Connecting complex networks to nonadditive entropies.

Boltzmann-Gibbs statistical mechanics applies satisfactorily to a plethora of systems. It fails however for complex systems generically involving nonlocal space-time entanglement. Its generalization based on nonadditive q-entropies adequately handles a wide class of such systems. We show here that scale-invariant networks belong to this class. We numerically study a d-dimensional geographically located network with weighted links and exhibit its 'energy' distribution per site at its quasi-stationary state. Our results strongly suggest a correspondence between the random geometric problem and a class of thermal problems within the generalised thermostatistics. The Boltzmann-Gibbs exponential factor is generically substituted by its q-generalisation, and is recovered in the [Formula: see text] limit when the nonlocal effects fade away. The present connection should cross-fertilise experiments in both research areas.

Pixantrone anticancer drug as a DNA ligand: Depicting the mechanism of action at single molecule level.

In this work we use single molecule force spectroscopy performed with optical tweezers in order to characterize the complexes formed between the anticancer drug Pixantrone (PIX) and the DNA molecule, at two very different ionic strengths. Firstly, the changes of the mechanical properties of the DNA-PIX complexes were studied as a function of the drug concentration in the sample. Then, a quenched-disorder statistical model of ligand binding was used in order to determine the physicochemical (binding) parameters of the DNA-PIX interaction. In particular, we have found that the PIX molecular mechanism of action involves intercalation into the double helix, followed by a significant compaction of the DNA molecule due to partial neutralization of the phosphate backbone. Finally, this scenario of interaction was quantitatively compared to that found for the related drug Mitoxantrone (MTX), which binds to DNA with a considerably higher equilibrium binding constant and promotes a much stronger DNA compaction. The comparison performed between the two drugs can bring clues to the development of new (and more efficient) related compounds.

Eag1, Eag2, and SK3 potassium channel expression in the rat hippocampus after global transient brain ischemia.

Transient global brain ischemia causes delayed neuronal death in the hippocampus that has been associated with impairments in hippocampus-dependent brain function, such as mood, learning, and memory. We investigated the expression of voltage-dependent Kcnh1 and Kcnh5, ether à go-go-related Eag1 and Eag2 (K(V) 10.1 and K(V) 10.2), and small-conductance calcium-activated SK3 (K(Ca) 2.3, Kcnn3) K(+) channels in the hippocampus in rats after transient global brain ischemia. We tested whether the expression of these channels is associated with behavioral changes by evaluating the animals in the elevated plus maze and step-down inhibitory avoidance task. Seven or tweny-eight days after transient global brain ischemia, one group of rats had the hippocampus bilaterally dissected, and mRNA levels were determined. Seven days after transient global brain ischemia, the rats exhibited a decrease in anxiety-like behavior and memory impairments. An increase in anxiety levels was detected 28 days after ischemia. Eag2 mRNA downregulation was observed in the hippocampus 7 days after transient global brain ischemia, whereas Eag1 and SK3 mRNA expression remained unaltered. This is the first experimental evidence that transient global brain ischemia temporarily alters Eag2. The number of intact-appearing pyramidal neurons was substantially decreased in CA1 and statistically measurable in CA2, CA3, and CA4 hippocampal subfields compared with sham control animals 7 or 28 days after ischemia. mRNA expression in the rat hippocampus. The present results provide further information for the characterization of the physiological role of Eag2 channels in the central nervous system.

DRR drives brain cancer invasion by regulating cytoskeletal-focal adhesion dynamics.

Malignant glioma invasion is a primary cause of brain cancer treatment failure, yet the molecular mechanisms underlying its regulation remain elusive. We developed a novel functional-screening strategy and identified downregulated in renal cell carcinoma (DRR) as a regulator of invasion. We show that DRR drives invasion in vitro and in vivo. We found that while DRR is not expressed in normal glial cells, it is highly expressed in the invasive component of gliomas. Exploring underlying mechanisms, we show that DRR associates with and organizes the actin and microtubular cytoskeletons and that these associations are essential for focal adhesion (FA) disassembly and cell invasion. These findings identify DRR as a new cytoskeletal crosslinker that regulates FA dynamics and cell movement.

