Cambios en el gasto energético de reposo después de la reducción ponderal en mujeres obesas / Changes in the energy expediture at rest after of the ponderal reduction in obese women

Para analizar el efecto de una dieta hipocalórica moderada sobre el peso corporal, masa grasa (por ciento MG), masa libre de grasa (MLG) y el gasto energético de reposo (GER), se estudio a mujeres con sobrepeso u obesidad con índice de masa corporal (IMC)>27,5 kg/m2. Material y métodos: en 34 pacientes (18-45 años), el GER fue medido por calorimetría indirecta (Deltatrac), el porciento MG y MLG por bioimpedanciometría, y la ingesta energética (IE) por registros de 3 días alternos. En 11 de ellas se controló la IE por recordatorio de 24 hs. al 10º día de la indicación de dieta hipocalórica, y se reevaluó el gasto energético de reposo y composición corporal a las 8 semanas. Resultados: x +- ds. Al ingreso (n=34), el IMC fue de 32,2 +- 2,6, el porciento MG de 36,8 +- 4,4. La IE reportada fue de 2.184 +- 590 kcal/día (1.185 - 4.339), o de 27,5 +- 6,9 kcal/kg/día (14,45). El GER fue de 18,0 +- 1,3 kcal/kg/día y el balance energético inicial (BE), fue de + 460 +- 586 (-804 a + 2.251)...

Gasto energético de reposo y cuociente respiratorio en mujeres obesas y no obesas / Energy expenditure of rest and rate respiratory in obese and lean women

Un gasto energético de reposo (GER) reducido y un cuociente respiratorio elevado, se han considerado como factores de riesgo de ganancia de peso a largo plazo. Con el objetivo de investigar la frecuencia de estos factores de riesgo, se estudió a 537 mujeres de entre 15 y 45 años antes de iniciar un plan de restricción alimentaria; 452 de ellas con obesidad (OB: IMC > 25) y 85 no obesas (no OB: IMC < 25). El GER y el cuociente respiratorio de ayunas (CRA) fueron medidos por calorimetría indirecta. En 106 mujeres (87 OB y 19 no OB) se midio el porcentaje de masa grasa por impedanciometría bioeléctrica (porcentaje MG). Resultados: se encontró una correlación negativa entre el IMC y CRA (r= -0,113; p < 0,01), y ninguna correlación entre el porciento MG y CRA. Al comparar 4 subgrupos según grado de obesidad (NO OB, OB grado I, II y III), a mayor grado de obesidad mayor es el GER como porcentaje del estimado por Harris y Benedict (GER/GEE por ciento = 90,9, 94,2, 95,8, y 98,5 por ciento...

Field evaluation of rapid HIV serologic tests for screening and confirming HIV-1 infection in Honduras.

OBJECTIVE: To determine the ability of simple, rapid tests to identify HIV-1 antibody-positive specimens in field settings using the World Health Organization's (WHO) alternative testing strategies. DESIGN: Three-phase evaluation of simple, rapid assays using banked specimens and prospectively collected serum specimens at regional hospitals and rural clinics. METHODS: Seven test (Retrocell, Genie, HIVCHEK, SUDS HIV-1, Testpack, Serodia HIV-1, and HIV-1/2 RTD) were evaluated and results compared with standard enzyme immunoassay (EIA) and Western blot results (phase 1). Further evaluation consisted of prospective testing of routine specimens at regional (phase 2; n = 900) and rural, peripheral laboratories (phase 3; n = 1266) throughout Honduras with selected assays. RESULTS: Sensitivity and specificity were calculated for each assay and combination of assays for each phase to evaluate the effectiveness of the WHO alternative testing strategies. All tests in all phases were > 99% sensitive after correcting for technical errors, with two exceptions (SUDS, phase 1; HIVCHEK, phase 3). In phase 3, where the testing algorithm was diagnostic, several combinations of assays were 100% sensitive and specific using WHO strategy II or III. For the Honduras Ministry of Health, the combination of Retrocell and Genie was found to be equally sensitive, more specific (no indeterminate results), and less expensive than EIA/Western blot. CONCLUSION: Combinations of rapid, simple HIV antibody assays provide sensitivity and specificity performance comparable to EIA/Western blot. Application of these combinations in the WHO alternative testing strategies provides an inexpensive and effective method of determining HIV status. Assay combinations using these strategies can be easily performed in small, rural laboratories and have been implemented in routine HIV screening in Honduras.

