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J Thomas

Publications and source records attributed to J Thomas.

At least 667 records · Page 37Linked to original sources
PubMed1984

Action of delta 9-tetrahydrocannabinol on the pool of acid soluble nucleotides.

The effects of delta 9-tetrahydrocannabinol (THC) treatment on acid soluble pools of uridine nucleoside and nucleotides were investigated in Tetrahymena pyriformis and in isolated mouse lymphocytes and spermatogenic cells. In THC treated Tetrahymena and mouse lymphocytes the uptake of labelled precursor into acid soluble pools of uridine nucleoside and nucleotides fluctuated, whereas in pachytene spermatocytes and round spermatid cells the labelled pool was reduced. The reduction in the labelled pool measured in mouse spermatogenic cells was attributed primarily to a reduction in radioactively labelled uridine nucleoside. Treatment of Tetrahymena in high concentrations of THC (960 and 3,200 microM) resulted in an increase of labelled uridine nucleoside and a reduction in the amount of labelled uridine nucleotides. Expansion of the acid soluble pool with radioactive uridine resulted in small differences in labelled nucleoside and nucleotides in control and THC treated Tetrahymena and mouse lymphocytes. The results are discussed in terms of the effects of THC on macromolecular synthesis in various cellular systems.

Animals↗
PubMed1984

[Monohydrate and dihydrate oxalic lithiasis. Calculi, their macroscopic structure (radiographic and therapeutic impact). Calciuria and oxaluria].

Calculi of pure calcium oxalate monohydroxide are hard, polish, dark brown stones, of a very tenuous crystalline structure. On the contrary, calculi of pure bihydroxide oxalate are clear irregular stones with a spiky surface. They are more friable and less hard than monohydroxide oxalate stones. Monohydroxide oxalate stones radiologically are regular and homogeneous, whereas bihydroxide oxalate stones have an irregular aspect. Monohydroxide oxalic lithiasis is less frequent than bihydroxide oxalic lithiasis. The proportion of monohydroxide lithiasis is the same in men and women whereas bihydroxide lithiasis is more frequent in men. Of a biologic point of view, in monohydroxide lithiasis, calciuria and oxaluria are often normal while proportion of hypercalciuria and hyperoxaluria is more important in bihydroxide lithiasis. Evolutivity is clearly inferior in monohydroxide lithiasis than in bihydroxide lithiasis.

Adult↗
PubMed1984

Precursors of hypertension in black medical students: the Meharry cohort study.

Data were collected on a cohort of 435 black medical students whose attendance at Meharry Medical College fell within the period 1958 to 1965, providing baseline measurements on multiple possible hypertension precursors. Relevant family history, sociodemographic, and clinical characteristics were obtained. Fifty percent of the students had at least one of the following possible precursors of hypertension: systolic blood pressure >120 mmHg; diastolic blood pressure >80 mmHg; pulse >80 beats/min; and relative body weight >120 percent of ideal body weight. Contrary to expectations, students from professional families were more likely to have higher systolic blood pressures. Students whose parents had a positive history of hypertension or stroke were likely to have higher diastolic blood pressures. Of the 24 students found to be hypertensive on survey (1981), 73 percent had a positive parental history of hypertension or stroke compared with only 40 percent of a control group matched by age and sex. A 17-year follow-up is currently underway to develop a risk profile for hypertension among black professionals.

Adult↗
PubMed1984

[Remarks on the metabolic evaluation of renal lithiasis].

Metabolic studies include certain routine investigations but which may be more or less limited or extended according to the individual case on the basis of its severity and the chemical nature of calculi. These studies are based upon the following data: analysis of one or more stones, aided and guided by methodical macroscopic examination; urine microscopy; study of urine pH which should be done by the patient himself on several samples during the 24-hour period; blood and urine calcium/phosphate balance, without omitting the measurement of urinary urea which provides information concerning protein intake and indicates its influence; oxalate balance studies and hyperoxaluria are correlated with cases of lithiasis when stones contain only calcium oxalate or a mixture of oxalate and calcium phosphate; uric acid balance, where once again the measurement of urinary urea is of fundamental importance and shows that all cases of hyperuricuria are related to a diet excessively rich in meat; urinary cystine levels with the need for a Brand reaction almost routinely in all lithiasis sufferers; electrolyte studies which may reveal a renal tubular acidosis syndrome, in fact rare; and, finally, in certain cases a magnesium balance may show a decreased erythrocyte magnesium.

Calcium↗
PubMed1983

Control of tubulin and actin gene expression in Tetrahymena pyriformis during the cell cycle.

Poly(A)-containing mRNA was isolated from division synchronized populations of the ciliated protozoan, Tetrahymena pyriformis. The level of tubulin and actin mRNA at specific cell cycle stages was analyzed by hybridization to tubulin and actin cDNA probes and by gel analysis of their in vitro translation products. The pattern of fluctuation of tubulin mRNA levels was similar to that observed for the in vivo tubulin synthesis previously reported [1]. This suggests that as the cells progress through the cell cycle, tubulin synthesis is controlled at the mRNA level. There was little fluctuation of actin synthesis or actin mRNA levels during the cell cycle, which may be indicative of a different regulatory mechanism for actin than for tubulin.

Actins↗
PubMed1983

[Oxaluria in urinary lithiasis].

The normal value of oxaluria, as determined by gasliquid chromatography, is about 30 mg/24 h. In most cases of renal stone formation (60-70%) the stones are composed of calcium oxalate alone or associated with calcium phosphate. The more evolutive the disease, the higher the oxaluria. The part played by oxaluria in renal stone formation and the need to include its determination in regular examinations of stone formers must be stressed. Treatment of hyperoxaluria is both medicinal and dietetic : control of oxalic acid-rich food intake and reduction of the intestinal absorption of oxalate caused by calcium-deprived diets. The diet must be completed by therapeutic measures aimed at reducing the oxaluria and increasing the urinary factors preventing crystallization.

Diet↗
PubMed1983

5q- anomaly in a patient with disseminated teratoma.

A 5q- anomaly associated with other chromosome anomalies was found in the infiltrated bone marrow of a patient with a highly malignant teratoma originally located in the mediastinum. There was no evidence of a second malignancy, and it is likely that the 5q- anomaly was, indeed, associated with the malignant teratoma cells.

Adult↗
PubMed1983

High yields from microcarrier cultures by medium perfusion.

A culture perfusion system is described for the growth of anchorage-dependent cells on microcarriers. The critical component of this system is a column separator, which removes medium while allowing the microcarriers to remain in the culture. Amino acids and ammonia were analysed during cell growth of the perfusion culture. None of the amino acids was completely utilized. The accumulation of ammonia to 2.3 mM was observed and may be responsible for, or coincident with, events limiting further cell growth. It is suggested that oxygen deprivation and growth inhibitor accumulation, rather than nutrient depletion, are the major factors in limiting even higher cell yields.

Amino Acids↗
PubMed1983

3q-, 3q+ anomaly in malignant proliferations in humans.

Anomalies of both No. 3 chromosomes, of the t(3q-; 3q+) type can be observed in human malignancy as reported previously. It is our experience that this anomaly is found predominantly in myeloproliferative disorders, as a rather rare event, though occurring more frequently than similar exchanges between other homologous chromosomes. Previous claims about a relationship between this anomaly and thrombocytosis could not be confirmed, but the features found in a few patients indicate that further research should be undertaken to clarify this point.

Adult↗