Amilton Cesar dos Santos

Increased muscle sympathetic nerve activity predicts mortality in heart failure patients

BACKGROUND Previous studies have associated neurohumoral excitation, as estimated by plasma norepinephrine levels, with increased mortality in heart failure. However, the prognostic value of neurovascular interplay in heart failure (HF) is unknown. We tested the hypothesis that the muscle sympathetic nerve activity (MSNA) and forearm blood flow would predict mortality in chronic heart failure patients. METHODS One hundred and twenty two heart failure patients, NYHA II-IV, age 50+/-1 ys, LVEF 33+/-1%, and LVDD 7.1+/-0.2 mm, were followed up for one year. MSNA was directly measured from the peroneal nerve by microneurography. Forearm blood flow was obtained by venous occlusion plethysmography. The variables were analyzed by using univariate, stepwise multivariate Cox proportional hazards analysis, and Kaplan-Meier analysis. RESULTS After one year, 34 pts died from cardiac death. The univariate analysis showed that MSNA, forearm blood flow, LVDD, LVEF, and heart rate were significant predictors of mortality. The multivariate analysis showed that only MSNA (P=0.001) and forearm blood flow (P=0.003) were significant independent predictors of mortality. On the basis of median levels of MSNA, survival rate was significantly lower in pts with >49 bursts/min. Similarly, survival rate was significantly lower in pts with forearm blood flow <1.87 ml/min/100 ml (P=0.002). CONCLUSION MSNA and forearm blood flow predict mortality rate in patients with heart failure. It remains unknown whether therapies that specifically target these abnormalities will improve survival in heart failure.

Effects of home-based exercise training on neurovascular control in patients with heart failure

The effect of home‐based exercise training on neurovascular control in heart failure patients is unknown.

Pharmacokinetics of tramadol and o‐desmethyltramadol in goats after intravenous and oral administration

The aim of this trial was to implement a method to obtain a tool for analyses of tramadol and the main metabolite, o-desmethyltramadol (M1), in goats plasma, and to evaluate the pharmacokinetics of these substances following intravenous (i.v.) and oral (p.o.) administration in female goats. The pharmacokinetics of tramadol and M1 were examined following i.v. or p.o. tramadol administration to six female goats (2 mg/kg). Average retention time was 5.13 min for tramadol and 2.42 min for M1. The calculated parameters for half-life, volume of distribution and total body clearance were 0.94+/-0.34 h, 2.48+/-0.58 L/kg and 2.18+/-0.23 L/kg/h following 2 mg/kg tramadol HCl administered intravenously. The systemic availability was 36.9+/-9.1% and half-life 2.67+/-0.54 h following tramadol 2 mg/kg p.o. M1 had a half-life of 2.89+/-0.43 h following i.v. administration of tramadol. Following p.o., M1 was not detectable.

Macroscopic and microscopic analysis of the tongue of the common opossum (Didelphis marsupialis)

We performed a macroscopic and microscopic study of the tongues of common opossums, Didelphis marsupialis, from South America. We studied two males and two females. We collected morphometric data on the tongue with precision calipers. For the light microscopy and scanning electron microscopy analyses, we fixed tissue fragments in 10% formaldehyde and 2.5% glutaraldehyde, respectively. The opossum tongues averaged 5.87 ± 0.20 cm in length, 3.27 ± 0.15 cm in width at the lingual body, and 3.82 ± 0.15 cm in width at the root. The mean thickness of the lingual body was 1.8 ± 0.1 cm, and the thickness of the root was 3.82 ± 0.15 cm. Sharp filiform papillae were scattered across the entire tongue; conical filiform papillae occurred on the lingual body and tongue tip; fungiform papillae were scattered among the filiform papillae on the lingual body and tongue tip; and there were three vallate papillae at the root of the tongue. We found two strands of papillary projections in the tongue root. Despite the low variability observed in the lingual papillae, the morphological data obtained in this study may be related to the opossums diverse food habits and the extensive geographic distribution of the species throughout America. Microsc. Res. Tech. 2012.

Characterization of the estrous cycle in Galea spixii(Wagler, 1831)

The Galea spixii inhabits semiarid vegetation of Caatinga in the Brazilian Northeast. They are bred in captivity for the development of researches on the biology of reproduction. Therefore, the aim of this study is characterize the estrous cycle of G. spixii, in order to provide information to a better knowledge of captive breeding of the species. The estrous cycle was monitored by vaginal exfoliative cytology in 12 adult females. After the detection of two complete cycles in each animal, the same were euthanized. Then, histological study of the vaginal epithelium, with three females in each phase of the estrous cycle was performed; five were paired with males for performing the control group for estrous cycle phases, and three other were used to monitor the formation and rupture of vaginal closure membrane. By vaginal exfoliative cytology, predominance of superficial cells in estrus, large intermediate cells in proestrus, intermediate and parabasal cells, with neutrophils, in diestrus and metestrus respectively was found. Estrus was detected by the presence of spermatozoa in the control group. By histology, greater proliferation of the vaginal epithelium in proestrus was observed. We conclude that the estrous cycle of G. spixii lasts 15.8 ± 1.4 days and that the vaginal closure membrane develops until complete occlusion of the vaginal ostium, breaking after few days. Future studies may reveal the importance of this fact for the reproductive success of this animal.

Follicular development and morphological changes in the vaginal epithelium during the estrous cycle of Galea spixii.

