Limiting dilution analysis reveals the precursors of interleukin-4-producing CD4+ cells induced by protein immunization.

Although cytokine-producing T cells play a key role in the response to vaccination, they are not always revealed by antigen stimulation of primed lymphoid cells in vitro. In this study, mice were immunized subcutaneously with alum-precipitated keyhole limpet haemocyanin (KLH) in adjuvant to activate interleukin-4 (IL-4)-producing CD4+ T cells. IL-4 mRNA was the dominant cytokine mRNA species found in draining lymph nodes (LN) 7 days after immunization and its levels were increased after in vitro stimulation with KLH for 24 hr. IL-4 protein, on the other hand, was not detected in the supernatants of such antigen-stimulated cultures. The presence of T cells primed for IL-4 production was nevertheless suggested by the findings that primed LN cells produced low IL-4 titres in response to anti-CD3 antibody, whereas normal LN cells did not, and primed CD4+ LN cells produced readily detectable IL-4 levels in response to antigen after one or more cycles of in vitro restimulation. Culture at limiting dilution showed that 1-2% of 7 day KLH-primed CD4+ LN cells were clonogenic and specific for KLH without prior expansion in vitro, and that this frequency was markedly increased by repeated stimulation in bulk culture. Most clonogenic cells in primed LN gave rise to IL-4-secreting clones and a smaller number gave rise to interferon-gamma (IFN-gamma)-producing clones. The precursor frequency of IL-4-producing CD4+ cells in primed LN and the average IL-4 titre per cloned cell support the conclusion that these two parameters account for the low levels of IL-4 produced in bulk culture by LN cells from immunized mice.     

Effect of polyphenolic compounds on the renal Na+,K(+)-ATPase during development and persistence of hypertension in rats

It has been suggested that polyphenolic substances provide protection against the risk factors of cardiovascular diseases. The present study was designed to investigate whether application of red wine polyphenols influences the kinetic properties of the renal Na+,K(+)-ATPase in rats with hypertension (164 +/- 8 mmHg) that was experimentally induced by the NO synthase inhibitor N(G.) -nitro-L- arginine methyl ester (L-NAME). Polyphenols in a dose of 40 mg kg(-1) day(-1) in drinking fluid induced different effects on the properties of the renal Na+,K(+)-ATPase depending on the mode of their administration. Preventive application of polyphenols during the development of hypertension (144 +/- 5 mmHg) partially protected the Na+,K(+)-ATPase molecule against hypertension-induced deterioration via increased capability of the enzyme to bind ATP and/or Na+ as suggested by decrease of Km and KNa, respectively, even to values lower than in controls. However, polyphenols did not prevent the hypertension-induced reduction of the number of active Na+,K(+)-ATPase molecules as shown by similar V(max) values as compared to the hypertensive L-NAME group. The above protection is probably secured by a NO-dependent mechanism as suggested by 150% increase of the NO synthesis. Additional treatment of already hypertensive animals with polyphenols (153 +/- 8 mmHg) resulted in partial restoration of the Na+,K(+)-ATPase affinities especially for sodium as indicated by significant diminution of KNa. However, polyphenols in this mode of application did not slow down the L-NAME-induced decrease in the number of Na+,K(+)-ATPase molecules in the kidney as suggested by additional significant decrease in V(max) values when comparing this group with the control group and also the hypertensive L-NAME group. In this case the polyphenols affected the Na,K-ATPase molecule in a NO-independent way as indicated by the fact that polyphenols failed to restore normal NO synthesis.     

Germline mutations of the CDKN2 gene in UK melanoma families

Germline mutations in CDKN2 on chromosome 9p21, which codes for the cyclin D kinase inhibitor p16, and more rarely, mutations in the gene coding for CDK4, the protein to which p16 binds, underlie susceptibility in some melanoma families. We have sequenced all exons of CDKN2 and analysed the CDK4 gene for mutations in 27 UK families showing evidence of predisposition to melanoma. Five different germline mutations in CDKN2 were found in six families. Three of the mutations (Met53Ile, Arg24Pro and 23ins24) have been reported previously. We have identified two novel CDKN2 mutations (88delG and Ala118Thr) which are likely to be associated with the development of melanoma, because of their co-segregation with the disease and their likely functional effect on the CDKN2 protein. In binding assays the protein expressed from the previously described mutation, Met53Ile, did not bind to CDK4/CDK6, confirming its role as a causal mutation in the development of melanoma. Ala118Thr appeared to be functional in this assay. Arg24Pro appeared to bind to CDK6, but not to CDK4. No mutations were detected in exon 2 of CDK4, suggesting that causal mutations in this gene are uncommon. The penetrance of these mutant CDKN2 genes is not yet established, nor is the risk of non-melanoma cancer to gene carriers.      

