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Biomedical subjects

D Baldwin

Publications and source records attributed to D Baldwin.

At least 37 records · Page 2Linked to original sources
PubMed1999

Individualized outcome feedback produces voluntary antiemetic prescribing practice changes.

STUDY OBJECTIVE: To determine the impact of individualized outcome feedback on antiemetic prescribing practices and compare outcomes of a cost-effective, standardized antiemetic protocol (PROT) to that of customized antiemetic therapy (NONPROT). DESIGN: Prospective, observational study with randomized component. SETTING: Postanesthesia care unit (PACU) of an academic medical center. PATIENTS: 3027 consecutive ASA physical status I, II, and III patients receiving general anesthesia. INTERVENTIONS: Patients were randomized to receive 0.625 mg droperidol or 4 mg ondansetron for postoperative nausea and/or vomiting (PONV) from a protocol, or received customized antiemetic therapy. MEASUREMENTS AND MAIN RESULTS: Incidence of PACU PONV, selection of PROT versus NONPROT, patient satisfaction, and use of PONV prophylaxis were measured and indexed by an attending anesthesiologist in a monthly report for 4 months. Monthly expenditures for antiemetic therapy prior to, during, and after the study were collected. Literature on PONV outcomes, appropriate timing, and selection of PONV prophylaxis was distributed. The NONPROT group was slightly older than the PROT group; otherwise, demographics were similar between all groups. The incidence of PONV did not differ between the PROT and NONPROT groups (11% vs. 10%), and the incidence of PONV in patients receiving prophylaxis was higher in both groups (17% PROT vs. 15% NONPROT). Patients receiving ondansetron as a first-line drug required rescue therapy less often (5%) than those receiving droperidol (14%); however, patient satisfaction was indistinguishable among all groups. During the study, the use of prophylaxis decreased 47% without an increase in PONV, and PROT selection increased 54%. CONCLUSIONS: Individualized outcome feedback produced a 48% reduction in monthly expenditures for ondansetron and droperidol, which was sustained after the study. Patients satisfaction between ondansetron 4 mg and droperidol 0.625 mg given in the PACU did not differ in spite of a slightly greater efficacy of ondansetron as a first-line drug.

Adult↗
PubMed1999

A comparison of gel-based, nylon filter and microarray techniques to detect differential RNA expression in plants.

An initial application of plant genomics has been to monitor gene expression on a scale much larger than previously possible. Although multiplexed assays of RNA abundance have developed more quickly than those for protein and metabolite levels, some combination of these approaches will soon be providing our best views yet into plant molecular biology. Three techniques that have made contributions to the RNA transcript portion of this combination are reviewed. Currently, each can produce a profile of expression levels for a large but incomplete set of plant genes, at reproducibly high levels of accuracy and over a range of labor and financial expenses.

Blotting, Northern↗
PubMed1999

Paroxetine in social phobia/social anxiety disorder. Randomised, double-blind, placebo-controlled study. Paroxetine Study Group.

BACKGROUND: Preliminary studies have suggested that paroxetine may be effective in social phobia/social anxiety disorder. AIMS: To assess the efficacy and tolerability of paroxetine in the acute (12-week) treatment of social phobia. METHOD: Two-hundred and ninety patients with social phobia were assigned randomly to paroxetine (20-50 mg/day flexible dose) or placebo for 12 weeks of double-blind treatment. Primary efficacy outcomes were the Liebowitz Social Anxiety Scale (LSAS) total score (patient-rated) and the Clinical Global Impression (CGI) scale global improvement item. The secondary efficacy variables included CGI scale severity of illness score and the patient-rated Social Avoidance and Distress Scale. RESULTS: Paroxetine produced a significantly greater reduction in LSAS total score (mean change from baseline: -29.4 v. -15.6; P < or = 0.001) and a greater proportion of responders (score < or = 2 on CGI global improvement) (65.7% v. 32.4%; P < 0.001) compared with placebo at the end of the 12-week study period. Both primary efficacy variables were statistically significant compared with placebo from week 4 onwards. Paroxetine was generally well tolerated. CONCLUSIONS: Paroxetine is an effective, well-tolerated treatment for patients with social phobia.

Adolescent↗
PubMed1998

Ion-exchange column chromatographic method for assaying purine metabolic pathway enzymes.