The current study aimed to determine if characteristics observed in vaginal cytology during the estrous cycle of female SYT cavies corresponded with proliferation of the vaginal epithelium, characterized by proliferating cell nuclear antigen (PCNA) immunolocalization, and with follicular development at different phases of the estrous cycle. After determining estrous cycle phases by vaginal cytology, females were euthanized at metestrus, diestrus, proestrus, and estrus. Histological study of the vaginal epithelium and ovary were then performed. Immunohistochemistry for PCNA in vaginal tissue at each cycle phase was also performed. Superficial cornified cells and early post‐ovulatory follicles were found at estrus. Few nuclei below the enucleate superficial cells were immunoreactive to PCNA. At metestrus, the vaginal epithelium underwent desquamation and lost the superficial cornified cells; basal and intermediate cells appeared, and the post‐ovulatory follicle formed an early corpus luteum. No PCNA immunoreactivity was observed. At diestrus, the corpus luteum was developed, and the vaginal epithelium contained basal and intermediate cells. There was PCNA immunoreactivity in the cellular nucleus in the germinative stratum of the epithelium. Because of the growth and maturation of ovarian follicles, the vaginal epithelium suffered intense proliferation at proestrus. Vaginal cytology revealed large intermediate cells and nucleated and enucleated superficial cornified cells. In the ovary, mature follicles were present. More apparent immunoreactivity of PCNA in the germinative layer was found. In summary, we inferred that vaginal exfoliative findings matched the proliferation process of the vaginal epithelium. PCNA immunolocalization occurred as well as corresponding follicular development in the ovaries.

Composition and significance of glycosaminoglycans in the uterus and placenta of mammals

Glycosaminoglycans (GAGs) are heteropolysaccharides in mammalian tissue and consist of repeated disaccharide units with mono-sulfated or non-sulfated monosaccharides. GAGs are important components of the Extracellular Matrix (ECM) with several physiological roles, in the recognition, migration, adhesion, proliferation and differentiation processes. They are also important in angiogenesis, blood homeostasis, immune reactions, follicule development and also in the development of pathologies such as infertility, tumors and metastases. It has been shown that the profile of glycosaminoglycans in the uterine and placental tissues is highly variable throughout the reproductive cycle and during pregnancy. It may be directly related to their physiological or pathological functions in the tissue. The latter has recently triggered special clinical interest. Current review collaborates for a deeper knowledge on the profile and importance of GAGs in uterine and placental tissues throughout the reproductive cycle and pregnancy. It also covers information on the involvement of these molecules in pathological processes.

Seasonal morphological variation of the vas deferens of scorpion mud turtle (Kinosternon scorpioides)

This study aimed to characterize the morphology of the vas deferens of Kinosteron scorpioides by macroscopic and microscopic analysis. Were used 20 adult male juraras collected at regular intervals during the year and divided into four experimental groups in the rainy and dry seasons, being processed for light microscopy, scanning electron microscopy and transmission electron microscopy. Morphometry for tubular and luminal diameters and epithelial height were also performed. On rainy season, vas deferens presented pseudostratified epithelium with cylindrical cells, spermatozoids and milky fluid in the lumen, with cytoplasmic organelles and lipid vesicles. On dry season, epithelium was pseudostratified with cuboid cells, with cellular debris and no spermatozoids. There was significant variation (p,0,05) for morphometry of vas deferens, with lower values of tubular and luminal diameters on rainy season, and higher epithelial height on dry season.

Análise microscópica e ultraestrutural das glândulas salivares mandibulares de Procyon cancrivorus

Due to the ecological importance of Procyon cancrivorus, the aim of this study was to characterize morphologically and ultrastructurally the mandibular salivary gland of this specie. We used 10 pairs (right and left) of mandibular salivary glands from five adult animals. The mandibular salivary glands were dissected and measured by precision calipers and later processed by histological routine technique, stained by HE (hematoxylin and eosin) and Picrossirius. Fragments of the glands were processed for analysis by scanning electron microscopy (SEM). The mandibular salivary gland, right and left from P. cancrivorus presents lobulated and oval-shape, and it was positioned between the fossa atlantis and basihyoideum ossis of skull. Microscopically, these glands are lined by a capsule formed by dense irregular connective tissue, which enters into the gland by septa, dividing it into lobules. Into the septa of connective tissue were present blood vessels and nerves, and interlobular excretory ducts. Inside the lobes of the mandibular salivary glands, striatum and intermediate-type ducts are found, and the predominance of mucous acini was observed. The results indicate that the mandibular salivary glands of Procyon cancrivorus, follows the structural pattern described in other mammalian species. However the types of acini may vary among species, and thus further histochemical and cell biology studies are required in order to uncover the significance of this variation for the specie here studied, according with their feeding habit.

Development of the central nervous system in guinea pig (Cavia porcellus, Rodentia, Caviidae)

This study describes the development of the central nervous system in guinea pigs from 12th day post conception (dpc) until birth. Totally, 41 embryos and fetuses were analyzed macroscopically and by means of light and electron microscopy. The neural tube closure was observed at day 14 and the development of the spinal cord and differentiation of the primitive central nervous system vesicles was on 20th dpc. Histologically, undifferentiated brain tissue was observed as a mass of mesenchymal tissue between 18th and 20th dpc, and at 25th dpc the tissue within the medullary canal had higher density. On day 30 the brain tissue was differentiated on day 30 and the spinal cord filling throughout the spinal canal, period from which it was possible to observe cerebral and cerebellar stratums. At day 45 intumescences were visualized and cerebral hemispheres were divided, with a clear division between white and gray matter in brain and cerebellum. Median sulcus of the dorsal spinal cord and the cauda equina were only evident on day 50. There were no significant structural differences in fetuses of 50 and 60 dpc, and animals at term were all lissencephalic. In conclusion, morphological studies of the nervous system in guinea pig can provide important information for clinical studies in humans, due to its high degree of neurological maturity in relation to its short gestation period, what can provide a good tool for neurological studies.