Profile of Maytenus aquifolium action over free radicals and reactive oxygen species

Reactive oxygen species (ROS) and free radical species have been implicated in initiating, accompanying or causing many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Maytenus species have long been used, in several countries, as traditional medicines against gastric ulcers, dyspepsia and others gastric problems and for their anti-inflammatory properties. In this study, Maytenus aquifolium (Celastraceae) root bark ethanol extract was assessed for its ability to scavenge free radicals and reactive oxygen species. The results were expressed as percentage inhibition of the active species. The extract was efficient against studied reactive species: DPPH radical (obtained inhibition = 35.5 ± 1.3 %), ABTS.+ (IC50 = 0.0036 ± 0.0003 mg/mL), HOCl (IC50 = 0.002 ± 0.0001 mg/mL), O2 .- (obtained inhibition = 36.0 ± 2.1 %), and NO. (obtained inhibition = 18.3 ± 0.4 %). Uniterms Oxidant species Free radicals Maytenus aquifolium Oxidative damage.

Tuberculose e o estudo molecular da sua epidemiologia

Systems that can distinguish epidemiologically-related Mycobacterium tuberculosis strains from unrelated ones are extremely valuable. Molecular biology techniques have allowed a great deal of information to be acquired about the infectious disease tuberculosis (TB) that was very hard or impossible to obtain by conventional epidemiology. A typing method based on bacterial DNA genome differences, known as RFLP (restriction fragment length polymorphism), is widely used to discriminate strains in the epidemiologic study of TB. However, RFLP is laborious and there is a tendency to replace it by other methods. Thus, other DNA sequences have been employed as epidemiological markers, as in Spoligotyping, a fast technique based on PCR followed by differential hybridization of amplified products. The polymorphism observed among different isolates is probably the product of strain-dependent recombination. MIRU (mycobacterial interspersed repetitive unit) typing is a reproducible and fast assay, involving the generation of genotypes based on the study of 12 loci containing VNTRs (variable-number tandem repeats) in strains of the M. tuberculosis complex. It compares strains from different geographic areas and allows the movement of individual lineages to be tracked, as in RFLP. This approach enables a greater number of isolates to be analyzed, leading to the identification of a larger number of foci of transmission within the population and thus to improved ways of slowing the progress of the disease.

Espectro de agentes etiológicos associados a surtos de doenças transmitidas por alimentos em núcleos receptores turísticos de três regiões geográficas do Estado de São Paulo

Foodborne and waterborne diseases are spread by the consumption of food or water contaminated with bacteria and/or their toxins, viruses, parasites or chemicals. The aim of the research reported here was to establish the spectrum of etiologic agents of foodborne outbreaks at 15 tourist resorts in three geographic regions of the State of Sao Paulo (Brazil). The study was based on the cases reported to the Epidemic Surveillance Center (CVE) of the Public Health Authority of the State of São Paulo (SES), from 2002 to 2005. The tourist centers were chosen at random in three regions of the state (Capital, Interior and Coast) and offered the following attractions: events, agribusiness, cultural history, shopping, town center, gastronomy, health and leisure, sun and sea. Among the bacteria, the results showed that Salmonella spp. were most frequently associated with outbreaks, followed by Shigella spp., enterotoxigenic Escherichia coli, Staphylococcus aureus, Clostridium perfringens, Bacillus cereus and Campylobacter spp. Viruses (Rotavirus and Hepatitis A) played a part in many of the cases, while the frequency of parasites and worm infestations was low in the foodborne disease outbreaks at these resorts. The mixed foods (rice, beans, liver, potatoes, barbecue, juice), fish and poultry were the three commonest vehicles implicated in the outbreaks.

Compostos fenólicos e atividade antioxidante de Leiothrix flavescens (Bong.) Ruhland (Eriocaulaceae)

This paper describes a chemical investigation (by high-speed counter-current chromatography) of an extract in methanol of the capitula (flower-heads) of the endemic Brazilian herb Leiothrix flavescens (Bong.) Ruhland (Eriocaulaceae). Fractionation of this extract by preparative chromatography and identification of the isolated compounds by spectrometric methods (IR, UV, ESI-MS, NMR) led to the identification of flavones (apigenin, luteolin and 6-methoxyluteolin) and 1,3-di-O-feruloyl glycerol. The antioxidant activity of the extract was determined by DPPH reduction and the total phenolic content by the Folin-Ciocalteau assay. It was found that the methanolic extract of L. flavescens possesses strong antioxidant activity. Additionally, the chemical profile provided useful data for a discussion of the taxonomy of the Eriocaulaceae.

