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Biomedical subjects

J J Wilson

Publications and source records attributed to J J Wilson.

At least 19 recordsLinked to original sources
PubMed1997

Coping strategies and laboratory pain in children with sickle cell disease.

Studies have found that coping strategies are significant predictors of pain report, health care use, and psychosocial adjustment in children with sickle cell disease (SCD); however, the mechanisms of the relationship are not clear. In this study, 41 children with SCD completed a laboratory pain task to analyze their pain perception under standardized conditions. Sensory decision theory analyses were used to analyze the pain perception data. Children and their parents also completed measures of coping strategies and adjustment. Hierarchical regression analyses controlling for the child's age indicated that children who reported using active cognitive and behavioral coping strategies had a lower tendency to report pain during the laboratory pain task. Results are discussed in terms of the utility of using laboratory pain models with children and the need for future intervention studies to target coping strategies in children with SCD pain.

Adaptation, Psychological↗
PubMed1997

The stability of pain coping strategies in young children adolescents, and adults with sickle cell disease over an 18-month period.

OBJECTIVE: The current study assessed stability of pain coping strategies over an 18-month period in adults, adolescents, and young children with sickle cell disease. DESIGN: Eighteen-month longitudinal study. Assessments of coping strategies were done at baseline, 9 months, and 18 months. PATIENTS: A total of 141 patients with sickle cell disease (SCD) presenting to adult and pediatric sickle cell clinics for regularly scheduled check-ups. OUTCOME MEASURES: Coping Strategy Questionnaire subscales (Coping Attempts, Negative Thinking, and Illness-Focused Strategies). RESULTS: pearson Product-Moment correlation coefficients comparing baseline and 18-month follow-up coping data were highly significant for Coping Attempts and Negative Thinking/Illness Focused Strategies for adults. For young children, the 18-month follow-up scores on Negative Thinking were significantly correlated with baseline scores, however, no other 18-month correlations were significant. The results from the adolescent subset of subjects indicated no significant correlations on any of the coping strategies from baseline to 18-month-follow-up. Stability was also assessed using intraclass correlations, which incorporates more than two test-retest values on the same subjects. These analyses confirmed that coping strategies in adults were highly stable, whereas for children and adolescents, there was instability ANOVAs indicated that adolescents scored significantly higher than young children on Negative Thinking and Illness-Focused Strategies at baseline and follow-up. CONCLUSIONS: As compared with the highly stable coping evidenced in adults with SCD, coping in children and adolescents with SCD is more variable. Thus, interventions should target children early before maladaptive coping patterns become entrenched.

Adaptation, Psychological↗
PubMed1997

Cyclophosphamide and fluorouracil combined with mitoxantrone versus doxorubicin for breast cancer: superiority of doxorubicin.

PATIENTS AND METHODS: We conducted a randomized, multicenter study of intravenous cyclophosphamide 500 mg/m2 plus fluorouracil 500 mg/m2 combined with either mitoxantrone (Novantrone, Lederle Cyanamid Canada Ltd, Willowdale, Ontario) 10 mg/m2 (CNF) or doxorubicin (Adriamycin, Adria Laboratories of Canada Ltd, Mississauga, Ontario) 50 mg/m2 (CAF) every 3 weeks in advanced breast cancer. RESULTS: The response rate in 249 randomized patients was 36% with CNF (44 of 121) and 48% with CAF (62 of 128) (P = .054), with complete remissions in 10 patients (8.3%) on CNF and in 13 (10.2%) on CAF. If only fully assessable patients are considered, the response rate was 48% (44 of 91) with CNF and 60% (62 of 103) with CAF (P = .098). At time of analysis, all except 10 patients (one CNF and nine CAF) had died. The median survival time with CAF was longer than with CNF (15.2 v 10.9 months; P = .003), and time to progression was also longer with CAF (5.3 v 3.2 months; P < .03). Survival differences remained significant (P = .006) if patients who failed to meet all eligibility criteria were excluded. Favorable prognostic factors for survival in a Cox regression model included good performance status (P < .0001); less than two organ systems involved by tumor (P < .0001); no involvement of lung, liver, or brain (P < .003); involvement of bone or bone marrow (P < .009), prior surgery for breast cancer (P < .006); being premenopausal (P < .03); > or = 3 years from diagnosis until randomization on this study (P < .03); and treatment with CAF (P < .03). Alopecia > or = grade 3 was reported in 55% of patients with CAF and 12% of patients with CNF (P < .001), while other > or = grade 3 toxicities did not differ significantly. Priestman-Baum quality-of-life assessment was comparable on the two study arms. CONCLUSION: In patients with advanced breast cancer, CAF was associated with longer survival than was CNF, with an increase in alopecia, but not in other toxicities.

