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Biomedical subjects

J Blomgren

Publications and source records attributed to J Blomgren.

At least 19 recordsLinked to original sources

Measurement of the absolute n p scattering differential cross section at 194 MeV.

We describe a double-scattering experiment with a novel tagged neutron beam to measure differential cross sections for np backscattering to better than +/-2% absolute precision. The measurement focuses on angles and energies where the cross section magnitude and angle dependence constrain the charged pion-nucleon coupling constant, but existing data show serious discrepancies among themselves and with energy-dependent partial-wave analyses. The present results are in good accord with the partial-wave analyses, but deviate systematically from other recent measurements.

Journal Article↗

Non-physiological levels of circulating cortisol in growth hormone-treated hypopituitary adults after conventional cortisone substitution.

OBJECTIVE: To assess the usefulness of measuring plasma cortisol profiles in growth hormone-treated hypopituitary adults and to compare these with cortisol levels in healthy controls. METHODS: Eleven ACTH-deficient adult patients received 12.5 mg cortisone-acetate orally at 16.00 h and 25 mg at 07.00 h. The patients arrived in the ward at 12.00 h. After tablet intake at 16.00 h, samples for serum cortisol were taken at hourly intervals for the next 24 h, except between 07.00 and 12.00 h when samples were drawn every half hour; 24-h urinary free cortisol (24-h-UFC) excretion was collected simultaneously. For comparison, 8 healthy controls were investigated. RESULTS: The patients had circulating cortisol levels with very low plasma cortisol at 07.00 h before their morning dose of cortisone acetate. At the same time period, controls had their highest plasma cortisol levels. After tablet intake the patients had a rapid initial absorption of cortisol, but a marked variability in the morning peak levels (Cmax), and the Cmax was in general higher and occurred 90 min later than the Cmax in the controls. The 24-h-UFC excretion and 24-h area under the curve (24-h-AUC) did not differ between patients and controls. The female patients had higher 24-h-AUC for plasma cortisol (p=0.032) and tended to have higher plasma cortisol peaks in the morning, but had levels of 24-h-UFC similar to those of the male patients. CONCLUSIONS: Conventional cortisone substitution with a twice-daily replacement regimen in hypopituitary adults results in abnormal circulating cortisol profiles with low or non-measurable morning values and variable individual peaks. This suggests that the present dosing schemes have to be improved and that cortisone substitution should be individualized.

Adult↗

Beyond kerma--neutron data for biomedical applications.

Presently, many new applications of fast neutrons are emerging or under development, like dose effects due to cosmic-ray neutrons for airplane crew, fast-neutron cancer therapy, studies of electronics failures induced by cosmic-ray neutrons, and accelerator-driven incineration of nuclear waste and energy production technologies. All these areas would benefit from improved neutron dosimetry. In this paper, the present rapid progress on measurements of double-differential neutron-induced nuclear reaction data are described. With such data at hand, the full response of, in principle, any system, including human tissue, can be calculated in detail. This could potentially revolutionise our understanding of biological effects in tissue due to fast neutrons.

Fast Neutrons↗

Mechanism of topical glucocorticoid treatment of hay fever: IL-5 and eosinophil activation during natural allergen exposure are suppressed, but IL-4, IL-6, and IgE antibody production are unaffected.

BACKGROUND: Allergic rhinitis is traditionally defined as an IgE- and mast cell-mediated hypersensitivity reaction. Allergen challenge models suggest that cytokines and eosinophil mediators may also play roles. However, the causal relationship among inflammatory cells, their products, and patients' symptoms during natural allergen exposure has not been established. OBJECTIVE: We sought to elucidate the mechanisms of seasonal allergic rhinitis and the beneficial effects of topical glucocorticoids. METHODS: Thirty patients with ragweed-induced hay fever and a strongly positive serologic test response for ragweed IgE antibody received budesonide nasal spray or placebo in a randomized, parallel, double-blind study. Nasal wash fluids and sera were collected before and during the hay fever season. The levels of inflammatory mediators and allergen-specific immunoglobulins were measured by immunoassay. The activation markers on blood eosinophils were quantitated by flow cytometry. RESULTS: Compared with placebo-treated patients, budesonide-treated patients had strikingly reduced symptoms. In the placebo group, nasal symptoms correlated with nasal lavage fluid eosinophil-derived neurotoxin and IL-5 levels. At the season peak, the budesonide-treated group had significantly lower nasal fluid eosinophil-derived neurotoxin, IL-5, and soluble intracellular adhesion molecule-1 levels. In the treated group eosinophil expression of CD11b was suppressed at the season peak. In contrast, levels of IL-4 and IL-6 in nasal fluid and the seasonal increases in serum ragweed-specific IgE and nasal fluid IgA antibodies did not differ between groups. CONCLUSION: Eosinophilic inflammation plays a critical role in seasonal allergic rhinitis symptoms. One of the therapeutic effects of glucocorticoids is to suppress this inflammation.

