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Biomedical subjects

R Mehl

Publications and source records attributed to R Mehl.

15 recordsLinked to original sources
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↗
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↗
PubMed1978

The first tick-borne encephalitis virus isolates from Norway.

Five virus strains with close serological relationship to the tick-borne encephalitis (TBE) complex have been isolated from Ixodes ricinus ticks. The ticks were collected in early June 1976 at three different locations in Sogn & Fjordane County, Norway. One of the virus-yielding pools was composed of ticks collected between the cabins on a tourist camping ground.

Animals↗
PubMed1978

California encephalitis group viruses isolated from mosquitoes collected in Southern and Arctic Norway.

Three virus strains serologically related to the California encephalitis group (Bunyaviridae) of arboviruses were isolated from 7331 mosquitoes collected in Norway in June-August 1975. Two of the isolates (S 548 and S 618) seemed to be closely related and the third, S 568, more distantly related by serological techniques to Tahyna virus. Viruses were found in the mosquito species Aedes sticticus, A. diantaeus and A. hexodontus colllected (in order) from Oyern (59 degrees N, 11 degrees 12' E), Trandum (60 degrees 08' N, 11 degrees 10' E) and Masi (69 degrees 26' N, 23 degrees 39' E). The Masi isolate seems to be the northernmost arbovirus isolate in the world so far. Strain S 568 was from 16 male A. diantaeus, indicating transovarial transmission of the virus. An accidental infection demonstrated the potential human pathogenicity of one of the newly-isolated strains (S 568), and the ability of CE viruses to persistently infect suckling mouse brains was indicated by in vivo findings. The biological characteristics of the new strains so far investigated are consistent with those of the California encephalitis group. During this work the Aerosil absorption method for production of haemagglutinating antigens proved useful for Tahyna virus and the newly-isolated strains. Trypsinization of erythrocytes improved the haemagglutinating capacities of these viruses.

Animals↗
PubMed1977

"Runde" viurs, a coronavirus-like agent associated with seabirds and ticks.

From 206 I. uriae collected in the seabird colonies at Runde, Norway, two identical virus strains demonstrating no antigenic relationships to major arbovirus groups were isolated. The new strains demonstrated a corona-virus like morphology, haemagglutinated chicken red cells and were sensitive to sodium desoxycholate. Multiplication with CPE was demonstrated in BHK 21/c13 and BSC-1 cells, and without CPE in Vero and GMK cell cultures. The mouse pathogenicity was relatively low. In gel precipitation three to five specific lines were seen. Precipitating antibodies have been found in seabird species commonly infested by I. uriae. The ecological cirucmstances of the isolates indicate an earlier unrecognized arbovirus circulating between seabirds and I. uriae. This corona-like virus has been tentatively termed Runde virus.

Animals↗
PubMed1975

Tick-borne viruses in Norway.

The purpose of the investigation was to chart the existence and extent of arboviruses in Norway and provide information on their possible significance. Virus isolations have been attempted from ticks (I. ricinus, I. trianguliceps, I. uriae) and host animal blood from selected locations. Serological screenings have been performed with bird, small mammal, cattle and human blood. Five virus strians have been identified to date. Three of them are related to Uukuniemi virus group. Two identical strains from I. uriae demonstrate the morphology of coronaviruses and no antigenic relationship to major arbovirus groups. Within the distribution areas of I. ricinus, antibodies to tick-borne encephalitis virus are prevalent in cattle. Antibodies to Uukuniemi viruses are found in passerine birds, small mammals, cattle and man. Antibodies to the coronavirus like agents have been demonstrated in seabirds.

Animals↗