High energy phosphate levels fall rapidly during cardiac ischemia and recover slowly (more than one week) during reperfusion. The slow recovery of ATP may reflect a lack of purine metabolic precursors and/or increased activity of purine catabolic enzymes such as 5'-nucleotidase (5'-NT, EC 3.1.3.5) and adenosine deaminase (ADA, EC 3.5.4.4). The activity of enzymes involved in both the catabolism of ATP precursors (5-NT and ADA) and the restoration of ATP from slow synthetic pathways [adenosine kinase (AK, EC 2.7.1.20), adenine phosphoribosyl transferase (APRT, EC 2.4.2.7) and hypoxanthine phosphoribosyl transferase (HPRT, EC 2.4.2.8)] may directly affect the rate of ATP recovery. Strategies to enhance recovery will depend on the relative activity of these enzymes following ischemia. Their activity in different species and their response to ischemia are not well characterized. Hence, rapid assay methods for these enzymes would facilitate detailed time course studies of their activities in postischemic myocardium. We modified a single ion-exchange column chromatographic method using DEAE-Sephadex to determine the products of incubation of 5'-NT, AK, APRT and HPRT with their respective substrates. The uniformity of the final product measurement procedure for all assays permits the activities of the four enzymes to be rapidly determined in a single tissue sample and facilitates the study of a large number of samples. This technique should also be useful for enzymes of the pyrimidine metabolic pathway.

5'-Nucleotidase↗
PubMed1998

Foot TcPO2 response to lumbar sympathectomy in patients with focal ischemic necrosis.

We prospectively evaluated all patients with superficial foot necrosis of 1-3 cm and transcutaneous oxygen tension (TcPO2) values of <30 mmHg who received a sympathectomy as the primary treatment of their vascular occlusive disease. Preoperatively, and every 2-3 days in the postoperative period, measurement of TcPO2 of the forefoot was performed. Clinical success was defined as healing of the necrosis or healing of a toe amputation and avoidance of a major below-knee/above-knee amputation for 1 year. Ten patients were available for long-term evaluation. During the first 4-5 days, all patients increased their foot TcPO2 and the mean increase (23 mmHg) was significant (p = 0.04). Clinical improvement was marked by an average increase of 29 mmHg by postoperative day 10. In contrast, patients with clinical failure had only an average increase of 5 mmHg in TcPO2 by the same postoperative interval. Preoperative increase in TcPO2 by at least 20 mmHg in response to dependency predicted a favorable response to sympathectomy. In addition, sustained postoperative increases in tissue oxygen levels by postoperative day 10 also favored wound healing.

Adult↗
PubMed1998

Adenosine receptor blockade enhances myocardial stunning without a sustained effect on fluorine-18-FDG uptake postreperfusion.

UNLABELLED: The aim of this study was to determine whether adenosine receptor blockade before ischemia would enhance the degree of stunning and induce a sustained decrease in glucose uptake after reperfusion. METHODS: Stunning was induced in 14 anesthetized swine by partially occluding the left anterior descending artery (LAD) for 20 min (> 80% flow reduction). Seven animals were pretreated with the nonspecific adenosine receptor blocker 8-phenyltheophylline (8-PT; 5 mg/kg), which decreased reactive hyperemia by an average of 38%. Myocardial glucose uptake was assessed 1 hr following reperfusion with PET and the glucose analog 18F-fluorodeoxyglucose (FDG). RESULTS: Before ischemia, systolic shortening in the LAD region was 15% +/- 6% in the control group and 16% +/- 4% in the 8-PT group and in both groups was reduced to - 1% +/- 2% during ischemia. After reperfusion, systolic shortening was 7% +/- 3% in the control group and 2% +/- 3% in the 8-PT group (p < 0.05). Myocardial oxygen consumption before ischemia was 4.58 +/- 3.03 micromol/min/g in the control group and 4.44 +/- 1.83 micromol/min/g in the 8-PT group (ns) and neither were different after reperfusion. In the postischemic LAD region, myocardial glucose uptake was 0.18 +/- 0.15 micromol/min/g in the control group and was similar to that of the 8-PT group (0.17 +/- 0.08 micromol/min/g; ns). CONCLUSION: The nonspecific adenosine blocker 8-PT enhanced the degree of stunning when given before ischemia but did not induce a sustained effect on myocardial glucose uptake after reperfusion.

Animals↗
PubMed1998

Diagnosing candidiasis. A new, cost-effective technique.