Diferenciação hepatocítica de células-tronco mesenquimais da medula óssea humana

Some recent articles have reported that mesenchymal stem cells (MSCs) can be induced to express hepatocyte markers by transplanting them into animal models of liver damage, or by in vitro culture with growth factors and cytokines. In this study, the aim is to evaluate the behavior of MSCs subjected to induction of hepatocyte differentiation. The MSCs were isolated from the bone marrow of 4 normal donors, characterized and subjected to both in vitro and in vivo induction of hepatocyte differentiation. The in vitro induced cells showed morphological changes, acquiring hepatocyte-like features. However, the immunophenotype of these cells was not modified. The induced cells exhibited no increase in albumin, cytokeratin 18 or cytokeratin 19 transcripts, when analyzed by real-time RT-PCR. The expression of albumin, cytokeratin 18 and alpha fetoprotein was also unchanged, according to immunofluorescence tests. In vivo, the MSC demonstrated a potential to migrate to damaged liver tissue in immunodeficient mice. Taken together, the results suggest that bone marrow MSCs are incapable of in vitro differentiation into hepatocytes by the approach used here, but are capable of homing to damaged hepatic tissue in vivo, suggesting a role for them in the repair of the liver. This contribution to tissue repair could be associated with a paracrine effect exerted by these cells.

Vascular hyporeactivity to angiotensin II induced by Escherichia coli endotoxin is reversed by Nω-Nitro-L-Arginine, an inhibitor of nitric oxide synthase

Septic shock or sepsis is reported to be one of the major causes of death when followed by systemic infectious trauma in humans and other mammals. Its development leads to a large drop in blood pressure and a reduction in vascular responsiveness to physiological vasoconstrictors which, if not contained, can lead to death. It is proposed that this vascular response is due to the action of bacterial cell wall products released into the bloodstream by the vascular endothelium and is considered a normal response of the body's defenses against infection. A reduction in vascular reactivity to epinephrine and norepinephrine is observed under these conditions. In the present study in rats, the aim was to assess whether those effects of hypotension and hyporeactivity are also related to another endogenous vasoconstrictor, angiotensin II (AII). We evaluated the variation in the power of this vasoconstrictor over the mean arterial pressure in anesthetized rats, before and after the establishment of hypotension by Escherichia coli endotoxin (Etx). Our results show that in this model of septic shock, there is a reduction in vascular reactivity to AII and this reduction can be reversed by the inhibitor of nitric oxide synthase, Nω-Nitro-L- Arginine (NωNLA). Our results also suggest that other endogenous factors (not yet fully known) are involved in the protection of rats against septic shock, in addition to the L-arginine NO pathway.

Razão de prevalências: Alcoolismo nas diferentes regiões geográficas do Brasil segundo o sexo

The present study applies a method of prevalence analysis to data obtained in two nationwide household surveys on alcohol use during life and dependence, for each of the sexes. The ratios of prevalences (R), for the lifetime alcohol use and dependence rates, between the two genders in the various Brazilian macro-regions, were calculated together with their respective 95% confidence intervals. It was found that lifetime use, both in 2001 and in 2005, was significantly greater in Brazilian males in all geographical regions. In 2001, the population of the North (male and female) had a higher rate of alcohol consumption than that in the Brazilian population as a whole and that in the Southeast. Dependence on the consumption of alcoholic drinks in 2001 and in 2005 was greater in the male sex, but similar among the various regions studied. It can be concluded that this method of analyzing the data on alcoholism could be of great use in assessing its magnitude and importance in terms of public health.

Potencial tóxico dos alginatos para uso odontológico

Alginate or irreversible hydrocolloid is one the most accepted and frequently employed impression materials in dental practice. Substances like zinc, cadmium, lead silicate and fluorides, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. Some brands of alginate have been reported to contain potentially toxic fluorides and metals such as cadmium, lead and zinc silicates, either singly or combined. Consequently, special care should be taken while preparing of these materials. It is necessary to monitor potentially toxic chemicals and metals in the alginates continually to avoid contamination of dental professionals and patients. In this review, alginates used in dentistry are analyzed for potential toxicity.

