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Biomedical subjects

A David

Publications and source records attributed to A David.

At least 271 records · Page 15Linked to original sources

The use of various immunochemical, biochemical and biological methods for the analysis of rabies virus production in tissue cultures.

For the preparation of rabies vaccines, virus was grown in cultures of primary cells (bovine fetal kidney) or heteroploid cell lines (Hak and Vero). Comparative analysis of concentrated and/or purified antigen has shown a good correlation between the protective capacity (as determined by the NIH test for potency) on one hand, and hemagglutinating titer, optical absorbance at 280 nm and glycoprotein content (evaluated by the Enzyme-Immuno Assay - EIA) on the other. Furthermore, the evaluation of the respective content of glycoprotein and nucleoprotein (EIA) before and after impairment of viral membrane can be done to know if the rabies glycoprotein is anchored in an intact membrane or not (soluble glycoprotein). In addition, a good correlation has been obtained for the virus harvest between the NIH-test and the EIA-glycoprotein titer. In the light of the easy and rapid application of Enzyme-Immunoassay it is suggested that this technique be used for the analysis and evaluation of expected potency of virus harvest during rabies vaccine production.

Animals↗

Ultrastructure of rabbit endosalpinx and glycoprotein pattern of the oviduct fluid in the presence of copper intrauterine devices.

Oviduct fluid was collected from 24 mature female rabbits in estrus fitted with a copper intrauterine device (IUD) in one of the uterine horns by laparotomy and examined for total sugar and protein content. The percentage of total sugar in the dry protein-containing material from the experimental side was 7.3 compared to 5.2 from the control side. The percentage of total protein was 67.0% of the total dry material from the experimental side, compared to 77.7% in the control side. Cellulose acetate electrophoresis confirmed these findings, demonstrating an increase in the strength of the periodic acid-Schiff stain bands of the glycoproteins from the copper IUD side and a weaker Ponceau-S stain of the protein bands. The ampullary-isthmic area and the uterotubal junction of both oviducts were examined with the scanning electron microscope. The secretory and ciliary cells on the copper IUD side were damaged in these two areas. These changes can be attributed to the presence and action of the copper ions in the oviduct milieu.

Animals↗

Role of time and concentration on carbon tetrachloride toxicity in rats.

The hepatotoxic effect of different exposure schemes to carbon tetrachloride (CCl4) was studied in inhalation experiments in rats. The duration of exposures at different concentrations of CCl4 vapours in air was changed in such a way as to give a constant product of concentration and time (CT). The animals were exposed for 4 successive days a week. A concentration of 1,625 mg/m3 (250 ppm) CCl4 for 72 min (CT = 300 ppm x h) caused a higher increase in SGPT activity than the exposure to 325 mg/m3 (50 ppm) for 6 h (CT = 300); the effect of 6,500 mg/m3 (1,000 ppm) for 3 min six times at 1-h intervals (CT = 300) had a much smaller effect than the exposure to 6,500 mg/m3 (1,000 ppm) for 18 min (again CT = 300) (1 ppm CCl4 = 6.5 mg/m3). Similar results were obtained at other concentrations and by increasing the number of exposures up to 18; the effects were also confirmed by other biochemical changes in blood serum and liver and by histological examination of the liver. The results indicate that the severity of liver lesions is more influenced by the concentration of CCl4 in the inhaled air (and accordingly in the blood entering the liver) than by the total inhaled (and absorbed) amount of CCl4. This also explains the differences between the two types of exposure in the concentration of 6,500 mg/m3 (1,000 ppm): blood cannot be saturated with CCl4 to the same level within 3 min as within 18 min of exposure.

Alanine Transaminase↗

Sacral intraspinal lipoma associated with congenital iliac anomaly.

2 cases of a peculiar unilateral protuberance near the iliac bone with intraspinal abnormalities are reported. 8 cases have been described in the literature with this characteristic congenital association; they indicate the frequency of an occult spinal dysraphism which must be proved by myelography. In each case, surgical treatment of bone abnormality or of intraspinal lesions, or of both, should be discussed.

Adolescent↗

Effect of copper intrauterine devices on the chemical composition of rabbit oviduct fluid.

Oviduct fluid, collected from 65 mature, female rabbits in estrus and in which a modified copper intrauterine device (IUD) was introduced by laparotomy in one of the uterine horns, was examined for chemical composition. No differences were noted for sodium, potassium, calcium, chloride and bicarbonate between the two sides. The copper content was found to be significantly higher in the IUD side (12.80 +/- 3.01 microgram/100 ml), as compared to the control side (9.0 +/- 1.0 microgram/100 ml), the toxicity of which, to blastocyst development, has been reported in some cases. Total protein in the experimental side was significantly higher (258.52 +/- 36.22 mg/100 ml) than in the control side (156.67 +/- 26.45 mg/100 ml). The same was found for sialic acid, 5.30 +/- 0.62 microgram/ml, compared to 3.66 +/- 0.27 microgram/ml, suggesting that a part of the increased protein can be ascribed to glycoprotein. Oviduct fluid glucose was found to be lower in the copper IUD side than in the control side (10.5 +/- 0.2 vs. 17.7 +/- 0.3 mg/100 ml). These findings may be explained on the basis of an inflammatory process, taking place in the side of the copper IUD, and should be used with cautiousness in adolescent, and nulligravidae women.

Animals↗

Effect of the carbon dioxide laser on the oviducts of rabbits.

Oviducts of 35 mature, white New Zealand rabbits were injured by a laser beam, using various powers from 25 to 40 W, and by a series of pulses of 1/10, 1/20 or 1/100 s duration. The contralateral oviducts served as controls and were injured at similar areas by a scalpel. The injured areas of both tubes were histologically examined at different periods from the time of injury. Enzyme histochemical studies were also carried out. The site of the laser injury was bloodless. There was a delay in the healing process of the laser side. Vessels were sealed at the area where the spot of the laser hits the vessels, but beyond that point a regular thermal damage was noted with thrombus formation such as seen in regular diathermia or scalpel injuries. Enzymatic activity of the epithelium in the vicinity of the laser-injured areas was intact. The thermal damage due to laser injury found in this study is still significant and would necessitate the use of the laser by microtechniques so as to limit the damage of oviduct tissues.

Animals↗

Extraovular instillations of normal saline for termination of midtrimester pregnancy.

Midtrimester abortion by extraovular instillation of normal saline was performed in 50 patients. All 50 aborted following the procedure, and there were no complications except for one case of endometritis that was successfully treated by antibiotics. The mean abortion time was 33 hours, without added oxytocin, and 30 hours when pitocin was administered intravenously. The extraovular route eliminates the necessity for amniocentesis, with its associated risks. By using normal saline instead of pharmacologic agents such as urea, glucose, hypertonic saline, prostaglandins, we were able to eliminate the complications related to drug side effects.

Abortion, Induced↗

Classification of threatened premature labor related to treatment with a prostaglandin inhibitor: indomethacin.

68 patients complaining of premature uterine contractions were treated with a prostaglandin synthetase inhibitor--indomethacin. This agent had a marked effect on uterine contractions suppressing them completely after 1--8 h from the administration of the drug. Classificaiton of the premature contractions according to a scoring system method is analyzed in this study. The score classified the patients into three groups and enabled us to treat them with a correct dosage and period according to the clinical findings at admission of the patients. Indomethacin treatment was effective in all the 68 patients. The drug was well tolerated by all the patients with minimal side effects. The outcome of the newborns was satisfactory, and laboratory tests on various systems of the pregnant women and newborns were normal during and after treatment with indomethacin.

Female↗