OBJECTIVE: To demonstrate the efficacy of normal saline as a culture medium for the rapid growth and detection of Candida. STUDY DESIGN: During a six-month period in 1995, the authors examined 302 patients with vulvovaginal complaints. A wet smear diagnosis was accomplished in 271 patients; 31 had symptoms suggestive of a Candida infection, which was not confirmed by microscopy. Two patients were excluded, leaving 29 in the study group. Two samples of the vaginal discharge were collected from the vaginal fornices, with one sample placed in a tube of liquid Sabouraud medium and the second placed in a sterile, red-topped tube containing 5 mL of normal saline. Each saline culture was placed in a test tube rack and left to incubate at room temperature. The samples containing the Sabouraud medium were incubated in the hospital microbiology laboratory. Both samples were evaluated microscopically within 24-72 hours to detect the presence or absence of Candida organisms. RESULTS: Of the 29 patients who had symptoms suggestive of Candida, 16 had a confirmed diagnosis of Candida employing both the saline method and Sabouraud medium. Eleven patients were negative for Candida with both the saline and Sabouraud; there was one false positive and one false negative in each group. The positive predictive value of the normal saline culture technique was 94.1%, with a negative predictive value of 91.7%. Sensitivity and specificity were 94.1% and 91.7%, respectively. CONCLUSION: Using normal saline instead of Sabouraud's medium to culture Candida proved inexpensive, cost-effective and highly accurate for rapid diagnosis.

Candidiasis, Vulvovaginal↗
PubMed1997

A novel receptor for Apo2L/TRAIL contains a truncated death domain.

Apo2 ligand (Apo2L [1], also called TRAIL for tumor necrosis factor (TNF)-related apoptosis-inducing ligand [2]) belongs to the TNF family and activates apoptosis in tumor cells. Three closely related receptors bind Apo2L: DR4 and DR5, which contain cytoplasmic death domains and signal apoptosis, and DcR1, a decoy receptor that lacks a cytoplasmic tail and inhibits Apo2L function [3-5]. By cross-hybridization with DcR1, we have identified a fourth Apo2L receptor, which contains a cytoplasmic region with a truncated death domain. We subsequently named this protein decoy receptor 2 (DcR2). The DcR2 gene mapped to human chromosome 8p21, as did the genes encoding DR4, DR5 and DcR1. A single DcR2 mRNA transcript showed a unique expression pattern in human tissues and was particularly abundant in fetal liver and adult testis. Upon overexpression, DcR2 did not activate apoptosis or nuclear factor-kappaB; however, it substantially reduced cellular sensitivity to Apo2L-induced apoptosis. These results suggest that DcR2 functions as an inhibitory Apo2L receptor.

Adult↗
PubMed1997

Control of TRAIL-induced apoptosis by a family of signaling and decoy receptors.

TRAIL (also called Apo2L) belongs to the tumor necrosis factor family, activates rapid apoptosis in tumor cells, and binds to the death-signaling receptor DR4. Two additional TRAIL receptors were identified. The receptor designated death receptor 5 (DR5) contained a cytoplasmic death domain and induced apoptosis much like DR4. The receptor designated decoy receptor 1 (DcR1) displayed properties of a glycophospholipid-anchored cell surface protein. DcR1 acted as a decoy receptor that inhibited TRAIL signaling. Thus, a cell surface mechanism exists for the regulation of cellular responsiveness to pro-apoptotic stimuli.

Amino Acid Sequence↗
PubMed1997

Transcutaneous partial oxygen pressure changes following skew flap and Burgess-type below-knee amputations.

OBJECTIVE: To evaluate the degree of flap hypoxia following different types of below-knee amputations. DESIGN: Prospective preoperative and postoperative measurements of transcutaneous partial oxygen pressure (TcPo2) at the site of amputation in 10 consecutive patients who underwent a Burgess-type below-knee amputation (group 1) and in 10 consecutive patients who underwent a skew flap amputation (group 2). SETTING: An academic, tertiary care Veterans Affairs medical center. PATIENTS: Individuals with severe arterial occlusive disease of the lower extremity, in many of whom vascular reconstruction has failed. INTERVENTION: Measurements of TcPo2 (in millimeters of mercury). MAIN OUTCOME MEASUREMENT: The decrease in TcPo2 associated with the different "flaps" of a Burgess-type below-knee amputation. RESULTS: In all skin flaps, regardless of the type of amputation, an early postoperative reduction of the TcPo2 was noted. The greatest reduction (11 mm Hg) and persistence at 20 postoperative days were noted in posterior flaps. CONCLUSIONS: Strict conformity to the Burgess-type of below-knee flap design may not provide an optimal incisional blood supply. Consideration should be given to the skew flap technique in patients who require amputation for severe lower limb arterial insufficiency.

Aged↗
PubMed1997

Flexible endoscope deflectability: changes using a variety of working instruments and laser fibers.

