| 1. |
- Bohgard, Mats, et al.
(författare)
-
Kontinuerliga tvåfraktionsinsamlare för övervakning av partikulära luftföroreningar i arbetsmiljö
- 1981
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten beskriver prototyper av kontinuerliga tvåfraktionsinsamlare för övervakning av partikulära luftföroreningar i arbetsmiljö som har konstruerats. En prototyp är personburen och ger möjligheter till insamling av två partikelstorleksfraktioner i 18 diskreta intervall. PIXE-metoden (analys med partikelinducerad röntgenstrålning) används för multielementanalys av de erhållna proven. Även med mycket korta insamlingstider, ner till 5 minuter, blir detektionsgränserna för de flesta element av yrkeshygieniskt intresse väsentligt lägre än sina respektive hygieniska gränsvärden. Rapporten inkluderar resultat från en enkel fältmätning som utgör ett exempel på de möjligheter den personburna provtagaren ger för yrkeshygieniska mätningar och undersökningar
|
|
| 2. |
- Moestrup, T, et al.
(författare)
-
Long term follow up of chronic hepatitis B virus infection in intravenous drug abusers and homosexual men
- 1986
-
Ingår i: BMJ: British Medical Journal. - 1756-1833. ; 292:6524, s. 854-857
-
Tidskriftsartikel (refereegranskat)abstract
- Long term follow up of 16 homosexual men and 78 intravenous drug abusers who were chronic carriers of hepatitis B surface antigen (HBsAg) showed fundamental differences between the two groups. Viral replication, expressed by the presence of hepatitis B e antigen, lasted for four years or more in 10 out of 14 (71%) of the homosexual men whereas it was not present in 43 out of 73 (59%) of the drug addicts within one year. This shows a difference in the immunological response between homosexual HBsAg carriers and addicts that is not related to infection with human T cell lymphotropic virus type III. Severe histological damage such as chronic aggressive hepatitis, cirrhosis, or primary liver cancer was found in more than half of the homosexual men who underwent biopsy examinations. In drug addicts chronic persistent hepatitis was a regular finding in the absence of markers of delta infection, but in those addicts infected with the delta agent the degree of liver damage was comparable with that found in homosexual men.
|
|
| 3. |
|
|
| 4. |
- Swietlicki, Erik, et al.
(författare)
-
PIXE elemental characterization of air masses using a multivariate statistical technique
- 1987
-
Ingår i: Nuclear Inst. and Methods in Physics Research, B. - 0168-583X. ; 22:1-3, s. 264-269
-
Tidskriftsartikel (refereegranskat)abstract
- An example is given to show the possibility of using a multivariate statistical evaluation technique in order to extract more information from a multielemental PIXE data set. Four weeks of continuous sampling was carried out at a background air pollution monitoring station in Sweden. Samples were collected both in fine and coarse mode, with a cutoff at 2 μm. In the subsequent PIXE analysis of the samples, 12-16 elements were detected in the fine fraction and 9-12 elements in the coarse fraction. The fine fraction PIXE data was further analysed using the multivariate statistical programme package SIMCA, which combines a pattern recognition technique and principal component analysis. Based on 1000 mbar back trajectories for the sampling period, principal component class models were constructed for Easterly and North-Westerly air masses using 15 elements (S, K, Ca, Ti, V. Cr, Mn, Fe, Ni, Cu, Zn, Ga. As, Br and Pb). For these elements, mean concentration values and standard deviations for the two classes are given. A methodology is presented which excluded outliers and facilitated the calculation of classes with a restricted and definable data distribution representative of the elemental composition of the air masses originating from the two source regions.
|
|
| 5. |
- Widell, Anders, et al.
(författare)
-
A microcarrier cell culture system for large scale production of hepatitis A virus
- 1984
-
Ingår i: Journal of Virological Methods. - : Elsevier BV. - 1879-0984 .- 0166-0934. ; 8:1-2, s. 63-71
-
Tidskriftsartikel (refereegranskat)abstract
- Hepatitis A virus (HAV) was isolated from human faeces using a fetal rhesus monkey kidney cell line (Frhk-4). Infectious medium from passage 12 was used to inoculate a large (5000 cm2) microcarrier cell culture maintained in suspension. The microcarriers used were swollen, collagen-coated dextran beads on which it was easy to propagate Frhk-4 cells. Intra- and extra-cellular virus levels were assayed and compared with conventional cultures in 25 cm2 plastic flasks. The results show that virus production per cell was similar in both systems. The number of cells per area unit in confluent cultures was initially lower in the microcarrier culture but subsequently increased. Two to three weeks post inoculation the virus yield per area unit in the microcarrier system was half of that of the conventional culture. The lower cell density per area unit in the microcarrier system was compensated by the large growth area that could be maintained in a single vessel and the total production of virus was substantial. Weekly harvests of medium with HAV antigen titres around 10(-2) contained antigenic material sufficient for several thousands of anti-HAV IgM tests. Propagation of HAV in microcarrier cell cultures thus seems a safe and simple way to produce large amounts of HAV.
