Creation of forest edges has a global impact on forest vertebrates.

Forest edges influence more than half of the world's forests and contribute to worldwide declines in biodiversity and ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species. We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200-400 m from sharp high-contrast forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to restructure ecological communities on a global scale.

What is the impact of surgical site infection on graft function in kidney transplant recipients?

The impact of surgical site infections (SSIs) on graft function in kidney transplant recipients is controversial. We conducted a matched case-control study (1:1 ratio) between April 2001 and December 2004 in a Brazilian cohort of kidney transplant recipients. The epidemiological and clinical characteristics of SSIs were described based on chart review. The impact on graft function was assessed by comparing serum creatinine measurements and creatinine clearance up to 18 months after transplantation with analysis of variance model. Among 1939 kidney transplants, 120 patients with 145 SSIs were enrolled. Most wound infections were superficial (73.1%). The mortality rate was 0.8%. No impact on graft function was detected. In conclusion, accurate identification of SSIs may have resulted in shorter hospitalization periods, but they had no impact on graft function up to 18 months post transplantation.

Quantifying the biodiversity value of tropical primary, secondary, and plantation forests.

Biodiversity loss from deforestation may be partly offset by the expansion of secondary forests and plantation forestry in the tropics. However, our current knowledge of the value of these habitats for biodiversity conservation is limited to very few taxa, and many studies are severely confounded by methodological shortcomings. We examined the conservation value of tropical primary, secondary, and plantation forests for 15 taxonomic groups using a robust and replicated sample design that minimized edge effects. Different taxa varied markedly in their response to patterns of land use in terms of species richness and the percentage of species restricted to primary forest (varying from 5% to 57%), yet almost all between-forest comparisons showed marked differences in community structure and composition. Cross-taxon congruence in response patterns was very weak when evaluated using abundance or species richness data, but much stronger when using metrics based upon community similarity. Our results show that, whereas the biodiversity indicator group concept may hold some validity for several taxa that are frequently sampled (such as birds and fruit-feeding butterflies), it fails for those exhibiting highly idiosyncratic responses to tropical land-use change (including highly vagile species groups such as bats and orchid bees), highlighting the problems associated with quantifying the biodiversity value of anthropogenic habitats. Finally, although we show that areas of native regeneration and exotic tree plantations can provide complementary conservation services, we also provide clear empirical evidence demonstrating the irreplaceable value of primary forests.

Frequency of Werner helicase 1367 polymorphism and age-related morbidity in an elderly Brazilian population.

Werner syndrome (WS) is a premature aging disease caused by a mutation in the WRN gene. The gene was identified in 1996 and its product acts as a DNA helicase and exonuclease. Some specific WRN polymorphic variants were associated with increased risk for cardiovascular diseases. The identification of genetic polymorphisms as risk factors for complex diseases affecting older people can improve their prevention, diagnosis and prognosis. We investigated WRN codon 1367 polymorphism in 383 residents in a district of the city of São Paulo, who were enrolled in an Elderly Brazilian Longitudinal Study. Their mean age was 79.70 +/- 5.32 years, ranging from 67 to 97. This population was composed of 262 females (68.4%) and 121 males (31.6%) of European (89.2%), Japanese (3.3%), Middle Eastern (1.81%), and mixed and/or other origins (5.7%). There are no studies concerning this polymorphism in Brazilian population. These subjects were evaluated clinically every two years. The major health problems and morbidities affecting this cohort were cardiovascular diseases (21.7%), hypertension (83.7%), diabetes (63.3%), obesity (41.23%), dementia (8.0%), depression (20.0%), and neoplasia (10.8%). Their prevalence is similar to some urban elderly Brazilian samples. DNA was isolated from blood cells, amplified by PCR and digested with PmaCI. Allele frequencies were 0.788 for the cysteine and 0.211 for the arginine. Genotype distributions were within that expected for the Hardy-Weinberg equilibrium. Female gender was associated with hypertension and obesity. Logistic regression analysis did not detect significant association between the polymorphism and morbidity. These findings confirm those from Europeans and differ from Japanese population.

