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Biomedical subjects

L Mitchell

Publications and source records attributed to L Mitchell.

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

Continuous handrail support, oxygen uptake, and heart rate in women during submaximal step treadmill exercise.

Past research suggests that continuous handrail support during exercise attenuates physiologic responses to exercise and reduces aerobic benefits; however, this phenomenon has not been systematically studied in women exercising on the step treadmill. The effects of three levels of handrail support (continuous light, continuous very light, or no handrail support) on oxygen uptake and heart rate during step treadmill exercise were examined in 15 healthy women. Measures were obtained during 6 bouts of exercise, 3 bouts at 25 steps/min followed by 3 bouts at 33 steps/min. At both step rates, mean oxygen uptake was significantly reduced during continuous light and continuous very light handrail support as compared with no handrail support, and mean heart rate was significantly reduced during continuous light versus no handrail support. At 25 steps/min only, mean heart rate was significantly reduced during continuous very light versus no handrail support. Findings indicate that women who use even continuous light or continuous very light handrail support attenuate physiologic responses during step treadmill exercise, thereby reducing aerobic requirements and gaining suboptimal benefits from exercise.

Adult↗
PubMed2000

Role of preoperative antibiotic prophylaxis in preventing postoperative peritonitis in newly placed peritoneal dialysis catheters.

The role of vancomycin and other antibiotics in the treatment of acute peritonitis in peritoneal dialysis (PD) patients is well established. However, the role of preoperative vancomycin or cephalosporins in preventing early infection in newly placed PD catheters remains controversial. We performed a prospective randomized study to examine the role of vancomycin or cefazolin prophylaxis in decreasing the incidence of postoperative peritonitis. Over a 6-year period, 221 patients undergoing 254 permanent peritoneal catheter placement procedures were randomized into three groups. Group I patients (86 procedures) were administered a single intravenous (IV) dose of vancomycin, 1,000 mg, 12 hours before peritoneal catheter placement procedures, whereas group II patients (85 procedures) were administered a single IV dose of cefazolin, 1,000 mg, 3 hours before the procedure. Group III patients (83 procedures) were not administered antibiotics preoperatively for at least 1 week before the procedure. Patients were monitored for peritonitis in the following 14 days. Peritonitis developed in 1 patient (1%) in group I (vancomycin group) and 6 patients (7%) in group II (cefazolin group) compared with 10 patients (12%) in group III (control group); P = 0.02. We conclude that the use of preoperative single-dose IV vancomycin prophylaxis for permanent PD catheter placement reduces the risk for postoperative peritonitis. Single-dose vancomycin is superior to single-dose cefazolin in reducing the risk for postoperative peritonitis. Absence of prophylaxis is associated with a high risk for developing postoperative peritonitis.

Adolescent↗
PubMed2000

Cotinine levels in Southeast Asian smokers.

Understanding the contribution of race to factors associated with cigarette smoking and nicotine metabolism is essential for the characterization of patterns of tobacco use, nicotine dependence and incidence of tobacco-related diseases. This paper reports an investigation of cotinine levels among Southeast Asian smokers in two separate studies. Study 1 included 327 male and female smokers who participated in community-based interviews where smoking history information was obtained and a saliva continine sample was collected. Results indicated that subjects smoked an average of 11.2 cigarettes/day, with men reporting significantly higher consumption rates as compared to women (p < 0.0001). Subjects' mean cotinine level was 65 ng/ml with an average cotinine/cigarette ratio of 8.2. In Study 2, plasma and saliva cotinine in six Southeast Asian adult smokers were measured during 2 days of smoking followed by 6 days of abstinence. On day 1, mean plasma and saliva continine levels were 268 and 235 ng/ml, respectively. After 6 days of abstinence, mean levels had dropped to 12 ng/ml for plasma and 8 ng/ml in saliva. On average, it required at least 4.7 days for saliva continine levels to reach < 14 ng/ml. Mean cotinine concentrations during smoking differed in these two separate studies. Implications of these findings are discussed and future research recommendations are presented.

