RESUMEN
OBJECTIVE: Our aim is to determine the effect of paced eating, exposure to an educational programme that promotes healthy eating habits and allowing the satiety reflex to limit food intake in controlling weight gain in healthy adolescents. METHODS: Fifty-four healthy individuals consisting of 18 adolescent girls and 36 boys aged 12 ± 2 years were given recommendations for reducing eating rate without changing diet or meal size according to the educational programme 'good manners for a healthy future'. Each participant was provided with a 30-s portable hourglass to pace time between bites. Individuals using and not using the hourglass were placed either into an 'adhering' or a 'non-adhering' group, respectively. Control data were obtained from a similar population. RESULTS: Initially, the adhering group had higher weight compared with the non-adhering group (64.1 ± 13.2 vs. 56.2 ± 11.7 kg). Control group weight was no different from the study group at baseline (56.3 ± 10.3 kg). Weight in the adhering group decreased after the first semester of participation by 2.0 ± 5.7% and after a year by 3.4 ± 4.8%, while the non-adhering group gained weight by 5.8 ± 4.5% and 12.6 ± 8.3%. The control group increased weight after a year by 8.2 ± 6.5%. In total, 18 non-adhering and 14 adhering adolescents completed the study. CONCLUSIONS: This 1-year study shows a statistically significant association between rate of food intake and weight control in adherence to an educational programme directed at developing healthy eating habits. The proposed behavioural training may serve as an option for weight control in adolescents.
Asunto(s)
Conducta Alimentaria , Educación en Salud , Promoción de la Salud/métodos , Sobrepeso/prevención & control , Obesidad Infantil/prevención & control , Programas de Reducción de Peso/métodos , Adolescente , Presión Sanguínea , Peso Corporal , Femenino , Humanos , Masculino , Comidas , Saciedad , Aumento de PesoRESUMEN
The most active metabolite of vitamin D, 1,25(OH)2D3 is a steroid hormone implicated in a wide range of cell functions such as differentiation, proliferation and apoptosis. Leishmania mexicana causes two kinds of cutaneous leishmaniasis: localized or diffuse. In this work we explored the effect of treatment of 1,25(OH)2D3 on a susceptible leishmaniasis mice model. A significant reduction in the lesion size was found in animals treated with 1,25(OH)2D3. Well preserved tissue and presence of large numbers of eosinophils and fibroblasts was found in the group treated with 1,25(OH)2D3. By contrast, destroyed epidermis was observed with large amount of neutrophils and epithelioid macrophages, on infected groups without 1,25(OH)2D3 treatment. The production of pro-inflammatory cytokines in mice infected and treated with 1,25(OH)2D3 was lower than the animals infected without 1,25(OH)2D3 treatment. Interestingly, there were no differences in the number of parasites in both groups. Finally, the amount of collagen was higher in animals with treatment compare with animals without 1,25(OH)2D3 treatment. In summary, mice treated with 1,25 (OH) 2D3 reflect a healing process without elimination of L. mexicana.
Asunto(s)
Calcitriol/administración & dosificación , Leishmania mexicana , Leishmaniasis Cutánea/tratamiento farmacológico , Animales , Calcitriol/farmacología , Calcitriol/uso terapéutico , Colágeno/metabolismo , Citocinas/metabolismo , Modelos Animales de Enfermedad , Femenino , Inmunohistoquímica , Inyecciones Intraperitoneales , Leishmania mexicana/efectos de los fármacos , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/patología , Ratones , Ratones Endogámicos BALB C , Piel/parasitología , Piel/patologíaRESUMEN
We have purified Gal/GalNAc lectin from Entamoeba histolytica by electroelution. The purified protein was used to immunize rabbits and obtain polyclonal IgG's anti-lectin. These antibodies were used as tools to analyze the expression and localization of the amoebic lectin in both virulent (vEh) and non-virulent (nvEh) variants of axenically cultured HM1:IMSS strain. vEh is able to induce liver abscesses in hamsters, whereas nvEh has lost this ability. In vitro, amoebic trophozoites from both variants equally express this protein as shown by densitometric analysis of the corresponding band in Western blots from lysates. In both types of trophozoites, the pattern of distribution of the lectin was mainly on the surface. We have also compared by immunohistochemistry the presence and distribution of lectin in the in vivo liver lesions produced in hamsters. In order to prolong the survival of nvEh to analyze both variants in an in vivo model, hamsters inoculated with nvEh were treated with methyl prednisolone. Our results suggest that the Gal/GalNAc lectin is equally expressed in both nvEh and vEh.
