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Biomedical subjects

J Salmon

Publications and source records attributed to J Salmon.

At least 37 records · Page 2Linked to original sources
PubMed2000

Comparative bioavailability of two cefadroxil formulations in healthy human volunteers after a single-dose administration.

OBJECTIVE: To compare the bioavailability of two cefadroxil capsule (500 mg) formulations (Cefadroxila from Eurofarma Laboratórios Ltd, Brazil, as test formulation and Cefamox from Bristol-Myers Squibb, Brazil S.A. as reference formulation) in 24 volunteers of both sexes. MATERIAL AND METHODS: The study was conducted open with randomized two-period crossover design and a 1-week washout period. Plasma samples were obtained over a 12-h interval. Cefadroxil concentrations were analysed by combined reversed-phase liquid chromatography and tandem mass spectrometry (LC-MS-MS) with positive ion electrospray ionization using a selected ion monitoring method. From the cefadroxil plasma concentration versus time curves the following pharmacokinetic parameters were obtained: AUC(last), AUC(0-infinity) and C(max). RESULTS: Geometric mean of Cefadroxila/Cefamox 500 mg individual percent ratio was 103.97% for AUC(last), 104.08% for AUC(0-infinity) and 95.23% for C(max). The 90% confidence intervals (CI) were 98.14-110.16%, 98.37-110.12%, and 85.59-105.96%, respectively. CONCLUSION: Since the 90% CI for C(max), AUC(last) and AUC(0-infinity) were within the 80-125% interval proposed by the Food and Drug Administration, it was concluded that the Cefadroxila 500 mg capsule was bioequivalent to the Cefamox 500 mg capsule, according to both the rate and extent of absorption.

Adolescent↗
PubMed2000

Leisure-time, occupational, and household physical activity among professional, skilled, and less-skilled workers and homemakers.

BACKGROUND: Adults in lower status occupations are at higher risk of premature cardiovascular disease, for which physical inactivity is a major risk factor. While lower rates of leisure-time physical activity have been found to be associated consistently with lower income and education levels, the association between occupational and home-based physical activity with membership of different occupational categories is not well understood. METHODS: An urban-representative population data set derived from a self-completion questionnaire was used to examine both self-reported leisure-time physical activity and a combined measure of occupational/home-based physical activity of adult less-skilled, skilled, and professional workers and homemakers (3795 males; 4140 females). chi(2) analyses, ANOVA, and logistic regressions were used to examine the associations between occupational group membership and physical activity. RESULTS: After adjustment for age, body mass index, education, country of birth, marital status, and smoking, less-skilled workers were less likely to report any form of leisure-time physical activity. However, occupational category was not a strong predictor of participation in combined vigorous occupational/home physical activity. Homemakers and those in lower status occupations were less likely to report participation in vigorous leisure-time physical activity sufficient for cardiorespiratory fitness. With the inclusion of time spent in combined vigorous occupational/home physical activity, there was no longer an association of activity with occupational status for males. However, for females the association remained. CONCLUSIONS: The assessment of occupational and household physical activity in addition to leisure-time activity may be important for understanding associations between occupational categories, physical activity, and increased levels of health risk and for the development of physical activity promotion strategies.

Adult↗
PubMed2000

Physical activity beliefs and behaviours among adults attempting weight control.

OBJECTIVE: To compare the frequency and duration of varying intensities of physical activity performed by adults trying to lose weight, avoid gaining weight and not actively trying to control their weight, and to compare these groups' beliefs about the physical activity they should perform. METHOD: Random postal survey of 2500 Victorian adults selected from the Australian electoral roll (response rate=42%). MEASURES: One-week physical activity recall (frequency and duration of walking, other moderate activity and vigorous activity), BMI (based on self-reported height and weight) and weight-control behaviour. RESULTS: At the time of the survey, 27% of respondents were actively trying to avoid gaining weight, 23. 9% trying to lose weight and 49.1% undertaking no weight control. Respondents spent a mean time of 4.0 (+/-7.1) h walking, 5.5 (+/-7. 9) h in moderate activity and 3.1(+/-5.9) h in vigorous activity during the week prior to the survey. Women trying to lose weight or avoid gaining weight engaged in vigorous activity more often than women not trying to control their weight. After adjusting for age, education and BMI, women trying to avoid gaining weight were 2.4 times more likely, and women trying to lose weight 2.5 times more likely, to have met current physical activity guidelines than women undertaking no weight control. On average, respondents believed they should spend 5.2 (+/-6.9) h walking, 6.5 (+/-8.2) h in moderate activity and 4.3 (+/-6.5) h in vigorous activity each week. Women trying to lose weight felt they should perform vigorous activity more often than other women. Weight-control behaviour was not associated with physical activity beliefs and behaviours of men. CONCLUSION: Walking is a common activity among adults attempting weight control. However, many men and women do not fully recognize the value of moderate-intensity physical activity. Future efforts should be directed at promoting the role of moderate-intensity activity in weight control, particularly activity that can be performed outside of planned activity sessions. International Journal of Obesity (2000)24, 81-87

Adult↗
PubMed2000

The association between television viewing and overweight among Australian adults participating in varying levels of leisure-time physical activity.

