[Characterization of liver RNA fractions methylated in vivo by dimethylnitrosamine].
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Biomedical subjects
Publications and source records attributed to K Petersen.
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A total of 76 repeat sperm retrievals were carried out in 47 azoospermic men. The outcome of the procedures was evaluated regarding to the interval between two successive procedures. Sperm motility and pregnancy rate were not increased by increasing the interval between two successive sperm retrievals from less than 90 days to more than 180 days. The pregnancy rate declined from 50% with a less than 90-day interval to 25% with a more than 180-day interval. The trend did not quite reach the significance level. Pregnancy was obtained in only 27% of the couples where TESE was done the last time against 48 and 57% where PESA and TESA, respectively, were performed the last time (p < .05). This study suggests that sperm retrieval procedures in men with obstructive azoospermia can be carried out with time intervals of only 3 months to obtain an optimal pregnancy rate, and it might suggest that an epididymal aspiration procedure should be preferred for a TESE.
A clinical, controlled trial was performed to study the effect of prophylaxis with lymecycline and the role of Chlamydia trachomatis and Mycoplasma hominis in postabortal genital infection. Of 532 women who were to undergo first-trimester abortion, 269 were randomized to treatment with oral lymecycline (300 mg bid) starting 2 days before the abortion and continuing for a total of 7 days, and 263 were randomized to placebo treatment. The rate of postabortal infection was 9.3% in the antibiotic group and 9.5% in the placebo group, an insignificant difference (P greater than .8). The presence of C. trachomatis in the cervix/urethra at the time of abortion showed a significant association with the occurrence of postabortal infection (P less than .005), but there was no correlation between the effect of treatment and the presence of infection (P greater than .4). The presence of M. hominis, a history of pelvic inflammatory disease, maternal age, gestational age, the number of births, spontaneous and induced abortion, and the Hegar number showed no significant association with postabortal infection (all P values greater than .05). It is recommended that women who are to undergo induced abortion be examined for the presence of C. trachomatis and treated, as they constitute a risk group.
This study examined the bacterial pathogens and the presence of possible risk factors for the development of chronic otitis media with effusion (OME) in a group of Alaska Native children. Middle ear aspirates were collected from 128 children < 6 years of age requiring tympanocentesis between 1987 and 1989. Bacterial pathogens were cultured from 40% of 209 fluids. Predominant isolates, after contamination of the outer ear was controlled for, were Haemophilus influenzae (21%; 84% of these were nontypeable), Streptococcus pneumoniae (8.1%; serotypes 6B, 10A, 11A, 14, 18B, 18C, 19A, and 23F), Staphylococcus epidermidis (3.8%), and Moraxella (Brahmanella) catarrhalis (2.9%). Pneumococcal-C-polysaccharide (PnC) was detectable in 3 of 135 (2.2%) aspirates that did not grow Streptococcus pneumoniae. Combining culture and PnC assay results evidence of pneumococcal infection was found in almost 10% of aspirates tested. There was not a significant difference in the number of episodes of acute otitis media after the first year of life based on the age at the first episode (< 6 mo, > or = 6 mo). However, 88% of infants in the study had their first acute otitis media episode before 1 year of age.
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The influence of glucagon on renal function and hemodynamics was studied on isolated perfused rat kidneys. During perfusion with solutions containing no vasoactive substances glucagon increased total renal perfusion flow, while the GFR remained unchanged. The autoregulation of blood flow under these conditions was completely abolished. Na-excretion was slightly reduced under the action of glucagon, due to an increased fractional Na-reabsorption. However, increased fractional Na-reabsorption was not due to a direct influence of glucagon on tubular transport mechanism as comparison of TNa at identical Na-loads demonstrated. In presence of angiotensin II renal perfusion flow was markedly reduced and doubled almost after starting glucagon infusion. GFR under these conditions rose by about 100%. It is concluded from the results that changes of kidney function following glucagon infusion are mainly due to a reduced vascular resistance.
The findings are based on a clinical investigation conducted on forty-nine patients suffering from osteogenesis imperfecta (OI), as well as on a questionnaire study in which 117 osteogenesis imperfecta-affected persons or their parents were involved. The survey established pathological tooth discolorations as well as tooth abrasions. Dentinogenesis imperfecta (DI) was more frequently found in primary teeth than in permanent teeth. There were no gender-specific differences. Radiological abnormalities were found in both, abraded and/or discolored teeth, as well as in clinically normal appearing teeth. In most cases there were club-shaped extensions of the pulp chambers and obliterations of the root canals. The probability that dentinogenesis imperfecta occurs as an accompanying symptom of osteogenesis imperfecta was not dependent on the degree of skeletal severity. The self-assignment according to A and B forms of osteogenesis imperfecta types I and IV in accordance with the presence/absence of dental symptoms was contradictory, since the literature was based on varying classifications.