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Biomedical subjects

S Johnson

Publications and source records attributed to S Johnson.

At least 307 records · Page 17Linked to original sources
PubMed1994

Effects of gender and menopausal status on the association of apolipoprotein E phenotype with plasma lipoprotein levels. Results from the Framingham Offspring Study.

Apolipoprotein (apo) E phenotype is an important genetic determinant of plasma low-density lipoprotein (LDL) cholesterol and apo B levels. We have determined apo E phenotype by isoelectric focusing and plasma lipid, lipoprotein cholesterol, apo A-I, apo B, and lipoprotein(a) levels, as well as LDL particle size, in 2258 men and women participating in the Framingham Offspring Study. Apo E phenotype (E2/2, E2/4, E3/2, E3/3, E3/4, and E4/4) was not associated with plasma lipoprotein(a) levels but was associated with plasma LDL cholesterol levels, apo B levels, and LDL size in men and with plasma total cholesterol, LDL cholesterol, and apo B levels in women. The average effect of the epsilon 2 allele was to lower plasma LDL cholesterol levels by 9.2 mg/dL in men and by 13.7 mg/dL in women, while the average effect of the epsilon 4 allele was to increase LDL cholesterol levels by 2.6 mg/dL in men and by 5.4 mg/dL in women. When men were divided into two groups according to their age (< 50 and > or = 50 years old), the average effect of the epsilon 2 allele was to lower plasma levels of LDL cholesterol by 10.2 mg/dL in younger men and by 7.5 mg/dL in older men. In premenopausal women, the average effect of the epsilon 2 allele was to lower LDL cholesterol by 8.2 mg/dL and, in postmenopausal women, by 20.4 mg/dL. An opposite effect of the epsilon 4 allele was observed: the epsilon 4 allele was associated with increases in plasma LDL cholesterol levels of 4.0 mg/dL in younger men and of 1.0 mg/dL in older men.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Effect of mailbag design on musculoskeletal fatigue and metabolic load.

The need for an alternative mailbag to the conventional U.S. postal mailbag, which hangs at the side over one shoulder, was investigated. Based on the results of a pilot study, two types of alternative mailbags, both including waist support and one that splits the load into two parts, are recommended. The metabolic energy requirement and lateral trunk muscle fatigue resulting from the use of the alternative mailbags were compared with those resulting from the conventional U.S. postal mailbag. The alternative mailbags resulted in no significant change in metabolic load. Both alternative mailbags resulted in significantly less lateral trunk muscle fatigue. It is proposed that this reduction in fatigue would result in reduced musculoskeletal stress and reduced potential for back injury.

Adult↗
PubMed1994

A time and money saver? Cost comparison of i.v. therapy with and without Pall 96 filters.

1. Nurses should not be adverse to performing their own research projects to inform their clinical practice. 2. Intravenous filters can reduce the risks involved in IV therapy from microbes, particulates or air, and reduce the incidence of phlebitis. 3. Use of Pall 96 filters may be cost-effective in general medical wards, but this study was too small for general application.

Filtration↗
PubMed1994

Surveillance of respiratory viruses. A 10-year laboratory-based study.

Respiratory virus isolates made at the National Institute for Virology from 1982 to 1991 were studied. An active virus surveillance programme, 'viral watch', which recruits throat swab specimens from a network of monitoring centres--mainly in the Witwatersrand and Vereeniging area with one centre in Middelburg--that represent a cross-section of the population, provided 68% of the specimens and 74% of the isolates, with an isolation rate of 25.5%. This was significantly higher than that of routine specimens (17.7%). Of the 966 isolates, influenza viruses accounted for 527 (54.7%), para-influenza for 122 (12.6%), respiratory syncytial virus for 34 (3.4%) and adenovirus for 106 (11.0%). Influenza viruses showed a definite seasonal peak between June and August whereas the other viruses, although they showed a winter predominance, were isolated throughout the year. An active virus surveillance programme is particularly valuable in monitoring respiratory virus epidemiology in the population.