Adult↗
PubMed2000

Investigation of a hydrophilic primer for orthodontic bonding: an in vitro study.

A common reason for bond failure is moisture contamination. This study investigates the in vitro bond strength of brackets bonded using a new hydrophilic primer, designed to be insensitive to moisture, and compares it with a conventional primer. Using a standardized technique, the in vitro bond strength of brackets bonded with the hydrophilic primer was compared to identical brackets bonded with a conventional primer. Although designed to be moisture insensitive, the directions for use stipulate drying the teeth before bonding. Therefore, for the purposes of comparison with a conventional primer the experiment was conducted under dry conditions. The results were analysed using the Weibull distribution modelling. The median bond strength with the hydrophilic primer (6.43 MPa, 95 per cent C.I. 7.69-9.50) was significantly lower (P = 0.0001) than the conventional primer (8.71 MPa, 95 per cent C.I. 5.89-7.59). The Weibull distribution modelling showed that brackets bonded with the hydrophilic primer were 3.96 times more at risk of failure (95 per cent C.I.: 2.39-6.56; P <0.0001). The bond strength at which 5 per cent of the brackets failed was also lower for the hydrophilic primer. The bond strengths obtained with the hydrophilic primer were significantly lower than with the conventional primer. Although the median bond strength values were promising, the laboratory results for this particular hydrophilic primer were disappointing when using the Weibull analysis, where the whole distribution of bond strength is taken into account.

Adolescent↗
PubMed2000

Immunization rate comparison for Oklahoma Medicaid managed care population by age two: 1995-1998.

Processes of care are used as one measure for the quality of care rendered by providers. One example is the immunization of children by the age of two. The Oklahoma Health Care Authority, with the Oklahoma Foundation for Medical Quality, has been tracking childhood immunization rates from 1995 through 1998. The rate calculated included the medical record data and the Oklahoma Statewide Immunization Information System (OSIIS) data set. The standards were based on Advisory Committee on Immunization Practices recommendations and Quality Assurance Reform Initiative standards. The rate of provision of documented immunizations in the Medicaid managed care population under the age of two has improved markedly from 1995 to 1998. The trend analysis suggests there might be areas for continued improvement in the provision of immunization to individuals in Oklahoma's Medicaid managed care population. Further, the OSIIS data is critical for maintaining a uniform data set for immunization information.

Humans↗
PubMed2000

Consumer Assessment of Health Plans Survey (CAHPS) results for Oklahoma managed care Medicaid, 1997, 1998, and 1999.

Consumer satisfaction surveys have become an important source of information for purchasers and consumers of health care and health care organizations themselves. Individuals receiving health care provide valuable information regarding access, use of services, and satisfaction with care that can be used for multiple evaluative purposes. The Oklahoma Health Care Authority has adopted the Consumer Assessment of Health Plans Survey (CAHPS) to measure patient satisfaction for the SoonerCare managed care programs. The Oklahoma Foundation for Medical Quality administered the surveys. The adult and child CAHPS core questionnaires served as the basis for the general surveys in 1997 and 1998. The CAHPS for Children with Special Needs survey results and the Pediatric Adaptation of the CAHPS Behavioral Health Survey results were administered in 1999 for baseline measures. Results indicated an overall increase in consumer satisfaction levels across the two CAHPS core questionnaires. Baseline measures for special needs populations were also established.

Adult↗
PubMed2000

Preoperative vancomycin prophylaxis for newly placed peritoneal dialysis catheters prevents postoperative peritonitis.