Asunto(s)
Antígenos de Carbohidratos Asociados a Tumores/metabolismo , Entamoeba histolytica/metabolismo , Entamoeba histolytica/patogenicidad , Lectinas/metabolismo , Animales , Anticuerpos Antiprotozoarios/inmunología , Especificidad de Anticuerpos , Antígenos de Carbohidratos Asociados a Tumores/inmunología , Antígenos de Carbohidratos Asociados a Tumores/aislamiento & purificación , Western Blotting , Cricetinae , Densitometría , Electroforesis en Gel de Poliacrilamida , Entamoeba histolytica/inmunología , Inmunohistoquímica , Lectinas/inmunología , Lectinas/aislamiento & purificación , Absceso Hepático Amebiano/inmunología , Absceso Hepático Amebiano/parasitología , Masculino , Conejos , Trofozoítos/inmunología , Trofozoítos/metabolismo , VirulenciaRESUMEN
OBJECTIVE: To describe and compare the clinical impacts of neurocysticercosis (NC) caused by Taenia solium in humans and pigs. METHODS: Comparative study of the brains of 16 asymptomatic pigs and 35 human NC cases (15 asymptomatic and 20 symptomatic). RESULTS: In humans, cysticerci were more frequently located in the ventricles and subarachnoid space at the base of the brain (11.8%vs. 1.6%; P = 0.001 and 25.9%vs. 0%; P < 0.0001, respectively) while in pigs, cysticerci were more frequently found in the parenchyma (44.4%vs. 7.6%; P < 0.0001). In human brains, 75.9% of the cysticerci were calcified, while in pigs all cysticerci were in the vesicular stage. CONCLUSION: The duration of infection and the host-parasite relationship (such as immune reactivity and brain haemodynamics) differ between humans and pigs. This may account for the different distribution and stage of the cysticerci among humans and pigs.
Asunto(s)
Encefalopatías/parasitología , Neurocisticercosis/parasitología , Enfermedades de los Porcinos/parasitología , Taenia solium/crecimiento & desarrollo , Animales , Encéfalo/parasitología , Encefalopatías/veterinaria , Cysticercus/crecimiento & desarrollo , Cysticercus/aislamiento & purificación , Humanos , Imagen por Resonancia Magnética , Neurocisticercosis/veterinaria , Porcinos , Taenia solium/aislamiento & purificaciónRESUMEN
Amebopore was purified from axenically grown trophozoites of the Entamoeba histolytica strain HM1:IMSS. The purification procedure involved Mono Q anion-exchange chromatography and electroelution. Sequence analysis of the final product revealed that amebopore A was completely pure. Polyclonal antibodies against the purified amebopore were obtained from rabbits, and Western blot studies demonstrated their specificity. Sections of experimental, acute (1, 2, 3, and 4 days), amebic liver abscesses produced in hamsters were stained with the anti-amebopore antibody; in all the analyzed stages, amebopore appeared as a constitutively expressed cytoplasmic molecule in trophozoites. No extracellular or hepatocyte-membrane amebopore was found. This study is the first to trace amebopore in an in vivo model of amebic liver abscesses.
Asunto(s)
Entamoeba histolytica/aislamiento & purificación , Absceso Hepático Amebiano/parasitología , Animales , Western Blotting , Cromatografía por Intercambio Iónico , Cricetinae , Electroforesis en Gel de Poliacrilamida , InmunohistoquímicaRESUMEN
We have examined the role of inflammatory cells, ischemia and serum complement on the development of acute experimental amoebic liver abscess in hamsters (AEALAH). In hamsters made leukopenic by whole body radiation (800 rad) and daily intraperitoneal glycogen injections, the absence of inflammatory cells and liver tissue damage surrounding the parasites resulted in their rapid (24 h) disappearance from the liver, which showed no lesions. Focal liver ischemia, always present in control AEALAH with inflammation and tissue destruction, was reproduced in radiated hamsters by injection of amoebae mixed with Superdex microspheres, but again in the absence of inflammation, amoebae caused no liver damage and disappeared in 24 h. In hamsters made hypocomplementemic by injection of purified cobra venom factor (CVF), amoebae caused AEALA indistinguishable from controls, but in leukopenic + hypocomplementemic hamsters, amoebae were unable to produce lesions and disappeared from the liver in 48 h. We conclude that inflammation and tissue damage are required for the survival of amoebae in AEALAH and for the progression of the experimental disease.
