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Biomedical subjects

J Thomas

Publications and source records attributed to J Thomas.

At least 685 records · Page 38Linked to original sources
PubMed1983

Alterations in circadian rhythmicity in calcium oxalate renal stone formers.

The circadian (circannual for oxalic acid) variations of 13 urinary variables (volume, creatinine, calcium, oxalic acid, glycolic acid, 17-ketosteroids, 17-hydroxycorticosteroids, phosphates, urea, uric acid, chloride, sodium, and potassium) have been documented in 7 calcium oxalate renal stone formers and 7 healthy men (control group). Urine was collected every 4 h over a period of 24 h. All subjects had the same synchronization: diurnal activity from 07(00) to 23(00) +/- 1 h and nocturnal rest; meals were given at fixed clock hours (08(00), 12(30) and 20(00) +/- 1 h). A statistically-significant rhythm (p less than 0.05) was validated for all variables except urea and calcium in healthy men. In renal stone formers, 6 variables (calcium, oxalic acid, and glycolic acid in particular) had no detectable circadian rhythm. However, a periodicity of c. 8 h (ultradian rhythm) was demonstrated for calcium and oxalic acid with peaks being located around 02(00), 10(00), and 18(00). No circannual variations in oxalic acid output could be observed. The present study shows an alteration of the periodicity of calcium and oxalic metabolisms, i.e. the loss of a circadian (24-h) rhythm and the occurrence of an ultradian rhythm of 8 h. The risk of calcium-oxalate crystallisation appears thus greater at 02(00), 10(00), and 18(00). Furthermore, any study dealing with oxalic acid excretion should state the season of urine collection when comparing renal stone formers and healthy subjects, as significant differences in oxaluria may appear during the summer months and not during the rest of the year.

Adult↗
PubMed1983

Precursors of hypertension: a review.

Recent advances in hypertension therapy have been remarkable; however, much less is known about those precursors that facilitate preventive and early intervention measures. This review of the literature indicates that relevant precursors are early elevated casual systolic blood pressures, positive family history, and obesity in females. Additional predisposing or enhancing factors point to high sodium ingestion, heavy smoking, and high socioecologic stress. Evidence for a high-risk hypertensive personality is not conclusive. There is a paucity of longitudinal data on hypertension in the black population.

Blood Pressure↗
PubMed1982

The effect of prostaglandins on the multiplication and cell-to-cell spread of herpes simplex virus type 2 in vitro.

Herpes simplex virus type 2 (HSV-2) after infecting an individual has the ability to remain latent in nervous tissues. The factors that control herpesvirus infection, latency, and reactivation are poorly understood. Fever, menstruation, emotional stress, exposure to sunlight, and surgical resection have been associated with activation of latent herpes. The situations which activate latent herpes are associated with a local or systemic rise in prostaglandins. The data presented show that prostaglandin F2 alpha (PGF2 alpha) and E2 (PGE2) enhanced cell-to-cell spread of HSV-2 in an in vitro model. Ibuprofen, a prostaglandin inhibitor, suppressed HSV-2 multiplication as well as cell-to-cell spread. Prostaglandins may play an important role in herpesvirus infections and latency.

Dinoprost↗
PubMed1982

Legume-Rhizobium interactions: cowpea root exudate elicits faster nodulation response by Rhizobium species.

Preinfection events in legume-Rhizobium symbiosis were analyzed by studying the different nodulation behaviors of two rhizobial strains in cowpeas (Vigna sinensis). Log-phase cultures of Rhizobium sp. strain 1001, an isolate from the plant nodule, initiated host responses leading to infection within 2 h after inoculation, whereas log-phase cultures of Rhizobium sp. strain 32H1 took at least 7 h to trigger a discernible response. The delay observed with strain 32H1 could be eliminated by incubating the rhizobial suspension, before inoculation, for 4.5 h either in the cowpea rhizosphere/rhizoplane condition or in the root exudate of cowpea plants, grown without NH(4) in the rooting medium. The delay could not be eliminated by incubating the rhizobial suspension in the rooting medium of plants grown in the presence of 5 mM NH(4), indicating that there is a regulatory role of combined nitrogen in triggering preinfection events by the legume. The substance(s) in the root exudate which elicited the faster nodulation response by Rhizobium sp. strain 32H1 could be separated into a high-molecular-weight fraction by Sephadex G-100 gel filtration. The data support the notion that legume roots release substances that favor the development of rhizobial features essential for infection and nodulation.

