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Biomedical subjects

B Lewis

Publications and source records attributed to B Lewis.

At least 91 records · Page 5Linked to original sources

Relationships between nutrient intake and progression/regression of coronary atherosclerosis as assessed by serial quantitative angiography.

To elucidate the direction and magnitude of effects of nutrition on coronary artery disease (CAD), the relation between nutrient intake and angiographic changes were examined in the course of a controlled dietary trial. Ninety men with symptomatic CAD and serum cholesterol greater than 232 mg/dL were entered into a randomized controlled trial of a lipid-lowering diet, or of diet plus cholestyramine, compared with usual cardiac care. Of those in the first and second groups, 50 patients completed the trial and are the subject of this report. Quantitative coronary angiography was performed at baseline and at 39 months. From repeated dietary assessment during the trial, mean nutrient intakes were computed, and their relationships with change of coronary artery narrowing were analyzed. Progression of coronary disease was directly, strongly and independently associated with intake of saturated fatty acids of chain length 14-18. This was not fully explained by the effects of saturated fat in raising serum cholesterol; after adjustment for low density lipoprotein cholesterol level, stearic acid (C18:0) intake remained independently predictive of progression. No 'protective' effect of linoleic, linolenic or eicosapentaenoic acid was demonstrable. Intake of trans fatty acids was directly related to progression. Together with the favourable treatment effects on angiographic appearance and clinical end-points, these findings provide further support for a causal role of saturated fats in CAD; restriction of foods containing such fats should be emphasized as part of regimens aimed to reduce progression of coronary atherosclerosis.

Adult↗

Hiring and selection: the Australian experience.

The Australian health care system has forced fundamental changes in expectations of leaders and management competencies required to thrive in a cost-constrained environment. By learning from the Australian experience, US managers can incorporate new ideas into reshaping our future leaders.

Australia↗

Successful treatment of heparin-associated thrombocytopenia and thrombosis using Hirulog.

Heparin-associated thrombocytopenia is a serious medical problem, especially when the patient requires continued anticoagulation. Hirulog is an immediate-acting intravenous anticoagulant that can be substituted for heparin. A new use of Hirulog in the treatment of life-threatening heparin-associated thrombocytopenia with thrombosis (HATT) is presented. Two patients suffering from the HATT syndrome were successfully treated with Hirulog to prevent further thrombosis. A third patient had developed heparin-associated thrombocytopenia after coronary artery bypass surgery in the past and was subsequently treated with Hirulog during a peripheral angioplasty procedure. Hirulog was an effective and predictable anticoagulant for these patients and was free from adverse effects.

Aged↗

A coordinated, communitywide program in Monroe County, New York, to increase influenza immunization rates in the elderly.

BACKGROUND: Despite the efficacy of influenza vaccination in preventing complications of influenza, rates of immunization among high-risk populations remain low. The Monroe County (New York) Influenza Vaccination Demonstration was a communitywide, collaborative effort to increase the rates of influenza immunization to greater than 60% in elderly Medicare recipients. METHODS: The local health department, university medical center, and practicing physicians collaborated to develop a communitywide demonstration directed to all Medicare part B enrollees 65 years of age or older, multiple coordinated approaches were used over a 4-year period (1988 to 1992). Most providers, including public agencies, private providers, hospital outpatient facilities, nursing homes, and insurance providers, were enrolled in a comprehensive program that included centralized claims processing, vaccine distribution and promotion, and extensive provider and public education efforts, including a special urban outreach program. An office-based, denominator-driven physician incentive project was also evaluated. RESULTS: The demonstration project resulted in a 1991 influenza immunization rate of 74.3% among 88,811 Medicare enrollees 65 years of age or older. The increase in immunization rate occurred primarily among the patients of private physicians. CONCLUSION: A communitywide, collaborative approach can succeed in achieving high rates of influenza immunization.

Aged↗

Nutrient intake and progression of coronary artery disease.

