Coumarin content and physicochemical profile of Mikania laevigata extracts

The 'guaco' lianous herb Mikania laevigata, which is widespread in Southern Brazil, is traditionally used to treat bronchitis, asthma and cough. This work investigates the influence of the extraction method, solvent:drug ratio, ethanol proportion, harvest season (summer or winter) and solvent heating on the physicochemical profile of the extracts (dry weight, density, pH) and the coumarin (1,2-benzopyrone) content determined by LC. Among the results obtained, it is observed that higher ethanol content increases the amount of coumarin in the extract. Leaves harvested in summer also produce an extract with a high coumarin yield. The most efficient method of extraction is percolation, independent of the solvent used.     

Lip anatomy and its implications for the pollination mechanisms of Bulbophyllum species (Orchidaceae)

BACKGROUND AND AIMS: The lip structure of six Brazilian and one Asiatic species of Bulbophyllum with wind-assisted fly pollination (B. involutum, B. ipanemense and B. weddellii) and non-wind-assisted fly pollination (B. epiphytum, B. glutinosum, B. regnellii and B. rothschildianum) was studied to investigate the presence of secretory tissues related to these pollination mechanisms. METHODS: The lip study was carried out through scanning electron microscopy (lip surface) and light microscopy (anatomical features). KEY RESULTS: In most of the species studied, the osmophores (odour glands) were located in the lobes and in the upper surface of the lip callus. Differences in the lip structure were observed between the two groups (the presence of a nectary and the extent of osmophore surface), depending on the mechanism of pollination. Nectaries were found in the cavity callus in B. ipanemense, B. involutum and B. weddellii, even though their pollinators were presumably attracted by the instinct to oviposit. CONCLUSIONS: These findings corroborate the hypothesis that, because pollination in these species is dependent on an unpredictable external factor (wind), nectar is necessary to keep the insect in the flower for a long period. Despite the occurrence of a liquid-like nectar in the flowers of B. epiphytum, B. glutinosum, B. regnelli and B. rothschildianum, no anatomical evidence for nectaries was found in the lips of these species, although a similar structure may occur in another region of the flowers. This observation agrees with the fact that pollination by lip movement in the latter species requires only gravity, with no additional mechanism being needed to keep the flies in the flower.     

Biologic data of Macaca mulatta, Macaca fascicularis, and Saimiri sciureus used for research at the Fiocruz primate center

Physiological parameters of laboratory animals used for biomedical research is crucial for following several experimental procedures. With the intent to establish baseline biologic parameters for non-human primates held in closed colonies, hematological and morphometric data of captive monkeys were determined. Data of clinically healthy rhesus macaques (Macaca mulatta), cynomolgus monkeys (Macaca fascicularis), and squirrel monkeys (Saimiri sciureus) were collected over a period of five years. Animals were separated according to sex and divided into five age groups. Hematological data were compared with those in the literature by Student's t test. Discrepancies with significance levels of 0.1, 1 or 5% were found in the hematological studies. Growth curves showed that the sexual dimorphism of rhesus monkeys appeared at an age of four years. In earlier ages, the differences between sexes could not be distinguished (p < 0.05). Sexual dimorphism in both squirrel monkeys and cynomolgus monkeys occurred at an age of about 32 months. Data presented in this paper could be useful for comparative studies using primates under similar conditions.     

Immunoblotting for the serodiagnosis of Helicobacter pylori infection in Brazilian patients with and without gastric carcinoma

We evaluated the performance of a commercial immunoblotting in the serodiagnosis of Helicobacter pylori infection in Brazilian patients. The presence of anti-H. pylori antibodies was also investigated in a group of 20 duodenal ulcer patients after successful treatment. One hundred and ninety one patients were studied. Among the 164 infected patients, 46 had gastric carcinoma. The duodenal ulcer patients were treated with antimicrobial drugs and the eradication of the microorganism was confirmed in all of them one month after the end of the treatment by the 13C-urea breath test. Sera were assayed for H. pylori antibodies using the Helicoblot 2.0 (Genelabs Diagnostics, Singapore). The sensitivity, specificity, positive, and negative predictive values of the test were 93.9%, 92.6%, 98.7%, and 71.4%, respectively. The sensitivity of the test was similar in patients with (93.5%) and without (95.7%) gastric carcinoma. Twenty-four months after the end of the treatment, the band of 116 kDa was still detected in one of the patients. In conclusion, the Helicoblot 2.0 is an accurate test to diagnose H. pylori infection and although it can not be employed to monitor the bacterium eradication, it may be useful for diagnosing past infection, especially in gastric carcinoma patients.     

