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Biomedical subjects

W Henderson

Publications and source records attributed to W Henderson.

At least 19 recordsLinked to original sources
PubMed2001

Hysterectomy in Veterans Affairs Medical Centers.

OBJECTIVE: To examine the indications and surgical morbidity for women veterans who underwent hysterectomies in Department of Veterans Affairs Medical Centers (VAs). METHODS: Data on hysterectomies performed in VAs from 1991 to 1997 were abstracted from a surgical quality improvement program. RESULTS: Records of 1722 women who had hysterectomies in VAs over 6 years were examined. Women were predominately white (62%) and their average age was 42.5 years. Operations included abdominal (74%), vaginal (22%), and laparoscopic-assisted (4%) methods. The most common indications for surgery included uterine leiomyomas (31%), abnormal uterine bleeding (14%), and endometriosis (11%). Indications differed by race (P <.01); nonwhite women were most likely to have surgery for leiomyoma (51%), whereas white women had hysterectomies for leiomyomas (19%), abnormal bleeding (15%), endometriosis (13%), and genital prolapse (11%). The mean postoperative stay was significantly longer for abdominal hysterectomies (4.51 days) than either vaginal or laparoscopic-assisted hysterectomies (2.92 and 2.21 days, respectively; P <.001). The overall complication rate within 30 days was 9%, and the most frequent complication was urinary tract infection (3.3%). CONCLUSION: Women who underwent hysterectomies in VAs had low complication rates, comparable to hysterectomy complication rates in the United States generally.

Adult↗
PubMed2001

Metal complexes of sporidesmin D and dimethylgliotoxin, investigated by electrospray ionisation mass spectrometry.

Electrospray ionisation mass spectrometry (ES-MS) has been used to probe the coordination chemistry of metabolites such as sporidesmin D (spdD), found in the saprophytic fungus Pithomyces chartarum, and the related bisdethiobis(methylthio)gliotoxin (dimethylgliotoxin, Megtx). SpdD forms complexes of the type [spdD+M(MeCN)] and [2spdD+M]+ (M=Cu, Ag) and, at higher cone voltages, [spdD+M]+. The bis(ligand) ion [2spdD+M]+ was observed at very high cone voltages, indicating it has appreciable stability; the proposed structure of this species has a four-coordinate metal ion with two bidentate spdD ligands, coordinated through their SMe groups. 1H NMR titrations of spdD with K+, Ag+ and Cu+ provided additional evidence for complex formation with the soft metals. SpdD forms only relatively weak complexes with Zn2+, Cd2+, Co2+ and Mn2+, in keeping with the known reduced tendency of these metals to form stable thioether complexes. ES-MS studies of Megtx showed similar results to spdD, with stable adducts formed with Cu+ and Ag+ ions. The X-ray crystal structure of spdD is also reported.

Gliotoxin↗
PubMed2001

Metal complexes of the mycotoxins sporidesmin A and gliotoxin, investigated by electrospray ionisation mass spectrometry.

The mycotoxin sporidesmin A (spdA), responsible for the intoxication of animals, causing facial eczema, has been investigated by electrospray ionisation mass spectrometry. Protonated [spdA+H](+) and deprotonated [spdA-H](-) ions are observed in positive and negative ion modes respectively. Reduced spdA, formed by cleavage of the disulfide bond by Na[BH(4)] gives an ion [spdA+H](-), and forms ions of the type [2spdA+M](2-) with a range of divalent metal ions M(2+)=Zn(2+), Cd(2+), Hg(2+), Sn(2+) and Fe(2+). Sodium-containing analogues [2spdA+M+Na](-) are observed, particularly at high cone voltages, where they are stable towards cone voltage-induced fragmentation, indicating appreciable stability of the (spdA)(2)M system. A competition experiment between Cd(2+) and Zn(2+) demonstrates that reduced spdA has a higher affinity for Cd(2+) ions. The related gliotoxin (gtx) forms analogous [2gtx+M](2-) and [2gtx+M+Na](-) ions. The reduction and metal complexation of spdA can be monitored by (1)H NMR spectroscopy, and results in chemical shift changes for those protons adjacent to the sulfur atoms. The isolation of a polymeric cadmium-spdA complex is also reported.

Cadmium↗
PubMed2001

Percutaneous coronary intervention versus coronary artery bypass graft surgery for patients with medically refractory myocardial ischemia and risk factors for adverse outcomes with bypass: a multicenter, randomized trial. Investigators of the Department of Veterans Affairs Cooperative Study #385, the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME).

