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Notizen: Objective To investigate the occurrence of invasive carcinomas following local destructive treatment for cervical intraepithelial neoplasia (CIN) and to evaluate the factors responsible.Design A multicentre retrospective study.Subjects Forty-nine women registered with the British Society for Colposcopy and Cervical Pathology from 24 centres throughout Great Britain between 1985 and 1992, who had been treated by local destructive methods for CIN and who subsequently developed invasive carcinoma of the cervix.Results Of the 49 women whose details were submitted, 42 had squamous cell carcinoma, six adenosquamous carcinoma and one adenocarcinoma. Eight had microinvasive carcinomas (Stage Ia) at the time of diagnosis, 24 had Stage Ib tumours and eight Stages II to IV. Thirteen women have died. Thirty-five women had been treated by laser vapourisation, ten by cold coagulator, two by diathermy and two by cryosurgery. In 19 women (39%) the diagnosis of invasive carcinoma was made on the first follow up visit or within one year of treatment. Five patients did not present with invasive disease until more than five years after treatment.Conclusions The data presented suggest that many, but not all, of the invasive carcinomas presenting after local destructive treatment for CIN resulted from failure to recognise early invasive disease at the time of the initial assessment. The importance of thorough evaluation before undertaking these forms of treatment is emphasised. The use of excisional procedures should further reduce the small risk of invasive carcinoma developing after treatment for CIN.

Notizen: Objectives To determine how micro-invasive carcinoma of the cervix is diagnosed and treated in the United Kingdom. To record the frequency of the various pathological features which comprise the histological diagnosis of micro-invasion, and to assess their relevance to outcome.Design Prospective observational study.Setting Hospitals throughout the United Kingdom.Subjects Two hundred and eighty-six cases were submitted for entry into the study. Following independent review of the histological material 116 cases were excluded: 41 were not accompanied by histological slides for review, 55 had no evidence of invasive disease, 17 had invasive disease greater than FIGO Stage 1a, and three were adenocarcinomas. The remaining 170 cases were registered for the study but follow up was incomplete in 18. This report concerns the 152 women with complete follow up to 1991.Results The age of the 152 women ranged from 22 to 65 years (median 36 years). In 116 women (76%) the diagnosis was made by cone biopsy (cold knife, loop diathermy, or laser) or wedge biopsy, in 9 women (6%) the diagnosis was made by hysterectomy, and in 27 women (18%) punch biopsy suggested an invasive lesion and subsequent excisional treatment (including radical hysterectomy with node dissection in three) demonstrated micro-invasion. The depth of invasion was up to 3 mm in 142 women (93%) and 3.1 to 5 mm in 10 women (7%). Capillary-like space involvement was present in 12 women (8%). Treatment methods used were local cervical surgery in 79 women (52%), simple hysterectomy in 63 (41%), and radical hysterectomy in 10 (7%). There was only one known recurrence and death due to cervical carcinoma.Conclusion There is no uniformity in the management of micro-invasive carcinoma of the cervix. The frequency of recurrence, lymph metastases, and death is low. Nonradical surgery appears to give satisfactory results.

