Liver abscess in the tropics: experience in the University Hospital, Kuala Lumpur

We reviewed 204 cases of liver abscess seen between 1970 and 1985. Ninety were found to be amoebic, 24 pyogenic and one tuberculous. The cause of the abscesses in the remaining 89 patients was not established. The patients were predominantly male, Indians, and in the 30-60 age group. The majority of patients presented with fever and right hypochondrial pain. The most common laboratory findings were leucocytosis, hypoalbuminaemia and an elevated serum alkaline phosphatase. Amoebic abscesses were mainly solitary while pyogenic abscesses were mainly multiple. Complications were few in our patients and included rupture into the pleural and peritoneal cavities and septicaemic shock. An overall mortality of 2.9% was recorded. The difficulty in diagnosing the abscess type is highlighted. The single most important test in helping us diagnose amoebic abscess, presumably the most common type of abscess in the tropics, is the Entamoeba histolytica antibody assay. This test should be used more frequently in the tropics.     

Chemokines and the microenvironment in neuroectodermal tumor–host interaction

Chemokines and chemokine receptors play an important role in immune homeostasis and surveillance. Altered or defective expression of chemokines and/or chemokine receptors could lead to a disease state including autoimmune disorder or cancer. Tumors from glioblastoma, melanoma, and neuroblastoma secrete high levels of chemokines that can promote tumor growth and progression or induce stromal cells present in the tumor microenvironment to produce cytokines or chemokines which, in turn, can regulate angiogenesis, tumor growth, and metastasis. On the other hand, chemokines secreted by tumor or stromal cells can also attract leukocytes such as dendritic cells, macrophages, neutrophils, and lymphocytes which may downmodulate tumor growth. New therapies that are aimed at limiting tumor growth and progression by attracting immune effector cells to the tumor site with chemokines may hold the key to the successful treatment of cancer, although this approach may be hampered by possible tumor growth-stimulating effects of chemokines.     

Impact of ivermectin drug combinations on Pediculus humanus capitis infestation in primary schoolchildren of south Indian rural villages

Background  Antifilarial drug combinations including ivermectin provide antifilarial activity with ancillary benefits on intestinal helminths and ectoparasites, such as chiggers and lice. The impact of single oral dose of antifilarial drugs, viz; (1) diethylcarbamazine (DEC) alone, (ii) DEC + albendazole (ALB), (iii) ivermectin (IVR) + DEC and (iv) IVR + ALB, was determined, on the head louse ( Pediculus humanus capitis ) in primary school children in a rural community in south India.
Methods  Primary school children ( n  = 534) of age 6–10 years from four villages of South India were examined for the presence of head lice before and after single dose of DEC + ivermectin drug combination. The effectiveness and the duration of cure sustained by these drugs were quantified. The head louse was examined by "combing method" during post-treatment periods at 15, 45, 60 and 75 days interval.
Results  The antifilarial drug consumption rate was similar (96–98%) in all treatment arms. In pre-treatment survey the prevalence of head lice in children administered with DEC, DEC + ALB, IVR + DEC and IVR + ALB arm was 86%, 80%, 87% and 80%, respectively, with the latter two arms demonstrating significant reduction in louse infestation ( P  < 0.05) for 60 days.
Conclusion  Single dose with IVR combination demonstrates a greater impact in reducing head louse infestation in the endemic rural communities for nearly 60 days. Therefore, in regions such as Africa where ivermectin is part of the antifilariasis campaign, this drug will have an additional benefit in reducing head lice infestation.     

Chemopreventive effect of bacoside A on N-nitrosodiethylamine-induced hepatocarcinogenesis in rats

Purpose

Chemoprevention is an effective approach to control hepatocarcinogenesis. Bacoside A, the active constituent of Bacopa monniera Linn., is anticipated to play a role in chemoprevention of liver cancer.

Methods

In the present study, we investigated the chemopreventive effect of bacoside A against N-nitrosodiethylamine-induced hepatocarcinogenesis in an animal model.

Results

Administration of carcinogen showed a significant elevation in the levels of lipid peroxidation, serum tumor marker enzymes and liver injury marker enzymes with subsequent decrease in the levels of both hemolysate and liver antioxidant status. Bacoside A co-treatment maintained the N-nitrosodiethylamine-induced alterations at near normal level. Histopathological and electron microscopic study of the liver tissue also supports the above biochemical observations.

Conclusions

From our findings we conclude that bacoside A is effective to prevent DEN-induced hepatocellular carcinoma by quenching lipid peroxidation and enhancing antioxidant status through free radical scavenging mechanism and having potential of protecting endogenous enzymatic and non-enzymatic antioxidant activity.     

Cell type and gender-dependent differential regulation of the p202 and Aim2 proteins: implications for the regulation of innate immune responses in SLE

Upon sensing cytosolic double-stranded DNA (dsDNA), the murine Aim2 (encoded by the Aim2 gene) protein forms an inflammasome and promotes the secretion of proinflammatory cytokines, such as IL-1β and IL-18. In contrast, the p202 protein (encoded by the Ifi202 gene) does not form an inflammasome. Previously, we have reported that the interferon (IFN) and female sex hormone-induced increased nuclear levels of p202 protein in immune cells are associated with increased susceptibility to develop a lupus-like disease. However, signaling pathways that regulate the expression of Aim2 protein remain unknown. Here we report that the expression of Aim2 gene is induced in bone marrow-derived macrophages (BMDMs) by IFN-α treatment and the expression is, in part, STAT1-dependent. However, treatment of splenic T or B cells with IFN-α or their stimulation, which induced the expression of Ifi202 gene, did not induce the expression of Aim2 gene. Furthermore, treatment of cells with the male hormone androgen increased levels of Aim2 mRNA and protein. Moreover, treatment of murine macrophage cell lines (RAW264.7 and J774A.1) with IFN-α differentially induced the expression of Aim2 and p202 proteins and regulated their sub-cellular localization. Additionally, activation of Toll-like receptors (TLR3, 4, and 9) in BMDMs and cell lines also differentially regulated the expression of Aim2 and Ifi202 genes. Our observations demonstrate that cell type and gender-dependent factors differentially regulate the expression of the Aim2 and p202 proteins, thus, suggesting opposing roles for these two proteins in innate immune responses in lupus disease.