Evaluating an AIDS sexual risk reduction program for young adults in public night schools in São Paulo, Brazil.

OBJECTIVES: To describe sexual risk for HIV infection among adult night school students in São Paulo, Brazil, and to evaluate the effect of an HIV/AIDS prevention workshop to reduce sexual risk. SUBJECTS AND METHODS: A longitudinal study was conducted among four demographically similar public night schools in the inner city of São Paulo. Schools were randomized into intervention and control conditions. Of 394 young adults who took part in the baseline survey, 304 (77%) completed a postintervention questionnaire. INTERVENTIONS: In a workshop consisting of four sessions of 3 h each, the students discussed AIDS symbolism, the impact of AIDS on their lives, risk perception, the way in which sexual norms shape knowledge and attitudes, AIDS-related knowledge, reproduction and sexual pleasure, and condom use negotiation. We fostered community-building through AIDS training courses for teachers in the schools, peer support programs and public events. RESULTS: At baseline, 87% had been sexually active at some time and 76% had had sex in the past 6 months. Among those who reported vaginal intercourse and/or anal intercourse, condom use was low. The workshops were positively process-evaluated and supported by the community, the students, their teachers and their parents. We obtained statistically significant effects from the workshops for females only, who reported improved communication with partners about sex and AIDS and less unprotected sex with non-monogamous partners after the intervention. CONCLUSION: These data show that the sexual risk of HIV infection can be lowered when Brazilian disenfranchized communities support AIDS prevention workshops. Even more impressive results may be achieved if the need to address socioeconomic obstacles and gendered sexual roles is emphasized through further long-term community development programs.

Age-associated mosaicism and polyploidy in Down's syndrome.

Age-related increases in the frequencies of cells with chromosome 21 loss and of polyploid cells were documented in short-term peripheral blood lymphocyte cultures from 54 patients with Down's syndrome (DS), ages 0 to 48 years. The polyploid data, together with previous work from this laboratory with non-DS subjects, suggest that this may be a useful indicator of aging in lymphocytes.

CFC index for the diagnosis of cardiofaciocutaneous syndrome.

Controversy exists concerning the delineation of cardiofaciocutaneous syndrome (CFC). Many authors have attempted to establish syndrome traits for CFC, but to date none are pathognomonic or obligatory. We have created a clinical and objective method, called the CFC index, for CFC diagnosis. This method also differentiates CFC from Noonan syndrome and Costello syndrome, CFC's main differential diagnosis. We propose the use of the CFC index for the confirmation of CFC diagnosis and to differentiate CFC from other phenotypically similar genetic conditions, while molecular studies are still in progress.

Relation between height and clinical course in Duchenne muscular dystrophy.

We have evaluated the relation between height and rate of clinical progression in boys with Duchenne muscular dystrophy (DMD). In all, 111 DMD patients with age ranging from 2 to 23 years (mean 8.2 +/- 3.4 years) were assessed; of these patients, 92 had their height measured. Clinical course was determined through Vignos scale of functional disability, motor ability, and timed functional tests. All patients had grossly elevated serum creatine-kinase (CK) and pyruvate-kinase (PK) levels. When height was adjusted for patients' age, a statistically significant correlation was found between height and clinical course (positive with Vignos scale and negative with motor ability), suggesting that smaller boys have a better clinical course than taller patients of comparable age. These results support our previous hypothesis and suggest that growth inhibition seems to be effective in diminishing the progression of DMD.

Serum creatine-kinase (CK) and pyruvate-kinase (PK) activities in Duchenne (DMD) as compared with Becker (BMD) muscular dystrophy.

