Comparison of Th1 and Th2 responses in non-healing and healing patients with cutaneous leishmaniasis

Background:

Cutaneous leishmaniasis is an endemic disease in many regions of Iran, including the city of Mashhad. In recent years, some cases have not responded to Glucantime, the usual treatment for this disease. The cellular immune response caused by T-helper type 1 (Th1) cells has an important role in protection against leishmaniasis, and activation of the T-helper type 2 (Th2) response causes progression of the disease. By analyzing these responses we hope to find a more effective treatment than that currently in use for leishmaniasis patients.

Methods:

The cellular immune responses in 60 cases of non-healing and healing cutaneous leishmaniasis, and individuals in a control group, were analyzed by measuring cytokines released by peripheral blood mononuclear cells (PBMCs) when stimulated with Leishmania major antigens by Enzyme Linked Immuno Sorbent Assay (ELISA).

Results:

Subjects from the healing group secreted more interleukin-12 (IL-12) and interferon gamma (IFN-γ) (p<0.05) and less interleukins -4, -5, -10 (IL-4, IL-5, and IL-10) (p<0.005) and -18 (IL-18) (p=0.003) than the non-healing group.

Conclusions:

The results demonstrate that secretion of cytokines that activate Th2 response including IL-4, IL-5 and IL-10 in non-healing subjects was higher than healing subjects and secretion of cytokines that activate Th1 response including IL-12 and IFN-γ in healing subjects was higher relative to the non-healing subjects. In this study it has been shown that the level of IL-18 progresses disease in non-healing patients when the level of IL-12 gets decreased. Key Words: Cytokines, Cutaneous leishmaniasis, Glucantime     

Leishmania species: Detection and identification by nested PCR assay from skin samples of rodent reservoirs

Many rodent species act as reservoir hosts of zoonotic cutaneous leishmaniasis in endemic areas. In the present study a simple and reliable assay based on nested PCR was developed for the detection and identification of Leishmania parasites from rodent skin samples. We designed Leishmania-specific primers that successfully amplified ITS regions of Leishmania major, Leishmania gerbilli and Leishmania turanica using nested PCR. Out of 95 field collected Rhombomys opimus, 21 were positive by microscopic examination and 48 by nested PCR. The percentage of gerbils infected with L. major, L. gerbilli and L. turanica was 3.2%, 1.1% and 27.4%, respectively. In 15.8% of the rodents, we found mixed natural infections by L. major and L. turanica, 1.1% by L. major and L. gerbilli, and 2.1% by the three species. We concluded that this method is simple and reliable for detecting and identifying Leishmania species circulating in rodent populations.     

Physiological changes induced by chromium stress in plants: an overview

This article presents an overview of the mechanism of chromium (Cr) stress in plants. Toxic effects of Cr on plant growth and development depend primarily on its valence state. Cr(VI) is highly toxic and mobile whereas Cr(III) is less toxic. Cr-induced oxidative stress involves induction of lipid peroxidation in plants that cause severe damage to cell membranes which includes degradation of photosynthetic pigments causing deterioration in growth. The potential of plants with the adequacy to accumulate or to stabilize Cr compounds for bioremediation of Cr contamination has gained engrossment in recent years.     

Detection of methicillin-resistance (mec-A) gene inStaphylococcus aureus strains by PCR and determination of antibiotic susceptibility

Methicillin-ResistantStaphylococcus aureus (MSRA) has become a frequent cause of serious infections. Extended hospitalization and antibiotic therapy have been identified as additional risk factors for MRSA carrier and infection. The aim of this study was to determine the incidence of MRSA infections in the hospitals affiliated to Hamedan University of Medical Sciences. SeventyS. aureus clinical strains were isolated from patients from June 2005 to June 2006 and examined by PCR and conventional microbiological tests. Then, the antibiotic susceptibility to methicillin/oxacillin and other antibiotics were performed by Disc Diffusion Agar (DDA). The results of this study showed that methicillin resistance gene was detected in 35 (50%) and 22 (31.4%) cases by PCR and DDA, respectively. The results of antibiotic susceptibility assays also showed there were high resistance MRSA strains to penicilin (100%), cloxacillin (91.4%), tetracycline (74.2%), cotrimoxazole (68.5%), erythromycin (68.5%) and less resistance to rifampin (11.4). Two MRSA also had decreased susceptibility to vancomycin. But the strains of Methicillin-SensitiveS. aureus (MSSA) showed high sensitivity to all antibiotics profiles except to penicillin (complete resistance). As a conclusion, the resistance to methicillin/oxacillin ofS. aureus in Hamedan hospitals has reached to 50% and they show multidrug resistance.     

Therapeutic potency of pharmacological adenosine receptors agonist/antagonist on cancer cell apoptosis in tumor microenvironment,current status,and perspectives

The hypoxic niche of tumor leads to a tremendous increase in the extracellular adenosine concentration through alteration of adenosine metabolism in the tumor microenvironment (TME). This consequently affects cancer progression, local immune responses, and apoptosis of tumor cells. Regulatory effect of adenosine on apoptosis in TME depends on the cancer cell type, pharmacological characteristics of adenosine receptor subtypes, and the adenosine concentration in the tumor niche. Exploiting specific pharmacological adenosine receptor agonist and antagonist inducing apoptosis in cancer cells can be considered as a proper procedure to control cancer progression. This review summarizes the regulatory role of adenosine in cancer cell apoptosis for a better understanding, and hence better management of the disease.     

Microbial hydroxylation of progesterone with Acremonium strictum

Microbial hydroxylation of progesterone occurred in the culture of Acremonium strictum PTCC 5282 to produce two hydroxylated pregnene-like steroids. The metabolites were purified and characterized using spectroscopic methods and identified as 15alpha-hydroxyprogesterone and 15alpha-hydroxydeoxycorticosterone.     

BIODEGRADABILITY OF HYDROCARBONS BY CYANOBACTERIA1

Five cyanobacterial species (Phormidium sp., Nostoc sp., Anabaena sp. Aphanothece conferta, and Synechocystis aquatilis) isolated from the Suez Canal coast at the city of Ismailia (Egypt) were tested for biodegradation of four hydrocarbon (HC) compounds: two aliphatic compounds (n‐octadecane and pristine) and two aromatic compounds (phenanthrene and dibenzothiophene). High degradation efficiencies for the two aliphatic compounds were measured for A. conferta (64% for n‐octadecane and 78% for pristine) and S. aquatilis (85% for n‐octadecane and 90% for pristane). However, the other biodegradation percentages ranged between weak and moderate percentages.