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Biomedical subjects

E Perez

Publications and source records attributed to E Perez.

At least 19 recordsLinked to original sources
PubMed1996

Compensation to a department of medicine and its faculty members for the teaching of medical students and house staff.

BACKGROUND: Changes in the organization and financing of health care threaten to alter the prevailing system of financing the teaching of medical students and residents. Little information is available from private medical schools and teaching hospitals about the extent of teaching by faculty members or the mechanisms and levels of reimbursement for teaching. METHODS: We surveyed faculty members in the Department of Medicine at Columbia-Presbyterian Medical Center to ascertain the extent of their teaching activities. A standard number of hours was assigned to each activity, and the total number of teaching hours was calculated for each faculty member. Teaching of fellows and in continuing medical education programs was excluded. We also determined how much money the Department of Medicine received in payment for faculty members' teaching activities, and the sources of this compensation. RESULTS: In the 1992-1993 academic year, the 188 full-time faculty members spent a total of 46,086 hours teaching (mean [+/- SD], 245 +/- 178 hours per faculty member); 10,780 hours (23.4 percent) were spent teaching medical students, and 35,306 hours (76.6 percent) teaching house staff. Eighty percent of faculty members taught for 137 or more hours each. In a multivariate analysis including faculty rank, subspecialty division, years since graduation from medical school, sex, and tenure or clinical track, senior faculty members (P = 0.02), members of certain subspecialty divisions (P < 0.001), and women (P = 0.05) contributed more than the average number of teaching hours. An additional 56 non-full-time faculty members contributed a total of 5684 hours. The net reimbursement to the department for teaching totaled $965,808, or about $16 per hour of teaching by full-time faculty members, after the cost of fringe benefits was excluded. CONCLUSIONS: Faculty members of the department of medicine at a major medical center contribute a large number of hours teaching medical students and house staff. This effort is poorly compensated. Cost-containment efforts have the potential to jeopardize fragile social contracts at academic health centers whereby the faculty participates in teaching by contributing unreimbursed or underreimbursed time.

Academic Medical Centers↗
PubMed1995

cAMP accumulation in the hypothalamus, cerebral cortex, pineal gland and brown fat across the wake-sleep cycle of the rat exposed to different ambient temperatures.

The concentration of adenosine 3':5' cyclic monophosphate (cAMP) was determined in the anteroventro-medial hypothalamus, the cerebral cortex, the pineal gland and the interscapular brown adipose tissue, during the different stages of the wake-sleep cycle of rats kept, under a 12-12-h light-dark cycle, in different environmental conditions, i.e., control (47-52 h at ambient temperature (Ta) 23 +/- 0.5 degrees C), exposure (47-52 h at Ta 0 +/- 1 degree C) and recovery (1-4 h at Ta 23 degrees C after 48 h at Ta 0 degree C). The results show that cAMP concentration consistently changed: (1) during the wake-sleep cycle in the anteroventro-medial hypothalamus, decreasing from wakefulness to sleep; (2) during the dark-light transition in the pineal gland, increasing with the onset of the light phase; and (3) with the environmental condition in the interscapular brown adipose tissue increasing, with respect to the control condition, in exposure and recovery. No significant changes in cAMP concentration were observed in the cerebral cortex.

Adipose Tissue, Brown↗
PubMed1995

Validity of the CELF-R, TONI, and sit for children referred for auditory processing problems.

Recent changes in legislation for persons with disabilities have led to an increased focus on Central Auditory Processing problems. Test scores from the Clinical Evaluation of Language Functioning-Revised (CELF-R), Test of Nonverbal Intelligence (TONI), and the Slosson Intelligence Test (SIT) obtained from folders of 40 clients referred for auditory processing problems were analyzed to ascertain the validity of using these tests with a population on which these tests were not normed. All tests and subscales were correlated significantly. Even so, mean differences were present, with one exception, on comparisons of test scores. Moreover, females obtained significantly higher scores on the TONI than did males. Our findings generally support the validity of using these tests with a Central Auditory Processing sample.

Adolescent↗
PubMed1995

Disseminated toxoplasmosis as a cause of diarrhea.

