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Biomedical subjects

S J Hoffman

Publications and source records attributed to S J Hoffman.

34 records · Page 2Linked to original sources

Use of differentiation-inducing agents in the myelodysplastic syndrome and acute non-lymphocytic leukemia.

The use of chemical agents that induce differentiation of malignant cells to normal cells has held great promise as an adjunct to standard chemotherapy. In vitro data has shown that 13-cis-retinoic acid can differentiate certain leukemia cell lines (e.g., HL-60) into stable granulocyte cells. In this study, oral 13-cis-retinoic acid was administered to four patients with the myelodysplastic syndrome (MDS) and to four patients with acute nonlymphocytic leukemia (ANLL). None of the MDS patients showed an hematologic response to the drug, while three of four ANLL patients responded with normalized peripheral blood counts. The side effects of the drug at 80-120 mg/d (dry skin, cheilitis, epistaxis) were self limiting.

Acute Disease↗

Glutathione S-transferases in human prostate.

A number of human prostatic tissue biopsies have been analyzed for glutathione S-transferase activity, using 1-chloro-2,4-dinitrobenzene (CDNB) as a substrate. Samples from nine patients (age range 61-90) with benign prostatic hypertrophy who had received no prior chemotherapy had a mean glutathione S-transferase activity of 137 +/- 44 nmol/min per mg with a range of 97-237. A qualitative comparison of the glutathione S-transferase of normal prostate and benign prostatic hypertrophy samples was carried out. Approximately 260-fold purification was achieved using glutathione-Sepharose affinity chromatography, with glutathione S-transferase accounting for approximately 0.19-0.33% of the total protein. Substrate specificity determinations suggested similar, but not identical, glutathione S-transferase subunits in normal prostate and benign prostatic hypertrophy. One- and two-dimensional electrophoresis (isoelectric focusing and 12.5% SDS-polyacrylamide gel electrophoresis) identified at least seven stained polypeptides in the purified glutathione S-transferase preparations. These ranged in Mr from approximately 24,000 to 28,500 and in pI from near neutral to basic. Western blot analysis using polyclonal antibodies raised against rat liver glutathione S-transferase suggested crossreactivity with five of the human isoenzymes in both normal prostate and benign prostatic hypertrophy. One of the glutathione S-transferases, present in both normal prostate and benign prostatic hypertrophy, had an Mr of approx. 24,000 and a near-neutral pI and crossreacted immunologically with a polyclonal antibody raised against human placental glutathione S-transferase (Yf, subunit 7 or pi). These data suggest that four glutathione S-transferases are expressed in human prostate, with subunits from each of the major classes alpha, mu and pi. These are characterized as Ya, Yb, Yb' and Yf (analogous alternative nomenclature subunits 1, 3, 4 and 7).

Aged↗

Imagery ability in recall of distance and location information.

The role of visual imagery in short-term retention of movement end locations and distances was examined by comparing performances of subjects with extreme scores on the space relations section of the Differential Aptitude Test. Twelve HIGHS and twelve LOWS were tested on reproduction accuracy of six distances and six end locations immediately following presentation a 30-sec rest, a 30 sec imaginal rehearsal condition, and a 30-sec imaginal distraction condition. Initial analysis of the data provided little support for the hypothesis that HIGHS would reproduce criterion locations with more accuracy than LOWS. However, when scores of HIGHS reporting use of an imaginal coding strategy (HIGHS) were compared with LOWS who did not (LOWS), several expected findings were disclosed. HIGHS reproduced end locations with significantly less error in the immediate and imaginal rehearsal conditions, and as expected, accuracy scores for HIGHS and LOWS did not differ for the distance task. The findings suggest that when subjects employ an imaginal coding strategy, visual imagery ability may be an important factor in the retention of location information, but of little functional significance in the recall of distance.

Journal Article↗

Effects of smoking and telic/paratelic dominance on the contingent negative variation (CNV).

Concepts from reversal theory, a general theory of motivation, emotion and action, have recently been shown to be relevant to smoking behavior and smoking cessation. One relevant concept is that of telic and paratelic dominance. Individuals who are paratelic-dominant are playful, spontaneous, and prefer high arousal seeking. Those who are telic-dominant are serious, tend to plan ahead, and prefer low arousal. This led to the hypothesis that smoking might increase the amplitude of the contingent negative variation (CNV) in paratelic-dominant smokers more than in telic-dominant smokers. CNV was obtained using a Go/NoGo reaction time task with a 2 s S1-S2 interval and variable intertrial intervals. S1 indicated whether the subject was to respond to S2 or not. Errors were punished with a burst of white noise. Subjects performed the CNV task three times: after being deprived of smoking for at least 4 h; after sham smoking; and after smoking a cigarette of their own brand. Telic-dominant subjects differed from paratelic-dominant subjects in the relative amplitude of early (1 s) and late (2 s) components of the CNV. Smoking did not differentially affect the dominance groups unless gender was taken into account, and the most striking interactions between smoking and dominance groups were noted for the NoGo trials. As expected, smoking decreased the amplitude of the early component of the NoGo CNV for telic-dominant women, but increased it for paratelic-dominant women; no significant differences were found for the late component. In men, smoking increased the late CNV more for telics than for paratelics, while smoking did not differentially affect the early component.

Acoustic Stimulation↗

Effects of a specialized prenatal adolescent program on maternal and infant outcomes.

The effects of a specialized prenatal educational program on perinatal outcomes in an urban adolescent maternity term population were examined. Fifty pregnant adolescents attended the program and 50 nonattenders served as controls. All subjects delivered at the same large metropolitan hospital. The data supported the hypotheses predicting that those adolescents exposed to the educational program and their infants would demonstrate fewer perinatal complications than those not exposed to the program. When analyzed by age, attenders and their infants in both groups (13 to 15 and 16 to 18 years of age) had fewer complications than nonattenders. Attenders also demonstrated lower frequencies of several obstetric and postnatal complications than did nonattenders. This study underscores the positive effects a specialized education program can have on adolescent perinatal outcomes.

Adolescent↗

Neuromas associated with tailor's bunion.

The purpose of this paper is to present to the physician a common clinical problem associated with tailor's bunion, a probable traumatic neuroma of the proper digital branch of the superficial division of the lateral plantar nerve. Many of the patients who presented to the authors with tailor's bunion also exhibited a traumatic neuroma. The authors discuss this clinical problem, its treatment, and its eradication.

Foot↗