BACKGROUND: Percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (CABG) are being applied to high-risk populations, but previous randomized trials comparing revascularization methods have excluded a number of important high-risk groups. OBJECTIVES: This five-year, multicenter, randomized clinical trial was designed to compare long-term survival among patients with medically refractory myocardial ischemia and a high risk of adverse outcomes assigned to either a CABG or a PCI strategy, which could include stents. METHODS: Patients from 16 Veterans Affairs Medical Centers were screened to identify myocardial ischemia refractory to medical management and the presence of one or more risk factors for adverse outcome with CABG, including prior open-heart surgery, age >70 years, left ventricular ejection fraction <0.35, myocardial infarction within seven days or intraaortic balloon pump required. Clinically eligible patients (n = 2,431) underwent coronary angiography; 781 were angiographically acceptable; 454 (58% of eligible) patients consented to random assignment between CABG and PCI. RESULTS: A total of 232 patients was randomized to CABG and 222 to PCI. The 30-day survivals for CABG and PCI were 95% and 97%, respectively. Survival rates for CABG and PCI were 90% versus 94% at six months and 79% versus 80% at 36 months (log-rank test, p = 0.46). CONCLUSIONS: Percutaneous coronary intervention is an alternative to CABG for patients with medically refractory myocardial ischemia and a high risk of adverse outcomes with CABG.

Aged↗
PubMed2001

Bioequivalence evaluation of lansoprazole 30-mg capsules (Lanfast and Lanzor) in healthy volunteers.

The bioequivalence of two lansoprazole 30-mg capsules was determined in healthy human, adult volunteers after a single dose in a randomized cross-over study. The study was conducted at Pharmaconsult, Flemington Pharmaceutical Corp., New Jersey, USA. Reference (Lanzor, Laboratoires Houde, Paris, France) and test (Lanfast, Julphar, UAE) were administered to volunteers with 240 ml water after overnight fasting. Blood samples were collected at specified time intervals, plasma was separated and analyzed for lansoprazole using a validated HPLC method. The pharmacokinetic parameters AUC(0-t), AUC(0-~), C(max), T(max), T(1/2) and elimination rate constant were determined from plasma concentration-time profile of both formulations and found to be in good agreement with previously reported values. The calculated pharmacokinetic parameters were compared statistically to evaluate bioequivalence between the two brands, using the statistical modules recommended by the Food and Drug Administration. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals fell within the acceptable range (80-120%) for bioequivalence. Based on these statistical inferences it was concluded that the two formulations exhibited comparable pharmacokinetic profiles and that Julphar's Lanfast is bioequivalent to Lanzor of Lab. Houde.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2001

Validating risk-adjusted surgical outcomes: chart review of process of care.

OBJECTIVE: The primary purpose of this study was to validate risk-adjusted surgical outcomes as indicators of the quality of surgical care at US Department of Veterans Affairs (VA) hospitals. The secondary purpose was to validate the risk-adjustment models for screening cases for quality review. DESIGN: We compared quality of care, determined by structured implicit chart review, for patients from hospitals with higher and lower than expected operative mortality and morbidity (hospital-level tests) and between patients with high and low predicted risk of mortality and morbidity who died or developed complications (patient-level tests). SUBJECTS: 739 general, peripheral vascular and orthopedic surgery cases sampled from the 44 VA hospitals participating in the National VA Surgical Risk Study. MAIN OUTCOME MEASURES: A global rating of quality of care based on chart review. RESULTS: Ratings of overall quality of care did not differ significantly between patients from hospitals with higher and lower than expected mortality and morbidity. On some of the secondary measures, patient care was rated higher for hospitals with lower than expected operative mortality. At the patient level of analysis, those who died or developed complications and had a high predicted risk of mortality or morbidity were rated higher on quality of care than those with a low predicted risk of adverse outcome. CONCLUSIONS: The absence of a relationship between most of our measures of process of care and risk-adjusted outcomes may be due to an insensitivity of chart reviews to hospital-level differences in quality of care. Site visits to National VA Surgical Risk Study hospitals with high and low risk-adjusted mortality and morbidity have detected differences on a number of dimensions of quality. The patient-level findings suggest that the risk-adjustment models are useful for screening adverse outcome cases for quality of care review.