The relation between nutrient intake and progression of coronary artery disease was examined in 50 men receiving a lipid-lowering diet or usual care in the St. Thomas' Atherosclerosis Regression Study. Nutrient intake was assessed by diet history. Changes in coronary angiograms were measured by quantitative image analysis. In univariate linear regression analysis progression of disease over 39 months, as measured by decrease in minimum absolute width of coronary segments, was directly related to dietary energy (p < 0.001) and to the absolute intakes of total fat (p < 0.001), saturated fat (p < 0.001), monounsaturated fat (p = 0.016) and cholesterol (p = 0.06). No significant associations were seen with polyunsaturated fat, carbohydrate, protein, fiber, alcohol or with the ratio of intakes of polyunsaturated fatty acids to saturated fatty acids. In multiple linear regression analysis the associations of change in minimum absolute width of coronary segments with total or saturated fat persisted when adjusted for plasma low-density lipoprotein cholesterol concentration, age, weight, blood pressure, smoking or treatment group assignment. The findings suggest that in middle-aged men, progression of CAD is strongly influenced by intake of saturated fatty acids, an effect mediated in part by mechanisms other than the influence of this nutrient on plasma cholesterol and low-density lipoprotein cholesterol.

Basal Metabolism↗

Treponematosis and Lyme borreliosis connections: explanation for Tchefuncte disease syndromes?

A convergence of evidence from macroscopic, radiographic and histologic examination indicates that treponemal infection was present in the 16ST1 Tchefuncte Indian burial population, dated 500 B.C. to 300 A.D. Pattern and nature of lesions suggests that chronic infection induced by variants of the spirochete Treponema pallidum, causing endemic syphilis and/or yaws, resulted in third-stage osseous response. It is suggested that Tchefuncte Indians acquired partial immunity to treponemal infection by exposure to a variant of the related spirochete, Borrelia burgdorferi, the causative agent of Lyme disease. Partial immunity would help explain the relatively mild expression of the treponemal disease process in the 16ST1 skeletal population and the apparent absence of venereal syphilis. Presence of the Borrelia burgdorferi spirochete might be linked to a single incidence of juvenile rheumatoid arthritis.

Arthritis, Juvenile↗

Ergot induced peripheral vascular insufficiency, non-interventional treatment.

We report a case of ergotamine tartrate induced severe vasospasm in the renal arteries and the arteries of the lower extremities. Classic features seen on peripheral angiography make the diagnosis. Anticoagulation, thrombolysis, vasodilation, steroids, and prostaglandin inhibitors all have been successfully used to treat symptomatic ergot induced arterial vasospasm. Although balloon angioplasty of ergot induced vasospasm has been described in case reports, ergot vasospasm is a self limited and medically treatable condition that does not require peripheral mechanical intervention, unless the immediate threat of necrosis and gangrene exists.

Adult↗

Recovery of neuromuscular function after atracurium and pancuronium maintenance of pancuronium block.

The study was undertaken to determine whether a neuromuscular blockade induced with pancuronium but maintained with atracurium was associated with a shorter time to complete recovery after administration of neostigmine than if the blockade was maintained with pancuronium alone. Anaesthesia consisted of thiopentone, N2O/O2/enflurane and fentanyl, and the neuromuscular blockade, induced by pancuronium 0.1 mg.kg-1 was monitored by the force of contraction of adductor pollicis during major abdominal surgery lasting 2-5 hr. In 24 patients--Group 1--atracurium 0.07 mg.kg-1 was repeated when the first twitch of the train-of-four (TOF) returned to 25% of control (T1/TC 25). In 28 patients--Group 2--pancuronium 0.015 mg.kg-1 was given at similar recovery of T1/TC. At the end of surgery, neostigmine 0.07 mg.kg-1 and glycopyrolate 0.015 mg.kg-1 were given to reverse the residual neuromuscular blockade which was indicated by a T1/TC of less than 25% in all patients. The time from injection of the reversal drugs to a TOF ratio of 70% was similar in both groups (Group 1, 11.6 +/- 7.6 min; Group 2, 10.1 +/- 6 min; P = NS), but the recovery index was smaller in Group 2 (Group 1, 4 +/- 2.6 min; Group 2, 2.61 +/- 1.2 min; P < 0.05). Furthermore, there was no difference between groups in the duration of action of each redose. The study showed that when compared with pancuronium, equipotent doses of atracurium were not associated with (a) a shorter time to complete recovery from a neuromuscular blockade induced with pancuronium or (b) a shorter duration of action.

Adult↗

Regional fat distribution by dual-energy X-ray absorptiometry: comparison with anthropometry and application in a clinical trial of growth hormone and exercise.

