Bilateral pneumothoraces following a bungee jump in a patient with cystic fibrosis.
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Biomedical subjects
Publications and source records attributed to P Logan.
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BACKGROUND AND PURPOSE: Trials of occupational therapy for stroke patients living in the community have varied in their findings. It is unclear why these discrepancies have occurred. METHODS: Trials were identified from searches of the Cochrane Library and other sources. The primary outcome measure was the Nottingham Extended Activities of Daily Living (NEADL) score at the end of intervention. Secondary outcome measures included the Barthel Index or the Rivermead ADL (Personal ADL), General Health Questionnaire (GHQ), Nottingham Leisure Questionnaire (NLQ), and death. Data were analyzed using linear or logistic regression with a random effect for trial and adjustment for age, gender, baseline dependency, and method of follow-up. Subgroup analyses compared any occupational therapy intervention with control. RESULTS: We included 8 single-blind randomized controlled trials incorporating 1143 patients. Occupational therapy was associated with higher NEADL scores at the end of intervention (weighted mean difference [WMD], 1.30 points, 95% confidence intervals [CI], 0.47 to 2.13) and higher leisure scores at the end of intervention (WMD, 1.51 points; 95% CI, 0.24 to 2.79). Occupational therapy emphasizing activities of daily living (ADL) was associated with improved end of intervention NEADL (WMD, 1.61 points; 95% CI, 0.72 to 2.49) and personal activities of daily living (odds ratio [OR], 0.65; 95% CI, 0.46 to 0.91), but not NLQ. Leisure-based occupational therapy improved end of intervention NLQ (WMD, 1.96 points; 95% CI, 0.27 to 3.66) but not NEADL or PADL. CONCLUSIONS: Community occupational therapy significantly improved personal and extended activities of daily living and leisure activity in patients with stroke. Better outcomes were found with targeted interventions.
A 21-year-old man presented with severe corneal cystinosis and steroid-related cataract bilaterally. Rather than combined cataract surgery and penetrating keratoplasty, the patient had uneventful phacoemulsification and intraocular lens implantation after which visual acuity improved to 66 in both eyes. The outcome indicates that conventional phacoemulsification is sufficient in these cases. A guarded prognosis is advised in patients with cystinosis having cataract surgery as the fundal view is often impaired and there may be associated maculopathy.
Concerns have been raised about the morality of using simulated altitude facilities in an attempt to improve athletic performance. One assumption that has been influential in this debate is the belief that altitude houses simply mimic the physiological effects of illegal recombinant human erythropoietin (r-HuEpo) doping. To test the validity of this assumption, the haematological and physiological responses of 23 well-trained athletes exposed to a simulated altitude of 2650-3000 m for 11-23 nights were contrasted with those of healthy volunteers receiving a low dose (150 IU x kg(-1) per week) of r-HuEpo for 25 days. Serial blood samples were analysed for serum erythropoietin and percent reticulocytes; maximal oxygen uptake (VO2max) was assessed before and after r-HuEpo administration or simulated altitude exposure. The group mean increase in serum erythropoietin (422% for r-HuEpo vs 59% for simulated altitude), percent reticulocytes (89% vs 30%) and VO2max (6.6% vs -2.0%) indicated that simulated altitude did not induce the changes obtained with r-HuEpo administration. Based on the disparity of these responses, we conclude that simulated altitude facilities should not be considered unethical based solely on the tenet that they provide an alternative means of obtaining the benefits sought by illegal r-HuEpo doping.
Dyslipidemia is a significant risk factor for the progression of cardiovascular disease, particularly when associated with other risk factors. An understanding of the pathophysiology and risks for patients with atherosclerotic diseases of undertreated dyslipidemia is essential for the healthcare provider. In this article, a review of epidemiologic data regarding the role of lipid levels in cardiovascular disease prognosis is presented. A familiarity with current dietary and drug treatment of lipid disorders is at the core of an evidence-based approach to dyslipidemia management in the patient with established cardiovascular diseases.
This investigation evaluated the effects of oral beta-hydroxy-beta-methylbutyrate (HMB) supplementation on training responses in resistance-trained male athletes who were randomly administered HMB in standard encapsulation (SH), HMB in time release capsule (TRH), or placebo (P) in a double-blind fashion. Subjects ingested 3 g x day(-1) of HMB or placebo for 6 weeks. Tests were conducted pre-supplementation and following 3 and 6 weeks of supplementation. The testing battery assessed body mass, body composition (using dual energy x-ray absorptiometry), and 3-repetition maximum isoinertial strength, plus biochemical parameters, including markers of muscle damage and muscle protein turnover. While the training and dietary intervention of the investigation resulted in significant strength gains (p < .001) and an increase in total lean mass (p = .01), HMB administration had no influence on these variables. Likewise, biochemical markers of muscle protein turnover and muscle damage were also unaffected by HMB supplementation. The data indicate that 6 weeks of HMB supplementation in either SH or TRH form does not influence changes in strength and body composition in response to resistance training in strength-trained athletes.