Notizen: Abstract: The synaptic convergence of the eyes and the vestibular hair cells in the nudibranch mollusc Hermissenda has been shown previously to mediate the learning of simple visual-vestibular associations. The neurotransmitter mediating this interaction between the visual and vestibular organs was characterized. HPLC chromatography, confirmed by mass spectroscopic analysis, demonstrated endogenous GABA in the statocysts, in a concentration approximately 150 times greater than in the whole CMS. Additional confirmation was provided by immunocytochemical localization of GABA in hair cell axons and branches that converge with photoreceptor terminal branches. Depolarization of the hair cells in the caudal region of the statocyst in response to positive current injection or vibratory stimulation caused a hyperpolarization and a cessation of the type B photoreceptor impulse activity. The inhibition of the B cell was unaffected by addition to the artificial sea water bath of the adrenergic antagonist yohimbine (250 μM), the cholinergic antagonist atropine (250 μM), and the serotonergic antagonist imipramine (50 μM). In contrast, the GABAA antagonist bicuculline (250 μM) significantly reduced the inhibitory interaction. Moreover, the GABA reuptake inhibitor guvisine (250 μM)M) increased the hyperpolarization. Pressure microapplication of GABA (12.5 or 25 μM) onto the terminal branches of the B cell resulted in a concentration-dependent hyperpolarization and cessation of spikes in the B cell. Depolarization of the caudal hair cell, or direct GABA application, decreased input resistance across the B cell soma membrane. Moreover, removal of chloride from the extracellular solution reduced inhibition of the B cell induced by GABA application or hair cell stimulation. Furthermore, application of the GABAB agonist baclofen hyperpolarized the type B cell and reduced or eliminated spontaneous impulse activity at the resting membrane potential. The reversal potentials for inhibition induced in all three procedures ranged from −70 to −80 mV and were consistent with mixed Cl- and K+ conductances. These results implicate GABA as the endogenous neurotransmitter mediating visual-vestibular interactions in this animal, and suggest a possible role of GABA in visual-vestibular associative learning.

Notizen: Computer modeling has been employed to study the effect of volume fraction and morphology of second-phase constituents on composite stiffness and strength. It is found that the efficiency of load transfer to the second-phase constituent increases with volume fraction vf for particulate composites. For aligned short-fiber composites, the efficiency of load transfer reaches a limiting value with increasing volume fraction for homogeneous fiber dispersions, while for fiber distributions which allow for fiber-rich and matrix-rich regions, the efficiency of load transfer decreases. The saturation or decrease in load transfer efficiency is due to fiber confinement, by which the interfiber matrix material is constrained by the presence of neighboring fibers. Hence, the amount of shear tractions and load transferred to a given fiber is altered by the local fiber distribution, as compared to the case of an isolated fiber (dilute limit). The strength of brittle particulate composites is reduced for most particulate volume fractions considered, while the strength of aligned short-fiber composites with a homogeneous fiber dispersion is marginally increased only for vf(approximately-greater-than)0.2. The composite strength has a downward concave shape, as a function of vf. This is accounted for by both the saturation in load transfer due to fiber confinement and the lower composite strain at failure (embrittlement) as vf is increased. The strength of viscoelastic aligned short-fiber composites with a homogeneous fiber dispersion displays a higher strength at high fiber volume fractions, as compared to a perfectly brittle matrix, which suggests that matrix toughness plays a key role in the strengthening of short-fiber composites.

Notizen: The effect of particulate volume fraction vp and diameter dp on the composite Young's modulus Ec is studied both experimentally, using a silica bead/epoxy system, as well as with the help of computer simulations. The experimental and simulation results show that for a given particulate size, the overall Ec vs vp curve displays a concave upward shape and not a linear shape. This superlinear trend of the data implies that the average strain normalized to the applied strain λ=ε¯p/εc transferred to the particulates increases with volume fraction. The above finding is explained in terms of a mean-field picture, where a single particle interacts with an effective medium consisting of the remaining particles embedded in the matrix. As the modulus of the effective medium surrounding a reference particle increases with vp, the modulus mismatch between the reference particulate and the medium is consequently reduced. This leads to an overall increase in the normalized average strain λ transferred to each particulate as vp is increased. The experimental results using silica particulates with various sizes dp, as well as the simulation results, show that smaller particulates provide an increased composite modulus as compared to larger particulates, at constant vp. General equations are developed, which relate the composite modulus to the average particle stress or strain, given only information about the volume fraction and the Young's modulus of each of the phases present.Through the application of these relations, it is found that smaller particulates display a greater amount of normalized average strain λ transferred than larger particulates. The effect of particulate Young's modulus Ep in combination with particulate size on the resulting Ec is also studied using simulations only. It is found that for a low particulate to matrix modulus ratio Ep/Em, the particulate size has very little influence on Ec. Moreover, the shape of the Ec vs vp curve can be well approximated by a straight line up to large values of vp. On the other hand, as the ratio Ep/Em is increased, the superlinear trend of the composite modulus Ec vs vp data is more apparent. This results in a smaller range of the Ec vs vp curve, which can be approximated by a linear function. It is also found that the extent of this linear region also decreases with particle size.

