Search PubMed⌕ Search

Biomedical subjects

P Johnson

Publications and source records attributed to P Johnson.

At least 181 records · Page 10Linked to original sources
PubMed1997

Human granulocytic ehrlichiosis in a renal transplant patient: case report and review of the literature.

BACKGROUND: Human ehrlichiosis, a newly described zoonotic infection, can be classified as human monocytic ehrlichiosis (HME) or human granulocytic ehrlichiosis (HGE). Although the clinical manifestations of HME and HGE are similar, the type of leukocyte infected, the etiologic agent, and the tick vector are distinct. METHODS: We report the first case of HGE in a solid organ transplant recipient and review the literature on HGE. RESULTS: Our patient displayed typical epidemiological, clinical, and laboratory features and responded promptly to therapy with doxycycline. CONCLUSIONS: Although opportunistic infections are relatively common in the posttransplant population, one must always consider other infections that occur in normal hosts as well. Human ehrlichiosis should be included in the differential diagnosis for transplant patients with fever, cytopenias, and hepatitis, especially if exposure to ticks in endemic areas has occurred.

Aged↗
PubMed1997

Effects of antihypertensive drugs on rat tissue antioxidant enzyme activities and lipid peroxidation levels.

The effects of three commonly used antihypertensive agents (captopril, hydralazine, and terazosin) on tissue antioxidant enzymes and lipid peroxidation in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY rats) were studied by analysis of antioxidant enzyme specific activities and lipid peroxidation levels in control and drug-treated animals. In the myocardium, changes in some of the enzyme activities between normotensive WKY and hypertensive SHR rats were mitigated by treatment of the SHR rats with an antihypertensive drug. Thus, all three drugs caused significant increases in myocardial Cu/Zn superoxide dismutase (up to 133% of SHR control activity) and decreases in glutathione peroxidase (down to 59% of SHR control activity) to values that were closer to those in untreated WKY rats. Captopril also increased Mn superoxide dismutase activity, and hydralazine and terazosin decreased catalase activity towards untreated WKY values. Hydralazine was the only drug to alter the lipid peroxidation level in the myocardium of SHR rats (a 28% decrease), but in WKY rats all three drugs caused significant decreases in myocardial lipid peroxidation levels. In WKY rats, none of the drugs affected myocardial Mn and Cu/Zn superoxide dismutase activities, although glutathione peroxidase activity was decreased by hydralazine and terazosin treatment and catalase activity was increased by captopril treatment. Enzyme activity changes in liver and skeletal muscle indicated that such changes were often tissue specific. No pattern was found for coordinated changes in antioxidant enzyme expression as a result of the drug treatments, and the changes in antioxidant enzyme specific activities did not correlate generally with changes in lipid peroxidation levels.

Animals↗
PubMed1997

A simplified method for detubularization in the construction of a continent ileocolic reservoir (Miami pouch).

The development of continent urinary diversions was an important step forward in improving the quality of life of patients undergoing pelvic exenteration. While the technique is relatively simple, it can be very time-consuming and uses a significant portion of the patient's colon in its construction. Here a modification of the technique for construction of a continent ileocolic reservoir which results in a similar reservoir that uses less colon and requires less time to construct is presented. We also report results of the use of this technique in seven patients.

Aged↗
PubMed1997

Treatment of histoplasmosis with fluconazole in patients with acquired immunodeficiency syndrome. National Institute of Allergy and Infectious Diseases Acquired Immunodeficiency Syndrome Clinical Trials Group and Mycoses Study Group.