Serum creatine-kinase (CK) activities were determined in 536 patients affected with X-linked muscular dystrophy (456 with Duchenne or DMD and 80 with Becker or BMD) and serum pyruvate-kinase (PK) in 360 among them (309 DMD and 51 BMD). The aim of this investigation was to assess the variability and rate of decrease in serum activity in DMD as compared with BMD as a function of age and in DMD as a function of Vignos scale as well. In DMD, maximum CK and PK activities were found around 1-6 years old and the average rate of decline according to age was estimated as 0.18 per year and 0.27-0.29 for both enzymes as a function of Vignos scale (assessed in 291 cases). For BMD, maximum serum enzyme levels were found around 10-15 years old and the rate of decline of serum activity per year was 0.06 for CK and 0.07 for PK. If maximum levels of serum enzyme reflect active muscle degeneration and the rate of decline per year to progressive loss of muscle mass (responsible for the release of muscle enzymes to the blood stream) our observations suggest: (a) active muscle degeneration occurs, on average, 5 years later in the group of outliers and 10 years later in BMD as compared with severe DMD; (b) the rate in which muscle mass is lost is significantly greater in DMD than in BMD and therefore serum enzyme determinations may represent an important test for evaluation of therapeutic trials; (c) serum enzymes determination may represent an important preliminary test to discriminate in a proportion of young patients if they will develop a severe or milder phenotype.

Effect of physical exercise on seizure occurrence in a model of temporal lobe epilepsy in rats.

Although the favorable effect of physical fitness on general health is unquestionable, physical exercise and fitness programs in patients with epilepsy are still a matter of controversy. Little objective evidence regarding the effect of exercise on seizure frequency and severity has been reported. One sought to clarify the relationship between exercise and epilepsy in an animal model of temporal lobe epilepsy (the pilocarpine model of epilepsy). To evaluate the effect of an aerobic physical program on seizure frequency, 29 epileptic animals were continuously monitored during 24 h for 135 days after the first spontaneous recurrent seizure (SRS) and divided into three groups. The first group (N = 14) was submitted to an aerobic exercise program (training group). The second group (N = 7) was maintained in the treadmill for the same time as the training group without being submitted to physical exercise (sham group). The third group (N = 8) served as control. The behavioral observation was divided in three periods of 45 days. The first period was used to determine the number of seizures before physical training program. The second period was utilized to determine the number of seizures during the physical training program. The third period was used to analyze the frequency of seizures after the physical training program. The mean frequency of seizures in the control and sham groups increased significantly from period 1 to period 2 and from period 1 to period 3. However, in the training group, the frequency of seizures did not change significantly between the three periods of 45 days of observation. When the same periods of the three groups were analyzed together, a significant reduction in seizure frequency was observed comparing the training group with the control and sham groups during the period of physical training. The data presented in this study suggest that physical exercise is not a seizure-inducing factor in this experimental model of epilepsy.

The course of untreated seizures in the pilocarpine model of epilepsy.

The course of untreated epilepsy is not well established. This study uses a model of chronic limbic epilepsy (pilocarpine model of epilepsy) to determine the pattern of occurrence of seizures in untreated animals. Following pilocarpine administration, 21 rats were monitored continuously with a video system for 135 days after the first spontaneous seizure. Animals showed a great variability in seizure numbers and were divided in two subgroups presenting either a low frequency of seizures (n = 9 animals presenting ten or less seizures in the first 15 days of observation) or a high frequency of seizures (n = 12 animals presenting more than ten seizures during this period). Animals with low number of seizures during the first 15 days of observation showed a significant increase in seizure frequency in the following period of analysis (until 105 days). On the other hand, those with initial high number of seizures showed significant changes in seizure frequency only in the first 2 months. The duration of each spontaneous seizure did not change significantly over time. These findings show that in untreated epilepsy there is a maturation process in the early stages and this accelerating process can be of predictive value for the treatment of epilepsy.

Density compensation in neotropical primate communities: evidence from 56 hunted and nonhunted Amazonian forests of varying productivity.

