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Biomedical subjects

G Berger

Publications and source records attributed to G Berger.

At least 163 records · Page 9Linked to original sources

Detection of sexual orientation by heterosexuals and homosexuals.

The purpose of this study was to determine if sexual orientation can be correctly identified under controlled conditions. A series of 24 brief videotaped interviews with homosexual and heterosexual men and women were presented to a sample of 143 subject raters divided into four sexual preference and gender groups. None of the groups were able to exceed levels of correct detection. Approximately 20% of the total subject pool did exceed chance levels. There were significantly more women than men in this sub-sample and homosexual women were represented disproportionately. Although there were some differences in the types of behavioral cues used by the different sexual preference groups to make their judgments, with the possible exception of homosexual women, these cues were unrelated to accurate identification of sexual orientation. The relatively better performance of female raters is discussed in terms of differences in the socialization process of men and women.

Adult↗

[The relationship between Ca++ ions and a protein specific to cromolyn in the degranulation of mast cells and basophils in the rat].

Previous research has shown that cromolyn (disodium cromoglycate) binds specifically to the membrane of rat mast and basophil leukemia (RBL) cells, forming a ternary complex with Ca++, blocking of the Ca++ results in inhibition of histamine release upon immunologic triggering. The specific cromolyn binding protein (CBP) has been isolated by using its high affinity form cromolyn. Specific monoclonal anti CBP antibodies have been obtained in mice and polyclonal anti-cromolyn antibodies in rabbits. These antibodies have been used for further purification and characterization of the CBP. Experiments on RBL cell lines have shown that CBP is essential for Ca++ influx and histamine liberation upon immunologic triggering by these cells. Variant CBP deficient RBL do not take up Ca++ and do not degranulate in response to immunologic triggering but their ability to respond normally can be induced by incorporating CBP into their membranes with help of Sendai virus carrier vesicles. This shows that CBP plays a crucial role for the RBL cells Ca++ influx and histamine release following IgE crosslinking.

Animals↗

[Peri-implant enzyme activities and mineralization in bone tissue after implantation of bioactive vitroceramics--a method for biomaterial testing of hard-tissue substitutes. 1. Establishment and representation of the method].

A method for testing the bioactivity of hard tissue implants is described by analysis of the periimplantary enzyme activities of the alkaline and the acid phosphatase in the femur of rats. Bioactive materials cause an increase of the activity of the alkaline phosphatase in the periimplantal bone tissue. An increase of the activity of the acid phosphatase is a measure for the biodepressive effect of the implant material.

Acid Phosphatase↗

Microfractures of the otic capsule. The possible role of masticatory stress.

Microfractures of the temporal bone have been recognized for more than seventy years and occur in certain well-defined areas of the otic capsule. The etiology and significance of these microfractures has been debated since their discovery. The most commonly held theory is that they result from stresses within the otic capsule that develop with growth. An alternative explanation might be that they result from masticatory stress placed upon the temporal bone. Fifty serially-sectioned temporal bones from the Ontario Temporal Bone Bank were examined in this study for the presence of microfractures. Our findings as to the most common sites of microfractures agree with previous studies. It is proposed that the constant stress placed upon the petrous temporal bone by the act of mastication is directed by the anatomy of the external, middle and inner ear through certain definite pathways, including the Fallopian canal, the bony semicircular canals and the cochlea. The most common sites of these fractures represent sites of weakness in the path of these directed forces within the otic capsule, and the statistically significant increase in the number of fractures with age lends support to the masticatory stress theory.

Adult↗

[Female transmitters of Duchenne's myopathy: detection by quantitative ultrasonography combined with blood creatine kinase].

Duchenne muscular dystrophy (DMD) is a disease inherited in an X-linked recessive manner. Nothing is yet known about the gene defect involved. The problem of DMD carrier detection is very important and now without satisfactory solution. Presently the best method, for this detection, is the determination of the serum creatine-kinase (CK) level. However about 30% of DMD children's mothers have normal CK levels. In this study we associated CK determination and a new echographic method. This physical investigation is based on the muscle attenuation measurements through the evolution of the running spectral moments. The parameter expressed is the slope of the ultrasound attenuation signal (in decibels by centimetre and by megahertz; dB . cm-1 . MHz-1). We measured this parameter in vivo on the vastus medialis. The use of the chemical technique and of the physical one improves largely the detection of obligate carriers of Duchenne muscular dystrophy than when one of these methods is employed alone. One such combination recognizes 17 out of the 19 obligate carriers in our series. The difference of the results obtained by these two unrelated methods cannot be yet interpreted, but can reflect genetic heterogeneity in DMD and the inactivation of the X chromosomes.

Creatine Kinase↗

Large perilymph fistulas.

