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Biomedical subjects

L Lewis

Publications and source records attributed to L Lewis.

At least 19 recordsLinked to original sources
PubMed1995

Daily gastrointestinal symptoms in women with and without a diagnosis of IBS.

This study compared daily gastrointestinal symptoms and stool characteristics across two menstrual cycles, and recalled bowel symptoms and psychological distress in women with irritable bowel syndrome (IBS, N = 22), IBS nonpatients (IBS-NP, N = 22), and controls (N = 25). Daily reports of abdominal pain, bloating, intestinal gas, constipation, and diarrhea did not differ significantly between the IBS and IBS-NP groups but both groups reported significantly higher symptoms than the control group. Stool consistencies was significantly looser in the IBS group relative to the control group. Menstrual cycle effects on symptoms were noted in all the groups. There were no significant differences in psychological distress between women with IBS and IBS-NP, but both groups reported significantly higher global distress than the control group. The lack of difference between the IBS and IBS-NP groups in contrast to the results of others, can be understood in terms of differences in recruitment strategies.

Abdominal Pain↗
PubMed1994

Symbolization in psychotherapy with patients who are disabled.

Symbols created during the process of psychotherapy serve psychological functions of giving form and substance to previously murky experiences, making what is private something shared, and forging meaningful linkages among thoughts, emotions, and perceptions. Symbols can also enable therapist and patient together to gain insight into transference themes, transformations in identity, and feelings about life changes, as well as serve as guides to articulating treatment goals. Clinical vignettes are used to illustrate the process.

Adult↗
PubMed1992

Anti-sulfatide antibodies in neurological disease: binding to rat dorsal root ganglia neurons.

Increased titers of anti-sulfatide antibodies were detected by ELISA in 5 of 200 patients and control subjects. All 5 patients had sensory impairment; 4 had neuropathy, and one had multiple sclerosis. Of the patients with neuropathy, 2 had a clinical syndrome of small fiber sensory neuropathy with normal electrophysiological or nerve biopsy studies, 1 had a sensorimotor axonal neuropathy associated with IgM monoclonal gammopathy, and 1 had sensorimotor neuropathy with multifocal motor conduction block and anti-GM1 antibodies. The anti-sulfatide antibodies bound to the surface of unfixed rat dorsal root ganglia neurons and human neuroblastoma cells, and to fixed sections of central and peripheral myelin. No binding was detected following intraneural injection into rat sciatic nerves. Pre-absorption with sulfatide but not with galactocerebroside eliminated the tissue binding activity. These findings indicate that increased titers of anti-sulfatide antibodies are found in patients with sensory impairment but are not restricted to a particular neurological syndrome or type of neuropathy. The significance of anti-sulfatide antibodies is uncertain although sulfatide on dorsal root ganglia neurons may be a target antigen.

Aged↗
PubMed1992

Evaluation of a summer prematriculation program for black and other nontraditional students.

This study evaluated the effectiveness of the Medical College of Georgia School of Medicine's Summer Prematriculation Program in facilitating participants' first-year achievement and retention from 1980 to 1989. The four-week curriculum included biochemistry, anatomy, immunology, learning skills, medical or anatomy terminology, and clinical forums. Of 101 black and 96 other nontraditional, at-risk students who had been invited to attend the program, the 115 attendees were compared with the 82 nonattendees on a variety of demographic and academic measures. For all measures examined, no statistically significant difference was found between the two groups. Several factors may have obscured the results. However, there were indications that the program had a favorable effect, including the evaluation by over 90% of the attendees that the program had contributed positively to their adjustment to medical school.

Black or African American↗
PubMed1992

Prematriculation program grades as predictors of black and other nontraditional students' first-year academic performances.

This study explored the relative strengths of select background variables, including grades in a summer prematriculation program (SPP), as predictors of students' first-year academic performances. During the years 1980-1989, 115 black and other nontraditional prematriculants at the Medical College of Georgia School of Medicine attended a four-week SPP featuring courses in biochemistry, anatomy, and immunology. Canonical correlation analysis revealed that the combination of undergraduate grade-point average (GPA) and SPP grades in biochemistry and anatomy was the best predictor of the students' academic performances based upon their first-year grades in biochemistry, anatomy, and microbiology, and upon their GPAs for all first-year basic science courses. The authors conclude that SPP grades can be used to identify the specific academic weaknesses of nontraditional students at highest risk of falling into academic jeopardy.

Black or African American↗
PubMed1992

Two neuropsychological models and their psychotherapeutic implications.