Adult↗
PubMed1996

Suppression of renal gamma-glutamylcysteine synthetase expression in dietary copper deficiency.

A dietary deficiency of copper (CuD) is associated with a 50-70% and a 2-fold increase in hepatic reduced glutathione (GSH) concentration and synthesis, respectively, which leads to a 50-80% increase in plasma GSH. Moreover, the kidneys of CuD rats remove 40% more GSH from the blood than copper adequate (CuA) rats. These findings have led us to propose that the increase in hepatic synthesis of GSH in CuD rats is accompanied by a comparable increase in the hepatic expression of gamma-glutamylcysteine synthetase (gamma-GCS), the rate limiting enzyme of glutathione biosynthesis, and that the enhanced uptake of GSH by the kidney would lead to a compensatory decrease in renal gamma-GCS expression. In experiment I, male weanling rats (3-4 weeks) were ad libitum fed a CuD (0.5 microgram Cu/g) or CuA (5.8 micrograms/g) diet for 70 days; and in experiment II, male weanling rats were pair-meal fed the CuD or CuA diet for 35 days. In both studies, CuD diet caused a significant increase in hepatic GSH concentration, but hepatic gamma-GCS activity and mRNA abundance were unchanged. In contrast, renal GSH concentration was unaffected by the CuD diet. However, renal gamma-GCS activity was reduced 40% and this was paralleled by a 50% decrease in gamma-GCS mRNA. Moreover, the decrease in renal gamma-GCS mRNA was caused by a reduction in renal gamma-GCS gene transcription. The results of these studies indicate that the increase in renal uptake of GSH resulting from a dietary Cu deficiency is associated with a compensatory decrease in gamma-GCS expression.

Animals↗
PubMed1996

Effects of cognitive coping skills training on coping strategies and experimental pain sensitivity in African American adults with sickle cell disease.

The present study examined whether training in cognitive coping skills would enhance pain coping strategies and alter pain perception in adults with sickle cell disease (SCD). Sixty-four African Americans with SCD were randomly assigned to either a cognitive coping skills condition (three 45-min sessions in which patients were trained to use 6 cognitive coping strategies) or a disease-education control condition (three 45-min didactic-discussion sessions about SCD). Pain sensitivity to calibrated noxious stimulation was measured at pre- and posttesting, as were cognitive coping strategies, clinical pain, and health behaviors. Results indicated that, compared with the randomly assigned control condition, brief training in cognitive coping skills resulted in increased coping attempts, decreased negative thinking, and lower tendency to report pain during laboratory-induced noxious stimulation.

Adaptation, Psychological↗
PubMed1996

Tracking hepatitis C virus quasispecies major and minor variants in symptomatic and asymptomatic liver transplant recipients.

To evaluate the possibility that distinct viral quasispecies play a role in the pathogenesis of progressive hepatitis C virus (HCV) infection, we performed a detailed evaluation of HCV quasispecies before and after liver transplantation in five patients infected with HCV genotype 1, three of whom developed severe recurrent hepatitis C and two of whom developed asymptomatic posttransplant infections with high-titered viremia. HCV quasispecies were characterized by using a combination of nucleotide sequencing plus heteroduplex tracking assay of the second envelope gene hypervariable region (HVR). An average of 30 HVR clones were analyzed per specimen; an average of five specimens were analyzed per patient over a 6- to 24-month study period. The complexity of HCV quasispecies in pretransplant serum varied, ranging from one to nine genetically distinct variants for the five patients. However, in all five cases, relatively homogenous quasispecies variants emerged after liver transplantation. In the three patients who developed recurrent hepatitis, quasispecies major variants present in pretransplant serum were efficiently propagated immediately after liver transplantation and were propagated throughout the course of acute and chronic hepatitis. In contrast, in the two asymptomatic cases, we observed rapid depletion of pretransplant quasispecies major variants from posttransplant serum, followed by emergence of new quasispecies variants by posttransplant day 30. Genetic analysis suggested that in these cases, the new quasispecies variants were derived from minor variants present at relatively low clonal frequency (less than 5% of HVR clones) within the pretransplant quasispecies populations. These data demonstrate that quasispecies tracking patterns are associated with the rapidity and severity of HCV-associated liver disease after liver transplantation. Further characterization of HCV quasispecies in animal model systems is warranted.

Amino Acid Sequence↗
PubMed1996

A model for the kinetic mechanism of sodium-coupled L-alanine transport in LLC-PK1 cells.

