Combined effect of tumor necrosis factor-related apoptosis-inducing ligand and ionizing radiation in breast cancer therapy

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent endogenous activator of the cell death pathway and functions by activating the cell surface death receptors 4 and 5 (DR4 and DR5). TRAIL is nontoxic in vivo and preferentially kills neoplastically transformed cells over normal cells by an undefined mechanism. Radiotherapy is a common treatment for breast cancer as well as many other cancers. Here we demonstrate that ionizing radiation can sensitize breast carcinoma cells to TRAIL-induced apoptosis. This synergistic effect is p53-dependent and may be the result of radiation-induced up-regulation of the TRAIL-receptor DR5. Importantly, TRAIL and ionizing radiation have a synergistic effect in the regression of established breast cancer xenografts. Changes in tumor cellularity and extracellular space were monitored in vivo by diffusion-weighted magnetic resonance imaging (diffusion MRI), a noninvasive technique to produce quantitative images of the apparent mobility of water within a tissue. Increased water mobility was observed in combined TRAIL- and radiation-treated tumors but not in tumors treated with TRAIL or radiation alone. Histological analysis confirmed the loss of cellularity and increased numbers of apoptotic cells in TRAIL- and radiation-treated tumors. Taken together, our results provide support for combining radiation with TRAIL to improve tumor eradication and suggest that efficacy of apoptosis-inducing cancer therapies may be monitored noninvasively, using diffusion MRI.     

Assessment of in vivo mutagenic potency of ethylenediaminetetraacetic acid in albino mice.

Ethylenediaminetetraacetic acid (EDTA) disodium salt, a widely used metal chelator, was studied for its potency to induce bone marrow micronuclei, dominant lethal mutations and sperm-head abnormalities in albino mice. The acute oral LD₅₀ dose computed by probit regression was 30 mg/kg body weight in the strain used. Preliminary studies showed that oral administration of EDTA disodium salt at doses of 5, 10 and 15 mg/kg body weight/day on 5 consecutive days did not induce any obvious signs of toxicity. In the bone marrow micronucleus assay acute doses of EDTA disodium salt (5–20 mg/kg body weight) induced a dose-dependent increase in the incidence of micronucleated polychromatic erythrocytes at a 24-hr sampling. However, administration at doses of 5, 10 and 15 mg/kg for 5 consecutive days did not produce any observable effect on either the testicular or epididymal weights and histology. No appreciable alterations were observed in the caudal sperm counts at any of the sampling intervals and there was no treatment-related increase in the incidence of sperm-head abnormalities. Furthermore, treatment of male mice with EDTA disodium salt (10 mg/kg body weight/day for 5 consecutive days) induced no increase in the incidence of post-implantation embryonic deaths, except for a marginal but statistically insignificant increase during wk 2 and 3 of mating.     

Assessment of in vivo mutagenic potency of ethylenediaminetetraacetic acid in albino mice

Ethylenediaminetetraacetic acid (EDTA) disodium salt, a widely used metal chelator, was studied for its potency to induce bone marrow micronuclei, dominant lethal mutations and sperm-head abnormalities in albino mice. The acute oral LD₅₀ dose computed by probit regression was 30 mg/kg body weight in the strain used. Preliminary studies showed that oral administration of EDTA disodium salt at doses of 5, 10 and 15 mg/kg body weight/day on 5 consecutive days did not induce any obvious signs of toxicity. In the bone marrow micronucleus assay acute doses of EDTA disodium salt (5–20 mg/kg body weight) induced a dose-dependent increase in the incidence of micronucleated polychromatic erythrocytes at a 24-hr sampling. However, administration at doses of 5, 10 and 15 mg/kg for 5 consecutive days did not produce any observable effect on either the testicular or epididymal weights and histology. No appreciable alterations were observed in the caudal sperm counts at any of the sampling intervals and there was no treatment-related increase in the incidence of sperm-head abnormalities. Furthermore, treatment of male mice with EDTA disodium salt (10 mg/kg body weight/day for 5 consecutive days) induced no increase in the incidence of post-implantation embryonic deaths, except for a marginal but statistically insignificant increase during wk 2 and 3 of mating.     

