PubMed Health⌕ Search

Biomedical subjects

J Segalen

Publications and source records attributed to J Segalen.

18 recordsLinked to original sources
PubMed2001

Sarcolemma phospholipid structure investigated by immunogold electron microscopy and (31)P NMR spectroscopy with lanthanide ions.

The biological functions of plasma membranes depend greatly on the biophysical properties resulting from protein and phospholipid structure. We investigated the phospholipid structure of the normal sarcolemma membrane, which is known to be highly dysfunctional in myopathies. Combining electron microscopy and (31)P nuclear magnetic resonance (NMR) spectroscopy on isolated sarcolemma vesicles, we find that (i) the sarcolemma vesicles maintain the in-vivo cellular sidedness, (ii) the phospholipid mobility is close to that observed in model membranes (similar lateral diffusion coefficients and spin-lattice T(1) relaxation times). Using broad-band and magic angle spinning (31)P NMR spectroscopy with lanthanide ions (Pr(3+)), it is possible to quantify the distribution of phospholipids between internal and external membrane layers, showing that the trans-bilayer distribution is highly asymmetrical.

Cell Polarity↗
PubMed1999

Static and magic angle spinning (31)P NMR spectroscopy of two natural plasma membranes.

Static and magic angle spinning (31)P NMR spectroscopy was used for the first time in natural plasma membranes from erythrocytes and skeletal muscle to study phospholipid arrangement and composition. Typical static powder-like spectra were obtained showing that phospholipids were in a bilayer arrangement. Magic angle spinning narrowed spectra into two components. The first one corresponded to phosphatidylcholine and the second one to the other phospholipids with intensities in agreement with the known phospholipid composition. These findings show that NMR data previously acquired using model membranes can be transposed to studies on phospholipids in their natural environment.

Animals↗
PubMed1999

[Adult bronchiectasis revealing familial ciliary anomaly].

We report a case of bronchiectasis in a 26-year-old man associated with the following congenital abnormalities: deafness, purulent bronchorrhea, nasal polyps, dysmorphic physical pattern and chronic sinusitis. Situs inversus was absent. A sampling was performed on the posterior nasal mucous membrane and displayed structural ciliary abnormality: a deficiency of the intern dynein-arm. The patient's bother was affected and had similar features: congenital bronchiectasis, deafness, mental deficiency and sinusitis. Young's syndrome was relevant in this case. Hereditary ciliary dyskinesia should be considered in adults with bronchiectasis together with rhinologic and alimentary canal disorders. Nasal biopsies are safe and allow cilia examination.

Adult↗
PubMed1996

Inhibition of autophagy of fetal rabbit gonoducts by puromycin, tunicamycin and chloroquin in organ culture.

At the end of ambisexual stage, mullerian or wolffian ducts are programmed to die. Cell degeneration is initialized by an appearance of lysosomes, subsequently involved in invading autophagic vacuoles. In an organ culture assay, performed for 6 days, treatments by puromycin, tunicamycin and chloroquine, known to act on synthesis, transport and activation of lysosomal enzymes, were applied to inhibit the duct regression. Four situations were studied: female genital tract of 17 day post coitum (d.p.c.) cultured with differentiated testis of 19 d.p.c.; male genital ducts of 17 d.p.c. cultured without testis; female and male genital tracts of 17 d.p.c. cultured alone as controls. The stabilization of the mullerian duct cultured with testis and of the wolffian duct cultured without testis was obtained. Ultrastructuraly, the lysosomes were scarce or absent and no autophagic vacuoles were observed. In preventing the formation of lysosomes, it was possible to avoid the duct cell autophagy and to comfirm the existence of a wolffian lysosomal system spontaneously active when testosterone is absent, while a mullerian one spontaneously inactive when AMH is absent.

Animals↗
PubMed1995

Diamine oxidase activity and biochemical markers in human seminal plasma.

Diamine oxidase (DAO), an enzyme which degrades polyamines, is present at a very high level in human seminal plasma and is assumed to come mainly from the prostate. The possible relationships between DAO activity and biochemical markers of accessory sex glands were evaluated in 139 men in barren marriages. Four groups were formed: normozoospermic (n = 41), asthenozoospermic (n = 29), oligoasthenozoospermic (n = 35) and azoospermic (n = 34). DAO activity was the highest in the asthenozoospermic group and was significantly different from that in the azoospermic one. For all specimens, a positive correlation was demonstrated between DAO activity and the prostatic markers citric acid and acid phosphatase. However, DAO activity was correlated with citric acid only in the oligoasthenozoospermic and the azoospermic groups. Acid phosphatase and citric acid were linked in all groups. These results implicate the DAO enzyme in changes in sperm metabolism leading to a loss of motility and suggest that DAO comes partly from the upper part of the genital tract (testis and/or epididymis), in addition to the prostatic gland secretion, accounting for the absence of correlation with prostatic markers in normozoospermic and asthenozoospermic groups.

