Biomedical subjects
Publications and source records attributed to J Thomas.
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Duration of survival from time of first evaluation was studied in 61 patients with clinically diagnosed Alzheimer's disease (senile dementia of the Alzheimer type [SDAT]) and 34 patients with clinically diagnosed multi-infarct dementia (MID). Duration of survival did not differ significantly between MID and SDAT. However, since MID patients were younger at onset, MID patients had a lower life quotient than SDAT patients. Race, sex, and age at onset were not predictive of survival in SDAT. History of hypertension, elevated systolic blood pressure, lower scores on tests of Block Designs, and Logico-Grammatical Comprehension predicted shorter survival in SDAT. Age at onset and race were not predictive of survival in MID. Male sex, lower educational attainment, as well as low scores on tests of Logico-Grammatical Comprehension, Digit Span, Naming, Verbal Fluency, and receptive vocabulary, predicted shorter survival in MID.
Cells were sorted onto nitrocellulose filters which were saturated with a lysing cocktail designed to preferentially immobilize cellular mRNA. After washing, these filters were incubated with 32P-labeled specific DNA probes. We used the phorbol ester/lipopolysaccharide (PMA + LPS) co-induction of IL-1 mRNA and CD13 expression in U937 cells to demonstrate the specificity of the technique. In addition we used the abundant expression of c-fos in U937 to demonstrate linearity. IL-1 beta mRNA is readily discernable autoradiographically from as few as 5,000 PMA + LPS-induced cells sorted onto a filter. With liquid scintillation counting we demonstrate good linearity of the c-fos quantitation over the range of 1,000 cells to 60,000 cells per filter target. The technique is easily adapted to any sorting flow cytometer and should prove useful to help correlate any flow cytometric cell phenotype with specific mRNA abundance.
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Sexual experiences of 1255 adolescents admitted to a juvenile detention facility were assessed through their responses to a health history questionnaire. More than 80% reported sexual experience. Age at first intercourse acknowledged by females was early (mean 13 years) but rarely prepubertal and was similar for blacks and nonblacks. Males commonly reported beginning sexual experience before age 10 years (40% in blacks and 20% in nonblacks). Sexual activity continued in most, with 73% of the sexually experienced teens reporting intercourse in the month prior to admission. Reports of recent sexual activity increased with age in all race/gender groups. For females, 26% reported sexual misuse compared to 2% of the males. Willingness to answer questions about sexual experiences varied with the question and increased with age. Prepubertal sexual activity is a more common phenomenon than is generally acknowledged. To what extent the experiences reported in our study represent the norm for behavior among individuals of similar background requires further study.
Baboons, rhesus monkeys, and chimpanzees were injected with the human immunodeficiency virus (HIV) and monitored for up to 4 years. Various immunosuppressive regimens were used during this time in attempts to induce development of the acquired immune deficiency syndrome (AIDS). No infectious virus was recovered or anti-HIV antibodies detected in the baboons and rhesus monkeys. Virus has been recovered from lymphocyte cultures of all five of the chimpanzees at intermittent periods following inoculation. The chimpanzees developed anti-HIV antibodies from 1 to 5 months after virus inoculation and had circulating antibodies that neutralized HIV. All the infected animals were capable of in vitro lymphocyte blastogenic responses to recombinant envelope and core HIV antigens. Despite immunosuppressive therapies and evidence of some immunologic abnormalities, none of the five chimpanzees has yet developed AIDS or a related disorder.