Asunto(s)
Proteínas del Sistema Complemento/inmunología , Entamoeba histolytica/fisiología , Hepatitis/patología , Isquemia/patología , Absceso Hepático Amebiano , Hígado/patología , Enfermedad Aguda , Animales , Proteínas Inactivadoras de Complemento/farmacología , Modelos Animales de Enfermedad , Venenos Elapídicos/farmacología , Entamoeba histolytica/efectos de la radiación , Femenino , Cobayas , Hepatitis/inmunología , Hepatitis/parasitología , Isquemia/inmunología , Isquemia/parasitología , Leucocitos/efectos de la radiación , Leucopenia/etiología , Hígado/inmunología , Hígado/parasitología , Absceso Hepático Amebiano/inmunología , Absceso Hepático Amebiano/parasitología , Absceso Hepático Amebiano/patología , Masculino , Traumatismos Experimentales por RadiaciónRESUMEN
A lecture was presented by the author at the Democratic Opinion Forum on Health Teaching and Research, organized by Mexico's National Health Institutes Coordinating Office, at National Cardiology Institute "Ignacio Chavez", where he presented a critical review of the conventional classification of basic and applied science, as well as his personal view on health science teaching and research. According to the author, "well-conducted science" is that "generating reality-checked knowledge" and "mis-conducted science" is that "unproductive or producing 'just lies' and 'non-fundable'. To support his views, the author reviews utilitarian and pejorative definitions of science, as well as those of committed and pure science, useful and useless science, and practical and esoterical science, as synonyms of applied and basic science. He also asserts that, in Mexico, "this classification has been used in the past to justify federal funding cutbacks to basic science, allegedly because it is not targeted at solving 'national problems' or because it was not relevant to priorities set in a given six-year political administration period". Regarding health education and research, the author asserts that the current academic programs are inefficient and ineffective; his proposal to tackle these problems is to carry out a solid scientific study, conducted by a multidisciplinary team of experts, "to design the scientific researcher curricula from recruitment of intelligent young people to retirement or death". Performance assessment of researchers would not be restricted to publication of papers, since "the quality of scientific work and contribution to the development of science is not reflected by the number of published papers". The English version of this paper is available at: http://www.insp.mx/salud/index.html
Asunto(s)
CienciaRESUMEN
The postoperative complications observed in a group of 27 patients with hematological diseases that underwent splenectomy are reported: 21 patients had a non-malignant hematological condition, whereas the rest had a hematological malignancy. Seven complications presented in 6 patients (two wound infections, two severe post-operative hemorrhages, one incisional hernia, one sepsis by capsulated bacteria and one fatal hemophagocytic syndrome). The overall complication rate was 27%, whereas the fatal complication rate was 3%. The complication rate in patients with malignant diseases was 83%, whereas that in benign conditions was 9%. The size of the spleen was related with the complication rate (median weight of patients with complications was 990 g versus 132 g in those without complications; p < 0.01). The two patients that underwent splenectomy before age six months had complications, in one case related to parental negligence. In splenectomies performed for hematological disease the benefits must be balanced carefully against the risks.
Asunto(s)
Enfermedades Hematológicas/cirugía , Complicaciones Posoperatorias , Esplenectomía , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Neoplasias Hematológicas/cirugía , Humanos , Lactante , Masculino , Persona de Mediana EdadRESUMEN
We produced a monoclonal antibody against a major cysteine proteinase of 30kDa from trophozoites of Entamoeba histolytica strain HM1:IMSS. The specificity of the monoclonal antibody was confirmed by specific inhibition of azocasein digestion and by electrophoretic analysis, in the presence of sodium dodecyl sulfate or on a substrate gel, of the antigen precipitated by the antibody. Immunofluorescent staining of trophozoites with the monoclonal antibody revealed heterogeneity in the intensity of whole cell fluorescence and subcellular localization of the stain. The latter was also observed in trophozoites, which were stained by conventional immunohistochemical methods, from experimental liver abscesses in hamsters. Ultrastructural analysis showed antigen distributed mainly in clear amorphous zones in the cytoplasm, which were not limited by a visible membrane. Proteinases are translocated from these compartments to phagocytic vacuoles after trophozoites ingest erythrocytes, suggesting that these regions might be a lysosomal equivalent of this primitive eukaryotic cell.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Cisteína Endopeptidasas/análisis , Entamoeba histolytica/enzimología , Animales , Especificidad de Anticuerpos , Western Blotting , Línea Celular , Cisteína Endopeptidasas/inmunología , Entamoeba histolytica/inmunología , Técnica del Anticuerpo Fluorescente , Humanos , Hibridomas , Inmunohistoquímica , Ratones , Microscopía Inmunoelectrónica , Pruebas de PrecipitinaRESUMEN
We examined the participation of polymorphonuclear leucocytes and amebic proteinases upon tissue damage by means of an experimental model of acute amebic lesions developed in rat's testicle. In leukopenic rats (less than 1,000 leucocytes/ml) intratesticular injection of axenic E. histolytica's trophozoites (HM-1) produced lesions undistinguishable from the normal controls. On the other hand, inhibition of 80% (average) of the proteinase activity by means of previous incubation of the trophozoites with human a2M gave way to minimal inflammatory lesions almost undistinguishable from the controls which were injected with PBS-A. Our data suggest that in this experimental model of acute amebiasis polymorphonuclear leukocytes do not participate in the tissue damage and that amebic proteinases are responsible for Entamoeba histolytica's virulence.