Density compensation is a community-level phenomenon in which increases in the abundance of some species may offset the population decline, extirpation, or absence of other potentially interacting competitors. In this paper we examine the evidence for density compensation in neotropical primate assemblages using data from 56 hunted and nonhunted, but otherwise undisturbed, forest sites of Amazonia and the Guianan shields from which population density estimates are available for all diurnal primate species. We found good evidence of density compensation of the residual assemblage of nonhunted mid-sized species where the large-bodied (ateline) species had been severely reduced in numbers or driven to local extinction by subsistence hunters. Only weak evidence for density compensation, however, was detected in small-bodied species. These conclusions are based on the effects of ordinal measures of hunting pressure on the aggregate primate biomass across different size classes after controlling for the effects of forest type and productivity. These results are interpreted primarily in relation to patterns of niche partitioning between different primate functional groups or ecospecies. This study suggests that while overhunting drastically reduces the average body size in multi-species assemblages of forest vertebrates, depletion of large-bodied species is only partially offset (i.e. undercompensated) by smaller taxa.

Radiation-induced dominant lethal mutations in oocytes of Musca domestica.

Dominant lethal mutations induced by gamma-radiation were measured in stage-7 and stage-14 oocytes of Musca domestica. At both stages the data are consistent with the multi-hit theory on radiation induction of dominant lethals. This conclusion is supported by fractionation experiments which indicate that both S7 and S14 oocytes are capable of repairing, in different periods of time, a similar amount of dominant lethal damage.

Helicobacter pylori and cagA and vacA gene status in children from Brazil with chronic gastritis.

Helicobacter pylori has been shown to be strongly associated with chronic gastritis, gastric and duodenal ulceration, and is a risk factor for gastric carcinoma. Histology, urease, culture, and polymerase chain reaction have been employed as for H. pylori diagnostic methods, pre and post treatment or during follow-up of dyspeptic adult individuals referred for endoscopy. In order to obtain a more-sensitive and specific method for H. pylori detection, we evaluated gastric body and antrum biopsies of 134 consecutive Brazilian consecutive dyspeptic children aged 1-16 years by rapid urease test, histology and polymerase chain reaction using two pairs of oligonucleotides. Our results indicated that polymerase chain reaction with Southern blotting and hybridization with specific chemiluminescent probes increased the number of positive H. pylori patients by 35%. The genotyping of H. pylori strains directly from gastric biopsy using the same nucleic acid methodology revealed that there is no association of chronic gastritis in our infant patients with vacA s1 and the presence of the cagA gene. These data suggest an initial infection of children with normal mucosa and probably others factors than vacA s1 genotype or the presence of the cagA gene are associated with the onset of gastric disease. Altogether, our results reinforce the need for using more sensitive diagnostic methods in order to understand the role of H. pylori in the genesis of gastric disease in children and its progression in adults.

Sawtooth waves during REM sleep after administration of haloperidol combined with total sleep deprivation in healthy young subjects.

We sought to examine the possible participation of dopaminergic receptors in the phasic events that occur during rapid eye movement (REM) sleep, known as sawtooth waves (STW). These phasic phenomena of REM sleep exhibit a unique morphology and, although they represent a characteristic feature of REM sleep, little is known about the mechanisms which generate them and which are apparently different from rapid eye movements. STW behavior was studied in 10 male volunteers aged 20 to 35 years, who were submitted to polysomnographic monitoring (PSG). On the adaptation night they were submitted to the first PSG and on the second night, to the basal PSG. On the third night the volunteers received placebo or haloperidol and spent the whole night awake. On the fourth night they were submitted to the third PSG. After a 15-day rest period, the volunteers returned to the sleep laboratory and, according to a double-blind crossover randomized design, received haloperidol or placebo and spent the whole night awake, after which they were submitted to the fourth PSG. The volunteers who were given haloperidol combined with sleep deprivation exhibited an elevation of the duration and density of the STW, without significant alterations of the other REM sleep phasic phenomena such as rapid eye movement. These findings suggest that sawtooth waves must have their own generating mechanisms and that the dopaminergic receptors must exert a modulating role since REM sleep deprivation, as well as administration of neuroleptics, produces supersensitivity of dopaminergic receptors.

