Entry screening to delay local transmission of 2009 pandemic influenza A (H1N1)

Background  

After the WHO issued the global alert for 2009 pandemic influenza A (H1N1), many national health agencies began to screen travelers on entry in airports, ports and border crossings to try to delay local transmission.     

Isolation and partial characterization of Brazilian samples of feline immunodeficiency virus

Feline immunodeficiency virus (FIV) causes a slow progressive degeneration of the immune system which eventually leads to a disease comparable to acquired immune deficiency syndrome (AIDS) in humans. FIV has extensive sequence variation, a typical feature of lentiviruses. Sequence analysis showed that diversity was not evenly distributed throughout the genome, but was greatest in the envelope gene, env. The virus enters host cells via a sequential interaction, initiated by the envelope glycoprotein (env) binding the primary receptor molecule CD134 and followed by a subsequent interaction with chemokine co-receptor CXCR4. The purpose of this study was to isolate and characterize isolates of FIV from an open shelter in S?o Paulo, Brazil. The separated PBMC from 11 positive cats were co-cultured with MYA-1 cells. Full-length viral env glycoprotein genes were amplified and determined. Chimeric feline × human CD134 receptors were used to investigate the receptor utilization of 17 clones from Brazilian isolates of FIV. Analyses of the sequence present of molecular clones showed that all clones grouped within subtype B. In contrast to the virulent primary isolate FIV-GL8, expression of the first cysteine-rich domain (CRD1) of feline CD134 in the context of human CD134 was sufficient for optimal receptor function for all Brazilian FIV isolates tested.     

Active matrix metalloproteinase-2 activity discriminates colonic mucosa, adenomas with and without high-grade dysplasia, and cancers

Pathologic assessment of colorectal adenomas, a complex task with significant interobserver variability, typically defines the scheduling of surveillance colonoscopies after removal of adenomas. We have characterized the activity levels of pro-matrix metalloproteinase-2, active matrix metalloproteinase-2, and matrix metalloproteinase-9 in colorectal adenomas and carcinomas as potential markers of pathologic progression during colorectal tumorigenesis. Endogenous fully activated matrix metalloproteinase-2, in particular, has been studied less frequently in adenomas due to difficulties in detection. For this report, tissues (n = 119) from 51 individuals were extracted and assayed on gelatin zymograms with digital standardization to nanogram quantities of purified active controls. Resulting data were assessed by graphical and multinomial logit regression analyses to test whether matrix metalloproteinase-2 or matrix metalloproteinase-9 activities could discriminate among 4 different types of colorectal tissue (normal mucosa, adenomas with or without high-grade dysplasia, and invasive carcinomas). Active matrix metalloproteinase-2 successfully discriminated among these tissue categories. Median activity for active matrix metalloproteinase-2 increased in a stepwise fashion with pathologic progression from normal mucosa to adenoma without high-grade dysplasia to adenoma with high-grade dysplasia to cancer. Although pro-matrix metalloproteinase-2 and pro-matrix metalloproteinase-9 activities could discriminate to some extent among tissue categories, those effects did not contribute additional information. Active matrix metalloproteinase-2 activity correlated significantly with histopathologic assessment of colorectal tissues. The ability of active matrix metalloproteinase-2 to distinguish adenomas with high-grade dysplasia from adenomas without high-grade dysplasia may be particularly useful in predicting future colorectal cancer risk for an individual, thus optimizing scheduling of surveillance colonoscopies.     

Lymphocyte migration through the blood–brain barrier (BBB) in feline immunodeficiency virus infection is significantly influenced by the pre‐existence of virus and tumour necrosis factor (TNF)‐α within the central nervous system (CNS): studies using an in vitro feline BBB model