1. The purpose of this study was to determine the suitability of ratios derived from dual-energy X-ray absorptiometry (DXA) whole body scans to assess regional fat distribution in older men and women by comparing them with the waist-to-hip ratio (WHR) and to evaluate their clinical utility by applying them in a clinical trial involving resistance exercise and recombinant human growth hormone. 2. Sixty-four healthy older adults (39 women and 25 men), aged 65-82 years, served as subjects. The ratios of trunk fat-to-total fat, trunk fat-to-body weight, trunk fat-to-limb fat and trunk fat % were determined by DXA. WHR was assessed on the same day, as was the ratio of subscapular/triceps skinfolds in men. Cardiovascular disease risk factors, functional capacity and serum lipids were also assessed. 3. A moderate relationship (r = 0.36-0.54) between the WHR- and DXA-derived ratios were observed for both men and women. Both DXA and WHR showed similar associations with cardiovascular disease risk factors. However, in men, all DXA ratios were able to detect subtle changes in regional fat distribution resulting from daily administration of recombinant human growth hormone in conjunction with resistance exercise for 10 weeks, whereas the WHR or subscapular/triceps ratios did not. 4. This suggests that DXA-derived ratios may be more sensitive than conventional anthropometric methods in the assessment and categorization of body fat distribution.

Absorptiometry, Photon↗

The comparative analgesic efficacy of transcutaneous electrical nerve stimulation and a non-steroidal anti-inflammatory drug for painful osteoarthritis.

Thirty-six non-hospitalized subjects with chronic pain from OA of the knee participated in an evaluation of transcutaneous electrical nerve stimulation (TENS) and naproxen, an NSAID. All pre-experiment treatment was withdrawn. Each subject experienced in some order three 3-week treatment phases: NSAID plus placebo TENS; TENS plus placebo drug; and double placebo. A broad range of pain measures was used, including daily diary ratings, and four-times-per-day ratings entered into a small electronic data logger (the PIPER) worn by the subject. A substantial placebo response occurred across all conditions, which may have masked treatment differences. Broad comparisons across subjects, combining the four main measures of pain, found no significant differences among the three experimental treatments. Analysis of diary and PIPER data for individuals suggested that, in a small minority of subjects, the NSAID plus placebo TENS combination may be more effective than double placebo. The PIPER ratings seemed to tap aspects of the pain experience different from those captured by conventional measures, suggesting the value of very frequent pain assessments, such as those entered by a subject into the PIPER, in the study of chronic pain.

Adult↗

Quantifying the effect of hand preference on upper limb bone mineral and soft tissue composition in young and elderly women by dual-energy X-ray absorptiometry.

The purpose of this study was to quantify the effect that hand preference has on upper limb bone mineral and soft tissue composition in healthy young and elderly women. Bone mineral content (BMC) in grams, bone mineral density (BMD) in g cm-2, fat-free soft tissue (FFST) in grams, fat tissue (g), and percent fat were determined by dual-energy X-ray absorptiometry (DXA) for dominant and non-dominant upper limbs as well as total body fat (%) in 25 young (26.6 +/- 4.3 years, mean +/- SD) and 35 elderly women (68.4 +/- 2.9 years). For both groups, the dominant upper limb had a greater BMC (P < 0.001), BMD (young, P < 0.001; elderly, P < 0.05), and FFST mass (P < 0.001), and a lower percent fat (young, P < 0.01; elderly, P < 0.05) than the non-dominant limb; however, there was no difference between limbs for total fat mass. BMC, BMD, and FFST in the dominant limb of young women were 7.1%, 1.8%, and 5.1% greater than the non-dominant limb, while for older women the differences were 5.3%, 1.0%, and 4.2%. Relative fat of the dominant limb was 3.0% and 1.3% less than the non-dominant limb for young and older women, respectively. Age did not affect the percent bone mineral or soft tissue difference. A higher bone mineral and FFST mass in the dominant limb is expected due to the greater activity demands placed upon these tissues. However, a larger bone and FFST mass increases the total mass of the dominant limb, resulting in a dilution of the fat tissue mass and hence a reduced fat percent for the limb. This study indicates that hand preference affects the tissue composition of the upper limb in both young and elderly women, resulting in an increased bone mineral and FFST mass with no change in absolute fat mass. Hand preference should be taken into account when upper limb bone mineral and/or soft tissue composition is assessed.

Absorptiometry, Photon↗

Psychotherapy, neuroscience, and philosophy of mind.

