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Biomedical subjects

David Katz

Publications and source records attributed to David Katz.

14 recordsLinked to original sources
PubMed2006

Do essential fatty acids have a role in the treatment of depression?

BACKGROUND: Complementary and alternative medicine (CAM) therapies are used more than conventional therapies by people with self-defined anxiety and depression. Preliminary evidence supports a hypothesis that low plasma concentration of essential fatty acids is associated with depression. Reported here is the result of a systematic review examining the therapeutic efficacy of essential fatty acids for depression. METHODS: Data sources included Medline, Psychinfo, AMED (Allied and Complementary Medicine), and Cochrane Controlled Trials Register databases searched from inception through September 2001. English language randomized controlled trials, controlled clinical trials, intervention studies, case control studies, reviews, and case reports of humans were selected, without limits for demographics or co-morbidities. Two abstractors independently evaluated each study, then reconciled findings. When possible, between group treatment effect size was noted or calculated. RESULTS: Six articles met inclusion criteria: one RCT, two reviews, and three case control trials. A common outcome measure among the case control trials allowed for direct comparison of effect sizes. CONCLUSIONS: The evidence implies promise of a treatment effect of omega-3 fatty acids for depression in adults; although a statement of definitive clinical efficacy is premature. Further study of essential fatty acids as independent and adjuvant therapy for adult depression is indicated, including more sophisticated investigation of dose-response in particular populations.

Boron Compounds↗
PubMed2006

BRIEF REPORT: nutrition and weight loss information in a popular diet book: is it fact, fiction, or something in between?

BACKGROUND/OBJECTIVE: Diet books dominate the New York Times Advice Best Seller list and consumers cite such books as an important source of nutrition information. However, the scientific support for nutrition claims presented as fact (nutrition facts) in diet books is not known. DESIGN/MEASUREMENTS: We assessed the quality of nutrition facts in the best-selling South Beach Diet using support in peer-reviewed literature as a measure of quality. We performed structured literature searches on nutrition facts located in the books' text, and then assigned each fact to 1 of 4 categories (1) fact supported, (2) fact not supported, (3) fact both supported and not supported, and (4) no related papers. A panel of expert reviewers adjudicated the findings. RESULTS: Forty-two nutrition facts were included. Fourteen (33%) facts were supported, 7 (17%) were not supported, 18 (43%) were both supported and not supported, and 3 (7%) had no related papers, including the fact that the diet had been "scientifically studied and proven effective." CONCLUSIONS: Consumers obtain nutrition information from diet books. We found that over 67% of nutrition facts in a best-seller diet book may not be supported in the peer-reviewed literature. These findings have important implications for educating consumers about nutrition information sources.

Books↗
PubMed2005

Homeopathy for attention-deficit/hyperactivity disorder: a pilot randomized-controlled trial.

OBJECTIVES: The aim of this study was to carry out a preliminary trial evaluating the effectiveness of homeopathy in the treatment of attention-deficit/hyperactivity disorder (ADHD). DESIGN: This work was a randomized, double-blind, placebo-controlled trial. SETTINGS/LOCATION: This study was conducted in a private homeopathic clinic in the Seattle metropolitan area. SUBJECTS: Subjects included children 6-12 years of age meeting Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV) criteria for ADHD. INTERVENTIONS: Forty-three subjects were randomized to receive a homeopathic consultation and either an individualized homeopathic remedy or placebo. Patients were seen by homeopathic physicians every 6 weeks for 18 weeks. OUTCOME MEASURES: Outcome measures included the Conner's Global Index-Parent, Conner's Global Index- Teacher, Conner's Parent Rating Scale-Brief, Continuous Performance Test, and the Clinical Global Impression Scale. RESULTS: There were no statistically significant differences between homeopathic remedy and placebo groups on the primary or secondary outcome variables. However, there were statistically and clinically significant improvements in both groups on many of the outcome measures. CONCLUSIONS: This pilot study provides no evidence to support a therapeutic effect of individually selected homeopathic remedies in children with ADHD. A therapeutic effect of the homeopathic encounter is suggested and warrants further evaluation. Future studies should be carried out over a longer period of time and should include a control group that does not receive the homeopathic consultation. Comparison to conventional stimulant medication for ADHD also should be considered.

Adolescent↗
PubMed2005

Cost-effectiveness of in-home automated external defibrillators for individuals at increased risk of sudden cardiac death.

