are hyperdispersed over distances within cellular contact, and it is concluded that this hyperdispersion results from contact-mediated negative interactions. The hyperdispersion is less strong in spot cells than interspot, and extends over larger areas in burnsi than in wild type epidermis. Over areas greater than chromatophore size, patterns are either random or clumped. Patterning of kandiyohi melanophores is clumped into aggregates small enough to be within the range of cellular contact, suggesting a lack of contact inhibition among these cells. The possible roles of cellular properties and the extracellular environment in pattern determination are discussed.

Notes: Interpretation of cross and tangential sections of the annulate lamellae and nuclear membrane of Rana pipiens oocytes provides evidence in these structures for the existence of diaphragms spanning the pores. The evidence appears to rule out explanations ascribing such diaphragms to an optical artifact. More detailed description is given of a component of the pore complex only briefly described heretofore and now called the “intracisternal ring.” The varied results and interpretations of studies of the pore complex in various cells are discussed.

Notes: The masticatory apparatus in the albino rat was studied by means of electromyography and subsequent estimation of muscular forces.The activity patterns of the trigeminal and suprahyoid musculature and the mandibular movements were recorded simultaneously during feeding. The relative forces of the individual muscles in the different stages of chewing cycles and biting were estimated on the basis of their physiological cross sections and their activity levels, as measured from integrated electromyograms. Workinglines and moment arms of these muscles were determined for different jaw positions.In the anteriorly directed masticatory grinding stroke the resultants of the muscle forces at each side are identical; they direct anteriorly, dorsally and slightly lingually and pass along the lateral side of the second molar. Almost the entire muscular resultant force is transmitted to the molars while the temporo-mandibular joint remains unloaded. A small transverse force, produced by the tense symphyseal cruciate ligaments balances the couple of muscle resultant and molar reaction force in the transverse plane. After each grinding stroke the mandible is repositioned for the next stroke by the overlapping actions of three muscle groups: the pterygoids and suprahyoids produce depression and forward shift, the suprahyoids and temporal backward shift and elevation of the mandible while the subsequent co-operation of the temporal and masseter causes final closure of the mouth and starting of the forward grinding movement. All muscles act in a bilaterally symmetrical fashion.The pterygoids contract more strongly, the masseter more weakly during biting than during chewing. The wide gape shifts the resultant of the muscle forces more vertically and more posteriorly. The joint then becomes strongly loaded because the reaction forces are applied far anteriorly on the incisors. The characteristic angle between the almost horizontal biting force and the surface of the food pellet indicates that the lower incisors produce a chisel-like action.Tooth structure reflects chewing and biting forces. The transverse molar lamellae lie about parallel to the chewing forces whereas perpendicular loading of the occlusal surfaces is achieved by their inclination in the transverse plane. The incisors are loaded approximately parallel to their longitudinal axis, placement that avoids bending forces during biting. It is suggested that a predominantly protrusive musculature favors the effective force transmission to the lower incisors, required for gnawing. By grinding food across transversely oriented molar ridges the protrusive components of the muscles would be utilized best. From the relative weights of the masticatory muscles and their topographical relations with joints, molars and incisors it may be concluded that the masticatory apparatus is a construction adapted to optimal transmission of force from muscles to teeth.

