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Biomedical subjects

J Thomas

Publications and source records attributed to J Thomas.

At least 559 records · Page 31Linked to original sources

Career talk.

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Career Choice↗

Cytogenetic studies in T-cell malignancies.

Clonal chromosome abnormalities in ten cases of T-cell lymphoproliferative disorders are reported. In addition, an extensive review of the literature on T-cell lymphomas shows the chromosomal sites most frequently involved in structural rearrangements.

Adolescent↗

Vitamin E supplementation and intense selection increase clonal life span in Paramecium tetraurelia.

Vitamin E added to standard Cerophyl medium at 0.025 mg/ml significantly increased the mean clonal life span of 32 lines of Paramecium tetraurelia from 52.5 days and 187 fissions to 59.9 days and 209 fissions (p less than .05) when compared to unsupplemented, paired controls. The age-specific death rates increased exponentially. Regression analyses found a significantly lower rate of increasing mortality for the supplemented lines compared to controls. Weekly fission rates of supplemented lines declined linearly; more slowly than controls, but not significantly so. A second experiment tested two higher levels of supplemental vitamin E (0.10 and 1.00 mg/ml). Sublines receiving 1.00 mg/ml of supplemental vitamin E had higher rates of mortality and lower fission rates initially, but the mortality rates increased and the fission rates decreased more slowly than in sublines receiving 0.10 mg/ml supplemental vitamin E, resulting in maximum clonal life spans of 141 days and 330 fissions (1.00 mg/ml sublines), compared to 74 days and 271 fissions (0.10 mg/ml sublines). Survivorship of the last individual cells (nondividing) of each clone followed an exponential decline, with a significant increase in mean survival time for supplemented compared to unsupplemented cells (p less than .05).

Animals↗

Glucocorticoids selectively inhibit the transcription of the interleukin 1 beta gene and decrease the stability of interleukin 1 beta mRNA.

Transcription of the interleukin 1 beta (IL-1 beta) gene was studied by mRNA hybridization with a cDNA probe in the human promonocytic cell line U-937. Phorbol ester and lipopolysaccharide increased the steady-state level of IL-1 beta mRNA. Glucocorticoids markedly decreased IL-1 beta mRNA levels by two mechanisms. Transcription of the IL-1 gene was inhibited, as shown by in vitro transcription assays with nuclei isolated from glucocorticoid-treated cells. Moreover, kinetic analyses and pulse-labeling of mRNAs showed that glucocorticoids selectively decrease the stability of IL-1 beta mRNA, without affecting the stability of beta-actin and FOS mRNAs. Inhibition of the formation and effects IL-1 is a mechanism by which glucocorticoids can exert antiinflammatory and immunosuppressive effects.

Cycloheximide↗

Diagnosis of pancreatic allograft rejection by measurement of urinary radioimmunoreactive insulin.

The accurate, early, and sensitive diagnosis of pancreatic allograft rejection is one of the major problems in clinical pancreas transplantation today. Pancreaticocystotomy is a popular technique for pancreas transplantation that permits simple and frequent urinary chemistry examinations. In this experiment, 20 mongrel dogs with a bladder-drained pancreatic transplant had serial monitoring of urinary amylase (UA) and urinary insulin (UI). The mean UI in the nonrejection state was 9.6 +/- 12 mIU/L. In eight dogs varying degrees of rejection were documented by histopathology. All three animals having severe acute rejection had high levels of IU (all greater than 300-800 mIU/L). Of the five animals with mild-to-moderate rejection, all had significant UI elevations to greater than 100 mIU/L but none had elevations above 200 mIU/L (P less than 0.05 for all groups). Ten animals were treated with prednisone, Imuran, and cyclosporine (CsA), and five of these dogs had good graft function for greater than 14 days, during which the mean UI was extremely low (11 +/- 6.4 mIU/L, P less than 0.05). These values were not significantly different from the 0-14-day values for three pancreas autotransplants with bladder drainage (8.9 +/- 7.2 mIU/L, P less than 0.05). All rejections were preceded by significant rises of UI occurring two to five days prior to rejection. In seven animals, early graft dysfunction (1-4 days) developed, with total graft necrosis by five days. This graft injury was presumably caused by preservation damage or early vascular thrombosis and was associated with early (1-4 days) marked elevations of the UI (greater than 300 mIU/L). None of the animals with grafts surviving to rejection at seven days or more had these early severe elevations, and thus these early UI rises are pathognomonic of graft damage. In contrast, UA and lipase showed inconsistent association with rejection or early damage, although falls in UA generally occurred at or following the time of rejection. Marked daily variations in UA measurements were the most difficult aspect of UA monitoring. Serial electromagnetic flow probe studies of blood flow to the pancreas graft showed a good correlation between loss of blood flow and rises in UI associated with early graft injury. These results suggested that the UI assay gives a sensitive, early, accurate, and specific differential prediction of pancreas graft dysfunction. Specifically, the UI assay appears to be of value not only in the early differential diagnosis of graft injury and graft rejection, but also in the assessment of the severity of rejection.(ABSTRACT TRUNCATED AT 400 WORDS)

