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Biomedical subjects

W Wilson

Publications and source records attributed to W Wilson.

At least 55 records · Page 3Linked to original sources
PubMed1998

Additional chemotherapy agents improve treatment outcome for children and adults with advanced B-cell lymphomas.

We report the updated results of an intensive treatment protocol for children (< 18 years) and adults (> or = 18 years) with advanced B-cell lymphomas. The protocol consists of two chemotherapy regimens: A, consisting of cyclophosphamide, doxorubicin, vincristine and high-dose methotrexate (CODOX-M), and B, consisting of ifosfamide, etoposide, and high-dose cytarabine (IVAC). Both cycles included intrathecal chemotherapy (cytarabine or methotrexate). Patients received a total of four cycles in the following sequence: A, B, A, B. Sixty-six previously untreated patients, enrolled before October 1996, were included in the present analysis. Of these, 55 had Burkitt's or Burkitt's-like lymphoma and 11 had diffuse large B-cell lymphoma. There were 53 males ad 13 females; 40 were children and 26 were adults (age range, 3 to 57 years). To date, 61 patients have achieved a complete response to therapy. Two patients subsequently relapsed, but one of these is a long-term survivor after further therapy and a bone marrow transplant. The event-free survival rate is 85% at I year and beyond. The median potential follow-up period is 48 months (range, 12 to 96 months) for patients remaining in complete remission. Neutropenia occurred in 98% of cycles and infection in 46% of A cycles and 50% of B cycles, but the duration was shortened in B cycles by the administration of granulocyte colony-stimulating factor. Positive blood cultures were observed in 21% of A cycles and 28% of B cycles, and there have been three toxic deaths. These results are better than those achieved with an earlier version of CODOX-M, suggesting that the addition of the IVAC regimen is responsible for the improved results. The similarity of the outcome in children and adults, however, confirms our previous observation that, at least in adults younger than 60 years with Burkitt's or Burkitt's-like lymphomas, treatment with regimens similar to those used in children is warranted.

Adolescent↗
PubMed1997

Prevention of bacterial endocarditis. Recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

American Heart Association↗
PubMed1997

Prevention of bacterial endocarditis. Recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Antibiotic Prophylaxis↗
PubMed1997

Expression of the multidrug resistance-associated protein gene in refractory lymphoma: quantitation by a validated polymerase chain reaction assay.

Previous work investigating the role of MDR-1 overexpression in relapsed and refractory lymphoma led us to investigate a possible role for multidrug resistance-associated protein (MRP) as a cause of resistance in patients who did not overexpress MDR-1. A quantitative polymerase chain reaction (PCR) method for measuring MRP expression was validated. Immunoblot analysis suggested that no major discrepancy was present between mRNA expression and protein levels. MRP levels were found to be independent of sample tumor content by immunophenotyping, suggesting that the presence of normal cells had no significant impact on measurements of MRP expression. We evaluated MRP in 55 biopsy samples from 40 patients with refractory lymphoma enrolled on a trial of infusional chemotherapy (EPOCH). Pre- and post-EPOCH samples were available from 15 patients. MRP levels were also evaluated in 16 newly diagnosed, untreated lymphoma patient samples. No significant difference in MRP mRNA expression was noted between pre- and post-EPOCH groups. Also, MRP levels in the newly diagnosed patient samples were not significantly different from either pre- or post-EPOCH groups. Two of 15 paired pre- and post-EPOCH patient samples exhibited overexpression of MRP after EPOCH chemotherapy, with measured increases of 10-fold and 18-fold. We conclude that MRP overexpression is not responsible for non-P-glycoprotein (Pgp)-mediated drug resistance in the majority of these patients, although it may be important in a subset of patients. Defining this subset prospectively could aid in the development of clinical trials of MRP modulation in drug-resistant lymphoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Identification of a profilin homologue in Trypanosoma brucei by complementation screening.

Using genetic complementation in Saccharomyces cerevisiae, we have isolated a Trypanosoma brucei gene encoding profilin. Overexpression of trypanosome profilin suppresses defects that are associated with the loss of the C-terminal domain of the adenylyl cyclase-associated protein in S. cerevisiae. Similarly, the T. brucei gene complements a profilin-deletion mutant of S. cerevisiae. The full-length cDNA clone isolated contains an open reading frame of 150 amino acids, with a predicted molecular mass of 16.1 kDa. The gene appears to be present at single copy and is expressed at approximately equal levels in both mammalian and insect forms of the parasite.

Amino Acid Sequence↗
PubMed1997

Concordance of common movement disorders among familial cases.

