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Biomedical subjects

W Wilson

Publications and source records attributed to W Wilson.

At least 73 records · Page 4Linked to original sources

Influence of carbohydrate supplementation early in exercise on endurance running capacity.

The aim of this study is to examine the effect of carbohydrate (CHO) ingestion during the first hour of treadmill running on endurance capacity. Eleven male subjects ran at 70% VO2max to exhaustion on three occasions one week apart. On two occasions two CHO-electrolyte solutions (a 5.5% (E) and a 6.9% (L) were ingested for the first hour of exercise; water was ingested until exhaustion. On the third occasion water (W) was ingested throughout the run. The order testing was randomly assigned. Exhaustion times for the W, E, and L trials were 109.6 +/- 9.6 min, 124.5 +/- 8.4 min, and 121.4 +/- 9.4 min, respectively. There was no difference between the two CHO trials, but time to exhaustion was longer only for the E trial (P < 0.05), compared with the W trial. Nevertheless the average performance times for the combined results of the two CHO trials were longer than the water trial. Carbohydrate ingestion resulted in higher blood glucose concentration (P < 0.01) at 20 min in the E trail only and lower (P < 0.05) serum growth hormone and plasma FFA and glycerol concentrations at 60 min but not at exhaustion in both E and L trials compared with the W trial. Blood lactate, plasma ammonia, electrolytes, catecholamines, and serum insulin and cortisol concentrations were not different in the three trials. In conclusion, CHO ingestion during the first hour of exercise improves endurance capacity go a greater extent compared with water alone.

Adult↗

Short-range orientation in electric fish: an experimental study of passive electrolocation.

Gymnotiform electric fish are capable of locating and approaching an electrically discharging conspecific over a range of 1-2 m in a behavior called passive electrolocation. This paper investigates the movements of two species in experiments with approaches to stationary dipoles that are either silenced or jumped to a new direction during an approach. Gymnotus carapo fail to find an electrode source in trials in which the dipole electrode is switched off in mid-track. They slow their approach, become disoriented and drift away from the target within seconds of the field being switched off. This result suggests that the fish are unable to construct a cognitive map of a dipole source from brief exposure to local electrosensory stimuli. The second set of trials shows that Brachyhypopomus diazi and Gymnotus carapo bend their body to track electric vectors which are suddenly jumped to a new direction. The latency of the bend response is 0.5 s after the jump. Bending initiates a turn that reduces to zero the error between the fish's direction and the electric field vector and helps keep the fish aligned with the local electric field vector. Together, these experiments suggest that passive electrolocation is stimulus-bound and that these fish find the electrical sources simply by tracking instantaneous local electric current vectors.

Animals↗

The nurse's role in clinical trials.

Parkinson's disease (PD) is a chronic and progressive degenerative disorder of the central nervous system characterized by tremor, rigidity, slowness of movement (bradykinesia) and postural abnormalities. The cause is unknown, but the pathology shows that dopamine is profoundly reduced in the basal ganglia of patients with PD. When dopamine is replenished by the administration of levodopa, most of the symptoms of parkinsonism are reduced significantly. Levodopa is considered to be the most reliable and effective symptomatic drug treatment for keeping patients autonomous and functionally independent for as long as possible.

Antiparkinson Agents↗

Influence of carbohydrate-electrolyte drinks on marathon running performance.

The aim of this study was to compare the effects of drinking two carbohydrate (CHO) electrolyte solutions and water on marathon running performance. Seven endurance-trained runners completed three 42.2-km treadmill time-trials which were randomly assigned and 4 weeks apart. On each occasion the subjects ingested 3 ml.Kg-1 body weight of either water (W), a 6.9% CHO solution (O) or a 5.5% CHO solution (L) immediately prior to the start of the run and 2 ml.kg-1 body weight every 5 km thereafter. The total volume of fluid ingested [mean (SEM)] was 1112 (42), 1116 (44) and 1100 (44) ml, respectively. Running times for W, O and L trials were 193.9 (5.0), 192.4 (3.3) and 190.0 (3.9) min, respectively. Performance time for the L trial was faster (P < 0.05) compared with that of the W trial. Running speed was maintained in the L trial, whereas it decreased after 10 km (P < 0.05) in the W and after 25 km (P < 0.05) in the O trial. Blood glucose and lactate, and hormonal responses to fluid ingestion were similar in all three trials. Higher plasma free fatty acid and glycerol concentrations were observed at the end of the W trial compared with those obtained after the O and L trials, respectively (P < 0.05). Plasma ammonia concentration was higher (P < 0.01) at the end of the L trial compared with the W trial. Plasma creatine kinase concentration was higher (P < 0.05) 24 h after the completion of the L trial than after the W trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Laboratory assessment of antibacterial activity of zwitterionic 7-methoxyimino cephalosporins.

