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Biomedical subjects

M Johnson

Publications and source records attributed to M Johnson.

At least 73 records · Page 4Linked to original sources
PubMed2001

Long term recovery of IgG and IgM production during HIV infection in a patient with common variable immunodeficiency (CVID).

AIMS: Common variable immunodeficiency (CVID) is the most common serious primary immunodeficiency. This paper describes the immunological consequences of human immunodeficiency virus (HIV) infection in a patient with familial CVID subsequently treated with highly active antiretroviral therapy (HAART). METHODS: Serial measurements over 11 years of serum immunoglobulins, specific antibodies to tetanus toxoid and pneumococcal polysaccharides, lymphocyte phenotypes, and HIV viral load were made. RESULTS: The patient recovered total serum IgG and IgM, but not IgA production, with adequate concentrations of specific antibodies, allowing withdrawal of intravenous immunoglobulin without an increase in infections. T cell numbers gradually declined and the patient developed a high grade B cell lymphoma. After successful chemotherapy, HAART was commenced, viral load fell from 472 000 to < 50 copies/ml, and CD4+ T cell numbers increased from 13 to 661 x 10(6)/litre. Antibody production was maintained after suppression of viral load. CONCLUSIONS: This is the first definitive report of reversal of IgG and IgM deficiency in familial CVID after HIV infection. Failure to normalise IgA supports the concept of separate predisposing genetic factors for selective IgA deficiency, which when combined with others lead to CVID. Furthermore, a persistently high viraemia is not required to maintain the recovery of immunoglobulin values, suggesting this depends either on a transitory effect of a high viral load, or a persistence of low amounts of virus.

Adult↗
PubMed2001

Is population bone mineral density variation linked to the marker D11S987 on chromosome 11q12-13?

Our purpose is to test linkage of human chromosome 11q12-13 to BMD variation. Chromosome 11q12-13 has been linked to three BMD-related phenotypes that are inherited as Mendelian traits in human pedigrees: an autosomal dominant high bone mass trait, autosomal recessive osteoporosis pseudoglioma, and autosomal recessive osteopetrosis. A sibling pair study with 374 sibships showed significant linkage of D11S987 to normal BMD variation, with a maximum logarithm of odds score of 3.5. However, a subsequent linkage study with a total of 595 sibling pairs demonstrated reduced significance for linkage of D11S987 to bone mineral density variation, with a logarithm of odds score less than 2.2. We genotyped five markers in a genomic region of approximately 27 cM centering on D11S987 and measured bone mineral density and other traits (weight, etc.) for 635 individuals from 53 human pedigrees. Each of these pedigrees was ascertained through a proband with bone mineral density Z-scores less than -1.28 at the hip or spine. Adjusting for age, sex, and weight as covariates, we performed two-point and multipoint linkage analyses using the variance component linkage analysis method implemented in Sequential Oligogenic Linkage Analysis Routines. We found little evidence of linkage of these five markers to bone mineral density at the spine, hip, wrist and total body bone mineral content. The maximum logarithm of odds score at these five markers was 0.25, and the maximum logarithm of odds score at D11S987 was 0.15. Therefore, although we cannot exclude the linkage of D11S987 region to bone mineral density variation, there is no evidence for linkage of the marker D11S987 on human chromosome 11q12-13 to bone mineral density variation in our study population.

Adult↗
PubMed2001

Alternative mechanisms for long-acting beta(2)-adrenergic agonists in COPD.

beta(2)-Adrenergic agonists are commonly used as bronchodilators to treat patients with COPD. In addition to prolonged bronchodilation, long-acting beta(2)-agonists (LABAs) exert other effects that may be of clinical relevance. These include inhibition of airway smooth-muscle cell proliferation and inflammatory mediator release, as well as nonsmooth-muscle effects, such as stimulation of mucociliary transport, cytoprotection of the respiratory mucosa, and attenuation of neutrophil recruitment and activation. This review details the possible alternative mechanisms of action of the LABAs, salmeterol and formoterol, in COPD.

Adrenergic beta-Agonists↗
PubMed2001

In vivo brain tumor demarcation using optical spectroscopy.

The applicability of optical spectroscopy for intraoperative detection of brain tumors/tumor margins was investigated in a pilot clinical trial consisting of 26 brain tumor patients. The results of this clinical trial suggest that brain tumors and infiltrating tumor margins (ITM) can be effectively separated from normal brain tissues in vivo using combined autofluorescence and diffuse-reflectance spectroscopy. A two-step empirical discrimination algorithm based on autofluorescence and diffuse reflectance at 460 and 625 nm was developed. This algorithm yields a sensitivity and specificity of 100 and 76%, respectively, in differentiating ITM from normal brain tissues. Blood contamination was found to be a major obstacle that attenuates the accuracy of brain tumor demarcation using optical spectroscopy. Overall, this study indicates that optical spectroscopy has the potential to guide brain tumor resection intraoperatively with high sensitivity.