Identification of 4-deoxythreonic acid present in human urine using HPLC and NMR techniques

The ¹H NMR spectrum of urine exhibits a large number of detectable and quantifiable metabolites and hence urine metabolite profiling is potentially useful for the study of systems biology and the discovery of biomarkers for drug development or clinical applications. While a number of metabolites (50–100) are readily detectable in urine by NMR, a much larger number is potentially available if lower concentration species can be detected unambiguously. Lower concentration metabolites are thought to be more specific to certain disease states and thus it is important to detect these metabolites with certainty. We report the identification of 4-deoxythreonic acid, a relatively low concentration endogenous metabolite that has not been previously identified in the ¹H NMR spectrum of human urine. The use of HPLC and NMR spectroscopy facilitated the unequivocal and non-invasive identification of the molecule in urine which is complicated by extensive peak overlap and multiple, similar resonances from other metabolites such as 3-hydroxybutanoic acid. High-resolution detection and good sensitivity were achieved by the combination of multiple chromatographic fraction collection, sample pre-concentration, and the use of a cryogenically cooled NMR probe.     

1H NMR metabolomics study of age profiling in children

Metabolic profiling of urine provides a fingerprint of personalized endogenous metabolite markers that correlate to a number of factors such as gender, disease, diet, toxicity, medication, and age. It is important to study these factors individually, if possible to unravel their unique contributions. In this study, age‐related metabolic changes in children of age 12 years and below were analyzed by ¹H NMR spectroscopy of urine. The effect of age on the urinary metabolite profile was observed as a distinct age‐dependent clustering even from the unsupervised principal component analysis. Further analysis, using partial least squares with orthogonal signal correction regression with respect to age, resulted in the identification of an age‐related metabolic profile. Metabolites that correlated with age included creatinine, creatine, glycine, betaine/TMAO, citrate, succinate, and acetone. Although creatinine increased with age, all the other metabolites decreased. These results may be potentially useful in assessing the biological age (as opposed to chronological) of young humans as well as in providing a deeper understanding of the confounding factors in the application of metabolomics. Copyright © 2009 John Wiley & Sons, Ltd.     

Divergent solid‐phase synthesis and candidacidal activity of MUC7 D1, a 51‐residue histidine‐rich N‐terminal domain of human salivary mucin MUC7

Abstract: Domain 1 of the low‐molecular‐weight human salivary mucin, designated MUC7 D1, spans the 51 N‐terminal amino acid residues. This domain contains a 15‐residue basic histidine‐rich subdomain (R3‐Q17) which has 53% sequence similarity to histatin 5 (Hsn‐5), a salivary molecule known to exert potent in vitro cidal activity against Candida albicans and many other medically important fungi. The MUC7 D1‐15mer and its derivatives have previously been synthesized in our laboratory and their candidacidal activities have been found to be inferior to that of Hsn‐5. We were therefore intrigued to explore the candidacidal potency of the full‐length MUC7 D1 (51‐mer). Linear solid‐phase synthesis of this domain has been accomplished following standard Fmoc chemistry. The problems of partial coupling, owing to the peptide chain length, at several stages of the solid‐phase step‐by‐step synthesis were circumvented either by double‐coupling techniques or efficient coupling procedures. The MUC7 D1 peptide was purified to homogeneity by conventional reverse‐phase HPLC using two columns connected in series. Secondary structure of the purified peptide was assessed by circular dichroism (CD) spectroscopy in phosphate buffer and trifluoroethanol and compared to that of MUC7 D1‐15mer and Hsn‐5. The MUC7 D1 candidacidal activity was assessed against azole‐sensitive and azole‐resistant C. albicans strains and was found, unlike that of the MUC7 D1‐15mer, to be comparable with that of Hsn‐5, indicating that in addition to Hsn‐5, MUC7 D1 could provide an attractive alternative to the classical antifungal agents. The candidacidal potency of MUC7 D1, like that of MUC7 D1‐15mer, and of Hsn‐5, appears to be largely dependent on peptide charge, irrespective of α‐helical structure.     

