Seroprevalence and seroincidence of Leptospira infection in dogs during a one-year period in an endemic urban area in Southern Brazil

INTRODUCTION: Leptospirosis is a zoonosis that affects both humans and animals. Dogs may serve as sentinels and indicators of environmental contamination as well as potential carriers for Leptospira. This study aimed to evaluate the seroprevalence and seroincidence of leptospirosis infection in dogs in an urban low-income community in southern Brazil where human leptospirosis is endemic. METHODS: A prospective cohort study was designed that consisted of sampling at recruitment and four consecutive trimestral follow-up sampling trials. All households in the area were visited, and those that owned dogs were invited to participate in the study. The seroprevalence (MAT titers ≥100) of Leptospira infection in dogs was calculated for each visit, the seroincidence (seroconversion or four-fold increase in serogroup-specific MAT titer) density rate was calculated for each follow-up, and a global seroincidence density rate was calculated for the overall period. RESULTS: A total of 378 dogs and 902.7 dog-trimesters were recruited and followed, respectively. The seroprevalence of infection ranged from 9.3% (95% CI; 6.7 - 12.6) to 19% (14.1 - 25.2), the seroincidence density rate of infection ranged from 6% (3.3 - 10.6) to 15.3% (10.8 - 21.2), and the global seroincidence density rate of infection was 11% (9.1 - 13.2) per dog-trimester. Canicola and Icterohaemorraghiae were the most frequent incident serogroups observed in all follow-ups. CONCLUSIONS: Follow-ups with mean trimester intervals were incapable of detecting any increase in seroprevalence due to seroincident cases of canine leptospirosis, suggesting that antibody titers may fall within three months. Further studies on incident infections, disease burden or risk factors for incident Leptospira cases should take into account the detectable lifespan of the antibody. .

Influence of the states of dehydration and rehydration on the in-situ intestinal absorption of calacctose and clucose in rats

This work aimed to evaluate the influence of an experimental model of diarrhea as well as the dehydration and rehydration rats. Reproducible model of mild and severe infectious diarrhea was produced by peroral challenges with Salmonella typhimurium in adult male rats. The in situ intestinal absorption of galactose and glucose was evaluated along 90 minutes in case of diarrhea in the presence and absence of oral rehydration solution as well as after rehydration. The utilized concentration of galactose was 325 mg%. Absorption was evaluated by determining the circulating fractions of galactose and glucose as well as the rate constants of absorption [K1 and K2]. A statistically significant reduction in the circulating amounts of sugar was occurred in the infected animals

Comparaçäo entre lidocaína 2 por cento com e sem glicose para raquianestesia / Comparison od 2 per cent lidocaine with or without glucose for spinal anesthesia

Justificativa e objetivos: näo existe na literatura nacional nenhum estudo comparando as diferenças na dispersäo e duraçäo dos bloqueios sensitivo e motor entre as soluçöes hiperbárica e isobárica de lidocaína 2 por cento pura com a lidocaína 2 por cento com glicose 8 por cento para raquianestesia. Método: participaram dos estudos 100 pacientes, estado físico ASA I e II, com idade entre 16 e 78 anos. Os pacientes foram divididos em dois grupos: ISO recebeu 4ml de lidocaína 2 por cento pura e grupo HIPER, recebeu também 4ml de lidocaína 2 por cento contendo glicose a 8 por cento. Os pacientes foram colocados em decúbito lateral e a punçäo lombar foi realizada com agulha 27G tipo Quincke. Foram analisados a densidade, o peso específico, a baricidade e o pH de ambas as soluçöes. Foram estudados os seguintes parâmetros: latência, bloqueio motor, duraçäo dos efeitos, dispersäo cefálica da analgesia, alteraçöes cardiovasculares e irritaçäo radicular transitória. Resultados: as baricidades encontradas foram: lidocaína hiperbárica de 1,02569 a 37ºC e lidocaína 2 por cento pura de 0,99920 a 37ºC. O início do bloqueio foi similar com ambas as soluçöes. A dispersäo cefálica foi significativamente mais alta com a lidocaína 2 por cento hiperbárica. As duraçöes dos bloqueios sensitivo e motor foram similares com ambas as soluçöes. A incidência de hipotensäo arterial foi significativamente maior com a lidocaína 2 por cento hiperbárica. Näo foi observado nenhum caso de irritaçäo radicular transitória com ambas as soluçöes de lidocaína. Conclusöes: consideramos a lidocaína 2 por cento com ou sem glicose segura como agente para raquianestesia para procedimentos de curta duraçäo. A lidocaína 2 por cento hiperbárica apreenta maior incidência de hipotensäo arterial