The role of vancomycin and other antibiotics in treatment of acute peritonitis in peritoneal dialysis patients is well established. However, the role of preoperative vancomycin or cephalosporins in preventing early infection in newly placed peritoneal dialysis catheters remains controversial. We performed a prospective randomized study to examine the role of vancomycin or cefazolin prophylaxis in decreasing the incidence of postoperative peritonitis. Over 8-year period, 265 patients undergoing 305 permanent peritoneal catheter placement procedures were randomized into three groups. Group I (103 procedures) received a single intravenous (i.v.) dose of 1000 mg vancomycin 12 hours before the peritoneal catheter placement procedure. Group II (102 procedures) received a single i.v. dose of 1000 mg of Ancef (cefazolin) 3 hours before the procedure. Group III (100 procedures) received no antibiotics preoperatively for a least one week before the procedure. Patients were monitored for peritonitis during the following 14 days. Peritonitis developed in 1 patient (1%) in Group I (vancomycin group) compared to 12 patients (12%) in Group III (control group), p = 0.002, and in 9 patients (9%) in Group II (cefazolin group) compared to Group III, p = 0.68. We conclude that the use of preoperative single-dose i.v. vancomycin prophylaxis for permanent peritoneal dialysis catheter placement reduces the risk of postoperative peritonitis. Cefazolin did not achieve a statistically significant difference from the control group and may not provide adequate prophylaxis.

Adolescent↗
PubMed1999

Analysis of warfarin therapy in pediatric patients: A prospective cohort study of 319 patients.

This study details warfarin use in a large pediatric population followed in a central anticoagulation clinic. A prospective, consecutive cohort of nonselected children were studied. Patients were divided into groups by age, target international normalized ratio (INR) range, disease, medications, and vitamin K supplemented enteral nutrition use. Groups were analyzed on multiple aspects of warfarin therapy using multivariate methods. A total of 319 patients received 352 warfarin courses representing 391 treatment years. Age independently influenced all aspects of therapy. When compared with all older children, the </=1 year of age group required increased warfarin doses, longer overlap with heparin, longer time to achieve target INR ranges, more frequent INR testing and dose adjustments, and fewer INR values in the target range. Although significantly different than children </=1 year, children 1 to 6 years of age showed the same findings when compared with 7- to 18-year-olds. Fontan patients required 25% decreased dosage as compared with other congenital heart disease patients. Children on corticosteroids had less INRs in the target range and children on phenobarbital/carbamazepine required increased maintenance dosages of warfarin. Also, patients receiving enteral nutrition required increased dosages of warfarin. Serious bleeding occurred in 2 children (0.5% per patient year). Recurrent thromboembolic events (TEs) occurred in 8 children. Two children had recurrences while receiving warfarin (1.3% per patient year). This study outlines the profound effect of age and relative complexity of clinical management of warfarin therapy in children.

Adolescent↗
PubMed1999

An intervention to increase use and effectiveness of self-care measures for breast cancer chemotherapy patients.

Outpatient chemotherapy treatment shifts the managing of side effects from health care providers to patients and families. The primary purpose of this quasi-experimental study was to determine whether women who receive an intervention of three telephone calls and oral and written self-care measures for specific side effects will use more self-care measures and have higher effectiveness scores as measured by the Exercise of Self-Care Questionnaire (ESCQ) after treatment 4 than women who receive standard care. A second purpose was to determine if women scoring higher on the Exercise of Self-Care Agency (ESCA) Scale before chemotherapy used more and effective self-care measures during chemotherapy than women scoring lower on this scale. Forty-eight women beginning chemotherapy for breast cancer completed the ESCA pretreatment and were interviewed using the ESCQ during a sequence of therapy. The experimental group (n = 26) received additional self-care measures. Subjects with higher ESCA scores before chemotherapy treatment used more self-care measures to alleviate chemotherapy side effects. A telephone call and written self-care measures after the second, third, and fourth chemotherapy treatments did not increase use or effectiveness of self-care measures. The implications of assessing patients' self-care agency before chemotherapy are discussed and a nursing intervention recommended.

Adult↗
PubMed1999

Therapeutic efficacy of zeta-cypermethrin pour-on for the treatment of biting and sucking lice in cattle under field conditions.