BACKGROUND: There were 783 recreational boating fatalities in the United States in 1994. One contributor to this toll is alcohol-influenced operation of boats. Our study objective was to determine the prevalence of alcohol-influenced motor boat operation, and describe its relationship to demographic factors and other risk behaviors. METHODS: In 1994, a randomly dialed national telephone survey contacted 5238 adult respondents who reported on their operation of motor boats, alcohol use, and other potential injury risk behaviors. Data were weighted to obtain national estimates and percentages. RESULTS: Of 597 respondents who operated a motor boat in 1994, 31% (206 respondents) reported doing so at least once while alcohol-influenced. Alcohol-influenced operation of a motor boat was significantly more likely among males, individuals between 25 and 34 years of age, and those with greater than a college education. Alcohol-influenced motor boat operation was also more common among those who drove motor vehicles while alcohol-influenced, and those who drove a motor vehicle without using a seat belt. CONCLUSIONS: To decrease alcohol-influenced boating, new strategies should be developed. Strategies used to decrease drinking and driving motor vehicles may prove adaptable to preventing alcohol-influenced boating. More effective means of monitoring alcohol-influenced boating is needed. Alcohol use by passengers on boats should not be overlooked as a problem.
Frequently, patients undergoing complex bone reconstructions for the treatment of osteomyelitis complicating tibial nonunion require extended exoskeletal support. Once the need for strict, continuous cast immobilization has passed, the patient can be fitted with a removable orthosis. Although prefabricated ankle foot orthoses are available, the purpose of this paper is to highlight the sophisticated new custom orthotic options available to the physician for the patient. Difficult to fit limbs now can be accommodated. Access to a skilled orthotist is the sine qua non of success.
Below the knee amputation after trauma is an appropriate option for many patients with recalcitrant infection and nonunion of the tibia. Patients who have had transtibial amputations have lower energy expenditure, heart rate, and oxygen cost when ambulating with their prostheses than when using a three-point gait with crutches without their artificial limb. Innovative prosthetists have improved each of the five essential components of the limb amputated below the knee: socket, insert, shaft and pylon, foot and ankle assembly, and suspension system. Prosthetists are integral members of the patient's healthcare team. Their recommendations and direct patient care are essential to optimizing the functional ability of patients who have had amputations.
AIM: To analyse the risk factors involved in the development of ocular complications after acoustic neuroma resection, in particular corneal complications and visual loss, and to identify measures that may reduce these. METHODS: 62 patients who underwent surgery for acoustic neuroma had a standardised ophthalmic examination and retrospective case note review. RESULTS: At final review (mean 37.6 months), although 38 patients reported ocular symptoms, only 22% saw 6/12 or worse. Patients with hypoaesthetic corneas had a higher incidence of corneal pathology (79%) than those with normal sensation (39%). Lagophthalmos increased the incidence of corneal pathology (to 80%); in those with normal closure, the incidence was only 46%. 20 patients required at least one ophthalmic surgical procedure. CONCLUSIONS: After acoustic neuroma resection patients place a considerable burden on the ophthalmologist. Immediate referral postoperatively, and frequent review of those with abnormal sensation may reduce the severity of long term ocular complications.
PURPOSE: A phase I study of vincristine encapsulated inside 120-nm-diameter distearoylphosphatidylcholine-cholesterol liposomes was performed. The primary objectives were to determine the maximum-tolerated dose (MTD), recommended phase II dose, toxicity, and pharmacokinetics of liposomal vincristine (ONCO-TCS). PATIENTS AND METHODS: Twenty-five patients with histologically confirmed malignancies were enrolled and assessable. Vincristine doses were increased from 0.5 mg/m2 to 1.0, 1.5, 2.0, 2.4, and 2.8 mg/m2 with cohorts of three or more patients per dose level. A total of 64 courses of ONCO-TCS were administered intravenously once every 3 weeks. The pharmacokinetics of total vincristine content in plasma were determined using a high-performance liquid chromatography method. RESULTS: Patients were treated with vincristine doses up to 2.8 mg/m2; however, 2.4 mg/m2 was defined as the MTD and 2.0 mg/m2 as the phase II recommended dose. Pain and obstipation were the dose-limiting toxicites. Other toxicities were fever, rigors, fatigue, myalgias, and peripheral neuropathy. Hematologic toxicity was mild. All patients who were treated with doses above 1.5 mg/m2 received in excess of 2.0 mg of vincristine, with doses as high as 6.2 mg. One partial response was seen in a patient with pancreatic cancer. Tumor response not meeting partial response criteria was seen in two other patients. Pharmacokinetic studies revealed significantly elevated concentrations of total vincristine, but parameters varied and were not directly correlated with toxicity or response. CONCLUSION: The ability to administer elevated doses of vincristine, as well as indications of efficacy, suggests that ONCO-TCS warrants further clinical investigation in a phase II setting.