OBJECTIVES: To investigate the effect of physical activity on the association between television viewing and overweight (body mass index (BMI) > or =25 kg/m2). DESIGN: Cross-sectional study administered by interview to adults randomly selected from the electronic white pages. SUBJECTS: 3392 adults (64% response rate) from a representative population sample in the State of New South Wales, Australia. MEASUREMENTS: Self-reported height and weight, two-week leisure-time physical activity recall, one-week average television viewing recall. RESULTS: BMI and physical activity patterns were both associated with hours of television watched. Compared to those participants who reported watching less than one hour of television per day, those watching 1 to 2.5 hours were 93% more likely to be overweight (BMI>/=25 kg/m2), those watching 2.5 to 4 hours were 183% more likely to be overweight, those watching more than 4 hours per day were four times more likely to be overweight. Physical activity was not directly associated with being overweight, but an interaction between activity and television watching was present. Respondents in the low, moderate and high physical activity categories who reported watching more than 4 hours of television per day were twice as likely to be overweight compared to those who watched less than one hour of television per day, irrespective of physical activity participation. CONCLUSIONS: With approximately half the Australian adult population overweight or obese, these findings indicate that public health strategies to reduce overweight and prevent weight gain may need to focus on reducing sedentary behaviours such as television viewing in addition to increasing physical activity.

Adolescent↗
PubMed2000

Variation in the nucleotide sequence of cottontail rabbit papillomavirus a and b subtypes affects wart regression and malignant transformation and level of viral replication in domestic rabbits.

We previously reported the partial characterization of two cottontail rabbit papillomavirus (CRPV) subtypes with strikingly divergent E6 and E7 oncoproteins. We report now the complete nucleotide sequences of these subtypes, referred to as CRPVa4 (7,868 nucleotides) and CRPVb (7,867 nucleotides). The CRPVa4 and CRPVb genomes differed at 238 (3%) nucleotide positions, whereas CRPVa4 and the prototype CRPV differed by only 5 nucleotides. The most variable region (7% nucleotide divergence) included the long regulatory region (LRR) and the E6 and E7 genes. A mutation in the stop codon resulted in an 8-amino-acid-longer CRPVb E4 protein, and a nucleotide deletion reduced the coding capacity of the E5 gene from 101 to 25 amino acids. In domestic rabbits homozygous for a specific haplotype of the DRA and DQA genes of the major histocompatibility complex, warts induced by CRPVb DNA or a chimeric genome containing the CRPVb LRR/E6/E7 region showed an early regression, whereas warts induced by CRPVa4 or a chimeric genome containing the CRPVa4 LRR/E6/E7 region persisted and evolved into carcinomas. In contrast, most CRPVa, CRPVb, and chimeric CRPV DNA-induced warts showed no early regression in rabbits homozygous for another DRA-DQA haplotype. Little, if any, viral replication is usually observed in domestic rabbit warts. When warts induced by CRPVa and CRPVb virions and DNA were compared, the number of cells positive for viral DNA or capsid antigens was found to be greater by 1 order of magnitude for specimens induced by CRPVb. Thus, both sequence variation in the LRR/E6/E7 region and the genetic constitution of the host influence the expression of the oncogenic potential of CRPV. Furthermore, intratype variation may overcome to some extent the host restriction of CRPV replication in domestic rabbits.

Animals↗
PubMed2000

Kienböck's disease: conservative management versus radial shortening.

Avascular necrosis of the lunate, first described by Kienbock, can be treated either conservatively or by various surgical procedures. We compared the results of 18 conservatively treated patients, all of whom had stage-2 or stage-3 disease, with those of 15 who underwent a radial shortening procedure. We evaluated pain, range of movement, grip strength and functional disability, and determined the progression of the disease by assessing radiologically carpal height, the width and flattening of the lunate, the radioscaphoid angle, the pattern of the fracture and sclerosis and cysts. The mean follow-up was for 3.6 years (1.5 to 9). Patients treated by radial shortening had less pain and better grip strength than those managed conservatively. In some patients with stage-3 disease treated conservatively there was rapid deterioration to carpal collapse. Although radial shortening did not reverse or prevent carpal collapse, it slowed down the process in patients with stage-3 disease. We recommend a radial shortening procedure for patients with severe pain and radiological signs of progressive carpal collapse.

