Increased mRNA expression of collagen V gene in pulmonary fibrosis of systemic sclerosis

Background Collagen V shows promise as an inducer of interstitial lung fibrosis in experimental systemic sclerosis (SSc). Materials and methods Remodelling of the pulmonary interstitium was evaluated based on the clinical data and open lung biopsies from 15 patients with SSc. Normal lung tissues obtained from eight individuals who died of traumatic injuries were used as control group. Immunofluorescence, immunohistochemistry, morphometry, tri-dimensional reconstruction and a real-time polymerase chain reaction were used to evaluate the quantity, structure and molecular chains of collagen V. The impact of these markers was tested on clinical data. Results The main difference in collagen V content between SSc patients and the control group was an increased, abnormal and distorted fibre deposition in the alveolar septa and the pre-acinar artery wall. The lungs from SSc patients presented [alpha 1(V)] and [alpha 2(V)] mRNA chain expression increased, but [alpha 2(V)] was proportionally increased compared with the control group. High levels of collagen V were inversely associated with vital capacity (r = -0.72; P = 0.002), forced vital capacity (r = -0.76; P < 0.001), forced expiratory volume in 1-s (r = -0.89; P < 0.001) and diffusing capacity for carbon monoxide (r = -0.62; P = 0.04). Conclusions Abnormal collagen V fibres are overproduced in lungs from SSc patients and may play an important role in the pathogenesis of the disease as this molecule regulates tissue collagen assembly. The aberrant histoarchitecture observed in SSc can be related to the overexpression of the [alpha 2(V)] gene of unknown origin.

IRF8 Mutations and Human Dendritic-Cell Immunodeficiency

BACKGROUND The genetic analysis of human primary immunodeficiencies has defined the contribution of specific cell populations and molecular pathways in the host defense against infection. Disseminated infection caused by bacille Calmette-Guerin (BCG) vaccines is an early manifestation of primary immunodeficiencies, such as severe combined immunodeficiency. In many affected persons, the cause of disseminated BCG disease is unexplained. METHODS We evaluated an infant presenting with features of severe immunodeficiency, including early-onset disseminated BCG disease, who required hematopoietic stem-cell transplantation. We also studied two otherwise healthy subjects with a history of disseminated but curable BCG disease in childhood. We characterized the monocyte and dendritic-cell compartments in these three subjects and sequenced candidate genes in which mutations could plausibly confer susceptibility to BCG disease. RESULTS We detected two distinct disease-causing mutations affecting interferon regulatory factor 8 (IRF8). Both K108E and T80A mutations impair IRF8 transcriptional activity by disrupting the interaction between IRF8 and DNA. The K108E variant was associated with an autosomal recessive severe immunodeficiency with a complete lack of circulating monocytes and dendritic cells. The T80A variant was associated with an autosomal dominant, milder immunodeficiency and a selective depletion of CD11c+CD1c+ circulating dendritic cells. CONCLUSIONS These findings define a class of human primary immunodeficiencies that affect the differentiation of mononuclear phagocytes. They also show that human IRF8 is critical for the development of monocytes and dendritic cells and for antimycobacterial immunity. (Funded by the Medical Research Council and others.)

Acute hyperglycemia rapidly stimulates VEGF mRNA translation in the kidney. Role of angiotensin type 2 receptor (AT2)