Data Interpretation, Statistical↗
PubMed2001

Detecting improvement in quality of life and symptomatology in schizophrenia.

Instrument-based scores are often used as outcome measures. However, little is known about what changes in scores mean in terms of a clinical assessment of improvement or deterioration. The purpose of this report was to determine how much change in standard instrument scores represents a clinically detectable improvement or deterioration. The Veterans Affairs (VA) Cooperative Study of Clozapine in Refractory Schizophrenia evaluated 423 patients on clozapine or haloperidol. Symptoms and quality of life scales were completed at baseline; 6 weeks; and 3, 6, and 12 months. Among patients judged as "improved" by clinicians, the average percentage changes were a 21 percent decrease in Positive and Negative Syndrome Scale (PANSS) scores and a 26 percent increase in Quality of Life Scale (QLS) scores across all followup periods. The change in mean seven-point item scores were -0.46 (PANSS) and 0.23 (QLS). A major gain in clinically assessed improvement to "much better" was associated with a 45 percent decline in PANSS scores and 50 percent increase in QLS scores (change in mean seven-point item scores -0.88 and 0.92, respectively). Thus, modest changes in psychometric scales assessing symptoms and quality of life reflect clinically detectable improvement.

Adult↗
PubMed2001

Luminescent visualization of latent fingerprints by direct reaction with a lanthanide shift reagent.

The utilization of the lanthanide shift reagent tris (6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato) europium (III) [Eu(fod)3] as a simple one-step reagent for the luminescent visualization of latent fingerprints has been investigated. UV excitation of Eu(fod)3-treated prints, achieved by using a hand-held UV lamp or a Polilight, results in an orange emission at 614 nm. Time-resolved imaging is not required for visualization. Visualization of latent fingerprints on paper under the conditions used, although good, was found to be inferior to that obtained by standard DFO (1,8-diazafluoren-9-one) treatment, whereas visualization of prints obtained on aluminum drink cans and galvanized iron proved superior to that obtained by Superglue/panacryl treatment. Eu(fod)3 treatment can also be used first without compromising subsequent ninhydrin or DFO treatment, making it a 'nothing-to-lose" reagent.

Aluminum↗
PubMed2000

Effectiveness of team-managed home-based primary care: a randomized multicenter trial.

CONTEXT: Although home-based health care has grown over the past decade, its effectiveness remains controversial. A prior trial of Veterans Affairs (VA) Team-Managed Home-Based Primary Care (TM/HBPC) found favorable outcomes, but the replicability of the model and generalizability of the findings are unknown. OBJECTIVES: To assess the impact of TM/HBPC on functional status, health-related quality of life (HR-QoL), satisfaction with care, and cost of care. DESIGN AND SETTING: Multisite randomized controlled trial conducted from October 1994 to September 1998 in 16 VA medical centers with HBPC programs. PARTICIPANTS: A total of 1966 patients with a mean age of 70 years who had 2 or more activities of daily living impairments or a terminal illness, congestive heart failure (CHF), or chronic obstructive pulmonary disease (COPD). Intervention Home-based primary care (n=981), including a primary care manager, 24-hour contact for patients, prior approval of hospital readmissions, and HBPC team participation in discharge planning, vs customary VA and private sector care (n=985). MAIN OUTCOME MEASURES: Patient functional status, patient and caregiver HR-QoL and satisfaction, caregiver burden, hospital readmissions, and costs over 12 months. RESULTS: Functional status as assessed by the Barthel Index did not differ for terminal (P=.40) or nonterminal (those with severe disability or who had CHF or COPD) (P=.17) patients by treatment group. Significant improvements were seen in terminal TM/HBPC patients in HR-QoL scales of emotional role function, social function, bodily pain, mental health, vitality, and general health. Team-Managed HBPC nonterminal patients had significant increases of 5 to 10 points in 5 of 6 satisfaction with care scales. The caregivers of terminal patients in the TM/HBPC group improved significantly in HR-QoL measures except for vitality and general health. Caregivers of nonterminal patients improved significantly in QoL measures and reported reduced caregiver burden (P=.008). Team-Managed HBPC patients with severe disability experienced a 22% relative decrease (0.7 readmissions/patient for TM/HBPC group vs 0.9 readmissions/patient for control group) in hospital readmissions (P=.03) at 6 months that was not sustained at 12 months. Total mean per person costs were 6.8% higher in the TM/HBPC group at 6 months ($19190 vs $17971) and 12.1% higher at 12 months ($31401 vs $28008). CONCLUSIONS: The TM/HBPC intervention improved most HR-QoL measures among terminally ill patients and satisfaction among non-terminally ill patients. It improved caregiver HR-QoL, satisfaction with care, and caregiver burden and reduced hospital readmissions at 6 months, but it did not substitute for other forms of care. The higher costs of TM/HBPC should be weighed against these benefits.

