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Biomedical subjects

A Morton

Publications and source records attributed to A Morton.

At least 55 records · Page 3Linked to original sources
PubMed1994

Sleep hypoxia in myotonic dystrophy and its correlation with awake respiratory function.

BACKGROUND: Tiredness and daytime respiratory failure occur frequently in myotonic dystrophy. Sleep hypoxaemia was studied in 12 patients with myotonic dystrophy and correlations were sought with their daytime lung and respiratory muscle function. METHODS: All patients underwent overnight sleep studies, clinical assessment, measurement of flow-volume loops and carbon monoxide transfer factor, arterial blood gas analysis, and physiological assessment of both thoracic muscle function and upper airways obstruction. RESULTS: The mean nadir of oxygen saturation during sleep was 75% (95% confidence interval 69% to 81%). A mean of 3.4% of total sleep duration was spent at an oxygen saturation level below 85%. Five of the 12 patients had an apnoea index of > 5, the group mean apnoea/hypopnoea index being 15.8 events/sleep hour. The mean awake arterial oxygen tension (PaO2) was 10.7 kPa. There was a trend to hypercapnoea with a mean awake arterial carbon dioxide tension of 6.1 kPa; carbon dioxide retention worsened during sleep. Respiratory muscle dysfunction was mainly evident as a low maximum expiratory mouth pressure. Upper airway obstruction assessed by physiological criteria was found in four of the 12 patients. The proportion of total sleep duration with oxygen saturation levels below 85% was directly related to body mass index (weight/height2) and inversely related to the awake PaO2. Body mass index was inversely related to the overnight nadir of oxygen saturation. CONCLUSIONS: Patients with myotonic dystrophy are often hypoxic during sleep and the subgroup that are obese, or have symptoms of sleep apnoea, or both, are particularly at risk. Sleep studies should be considered in this subgroup of patients with myotonic dystrophy.

Adult↗
PubMed1994

Extracorporeal membrane oxygenation for pediatric respiratory failure: five-year experience at the University of Pittsburgh.

OBJECTIVES: To describe the etiology, respiratory severity of illness, and outcome in patients with pediatric respiratory failure who were treated with extracorporeal membrane oxygenation (ECMO). To identify predictors of death, and to compare our morbidity and mortality rates with those rates of a previously reported series of patients with pediatric respiratory failure managed conventionally. DESIGN: Survey, case series. SETTING: Intensive care unit in a tertiary care pediatric hospital. PATIENTS: Twenty-eight pediatric patients (3 wks to 20 yrs of age) who underwent ECMO for pediatric respiratory failure between 1985 and 1991. MEASUREMENTS AND MAIN RESULTS: Thirteen (46%) of the 28 patients survived. The most common diagnoses were adult respiratory distress syndrome and nonspecific pneumonitis. Multiple organ system failure occurred in only four (14%) patients; most patients died of respiratory failure. The occurrence of persistent airleak during ECMO was significantly greater in nonsurvivors than in survivors. Furthermore, nonsurvivors had significantly less response to lung reexpansion maneuvers compared with survivors, as measured by a calculated compliance index (effective tidal volume/mean airway pressure x 100). The mortality rate was comparable with those rates of other published studies of conventionally managed and ECMO-treated patients with pediatric respiratory failure. Moreover, our patients appeared to exhibit more severe respiratory failure at the start of ECMO than those patients in other studies. CONCLUSIONS: ECMO appears to be a rational therapy for patients with pediatric respiratory failure who are likely to die with continued conventional management. Recovery of lung function by the end of the first week of ECMO may be a favorable prognostic indicator. Persistent airleak may be a nonfavorable prognostic indicator.

Adolescent↗
PubMed1993

Helicobacter (Campylobacter) fennelliae-like organisms as an important but occult cause of bacteraemia in a patient with AIDS.

We describe the isolation and identification of a Helicobacter (Campylobacter)-like organism obtained from the blood of a 32-year-old homosexual man with a 10 months' history of AIDS and progressive mucocutaneous Kaposi sarcoma. Fever and bacteremia persisted despite sequential administration of ciprofloxacin and trimethoprim-sulfamethoxazole, antibiotics reported to be active against this organism in vitro. Facultative organisms like Campylobacter fennelliae and Campylobacter cinaedi which are difficult to isolate by standard techniques may be important but unrecognized causes of febrile illness in patients with human immunodeficiency virus infection. Laboratories should consider use of acridine orange staining and more extensive subculture protocols for blood cultures with progressive growth indices which appear negative by conventional staining and subculture technique.

Acquired Immunodeficiency Syndrome↗
PubMed1993

The structure of large and small airways in nonfatal and fatal asthma.