Angiotensin II (Ang II) and vascular endothelial growth factor (VEGF) are important mediators of kidney injury in diabetes. Acute hyperglycemia increased synthesis of intrarenal Ang I and Ang II and resulted in activation of both Ang II receptors, AT1 and AT2, in the kidney. Losartan (specific AT1 antagonist) or PD123319 (specific AT2 antagonist) did not affect hyperglycemia but prevented activation of renal AT1 and AT2, respectively. In murine renal cortex, acute hyperglycemia increased VEGF protein but not mRNA content after 24 h, which suggested translational regulation. Blockade of AT2, but not AT1, prevented increase in VEGF synthesis by inhibiting translation of VEGF mRNA in renal cortex. Acute hyperglycemia increased VEGF expression in wild type but not in AT2 knockout mice. Binding of heterogeneous nuclear ribonucleoprotein K to VEGF mRNA, which stimulates its translation, was prevented by blockade of AT2, but not AT1. The Akt-mTOR-p70(S6K) signaling pathway, involved in the activation of mRNA translation, was activated in hyperglycemic kidneys and was blocked by the AT2 antagonist. Elongation phase is an important step of mRNA translation that is controlled by elongation factor 1A (eEF1A) and 2 (eEF2). Expression of eEF1A and activity of eEF2 was higher in kidney cortex from hyperglycemic mice and only the AT2 antagonist prevented these changes. To assess selectivity of translational control of VEGF expression, we measured expression of fibronectin (FN) and laminin beta 1 (lam beta 1): acute hyperglycemia increased FN expression at both protein and mRNA levels, indicating transcriptional control, and did not affect the expression of lam beta 1. To confirm results obtained with PD123319, we induced hyperglycemia in AT2 knockout mice and found that in the absence of AT2, translational control of VEGF expression by hyperglycemia was abolished. Our data show that acute hyperglycemia stimulates Ang II synthesis in murine kidney cortex, this leads to AT2 activation and stimulation of VEGF mRNA translation, via the Akt-mTOR-p70(S6K) signaling pathway. Our data show that exclusive translational control of protein expression in the kidney by acute hyperglycemia is not a general phenomenon, but do not prove that it is restricted to VEGF. (C) 2010 Elsevier Inc. All rights reserved.

Screening for serious mental illness in the general population with the K6 screening scale: results from the WHO World Mental Health (WMH) survey initiative

Data are reported on the background and performance of the K6 screening scale for serious mental illness (SMI) in the World Health Organization (WHO) World Mental Health (WMH) surveys. The K6 is a six-item scale developed to provide a brief valid screen for Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV) SMI based on the criteria in the US ADAMHA Reorganization Act. Although methodological studies have documented good K6 validity in a number of countries, optimal scoring rules have never been proposed. Such rules are presented here based on analysis of K6 data in nationally or regionally representative WMH surveys in 14 countries (combined N = 41,770 respondents). Twelve-month prevalence of DSM-IV SMI was assessed with the fully-structured WHO Composite International Diagnostic Interview. Nested logistic regression analysis was used to generate estimates of the predicted probability of SMI for each respondent from K6 scores, taking into consideration the possibility of variable concordance as a function of respondent age, gender, education, and country. Concordance, assessed by calculating the area under the receiver operating characteristic curve, was generally substantial (median 0.83; range 0.76-0.89; inter-quartile range 0.81-0.85). Based on this result, optimal scaling rules are presented for use by investigators working with the K6 scale in the countries studied. Copyright (c) 2010 John Wiley & Sons, Ltd.

A Duplex Allele-Specific Amplification PCR to Detect SMN1 Deletion

Spinal muscular atrophy (SMA), the leading genetic cause of death in childhood, is an autosomal recessive neuromuscular disorder characterized by progressive muscle weakness, associated with deletions of the survival motor neuron (SMN) gene identified and mapped to chromosome 5q13. SMN is present in two highly homologous copies (SMN1 and SMN2). In the general population, normal individuals (noncarriers) have at least one telomeric (SMN1) copy, and 5% of them have no copies of SMN2. Approximately 95% of SMA patients carry homologous deletions of SMN1 exon(s) 7 (and 8). SMN1 and SMN2 exons 7 and 8 differ only by 1 bp each, and SMA diagnosis might be performed by single-strand conformational polymorphism, PCR amplification followed by restriction fragment length polymorphism (RFLP), multiple ligation-dependent probe amplification, or realtime PCR of SMNs exons 7 and 8. We developed a simpler and cost-effective method to detect SMN1 exon 7 deletion based on allele-specific amplification PCR.