Effect of Walker 256 tumor growth on intestinal absorption of leucine, methionine and glucose in newly weaned and mature rats

In tumor-bearing rats, most of the serum amino acids are used for synthesis and oxidation processes by the neoplastic tissue. In the present study, the effect of Walker 256 carcinoma growth on the intestinal absorption of leucine, methionine and glucose was investigated in newly weaned and mature rats. Food intake and carcass weight were decreased in newly weaned (NT) and mature (MT) rats bearing Walker 256 tumor in comparison with control animals (NC and MC). The tumor/carcass weight ratio was higher in NT than in MT rats, whereas nitrogen balance was significantly decreased in both as compared to control animals. Glucose absorption was significantly reduced in MT rats (MT = 47.3 ñ 4.9 vs MC = 99.8 ñ 5.3 nmol min-1 cm-1, Kruskal-Wallis test, P<0.05) but this fact did not hamper the evolution of cancer. There was a significant increase in methionine absorption in both groups (NT = 4.2 ñ 0.3 and MT = 2.0 ñ 0.1 vs NC = 3.7 ñ 0.1 and MC = 1.2 ñ 0.2 nmol min-1 cm-1, Kruskal-Wallis test, P<0.05), whereas leucine absorption was increased only in young tumor-bearing rats (NT = 8.6 ñ 0.2 vs NC = 7.7 ñ 0.4 nmol min-1 cm-1, Kruskal-Wallis test, P<0.05), suggesting that these metabolites are being used for synthesis and oxidation processes by the neoplastic cells, which might ensure their rapid proliferation especially in NT rats.

La glucosa en conjunto con péptidos derivados de cininógenos podrían actuar desde el aparato digestivo como bloqueadores de la acción diurética-natriurética del péptido natriurético auricular / Glucose in conjunction with peptides derived from kininogens might act from digestive tract as blockers of ANP mediated diuresis-natriuresis

This paper describes long term research efforts wich have lead: 1) to the identification of peptides present in pepsanurin, a peptidic fraction obtained by pepsin hydrolisis of plasma globulins that inhibits the renal excretory action of atrial natriuretic peptide (ANP) and 2) to the discovery of an unexpected role of glucose, as a requisite, for these inhibitory effects. The active peptides identified in pepsanurin are derived from plasma kininogens, substrates of the kallikrein-kinin system. Pro-kinins of 15, 16 and 18 aminoacids, and bradykinin itself, block ANP-induced diuresis and natriuresis when injected iv, ip or into, the duodenal lumen of anesthetized rats in picomol doses. Furthermore, a novel 20 aminoacids fragment derived from kininogen dominium-1, named PU-D1, is the most potent and longer lasting blocker of ANP renal effects. The anti-ANP effects of those peptides are prevented by B2- kinin receptor antagonists. The inhibition of ANP by kinins and PU-D1 was evident only in rats infused with isotonic glucose; whereas the excretory effect of ANP was not affected in fasted rats not infused, or infused with saline. These findings provide evidence that glucose facilitates liquid retention through a kinin-mediated inhibition of ANP excretory action that may be related to the prandial cycle

Intestinal transport of water, sodium & glucose from an electrolyte solution with & without bicarbonate.

