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Biomedical subjects

B Niklasson

Publications and source records attributed to B Niklasson.

At least 109 records · Page 6Linked to original sources
PubMed1983

Contact allergic reaction to D & C Yellow No. 11 and Quinoline Yellow.

D & C Yellow No. 11 and Quinoline Yellow belong to a group of quinophtalone dyes with a common basic structure. D & C Yellow No. 11 is used mostly in plastics, spirit lacquers, coloured smokes and cosmetics, but it is also increasingly used as a dye in soaps and shampoos. Quinoline Yellow is used for dyeing wool, silk and nylon in cases where good light fastness is not required, but is most commonly used as a drug and food colouring agent. A patient, extremely sensitive to D & C Yellow No. 11 with a positive patch test reaction down to 0.00001%, also reacted to Quinoline Yellow at a test concentration of 0.1%. To establish if any cross-reactivity occurs between the two compounds, a high pressure liquid chromatograph was used for analysis, purification and separation of the two colours. The patient was then patch tested with the two colours and the pure fraction of Quinoline Yellow. The test results confirm a true sensitivity to Quinoline Yellow and to D & C Yellow No. 11, and may indicate cross-reactivity between the colours.

Chromatography, High Pressure Liquid↗
PubMed1983

Detection of Rift Valley fever virus antigen by enzyme-linked immunosorbent assay.

A double-antibody (sandwich) enzyme-linked immunosorbent assay (ELISA) was adapted to detect Rift Valley fever virus antigen. Antibodies were purified from hyperimmune mouse and rabbit sera by affinity chromatography, using CNBr-activated Sepharose 4B coupled to a beta-propiolactone-inactivated sucrose-acetone-extracted suckling mouse liver antigen. In the assay, antigen was captured by mouse antibody adsorbed to polystyrene plates and then detected by reacting sequentially with rabbit anti-Rift Valley fever virus antibody and swine anti-rabbit immunoglobulin G conjugated to alkaline phosphatase. ELISA proved to be useful in measuring viral antigen in different animal systems. However, great variation was found in the amount of antigen per PFU encountered in different circumstances. The ELISA system was optimized using supernatant fluids from infected Vero cell cultures and had a sensitivity of 10(5) PFU/ml. Hamsters develop progressive viremia, much as seen in susceptible domestic animals, such as lambs; ELISA could reliably detect 10(6) PFU/ml of viremic hamster serum. Rhesus monkeys with Rift Valley fever infection were positive by ELISA even when viremias were only 5 X 10(3) PFU/ml. ELISA also proved to be useful in measuring viral antigen in infected mosquitoes.

Animals↗
PubMed1983

An epidemiological survey of nephropathia epidemica in Sweden.

The indirect immunofluorescence test (IFT) using the Hantaan virus (agent of Korean hemorrhagic fever, KHF) was applied for detection of antibodies to nephropathia epidemica (NE). From 103 patients with symptoms suggesting NE, 61% revealed KHF/NE antibodies in the convalescent sera. All seropositive patients seemed to have acquired their disease in NE endemic areas (north of the 60th parallel). Only patients found to have a typical clinical NE (fever, abdominal pain and renal engagement) were seropositive. Antibodies to KHF/NE were found in 4.2% of sera from 647 healthy persons living in NE endemic areas. Signs of local clusters were found. Subclinical or mild disease seems common. Proof of man to man spread of the disease was not found. Sera from 355 persons living outside NE endemic areas were also tested and 2.4% contained KHF/NE antibodies.

Adolescent↗
PubMed1981

Clinical and subclinical hepatitis A occurring after immunoglobulin prophylaxis among Swedish UN soldiers in Sinai.

This study was performed to investigate the efficiency of 5 ml of 16.5% immunoglobulin (Ig) with an antibody titer against hepatitis A (anti-HAV) of 1:4000, using the HAVAB RIA technique, as pre-infection prophylaxis in 610 Swedish UN soldiers stationed in Sinai for 6 months. Sera were collected from 553 of these soldiers before, during, and after their service and were tested by the HAVAB technique for anti-HAV. Only 13 of 553 (2.4%) were immune before their service. During the first 5 months in Sinai, only one subclinical case of hepatitis A occurred among the men. Thereafter, two subclinical and four clinical cases occurred, although one of the subclinical cases and the four clinical ones did not occur until after the 6-month period. Thus, the Ig prophylaxis scheme used seems to offer almost complete passive protection for 5 months.

Adult↗
PubMed1979

Antibodies to Rift Valley fever virus in Swedish U.N. soldiers in Egypt and the Sinai.

Swedish United Nations Emergency Forces soldiers serving in Egypt and the Sinai peninsula were serologically tested for hemagglutination-inhibiting antibodies to Rift Valley fever (RVF) virus. Eight of 170 were positive. RVF has not been reported outside Africa, and a survey of 500 Swedish soldiers who had not served in the Middle East or Africa revealed no RVF virus antibodies. There were extensive RVF epidemics in Egypt in 1977 and 1978, and it is considered that these serologically positive soldiers contracted RVF disease while on duty in the Middle East.

Adult↗
PubMed1978

Transplacental passage of atenolol in man.

Maternal and umbilical serum concentrations of atenolol, a hydrophilic, cardioselective beta-adrenoceptor antagonist, were studied at delivery in seven cases of pregnancy hypertension. The drug had been administered to each patient for at least one week. Atenolol was detected in both maternal and umbilical serum in six cases, showing that there is transplacental passage of the drug. In the seventh case, who had stopped taking atenolol more than one day before delivery, neither maternal nor umbilical serum contained a measurable quantity of the drug. Atenolol concentration varied 3- to 6-fold between individuals, but there was no systematic difference between maternal and umbilical levels. It seems reasonable to assume that during steady state conditions the blood level of atenolol in mother and fetus is approximately equal, and that fetal accumulation of the drug does not occur.