Asunto(s)
Endopeptidasas/fisiología , Entamoeba histolytica/patogenicidad , Entamebiasis/patología , Neutrófilos/fisiología , Orquitis/parasitología , Proteínas Protozoarias/metabolismo , Animales , Entamoeba histolytica/enzimología , Entamebiasis/complicaciones , Entamebiasis/enzimología , Leucopenia/inducido químicamente , Leucopenia/complicaciones , Masculino , Mecloretamina/toxicidad , Necrosis , Orquitis/complicaciones , Orquitis/patología , Inhibidores de Proteasas/farmacología , Ratas , Ratas Endogámicas , Virulencia , alfa-Macroglobulinas/farmacologíaRESUMEN
Even though eosinophiles are not characteristic of amebiasis, polymorphonuclear eosinophilic cells are regularly found in the inflammatory lesion which occurs in the early phases of amebic invasion. To acquire better knowledge of the intervention of these cells when confronted with E. histolytica, testicular lesions were produced by means of direct injection of amebas in rats with eosinophilia. Eosinophilia (greater than or equal to 4%) was induced in male Sprague Dawley rats by an intravenous injection of Sephadex G200 suspension. Later, both the eosinophilic and normal (control) rats were challenged with an intratesticular injection (on the left side) of 2 x 10(6) amebas of the virulent strain HM1-IMSS. The other testicle was injected with BFS-A to serve as control. The testicles were removed 5 hours later and evaluated histologically. The size and celullarity of the testicular lesions produced by the ameba on both eosinophilic and controls were similar, whereas lesions were not found in testicles injected with BSF-A. Within the limits of our experimental model, the results suggest that eosinophils do not contribute substantially to the genesis of tissue lesions produced by E. histolytica.
Asunto(s)
Entamebiasis/patología , Eosinófilos/fisiología , Orquitis/parasitología , Animales , Dextranos/toxicidad , Entamoeba histolytica/patogenicidad , Entamoeba histolytica/fisiología , Entamebiasis/complicaciones , Eosinofilia/inducido químicamente , Eosinofilia/complicaciones , Inyecciones , Masculino , Ratas , Ratas EndogámicasRESUMEN
The data presented in this paper may be summarized as follows: 1) intraportal injection of a virulent strain (HM-1) of Entamoeba histolytica in Wistar rats, of both sexes, gives way to non-progressive microscopic changes, characterized by a rapid leukocytic reaction surrounding the amebas, disappearance of the parasites within 5 hours, and total lack of hepatic damage; 2) leucopenia only modifies the previous description by the fact that there are no leucocytes around the amebas, although these disappear in the same time, showing, at this moment, an early and prominent vacuolar degeneration; 3) hypocomplementaemia shows the same results as leucopenia; 4) fragments and extracts from various tissues from the rat and hamster show variable degrees of interference with the viability of axenic amebas of Entamoeba histolytica conserved in culture; only a minimal part of the interference to be due to the activity of the complement which is present in the tissue extracts.
