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Biomedical subjects

P S Young

Publications and source records attributed to P S Young.

14 recordsLinked to original sources

Effects of salinity, hypophysectomy, and prolactin on whole-animal transepithelial potential in the tilapia Oreochromis mossambicus.

We have examined whether two recently isolated forms of tilapia (Oreochromis mossambicus) prolactin exert similar effects on osmoregulatory physiology. The effects of salinity, hypophysectomy, and replacement therapy with tilapia prolactins on whole-animal transepithelial potential (TEP), gill Na+, K+-ATPase activity, and plasma ions were determined. When intact fish adapted to 25% seawater (SW) were transferred to different salinities, TEP reached a steady state after 10 hr; TEP increased with increasing salinity from fresh water (FW) to 75% SW but was stable from 75 to 125% SW. Plasma osmolality, [Na+], and [Cl-] of these fish 24 hr after salinity change showed that fish in 100 and 125% SW had greater osmotic perturbation than those transferred to lower salinities. Following a 5-day recovery period in 25% SW, hypophysectomized fish transferred to FW for 10 hr had significantly lower TEP and plasma ion levels than either sham-operated fish or intact fish under the same conditions. Injection of hypophysectomized fish with "small" prolactin (tPRL177), "large" prolactin (tPRL188), or a combination of both (0.5 micrograms/g body weight) 22 hr and again 20 min prior to transfer from 25% SW to FW, restored TEP and plasma ion levels to those of sham-operated fish. Neither prolactin affected the TEP or plasma ions of sham-operated (intact) fish. Hypophysectomized fish had lower gill Na+,K+-ATPase activity than sham-operated fish in FW, but prolactin injections as described above did not affect gill Na+,K+-ATPase activity in either hypophysectomized or sham-operated fish. Our results indicate that the two forms of prolactin are indistinguishable with regard to several aspects of tilapia osmoregulation.

Animals↗

Postthoracotomy pain and pulmonary function following epidural and systemic morphine.

Thirty patients undergoing thoracotomy for lung resection were entered in a randomized, double-blind trial comparing the effects of epidural (E) versus intravenous (iv) morphine on postoperative pain and pulmonary function. Postoperatively the patients were given repeated doses of either 5.0 mg of morphine epidurally or 0.05-0.07 mg/kg morphine intravenously until there were no further spontaneous complaints of pain. Two, 8, and 24 h postoperatively, the following indices were measured: linear analogue pain score, somnolence score, vital signs, arterial PaO2, PaCO2, and pH, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and peak expiratory flow rate (PEFR). Patients receiving epidural morphine had significantly less pain at 2 h (P less than 0.01) and 8 h (P less than 0.004) postoperatively. There was no difference in vital signs except for significantly slower respiratory rates at 2 h (P less than 0.04), 8 h (P less than 0.02) and 24 h (P less than 0.01) in the epidural group. No significant differences occurred in the somnolence scores or blood-gas measurements, which were within normal limits.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Treatment of infection in the presence of an indwelling urethral catheter.

It is unnecessary to treat laboratory-diagnosed urinary tract infection in the absence of clinical symptoms and signs in patients from whom specimens of urine have been taken from indwelling urethral catheters left in situ for more than one week. If there is clinical evidence of infection, the catheter should be removed, a new catheter inserted and a specimen taken for examination. Alternatively, a suprapubic aspirate of urine may be examined bacteriologically as a treatment guide. In the absence of symptoms or other signs of infection it is doubtful whether chemotherapy is indicated.

Catheters, Indwelling↗

Gonorrhoea and non gonococcal urethritis in the male. The specialist view.

Although exact figures of the incidence of gonococcal and non gonococcal urethritis is Australia are not available the majority of cases seen in sexually transmitted disease clinics are male patients with these conditions. Evidence of increasing resistance of the gonococcus to penicillin--particularly that due to plasmid mediated penicillinase production--and current interest in Chlamydia trachomatis associated diseases in males, females and neonates, necessitate constant review of the diagnosis and treatment of these conditions.

Adolescent↗

A randomized evaluation of the reversal of ketamine by physostigmine.