In this study we have evaluated the role of bicarbonate on water and sodium transport in normal and secreting ilea of rabbits as controversy exists regarding the inclusion of bicarbonate in oral rehydration solution (ORS). In anaesthetized rabbits 10 cm closed ileal loops were constructed and filled with 5 ml of an electrolyte solution with and without bicarbonate, which contained polyethylene glycol (PEG; mol wt 4,000) as a non-absorbable marker. The fluid was withdrawn after an hour and analyzed for PEG, sodium and glucose. Similar studies were carried out in loops one hour after exposure to 1 microgram/ml of purified cholera toxin. Body temperature was maintained at 37 degrees C during the experiment by using a lamp. The mean +/- SE of water and sodium absorption, with bicarbonate versus without bicarbonate, was -1.4 +/- 0.1 vs -1.1 +/- 0.3 ml/h/10 cm, and -340.8 +/- 23.0 vs -308.4 +/- 35.6 mM/h/10 cm, respectively from secreting rabbit ilea. A similar effect was observed in normal ilea. It is concluded that bicarbonate containing electrolyte solution has no additional promoting effect on water and sodium absorption in normal or secreting ilea of rabbits.

Atividade física, suplementaçäo nutricional de aminoácidos e resistência periférica à insulina / Physical exercise, amino acids supplementation and insulin peripheric resistance

O consumo de suplementos nutricionais voltados a praticantes de atividade física se eleva continuamente. Dentre os suplementos, os mais comercializados sao os aminoácidos. A eficiência destes no aumento do desempenho é ainda questionada. Dentre os aminoácidos testados, indubitavelmente, os de cadeia ramificada (leucina, isoleucina e valina) foram os mais explorados. Estes, juntamente com asparatato e asparagina formam o conjunto de aminoácidos metabolizados no músculo esquelético. Durante o exercício físico prolongado, o consumo de aminoácidos pelo músculo se eleva proporcionalmente pela duraçao do esforço. Recentemente, apresentamos que a suplementaçao de aspartato e asparagina promovem: aumento da resistência ao esforço, aumento do consumo de lipídeos e aumento no conteúdo de glicogênio e consequentemente, resistência periférica à insulina. A resistência periférica à insulina pode ser modulada pelo exercício físico por aumentar a capacidade de transporte de glicose pelo músculo independente da açao hormonal. O presente artigo, enfoca o possível efeito da suplementaçao de aminoácidos (aspartato, asparagina, leucina, isoleucina e valina) sobre a capacidade de transporte de glicose no músculo bem como o efeito do exercício físico sobre o metabolismo dos aminoácidos. A relevância do tema em questao se dá pelos possíveis efeitos ergogênicos pelos aminoácidos e a provável açao periférica dos mesmos no metabolismo da glicose.

Alterations in plasma prolactin and glucose levels induced by surgical stress in hyperprolactinemic female rats

The effects of hyperprolactinemia on plasma prolactin (PRL) and glucose were investigated in female rats submitted to surgical stress (laparotomy under ether anesthesia). Wistar rats weighing 250-280g received pituitary grafs under the kidney capsule three weeks before the experiments (N = 15) while a control group underwent sham transplantation (N = 14). The sham-operated rats presented a threefold increase of PRL levels as early as after 5 min of surgical stress (P<0.01); the PRL levels reached a peak at about 15 min and returned to baseline at 40 min. The PRL levels of the grafted rats were increased 3.5-fold compared to the sham-operated controls before stress (20.2 + 5.6 ng/ml vs 5.8 + 0.9 ng/ml, respectively; P<0.05), but did not change significantly during the experimental period. Plasma glucose was already significantly increased at 5 min in sham-operated control and grafted rats (P<0.01) and reached maximal concentrations at about 15 min. The grafted rats presented higher glucose levels than sham-operated controls before stress (122.2 + 3.3 vs 100.5 + 4.2 mg/dl; P<0.01) and at 40 min (182.6 + 13.6 vs 146.7 + 8.4 mg/dl; P<0.05). The hyperprolactinemic rats showed impaired surgical stress-induced PRL release and higher glucose levels both at rest and during the first postoperative hour. These results indicate that chronic hyperprolactinemia inhibited PRL secretion and enhanced the hyperglycemic stress response in the female rat.