Adenoviruses, Human↗
PubMed1994

The neurosurgical intensive care unit in an era of health care reform.

Health care reform, public concern, and managed care will create an environment that demands highly creative strategies to deliver quality care while reducing costs. Patient satisfaction and outcomes will take on a high priority. To meet this challenge, the neurosurgical ICU of the future will be designed with a patient-focused theme wherein the physical environment embodies healing and humanism. Services will be brought to the patient rather than the patient accommodating the system. Patients and families will be the directors of their own care. Staff and families will have access to a highly sophisticated clinical information system, and learning for staff at all levels will be a part of everyday life in the ICU. Unit management will be within a framework of shared governance wherein the power base is with the direct care givers, and decision and policy making happens at the point closest to the patient. Patient outcomes will be a result of a highly organized collaborative model that includes primary nursing, critical paths, and case management. Partnerships between nurses and unit support staff will create skill-mix changes that allow the nurse to spend less time on nonclinical unit maintenance-type functions and more time with the patient and family. This will have a positive fiscal impact as well as enhance patient satisfaction and outcomes.

Cost-Benefit Analysis↗
PubMed1994

Benefits and limitations of the Witwatersrand influenza and acute respiratory infections surveillance programme.

OBJECTIVE: To establish an ongoing active surveillance programme for acute respiratory infections in general, and influenza in particular. DESIGN: A network of 16 sentinel primary health care providers furnished morbidity information and clinical specimens for virus characterisation supplemented by school absenteeism and regional mortality data. SETTING: General practices, hospital outpatient departments and staff clinics in the Witwatersrand area. PARTICIPANTS: Subjects treated for acute respiratory infections by 7 general practitioners, 1 specialist pulmonologist, 4 paediatric outpatient departments, 1 mine hospital and university, factory and institutional staff clinics. Absenteeism data were obtained from 8 primary and 6 high schools in the region (representing 9,000 pupils). OUTCOME MEASURES: Morbidity information and strain characterisation of influenza isolates as well as other viral respiratory pathogens, school absenteeism, seasonal excess mortality. RESULTS: The most sensitive indicator of influenza activity was virus isolation, which gives an earlier warning signal of an impending epidemic than morbidity or absenteeism parameters. Both morbidity and school absenteeism provided quantitative indicators of the severity of the epidemic. Mortality from all causes showed characteristic winter increases in the 65-year-old and older population which were not seen in younger individuals. Circulating influenza viral strains matched the strains recommended for the vaccine in 1991 and 1992, but not in 1993. CONCLUSIONS: The course and extent of the annual winter influenza epidemic can be charted by means of an active surveillance programme, with sentinel primary health care providers furnishing morbidity data and clinical material from which virus isolations can be made. Antigenic characterisation of the isolates demonstrated that circulating strains may not match recommended strains in northern hemisphere-formulated vaccines and stresses the need for a southern hemisphere vaccine formulation for South Africa. Absenteeism information provides an indicator of the impact of influenza on the economy and excess mortality data emphasise the need for routine immunisation of the elderly.

Absenteeism↗
PubMed1993

Characterization of human tumor cell lines transduced with the cDNA encoding either tumor necrosis factor alpha (TNF-a) or interleukin-2 (IL-2).