Antimycobacterial activity of some Brazilian indigenous medicinal drinks

Tuberculosis (TB) is a very serious problem worldwide and the increasing number of multiple drugs resistant TB cases makes the search for new anti-TB drugs an urgent need. Indigenous knowledge about the use of native plants to treat illnesses has contributed to the discovery of new medicines. In this study, the antimycobacterial activity of seven medicinal drinks was assessed: Ananas sativus (hydroalcoholic fruit extract), Aristolochia triangularis (aqueous and hydroalcoholic leaf, root and stem extracts), Bromelia antiacantha (hydroalcoholic fruit extract), Stryphnodendron adstringens (hydroalcoholic bark extract), Tabebuia ovellanedae (hydroalcoholic bark extract), Vernonia polyanthes (hydroalcoholic root extract), all used by the Vanuíre indigenous community in the treatment of respiratory diseases. The activity was evaluated by using a time-to-kill assay, in which Mycobacterium tuberculosis H37Rv was cultured on Löwenstein-Jensen medium, after thirty minutes, one, three, six, twelve and twenty-four hours contact of the bacteria with each drink. Within half to one hour contact, the hydroalcoholic drinks of A. triangularis, S. adstringens, T. ovellanedae and V. polyanthes reduced the bacterial growth by 2 orders of magnitude in CFU/mL, and all bacterial growth was absent after three hours contact. In contrast, no mycobactericidal effect was detected in the aqueous extract of A. triangularis or in the hydroalcoholic beverages of A. sativus and B. antiacantha, even after twenty-four hours contact.

Plesiomonas shigelloides: Um enteropatógeno emergente?

Plesiomonas shigelloides is a Gram-negative rod-shaped bacterium, of the family Enterobacteriaceae, which has been isolated from freshwater and salt water, freshwater fish, shellfish and many species of animals. Most human P. shigelloides infections are suspected to be waterborne. The organism can be found in untreated water used as drinking water, in recreational water, or in water used to rinse food that is consumed without cooking or heating. The ingestion of P. shigelloides does not always cause illness in the host animal, and the organism may be present temporarily as a transient, noninfectious member of the intestinal flora. It has been isolated from the stools of patients with diarrhea,but it is also sometimes isolated from healthy individuals. P. shigelloides has been implicated in gastroenteritis, usually a self-limiting disease characterized by fever, chills, abdominal pain, nausea, diarrhea or vomiting; in severe cases the diarrhea may be yellowish-green, foamy and tinged with blood. The bacteria may also cause extra-intestinal infection. Furthermore, it can produce toxins and may be invasive. The evidence in favor of considering P. shigelloides as an enteropathogen is not totally convincing. Although it has been isolated from patients with diarrhea and incriminated in some outbreaks involving contaminated water and food, it was not possible, in many P. shigelloides samples associated with gastrointestinal infections, to identify a definite mechanism of virulence.

Produção deficiente de citocinas Th1 em camundongos BALB/c jovens

O objetivo do presente estudo foi comparar a produção de IFN-γ, IL-12 e IL-4 entre camundongos jovens (5, 12 e 19 dias de idade) e adultos (30 dias de idade). As avaliações foram feitas por estimulação, in vitro, de células esplênicas com Concanavalina A (ConA) , Staphylococcus aureus (S. aureus) e lipopolissacarídeo (LPS). Diferentes concentrações de cada estímulo foram testadas e os sobrenadantes das culturas foram coletados após 48 horas de incubação e as concentrações de IFN-γ, IL-12 e IL-4 determinadas por ELISA. Células de camundongos jovens e adultos produziram níveis igualmente elevados de IFN-γ após estímulo com ConA. Somente animais adultos produziram IFN-γ em resposta ao estímulo com S. aureus. Em culturas estimuladas com LPS, a produção desta citocina foi baixa e similar nos animais jovens e significativamente elevada nos animais adultos. Somente células de animais adultos estimuladas com S. aureus foram capazes de produzir IL-12. O único estímulo capaz de induzir níveis detectáveis de IL-4 foi ConA, sendo que estes níveis foram mais elevados nos animais com 12 e 19 dias de idade em comparação com animais neonatos e adultos. A diminuição das doses ótimas dos estímulos não mudou o perfil de produção de cada citocina nos animais jovens. Estes resultados permitem concluir que a idade afeta a produção de citocinas: ocorre maior produção de IL-4 em camundongos jovens e maior produção de IL-12 e IFN-γ em animais adultos. Estas informações são importantes devido ao papel destas citocinas na polarização das respostas imunes nos sentidos Th1 e Th2. Palavras-chave: camundongo; citocina; interferon-gama; interleucina-4; interleucina-12.