To measure the effects of different working instruments and holmium laser fibers on the deflectability in a variety of actively deflectable flexible endoscopes, a benchtop study was performed. The endoscopes studied were the Storz 7.5 flexible ureteroscope, the AUR-7 and AUR-9 flexible ureteroscopes (Circon-ACMI), a prototype Mitsubishi flexible ureteroscope (Mitsubishi Optics, Inc.), the ACN flexible cystoscope (Circon-ACMI), and the Storz flexible cystoscope. Working instruments included 1.6F (Wolf) and 1.9F (Microvasive) electrohydraulic lithotripsy (EHL) probes, 1.9F two-prong graspers and Bagley baskets, 2.4F Segura and helical baskets (Microvasive), 3.0F Segura basket, and 200- and 365-micron holmium laser fibers (Xintec). In ureteroscopes, the effect of 1.6F and 1.9F EHL probes ranged from having no effect in the Xintec 6,000, to decreasing deflection by 30 degrees in the AUR-7. Working instruments that were 2.4F or greater reduced deflection from 33 degrees to 93 degrees. Better deflectability was noted with the 200-micron holmium laser fiber than with the 365-micron fiber. The diameter of the working instrument did not affect deflectability as severely in cystoscopes. No significant differences in deflection existed between the 365-micron and 200-micron fibers in the flexible nephroscopes tested. In general, working instruments less than 2.4F and the 200-micron laser fiber have little effect on deflectability compared with working instruments 2.4F or larger and the 365-micron fiber. Flexible cystoscopes, with their larger working channels and stronger deflection cables, are affected less by working instrument diameter than are flexible ureteroscopes.

Cystoscopes↗
PubMed1997

Selective serotonin reuptake inhibitor-induced serotonin syndrome: review.

The selective pharmacology of the selective serotonin reuptake inhibitors (SSRIs) results in a lower potential for pharmacodynamic drug interactions relative to other antidepressants such as the tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs). However, the SSRIs have been implicated in the development of the serotonin syndrome--a potentially life-threatening complication of treatment with psychotropic drugs. The syndrome is produced most often by the concurrent use of two or more drugs that enhance central nervous system serotonin activity and often goes unrecognized because of the varied and nonspecific nature of its clinical features. The serotonin syndrome is characterized by alterations in cognition (disorientation, confusion), behavior (agitation, restlessness), autonomic nervous system function (fever, shivering, diaphoresis, diarrhea), and neuromuscular (ataxia, hyperreflexia, myoclonus) activity. The difference between this syndrome and the occurrence of adverse effects caused by serotonin reuptake inhibitors alone is the clustering of the signs and symptoms, their severity, and their duration. There are important pharmacokinetic interactions between SSRIs and other serotonergic drugs due principally to their effects on the cytochrome P450(CYP) isoenzymes, the potential for which varies widely amongst the SSRI group, which may increase the likelihood of a pharmacodynamic interaction. The exceptionally long washout period required after fluoxetine discontinuation may cause additional problems and/or inconvenience. Patients with serotonin syndrome usually respond to discontinuation of drug therapy and supportive care alone, but they may also require treatment with antiserotonergic agent such as cyproheptadine, methysergide, and/or propranolol. To reduce the occurrence, morbidity, and mortality of the serotonin syndrome, it must be both prevented by prudent pharmacotherapy and given prompt recognition when it is present.

Antidepressive Agents↗
PubMed1997

Regional glucose uptake within hypoperfused swine myocardium as measured by positron emission tomography.

Chronic myocardial ischemia and 2-[18F]fluoro-2-deoxy-D-glucose (FDG) uptake were studied with positron emission tomography in 12 swine instrumented with an external constrictor on the left anterior descending coronary artery (LAD). Serial changes in function (by echocardiography), blood flow (with H215O) and FDG were determined weekly. At 1 wk, function was normal and FDG uptake in the LAD and non-LAD regions was 0.43 +/- 0.12 and 0.45 +/- 0.11 mumol. min-1.g-1, respectively (not significant). At approximately 5 wk, LAD wall thickening decreased to 18 +/- 5 from 27 +/- 8% (P < 0.05), whereas LAD and non-LAD blood flows were 0.68 +/- 0.28 and 1.03 +/- 0.25 ml.min-1.g-1, respectively (P < 0.05). At that time, FDG uptake in LAD and non-LAD regions was 0.60 +/- 0.43 and 0.49 +/- 0.30 mumol.min-1.g-1, respectively (P < 0.05). By the use of transmural biopsies (n = 6), ATP and creatine phosphate in the LAD region were 3.62 +/- 0.73 and 5.91 +/- 1.44 mumol/g wet wt, respectively, and neither differed from values in remote regions. In this model of chronic ischemia, hypoperfused dysfunctional regions were characterized by enhanced glucose uptake and preserved bioenergetics. This supports the concept that the myocardium adapts to chronic ischemia.

Adenosine Triphosphate↗