Activities of Daily Living↗
PubMed2000

Environmental determinants of physical activity and sedentary behavior.

Environmental changes are expected to lead to decreased time in sedentary behavior and to increased levels of physical activity in populations. Past research has emphasized psychosocial determinants of physical activity. Progress in the field will require more focus on understanding sedentary behaviors and the role of environmental determinants.

Adult↗
PubMed1999

Insufficiently active Australian college students: perceived personal, social, and environmental influences.

BACKGROUND: A sustainable pattern of participation in physical activity is important in the maintenance of health and prevention of disease. College students are in transition from an active youth to a more sedentary adult behavior pattern. METHODS: We assessed self-reported physical activity and other characteristics in a sample of 2,729 male and female students (median age was 20 years) recruited from representative courses and year levels at four Australian College campuses. They were categorized as sufficiently or insufficiently active, using estimates of energy expenditure (kcal/week) derived from self-reported physical activity. Personal factors (self-efficacy, job status, enjoyment), social factors (social support from family/friends), and environmental factors (awareness of facilities, gym membership) were also assessed. RESULTS: Forty-seven percent of females and 32% of males were insufficiently active. For females, the significant independent predictors of being insufficiently active were lower social support from family and friends, lower enjoyment of activity, and not working. For males, predictors were lower social support from family and friends, lower enjoyment of activity, and being older. CONCLUSIONS: Factors associated with physical activity participation (particularly social support from family and friends) can inform physical activity strategies directed at young adults in the college setting.

Adolescent↗
PubMed1999

Physical inactivity and other health risks among Australian males in less-skilled occupations.

Male workers in less-skilled occupations have higher rates of cardiovascular disease, compared with higher-skilled workers. A representative population sample of Australian male workers was used to compare physical activity levels and selected cardiovascular disease risk factors in less-skilled versus professional and skilled workers. Workers in the less-skilled occupational categories reported significantly more vigorous work and home-based activity than did those in the professional and skilled categories. In multivariate comparisons, cigarette smoking was the only factor that discriminated between the less-skilled versus the professional and skilled employees. Although worksites can potentially provide health-promoting physical activity options for higher-risk groups, our findings suggest that smoking and possibly overweight are risk factors that are more strongly present in less-skilled occupations.

Adult↗
PubMed1997

A cottontail rabbit papillomavirus strain (CRPVb) with strikingly divergent E6 and E7 oncoproteins: An insight in the evolution of papillomaviruses.

We previously observed that warts induced by an isolate of cottontail rabbit papillomavirus (CRPV) showed incomplete instead of systemic regression in some domestic rabbits. We report that the viral isolate contained, as a major component, a CRPV strain (CRPVb) showing an unexpectedly high divergence in the E6 and E7 open reading frames (ORFs), compared to the prototype CRPVa present in the isolate as a minor component. The E6 and E7 oncoproteins of CRPVa and -b disclosed only 87.5% identical amino acids and differed in size by three and two amino acids, respectively. This divergence involved (i) a great number (4.4%) of nucleotide substitutions and a high rate (83.3%) of nonsynonymous mutations; (ii) mutations changing the E6 and E7 stop codons; and (iii) in-frame sequence insertions in the E6 ORF (18 nucleotides) and downstream of the mutated E7 stop codon (6 nucleotides), both likely to result from a duplication of adjacent sequences. These extensive differences could account for distinct biological and antigenic properties. Strikingly, only four (0.8%) amino acids of the L1 major capsid protein were variable. Thus, it seems likely that sequence duplications and mutations affecting stop codons exert a strong selection pressure on the fixation of nonsynonymous mutations and that phylogenetic calculations based only on point mutations may misevaluate the time scale of the evolution of papillomaviruses.

Amino Acid Sequence↗
PubMed1997

Adenosine A1 receptor promotion of multinucleated giant cell formation by human monocytes: a mechanism for methotrexate-induced nodulosis in rheumatoid arthritis.

