Drug and Alcohol Rehabilitation: Lipid Raft Involvement in Yeast Cell Growth and Death.

Lipid raft involvement in yeast cell growth and death.

Filed under: Drug and Alcohol Rehabilitation

Front Oncol. 2012; 2: 140
Mollinedo F

The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Cryptococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na(+), K(+), and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases.
HubMed – drug

Overexpression of lung resistance-related protein and P-glycoprotein and response to induction chemotherapy in acute myelogenous leukemia.

Filed under: Drug and Alcohol Rehabilitation

Hematol Rep. 2012 Jul 11; 4(3): e18
Tsuji K, Wang YH, Takanashi M, Odajima T, Lee GA, Sugimori H, Motoji T

Lung resistance-related protein (LRP) and P-glycoprotein (P-gp) are associated with multidrug resistance. P-gp overexpression reduces intracellular anticancer drug concentrations and is correlated with low remission rates. However, whether the presence of LRP influences the response to induction chemotherapy remains controversial. Therefore, we investigated the relationship of LRP and P-gp overexpression with the response to induction chemotherapy. Univariate analysis revealed that there was a significant difference between complete remission rates for acute myelogenous leukemia patients depending on their blast cell expressions, between LRP positive versus negative, P-gp positive versus negative, and LRP/P-gp double positive versus other groups. Crude odds ratios (ORs) for complete remission were 0.390, 0.360, and 0.307 for LRP positive, for P-gp positive, and LRP/P-gp double positive patients, respectively. After controlling the confounding variables by stepwise multivariate logistical regression analysis, the presence of LRP/P-gp double positivity and P-gp positivity were found to be independent prognostic factors; adjusted ORs were 0.233 and 0.393, respectively. Furthermore, the monoclonal antibody against LRP significantly increased daunorubicin acumulation (P=0.004) in the nuclei of leukemic blast cells with LRP positivity in more than 10% of the cells. An LRP reversing agent, PAK-104P, was found to increase the daunorubicin content with marginal significance (P=0.060). The present results suggest that not only the presence of P-gp, but also LRP in leukemic blast cells is a risk factor for resistance to induction chemotherapy. Inhibiting LRP function, similar to the inhibition of P-gp function, will be necessary to improve the effectiveness of induction chemotherapy.
HubMed – drug

Natural history of gastric cancer-a case followed up for eight years: early to advanced gastric cancer.

Filed under: Drug and Alcohol Rehabilitation

Clin J Gastroenterol. 2012 Oct; 5(5): 351-354
Fujisaki J, Nakajima T, Hirasawa T, Yamamoto Y, Ishiyama A, Tsuchida T, Hoshino E, Igarashi M, Yamaguchi T

We experienced a case of gastric cancer that was prospectively followed up for 8 years. With severe heart disease, the patient did not wish surgery or anticancer drug treatment. After informed consent was obtained, he was followed up for 8 years. He received upper gastrointestinal endoscopy every year, which revealed IIc early gastric cancer, and biopsy showed well differentiated adenocarcinoma. A flat and mildly depressed lesion with redness was observed on endoscopy, exhibiting typical morphology of IIc-type early gastric cancer. The appearance of IIc M cancer was observed macroscopically from 2000 to 2003. Four years later, surface irregularity with ulceration appeared. Then, the whole lesion was elevated, which suggested submucosal invasion, and the tumor exhibited the morphology of IIa + IIc or type 3. The ulcer became deeper and elevated boundaries were formed. Horizontal expansion of the flat lesion was mild, while invasion to deeper layers was predominant. Eventually, he died of heart failure. Estimated M cancer was observed for about 3 years, followed by invasion to deeper layers. Taken together, this is a valuable case that followed up the manner of invasion to deeper layers over time from early to advanced gastric cancer.
HubMed – drug

Effects of Oral Levamisole as an Adjuvant to Hepatitis B Vaccine in HIV/ AIDS Patients: A Randomized Controlled Trial.

Filed under: Drug and Alcohol Rehabilitation

Hepat Mon. 2012 Sep; 12(9): e6234
Sayad B, Alavian SM, Najafi F, Soltani B, Shirvani M, Janbakhsh A, Mansouri F, Afsharian M, Vaziri S, Alikhani A, Bashiri H

Human immunodeficiency virus (HIV) infected patients are also frequently exposed to the hepatitis B virus (HBV), due to the common routes of transmission, therefore, prevention of hepatitis B results in decreased complications of the disease.Since the immune response of HIV patients to hepatitis B vaccination is less robust than that found in healthy individuals, this study aimed to evaluate the effect of a levamisole adjuvant on increasing the immune response.In this study, 89 HIV infected patients, without a history of HBV infection or vaccination, were randomly allocated into experimental (44 patients) and control (45 patients) groups. HBV vaccination was performed using the Hepavax-Gene TF vaccine, 40 ?g three times at intervals of; zero, one, and three months. Levamisole 50 mg twice a day or a placebo, was administered to the experimental and control groups, respectively, for a period of six days before to six days after the vaccination. Immune response was evaluated by measuring hepatitis B surface antibodies (HBsAb) concurrently with the second and third vaccine administration, and at one and three months at the conclusion of the vaccination program.The immune response following the threevaccinations was higher in those who were receiving levamisole compared with the controls (90% vs. 65.38%) (P = 0.05). Furthermore, the immune response and the mean antibody titer following the repeated vaccination in the experimental group showed a higher increase than in the control group. The immune response and the mean titer of antibody were not associated with; age, sex, body mass index, history of smoking and/or intravenous drug use in either of the groups. However, regarding CD4+ cells more than 200 cell/mm3, mean antibody production significantly increased in both groups.Using levamisole with the hepatitis B vaccination can increase the immune response and antibody titer mean in HIV infected patients. Since these patients have a more complete response with CD4+ cells more than 200 cell/mm3, vaccination and effective adjuvants seem to be most beneficial when CD4+ cells are greater than 200 cell/mm3, in HIV infected patients.
HubMed – drug

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