Titrimetric Determination of a-Amino Acids via Formation of Dithiocarbamates

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Titrimetric Determination of α-Amino Acids via Formation of Dithiocarbamates

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A study to determine the knowledge and level of awareness of medical undergraduates about herbal medicines and herb-drug interactions

Background: The increasing usage of herbal medicines worldwide has increased the probability of co-administration of herbal and allopathic medicines. This may lead to serious safety concerns, including herb-drug interactions (HDIs). Many HDIs may be overlooked due to poor doctor-patient communication about herbal drug usage probably because of lack of knowledge of herbal medicines and HDIs among physicians. The study was thus planned to identify the knowledge and awareness of medical students regarding the use of herbal medicines and about HDIs, to help improve the teaching skills and curriculum development for medical students.Methods: 286 medical students of 2nd, 3rd and 4th year MBBS course completed the study. All the participants were asked to fill a self-administered questionnaire consisting of 15 questions which included both open-ended and close-ended questions related to age, sex, knowledge, awareness and usage of herbal medicines and about herb-drug interactions. Data was analyzed and expressed as counts and percentages.Results: Majority (95.45%) of the students were aware of the fact that herbs can be used as medicines. They were most familiar with the herbs tulsi, neem, turmeric, aloe, ashwagandha and ginger. 46.85% consider herbal medicines to be risk free, and majority (55.6%) were not aware of the fact that herbs can cause herb-drug interactions. Media and elderly family members were their most common sources of information regarding herbal medicines. Majority (75.17%) would prefer allopathic medicines over herbal medicines. Only 23.07% always informed the physician about their usage of herbal medicines, although most (84.96%) felt that history regarding use of herbal medicines should be taken. Majority were not aware of the regulatory status of herbal medicines.Conclusions: Lack of knowledge and awareness of medical students about herbal medicines and herb-drug interactions was seen in the study. There is a need to inform the students of allopathic system of medicine about the adverse outcomes of herbal medicines and the knowledge about herb-drug interactions should be a part of the medical curriculum

Duration of Rapamycin Treatment Has Differential Effects on Metabolism in Mice

SummaryThe evolutionarily conserved target of rapamycin (TOR) signaling controls growth, metabolism, and aging. In the first robust demonstration of pharmacologically-induced life extension in mammals, longevity was extended in mice treated with rapamycin, an inhibitor of mechanistic TOR (mTOR). However, detrimental metabolic effects of rapamycin treatment were also reported, presenting a paradox of improved survival despite metabolic impairment. How rapamycin extended lifespan in mice with such paradoxical effects was unclear. Here we show that detrimental effects of rapamycin treatment were only observed during the early stages of treatment. These effects were reversed or diminished in mice treated for 20 weeks, with better metabolic profiles, increased oxygen consumption and ketogenesis, and markedly enhanced insulin sensitivity. Thus, prolonged rapamycin treatment lead to beneficial metabolic alterations, consistent with life extension previously observed. Our findings provide a likely explanation of the “rapamycin paradox” and support the potential causal importance of these metabolic alterations in longevity

Boceprevir for untreated chronic HCV genotype 1 infection.

International audienceBACKGROUND: Peginterferon-ribavirin therapy is the current standard of care for chronic infection with hepatitis C virus (HCV). The rate of sustained virologic response has been below 50% in cases of HCV genotype 1 infection. Boceprevir, a potent oral HCV-protease inhibitor, has been evaluated as an additional treatment in phase 1 and phase 2 studies. METHODS: We conducted a double-blind study in which previously untreated adults with HCV genotype 1 infection were randomly assigned to one of three groups. In all three groups, peginterferon alfa-2b and ribavirin were administered for 4 weeks (the lead-in period). Subsequently, group 1 (the control group) received placebo plus peginterferon-ribavirin for 44 weeks; group 2 received boceprevir plus peginterferon-ribavirin for 24 weeks, and those with a detectable HCV RNA level between weeks 8 and 24 received placebo plus peginterferon-ribavirin for an additional 20 weeks; and group 3 received boceprevir plus peginterferon-ribavirin for 44 weeks. Nonblack patients and black patients were enrolled and analyzed separately. RESULTS: A total of 938 nonblack and 159 black patients were treated. In the nonblack cohort, a sustained virologic response was achieved in 125 of the 311 patients (40%) in group 1, in 211 of the 316 patients (67%) in group 2 (P<0.001), and in 213 of the 311 patients (68%) in group 3 (P<0.001). In the black cohort, a sustained virologic response was achieved in 12 of the 52 patients (23%) in group 1, in 22 of the 52 patients (42%) in group 2 (P=0.04), and in 29 of the 55 patients (53%) in group 3 (P=0.004). In group 2, a total of 44% of patients received peginterferon-ribavirin for 28 weeks. Anemia led to dose reductions in 13% of controls and 21% of boceprevir recipients, with discontinuations in 1% and 2%, respectively. CONCLUSIONS: The addition of boceprevir to standard therapy with peginterferon-ribavirin, as compared with standard therapy alone, significantly increased the rates of sustained virologic response in previously untreated adults with chronic HCV genotype 1 infection. The rates were similar with 24 weeks and 44 weeks of boceprevir

