Intravital Microscopy of the Mouse Brain Microcirculation using a Closed Cranial Window

This experimental model was designed to assess the mouse pial microcirculation during acute and chronic, physiological and pathophysiological hemodynamic, inflammatory and metabolic conditions, using in vivo fluorescence microscopy. A closed cranial window is placed over the left parieto-occipital cortex of the mice. Local microcirculation is recorded in real time through the window using epi and fluorescence illumination, and measurements of vessels diameters and red blood cell (RBC) velocities are performed. RBC velocity is measured using real-time cross-correlation and/or fluorescent-labeled erythrocytes. Leukocyte and platelet adherence to pial vessels and assessment of perfusion and vascular leakage are made with the help of fluorescence-labeled markers such as Albumin-FITC and anti-CD45-TxR antibodies. Microcirculation can be repeatedly video-recorded over several days. We used for the first time the close window brain intravital microscopy to study the pial microcirculation to follow dynamic changes during the course of Plasmodium berghei ANKA infection in mice and show that expression of CM is associated with microcirculatory dysfunctions characterized by vasoconstriction, profound decrease in blood flow and eventually vascular collapse

Pathophysiological Mechanisms In Gaseous Therapies For Severe Malaria.

Over 200 million people worldwide suffer from malaria every year, a disease that causes 584,000 deaths annually. In recent years, significant improvements have been achieved on the treatment of severe malaria, with intravenous artesunate proving superior to quinine. However, mortality remains high at 8% in children and 15% in adults in clinical trials, and even worse in the case of cerebral malaria (18% and 30%, respectively). Moreover, some individuals who do not succumb to severe malaria present long-term cognitive deficits. These observations indicate that strategies focused only on parasite killing fail to prevent neurological complications and deaths associated with severe malaria, possibly because clinical complications are associated in part with a cerebrovascular dysfunction. Consequently, different adjunctive therapies aimed at modulating malaria pathophysiological processes are currently being tested. However, none of these therapies has shown unequivocal evidence in improving patients' clinical status. Recently, key studies have shown that gaseous therapies based mainly on nitric oxide (NO), carbon monoxide (CO) and hyperbaric (pressurized) oxygen (HBO) alter vascular endothelium dysfunction and modulate host immune response to infection. Considering gaseous administration as a promising adjunctive treatment against severe malaria cases, we review here the pathophysiological mechanisms and the immunological aspects of such therapies.8

Cell-Envelope Remodeling as a Determinant of Phenotypic Antibacterial Tolerance in Mycobacterium tuberculosis

[Image: see text] The mechanisms that lead to phenotypic antibacterial tolerance in bacteria remain poorly understood. We investigate whether changes in NaCl concentration toward physiologically higher values affect antibacterial efficacy against Mycobacterium tuberculosis (Mtb), the causal agent of human tuberculosis. Indeed, multiclass phenotypic antibacterial tolerance is observed during Mtb growth in physiologic saline. This includes changes in sensitivity to ethionamide, ethambutol, d-cycloserine, several aminoglycosides, and quinolones. By employing organism-wide metabolomic and lipidomic approaches combined with phenotypic tests, we identified a time-dependent biphasic adaptive response after exposure of Mtb to physiological levels of NaCl. A first rapid, extensive, and reversible phase was associated with changes in core and amino acid metabolism. In a second phase, Mtb responded with a substantial remodelling of plasma membrane and outer lipid membrane composition. We demonstrate that phenotypic tolerance at physiological concentrations of NaCl is the result of changes in plasma and outer membrane lipid remodeling and not changes in core metabolism. Altogether, these results indicate that physiologic saline-induced antibacterial tolerance is kinetically coupled to cell envelope changes and demonstrate that metabolic changes and growth arrest are not the cause of phenotypic tolerance observed in Mtb exposed to physiologic concentrations of NaCl. Importantly, this work uncovers a role for bacterial cell envelope remodeling in antibacterial tolerance, alongside well-documented allterations in respiration, metabolism, and growth rate

Cross-sectional study of deaths by acute pancreatitis necropsied in the Forensic Medicine Institute of Belo Horizonte, 2006?2012.