Vascular endothelial growth factor concentrations in the serum and peritoneal fluid of women with endometriosis.

OBJECTIVES: To investigate whether there is an association between vascular endothelial growth factor (VEGF) levels in serum and peritoneal fluid, and the presence of pelvic endometriosis and its clinical symptoms. METHODS: Blood and peritoneal fluid sample levels of VEGF were measured in 46 women undergoing laparoscopy: 32 with suspected endometriosis and 14 with confirmed endometriosis. Data were analyzed according to phase of the menstrual cycle, symptoms, disease stage, and disease site. RESULTS: There were no significant associations between serum and peritoneal fluid levels of VEGF and the presence of endometriosis, even when controlling for the menstrual phase. However, among the women with confirmed endometriosis, there was a significant increase (P=0.002) in the mean peritoneal VEGF level in those in the late secretory phase compared with those in the proliferative and early secretory phases. CONCLUSIONS: Measuring VEGF levels in symptomatic patients is not helpful to differentiate those with endometriosis from those with a different condition. However, in the late secretory and menstrual phases, mean VEGF levels were higher in women with confirmed endometriosis than in those suspected of having the disease.

Endometriosis: an inflammatory disease with a Th2 immune response component.

BACKGROUND: Efforts have been made to correctly characterize the role of the immune response in endometriosis. The objective of this study was to analyse the interaction between Th1 and Th2 immune response patterns and endometriosis by evaluating a panel of cytokines. METHODS: Between January 2004 and November 2005, 98 patients, classified into two groups according to the histologically confirmed presence (Group A) or absence of endometriosis (Group B), were evaluated. Interleukins (IL) 2, 4 and 10, tumour necrosis factor-alpha and interferon-gamma (IFN-gamma) were measured by flow cytometry in the peripheral blood and peritoneal fluid of all patients. RESULTS: IFN-gamma and IL-10 levels were significantly higher in the peritoneal fluid of patients with endometriosis compared to those without endometriosis (P < 0.05). There was a significant alteration in the IL-4/IFN-gamma (P < 0.001), IL-4/IL-2 (P = 0.006), IL-10/IFN-gamma (P < 0.001) and the IL-10/IL-2 ratios (P < 0.001) in the peritoneal fluid of patients with endometriosis, with a predominance of IL-4 and IL-10, reflecting a shift towards Th2 immune response despite the increase in IFN-gamma concentrations. CONCLUSIONS: Endometriosis is an inflammatory disease involving a possible shift towards Th2 immune response component, as demonstrated by the relative increase in cytokines characteristic of this pattern of immune response.

Serotypes of carriage and invasive isolates of Streptococcus pneumoniae in Brazilian children in the era of pneumococcal vaccines.

Nasopharyngeal carriage of Streptococcus pneumoniae is a key factor in the development of invasive disease and the spread of resistant strains within the community. A single nasopharyngeal swab was obtained from 648 unvaccinated children aged <5 years, either healthy or with acute respiratory tract infection or meningitis, during the winters of 2000 and 2001. The overall pneumococcal carriage rate was 35.8% (95% CI 32.1-39.6). The pneumococcal serotypes found most frequently in the nasopharynx were 14, 6B, 6A, 19F, 10A, 23F and 18C, which included five of the seven serotypes in the currently licensed seven-valent conjugate vaccine (PCV7); serotypes 4 and 9V were less common. Serotypes 1 and 5 were isolated rarely from the nasopharynx. A comparison of 222 nasopharyngeal isolates with 125 invasive isolates, matched for age and time to the carrier isolates, showed a similar prevalence of penicillin non-susceptible pneumococci (PNSp) (19.8% and 19.2%, respectively). PNSp serotypes were similar (6B, 14, 19F, 19 A, 23B and 23F) for carriage and invasive disease isolates. The coverage of PCV7 for carriage isolates (52.2%) and invasive isolates (62.4%) did not differ significantly (p 0.06); similarly, there was no significant difference in PCV7 coverage for carriage isolates (34.5%) and invasive isolates (28.2%) of PNSp. These data suggest that PCV7 has the potential to reduce pneumococcal carriage and the number of carriers of PNSp belonging to vaccine serotypes.

