Assessment of telomerase as drug target in breast cancer

Telomerase is a specialized enzyme which maintains telomere length at the extreme end of the chromosome.Over 90% of all cases of cancer show high expression of telomerase while in normal cells, its expression isextremely low or undetectable. Detection of telomerase activity in a wide range of breast cancer makestelomerase an interesting target for diagnosis and therapy. In this review, we have aimed to describe telomeraseas a therapeutic and accurate diagnostic target in breast cancer. Telomerase performs many extracurricularactivities apart from maintaining telomere length; here, we have also tried to address its role in epithelialmesenchymal transition (EMT) of breast cancer progression.

Antiretroviral-induced adverse drug reactions in HIV-infected patients in Mali: a resource-limited setting experience

Background: There are few reports in the literature from sub-Saharan Africa (SSA) regarding antiretroviral-induced adverse drug reactions (ADRs). Antiretroviral therapy (ART) is now widely available in SSA, and ADRs during HIV infection are also frequent. In this study, we reported the frequency and risk factors of ART-induced ADRs in a Malian population.Methods: This prospective cohort study was performed in the HIV Care and Counseling Centre (CESAC) of Mali from 2011 to 2012. Adult patients infected with HIV and who had recently started ART were included and followed-up clinically Were included in this study, adult patients living with HIV and had recently started ART who were followed up for at least 6 months to determine the incidence of ADRs using Naranjo’s classification scale.Results: During this study, 357 (42.3%) patients presented ADRs (40.1% of our patients (n=338) experienced at least one ADR, and 2.2% (n=19) experienced at least two ADRs). The prevalence of ADRs by organ system was: 45.9% neurological (n=164); 29.4% metabolic (blood chemistry) (n=105); 15.4% hematological (n=55). High probable rate of ADR was observed as indicated by the Naranjo score in 83.7% of the cases. Zidovudine (AZT) and stavudine (d4T) use was identified as a risk factor for either anaemia or peripheral neuropathy whereas nevirapine (NVP) and female gender were risk factors for skin reactions. Patients with advance disease had the highest rate of ADRs compared to the others.Conclusions: Based on the Naranjo probability scale, our data show that ADRs such as peripheral neuropathy and anemia are very frequent. These ADR was linked to AZT and D4T. Our findings highlight the need for active monitoring, continuous pharmacovigilance of ART and change of some ART drug in this population.

Understandingabsorption: regulatory aspects and contemporary approaches to tackling solubility and permeability hurdles

Oral drug absorption is a process influenced by the physicochemical and biopharmaceutical properties of the drug and its inter-relationship with the gastrointestinal tract. Drug solubility, dissolution and permeability across intestinal barrier are the key parameters controlling absorption. This review provides an overview of the factors that affect drug absorption and the classification of a drug on the basis of solubility and permeability. The biopharmaceutical classification system (BCS) was introduced in early 90׳s and is a regulatory tool used to predict bioavailability problems associated with a new entity, thereby helping in the development of a drug product. Strategies to combat solubility and permeability issues are also discussed.

A comparative analysis of the efficacy of HAART with TDF and with AZT / 实用医学杂志

Objective To compare the efficacy of highly active anti-retroviral treatment (HAART) with and with AZT. Methods Data of 235 HIV patients accepted from Oct. 2010 to Nov. 2013 who took AZT (133) or TDF (102) containing regimen as first-line HAART are analyzed retrospectively. CD4+ T cell counts acted as the base line after 12 months of HAART. Increase in CD4+ T cell count number after the HAART, virological failures and drug resistance were compared between the two groups. Results The two groups had comparable baseline CD4+T cell count, gender ratio, and HIV transmision mode; after 12 months of HARRT, no statistically differences were found between the two groups with regard to CD4 + T cell count and increase in CD4+ T cell count after the 12-month HAART (P > 0.05); AZT-containing group had more virological failure (3/0). Meanwhile AZT-containing group had one thymidine analog mutation (TAMs) which confers resistance to AZT (P > 0.05 for both). Conculsion The two HAARTs have same immunological effects; AZT-containing group exhibits 2.2% viralogial failure, but its direct relationship with AZT has not been confirmed.

