Occupational asthma in radiographers.
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Biomedical subjects
Publications and source records attributed to J Hayes.
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In a prospective study, we measured compliance with breast self-examination, using an anonymous questionnaire, in suburban high school students three months (n = 85) and eight months (n = 54) after group instruction. Post-instruction proficiency in performing the procedure and personal health beliefs regarding breast cancer were also evaluated. At three months, 40% of the group reported practicing breast self-examination at some time since instruction; 12% had performed the procedure timed correctly with their menstrual cycle. At eight months, only two girls (4%) had practiced breast self-examination at least once since the three-month evaluation. Proficiency scores overall were high, with 77% scoring 12 points or above on a 15-item questionnaire; however, scores were significantly lower in the 15-year-olds than in the older adolescents. No significant relationships were found between compliance and most personal health beliefs, previous instruction, or level of knowledge of the procedure. Attention should be directed toward assessing the ability and willingness to practice preventive health behaviors before instruction programs are instituted in this age group.
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The influence of cis-diamminedichloroplatinum (II) (cis-DDP) binding to chromatin in chicken erythrocyte nuclei and the nucleosomal core particle is investigated. The cis-DDP modifications alter DNA-protein interactions associated with the higher order structure of chromatin to significantly inhibit the rate of micrococcal nuclease digestion and alter the digestion profile. However, cis-DDP modification of core particle has little effect on the digestion rate and the relative distribution of DNA fragments produced by microccocal nuclease digestion. Analysis of the monomer DNA fragments derived from the digestion of modified nuclei suggests that cis-DDP binding does not significantly disrupt the DNA structure within the core particle, with its major influence being on the internucleosomal DNA. Together these findings suggest that cis-DDP may preferentially bind to the internucleosomal region and/or that the formation of the intrastrand cross-link involving adjacent guanines exhibits a preference for the linker region. Sucrose gradient profiles of the modified nucleoprotein complexes further confirm that the digestion profile for micrococcal nuclease is altered by cis-DDP binding and that the greatest changes occur at the initial stages of digestion. The covalent cross-links within bulk chromatin fix a sub-population of subnucleosomal and nucleosomal products, which are released only after reversal by NaCN treatment. Coupled with our previous findings, it appears that this cis-DDP mediated cross-linking network is primarily associated with protein-protein crosslinks of the low mobility group (LMG) proteins.
Obesity is an important risk factor for cardiovascular diseases and non-insulin-dependent diabetes, which are chronic diseases that afflict American Indians and Alaska Natives today. Because American Indians are not represented in most national health and nutrition surveys, there is a paucity of data on actual prevalence of obesity in American Indians. We estimated prevalence of overweight and obesity for American Indian adults, school-age children, and preschool children from existing data. The prevalence of obesity in adults was estimated from self-reported weights and heights obtained from a special survey of American Indians performed as part of the 1987 National Medical Expenditure Survey. Prevalence of obesity in American Indians was 13.7% for men and 16.5% for women, which was higher than the US rates of 9.1% and 8.2%, respectively. Obesity rates in American Indian adolescents and preschool children were higher than the respective rates for US all-races combined.
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Steady-state plasma carbamazepine (CBZ) concentrations were measured in 196 pediatric inpatients taking CBZ alone or CBZ combined with other drugs. The steady-state CBZ concentrations divided by the daily administered dose (dose ratio, reciprocal of apparent clearance) increased significantly (r = 0.183, p less than 0.01) with age. The correlation between dose and CBZ concentration, while significant (r = 0.265, p = 0.023), was weak because of wide interindividual differences in dose ratio. There was a negative correlation between CBZ daily dose and CBZ dose ratio. This negative correlation was significant in children 4-6 (r2 = 0.481, p less than 0.01), 7-11 (r2 = 0.399, p less than 0.01), and greater than 11 years of age (r2 = 0.401, p less than 0.01), but not in children less than 4 years of age (r2 = 0.172, p greater than 0.1). The CBZ dose ratio was significantly (p less than 0.001) lower in patients taking CBZ in combination with more than one other antiepileptic drug compared with those on CBZ monotherapy. No significant (p greater than 0.1) difference in CBZ dose ratio was found between male and female patients. These findings suggest that CBZ clearance was influenced by age, dose, and comedication with more than one other antiepileptic drug but not sex. The concentration necessary for efficacy is a clinical, not an analytical decision. However, the dose-concentration relationships show that recommended pediatric CBZ doses of 10-30 mg/kg/day are not enough to attain published therapeutic CBZ concentrations in many children.(ABSTRACT TRUNCATED AT 250 WORDS)
Steady-state plasma valproic acid (VPA) concentrations were measured in 118 pediatric inpatients taking VPA. There was a significant (p less than 0.0001) inverse correlation between the daily VPA dosage and the VPA dose ratio (concentration/dose or 1/clearance). The VPA dose ratio was significantly lower in patients taking VPA in combination with phenobarbital (p less than 0.01), carbamazepine (p less than 0.05), or multiple other antiepileptic drugs (p less than 0.0001), compared with those on VPA monotherapy. Neither age nor sex had any influence on VPA dose ratios. No significant (p greater than 0.1) correlation was found between VPA doses and concentrations in children on monotherapy. The distribution of VPA dose concentrations suggests that children, especially those on VPA polytherapy, require higher than recommended pediatric VPA maintenance doses (greater than 60 mg/kg/day) to maintain concentrations greater than 50 mg/L. Results also indicate that at higher concentrations (greater than 80 mg/L), increasing doses may produce less than proportional increases in total VPA concentration.