Zwitterionic 7-methoxyimino cephalosporins (cefpirome, cefepime, cefclidin, DQ2556, FK037 and SCE2787) possess a variable substitution at C3 which contains a quarternary nitrogen. These cephalosporins display low affinities for Class I beta-lactamase and rapid penetration through the outer membrane of Gram-negative bacilli, so that an increased number of periplasmic beta-lactam molecules interact with PBP's per unit of time. As a consequence, the new zitterionic compounds remain active against some, but not all, ceftazidime-resistant Enterobacteriaceae producing high levels of Class I beta-lactamase or Bush type 2b beta-lactamases. Antipseudomonas activities are generally similar to that of ceftazidime except that cefclidin is more active. The new zwitterionic compounds, especially cefpirome and FK037, express greater antistaphylococcal potency than does ceftazidime. A variety of animal models including meningitis and endocarditis have confirmed the potential of these compounds in-vivo. On the basis of structural and antibacterial characteristics, the expression 'forth generation' is acceptable to describe the zwitterionic 7-methoxyimino cephalosporins.

Cephalosporins↗

The effect of training on equine metacarpal bone breaking strength.

Right third metacarpal bones (n = 24) from Thoroughbreds, 24 to 48 months old and in race training, were tested to failure in 3 point bending. The neutral load axis was estimated and the distance from the axis to the outer dorsal cortical surface measured. Mid-diaphyseal dorsopalmar and lateromedial outer cortical and medullary diameters were measured. Breaking strength, cortical area and area moment of inertia were also calculated. Significant correlations were demonstrated between months in training and dorsopalmar bone diameter, cortical area and area moment of inertia. Significant linear models were illustrated between the same 3 variables and number of months in training. It was concluded that increased duration of training significantly enlarges dorsopalmar bone diameter, cortical area and area moment of inertia. Training did not affect metacarpal bone breaking strength as determined by 3 point bending.

Age Factors↗

A prospective, randomized comparison of open vs arthroscopically assisted ACL reconstruction.

A prospective, randomized study comparing arthroscopic and open anterior cruciate ligament (ACL) reconstructions was undertaken. Neither the patients nor the physical therapists were made aware of which technique was used. The central one third of the patellar tendon with proximal and distal bone plugs was utilized as the graft material to reconstruct the ACL in all cases. Rehabilitation was identical for each group. The following variables were compared: postoperative pain score, operating time, estimated blood loss (EBL), quantity of analgesics used, complications, range of motion at 1, 3, and 6 months, a 6-month evaluation consisting of Lachman's, anterior drawer, and pivot shift tests, amount of thigh atrophy, and Cybex II tests. Statistical significance was achieved (P < .05) in only three parameters. The 1-month postoperative range of motion, the 6-month postoperative thigh atrophy, and the Cybex II test (knee extension at 60 degrees/sec) were statistically different favoring the arthroscopic method.

Adolescent↗

Retroviral mediated transfer of the human multidrug resistance gene (MDR-1) into hematopoietic stem cells during autologous transplantation after intensive chemotherapy for metastatic breast cancer.

Patients with metastatic breast cancer will receive 4-5 cycles of induction chemotherapy on one of the ongoing Medicine Branch protocols. Patients achieving at least a partial response, and who do not have evidence of bone marrow involvement and who do not have metastatic bone disease, will undergo PBSC and bone marrow harvest when hematologic recovery has occurred. Patients who have not achieved a PR, but who are responding to therapy, may be treated with additional cycles of therapy in an attempt to achieve a PR. Such patients will be eligible for transplant if a PR is obtained. 70% of the bone marrow and PBSC will be cryopreserved. The CD34+ subpopulation from the remaining 30% of the bone marrow and PBSC harvest will be obtained using an anti-CD34+ antibody and immunoabsorption column. The bone marrow and peripheral blood CD34 cells will be transduced with a retroviral vector expressing the human MDR-1 cDNA. Patients with positive bone scans or histologic evidence of bone marrow involvement will be excluded from the gene transfer component of the protocol. The MDR-1 transduced CD34 cells will be reinfused along with the non-transduced bone marrow and PBSC into patients following high dose ICE chemotherapy. Serial peripheral blood and bone marrow samples will be obtained to study hematopoietic reconstitution with MDR-1 transduced cells. Patients with residual or progressive disease after ABMT will be treated with taxol or vinblastine. In these relapsed patients, peripheral blood and bone marrow samples will be obtained to study whether chemotherapy amplifies the proportion of hematopoietic cells containing the MDR-1 provirus. We will monitor the nadir blood counts of each patient receiving salvage chemotherapy for evidence of myeloprotection and correlate this data with changes in the mean proviral copy number. Sites of relapsed tumor will be biopsied to test for the presence of the MDR-1 provirus.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Invasive zygomycosis due to Conidiobolus incongruus.

During the past decade, an increasing spectrum of pathogenic Zygomycetes fungi have caused infections in humans. The preponderance of these deeply invasive infections have been caused by members of the order Mucorales. However, deeply invasive zygomycoses due to genera of the order Entomophthorales (Conidiobolus species and Basidiobolus species) have seldom been reported. We describe a granulocytopenic patient with pulmonary and pericardial zygomycosis due to Conidiobolus incongruus, describe this organism's susceptibility to antifungal agents, characterize its diagnostic microbiological characteristics, and review previously reported cases of deeply invasive zygomycosis due to Conidiobolus species. In immunocompromised patients, C. incongruus is an uncommon but highly invasive fungal pathogen that may be resistant to amphotericin B and can be distinguished from other Zygomycetes fungi by characteristic mycological features.