One hundred and eleven patients undergoing ketamine anaesthesia for therapeutic abortion were studied in a double-blind trial of the reversal of ketamine by physostigmine administered postoperatively. The results demonstrate that physostigmine does not shorten recovery time or reduce the occurrence of ketamine emergence phenomena such as hallucinations, restlessness and dreams. In fact, the recovery course was prolonged in patients given physostigmine immediately upon termination of anaesthesia as compared with controls. By contrast, when physostigmine was given 30 minutes after the last dose of ketamine, the recovery was not prolonged as compared with that of the placebo-treated controls. These findings suggest some synergism between the effects of ketamine and physostigmine and should discourage the use of physostigmine as a ketamine antidote.

Abortion, Therapeutic↗

Group B streptococcal infection in neonates.

A study of 866 vaginal swabs from non-pregnant women showed that 167 (19.3%) contained Group B beta-haemolytic streptococci, with a predominance of Types 3 (31.4%) and Ib (25.2%). The incidence of severe neonatal infections due to Group B streptococci during a 3 1/2 year period at The Prince of Wales Hospital was examined, and a study was made of the distribution of serotypes and associated clinical features (including prematurity and abnormal deliveries) in 16 neonates with septicaemia and/or meningitis admitted to the Royal Alexandra Hospital for Children, and the Paediatric Department of The Prince of Wales Hospital. From this study it was concluded that prophylactic antibiotic therapy should be administered to neonates with evidence of Group B streptococcal colonization of the throat, umbilicus, or gut, when there is also evidence of prematurity, prolonged interval between membrane rupture and delivery, or other associated obstetric complications.

Adolescent↗

The detection of toxin production by Corynebacterium diphtheriae in diagnostic laboratories.

In vitro tests for assessing the toxigenicity of strains of C. diphtheriae using the original agar plate precipitin method of Elek are unreliable. At high concentrations of antitoxin (500-1000 U/ml) multiple non-specific precipitin lines occur making interpretation difficult. Increased specificity was obtained by diluting the antitoxin but this in turn caused a delay in the appearance of toxin-antitoxin lines. Also, the failure of lines to appear on media enriched with unsuitable serum may lead to false-negative results. Final assessment of the toxigenicity of strains of C. diphtheriae can probably only be made reliably by guinea-pig tests.

Animals↗

Adrenal function in chickens experiencing mercury toxicity.

Dietary mercury when administered to young chickens via the drinking water depressed growth, increased the rate of mortality and inhibited the normal maturation of the adrenal glands. Additionally, deficiencies of cholesterol and corticosterone were demonstrated in the adrenals. The exogenous administration of 0.5 or 1.5 mg. of corticosterone/100 gm. of body weight alleviated, in part, the toxic effects of mercury as evidenced by a rapid increase in body weight.

Adrenal Glands↗

Enhanced immunosuppression in bursectomized chickens by passive transfer of antibody.

Three trials were conducted using commercial broiler cockerels to determine the immunological consequences of passive transfers of immune sera to bursectomized chickens. The data illustrate that passive transfers of immune sera to juvenile chickens which had been surgically bursectomized immediately after hatching caused a suppression of the primary hemagglutination response which was greater than that caused by bursectomy or passive transfer of immune sera alone. However, when these same birds were given a secondary challenge of antigen the resulting secondary hemagglutination response was normal. These data indicate that the passive transfer of immune sera to bursectomized chickens greatly limits their ability to mount primary humoral responses, while not affecting the ability to develop anamnestic immunity.

Animals↗

In vitro reactivity of chicken hemagglutinins in the presence of corticosterone.

Exogenous corticosterone at the levels of 0, 2, 4, or 8 mug./100 ml. in excess of physiological levels did not affect the in vitro reactivity of chicken anti-SRBC hemagglutinins. These results suggest that immunosuppression which results via stimulation of the adrenal cortex is not attributable to a direct effect of corticosterone on antibody reactivity.

Agglutinins↗

Specific and non-specific immunosuppression in chickens.

Specific immunosuppression, caused by the passive transfer of immune sera, and non-specific immunosuppression, caused by ACTH, were investigated for possible interactions. The data confirm earlier studies which show that both types of suppression when administered independently cause reductions in humoral immune responsiveness. However, when both suppressive methods were administered simultaneously a level of suppression occurred which was not greater than that caused by either method alone. Additionally, when ACTH-induced non-specific immunosuppression was established in donors, passive transfers of sera from these donors did not cause suppression in the recipients.

Adrenocorticotropic Hormone↗