Cytoplasmic and nuclear localization of cadherin in honey bee (Apis mellifera L.) gonads

Cadherins are crucial molecules mediating cell-cell interactions between somatic and germline cells in insect and mammalian male and female gonads. We analysed the presence and localization of cadherins in ovaries of honeybee queens and in testes of drones. Transcripts representing two classical cadherins, E-cadherin (shotgun) and N-cadherin, as well as three protocadherins (Starry night, Fat and Fat-like) were detected in gonads of both sexes. Pan-cadherin antibodies, which most probably detect a honeybee N-cadherin, were used in immunolocalization analyses. In the germarium of ovarioles, cadherin-IR (cadherin immunoreactivity) was evidenced as homogeneously distributed in the cytoplasm and as nuclear foci, in both germline and somatic cells. It was also detected in polyfusomes and ring canals. In testiolar tubules, cadherin-IR showed a cytoplasmic and nuclear distributon alike in ovaries. The unexpected nuclear localization and cytoplasmic distribution in ovaries and testes were corroborated by immunogold electron microscopy, which revealed cadherin aggregates associated with electron-dense nuclear structures. With respect to cadherin localization, the honeybee differs from Drosophila, the model for gametogenesis in insects, raising the question as to how differences among solitary and social species may be built into and generated from the general architecture of polytrophic meroistic ovaries. It also indicates the possibility of divergent roles for cadherin in the functional architecture of insect gonads, in general, especially in taxa with high reproductive output.

Molecular biology in tropical dermatoses

Initially, basic concepts are presented concerning the cell, genetic code and protein synthesis, and some techniques of molecular biology, such as PCR, PCR-RFLP, DNA sequencing, RT-PCR and immunoblotting. Protocols of nucleotides and of proteins extraction are supplied, such as salting out in peripheral blood allied to phenol-chloroform and trizol methods in skin samples. To proceed, commented examples of application of those techniques of molecular biology for the etiologic diagnosis and for research in tropical dermatoses, with emphasis to American tegumentary leishmaniasis and leprosy are presented.

Cultural consonance and adult body composition in urban Brazil

In previous research in Brazil, we found socioeconomic and gender differences in body mass and percent body fat, consistent with a model in which individuals in higher socioeconomic strata, especially women, could achieve a cultural ideal of body size and shape. In this article, using new data, we examine these processes more precisely using measures of cultural consonance. Cultural consonance refers to the degree to which individuals approximate, in their own beliefs and behaviors, the shared prototypes for belief and behavior encoded in cultural models. We have found higher cultural consonance in several domains to be associated with health outcomes. Furthermore, there tends to be a general consistency in cultural consonance across domains. Here we suggest that measures of body composition can be considered indicators of individuals` success in achieving cultural ideals of the body, and that cultural consonance in several domains will be associated with body composition. Using waist circumference as an outcome, smaller waist size was associated with higher cultural consonance in lifestyle (beta = -0.311, P < 0.01) and higher cultural consonance in the consumption of high prestige foods (beta = -0.260, P < 0.01) for women (n = 161), but not for men (n = 106), controlling for age, family income, tobacco use, and dietary intake of protein and carbohydrates. Similar results were obtained using the body mass index and weight as outcomes, while there were no associations with height. These results help to illuminate the cultural mediation of body composition.