Two neuropsychological models of normal brain functioning--cerebral laterality and hierarchical brain organization--are reviewed and their implications for psychotherapy are discussed. The purpose is not to reduce or translate complex psychological phenomena into neural terms or to suggest that psychopathology will ultimately be viewed as neuropathology. Rather, the effort is to point out convergences in findings of the two disciplines and to discuss the possible neurophysiological mechanisms underlying the resolution of psychopathology through psychotherapeutic interventions.

Brain↗
PubMed1991

High-moisture diet for laboratory rats: nutrient analysis, growth, and organ weights.

A diet (KSC-25) to be sterilized by irradiation was formulated to contain 66% moisture and to provide the required nutrients for growing rats. Analyses of the irradiated dry diet provided data to evaluate its nutrient content. The diet was evaluated for its ability to supply all nutrients, including water, required by immature rats. Sixteen Sprague-Dawley rats were fed the high-moisture diet with or without access to a water bottle. Rats (n = 16) fed an irradiated purified diet in a meal form with access to a water bottle were the control animals. Feed efficiency, food and water consumption, and growth rate data were collected during the 28-day study. Organ weights were collected on day 28. The test diet met or exceeded the National Research Council (NRC) estimated nutritional requirements for immature laboratory rats. The 66% moisture KSC-25 diet provided all nutrients, including water, required by weanling male Sprague-Dawley rats for growth equivalent to the established purified diet.

Animal Feed↗
PubMed1991

High-moisture diet for laboratory rats: complete blood counts, serum biochemical values, and intestinal enzyme activity.

Rats were fed an irradiated high-moisture diet (KSC-25) with or without access to a water bottle. Physiologic values were compared between these two groups and a group of rats fed a purified diet. Hematologic and serum biochemical values, urine specific gravity, and intestinal enzyme activities were determined from samples collected from the three groups of rats. Sprague Dawley rats (n = 32) fed the irradiated high-moisture diet with or without a water bottle were the test animals. Rats (n = 16) fed an irradiated purified diet and water provided via a water bottle were the control group. The purified diet formulation modified AIN-76A, is a commonly used purified diet for laboratory rodents. All rats remained alert and healthy throughout the study. A comparison of the physiologic values of rats in this study with reported normal values indicated that all of the rats in the study were in good health. Significant differences (P less than 0.05) of the physiologic values from each rat group are reported.

Animal Feed↗
PubMed1990

Psychoanalytic psychotherapy with brain-injured adult psychiatric patients.

Scant attention has been paid to psychotherapy with patients who have acquired neurological conditions. In this paper the authors describe the common psychological problems and repetitive themes that emerge in the therapeutic process with these patients, as well as the salient attitudes toward therapy and the therapist that these patients manifest. Case vignettes illustrate the theoretical and technical considerations.

Affect↗
PubMed1989

Angiotensin II-producing enzyme III from acidified serum of nephrectomized dogs.

A highly active angiotensin-producing enzyme (enzyme III) was obtained from the serum of bilaterally nephrectomized dogs by acid treatment and ammonium sulfate fractionation. An inactive precursor (proenzyme III) was converted to enzyme III during prolonged storage (or by treatment with acid or with cathepsin G or by incubation at 38 degrees C as described in the following paper). Enzyme III reacted maximally at pH 7.7 and it produced up to 400 ng of angiotensin II/mL serum/h (i.e., amounts 4000 times higher than that generated by the endogenous renin present in serum after bilateral nephrectomy). Enzyme III produced angiotensin II at identical rates when either dog angiotensinogen or angiotensin I was used as substrate, but the rate was 710 times higher with synthetic tetradecapeptide renin substrate. Enzyme III is not identical to renin, cathepsin G, tonin, enzyme I, enzyme II, the calcium-dependent angiotensin I-converting enzyme, or the calcium-independent carboxy peptidase, which acts by sequential cleavage of angiotensin I. Enzyme III was inhibited by alpha-1-antitrypsin, diisopropyl fluorophosphate, and lima bean trypsin inhibitor (hence it is a serine proteinase). It was not inhibited by Captopril, Teprotide, or Enalapril. It had been reported previously that cathepsin G released from neutrophil granulocytes, by producing high local concentrations of angiotensin II, may provide a mobile means for modulating blood flow in tissue microvasculature during the inflammatory response. The present study offers a new, additional pathway, by enzyme III, for a similar rapid formation of angiotensin II from serum protein substrate or angiotensin I.

Adrenergic alpha-Antagonists↗
PubMed1989

Angiotensin II-producing enzyme III from acidified serum of nephrectomized dogs. Activation of proenzyme III to enzyme III by cathepsin G.