Amylases↗

Underwater audiogram of a false killer whale (Pseudorca crassidens).

Underwater audiograms are available for only a few odontocete species. A false killer whale (Pseudorca crassidens) was trained at Sea Life Park in Oahu, Hawaii for an underwater hearing test using a go/no-go response paradigm. Over a 6-month period, auditory thresholds from 2-115 kHz were measured using an up/down staircase psychometric technique. The resulting audiogram showed hearing sensitivities below 64 kHz similar to those of belugas (Delphinapterus leucas) and Atlantic bottlenosed dolphins (Tursiops truncatus). Above 64 kHz, this Pseudorca had a rapid decrease in sensitivity of about 150 dB per octave. A similar decrease in sensitivity occurs at 32 kHz in the killer whale, at 50 kHz in the Amazon River dolphin, at 120 kHz in the beluga, at 140 kHz in the bottlenosed dolphin, and at 140 kHz in the harbor porpoise. The most sensitive range of hearing was from 16-64 kHz (a range of 10 dB from the maximum sensitivity). This range corresponds with the peak frequency of echolocation pulses recorded from captive Pseudorca.

Acoustic Stimulation↗

Non-Hodgkin's lymphomas in 137 patients aged 70 years or older: a retrospective European Organization for Research and Treatment of Cancer Lymphoma Group Study.

The results of a European Organization for Research and Treatment of Cancer (EORTC) retrospective study on non-Hodgkin's lymphoma (NHL) in elderly patients (greater than or equal to 70 years of age) seen in Europe in 1984 are reported. A precodified form was sent to 55 European institutes in order to evaluate the incidence of NHL in the elderly with regard to natural history, treatment-related toxicity, response, and survival. Thirteen institutes participated in the study. One hundred thirty-seven cases of NHL were observed in the elderly during 1984, making up 28% of the total number of NHL seen in those institutes. The median age was 77 years; 21% of the patients had favorable (low-grade) and 73% unfavorable (intermediate- and high-grade) histology, according to the Working Formulation. Stage at presentation was localized (I and II) in 60% and advanced in 37% of the patients. Most of the physicians used standard therapy regimens at reduced doses, from the beginning of the treatment. Sixty patients (44%) underwent a "conservative" treatment (one or two antineoplastic drugs or local field radiotherapy) and 77 (56%) an "aggressive" treatment (polychemotherapy regimens or extended field radiotherapy). Response was similar between the two treatment groups, but severe and lethal toxicity was significantly higher among patients treated with aggressive therapy. Prospective randomized studies are clearly needed to define the optimal treatment in elderly patients with advanced unfavorable NHL.

Aged↗

Prolonged prednisolone therapy in adult nephrotic syndrome: a preliminary study.

Twenty-five adult Nigerian patients suffering from the nephrotic syndrome with normocomplementaemic mesangiocapillary glomerulonephritis were studied. Twelve of these were treated with prednisolone at a dose of 1.5 mg/kg body weight/day, with maximum dose of 90 mg/day initially for 2 weeks. Thereafter, a quarter of the daily dose was given on alternate days for a period varying from 6 to 12 months. The 13 others were similarly followed up on a dietary and diuretic regime alone. Oedema disappeared completely in all the steroid group except one, whilst it persisted in five of the controls. Proteinuria persisted in all the controls but remitted in five of the test patients. Renal function deteriorated with rising plasma creatinine in five of the controls, in contrast with one of the test patients. The beneficial effect of prednisolone observed here calls for further long-term studies.

Adolescent↗

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Ethics, Medical↗