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Biomedical subjects

R Mehl

Publications and source records attributed to R Mehl.

At least 37 records · Page 2Linked to original sources
PubMed1993

Predictors of frequent middle school health room use.

Disproportionately high use of school health room (HR) services by small groups of users has been reported. This study investigated predictors of frequent HR use in two suburban middle schools involving 1089 students who made at least one HR visit during a single academic year. Subsets of high and low users were compared using logistic regression. Predictor variables included gender, grade, academic ability, and existence of a chronic health condition. Although demographic characteristics of the study schools varied significantly, a pattern of increasing HR use associated with progressive lowering of academic ability was demonstrated in both schools. Existence of a chronic health condition was associated with increased HR use, even when controlling for routine medication visits. Gender and grade were not predictive. These findings suggest that HR use reflects more than medical concerns. Patterns of HR use by students with chronic health conditions deserve additional study to determine whether current strategies to meet their needs are adequate.

Adolescent↗
PubMed1992

Fleas (Siphonaptera) from seabirds and their nests in mainland Norway and Spitzbergen.

Ceratophyllus vagabundus insularis was recorded in all typical nesting cliffs in mainland Norway in nests of puffins, shags, cormorants, and kittiwakes, but not in nests of gulls. Ceratophyllus vagabundus vagabundus was recorded in Spitzbergen associated with geese and gulls. Ceratophyllus garei, the only flea species in Larus gull's nests, was present in small numbers in nests of kittiwakes and shags in the southern part of the investigation area. Mioctenopsylla arctica arctica was recorded in kittiwake nests on Spitzbergen and in one nesting cliff in the most arctic part of mainland Norway, where it also was the dominating species. C. vagabundus was reported to attack man.

Animals↗
PubMed1991

[Early serological diagnosis of nephropathia epidemica].

The viral disease nephropathia epidemica is probably more common throughout Norway than previously reported. Since 1986, outbreaks of the disease have been registered every year but in different regions of the country. Very few cases have been reported in certain counties in spite of the presence of a small rodent reservoir for this zoonosis. Nephropathia epidemica may be underdiagnosed, since the disease is not equally well recognized in all parts of Norway. However, effective and reliable serological diagnostic tests are now available which use a single serum sample taken early in the acute phase of the disease. Test results are available at a time when they can help the physician to make an early diagnosis. This should lead to a more effective and rational treatment of these patients.

Enzyme-Linked Immunosorbent Assay↗
PubMed1989

Intradermal challenge of Icelandic horses with extracts of four species of the genus Culicoides.

Twenty-three Icelandic horses were challenged with extracts of four species of biting midges: Culicoides pulicaris, C chiopterus, C obsoletus and C impunctatus. Fourteen of the tested horses were affected with summer eczema. The horses were challenged intradermally with 0.1 ml of whole-body extracts of midges at a concentration of 0.01 or 0.005 per cent weight/volume. The skin reactions were measured after 30 minutes, 60 or 180 minutes and four, 24 and 48 hours after injection. Antigen titration showed that the reaction was dependent on the antigen concentration. Eight of nine unaffected horses failed to respond to any of the four antigens; the remaining animal responding to two of the four antigens. Ten of the 14 affected horses responded to at least three of the four antigens, while two of the animals in this group failed to respond to any. The mean responses to C chiopterus, C obsoletus and C impunctatus, read after 30 minutes, 60 minutes and four hours were significantly higher in the affected horses than in the unaffected horses. A significant difference was also found in the mean response to C chiopterus and C impunctatus, read after 24 hours.

Animals↗
PubMed1988

Muscle is the major source of plasma gelsolin.

Gelsolin, a Ca2+- and polyphosphoinositide-regulated actin-binding protein, is unique among vertebrate proteins in being both cytoplasmic and secreted. Plasma gelsolin, present at greater than 200 micrograms/ml in human plasma, may have a protective function by promoting the clearance of actin filaments released during tissue injury. Although there is evidence that smooth muscle tissues and HepG2 cells synthesize plasma gelsolin, the predominant secretory source is hitherto unknown. We report here that skeletal, cardiac, and smooth muscles have large amounts of plasma gelsolin mRNA and devote 0.5-3% of their biosynthetic activity to plasma gelsolin, whereas liver makes relatively little. Since skeletal muscle accounts for a large fraction of body mass and total protein synthesis, it is the major source of plasma gelsolin.

Animals↗
PubMed1988

Genomic organization and biosynthesis of secreted and cytoplasmic forms of gelsolin.

Gelsolin is an actin regulatory protein which is unique among vertebrates in that it is found as both an intrinsic cytoplasmic protein and as a secreted plasma protein. We demonstrate that plasma and cytoplasmic gelsolins are derived by alternative transcriptional initiation sites and message processing from a single gene 70 kb long, containing at least 14 exons. Their message and amino acid sequences are identical except at the 5' end/NH2 termini. The cytoplasmic-specific 5' sequence is derived from two exons that encode untranslated sequence, while the plasma message-specific 5' sequence is derived from a single exon that encodes untranslated sequence, the signal peptide, and the first 21 residues of the plasma protein. The two transcriptional initiation sites are separated by greater than or equal to 32 kb. Biosynthetic and RNase protection studies indicate that a number of cell types make both plasma and cytoplasmic gelsolin in widely varying amounts and ratios.