SERDP ER-1376 Enhancement of In Situ Bioremediation of Energetic Compounds by Coupled Abiotic/Biotic Processes:Final Report for 2004 - 2006

This project was initiated by SERDP to quantify processes and determine the effectiveness of abiotic/biotic mineralization of energetics (RDX, HMX, TNT) in aquifer sediments by combinations of biostimulation (carbon, trace nutrient additions) and chemical reduction of sediment to create a reducing environment. Initially it was hypothesized that a balance of chemical reduction of sediment and biostimulation would increase the RDX, HMX, and TNT mineralization rate significantly (by a combination of abiotic and biotic processes) so that this abiotic/biotic treatment may be a more efficient for remediation than biotic treatment alone in some cases. Because both abiotic and biotic processes are involved in energetic mineralization in sediments, it was further hypothesized that consideration for both abiotic reduction and microbial growth was need to optimize the sediment system for the most rapid mineralization rate. Results show that there are separate optimal abiotic/biostimulation aquifer sediment treatments for RDX/HMX and for TNT. Optimal sediment treatment for RDX and HMX (which have chemical similarities and similar degradation pathways) is mainly chemical reduction of sediment, which increased the RDX/HMX mineralization rate 100 to150 times (relative to untreated sediment), with additional carbon or trace nutrient addition, which increased the RDX/HMX mineralization rate an additional 3 to 4 times. In contrast, the optimal aquifer sediment treatment for TNT involves mainly biostimulation (glucose addition), which stimulates a TNT/glucose cometabolic degradation pathway (6.8 times more rapid than untreated sediment), degrading TNT to amino-intermediates that irreversibly sorb (i.e., end product is not CO2). The TNT mass migration risk is minimized by these transformation reactions, as the triaminotoluene and 2,4- and 2,6-diaminonitrotoluene products that irreversibly sorb are no longer mobile in the subsurface environment. These transformation rates are increased 13 times further by chemical reduction of sediment. Dithionite reduction alone is not an effective treatment for TNT (intermediates that irreversibly sorb are not produced), even though the TNT degradation rate (to 2- or 4-aminodinitrotoluene) increases

Risk Factors for Colorectal Cancer in Patients with Multiple Serrated Polyps: A Cross-Sectional Case Series from Genetics Clinics

Patients with multiple serrated polyps are at an increased risk for developing colorectal cancer (CRC). Recent reports have linked cigarette smoking with the subset of CRC that develops from serrated polyps. The aim of this work therefore was to investigate the association between smoking and the risk of CRC in high-risk genetics clinic patients presenting with multiple serrated polyps. Methods and Findings We identified 151 Caucasian individuals with multiple serrated polyps including at least 5 outside the rectum, and classified patients into non-smokers, current or former smokers at the time of initial diagnosis of polyposis. Cases were individuals with multiple serrated polyps who presented with CRC. Controls were individuals with multiple serrated polyps and no CRC. Multivariate logistic regression was performed to estimate associations between smoking and CRC with adjustment for age at first presentation, sex and co-existing traditional adenomas, a feature that has been consistently linked with CRC risk in patients with multiple serrated polyps. CRC was present in 56 (37%) individuals at presentation. Patients with at least one adenoma were 4 times more likely to present with CRC compared with patients without adenomas (OR = 4.09; 95%CI 1.27 to 13.14; P = 0.02). For females, the odds of CRC decreased by 90% in current smokers as compared to never smokers (OR = 0.10; 95%CI 0.02 to 0.47; P = 0.004) after adjusting for age and adenomas. For males, there was no relationship between current smoking and CRC. There was no statistical evidence of an association between former smoking and CRC for both sexes. Conclusion A decreased odds for CRC was identified in females with multiple serrated polyps who currently smoke, independent of age and the presence of a traditional adenoma. Investigations into the biological basis for these observations could lead to non-smoking-related therapies being developed to decrease the risk of CRC and colectomy in these patients.Daniel D. Buchanan, Kevin Sweet, Musa Drini, Mark A. Jenkins, Aung Ko Win, Dallas R. English, Michael D. Walsh, Mark Clendenning, Diane M. McKeone, Rhiannon J. Walters, Aedan Roberts, Sally-Ann Pearson, Erika Pavluk, John L. Hopper, Michael R. Gattas, Jack Goldblatt, Jill George, Graeme K. Suthers, Kerry D. Phillips, Sonja Woodal, Julie Arnold, Kathy Tucker, Amanda Muir, Michael Field, Sian Greening, Steven Gallinger, Renee Perrier, John A. Baron, John D. Potter, Robert Haile, Wendy Franke, Albert de la Chapelle, Finlay Macrae, Christophe Rosty, Neal I. Walker, Susan Parry and Joanne P. Youn

