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M Cury

Publications and source records attributed to M Cury.

16 recordsLinked to original sources
PubMed1990

Three-dimensional morphometry of mammalian cells. II. Areas, volumes, and area-volume ratios.

From three-dimensional diameter measurements of eleven kinds of cells pertaining to five different organs, which were excised from eleven adult mammals (nine species) whose body weight range was 40 g to 450 kg, we calculated the corresponding cell soma areas (A), volumes (V), and finally their area-volume ratios (A/V). The dissimilarities among these eleven cell types could be established quantitatively by means of a cluster analysis. The dendrograms for cell areas (A), volumes (V), and their corresponding area-volume ratios (A/V), yielded similar groupings when cell areas and volumes were compared, yet the grouping of the area-volume ratios (A/V) for the eleven types of cells was different. These results were corroborated by means of the principal components analysis, where five distinct cell groupings could be established. The relationship between cellular morphometry, oxidative metabolism, and body mass, was established by means of the fractal geometry of the transport systems (respiration and circulation), which provides the tools for the scale-dependent analysis of the surfaces across which the transport of metabolites is performed.

Animals↗
PubMed1989

Three-dimensional morphometry of mammalian cells. I. Diameters.

Three-dimensional measurements of eleven kinds of cells, obtained from serial sections of five different organs, excised from eleven adult mammals of different body sizes-from a 40 g mouse to a 450 kg cow-were made. In order to minimize technical errors all organs were submitted to standardized fixation and staining procedures. Twenty cell diameters (at the nuclear level) were measured in each of the 7 microns serial tissue section which were made in two planes, after a 90 degree rotation of the fixed and embedded organ specimens. The mean values of the cell diameter measurements were submitted to a cluster analysis by means of a computer program, to establish the cell type groups with similar morphometric characteristics. The dendrograms of the cell-type groupings were then compared with the results obtained by applying the traditional statistical analysis of the cell sizes (in micrometers) in the three dimensions of space, and also with the principal component analysis. With the three statistical methods we came to analogous conclusions. The empirical allometric exponents for the three cell diameters, when expressed independently as functions of body mass, are not significantly different from zero, and in consequence cell sizes are independent of body mass. The physiological meaning of the body-size-independence of the mean three cell diameters is discussed.

Animals↗
PubMed1987

Sex ratio of hamster fetuses assessed by gonadal morphology: effect of mother's age.

This paper describes the assessment of phenotypic sex in hamster fetuses 12-15 days postcoitum. External morphometric parameters such as body weight, crown-rump length and anus-genital distance did not permit the differentiation of males from females. The sex was determined easily by inspection of the internal genital structures under low power magnification on Days 13-15 postcoitum. The size, shape and location of the gonads and the presence of a conspicuous blood vessel on the testis were the most useful criteria. An inverse relationship was found between the age of the mother at conception and the number of fetuses in mothers 2 to 7 months old. The decrease in the number of fetuses with increasing age of the mothers affected preferentially the population of phenotypic males.

Age Factors↗
PubMed1986

Tetrodotoxin-sensitive sodium channels in a continuously cultured cell line derived from the adult rat cerebellum.

A method to establish continuously cultured cell lines from adult cerebellar cortex is reported. Clones (prepared by this procedure) were isolated from cerebellar established cultures at the 25th passage and after 15 months in vitro. One clone (UCHCC1) was maintained in culture and studied while the others were frozen. The cerebellar cell line UCHCC1 retained a neuronal-like morphology; the addition of dimethylsulfoxide (DMSO) to the culture medium elicited a reproducible morphological 'differentiation' event, characterized mainly by process extension. In 'differentiated' cells, veratridine significantly increased the uptake of 22Na. Such enhanced uptake was blocked by tetrodotoxin (TTX) with a half-maximal inhibitory concentration of 0.9 nM. Binding of an [3H]ethylenediamine derivative of TTX ([3H]en-TTX) to the microsomal fraction prepared from same DMSO-treated cells, showed a single class of receptors with a maximal binding (Bmax) of 173 fmol/mg protein and a Kd of 1.1 nM. Thyroid UCHT1 cells and 'undifferentiated' (cultured without DMSO) cerebellar cells, did not show significant effects of veratridine on 22Na-uptake, or [3H]en-TTX binding. The 'differentiated' nerve-like properties, induced by appropriate environmental manipulation, demonstrate the usefulness of cerebellar UCHCC1 cells as a model system for the developing central neuron. On the other hand, the novel transforming procedure opens new possibilities for obtaining permanent cell lines from other regions of the adult CNS.