Adult↗
PubMedDate not supplied

Haemorrhagic fever with renal syndrome: evaluation of ELISA for detection of Puumala-virus-specific IgG and IgM.

IgM and IgG ELISA to Puumala virus were evaluated using sera from patients with haemorrhagic fever with renal syndrome (HFRS) from different geographical regions: Sweden, Denmark, Norway, Belgium and the European USSR. IgM ELISA proved useful in the diagnosis of HFRS in patients from all the regions mentioned above. Specific IgM could be detected as early as day 1 post onset of disease, and patients remained IgM-positive for several months. Specific IgG ELISA antibodies were also frequently detected in acute sera, and acute-convalescent serum pairs often failed to show a significant titre rise or increase in optical density (OD) values. This limits the use of IgG ELISA in patient diagnosis. Sera collected 2 years after infection revealed higher IgG ELISA OD readings than convalescent sera, and very high values were still detectable 10 to 20 years postinfection. IgG ELISA is therefore useful for the testing of immunity and in seroepidemiological studies. Acute and convalescent sera from HFRS patients in Korea and the Asian USSR showed no or only very weak reactivity in the Puumala virus IgG and IgM ELISA. These results are consistent with the "one-way" crossing described earlier.

Adolescent↗
PubMedDate not supplied

ELISA for detection of IgM and IgG antibodies to sandfly fever Sicilian virus.

An enzyme-linked immunosorbent assay (ELISA) was developed to detect specific human immunoglobulin G and M antibodies to sandfly fever Sicilian (SFS) virus. Acute and early convalescent serum pairs with greater than or equal to 7 days between the 2 specimens were available from 20 patients and all showed significant optical density (OD) increase and significant titre rise (greater than or equal to 4-fold) by IgG ELISA. However, negative or borderline-positive sera were found as late as 11 days after onset of symptoms when tested by IgG ELISA. Specific IgM antibodies were detected during the first week of symptoms, and maximum OD values were obtained during the first 4 weeks after onset of disease. The IgM OD values declined over the following 3-9 months. All sera collected later than 14 months post-onset were negative by IgM ELISA. The combination of early antibody response and the need to test only one serum specimen gives IgM ELISA an advantage over IgG ELISA in patients diagnosis. The IgG ELISA was also evaluated as a seroepidemiological tool and compared to a plaque reduction neutralization test (PRNT) using sera from a normal Cypriot population. Of 183 sera tested, 34 (19%) were positive in plaque reduction neutralization tests (PRNT) and 113 (62%) by IgG ELISA. A number of PRNT-negative sera were strongly positive by IgG ELISA and also by indirect immunofluorescence test, which may suggest the presence of a virus related to SFS in Cyprus which has not yet been isolated.

Acute Disease↗
PubMedDate not supplied

A study of nephropathia epidemica among military personnel in Sweden.

The incidence of nephropathia epidemica (NE), caused by Puumala virus, among military troops operating in an endemic area of Sweden was investigated. A total of 705 soldiers (age 18-25) involved in field training in three different endemic counties were bled twice within a 6-month interval. Three individuals seroconverted when tested for Puumala virus antibodies by IgG ELISA. Symptoms typical of NE were not recorded in any of the patients. However, mild febrile episodes were recorded in 2 of the 3 individuals. One serologically confirmed soldier with typical NE symptoms was found in another group of 12,000 troops. This soldier fell ill 3 weeks after a 7-day-long field exercise. The present study indicates that military populations are at considerably greater risk of contracting NE when compared to the entire population residing in the same area.

Adolescent↗
PubMedDate not supplied

Virologic investigation of a case of suspected haemorrhagic fever.

After travelling in subSaharan Africa, an area known for sporadic cases of Marburg virus infection, a young Swedish man presented with a classical picture of severe viral haemorrhagic fever complicated by disseminated intravascular coagulation and septicaemia. Serum samples examined by electron microscopy revealed particles of a size compatible with filovirions. Indirect fluorescent antibody tests indicated transient seroconversion to Marburg virus. In lymphocyte transformation assays of cells isolated from the patient 11 months after the onset of acute disease, Marburg viral antigen was able to stimulate lymphocyte proliferation 3.9-fold; however, exhaustive attempts to isolate virus from acute phase blood cultured in vitro or in vivo from guinea pigs and monkeys failed. Data suggest that this patient may have been infected with a filovirus. This case demonstrates the difficulties that may occur in laboratory diagnosis of viral haemorrhagic fevers.

Adult↗
PubMedDate not supplied

Could myocarditis, insulin-dependent diabetes mellitus, and Guillain-Barré syndrome be caused by one or more infectious agents carried by rodents?

The numbers of small rodents in northern Sweden fluctuate heavily, peaking every 3 or 4 years. We found that the incidence of Guillain-Barré syndrome and insulin-dependent diabetes mellitus, as well as the number of deaths caused by myocarditis, followed the fluctuations in numbers of bank voles, although with different time lags. An environmental factor, such as an infectious agent, has been suggested for all three diseases. We hypothesize that Guillain-Barré syndrome, myocarditis, and insulin-dependent diabetes mellitus in humans in Sweden are caused by one or more infectious agents carried by small rodents. Also, a group of novel picornaviruses recently isolated from these small rodents is being investigated as the possible etiologic agent(s).

Adolescent↗