Nanoscale Metallic Iron for Environmental Remediation: Prospects and Limitations

The amendment of the subsurface with nanoscale metallic iron particles (nano-Fe0) has been discussed in the literature as an efficient in situ technology for groundwater remediation. However, the introduction of this technology was controversial and its efficiency has never been univocally established. This unsatisfying situation has motivated this communication whose objective was a comprehensive discussion of the intrinsic reactivity of nano-Fe0 based on the contemporary knowledge on the mechanism of contaminant removal by Fe0 and a mathematical model. It is showed that due to limitations of the mass transfer of nano-Fe0 to contaminants, available concepts cannot explain the success of nano-Fe0 injection for in situ groundwater remediation. It is recommended to test the possibility of introducing nano-Fe0 to initiate the formation of roll-fronts which propagation would induce the reductive transformation of both dissolved and adsorbed contaminants. Within a roll-front, FeII from nano-Fe0 is the reducing agent for contaminants. FeII is recycled by biotic or abiotic FeIII reduction. While the roll-front concept could explain the success of already implemented reaction zones, more research is needed for a science-based recommendation of nano- Fe0 for subsurface treatment by roll-front

Evaluating in situ redox manipulation for remediating pesticide- and explosive -contaminated groundwater

The prevalent use of chloroacetanilide herbicides has resulted in contamination of some ground and surface waters in the U.S. When natural attenuation is not sufficient, remediation may be required. Dithionite is a strong chemical reductant with potential use for remediating contaminated water, sediment, and soil. Used alone, dithionite rapidly dechlorinated chloroacetanilide herbicides in water. Treating aquifer sediment with dithionite reduces native Fe III, creating a redox barrier of FeII-bearing minerals and surface-bound FeII. Exposing alachlor to dithionite-reduced aquifer sediment in citrate-bicarbonate (C-B) buffer produced the thiosufate derivative of alachlor as the major product. Washing the reduced sediment (in C-B buffer) removed FeII and excess dithionite and no alachlor transformation was observed. Exposing alachlor to reduced sediment in K 2CO3 buffer produced dechlorinated alachlor as the major product. Dechlorination also occurred when washed, reduced sediment (in C-B buffer) was amended with FeII (pH = 8.5) and continued as long as additional FeII was provided. Along with pesticide contamination, soil and water contaminated with munitions is also a serious problem. Major high explosive contaminants include RDX, HMX, and TNT. The transformation rates of all three explosives were a function of pH and they were rapidly degraded by buffered, reduced sediment. RDX transformation increased with the amount of reduced sediment or dithionite concentration. Exposing RDX to reduced, washed sediment (in C-B buffer) slowed transformation but the rate was increased by adding FeII. Permeable reactive barriers of zerovalent iron and dithionite-reduced sediment leave behind dissolved, structural, and adsorbed FeII. Aqueous FeII and its associated mineral precipitates degraded RDX, HMX, and TNT. Reaction rates increased with increasing FeII concentration and RDX degradation was greatest at pH \u3e 6.85. This pH is readily obtainable in aquifers. After adding FeII to alkaline aquifer sediment, RDX was degraded without adjusting pH. Considering that iron corrosion increases the pH of the surrounding pore water to \u3e9 and oxidation of FeII produces significant quantities of FeIII, the effect of FeIII on RDX transformation at alkaline pH was investigated. RDX was hydrolyzed at pH 10 under anaerobic conditions and was enhanced significantly when Fe III was present. The results of this research demonstrate that dithionite is a remediation option in natural environments where iron-bearing minerals are abundant and illustrate the important role of FeII and its freshly precipitated minerals in the degradation of contaminants