Notes: The description of stages of the molt cycle in mantis shrimp (emphasizing Gonodactylus but compared in a number of Gonodactylidae, Squillidae, and Lysiosquillidae) includes data on texture, hardness, and color of the exoskeleton; behavior; and the micromorphology of the integument and developing setae.After stage A1, When the exoskeleton feels soft and soapy, and A2, when the abdomen attains parchment consistency, the exoskeleton continues to harden until stage C1, when the telson carinae can no longer be depressed with a fingernail. The propodus (C2) and the merus (C3) of the raptorial appendage are the last elements to become rigid. The meral spot achieves indistinct coloration at B1 and distinct but pale coloration at B2; body color continues to intensify until C4.Changes in behavior are particularly marked before and after the molt. After the molt defensive and avoidance behaviors characterize A1 and A2. Threatening increases from low to intense levels in A2 and B1. Striking and offensive behavior increase from weak to normal intensities from B2 to C4. One or two days before the molt, animals lower activity and dominance and feeding levels, exhibit reclusive behavior, and sometimes seal the cavity entrance.The morphology of setagenesis is particularly valuable for determining the stage of the molt after the exoskeleton hardens. The ratio of setae containing cellular contents throughout the lumen to those condensed into strands separates stages A2 through C3. “Cones,” although variable within and between individuals in some species, form initially in B2 and continue to condense through D. Initiation of C4, D0 and D1 overlaps variously in some individuals. Apolysis (D0) and morphogenesis of new setae (D1-D3) provide cues for identifying approach of the molt. Setagenesis and setal morphology differ among families, genera and some species of stomatopods. The structure and functional morphology of setae can be explained by the form of setagenesis.Passive swelling and active muscular peristalsis effect the shedding of the exoskeleton and setal eversion at the molt. The carapace and rostrum are shed as one unit. Patterns of meral sutures vary among taxa with enlargement of the merus and with subterminal or terminal ischiomeral articulation. Middorsal sutures open only on the sixth and seventh thoracic segments, suggesting loss of the first rather than the last abdominal segment and therefore a distant relationship to other eumalacostracans.Approximate durations of the molt stages in stomatopods are compared to those of 11 crustacean taxa. Extensive overlap seems to occur among midinterval stages, particularly in stomatopods. The developmental plateau occurs in different stages in different taxa. Late postmolt (C), associated with calcification, requires longer in more heavily calcified than in thinly calcified species, except for stomatopods. The physiological events immediately surrounding the the molt (A1-B1 and D3-D4) are compressed in time in crayfish, brachyurans, and especially in stomatopods. Behavioral adaptations maximize this compression of physiological events at the molt in stomatopods. These three groups also possess the most asymmetrical molt cycles of the crustacean taxa examined. It is hypothesized that these modifications of the molt cycle allow opportunistic molting and represent adaptations to agonistic behavior.Temporal variation in behavior and in color over the molt cycle may increase the potential for speciation by processes resembling neoteny.

Notes: Pheromone systems from seven species of noctuid are examined. Much of the structure of scales from the wings and/or the abdomen is interpreted as a modification for secretion or release of a pheromone. Scales with an extremely complex surface provide a large evaporation surface, while those connected to secretory cells show less superficial folding than body-covering scales.The development of the secretory gland and diseminatory scales in Mamestra configurata is followed from the exuvial pharate adult stage to emergence. Both components are paired and develop from epidermal cells lining a pair of large lateral invaginations. They may have resulted through division of a group of less specialized cells that originally combined the function of pheromone production and release.

Notes: Examinations of stages of fibril development in muscle fibers of seven Rhesus monkey and six human fetuses reveal SR tubules encircling the Z lines at all stages of fibril development. The encircling SR tubules are continuous with the SR network of tubules which is found surrounding fibrils at all stages of development observed. The SR tubules encircling the Z lines show connections (electron-opaque strands) with the Z lines. The developing triadic junction shows a progressive increase in complexity of structures within the junction. First, membranes of T and SR become apposed with no visible structure between them. Second, tenuous connections are found traversing the space between apposed membranes. Third, well developed bridges are seen traversing the space. And finally, an intermediate density midway between the apposed membranes and parallel to them is found in favorable sections. Junctions between T tubule membranes were also observed and the structures in these junctions are somewhat similar to those found in junctions between T and SR membranes. The change in orientation of triads from predominantly longitudinal to predominantly transverse is complete in the 18-week monkey fetus and incomplete in the latest stage (28-week) of fetal development observed in humans.

Notes: The complex and conspicuous basket-like structure attached to the third segment of each maxillary palp of Melittomma sericeum males is densely covered with tactile hairs on its outer or convex surface and with thinwalled chemoreceptors on its inner or concave surface. In a living male the structure is highly mobile and is extended laterally and ventrally. It evidently serves to detect odors produced by the female.