Safety evaluation of Monascus purpureus red mould rice in albino rats

Monascus purpureus MTCC 410-fermented rice (red mould rice) is one of the food supplements to lower blood–lipid levels and monacolins have been proven to be the main active constituents in red mould rice (RMR). In this study, we have assessed the safety of RMR by conducting toxicological studies in albino rats. Acute and sub-chronic toxicity studies were conducted on both sexes of albino rats. Feeding acute doses of RMR at 0.5, 1.0, 2.5 and 5.0 g/kg body weight to rats did not cause any symptoms of toxicity or mortality. Similarly, dietary feeding of RMR at 2.0%, 4.0%, 8.0% and 12.0% level (w/w) for 14 weeks did not produce any significant changes in food intake or gain in body weight of the experimental rats compared to control rats. There were no significant differences in the relative weight of vital organs, hematological parameters, macroscopic and microscopic changes in vital organs and serum clinical enzyme levels between the experimental and control groups. Moreover, the rats fed with RMR showed a significant reduction in cholesterol and triglyceride levels in both serum and liver. The results showed that toxicity studies with RMR of M. purpureus did not cause any toxic effects in albino rats.     

Human papillomavirus genotypes in women with invasive cervical cancer with and without human immunodeficiency virus infection in Botswana

Cervical cancer remains a significant cause of morbidity and mortality in women worldwide and is the leading cause of cancer-related death in Botswana. It is well established that women with HIV have a higher risk of persistent HPV infection leading to cervical cancer. We assessed HPV prevalence and genotype distribution in 126 tissue specimens from confirmed invasive cervical cancer cases using Abbott real-time PCR assay. Overall, 88 (69.8%) women were HIV-infected. Fifty-seven (64.8%) of the HIV-infected women had a baseline CD4⁺ count ≥350 cells/μl, and 82 (93.2%) were on antiretroviral therapy at the time of cervical cancer diagnosis. The median age of HIV-infected patients was significantly younger than that of HIV-uninfected patients (p < 0.001). HPV DNA was detected in all of 126 (100%) of tissues analyzed in our study. The HPV genotypes identified included the HPV-16 (75.4%), HPV-18 (28.6%) and other high-risk (hr) HPV genotypes (16.7%). HIV infection was positively associated with the presence of the HPV-16 genotype (p = 0.036), but not with HPV-18 or with other high-risk (hr)-HPV genotypes. Thirty-three percent of the patients had multiple hr-HPV genotypes, with higher rates in HIV-infected women. These results highlight the importance and potential impact of large-scale HPV vaccination programs covering HPV-16 and HPV-18 genotypes in countries like Botswana with high burden of HIV infection.     

Effect of vitamin A on hexachlorocyclohexane (HCH) toxicity in the rat.

1. Technical hexachlorocyclohexane (HCH) depleted hepatic stores of vitamin A in male albino rats to cause secondary vitamin A deficiency. 2. Toxicity of HCH in rats is augmented by dietary vitamin A-deficiency as evidenced by growth retardation, organ hypertrophies and alterations in the serum and liver levels of the marker enzymes of toxicity. 3. Supplementation of dietary vitamin A to the rats either in adequate (2000 IU/kg diet) or in an excess but not hypervitaminotic level (10(5) IU/kg diet) resulted in significant protection against the toxicity of HCH. 4. The activities of the hepatic xenobiotic metabolizing enzymes were generally low (with the exception of glutathione S-transferase) in the vitamin A-deficient rats compared to those of the vitamin A supplemented diet groups. 5. The results indicated that dietary vitamin A influences the response of male albino rats to HCH toxicity possibly by modulating the activities of hepatic xenobiotic metabolizing enzymes.     

Assessment of oxidative status in chronic pancreatitis and its relation with zinc status

Background  

Oxidative stress-induced free radicals have been implicated in the pathology of chronic pancreatitis (CP).