RESUMO
Feeding habits of seven cichlid species (Archocentrus octofasciatus, A. spilurus, "Cichlasoma" robertsoni, "C." synspilum, "C." urophthalmus, Petenia splendida, Thorichthys meeki) in Lake Caobas, southern Yucatan Peninsula, were studied. Samples were taken with enclosure and cast nets during the dry and rainy seasons of 1995 (day and night). The environment was characterized by measuring temperature, conductivity and pH. All individuals were below 41 mm SL (N = 281). Frequency of occurrence and prey abundance were analyzed. Main prey items were chironomids, mites, copepods, cladocerans, and ostracods. The cichlids fed mainly on zooplankton, with the partial exceptions of P. splendida (piscivore), "C." synspilum and A. spilurus (herbivores). A cluster analysis showed that the most similar trophic spectra were those of T. meeki, "C." robertsoni and "C." salvini, which were also the least diverse. "C." synspilum and A. spilurus had an intermediate distance between their diets and those of other species. The species with the most distinctive feeding composition were P. splendida (with the most diverse and equitable diet) and the omnivore A. octofasciatus (whose diet was the richest one). T. meeki showed quantitative diel, ontogenetic, and seasonal diet changes, but none between sexes. "C." robertsoni, "C." salvini and "C." synspilum differ in food habits in Caobas and in other localities, a fact that underscores the trophic adaptability of cichlids. Trophic overlap between cichlids in Caobas could imply absence of competition, perhaps because resources are abundant in the ecosystem.
Assuntos
Comportamento Alimentar/fisiologia , Perciformes/fisiologia , Animais , Feminino , Água Doce , Conteúdo Gastrointestinal , Masculino , México , Estações do Ano , Fatores de TempoRESUMO
OBJECTIVE: To evaluate a screening questionnaire to identify individuals with undiagnosed diabetes. DESIGN AND METHODS: We conducted a community survey to detect people at increased risk for diabetes using a questionnaire proposed by Herman et al. (1995), that incorporates major risk factors as age, obesity, family history of diabetes, sedentary lifestyle and personal history of delivering a macrosomic infant. Blood glucose test was made by means of reagent strip and a reflectance meter system. We used the ADA recommendations and cut-points for screening programs, adjusted for fasting and random blood glucose. RESULTS: We included 360 participants older than 20 years of age. A total of 200 subjects (55.5%) were at risk for diabetes according to the questionnaire, of whom 31 (15.5%) had an abnormal glucose test compared to the 4.4% of the low-risk group (p < 0.001). The 1995 Herman et al. Questionnaire had sensitivity of 81.6%, specificity of 47.5, positive predictive value of 15.5 and negative predictive value of 95.6%. The high-risk group was older (44.9 vs. 34.6 y, p < 0.001) and heavier (30.5 vs. 24.4 kg/m2, p < 0.001) than the low-risk group. There were 38/360 (10.5%) abnormal glucose readings, of which 31 (81.5%) had a positive questionnaire (p < 0.01). The mean fasting glucose in the high-risk group was higher (90.6 vs. 84.2 mg/dL, p = 0.015) than in those with low risk by questionnaire, as well as for random blood glucose (116.1 vs. 100 mg/dL, p < 0.01). CONCLUSIONS: The questionnaire proposed by Herman et al. combined with capillary blood glucose testing performance good in mexican population to identify people at high risk for undiagnosed diabetes, and improved the detection rate.
Assuntos
Diabetes Mellitus/diagnóstico , Programas de Rastreamento/métodos , Inquéritos e Questionários , Adulto , Feminino , Humanos , Estilo de Vida , Masculino , México , Fatores de RiscoRESUMO
Five new cytotoxic cembranolides possessing a rare 4,7-oxa-bridged functionality were isolated from the gorgonian Eunicea mammosa. The structures of 5, 7-9, and 10 were deduced from spectroscopic data and by chemical correlation experiments.
Assuntos
Antineoplásicos/química , Cnidários/química , Diterpenos/química , Animais , Antineoplásicos/farmacologia , Cromatografia Líquida de Alta Pressão , Diterpenos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Espectroscopia de Ressonância Magnética , Porto Rico , Espectrofotometria Infravermelho , Células Tumorais CultivadasRESUMO
This paper comprises a systematic survey of larval nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southern Mexico, in 1993-1994. Larvae of the following nine species were recorded: Physocephalus sexalatus, Acuariidae gen. sp., Spiroxys sp., Falcaustra sp., Hysterothylacium cenotae, Contracaecum sp. Type 1, Contracaecum sp. Type 2, Goezia sp., and Eustrongylides sp. Larvae of P. sexalatus are recorded from fishes (Rhamdia guatemalensis) for the first time. The larvae are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Adults of these larvae are parasitic in piscivorous fishes, reptiles, birds and mammals (definitive hosts). Fishes harbouring the larvae of these parasites serve as paratenic hosts, being mostly an important source of infection for the definitive hosts.