Passiflora actinia Hooker extracts and fractions induce catalepsy in mice.

Leaves from several Passiflora species are largely employed in the Brazilian folk medicine for its anxiolytic and sedative properties. In behavioral studies, to analyze the tranquillizer action of Passiflora actinia Hooker, it was noteworthy that animals treated with the hydroethanol (HE) and methanol (ME) extracts presented an abnormal postural immobility compared to control animals. That observation led to an investigation of the effects of HE and its fractions on evaluation of catalepsy in mice. The results showed that HE extract, methanol extract, the sequent aqueous crude fractions (AF), and fa, fb and fc chromatographic fractions obtained from Passiflora actinia induced catalepsy in mice. Apparently, the active principles responsible for catalepsy are present in all of the fractions of the extract.

[Living conditions and life experiences of working-class groups in Rio de Janeiro: rethinking dengue control and popular mobilization]. / As condições e as experiências de vida de grupos populares no Rio de Janeiro: repensando a mobilização popular no controle do dengue.

Using narratives of an experience with popular mobilization during the 1986-91 dengue epidemic in the city of Rio de Janeiro, the authors discuss the scientific research and technical counseling involving basic sanitation conditions for vulnerable social groups. They present research results on water distribution in the slums from the Leopoldina area of the city. The research stemmed from demands by community leaders at local forums discussing health conditions. Gathering, systematizing, and analyzing the data were based on what they call "shared knowledge construction", resulting by crossing accumulated scientific knowledge with popular knowledge produced as a result of living conditions and life experiences among working-class groups. Finally, the authors comment on the need for local health professionals to be aware of relationships between epidemic and endemic processes and protection of life.

Effects of excitatory amino acids and nitric oxide on flight behavior elicited from the dorsolateral periaqueductal gray.

Microinjection of excitatory amino acids (EAA) into the dorsolateral periaqueductal gray (dlPAG) induces flight reactions while EAA antagonists show anxiolytic effects. Part of the effects mediated by NMDA receptors may involve an increase in nitric oxide (NO) production. We showed that nitric oxide synthase (NOS) inhibitors injected into the dlPAG induced anxiolytic effects. Conversely, SIN-1, a NO donor, produced orientated flight reactions that resemble stimulation of the medial hypothalamus. This compound also produced extensive Fos-like immunoreactivity in this region and in other areas related to defensive reactions such as the medial amygdala and cingulate cortex. Since part of the effects of NO involves increases in guanylate cyclase levels, we found that intra-dlPAG injection of 8-Br-cGMP induced a brief flight reaction followed by increased locomotion. In another experiment, we showed that single or repeated restraint stress produced an increased expression of neuronal NOS in the dlPAG and other areas related to defense, as measured by in situ hybridization, diaphorase histochemistry and immunocytochemistry. Together, these data suggest that NO may participate in the modulation of defensive responses in the dlPAG.

Differences in Brazilian strains of Schistosoma mansoni evaluated by means of morphometric analysis of cercariae of both sexes.

Morphometrics of Brazilian strains (BH, SJ and CMO) of Schistosoma mansoni cercariae were obtained with a computerized image analyzer (IMAGE PRO PLUS, MEDIA CYBERNETICS), considering the following characters: body area, tail, furcae, oral and ventral suckers and distance between them. For statistical analysis, the variance test (one-way Anova) was applied and significant differences of p< 0.05 were considered. All morphometric values in the BH strain were significantly higher (p< 0.05) than in the others. Lower values were obtained in females of SJ strain for all characters, excepting the body area. Only this character showed to be significantly different in males and females of the three strains. Specimens of both sexes in the BH and SJ strains showed significant differences regarding all characters. It was observed that this morphometric analysis permits the characterization of strains and also the sex identification in S. mansoni cercariae. Due to its feasibility, this method can be applied as a tool in laboratories devoid of more complex equipment.

