PubMed Health⌕ Search

Biomedical subjects

U Müller

Publications and source records attributed to U Müller.

At least 541 records · Page 30Linked to original sources
PubMed1981

[Pathogenesis of and causal surgery for senile entropion by en bloc resection (author's transl)].

The pathogenetic factors responsible for senile entropion are: age-induced relaxation of the lower lid structures with elongation of the lid and improper loose adaptation between lid margin and globe, a weak tarsal plate and a lower stimulus threshold of the facial nerve. A surgical intervention which consists of radical lid-shortening by an bloc tarsal resection seems to be the most logical procedure. It was performed on 285 patients. The methods results in a lower rate of recurrence, normalizes lacrimal flow and has an excellent cosmetic side-effect improving the configuration of the lid-fissure. A special indication exists for cases in which there is a relapse following surgery.

Aged↗
PubMed1981

H-Y and antigens of the major histocompatibility complex. H-Y and H-2D antigens are associated on unfixed lymphocytes and thymocytes but not on testicular cells.

The results of an antibody blocking technique indicate that H-Y and H-2D antigens are close to one another on the surfaces of unfixed thymocytes and lymphocytes, but distant on testicular cells. The findings are the same using cells from mice of several inbred strains (C57BL/10, BALB/c, b6.H-2k). The data indicate moreover that H-2K antigens and H-Y are distant on all cell types tested. The gonad specific H-Y receptor-presumed necessary for H-Y directed testicular differentiation is associated with neither H-2D nor H-2K antigens.

Animals↗
PubMed1981

Cell reorganization in vitro of heterosexual gonadal cocultures.

Male and female gonadal cells of newborn rats were cocultured in varying proportions. As low a proportion as 20% of male cells essentially yielded tubular structures. At lower quotas of testicular cells, however, only follicular structures occurred. Mixed structures were not observed except one experiment (20% male cells). When ovarian cells were cocultivated with male nongonadal cells, no conversion occurred. It is assumed that H-Y antigen secreted by male gonadal cells is bound by the ovarian receptor sites and induces conversion into tubular structures. H-Y antigen integrated into the cell membrane of nongonadal male cells does not seem to be able to exert this morphogenetic effect.

Animals↗
PubMed1981

An oocyte-specific antigen and its possible role in the organization of the ovarian follicle of the rat.

An oocyte-specific antigen was detected by an antiserum produced in isogenic Lewis rats. The antigen was sensitive to trypsin treatment. Dissociation-reorganization experiments in vitro, using ovarian cells demonstrated that the antigen is required for the interaction of germ cells and somatic cells. A physiologic role is suggested for this differentiation antigen in follicular morphogenesis and ovarian function.

Animals↗
PubMed1981

Reaggregation of rat gonadal cells in vitro: experiments on the function of H-Y antigen.

Dispersed cells of the gonads of newborn rats reaggregate histotypically in rotation culture. Ovarian cells form follicles, while testicular cells organize tubuli. When testis cell supernatant is added to ovarian cells, they form tubulus-like structures. This effect is impeded by simultaneous addition of monoclonal anti-H-Y antibody. It is concluded that H-Y antigen is the active factor of testis cell supernatant that induces sex-reversal of ovarian cells in vitro. The reverse experiment, i.e., exposure of testicular cells to anti-H-Y antiserum, does not result in the organization of follicular structures. These findings are consistent with the view that H-Y antigen is involved in testis differentiation by inducing testis cell-specific functions, rather than by cross-linking cells.

Animals↗
PubMed1981

Development and regulation of the prostaglandin F2 alpha receptor in the rat ovary.

Ovaries of adult rats specifically bind PGF2 alpha while those of immature animals do not. Induction of luteinization by hCG in juvenile animals, however, results in specific binding of PGF2 alpha. It is suggested that luteal cells are the only cell type of the ovary, which is endowed with specific receptors for PGF2 alpha. The number of PGF2 alpha binding sites varies during the ovarian cycle. Most free receptors are detectable in early pro-oestrus, least in the oestrus stage. The oscillation of receptors disappears after inhibition of prostaglandin synthesis by indomethacin. Therefore the apparent cyclic variation of prostaglandin receptors must be ascribed to occupancy of the receptors by varying amounts of endogenous prostaglandin F2 alpha.

Animals↗
PubMed1981

[Rare localisation of osteochondrosis juvenilis (author's transl)].

A survey of rare localisations of osteochondrosis juvenilis is given and illustrated by cases of Morbus Friedrich, Morbus Panner, Vertebra plana Calvé, Morbus Blount, Morbus Iselin, Morbus Hegemann and Morbus Thiemann. This is followed by discussion of etiology and differential diagnosis.

Child↗
PubMed1980

Lateral segregation of proteins induced by cholesterol in bacteriorhodopsin-phospholipid vesicles.

Bacteriorhodopsin in dimyristoylphosphatidylcholine vesicles is randomly distributed in the plane of the membrane and exhibits rotational diffusion above the gel to liquid-crystalline phase transition. Incorporation of cholesterol results in loss of rotational mobility of bacteriorhodopsin, which on the basis of electron microscopy and CD measurements can be assigned to the formation of protein aggregates. It is concluded that bacteriorhodopsin is soluble in the fluid phosphatidylcholine phase but segregates when cholesterol is present in the lipid bilayer.

Bacteriorhodopsins↗
PubMed1980

Phenotypic conversion of human erythrocytes by H-Y antigen.

Human male erythrocytes absorb H-Y antiserum while those of human females do not. Studies on the mode of attachment of H-Y antigen to the erythrocyte membrane reveal: (1) After several washes H-Y antigen can only be removed from male erythrocytes and not from other male cells such as granulocytes. (2) Female erythrocytes absorb exogenous H-Y antigen and thus become H-Y positive. (3) Complement mediated lysis of erythrocytes by H-Y antiserum is not sex specific but is dependent on the ABO blood group type of the red blood cells. It is concluded that H-Y antigen is unspecifically attached to red blood cells and is therefore not an integral part of the erythrocyte membrane.

ABO Blood-Group System↗
PubMed1980

Regulation of LH/HCG receptors during the ovarian cycle in rats.

The number of LH/HCG receptors varied during the ovarian cycle. Most 125I-HCG was bound in the diestrous II stage, least amounts of free binding sites were detectable in estrous. Bromocriptine, an inhibitor of prolactin secretion, suppressed the cyclic variations in free LH/HCG receptors. From this finding it is concluded that LH/HCG receptors of the corpus luteum of the cycle are occupied by LH just once and then degraded. The variations in the number of free LH/HCG receptors are probably due to the synthesis and degradation of only luteal receptors.

Animals↗
PubMed1980

[Inhibition of implantation in the rat due to bromocriptine (author's transl)].

The increase in the number of the ovarian LH/HCG-receptors and the rise in serum progesterone concentration during pregnancy in the rat depend on the presence of prolactin during the process of luteinization. Blocking of the hypophyseal prolactin secretion in rats by twice daily injections of 2 micrograms/g of body weight of bromocriptine from the first day of pregnancy onwards prevents the increase in ovarian HCG-binding, progesterone production, and the implantation of blastocysts. The lack of implantation is not due to a teratogenic effect of bromocriptine but is due to deficient decidual changes caused by a lack of progesterone production by luteal cells.

Animals↗