Activities of Daily Living↗
PubMed2000

Quantum-critical conductivity scaling for a metal-insulator transition

Temperature (T)- and frequency (omega)-dependent conductivity measurements are reported here in amorphous niobium-silicon alloys with compositions (x) near the zero-temperature metal-insulator transition. There is a one-to-one correspondence between the frequency- and temperature-dependent conductivity on both sides of the critical concentration, thus establishing the quantum-critical nature of the transition. The analysis of the conductivity leads to a universal scaling function and establishes the critical exponents. This scaling can be described by an x-, T-, and omega-dependent characteristic length, the form of which is derived by experiment.

Journal Article↗
PubMed2000

Comparison of complications after radical and partial nephrectomy: results from the National Veterans Administration Surgical Quality Improvement Program.

OBJECTIVE: To determine whether radical nephrectomy causes less morbidity, less mortality and is associated with a shorter hospital stay than is partial nephrectomy. PATIENTS AND METHODS: A total of 1885 nephrectomies (1373 radical and 512 partial) conducted between 1991 and 1998 in the Department of Veterans Affairs (VA) National Surgical Quality Improvement Program were evaluated. Using multivariate analyses, outcomes were risk-adjusted based on 45 preoperative variables to compare mortality and morbidity rates. RESULTS: The unadjusted 30-day mortality was 2.0% for radical and 1.6% for partial nephrectomy (P = 0.58). Risk-adjusting the two groups did not result in a statistically significant difference in mortality. The 30-day overall morbidity rate was 15% for radical and 16.2% for partial nephrectomy (P = 0.52); risk-adjusted morbidity rates were not statistically different. There were no statistically significant differences in the rates of postoperative progressive renal failure, acute renal failure, urinary tract infection, prolonged ileus, transfusion requirement, deep wound infection, or extended length of stay. CONCLUSIONS: Partial nephrectomy carried out in the VA program has low morbidity and mortality rates, comparable with the complication rates after radical nephrectomy.

Carcinoma, Renal Cell↗
PubMed2000

Quality of life in schizophrenia: a comparison of instruments. Department of Veterans Affairs Cooperative Study Group on Clozapine in Refractory Schizophrenia.

Health-related quality of life in schizophrenia can be assessed by direct patient response or by a rating based on a structured interview. This study compares both types of instruments using a series of five standards: (1) sensitivity to change over time, (2) sensitivity to treatment effect, (3) correlation with symptom severity, (4) correlation with global clinical ratings, and (5) correlation with other measures of health-related quality of life. Four hundred and twenty-three inpatients with schizophrenia participating in a clinical trial comparing clozapine and haloperidol (VA Cooperative Study in Health Services #17) were evaluated using multiple measures of health-related quality of life (Lehman Quality of Life Interview; Heinrichs-Carpenter-Hanlon Quality of Life Scale; Strauss-Carpenter Level of Function scale, and clinical response.) The Quality of Life Interview showed less sensitivity to change and treatment effect, as well as lower correlations with all other measures than the Quality of Life Scale and the Level of Function scale. The latter scales showed high sensitivity to both change and treatment effect, and moderate-high correlations with other measures and with each other. The Quality of Life Scale and the Level of Function scale rater assessments appeared to be substantially more sensitive to subtle change and treatment effects than the patient-reported Quality of Life Interview for clinical trials. Health-related quality of life in schizophrenia is a more heterogeneous concept than previously appreciated.

Adult↗
PubMed2000

Clinical and psychopharmacologic factors influencing family burden in refractory schizophrenia. The Department of Veterans Affairs Cooperative Study Group on Clozapine in Refractory Schizophrenia.