BACKGROUND/OBJECTIVE: In-home automated external defibrillators (AEDs) are increasingly recommended as a means for improving survival of cardiac arrests that occur at home. The current study was conducted to explore the relationship between individuals' risk of cardiac arrest and cost-effectiveness of in-home AED deployment. DESIGN: Markov decision model employing a societal perspective. PATIENTS: Four hypothetical cohorts of American adults 60 years of age at progressively greater risk for sudden cardiac death (SCD): 1) all adults (annual probability of SCD 0.4%); 2) adults with multiple SCD risk factors (probability 2%); 3) adults with previous myocardial infarction (probability 4%); and 4) adults with ischemic cardiomyopathy unable to receive an implantable defibrillator (probability 6%). INTERVENTION: Strategy 1: individuals suffering an in-home cardiac arrest were treated with emergency medical services equipped with AEDs (EMS-D). Strategy 2: individuals suffering an in-home cardiac arrest received initial treatment with an in-home AED, followed by EMS. RESULTS: Assuming cardiac arrest survival rates of 15% with EMS-D and 30% with AEDs, the cost per quality-adjusted life-year gained (QALY) of providing in-home AEDs to all adults 60 years of age is 216,000 dollars. Costs of providing in-home AEDs to adults with multiple risk factors (2% probability of SCD), previous myocardial infarction (4% probability), and ischemic cardiomyopathy (6% probability) are 132,000 dollars, 104,000 dollars, and 88,000 dollars, respectively. CONCLUSIONS: The cost-effectiveness of in-home AEDs is intimately linked to individuals' risk of SCD. However, providing in-home AEDs to all adults over age 60 appears relatively expensive.

Cost-Benefit Analysis↗
PubMed2004

Portable colposcopy in low-resource settings.

Screening for cervical dysplasia is an important public health effort worldwide. In unscreened populations, the incidence of cervical cancer ranges between 2 and 4% of the adult female population, whereas less than 0.1% of the screened population of Caucasian women has cervical cancer in the United States. In developing countries, cervical cytology is difficult to implement successfully because of the cost, cultural constraints, limited access to pathology services, etc. Bypassing cytology and going directly to colposcopy has been successfully implemented as a screening strategy for dysplasia in low resource settings. In this article we describe the development and utilization of a portable binocular colposcope that does not require electricity.

Adult↗
PubMed2003

Stepwise progression of familial adenomatous polyposis-associated desmoid precursor lesions demonstrated by a novel CT scoring system.

INTRODUCTION: Desmoids are rare, locally aggressive but nonmetastasizing clonal proliferations of fibroblasts that occur both sporadically and in association with familial adenomatous polyposis. Most occur in intra-abdominal sites, where they may lead to major morbidity and mortality. A proposed desmoid precursor lesion occurs in the mesentery of one-third of patients with familial adenomatous polyposis, and postoperative mesenteric fibromatosis has been identified in 20 percent of such patients. True desmoids occur in 10 percent, which suggests a model of development in which the phenotype becomes increasingly severe in a manner analogous to the adenoma-carcinoma sequence. This work aimed to confirm such a progression. METHODS: A five-point CT scoring system for mesenteric fibromatosis and desmoids was devised and validated, and in doing so, their incidence was observed. In the second part of the study, seven patients known to have a precursor lesion underwent abdominal CT a median of 27.5 months after the surgery that identified the lesion. Scans were assessed by the scoring system and compared with those of a matched control group of familial adenomatous polyposis patients. RESULTS: The CT scoring system was reliable and reproducible. Of 103 scans of asymptomatic patients with familial adenomatous polyposis, mesenteric fibromatosis and desmoid tumors were identified in 21 and 2 percent, respectively. In the follow-up of patients with desmoid precursor lesions, those in the precursor lesion group had a significantly greater degree of mesenteric fibromatosis and desmoid formation than their corresponding controls (P = 0.009, Mann-Whitney U test). CONCLUSION: A reliable CT scoring system for mesenteric fibromatosis and desmoid tumors in familial adenomatous polyposis is presented. Results with this system provide further evidence for a stepwise progression in the development of desmoids.

Adenomatous Polyposis Coli↗
PubMed2002

Size-dependent tunneling and optical spectroscopy of CdSe quantum rods.

Photoluminescence excitation spectroscopy and scanning-tunneling spectroscopy are used to study the electronic states in CdSe quantum rods that manifest a transition from a zero-dimensional to a one-dimensional quantum-confined structure. Both optical and tunneling spectra show that the level structure depends primarily on the diameter of the rod and not its length. With increasing diameter, the band gap and the excited state level spacings shift to the red. The level structure was assigned using a multiband effective-mass model, showing a similar dependence on rod dimensions.

Cadmium↗
PubMed2002

Distinct requirements for TrkB and TrkC signaling in target innervation by sensory neurons.