Journal Article↗
PubMed1982

Zinc deficiency: improvement in growth and growth hormone levels with oral zinc therapy.

A 14-year-old girl and a 13-year-old boy were found to be growth hormone deficient by insulin-arginine stimulation tests, and were also found to be zinc deficient. When oral zinc replacement was given, they both had a significant increase in growth rate which continued for at least 2 years, and subsequent growth hormone tests were normal.

Administration, Oral↗
PubMed1982

Differential effects of intravenous anaesthetic agents on cell-mediated immunity in the Rhesus monkey.

Considerable evidence has accumulated to implicate general anaesthetic agents as a cause of post-surgical immune depression. In the present study we evaluated the immuno-suppressive effects of three in vivo administered anaesthetic agents on cellular immune function in sub-human primates which did not undergo surgery. Normal rhesus monkeys received a minimal anesthetic dose of ketamine HCl, meperidine HCl, or sodium pentobarbital. Peripheral blood mononuclear cells were assayed for mitogen-induced lymphocyte proliferative responses and cell-mediated cytotoxicity (CC), including antibody-dependent CC, spontaneous CC and alloimmune CC. In vivo administration of the three agents caused significant reduction in lymphocyte functional capabilities. Within 30 min after administration of ketamine HCl or sodium pentobarbital, cytotoxic effector function was significantly depressed, with variable recovery occurring at 48 hr; cytolytic effector function was not impaired after meperidine HCl or in untreated controls. Ketamine HCl selectively suppressed effector function; mitogen-induced lymphocyte proliferative responses were not suppressed. Monkeys given meperidine HCl showed stable effector function and depressed lymphocyte proliferative function. Effects from sodium pentobarbital were non-selective, with reduced cytotoxic and proliferative lymphocyte functions. In summary, this study shows that intravenous anaesthetic agents are immunosuppressive in primates and exhibit disparate effects on afferent and efferent expressions of cellular immunity.

Anesthetics↗
PubMed1982

Menstrual cycle changes with marathon training: anovulation and short luteal phase.

Fourteen normal women (self-selected from 180 women enrolled) in a marathon training clinic kept basal body temperature (BBT), mileage, and weight records for 48 cycles before the marathon. Entry criteria were: Age 20-45, gynecologic age greater than 5 years, no hormone use, or weight change in 3 months. The women were 35.2 +/- 5.6 years in age, 22.6 +/- 5.1 years gynecologic age, runners of 4.1 +/- 2.5 years with premenstrual symptoms, previous pregnancy 4/14, no infertility and 2/14 remote amenorrhea. BBT records were obtained and analyzed by Vollman's criteria (1977). There was no weight loss. 32/48 cycles were biphasic but only 16 were normal in the length of the premenstrual phase (PreM = luteal, nl 10 - 16 d) with a mean of 11.1 +/- 1.2 days. The other 16 biphasic cycles had short PreM phase of 6.4 +/- 1.8 days. Monophasic (M = anovulatory) cycles occurred in 16/48 records. Cycles which were abnormal (Short PreM and M) differed only in that usual run length was longer (9.6 - 9.9 miles) than in normal cycles (7.9 +/- 2.4 miles). Marathon training may be associated with normal length but M and short PreM type cycles.

Adult↗
PubMed1981

Effect on growth in pemoline-treated children with attention deficit disorder.

The growth of 22 children with attention deficit disorder (ADD) was monitored longitudinally for up to four years. Each child received at least one year of continuous, successful pemoline (Cylert) therapy, after which drug "vacations" were allowed. The effective dosage of pemoline ranged from 56 to 150 mg/day during the first year of treatment. Stature and weight measurements at six-month intervals were matched to those of paired "normal" children from the Fels Longitudinal Study. Significant deficits were observed for mean weight change at six and 12 months after baseline, and for mean stature change at 12 and 18 months after baseline. However, all subsequent six-month results up to four years did not differ significantly between the two groups. These results show a temporary retardation in the rate of growth in weight and stature with later catch-up growth in children treated wih pemoline.

Adolescent↗