A role for the integrin alpha6beta1 in the differential distribution of CD4 and CD8 T-cell subsets within the rheumatoid synovium.

OBJECTIVE: CD4 and CD8 T-cell subsets accumulate in distinct microdomains within the inflamed rheumatoid synovium. The molecular basis for their differential distribution remains unclear. Since chemokines and adhesion molecules play an important role in the positioning of leucocytes at sites of inflammation, we tested the hypothesis that the differential expression and function of chemokine and/or adhesion molecules explains why CD4(+) T cells accumulate within perivascular cuffs, whereas CD8(+) T cells distribute diffusely within the tissue. METHODS: Expression of an extensive panel of chemokine receptors and adhesion molecules on matched CD4(+) and CD8(+) T cells from peripheral blood (PB) and synovial fluid (SF) was analysed by multicolour flow cytometry. Migration assays and flow-based adhesion assays were used to assess the functional consequences of any differences in the expression of chemokine and adhesion receptors. RESULTS: CD4(+) and CD8(+) T cells from PB and SF expressed unique yet consistent patterns of chemokine and adhesion receptors. SF CD8(+) T cells were much less promiscuous in their expression of chemokine receptors than SF CD4(+) T cells. The alpha(6)beta(1) integrin was highly expressed on PB CD4(+) T cells, but not on PB CD8(+) T cells. Laminin, the ligand for alpha(6)beta(1), retained CD4(+) T cells, but less so CD8(+) T cells, within inflamed synovial tissue. CONCLUSION: Infiltrating PB CD4(+) T cells, but not CD8(+) T cells, express functional levels of the alpha(6)beta(1) integrin. We propose that this leads to their retention within the rheumatoid synovium in perivascular cuffs, which are defined and delineated by the expression of laminin.

Generalised cranial artery spasm in human rabies.

In 2004, a teenager survived bat-associated rabies through the Milwaukee protocol (MP). This survivor and another patient with dog-associated rabies were found to have developed deficiencies of tetrahydrobiopterin (BH4) and associated neurotransmitters. BH4 is also essential for neuronal nitric oxide synthase (nNOS), so rabies is predicted to cause constriction of cerebral arteries. We assume that rabies virus, which almost exclusively targets neurons, would disproportionately affect cerebral over systemic perfusion by disrupting nNOS and lead to generalised cerebral artery spasm. Cranial artery vasospasm, therefore, was actively sought in two rabies patients, with the intention to specifically treat with BH4 and L-arginine when necessary. Flow velocities and resistive (RI) or pulsatility indices (PI) of middle cerebral arteries (MCA) were obtained by transcranial doppler ultrasound (TCD). A survival analysis of 8 attempts at the MP is presented. Of these, two cases are reported here. The first case is one child with bat-associated rabies who developed severe bilateral MCAspasm on hospital day (HD)-10 that responded to very low dose (0.2 mcg/kg/min) nitroprusside. The second case, a child with dog-associated rabies, developed spasm of MCA on HD-6 that responded to 6 mg/kg/day BH4. A second spasm with high RI (without cerebral oedema or increased intracranial pressure) responded to 20 mg/kg/day BH4 and 0.5 g/kg/dose L-arginine. Review of the TCD of the first child showed a similar second spasm seven days after first episode. Cerebral artery vasospasm occurred in the two children with rabies, but was clinically silent by standard monitoring. Spasm responded to drugs directed at the NOS pathway. Animal models for treatment of rabies are sorely needed to evaluate therapy.

Type III protein secretion is associated with death in lower respiratory and systemic Pseudomonas aeruginosa infections.