Adult↗
PubMed2001

Nuclear magnetic resonance study of water mobility in pasta filata and non-pasta filata mozzarella.

Changes in molecular mobility of water in pasta filata and non-pasta filata Mozzarella cheeses were investigated during the first 10 d of storage using nuclear magnetic resonance (NMR) relaxation techniques. Water in pasta filata Mozzarella was classified into two fractions by spin-spin relaxation times, T21 and T22, and corresponding proton intensities, A1 and A2, representing low and high molecular mobility, respectively. Increase in A1 (and decrease in A2) suggested that, there was a redistribution of water from more- to less-mobile fraction (from T22 to T21 fraction) during the first 10 d of storage. The NMR data did not indicate the two-state behavior of water molecules in non-pasta filata Mozzarella. However, the T2 values of non-pasta filata Mozzarella were comparable to the T21 values of pasta filata Mozzarella indicating that the molecular mobility of water in non-pasta filata Mozzarella is comparable to that of the less mobile water fraction in pasta filata Mozzarella. Generally, T2 and T1 values of pasta filata and non-pasta filata Mozzarella cheeses increased during the 10-d storage. This is believed to be due to structural changes in the protein matrix.

Cheese↗
PubMed2001

Words in a sentence become less accessible when an anaphor is resolved.

A noun that identifies an entity in a discourse becomes less accessible following an anaphoric reference to another entity. The phenomenon cannot be attributed to ad hoc strategies, memory decay, or context checking. It occurs for both common and proper nouns and for nouns that identify both characters and inanimate objects. It is stronger for nouns that identify important entities, as opposed to more peripheral ones.

Cognition↗
PubMed2001

Nursing skill assessment within populations: scale development and testing.

This study examined the reliability and validity of an instrument to measure the skill level of registered nurses within an Australian state. Internal consistency and construct validity of the scale and subscales were investigated in a sample of 1223 registered nurses from varying practice areas. The scale consisted of 105 skills within 13 practice domains: nursing practice, professional practice, acute care, community and public health, rural and remote area nursing, service delivery, self-management, supervision, resource management, improving processes, training and development, research, and technology. Twelve subscales obtained reliability co-efficients of 0.85 or more, with one at 0.81. The 13 factors explained 64.5 per cent of the cumulative variance, adequately capturing the concept of nursing skill. This scale, and its subscales, represent valid and reliable tools for the assessment and monitoring of skill levels in a population of nurses, within some limitation.

Australia↗
PubMed2001

Older female inpatients in Arkansas.

The purpose of this study was to examine age and Major Diagnostic Categories (MDCs) and compare the variables to mortality and length of stay among inpatient women age 50 and over. Archival statistical data were obtained for 2,238 inpatients in a private, nonprofit hospital in 1998. The ages ranged from 50 to 107 years old, with a mean age of 71.21 years. Quantitative analyses were conducted to examine the data from a private, nonprofit hospital and determine if there were significant relationships between age, major diagnostic category, length of stay, and mortality in older women. The MDC distribution indicated that the highest frequency of diseases and disorders were in the following three systems: circulatory system, musculoskeletal system and connective tissue, and the digestive system. The average length of stay was 8.01 days. The 30-day readmission percentage and the 365-day readmission percentage were 12.24% and 28.02%, respectively. The mortality rate was 6%. In addition, 63.97% went home after discharge, and 67.07% were Medicare recipients. The risk of musculoskeletal diseases and disorders increased with age (p = .0001). The conditional probability of death was nearly nine times higher for the diseases of the nervous system, myeloproliferative diseases and disorders, poorly differentiated neoplasms and respiratory diseases. As age increased, the probabilities of a long hospital stay decreased. The mortality analyses found that the lowest probabilities of survival were in categories of myeloproliferative diseases and disorders, poorly differentiated neoplasms, and infectious and parasitic diseases. According to current health statistics, our society is getting older. Not only are people living longer, they are accessing more health care (American Association for World Health, 1999). Overall, the average life expectancy at birth has been identified at 76.5 years. The female has a longer life expectancy than the male, averaging 5.8 years longer. The highest life expectancy has been identified in the white female, who can expect to live to 79. The black woman has the second-highest life expectancy, 74.7 years. Peters, Kochanek, and Murphy reported an all-time-low age-adjusted death rate for the United States and a continuing trend in the decline in mortality for all age groups. With a growing number of people living longer, there is a need to know about the most common health issues that affect quality of life. The top three national causes of death in older Americans were diseases of the heart, malignant neoplasms, and cerebrovascular diseases/stroke. Arkansas health statistics mirror the national statistics. In April 1999, the Arkansas Department of Health reported that 30.5% percent of all female deaths were caused by heart disease. Malignant neoplasms were responsible for 20.1%, followed by cerebrovascular diseases at 10.8%. Other than three Connecticut hospital studies that explored the relationship of diagnosis code, mortality, and readmission, research is meager in this area. There is a need for hospital-based research that addresses the diagnosis categories and the relationship to age and other variables.

