Antibothropic action of Casearia sylvestris Sw. (flacourtiaceae) extracts

Casearia sylvestris Sw., popularly known in Brazil as `guacatonga`, has been used as antitumor, antiseptic, antiulcer, local anaesthetic and healer in folk medicine. Snakebite envenomation by Bothrops jararacussu (Bjssu) constitutes a relevant public health hazard capable of inducing serious local damage in victims. This study examined the pharmacological action of apolar and polar C sylvestris leaf extracts in reverting the neuromuscular blockade and myonecrosis, which is induced by Bjssu venom and its major toxin bothropstoxin-I on the mouse phrenic nerve-diaphragm preparations. The polar methanol extract (ME) was by far the most efficacious. ME not only prevented myonecrosis and abolished the blockade, but also increased ACh release. Such facilitation in neuromuscular transmission was observed with ME alone, but was accentuated in preparations incubated with ME plus venom or toxin. This established synergy opens an interesting point of investigation because the venom or toxin in contact with ME changes from a blocking to a facilitating effect. It is suggested that rutin, known to have potent antioxidant properties, and one of the components present in the ME, could have a role in the observed effects. Since commercial rutin did not reproduce the ME effects, it is likely that a rutin-containing phytocomplex is neutralizing the bothropic envenoming effects. Copyright (C) 2008 John Wiley & Sons, Ltd.

Short-Term Effects of Duodenocecostomy on Body Weight, Glucose Absorption, Serum Components, and Intestinal Histopathology in Four Normal Horses

The objective of this study was to evaluate duodenocecostomy in horses performed through a ventral midline laparotomy and report its influence oil body weight, glucose absorption, serum components, and characteristics of jejunum, cecum, and large colon histology. Four horses were submitted to the duodenocecostomy technique through a ventral midline laparotomy with animals in dorsal recumbency under inhalation anesthesia, followed by abdominal exploration. A side-to-side anastomosis was performed between the duodenojejunal flexure and the base of the cecum with two simple continuous suture lines of the serosal and muscular layers. The size of the opening created was approximately 2 cm in diameter. The mucosa layer was not Sutured. After 30 days, animals were submitted to a second laparotomy to check the patency of the duodenocaecal fistula. During both laparotomy procedures, excisional biopsies of different segments of the gastrointestinal tract were performed. Information on physical examination findings, results of hematologic and histopathologic evaluations, and oral glucose absorption test were recorded. The horses did not have significant weight loss from baseline, and absorption curve of glucose did not significantly vary from baseline. Only triglycerides had significant alterations. Histologic evaluation of jejunum, cecum, and large colon did not show alterations of intestinal structure and morphology. We concluded that the proposed technique, principally in relation to the fistula size and not suturing the mucosa layer, allowed partial or total Occlusion of the fistulae without the necessity of a second surgery and avoided the permanent bypass of ingesta and weight loss.

Use of lignin extracted from different plant sources as standards in the spectrophotometric acetyl bromide lignin method

A nongravimetric acetyl bromide lignin (ABL) method was evaluated to quantify lignin concentration in a variety of plant materials. The traditional approach to lignin quantification required extraction of lignin with acidic dioxane and its isolation from each plant sample to construct a standard curve via spectrophotometric analysis. Lignin concentration was then measured in pre-extracted plant cell walls. However, this presented a methodological complexity because extraction and isolation procedures are lengthy and tedious, particularly if there are many samples involved. This work was targeted to simplify lignin quantification. Our hypothesis was that any lignin, regardless of its botanical origin, could be used to construct a standard curve for the purpose of determining lignin concentration in a variety of plants. To test our hypothesis, lignins were isolated from a range of diverse plants and, along with three commercial lignins, standard curves were built and compared among them. Slopes and intercepts derived from these standard curves were close enough to allow utilization of a mean extinction coefficient in the regression equation to estimate : lignin concentration in any plant, independent of its botanical origin. Lignin quantification by use of a common regression equation obviates the steps of lignin extraction, isolation, and standard curve construction, which substantially expedites the ABL method. Acetyl bromide lignin method is a fast, convenient analytical procedure that may routinely be used to quantify lignin.