Expression of neuronal nitric oxide synthase mRNA in stress-related brain areas after restraint in rats.

The objective of the present study was to investigate the expression of neuronal nitric oxide synthase (nNOS) mRNA in stress-related areas after restraint. Male Wistar rats (n=4-6/group) submitted to 2 h of restraint during one (acute) or seven (chronic) days were sacrificed 24 h after the last restraint period. In situ hybridisation was performed with oligonucleotide probes radiolabeled with (35)S. Acute restraint induced a significant increase in nNOS mRNA in the paraventricular hypothalamic nucleus (PVN), medial parvocellular part, dorsolateral periaqueductal grey (DLPAG) and medial amygdaloid nucleus, but not in the hippocampal formation. This effect persisted after chronic restraint in the PVN and DLPAG. These results suggest that restraint stress induces changes in gene expression of nNOS in areas related to stress reactions.

Mandibular flexure and dental implants: a case report.

The mandibular deformation as a result of jaw movement from rest position has been studied and documented by other authors. Here, we report that there is a possible correlation between this phenomenon and the discomfort experienced by a patient rehabilitated with implant-supported restoration for the mandibular arch during function. The recovery from pain and symptoms was achieved only after splitting the prosthesis into three sections. This case report serves to remind clinicians of the importance of following biological concepts as the key to a successful result.

Tumor markers in endometriosis.

OBJECTIVES: The objective of the present study was to determine the concentrations of CA 125, CA 15-3, CA 19-9, carcioembryogenic antigen (CEA), alpha-fetoprotein (AFP) and beta-2 microglobulin (B2MG) in patients with pelvic endometriosis. METHOD: Fifty women were divided into two groups: group A (control) had no endometriosis or other diseases, and group B consisted of 35 women with pelvic endometriosis. All women were submitted to serum determination of CA 125, CA 15-3, CA 19-9, CEA, AFP and B2MG. Samples were collected during the menstrual cycle and 1 week later. RESULTS: Mean CA 125 concentrations were altered in patients with endometriosis, but all 50 patients studied presented normal CEA, AFP and B2MG concentrations. Small variations detected in CA 19-9 and CA 15-3 had no statistical significance. CONCLUSION: CA 125 is the only important marker in the diagnosis of stages III/IV of endometriosis, especially when blood samples for its determination are obtained during the first 3 days of the menstrual cycle.

Central nervous system metastases from breast carcinoma. A clinical and laboratorial study in 47 patients.

In this retrospective study, 47 patients with clinical diagnosis of central nervous system metastases of breast cancer were evaluated by computerized tomography (CT), magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) examination. The patients were divided in 2 groups: 1, without leptomeningeal neoplasm and 2, with leptomeningeal neoplasm. In the group 2, the time interval between the primary disease and the central nervous system metastasis as well as the survival time were shorter than in group 1 (40 and 4.3 months in group 2 versus 57 and 10 months respectively, in group 1). In both groups the most common neurological symptoms and signs were intracranial hypertension and motor deficits. The most sensitive diagnostic methods were CT and MRI in group 1, and the CSF examination in group 2. The use of the tumor markers CEA and CA-15.3 in the routine examination of CSF showed promising results, mainly in leptomeningeal forms.

[Dengue in Rio de Janeiro: rethinking popular participation in health]. / A dengue no Rio de Janeiro: repensando a participação popular em saúde.

This paper discusses popular participation in health from the point of view of an experience in dengue epidemic control in the late 1980s and early 1990s in the city of Rio de Janeiro. It refers specifically to a social movement called "Se Liga, Leopoldina", combining professionals (from health services and public schools) and members of popular organizations from the suburban neighborhoods served by the Leopoldina railway. The paper reviews the ideas motivating actions undertaken by the movement, principally the role of popular organizations in the control of endemics. It calls attention to the danger of preconceived notions when analyzing participation by members of popular organizations in the social movement. The author also calls attention to the fact that social scientists researching social movements should focus on being part of a wider social network of conviviality rather than seeing their role as educating members of the popular organization. Such networks should seek to strengthen and expand social support for the endemic control process.