PURPOSE: This study assesses the efficacy and safety of fluconazole therapy in patients with acquired immunodeficiency syndrome (AIDS) and mild to moderately severe manifestations of disseminated histoplasmosis. PATIENTS AND METHODS: This was a multicenter, open-label, nonrandomized prospective trial. All patients had AIDS and disseminated histoplasmosis. Patients were treated with 1,200 mg of fluconazole given by mouth once on the first day, then 600 mg once daily for 8 weeks, and those patients who improved clinically were then assigned fluconazole maintenance therapy 200 mg once daily for at least 1 year. Interim analysis revealed a high failure rate (10 of 20, 50%), causing revision of the protocol to increase the fluconazole dose to 1,600 mg given once on the first day, then 800 mg once daily, and the duration to 12 weeks for induction therapy and then 400 mg daily for 1 year for maintenance therapy. MEASUREMENTS AND MAIN RESULTS: Thirty-six of 49 patients (74%; 95% confidence interval [CI]: 59% to 85%) with mild to moderately severe clinical manifestations who entered into the revised study responded to 800 mg of fluconazole daily for 12 weeks as induction therapy. Of the seven patients who failed induction therapy because of progression of histoplasmosis, one died of the infection. Of 36 patients who entered into the maintenance phase of the study receiving 400 mg of fluconazole daily for 1 year, 11 (30.5%) relapsed, including one who died (2.8%). Two of the 49 patients (4.1%) were removed because of grade 4 adverse events, alkaline phosphatase elevation for one and aspartate aminotransferase elevation in the other. The relapse-free rate at 1 year was 53% (95% CI: 32% to 89%), prompting closure of the study. CONCLUSIONS: Fluconazole 800 mg daily is a safe and moderately effective induction therapy for mild or moderately severe disseminated histoplasmosis in patients with AIDS. On the basis of historic comparison, fluconazole 400 mg daily is less effective than itraconazole 200 to 400 mg daily or amphotericin B 50 mg given weekly as maintenance therapy to prevent relapse.

AIDS-Related Opportunistic Infections↗
PubMed1997

Cannabinoid receptor gene (CNR1): association with i.v. drug use.

The receptors for tetrahydrocannabinol, the active ingredient of marijuana, have been identified. A microsatellite polymorphism (AAT)n at the cannabinoid CB1 (brain) receptor gene (CNR1) consists of 9 alleles. Since the cannabinoid system is part of the reward pathway we examined the hypothesis that genetic variants of the CNR1 gene might be associated with susceptibility to alcohol or drug dependence. The study consisted of 92 subjects on an Addiction Treatment Unit (ATU) and 114 controls. All were non-Hispanic Caucasians. The ATU subjects were screened for all types of substance dependence using the Diagnostic Interview Schedule (DIS), and for a variety of substance abuse symptoms using the Addiction Severity Index (ASI). Since inspection of the distribution of alleles in controls vs i.v. drug use showed a decrease in the frequency of the 4 allele, and the < 4 alleles were rare, the alleles were divided into two groups, < 5 and < or = 5, and three genotypes < 5/< 5, heterozygotes, and > or =/> or = 5. When all variables were subjected to factor analysis, factor 1 showed a clustering of drug dependence variables and factor 2 of alcohol dependence variables. By ANOVA only factor 1 showed significant differences by genotype consistent with a model where homozygosity for the > or = 5 repeat alleles showed the greatest effect. The number of i.v. drugs used was significantly greater for those carrying the > or =/> or = 5 genotype than for other genotypes (P = 0.005). The association with specific types of drug dependence was greatest for cocaine, amphetamine, and cannabis dependence. The results are consistent with a role of cannabinoid receptors in the modulation of dopamine and cannabinoid reward pathways. Independent studies should be designed to further confirm the hypothesis that cannabinoid receptors may contribute to the susceptibility to drug abuse.

Administration, Inhalation↗
PubMed1997

A mutation analysis on GYPC, the gene encoding the Gerbich blood group antigens.

The four exons of GYPC genomic DNA were amplified together with their flanking sequences and analysed by denaturing gradient gel electrophoresis (DGGE) or single-strand conformational analysis (SSCA). Exons 2 and 3 were amplified by a common set of primers so as to provide an internal control for exon deletion mutants. Ge:-2,-3,4(Ge) and Ge:-2,3,4(Yus) phenotypes were always associated with exon 3 and exon 2 deletions, respectively, as determined by DGGE. Ge:-2,-3,-4(Leach) was associated with a deletion of exons 3 and 4. Two single base mutations within exon 2 were detected, one of which represented the Ana allele and encoded an amino acid substitution. A previously undetected single base mutation in exon 3 encoded a Val61Ile substitution within the membrane spanning domain. DGGE analysis of exon 4 product revealed two distinct haplotypes of frequencies 41% and 59%. DGGE was not found suitable for analysis of exon 1, so SSCA was utilized. This method distinguished the single base mutation responsible for Wb antigen, but not that responsible for Dha.

Blood Group Antigens↗
PubMed1997

Limitations of school entry immunization certificates.