Animals↗
PubMed1986

The head-eye-body turning behavior induced by electrical or cholinergic stimulation of the pulvinar-lateralis posterior nucleus complex is not dependent on the catecholaminergic system.

Two experimental designs were developed in cats in order to analyze the role of the catecholaminergic system in the turning response evoked by cholinergic or electrical stimulation of the pulvinar-lateralis posterior nucleus complex (P-LP). Twenty one adult cats were employed. In one series of experiments, nine cats had a cannula implanted in one P-LP, and through it, apomorphine alone or mixed with carbachol were microinjected. The behavior was observed and the EEG was recorded. In the second experimental design, a cannula and bipolar electrodes were implanted unilaterally in the P-LP of nine cats, and a series of electrical stimulations were performed before and after 6-OHDA administration into the P-LP, and apomorphine was injected parenterally in order to induce turning behavior. Finally three cats received 16 micrograms of 6 OHDA into the P-LP, through a Hamilton syringe and no electrodes or cannula were implanted, to study the histological damage. No evidence of involvement of the catecholaminergic system was found in either of these two experimental series. These results contrast with what has been found in the nigrostriatal dopaminergic system, where an imbalance in dopamine concentration induces turning behavior. High doses (16 micrograms) of 6-OHDA induced minimal damage in the P-LP.

Animals↗
PubMed1985

Morpho-functional effects of kainic acid injection into the cat's pulvinar-lateralis posterior nucleus complex.

The histological, electroencephalographic, behavioral changes as well as the changes in the intensity threshold of stimulation necessary to induce contralateral turning were studied in 16 cats, in which kainic acid (KA) was injected locally into the pulvinar-lateralis posterior nucleus complex (P-LP). In 13 cats a stainless-steel tube with two attached electrodes was implanted in P-LP, and electrodes were also implanted in the ipsilateral dorsal hippocampus, the superior colliculus and the caudate nucleus. KA was injected through the tube using a 10 microliters Hamilton syringe. In other 3 cats, KA was injected stereotaxically through the needle of the Hamilton syringe and two electrodes were implanted in these areas after withdrawal of the syringe. The intensity thresholds of stimulation required to induce turning behavior were controlled before and after KA administration in the 13 cats with an implanted tube and only after KA injections in the three cats without a tube; in these instances the current threshold of the contralateral P-LP served as control. The histological results showed a moderate KA damage of the P-LP, with destruction of neuronal soma and gliosis and additional involvement, in all the experiments, of the dorsal hippocampus; however, passage fibers were spared by the lesions. A dose-dependent epileptic effect of KA was seen, which was slight with the 3 micrograms dose and intense with 6 micrograms. The EEG recording showed a prominent and almost simultaneous epileptic involvement of the hippocampus and the P-LP after KA, with less involvement of the other implanted structures. Turning behavior induced by electrical stimulation of the P-LP was suppressed when the electrode tip was located inside the lesioned area. When the electrode tip was placed inside a slight or moderate damaged tissue, a significative increase in current threshold was found, and finally when the tip of the electrode was outside the lesioned area no change in threshold was observed. These findings do not contradict our previous hypothesis of an intrinsic cholinergic mechanism involved in the turning response evoked by P-LP electrical stimulation, although it cannot be excluded that fibers coming presumably from the superior colliculus or pretectum may contribute to the response.

