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Biomedical subjects

A Nilsen

Publications and source records attributed to A Nilsen.

At least 19 recordsLinked to original sources
PubMed2005

Prevalence of, and risk factors for, HSV-2 antibodies in sexually transmitted disease patients, healthy pregnant females, blood donors and medical students in Tanzania and Norway.

The prevalence of specific HSV-2 antibodies was studied in Tanzanian and Norwegian sexually transmitted disease (STD) patients (1095) and non-STD patients (488). Correlates to demographic and behavioural factors were evaluated. Seropositivity was determined by the non-commercial peptide-55 enzyme-linked immunoassay. The prevalence of HSV-2 antibodies was 70% in Tanzanian and 17% in Norwegian STD patients, 35% in Tanzanian blood donors and pregnant women, and 4, 7 and 14% in Norwegian medical students, blood donors and pregnant women respectively. A higher HSV-2 prevalence was associated with female sex, increasing age, previous STDs, history of genital HSV infection, coitarchal age (age at first intercourse) <15 years and HIV seropositivity. Compared to previous data, the prevalence of HSV-2 antibodies in Tanzanian STD patients has increased remarkably. In Norwegian STD patients our results are consistent with, or lower than, the prevalence previously reported in Western Europe. Demographic rather than behavioural factors were associated with higher prevalence of HSV-2 antibodies in STD patients.

Adolescent↗
PubMed2000

Changing trends in genital herpes simplex virus infection in Bergen, Norway.

AIM OF STUDY: To document the proportion of each herpes simplex virus (HSV) type in genital HSV infection and changes over time during a 10 year period. DESIGN: Retrospective comparative study in sexually transmitted disease (STD) patients with genital HSV infection at the outpatient clinic for STD, Haukeland Hospital, Bergen, Norway. RESULTS: HSV-2 was the major cause during the 80's, whereas HSV-1 constitutes a greater part of the cases during the 90's, especially in female patients and in the younger age groups with primary or initial disease, where HSV-1 is the causative viral type in up to 70-90% of the cases. CONCLUSION: The documented change from HSV-2 towards HSV-1 in cases of genital HSV infection may have implications as to prognosis, future usefulness of vaccines, present and future usefulness of new type-specific serological tests.

Adult↗
PubMed1999

Measurement of HPRT mutations in splenic lymphocytes and haemoglobin adducts in erythrocytes of Lewis rats exposed to ethylene oxide.

Young adult male Lewis rats were exposed to ethylene oxide (EO) via single intraperitoneal (i.p.) injections (10-80 mg kg-1) or drinking water (4 weeks at concentrations of 2, 5, and 10 mM) or inhalation (50, 100 or 200 ppm for 4 weeks, 5 days week-1, 6 h day-1) to measure induction of HPRT mutations in lymphocytes from spleen by means of a cloning assay. N-ethyl-N-nitrosourea (ENU) and N-(2-hydroxyethyl)-N-nitrosourea (HOENU) were used as positive controls. Levels of N-(2-hydroxyethyl)valine (HOEtVal) adducts in haemoglobin (expressed in nmol g-1 globin) were measured to determine blood doses of EO (mmol kg-1 h, mM h). Blood doses were used as a common denominator for comparison of mutagenic effects of EO administered via the three routes. The mean HPRT mutant frequency (MF) of the historical control was 4.3 x 10(-6). Maximal mean MFs for ENU (100 mg kg-1) and HOENU (75 mg kg-1) were 243 x 10(-6) and 93 x 10(-6), respectively. In two independent experiments, EO injections led to a statistically significant dose-dependent induction of mutations, with a maximal increase in MF by 2.3-fold over the background. Administration of EO via drinking water gave statistically significant increases of MFs in two independent experiments. Effects were, at most, 2.5-fold above the concurrent control. Finally, inhalation exposure also caused a statistically significant maximal increase in MF by 1.4-fold over the background. Plotting of mutagenicity data (i.e., selected data pertaining to expression times where maximal mutagenic effects were found) for the three exposure routes against blood dose as common denominator indicated that, at equal blood doses, acute i.p. exposure led to higher observed MFs than drinking water treatment, which was more mutagenic than exposure via inhalation. In the injection experiments, there was evidence for a saturation of detoxification processes at the highest doses. This was not seen after subchronic administration of EO. The resulting HPRT mutagenicity data suggest that EO is a relatively weak mutagen in T-lymphocytes of rats following exposure(s) by i.p. injection, in drinking water or by inhalation.