Modeling the Competition Between Viruses in a Complex Plant-Pathogen System

In this article, we propose a mathematical model that describes the competition between two plant virus strains (MAV and PAV) for both the host plant (oat) and their aphid vectors. We found that although PAV is transmitted by two aphids and MAV by only one, this fact, by itself, does not explain the complete replacement of MAV by PAV in New York State during the period from 1961 through 1976; an interpretation that is in agreement with the theories of A. G. Power. Also, although MAV wins the competition within aphids, we assumed that, in 1961, PAV mutated into a new variant such that this new variant was able to overcome MAV within the plants during a latent period. As shown below, this is sufficient to explain the swap of strains; that is, the dominant MAV was replaced by PAV, also in agreement with Power`s expectations.

Lp95, a novel leptospiral protein that binds extracellular matrix components and activates e-selectin on endothelial cells

Objectives: The study of a predicted outer membrane leptospiral protein encoded by the gene LIC12690 in mediating the adhesion process. Methods: The gene was cloned and expressed in Escherichia coli BL21 (SI) strain by using the expression vector pAE. The recombinant protein tagged with N-terminal hexahistidine was purified by metal-charged chromatography and used to assess its ability to activate human umbilical vein endothelial cells (HUVECs). Results: The recombinant leptospiral protein of 95 kDa, named Lp95, activated E-selectin in a dose-dependent fashion but not the intercellular adhesion molecule 1 (ICAM-1). In addition, we show that pathogenic and non-pathogenic Leptospira are both capable to stimulate endothelium E-selectin and ICAM-1, but the pathogenic L. interrogans serovar Copenhageni strain promotes a statistically significant higher activation than the non-pathogenic L. biflexa serovar Patoc (P < 0.01). The Lp95 was identified in vivo in the renal tubules of animal during experimental infection with L. interrogans. The whole Lp95 as well as its fragments, the C-terminal containing the domain of unknown function (DUF), the N-terminal and the central overlap regions bind laminin and fibronectin ECM molecules, being the binding stronger with the DUF containing fragment. Conclusion: This is the first leptospiral protein capable to mediate the adhesion to ECM components and the activation of HUVECS, thus suggesting its participation in the pathogenesis of Leptospira. (C) 2009 The British Infection Society. Published by Elsevier Ltd. All rights reserved.

Cytotoxic effects of butanolic extract from Pfaffia paniculata (Brazilian Ginseng) on cultured human breast cancer cell line MCF-7

Roots of Pfaffia paniculata have been well documented for multifarious therapeutic values and have also been used for cancer therapy in folk medicine. This study has been performed in a human breast tumor cell line, the MCF-7 cells. These are the most commonly used model of estrogen-positive breast cancer, and it has been originally established in 1973 at the Michigan Cancer Foundation from a pleural effusion taken from a woman with metastatic breast cancer. Butanolic extract of the roots of P. paniculata showed cytotoxic effect MCF-7 cell line. as determined with crystal violet assay, cellular death with acridine orange/ethidium bromide staining, and cell proliferation with immunocytochemistry of bromodeoxyuridine (BrdU). Subcellular alterations were evaluated by electron microscopy. Cells treated With butanolic extract showed degeneration of cytoplasmic components and profound morphological and nuclear alterations. The results show that this butanolic extract indeed presents cytotoxic substances, and its fractions merit further investigations. (C) 2008 Elsevier GmbH. All rights reserved.

A note on averting goats to a toxic but palatable plant, Leucaena leucocephala

Conditioned taste aversions are a useful tool to reduce livestock consumption of toxic plants. The forage legume Leucaena leucocephala (leucaena) is both toxic and palatable. The objective of this study was to determine if goats could be aversively conditioned to avoid leucaena. Adult and juvenile female goats, naive to leucaena, were divided into control and averted groups. Animals were exposed to leucaena, and time(s) spent eating leucaena was measured. During initial conditioning with lithium chloride (LiCl), averted goats spent less time eating leucaena (P < 0.05) than did controls. The averted groups maintained their reduced consumption (P < 0.05) of leucaena compared to controls during open field tests when goats could chose between leucaena and sugar cane. In final tests (two tests per week), averted goats reduced (P < 0.05) the amount of time they spent eating leucaena compared to control animals, but the aversion eventually extinguished. Aversive conditioning was successful in greatly reducing, but not entirely eliminating goats` consumption of leucaena. (C) 2007 Elsevier B.V. All rights reserved.