A pancreatite aguda ? caracterizada pela inflama??o do p?ncreas, em que as les?es variam de edema intersticial a necrose do par?nquima com hemorragia grave. A mortalidade ? alta quando associada ? fal?ncia multissist?mica. A pancreatite aguda pode ser causa de morte s?bita e seu diagn?stico, em especial a forma necrotizante, ? feito somente ap?s a necropsia em at? metade dos casos. Objetivos: Avaliar, retrospectivamente, as caracter?sticas epidemiol?gicas e patol?gicas das mortes por pancreatite aguda examinadas no Instituto M?dico-Legal de Belo Horizonte (IML-BH). Materiais e m?todos: An?lise retrospectiva dos laudos de necropsia do IML-BH cuja causa da morte foi pancreatite aguda realizados no per?odo de 2006 a 2012. Resultados: Houve predomin?ncia de homens e a maioria dos casos foi de pancreatite aguda hemorr?gica, com o etilismo sendo a etiologia predominante. A m?dia et?ria foi de 43 anos, com metade dos casos entre 40 e 60 anos. A maioria dos necropsiados foi encontrada morta no pr?prio domic?lio. Houve rela??o estat?stica entre a faixa et?ria de 40 e 60 anos e a ocorr?ncia de hematoma retroperitoneal. Complica??es sist?micas inclu?ram edema pulmonar e cerebral, derrame pleural e pneumonia. Conclus?o: Apesar do principal papel da necropsia forense ser a investiga??o das causas externas de morte, este estudo confirma que h? situa??es nas quais a Medicina Legal apresenta papel importante, em especial nas localidades que n?o disp?em de servi?os de verifica??o de ?bito, na avalia??o de potencias causas de morte s?bita, como a pancreatite aguda hemorr?gica.Acute pancreatitis is characterized by inflammation of the pancreas, in which lesions range from interstitial edema to necrosis of the parenchyma with severe hemorrhage. Mortality is high when associated with multisystemic failure. Acute pancreatitis may be the cause of sudden death and its diagnosis, especially the necrotizing form, is made only after necropsy in up to half of the cases. Objectives: To evaluate the epidemiological and pathological characteristics deaths caused by acute pancreatitis examined at the Forensic Medicine Institute of Belo Horizonte (FMI-BH). Materials and methods: Retrospective analysis of FMI-BH necropsy reports whose cause of death was acute pancreatitis, performed from 2006 to 2012. Results: There was a predominance of men and the majority of cases were acute hemorrhagic pancreatitis, with the alcohol abuse being the predominant etiology. The mean age was 43 years, with half of the cases between 40 and 60 years old. Most corpses were found dead at home. There was a statistical relationship between the age group of 40 and 60 years and the occurrence of retroperitoneal hematoma. Systemic complications included pulmonary and cerebral edema, pleural effusion, and pneumonia. Conclusion: Although the main role of forensic necropsy is the investigation of the external causes of death, this study confirms that there are situations in which Legal Medicine plays an important role, especially in locations that do not have death verification services, in the evaluation of potential causes of sudden death, such as acute hemorrhagic pancreatitis

Resenha bibliográfica

DIAMOND, J.; ROBINSON, J. A. (Ed.). Natural experiments of History.Cambridge, Massachusetts: Belknap Press of Harvard University Press,2010. 288 p

Integration of miRNA and mRNA expression profles reveals microRNA-regulated networks during muscle wasting in cardiac cachexia

Cardiac cachexia (CC) is a common complication of heart failure (HF) associated with muscle wasting and poor patient prognosis. Although different mechanisms have been proposed to explain muscle wasting during CC, its pathogenesis is still not understood. Here, we described an integrative analysis between miRNA and mRNA expression profiles of muscle wasting during CC. Global gene expression profiling identified 1,281 genes and 19 miRNAs differentially expressed in muscle wasting during CC. Several of these deregulated genes are known or putative targets of the altered miRNAs, including miR-29a-3p, miR-29b-3p, miR-210-5p, miR-214, and miR-489. Gene ontology analysis on integrative mRNA/miRNA expression profiling data revealed miRNA interactions affecting genes that regulate extra-cellular matrix (ECM) organization, proteasome protein degradation, citric acid cycle and respiratory electron transport. We further identified 11 miRNAs, including miR-29a-3p and miR-29b-3p, which target 21 transcripts encoding the collagen proteins related to ECM organization. Integrative miRNA and mRNA global expression data allowed us to identify miRNA target genes involved in skeletal muscle wasting in CC. Our functional experiments in C2C12 cells confirmed that miR-29b down-regulates collagen genes and contributes to muscle cell atrophy. Collectively, our results suggest that key ECM-associated miRNAs and their target genes may contribute to CC in HF

Methylene tetrahydrofolate reductase (MTHFR) and vascular endothelial growth factor (VEGF) polymorphisms in Brazilian patients with Hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC)

OBJECTIVE: The folate pathway is involved in hepatic carcinogenesis and angiogenesis. Polymorphisms in genes related to such processes, including methylene tetrahydrofolate reductase (MTHFR) and vascular endothelial growth factor (VEGF)] may play an important role in the development of hepatocellular carcinoma (HCC). The objective of this study was to evaluate MTHFR and VEGF polymorphisms in Brazilian patients with hepatitis C virus (HCV)-related HCC. METHODS: A total of 119 patients diagnosed with confirmed HCC and HCV were included in the study. SNP genotyping assays were performed using real-time PCR. VEGFA (rs2010963, rs3025039, and rs833061) and MTHFRC677T (rs1801133, rs1801131) polymorphisms were evaluated. RESULTS: The C alleles of MTHFR (rs1801131) and VEGF (rs2010963) were associated with protection against the development of multinodular HCC, while the T allele of MTHFR (rs1801133) was associated with a higher risk of multinodular presentation [p=0.04 OR 1.835 CI (1.022-3.297)]. Multivariate analysis revealed that the GG/GC genotypes of VEGF rs2010963 were independently associated with multinodular tumors at diagnosis (p=0.013; OR 4.78 CI (1.38-16.67)]. CONCLUSION: Our results suggest that these polymorphisms may increase the risk of rapid tumor progression in patients with HCV infection. This subgroup of patients with HCC and who present polymorphism is more likely to be diagnosed with multinodular disease and not be amenable to receiving curative treatments. These data must be validated in larger cohorts, and the screening intervals can be customized based on genetic history