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Biomedical subjects

S Watson

Publications and source records attributed to S Watson.

At least 145 records · Page 8Linked to original sources
PubMed1987

Sequential hydroxyurea-cytarabine chemotherapy for refractory non-Hodgkin's lymphoma.

In experimental systems, hydroxyurea (HU) and cytarabine (ara-C) produce synergistic cytotoxicity to murine and human leukemia cells due to both cytokinetic and biochemical interactions that tend to enhance the effectiveness of ara-C. Therefore, we began a phase II trial of the combination of HU and ara-C to determine the efficacy and toxicity of this combination in treatment of patients with refractory non-Hodgkin's lymphoma. Chemotherapy began with HU 500 mg administered orally every six hours for four doses. Twelve hours following the fourth HU dose, ara-C 100 mg/m2/d was administered by continuous intravenous (IV) infusion for three days. Concomitantly with the three-day ara-C infusion, patients again received HU 500 mg orally every four hours. Cycles of therapy were repeated every 28 days. Twenty-five patients ranging in age from 26 to 70 years were enrolled in the study. Of 21 patients evaluable for response, nine (43%) obtained complete (CR) or partial remissions (PR). Most responding patients had either large-cell or cutaneous T cell lymphoma, and all but two had a performance status of 0 to 1 at entry in the study. The median survival for all responding patients was 13 months compared with 2.5 months for nonresponders. Patients obtaining a CR had a median survival of 27.5 months, and two of the four CRs remain alive and in remission at 10+ and 30+ months from achievement of CR status. The primary toxic effect of this regimen was bone marrow suppression. The median WBC nadir was 2,200 cells/microL, and the median platelet nadir was 80,000/microL. Other toxicities included mild nausea and vomiting and diffuse maculopapular rash. This biochemically rational approach to enhancing ara-C activity may have significant clinical utility and should be further explored in treatment of patients with large-cell and cutaneous T cell lymphomas.

Adult↗
PubMed1986

Detection of antibodies to Mycoplasma felis in horses.

Mycoplasma felis has been isolated from horses with pleuritis, and limited research indicates that mycoplasma pleuritis can be reproduced in horses. The serodiagnostic potential of the indirect hemagglutination and the metabolism-inhibition tests was evaluated by testing 177 horses for antibodies to M felis. Seven horses with M felis pleuritis developed antibodies, and 6 horses with sterile or bacterial pleuritis had high titers suggesting a previous M felis infection. Six horses with pleuritis (one sterile and five bacterial) had low or no titers to M felis. Only one of 30 horses with conditions other than respiratory diseases seroconverted during hospitalization and the remaining horses had low titers. Seventy-eight foals, 4 to 6 months old, from one farm did not have titers, whereas 7 out of 50 yearlings from the same farm had high titers in the indirect hemagglutination test and titers in the metabolism-inhibition test. It appears that both tests are suitable for serodiagnosis of M felis infection in horses.

Animals↗
PubMed1986

Infections of the lower extremities due to gas-forming and non-gas-forming organisms.

From 1977 to 1984, 87 above- and below-knee amputations were done on 77 patients for ischemic ulcerations and gangrene of the lower extremities. The overall three-month mortality was 14% and was mainly related to generalized atherosclerosis. Patients having infections with gas formations were more likely to be diabetic (80% vs 15%, P less than .01), have clinical sepsis and a higher preoperative WBC (19,000 vs 12,600/cu mm, P less than .01), and have a higher mortality (40% vs 12%, P less than .05) than those with infections due to non-gas-forming organisms. Mixed bacterial flora were cultured from most wounds. We conclude that infections with gas formation may be due to either clostridial or nonclostridial organisms, mortality is higher if gas accumulates and if the patient is diabetic, gas is more likely to accumulate in infected extremities of diabetic patients, and the combination of gas formation and diabetes is highly lethal.

Aged↗
PubMed1985

Affective disorders in referred children and younger siblings of manic-depressives. Mode of onset and prospective course.

We studied 68 referred juvenile offspring or siblings of adult bipolar patients. Mean age at onset of affective and related disturbances was 15.9 years (range, 6 to 24 years). Although four of the ten prepubertal children had hypomanic features, full-blown manic psychosis did not appear before puberty. In the sample at large, 12 were classified as dysthymic and ten as cyclothymic. Eleven additional subjects with polysubstance abuse, who at onset did not meet criteria for affective disorder, were reclassified as having either a dysthymic or a cyclothymic disorder during follow-up. Of the remaining patients--24 depressive, eight manic, and three mixed state--71% experienced recurrences; mood-incongruent features, present in four cases at onset, recurred in only one patient during subsequent episodes. Overall, half the sample evidenced signs of bipolarity during a mean prospective follow-up period of three years.

Acute Disease↗
PubMed1985

Indium 111 toxicity in the human lymphocyte.

Indium-labeled lymphocytes were examined for response to a variety of mitogens, ability to synthesize immunoglobulins, mitotic index, and presence of chromosome aberrations at a range of exposures from 0.2 to 500 muCi/10(8) cells. Results of all four tests were found to be abnormal when the lymphocytes were labeled with 111In activities well within those employed for diagnostic testing.

Cell Survival↗
PubMed1984

Interleukin 1 production by peripheral blood mononuclear cells from leprosy patients.

Quantitation of interleukin 1 production by adherent mononuclear cells from peripheral blood was performed in patients with tuberculoid and lepromatous forms of leprosy. Cells from patients with tuberculoid leprosy either secreted interleukin 1 spontaneously or produced amounts within the normal range in response to lipopolysaccharide stimulation. Conversely, stimulated cells from lepromatous patients failed to produce interleukin 1 in 5 of 13 (38.5%) cases.

