A report from the international consensus on diagnosing and treating the infected diabetic foot

In persons with diabetes, foot infection, that is, invasion and multiplication of microorganisms in tissues accompanied by tissue destruction or a host inflammatory response, usually begins with skin trauma or ulceration 1. While most foot infections remain superficial, they can spread to subcutaneous tissues, including muscle, joints, and bone. Many diabetic foot ulcers eventuate in an amputation; infection plays a role in approximately 60% of cases 2-4. Neuropathy is the main factor leading to skin breaks, while arterial perfusion largely affects infection outcome. Among the factors predisposing diabetic patients to foot infections are ill-defined immunological perturbations 56; foot anatomy may foster proximal spread of infection and ischemic necrosis 78.     

Differential expression of human COMT alleles in brain and lymphoblasts detected by RT-coupled 5′ nuclease assay

Rationale A common polymorphism, Val158Met, alters catechol-O-methyltransferase (COMT) enzyme activity and has been linked to psychiatric phenotypes. Bray et al. (2003) reported that COMT is subject to differential allele expression in brain, finding modest (13–22%) underexpression of a haplotype containing Val158. However, disparate findings by another group who used the same method, but in lymphoblasts, raise the issues of tissue specificity, magnitude of differential expression, and identity of loci altering expression.Objectives We measured COMT allele expression ratios in heterozygous human lymphoblast cell lines and brains.Methods Using transcribed single nucleotide polymorphisms as endogenous reporters, we developed an RT-coupled 5 nuclease assay for allele expression ratios and applied it to 63 COMT rs4818(C>G) heterozygotes and 68 Val158Met [rs4680(G>A)] heterozygotes.Results For rs4818(C>G), the C allele was overexpressed relative to the G allele in 18 of 27 lymphoblast lines and 23 of 36 brains. For Val158Met, Met158 was overexpressed relative to Val158 in all (29 of 29) lymphoblast lines and all (39 of 39) brains. Each of the 22 rs4818 heterozygotes without differential allele expression was a Val158/Val158 homozygote. The Met158 allele was overexpressed by 65–77% when compared with Val158 in lymphoblasts and brain. Haplotype augmented ability to predict expression in brain only. However, the expression of the Val158 allele on the high-expressing haplotype was only 19% higher than Val158 alleles on the other haplotype background.Conclusions COMT alleles are differentially expressed. The Met158 allele predicts higher mRNA expression in both brain and lymphoblasts. As exemplified here, the RT-coupled 5 nuclease assay is a reliable method for the quantitative evaluation of cis-acting regulatory effects.     

Diminished peripheral blood memory B cells and accumulation of memory B cells in the salivary glands of patients with Sjögren's syndrome

OBJECTIVE: To delineate the mechanism of the abnormalities in B cell biology found in patients with primary Sj?gren's syndrome (SS). METHODS: The distribution of peripheral B cell subpopulations in 21 patients with primary SS was analyzed by immunofluorescence labeling and flow cytometry. Immunoglobulin rearrangements were analyzed in single B cells isolated from the peripheral blood and parotid glands by fluorescence-activated cell sorting. RESULTS: A significant reduction in the number of peripheral CD27+ memory B cells was found in SS patients, including a significantly reduced number of CD27+/IgD+/IgM+/CD5+ memory B cells. Remarkably, SS patients with secondary lymphoma uniquely exhibited an increase in CD27-expressing peripheral B cells, including CD27(high) plasmablasts. Molecular analysis for mutated Ig gene rearrangements confirmed that CD27 expression distinguished naive and memory cells in SS. In contrast to the peripheral blood, the majority of parotid B cells from 1 patient examined exhibited both the mutational status and phenotype of memory B cells. Accordingly, the mutational frequencies of V(H) rearrangements were significantly greater in parotid B cells than in peripheral blood B cells, whereas the V(H) gene repertoire appeared to be very similar between the compartments. CONCLUSION: These data indicate that there is an accumulation/retention of memory B cells in the inflamed salivary glands of SS patients. It is possible that preferential accumulation of CD27+ memory B cells in the inflamed parotid gland explains their reduction in the peripheral blood.     