Base Sequence↗
PubMed1988

Hemorrhagic fever with renal syndrome (nephropathia epidemica) in Norway: seroepidemiology 1981-1985.

An indirect fluorescent antibody technique (IFAT) was applied to serologically confirm the clinical diagnosis in 507 nephropathia epidemica (NE) suspected patients. Hantaan virus (HV), the agent of Korean hemorrhagic fever, which is serologically related to the NE agent, was used as antigen. Both IgG and IgM reactions were detected. High levels of IgG antibodies to HV were common, even in the acute phase of illness. Over a 5-year period, a total of 35% of the NE suspected patients revealed antibodies to HV, but this varied considerably in the different years. In 2 endemic areas the serological confirmation of the NE diagnosis was 60%. 82% of the seropositive NE patients lived in 4 endemic areas. The bank vole (Clethrionomys glareolus) was common in all areas and predominant in 2. The wood mouse (Apodemus sylvaticus) was abundant in the other 2. In years with high bank vole population, the number of seropositive NE cases increased, with a peak in October/November. When the bank vole population was low, the relatively few seropositive NE cases occurred more regularly throughout the year. Subclinical infections were common. Antibodies to HV were detected in 74% male and 26% female NE patients, but the ratio varied between age groups.

Adult↗
PubMed1986

Immediate type hypersensitivity in dogs induced by storage mites.

Results of intradermal skin tests on 53 dogs, employing storage mite extracts as antigen, indicated that storage mite allergy is fairly common. Only four of 29 dogs exhibiting no allergic symptoms showed skin reactions to the most common storage mite, Acarus siro, whereas 18 out of 24 dogs with symptoms assumed to be associated with allergy showed such reactions. The passive cutaneous transfer test revealed that an immediate type hypersensitivity reaction was involved.

Animals↗
PubMed1985

Mosquito-borne arboviruses in Norway: further isolations and detection of antibodies to California encephalitis viruses in human, sheep and wildlife sera.

Seven virus strains antigenically related to the California encephalitis (CE) virus group were isolated from Norwegian Aedes spp. mosquitoes collected in 1976. So far CE viruses have been isolated from five different Aedes spp. in Norway. Furthermore, two virus strains related to the Bunyamwera group were isolated from Anopheles claviger. Antibodies to CE viruses were demonstrated in 22% of 1014 military recruits tested. Among 91 soldiers who were monitored by monthly blood samples during the mosquito season, seroconversions were detected in 11 individuals. Specific IgM antibodies were found in seven of them. Disease symptoms in connexion with the CE virus infections were not seen. The prevalence of CE antibodies in patients with CNS or respiratory infections was not higher than in control groups. Seroconversions were not seen in any of the groups. Screening of sheep sera from six different areas in northern Norway indicated significantly different degrees of CE virus activity. Passerine birds may be important CE virus hosts, while small rodents seem unimportant. Specific IgM antibodies were detected in the sera of one of three hares and one of two squirrels. Of the methods used, single radial haemolysis (SRH) and immuno-electro-osmophoresis (IEOP) seemed to be well suited for serological screenings. However, an indirect immunofluorescence antibody test (IFAT) which was used may be an attractive alternative if high-quality anti-species conjugates are available. The haemagglutination-inhibition (HI) test used gave a high number of false positive results.

Aedes↗
PubMed1985

Reservoir animals for nephropathia epidemica in Norway: indications of a major role for the bank vole (C. glareolus) in comparison with the woodmouse (A. sylvaticus).

Small rodents were collected live in two different locations within a nephropathia epidemica (NE) endemic area, and tested for both antiviral serum antibodies and viral antigens in lung sections. In one location, only Apodemus sylvaticus (woodmice) were found in the traps, in the other, both A. sylvaticus and Clethrionomys glareolus (bank voles) were collected. Among the woodmice from the former location the prevalence of NE virus markers was significantly lower than for either woodmice or bank voles from the other location, and no NE antigen-positive animals was found. The woodmice co-existing with bank voles had a lower prevalence of NE antigen and antibodies than the bank voles, and fewer woodmice had both antibodies and antigen. The results emphasize the important role of bank voles as a major NE virus reservoir and probable source of human infections.

Animals↗
PubMed1984

Evidence for flavivirus(es) outside of the distribution area for Ixodes ricinus in Norway.

Small rodent (vole) sera were collected from three different locations in Norway. One of these was within the distribution area for Ixodes ricinus, and a tick-borne encephalitis (TBE) virus strain had been isolated from ticks collected there (Traavik & Mehl, 1977). The two other locations were outside the I. ricinus area, one in southern Norway, the other at nearly 70 degrees N. The sera were tested for TBE antibodies by hemagglutination inhibition (HI), hemolysis-in-gel (HIG) and complement fixation (CFT). All sera were also tested for HI antibodies to Uukuniemi (UUK) virus, and some positive TBE HI reactions were verified by separation of immunoglobulins and serum lipoproteins in NaBr gradients. Animals containing TBE virus antibodies reacting in all three serological tests and animals with UUK HI antibodies were detected only from the location within the I. ricinus area. From the two locations outside the I. ricinus area we found animals which had antibodies reacting with TBE virus in HI and HIG, but not in CFT. Antibodies to UUK were not detected. The results indicate that flavivirus(es) related to, but not identical with TBE viruses are transmitted by other vectors than I. ricinus in parts of Norway.

Animals↗