The kinetics of sodium-dependent L-alanine transport were characterized in ATP-depleted LLC-PK1 cells, which allows experimental imposition of an interior negative diffusion potential across the plasma membrane. Under these conditions a wide range of sodium concentrations can be studied without altering the membrane potential. When Na+ is the variable substrate, the apparent maximal velocity (V max) for transport changes nearly fourfold for the five different alanine concentrations studied (0.05-2.0 mM). In contrast, at five different sodium concentrations, ranging from 10 to 135 mM, the apparent V max with variable alanine remains nearly constant at 5.3 +/- 1.2 nmol.min-1.mg cell protein-1. The ratio of the two primary kinetic parameters, Michaelis constant (Km)/V max, varies markedly no matter which solute is treated as the variable illustrate. These data are consistent with a simultaneous ordered transport mechanism in which sodium binds before alanine to the transport protein at the extracellular surface of the membrane. Alanine-dependent 22Na+ influx is more than five times faster if unlabeled intracellular sodium is present than in its absence. Sodium-dependent influx of [14C]alanine is more rapid than net alanine flux only if unlabeled Na+ and alanine are both present intracellularly. These results indicate that the cotransporter can function more rapidly in an exchange mode than when it catalyzes net solute uptake and that Na+ is the first solute to be released at the intracellular side of the membrane. A model is presented that can be used for further quantitative analysis of the kinetic and functional properties of the cotransport system.

Amino Acid Transport Systems↗
PubMed1996

Chemotherapy with mitoxantrone plus prednisone or prednisone alone for symptomatic hormone-resistant prostate cancer: a Canadian randomized trial with palliative end points.

PURPOSE: To investigate the benefit of chemotherapy in patients with symptomatic hormone-resistant prostate cancer using relevant end points of palliation in a randomized controlled trial. PATIENTS AND METHODS: We randomized 161 hormone-refractory patients with pain to receive mitoxantrone plus prednisone or prednisone alone (10 mg daily). Nonresponding patients on prednisone could receive mitoxantrone subsequently. The primary end point was a palliative response defined as a 2-point decrease in pain as assessed by a 6-point pain scale completed by patients (or complete loss of pain if initially 1 +) without an increase in analgesic medication and maintained for two consecutive evaluations at least 3 weeks apart. Secondary end points were a decrease of > or = 50% in use of analgesic medication without an increase in pain, duration of response, and survival. Health-related quality of life was evaluated with a series of linear analog self-assessment scales (LASA and the Prostate Cancer-Specific Quality-of-Life Instrument [PROSQOLI]), the core questionnaire of the European Organization for Research and Treatment of Cancer (EORTC), and a disease-specific module. RESULTS: Palliative response was observed in 23 of 80 patients (29%; 95% confidence interval, 19% to 40%) who received mitoxantrone plus prednisone, and in 10 of 81 patients (12%; 95% confidence interval, 6% to 22%) who received prednisone alone (P = .01). An additional seven patients in each group reduced analgesic medication > or = 50% without an increase in pain. The duration of palliation was longer in patients who received chemotherapy (median, 43 and 18 weeks; P < .0001, log-rank). Eleven of 50 patients randomized to prednisone treatment responded after addition of mitoxantrone. There was no difference in overall survival. Treatment was well tolerated, except for five episodes of possible cardiac toxicity in 130 patients who received mitoxantrone. Most responding patients had an improvement in quality-of-life scales and a decrease in serum prostate-specific antigen (PSA) level. CONCLUSION: Chemotherapy with mitoxantrone and prednisone provides palliation for some patients with symptomatic hormone-resistant prostate cancer.

Adenocarcinoma↗
PubMed1995

Characterization of simple and complex hepatitis C virus quasispecies by heteroduplex gel shift analysis: correlation with nucleotide sequencing.