Administration, Topical↗

Fluconazole versus nystatin in the treatment of oral candidosis.

The efficacy of oral fluconazole versus nystatin was evaluated as a treatment modality for oral candidosis. Of the included patients (n = 60), two-thirds presented with an erythematous candidosis, and the others showed clinical signs compatible with a pseudomembranous candidosis. Predisposing factors were xerostomia (n = 18), HIV (n = 5), immunosuppression in conjunction with organ transplantation (n = 10), and wearing of dentures (n = 14). For the remaining patients no specific predisposing factors were found. One patient who was treated with nystatin was excluded owing to nausea that was related to the antifungal treatment. After 7 days of treatment with fluconazole (50 mg/day), the affected oral mucosa, assessed by the investigator, was cured or showed considerable improvement in 87% of the patients (n = 30). The corresponding figure for the nystatin group (n = 30), rinsing with 1 mL 4 times a day for 21 days, was 80%. Following treatment with fluconazole, 20 of 22 patients with symptoms at the start (91%) reported improvement. The comparable figures for the nystatin group were 10 of 12 patients (83%). Half of the patients in the nystatin group reported inconvenience from taking the medication (mean value = 25.9) compared with 23% of the patients in the fluconazole group (mean value = 6.6). Eight patients in the fluconazole group and 12 patients in the nystatin group exhibited a relapse within 6 months. These differences were not found to be statistically significant. The patients in the fluconazole group reported less inconvenience from taking the medication, a finding that may have clinical implications for compliance.

Administration, Oral↗

Oral hairy leukoplakia in a patient with multiple myeloma.

The first case of oral hairy leukoplakia in an HIV-negative patient with multiple myeloma is reported. The patient is a 56-year old man who has had monoclonal gammopathy of undetermined significance since 1986 and has been treated for a symptomatic multiple myeloma since 1993. The clinical and histopathologic findings are typical for oral hairy leukoplakia, and Epstein-Barr virus was demonstrated with polymerase chain reaction technique. Although a relatively large number of cases of oral hairy leukoplakia has been reported in HIV-negative patients, both immunocompromised and immunocompetent, only a few of these patients have had a malignant hematologic disease.

Antineoplastic Combined Chemotherapy Protocols↗

Adverse reactions in the oral mucosa associated with anterior composite restorations.

This is a descriptive study of patients with symptomatic lichenoid-like reactions of the lips in contact with composite restorations (n = 12). Clinically, the lesions appeared as symptomatic single or multiple erythematous areas that included white papules. Candida was found by cultivation or histopathological examination in 7 of the lesions. Patch testing (n = 7) did not reveal any reactions to composite components, except for one patient who showed a delayed hypersensitivity reaction to formaldehyde. Replacement of existing dental materials parallel to antifungal treatment resulted in healing or significant improvement in 7 of 9 patients. This study shows that resin components can be associated with adverse reactions in the oral mucosa of the lips and that these reactions may be accompanied by an infection with Candida.

Adult↗

Ragweed-specific IgA in nasal lavage fluid of ragweed-sensitive allergic rhinitis patients: increase during the pollen season.

Because the secretions of asthma and rhinitis contain toxic eosinophil granule proteins and because secretory IgA is the most potent immunoglobulin stimulus for eosinophil degranulation, we measured eosinophil-derived neurotoxin and ragweed-specific IgA and IgE antibodies in nasal lavage before and during the ragweed pollen season in 44 hay fever patients. We found IgA antibody in nanogram/milliliter concentrations before the season and rising 20-fold by the end of the season. IgE antibody was present in picogram/milliliter concentrations and did not change. Eosinophils and eosinophil-derived neurotoxin also increased. We conclude that IgA is the predominant antibody in allergic nasal secretions and increases with allergen exposure. The hypothesis that secretory IgA antibody-allergen complexes contributes to allergic inflammation by stimulating eosinophil degranulation warrants further study.

Humans↗