Effect of D-glucose and L-glutamate on the kinetics of bicarbonate reabsorption in rat proximal tubules

The effect of D-glucose or L-glutamate on the kinetics of bicarbonate reabsorption in the early (EPT) and middle proximal tubule (MPT) was studied in vivo in Munich-Wistar rats by microperfusion techniques. The presence of 20 mM D-glucose in the lumen increased acidification half-time (t/2) (from 2.54 + or - 0.09s to 3.11 + or - 0.17 s in EPT and from 4.75 + or - 0.20 s to 6.04 + or - 0.49 s in MPT). Bicarbonate reabsorption 9JHCO-3) decreased as a consequence of this change (from 3.80 + or - 0.17 to 2.46 + or - 0.20 nmol cm-2s-1 in EPT and from 2.30 + or - 0.10 to 1.64 + or - 0.10 nmol cm-2s-1 in MPT). In this situation the basolateral membrane potential difference (BLMPD) in the MPT decereased from -41.6 + or - 2.47 to -29.7 + or - 2.45 mV and returned to control values after perfusion with D-glucose. The addition of 20 mM L-glutamate to the luminal perfusion caused an opposite effect, i.e., a decrease in t/2 (1.54 + or - 0.21 s in EPT and 3.25 + or - 0.26 s in MPT) and a consequent increase in JHCO-3 in both segments (5.09 + or - 0.58 nmol cm-2s-1 in EPT and 3.92 + or - 0.30 nmol cm-2s-1 in MPT). The BLMPD of MPT increased during L-glutamate perfusion (-39 + or - 2.48 mV in control and -52.0 + or - 2.72 mV with L-glutamate) and returned to control values after perfusion. The results observed may be the consequence of coupled Na+ - substrate transport altering the BLMPD with modifies the electrical driving force for coupled Na+ -HCO-3 efflux across the basolateral membrane. The alteration of this process may in turn affect intracellular pH, which is an important modulator of luminal Na+./H+ enchange. This possibility is supported by the observed depolarization of BLMPD by D-glucose (electroneutral molecule), and hyperpolarization by glutamate anion

Transporte jejunal eletrogênico da glicose em ratos com deficiência de niacina / Jejunal electrogenic transport of glucose in rats with niacin deficiency

A absorçäo jejunal eletrogênica ativa da glicose foi estudada pelo método da perfusäo intestinal "in vivo", infundido-se soluçöes de glicose com concentraçäo crescente (2,5;5,0; 10,0; 20,0; 50,0 e 100,0 mM/L) em 15 cm de jejuno isolado de 12 ratos com deficiência de niacina. Os resultados dos animais carentes foram comparados com os de 12 animais que ingeriram dieta controle na mesma quantidade ingerida pelo seu par carente. A diferença de potencial transmural média em cada concentraçäo infundida de glicose foi estatisticamente menor nos animais carentes, em relaçäo aos controles. Além disso, nos ratos carentes, o Km foi maior (16,1 x 12,7), enquanto que Pdmax foi menor que o dos controles (12,5 x 19,4), respectivamente, demonstrando a ocorrência da depleçäo do transporte ativo eletrogênico da glicose, na carência de niacina. Uma possível explicaçäo para este achado seria a depleçäo das fontes de energia intra-enterocitária

The effect of capsaicin on the small intestinal absorption of glucose and alanine in the rat.

Chilli (containing the active ingredient capsaicin) forms an important flavouring agent in the preparation of meals in the tropics. Previous studies have shown that capsaicin in high doses causes gross structural and functional changes in the gut. The present study investigates the effect of pure capsaicin on the absorption of glucose, water and alanine by the small intestine of the rat. Perfusion studies were carried out using a 10 cm jejunal segment. Absorption rates of glucose, water and alanine from a control solution containing the nutrient and from a test solution containing added capsaicin were compared. Recovery of absorptive function of the intestinal mucosa after exposure to capsaicin was also studied. Absorption of water, glucose and alanine was found to be significantly reduced in the presence of capsaicin. Recovery of absorptive function occurred when capsaicin was withdrawn from the perfusate. It was concluded that capsaicin adversely affected absorption of nutrients from the rat small intestine; this effect was reversible at least in the case of some nutrients.

In vitro influence of hormones on transport of glucose and glycogen in liver and muscle of pinealectomised pigeons, Columba livia Gmellin.