Asthma is characterized by excessive airway narrowing and airway wall inflammation. In cases of fatal asthma, increased thickness of the airway wall is observed and may account for excessive airway narrowing when smooth muscle contracts. This study was undertaken to examine airway dimensions in large and small airways in both fatal and nonfatal cases of asthma. Airway wall areas (total, inner, and outer relative to smooth muscle layer), epithelial integrity, smooth muscle shortening, and the areas of smooth muscle, cartilage, and mucous glands were compared in transverse sections of large and small airways of subjects dying of asthma (fatal asthma, n = 11), those dying suddenly of nonrespiratory diseases and having a definite history of asthma (nonfatal asthma, n = 13), and those dying suddenly without any history of respiratory illness (control, n = 11). Airways were grouped by size using the basement membrane perimeter for comparison. All areas were expressed as areas per millimeter of basement membrane. In cartilaginous airways, the cases of fatal asthma had greater (p < 0.05) total wall, inner wall, outer wall, smooth muscle, mucous gland and cartilage areas than did control and nonfatal cases. The inner wall area was greater in the fatal and nonfatal cases than in the control cases (p < 0.05) in the small cartilaginous airways and membranous bronchioles (MB). In small MB (perimeter < 2 mm), the total and outer wall areas were greater (p < 0.05) in cases of fatal and nonfatal asthma than in control cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

The patient profile approach to assessing the cost of AIDS and HIV infection.

Despite interest in the costs associated with HIV infection, little useful information exists to aid those planning patient care. The results of costing studies, which are mainly North American, are difficult to apply to the National Health Service. Moreover, they have generally ignored HIV infection before formal diagnosis of AIDS. A patient profile approach was devised to supply data on the type, amount and cost of services supplied to patients in the Northern region. This method produces longitudinal treatment and cost profiles, and provides a temporal perspective, which is essential given the speed at which care has changed to date. This method also allows identification of a wide array of services, costs and social factors. This paper describes a pilot study to develop and test these methods. The sample of 24 randomly selected patients constituted a heterogeneous group; the individuals affected, the type and number of services supplied and costs all varied widely. A typical patient could not be described. Our results illustrate the powerful analyses which this approach permits. Further application will allow improved evaluation of the overall costs and the effects of different patterns of care.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Principles behind practice. 5. Clinical disagreement.

With clinical information it is frequently difficult or impossible to make objective measurements to prove that a particular finding is correct. In these circumstances, the agreement of experienced clinicians is the best guide to the accuracy of clinical findings. However, studies of clinical judgement usually show a distressingly high level of disagreement among clinicians. We examine why such disagreement is so common, how clinical disagreement can be measured and how clinicians can be trained so that they are able to agree on important findings.

Adult↗
PubMed1991

AIDS in California family medicine. Changing experiences, knowledge, and geographic distribution.

Information regarding practice patterns specific to acquired immunodeficiency syndrome (AIDS) was obtained in 1988 from 1774 family physicians in California using a mail survey. Data were analyzed across the following county groupings: Los Angeles County, other counties in standard metropolitan statistical areas, and counties outside standard metropolitan statistical areas. Comparisons were made with the data from a telephone survey conducted in 1986. Differences over time were analyzed. By 1988, the percentage of physicians treating or referring patients for possible AIDS had more than doubled in counties outside standard metropolitan statistical areas. The percentage of physicians reporting one or more diagnosed cases of AIDS had tripled, a finding that suggests the importance of AIDS in family medicine is increasing at a rapid rate. In addition, survey results indicate that a majority of those surveyed still lack the AIDS-related knowledge and competency necessary to effectively deal with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Comparative trial of low-dose, intradermal, recombinant- and plasma-derived hepatitis B vaccines.

The immunogenicity and reactogenicity of low-dose, recombinant DNA and plasma-derived hepatitis B vaccines were investigated in a prospective, double-blind, randomized, controlled trial. Volunteers (153) received either recombinant vaccine, 10 micrograms in 1 ml intramuscularly; plasma-derived vaccine, 2 micrograms in 0.1 ml intradermally or recombinant vaccine, 1 microgram in 0.1 ml intradermally at 0, 30, and 150 days. Peak geometric mean concentrations of antibody to hepatitis B surface antigen at day 200 were 1094, 387, and 43 mIU/ml, respectively. By day 360, these concentrations had fallen to 346, 124, and 19 mIU/ml, respectively (P less than .05 between groups both dates). Number of subjects with antibody greater than or equal to 10 mIU/ml at day 200 was similar between the 10-micrograms recombinant and 2-micrograms plasma-derived groups (94% vs. 90%), while only 78% of the 1-microgram recombinant group had protective concentrations of antibodies (P less than .05). Erythema and induration occurred in most subjects in both intradermal groups, while pain was prominent at the intramuscular site especially after the second dose. Thus, plasma-derived vaccine, 2 micrograms in 0.1 ml intradermally, appears to be an acceptable cost-saving method for hepatitis B immunization, while recombinant-derived vaccine, 1 microgram in 0.1 ml intradermally, produced less satisfactory results.