|
|
| 6. |
- Widell, Anders, et al.
(författare)
-
Enhancement of hepatitis A propagation in tissue culture with 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole
- 1988
-
Ingår i: Journal of Medical Virology. - : Wiley. - 1096-9071 .- 0146-6615. ; 24:4, s. 369-376
-
Tidskriftsartikel (refereegranskat)abstract
- The adenosine analog 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) was found to increase the production of hepatitis A (HAV) antigen in two monkey kidney cell lines (Frhk-4 and Vero cells). DRB, a known inhibitor of the synthesis of messenger RNA, caused moderate changes in cell morphology. However, Frhk-4 cells could be maintained for several weeks at 80 microM of DRB, the concentration that caused maximal enhancement on HAV. DRB should be present from about the time of virus inoculation and its strongest effect was seen at low multiplicities of infection. Using radioimmunofocus assay it could be shown that DRB increased the amount of infectious virus. DRB treatment was applied in primary isolation of HAV from feces. In nine of ten strains HAV antigen expression was strongly increased and in six of the ten strains infectivity of harvested material increased by one 10log or more. DRB thus seems to be a useful enhancer of HAV growth in tissue culture.
|
|
| 7. |
- Widell, Anders, et al.
(författare)
-
Influence of twenty potentially antiviral substances on in vitro multiplication of hepatitis A virus
- 1986
-
Ingår i: Antiviral Research. - : Elsevier BV. - 0166-3542. ; 6:2, s. 103-112
-
Tidskriftsartikel (refereegranskat)abstract
- A multiwell tissue culture system was developed to study the influence of various substances on hepatitis A virus (HAV) propagation. A panel of 20 substances of different structure types, each with known effect against at least some viruses, was studied at a concentration of 100 microM. Three substances showed reproducible inhibition. The strongest inhibitor, arabinosylcytosine, also produced cytotoxic changes in cells down to a concentration of 1 microM, and its effect was considered as nonspecific. Amantadine and ribavirin showed a moderate effect at 100 microM. A stronger inhibition was seen at 250 and 500 microM, doses that are toxic and impractical for clinical use. Although no promising candidates for antiviral treatment of hepatitis A have emerged from the present study, the assay model described here would seem useful in the screening of substances with inhibitory effects on HAV.
|
|
| 8. |
- Widell, Anders, et al.
(författare)
-
Post-transfusion hepatitis type non-A, non-B in southern Sweden: occurrence and clinical significance
- 1987
-
Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 1651-1980 .- 0036-5548. ; 19:6, s. 603-610
-
Tidskriftsartikel (refereegranskat)abstract
- Two prospective studies of the occurrence and clinical significance of post-transfusion hepatitis non-A, non-B were performed in Malmo, Sweden. In both studies, patients of a broad clinical spectrum were followed up 6 and 12 weeks after transfusion. In a 7 week study from 1983, hepatitis non-A, non-B occurred in 9/173 transfused patients (5.2%) versus 1/203 untransfused controls (0.5%) (p less than 0.01). In a 6 month study from 1984-85, the incidence of hepatitis non-A, non-B had declined to 2.4% (18/739 transfused patients). The mean number of transfused units was about 5 in both studies and most patients had subclinical disease. Despite similar transfusion volumes to patients above or below 70 years of age, hepatitis non-A, non-B was predominantly seen among patients less than 70 years. In the 1984-85 study, hepatitis non-A, non-B incidence was 1.2% in recipients greater than or equal to 70 years, 3.4% in recipients less than 70 years and 4.5% in recipients less than 40 years. One year after the initial hepatitis non-A, non-B episode, 4/18 patients (22%) had biochemical signs of chronic hepatitis.
|
|