Two indium-111 labeled anti-melanoma murine monoclonal antibodies (MAb), 96.5 and ZME-018, each recognizing separate antigens on melanoma cells, were administered intravenously to 17 patients with melanoma in a sequential fashion to determine whether: 1) additional tumor sites could be imaged with the combination compared to a single Mab; 2) the first MAb influenced the biodistribution and tumor localization of the second; and 3) significantly toxicity occurred with the combination. Patients were randomized to receive either 96.5, followed by ZME-018, ZME-018 followed by 96.5, or each MAb followed by itself (controls). Infusions of the second MAb occurred 10 days after the first infusion. Gamma camera images were obtained 72 hours after each antibody infusion. There were 139 known metastatic sites of which 72 lesions were localized by either MAb for an overall sensitivity of 52%. The detection rate was higher when lesions only greater than 1.5 cm were considered. Imaging results were independent of MAb administration sequence. When ZME-018 was given as the first infusion, when ZME-018 was given as a second infusion (p = NS). However, mean sensitivities using 96.5 as the first or second infusion were 48% and 66% respectively (p = NS). There was not a significant number of sites detected by MAb 2 that were missed by MAb 1. Human anti-murine antibody (HAMA) response occurred in seven of eight patients studied; two patients who experienced toxicity had levels of HAMA greater than 2000 ng/ml. We conclude that the use of these two murine anti-melanoma monoclonal antibodies given in sequential fashion did not significantly change the imaging sensitivity from that seen with each individual antibody. Moreover, with the exception of one patient, mean plasma half-life of the MAb did not change significantly, suggesting that overall clearance mechanisms were not saturated by the consecutive doses of monoclonal antibody or significantly altered by the presence of HAMA.
The Stroop Word-Color Test was used to study selective attention deficits in schizophrenic and nonschizophrenic psychiatric patients, compared with nonpsychiatric control subjects. Parts of the Weschler Memory Test and a shortened version of the Stroop Test were administered to test the hypotheses that the attentional deficit could be explained by problems of memory or cognitive fatigue. All patients showed deficits on all of the Stroop scales, but closer analysis of the results permitted discrimination of schizophrenic from nonschizophrenic patients. Schizophrenic patients showed as much difficulty as nonschizophrenic subjects on a limited-duration selective-attention task, but deteriorated significantly more when selective attention had to be maintained. The results could not be attributed to memory problems in the schizophrenic group. The results support the existence of two separable selective attention deficits in schizophrenic patients: a difficulty in selectively attending to the salient aspect of a complex stimulus, a difficulty shared with nonschizophrenic subjects, and a difficulty in maintaining selective attention over time that seems to be more marked in schizophrenic subjects.
Presence of certain nitrogenous compounds in the growth medium significantly enhanced the salt tolerance of the fresh-water cyanobacterium Anabaena sp. strain L-31 as well as the brackish water cyanobacterium Anabaena torulosa. Among these, nitrate, ammonium, and glutamine were most effective followed by glutamate and aspartate. These nitrogenous compounds also inhibited Na(+) influx in both Anabaena spp. with the same order of effectiveness as that observed for protection against salt stress. The inhibition of Na(+) influx on addition of the nitrogenous substances was rapid; nitrate and ammonium inhibited Na(+) influx competitively. Proline and glycine did not affect Na(+) influx and also had no influence on the salt tolerance of either Anabaena sp. The observed protection was not consequent to a stimulatory effect of combined nitrogen on growth per se. Uptake of NO(3) (-) and NH(4) (+) increased during salt stress but was not correlated with growth. Intracellular levels of NO(3) (-) and NH(4) (+) were found to be inadequate to constitute a major component of the internal osmoticum. The results suggest that inhibition of Na(+) influx by combined nitrogen is a major mechanism for protection of cyanobacteria against salt stress.
Considerable information has been obtained about the primary structures of suspension-cultured sycamore (Acer pseudoplatanus) cell-wall pectic polysaccharides, i.e. rhamnogalacturonan I, rhamnogalacturonan II, and homogalacturonan. However, these polysaccharides, which are solubilized from the walls by endo-alpha-1,4-polygalacturonase, account for only about half of the pectic polysaccharides known to be present in sycamore cell walls. We now report that, after exhaustive treatment with endo-alpha-1,4-polygalacturonase, additional pectic polysaccharides were extracted from sycamore cell walls by treatment with Na(2)CO(3) at 1 and 22 degrees C. These previously uncharacterized polysaccharides accounted for approximately 4% of the cell wall. Based on the glycosyl and glycosyl-linkage compositions and the nature of the products obtained by treating the quantitatively predominant NaCO(3)-extracted polysaccharides with lithium metal dissolved in ethylenediamine, the polysaccharides were found to strongly resemble rhamnogalacturonan I. However, unlike rhamnogalacturonan I that characteristically had equal amounts of 2- and 2,4-linked rhamnosyl residues in its backbone, the polysaccharides extracted in Na(2)CO(3) at 1 degrees C had markedly disparate ratios of 2- to 2,4-linked rhamnosyl residues. We concluded that polysaccharides similar to rhamnogalacturonan I but with different degrees of branching are present in the walls of suspension-cultured sycamore cells.