Animals↗
PubMed1984

Vesical endometriosis.

A case is presented of vesical endometriosis treated surgically in a thirty-one-year-old woman who presented with hypogastric pain and a pelvic mass. Echography showed an intravesical tumor, and cystoscopy led to a presumptive diagnosis of bladder endometriosis. The clinical features, diagnosis, and management are discussed, based on a review of the literature.

Adult↗
PubMed1983

Effect of exogenous sex steroids upon the number of germ cells and the growth of foetal ovaries grafted under the kidney capsule of adult ovariectomized hamsters.

The effect of estradiol E, progesterone P and testosterone propionate T upon growth and germ cell population of foetal ovaries transplanted under the kidney capsule of adult ovariectomized hamsters was examined. Foetal ovaries were obtained 15 days postcoitum and the host received daily subcutaneous injections of E (1 micrograms/day), P (5 mg/day), T (500 micrograms/day) or E + P in 0.1 ml oil for 25 days beginning 5 days before grafting. One day after the last injection, the size of the ovary, the germ cell population and plasma steroid levels were assessed. The results of hormone assays indicate that daily steroid administration was able to maintain continuously elevated plasma levels of the corresponding hormone. Interconversions or steroid secretion by the graft, if any, were not reflected in the peripheral circulation. The growth of the graft was stimulated by T and inhibited by P, in comparison with E and oil-treated controls. All germ cells were at the stage of primary oocyte forming part of a primordial or growing follicle. Their absolute number was significantly increased by T and E and significantly decreased by P and E + P. The number of oocytes per mm3 of ovary was increased 80%, 48% and 40% with E, T and E + P, respectively. It is concluded that, in the hamster, exogenous sex steroids given to the host can exert specific effects upon the growth and oocyte population of a grafted foetal ovary. Whether or not the action of steroids upon the graft is a direct one and whether they influenced oogonial mitosis, the evolution of the meiotic prophase or atresia of primary oocytes remains to be determined.

Animals↗
PubMed1981

New observations on the onset and duration of the meiotic prophase in the female golden hamster (Mesocricetus auratus).

The onset and evolution of the meiotic prophase were assessed by histological and cytological techniques in fetal and neonatal ovaries obtained from day 13 postcoitum to day 11 postpartum in the golden hamster (Mesocricetus auratus). The histological technique based on the Feulgen stain and the cytological technique based on the Giemsa stain of isolated nuclei were judged to be specific for staining chromatin and chromosomal DNA. The results obtained with both techniques were quite similar and confirmed most of the meiotic prophase takes place during the neonatal period. However, at variance with other reports, it was found that the meiotic prophase starts on day 14 postcoitum. This discrepancy is attributed to the greater specificity of techniques and time span covered in the present study.

Animals↗
PubMedDate not supplied

[Evaluation of rapid urease test stored in refrigerator].

UNLABELLED: The rapid urease test is an accurate and cheap method, which results are readily available, and broadly used for routine Helicobacter pylori infection diagnosis. AIM: The evaluation of rapid urease test stored in refrigerator at 4 degrees C (SRUT) compared to regular rapid urease test. PATIENTS AND METHOD: Endoscopic biopsies were obtained from gastric antrum in 104 consecutive patients. Diagnosis of Helicobacter pylori infection was accomplished by rapid urease test, histology and rapid urease test stored (kept in refrigerator by a period ranging from 1 to 8 days). RESULTS: Infection was considered present if both rapid urease test and histology were positive. Helicobacter pylori was present in 45/104 patients (42%). Rapid urease test stored had specificity comparable to rapid urease test (93%), with sensitivity of 88%. CONCLUSION: We concluded that rapid urease test can be stored in refrigerator for up to 1 week, without loss of clinical applicability, and that can make the test even easier to use for routine Helicobacter pylori tests in a busy endoscopy unit.

Adolescent↗