Biomedical subjects
G R Hansen
Publications and source records attributed to G R Hansen.
An outbreak of Campylobacter jejuni infections associated with food handler contamination: the use of pulsed-field gel electrophoresis.
In 1998, an outbreak of Campylobacter jejuni infections occurred in Kansas among persons attending a school luncheon; community cases were also reported. In a cohort study of luncheon attendees, 27 (17%) of 161 persons reported illness. Consuming gravy (relative risk [RR], 4.2; 95% confidence interval [CI], 1.5-11.7) or pineapple (RR, 2.4; 95% CI, 1.0-5.7) was associated with illness. Both foods were prepared in a kitchen that served 6 other schools where no illness was reported. A cafeteria worker at the luncheon had a diarrheal illness and was the likely source of the outbreak. The pulsed-field gel electrophoresis (PFGE) patterns of the isolates from the food handler and those of 8 lunch attendees were indistinguishable. Isolates from 4 community patients differed. This was the first use of PFGE in a Campylobacter outbreak in the United States; its use was critical in determining that community cases were not linked.
The incubation period of hantavirus pulmonary syndrome.
In 1993 Sin Nombre virus was recognized as the cause of hantavirus pulmonary syndrome (HPS) and the deer mouse (Peromyscus maniculatus) was identified as the reservoir host. Surveillance by the Centers for Disease Control and Prevention and state health departments includes investigation to determine the likely site(s) and activities that led to infection, an environmental assessment of the home and workplace, and possibly rodent trappings at these sites. As of December 31, 1998, there were 200 confirmed cases from 30 states (43% case-fatality ratio). The national HPS case registry was examined to determine the incubation period of HPS. Review of 11 case-patients with well-defined and isolated exposure to rodents suggests that the incubation period of HPS is 9 to 33 days, with a median of 14-17 days. Case investigations allow a better understanding of the incubation time of HPS and may define high-risk behaviors that can be targeted for intervention.
Brucellosis induced by RB51 vaccine in a pregnant heifer.
Brucellosis developed in a 14.5-month-old Gelbvieh heifer after the animal was vaccinated with the calfhood dose of strain RB51 Brucella abortus vaccine s.c. during the fourth month of its first pregnancy. The heifer experienced dystocia and was euthanatized during cesarean section because of a large uterine tear. The fetus was dead at delivery. Suppurative placentitis and fetal pneumonia were evident at necropsy. Brucella abortus strain RB51 was isolated from the placenta and the fetus' lung.
Loratadine in the high performance aerospace environment.
BACKGROUND: Authors have unanimously reported that 10 mg of loratadine does not produce sedation. A small risk of sedation may exist and may not have been discovered by those studies due to their small sample size. HYPOTHESIS: Using combined data, there is no increased risk of sedation over placebo for patients using 10 mg of loratadine daily. METHODS: Literature search and meta-analysis of published data was performed. RESULTS: Pooled data showed sedation in 25 of 517 patients given 10 mg of loratadine, and 24 of 510 patients given placebo. The relative risk was 1.03, with a confidence interval from 0.59 to 1.77. Sleepiness was objectively studied using the multiple sleep latency test. Patients treated with 10 mg of loratadine did not have excess sleepiness induced; patients treated with 40 mg of loratadine did. Using 10 different methods, 20 studies did not find performance impairment in subjects given 10 mg of loratadine. Two performance studies, digit substitution and driving, showed impairment with 20 mg and 40 mg of loratadine, respectively. Physiologic studies using resting EEG had conflicting reports. There was no impairment detected in altitude studies or vestibular studies. No centrifuge or color vision data were found. CONCLUSION: Ingesting 10 mg of loratadine daily does not have sedative effects or impair cognitive-motor performance. Higher doses have demonstrated impairment. Aviation concerns that have not been addressed include centrifuge studies and color vision studies. It would be reasonable to employ loratadine in the high performance aerospace environment if these latter tests prove to be negative.
The relationship between fatigue, psychological and immunological variables in acute infectious illness.
OBJECTIVE: The aim of this paper is to explore the longitudinal relationships between physical and psychological symptoms and immunological factors following acute infective illnesses. METHOD: Preliminary data from a prospective investigation of patients with serologically proven acute infectious illnesses due to Epstein-Barr virus (EBV), Ross River virus (RRV) or Q fever are reported. Patients were assessed within 4 weeks of onset of symptoms and then reviewed 2 and 4 weeks later. Physical illness data were collected at interview. Psychological and somatic symptom profiles were assessed by standardised self-report questionnaires. Cell-mediated immune (CMI) function was assessed by measurement of delayed-type hypersensitivity (DTH) skin responses. RESULTS: Thirty patients who had been assessed and followed over the 4-week period (including 17 patients with EBV, five with RRV and eight with Q fever) were included in this analysis. During the acute phase, profound fatigue and malaise were the most common symptoms. Classical depressive and anxiety symptoms were not prominent. Initially, 46% of cases had no DTH skin response (i.e. cutaneous anergy) indicative of impaired cellular immunity. Over the 4-week period, there was a marked improvement in both somatic and psychological symptoms, although fatigue remained a prominent feature in 63% of subjects. The reduction in reported fatigue was correlated with improvement in the DTH skin response (p = 0.001) and with improvement in General Health Questionnaire (GHQ) scores (p < 0.01). CONCLUSIONS: Acute infectious illnesses are accompanied by a range of nonspecific somatic and psychological symptoms, particularly fatigue and malaise rather than anxiety and depression. Although improvement in several symptoms occurs rapidly, fatigue commonly remains a prominent complaint at 4 weeks. Resolution of fatigue is associated with improvement in cell-mediated immunity.
Monitoring of ajmaline in plasma with high-performance liquid chromatography.
A rapid, reliable and sensitive assay for routine determination of ajmaline in plasma by high-performance liquid chromatography with fluorimetric detection is presented. A low limit of detection in plasma (less than 1 ng/ml ajmaline) could be achieved by the extraction of plasma samples and the use of fluorimetric detection. Deproteinization of the plasma sample instead of extraction, or the use of an ultraviolet detector, yielded a higher limit of detection (less than 50 ng/ml). Two different eluents were studied. Eluent 1 allowed clear separation of ajmaline from isoajmaline and sandwicine, but did not separate isoajamaline from sandwicine. With eluent 2, separation of isoajmaline and sandwicine was achieved, but separation of ajmaline from sandwicine was less optimal than with eluent 1. Therefore, eluent 1 was used for further clinical studies. No interference was observed from therapeutic doses of other commonly co-administered drugs, such as acetylsalicylic acid, digoxin, digitoxin, ranitidine, dopamine, dobutamine, furosemide, captopril or glycerol trinitrate. In addition, the chemical stability of ajmaline and a possible rearrangement of ajmaline to its stereoisomers isoajmaline and sandwicine was studied in vivo and in vitro. Ajmaline proved to be unusually stable under both in vivo and in vitro conditions.
Security investigations in a healthcare environment.
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Practice tip . . . the cauliflower ear.
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Sonographic evaluation of a left ventricular aneurysm presenting as an upper abdominal mass.
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Optimal use of fluorescamine for in situ thin-layer chromatographic quantitation of amino acids.
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