Immunohistochemical study of stromal and vascular components of tonsillar polyps: high endothelial venules as participants of the polyp`s lymphoid tissue

Tonsillar polyps are nonneoplastic lesions usually composed of variable amounts of lymphoid and vascular and connective tissues. All of them are generally assumed to be hamartomatous proliferations, but the profile of vascular and connective components has yet to be explored. The vascular system of the tonsils is complex and includes highly specialized structures (i.e., high endothelial venules (HEVs)) involved in lymphocyte homing into lymphoid tissues. In 14 tonsillar polyps and 26 control tonsils, an immunohistochemical study was performed using CD34 (blood vessels and HEVs), MECA-79 (HEVs), D2-40 (lymphatic vessels), Ki-67, collagens I and III, fibronectin, and tenascin-C. The polyps showed increased total lymphatic area, whereas the number of blood vessels and lymphatics and the blood vascular area did not differ significantly from those of control tonsils. Rare Ki-67+ endothelial cells were found. In the polyps, we detected, possibly for the first time, HEVs amid lymphoid tissue, and that the amount of the latter correlated positively with HEV density. The polyps also presented lesser amounts of fibronectin and collagens I and III than in normal tonsils, which were distributed in a disorganized fashion. Tenascin-C expression was uncommon in the polyps and control tonsils. Tonsillar polyps are composed of disorganized connective tissue and lymphatic channels which can be considered hamartomatous proliferations. However, the lymphoid component is possibly reactive due to its relationship with the HEVs. The highly differentiated phenotype of the HEVs and their complex biology are not in agreement with what would be expected for a component of hamartomatous nature.

Esthetic Analysis of Gingival Components of Smile and Degree of Satisfaction in Individuals With Cleft Lip and Palate

Objective: To evaluate soft tissue characteristics in individuals with cleft lip and palate and the degree of satisfaction of these individuals after rehabilitation. Setting: Hospital for Rehabilitation of Craniofacial Anomalies, Brazil. Patients: Forty-five individuals with repaired complete unilateral cleft lip and palate, aged 15 to 30 years. Interventions: One hundred thirty-five frontal facial photographs were obtained at rest and in natural and forced smile. Specialists in periodontics evaluated the soft tissue characteristics. Both patients and specialists evaluated the smiles and scored them as esthetically unpleasant, acceptable, or pleasant. Main Outcome Measures: Comparison of the cleft area with the contralateral region was performed for evaluation of soft tissue. The results of the degree of satisfaction with smile were expressed as percentages and means. The findings between patients and periodontists experienced or inexperienced with cleft care were compared. Results: Statistically significant differences were observed for alveolar process deficiency and absence of papilla in the esthetic area between groups (p < .05). Results show 84.4% of individuals considered their smile as esthetically pleasant. Specialists in periodontics of both groups scored the natural smile and forced smile as esthetically acceptable. There was a statistically significant difference in the mean of patients compared with both groups of specialists in periodontics (p < .05). Conclusions: Evaluation and knowledge of the soft tissue characteristics is extremely important for successful rehabilitation. The esthetic values and degree of patient satisfaction are essential for treatment success, since smile reconstruction should be esthetically pleasant to the patient.

Influences of surface and solvent on retention of HEMA/mixture components after evaporation

Objectives: This study examined the retention of solvents within experimental HEMA/solvent primers after two conditions for solvent evaporation: from a free surface or from dentine surface. Methods: Experimental primers were prepared by mixing 35% HEMA with 65% water, methanol, ethanol or acetone (v/v). Aliquots of each primer (50 mu l) were placed on glass wells or they were applied to the surface of acid-etched dentine cubes (2 mm x 2 mm x 2 mm) (n = 5). For both conditions (i.e. from free surface or dentine cubes), change in primers mass due to solvent evaporation was gravimetrically measured for 10 min at 51% RH and 21 degrees C. The rate of solvent evaporation was calculated as a function of loss of primers mass (%) over time. Data were analysed by two-way ANOVA and Student-Newman-Keuls (p < 0.05). Results: There were significant differences between solvent retention(%) and evaporation rate (%/min) depending on the solvent present in the primer and the condition for evaporation (from free surface or dentine cubes) (p < 0.05). For both conditions, the greatest amount of retained solvent was observed for HEMA/water primer. The rate of solvent evaporation for HEMA/acetone primer was almost 2- to 10-times higher than for HEMA/water primer depending whether evaporation occurred, respectively, from a free surface or dentine cubes. The rate of solvent evaporation varied with time, being in general highest at the earliest periods. Conclusions: The rate of solvent evaporation and its retention into HEMA/solvent primers was influenced by the type of the solvent and condition allowed for their evaporation. (C) 2009 Elsevier Ltd. All rights reserved.