OBJECTIVE: To compare the immunization certificate submission rate for kindergarten school children on the Central Coast of New South Wales for 1994 and 1995; to contact individual parents of children with incomplete or missing immunization certificates by issuing a personalised immunization reminder letter, and measuring their response. METHODOLOGY: Seventy Central Coast schools were surveyed. Immunization documentation for 4177 kindergarten enrolements in 1995 were assessed. Children with incomplete or unknown immunization status were identified. Immunization reminder letters were sent by the schools to parents of the children that were identified. The school recorded any additional immunization certificates submitted. RESULTS: In 1995, 79% of kindergarten children submitted immunization certificates, unchanged from the previous year. Immunization reminder letters were sent to 856 families of children with no certificate and 215 families of children with an incomplete certificate. A further 263 immunization certificates were submitted, representing a 25% response rate. This intervention increased the percentage of kindergarten children with a certificate from 79% to 86%. CONCLUSIONS: Education of school staff during the 1994 immunization survey did not change the overall immunization certificate submission rate. Specifically targeting parents through schools can be an effective way of increasing immunization certificate submission.

Child, Preschool↗
PubMed1997

Evaluating the merits of option-3 methods in relative attachment level measurement in a healthy population.

Attachment loss is the principal clinical indicator for periodontal disease progression. However, the attachment measurement can be inaccurate due to outliers. A remedial scheme, the option-3 scheme, has been suggested in the literature. This scheme involves first measuring the relative attachment twice at any given site. A third measurement is required if there is a large disagreement between the first two probings. When the third measurement is taken, there are several possible ways to make the final assessment of the true attachment level. Among them are the average of the 3 measurements, the average of the closest 2, and the median of the 3. This report evaluates the merits of the option-3 scheme by comparing it with other schemes to reduce measurements variance and outliers. Since true attachment levels are unknown, we chose to check accuracy through measurement consistency between visits in healthy subjects using the fact that such subjects should have little real change in attachment levels. 12 healthy subjects participated in the study. They visited the clinic 4 times in 4 months. Two types of the Florida stent probe were used by 2 calibrated examiners. It was found that option-3 schemes were more accurate than a single probing or duplicate probings in estimating the relative attachment level. The 3 final assessment schemes performed almost equally well from a practical standpoint, but the median was the best among them in a statistical sense.

Adult↗
PubMed1997

Influence of topical human epidermal growth factor on postkeratoplasty re-epithelialisation.

AIM: To test the efficacy and safety of recombinant human epidermal growth factor (hEGF) on corneal re-epithelialisation following penetrating keratoplasty. METHODS: A prospective, randomised, placebo controlled study was carried out in which patients were matched for diagnosis and received either hEGF ophthalmic solution (30 micrograms/ml or 100 micrograms/ml) or placebo in a double masked fashion. Matched pairs of patients received donor corneas from the same donor and were operated by the same surgeon on the same day. At the end of surgery all donor epithelium was removed mechanically. Patients were examined twice daily and fluorescein stained photographs were taken until the epithelium had closed. The area of the defect was measured by planimetry of the fluorescein stained defect on the photographs. RESULTS: There were no significant differences in re-epithelialisation of the donor cornea between the placebo group and the group treated with 30 micrograms/ml hEGF. Time until complete closure was slightly longer with 100 micrograms/ml hEGF compared with 30 micrograms/ml hEGF and with placebo. Mean healing rate of the epithelial defect with 100 micrograms/ml hEGF was significantly slower than in the other groups. CONCLUSION: No significant acceleration of corneal re-epithelialisation was demonstrated with the use of recombinant hEGF after penetrating keratoplasty in humans.

Administration, Topical↗
PubMed1997

Telematics for clinical guidelines: a conceptual modelling approach.

PRESTIGE is a project for applying telematics to assist the dissemination and application of clinical practice guidelines and protocols. Previous publications have described PRESTIGE's technical approach, including the use of a generic model for representing the knowledge content of clinical guidelines. This approach offers the possibility of 'plug-and-play' electronic distribution of clinical guidelines produced by multiple authoring bodies for use on multiple healthcare clinical management software platforms. A recent joint workshop held with the Section on Medical Informatics, Stanford University School of Medicine compared the European consensus approach developed in PRESTIGE with a parallel series of projects for computer-assisted protocol-based healthcare undertaken at Stanford and other American centres over the past, which confirmed the convergence and complementarity of our approaches, and holds out prospects of world-wide standardization in healthcare protocol knowledge representation. This paper summarises PRESTIGE conceptual model set which is the design of the project's approach.

Artificial Intelligence↗