In infected humans, hepatitis C virus (HCV) exists as a quasispecies typically characterized by multiple nucleotide substitutions within the second envelope gene hypervariable region 1 (HVR1). In the current study, we used heteroduplex gel shift analysis (GSA) of HVR1 sequences amplified directly from patients' sera to define two patterns of HCV quasispecies: (i) simple quasispecies, which gave a mostly homogeneous gel shift profile with a single predominant band and (ii) complex quasispecies, which gave a gel shift profile with multiple bands. Recombinant HVR1 libraries were generated from two patients with complex HCV quasispecies (cases 1 and 2) and two patients with simple HCV quasispecies (cases 3 and 4), and 129 individual clones were analysed by either GSA, nucleotide sequencing or both techniques. In case 1 we identified a highly complex HCV quasispecies with 11 distinct HVR1 variants differing by 1-51 nucleotide changes. We found a general but not absolute correlation between GSA pattern and the number or position of nucleotide changes within HVR1. In case 2, the complex HCV quasispecies consisted of three distinct major variants; GSA of individual HVR1 clones allowed us to reconstruct the complex quasispecies pattern in vitro. In case 3, the simple quasispecies comprised 66% homogeneous clones and 33% unique minor variants differing by 1-3 nucleotides from the consensus sequence. In case 4, the simple quasispecies was 84% homogeneous, but six unique major shift variants were identified among 31 clones by GSA. In summary, HCV quasispecies can be characterized based on GSA profiles following direct PCR amplification of HVR1 sequences from patients' serum; the GSA profiles approximate the clonal population of HCV as determined by clonal analysis. GSA of HVR1 clones showed a strong correlation with nucleotide sequencing.

Base Sequence↗
PubMed1995

Bovine fast-twitch myosin light chain 1: cloning and mRNA amount in muscle of cattle treated with clenbuterol.

The cDNA clone encoding the fast-twitch isoform of myosin light chain 1 (MLC-1f) was isolated from bovine longissimus dorsi muscle and sequenced in M13 and pUC8. An 0.8-kb subclone, produced by digestion of the cDNA with EcoRI, contained the portion of the molecule common to MLC-1f and MLC-3f. The cDNA in pUC8 contained an additional 81 bp upstream of the EcoR I digestion site, which was unique to MLC-1f. The cDNA clone was used to measure MLC-1f mRNA in longissimus dorsi muscle of cattle chronically administered the beta-adrenergic agonist clenbuterol. Treatment with clenbuterol for 50 days increased succinic dehydrogenase negative (type IIB) and positive (types I and IIA) myofiber cross-sectional areas by 25%. After the 50-day treatment period, the amount of MLC-1f mRNA was 90% greater in longissimus dorsi muscle of treated animals than in the initial group. This effect was lost when clenbuterol treatment was withdrawn for a 78-day period, during which time muscle growth in the treated animals stopped completely. We conclude that we have cloned the bovine cDNA for MLC-1f, which has provided additional evidence that beta-adrenergic agonists increase myofibrillar gene expression.

Amino Acid Sequence↗
PubMed1995

Transmission of the hepatitis-C virus by tissue transplantation.

The hepatitis-C virus has been the most prevalent cause of chronic hepatitis in both blood and organ recipients. The introduction of a second-generation immunoassay for antibodies to the hepatitis-C virus (HCV 2.0) provided the opportunity to determine if the hepatitis-C virus can be transmitted through tissue transplantation. Banked sera from tissue donors that had previously been found to be non-reactive to the first-generation hepatitis-C virus antibody assay (HCV 1.0) and non-reactive for antibodies to hepatitis-B core antigen were retested with HCV 2.0. The sera from two donors were reactive; the transplant records of recipients of tissues from these donors were reviewed, and the surgeons or hospitals were contacted. The tissue recipients were tested with HCV 2.0, and positive sera were tested for hepatitis-C virus RNA by polymerase chain reaction. Viral nucleic acids isolated from viremic donors and recipients were analyzed for identity by sequencing of the hepatitis-C virus envelope gene (E2) hypervariable region. There were twenty-one grafts, which had been treated with gamma radiation, from one donor; thirteen had been transplanted to twelve recipients. Serum samples from six of the recipients were tested; one was reactive. This patient had other risk factors for infection with the hepatitis-C virus, and sequence analysis demonstrated non-identity between the donor and recipient hepatitis-C virus isolates. Nine of twelve grafts from a second donor had been transplanted in nine recipients. Serum samples from five patients were tested with HCV 2.0; four were reactive. In three of the four patients, the sera were determined to be positive for the hepatitis-C virus by polymerase chain reaction. E2 sequence analyses of hepatitis-C virus RNA isolates from two of these recipients demonstrated sequence identity with the donor isolate. The results of the present report demonstrate that the hepatitis-C virus can be transmitted by bone, ligament, and tendon allografts. They also support the need for testing of all tissue donors for antibodies to the hepatitis-C virus before the tissue is released for transplantation. The results also suggest that seventeen kilo-gray of gamma radiation may inactivate the hepatitis-C virus in tissue.

Adolescent↗
PubMed1995

Lipogenic activity of intramuscular and subcutaneous adipose tissues from steers produced by different generations of angus sires.