Vascular biology of magnesium and its transporters in hypertension

Magnesium may influence blood pressure by modulating vascular tone and structure through its effects on myriad biochemical reactions that control vascular contraction/dilation, growth/apoptosis, differentiation and inflammation. Magnesium acts as a calcium channel antagonist, it stimulates production of vasodilator prostacyclins and nitric oxide and it alters vascular responses to vasoconstrictor agents. Mammalian cells regulate Mg(2+) concentration through special transport systems that have only recently been characterized. Magnesium efflux occurs via Na(2+)-dependent and Na(2+)-independent pathways. Mg(2+) influx is controlled by recently cloned transporters including Mrs2p, SLC41A1, SLC41A2, ACDP2, MagT1, TRPM6 and TRPM7. Alterations in some of these systems may contribute to hypomagnesemia and intracellular Mg(2+) deficiency in hypertension and other cardiovascular pathologies. In particular, increased Mg(2+) efflux through dysregulation of the vascular Na(+)/Mg(2+) exchanger and decreased Mg(2+) influx due to defective vascular and renal TRPM6/7 expression/activity may be important in altered vasomotor tone and consequently in blood pressure regulation. The present review discusses the role of Mg(2+) in vascular biology and implications in hypertension and focuses on the putative transport systems that control magnesium homeostasis in the vascular system. Much research is still needed to clarify the exact mechanisms of cardiovascular Mg(2+) regulation and the implications of aberrant cellular Mg(2+) transport and altered cation status in the pathogenesis of hypertension and other cardiovascular diseases.

A general hazard model for lifetime data in the presence of cure rate

Historically, the cure rate model has been used for modeling time-to-event data within which a significant proportion of patients are assumed to be cured of illnesses, including breast cancer, non-Hodgkin lymphoma, leukemia, prostate cancer, melanoma, and head and neck cancer. Perhaps the most popular type of cure rate model is the mixture model introduced by Berkson and Gage [1]. In this model, it is assumed that a certain proportion of the patients are cured, in the sense that they do not present the event of interest during a long period of time and can found to be immune to the cause of failure under study. In this paper, we propose a general hazard model which accommodates comprehensive families of cure rate models as particular cases, including the model proposed by Berkson and Gage. The maximum-likelihood-estimation procedure is discussed. A simulation study analyzes the coverage probabilities of the asymptotic confidence intervals for the parameters. A real data set on children exposed to HIV by vertical transmission illustrates the methodology.

Detection of Auditory Cortex Activity by fMRI Using a Dependent Component Analysis

Functional MRI (fMRI) data often have low signal-to-noise-ratio (SNR) and are contaminated by strong interference from other physiological sources. A promising tool for extracting signals, even under low SNR conditions, is blind source separation (BSS), or independent component analysis (ICA). BSS is based on the assumption that the detected signals are a mixture of a number of independent source signals that are linearly combined via an unknown mixing matrix. BSS seeks to determine the mixing matrix to recover the source signals based on principles of statistical independence. In most cases, extraction of all sources is unnecessary; instead, a priori information can be applied to extract only the signal of interest. Herein we propose an algorithm based on a variation of ICA, called Dependent Component Analysis (DCA), where the signal of interest is extracted using a time delay obtained from an autocorrelation analysis. We applied such method to inspect functional Magnetic Resonance Imaging (fMRI) data, aiming to find the hemodynamic response that follows neuronal activation from an auditory stimulation, in human subjects. The method localized a significant signal modulation in cortical regions corresponding to the primary auditory cortex. The results obtained by DCA were also compared to those of the General Linear Model (GLM), which is the most widely used method to analyze fMRI datasets.

The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution

To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.

Stereological and allometric studies on neurons and axo-dendritic synapses in the superior cervical ganglia of rats, capybaras and horses

The superior cervical ganglion (SCG) in mammals varies in structure according to developmental age, body size, gender, lateral asymmetry, the size and nuclear content of neurons and the complexity and synaptic coverage of their dendritic trees. In small and medium-sized mammals, neuron number and size increase from birth to adulthood and, in phylogenetic studies, vary with body size. However, recent studies on larger animals suggest that body weight does not, in general, accurately predict neuron number. We have applied design-based stereological tools at the light-microscopic level to assess the volumetric composition of ganglia and to estimate the numbers and sizes of neurons in SCGs from rats, capybaras and horses. Using transmission electron microscopy, we have obtained design-based estimates of the surface coverage of dendrites by postsynaptic apposition zones and model-based estimates of the numbers and sizes of synaptophysin-labelled axo-dendritic synaptic disks. Linear regression analysis of log-transformed data has been undertaken in order to establish the nature of the relationships between numbers and SCG volume (V(scg)). For SCGs (five per species), the allometric relationship for neuron number (N) is N=35,067xV (scg) (0.781) and that for synapses is N=20,095,000xV (scg) (1.328) , the former being a good predictor and the latter a poor predictor of synapse number. Our findings thus reveal the nature of SCG growth in terms of its main ingredients (neurons, neuropil, blood vessels) and show that larger mammals have SCG neurons exhibiting more complex arborizations and greater numbers of axo-dendritic synapses.