Administration, Inhalation↗
PubMed1999

Short-term exposure of rodents to diesel exhausts: usefulness for studies of genotoxic and immunotoxic effects.

An exposure facility was tested with regard to the information obtainable from short-term animal experiments for the assessment of health hazards from automotive engine exhausts. Indicators of immunotoxicity and genotoxicity were studied in guinea pigs and mice, respectively, exposed for 2 weeks, 8 h/day, to ten times diluted exhausts from a one-cylinder research diesel engine running at constant load. Regulated and non-regulated pollutants were determined. Besides increased number of lavageable cells in the airways, exposed guinea pigs exhibited, after immunization and challenge to ovalbumin, reduced leukotrienes B4 and C4 in lavage fluid and reduced anti-ovalbumin IgG in serum. Absence of increased CYP1A activity indicated that the exposure was below the threshold for induction of these enzymes. Instead a certain reduction of this activity indicated interaction with active enzyme sites. In vivo doses of some reactive metabolites of low molecular mass were measured by adducts to hemoglobin. Doses from aliphatic epoxides were low, in accordance with low hydrocarbon levels in the exhaust. The levels of hemoglobin adducts from aldehydes showed no clearcut influences of exposure. Genetic effects determined by DNA fingerprint analysis were indicated. It is concluded that repeated dose inhalation exposure of small numbers of animals is a useful mode of exposure for studying parameters that may elucidate toxic effects of air pollutants emitted from automotive engines, with a possibility to evaluate engine and fuel with regard to health hazards.

Administration, Inhalation↗
PubMed1997

The adjuvant activity of diesel exhaust particles and carbon black on systemic IgE production to ovalbumin in mice after intranasal instillation.

The adjuvant activity of diesel exhaust particles (DEP) on systemic IgE production to ovalbumin (OA) was studied in mice after intranasal administration. The main purpose was to elucidate which part of the particles was responsible for the effect, the carbon core and/or the adsorbed organic substances. Female Balb/cA mice were immunized with OA either alone or in combination with DEP or carbon black particles (CB), the latter used as a surrogate for the non-extractable carbon core of DEP. Controls were given DEP, CB or buffer alone. The animals were immunized four times. 1 and 2 weeks after the last immunization anti OA IgE antibody in serum was analysed by enzyme linked immunosorbent assay (ELISA). An increased response to the antigen was observed in animals receiving OA together with DEP or CB, compared with animals receiving OA alone. The increased response was seen as both increased number of responding animals and increased serum anti OA IgE antibody. For OA + DEP 37% of the animals showed a serum anti OA IgE response, whereas 22% of the OA + CB animals and 10% of the OA animals responded. In conclusion, this work shows that not only DEP, but also CB have an adjuvant activity for specific IgE production after intranasal instillation. However, the activity of DEP may be more pronounced than that of CB. The results imply that both the organic matter adsorbed to DEP and the non-extractable carbon core are responsible for the observed adjuvant effect.

Adjuvants, Immunologic↗
PubMed1996

Casual sex, extramarital sex, condom use and alcohol intake among heterosexual patients attending an STD clinic in Norway.

A study excluding homosexuals was performed to study casual sex, extramarital sex, the use of a condom with a casual sexual partner and the combination of alcohol intake and casual sex among patients attending a clinic for sexually transmitted diseases (STDs). Heterosexual patients (467) received a questionnaire, and 458 were included. Men reported more (94%) casual sexual partners than did women (76%). According to a multiple logistic regression analysis a condom was used significantly less frequently in "old" respondents, those having a permanent sexual partner, those having low education, those infected with STDs (earlier STDs), those who had had more than 4 sexual partners over the last year, and those combining alcohol intake and casual sex. Intravenous drug users/prostitutes used a condom more often than did men with paid sex and "other heterosexuals". To have an effect on STD patients, innovative forms of health education may be necessary, and greater emphasis should be placed on more informal means of information, including interactive health education and communication strategies to promote positive attitudes regarding condom use.

Adolescent↗
PubMed1995

Experimental evaluation of the effect of filtration of diesel exhaust by biologic exposure indicators.

The airway resistance, compliance of the respiratory system, transfer factor, and alveolar volume of 33 healthy rabbits were studied before and after exposure to diluted diesel exhaust generated in an experimental motor. Three diesel fuels and two particle traps were tested. Subsequent to the post-exposure lung function measurements, the animals were sacrificed and the lungs were processed for morphologic examination. The concentrations of particles, nitrogen dioxide, and formaldehyde were measured. The inflammatory airway changes were most pronounced in animals exposed to exhaust from standard fuel. Small changes were identified in animals exposed to exhaust filtered through the catalytic trap as well or exposed to unfiltered exhaust from fuels intended for densely built-up areas. Increase in compliance of the respiratory system was associated with the concentration of soot particles and formaldehyde. Compliance decreased significantly in animals exposed to exhaust from standard fuel filtered through the particle traps and increased almost significantly in animals exposed to unfiltered exhaust from the same fuel.