Age Factors↗
PubMed2001

The presence and properties of myocilin in the aqueous humor.

PURPOSE: To determine whether myocilin is present in the aqueous humor (AH) and to examine certain properties of this protein. METHODS: Human AH was obtained at the time of either glaucoma surgery or cataract extraction. Monkey AH was obtained at the time of death, and bovine aqueous was obtained from eyes delivered from an abattoir. Column chromatography was performed on aqueous samples to determine the approximate size of the myocilin present. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blot analysis were performed using antibody prepared against a peptide sequence in myocilin. Analysis of the bovine proteins present in AH that were retained by a microporous filter was also performed using western blot analysis. RESULTS: By western blot analysis, myocilin was present in human, monkey, and bovine AH. The apparent molecular size of the myocilin present in the AH were greater than 250,000 Da, when quantified with a gel filtration column. Myocilin appeared to be hydrophobic and was one of the proteins that was retained on microporous filters that were obstructed by AH. CONCLUSIONS: Myocilin is a constituent in the AH. It appears that myocilin is a hydrophobic protein that may exist in an oligomeric state or in association with other proteins. Myocilin is retained by microporous filters and may be involved in the obstruction of these filters that occurs when AH is perfused through them.

Animals↗
PubMed2001

The effect of aloe vera gel/mild soap versus mild soap alone in preventing skin reactions in patients undergoing radiation therapy.

PURPOSE/OBJECTIVES: To determine whether the use of mild soap and aloe vera gel versus mild soap alone would decrease the incidence of skin reactions in patients undergoing radiation therapy. DATA SOURCES: Prospective, randomized, blinded clinical trial. SETTING: Radiation therapy outpatient clinic in a cancer center affiliated with a major teaching medical facility. SAMPLE: The mean age of the participants was 56 years. The group consisted of Caucasians (74%) and African Americans (26%). The ethnic mix was non-Hispanic (65%) and Hispanic (35%). METHODS: Prophylactic skin care began on the first day of radiation therapy. Patients cleansed the area with mild, unscented soap. Patients randomized into the experimental arm of the trial were instructed to liberally apply aloe vera gel to the area at various intervals throughout the day. FINDINGS: At low cumulative dose levels < or = 2,700 cGy, no difference existed in the effect of adding aloe. When the cumulative dose was high (> 2,700 cGy), the median time was five weeks prior to any skin changes in the aloe/soap arm versus three weeks in the soap only arm. When the cumulative dose increases over time, there seems to be a protective effect of adding aloe to the soap regimen. IMPLICATIONS FOR NURSING PRACTICE: Skin products used to treat radiation dermatitis vary among institutions. Nurses should be aware that some patients may be predisposed to skin problems. Nurses must be aware of newly developed products and research regarding these products so that effective treatment can be instituted.

Adolescent↗
PubMed2001

Fluticasone propionate compared with zafirlukast in controlling persistent asthma: a randomized double-blind, placebo-controlled trial.

OBJECTIVE: The objective of our study was to compare the efficacy and safety of fluticasone propionate (an inhaled corticosteroid) with zafirlukast (a leukotriene modifier) for persistent asthma. STUDY DESIGN: In this randomized placebo-controlled, parallel-group, double-blind, double-dummy trial, patients underwent an 8- to 14-day run-in period followed by 12 weeks of treatment with inhaled fluticasone propionate (88 mg twice daily by metered-dose inhaler), oral zafirlukast (20 mg twice daily), or placebo. POPULATION: We included a total of 338 persistent asthma patients, 12 years of age or older, using short-acting b2-agonists alone. OUTCOMES: measured Efficacy outcomes included changes in pulmonary function, asthma symptoms, rescue albuterol use, nighttime awakenings due to asthma, and quality of life. Safety outcomes included asthma exacerbations, adverse events, and clinically significant laboratory test results. RESULTS: After 12 weeks of treatment, patients taking fluticasone propionate experienced significantly greater improvements in all clinical parameters (symptom scores, percentages of symptom-free and albuterol-free days, albuterol use, and nighttime awakenings) compared with patients taking zafirlukast (P <.05) or placebo (P <.05). Treatment with fluticasone propionate resulted in significantly greater improvements in pulmonary function compared with zafirlukast (P <.05) or placebo (P <.05). Fewer fluticasone propionate patients (4%) had an exacerbation requiring oral corticosteroids compared with those taking zafirlukast (12%) or placebo (10%). CONCLUSIONS: Inhaled fluticasone propionate is more effective than zafirlukast in controlling asthma symptoms, improving pulmonary function, and improving quality of life for patients who are symptomatic with the use of short-acting b2-agonists alone.