Notes: This study of the postnatal development (from 1 to 60 days) of smooth muscle elements in the rat testicular capsule has demonstrated that while such elements are identifiable by light microscopy at 30 days, myocytes are present at birth as seen by electron microscopy. The differentiation of smooth muscle from birth to 30 days has been described, by which time it is of adult morphology and content. Perhaps significantly, it is at 30 days that the testis achieves a scrotal position, although sexual maturity does not occur until about 60 days. Presumably, at 30 days the testicular capsule of the rat is capable of the spontaneous contractions which are known to occur in the adult and which are assumed to aid the transport of non-motile spermatozoa from the testis to the epididymis.The presence of occasional striated muscle fibers in the rat testicular capsule as reported previously has not been confirmed by this investigation, although their possible origin is discussed.

Notes: A chromatolysis study, 14 to 21 days following denervation, showed the spinal cord representation of the nerve to the posterior latissimus dorsi muscle to be in the ventrolateral cell column between cervical ganglia 14 and 15. To characterize cervical neurons not undergoing chromatolysis, histochemical studies were done on the cords of additional nondenervated animals. Staining reactions for beta-hydroxybutyrate dehydrogenase, succinic dehydrogenase and cholinesterase did not reveal any quantitative differences between motor neurons in cervical segments 14 and 15 of normal and dystrophic birds. Motor neurons are positive for beta-hydroxybutyrate dehydrogenase and succinic dehydrogenase, but the surrounding neuropil is positive for the latter only. No pseudochlinesterase activity is found in the ventral horn cells, but true cholinesterase is present in most of the neurons. With the periodic acid-Schiff reaction the dystrophic cords exhibit many neurons with large amounts of glycogen in them. Normal cords examined show either no glycogen positive cells or an occasional ventral horn cell with much glycogen in it. Normal muscles contain less succinic dehydrogenase and beta-hydroxybutyrate dehydrogenase positive fibers than dystrophic muscle. More periodic acid-Schiff positive fibers are present in normal muscles than in dystrophic muscle. The motor endplates in normal muscle contain only true cholinesterase. Both true and pseudocholinesterase activity is present in the motor endplates of dystrophic muscle.

Notes: High speed cinematography was used to record the feeding activities of terrestrial Ambystoma tigrinum melanostictum. A description of these activities based on films of more than 50 feeding sequences is presented, and the mechanical units involved are defined, described, and functionally analyzed. Evolutionary implications of the feeding system are discussed.In a typical feeding sequence, A. t. melanostictum stations and maintains its lower jaw 3-5 mm from the prey. The mouth is then opened to form a gape of ∼60° by raising the anterior end of the flexed skull and by elevating and advancing the trunk while the mental symphysis of the lower jaw remains stationary. As the mouth opens the bulging tongue is recontoured so that the posterior glandular region becomes the tip of the fully protruded tongue, which may extend 3 to 7 mm beyond the symphysis. Dorsally the protruded tongue has a deep central depression and pronounced anterolateral rims. The anterior rim collapses on contact, thereby engulfing the prey in a sticky trough that retains it during tongue withdrawal. The cervical region is then flexed and the skull snaps downward. If the prey resists the tongue and is captured by marginal teeth, A. t. melanostictum relies on repeated tongue protraction and retraction, in some cases accompanied by inertial feeding. Swallowing involves gular expansion and contraction, and is accompanied by eye depression. When the mouth is opened during ingestive activities, the lower jaw remains in place.Apparently, A. t. melanostictum uses the dorsal trunk, the cucullaris major and the robust heads of the depressor mandibulae muscles to open the mouth. During skull elevation the lower jaw is partially immobilized by the geniohyoideus, and rectus cervicis superficialis muscles. The subarcualis rectus I muscles are prime movers in tongue projection. Hebosteoypsiloideus muscles assist in tongue protrusion by slackening the rectus cervicis profundus muscles that would otherwise restrict anterior displacement of the otoglossal cartilage and copula. Tongue contouring is performed by the complex genioglossus musculature. Sublingual and anterolingual sinuses facilitate protrusion and contouring by providing space and lubrication. Rectus cervicis muscles (profundus and superficialis) are responsible for tongue withdrawal. Closure of the mouth is accomplished by the four levator mandibulae muscles, and again the lower jaw is immobilized, mostly by ventral longitudinal muscles.Skull-trunk elevation during prey capture and ingestion was also observed and filmed in several other species of Ambystoma, in Dicamptodon ensatus, and in two salamandrid species. Apparently raising and straightening the craniovertebral axis, while the mental symphysis retains contact with the substratum, is a common feature of urodele feeding systems, and does not require peculiar morphological adaptations.

