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Notes: The use of fresh autologous pericardium in valve surgery has shown poor results in the past mainly due to thickening and retraction. Recently, it has been suggested that a short treatment with glutaraldehyde might radically change its behavior. In an attempt to determine whether this disparity in results is due to the glutaraldehyde treatment or to a better present-day surgical technique, fresh and glutaraldehyde-treated autologous pericardium was mounted in a frame and implanted in the pulmonary position of adult sheep. Six survivors obtained in each group were sacrificed between 2 and 8 months in the “fresh” group and between 2 and 6 months in the “glutaraldehyde-treated” group. Macroscopically, the fresh pericardium became thickened and retracted in all specimens, eventually resulting in severe regurgitation, while the glutaraldehyde-treated, although slightly thickened, retained its pliability without significant retraction. Microscopically, viability of the central core of the collagen was more often preserved in the fresh pericardium. Endothelialization was irregular. In conclusion, short glutaraldehyde treatment seems to improve the results of autologous pericardium mounted on a valve stent. Its effect on calcification remains to be ascertained.

Notes: The surgical technique of aortic valve replacement with freehand glutaraldehyde-treated autologous pericardium is described. Forty-nine patients underwent this procedure without hospital mortality and no thromboembolic episodes without anticoagulation. Three patients underwent reoperation: for infective endocarditis in two; and tear of one commissure 8 months after surgery in another. This technique because of its excellent hemodynamics and low thrombogenicity might be a valid alternative particularly in patients with a small aortic annulus.

Notes: Gabapentin is an anticonvulsant that successfully treats many neuropathic pain syndromes, although the mechanism of its antihyperalgesic action remains elusive. This study aims to help delineate gabapentin's antihyperalgesic mechanisms. We assessed the effectiveness of gabapentin at decreasing mechanical and cold hypersensitivity induced in a rat model of neuropathic pain. Thus, we compared the effectiveness of pre- or post-treatment with systemic or intrathecal (i.t.) gabapentin at reducing the development and maintenance of the neuropathic pain symptoms. Gabapentin successfully decreased mechanical and cold hypersensitivity, both as a pretreatment and post-treatment. Furthermore, both i.t. and systemic administration of gabapentin were effective in reducing the behavioral hypersensitivity; however, the i.t. administration was superior to the systemic. We also examined gabapentin's effects at inhibiting hindpaw formalin-induced release of excitatory amino acids (EAAs) in the spinal cord dorsal horn (SCDH) both in naïve rats and in rats with neuropathic pain. We present the first evidence that gabapentin reduces the formalin-induced release of both glutamate and aspartate in SCDH. Furthermore, i.t. gabapentin reduces the enhanced noxious stimulus-induced spinal release of glutamate seen in neuropathic rats. These data suggest that gabapentin reduces neuropathic pain symptoms by inhibiting the release of glutamate in the SCDH.

Notes: Tidal inlets, narrow, comparatively deep gaps between barrier islands, are channels through which tidal currents flow vigorously as the water enters and leaves the backbarrier lagoons, bays, and intertidal flats and marshes. Many geologists have compared tidal inlets to river channels and have speculated that if an inlet shifts laterally, it should deposit a distinctive sequence of sediments, analogous to the point-bar sequence left by a meandering stream channel.Fire Island Inlet, located 56 km east of New York City, has migrated WSW at a mean rate of 64 m/year during the period 1825–1940. Waves approaching the coast, predominantly from the southeast, have shifted sediment along the shore toward the WSW. Deposition of sediment on the east side of the inlet has forced the tidal currents to erode the west side of the inlet, thus causing lateral migration.Because hydraulic conditions vary from the channel floor to the subaerial part of the spit which is present on the ENE side of the channel, sedimentary structures and textures vary systematically with depth. We have determined the various sedimentary environments associated with the modern Fire Island Inlet, sampled and described the sediments from these environments, and have collected samples from corings made on that part of Fire Island through which the inlet has migrated.On the basis of our studies, we propose an inlet sequence which is formed by the lateral migration of a tidal inlet. The sequence includes five major units, as follows on p. 492.The sediments belonging to various units in this sequence have been identified in four borings made on those parts of Fire Island through which the Fire Island Inlet has migrated since 1825.This sequence should be applicable to other inlets also. We think that the boundary between deep channel and shallow channel units remains relatively fixed at −4.5 m, whereas the thickness of the deep channel unit is determined by the depth range between −4.5 m and the total depth of the inlet. Hence, the main source of variation in the inlet sequence will be the thickness of the deep-channel unit.Most of the sediments of the inlet sequence are incised below mean low water; hence they will almost certainly be preserved in the geologic record, even if all other associated sediments from barrier environments located above mean low water are not preserved. Because of the great variability possible in rates of lateral migration of inlets along the shore compared with the rates of barrier displacement perpendicular to the shore, inlet sediments may be preserved as elongate lenses, or as widespread blankets. The shape of inlet deposits reveals much about the behaviour of barriers during a submergence. Hence, inlet sediments should shed new light on sediments of the continental shelves and on basal transgressive sands in the geologic record.〈inlineGraphic alt="inline image" href="urn:x-wiley:00370746:SED491:SED_491_tu1" location="image_n/SED_491_tu1.gif"/〉