Asunto(s)
Proteínas del Sistema Complemento/fisiología , Entamoeba histolytica/patogenicidad , Entamebiasis/inmunología , Ratas Endogámicas/parasitología , Animales , Proteínas del Sistema Complemento/deficiencia , Cricetinae , Entamoeba histolytica/aislamiento & purificación , Entamebiasis/complicaciones , Femenino , Inmunidad Innata , Riñón/parasitología , Leucopenia/inducido químicamente , Leucopenia/complicaciones , Hígado/parasitología , Masculino , Mecloretamina/toxicidad , Mesocricetus/parasitología , Neutrófilos/fisiología , Ratas , Especificidad de la Especie , Testículo/parasitología , VirulenciaRESUMEN
Changes in lung structure and collagen metabolism were studied at 1, 2, 3, 4, 6, and 8 weeks in a model of pulmonary fibrosis induced in rats with paraquat plus hyperoxia. Morphologic examination of the lungs revealed that the earliest lesions consisted of severe and irreversible endothelial and alveolar epithelial cell damage. Afterward, an inflammatory process took place, initially dominated by polymorphonuclear leukocytes and then by mononuclear cells, but with the constant presence of granulocytes. From the fourth week on there were fibroblast proliferation and a moderate increase of mast cells. In the early stages alveolitis was focal, but from the second week the lungs were diffusely affected with severe distortion of the architecture. Collagen content was moderately increased in the first 2 weeks and then showed a progressive increment until the end of the experiment. Collagen synthesis was significantly elevated from the fourth week, coinciding with interstitial fibroblast proliferation, although there were some animals that showed increased collagen production from the first week. Collagenolytic activity occurred in 3 stages: at 2 weeks there was increased collagen degradation, at 3, 4, and 6 weeks the values showed a trimodal behavior, and at 8 weeks almost all experimental rats presented an important decrease of collagenolysis. Thus, the development of lung fibrosis was associated first with increased rates of collagen synthesis and later with a decrease of collagen degradation.
Asunto(s)
Fibrosis Pulmonar/patología , Animales , Colágeno/análisis , Colágeno/metabolismo , Modelos Animales de Enfermedad , Pulmón/análisis , Pulmón/patología , Pulmón/ultraestructura , Masculino , Microscopía Electrónica , Oxígeno , Paraquat , Fibrosis Pulmonar/inducido químicamente , Ratas , Ratas EndogámicasRESUMEN
There is preliminary evidence that colchicine, an inhibitor of collagen synthesis, may be beneficial in the treatment of cirrhosis of the liver. To evaluate the use of colchicine (1 mg per day, five days per week) in the treatment of hepatic cirrhosis, we performed a randomized, double-blind, placebo-controlled trial in which 100 patients were followed for up to 14 years. Forty-five patients had alcoholic cirrhosis, 41 had posthepatitic cirrhosis, and the remaining 14 had cirrhosis with various other causes. Histologic studies were available for 92 percent of patients. Seventy-three patients were in Child-Turcotte class A, 26 were in class B, and one was in class C. Fifty-four patients received colchicine, and 46 received placebo. The overall survival in the colchicine group was markedly better than in the placebo group (median survival, 11 and 3.5 years, respectively; P less than 0.001). The cumulative 5-year survival rates were 75 percent in the colchicine group and 34 percent in the placebo group; the corresponding 10-year survival rates were 56 percent and 20 percent. Among the 30 patients treated with colchicine who underwent repeated liver biopsies, histologic improvement was seen in 9; the liver appeared normal in 2, and 7 had minimal portal fibrosis. No histologic improvement was observed in the 14 members of the placebo group who had two or more biopsies. Few side effects were observed in either group.
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Colchicina/uso terapéutico , Cirrosis Hepática/tratamiento farmacológico , Ensayos Clínicos como Asunto , Colchicina/administración & dosificación , Colchicina/efectos adversos , Método Doble Ciego , Femenino , Estudios de Seguimiento , Hepatitis/complicaciones , Humanos , Cirrosis Hepática/mortalidad , Cirrosis Hepática Alcohólica/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Distribución AleatoriaRESUMEN
We have studied the effects of soluble factors obtained from rat lungs with experimentally-induced pulmonary fibrosis of 2 months duration on the in vitro rates of biosynthesis and degradation of collagen in normal rat lung preparations. Factors soluble in phosphate-buffered saline were prepared from the minced lungs of normal controls and of silicotic animals. The in vitro rate of collagen biosynthesis of normal rat lung explants was measured as the rate of incorporation of radioactive proline into total and collagenous protein. The in vitro rate of collagen degradation in normal rat lung homogenates was measured as the rate of release of hydroxyproline-containing materials of less than 100,000 daltons to the supernatant. Our results suggest that in this experimental model of pulmonary fibrosis there are soluble factors that stimulate both collagen biosynthesis and collagen degradation in in vitro preparations of normal rat lung.