Administration, Inhalation↗
PubMed2001

Treatment of migraine with targeted nutrition focused on improved assimilation and elimination.

This study was undertaken to assess the impact of three months of targeted nutritional therapy for migraine on health-related quality of life. The study is also intended to lend support to a theory that migraine is caused by an underlying dysfunction involving assimilation or elimination mechanisms. Forty people were selected from approximately 120 applications. Fourteen participants were selected from among those applicants within the authors' practices and 26 from applicants solicited via the Internet. Participants were required to complete the Medical Outcomes Trust Migraine Specific Quality of Life (MSQ) Questionnaire. Eighty percent of the study participants experienced significant and sustained improvements in quality of life during the 90 days of the study. The study instrument is specifically designed to measure quality of life improvement and thus does not solicit responses relative to number of migraine attacks or duration of each migraine. However, it should be noted that improvement in quality of life is likely due to a reduction in the duration and frequency of migraine attacks.

Adult↗
PubMed2001

Caring carers.

Explore the source record for details and available documents.

Adaptation, Psychological↗
PubMed2001

Junior medical students' perceptions of an introductory hospice experience.

INTRODUCTION: The importance of palliative care education in the medical school curriculum is becoming more recognized. The purpose of this study was to assess medical students' perceptions of an introductory hospice experience. METHODS: Forty-one second-year medical students took part in an introductory hospice experience in which they were acquainted with a wide range of hospice services provided to patients and families by an interdisciplinary team involved in hospice care. In addition, the students visited patients' homes individually with an experienced hospice nurse or social worker. At the end of their experience, the students were asked to complete a multi-item evaluation questionnaire in order to share their perceptions of the hospice experience and their suggestions for improvement of the course. RESULTS: The students spent an average of four hours on their introductory hospice experience, and they indicated that all of their personal goals for their experience had been met. Suggestions for improvement of the course were to increase the amount of course time allotted and to provide further opportunity to see more patients. Overall, the students rated their experience as "above average" to "excellent." CONCLUSIONS: According to the medical students who participated, the introductory hospice experience was a worthwhile and valuable educational experience. An equal or increased amount of hospice time should be allotted in the education of future junior medical students.

Attitude of Health Personnel↗
PubMed2000

Circadian rhythm of serum total homocysteine in men.

Serum homocysteine levels were examined in a 24-hour study of 7 healthy and 5 diabetic men, revealing a statistically significant circadian rhythm (p = 0.030), normal concentrations of 11.83 +/- 1.2 vs 12.99 +/- 1.2 micromol/L, with peak values occurring during the evening (10:37 P.M.) and lowest levels occurring during the morning. These findings imply that increased atherosclerotic risk in insulin-resistant diabetics during morning hours does not appear to be explained by differences in homocysteine levels in the normal population.

Adult↗
PubMed2000

IV immunoglobulin does not reverse established weakness in MS.

BACKGROUND: Immunoglobulin (Ig) administration induces remyelination in the Theiler's virus model of MS. METHODS: A randomized, double-blinded, placebo-controlled trial of IV immunoglobulin (IVIg) was performed in patients with MS who had persistent muscle weakness that had been stable for between 4 and 18 months to determine whether this would improve muscle strength (primary outcome: isometric muscle strength). Patients received either IVIg (0.4 g/kg) or placebo daily for 5 days, then single infusions every 2 weeks for 3 months (total, 11 infusions). Muscle groups identified by clinical measures to have unchanging significant weakness were the major targets for therapeutic response (targeted neurologic deficit [TND]). RESULTS: IVIg was well tolerated. An interim analysis after 67 patients were enrolled indicated no difference in the degree of change in strength between treatment groups in either the TND or non-TND muscle groups at 6 months, and the trial was terminated. There was no apparent benefit in relapse behavior or impairment measures during the 6-month observation period. Nor was there apparent benefit in either patients who remained clinically stable or in those with evidence of disease activity. Patients with active MS during the trial worsened in both TND and non-TND muscle groups. This worsening was seen regardless of whether the clinical manifestations of disease activity involved the TND muscle groups. CONCLUSIONS: IVIg does not reverse established weakness in MS. Measurements of isometric muscle strength were reliable (reproducible) indices of strength and may be sensitive, objective methods to document functional changes in impairment in future MS trials.

Adult↗