Notes: The structure and evolution of the mandible, suspensorium, and stapes of mammal-like reptiles and early mammals are examined in an attempt to determine how, why, and when in phylogeny the precursors of the mammalian tympanic bone, malleus, and incus (postdentary jaw elements and quadrate) came to function in the reception of air-borne sound. The following conclusions are reached.It is possible that at no stage in mammalian phylogeny was there a middle ear similar to that of “typical” living reptiles, with a postquadrate tympanic membrane contacted by an extrastapes. The squamosal sulcus of cynodonts and other therapsids, usually thought to have housed a long external acoustic meatus, possibly held a depressor mandibulae muscle.In therapsids an air-filled chamber (recessus mandibularis of Westoll) extended deep to the reflected lamina and into the depression (external fossa) on the outer aspect of the angular element. A similar chamber was present in sphenacodontids but pterygoideus musculature occupied the small external fossa. The thin tissues superficial to the recessus mandibularis served as eardrum. Primitively, vibrations reached the stapes mainly via the anterior hyoid cornu, but in dicynodonts therocephalians, and cynodonts, vibrations passed mainly or exclusively from mandible to quadrate to stapes and the reflected lamina was a component of the eardrum.In the therapsid phase of mammalian phylogeny, auditory adaptation was an important aspect of jaw evolution. Auditory efficiency, and sensitivity to higher sound frequencies, were enhanced by diminution and loosening of the postdentary elements and quadrate, along with transference of musculature from postdentary elements to the dentary. These changes were made possible by associated modifications, including posterior expansion of the dentary. Establishment of a dentray-squamosal articulation permitted continuation of these trends, leading to the definitive mammalian condition, with no major change in auditory mechanism except that in most mammals (not monotremes) the angular, as tympanic, eventually became a non-vibrating structure.

Notes: The striations and the intervening filaments observed in the present study have been variously designated in the literature as: prodromal pattern, leptomeric myofibril, microladder, leptomeric organelle, leptofibril and zebra body. Electron microscope examinations of Purkinje fibers from the septa, papillaries, trabeculae carneae and small endocardial strands from chicken, sheep, dog and monkey hearts have revealed a close association between densely stained striations of supernumerary Z line material and successive parallel tubules in the network formed by the sarcoplasmic reticulum (SR). The striations appear to be linked together by filaments that somewhat resemble the part of thin filaments attached to Z lines in normal fibrils. The evidence for a close association of striations and SR tubules is derived from a similarity of spacing between striations and successive parallel tubules in the SR network and from a resemblance of striation and SR network patterns. The evidence for a structural relationship between striations and SR tubules is derived from the observation of electron-opaque strands traversing the space between striations and SR tubules.

Notes: The swimbladder system of the plainfin midshipman consists of a gas-filled bladder and two intrinsic sonic muscles which are attached to the bladder at opposite sides. An experimental and analytical study was conducted to define the physical characteristics of this dynamic system, and to relate these characteristics to radiated acoustical pressure pulses. Results indicate that the system has two degrees of freedom, being comprised of two inertial, stiffness and damping components; the first and second mode components of a 23.1-centimeter midshipman are 0.002 and 0.019 kg (inertial) 2130 and 106,000 newtons per meter (stiffness) and 0.25 and 0.10 (damping) respectively. This system is excited by the sonic muscle forcing function which equals \documentclass{article}\pagestyle{empty}\begin{document}$ 0.00236{\rm}\sin \frac{{2\pi {\rm t}}}{{0.0045{\rm}\sec}}{\rm newtons}. $\end{document}Two system frequency response peaks were observed; the first was 110 hertz, at the flat section next to the sonic muscle, and was very near the repetition frequency of the sonic muscle pulses; the second was 350 hertz, at the hemispherical section, which was the frequency of the acoustical pressure pulse. These phenomena describe a dynamical system closely “tuned” to its forcing function, and a system which is highly responsive to acoustical pressure pulses radiated by neighboring midshipmen. The acoustical pressure pulse coincides in wave form with the hemispherical bladder wall acceleration.