Disseminated toxoplasmosis in patients with acquired immunodeficiency syndrome is often a central nervous system disease but may be seen as myocarditis or pneumonitis. Toxoplasmic colitis is a rarity. We report a case of toxoplasma colitis in a patient with diarrhea and hypokalemia. The microorganisms were identified in the colonic mucosa on H&E sections and confirmed by immunoperoxidase study.

Adult↗
PubMed1994

Prognostic indicators in bulimia nervosa treated with cognitive-behavioral group therapy.

Prognostic indicators of short-term outcome were identified in 69 women with the DSM-III-R diagnosis of bulimia nervosa who participated in a weekly 10-session structured cognitive-behavioral outpatient group program. Prior to treatment, all subjects completed the computerized Diagnostic Interview Schedule (DIS), the Moos Family Environment Scale (FES), the Diagnostic Survey for Eating Disorders (DSED), the Beck Depression Inventory (BDI), the Hopkins Symptom Checklist, Revised (SCL-90-R), the Bulimic Cognitive Distortions Scale (BCDS), the Eating Disorders Inventory (EDI), and the Bulimic Symptoms Checklist (BSCL). The latter three scales were readministered on completion of the 10-week group. Symptom improvement was assessed by examining percentage reduction in binge frequency, purge frequency, and summed scores for the EDI subscales Bulimia, Drive for Thinness, and Body Dissatisfaction. The only significant predictor of improvement in binge frequency and bulimic cognitions was family environment. Conflicted, controlling, and over-organized family environments appear to impede both reductions in binge frequency and changes in bulimic cognitions. Reduction in vomit frequency was associated with weight history and with laxative or diuretic use. The implications for planning psychotherapeutic interventions in bulimia nervosa are discussed.

Adolescent↗
PubMed1994

Do trehalose and dimethyl sulfoxide affect intermembrane forces?

The sugar trehalose is produced in some organisms that survive dehydration and desiccation, and it preserves the integrity of membranes in model systems exposed to dehydration and freezing. Dimethyl sulfoxide, a solute which permeates membranes, is added to cell suspensions in many protocols for cryopreservation. Using a surface forces apparatus, we measured the very large, short-range repulsion between phosphatidylcholine bilayers in water and in solutions of trehalose, sorbitol, and dimethyl-sulfoxide. To the resolution of the technique, the force-distance curves between bilayers are unchanged by the addition of trehalose or sorbitol in concentrations exceeding 1 kmol.m-3. A relatively small increase in adhesion in the presence of trehalose and sorbitol solutions may be explained by their osmotic effects. The partitioning of trehalose between aqueous solutions and lamellar phases of dioleylphosphatidylcholine was measured gravimetrically. The amount of trehalose that preferentially adsorbs near membrane surfaces is at most small. The presence of dimethyl sulfoxide in water (1:2 by volume) makes very little difference to the short-range interaction between deposited bilayers, but it sometimes perturbs them in ways that vary among experiments: free bilayers and/or fusion of the deposited bilayers were each observed in about one-third of the experiments.

Adhesiveness↗
PubMed1994

Detection of bovine trichomoniasis with a specific DNA probe and PCR amplification system.

Trichomoniasis is a widespread, economically important venereal disease of cattle which causes infertility and abortion. Effective control of trichomoniasis has been impeded by the insensitivity of traditional diagnostic procedures, which require the isolation and cultivation of the parasite, Tritrichomonas foetus, from infected cattle. We developed a 0.85-kb T. foetus DNA probe by identifying conserved sequences in DNAs from T. foetus that were isolated from cattle in California, Idaho, Nevada, and Costa Rica. The probe hybridized specifically to DNAs of T. foetus isolates from different geographic areas but not to DNA preparations of Trichomonas vaginalis, bovine cells, or a variety of bacteria from cattle. The probe detected DNA from a minimum of 10(5) T. foetus organisms. To improve sensitivity, a partial sequence of the probe was used to identify oligonucleotide primers (TF1 and TF2) which could be used to amplify a 162-bp product from T. foetus DNAs by PCR. A chemiluminescent internal T. foetus sequence probe was hybridized to Southern blots of the amplification product. This system detected as few as one T. foetus organism in culture media or 10 parasites in samples containing bovine preputial smegma. Analysis of 52 clinical samples showed that 47 (90.4%) of the 52 samples were correctly identified, with no false-positive reactions. In comparison, the traditional cultivation method detected 44 (84.6%) of the 52 samples from T. foetus-infected and uninfected bulls. These results indicate that the PCR-based amplification system could be a useful alternative method for the diagnosis of bovine trichomoniasis.