Air Pollutants↗
PubMed1995

Longitudinal study of cytomegalovirus antibodies in individuals infected with the human immunodeficiency virus.

Cytomegalovirus (CMV) antibody profiles were studied in 25 HIV-infected patients over periods of up to 56 months. Specific antibodies against CMV antigen components were monitored by complement-fixation (CF) test, EIA, Western blot and a neutralization assay. Three subjects remained CMV seronegative throughout the study. Marked fluctuations were observed in anti-CMV antibodies assayed by the CF test as compared to a control group. Fluctuations on immunoblots of purified virion antigens were also observed in the HIV-infected patients; neutralizing antibodies and anti-CMV nucleocapsid antibodies showed less variability. Seven of 22 individuals exhibited an increase in CF-test titre of up to 64-fold without clinically apparent CMV disease. On Western-blot testing of IgG reactivity with disrupted virions, ten individuals exhibited increasing reactivity to pp65, and only three of these also showed a titre rise in the CF test. In contrast, 7 of 22 showed low reactivity to the pp28 antigen. The homosexual patient group exhibited the highest levels of anti-CMV antibody. In conclusion, many asymptomatic HIV-infected subjects showed fluctuations at different levels of their antibody response to CMV, thought to be indicative of CMV reactivation/reinfection. Western-blot findings indicated that some CMV antibodies increased in level while others were lost.

AIDS-Related Opportunistic Infections↗
PubMed1995

Knowledge of HIV infection and the fear of mixing socially with HIV-infected and AIDS-sick patients among STD patients in Bergen, Norway.

This is a study of data from 599 STD (sexually transmitted disease) clinic patients in Bergen, Norway who visited the clinic in April-June 1989. We studied the patients' knowledge of modes of HIV transmission and their degree of ignorance of how HIV is not transmitted. Particular interest was focused on how misconceptions influenced the respondents' perception of HIV/AIDS sick persons and the importance of confidence in AIDS information from the health authorities. The objective of the study was to compare the data from this investigation of STD patients with data from similar studies in the general public conducted in Norway between 1986 and 1991. HIV-infected blood (98.3%; 589/599) and unprotected vaginal intercourse (91%; 545/599) were frequently suggested as a mode of HIV transmission, while 22.4% (134/599) did not recognize anal sex as an unsafe sexual practice. There was no statistically significant difference in their knowledge of modes of HIV transmission between the following patient subgroups: homosexuals/bisexuals, intravenous drug users (IVDUs)/prostitutes, sex customers and respondents classified as 'other heterosexuals'. Regarding ways in which HIV is not transmitted, ignorance was first and foremost related to whether the HIV virus could be passed on by oral kissing (wrong: 38.5%). Knowledge of how HIV is not transmitted was positively correlated with education (p < 0.05) and confidence in the HIV/AIDS information from health authorities (p < 0.05), and negatively correlated with age (p < 0.05). Respondents knowing how HIV is not transmitted considered social contact with HIV/AIDS sick persons to be harmless (p < 0.001). The present information campaigns on HIV/AIDS have been less effective than expected. In the future we must find new ways of informing the public by identifying the essential components that are missing from the information campaigns we have today.

Acquired Immunodeficiency Syndrome↗
PubMed1994

A longitudinal study of phagocyte function in HIV-infected patients.

OBJECTIVE: To study the influence of HIV infection on phagocyte function. To date, the results of phagocyte function studies in HIV-infected patients have been contradictory. This is the first longitudinal study of these functions in HIV infection. DESIGN: We followed 50 individuals with HIV infection for 2-51 months (mean, 28 months) and examined polymorphonuclear leukocyte (PMNL) and monocyte functions at intervals of 0.5-1 years. METHODS: PMNL random migration and chemotaxis were assessed using an under-agarose method, and PMNL and monocyte oxidative metabolism by chemiluminescence production during phagocytosis of opsonized zymosan. RESULTS: PMNL random migration and chemotaxis were impaired at entry into the study by 15 and 19%, respectively. After 3 years the reduction was 35 and 32%, respectively. The mean chemiluminescence production by PMNL was reduced by 6% at entry into the study. After 4 years a decrease of 18% was observed. The decrease in PMNL function was most marked in patients with lymphadenopathy syndrome or AIDS. No significant change in monocyte chemiluminescence production was detected at any time during the study. CONCLUSIONS: A distinct and progressive decrease of PMNL function occurs during HIV infection. This may contribute to increased susceptibility to opportunistic infections in HIV-infected patients. For monocytes, chemiluminescence production is not influenced by HIV infection.