Tumor cell lines were generated from cancer patients, 17 with metastatic melanoma and one with colon adenocarcinoma. The lines were characterized as tumor cells by the presence of tumor associated antigens demonstrated by indirect immunofluorescence and analysing using a fluorescence activated cell sorter (FACS). The tumor cell lines were transduced using retroviruses encoding neomycin phosphotransferase and either human tumor necrosis factor alpha (TNF-alpha) or interleukin-2 (IL-2). Following transduction, cells were selected and grown in the neomycin analogue G418. Fibroblasts overgrew tumor cells in 6/18 cases following selection in G418 and 1/18 lines did not grow at all after selection. In the remaining 11 lines the expression of tumor associated antigens, growth, and susceptibility to lysis by LAK cells was similar between the selected transduced tumor cell lines and the nontransduced controls. Of the lines tested, all were positive for the presence of the cytokine gene by Southern blot or PCR analysis. In addition, no replication competent retrovirus was detected in the cell lines following transduction using an extended mink S+L- focus assay. The amount of specific cytokine produced per 10(5) transduced tumor cells in 24 h ranged from 0.2 ng to 5.8 ng of TNF-alpha for the TNF transduced lines and from 0.1 ng to 3.6 ng of IL-2 for the IL-2 transduced tumor cell lines. One transduced tumor cell line examined maintained consistent levels of cytokine production when studied at 15 different time intervals over a period of 198 days. Additionally, 40,000 rads of gamma irradiation did not stop cytokine production from two transduced tumor cell lines when studied over 6 days. This study demonstrates the feasibility of growing human tumor cell lines from surgical biopsies and genetically modifying those lines to produce a cytokine of choice for possible use as a tumor cell vaccine.

Adenocarcinoma↗
PubMed1993

Rheumatic fever and chronic rheumatic heart disease in Yarrabah aboriginal community, north Queensland. Establishment of a prophylactic program.

OBJECTIVE: To establish a program for the prevention of rheumatic fever and rheumatic heart disease in a semi-isolated Aboriginal community in far north Queensland and to test its efficacy. DESIGN: A prevalence study of acute rheumatic fever and chronic rheumatic heart disease was conducted in the community in 1985 and subjects with possible acute rheumatic fever were assessed. A prophylactic antibiotic program was instituted. Records were kept of the prevalence of acute rheumatic fever for six years after the 1985 survey. A second survey of the community was held in 1991 to detect chronic rheumatic carditis resulting from undetected acute rheumatic fever. SETTING: The Yarrabah Aboriginal community in north Queensland (latitude 17 degrees S). The program was conducted by the Yarrabah Health Team, a part of the North Queensland Aboriginal Health Division. PARTICIPANTS: The whole Yarrabah community (population 1250) was invited to participate. In 1985, after the completion of an educational program, 89% of the community cooperated in the survey. There was no educational program before the 1991 survey and the compliance rate was much lower. Importantly, however, 87% of the vulnerable group (4-16 year olds) were examined. INTERVENTIONS: After the 1985 survey, all community members aged 4-16 years had throat swabs taken three times each year. Those with swabs showing Group A streptococci were treated; their contacts were also swabbed and treated if Group A streptococci were found. RESULTS: Before the institution of the swabbing program there were four new cases of acute rheumatic fever each year in the Yarrabah community. In the six years after the program was introduced only one case of acute rheumatic fever occurred. This was at a time when swabbing had temporarily lapsed for a three-month period. CONCLUSIONS: These results support the use of a prophylactic antibiotic program in Aboriginal communities as a cost effective and efficient method for the prevention of rheumatic fever. The cooperation of the community is an integral part of its success and this can be obtained by community education.

Adolescent↗
PubMed1993

Structure-activity of deleted and substituted systemin, an 18-amino acid polypeptide inducer of plant defensive genes.