Animals↗
PubMed1994

kappa-Immunoglobulin corneal deposits associated with monoclonal gammopathy. Immunohistochemical and electron microscopic findings.

A 62-year-old man had a 1-year history of bilaterally decreased visual acuity associated with irregular, patchy, grayish-white stromal infiltrates involving both corneas. As visualized by light microscopy, the keratectomy specimen showed numerous homogeneous, eosinophilic deposits located mostly within keratocytes in the posterior one-third of the stroma. The deposits stained reddish-brown with Masson's trichrome but were periodic acid/Schiff-negative. As visualized by electron microscopy, the intracytoplasmic deposits were located within dilated cisternae of rough-surfaced endoplasmic reticulum of keratocytes and disclosed a 10-nm periodicity with a distinct lattice pattern. Immunoperoxidase strains confirmed that the deposits contained immunoglobulin (IgG-kappa). At 2 weeks following a histopathologic examination of the keratectomy specimen, serum protein analysis and immunoelectrophoresis with quantitation of immunoglobulins demonstrated an IgG-kappa monoclonal gammopathy. The abnormal corneal deposits may be the first clinical sign of a malignant lymphoproliferative process that may be associated with a monoclonal gammopathy.

Corneal Diseases↗
PubMed1993

A comparative field study of the relative importance of Lutzomyia peruensis and Lutzomyia verrucarum as vectors of cutaneous leishmaniasis in the Peruvian Andes.

A two-year field study of Andean cutaneous leishmaniasis (uta) in the valley of Purisima, Ancash Department, Peru has provided quantitative epidemiologic and entomologic evidence for the predominant role of Lutzomyia peruensis in the transmission of Leishmania peruviana in this endemic area. The monthly incidence in the valley was greatest in the wet season (from December to May), when Lu. peruensis was particularly endophilic. A significant correlation was detected between intradomiciliary (but not extradomiciliary) Lu. peruensis abundance and the monthly incidence of uta in the valley following a one-month time lag. In contrast, no significant correlation was detected between any measure of Lu. verrucarum abundance and the incidence of uta. Lutzomyia peruensis and Lu. verrucarum comprise more than 98% of all the sand fly captures made in this valley. The increase in incidence of uta with altitude, which reached a peak rate between 2,250 and 2,750 meters above sea level, was associated with an increase in the relative abundance of Lu. peruensis as compared with Lu. verrucarum. Seasonal and altitudinal variation was also detected in the peak time of activity for both sand fly species, a phenomenon that could significantly influence the transmission rate: later host-seeking sand flies being more likely to find sleeping, nondefensive, human hosts.

Altitude↗
PubMed1993

Chromatographic, immunochemical and electrophoretic studies of human uterotrophic placental factor (hUTPF).

The human uterotrophic placental factor (hUTPF) is a protein obtained from human term placentae and acts on uterine growth, mammary gland, and blastocyst development and implantation. In the present work, we further define some molecular characteristics of hUTPF using chromatographic, electrophoretic and immunochemical methods. It is concluded that in human term placenta a high molecular weight hUTPF is present, bound to albumin and immunoglobulins, which could represent a storage or transport form of this factor. hUTPF presents several molecular forms, one of them of 270 kDa and others of approximately 90 kDa and 27 kDa.

Animals↗
PubMed1992

Determination of IgE antibodies to the benzyl penicilloyl determinant. A comparison between poly-L-lysine and human serum albumin as carriers.

