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Biomedical subjects

I Clarke

Publications and source records attributed to I Clarke.

24 records · Page 2Linked to original sources
PubMed1985

Use of an enzyme-linked immunosorbent assay in a bovine brucellosis eradication program.

An enzyme-linked immunosorbent assay (ELISA) was developed and was compared with the complement fixation test (CFT) in a bovine brucellosis eradication program. The ELISA detected significantly more reactors than the CFT in both strain 19 vaccinated infected herds (1.79% versus 1.14%) and non-vaccinated infected herds (4.2% versus 3.59%) but not in either vaccinated or non-vaccinated brucella-free herds. The specificity for both tests in brucella-free herds was greater than 0.998. The specificity and sensitivity of the ELISA were compared with those of 3 other tests (the Rose Bengal test; the indirect haemolysis test [IHLT] and the CFT) on serum from 151 animals cultured at slaughter. The calculated specificity of the ELISA in this infected group was lower than for both the CFT and the IHLT (0.58 versus 0.67 versus 0.75). The sensitivity however was much greater (1.0 versus 0.73 versus 0.71). The value of the ELISA when used in an eradication program is discussed.

Animals↗
PubMed1984

Induction of ovulation and fertility in amenorrheic women by pulsatile low-dose gonadotropin-releasing hormone.

In functional hypothalamic amenorrhea, failure of ovulation probably results from deficient hypothalamic secretion of gonadotropin-releasing hormone (GnRH). We treated 14 infertile women in whom this condition was resistant to clomiphene with pulses of 5 to 15 micrograms of GnRH administered subcutaneously by portable pumps at 90-minute intervals in 36 cycles of treatment. Ovulation occurred in 30 cycles (83 per cent) and was followed by normal luteal function in 24. Singleton pregnancy occurred after 13 (54 per cent) of these cycles. Ovarian ultrasound consistently showed a single dominant follicle, and follicular-phase levels of gonadotropins and urinary estrone glucuronide were in the normal range in all cycles of treatment except two in which mild ovarian overstimulation occurred. Plasma profiles of GnRH and luteinizing hormone were highly pulsatile after subcutaneous administration of GnRH, and mean peak plasma levels of GnRH were comparable to those in pituitary portal blood. We conclude that treatment with low-dose subcutaneous pulses of GnRH is a safe, effective, and physiologic method of restoring reproductive function in hypothalamic amenorrhea and that it has advantages over gonadotropin therapy.

Adult↗
PubMed1984

Cardiac dysrhythmias during outpatient dental anaesthesia with enflurane. The role of "beta blockade".

In a study of 120 unpremedicated outpatients presenting for outpatient dental anaesthesia, the incidence of dysrhythmias was lower with enflurane than had previously been found with halothane (1). The intravenous use of the cardioselective beta adrenergic blocking agents practolol and metoprolol, in a dose of 0.05-0.22 and 0.16-0.17 mg/kg body weight, respectively, proved effective in the treatment of sinus tachycardia in excess of 150 beats/min and/or ventricular dysrhythmias. Although metoprolol, unlike practolol, has no intrinsic sympathetic activity, there were no side-effects related to either beta-blocker in the dosages used during enflurane anaesthesia.

Adolescent↗
PubMed1981

Friction and wear properties of polymer, metal, and ceramic prosthetic joint materials evaluated on a multichannel screening device.

A 12-channel wear screening device was used to compare the wear properties of a variety of prosthetic joint materials. Two types of tests were run: (1) Ultrahigh molecular weight (UHMW) polyethylene bearing against metal or ceramic counterfaces and (2) various polymers bearing against 316 stainless steel as a standard counterface. Wear was quantified by weighing the polymer specimens, with presoaking and control-soak specimens used to minimize the error due to fluid absorption. The specimens were lubricated with bovine blood serum. Friction and polyethylene wear was very low with each of the metals (316 stainless steel, cobalt-chrome alloy, multiphase alloy, and titanium 6-4 alloy) such that the differences in wear rate would not be significant in terms of choosing a material for clinical application. However, titanium 6-4 alloy was found to be especially susceptible to abrasive wear by particles of acrylic cement. Nitrided titanium 6-4 counterfaces were impervious to acrylic abrasion. Polyethylene wear against highly polished, fully dense ceramics (Sialon, Alumina, Macor, and pyrolytic graphite) was as low as that with the metal counterfaces. Wear increased slightly with increasing ceramic surface roughness. The coefficient of friction of polyethylene against pyrolytic graphite was two to three times higher than with the metals or other ceramics. All of the alternate polymers underwent more wear than UHMW polyethylene. Teflon and polyester, two polymers that have proven unsuccessful in prior clinical use, had wear rates 1,600 and 830 times greater than polyethylene, respectively, an indication that the laboratory wear test provided a quantitative prediction of the behavior of the materials in vivo. However, it was difficult to assess the clinical significance of the less extreme wear rates since the ability of the tissues encapsulating a prosthesis to accomodate wear debris is not known on a quantitative basis.

Animals↗
PubMedDate not supplied

The story of Jane.

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Adult↗