The primary structure-activity relationships of systemin, an 18-amino acid polypeptide from tomato leaves that regulates the expression of two wound-inducible proteinase inhibitor genes in tomato and potato plants, were investigated. Analogs of systemin, the only example of a polypeptide signal from plants, were synthesized with progressive deletions of amino acids from both the NH2 terminus and COOH terminus and assayed in young excised tomato plants. All of the analogs exhibited severely decreased proteinase inhibitor-inducing activities, indicating that the entire 18-amino acid sequence is necessary for maximal activity. Deletion of the COOH-terminal Asp abolished inducing activity. Progressive replacement of each amino acid of the entire polypeptide with Ala revealed two regions, near residues Pro13, where Ala substitution reduced activity to less than 0.2%, and Thr17, which totally inactivated the analog. Other replacements with Ala had little or only moderate effects on activity. The two inactive analogs, des-Asp18 systemin and Ala17 systemin, were potent inhibitors of the inducing activity of the native systemin. These analogs, therefore, contain structural conformations sufficient for competition with systemin, but they are not competent for proteinase inhibitor gene induction. A synthetic COOH-terminal tetrapeptide, Met-Gln-Thr-Asp, retained low proteinase inhibitor inducing activity, but virtually any replacements with other amino acids either eliminated activity or reduced the activity to very low or nearly undetectable levels. These results indicate that residues near the COOH terminus of systemin are necessary for activity, possibly involving a phosphorylation at Thr17, and that other regions of the systemin sequence are important for interacting with a receptor(s) but are not sufficient to activate proteinase inhibitor gene expression.

Amino Acid Sequence↗
PubMed1993

Coronavirus JHM OMP1 pathogenesis in owl monkey CNS and coronavirus infection of owl monkey CNS via peripheral routes.

Two separate studies are described in this report. First, 5 Owl monkeys were inoculated intracerebrally (IC) with coronavirus JHM OMP1; this virus isolate was cultured from the brain of an animal inoculated with uncloned MHV JHM. Two of the animals became neurological impaired and were sacrificed; these animals had developed severe encephalomyelitis as previously described. Two of the remaining 3 healthy animals were inoculated IC again at 90 days post-inoculation (DPI) and all 3 were sacrificed approximately 5 months after the first virus inoculation. Despite the lack of detectable infectious virus, viral RNA and antigen, all 3 animals had significant white matter inflammation and areas of demyelination in the spinal cord. In the second study 4 Owl monkeys were inoculated intranasally (IN) and ocularly and 4 inoculated intravenously (i.v.) with JHM OMP1. The animals were sacrificed between 16 and 215 DPI with 2 IN and 2 i.v. animals receiving a second i.v. inoculum at 152 DPI. Viral RNA and/or antigen was detected in the brains of all animals and the distribution corresponded to areas of inflammation and edema. One of the animals that received the second inoculum developed neurological impairment and subsequent analysis of tissues showed viral antigen in both brain and spinal cord. Viral products were predominantly found in blood vessels suggesting hematogenous spread with entry into the central nervous system (CNS) through endothelium.

Administration, Intranasal↗
PubMed1993

Influence of pelvic osteotomy on birth canal size.

Six pelvic osteotomies (Salter, Sutherland, Steel, Tönnis, Chiari, and periacetabular) were performed on the right hemipelvis of adult female pelvic plastic models. Each pelvis underwent conventional X-ray and computed tomographic digital pelvimetry before and after osteotomy. The change in the anteroposterior and transverse dimensions at the inlet, midpelvis, and outlet were calculated. None of the osteotomies significantly decreased the inlet. The Salter and Sutherland osteotomies decreased the midpelvis to borderline low. The Salter, Sutherland, and Steel osteotomies significantly decreased the pelvic outlet. These changes correlated closely with those in living patients. Much of this decrease is nullified when the osteotomy is performed prior to the pubertal growth spurt.

Adult↗
PubMed1993

The sectorisation of psychiatric services in England and Wales.

Sectorisation is the establishment of small geographical catchment areas with dedicated mental health staff providing services to all patients living in the area. This model of care became very widespread during the 1980s in England and Wales: 81% of District Health Authorities responding to a postal questionnaire in this study were sectorised, and around three-quarters of these had become sectorised after 1980. However, this has occurred without central planning and with very little evaluation. Important questions remain to be answered about its efficacy for the severely mentally ill, about the provision of 24-h cover in a sectorised service, and about which services are appropriately provided at a sectorised and which at a centralised level.

Catchment Area, Health↗