Notes: In cell-free Pseudomonas aeruginosa culture supernatants, we identified two compounds capable of activating an N-acylhomoserine lactone (AHL) biosensor. Mass spectrometry and NMR spectroscopy revealed that these compounds were not AHLs but the diketopiperazines (DKPs), cyclo(ΔAla-l-Val) and cyclo(l-Pro-l-Tyr) respectively. These compounds were also found in cell-free supernatants from Proteus mirabilis, Citrobacter freundii and Enterobacter agglomerans [cyclo(ΔAla-l-Val) only]. Although both DKPs were absent from Pseudomonas fluorescens and Pseudomonas alcaligenes, we isolated, from both pseudomonads, a third DKP, which was chemically characterized as cyclo(l-Phe-l-Pro). Dose–response curves using a LuxR-based AHL biosensor indicated that cyclo(ΔAla-l-Val), cyclo(l-Pro-l-Tyr) and cyclo(l-Phe-l-Pro) activate the biosensor in a concentration-dependent manner, albeit at much higher concentrations than the natural activator N-(3-oxohexanoyl)-l-homoserine lactone (3-oxo-C6-HSL). Competition studies showed that cyclo(ΔAla-l-Val), cyclo(l-Pro-l-Tyr) and cyclo(l-Phe-l-Pro) antagonize the 3-oxo-C6-HSL-mediated induction of bioluminescence, suggesting that these DKPs may compete for the same LuxR-binding site. Similarly, DKPs were found to be capable of activating or antagonizing other LuxR-based quorum-sensing systems, such as the N-butanoylhomoserine lactone-dependent swarming motility of Serratia liquefaciens. Although the physiological role of these DKPs has yet to be established, their activity suggests the existence of cross talk among bacterial signalling systems.

Notes: Abstract Polarographic behaviour of o-aminobenzenethiol (RSH) is studied at dme in 0.1M-HClO4, 0.1M-NaOH,Britton-Robinson buffers of different pH values and aqueous acetic acid. A well defined single wave is obtained in 0.1M-HClO4 and buffers of pH 2.0 at all concentrations of the depolarizer whereas in all the other buffers, a well defined single wave is obtained only if the concentration is less than 2×10−4 M. In other cases, two waves are observed. With the increase in pH, theE 1/2 becomes more negative and finally attains a constant value. Thus the dissociation constant of sulphydryl group under the experimental conditions is 5.14. The diffusion coefficient in buffer of pH 2.0 is calculated to be 5.76×10−6 usingIlkovič equation. The reaction is reversible and the oxidation product is a mercurous compound (RSHg) which converts quickly to (RS)2Hg. Even in acetic acid media, well defined reversible anodic wave is obtained in all proportions of acetic acid and water.

Notes: Abstract Rhabdoid tumour of the kidney is a rare paediatric neoplasm usually associated with a grave prognosis. We report a case of left renal rhabdoid tumour with involvement of the inferior vena cava (IVC) and right atrium in a 13-year-old girl. Left nephrectomy together with removal of the IVC and atrial extension was undertaken on cardiopulmonary bypass and hypothermia. She remained disease-free and in good health for 1 year, however, recent review has shown recurrence in the abdominal lymph nodes.

Notes: Summary 2- and 3-Mercaptopropionic acids, thiomalic acid, 2-mercaptoethanol and propyl mercaptan have been determined by direct titration with potassium persulphate in the presence of iodide in acidic aqueous medium. These mercaptans react with the oxidant in 2 ∶ 1 molar ratio forming corresponding disulphides. The reaction of thio-p-cresol, thioglycollic acid and thioacetic acid with persulphate is too slow to be followed titrimetrically. However, they are oxidised to disulphide when allowed to stand with excess persulphate for 2.0, 1.75 and 0.75 hours respectively. The reaction stoichiometry is not a function of time. 2- and 3-Mercaptopropionic acids, cysteamine hydrochloride, thiomalic acid, thioacetic acid and thioglycollic acid react with potassium persulphate in acidic medium in the presence of iodine cyanide which acts as preoxidiser and catalyst, in the molar ratio 1 ∶ 3 forming corresponding sulphonic acids. As little as 0.50 mg of the mercaptan can be determined in 50 ml solution with ± 0.25 % error.