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Biomedical subjects

E Perez

Publications and source records attributed to E Perez.

At least 55 records · Page 3Linked to original sources
PubMed1998

Bus rounds for medical congresses on palliative care.

Three 4-hour bus rounds were organized as part of an international palliative care congress, to promote patient-based education both at home and in acute care hospitals. Patient cases were presented and discussed en route to and from each visit. A total of 23 medical specialists visited 16 patients (10 in three different hospitals and 6 at home). A mean of 5.3 cases were presented during each round. A total of nine journal club articles were presented, a mean of three (2-4) articles per round. A questionnaire was filled out anonymously by all 23 participants. On a scale of 1 (worst) to 5 (best) they gave the rounds an overall rating of 5 (range 4-5). These findings suggest bus rounds provide an opportunity for intensive exposure to patient-based learning, both in acute care hospitals and at home.

Canada↗
PubMed1998

Analysis of test day yield data of Costa Rican dairy cattle.

Estimates of variance components for test day records in an animal model that considered multiple traits over multiple lactations were calculated using REML methodology. Test day records were classified into 11 periods within first and later lactations. Missing ancestors in the relationship matrix were classified in genetic groups. Data were collected from Costa Rican dairy farms. Estimates of components for total and additive genetic variance were clearly heterogeneous during the lactation. Heritabilities for traits in later parities were slightly higher than those for traits in first parity. Heritabilities were highest for records of midlactation. Phenotypic and genetic correlations for adjacent test days were close to 1. Phenotypic correlations were lower than genetic correlations. Heterogeneity of variances during the lactation suggests the adequacy of the multiple-trait test day model to describe milk yield during the lactation. When missing ancestors were allocated to a single base population instead of genetic groups, the estimates of residual variance were lower, and the estimates of genetic variance and genetic correlations were higher. When standardized records were used instead of actual test day records, the estimates of residual and total variance were lower, and the estimates of genetic variance were higher. Consequently, estimates of heritability and genetic correlations were also higher. Use of standardized data obtained by interpolation procedures is not advised for estimation of genetic variance components in a test day model.

Animals↗
PubMed1997

Secretion of soluble pre-B cell receptors by pre-B cells.

Pre-B cells can express secretory mu (mu(s))- as well as membrane mu (mu(m))-chains. We evaluated the ability of mu(s)-chains to associate with surrogate light chains and assemble into a pre-B cell receptor (BCR) complex in pre-B cells, and explored whether mu(s)-chains could be exploited to generate a secreted soluble pre-BCR. We demonstrate that mu(s)-chains can associate with SLC internally. The mu(s)-containing complexes form higher order polymeric structures, but these are never assembled into completed covalent structures. Instead, the complexes are efficiently retained and rapidly degraded. Alteration of the intracellular redox state by incubation with 2-ME resulted in the secretion of mu(s)-chains, suggesting that they are retained by a thiol-mediated retention mechanism. To identify the sequences on mu(s)-chains responsible for their retention, we generated stable transfectants of a mu-negative pre-B cell line expressing either wild-type or mutant mu(s) constructs. Mutation of a single cysteine (Cys575) in the mu(s) tailpiece resulted in the release and secretion of the mu(s) H chains. These were associated with the surrogate light chain proteins lambda5 and VpreB, and thus appear to constitute an authentic secreted soluble pre-BCR. The soluble pre-BCR has a specificity distinct from Ab consisting of the same heavy chain V region paired with conventional light chains.

Animals↗
PubMed1997

[Clinical lung function investigations in sheep].

In 144 clinical healthy and 97 sick sheep pneumotachographic investigations were performed. In 119 sheep the diagnoses "healthy" based on adspection, auscultation and palpatory percussion. In 25 additional healthy and in the sick animals the diagnoses based on clinical, endoscopical, serological, parasitological, and in 82 animals also pathomorphological findings. According to these diagnoses the animals were divided into the following groups: G = healthy, K = catarrhal purulent bronchopneumonia, E = suppurative pneumonia, W = verminous pneumonia, M = Maedi, MKE = Maedi + catarrhal purulent or suppurative pneumonia, MAKE = Maedi + Adenomatosis + catarrhal purulent or suppurative pneumonia, AKE = Adenomatosis + catarrhal purulent or suppurative pneumonia, and FAKE = animals of the AKE group at an earlier date of investigation. In all sheep respiration rate, tidal and minute volumes, forced tidal volume, peak flow and resistance were measured with the portable pneumotachograph Flowscreen. Tidal and minute volumes and flow rates depended at rest as well as after forced ventilation essentially from the respiratory rate and from the body weight of the animals. The average individual coefficients of variation of repeated measurements of healthy animals were between 21% and 36%. Only in tidal volume after forced ventilation (10%) and in the resistance (18%) the individual coefficients of variations were lower. In 57% of the animals with Lung Adenomatosis resistance-values over 0.4 kPa*s/l were measured, but in 94% of the sheep without adenomatosis resistance-values remained under this limit.