The use of macrolides in respiratory tract infections

Macrolides have enjoyed continued use for over 40 years, being increasingly used for the treatment of respiratory tract infections. Newer macrolides have been introduced that show improved absorption after oral administration, better gastrointestinal tolerance, and delivery of increased amounts of drug to the infection site. Macrolides are commonly used in community-acquired pneumonia, as well as in atypical pneumonia and legionellosis. The newer macrolides, in comparative studies, have been shown to be as affective as the conventional therapies for treating acute otitis media, acute sinusitis and acute pharyngitis, with a low incidence of side-effects. However, dosing can be simplified because of their unique pharmacokinetic properties. Limitations in the use of macrolides for respiratory infections include rather marginal activity in the most severe cases of Haemophilus influenzae infections, lack of activity against Klebsiella and other coliforms, which precludes their use as single agents in the therapy of pneumonia in patients with significant underlying disease or in the elderly, and development of resistance in streptococci and staphylococci.     

IMPORTANCE OF DONOR SELECTION IN RENAL TRANSPLANTATION

Renal transplantation has become a treatment of choice for patients with end stage renal disease. A successful transplant is the result of a combination of several factors acting synergistically, such as the degree of HLA compatibility between donor and the recipient, pretransplant blood transfusions, the recipient''s state of immunoreactivity and sensitization, immunosuppressive therapy given in post operative period etc. Donor selection appears to be the most critical factor for the long term success of the organ graft. In this brief review, some of the important parameters of donor selection in renal transplantation are highlighted.KEY WORDS: Histocompatibility (HLA) matching, Cross match, Sensitization     

Proteus syndrome

Abstract: This female Asian (Malay) baby had clinical features of Proteus syndrome. She had a large right facial lipolymphangioma with hyperpigmentation of the overlying skin. There was a smaller lymphangioma over the left side of her neck with excess nuchal folds, macrodactyly and bilateral talipes equinovarus. Despite the extensive hemifacial swelling, there was no evidence of upper respiratory tract obstruction. Generalized seizures developed on the sixth day of life which were controlled with phenobarbital. The lymphangiomas were excised without recurrence.     

ANTIBIOTIC RESISTANCE PATTERN OF ISOLATES FROM WOUND AND SOFT TISSUE INFECTIONS

Two-hundred and eighty bacterial isolates from wound and soft tissue infections were studied for species identification and antibiotic resistance pattern. Amongst them 122 isolates were from community acquired infection and 158 were from nosocomial infections. The common community acquired pathogens were Staphylococcus aureus (67.8%) and Streptococcus pyogenes (10.7%), whereas Staphylococcus aureus (60.1%) and E. Coli (8.9%) were common in nosocomial infection. Only two anaerobes (Cl perfringens) were isolated. Penicillin resistance was found to be 87% and 92% for Staphylococccus aureus in community acquired and noscomial infections respectively. 85% of Proteus isolates were resistant to ampicillin. There was relatively lower level of resistance by all isolates to cefotaxime. Gentamicin showed higher rate of resistance than netilmicin and amikacin. Resistance of E. coli isolates to fluoroquinolones being 79% for norfloxacin, 81% for ciprofloxacin and 60% for ofloxacin. The study showed a higher resistance of methicillin resistant Staphylococcus aureus (MRSA) to other antibiotics. Amikacin and ofloxacin were the best recommended drugs for empirical therapy for all organisms, the susceptibility rate being 80.7% and 80.4%.KEY WORDS: Antibiotic resistance, Soft tissue infections, Wound infections     

Perioperative infliximab application has marginal effects on ischemia–reperfusion injury in experimental small bowel transplantation in rats

Purpose  

Ischemia-reperfusion injury leads to impaired smooth muscle function and inflammatory reactions after intestinal transplantation. In previous studies, infliximab has been shown to effectively protect allogenic intestinal grafts in the early phase after transplantation with resulting improved contractility. This study was designed to reveal protective effects of infliximab on ischemia–reperfusion injury in isogenic transplantation.