Effects of mycophenolic acid on detection of glial filaments in human and rat astrocytoma cultures

Expression of glial fibrillary acidic protein (GFAP) was assayed in 11 glioma-derived cell cultures. Treatment of cells with an inhibitor of guanine nucleotide biosynthesis, mycophenolic acid, enhanced detection of GFAP by indirect immunofluorescence microscopy. Quantitation of GFAP and vimentin demonstrated that enhanced fluorescence occurs without an increase in the level of intermediate filament proteins. Immunoblots provided the most sensitive method for monitoring GFAP expression and showed the limitations of using immunofluorescence detection methods. GFAP was detectable in cultures derived from malignant Grade IV astrocytomas and its expression was stable during the course of the study. While mycophenolic acid has been reported to induce differentiation in leukemia cells at low concentration (D.L. Lucas et al., J. Clin. Invest., 72: 1889-1990, 1983), its effect on glioma cultures at concentrations of 100 microM was consistent with a role as an inhibitor of DNA synthesis, and as an effector of altered intermediate filament organization.     

Cellular basis for rheumatoid inflammation

Rheumatoid arthritis (RA) is a chronic idiopathic disease characterized by persistent inflammation of the synovium, local destruction of bone and cartilage, and a variety of systemic manifestations. Although the etiologic stimulus has not been identified, rheumatoid synovitis is characterized by persistent immunologic activity, with CD4(+)/CD29(+) memory T cells prominently involved. Many of the local and systemic manifestations of RA appear to result from the production of a variety of cytokines within the inflamed synovium. A number of other inflammatory mediators produced in the rheumatoid synovium, including arachidonic acid metabolites, vasoactive amines, platelet-activating factor, and complement cleavage products contribute to the inflammatory process. In addition, the local production of immunoglobulin and the autoantibody, rheumatoid factor, along with the local production of immune complexes and complement activation, play a major role in the destructive potential of rheumatoid synovitis. The driving force behind rheumatoid inflammation, however, is likely to be CD4(+) T cells responding to an antigenic epitope in the synovium in an HLA-DR restricted manner. Understanding the immunopathogenic process underlying rheumatoid inflammation should provide insight into approaches to control the disease effectively and specifically.     

Obstetric and nonmalignant gynecologic bleeding: treatment with angiographic embolization

Eight patients (seven post partum, one post abortion) with massive pelvic hemorrhage related to pregnancy and one patient with uncontrollable bleeding following a cervical biopsy underwent angiography to facilitate the identification and treatment of bleeding sites. In all nine patients pelvic hemorrhage was successfully controlled with embolization under angiographic guidance. Angiographic embolization allowed preservation of the uterus in six patients referred prior to hysterectomy, and one patient subsequently became pregnant. When conservative measures and minor surgical repairs have failed, embolization should be the next step in the treatment of postpartum hemorrhage to avoid major surgery in an unstable patient and to maintain reproductive function.     

Hyperplastic and neoplastic alterations in the livers of white perch (Morone americana) from the Chesapeake Bay

White perch (Morone americana) sampled from 15 estuaries of the Chesapeake Bay contained a variety of hyperplastic and neoplastic alterations in their livers. The lesions were derived from bile ductular epithelium and/or hepatocytes. The biliary lesions consisted of hyperplasias and adenomas. The hepatocellular lesions consisted of focal populations of altered cells and neoplasms, of clear-cell and basophilic morphologic appearance. The hepatocellular lesions were conspicuous in the absence of the decreased amount of copper accumulation. In this respect, the cells comprising these lesions are reminiscent of cells from hepatocellular neoplasia in mice and rats resistant to accumulation of iron.     

Molecular mimicry in the pathogenesis of rheumatic diseases

Evidence has been presented to support the conclusion that epitope-specific cross-reactive autoimmunity generated in response to a microorganism can result in an inflammatory sequela. The role of this mechanism in the pathogenesis of the experimental disease, adjuvant arthritis, appears clear. In the case of human rheumatic conditions, such as rheumatic fever and the HLA-B27-associated reactive arthritides, the role is not yet established, but clinical evidence suggests that the hypothesis is an attractive one.