Steady-state plasma phenobarbital (PB) concentrations (n = 671) were measured in 438 inpatients. There was a significant relationship between age and PB dose ratio (concentration/dose or 1/clearance) for monotherapy patients; the dose ratio declined in the first year of life, but the dose ratio increased after age 1. The dose ratios were significantly higher in patients receiving PB in combination with other antiepileptic drugs. However, neither sex nor formulations used (tablet, elixir and intravenous) had any influence on the PB dose ratio. The age-dose-concentration relationships indicate that children, especially those under 11 years of age, may require maintenance PB doses more than 5 mg/kg/day to achieve the commonly recommended 'therapeutic' concentration range (10-40 mg/l).
BACKGROUND: The development of a microcomputer-based device permits quick, simple, and noninvasive quantification of the respiratory sinus arrhythmia (RSA) during quiet breathing. METHODS AND RESULTS: We prospectively and serially measured the radionuclide left ventricular ejection fraction and the RSA amplitude in 34 cancer patients receiving up to nine monthly bolus treatments with doxorubicin hydrochloride (60 mg/m2). Of the eight patients who ultimately developed symptomatic doxorubicin-induced congestive heart failure, seven (87.5%) demonstrated a significant decline in RSA amplitude; five of 26 subjects without clinical symptoms of cardiotoxicity (19.2%) showed a similar RSA amplitude decline. On average, significant RSA amplitude decline occurred 3 months before the last planned doxorubicin dose in patients destined to develop clinical congestive heart failure. CONCLUSION: Overall, RSA amplitude abnormality proved to be a more specific predictor of clinically significant congestive heart failure than did serial resting radionuclide ejection fractions.
Endoscopic CO2 laser excisional biopsy of selected early supraglottic cancer patients has been described. None of these patients experienced the perioperative morbidities of bleeding, airway obstruction, or aspiration beyond 3 or 4 days. All patients were treated with full-course standard irradiation therapy after their laser procedures. Our very preliminary data suggest that stage I and stage II patients are effectively treated with endoscopic CO2 laser excisional biopsy, whereas stage III patients should undergo open surgeries where medically possible.
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Various reports from the surgical and gastroenterologic literature have stated that the incidence of primary gastric lymphoma has increased. Other reports have claimed that this is a relative increase or represents referral center bias. The current study was designed to determine if the incidence of primary gastric lymphoma has increased in the community hospital setting. A total of 147 cases of gastric neoplasms were reviewed over a 10-year study period. The cases were divided into two 5-year periods, i.e., 1978-82 and 1983-87. There were two new cases (2.8%) of primary gastric lymphoma in the period 1978-82 and 11 new cases (19%) in the period 1983-87. The difference in proportion of primary gastric lymphoma between these two time periods was statistically significant (P = 0.01 by chi-square analysis). This increased incidence of primary gastric lymphoma is difficult to explain, but it must be recognized by surgeons and endoscopists.
Stable complex formation on a Xenopus somatic 5 S RNA gene requires protein-protein interactions between the non-DNA binding domain of transcription factor (TF) IIIA and activities in a TFIIIC fraction. No significant changes in the structure of the TFIIIA.DNA complex can be detected as a consequence of stabilization, indicating that protein confirmation is the primary determinant of stability.
Impedance cardiography was used to determine the classical systolic time intervals (STI's) (i.e., pre-ejection period (PEP), left ventricular ejection time (LVET) and the quotient PEP/LVET), in young, healthy, male subjects during supine and seated exercise. With increasing exercise, there was a tendency toward decreases in PEP, LVET, and PEP/LVET. In the seated position, there was an increase in transthoracic Zo incident to the caudal migration of thoracic blood--a result of the postural change. With seated exercise, there were--in contrast to supine exercise-greater decreases in PEP/LVET and greater increases in the Heather index. Similarly, there was a tendency toward increases in dZ/dtmin and the Rapid Ejection Index. We suggest that these differences are related to increased myocardial contractility resulting from the postural augmentation of cardio-sympathetic activity, added to that of exercise per se. This study, as well as previous ones, indicates that impedance cardiography is reliable, effective, and more practicable than the arteriographic method for monitoring STI's. We also believe that certain impedance-derived indices (i.e., transthoracic Zo, dZ/dtmin and the Heather Index) have considerable potential value for physiologic and clinical investigation.
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1. Allopurinol usage in 50 patients of a city teaching hospital was surveyed. 2. The plasma concentrations of oxipurinol and uric acid and the urinary production of uric acid were examined. 3. The daily doses of allopurinol ranged from 50 to 1200 mg but 83% of patients were taking 300 mg daily. 4. A wide range of plasma oxipurinol concentrations was observed from 2.8 to 55.8 mg l-1 with a mean +/- s.d. of 15.2 +/- 11.7 mg l-1. 5. The population studied included a high proportion of patients with renal impairment and creatinine clearance was a significant determinant of oxipurinol concentrations (P less than 0.005). 6. There was no significant correlation between plasma urate and plasma oxipurinol concentrations and only a few plasma urates were above the upper limit of the reference range of the laboratory. 7. It was apparent that many patients were taking unnecessarily high daily doses of allopurinol and that renal status was not always considered when deciding dosage regimens of allopurinol.