The ability of Pseudomonas aeruginosa to secrete specific toxins using the type III-mediated pathway has been reported. To determine the association of this phenotype with human illness, immunoblot analysis was used to detect expression of type III secretory proteins in P. aeruginosa isolates from respiratory tract or blood cultures of 108 consecutive patients. Relative risk of mortality was 6-fold greater with expression of the type III secretory proteins ExoS, ExoT, ExoU, or PcrV. Phenotype was independently correlated with toxicity in cellular and murine models. Prevalence of this phenotype was significantly higher in acutely infected patients than in chronically infected patients with cystic fibrosis. These results suggest that the type III protein secretion system is integral to increased P. aeruginosa virulence. A positive phenotype is a predictor of poor clinical outcome. In the future, such analyses may help distinguish potentially lethal infection from colonization and help determine appropriate therapy for critically ill patients.

Novel HPV types present in oral papillomatous lesions from patients with HIV infection.

Patients infected with the human immunodeficiency virus (HIV) often develop multiple papillomatous lesions of the oral cavity. In the present study, a total of 67 biopsies from benign oral lesions were analyzed for the presence of human papillomavirus (HPV) DNA using Southern-blot hybridization in combination with a polymerase chain reaction designed to detect all known HPV types, as well as unidentified types. These samples, collected at random from a high-risk population, were subsequently divided into 57 biopsies originating from patients with confirmed HIV infection and 10 biopsies from patients with unknown HIV status. Each sample was amplified with 7 different combinations of degenerate primers. All amplified products were sequenced. HPV DNA sequences were detected in 67% (45/67) of the samples. HPV 7 (19%) and HPV 32 (28%) were the predominant HPV types. HPV 32 was present in 2/4 fibromas tested. Two new HPV types, HPV 72 and HPV 73, were identified in oral warts with atypia. The complete genomes of these viruses were cloned and sequenced. Other HPV types detected were HPV 2a, HPV 6b, HPV 13, HPV 16, HPV 18, HPV 55, HPV 59 and HPV 69.

Nucleotide sequence and phylogenetic classification of human papillomavirus type 59.

The complete nucleotide sequence of the HPV 59 DNA genome, isolated from a vulvar intraepithelial neoplasia, was determined. It consists of 7896 nucleotides. A comparative analysis of this sequence with the sequences of other HPV types revealed the closest homology to HPV 18 (71%), HPV 45 (70%), and HPV 39 (69%). Phylogenetic analysis of the complete L1 ORFs of HPV 59 and other papillomaviruses exclusively groups all HPVs which have been detected in mucosal lesions into one major branch. This major branch, in turn, includes two specific subgroups containing all high risk viruses associated with malignant mucosal lesions. The motif in the L2 ORF thr-thr-pro-ala-val/ile-leu/ile-asp/asn-val/ile, an extension of a previously reported mucosal motif, is highly conserved in all HPV types detected in mucosal lesions, whereas it is totally absent in those viruses exclusively associated with cutaneous lesions.

Anaesthesia and the elderly.

The peri-operative management of elderly patients presents a variety of problems to the anaesthetist. These include organ dysfunction associated with the ageing process and the high incidence of serious disease affecting major organ systems. In addition, elderly patients commonly require multiple drug therapy. As such they are likely to suffer adverse drug effects and interactions, events more liable to occur in these patients as a result of both pharmacokinetic and pharmacodynamic factors. Occasionally serious interactions may occur with drugs used during anaesthesia. The importance of adequate pre-operative assessment and preparation cannot be overemphasized, as well as the need for a team approach to the management.

EEG alpha-biofeedback training: an experimental technique for the management of anxiety.

This paper outlines the design of a specialized alpha-biofeedback system for use in the treatment of anxiety. The relationship of electroencephalographic (EEG) alpha activity to various anxiety states is described, and the rationale for use of alpha-biofeedback training with chronic anxiety patients is explained. Those features of the specialized system, and associated training methods, which are considered essential for this particular application are described and include the following: (1) use of visual feedback and eyes-open training; (2) use of oculomotor influences to facilitate alpha production; (3) encouragement of a passive attitude in the patient by using both verbal instructions and 'low-information' feedback with covert shaping. The training procedures used and the design and function of the instrument are described. The initial clinical results obtained with this equipment are also presented.