Biology of Amblyomma aureolatum (Pallas, 1772) (Acari: Ixodidae) on some laboratory hosts in Brazil

The ixodid Amblyomma aureolatum is suspected to play a role in the epidemiology of wild life-cycle hemoparasites, which frequently infect dogs in rural and hunting areas in Brazil. Little is known about its bionomics. The objective of the present study was to evaluate some bionomic aspects of A. aureolatum ticks in Brazil. One engorged female, collected from a dog (Canis familiaris) in S?o Sebasti?o das Aguas Claras, State of Minas Gerais, was used to establish a colony in the laboratory. Subsequently its parasitic stage progeny were fed on domestic dogs and laboratory animals. The free-living stages were incubated at 27 degrees C +/- 2 degrees C and minimum 70% relative humidity in a BOD incubator. The egg incubation period ranged from 31 to 34 days; the parasitic period of larvae ranged from 4 to 6 days and ecdysis to nymphs occurred from day 19 up to day 22. The parasitic period of nymphs ranged from 5 to 8 days and the period of ecdysis to adults from 31 to 33 days. The parasitic period of adults ranged from 11 to 15 days, the pre-oviposition period from 6 to 12 days, and the oviposition period from 9 to 38 days. The total duration of the life cycle ranged from 116 to 168 days.     

Route of jejunal mucosa absorption of trypsin demonstrated by immunofluorescence

Previous studies have demonstrated the absorption of porcine trypsin in isolated jejunal loops from male Wistar rats by open-loop perfusion. The possible routes of absorption were examined in the study reported here. Trypsin (0.5 mg/ml) was dissolved in tyrode solution and perfused at a rate of 0.5 ml/min, at 37 degrees C, for 40 min. Using immunoperoxidase and immunofluorescence techniques, strong reactivity towards anti-TLCK-trypsin antibody was demonstrated through out the enterocyte cytosol. The present data indicate that trypsin was absorbed by enterocytes, probably through a transcellular route.     

Topographical analysis of Schizolobium parahyba chymotrypsin inhibitor (SPCI) by atomic force microscopy

Atomic Force Microscopy (AFM) has been a useful tool for molecular surface analysis and to estimate topographical properties of proteins. Here we report a topographical study of a chymotrypsin inhibitor from Schizolobium parahyba seeds (SPCI) by AFM. The underlying structure of SPCI oligomers has been resolved in nanometer order resolution. SPCI oligomerize in hexagonal, ellipsoid, comet, pyramidal, and "Z" shaped. The hexagonal was the most observed oligomer shape.     

Eosinophil and mast cell expression in host skin during larval development of the human bot fly Dermatobia hominis

Eosinophils and mast cells in the skin of Wistar rats (Rattus norvegicus) infested with Dermatobia hominis larvae were quantified and analysed. Eosinophils in parasitised skin increased markedly until 10 days post-infestation (dpi) and then decreased up to 28 dpi, close to the point at which third stage larvae (L3) emerged from the host. In ascending order, the highest numbers of eosinophils were seen in rats at 1, 4, 28, 20, 15 and 10 dpi, corresponding to the first, (1 and 4) third (20 and 28) and second (10 and 15) instars. Except for 1 dpi, eosinophil numbers were significantly higher than those seen in control animals. Mast cell numbers were highest in early infestation (4 dpi), followed by those at 20 dpi. In increasing order, numbers of mast cells were greatest at 10, 28, 15, 1, 20 and 4 dpi, although significant differences with control animals were only seen at 10 and 28 dpi. Eosinophils and mast cells showed negative correlation only in animals with second instar larvae (10 and 15 dpi). Comparative analyses were also carried out after considering the skin into four distinct regions. The results suggest that the expression of both cell types, particularly eosinophils, is an important host response to infestation by D. hominis.