73 research outputs found
Phase I Evaluation of Intravenous Ascorbic Acid in Combination with Gemcitabine and Erlotinib in Patients with Metastatic Pancreatic Cancer
Preclinical data support further investigation of ascorbic acid in pancreatic cancer. There are currently insufficient safety data in human subjects, particularly when ascorbic acid is combined with chemotherapy.14 subjects with metastatic stage IV pancreatic cancer were recruited to receive an eight week cycle of intravenous ascorbic acid (three infusions per week), using a dose escalation design, along with standard treatment of gemcitabine and erlotinib. Of 14 recruited subjects enrolled, nine completed the study (three in each dosage tier). There were fifteen non-serious adverse events and eight serious adverse events, all likely related to progression of disease or treatment with gemcitabine or erlotinib. Applying RECIST 1.0 criteria, seven of the nine subjects had stable disease while the other two had progressive disease.These initial safety data do not reveal increased toxicity with the addition of ascorbic acid to gemcitabine and erlotinib in pancreatic cancer patients. This, combined with the observed response to treatment, suggests the need for a phase II study of longer duration.Clinicaltrials.gov NCT00954525
Vitamin C: Intravenous Use by Complementary and Alternative Medicine Practitioners and Adverse Effects
Background: Anecdotal information and case reports suggest that intravenously administered vitamin C is used by Complementary and Alternate Medicine (CAM) practitioners. The scale of such use in the U.S. and associated side effects are unknown. Methods and Findings: We surveyed attendees at annual CAM Conferences in 2006 and 2008, and determined sales of intravenous vitamin C by major U.S. manufacturers/distributors. We also queried practitioners for side effects, compiled published cases, and analyzed FDA’s Adverse Events Database. Of 199 survey respondents (out of 550), 172 practitioners administered IV vitamin C to 11,233 patients in 2006 and 8876 patients in 2008. Average dose was 28 grams every 4 days, with 22 total treatments per patient. Estimated yearly doses used (as 25g/50ml vials) were 318,539 in 2006 and 354,647 in 2008. Manufacturers ’ yearly sales were 750,000 and 855,000 vials, respectively. Common reasons for treatment included infection, cancer, and fatigue. Of 9,328 patients for whom data is available, 101 had side effects, mostly minor, including lethargy/fatigue in 59 patients, change in mental status in 21 patients and vein irritation/phlebitis in 6 patients. Publications documented serious adverse events, including 2 deaths in patients known to be at risk for IV vitamin C. Due to confounding causes, the FDA Adverse Events Database was uninformative. Total numbers of patients treated in the US with high dose vitamin C cannot be accurately estimated from this study
Providing competency-based family medicine residency training in substance abuse in the new millennium: a model curriculum
<p>Abstract</p> <p>Background</p> <p>This article, developed for the Betty Ford Institute Consensus Conference on Graduate Medical Education (December, 2008), presents a model curriculum for Family Medicine residency training in substance abuse.</p> <p>Methods</p> <p>The authors reviewed reports of past Family Medicine curriculum development efforts, previously-identified barriers to education in high risk substance use, approaches to overcoming these barriers, and current training guidelines of the Accreditation Council for Graduate Medical Education (ACGME) and their Family Medicine Residency Review Committee. A proposed eight-module curriculum was developed, based on substance abuse competencies defined by Project MAINSTREAM and linked to core competencies defined by the ACGME. The curriculum provides basic training in high risk substance use to all residents, while also addressing current training challenges presented by U.S. work hour regulations, increasing international diversity of Family Medicine resident trainees, and emerging new primary care practice models.</p> <p>Results</p> <p>This paper offers a core curriculum, focused on screening, brief intervention and referral to treatment, which can be adapted by residency programs to meet their individual needs. The curriculum encourages direct observation of residents to ensure that core skills are learned and trains residents with several "new skills" that will expand the basket of substance abuse services they will be equipped to provide as they enter practice.</p> <p>Conclusions</p> <p>Broad-based implementation of a comprehensive Family Medicine residency curriculum should increase the ability of family physicians to provide basic substance abuse services in a primary care context. Such efforts should be coupled with faculty development initiatives which ensure that sufficient trained faculty are available to teach these concepts and with efforts by major Family Medicine organizations to implement and enforce residency requirements for substance abuse training.</p
The Helicobacter pylori CZB Cytoplasmic Chemoreceptor TlpD Forms an Autonomous Polar Chemotaxis Signaling Complex That Mediates a Tactic Response to Oxidative Stress
Cytoplasmic chemoreceptors are widespread among prokaryotes but are far less understood than transmembrane chemoreceptors, despite being implicated in many processes. One such cytoplasmic chemoreceptor is Helicobacter pylori TlpD, which is required for stomach colonization and drives a chemotaxis response to cellular energy levels. Neither the signals sensed by TlpD nor its molecular mechanisms of action are known. We report here that TlpD functions independently of the other chemoreceptors. When TlpD is the sole chemoreceptor, it is able to localize to the pole and recruits CheW, CheA, and at least two CheV proteins to this location. It loses the normal membrane association that appears to be driven by interactions with other chemoreceptors and with CheW, CheV1, and CheA. These results suggest that TlpD can form an autonomous signaling unit. We further determined that TlpD mediates a repellent chemotaxis response to conditions that promote oxidative stress, including being in the presence of iron, hydrogen peroxide, paraquat, and metronidazole. Last, we found that all tested H. pylori strains express TlpD, whereas other chemoreceptors were present to various degrees. Our data suggest a model in which TlpD coordinates a signaling complex that responds to oxidative stress and may allow H. pylori to avoid areas of the stomach with high concentrations of reactive oxygen species. IMPORTANCE Helicobacter pylori senses its environment with proteins called chemoreceptors. Chemoreceptors integrate this sensory information to affect flagellum-based motility in a process called chemotaxis. Chemotaxis is employed during infection and presumably aids H. pylori in encountering and colonizing preferred niches. A cytoplasmic chemoreceptor named TlpD is particularly important in this process, and we report here that this chemoreceptor is able to operate independently of other chemoreceptors to organize a chemotaxis signaling complex and mediate a repellent response to oxidative stress conditions. H. pylori encounters and must cope with oxidative stress during infection due to oxygen and reactive oxygen species produced by host cells. TlpD's repellent response may allow the bacteria to escape niches experiencing inflammation and elevated reactive oxygen species (ROS) production
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