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Biomedical subjects

J Johnson

Publications and source records attributed to J Johnson.

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

An emergency department-based randomized trial of nonbronchoscopic bronchoalveolar lavage for early pathogen identification in severe community-acquired pneumonia.

STUDY OBJECTIVES: Many patients with community-acquired pneumonia are treated empirically without an aggressive search for causative pathogens, an approach adopted largely because of the costs and difficulties encountered during efforts to identify the causative organisms. Blood and sputum cultures are not sensitive, and the more invasive techniques of bronchoscopy and lung biopsy are generally time consuming and not cost-effective. The technique of nonbronchoscopic bronchoalveolar lavage (BAL) has been shown to accurately diagnose the causes of nosocomial pneumonia. The purpose of this study was to determine whether an emergency department-based BAL protocol would lead to more frequent isolation of pneumonia pathogens and result in more changes to tailored antibiotic therapy in comparison with standard care. METHODS: We studied all adult patients admitted with a diagnosis of pneumonia who were tracheally intubated and who had obtainable familial consent in the ED of an urban county hospital from March 1998 to October 1999. Exclusions included antibiotic use within the past 5 days, pneumothorax, hemoptysis, or persistent hypoxia using 100% oxygen. Patients were randomized to standard care versus standard care plus BAL. Blood culture specimens were drawn from all patients before the initiation of antibiotics. All other diagnostic tests were ordered at the discretion of treating physicians. BAL fluid, sputum, and blood culture specimens were tracked, and patient antibiotic course was followed to assess any change in regimen. RESULTS: Twenty-six of 64 patients evaluated for study participation met all eligibility criteria; 14 patients received standard care, and 12 patients received standard care plus BAL. Pneumonia pathogens were identified in 10 (83.3%) of 12 patients in the BAL group and in 4 (28.6%) of 14 patients in the standard care group (P =.007). Comparing BAL versus non-BAL groups, there was no significant difference in the likelihood of overall antibiotic regimen changes (P =.149), but there was a difference with regard to antibiotic changes made in patients with positive culture test results (P =.026). No major complications occurred with BAL catheterizations. CONCLUSION: ED-based BAL catheterization allows for early identification of pathogens in severe community-acquired pneumonia, which leads to changes in antibiotic therapy.

Adult↗
PubMed2001

Reason for medical hospitalization among adult alcohol and drug abusers.

This study attempts to identify the associations between types of substance use and particular medical problems as causes of acute hospital admission on an inpatient substance abuse consultation service. Records of all consultations performed from 1994 to 1998 were analyzed. A total of 4,526 complete records were available. Cocaine (p < .01), heroin (p < .001), and injection drug (p < .001) users were more likely to be admitted to the hospital for infection. Both alcohol (p < .001) and marijuana (p < .001) users were more likely to be hospitalized for trauma related injuries. Individuals that used alcohol were also more likely to be admitted for the treatment of gastrointestinal disorders (p < .001). Clinicians who treat patients with these diagnoses should have a high index of suspicion of co-morbid substance use disorders. Effective treatment of substance use disorders can lead to a decrease in medical morbidity, improved outcomes for individual patients, and decreased costs for the health care system.

Adult↗
PubMed2001

Efficacy of diclazuril in comparison with chemical and ionophorous anticoccidials against Eimeria spp. in broiler chickens in floor pens.

Two 42-d floor pen studies were conducted with commercial broiler chickens to measure the efficacy of 1 ppm diclazuril in the starter or grower diet in shuttle programs with 66 ppm salinomycin. Study 1 compared a salinomycin to diclazuril (starter to grower diet) shuttle treatment with salinomycin to salinomycin, salinomycin to 100 ppm monensin, salinomycin to 99.8 ppm lasalocid, and unmedicated treatments. Study 2 compared a diclazuril to salinomycin (starter to grower) shuttle treatment with 125 ppm nicarbazin to salinomycin, 79.2 ppm narasin + nicarbazin to salinomycin, 125 ppm zoalene to salinomycin, and unmedicated treatments. Fifty 1-d-old chicks were randomly allotted to each of 10 pens per treatment in each study using a randomized complete block design. Starter (Days 0 to 21) and grower (Days 22 to 37) diets in each study contained 55 ppm bacitracin methylene disalicylate. The finisher diet (Days 38 to 42) in each study was unmedicated. Birds were inoculated via their feed on Day 22 (Study 1) or Day 15 (Study 2) with a mixed inoculum of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Four birds per pen (two male and two female) were randomly selected in each study for coccidial lesion scores on Day 6 postinoculation. These studies demonstrated that the use of 1 ppm diclazuril in shuttle programs was highly efficacious against a mixed inoculum of Eimeria spp. in comparison with nicarbazin, narasin + nicarbazin, and zoalene in starter diets and salinomycin, monensin, and lasalocid in grower diets.