Adult↗
PubMed1990

Selection of admissions to a therapeutic community using a group setting: association with degree and type of psychological distress.

Henderson Hospital is a therapeutic community offering treatment for personality disordered young adults. The community operates a unique system of selection, whereby a group of residents and staff jointly decide upon offering admission to new referrals. This study is a preliminary investigation examining, in part, the basis upon which the selection group makes its decision. A measure of symptomatic psychological distress (SCL-90) was completed by 156 selection candidates. Comparison of those candidates selected with those who were rejected showed no difference between groups in number of symptoms reported nor the degree of distress attributable to those symptoms. However, analysis of symptom sub-scale scores revealed that those subjects not selected scored significantly higher on measures of somatisation, obsessive-compulsive features and phobic anxiety. It could be argued that these three symptoms are indicative of a tendency to deny or avoid feeling emotional distress. We propose that at one level, the selection group may operate by identifying those candidates who are more able to verbalise their distress, i.e. those presumed most likely to benefit from the Therapeutic Community's psychotherapeutic approach.

Adult↗
PubMed1989

An open multicenter long-term treatment evaluation of Sinemet CR. Sinemet CR Multicenter Study Group.

The safety and efficacy of Sinemet CR were studied in an open-label, 52-week trial. The study was completed by 156 mildly to moderately ill Parkinson's patients (primarily Hoehn and Yahr stage II to III) at 10 sites. Patients had their treatment optimized on standard Sinemet prior to beginning Sinemet CR treatment. Following titration, there was a median reduction in dosing frequency of 25% (from 4.1 to 3.2 doses/day) relative to the standard Sinemet baseline. Total daily levodopa dosage increased from 623 to 808 mg/day (+33%), a factor consistent with the lower bioavailability of the controlled-release formulation. Mean efficacy scores on the New York University Parkinson's Disease Scale decreased from 7.4 at the end of baseline to 5.8 at 12 weeks, a decline of 20%. The scores remained at this level throughout 52 weeks of treatment. At the end of 1 year of treatment, 60% of patients rated themselves as improved, while physicians rated 64% of the patients as improved. Adverse experiences were similar to those reported by patients taking standard levodopa preparations. Two thirds of the reported adverse experiences occurred within the 1st 3 months of Sinemet CR therapy, indicating that increased length of exposure to Sinemet CR was not associated with an increasing incidence of adverse experiences.

Aged↗
PubMed1986

Marathon fatigue: the role of plasma fatty acids, muscle glycogen and blood glucose.

The role of carbohydrate depletion in marathon fatigue was examined in 6 marathon runs. Four of the runs were potentially 'fast-time' marathons and culminated in fatigue. The utilization of carbohydrate, lipid and protein, and plasma concentrations of free fatty acids (FFA), glucose and lactate were measured at intervals throughout the runs. The contribution from protein to energy output was low (1-2%). The utilization of lipid was dependent upon plasma concentrations of FFA, which rose throughout the run. The utilization of carbohydrate mirrored that of FFA and thus fell throughout the run. Fatigue was characterized by a drop in running speed, a drop in carbohydrate utilization, an unchanging FFA utilization and a fall in blood glucose. The fall in blood glucose was not seen in the non-fatigued runners. These results are consistent with carbohydrate depletion being the cause of fatigue. The implications of these data are that lipid is the preferred fuel, but is rate-limiting, and that carbohydrate depletion, even though it causes fatigue, ensures an optimal-time marathon.

Adult↗
PubMed1985

Effect of acute alcohol consumption on lithium kinetics.

Lithium carbonate is used in several psychiatric disorders in the context of alcohol abuse. In a randomized, double-blind, crossover study the single-dose kinetics of lithium were followed after alcohol or placebo. Lithium carbonate capsules were taken by mouth by 10 healthy young men with alcohol on one occasion and with placebo on a separate occasion (at least 7 days apart). Lithium concentrations were determined in serum and urine samples for 24 hours after dosing and served as the basis for kinetic analysis. Acute alcohol had no effect on lithium absorption, elimination, distribution, or clearance. Alcohol did, however, increase the peak serum lithium level in nine of 10 subjects, from a mean of 0.62 mEq/L in the placebo condition to 0.70 mEq/L in the alcohol condition. Our data suggest that alcohol has limited effects on lithium carbonate kinetics. The possibility of elevated serum lithium concentrations when lithium is taken with alcohol is suggested.

Absorption↗
PubMed1984

Aeromedical transportation via commercial airlines.

A report on 72 patients requiring medical escorts on long international flights by commercial airlines is presented. From experience gained, advice is given on facilitating medical attention during such journeys. Adequate preflight planning is the most important aspect.

Aircraft↗