Perilymph fistulas may manifest themselves either by otologic symptoms, as in cases of small fistulas, or primarily through neurologic symptoms, as with large fistulas. A case history is presented of a 3-year-old girl with recurrent bouts of meningitis who was found to have a large perilymph fistula. She had a right undeveloped cochlea and labyrinth, as well as multiple defects of the medial wall of her middle ear. The only way of preventing the recurrent bouts of bacterial meningitis in cases of large perilymph fistulas is surgical repair. Our conclusion is that, considering the problems involved in cases of large congenital perilymph fistulas, a simple closure of the fistula is not sufficient and the method of choice is obliteration of a deeper structure--such as the vestibule itself.

Child, Preschool↗

The infant's "post-isthmus" region of the eustachian tube in health and disease.

The size of the eustachian tube post-isthmic lumen in infants and children less than 2 years old is discussed. The material in our study consisted of serially sectioned eustachian tubes of twenty-six normal temporal bones and fourteen temporal bones harboring acute and secretory otitis media. The size of the eustachian tube lumen was measured with the aid of a millimetric grid mounted on a microscope. These measurements have shown that: There is no increase in the lumen size of the post-isthmic region of the eustachian tube from birth to 2 years of age. Each age group presents a considerable range in luminal area, compatible with the natural biologic distribution. No obstruction of the eustachian tube lumen was encountered in any of the pathologic specimens. There is no significant statistical difference between the lumen size of the post-isthmic region coming from normal temporal bones as compared with those from temporal bones with acute or secretory otitis media.

Acute Disease↗

The eustachian tube lumen in chronic otitis media.

The measurements of the size of the eustachian tube lumen, in its various regions, in adults are presented. The material consisted of serially sectioned eustachian tubes of 26 normal temporal bones and four pathologic temporal bones, three of them with simple chronic otitis media and one with cholesteatoma. These measurements reveal: (1) in adults (as in children) that there is a considerable variance of the eustachian tube lumen sizes corresponding to other variations in sizes of other organs; (2) no obstruction of the eustachian tube lumen was encountered in any of the pathologic specimens; and (3) there was no significant statistical difference between the lumen size of the eustachian tube retrieved from normal temporal bones compared with those from temporal bones with chronic otitis media.

Adolescent↗

Localisation of C-terminal gastrin immunoreactivity in gastrinoma cells. An immunoelectron microscopy study on conventionally processed tissue.

Localisation of C-terminal gastrin immunoreactivity has been studied, using the immunogold staining procedure, on ultrathin sections of 6 human gastrinomas conventionally processed for electron microscopy. The specific labelling, whose density depended on the mean diameter of the gold marker, was restricted to endocrine secretory granules. However, in poorly differentiated cells from malignant tumours, a number of granules remained unreactive. The labelling pattern depended also on the functional state of each cell. The immunoreactive granules showed various morphological features. A moderate number of gold particles was demonstrated over the floccular content of the infrequent diagnostic G-type granules. Non-diagnostic round granules of varying size and electron density were prevalent in most cells; their usually strong immunostaining allowed immediate recognition of cell specificity. Dense granules which were large in size and angular in shape and present in one case, were also intensely labelled. In the same tumour, unequal labelling occurred over polymorphous, often elongated granules, of varying size. Granules of different types, including intermediate forms, could be found in the same cell, indicating a spectrum of granule maturation towards well-defined types of the fetal or adult normal tissues. The present methodology would help to identify gastrin-producing cells in prospective or retrospective electron microscopy studies of multi-hormonal endocrine tumours.

Adult↗

[Where and when does surgery achieve cancer prevention? Precancerous conditions of the stomach].

The early diagnosis of stomach diseases, that are high risk factors for cancer is of paramount importance, because the early cancer can be healed nowadays. Distinguish between precancerous lesions (adenoma, borderline-lesion, dysplasia III) and precancerous conditions (chronical atrophic gastritis, pernicious anemia, Ménétrier syndrome, hyperplasiogene polyps, the operated stomach, rarely ulcus ventriculi). Whereas precancerous lesions must be removed by diathermy-biopsy or operation, precancerous conditions need thorough endoscopic control. In operations for ulcerous disease the operation tactics must be chosen with the aim to avoid a carcinoma after gastric resection.

Biopsy↗

A rapid quantitative method based on motility of bull sperm cells for in vitro toxicity testing of biomaterials.

A quantitative method for in vitro toxicity testing of biomaterials, based on measurements of time-dependent changes of bull sperm motility, is described. In comparison to the haemolytic and toxic effects of biomaterials such as polyurethanes, poly(vinyl chloride) tubes and bioglass ceramics on erythrocytes and the proliferation rate of human embryonic lung fibroblasts, this method is shown to be more sensitive. The simplicity, rapidity and reproducibility of the test under application of genetically identical cells are advantages that make it suitable for screening large numbers of samples. The quantification of test results allows inter-laboratory comparison.

Animals↗