OBJECTIVE: To determine why methotrexate (MTX) exacerbates rheumatoid nodules in some patients, despite the effective suppression of synovial inflammation. METHODS: Phorbol myristate acetate (PMA)-induced differentiation of monocytes into multinucleated giant cells was used as an in vitro model to study the effects of adenosine on nodulosis. RESULTS: MTX at 200-2,000 nM or the adenosine A1 agonist N5-cyclopentyl adenosine (CPA) (10(-12) to 10(-9) M) or the A2 antagonist 3,7-dimethyl-1-propargylxanthine markedly enhanced giant cell formation, whereas the adenosine A1 antagonist 8-cyclopentyl-dipropylxanthine completely reversed these effects. PMA, CPA, and MTX induced adenosine release by cultured monocytes at concentrations consistent with those associated with predominantly A1 effects. Furthermore, surface expression of A1 receptors was found to remain unchanged on the differentiating cells throughout the culture period. CONCLUSION: Agents that inhibit adenosine A1 receptors might be useful in the treatment of MTX-induced rheumatoid nodulosis, while still potentiating the A2-mediated antiinflammatory effects of MTX on synovitis.

Adenosine↗
PubMed1997

Continuous venovenous haemofiltration using polyacrylonitrile filters does not activate contact system and intrinsic coagulation pathways.

OBJECTIVES: To investigate whether continuous venovenous haemofiltration using polyacrylonitrile filters causes activation of the contact system and intrinsic coagulation pathways and if this, and/or low plasma levels of endogenous anticoagulants, influences filter lifespan. DESIGN: Observational study. SETTING: University Teaching Hospital Intensive Care Unit. PATIENTS: Twelve critically ill patients with acute renal failure receiving continuous venovenous haemofiltration. INTERVENTIONS: Blood samples were taken before starting haemofiltration, at 15 min, 1 h, 3-4 h, 8-12 h, 24 h and at 24-h intervals thereafter until filter blockage occurred. Measurement was made of the contact and intrinsic coagulation system proteins factor XII, activated factor XII and prekallikrein and the protease inhibitors antithrombin III, heparin co-factor II, alpha 2-macroglobulin and C1-esterase inhibitor. Thrombin-antithrombin complex levels were measured to provide evidence of thrombin generation. RESULTS: (i) Factor XII, prekallikrein and contact system inhibitors were subnormal in 10/12 and activated factor XII raised in 11/12 patients at baseline, implying pre-existing contact pathway activation. (ii) No change occurred during haemofiltration in the intrinsic coagulation pathway factor or inhibitor levels. (iii) Clotting of the filter circuit within the first 24 h occurred in 5/12 and was associated with low baseline levels of antithrombin III and heparin co-factor II. Only in these patients did thrombin-antithrombin complex levels rise significantly. CONCLUSIONS: The contact system was not activated further by continuous venovenous haemofiltration using polyacrylonitrile filters in critically ill patients. Premature clotting of the haemofilter circuit was more common in patients with very low levels of antithrombin III and heparin co-factor II; although this was related to thrombin generation, the intrinsic coagulation pathway does not appear to be implicated.

Acrylic Resins↗
PubMed1997

Interaction between certain major histocompatibility complex class II and T-cell receptor V beta alleles promotes the antibody production to extractable nuclear antigen-related peptides.

Our objective was to study the interaction between major histocompatibility complex (MHC) class II and T-cell receptor (TCR) alleles in the recognition of extractable nuclear antigen-derived peptides in 32 patients with systemic lupus erythematosus and 173 of their family members. MHC genes were analyzed using sequence specific oligonucleotides, and TCR beta-chain gene polymorphism using restriction fragment-length polymorphism. One dominant peptide (as defined by enzyme-linked immunosorbent assay autoantibody reactivity) was identified in each antigen studied: peptide 1-20 in Sm-D, peptide 35-58 in U1-RNP-A, and peptide 304-324 in the Ro/SSA 60 Kd protein. None of the MHC class II and TCR beta haplotypes was directly associated with any of the autoantibodies. Twenty-six subjects had antibodies to the peptide Sm-D1-20; nine of them were DRB1*0101/DQB1*0501. Among subjects with this haplotype, the number of responders was higher (p < 0.028, p corrected, pc = 0.336) in those with the 2-25-9 TCR beta haplotype than in the remainder. Conversely, the number of DRB1*04/DQB1*0302 responders was lower (p < 0.030, pc = 0.360) among subjects with the 23-20-9 TCR beta haplotype than in those without. The odds ratios (OR) were 4.23 and 0.21, respectively. Of the 54 subjects positive for anti-U1-RNP-A 35-38, 13 were DRB1*0101/DQB1*0501 and eight DRB1*04/DQB1*0302. The percentage of responders was higher (p < 0.041, pc = 0.492, OR = 3.48) in the former group of subjects with the 2-25-9 TCR beta haplotype, and lower (p < 0.02, pc = 0.024, OR = 0.09) in the latter with the 23-20-9 TCR beta haplotype. Three of the 12 anti Ro/SSA 60Kd 304-324-positive subjects were DRB1*0101/DQB1*0501. All had the 2-25-9 TCR beta haplotype (p < 0.046, pc = 0.552, OR = 6.29) and none the 23-20-9 (p < 0.031, pc = 0.372, OR = 0.10). The same combinations of genes were associated with high/low response toward the three peptides. These data provide evidence for an interplay of the MHC class II and TCR beta alleles in the control of specific autoantibody response to well-defined nuclear Ag peptides.