Enzyme III and its inactive precursor proenzyme III have been obtained from the acidified serum of bilaterally nephrectomized dogs. Enzyme III occurs in a concentration producing angiotensin at a rate 50 times higher than the residual renin. Much higher concentrations of enzyme III have been obtained by three activation procedures: a) by storage for several months in the frozen state; b) by treatment at 0 degrees C and pH 3.0; or c) by incubation at 38 degrees C and pH 7.7. These procedures yielded levels of enzyme III that produced up to 400 ng angiotensin II/mL serum/h, i.e., 4000 times higher than the endogenous renin. Of further significance, the angiotensin II produced by enzyme III represents the octapeptide with the highest known vasoconstrictor activity. This is in contrast to renin, enzyme I, and enzyme II, all of which produced angiotensin I, the decapeptide without appreciable vasoconstrictor activity. The endogenous activating enzyme has been identified as cathepsin G by the following six experimental observations: both the endogenous activating enzyme and exogenous cathepsin G produced enzyme III from proenzyme III according to the same unusual sigmoid kinetics; they were blocked identically by antibody to human cathepsin G. Also, both were inhibited similarly by alpha-1-antitrypsin, lima bean trypsin inhibitor, diisopropyl fluorophosphate, or by an inhibitor present in dog serum. Thus, removal of this inhibitor and activation of proenzyme III by endogenous or by added cathepsin G are prerequisites to obtaining enzyme III; this provides a novel mechanism for the rapid formation of angiotensin II from serum protein substrate or from angiotensin I.

Angiotensin II↗
PubMed1988

Expression of polymorphic B-cell antigens on human kidneys.

We have examined the expression on a panel of 22 human kidneys of polymorphic B-cell determinants recognized by mouse monoclonal antibodies. Monoclonal antibodies from a mouse immunized with an antigenic preparation from a DR4 positive B-cell line reacted preferentially with kidneys from DR4 positive donors (p less than 0.005), and the pattern of reactivity with kidney tissues was similar to that of antibodies to monomorphic determinants of class II. However, these antibodies did not show clear specificity for DR4 on lymphocytes in standard serological analyses. These results provide evidence for the expression of polymorphic class II determinants on human kidneys. Reasons for the differences in the apparent specificities of the monoclonal antibodies when tested on kidney sections and lymphocytes are discussed.

Absorption↗
PubMed1987

Distribution of multiple centrospheres determines migration of BHK syncitia.

After fusion of BHK cells with polyethylene glycol, the resulting syncitia contained in 77% of the cases multiple microtubule organizing centers (MTOCs), which were aggregated into a common centrosphere. Based on the observation of phagokinetic tracks, we found that the syncitia were able to locomote if the MTOCs aggregated into a common centrosphere cluster, and the clustered centrospheres were excluded from the cluster of nuclei of the syncitium. The results suggest that each individual pair of one nucleus and one centrosphere contributes, in a process of vectorial addition, its individual polarity to the polarity of the syncitium. Thus the widely accepted idea that the centrosphere is involved in the determination of cell polarity can be generalized beyond the case of single cells.

Animals↗
PubMed1987

Skeletal muscle creatine kinase MB alterations in women marathon runners.

Total creatine kinase (CK) and CK MB activities were determined in gastrocnemius muscle and serum obtained from 14 female marathon runners. The level of CK MB in muscle increased significantly (p less than 0.05) after chronic exercise training from 5.3% to 10.5% of the total CK activity, but not after acute exercise (post-marathon 8.9%). No significant differences in total CK activities were detected. However, the total CK activity in the muscles were significantly (p less than 0.05) less than those previously reported from the muscle of men runners (1800 U/g, 3000 U/g respectively). No significant correlation existed between fiber type and muscle CK MB activity. Additionally, trace amounts of mitochondrial CK and CK BB were present in muscle homogenates. A significant correlation was observed in the increase in mean serum total CK (597 UL-1) and CK MB (23 UL-1) activities 24 h after the race (r = 0.97, p less than 0.05). These results suggest that gastrocnemius muscle in women adapts to training with increased CK MB activities and imply that skeletal muscle is the major source of elevated serum CK MB activities in women marathon runners.

Adult↗
PubMed1987

A prospective randomized study of the aggressive management of early labor.

The aggressive management of early labor has been suggested as a means to lower the cesarean section rate for dystocia. The aim of our study was to prospectively evaluate a protocol of early intervention in primigravid women with infrequent uterine contractions during early labor in relation to the course of labor, the cesarean section rate, and the perinatal morbidity. In our population the active management of labor did not alter the mode of delivery or the perinatal outcome. Furthermore, the course and duration of labor were not significantly different between the management and control groups.

Adult↗