Assuntos
Peixes/parasitologia , Nematoides/isolamento & purificação , Animais , Larva , México , Nematoides/anatomia & histologiaRESUMO
The purpose of the present experiments was to establish the factors that determine the intracellular Cl- concentration ([Cl-]i) of lymphocytes. Coulometric and isotope equilibration determinations indicated that [Cl-]i was in the range of 70-85 mmol/l cells. Since the membrane potential (Em) of these cells approximates -55 mV, [Cl-]i is severalfold higher than the level expected at electrochemical equilibrium (approximately 16 mM). This suggests that conductive pathways contribute marginally to the distribution of Cl-. Accordingly, altering the force driving conductive Cl- fluxes by manipulating Em had little effect on [Cl-]i. The possible role of electroneutral cation-Cl- cotransport in the accumulation of intracellular Cl- was also assessed. 36Cl- uptake was largely unaffected by omission of extracellular Na+ and K+ or by addition of bumetanide, a potent cotransport inhibitor. Moreover, [Cl-]i remained unaltered for at least 1 h in cells incubated without Na+ or K+ or in the presence of loop diuretics. Thus it appears unlikely that Cl(-)-anion cotransport plays a major role in maintaining [Cl-]i. A vigorous stilbene disulfonate-sensitive anion exchanger was detected in thymocytes. This system constitutes a large fraction of the Cl- flux pathways and is possibly a major contributor to the establishment of [Cl-]i. Accordingly, modifying the force driving Cl- through the exchanger, by altering pH at constant PCO2, resulted in changes in cellular Cl- content and associated changes in cell volume. These effects were markedly reduced in the nominal absence of HCO3- or in the presence of disulfonic stilbene derivatives, suggesting that they are mediated by Cl(-)-HCO3- exchange.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Bicarbonatos/metabolismo , Membrana Celular/metabolismo , Cloretos/metabolismo , Linfócitos/metabolismo , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico , Ácido 4-Acetamido-4'-isotiocianatostilbeno-2,2'-dissulfônico/análogos & derivados , Ácido 4-Acetamido-4'-isotiocianatostilbeno-2,2'-dissulfônico/farmacologia , Animais , Bicarbonatos/farmacologia , Transporte Biológico Ativo/efeitos dos fármacos , Bumetanida/farmacologia , Membrana Celular/efeitos dos fármacos , Furosemida/farmacologia , Ionóforos/farmacologia , Cinética , Masculino , Matemática , Ratos , Ratos EndogâmicosRESUMO
Prevalence of gestational diabetes was investigated in 693 pregnant patients between the 24th and 28th wk of gestation. A glucose screening test (GST) was performed with a 50-g glucose load, followed by a blood sample 1 h later. Patients with glucose levels greater than 140 mg/dl 1 h after the GST were scheduled for a full oral glucose tolerance test (OGTT). One hundred seven patients had an abnormal GST, and 30 patients (4.3%) were diagnosed as having gestational diabetes mellitus (GDM). The percentage of GDM increased significantly when glucose levels were greater than 180 mg/dl to a maximum of 84.61% when glucose levels were greater than 200 mg/dl. Also, patient age was directly related to GDM, which increased in incidence to 20% when patients greater than 26 yr had an abnormal GST. After delivery, newborn weights were compared between those born to mothers with GDM (n = 30) and those born to mothers with an abnormal GST (n = 77). Patients with an abnormal GST and normal OGTT had 12 (15.58%) macrosomic and 2 premature newborns. However, patients with GDM had 5 (16.66%) macrosomic and no premature newborns. Patients with a normal GST had 7.33% of the macrosomic newborns. There was no perinatal mortality in newborns of GDM mothers; only 1 of the 5 macrosomic newborns presented transient hypoglycemia. Evaluation of 26 GDM patients was possible after delivery, disclosing 3 (11.53%) with non-insulin-dependent diabetes mellitus and 5 (19.23%) with impaired glucose tolerance. These results showed 4.3% undetected GDM in our population and no differences in the proportion of macrosomic newborns between those born to mothers with GDM and those born to mothers with an abnormal GST.