The pharmacokinetic behavior of vincristine sulfate (VINC) following administration of vincristine sulfate liposome injection (VSLI), 0.16 mg/ml, as an intravenous infusion over 60 min in 24 of 25 patients enrolled in a phase I clinical study of this drug is described. Plasma samples for determination of the pharmacokinetic behavior of VINC were collected during the infusion at 15, 30 and 60 min as well as at 2, 4, 8, 12, 48 and 72 h postinfusion. Total VINC concentration was determined using a validated high-performance liquid chromatographic (HPLC) assay. Patients receiving doses of 0.5 to 1.5 mg/m2 VSLI did not provide useful pharmacokinetic data at late time-points owing to the limit of quantitation of the HPLC assay (28.6 ng/ml). Sufficient concentration-time data were available for seven of the patients receiving doses of VSLI from 2.0 to 2.8 mg/m2 for compartmental modelling. A two-compartment open model (PCNONLIN Model 10) was the best fit for the observed VINC plasma data for these patients. The mean maximum observed concentration values were significantly greater for patients receiving VSLI at 2.8 mg/m2 (2260 +/- 212 ng/ml, n = 2) than for those receiving 2.0 mg/m2 and 2.4 mg/m2 (891 +/- 671 ng/ml, n = 6; 679 +/- 634 ng/ml, n = 6, respectively). No significant differences were observed in maximum concentration values between patients at 2.0 mg/m2 and those at 2.4 mg/m2. A trend towards higher parametric AUC (0 to infinity) values with increasing dose (on a milligram per meter squared basis) was observed but statistical significance was not reached. Comparison of the pharmacokinetic behavior of VSLI observed in this study with nonencapsulated VINC demonstrated that (1) the variability observed for VSLI pharmacokinetic parameters was similar to nonencapsulated VINC, (2) although variability in absolute concentration was observed between patients, the behavior of VSLI in individual patients followed a two- rather than a three-compartment open model, and (3) VINC plasma concentrations were significantly greater following administration of VSLI than described for nonencapsulated VINC. Overall, the results for patients treated with VSLI from 2.0 to 2.8 mg/m2 suggest that this formulation protects VINC from the early phase of rapid elimination seen with nonencapsulated drug, resulting in significantly elevated VINC plasma concentrations over extended periods of time.
PURPOSE: To establish the pharmacodynamic relationships between drug biodistribution and drug toxicity/efficacy, a comprehensive preclinical evaluation of sphingomyelin/cholesterol (SM/chol) liposomal vincristine and unencapsulated vincristine in mice was undertaken. METHODS: Pharmaceutically acceptable formulations of unencapsulated vincristine and liposomal vincristine at drug/lipid ratios of 0.05 or 0.10 (wt/wt) were evaluated for toxicity, antitumor activity and pharmacokinetics following intravenous administration. RESULTS: Mice given liposomal vincristine at 2 mg/kg vincristine had concentrations of vincristine in blood and plasma at least two orders of magnitude greater then those achieved after an identical dose of unencapsulated drug. One day after administration of the liposomal vincristine, there were at least tenfold greater drug quantities, relative to unencapsulated vincristine, in the axillary lymph nodes, heart, inguinal lymph nodes, kidney, liver, skin, small intestines and spleen. Increased plasma and tissue exposure to vincristine as a result of encapsulation in SM/chol liposomes was not associated with increased drug toxicities. Treatment of the murine P388 ascitic tumor with a single intravenous dose of unencapsulated drug at 2, 3 and 4 mg/kg, initiated 1 day after tumor cell inoculation, resulted in a 33 to 38% increase in lifespan. In contrast, long-term survival rates of 50% or more were achieved in all groups treated with the SM/chol liposomal vincristine formulations at doses of 2, 3 and 4 mg/kg. At the 4 mg/kg dose, eight of ten and nine of ten animals survived past day 60 when treated with SM/chol liposomal vincristine prepared at the 0.05 and 0.1 drug/lipid ratios, respectively. CONCLUSIONS: Overall, increased and prolonged plasma concentrations of vincristine achieved by liposomal encapsulation were correlated with dramatically increased antitumor activity in comparison with the unencapsulated drug, but no correlations could be established between pharmacokinetic parameters and toxicity.