Adult↗
PubMed1983

Postnatal ontogeny of acetylated and non-acetylated B-endorphin in rat pituitary.

Extracts of the anterior lobe and intermediate lobe of postnatal (P) (Day P1, P7, P14, P21, P28, P35, P42) and adult male Sprague-Dawley rats were analyzed by both a Beta-endorphin (B-END) radioimmunoassay and a radioimmunoassay for N-acetyl-B-END. In the anterior lobe, on P1, less than 2% of the adult level of B-END was present. By P42 this level had increased to 21% of adult levels. In the intermediate lobe, on P1, the B-END levels were less than 0.1% of the adult level, and by P42 this level approached approximately 45% of the adult levels. N-acetylated B-END was identified in both anterior lobe and intermediate lobe from P1 through adulthood. In the anterior lobe at P1, N-acetyl-B-END immunoreactivity contributes approximately 25% of the total B-END immunoreactivity. This level drops to less than 10% by P21, and to adult-like levels by P42 (less than 5%). On the other hand, in the intermediate lobe, the N-acetyl-B-END levels start at 70% of the total B-END immunoreactivity at P1 and by P14 reaches adult-like proportions of 90% or more of the total B-END immunoreactive material.

Aging↗
PubMed1983

Cholestasis in infancy. A review.

The natural history of cholestatic syndromes in infancy remains largely unclarified for lack of sufficient data. Newborn and premature infants are particularly vulnerable to cholestasis because of immaturities in bile-forming mechanisms. Until recently, two board categories of etiologic factors has been thought to be associated with cholestasis in early infancy: mechanical obstruction (almost always extrahepatic), and hepatocellular damage (the "neonatal hepatitis" group). Although in both groups specific etiologic factors have been identified, the majority of cases are currently of unknown etiology. Problems in differential diagnosis are reviewed. In the neonatal period, laboratory screening procedures usually do not uncover cholestatic liver disease until the infants become icteric. It is important to not that patients with liver dysfunction may remain anicteric or become anicteric while cholestasis persists. It is, therefore, important that biochemical markers of cholestasis other than conjugated bilirubin be found.

Bile↗
PubMed1983

Analysis for Fusarium toxins in various samples implicated in biological warfare in Southeast Asia.

Samples of leaves, water, cereal grains, soil, and yellow powder as well as blood, urine, and body tissues from chemical warfare victims were analyzed for Fusarium toxins by using gas chromatography and mass spectrometry. The leaves, water, and yellow powder samples contained various combinations of T-2 toxin, diacetoxyscirpenol, deoxynivalenol, nivalenol, and zearalenone in concentrations ranging from trace (1.0 ppb) amounts to 143 ppm. These trichothecenes do not occur naturally on the substrates described and were correlated with the so-called "yellow rain" chemical attacks against Hmong people in Southeast Asia. Analysis of leaves, soil, water, and cereals collected in areas adjacent to but apart from the area where chemical attacks had been staged did not contain any Fusarium toxins. Moreover, T-2 and HT-2 toxins were found in human blood, urine, and body tissues (heart, esophagus, kidney, lung, and large intestine) of alleged victims. In addition, diacetoxyscirpenol was found in the kidney of one person who had died.

Adult↗
PubMed1982

Aberrant immunoregulatory control of B lymphocyte function in lepromatous leprosy.

The capacity of peripheral blood mononuclear (PBM) cells from patients with leprosy to generate immunoglobulin-secreting cells in response to pokeweed mitogen (PWM) was evaluated by a reverse haemolytic plaque forming cell (PFC) assay. The PFC responses of PBM cells from patients with lepromatous (Lpr) leprosy were significantly higher (P less than 0.01) than those of PBM cells from normal controls and patients with tuberculoid leprosy. Co-culture of T lymphocytes from normal donors with PBM cells from Lpr patients reduced the PFC response of these cells to the normal range. T4+-helper lymphocytes from Lpr donors did not induce supranormal responses to PWM by normal PBM cells enriched for B lymphocytes. T8+-suppressor lymphocytes from normal donors greatly reduced the response of cultures containing normal allogeneic B cells plus T4+ cells. Conversely, when T8+ cells from Lpr donors were cocultured with normal B cells plus T4+ cells, they failed to suppress the response to PWM. In summary, these studies have demonstrated abnormally high PWM-stimulated PFC responses by B lymphocytes from patients with Lpr leprosy. This aberration, in turn, is associated with a loss of regulatory function by T8+-suppressor cells in Lpr patients.

Adult↗
PubMed1979

Experimental Trypanosoma cruzi infection in rhesus monkeys 111. Electrocardiographic and histopathological findings.

In five rhesus monkeys surviving 'Peru strain' or 'strain 7' Trypanosoma cruzi infection for six to eight years, positive xenodiagnosis results and high indirect fluorescent antibody titres (4096 - 65536) persisted until the animals were killed. Abnormal electrocardiograph patterns in two monkeys (H and K) were possibly compatible with myocardial damage. Histopathological changes attributable to T. cruzi infection were minor in four monkeys but severe in one (R). In this animal, infected with what was judged previously to be the less virulent of the two T. cruzi stocks used ('strain 7'), there was severe myocarditis, with myofibre degeneration, and lesions of the oesophagus. Elevated serum levels of five enzymes were not detected in any of the chronically infected monkeys.

Animals↗