Both Th1 and Th2 cells require P-selectin glycoprotein ligand-1 for optimal rolling on inflamed endothelium

The acquisition of homing receptors that redirect lymphocyte trafficking to nonlymphoid tissues after antigen encounter is a fundamental aspect of effector T-cell development. Although a role for selectins and their ligands has been well characterized for trafficking of Th1 cells to nonlymphoid sites, mechanisms responsible for Th2 trafficking are not well understood. Using a flow chamber system in which the endothelial interactions of two distinct T-cell populations could be examined simultaneously, we directly compared the requirements for Th1 and Th2 cell tethering and rolling. We found that although Th2 cells expressed significantly lower levels of selectin ligands than Th1 cells, activation of the endothelium by Th2-derived factors induced rolling interactions that were comparable for both Th1 and Th2 populations. Further, in the absence of PSGL-1, no other adhesion molecule could effectively compensate for lack of PSGL-1 to mediate rolling of either Th1 or Th2 cells. Thus, both Th1 and Th2 populations express functional PSGL-1-based selectin ligands for tethering and rolling on activated endothelium, and both effector populations can use PSGL-1 as the dominant scaffold for functional selectin ligand expression.     

Blood feeding patterns of Aedes aegypti and Aedes albopictus in Thailand

Aedes aegypti (L.) and Aedes albopictus (Skuse) were collected with aspirators from Mae Sot, Nakhon Sawan, Nakhon Ratchasima, Surat Thani, and Phatthalung study sites in Thailand from July 2003 though April 2004. The sandwich-B enzyme-linked immunosorbent assay was used to analyze 1,021 blood-fed specimens. Ae. aegypti almost exclusively fed on humans (99%, 658/664) in single host species, and 97% (86/88) of multiple-host bloodmeals included at least one human host. A low frequency of other hosts, including bovine, swine, cat, rat, and chicken were detected, but they represented <1% of bloodmeals. An even higher percentage of human feeding was detected in Ae. albopictus. Hosts of Ae. albopictus collected from sites in southern Thailand were entirely human (100%, n = 105) from both single and mixed meals. In the small number of double-host meals from Ae. albopictus, we detected 3.8% as swine-human and <1% from dog-human and cat-human. Forage ratios for Ae. aegypti indicated that human, dog, and swine were preferred hosts in order of preference. In contrast, bovine and chicken were avoided hosts for this species in Thailand.     

Evidence for recombination in the flagellin locus of Campylobacter jejuni: implications for the flagellin gene typing scheme.

The flagellin subunit of the flagellar filament in Campylobacter jejuni is encoded by two highly homologous tandem genes, flaA and flaB. The flaA gene was sequenced in 18 strains of C. jejuni, including isolates from three outbreak groups. Sequences obtained were compared with flaA sequences available in the GenBank database, and all were analyzed for mosaic gene structure by using recently described statistical tests for detecting gene conversion among aligned sets of sequences. Strong evidence was found supporting recombination between flaA genes of different strains (i.e., intergenomic recombination). Intragenomic recombination between the flaA and flaB genes of C. jejuni TGH9011 was also demonstrated. Both mechanisms of recombination may act as a potential means by which pathogenic strains can generate increased antigenic diversity, so allowing them to escape the immunological responses of the host. Furthermore, demonstration of recombination within and between flagellin loci of natural strains suggests that flagellin gene typing (restriction fragment length polymorphism analysis of PCR-amplified flagellin genes) cannot be considered a stable method for long-term monitoring of pathogenic Campylobacter populations.     

Soluble B7-H1: differences in production between dendritic cells and T cells

Tumor cells aberrantly express several T cell inhibitory molecules including members of the B7-H co-regulatory family. Presumably tumor-expressed B7-H1 and B7-H3 confer resistance to elimination by the immune system. In addition, elevated levels of soluble B7-H1 (sB7-H1) has been identified in the sera of cancer patients, including renal carcinoma patients and is associated with increased cancer related death. Here we report that sB7-H1 is produced and released by activated mature dendritic cells (mDC). Immature DC, macrophages, monocytes, or T cells are refractory to releasing sB7-H1. Exposure of CD4+ and CD8+ T cells to mDC-derived sB7-H1 molecules induced apoptosis. These data suggest that the immunobiology of B7-H1 is perhaps more complex than previously thought. sB7-H1 molecules may represent an unanticipated contributing factor to immune homeostasis. That both immune and tumor cells can be sources of sB7-H1 suggests that optimization of co-regulatory blockade immunotherapy for solid malignancies of necessity will require impact of targeting tumor and immune-derived B7-H1 molecules.     

Research workshop to research work: initial steps in establishing health research systems on Malaita,Solomon Islands

Introduction  

Atoifi Adventist Hospital is a 90 bed general hospital in East Kwaio, Malaita, Solomon Islands providing services to the population of subsistence villagers of the region. Health professionals at the hospital and attached College of Nursing have considerable human capacity and willingness to undertake health research. However they are constrained by limited research experience, training opportunities, research systems, physical infrastructure and access to resources. This brief commentary describes an 'Introduction to Health Research' workshop delivered at Atoifi Adventist Hospital in September 2009 and efforts to move from 'research workshop' to 'research work'.     