The fluoroquinolone antibiotic ciprofloxacin has been encapsulated into large unilamellar vesicles (LUV) at efficiencies approaching 100%. Drug accumulation proceeded in response to a transmembrane gradient of methylammonium sulfate and occurred concomitantly with the efflux of methylamine. A mechanism for the encapsulation process is described. LUV composed of dipalmitoylphosphatidylcholine-cholesterol (DPPC/chol), distearoylphosphatidylcholine-cholesterol (DSPC/chol), or sphingomyelin-cholesterol (SM/chol) increased the circulation lifetime of ciprofloxacin after intravenous (i.v.) administration by > 15-fold. The retention of ciprofloxacin in liposomes in the circulation decreased in the sequence SM/chol > DSPC/chol > DPPC/chol. Increased circulation lifetimes were associated with enhanced delivery of the drug to the livers, spleens, kidneys, and lungs of mice. Encapsulation of ciprofloxacin also conferred significant increases in the longevity of the drug in the plasma after intraperitoneal administration and in the lungs after intratracheal administration in comparison to free ciprofloxacin. The efficacy of a single i.v. administration of an SM/chol formulation of ciprofloxacin was measured in a Salmonella typhimurium infection model. At 20 mg of ciprofloxacin per kg of body weight, the encapsulated formulation resulted in 10(3)- to 10(4)-fold fewer viable bacteria in the livers and spleens of infected mice than was observed for animals treated with free ciprofloxacin. These results show the utility of liposomal encapsulation of ciprofloxacin in improving the pharmacokinetics, biodistribution, and antibacterial efficacy of the antibiotic. In addition, these formulations are well suited for i.v., intraperitoneal, and intratracheal or aerosol administration.
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OBJECTIVE: To determine the effect of a bicycle helmet giveaway program on helmet use among children. METHODS: In 1995, a bicycle helmet giveaway program was conducted in two rural towns in Texas. Helmets were given to all 403 school children in kindergarten through grade 8. Helmet education, a bicycle rodeo, and incentives to increase helmet use were part of the program. Observations of helmet use were made before the helmet program began and after the program at several intervals throughout the school year and during the summer. A self-reported survey questionnaire was administered to children in grades 4 through 8 before the helmet program began and at several intervals during the school year to determine their attitudes about helmet use, safety perceptions, and peer pressure. A questionnaire also was administered to the parents of these children to determine attitudes and bicycle helmet use among parents. RESULTS: Helmet use increased from 3% before the giveaway to 38% at the end of the school year, 7 months later. However, during the subsequent summer, helmet use decreased to 5%. Helmet use among 7th- and 8th-grade students was 0% at all observations periods after the giveaway. Even though 96% of all students thought that helmet use increased riding safety and 68% thought helmets should be worn at all times when riding, only 25% thought that their friends would approve of helmet use. Most parents also believed that helmets increased riding safety and should be worn, but only 23% reported always wearing one when riding a bicycle. CONCLUSIONS: Bicycle helmet giveaway programs can increase helmet use temporarily, but they may not be sufficient to sustain it. This program was not effective among 7th- and 8th-grade students.
OBJECTIVES: To determine the prevalence of proper fencing around outdoor swimming pools among US households and to describe this fencing in relation to demographic and other household factors. To estimate the number of drownings among children <5 years of age that might be prevented by having proper fencing around all residential pools in the United States. METHODS: A 1994, randomly dialed national telephone survey contacted 5238 adults who reported demographic information and household characteristics including whether the household had an outdoor swimming pool and the fencing around the pool. Data were weighted to obtain national estimates and percentages. The number of preventable drownings was estimated with a population-attributable risk equation. RESULTS: Approximately 18.5 million American households owned or had access to an outdoor swimming pool in 1994, and 76% (13.9 million) of them appeared to have had adequate fencing. Adequate fencing was associated with household income and type of home. We estimate that 19% of pool-related drownings among children <5 years of age in 1994 (88 drownings) might have been prevented if all residential pools in the United States were properly fenced. CONCLUSIONS: Adequate pool fencing prevents a child from having access to a swimming pool if a responsible adult is not present and has been promoted as a method to prevent drowning. Our research suggests that even if all residential pools in the United States were properly fenced, most drownings among children <5 years of age would not be prevented. Thus, additional strategies to prevent drowning will be needed.
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