Animal Feed↗
PubMed2001

Assessment of spinal kinematics using open interventional magnetic resonance imaging.

Assessment of spinal intersegmental motion has been a focus for research and has depended on radiographic techniques. Radiographic techniques are limited because of ionizing radiation exposure, magnification errors, and image quality. Interventional magnetic resonance scanners, however, allow dynamic imaging in the scanner in different positions. Twelve healthy subjects were scanned using a General Electric Signa SP10 open interventional magnetic resonance scanner. Subjects were scanned while they were in the supine position and during sitting in flexed and extended positions. Measurements of lumbar curvature and intersegmental motion were made from the sagittal images obtained. The results showed that it was possible to obtain repeatable measures of intersegmental rotation and translation from open magnetic resonance images of the spine in flexed and extended positions. These measures of motion are in agreement with previous data and suggest that the greatest motion occurs at the L4-L5 level. The use of interventional magnetic resonance imaging for assessing lumbar intersegmental mobility seems promising.

Adult↗
PubMed2001

Management of blebitis by members of the American Glaucoma Society: a survey.

PURPOSE: To investigate the practice patterns among glaucoma subspecialists in the American Glaucoma Society regarding the management of blebitis. METHODS: An anonymous survey incorporating 14 questions regarding the management of blebitis was mailed to all current active American Glaucoma Society members, including provisional members, in October 1999. RESULTS: A total of 319 physicians received the survey, and 204 members (64%) returned surveys. Sixty-nine percent of respondents do not ask their patients with functioning blebs to use topical antibiotics at home for early symptoms of blebitis. Thirty-four percent never or almost never obtain conjunctival cultures at the onset of isolated blebitis, whereas 44% always or usually do. Fifty-one percent prescribe a topical fluoroquinolone alone as the initial empirical treatment of isolated blebitis. Twenty-three percent use a fluoroquinolone in combination with one or two other antibiotics. Twenty-one percent choose a combination of fortified topical agents, usually including a fortified aminoglycoside, vancomycin, or cephalosporin. Thirty-one percent use fortified agents in some combination with or without a fluoroquinolone. Five percent prescribe some other single agent alone. Only 6% routinely use an oral antibiotic in cases of blebitis. Sixty-two percent use topical corticosteroids in conjunction with antibiotic treatment. Of these, 68% start them after initial antibiotic treatment is established or once improvement of blebitis is noted. Fifty-six percent indicated that a moderate or severe anterior chamber reaction, including fibrin, would prompt treatment as a possible endophthalmitis. In a persistently Seidel-positive bleb, 77% generally attempt surgical bleb revision. CONCLUSIONS: Methods of the management of blebitis differ among members of the American Glaucoma Society. Treatment recommendations generated from randomized clinical trials are needed.

Anti-Infective Agents↗
PubMed2001

Effect of organizational change on the individual employee.

Increasing market pressures force companies to implement drastic organizational changes in order to remain competitive. Budget decreases, reduction efforts, and similar changes create significant morale and job-satisfaction concerns. This study assesses the effects of budget reductions and other organizational changes on the morale of hospital employees. A survey dealing with employee perceptions of stress, workload, and performance was given to hospital employees. Not surprisingly, the survey found that morale problems resulted from the organizational changes. Employees' gender and job classification showed little significant effect on the survey results, while respondents' length of employment with the organization influenced the results slightly. The findings provide information useful for dealing with challenges of employee satisfaction, morale, and trust during times of budget limitations.

Budgets↗
PubMed2001

Free living energy expenditure in post menopausal women before and after exercise training.