Impact of Strain Typing Methods on Assessment of Relationship between Paired Nares and Wound Isolates of Methicillin-Resistant Staphylococcus aureus

The anterior nares are the site of choice for the Veterans Administration methicillin-resistant Staphylococcus aureus (MRSA) surveillance program; however, a correlation between nares colonization and concomitant wound infections has not been well established. The purpose of this study was 3-fold: to determine the relatedness of MRSA isolates from 40 paired wound and nares specimens by four different strain typing methods, to determine concordance of typing methods, and to establish a baseline of MRSA types at this medical center. Isolates were typed by repetitive PCR (rep-PCR) (DiversiLab System; DL) and SpectraCell Raman analysis (SCRA) (commercially available methods that can be performed within a clinical lab), pulsed-field gel electrophoresis (PFGE), and an antibiotic susceptibility profile (AB). Whole-genome optical mapping (WGM) (OpGen, Inc.) was performed on selected isolates. All methods agreed that 26 pairs were indistinguishable and four pairs were different. Discrepant results were as follows: 4 where only SCRA was discordant, 3 where only AB was discordant, 2 where both DL and AB were discordant, and 1 where both DL and SCRA were discordant. All WGM agreed with PFGE. After discrepancy resolution, 80% of the pairs were indistinguishable and 20% were different. A total of 56% of nares results were nonpredictive if negative nares and positive wound cultures are included. Methods agreed 85 to 93% of the time; however, congruence of isolates to a clade was lower. Baseline analysis of types showed that 15 pairs were unique to single patients (30 strains, 38%; 47% of the matching pairs). Twenty-five strains (30%) represented a single clade identical by PFGE, SCRA, and DL, decreasing specificity. Typing method and institutional type frequency are important in assessing MRSA strain relatedness.     

Deletion of the <Emphasis Type="Italic">MAT-</Emphasis>2 mating-type gene during uni-directional mating-type switching in <Emphasis Type="Italic">Ceratocystis</Emphasis>

 Ceratocystis eucalypti is strictly heterothallic, with single ascospore strains representing one of two opposite mating types. Most other Ceratocystis species, including C. virescens, C. pinicola, and C. fimbriata, are homothallic. In the homothallic species, the MAT-2 strains are self-fertile, while MAT-1 strains are self-sterile and grow more slowly than MAT-2 strains. The current hypothesis is that self-fertility of MAT-2 strains is due to the deletion of the MAT-2 mating-type gene, resulting in the expression of the MAT-1 mating type. These mutant MAT-1 strains are able to cross with MAT-2 strains. Part of the MAT-2 mating-type gene in C. eucalypti, C. pinicola, and C. fimbriata was amplified using degenerate primers designed from the conserved MAT-2 HMG DNA-binding motif. The expected approximately 300-bp PCR products were cloned and sequenced. Specific primers were designed that amplified 210-bp fragments only in MAT-2 isolates of C. eucalypti, C. virescens, C. pinicola, and C. fimbriata. These fragments were present in self-fertile field isolates and self-fertile progeny but were absent in the self-sterile (MAT-1) progeny from selfings of C. virescens, C. pinicola, and C. fimbriata, thus supporting the hypothesis that the MAT-2 mating-type gene is deleted during uni-directional mating-type switching. A Southern-blot analysis was performed to confirm the deletion of MAT-2 gene in self-sterile progeny. The DNA sequence data for the C. eucalypti MAT-2 mating-type gene was increased to 1371-bp using TAIL-PCR and uneven PCR, representing a portion of the complete MAT-2 gene DNA sequence. Received: 5 November 1999 / 25 February 2000     

Evaluation of a community-based model of rehabilitation following traumatic brain injury

In recent years there has been a growing trend towards community-based post-acute rehabilitation for individuals with traumatic brain injury (TBI), as opposed to the traditional centre-based model, based on the premise that these individuals will learn more effectively in settings where they usually have to perform. In the present study, outcomes at two years post-injury in 77 individuals with TBI, treated within the community were compared on measures of activities of daily living (ADL), vocational status, and emotional adjustment with those of 77 TBI patients individually matched for gender, age, education, occupation, post-traumatic amnesia (PTA) duration, Glasgow Coma Scale (GCS) score and time in inpatient rehabilitation, who had attended the hospital for outpatient therapy. There were no significant differences between groups in terms of employment outcomes or independence in personal or domestic ADL. However those treated in the community were less likely to be independent in shopping and financial management and reported more changes in communication and social behaviour. Due to constraints of time and resources, these patients had received fewer one-on-one therapy sessions and thus treatment costs were somewhat lower. Attendant care costs were also lower in the community treatment group. Strengths and weaknesses of community-based post-acute rehabilitation are discussed.     

Sexual difficulties within a group of patients with vulvodynia

Dyspareunia, caused by vulvodynia, has, like other sexual problems, evolved from being conceptualized as a psychological problem through a period when it became viewed by the medical world as a physical problem. It is now seen as being a combination of psychological and physical factors. However, no research to our knowledge has explored in depth the level of sexual and relationship difficulties of this population. This investigation involved 172 women (85 suffering with vulvodynia and 87 women in a control group with general dermatology conditions) to establish the prevalence of relationship and sexual difficulties, using validated questionnaires, a newly devised symptom checklist and a structured interview. The results demonstrated increased levels of sexual and relationship difficulties within the vulvodynia group that need further exploration.