Notes: Fine structural changes in mitochondrial morphology pertaining to size, number and growth were examined in flight muscles of normal and experimentally dewinged male Drosphila melanogaster ranging up to 26 days of age. In the normal winged flies, the number of mitochondria decreases during the first week of adult life whereas the size of individual mitochondrial profile increases significantly. Changes in mitochondrial size and number are due to the fusion of mitochondria. Fused mitochondria are extremely large in size and irregular in shape. In 26-day old normal flies, the number of mitochondria increases while the mitochondrial size is reduced indicating mitochondrial division. In comparison to the normal flies, dewinged flies exhibit a similar degree of mitochondrial fusion and growth during the first week of life. However, the extent of mitochondrial fission in 26-day old dewinged flies is greater than in the normal flies of this age. Structural mechanisms of mitochondrial fusion and fission are described. The objective of this study was to examine the relative effects of age and flight activity on the mitochondria.

Notes: The dendritic patterns of cells in the optic tectum of the tegu lizard, Tupinambis nigropunctatus, were analyzed with the Ramon-Moliner modification of the Golgi-Cox technique. Cell types were compared with those described by other authors in the tectum of other reptiles; particular comparisons of our results were made with the description of cell types in the chameleon (Ramón, 1896), as the latter is the most complete analysis in the literature. The periventricular gray layers 3 and 5 consist primarily of two cell types  -  piriform or pyramidal shaped cells and horizontal cells. Cells in the medial portion of the tectum, in an area coextensive with the bilateral spinal projection zone, possess dendrites that extend across the midline. The latter cells have either fusiform or pyramidal shaped somas. The central white zone, layer 6, contains fibers, large fusiform or pyramidal shaped cells, fusiform cells, and small horizontal cells. The central gray zone, layer 7, is composed predominantly of fusiform cells which have dendrites extending to the superficial optic layers, large polygonal cells, and horizontal cells. The superficial gray and white layers, layers 8-13, contain polygonal, fusiform, stellate, and horizontal elements. Layer 14 is composed solely of afferent optic tract fibers.Several differences in the occurrence and distribution of cell types between the tegu and the other reptiles studied are noted. Additionally, the laminar distribution of retinal, tectotectal, telencephalic, and spinal projections in the tegutectum can be related to the distribution of cell types, and those cells which may be postsynaptic to specific inputs can be identified. The highly differentiated laminar structure of the reptilian optic tectum, both in regard to cell type and to afferent and efferent connections, may serve as a model for studying some functional properties of lamination common to cortical structures.

Notes: Volumetric and histological changes of the central nervous system were studied during post embryonic development of a spider, Argiope aurantia.The neural mass of Argiope grows allometrically with respect to volume of the cephalothorax and body weight. In the first instar 46% of the cephalothoracic volume constitutes the neural mass and this is reduced to 4% in the female (9th stage) and 12% in the male (7th stage) spider.Growth curves for the cephalic ganglion, measured at all stages, represent a straight line. The neural mass of females is two and a half times larger than that of the males. The ganglion increased 24 fold in female and 10 fold in male spiders. Addition of neural mass occurs in all stages.The brain volume is greater than that of the subesophageal ganglion in the first two instars. In subsequent stadia, the subesophageal ganglion grows faster, and in females it is finally three times and in males two times larger than the brain.Growth of cortex and neuropile depict exponential curves. Comparison of growth patterns of these shows an inverse relationship during development. While the volume of the cortex is higher in the first two or three stages, the volume of the neuropile is higher in the remaining stadia. The causes for this growth pattern are discussed.Counts of cell numbers show that there is a constant population of neurons throughout the post-embryonic development. The number of nerve cells in females is higher than in males, 11% in the subesophageal ganglion and 58% in the brain.The growth of the cortex is partly accomplished by an increase in cell volume. In male and female spiders the increase in Type-B cells is 20 and 50 fold, while that of large motor neurons is 200 and 600 fold respectively. The motor neurons of 20 μ and above number 63 in male and 916 in female adult spiders.The growth of neuropile occurs through an increase of dendritic arborization and axonal branching. The largest axons measure 1 μ in the first and 16 μ in adult stages. An increase of incoming sensory fibers is also noticed during development.Invasion of neural lamella into cortex and neuropile increases during development. Neural lamella which are 1-2 μ in the first stage grow to 40-100 μ thickness in adult female spiders, near the origin of the main nerves. One type of astral cells, counted in neuropile, increases 10 fold.The appearance of a central body and the beginning of web construction coincide during the second instar. The relationship between these two is discussed.