The aim of the study was to determine the effects of 8 weeks of moderate exercise training, on 24-hour free living energy expenditure in previously sedentary post-menopausal women. The experimental group (EX) included 9 women. Ten non-exercising control subjects (CON) were recruited to undergo pre- and post-testing. Estimated total daily energy expenditure (TDEE), total 24-hour heart beats (HB), total energy intake (TEI), resting metabolic rate, maximal oxygen consumption (VáO2max), body composition, and submaximal heart rate were measured before and after the exercise intervention. Body composition did not change (body fat % in CON 34.0 +/- 4.0% vs. 33.9 +/- 3.6% and EX 34.1 +/- 4.0% vs. 34.0 +/- 3.4%). Mean submaximal heart rate during steady-state exercise in EX was lower after training compared to CON (p < .05); however, VáO2max did not increase significantly (CON 1.96 +/- 0.23 vs. 1.99 +/- 0.24 l L O2/min and EX 1.86 +/- 0.39 vs. 1.94 +/- 0.30 L O2/min). Neither estimated TDEE (CON, 11.6 +/- 2.0 vs. 11.4 +/- 2.78 MJ; and EX 11.4 +/- 3.3 vs. 11.5 +/- 2.5 MJ, pre vs. post, respectively), RMR (CON 134.2 +/- 9.4 vs. 136.9 +/- 15.0 KJ/kgFFM/day, and EX 138.4 +/- 6.4 vs. 140.7 +/- 14.2 KJ/kgFFM/day, pre vs. post, respectively), TEI (CON 7.9 +/- 2.2 vs. 8.2 +/- 2.5 MJ, and EX 9.4 +/-1.6 vs. 8.3 +/- 2.8 MJ), nor HB (CON 110,808 +/- 12,574 vs. 107,366 +/- 12,864 beats, and EX 110,188 +/- 9,219 vs. 114,590 +/- 12,750 beats) change over 8 weeks in either group. These data suggest that a moderate exercise program may not impact on TDEE, RMR, TEI, or HB in previously sedentary, older women.

Basal Metabolism↗
PubMed2001

Strategy for diagnosis of congenital toxoplasmosis: evaluation of methods comparing mothers and newborns and standard methods for postnatal detection of immunoglobulin G, M, and A antibodies.

In a study involving 14 laboratories supported by the European Community Biomed 2 program, we evaluated immunologic methods for the postnatal diagnosis of congenital toxoplasmosis (CT). Among babies born to mothers who seroconverted to positivity for toxoplasmosis during pregnancy, we analyzed 55 babies with CT on the basis of persistent anti-Toxoplasma immunoglobulin G (IgG) at 1 year of life and 50 control babies without anti-Toxoplasma IgG at 1 year of life in the absence of curative treatment with pyrimethamine-sulfonamides. We tested in-house methods such as the enzyme-linked immunofiltration assay (ELIFA) or Immunoblotting (IB) for the detection of IgG or IgM; these methods allowed comparison of the immunologic profiles of the mothers and the infants. We compared ELIFA and IB with a commercial enzyme immunoassay (EIA) or in-house immunosorbent agglutination assay (ISAGA) for the detection of IgM or IgA. The performances of combinations of methods were also assessed. A cumulative sensitivity of 98% during a 1-year follow-up was obtained with the ELIFA plus ISAGA combination. Only one case of CT was missed by the ELIFA plus ISAGA combination, whereas three cases were missed by the IB plus ISAGA combination, even though 48% of patients with CT were treated with pyrimethamine-sulfonamides, which are known to inhibit antibody neosynthesis. A similar performance was obtained with either ELIFA or IB in combination with EIA. The difference in performance between ELIFA plus ISAGA and IB plus ISAGA was not statistically significant (P = 0.31), and we conclude that both combinations of tests can be used for the diagnosis of CT in newborns.

Adult↗
PubMed2001

What is the prevalence of rheumatic disorders in general medical inpatients?

It has been suggested that rheumatological disorders are underdiagnosed in patients with medical problems and that this might be rectified by incorporating a standard brief screening examination as part of the routine assessment of all patients admitted to hospital with medical conditions. Therefore the GALS screening examination was used to assess the prevalence of rheumatic disease in 100 patients admitted with acute medical problems and in a further 100 in the rehabilitative phase of their disease. The nature of locomotor dysfunction in all patients with a positive result was defined by an independent review and then sensitivity and specificity of the screening test was calculated for rheumatic disease in both populations. The median age of the two populations were 63 and 78 years respectively, with more females in the rehabilitation group. The overall prevalence of a positive screening test was 53% in the acute and 94% in the chronic disease groups, although the false positive rate in the rehabilitation patients was 30% due to factors other than rheumatic disorders limiting locomotor function (mainly orthopaedic and neurological conditions). The diagnosis of a rheumatological disorder was made de novo in a significant minority (10%) of patients and was usually amenable to treatment. The commonest rheumatic disorder was osteoarthritis which accounted for 55% of all rheumatic disease, followed by inflammatory joint disease (16%), and osteoporosis (12%). In addition to osteoporosis, Paget's disease of bone and polymyalgia rheumatica were found more frequently in those patients undergoing rehabilitation than in those admitted with an acute medical problem. A number of clinically important associations between medical and rheumatic disorders were found, such as stroke disease with shoulder capsulitis and heart failure with gout. The sensitivity of the GALS screening test was extremely high (92% and 100%), while its specificity fell in the rehabilitation group from 83% to 17%. None the less, it is felt that this study indicates that the routine use of this test should be considered as part of the assessment of all hospitalised patients with medical problems, whether acute or chronic.