A total of 1023 women attending hospital antenatal clinics in West Glamorgan was surveyed by means of a self-administered questionnaire, to determine their attitudes to HIV testing in pregnancy. The response rate was 98%. Of the responders, 94% had no objection to their antenatal blood specimen being tested for HIV infection. Of the non-objectors, 55% wished their permission to be asked first, and 92% wished to be informed of the result, i.e. they wished for named testing. With regard to knowledge of other tests for infectious diseases performed on antenatal blood specimens, only 1.5% had totally correct knowledge, and only one in three knew that their blood was tested for syphilis. The implications of anonymous and named HIV testing are discussed, together with estimates of prevalence of HIV infection in women attending antenatal clinics, the rate of vertical transmission, and the prognosis for an infected baby.
Microscopic dissociation constants of 3-hydroxy-alpha-(methylamino)methyl-benzenemethanol have been calculated from the titration spectrophotomeric data (c = 3.8 x 10(-4) M. Ionic strength = 0.16; buffer system: H3BO3/KOH) by application of a spectral deconvolution method. The results found (pKa = 9.48; pKb = 9.71; pKc = 10.12 and pKd = 9.88) are in good concordance with those obtained from the conventional regression linear method (pKa = 9.45; pKb = 9.77; pKc = 10.14 and pKd = 9.81).
The time constant (T) of left ventricular pressure fall is widely used as an index of ventricular "relaxation". It is not known whether its rate limiting step is deactivation, an enzymic energy consuming reaction whose rate is therefore sensitive to temperature, or elastic recoil. To distinguish between these possibilities, the time constant was measured by simple logarithmic (Tlog) and exponential (Texp) methods in 12 patients during cooling before coronary artery grafting. Ventricular loading conditions were altered by transfusion from bypass to maintain arterial and left atrial pressures constant in individual patients, though heart rate fell from 86 (8.4) to 68 (10) beats/min. Tlog increased from 49 (10) ms mean (SD), at 37 degrees C to 86 (15) ms at 31 degrees C, and Texp from 63(14) at 37 degrees C to 112 (23) ms at 31 degrees C with intermediate values at 34 degrees C. Texp proved sensitive to "noise" at low temperatures, but the overall change in Tlog with temperature was 9% per degree C--considerably less than that observed experimentally for the rate of tension decline of isolated myocardium, and possibly itself an overestimate because of the concomitant fall in heart rate. The relatively small effect of temperature on Tlog in humans, associated with a considerable load sensitivity appearing under hypothermic conditions, does not favour simple dependence on deactivation as the rate limiting step of left ventricular pressure fall, but suggests that its determinants may be complex.
Captopril is commonly prescribed to patients with hypertension and congestive heart failure. Adverse dermatological reactions have been reported in about ten percent of patients receiving captopril. This case report describes a 77-year-old white woman who developed bullous pemphigoid associated with the use of captopril. The patient presented with bullous eruptions localized on the palms of both hands about 50 days after captopril 25 mg bid was started. Biopsy report was consistent with bullous pemphigoid. Captopril therapy was discontinued and the lesions healed after oral corticosteroid therapy was initiated.
A problem with posterior composites is an unacceptable wear level. One factor contributing to inadequate wear resistance may be the way the restoration is surfaced or finished. A clinical study was carried out to determine the influence of finishing on the wear rate of a posterior composite resin. Except for the first 30 days, the resistance to wear was significantly higher for the unfinished group as compared to those that received a conventional finish. The average difference in wear between the two groups was nearly 40 microns.