Multicase families are frequently utilized in studies of movement disorders (MDs). We report families with two or more MD cases seen at the Movement Disorder Clinic, Saskatoon (MDCS). In 30% of the MD probands, there was either a history or documentation of at least one secondary MD case in the family. Only those MD cases that were seen at the MDCS were considered in this study. A total of 56 probands and 77 secondary MD cases were seen at the MDCS between 1968 and 1996. In 24 (31.2%) of the secondary cases, the diagnosis was different from that in the proband. In 46 families (82%), only one secondary case was seen, and the diagnosis was concordant with the proband in 71.7%. In the remaining 10 families with two or more secondary cases, the diagnosis was concordant in 64.5% of cases. The largest subgroup was Parkinson's disease (PD)--40 probands and 53 secondary cases. of these secondary cases, 73.6% had PD. The concordance rate was 91% in essential tremor, but only 12.5% if the proband had essential tremor + parkinsonism. Considering that a large proportion of secondary cases have a diagnosis discordant with the proband, we recommend that, whenever possible, MD diagnosis in secondary cases be based on clinical assessment.

Age of Onset↗
PubMed1997

Determination of molecular weight of hyaluronic acid in bovine vitreous humour and Healon by high performance gel permeation chromatography and its depolymerization with ascorbic acid.

A method has been developed for the determination of the molecular weight of hyaluronic acid by high performance gel permeation chromatography. The molecular weight distribution was determined using three polymeric columns. Columns were calibrated using Pullulan Polymer molecular weight standards. The average molecular weight (+/- SD) of the hyaluronic acid in bovine vitreous humour and Healon were 1.20 x 10(6) Da (+/- 0.49 x 10(6) and 3.01 x 10(6) Da (+/- 0.14 x 10(6), respectively. Furthermore, the depolymerization of the hyaluronic acid in the presence of ascorbic acid (the concentration found in human eye) was studied. Samples incubated in the presence of atmospheric air showed more depolymerization than those where atmospheric air had been flushed-out with nitrogen.

Animals↗
PubMed1997

Prevention of bacterial endocarditis: recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Anti-Bacterial Agents↗
PubMed1997

VP7: an attachment protein of bluetongue virus for cellular receptors in Culicoides variipennis.

The importance of VP7 of bluetongue virus (BTV) in the binding of BTV to membrane proteins of the BTV vector Culicoides variipennis was investigated. Core BTV particles, prepared from whole viruses, lacked outer proteins VP2 and VP5 and had VP7 exposed. More core particles and whole viruses bound to membrane preparations of adults of C. variipennis and KC cells, which were cultured from this vector insect, than to membrane preparations of Manduca sexta larvae. More core particles than whole viruses bound to membrane preparations of adults of C. variipennis and KC cells. Polyclonal anti-idiotypic antibodies (anti-Id), which were made against an antigen-combining region of an anti-BTV-10 VP7 antibody and functionally mimicked VP7, bound more to the membrane preparations of adults of C. variipennis and KC cells, and less to cytosol preparations. In Western overalay analysis, the Culicoides plasma membrane preparation reduced binding of an anti-VP7 monoclonal antibody to VP7. Whole and core BTV particles and the anti-Id bound to a membrane protein with a molecular mass of 23 kDa that was present predominantly in membrane preparations of adults of C. variipennis and KC cells. This protein was present in much lower concentrations in membrane preparations of C6/36 and DM-2 insect cells.

Animals↗
PubMed1997

Prevention of bacterial endocarditis: recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the infectious Diseases Society of America, the American Academy of Pediatrics and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using root words endocarditis, bacteremia and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the U.S. Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate- and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered.

Algorithms↗
PubMed1997

The role of MDR-1 in refractory lymphoma.

Although lymphoma is one of the few solid tumours for which chemotherapy can be curative, the treatment of refractory lymphoma remains a major clinical problem. P-glycoprotein (Pgp), the drug efflux pump encoded by the MDR-1 gene is associated with multidrug resistance in several laboratory models of drug resistance, and a number of investigators have attempted to establish a role for Pgp in refractory lymphoma. Despite a considerable variability in the results of these studies investigating Pgp expression in lymphoma, the preponderance of the data suggests that Pgp may at least in part account for drug resistance in this disease. Several clinical trials using Pgp modulating compounds have attempted to reverse the drug resistant phenotype of refractory lymphoma. These studies, although difficult to interpret because of the effect of Pgp modulators on chemotherapeutic drug pharmacokinetics, also suggest a role for Pgp in mediating drug resistance in a subset of patients with refractory lymphoma. Studies with newer Pgp modulating agents with phase III designs will be needed before Pgp modulation can be considered for incorporation into routine oncologic practice.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Behaviour of the transgenic (mREN2)27 rat.