Acute Disease↗
PubMed2001

Hormonal regulation and differential actions of the helix-loop-helix transcriptional inhibitors of differentiation (Id1, Id2, Id3, and Id4) in Sertoli cells.

The testicular Sertoli cells support spermatogenesis by providing a microenvironment and structural support for the developing germ cells. Sertoli cell functions are regulated by the gonadotropin FSH. Sertoli cells become a terminally differentiated nongrowing cell population in the adult. In response to FSH, the Sertoli cells express a large number of differentiated gene products, such as transferrin, which transports iron to the developing germ cells. Previously, members of the basic helix-loop-helix (bHLH) family of transcription factors have been shown to influence FSH-mediated gene expression in Sertoli cells. The functions of the bHLH proteins are modulated by Id (inhibitor of differentiation) proteins, which lack the DNA-binding basic domain. The Id proteins form transcriptionally inactive dimers with bHLH proteins and thus regulate cell proliferation and differentiation. The current study investigated the expression and function of Id proteins in the postmitotic Sertoli cell. Freshly isolated and cultured Sertoli cells coexpress all four isoforms of Id (Id1, Id2, Id3, and Id4), as determined by immunoprecipitation with isoform-specific anti-Id antibodies, RT-PCR, and Northern blot analysis. Id2 and Id3 expression levels seem higher than Id1. Interestingly, the expression of Id4 in Sertoli cells is only detectable after stimulation with FSH or cAMP. The Id1 expression is down-regulated by FSH and cAMP, whereas Id2 and Id3 levels remain unchanged in response to FSH. In contrast, serum induces the expression of Id1, Id2, and Id3. Treatment of Sertoli cells with serum significantly reduces the expression of the larger 4-kb Id4 transcript and promotes the presence of a novel 1.3-kb transcript of Id4. The regulatory role of FSH in the expression of all four isoforms of Id is mimicked by a cAMP analog, suggesting that the actions of FSH are mediated through the protein kinase A pathway. An antisense approach was used to study the functional significance of Id proteins in Sertoli cells. Antisense to Id1 stimulated transferrin promoter activity in a transient transfection assay. Interestingly, an antisense to Id2 down-regulated transferrin promoter activity. Id3 and Id4 antisense oligonucleotides had no effect on FSH-mediated transferrin promoter activation. Contrary to the hypothesis that Id proteins have redundant functions, the results of the current study suggest that Id1, Id2, Id3, and Id4 are differentially regulated and may have distinct functions. Id1 may act to maintain Sertoli cell growth potential, whereas Id2 and Id4 may be involved in the differentiation and hormone regulation of Sertoli cells.

Animals↗
PubMed2001

Intestinal and blood parasites in Amazon parrots destined for relocation in Guatemala.

Approximately 350 Amazon parrots were destined for relocation in Peten province, northeastern Guatemala. In random sampling of the parrots, 95 blood and 75 fecal samples were examined individually for parasites. Coccidia were present in 6.0% (3/50) of Amazona autumnalis autumnalis, and they were the only parasites detected. There were no blood parasites observed in 64 A. a. autumnalis, four Amazona pionus senilis, 16 Amazona ferinosa guatemala, 10 Amazona albifronsus albifronsus, and one Amazona xantholora. No fecal parasites were observed in four A. p. senilis, 12 A. f. guatemala, eight A. a. albifronsus, and one A. xantholora.

Animals↗
PubMed2001

An economic model for determining the costs and consequences of using various treatment alternatives for the management of arthritis in Canada.