Acid Phosphatase↗
PubMed1995

1H nuclear magnetic resonance of human seminal plasma in in vitro fertilization attempts: use of automatic spectrum analysis.

Seminal plasma affects the quality of spermatozoa. The possible use of 1H nuclear magnetic resonance (NMR) analysis of human seminal plasma to determine a full biochemical profile that would allow the prediction of successful in vitro fertilization was examined. Two seminal plasma patterns (GI and GII) were found. The main compounds in GI were glycerophosphorylcholine, citrate and lactate, and in GII, choline and amino acids. These patterns did not fit into the usual spermogram classes. However, GI exhibited the higher pregnancy rate, suggesting that the equilibrium established between the components in seminal plasma affected not only the quality of spermatozoa but also embryonic quality.

Adult↗
PubMed1994

Ultrastructure of mullerian and wolffian ducts of fetal rabbit in vivo and in organ culture.

Emphasis is put on programmed cell death in the epithelial cells of mullerian and wolffian ducts, in rabbit fetuses, by observations on the timing and ultrastructural characteristics of cell degeneration. Genital tracts were collected on days 17 to 25 post-coitum and processed for electron microscopy. An organ culture assay was performed on fetal ducts and testis or ovary, for 4 days. Then, ducts and gonads were processed for electron microscopy. The involution of male mullerian and female wolffian ducts in culture and in vivo follows a similar pattern. Cell degeneration is initialized by an increase in the number of lysosomes which are subsequently involved in invading autophagic vacuoles. Cytochemical localizations of acid phosphatase and aminopeptidase indicate the presence of new lysosomes within the cells. In conclusion, this cell degeneration seems to be due to a double lysosome system in the rabbit urogenital ridge: A mullerian one spontaneously inactive when mullerian inhibiting substance is absent, and a wolffian one, spontaneously active when testosterone is absent. The organ culture is reliable for further attempts to study the responses to substances known to act on lysosome formation or activity.

Acid Phosphatase↗
PubMed1990

[Not Available].

Explore the source record for details and available documents.

France↗
PubMed1989

[Interpretation of the sperm count].

The sperm count has proved to be one of the first examination performed in evaluating the fertility of a couple. It has been possible to establish a few standardized norms from the sperm count of fertile men, but, except for azoospermia, there is no specific limit beyond which it is possible to confirm the absence of fertilization of a sperm. The various criteria of the sperm count then examined, emphasizing the importance of studying the morphology, on optical as well as electron microscopy, since it is the spermatozoid's morphology as well as their mobility that differentiate fertile man from infertile ones. Any abnormality often severely compromises the ability to fertilize spermatozoids.

Ejaculation↗
PubMed1986

Effect of duration of abstinence on maturity of human spermatozoa nucleus.

Human sperm are a heterogeneous population, particularly with respect to their morphology, motility, and degree of nuclear maturity. The characteristics of human sperm and the degree of nuclear condensation with variable sexual abstinence times (long, 7 days; short, 12 h) have been studied. Long abstinence led to an increase in the number of sperm and a decrease in their motility, but their morphology remained unchanged. The DNA-protein complex demonstrated by ethidium bromide uptake was unchanged, but there was a significant increase in nuclear stability upon treatment with SDS. The duration of abstinence hardly affected the degree of nuclear condensation or stability of human sperm. The heterogeneity observed is essentially of testicular origin.

Adult↗
PubMed1985

[Hydrosalpinx and sterility. Value of studying tubal microbiopsies using scanning electron microscopy].

Microbiopsies were taken from the tubes of 13 women who were sterile with hydrosalpinges. They were studied using scanning electron microscopy. It was possible to point out several degrees in the evolution of these lesions of the tubal epithelium. These lesions occurred in the fimbrial portion, the ampulla and the isthmus of the tubes. The value of this investigation in diagnosis and prognosis in cases of sterility due to hydrosalpinx is discussed.

Biopsy↗
PubMed1984

Scanning electron microscopic study of hedgehog uteri.