Adult↗
PubMed1994

Repeated measurements of transfer factor in rabbits: an animal model suitable for evaluation of short-term exposure.

Acute temporary changes in lung function may be of use as a biological exposure indicator. However, studies of humans occupationally exposed to complex airborne irritants are often expensive and time demanding. Therefore, an animal model could be a valuable complement. A rabbit model has been evaluated where transfer factor was measured twice during the same day, and with the rabbit awake and available for exposure, in between. Anaesthesia and intubation in 22 rabbits (2.6 [0.2] kg [Mean (SD)]) were immediately followed by two measurements of transfer factor and alveolar volume. Transfer factor was estimated by the single breath CO-technique used in humans. The samples were analysed for CO and He on a gas chromatograph. After one pair of measurements the rabbit was allowed to wake up and after 5 h the duplicate measurements were repeated. The mean values of transfer factor, alveolar volume and transfer constant were 0.50 (0.09) mmol min-1 kPa-1, 127 (8) ml and 3.9 (0.6) mmol min-1 kPa-1 l-1, respectively. The intraindividual coefficients of variation were 7.3%, 5.3% and 6.7%, respectively. Five hours later when the duplicate measurements were repeated, transfer factor, alveolar volume and transfer constant were unchanged still. The results suggest that relatively small changes in transfer factor may be detected without losing power, and thus that this model could be used as a biological exposure indicator.

Anesthesia↗
PubMed1994

Casual sexual experience abroad in patients attending an STD clinic and at high risk for HIV infection.

OBJECTIVE: To study possible "import" routes of HIV infection to Norway (by obtaining information on casual sexual contacts abroad from patients attending an STD clinic), and to assess their behavioural risk factors (such as alcohol intake, use of condom) for HIV infection. DESIGN AND SETTING: Patients visiting the clinic for sexually transmitted diseases (STD), April-June 1989, received a questionnaire. SUBJECTS: 606 consecutive persons of whom 599 agreed (98.8%) to participate. We grouped the patients in four categories. 1: Sex with a prostitute during the last 5 years, 2: Homosexuals/bisexuals, 3: prostitutes/intravenous drug abusers (IVDUs) and 4: Other heterosexuals. RESULTS: 245 patients (41%) reported having a casual sex partner abroad (M: 182, F: 63), mainly in Europe, particularly in Spain, Denmark and Greece. Outside Europe such contacts were most frequently reported from USA, Brazil and Thailand. Among men who had had sex with a prostitute, 93.5% reported such sex abroad (homosexuals/bisexuals: 63.6%, prostitutes/IVDUs: 66.7%, "other heterosexuals: 32.1%). Homosexual/bisexual men with casual partner(s) abroad used a condom more frequently than did others. CONCLUSION: 245 of 599 persons reported casual sex abroad during 1985-1989, and the different "risk groups" reported countries where most HIV infected persons belonged to their own "risk group". We have reason to believe that alcohol intake increased the likelihood of casual sexual activity and decreased the use of condom. Norwegian travellers need more information on the risks of casual sex abroad, the use of condoms and the combination of alcohol intake and casual sex.

Alcohol Drinking↗
PubMed1994

Immunohistochemical identification of Renibacterium salmoninarum by monoclonal antibodies in paraffin-embedded tissues of Atlantic salmon (Salmo salar L.), using paired immunoenzyme and paired immunofluorescence techniques.