Notes: Middle ears (515) from 26 species of the rodent family Heteromyidae  -  genera Dipodomys, Microdipodops, Perognathus, and Liomys  - were studied both grossly and histologically, for qualitative and quantitative comparisons. Middle ear modifications characteristic of each genus are qualitatively described. Quantitative comparisons are made among the 26 species in the study. Some correlations between middle ear size and other measurements are discussed.The middle ear is an acoustical transformer that for best efficiency must match the impedance of the cochlea to the impedance of the air in the external auditory meatus. It accomplishes this by a pressure increase and a velocity decrease through the combined effects of the lever and areal ratios; however, because the important consideration is a matching of two impedances rather than an absolute pressure increase, the pressure transformer ratio is a less informative measure of the middle ear's efficiency than is the impedance transform ratio. The impedance transformer mechanism is explained (from a morphological point of view), and equations are presented. Dipodomys, Microdipodops, and Perognathus have a theoretical transmission (at the resonant frequency) of 94-100% of the incident acoustical energy; Liomys, 78-80%. The areal ratio of stapes footplate to 2/3 tympanic membrane is remarkably constant among the species, varying only from 0.04 to 0.07: in Dipodomys and Microdipodops this small ratio is due to the very large tympanic membrane; in Perognathus and Liomys it is due to the extremely small stapes footplate. The lever ratio of incus to malleus varies from 0.28 to 0.33 in Dipodomys and Microdipodops, from 0.37 to 0.46 in Perognathus, and from 0.55 to 0.60 in Liomys. In addition, the middle ear volumes and the morphology of tympanic membrane, ossicles, ligaments, and muscles, all combine to minimize both mass and stiffness. All these data suggest middle ear mechanisms which are very efficient over a broad frequency range.The middle ear modifications found in heteromyids are adaptive in predator avoidance, especially in areas of little natural cover; nevertheless, contrary to expectations, there is no firm relationship between habitat and the extent of these modifications in the 26 species. However, environment did apparently play an important role in the evolution of the family, and this is discussed.

Notes: Serial histological sections of kangaroo rats of postnatal ages 0-, 3-, 7-, 10-, and 14-days were prepared and studied. At birth the middle ear is mostly filled with mesenchyme and small in size, having only a small hypotympanum and a very small epitympanic recess. During the first postnatal two weeks, much of the hypertrophy found in the adult middle ear develops. Because an entotympanic element is never formed, the previously called entotympanic chamber is here renamed the hypotympanum. The epitympanic recess greatly expands to form what has been called the dorsal (or anterior) mastoid sinus. Since this chamber has no relation to the mastoid, it is here renamed the epitympanum. Posteriorly, the previously called posterior mastoid sinus develops from the growth of the hypotympanum into and beyond the region of the posterior and horizontal semicircular canals. In development and adult position it is comparable to the primate antrum and so is here renamed the antrum.At birth the organ of Corti is very immature but its major cell types can be identified. During the first two weeks of development the following events occur: (1) the vas spirale disappears, (2) the inner spiral sulcus cells atrophy, (3) the hair cells and supporting cells mature, (4) the cells of Hensen differentiate with their apical processes elevating the reticular lamina, (5) the innermost cell of Claudius migrates under and supports the Hensen's cells, and (6) the hyaline mass of the zona pectinata of the basilar membrane loses its connective tissue cells and expands in size. The developmental events support the previous description and identification of Hensen's and Claudius' cells.