The first model of genetically engineered hypertension, the transgenic rat TGR (mREN2)27, provides a unique opportunity to study the behavioural effects of an altered brain renin-angiotensin system. The TGR (mREN2)27 rats, characterised by fulminant hypertension, show differences in both the peripheral and central angiotensin systems. The behaviour of male transgenic TGR (mREN2)27 and male Sprague-Dawley rats were determined by 4 behavioural tests. While on the elevated X-maze the TGR (mREN2)27 rat showed a greater 'anxiogenic' profile (fewer open arm entries) than the control Sprague-Dawley rats, this 'anxiogenic' profile increased further during a second exposure to the elevated X-maze 24 h later. In comparison the behaviour of the male Sprague-Dawley rats was not different between the two exposures to the elevated X-maze. Locomotor activity did not differ between either the TGR (mREN2)27 or Sprague-Dawley rats when placed in a 1 m2 open-field for 10 min. A short period of fluid-deprivation (3 h) reversed the 'anxiogenic' profile of the TGR (mREN2)27 on the elevated X-maze. Administration of captopril (20 mg . kg-1 body weight) in the drinking water of the TGR (mREN2)27 rats and Sprague-Dawley rats reversed the anxiogenic profile of the TGR (mREN2)27 rat on the elevated X-maze but did not alter the behaviour of the Sprague-Dawley rats.

Animals↗
PubMed1996

Acoustically activated c-fos expression in auditory nuclei of the anaesthetised guinea pig.

The spatial expression of the immediate-early gene c-fos in central auditory nuclei of the anaesthetised guinea pig was investigated following exposure of the animal to acoustic stimulation. Accurate control of both the spectra and the level of the stimulus was designed so that the presumed excitation of central auditory nuclei was similar across animals. For unstimulated anaesthetised control animals levels of labelling were significantly higher when compared with unanaesthetised controls. This appeared to a result of the combination of the experimental manipulations and also the use of the anaesthetic. A surprising finding was that unstimulated control animals placed in an anechoic chamber demonstrated the highest levels of fos-like immunoreactivity (Fos-LIR). When anaesthetised animals were exposed to acoustic stimuli the total number of cells showing Fos-LIR was elevated when compared to anaesthetised, but unstimulated animals. There was no evidence at any level of the auditory pathway that these animals demonstrated spatially restricted Fos-LIR which may have suggested place-frequency mapping. In contrast, spatially restricted labelling was found in awake animals exposed to an identical stimulus.

Acoustic Stimulation↗
PubMed1996

Nicotine-haloperidol interactions and cognitive performance in schizophrenics.

Nearly 90% of schizophrenics smoke cigarettes, considerably higher than the general population's rate of 25%. There is some indication that schizophrenics may smoke as a form of self-medication. Nicotine has a variety of pharmacologic effects that may both counteract some of the cognitive deficits of schizophrenia and counteract some of the adverse side effects of antipsychotic drugs. In the current study, we assessed the interactions of haloperidol and nicotine on cognitive performance of a group of schizophrenics. These patients were in a double-blind study, randomly assigning them to low, moderate, and high dose levels of haloperidol. The subjects, all smokers, came to the laboratory on four different mornings after overnight deprivation from cigarettes. In a double-blind fashion, they were administered placebo, low (7 mg/day), medium (14 mg/day), or high (21 mg/day) dose nicotine skin patches. Three hours after administration of the skin patch, the subjects were given a computerized cognitive test battery including: simple reaction time, complex reaction time (spatial rotation), delayed matching to sample, the Sternberg memory test, and the Conners continuous performance test (CPT). With the placebo nicotine patch, there was a haloperidol dose-related impairment in delayed matching to sample choice accuracy and an increase in response time on the complex reaction time task. Nicotine caused a dose-related reversal of the haloperidol-induced impairments in memory performance and complex reaction time. In the CPT, nicotine reduced the variability in response that is associated with attentional deficit. These results demonstrate the effects of nicotine in reversing some of the adverse side effects of haloperidol and improving cognitive performance in schizophrenia.

Adult↗
PubMed1996

Common sense, insight, and neuropsychological test performance in schizophrenia patients.

We report an exploratory study examining the interrelationships among common sense, insight into psychosis, and performance on a battery of neuropsychological tests in 32 patients with schizophrenia evaluated at the time of discharge from involuntary hospitalization at a State psychiatric hospital. Common sense, as measured by the Social Knowledge Questionnaire, was associated with better performance across tests measuring parietal lobe functioning and vocabulary. In addition, patients with more common sense were more likely to say that they were ill and needed treatment. A global measure of insight, the Insight and Treatment Attitudes Questionnaire (ITAQ), was related to performance on a test of left parietal lobe function. However, the responses to the ITAQ item that may best reflect current awareness of mental illness in patients at the time of discharge ("After you are discharged, is it possible you may have mental problems again?") were related to performance on tests of the functioning of the prefrontal lobes and the right and left parietal lobes. These results add to the growing evidence that some of the deficits in awareness of illness among patients with schizophrenia are related to the neuropsychological dysfunction commonly seen in patients with this disorder.

Adult↗