OBJECTIVE: To assess the efficacy of zeta-cypermethrin pour-on to control cattle lice. DESIGN: Five field trials in south-eastern Australia. PROCEDURE: Zeta-cypermethrin pour-on, deltamethrin pour-on and pour-on vehicle were applied to groups of 10 cattle. Lice were counted before treatment and 14, 28, 42 and 56 days after treatment. RESULTS: Zeta-cypermethrin pour-on given at 2.5 mg/kg was equivalent to, or marginally more effective than a deltamethrin pour-on at 0.75 mg/kg. It eliminated B bovis and H eurysternus and gave good control of L vituli and S capillatus. Zeta-cypermethrin at 1 mg/kg gave good control of B bovis and H eurysternus but was not satisfactory against L vituli and S capillatus. CONCLUSION: Zeta-cypermethrin pour-on, given at 2.5 mg/kg, is an effective treatment for cattle lice control. Zeta-cypermethrin, and other synthetic pyrethroid pour-ons, are the treatment of choice to control B bovis.

Administration, Cutaneous↗
PubMed1999

Oklahoma physician needs.

State policy makers, healthcare professionals, and advocates have been asking various iterations of the question, Do we have too many or too few physicians? In order to address this question, a relative-needs analysis was conducted for the state of Oklahoma. Six projection-needs studies were used for comparison with Oklahoma's supply of practicing physicians. This analysis found that Oklahoma did not have a surplus of primary care physicians. While the national average for primary care physicians per 100,000 was 79, Oklahoma's ratio was 68. This analysis also compares not only the number of physicians in Oklahoma per 100,000 population, it also discusses the proportion of primary care physicians in the physician workforce. Primary care physicians were found to be neither oversupplied nor undersupplied in Oklahoma. Oklahoma was found to be closer to national planning model goals than most states in the United States. Because this study combines both allopathic and osteopathic physicians and includes only those physicians in active practice, it is unique in comparison to many other studies concerning physician workforce needs.

Family Practice↗
PubMed1998

Investigation of the anticoagulant mechanisms of a covalent antithrombin-heparin complex.

Recently, we developed a covalent antithrombin-heparin complex (ATH) as a possible treatment for respiratory distress syndrome. ATH reacted rapidly with thrombin and efficiently catalyzed the inhibition of either thrombin or factor Xa by exogenous antithrombin. In order to investigate mechanisms for the conjugate's unusual anticoagulant properties, changes in fluorescence due to covalent linkage or addition of exogenous antithrombin were studied in relation to reaction with thrombin derivatives or factor Xa. The emission spectrum of ATH was similar to that of antithrombin plus heparin mixtures. ATH quickly inhibited thrombin or factor Xa activities, as measured by a fluorogenic substrate. Fluorescein-labeled heparin was displaced from either thrombin or active site blocked thrombin by ATH, indicating that thrombin must bind to the conjugate's heparin moiety. Interaction of thrombin with ATH's heparin component was confirmed by a slow reaction rate of conjugate with a thrombin mutant that has weak heparin binding. Total intrinsic fluorescence increased when exogenous antithrombin was added to ATH, indicating that the catalytic mechanism may occur through a second inhibitor binding site. Thus, ATH reacts directly with thrombin through a bridge mechanism and probably catalyzes the reaction of thrombin with antithrombin by a second binding sequence on its heparin chain.

Anticoagulants↗
PubMed1998

Anticoagulant dermatan sulfate proteoglycan (decorin) in the term human placenta.

Normal pregnancy is characterized by increased in vivo thrombin generation. A greater proportion of endogenously generated thrombin is complexed to heparin cofactor II in plasma from pregnant women compared to plasma from nonpregnant ones. The increase in thrombin-heparin cofactor II complexes suggests that the site of the additional thrombin generation is relatively rich in dermatan sulfate. We postulated that the site of thrombin generation may be the placenta since endogenous thrombin generation returns rapidly to normal after delivery. This report describes the isolation and characterization of placental dermatan sulfate proteoglycan from villous tissue of the term human placenta. Placental dermatan sulfate was isolated by guanidine HCI extraction and anion exchange chromatography. The isolated material was found to have anticoagulant activity with a relative activity of approximately 40% of that of a porcine mucosal dermatan sulfate which is undergoing clinical trial as an antithrombotic agent. The dermatan sulfate was present as a proteoglycan with a molecular mass of 90-150 kD. Upon degradation with chondroitin ABC lyase, the core protein was demonstrated to be a doublet with molecular masses of 42 and 44 kD. This core protein reacted with antiserum against the core protein of decorin on Western analysis. The role of this placental dermatan sulfate in local regulation of thrombin in the placenta warrants further study.