Ultrastructural aspects of lingual papillae in squirrel monkey (Saimiri sciureus)

Saimiri sciureus is one of the smallest Cebidae native of Amazon region and also found at the biological reserve of northeast Atlantic forest. It is an omnivore animal, with diversified diet that directly influences the lingual mucosa, which includes certain types of papillae with different organization levels. The present study attempted to describe the morphological and ultrastructure aspects of the dorsal surface of the S. sciureus. Five tongues of de S. sciureus were analyzed from three males and two females who died from natural causes and were obtained from breeding colonies of CENP-Ananindeua-PA. Main macroscopic features were a general triangular shape with a craniocaudal elongation pointed apex. Tissue samples-apex, body, and root of tongue-were fixed in modified Karnovsky solution, following standard scanning protocol, mounted in stubs, coated by gold, and analyzed by Scanning Electron Macroscopy (SEM). Four types of papillae were described: filiform (along all tissue extension with 154 mu m of diameter), fungiform (along all tissue extension with 272 mu m of diameter), vallate [just three units in caudal (dorsal) portion with 830 mu m of diameter] and foliate (one pair at caudolateral surface with similar to 13 projections and 3000 mu m in length). Data analysis indicates that the distribution and ultra structural morphology of the S. sciureus lingual papillae are some similar to other primates. Microsc. Res. Tech. 74:484-487, 2011. (C) 2010 Wiley-Liss, Inc.

Experimental infection of the rabbit tick, Haemaphysalis leporispalustris, with the bacterium Rickettsia rickettsii, and comparative biology of infected and uninfected tick lineages

The present study consisted of two experiments that evaluated experimental infections of Haemaphysalis leporispalustris ticks by a Brazilian strain of Rickettsia rickettsii, and their effect on tick biology. In experiment I, ticks were exposed to R. rickettsii during the larval, nymphal or adult stages by feeding on rabbits (Oryctolagus cuniculus) needle-inoculated with R. rickettsii, and thereafter reared on uninfected rabbits for the entire next tick generation. Regardless of the tick stage that acquired the infection, all subsequent tick stages were shown to be infected by PCR (infection rates varying from 1.3 to 41.7%), and were able to transmit R. rickettsii to uninfected rabbits, as demonstrated by rabbit seroconversion, guinea pig inoculation with rabbit blood, and PCR on rabbit blood. In Experiment II, ticks were exposed to R. rickettsii during the larval stage by feeding on rabbits co-infested with R. rickettsii-infected adult ticks, and thereafter reared on uninfected rabbits until the next generation of larvae. Again, all subsequent tick stages were shown to be infected by PCR (infection rates varying from 3.0 to 40.0%), and were able to transmit R. rickettsii to uninfected rabbits. Thus, it was demonstrated that larvae, nymphs, and adults of H. leporispalustris were able to acquire and maintain the R. rickettsii infection by transstadial and transovarial transmissions within the tick population, with active transmission of the bacterium to susceptible rabbits by all parasitic stages. Analyses of biological parameters of uninfected and R. rickettsii-infected tick lineages were performed in order to evaluate possible deleterious effects of R. rickettsii to the infected tick lineages. Surprisingly, all but one of the four R. rickettsii-experimental groups of the present study showed overall better biological performance than their sibling uninfected control ticks. Results of the present study showed that H. leporispalustris could support infection by a high virulent strain of R. rickettsii for at least two generations, in which infected tick lineages tended to have better performance than uninfected ticks. Our results support a possible role of H. leporispalustris in the enzootic maintenance of R. rickettsii in Latin America, as previously suggested by earlier works.