Efeito do praziquantel incorporado a lipossomas nos diferentes estágios de desenvolvimento dos ovos de Schistosoma mansoni

Mansonian schistosomiasis is caused by an intravascular digenetic trematode Schistosoma mansoni. Praziquantel (PZQ) and oxamniquine (OXA) are the drugs of choice for the treatment of this disease. However, both drugs are subject to some limitations in their action and cases of tolerance and resistance have been reported. Moreover, tolerance and resistance cases have been reported. For this reason, there is an urgent need for research on new alternatives aimed at improving the action of existing drugs, such as the incorporation of these drugs into liposomes. In this study, the efficiency of action of liposome- encapsulated praziquantel (lip.PZQ) on oviposition by S. mansoni, strain BH, was assessed in Mus musculus mices (SPF Swiss mice). Four PZQ and lip.PZQ doses (47; 60; 250 e 300mg/kg) were tested. Some mice were treated 30 days post-infection and others after 45 days. The oogram analyses showed that the most effective lip.PZQ treatment was 300mg/kg dose given on the 45th day post infection, which reduced the number of S. mansoni eggs per gram of tissue.

Ocorrência de infecção urinária em pacientes de um hospital universitário

Infection in hospitals is a serious problem for the Public Health System. It is responsible for the increasing number of hospital deaths, as well as the longer time patients may have to stay in hospital, raising the costs of confinement more and more. The most common hospital infection is urinary tract infections (UTI), the use of the urinary catheter being the main risk factor. The aim of this study was to evaluate the profile of UTI among hospitalized patients in a University Hospital in Brazil, from October to December 2003. Out of 271 samples of urine checked, 51 were positive, 27 of these from patients having community-acquired UTI and 24 whose infection originated in the hospital. The community-acquired UTIs were more frequent in female patients (63%). The highest incidence of infection was caused by Escherichia coli (74%), especially in patients aged from 0 to 15 (37%). The episodes of hospital-acquired infection happened, in the main, in male patients aged above 50 (68%) who were using a lasting vesical catheter; in this group of patients the infection was frequently caused by E. coli (29.1%) and Klebsiella spp. (29.1%). E. coli and Klebsiella pneumoniae exhibited strong resistance (62.5%) to trimethoprim-sulfamethoxazole, as well as to ampicillin, showing that these drugs should not be used to cure UTIs in this institution.

Bioprospecção de atividade antioxidante e antimicrobiana da casca de Stryphnodendron adstringens (Mart.) Coville (Leguminosae-Mimosoidae)

The aim of this work was to evaluate the class of secondary metabolites responsible for the antioxidant and antimicrobial activities of bark extracts of Stryphnodendron adstringens (Mart.) Coville (Leguminosae-Mimosoidae), a plant widely used in folk medicine in Brazil. Extracts of the bark were prepared with 50% ethanol, 70% ethanol, acetone:water (7:3, v/v) and chloroform. Antioxidant activity was prospected by spraying thin-layer chromatographs of the extracts with 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and measuring the DPPH radical scavenging capacity by spectrophotometry. Antibacterial activity was revealed by the agar diffusion method and bioautography. TLC spots assigned to tannins in the polar extracts showed antioxidant activity by DPPH radical scavenging and the chloroform extract showed the least scavenging activity. Antimicrobial activity was indicated by the bacterial growth inhibition haloes around polar extracts and bioautography showed activity in the TLC spots assigned to tannins. It was concluded that polar extracts of the bark of S. adstringens possessed antioxidant and antimicrobial activities which were due to secondary metabolite derived from the tannin class, which are the main constituent of these bark extracts, according to the literature.

Síntese e modelagem molecular do novo derivado indolinônico como candidato a antiinflamatório COX-2 seletivo

Anti-inflammatory drugs are known to be the most widely-marketed drugs in the world, despite their serious side effects, mainly on the gastrointestinal tract. Thus, there are constant efforts to discover new prototypes with improved therapeutic activity and safety for the patient. Since the advent of the computational chemistry, the theoretical study of the physiological behavior of a new compound and hence an understanding of its supposed mechanism of action have been made a lot more accessible. Thus, molecule-receptor mathematical modeling was applied to compound I (1-(2,6-dichlorophenyl)indolin-2-one), to predict theoretically its ability to inhibit, selectively, the COX-2 isoform of prostaglandin endoperoxide synthase (PGHS-2), and the best positions to introduce chemical groups and to make molecular modifications.