PIP: In 1992, the World Health Organization (WHO) introduced 3 HIV testing algorithms designed to provide rapid, accurate results equivalent to those obtained by enzyme immunoassay (EIA) and Western blot but at reduced costs. The capability of the WHO strategy to identify HIV-1 antibodies in field settings was evaluated at regional hospitals and rural clinics in Honduras. In the study's first phase, the results of 7 tests (Retrocell, Genie, HIVCHEK, SUDS HIV-1, Testpack, Serodia HIV-1, and HIV-1/2 RTD) were compared with results for 600 sera previously tested by EIA and Western blot. Phase 2 entailed prospective testing of 900 routine specimens at regional laboratories, while phase 3 screened 1266 specimens at rural, peripheral laboratories. In the first phase of the analysis, 5 assays had a sensitivity of 100%; the remaining 2 were 99.7% and 99.3% sensitive and specificities ranged from 92.8 to 100%. In field settings, sensitivities ranged from 96.4 to 99.3%. Moreover, in the third phase, several combinations of tests were 100% sensitive or specific when the WHO strategy of basing the choice of assay on the purpose of the screening (seroprevalence studies, screening of blood, or patient diagnosis) was employed. The combination of Retrocell and Genie was found to be equally sensitive, more specific, and less expensive than EIA or Western blot.

Immunoglobulin recombinase gene activity is modulated reciprocally by interleukin 7 and CD19 in B cell progenitors.

Bone marrow stromal cells promote B cell development involving recombinase gene-directed rearrangement of the immunoglobulin genes. We observed that the stromal cell-derived cytokine interleukin 7 (IL-7) enhances the expression of CD19 molecules on progenitor B-lineage cells in human bone marrow samples and downregulates the expression of terminal deoxynucleotidyl transferase (TdT) and the recombinase-activating genes RAG-1 and RAG-2. Initiation of the TdT downregulation on the first day of treatment, CD19 upregulation during the second day, and RAG-1 and RAG-2 downmodulation during the third day implied a cascade of IL-7 effects. While CD19 ligation by divalent antibodies had no direct effect on TdT or RAG gene expression, CD19 cross-linkage complete blocked the IL-7 downregulation of RAG expression without affecting the earlier TdT response. These results suggest that signals generated through CD19 and the IL-7 receptor could modulate immunoglobulin gene rearrangement and repertoire diversification during the early stages of B cell differentiation.

Expression of surrogate light chain receptors is restricted to a late stage in pre-B cell differentiation.

Surrogate light chain (psi LC) genes are transcriptionally active in progenitor B (pro-B) cells before immunoglobulin genes are rearranged. Current hypothetical models suggest that the psi LC proteins may couple with surrogate or conventional heavy chain proteins to form cell surface receptors that signal the progressive differentiation of pro-B, precursor B (pre-B), and immature B cells. Monoclonal antibodies were produced and used to examine the synthesis, expression, intermolecular interaction, and function of psi LC during B cell differentiation. The results indicate that, while psi LC production spans several developmental stages, cell surface expression is confined to a relatively late stage in normal pre-B cell differentiation, during which receptor cross-linkage does not impede cell growth or B cell differentiation.

The mystique of the mistake. With proposed standards for validating proficiency tests in anatomic pathology.