Animals↗
PubMed1996

Light therapy in bulimia nervosa: a double-blind, placebo-controlled study.

The effects of light therapy on food intake and affective symptoms of bulimia nervosa (BN) were examined in a double-blind study. Eighteen women who met DSM-III-R criteria for BN were randomly assigned to receive either 2500 lux of bright light (experimental condition) or < 500 lux of dim light (placebo condition) daily in the early evening for a 1-week period. The Structured Interview Guide for the Hamilton Depression Rating Scale-Seasonal Affective Disorder Version (SIGH-SAD), the Beck Depression Inventory (BDI), and the Bulimic Symptoms Checklist were administered to subjects before light exposure, after 1 week of light exposure, and after 7 days of withdrawal of light exposure. Throughout the study, the Profile of Mood States and the Daily Binge Record were completed daily. Compared with subjects in the dim light condition, subjects in the bright light condition showed a significant improvement in depressed mood during light exposure, as measured by both the BDI and the SIGH-SAD. There was a return to pretreatment levels of depression after withdrawal of light exposure. No changes in depression were noted in the placebo group. No effect of light therapy was found on the frequency, size, or content of binge-eating episodes. The results are discussed in terms of the physiological processes associated with light therapy and seasonal affective disorder that may underlie the affective and food intake symptoms of BN.

Adult↗
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↗
PubMed1996

The capacity to accumulate cyclic AMP in the preoptic-anterior hypothalamic area of the rat is affected by the exposition to low ambient temperature and the subsequent recovery.

The accumulation of adenosine 3':5'-cyclic monophosphate (cAMP) was measured in the preopticanterior hypothalamic area, the cerebral cortex, and the hippocampus of rats exposed to different ambient temperatures: (1) 23 +/- 0.5 degrees C, for 53 h +/- 20 min (control); (2) -10 +/- 1 degrees C, for 53 h +/- 20 min (exposure to low ambient temperature); (3) -10 degrees C for 48 h and 23 degrees C for the following 5 h +/- 20 min (recovery). The capacity to accumulate cAMP was tested by subjecting animals to acute hypoxia, a stimulus which is known to induce a large increase in brain cAMP concentration. In the control condition, hypoxic stimulation increases cAMP concentration in all the brain regions studied. In contrast, during the exposure to low ambient temperature, whilst both the cerebral cortex and the hippocampus show the same levels of accumulation found in the control condition, cAMP accumulation is reduced in the preoptic-anterior hypothalamic area. However, during the first few hours of the recovery period, the preoptic-anterior hypothalamic area is able to reattain the capacity for cAMP accumulation observed in the control condition.

Animals↗
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

Pattern of desynchronized sleep during deprivation and recovery induced in the rat by changes in ambient temperature.

The pattern of desynchronized sleep (DS) occurrence in the rat was studied during exposure to an ambient temperature (Ta) of 0 degrees C for 48 h and during a 12 h recovery period at laboratory Ta (23 degrees C) following the first and second 24 h of cold exposure. The exposure to low Ta induces a DS deprivation which is followed, during recovery, by a clear DS rebound. Both the decrease and the following increase in the amount of DS are due to changes in the frequency rather than in the duration of DS episodes. The frequency distribution of the intervals between the end of one DS episode and the beginning of the next (DS interval) has shown that two populations of DS intervals exist, i.e. short DS intervals (</=3 min) and long DS intervals (>3 min). On the basis of this, two types of DS episodes have been identified: the 'single DS episode', which is both preceded and followed by a long DS interval, and the 'sequential DS episode', which is a DS episode occurring within a cluster or a sequence of DS episodes and is characteristically separated by short DS intervals. The occurrence of such sequential DS episodes in a 'DS cluster', allows a high amount of DS to occur without increasing the duration of the DS episode. DS clusters are repressed during cold exposure, when the DS drive is counteracted by the need to thermoregulate, and enhanced during recovery, when the DS drive is unrestrained. In contrast, the occurrence of single DS episodes is much less affected by such different experimental conditions.

Journal Article↗