The influence of two different carriers, poly-L-lysine (PLL) and human serum albumin (HSA) in the binding of specific IgE antibodies to the benzyl penicilloyl hapten (BPO) was determined in a solid-phase assay. Serum samples from patients with a history of immediate reaction to penicillin and which had shown the presence of IgE antibodies to BPO were used. Benzyl penicilloyl derivatized cellulose discs were prepared using PLL of different molecular weight and HSA as carriers. These were treated with different molar ratios of benzyl penicillin. These reagents were compared for uptake of BPO-specific IgE using a pool of sera in a radioallergosorbent test (RAST) type assay. Two PLL systems and two HSA systems were finally compared using 26 individual sera. RAST values were compared by Kruskal-Wallis and Wilcoxon tests. The relationships between the four different assays were evaluated by determining Pearson correlation coefficients and the concordance by determining intraclass correlation coefficients (ICC). Analysis of means by the Wilcoxon test revealed significant differences (P less than 0.01) only when the different carrier assays were compared. The correlation coefficients between all the assays were significant (P less than 0.0001), but the ICC was low when the different carrier assays were compared. These results indicate that the nature of the carriers studied (PLL and HSA) influences the capacity for binding IgE antibodies in the RAST procedure. The differences observed indicate that one conjugate cannot be substituted for the other in the determination of IgE antibodies to BPO and that BPO-PLL is preferable.

Antibodies↗
PubMed1992

Seasonal patterns of bulimia nervosa.

OBJECTIVE: The aim of this research was to determine whether a seasonal pattern to symptoms of bulimia nervosa could be identified. METHOD: In study 1, seasonal patterns of binge-purge frequency and mood were compared between 31 patients with bulimia nervosa and 31 age-matched normal comparison subjects, using a modified (to include binge and purge items) version of the Seasonal Pattern Assessment Questionnaire. Study 2 involved a cross-sectional examination of binge and purge frequency and of depressive symptoms in 197 patients with bulimia nervosa assessed at various months of the year over a 4-year period. RESULTS: In both the retrospective and cross-sectional studies, binge behavior was found to be highly associated with photoperiod. According to the modified Seasonal Pattern Assessment Questionnaire, purging behavior and mood also varied seasonally among patients with bulimia nervosa. However, purging behavior and severity of depression did not appear to be related to photoperiod in the cross-sectional study. The rate of seasonal affective disorder (syndromal and subsyndromal) defined by the Seasonal Pattern Assessment Questionnaire was higher among the bulimic group than the comparison subjects, but not as high as has been reported for depression in bulimia nervosa. CONCLUSIONS: The results strongly support the interpretation that symptoms of bulimia nervosa primarily associated with food intake patterns are influenced by seasonal variation, and this effect may be mediated by light availability.

Adult↗
PubMed1992

The role of stress in interpreting the dexamethasone suppression test.

Stress has been implicated as a major confounding factor in the interpretation of Dexamethasone Suppression Test (DST) results. This study was designed to examine the effects of stress on DST results. Fifty patients with high levels of acute, chronic, and environmental stress participated in the study. Each patient was given a comprehensive psychiatric and psychological assessment, a routine administration of dexamethasone, and blood tests of cortisol values. The results indicate that the three measures of stress do not appear to affect levels of cortisol suppression, however, all three measures of stress predicted depression. As expected, DST cortisol levels were related to depression. Results are discussed in terms of their implications for understanding the associations among stress, depression and DST results.

Adult↗
PubMed1991

Ultradian and circadian changes in the cAMP concentration in the preoptic region of the rat.

The concentration of adenosine 3',5'-cyclic monophosphate was measured, during the wake-sleep cycle, in the preoptic region and the cerebral cortex of rats kept in normal laboratory conditions (ambient temperature 22 +/- 0.5 degrees C, 12 h:12 h light-dark cycle) and, during wakefulness, in the preoptic region of rats exposed to extended light and dark periods (i.e. dark in the light hours of the normal photoperiod, and light in the dark hours of the normal photoperiod). The results show that the concentration of cAMP in the preoptic region changes according to the ultradian wake-sleep cyclic, decreasing from wakefulness, through synchronized sleep and to desynchronized sleep. This pattern of change was found to occur both in light and dark hours, however, in the dark hours the levels of preoptic cAMP are higher than those observed in the light hours. In contrast, no significant modification in cAMP concentration was found in the cerebral cortex. In the extended light and dark periods preoptic cAMP concentration increases above the levels found during wakefulness in normal photoperiods. These results show that preoptic cAMP concentration is influenced by ultradian and circadian factors which also appear to be related to sleep processes.

Activity Cycles↗