BACKGROUND: This study compares the effect of clozapine and haloperidol and identifies other factors related to family burden as experienced by relatives of patients with refractory schizophrenia (DSM-III-R). METHOD: Of 423 patients participating in a multisite randomized clinical trial, 221 identified a family member who was actively involved in their care and who agreed to complete a standardized measure of family burden at 6 weeks and 3, 6, 9, and 12 months after randomization, simultaneous with comprehensive patient assessments. RESULTS: Patient factors most consistently correlated with greater family burden were symptom severity, days living in the community (i.e., not in the hospital), and frequency of family contact. Among family members, clozapine was associated with significantly (p = .048) greater reduction in feelings of dissatisfaction related to providing support to the patient, but not in objective measures of support, amount of worry the patient engendered, or days of missed employment or household activity. Although clozapine reduces symptoms, thus lowering family burden, it also increases days living in the community, which tends to increase family burden, perhaps canceling out the benefit to families of reduced symptoms. CONCLUSION: Clozapine has a small but significant effect on the experience of families of patients. This is the first study to demonstrate that effective pharmacotherapy may be of some benefit to families as well as to patients.

Adult↗
PubMed2000

Medication continuation and compliance: a comparison of patients treated with clozapine and haloperidol.

BACKGROUND: This study compares medication continuation and regimen compliance with the atypical antipsychotic medication clozapine versus the conventional antipsychotic haloperidol. METHOD: Data from a 15-site double-blind, randomized clinical trial (N = 423) were used to compare patients with DSM-III-R schizophrenia assigned to clozapine or haloperidol in terms of duration of participation while taking the randomly assigned study drug (continuation) and the proportion of prescribed pills that were taken (compliance). Multiple regression analysis was used to determine the relationship of baseline characteristics and measures of clinical change to continuation for the entire sample and for patients assigned to each medication. RESULTS: Patients assigned to clozapine continued taking the study drug for a mean of 35.5 weeks as compared with only 27.2 among patients assigned to haloperidol (F = 4.45, df = 1,422; p = .0001). No differences were found between the groups in the proportion of prescribed pills that were returned at any timepoint. Among patients assigned to haloperidol, poorer continuation was associated with being older and greater continuation with receiving public support. Among patients on clozapine treatment, continuation was poorer among African American patients and greater among patients who showed reduced clinical symptoms and akathisia. Continuation with clozapine was greater even after adjusting for these factors. CONCLUSION: Continuation with medication is greater with clozapine than haloperidol and is partly explained by greater symptom improvement and reduced side effects. No differences were found in regimen compliance.

Adult↗
PubMed2000

ABTS: a safe alternative to DAB for the enhancement of blood fingerprints.

The use of 2,2'-azino-di-[3-ethylbenzthiazolinesulfonate(6)] diammonium salt (ABTS) for the enhancement of fingerprints in blood has been investigated. Optimal pH conditions and H2O2 concentrations have been determined using UV/Vis spectroscopy. ABTS is an effective and safe noncarcinogenic (though more expensive) alternative to the presently used 3,3'-diaminobenzidine (DAB) for the development of blood fingerprints, especially on porous surfaces. The bright green color of the oxidized ABTS is an advantage on certain colored surfaces where the dark brown color of DAB does not stand out well from the background. Development with ABTS does not interfere with subsequent DAB treatment, making ABTS a "nothing-to-lose" reagent. ABTS can be used after ninhydrin treatment, but the reverse is not the case.

Benzothiazoles↗
PubMed2000

A critical examination of the USMLE II: does a study month improve test performance?

Students often are encouraged to elect a study month prior to taking the USMLE II. OBJECTIVE: To determine if a study month prior to the September USMLE II improves student test performance. METHODS: Student clerkship sequence was prospectively recorded for each senior at a large midwestern medical school during the 1998-99 academic year, and USMLE I and II scores were obtained. USMLE II scores were compared between students who elected a study month prior to the September testing date versus those who elected clerkships, while controlling for USMLE I test scores using multiple linear regression. RESULTS: Complete data were obtained for 167 senior year medical students. 124 (74.3%) students took the September USMLE II after electing a study month, and 43 (25.7%) students took the September USMLE II after electing clerkships. The mean score for those who elected a study month before the USMLE II test was higher than those electing clerkships (210.56 +/- 17.12 vs 208.65 +/- 20.83). However, after controlling for USMLE I scores (r(2) = 0.53; p < 0.01), the election of a study month prior to the September USMLE II was not associated with an increase in student performance (r(2) < 0.01; p = 0.73). CONCLUSIONS: These results do not support study months as a means to improve USMLE II test performance, and suggest that rotations may be equally beneficial.

Journal Article↗