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Biomedical subjects

S Randall

Publications and source records attributed to S Randall.

At least 55 records · Page 3Linked to original sources

The solar wind and hallucinations--a possible relation due to magnetic disturbances.

Data from the 19th century on hallucinations and magnetic disturbances were found to exhibit a direct and statistically significant correlation. The aa magnetic index over the period 1868-89 and concurrent visual hallucinatory activity were found to co-vary (Spearman coefficient = .64; P less than .05). Magnetic influences on the pineal hormone, melatonin, are suggested as a possible source of variation.

Hallucinations↗

Serum fatty acid profiles after intravenous medium chain triglyceride administration.

The serum fatty acid profiles of patients receiving either intravenous medium or long chain triglycerides were studied. Seventeen hospitalized patients, dependent on total parenteral nutrition, were randomly enrolled into a prospective study. The total parenteral nutrition (TPN) delivered amino acids and glucose and either a 75% medium chain triglyceride and 25% long chain triglyceride (MCT group) physical mixture or all long chain triglyceride (LCT group), as the respective fat sources. The amino acids and glucose were given continuously, and the lipid was given for 10 hours each day over five days. Fatty acid profiles on serum triglycerides and free fatty acids were done in the morning before any lipid was given and also later in the afternoon, near the end of the lipid administration, on days 1, 3 and 5. Medium chain fatty acids rose quickly in the triglyceride fraction in patients given MCT. Rapid MCT hydrolysis occurred as evidenced by the appearance of medium chain fatty acids in the free fatty acid fraction in the afternoon sampling. Clearance of the hydrolyzed medium chain free fatty acids (MCFFA) occurred so that little, if any, were present in the morning sampling one day later. Long chain fatty acids, as either triglycerides or free fatty acids, showed expected increases during the daily infusion, but not of such relative magnitude as the medium chain fatty acids. Medium chain fatty acid incorporation into the phospholipid or cholesterol ester fractions by the end of the five-day feeding period was present but minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Development of metabolic alkalosis after massive transfusion during orthotopic liver transplantation.

Five patients undergoing orthotopic liver transplantation were investigated for changes in acid-base homeostasis secondary to large volume transfusions. All patients developed a transient acidemia during the operative period, followed by alkalemia which persisted into the early postoperative period. The patients received an estimated mean of 750 mEq of citrate, which appeared to cause metabolic alkalosis. The biochemical basis underlying the regulation of citrate metabolism that may have led to the timing, extent, and duration of the subsequent metabolic alkalosis is presented. Finally, the time course for the development of metabolic alkalosis may be a potentially sensitive indicator of early allograft function.

Acid-Base Imbalance↗

Placentation in the fallopian tube.

The processes of implantation and placentation have been studied in 105 tubal pregnancies. Successful placentation occurred only with plicomural or mural implantations and in these the early development of the placenta occurred in the tube in exactly the same way as it does in the uterus, although tubal placentation was usually membranaceous in nature, possibly because of an inadequate blood supply. Invasion of the placental bed by interstitial extravillous cytotrophoblast occurred in the tube in the same manner as it does in the uterus whereas extravillous trophoblast invaded tubal vessels in the same fashion as it does the spiral arteries in the uterus. Subsequent development of the placenta in the tube differed from that in the uterus in so far as villous invasion of the tubal tissues, with consequent development of the placenta in the subserosa or on the serosa, was common. The ability of the blastocyst to implant in the tube with subsequent normal placentation indicates that these processes are purely a function of trophoblastic tissue, with maternal tissues playing only a passive role.

Decidua↗

Increased protein catabolism without hypermetabolism after human orthotopic liver transplantation.

To evaluate the surgical stress of transplantation, resting energy expenditure (REE) and 24-hour urinary urea nitrogen (UUN) were measured in 11 patients with end-stage liver disease (ELD) before and after liver transplantation. Predicted mean basal energy expenditure as determined by the Harris-Benedict equation was 860 +/- 110 kcal/m2/day. Pretransplant mean REE was 930 +/- 130 kcal/m2/day versus 920 +/- 190 kcal/m2/day in the posttransplant period (p = NS). Pretransplant mean UUN was 7.7 +/- 3.5 gm/day versus 12.9 +/- 4.4 gm/day in the posttransplant period (p less than 0.05). It is concluded that the patients in the early period after liver transplantation are hypercatabolic (increased tissue breakdown) but not hypermetabolic (increased REE) when compared with their stable state before transplantation.

Energy Metabolism↗

Ectopic pregnancy.

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Contraception↗

Grooming reflexes and Brown-Séquard epilepsy in cats with pontile lesions.

The literature on the relation between the scratch reflex and Brown-Séquard epilepsy in the guinea pig indicates that the scratch reflex is a stimulus-induced myoclonus that is the first component of a complete seizure. Cats with pontile lesions and cats with frontal neocortical lesions exhibit the scratch reflex and other grooming reflexes. The grooming reflexes in cats with pontile lesions develop over a period of a year or more into complete seizures that are similar to Brown-Séquard epilepsy as described for the guinea pig by Brown-Séquard and others. Cinematographic analyses revealed that the scratch reflex in cats with pontile lesions and in cats with frontal neocortical lesions has the same frequency and the same complex spatial and temporal pattern as normal scratching behavior. In addition, the myoclonus of the complete seizures is identified as the scratch reflex, representing a very vigorous and long-lasting afterdischarge. Reconstruction of the pontile lesions indicate that the lateral and rostral portions of the paralemniscal tegmental fields were destroyed along with portions of the pontile gray and pyramidal tract.