Renibacterium salmoninarum was identified in situ by immunoenzymatic and immunofluorescence techniques in paraffin-embedded tissue specimens collected during a natural outbreak of bacterial kidney disease (BKD) and from an experimental infection in Atlantic salmon (Salmo salar L.). Monoclonal antibodies (MAbs) 4D3 and 2G5 were used in this study, both specific for the 57-58-kD outer membrane protein (p57) of the bacterium. Both MAbs revealed positive staining in ethanol-fixed tissue specimens, but only the epitope identified by MAb 4D3 was formalin resistant. Pretreatment with trypsin did not reestablish the antigenicity for the epitope identified by Mab 2G5. Paired immunoenzymatic staining for identification of the bacterium in sequential incubation steps on ethanol-fixed tissue specimens using an avidin-biotin-peroxidase system was obtained after serial dilution of the Mab (2G5) or the chromagen, amino ethyl carbazole, in the first sequence. Paired immunofluorescence staining with well-balanced color mixing was easily obtained on ethanol-fixed tissue specimens using sequential incubations. Single exposures gave blue (aminomethyl coumarin acetic acid) and green (fluorescein isothiocyanate) fluorescence for MAbs 2G5 and biotinylated 4D3, respectively. Color mixing was revealed as a turquoise staining. Studies on method sensitivity was performed by incorporating a known amount of a protein preparation of p57 into an inert matrix, creating an artificial test substrate.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1994

HIV-seropositive rate and HIV test activity among STD clinic attendees in Bergen, Norway.

We wanted to determine the HIV seropositive rate and to study the connection between previous HIV testing, acceptance of HIV testing and sexual behaviour among STD clinic patients in Bergen, Norway. Patients attending the STD clinic in 1986-93 requesting HIV testing were registered, and all patients visiting the clinic in April-June 1989 received a questionnaire and were asked if they wanted to be HIV tested. The overall HIV seropositive rate was 0.4% (14/3805); in homo-/bisexual men: 2.9% (8/278); IVDUs: 0.4% (1/236) and in heterosexual non-IVDUs: 0.2% (5/3291). Among the 599 individuals offered anonymous HIV testing, 42.2% were HIV tested and 69.2% did not object to HIV-testing. IVDUs/prostitutes (p < 0.001), customers of prostitutes (p < 0.001), homo-/bisexuals (p < 0.01), and patients receiving blood transfusion (p < 0.005) had all been HIV tested more frequently than 'other heterosexuals'. Respondents reporting casual sex, casual sex abroad, infection with STDs, and a greater number of partners were more frequently HIV tested and also accepted HIV testing more frequently than respondents without such behaviour, indicating that there is some rationale behind the decision to be tested.

AIDS Serodiagnosis↗
PubMed1993

Diagnosis of infection with human T-lymphotropic virus type II (HTLV-II) in Norwegian HIV-infected individuals.

Sera from 298 HIV-infected individuals from Southern Norway were examined for antibodies against HTLV. 30 sera (10.1%) were HTLV-II positive and 1(0.3%) HTLV-I positive. 25 of the HTLV-II infected subjects were intravenous drug abusers (IVDAs), giving a prevalence of HTLV-II infection of 24.5% in this group. Examination of blood samples by polymerase chain reaction followed by restriction enzyme analysis or sequencing confirmed the serological diagnosis. To evaluate current screening and verification HTLV tests, 44 sera were examined using a gelatin particle agglutination test, 5 different enzyme-linked immunoassays (ELISA) and 4 Western blots (WB). While earlier ELISAs and WBs were inadequate, a recent ELISA and WB including recombinant envelope glycoproteins from both viruses permitted serological diagnosis and distinction between HTLV-I and HTLV-II. Thus, HTLV-II now spreads among IVDAs in a North-European country. Health authorities in other countries should estimate the magnitude of the problem to decide upon measures to avoid transmission through blood transfusion.

Journal Article↗
PubMed1993

Serum antibodies to viral pathogens and Toxoplasma gondii in HIV-infected individuals.

Sera from 38 HIV-infected individuals were examined longitudinally for antibodies to viruses that may increase morbidity in HIV infection, as well as commensal viruses and Toxoplasma gondii. HTLV infection was seen in Norway for the first time as four patients had antibodies to HTLV-II and one had antibodies to HTLV-I. Antibodies to hepatitis B virus (HBV) were found in 47.2%, while 21.6% of the patients had antibodies to hepatitis C virus (HCV). There was no evidence of acquisition of HBV or HVC during the mean observation period of 2 years. A titre increase in CMV antibody with time was observed for 7 out of 21 patients and a decrease for 2 patients. For Epstein-Barr virus, herpes simplex, varicella-zoster, rubella and measles viruses, human polyomavirus BK as well as for Toxoplasma gondii, antibody prevalences and titres were within the range seen in normal populations. Also, no longitudinal changes were observed in titres of these antibodies, indicating that humoral immunity remained intact during the study period. The high prevalences of HTLV-I/II, HBV and HCV antibodies in HIV-infected patients reflect common modes of virus transmission, and the fluctuations in CMV antibody titre are indicative of reactivations. Such coinfections may influence disease progression.

Adult↗