Alcian Blue↗
PubMed1998

The dental problems and management of a patient suffering from congenital insensitivity to pain.

Congenital insensitivity to pain is a rare condition usually manifested in childhood by a history of unrecognized trauma, indifference to painful stimuli or self-mutilation. This paper describes the management of a 13-month-old male who had severely lacerated his tongue by habitually chewing it, using soft polyvinyl mouthguards retained with a minimal amount of denture fixative.

Dental Care for Children↗
PubMed1998

Effect of a novel covalent antithrombin-heparin complex on thrombin generation on fetal distal lung epithelium.

Respiratory distress syndrome is characterized by fibrin deposition in the lung. Fibrin adversely affects surfactant function and stimulates proliferation of fibroblasts. There is evidence that these properties may be important to the development of bronchopulmonary dysplasia. Despite successful initial treatment of neonatal respiratory distress syndrome with surfactant, the incidence of bronchopulmonary dysplasia has not decreased. In previous studies, it has been demonstrated that rat fetal distal lung epithelium (FDLE) possesses both procoagulant and anticoagulant properties. In this report, we have demonstrated (using factor VII-deficient plasma) that tissue factor is expressed on the FDLE surface and promotes thrombin generation. To regulate thrombin within this procoagulant environment, we have developed a novel anticoagulant, antithrombin-heparin covalent complex (ATH) that can be retained within the lung after intrapulmonary instillation. We have demonstrated that ATH was superior to antithrombin plus standard heparin in suppressing thrombin generation (P < 0.001) and prothrombin consumption (P < 0.01) in recalcified defibrinated plasma on the surface of FDLE. Further studies with ATH in vivo need to be performed.

Adult↗
PubMed1998

A placebo-controlled randomized trial of antithrombin therapy in neonatal respiratory distress syndrome.

Neonatal respiratory distress syndrome (RDS) is associated with decreased plasma activity of antithrombin (AT) and increased formation of thrombin. We tested whether AT reduces thrombin formation, improves gas exchange, and decreases the duration of mechanical ventilation and supplemental oxygen. One hundred twenty-two infants were randomized to pasteurized AT concentrate or to placebo. Two ml/kg (equivalent to 100 IU AT/kg) were followed by 1 ml/kg (50 IU/kg) every 6 h for 48 h. Outcome measures included plasma AT activity, thrombin-AT (TAT) complex, prothrombin fragment (F1+2), the ratio of arterial to alveolar oxygen pressure [(a/A)PO2], and the ventilator efficiency index (VEI). In the AT group (n = 61), mean (SD) birth weight was 1,198 (301) g, mean (SD) gestational age (GA) was 28.3 (2.0) wk, 54% were male. In the placebo group (n = 61), mean (SD) birth weight was 1,201 (315) g, mean (SD) GA was 28.8 (2. 3) wk, 51% were male. In treated infants, AT activity was raised to means of 1.69 and 2.25 U/ml at 24 and 48 h, respectively. Corresponding means in control infants were 0.37 and 0.44 U/ml (p < 0.0001). F1+2, but not TAT, was significantly reduced by AT (p = 0. 004). VEI and (a/A)PO2 were similar in both groups throughout the first week of life. Median days receiving mechanical ventilation were 7.1 (AT) versus 4.8 (placebo), p = 0.0014. Median days receiving supplemental oxygen were 7.9 (AT) versus 5.5 (placebo), p < 0.0001. There were seven (11.5%) deaths in the AT group and three (4.9%) deaths in the placebo group. We conclude that treatment with AT cannot be recommended in premature infants with RDS.

Antithrombin III↗