Schistosoma mansoni Sambon, 1907: morphometric differences between adult worms from sympatric rodent and human isolates.

A computer software for image analysis (IMAGE PRO PLUS, MEDIA CYBERNETICS) was utilized in male and females adult worms, aiming the morphological characterization of Schistosoma mansoni samples isolated from a slyvatic rodent, Nectomys squamipes, and humans in Sumidouro, Rio de Janeiro, Brazil and recovered from Mus musculus C3H/He. The following characters for males's testicular lobes were analyzed: number, area, density, larger and smaller diameter, longer and shorter axis and perimeter and extension; for females: area, longer and shorter axis, larger and smaller diameter and perimeter of the eggs and spine; oral and ventral suckers area and distance between them in both sex were determined. By the analysis of variance (one way ANOVA) significant differences (p < 0.05) were observed in all studied characters, except for the density of testicular lobes. Significant differences (p < 0.05) were detected for all characters in the female worms. Data ratify that sympatric isolates present phenotypic differences and the adult female characters are useful for the proper identification of S. mansoni isolates.

Highly sensitive single-step PCR protocol for diagnosis and monitoring of human cytomegalovirus infection in renal transplant recipients.

A multiplex, single-step PCR protocol for the detection of human cytomegalovirus (HCMV) DNA is described. The protocol amplifies regions of the viral LA and IE genes and employs elevated temperatures for both reagent mixing and primer annealing together with product detection by silver staining on polyacrylamide gels. This assay detects one to five HCMV genomes in clinical samples containing up to 100 ng of human DNA, a level of sensitivity equivalent to that of more complex assays involving either nested PCR or postamplification hybridization. As well as being of importance in clinical situations where high-sensitivity qualitative diagnosis is required, this assay is also applicable to the monitoring of HCMV infection in renal transplant recipients. Due to its multiplex format the assay provides quantitative information, in that samples from which a single target is amplified contain on average sevenfold fewer viral genomes per 10(6) leukocytes than those from which both targets are amplified. When weekly blood leukocyte DNA preparations from renal transplant patients were assayed, findings of three consecutive tests in which both HCMV targets were amplified were highly indicative of patients who had developed very high loads of HCMV (100% sensitivity, 88% specificity). We thus show that the same simple PCR assay which permits highly sensitive HCMV diagnosis can also be used for the efficient identification of transplant recipients at risk of clinically significant infection.

[Anti-beta-2-microglobulin antibodies in systemic lupus erythematosus]. / Estudo da antibeta-2-microglobulina sérica em portadores de lúpus eritematoso sistêmico.

The aim of this work was the study of 88 patients with SLE for clinical, laboratorial and demographical parameters. The patients sera were assayed for the presence of anti-beta-2-microglobulin antibodies by ELISA. These spectrofotometric results were converted in a standard-deviation unity in relation to the average of 29 control individuals values. It was established a cut-off of 2.5 standard-deviation in order to determine the limit of normality as well as the cut-off of 10 standard deviation was chosen in order to defined the higher values. Several statistical significant associations were observed between the anti-beta-2-microgobulin and the clinical and laboratorial parameters. The clinical applications of those associations were determined by the predictive value. It was only considered the values greater then 75%. The negative predictive values found in the lower cut-off were 92% to ANA (homogeneous-peripheral pattern), 89% to high levels CIC, 81% to mucocutaneous vasculitis and 80% to depressed CH50 levels. The positive predictive values found in 88% to high level of mucoprotein, 83% to mucocutaneous vasculitis, 83% to the onset-disease-time lower six years and 78% to limphopenia. Special attention may be paid to the high sensibility and specificity of the anti-beta-2-microglobulin test to some of the parameters in the evaluation of the disease activity, mainly in mucocutaneous vasculitis.