Notizen: The electronic states of vapor-deposited materials used in electroluminescent devices were measured by ultraviolet and x-ray photoelectron spectroscopy, UV-visible absorbance, and photoluminescence spectroscopy. The combination of these measurements on ultrathin films of these materials allows (1) the determination of the energy (with respect to vacuum) of the highest occupied molecular orbital (HO) and the ionization potential (IP), and (2) the estimation of the lowest unoccupied molecular orbital (LU) energy and an approximation of the electron affinity, (EA). The knowledge of the binding energies of these states is important for the understanding of light-emitting diode properties and the potential optimization of such devices. The luminescent material tris(8-hydroxy-quinoline) aluminum has an IP of 5.9 eV and an apparent EA smaller than 3.5 eV. The IP of both hole transport agents, tri-p-tolylamine and 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, is 5.4 eV and their EA is estimated to be smaller than 1.8 eV. The electron transport agents 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, 2-t-butyl-9,10-n,n'-dicyano-anthraquinonediimine and dicyano-diphenylsulfone differ in IP from 7.1 to 7.6 eV and the EA for these materials are estimated to be smaller than 3.5, 4.9 and 5.5 eV, respectively. © 1995 American Institute of Physics.

Notizen: Pure rotational spectra of the MgOH and MgOD radicals have been recorded in the v2 bending vibration of their X 2Σ+ ground electronic states using millimeter-wave direct absorption spectroscopy. Multiple rotational transitions arising from the v2l=11, 22, 20, 31, 33, 42, and 44 substates have been measured in the frequency range 240–520 GHz for these species. Both the spin-rotation and l-type doubling interactions have been resolved in the spectra. The complete data sets for MgOH and MgOD have been analyzed using a linear model for the Hamiltonian which takes into account higher order (l=±4) l-type interactions. The global analyses were adequate, but anomalous behavior was apparent in both molecules. In particular, the Bv vs v2 relation was found to be highly nonlinear, large variations in the l-type doubling constant q were observed with vibrational level, and r0, rs, and r˜e structures determined differed substantially. Such findings suggest that MgOH is highly quasilinear, comparable to HNCO. The competition between ionic and covalent bonding is therefore becoming apparent in the lighter alkaline earth hydroxide species. © 1999 American Institute of Physics.

Notizen: Objective— To determine whether bilateral oophorectomy combined with hysterectomy is an effective treatment for chronic pelvic pain due to congestion. Design—Prospective non-randomized single centre study.Setting— Tertiary referral centre to a specialist pelvic pain clinic in a teaching hospital.Subjects— 36 women, 33 of whom had failed to obtain long term relief of pain on medical therapy.Main outcome measures— Relief of pain, coital frequency, and effect on daily life. Histology of uterus and ovaries.Results— Median pain score on visual analogue scale fell from a prc-operativc value of 10 to 0 at one year. Twelve of the 36 women had some residual pain at one year postoperativcly, but in only one woman was the pain affecting her daily life. Thirty women were noted to have pelvic tenderness pre-opcratively, at one year, 26 had no tenderness and four minimal tenderness on pelvic examination. The median frequency of sexual intercourse increased from once per month preoperatively to eight times per month one year postoperatively. The uterus was histologically normal in 25 women, adenomyosis was present in eight of whom two had ovarian endometriosis. Fibroids were present in three and endometriosis was found confined to the ovaries in one woman. Multiple peripheral cysts were present in the ovaries of 25 women.Conclusion— Bilateral oophorectomy combined with hysterectomy and hormone replacement therapy is an effective treatment for chronic pelvic pain due to venous congestion, which has failed to respond to medical treatment and leads to restoration of normal coital function and daily life.