To substantiate the increased peripheral utilization of blood glucose by pineal in wild pigeons, an in vitro study on the ability of liver and muscle slices of intact and pinealectomised wild pigeons (C. livia) in terms of uptake and release of glucose, and deposition and depletion of glycogen, in presence of insulin, acetylcholine, glucagon and adrenaline has been undertaken. A total insensitivity of liver and muscle of pinealectomised birds for glycogen deposition and insensitivity of liver for glucose uptake has been observed. Increased glucose release from liver in response to adrenalin has been observed. The results are discussed in terms of involvement of pineal in metabolic regulation associated with breeding activities.

Transport of glutamine, alanine and glucose by rabbit intestinal membrane

Malnutrition and dehydration are the immediated consequences of diarrheal diseases. To investigate the biological significance ofglutamine, alanine and glucose in the intestinal mucosa, we have used Ussing chambers to determine electrolyte transport by measuring short-circuit current (Isc), potential difference (PD) and tissue resistance (TR) in rabbit intestinal mucosa. Increasing doses (10-5 M to 10-1 M)of glutamine,alanine and glucose cause a significant increase in intestinal cation cotransport. Although glucose had a slightly earlier effect, 30mM glutamine and 0.1 M alanine had a maximal effect which was more than two times that caused by 30 nM glucose. The pD2 values for glucose, glutamine and alanine were 3.0, 2.5, and 2.0, respectively. The dose-response curves of these substrates suggest that the intestinal cotransport kinetics for glutamine is differentfrom that of glucose and alanine. Our results demonstrated that all three substrates cause a significant increase in Isc or PD, suggesting an increase in the intestinal mucosa cation cotransport. Glutamine has a larger effect on cation cotransport than alanine and glucose. These combinations should be studied further for the development of an oral rehydrating solution for diarrhea treatment which could prevent the resulting malnutrition, especially in those cases of prolonged diarrheal diseases

Cinética do transporte jejunal de glicose em ratos com deficiência de niacina / Kinetics of jejunal glucose transport in niacin deficient rats

Estudou-se a cinética da absorçäo jejunal da glicose pelo método da perfusäo intestinal in vivo em 180 ratos jovens, 90 dos quais receberam dieta deficiente em niacina e o restante dieta controle. Foram infundidas sete soluçöes de glicose (5, 10, 20, 40, 80, 160 e 320 mM), uma para cada grupo de animais. Determinou-se o V max. e o Km aparente para os animais controles e carentes. Verificou-se que os animais carentes absorveram menos glicose em cada concentraçäo infundida e que seu Vmax e Km (133.3 µM/15 cm e 92.2 mM/1, respectivamente) foram menores em relaçäo aos animais controles (294.1 µM/15 cm e 171.8 µ M/1, respectivamente). Com o modelo experimental utilizado, pode-se afirmar que na deficiência de niacina ocorre menor absorçäo de glicose

Hypoglycemic activity of Swertia chirayita (Roxb ex Flem) Karst.

Hexane fraction of S. chirayita (250 mg/kg body wt.) induced significant fall in blood sugar and significant increase in plasma IRI simultaneously after single oral administration without influencing liver glycogen concentration in albino rats. On the other hand, daily administration for 28 days resulted in significant lowering of blood sugar and increase in plasma IRI along with a significant rise in liver glycogen. Intestinal absorption of glucose was not inhibited by hexane fraction. It is suggested that hexane fraction of S. chirayita possibly acts through its insulin releasing effect.

Effect of acute glucose infusion on plasma levels of insulin, glucose and free fatty acids, and on the glucose removal rate in obese women

The objective of the present study was to report the variations in levels of insulin, free fatty acids and glucose occurring in a group of obese and nonobese women after acute intravenous glucose infusion. The difference between glucose and insulin levels in obese and nonobese women in response to glucose infusion was statistically significant. The mean maximum value for glucose detected in the obese group was 256 mg/dl versus 283 mg/dl in the nonobese group (p < 0.05). Insulin content was 147 muU/ml in the obese group versus 36 muU/ml in the nonobese group (p < 0.05). K (fractional removal rate constant for glucose) values were similar in both groups suggesting that the higher glucose and insulin peaks showed by the obese were due to the higher glucose uptake by the blood rather than its removal impairment.