Adolescent↗
PubMed1997

Pharmacokinetic interaction between itraconazole and ceftriaxone in Yucatan miniature pigs.

Since ceftriaxone and itraconazole are highly protein bound, are excreted via a biliary pathway, and are in vitro modulators of the efflux pump P glycoprotein, a pharmacokinetic interaction between these antimicrobial agents can be hypothesized. Therefore, we evaluated the pharmacokinetics of itraconazole and ceftriaxone alone and in combination in a chronic model of catheterized miniature pigs. Itraconazole does not influence ceftriaxone kinetic behavior. The mean areas under the concentration-time curve (AUC) were 152.2 microg x h/ml (standard deviation [SD], 22.5) and 129.2 microg x h/ml (SD, 41.2) and the terminal half-lives were 1.1 h (SD, 0.3) and 0.9 h (SD, 0.2) when ceftriaxone was given alone and combined with itraconazole, respectively. Regarding itraconazole kinetics, ceftriaxone was shown to alter the disposition of the triazole. Contrary to what was expected, the AUC (from 0 to 8 h) decreased from 139.3 ng h/ml with itraconazole alone to 122.7 ng h/ml with itraconazole and ceftriaxone combined in pig 1, from 398.5 to 315.7 ng x h/ml in pig 2, and from 979.6 to 716.6 ng x h/ml in pig 3 (P of <0.01 by analysis of variance).

Administration, Oral↗
PubMed1997

[In vivo pharmacokinetic of amikacin and its pharmacodynamic in combination with cefepime, cefpirome and meropenem in an in vitro/ex vivo micropig model].

Three female Yucatan micropigs were included and received a single dose of amikacin (15 mg/kg) by short infusion (30 min) combined either with a single dose of cefepime or cefpirome (30 mg/kg/12 h) or meropenem (7 mg/kg/8 h). The beta-lactams were administered either by intravenous intermittent injection or by continuous infusion. The mean elimination half-life and clearance value of amikacin were 1.88 h and 2.15 ml/min.kg-1 respectively. These pharmacokinetic parameters were similar to those obtained in man (t1/2 = 2,42 h et Cl = 1,61 ml/min kg-1). Furthermore, they were not affected by coadministration of cefepime, cefpirome and to meropenem. While resistant to cefepime, cefpirome and amikacin, Klebsiella pneumoniae producing ESBL was susceptible to combination of these cephalosporins with amikacin in an in vitro/ex vivo micropig model. For the six dosage regimens used in this study, the killing activities were similar and resulted in at least 4 log decrease at 6 h after drug exposure. For antimicrobial combination consisting of bolus dosing of amikacin plus continuous infusion of cefepime or cefpirome, the 12 h serum bactericidal titers (SBTs) were 1:8 for cefepime and 1:2 for cefpirome dosage regimen. When each drug administered intermittently, the 12 h SBTs were 1:4 for cefepime and 1:2 for cefpirome. The 8 h SBTs for dosing schedule containing meropenem combined with amikacin were 1:4 and 1:16 after 30 min short infusion and continuous infusion respectively. In conclusion, our study showed that the micropig model is a reliable model for pharmacokinetic investigation of amikacin. It was concluded that beta-lactam antibiotics tested with amikacin may be coadministered by using the standard recommended dosing regimen of amikacin. Continuous infusion of beta-lactams combined with once dosing of amikacin seems to be as or more effective than intermittent injection of each drug.

Amikacin↗
PubMed1996

Nonlinkage of D6S260, a putative schizophrenia locus, to bipolar affective disorder.

To examine whether genes that predispose to schizophrenia also confer a predisposition to other psychiatric disorders such as bipolar affective disorder (BAD), we tested for linkage between the recently identified schizophrenia susceptibility locus D6S260 and the inheritance of BAD in 12 large Australian pedigrees. We found no evidence for linkage over a region of 12-27 cM from the D6S260 locus, depending on the model used. Our results therefore do not provide support for the continuum theory of psychosis.

Australia↗