Signaling by brain-derived neurotrophic factor (BDNF) via the TrkB receptor, or by neurotrophin-3 (NT3) through the TrkC receptor support distinct populations of sensory neurons. The intracellular signaling pathways activated by Trk (tyrosine kinase) receptors, which in vivo promote neuronal survival and target innervation, are not well understood. Using mice with TrkB or TrkC receptors lacking the docking site for Shc adaptors (trkB(shc/shc) and trkC(shc/shc) mice), we show that TrkB and TrkC promote survival of sensory neurons mainly through Shc site-independent pathways, suggesting that these receptors use similar pathways to prevent apoptosis. In contrast, the regulation of target innervation appears different: in trkB(shc/shc) mice neurons lose target innervation, whereas in trkC(shc/shc) mice the surviving TrkC-dependent neurons maintain target innervation and function. Biochemical analysis indicates that phosphorylation at the Shc site positively regulates autophosphorylation of TrkB, but not of TrkC. Our findings show that although TrkB and TrkC signals mediating survival are largely similar, TrkB and TrkC signals required for maintenance of target innervation in vivo are regulated by distinct mechanisms.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Alphaherpesvirus antigen quantitation to optimize the diagnosis of herpes B virus infection.

Standardized, quantified virus antigen stocks are essential for dependable quality control of diagnostic assays. Five simple, rapid and economical direct enzyme linked immunoassays (dELISA) were developed to standardize and optimize antigen from five major cross-reacting alphaherpesviruses: herpes B virus, herpesvirus papio 2, langur monkey herpesvirus, herpes simplex virus-1 and herpes simplex virus-2. Each dELISA relied on pools of convalescent sera from rhesus monkeys, baboons, langurs and humans. Conjugates were prepared from purified IgG preparations, fractionated from the same sera and then labeled with peroxidase. Serum coated microplates could be stored at -70 degrees C for at least 1 year before use. The duration of the test was approximately 2.5 h if plates were prepared at an earlier time. Virus antigen titers could be determined from titration curves or from single dilutions using a standard curve. The sensitivity of detection was approximately 8x10(5) PFU/ml. This sensitivity sufficed for the determination of viral antigen mass in live or detergent treated virus stocks that usually contain at least 1x10(8) PFU/ml. The assays were valuable for quality assurance of diagnostic serological assays for herpes B virus and other alphaherpesviruses.

Alphaherpesvirinae↗
PubMedDate not supplied

Coalescence of psychiatry, neurology, and neuropsychology: from theory to practice.

In a climate of renewed interest in the synergy between neurology and psychiatry, practitioners are increasingly recognizing the importance of exchange and collaboration between these two disciplines. However, there are few working models of interdisciplinary teams that freely share expertise in real time, while providing clinical and academic training to future physicians who specialize in the central nervous system. Over the past 11 years, the McLean Hospital Neuropsychiatry and Behavioral Neurology service has provided proof-of-principle for such collaboration, demonstrating that a team comprising psychiatrists, neurologists, and neuropsychologists can function effectively as a unit while maintaining the autonomy of these three disciplines and also synthesizing their combined knowledge. In addition to delivering enhanced patient care and promoting medical research, this clinical service has provided enriched cross-specialty training for fellows, residents, and medical students. The practical functioning of the team is described, and case vignettes are presented to illustrate the team's collaborative synergism in practice.

Adult↗
PubMedDate not supplied

Implantable or external defibrillators for individuals at increased risk of cardiac arrest: where cost-effectiveness hits fiscal reality.

OBJECTIVES: Implantable cardioverter defibrillators (ICDs) are highly effective at preventing cardiac arrest, but their availability is limited by high cost. Automated external defibrillators (AEDs) are likely to be less effective, but also less expensive. We used decision analysis to evaluate the clinical and economic trade-offs of AEDs, ICDs, and emergency medical services equipped with defibrillators (EMS-D) for reducing cardiac arrest mortality. METHODS: A Markov model was developed to compare the cost-effectiveness of three strategies in adults meeting entry criteria for the MADIT II Trial: strategy 1, individuals experiencing cardiac arrest are treated by EMS-D; strategy 2, individuals experiencing cardiac arrest are treated with an in-home AED; and strategy 3, individuals receive a prophylactic ICD. The model was then used to quantify the aggregate societal benefit of these three strategies under the conditions of a constrained federal budget. RESULTS: Compared with EMS-D, in-home AEDs produced a gain of 0.05 quality-adjusted life-years (QALYs) at an incremental cost of $5225 ($104,500 per QALY), while ICDs produced a gain of 0.90 QALYs at a cost of $114,660 ($127,400 per QALY). For every $1 million spent on defibrillators, 1.7 additional QALYs are produced by purchasing AEDs (9.6 QALYs/$million) instead of ICDs (7.9 QALYs/$million). Results were most sensitive to defibrillator complication rates and effectiveness, defibrillator cost, and adults' risk of cardiac arrest. CONCLUSIONS: Both AEDs and ICDs reduce cardiac arrest mortality, but AEDs are significantly less expensive and less effective. If financial constraints were to lead to rationing of defibrillators, it might be preferable to provide more people with a less effective and less expensive intervention (in-home AEDs) instead of providing fewer people with a more effective and more costly intervention (ICDs).

Adult↗