Variability in classification in anatomic pathology does not necessarily indicate that a mistake has been made. It is usually an artifact, created when pathologists choose a single category from among two or more justifiable alternatives. This is most common when standard classifications with uniform terminology are not used. It also can occur when classification systems are not constructed so as to insure mutual exclusivity of categories. It is proposed that a proficiency test in anatomic pathology should not be considered scientifically valid until a professional organization primarily concerned with anatomic pathology has endorsed its proposed classification system as having categories that are close to 100% mutually exclusive in the hands of expert pathologists not involved in developing the system. All possible precautions should be taken to insure that the "right answers" for any proficiency test are generated in a way that excludes the possibility of multiple justifiable alternatives.

Evaluation of the reproducibility of the World Health Organization classification of common ovarian cancers. With emphasis on methodology.

Seven pathologists independently classified 50 slides of ovarian tumors using category I of the World Health Organization classification (WHO I), each case being seen twice under different random code numbers. Intraobserver reproducibility and interobserver reproducibility, based on consistent interpretations, were both suboptimal. However, scrutiny suggested that no pathologist was a source of excessive variability, nor was suboptimal interobserver reproducibility simply due to intraobserver variability. Neither could excessive variability be attributed to skewing of results by a subgroup of unclassifiable cases. However, clearcut sources of variability were identified among the categories of WHO I, namely, mixed epithelial, unclassified epithelial, and undifferentiated carcinoma. There was also considerable variability in distinguishing serous and endometrioid neoplasms, and in identifying tumors of low malignant potential. These findings should not be misconstrued as implying that pathologists in routine practice cannot diagnose common ovarian cancers reproducibly for patient care purposes. Availability of clinical and macroscopic data, extensive sampling, histochemistry, and consultation combine, in an uncontrolled and highly individualistic fashion, to render routine service work very different from this highly controlled formal exercise. Furthermore, at the current state of the therapeutic art, many of the taxonomic problems identified in this study may have little clinical significance. Nonetheless, this study has strengthened the evidence that there may be important problems in classifying common ovarian cancers reproducibly using WHO I, and that WHO I may require greater clarity to enhance reproducibility. Current emphasis on quality assurance dictates reconsideration of the literature on reproducibility of histopathologic taxonomy, which has tended to inculpate pathologists as sources of variability. Virtually all of this literature is subject to some degree of skepticism due to deficiencies in methodology. Consideration of the question of how to measure reproducibility in anatomic pathology leads us to suggest that the community of pathologists should address the need to decrease ambiguity in classification systems as an important step toward optimizing reproducibility.

Antibodies against spermatozoids. Studies in homosexuals, AIDS and infertile men.

The presence of antibodies against spermatozoids was evaluated in one person with AIDS and six homosexuals (HS). Indirect immunofluorescence was utilized along with immunoenzymatic trial with peroxidase (ELISA) in order to detect antibodies class IgG towards spermatozoids and their membrane proteins. Optic densities of the following groups of patients were compared: 1) One patient with AIDS. 2) Six homosexuals (HS). 3) Three HS with cells OKT8 greater than 30%. 4) Three HS with cells OKT8 less than 30%. 5) Three men with auto-antibodies against spermatozoids + infertility. 6) Two men without auto-antibodies against spermatozoids + infertility. 7) Five women, spouses of the infertile men. 8) Five multiparous with more than 3 pregnancies. 9) One man with orchitis. 10) Ten fertile and healthy (C.G.) heterosexual persons. The patient with AIDS and the one with orchitis had the highest optic densities (OD), (groups 1 and 9). Groups 8 and 10 had the lowest, non-significant values. Groups 2, 5 and 7 ranked second in place in reference to O.D. Groups 3, 4 and 6 ranked third in O.D. values. Groups 8 and 10 differed significantly at P less than 0.005 compared with the others. The presence of antibodies against spermatozoids was considered as an important factor associated with AIDS and previous states of the AIDS detected by OKT8 greater than 30% of lymphocytes. The IIF and ELISA were able to detect antigenic system in spermatozoids with allelic form, which may be similar to the mice locus t, or a new tissue specific system.