Adult↗

Molecular and phenotypic mapping of the short arm of chromosome 5: sublocalization of the critical region for the cri-du-chat syndrome.

Forty-nine individuals have been identified with deletions or translocations involving the short arm of chromosome 5. While most display the classical phenotype of the cri-du-chat syndrome, several of the patients do not have the syndrome or have only a subset of the clinical features. Somatic cell hybrids containing the deleted chromosome 5 were derived from each patient. Each somatic cell hybrid was analyzed at the DNA level using 136 chromosome 5p-specific DNA fragments. It was possible to unambiguously order most of the chromosomal breakpoints present in the somatic cell hybrids based on the hybridization patterns of Southern blots. Further comparisons between the deletions present in the patients and their clinical features identified several chromosomal regions that were involved in specific clinical features. A critical chromosomal region involved the high-pitched cry mapped to 5p15.3, while the chromosomal region involved in the remaining features of the cri-du-chat syndrome mapped to a small region within 5p15.2. Deletions that did not include these two chromosomal regions presented varying clinical phenotypes from severe mental retardation and microcephaly to a clinically normal phenotype. These results demonstrate the need for careful characterization of a 5p deletion in prenatal cases before clinical predictions are made.

Animals↗

Comparison between carbohydrate feedings before and during exercise on running performance during a 30-km treadmill time trial.

The purpose of this study was to compare the effects of a carbohydrate-electrolyte solution, ingested during exercise, with the effects of a preexercise carbohydrate meal on endurance running performance. Ten endurance-trained males completed two 30-km treadmill runs. In one trial subjects consumed a placebo solution 4 hr before exercise and a carbohydrate-electrolyte solution immediately before exercise and every 5 km (C). In the other trial, subjects consumed a 4-hr preexercise high-carbohydrate meal and water immediately before exercise and every 5 km (M). Performance times were identical for M and C, and there was no difference in the self-selected speeds. Oxygen uptake, heart rates, perceived rate of exertion, and respiratory exchange ratios were also similar. However, blood glucose concentration was higher in C during the first 20 km of the 30-km run. In M, blood glucose concentration was maintained above 4.5 mmol.L-1 throughout exercise. Thus, the two conditions produced the same 30-km treadmill running performance time.

Adult↗

Human immunodeficiency virus type 1 integrase: effect on viral replication of mutations at highly conserved residues.

Sequence comparisons of the integrase (IN) proteins from different retroviruses have identified several highly conserved residues. We have introduced mutations at 16 of these sites into the integrase gene of human immunodeficiency virus type 1 and analyzed the phenotypes of the resulting viruses. The viruses were all normal for p24 content and reverse transcriptase activity. In addition, all of the mutants could infect T-cell lines and undergo reverse transcription, as assessed by PCR analysis. Most of the mutant viruses also had normal Western blot (immunoblot) profiles, although three of the mutations resulted in reduced signals for IN relative to the wild type on the immunoblots and mutation of residue W235 completely abolished recognition of the protein by pooled sera from human immunodeficiency virus type 1-positive patients. Mutations that have previously been shown to abolish activity in in vitro studies produced noninfectious viruses. The substitution of W235 was notable in producing a noninfectious virus, despite previous reports of this residue being nonessential for IN activity in vitro (A.D. Leavitt, L. Shiue, and H.E. Varmus, J. Biol. Chem. 268:2113-2119, 1993). In addition, we have identified four highly conserved residues that can be mutated without any affect on viral replication in T-cell lines.

Amino Acid Sequence↗

Guidelines for long-term management of patients with Kawasaki disease. Report from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association.

Long-term management of patients with Kawasaki disease should be tailored to the degree of coronary arterial involvement. This committee has made recommendations for each risk level about antiplatelet and anticoagulant therapy, physical activity, follow-up assessment by a pediatric cardiologist or primary care physician, and the appropriate diagnostic procedures that may be performed to evaluate cardiac disease. The risk level for a given patient with coronary arterial involvement may change over time because of changes in coronary artery morphology. The recommendations for management presented here are intended as practical interim guidelines until additional prospective or retrospective data are compiled to define more clearly the natural history of Kawasaki disease.

Cardiology↗

The Internet: will this highway serve the digital library?

The future of the biomedical enterprise and the biomedical libraries that serve it is tied closely to digital information. The changing nature of this type of information will create new pressures on libraries, particularly in health care organizations. Libraries must learn to deal with these pressures. Currently, libraries depend on the Internet primarily for connections to resources and other libraries; thus enhancements to the Internet will impact the libraries of the present and future significantly. This paper provides an overview of the technical capabilities that will be available in the near to midterm, what libraries will be able to do with those capabilities, and how libraries can position themselves to take advantage of the impending changes.

Computer Communication Networks↗