Aims: In human immunodeficiency virus infection, macrophage‐tropic and lymphotropic viruses exist in the host. Central nervous system (CNS) infection is an early and ongoing event, important to understand when developing strategies to treat infection. Some knowledge exists on macrophage‐tropic virus interactions with the blood–brain barrier (BBB), and the aim of this study was to investigate lymphotropic lentivirus interactions with the BBB. Methods: Interactions of the lymphotropic feline immunodeficiency virus (FIV) with an in vitro model of the feline BBB were evaluated in scenarios to mimic in vivo infections. Results: Cell‐free FIV crossed the BBB in very low quantities, and in the presence of tumour necrosis factor (TNF)‐α, BBB integrity was unaffected. However, cell‐associated FIV readily crossed the BBB, but BBB integrity was not significantly altered. Transmigration of uninfected and infected lymphocytes increased in response to TNF‐α, accompanied by a moderate disruption of barrier integrity and an upregulation of vascular cell adhesion molecule‐1 rather than intercellular adhesion molecule‐1. Significant enhancement of migration and disruption of BBB tight junctions occurred when infected cells and TNF‐α were added to the brain side of the BBB and this enhancement was not mediated through additional TNF‐α production. Conclusions: Small quantities of virus in the brain together with TNF‐α have the potential to stimulate greater cell and viral entry into the CNS and this is likely to involve important factors other than further TNF‐α production. Lymphotropic lentivirus entry to the CNS is governed by many factors similar to macrophage‐tropic strains.     

A longitudinal study of infant feeding and obesity throughout life course

BACKGROUND: The Centers for Disease Control and Prevention and the US Department of Health and Human Services promote breastfeeding as a strategy for reducing childhood overweight. We evaluated the relation between infant feeding and the development of overweight and obesity throughout life course. METHODS: We investigated the association between infant feeding and obesity among 35,526 participants in the Nurses' Health Study II who were followed prospectively from 1989 to 2001. Mothers of participants provided information by mailed questionnaires on the duration of breast- and bottle-feeding, as well as the type of milk or milk substitute in the bottle. Information on body shape at ages 5 and 10, weight at age 18, current weight between 1989 and 2001, and height was reported by the participants. RESULTS: The duration of breastfeeding, including exclusive breastfeeding, was not related to being overweight (25< or = body mass index (BMI) <30 kg/m(2)) or obese (BMI> or =30 kg/m(2)) during adult life. Women who were exclusively breastfed for more than 6 months had a risk of 0.94 (95% confidence interval (CI) 0.83-1.07) of becoming obese as adults compared with women who were not breastfed. Exclusive breastfeeding for more than 6 months was associated with leaner body shape at age 5 (odds ratio (OR)=0.81; 95% CI 0.65-1.01 for the highest vs the lowest category of body shape) compared to women who were not breastfed or breastfed for less than 1 week, but this association did not persist during adolescence or adulthood. CONCLUSIONS: We did not find that having been breastfed was associated with women's likelihood of becoming overweight or obese throughout life course. Although breastfeeding promotes the health of mother and child, it is unlikely to play an important role in controlling the obesity epidemic.     

The combined influence of multiple sex and growth hormones on risk of postmenopausal breast cancer: a nested case-control study

Introduction  

Sex and growth hormones are positively associated with postmenopausal breast cancer risk. However, few studies have evaluated the influence of multiple hormones simultaneously.     

Exploring the oral bacterial flora: current status and future directions

Oral Diseases (2010) 16 , 136–145 Objective: The oral cavity forms an indispensable part of the human microbiome, for its unique and diverse microflora distributed within various niches. While majority of these organisms exhibit commensalism, shifts in bacterial community dynamics cause pathological changes within oral cavity and distant sites. The aim of this review was to appraise the current and emerging methods of detecting bacteria of the oral cavity paying particular attention to the cultivation independent methods. Design: Literature pertaining to cultivation based and cultivation independent methods of oral bacterial identification was reviewed. Methods: The specific advantages and disadvantages of cultivation based, microscopic, immunological and metagenomic identification methods were appraised. Results: Because of their fastidious and exacting growth requirements, cultivation based studies grossly underestimate the extent of bacterial diversity in these polymicrobial infections. Culture independent methods deemed more sensitive in identifying difficult to culture and novel bacterial species. Conclusion: Apart from characterizing potentially novel bacterial species, the nucleic acid sequence data analyzed using various bioinformatics protocols have revealed that there are in excess of 700 bacterial species inhabiting the mouth. Moreover, the latest pyrosequencing based methods have further broadened the extent of bacterial diversity in oral niches.     

Life-course weight characteristics and the risk of gestational diabetes

Aims/hypothesis  

We prospectively determined the risk of gestational diabetes mellitus in association with life-course weight characteristics and adult abdominal adiposity.