Ultrastructural studies of hedgehog uteri (Erinaceus europaeus L.) have been made using animals in anestrus, in estrus and in estrus after sojourn of a week with a male. In estrus and anestrus the uterine epithelium is homogeneous, regularly interrupted by orifices of glands. It is composed of microvillous cells only. Microvilli decrease in number and length in anestrus. A new type of cell, a ciliated cell, appears after copulation. Probable correlation of ultrastructural aspects of endometrium with hormonal situation is discussed.

Animals↗
PubMed1984

Implantation in the rabbit: ultrastructural features of nuclei involved in symplasm formation.

Mitoses, direct division or cell fusion are observed during symplasm formation in the rabbit uterus epithelium. These phenomenon are examined through transmission electron-microscopic studies. Two types of direct division are described: (1) nuclear scission after folding of the membrane and (2) nuclear scission by invagination of the membrane. The existence of amitoses has long been contested in mammals; the present study tends to show that direct division is not an accidental karyorrhexis but is organized at the cellular level.

Animals↗
PubMed1983

Ultrastructural aspects of the antimesometral implantation in the rabbit.

A scanning and transmission electron microscope study of blastocysts immediately prior to ovo implantation and of antimesometrial implantation sites was conducted. External membranes of the eggs showed at 6 days post coitum the imprint of the endometrial surface, pointing to the early establishment of contact between egg and uterus. At 7 days the antimesometrial region showed flattening with continued evidence of gland openings that appear to be the elective sites of attraction of the trophoblastic knobs. Attachment of the trophoblastic knobs followed on days 8 and 9.

Animals↗
PubMed1983

[Anhidrotic ectodermal dysplasia (apropos of 3 families). Abnormal hair, a sign of heterozygosity?].

The authors report three cases of anidrotic ectodermal dysplasia with an X-linked form. Two cases are sporadic forms, followed up during ten years; the third case is a familial form followed-up through six generations. With their personal cases, the authors insist on the repercussions in the everyday life; they report the signs which must search for an heterozygosis among the females of this families: hypoidrosis, hypodontia, hair shaft abnormalities under polarized light, special look of the face of those females who are alike sometimes wonderfully.

Anodontia↗
PubMed1982

[Blastocyst-endometrial relationships before ovo-implantation in the rabbit (author's transl)].

Transmission and scanning electron microscope appearances of epithelium in a pregnant uterine horn at and between the eggs, in a non-gravid horn of a unilaterally pregnant animal, and in the uterine horn of a pseudopregnant animal provided evidence of short-, medium- and long-range blastocyst effects. While cessation of mitotic division at 5 to 6 days post-coitum is solely the result of ovarian activity, the changes that occur in the shape of uterine epithelial cells apex seem to be due to the combined actions of ovaries and eggs. The development of apical club-shaped structures between 4 and 6 days, more pronounced in the pregnant horn compared with the pseudopregnant horn is apparently determined by ovarian and ovular effects. On the other hand, blastocysts induce the apparition of crater-cells at days 4 and 5 only in the pregnant horn : this could involve a mechanical or a chemical action of short- and medium-range egg effects. Similarly, on days 5 and 6, apical elongations are seen in the uterine regions occupied by the eggs, this finding points to a possible short-range blastocyst action.

Animals↗
PubMedDate not supplied

[A new case of Menkes syndrome. Prenatal exclusion diagnosis in a subsequent pregnancy].

Authors report the cases of a boy with a Menkes' disease which began by a convulsive encephalopathy at the age of two months with growth failure and metaphysical abnormalities. An oldest brother died at 2 years of age in an analogous scene. The diagnosis proved to be founded by the low serum copper and coeruleo-plasmia levels and by the increased uptake of copper in the cultured skin-fibroblasts. The hair was thin and kinky; microscopical study showed pili torti and trichorrhexis nodosa. For the following pregnancy of the mother, a prenatal diagnosis by precocious amniocentesis (amniotic fluid punction) allowed to say that the boy she was expecting for was clear of the disease because of the normal uptake of copper 64 Cu in cultured amniotic fluid cells of the foetus. Authors recall that Menkes' disease is a X linked recessive disorder beginning by epileptic seizure in the early months of life. The basic biochemical lesion of copper metabolism is unknown; there are abnormalities in copper and his binding protein (metallothionein) distribution with increased level is the kidney and decreased level in brain and liver. The copper therapy does not lead to clinical improvement. There is now a prenatal diagnosis: the study of copper uptake in cultured amniotic fluid cells of male fetus. It is abnormally increased in Menkes' disease.

Adult↗