Azidothymidine and recombinant human interferon-alpha therapy in a cat with feline immunodeficiency virus / 동물의과학연구지

A 7-year-old, spayed female, domestic short hair cat showed signs of a 2-week history of chronic anorexia, depression, and severe weight loss. Upon physical examination, pyrexia, mild gingivitis, and pale mucus membranes were noted. Laboratory analysis revealed normocytic normochromic non-regenerative anemia, severe thrombocytopenia, and hypergammaglobulinemia. Serum protein electrophoresis revealed the presence of elevated alpha-2 fraction within the globulin concentration. Based on history, clinical signs, and laboratory results, systemic viral infection was strongly suspected. Reverse transcriptase polymerase chain reaction identified the presence of feline immunodeficiency virus (FIV) in the serum. Furthermore, gene sequencing revealed the virus as FIV subtype A. Treatment with anti-retroviral agents, including azidothymidine (AZT) and recombinant human interferon-alpha, was continued for 4 weeks. However, the patient's clinical condition deteriorated, resulting in death 1 month after initiation of treatment due to progressive renal failure. Necropsy and histopathology revealed hepatic and renal necrosis with hyper-cellular bone marrow mainly comprised of myeloid precursor cells. This case report is the first to describe phylogenetic subtyping, anti-retroviral combination treatment, and clinical outcomes in an FIV-infected cat in Korea. In addition, this report suggests that treatment should be initiated during the early phase of infection that could be effective for the virus.

Reversed phase HPLC determination of zidovudine in rat plasma and its pharmacokinetics after a single intranasal dose administration

The development and validation of a simple and accurate method based on HPLC with ultraviolet detection for the quantification of zidovudine in rat plasma and its application to a pharmacokinetic study following a single intranasal dose zidovudine is described. Zidovudine was extracted from the plasma using a single-step deproteinization. Chromatographic separation of zidovudine from interfering components was achieved with a C-18 reverse phase column, a mobile phase consisting of a mixture of sodium acetate buffer (55mM) with pH adjusted to 7.0 and acetonitrile (91:9 v/v) and UV detection set at 265 nm. The method was linear from 100 to 10000 ng.mL"¹ (r² > 0.9995), and zidovudine had a mean recovery from plasma of 92.8 percent. The coefficient of variation of inter-day and intra-day quality control samples was less than 15 percent. After a single intranasal dose of zidovudine administered to rats, pharmacokinetic parameters (AUC0 24, Cmax, t , t1/2) were determined. The proposed method was found to be simple, specific, accurate, and precise and could be applied to the quantitative analysis of clinical pharmacokinetic studies of zidovudine in rats.

Study on Anti-HIV-1 Activity of Wuweilingqi Capsule in Vitro / 中国中医药信息杂志

Objective To study the activity of Wuweilingqi capsule alone and the synergy with other anti-HIV-1 inhibitors against various HIV-1 isolates,and investigate its immunological impacts for CD4+ and CD8+ T cells. Method Wuweilingqi capsule was extracted from a traditional Chinese medicine recipe which contains 5 herbs,it showed anti-retroviral activity in vitro in the cultures of human peripheral blood mononuclear cells (PBMC) and T cell lines (H9 and MT2). Results Wuweilingqi capsule inhibited HIV-1018a (an AZT-sensitive clinical isolate) in PBMC and HTLV-ⅢB (a HIV-1 lab isolate) in H9 and MT-2 T cell lines markedly,and the therapeutic indexes (TI) were 96,84 and 181 separately,but weakly inhibitory activity against HIV-1018c (an AZT-resistant clinical isolate) and chronically infective HTLV-ⅢB were demonstrated. Significant synergy against HIV-1018a and HIV-1018c replication between Wuweilingqi capsule and AZT,indinavir or T-20 were observed. In addition,Wuweilingqi capsule significantly increased PBMC proliferation,interferon-gamma secreting cell number with or without a stimulation of PHA or candida. Conclusion Although Wuweilingqi capsule did not show so strong anti-HIV-1 activity as known west drugs in clinical,its good synergy and significant increase of immune activity suggests that it will be an available and characteristic agent against HIV-1 replication.

