Mucoadhesive polymers as efficient drug delivery systems

The drug action can be reinforced as a result of the development of new drug delivery systems. Over the past few decades, mucosa/ drug delivery has received a great deal of attention to improve both the local and systemic drug effects. Drug delivery across the mucosa bypasses the first-pass hepatic metabolism and avoids the degradation caused by the gastrointestinal enzymes. Mucoadhesive dosage forms are designed to enable prolonged retention at the desirable site of action, provide sustained release of drug and thus, lead to an improved bioavailability, as well as therapeutic outcomes. Compared with other mucosa/ rissues, vaginal mucosa/ cavity is more appropriate and attractive for drug delivery. In addition, a prolonged contact of mucoadhesive dosage forms with the vaginal mucosa may be achieved more easily than at other absorption sites like rectum or intestinal mucosa. This review aims to highlight the recent advances in the study of mucoadhesion and mucoadhesive polymers. It provides an overview of the structure of mucosa/ membranes, the mechanism and theories involved in mucoadhesion, and finally it describes briefly the main characteristics and the advantages of vaginal mucoadhesive drug delivery systems compared with other delivery systems

role of interleukin 16 in the immunopathogenesis of rheumatoid arthritis

Rheumatoid Arthritis [RA] is a chronic inflammatory disease characterized by hyperplasia of the synovium and excessive cellular infiltration, which leads to progressive joint destruction. We analyzed, interleukin 16 [IL16], in relation to disease activity to characterize its biologic function in RA. Secreted IL-16 was measured by enzyme immunoassay in sera from 30 RA patients and 30 healthy controls [HC], and also in synovial fluid [SF] from 16 RA patients and 15 patients with non-RA synovitis as controls. IL-16 expression in peripheral blood mononuclear cells [PBMC] was characterized by flow cytometric analysis after intracellular cytokine staining for IL-16. In synovial tissue specimens, both were done: Immunohistochemistry for localization of IL-16, and histopathology, in which the tissue scored semiquantitatively for synovial hyperplasia and cellular infiltration. IL-16 was detected at significantly higher levels in sera and SF of RA patients in comparison to HC and non-RA synovitis [p<0.001 and p<0.0001 respectively]. Also, IL-16 was detected significantly higher in SF in comparison to sera in RA patients [p<0.001]. Flow cytometry of PBMC showed that a great proportion of both CD4+ and CD8+ cells expressed IL-16 protein. Also, immunohistochemistry revealed more CD4+ and less frequency of CD8+ cells in synovial infiltration. A significant correlation between IL-16 expression and local inflammatory activity could not be established [p>0.21] by microscopic analysis of the synovial cells infiltrate. In addition, no significant association was observed between serum, SF, and synovial tissue expression of IL-16 and clinical disease activity in RA [p>0.61, p>0.5 and p>0.42 respectively]. This indicated that, IL-16 played a regulatory rather than a proin-flammatory role in the immunopathogenesis of RA

Relationship between cutaneous lesion of necrolytic acral erythema and hepatitis C virus

Hepatitis C [HCV] is a plus strand RNA virus. The plus-strand RNA enters hepatocytes and produces minus-strand RNA that serves as a templates in virus proliferation. HCV infection can be associated with disorders of various organs other than the liver, including the skin. Necrolytic acral erythema [NAE] have been reported to occur in setting of chronic HCV infection which belongs to the family of necrolytic erythemas which characterized clinically by erythematous lesions that frequently develop blisters and microscopically by epidermal necrolytic changes involving mostly the upper part of the epidennis. The aim of this study was to examine HCV-infected patients for the presence of viral genome within the lesional cutaneous biopsy sample of NAE and to find the relationship between it and HCV infection. The study included 8 [5 males and 3 females] anti-HCV-positive patients with NAE. Reverse-transcriptase polymerase-chain reaction [RT-PCR] was performed to detect; HCVRNA plus strand in all sera samples and in peripheral blood mononuclear cells [PBMC] for certain cases and HCV-RNA plus and minus strands in cutaneous lesional biopsy samples of NAE. Although all patients were sero-positive for HCV antibodies, RT-PCR could only detect HCV genome in the sera of 5/8 patients [62.5%]. The HCV diagnosis in the 3 subjects who tested negative was established on the basis of detectable MCV genome in J'BMC. RT-PCR could not detect, the HCV-RNA plus strand in 6/8 [75%] of skin tissue biopsies and the HCV-RNA minus strand in all skin biopsies. Conclusion; the absence of MCV-RNA minus strand in tissue samples indicates that the skin lesion of NAE is not a site of HCV proliferation and that, HCV is not the primary cause of NAE per se. Further studies of lesional and non-lesional cutaneous biopsy specimen from HCV-infected patients with NAE are needed to evaluate the inter-relationship between HCV and NAE

Predicting factors for distant failure in head and neck cancer-impact of grade

This retrospective study was performed on 157 patients treated by radiotherapy between 1993-1998 years. The frequency of distant metastases and the influence of different variables as tumor stage, nodal stage, tumor grade and anatomic site in addition to p53 on the appearance of distant metastases were evaluated. The study showed that patients with high grade squamous cell carcinoma of head and neck presented with advanced tumor stage combined with advanced nodal stage, arising mainly from nasopharynx, are at a high risk of developing distant failure and should be candidates for extensive evaluation by recent imaging studies as well as pathological markers. This subset of patients should be considered for combined modality treatment

Percutaneous nephrostomy versus retrograde ureteric stenting in decompression of acutely obstructed and infected system

To compare the efficacy of percutaneous nephrostomy [PCN] with uretcral catheterizatin for renal drainage in cases of obstruction and infection. 42 patients were randomized between the two methods. The results of both groups were compared [procedural parameters, patient outcome, failure rate. etc]. Both methods effectively relieved obstruction and infection. The decision of which mode of drainage to be used may be based on surgeon preference