Animals↗

Circadian rhythms in food intake and activity in domestic cats.

Daily patterns of food intake and activity were determined for normal cats and cats with pontile lesions. Food intake in the dark and in the light of LD (light/dark) cycles were determined separately by weighing the food, and a "percentage nocturnal" score was calculated. The measure of activity was infrared photobeam interruptions, with the photobeam placed in front of the cages, over the food bowl. No differences between normal cats and cats with pontile lesions were detected for any of the measures. Food intake of cats was influenced by simulated starlight and moonlight conditions and by the presence of humans. Cats in isolation from humans and human noises exhibited random patterns of activity in constant light and free-running circadian rhythms in constant dark. Idiosyncratic differences in entrainment to LD cycles were found among cats, and the relevance of this variability is noted for studies of photoperiodic phenomena in this species.

Animals↗

Temporal difference of thyrotropin-releasing hormone in prevention of testicular regression in golden hamsters exposed to short photoperiods: possible involvement of beta-endorphin.

Male golden hamsters were exposed to long photoperiod or short photoperiod (SP) and injected with 1 microgram TRH and/or 1 microgram LHRH at lights on (LO) or lights off (LX) for a total of 8 weeks. Both TRH and LHRH prevented testicular regression if they were injected at LO. Injected at LX, TRH did not prevent testicular regression, and LHRH was only partially effective. Plasma beta-endorphin levels were significantly higher in groups with atrophic testes. These results indicate that TRH like LHRH can prevent SP-induced testicular regression in hamsters by some unknown mechanism and that beta-endorphin may be involved in the control of testicular function in hamsters.

Animals↗

Generation of genetic diversity in herpes simplex virus: an antimutator phenotype maps to the DNA polymerase locus.

We have measured the spontaneous production of mutants in derivatives of herpes simplex virus type 1 resistant to phosphonoacetic acid. Six such derivatives produced 9- to 123-fold fewer iododeoxycytidine (ICdR-)-resistant progeny (i.e., thymidine kinase deficient) than their wild-type parents. To locate the mutation which controls mutant production in one of the strains (PAAr-5), we constructed phosphonoacetic acid-resistant, recombinant viruses by marker transfer, using wild-type viral DNA and DNA restriction fragments conferring the resistance phenotype. The resultant recombinants also produced very low levels of ICdR-resistant progeny during growth, indicating a close linkage (within 1.1 kilobase pairs) between the drug resistance locus and the sequences controlling production of mutant progeny. Evidence is presented that the low mutant yield in PAAr-5 is not due to abnormal expression of mutants, hypersensitivity to ICdR, altered thymidine kinase activity, or slow replication rates. Since the locus conferring resistance to phosphonoacetic acid in PAAr-5 has been shown previously to be the DNA polymerase gene, we hypothesize that the reduced yield of mutants results from enhanced replication fidelity by the altered DNA polymerase. The existence of antimutator derivatives of herpes simplex indicates that the observed high mutation rate for wild-type strains is an intrinsic property of the virus and may provide a selective advantage during growth in animal hosts.

Cell Line↗

Age difference in endogenous opiate modulation of short photoperiod-induced testicular regression in golden hamsters.

Effects of age and naloxone on testicular function were studied in golden hamsters exposed to short photoperiods. Subjection of hamsters to short photoperiods of 6 h light: 18 h darkness for 6 weeks led to testicular regression in young adult (5-6 months) or middle-aged (11-12 months) golden hamsters but not in prepubertal hamsters of 1-2 months of age. The middle-aged hamsters had decreased testis width by week 4 of treatment and the young hamsters by week 5. Daily injection of naloxone at the time of 'lights on' partially prevented testicular regression in young and middle-aged hamsters but the extent of regression was significantly greater in the middle-aged animals. Plasma LH and FSH concentrations were significantly reduced in hamsters placed in short photoperiods regardless of age or testicular weight, while naloxone treatment significantly increased the LH concentrations in all age groups. Plasma beta-endorphin-like immunoreactivity was significantly increased by short photoperiod or older age. These results indicated that (a) the sensitivity of the testicular suppression to short photoperiod increases as a function of age, (b) naloxone, a specific opiate receptor blocker, can partially prevent short photoperiod-induced testicular regression and (c) ageing and short photoperiods increase beta-endorphin-like immunoreactivity. It is concluded that the opiate system may be involved in ageing and photoperiod regulation of reproductive function.

Aging↗

Pregnancies in women with hyperprolactinaemia: obstetric and endocrinological management of 50 pregnancies in 37 women.

Fifty pregnancies occurred in 37 women with hyperprolactinaemia. Thirty women (81%) initially attended with infertility and 24 (65%) had secondary amenorrhoea. Twelve women (31%) had pituitary macroadenomas, of whom seven (19%) were treated with neurosurgery and/or external radiotherapy before conception. Forty-one conceptions (82%) followed treatment with bromocriptine. There were no unusual obstetric or endocrinological complications. Serum prolactin measured at least 6 months post partum when under basal conditions, without bromocriptine and not breast feeding, showed no significant trends compared with initial values. Tumour growth was not stimulated by the high oestrogen levels of pregnancy.

Adolescent↗