On the dose equivalence of flurazepam and triazolam.

Flurazepam (30 mg), triazolam (0.5 mg) and placebo were given in the morning to 6 normal volunteers in a double-blind crossover study. Subjects were evaluated by a large battery of psychophysiological tests before and 1 and 5 hours after drug administration. Triazolam was significantly more sedative than flurazepam and both were significantly different from placebo. Slope-ratio assay analysis of the results from the present study pooled with those from a similar previous study (C. Gorenstein and V. Gentil, Psychopharmacology, 80: 376-379, 1983) indicated that these doses are non-equivalent. We suggest that dose-equivalence studies based on the present method should be carried out early in the development of new hypnotic drugs.

Comparison of the biological activities in venoms from three subspecies of the South American rattlesnake (Crotalus durissus terrificus, C. durissus cascavella and C. durissus collilineatus)

The subspecies of the South American rattlesnake, Crotalus durissus are classified according to their external morphological features and geographical distribution. We have determined some biological activities of C. durissus cascavella, C. durissus collilineatus and C. durissus terrificus venoms. C. durissus terrificus had a significantly higher clotting activity on bovine plasma and fibrinogen, human fibrinogen and rabbit plasma. C. durissus cascavella presented a statistically higher phospholipase A2 (PLA2) activity in regard to C. durissus collilineatus. Their myotoxic and proteolytic activity, median lethal doses, or median platelet aggregating doses (on rabbit and human platelets) could not differentiate the three subspecies examined. However, the electrophoretic profile and the dose-response curve for edematogenic activity for C.d. cascavella venom were different from the others. With regard to the inorganic element content of the venoms, higher levels of Br, Cl and Mg, and a lower level of Zn, were found in C.d. cascavella venom. Crotamine-like activity could not be detected in C.d. cascavella venom. Furthermore, equine antivenom specific for C. durissus terrificus venom cross-reacted equally with the antigens of the three venom pools by ELISA and Western blotting. These results indicate that the venoms from the three studied subspecies of C. durissus were very similar, except for minor differences in paw edema-inducing activity, electrophoretic profile, phospholipase A2 activity, crotamine-like activity and inorganic element contents of C.d. cascavella venom.

Sensations and reaction times evoked by electrical sinusoidal stimulation.

OBJECTIVE: To determine whether 5 Hz and 2000 Hz sinusoidal electric currents evoke different sensations and to indirectly evaluate which peripheral nerve fibers are stimulated by these different frequencies. METHODS: One hundred and fifty subjects chose three among eight descriptors of sensations evoked by 5 Hz and 2000 Hz currents and the results were submitted to factor analysis. In 20 subjects, reaction times to 5, 250 and 2000 Hz currents were determined at 1.1 x ST and reaction times to 5 Hz currents were also determined at 2 x ST. RESULTS: Responses were grouped in four factors: Factor 1, which loaded mainly in descriptors related to tweezers stimulation, was higher than the other factors during 2000 Hz stimulation at 1.5 x ST. Factor 2, which loaded mainly in descriptors related to needle stimulation, was higher than the other factors during 5 Hz stimulation. Factor 1 increased and Factor 2 decreased with an increase in 5 Hz intensity from 1.5 to 4x ST. Reaction times measured from the fastest responses were significantly different: 0.57 s (0.16 to 1.60), 0.34 s (0.12 to 0.71) and 0.22s (0.08 to 0.35) for 5, 250 and 2000 Hz, respectively, and 0.22s (0.11 to 0.34) for 5 Hz at 2 x ST. CONCLUSIONS: Sinusoidal electrical stimulation of 5 Hz and 2000 Hz evoke different sensations. At juxta-threshold intensities, RT measurements suggest that 2000 Hz stimulates Abeta-fibers, 250 Hz Abeta- or A partial differential-fibers, 5 Hz Abeta-, A partial differential- or C-fibers. The fiber type, which was initially stimulated by the lower frequencies, depended on inter-individual differences.