OBJECTIVE: To construct a decision analytical model to compare the costs and clinical consequences of treating patients with celecoxib or various nonsteroidal anti-inflammatory drug (NSAID)/gastrointestinal (GI) co-therapy regimens for the management of osteoarthritis and rheumatoid arthritis. The model quantified the number of patients expected to experience any GI complication commonly associated with NSAID therapy. DESIGN: Resource use for the treatment of each GI complication in the model was estimated after consulting Canadian experts. Standard unit costs from Ontario were applied to resources to calculate the cost of each complication. MAIN OUTCOME MEASURES AND RESULTS: The model revealed that the NSAID-alone regimen was associated with the lowest cost [$262 Canadian dollars ($Can) per patient per 6 months] followed by the celecoxib regimen ($Can273), diclofenac/misoprostol ($Can365), NSAID + histamine H2 receptor antagonist ($Can413), NSAID + misoprostol ($Can421), and NSAID + proton pump inhibitor ($Can731). A break-even analysis showed that up to 80% of the study cohort could be treated with celecoxib instead of the NSAID-alone regimen without increasing the health system's overall budget. Celecoxib was associated with the fewest GI-related deaths, hospitalised events; symptomatic ulcers, and cases of anaemia. The celecoxib regimen was also associated with the fewest cases of upper GI distress. Sensitivity analyses revealed that the model was most sensitive to the distribution of GI risk in the population and to the ingredient costs of the treatment alternatives. CONCLUSIONS: This model indicates that the use of celecoxib could lead to the avoidance of a significant number of NSAID-attributable GI adverse events, and the incremental cost of using celecoxib for arthritis patients > or = 65 years of age in place of current treatment alternatives would not impose an excessive incremental impact on a Canadian provincial healthcare budget.

Aged↗
PubMed2001

In vivo visualization of pyloric mucosal hypertrophy in infants with hypertrophic pyloric stenosis: is there an etiologic role?

OBJECTIVE: Infantile hypertrophic pyloric stenosis (IHPS) is a common condition which presents in infants at 2-12 weeks of postnatal life, and whose cause remains obscure. Multiple associated abnormalities have been recognized within the external hypertrophied pyloric muscle layer, but the internal component of the pyloric mucosa has received scant attention in the literature to date. Our purpose in this study was to show that pyloric mucosal redundancy is a constant finding in infants with IHPS, to discuss its possible cause, and to explore the hypothesis of a relationship between pyloric mucosal redundancy and the development of IHPS. MATERIALS AND METHODS: We identified 102 consecutive infants with surgically confirmed IHPS and determined the thickness of the pyloric mucosa compared with the thickness of the surrounding hypertrophied muscle. Fifty-one infants who did not have pyloric stenosis served as controls. RESULTS: Mean mucosal thickness in patients with IHPS approximated mean muscle thickness, with a ratio of 0.89. In infants with IHPS, the pyloric mucosa constitutes approximately one third of the cross-sectional diameter of the pyloric mass and fills and obstructs the pyloric canal. CONCLUSION: Mucosal redundancy is a constant associated finding in IHPS. Although the origin of the redundancy and a cause-and-effect relationship are difficult to establish, our findings support the hypothesis that hypergastrinemia may be implicated in the pathogenesis of IHPS, and suggest that mucosal thickening could be implicated as one of the initiating factors in its development.

Female↗
PubMed2001

Search and selection processes in implicit and explicit word-stem completion performance in young, middle-aged, and older adults.

In the present investigation, we sought to (1) replicate previous reports of impaired word-stem completion (WSC) priming and cued recall performance in older adults, (2) gain a better understanding of the differential roles of search and selection processes in implicit and explicit WSC, and (3) determine the particular aspects of WSC performance that are influenced by age. Experiment 1 demonstrated that older adults primed and recalled fewer items on a WSC task than middle-aged adults did, who in turn primed and recalled fewer items than young adults did. A series of item analyses indicated that choice of a stem completion is influenced by two independent sources of information: the familiarity of the completion reflected by word frequency and the cue-specific match between the stem and the completion word based on the common pronunciation of the stem. Experiment 2 demonstrated that older adults utilized cue-specific matching to the same degree as young and middle-aged adults. However, the impact of target familiarity changed across the lifespan. Older adults produced and recalled high-frequency targets as well as young adults but produced and recalled fewer low-frequency targets than did young participants. The results are consistent with the view that older adults rely on familiarity to a greater degree than do young adults.

Adolescent↗