Differences between species in seed bank and vegetation helps to hold functional diversity in a floodable Neotropical savanna

种子库和植被物种之间的差异有助于保持新热带稀树草原的功能多样性 本研究的目的是量化种子库和建立的植被对物种组成、功能组成和多样性的贡献,并讨论这些差异对冲积平原植物群落更新和稳定性的影响。我们在巴西潘塔纳尔湿地的一个周期性洪水泛滥的稀树大草原上,在旱季和雨季对分布在5个地点的25个地块(10 m × 1 m)的1.5 m高度的地面覆盖植被和种子库进行了采样。采用出苗法对土壤种子库进行了评价。研究结果表明,种子库物种具有赋予群落更新的特征,而植被则具有稳定性特征。种子库的功能丰富度高于植被,而功能均匀度则低于植被。由于种子库和植被的植物特征不同,使得具有不同功能稳定性和更新特性的物种得以共存,这将有助于维持植物的功能多样性。这可能会让植物种群在应对干旱、火灾和洪水等不同的环境选择时更具有弹性。     

CCR2 and CCR5 genes polymorphisms in women with cervical lesions from Pernambuco,Northeast Region of Brazil: a case-control study

Polymorphisms in chemokine receptors play an important role in the progression of cervical intraepithelial neoplasia (CIN) to cervical cancer (CC). Our study examined the association of CCR2-64I (rs1799864) andCCR5-Δ32 (rs333) polymorphisms with susceptibility to develop cervical lesion (CIN and CC) in a Brazilian population. The genotyping of 139 women with cervical lesions and 151 women without cervical lesions for the CCR2-64I and CCR5-Δ32 polymorphisms were performed using polymerase chain reaction-restriction fragment length polymorphism. The individuals carrying heterozygous or homozygous genotypes (GA+AA) for CCR2-64I polymorphisms seem to be at lower risk for cervical lesion [odds ratio (OR) = 0.37, p = 0.0008)]. The same was observed for the A allele (OR = 0.39, p = 0.0002), while no association was detected (p > 0.05) with CCR5-Δ32 polymorphism. Regarding the human papillomavirus (HPV) type, patients carrying the CCR2-64Ipolymorphism were protected against infection by HPV type 16 (OR = 0.35, p = 0.0184). In summary, our study showed a protective effect ofCCR2-64I rs1799864 polymorphism against the development of cervical lesions (CIN and CC) and in the susceptibility of HPV 16 infection.     

Brazilian red propolis reduces orange-complex periodontopathogens growing in multispecies biofilms

This study investigated the antimicrobial effects of the ethanolic extract of Brazilian red propolis (BRP) on multispecies biofilms. A seven-day-old subgingival biofilm with 32 species was grown in a Calgary device. Biofilms were treated with BRP (1,600, 800, 400 and 200?μg ml^?1) twice a day for 1?min, starting from day 3. Chlorhexidine (0.12%) and dilution-vehicle were used as positive and negative controls, respectively. On day 7, metabolic activity and the microbial composition of the biofilms by DNA-DNA hybridization were determined. The viability data were analyzed by one-way ANOVA followed by Tukey’s post hoc, whereas the microbial composition data were transformed via BOX-COX and analyzed using Dunnett’s post hoc. BRP (1,600?μg ml^?1) decreased biofilm metabolic activity by 45%, with no significant difference from chlorhexidine-treated samples. BRP (1,600?μg ml^?1) and chlorhexidine significantly reduced levels of 14 bacterial species compared to the vehicle control. Taken together, BRP showed promising antimicrobial properties which may be useful in periodontal disease control.     

Effect of Bauhinia forficata extract in diabetic pregnant rats: maternal repercussions.

Bauhinia forficata, commonly known as "paw-of-cow", is widely used in Brazil folk medicine for the treatment of Diabetes mellitus. The purposes of present study were to determine the repercussions of diabetes on the defense system against oxidative stress in pregnant female rats and to characterize the influence of the treatment with Bauhinia forficata extract on the antioxidant system, glycemic control, hepatic glycogen, cholesterol, triglycerides, total proteins and lipids. Virgin female Wistar rats were injected with 40 mg/kg streptozotocin (STZ) before mating. Oral administration of an aqueous extract of Bauhinia forficata leaves was given to non-diabetic and diabetic pregnant rats in 3 doses: 500 mg/kg from 0 to 4th day of pregnancy, 600 mg/kg from 5th to 14th day and 1000 mg/kg from 15th to 20th day. All the females were killed on the day 21 of pregnancy. A maternal blood sample was collected by venous puncture and the maternal liver was removed for biochemical measurement. The diabetic pregnant rats presented hyperglycemia, hyperlipemia, hypertriglyceridemia, hypercholesterolemia, hyperuricemia, decreased determinations of reduced glutathione (GSH) and superoxide dismutase (SOD). Treatment with B. forficata extract did not interfere in the albumin, total protein and lipid, triglyceride, cholesterol and SOD determinations. Increased hepatic glycogen, decreased uric acid concentration and increased GSH activity was observed. This last fact suggests that the plant may have some action on antioxidant defense system. However, the demonstration of the active component present in B. forficata responsible for its antioxidant effect and the increase in hepatic glycogen deserve further investigation.     

Oxidative stress and diabetes in pregnant rats

A considerable amount of clinical and experimental evidence now exists suggesting the involvement of free radical-mediated oxidative processes in the pathogenesis of diabetic complications. If the diabetic state is associated with a generalized increase in oxidative stress, it might well be reflected in the alterations in embryonic and fetal development during pregnancy. In the present study, incidence of the malformed fetuses, biochemical parameters and antioxidant system activity of streptozotocin (STZ)-induced diabetic pregnant rats was investigated and the results obtained were compared with those of the control group (non-diabetic). Virgin female Wistar rats were injected with 40 mg/kg streptozotocin (STZ) before mating. All the females were killed on Day 21 of pregnancy and the fetuses were analyzed. A maternal blood sample was collected by venous puncture and the maternal liver was removed for biochemical measurement. The diabetic dams presented hyperglycemia, hyperlipemia, hypertriglyceridemia, hypercholesterolemia, hyperuricemia, decreased reduced glutathione (GSH), hepatic glycogen and superoxide dismutase (SOD) determinations. There was an increased incidence of skeletal and visceral malformation in fetuses from diabetic rats. Our findings suggest that oxidative stress occurs in the diabetic pregnant state, which might promote maternal homeostasis alterations. These diabetic complications might be a contributory factor to conceptus damage causing embryonic death (abortion/miscarriage) or the appearance of malformations in the fetuses of diabetic dams. Antioxidant treatment of women with diabetes may be important in future attempts to prevent congenital malformations.