Simmental and Hereford cows (n = 74) were inseminated with semen from purebred Angus bulls from the 1960s or with semen from purebred Angus bulls from the 1980s. The F1 calves provided the foundation for two investigations, one addressing growth and carcass characteristics, and another measuring the impact of sire generation on lipid metabolism and adiposity. Calves sired by the 1980s-type bulls had greater (P < .05) birth, weaning, and final live weights and carcass weights. They also had larger (P < .05) hip heights and hip widths at weaning and larger (P < .05) hip heights and lower (P < .05) body condition scores at slaughter. There were no differences (P > .05) in any measure of fatness between groups (adjusted fat thickness, kidney, pelvic, and heart fat, or marbling scores), but yield grade was higher numerically (P < .1) for the 1980s steers. The second aspect of this research addressed the influence of different generations of Angus sires on specific carcass traits and adipose tissue metabolism. A subset of six steers for each generation type (from Simmental cows) were selected and samples were collected at slaughter for measurements in vitro. For both generation types, intramuscular (i.m.) adipocytes had lesser (P < .05) cell volumes than subcutaneous (s.c.) adipose tissue. Correspondingly. i.m. adipose tissue exhibited lower (P < .05) rates of 14C-labeled acetate incorporation into lipids as measured immediately after slaughter. Intramuscular and s.c. adipocytes from 1980s-type steers were smaller (P < .05) than those from the 1960s-types steers, with correspondingly more cells per gram of tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1994

Evidence for preadipocyte proliferation during culture of subcutaneous and intramuscular adipose tissues from Angus and Wagyu crossbred steers.

The primary objective of this study was to provide evidence for preadipocyte proliferation during culture of adipose tissue explants; a secondary objective was to compare the lipogenic activity and cellularity of adipose tissues from American Wagyu crossbred steers. Subcutaneous (s.c.) and intramuscular (i.m.) adipose tissues were obtained at slaughter from the 2nd to 6th lumbar region of the loin from Angus (n = 10) and Wagyu crossbred steers (n = 10) that had been fed for 552 d by typical Japanese production standards. Adipose tissue explants were incubated 36 h with [3H]thymidine in the absence and presence of aphidicolin (a specific inhibitor of genomic DNA replication). Adipocytes were liberated by collagenase treatment and [3H]thymidine incorporation into DNA was measured. Whereas there were no significant differences between adipose tissue depots, Wagyu s.c. and i.m. preadipocytes and stromal-vascular cells exhibited greater (P < .05) [3H]thymidine incorporation into DNA than adipocytes from Angus steers. Intramuscular adipose tissue from both breeds exhibited lower (P < .05) rates of lipogenesis from acetate both before and after long-term (36-h) incubation than s.c. adipose tissue. Furthermore, i.m. adipocytes were smaller (P < .05) than s.c. adipocytes. The activities of fatty acid synthetase and glucose-6-phosphate dehydrogenase were greater (P < .05) in Wagyu s.c. adipose tissue and less in Wagyu i.m. adipose tissue than in corresponding Angus tissues. There were no differences between breed types (P = .17) in rates of lipogenesis from acetate, either before or after explant culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipocytes↗
PubMed1993

Detection of hepatitis C virus RNA: comparison of one-stage polymerase chain reaction (PCR) with nested-set PCR.

We evaluated a new hepatitis C virus RNA assay based on one-stage PCR followed by liquid hybridization with an oligonucleotide probe and compared it with nested-set PCR. The one-stage and nested-set PCR assays had identical sensitivities in analytical experiments and showed 100% concordance when clinical specimens were used. One-stage PCR may be less prone to contamination than nested-set PCR.

DNA, Viral↗
PubMed1992

Triacylglycerol biosynthesis in bovine liver and subcutaneous adipose tissue.

1. Adipose tissue from Angus and Brahman steers incubated with [1-14C]palmitate in the absence and presence of glucose exhibited a greater rate of lipid production than liver (P < 0.05). 2. Homogenates of adipose tissue used in the glycerol-3-phosphate acyltransferase assay exhibited a greater glycerolipid specific activity (nmol lipid/mg protein/30 min) when compared to liver (P < 0.05). 3. The inverse was true for liver homogenates when calculated for tissue activity (nmol lipid/g tissue/30 min). 4. Lysophosphatidate was produced in greater (P < 0.05) amounts than all other glycerolipids in the glycerol-3-phosphate acyltransferase assay. 5. The activity of phosphatidate phosphohydrolase in liver homogenates displayed greater rates than their respective adipose tissue homogenates. 6. Diacylglycerol acyltransferase activity was greater in adipose tissue homogenates compared to liver homogenates.

Acyltransferases↗