Neuroscience is conceptually founded on a philosophy of mind known as identity theory. This theory claims that mental phenomena are reducible to the physical organ of the brain. But identity theory, and consequentially neuroscience, is unable to address essential human features of intentionality, consciousness, and autonomy, i.e., free will. Intentionally is the quality of having content or "aboutness," consciousness is quality of self-awareness, and autonomy is the ability to make undetermined choices. These essential human features make up our common sense and our psychodynamic understanding of ourselves. Without these features we would have to change our entire way of seeing ourselves and our dynamic psychotherapy would be impossible. We need intentionality in psychotherapy because it is only through the content of our patients' thoughts and feelings that we can help them derive meaning; we need consciousness because it is primarily through introspection that we get access to our patients' inner world; and we need autonomy because unless our patients have the option of doing things differently there is no point to the therapeutic endeavor. Consequently, psychiatry cannot rely solely on neuroscience as its basic science without creating a conception of people devoid of essential human features and without eviscerating its psychotherapeutic capacity.

Awareness↗

Isolated glycerol kinase deficiency in a neonate.

Glycerol kinase deficiency occurs either as a relatively benign isolated enzyme deficiency, or as part of a syndrome resulting from a microdeletion in the p21 region of the X chromosome associated with congenital adrenal hypoplasia and/or Duchenne muscular dystrophy. Developmental delay is a consistent feature of the microdeletion syndrome but not of the isolated enzyme defect. We report a case of isolated glycerol kinase deficiency in a neonate presenting with hypotonia, apnea, mild developmental delay, and glyceroluria, without evidence of adrenal insufficiency or myopathy. A mild communicating hydrocephalus was noted on magnetic resonance imaging brain scan. It is important, therefore, to exclude glyceroluria in infants being investigated for apnea and hypotonia.

Apnea↗

Radioimmunoassay of hair for determination of cocaine, heroin, and marijuana exposure: comparison with self-report.

Radioimmunoassay of hair (RIAH) was compared with self-report for cocaine, heroin, and marijuana in two populations: 109 persons entering residential drug user treatment and 86 at follow-up posttreatment. Among treatment entrants, 89% of 87 RIAH cocaine-positives and 96% of 45 RIAH heroin-positives were confirmed by self-report. However, among those followed-up posttreatment, only 51% of 43 RIAH cocaine-positives and 67% of 18 RIAH heroin-positives were so confirmed. Whereas 95% of 104 self-reports of cocaine use in the combined population were confirmed by RIAH, only 69% of 80 self-reports of heroin use were. Self-report and RIAH for marijuana were weakly associated.

Adolescent↗

Atropine and ephedrine adsorption to syringe plastic.

The purpose of this study was to compare daily changes in the concentration of atropine or ephedrine sulfate solutions that had been stored up to 4 days in plastic or glass syringes. Sets of three plastic and one glass syringe were used for each drug; the glass syringes acted as controls. Each set of syringes was labeled as day 0, 1, 2, 3, or 4. Syringes with medication were laid horizontally, had needles attached, and were stored in the dark at an ambient temperature. Each day, the assigned set of syringes was analyzed by high-performance liquid chromatography. Results showed that the change in the ephedrine sulfate concentration in the plastic syringes from day 0 to day 4 was less than 1.4%. Atropine sulfate decreased 52% over 4 days, with the largest single drop occurring during the first 24 hours. It can be concluded that the two brands of ephedrine sulfate stored up to 4 days at ambient temperature in the brand of syringe used do not significantly decrease in concentration. However, this was not the case with the brand of atropine sulfate studied. The practice of storing atropine sulfate in plastic syringes should be discouraged, because of the possibility of loss of potency due to medication adsorption to syringe plastic.

Adsorption↗

Metabolic determinants of the course of coronary artery disease in men.

We examined associations between metabolic variables and changes in coronary artery disease (CAD) in the St. Thomas' Atherosclerosis Regression Study (STARS). The course of CAD over 3 years was measured continually by quantitative coronary angiography, i.e., as the per patient change in the mean absolute width of coronary segments (delta MAWS). The decrease in MAWS (progression of CAD) was significantly correlated with in-trial plasma concentrations of cholesterol (P = 0.002), low-density lipoprotein (LDL) cholesterol (P = 0.001), apolipoprotein B (apoB) (P = 0.008), and lipoprotein(a) [Lp(a)] (P = 0.004); no significant associations were found with high-density lipoprotein (HDL) cholesterol, apoA-I, vitamin E, thyroid hormones, fibrinogen, von Willebrand factor, or post-load plasma glucose and insulin concentrations. By multiple regression analysis, LDL cholesterol was the best predictor of delta MAWS, the adjusted model explaining 22% of the variance (P = 0.04). Thus, in men with symptomatic CAD the most important metabolic predictor of change in CAD is plasma LDL cholesterol, there being no advantage in measuring other variables, in particular, apoB or Lp(a).

Adult↗