Subcellular Distribution of Microtubule in Artificially Induced Senescent PC12 Cells

Background: Since recent reports showed the possibility that cytoskeletal proteins, which were known to be exclusively within the cytoplasm, might play a role in the re-distribution of the intranuclear chromatin in a certain type of the cells under specific circumstances, we tried to show a change in the intracellular distribution of microtubule protein in artificially induced senescent PC12 pheochromocytoma cells. Methods: PC12 pheochromocytoma cells (ATCC CRL-1721) were grown in the culture media including 1 micrometer 3'-Azido-3'-deoxythymidine (AZT, Sigma-Aldrich, USA). The senescence of the cells was confirmed by senescence detection kit (Calbiochem, San Diego, CA). Immunocytochemical study was also performed in the cells treated with AZT during 0, 75 and 153 days. Results: beta-tubuline was not observed in the cells not treated with AZT. The same protein was localized within the nuclei in the senescent cells treated with AZT during 153 days. Conclusion: Microtubule might be involved in some crucial roles in the redistribution of chromatin within the nuclei of the senescent cells.

An Effect of Testesterone on the Proliferation of Artificially Induced Senescent PC12 Pheochromocytoma Cells

BACKGROUNDS: Although the role of testosterone in the neuroprotection is still poorly known, accumulating evidence suggests that testosterone may be an important role in neurodegenerative disease including dementia. So we would like to investigate the effect of testosterone on the proliferation of senescent PC12 cells, using as a model of neural cell aging. METHODS: Rat pheochromocytoma PC12 cells from the ATCC were induced senescence artificially by AZT, the telomerase inhibitor, After 4 weeks of culture with AZT, PC 12 cells treated with testosterone overnight. The proliferating capacity of PC12 cells was determined by a difference in subcellular distribution of Ki67 expression, using as intranuclear marker for cell proliferation, and then we counted the numbers of proliferating cells which showed Ki67 IRs within nuclei to be compared with the total cell numbers. RESULTS: We observed Ki67 IRs in nucleus of the senescent PC12 cells with testosterone treated group and control group. In the quantitative assessment of nuclear Ki67 IR proliferating cells against total cells, the senescent cells treated with testosterone showed marked enhancement of proliferation. CONCLUSION: Testosterone seems to be a protective effect in the cellular senescence in PC 12 cells by maintaining the proliferating capabilities.

AZT inhibit telomerase activity of squamous cell carcinoma of tongue / 中国癌症杂志

Purpose:To study the effect of inhibition of telomerase activity and cell cycle by transcriptase telomerase inhibitors (3′ azido 3′ deoxythymidine, AZT) on squamous cell carcinoma of tongue in vitro.Methods:Human squmous cell carcinoma of tongue cell line Tca8113 was used as target cell. Telomerase activity was determined by TRAP PCR ELISA in untreated and treated Tca8113 by AZT, cell cycle phases were analyzed by flow cytometry. Results:Telomerase activity of Tca8113 was significantly inhibited when treated with AZT, and the effect of inhibition was dose dependant (rate of telomerase activity treated with AZT in 0.3, 0.6, 1.0, 1.5mol 10 -1 was 0.69 0.03, 0.61 0.08, 0.53 0.11, 0.50 0.02 respectively, rate of telomerase activity treated without AZT was 0.76 0.06). Cell cycle of treated Tca8113 was changed with marked increase in G 2 /M phase compared with untreated Tca8113 (62.8% vs 19.7%, P