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Biomedical subjects

K Hansen

Publications and source records attributed to K Hansen.

At least 217 records · Page 12Linked to original sources
PubMed1989

Serosurvey for antibodies to Borrelia burgdorferi in Danish dogs.

To estimate the regional presence of B. burgdorferi we performed a serosurvey for antibodies to B. burgdorferi in 205 healthy dogs from representative areas of Denmark. Blood samples were collected from November 1986 to March 1987. Twenty dogs bred for research purposes served as negative controls. IgG-antibodies to the B. burgdorferi strain DK-ECM 1 were measured by indirect immunofluorescens assay. Antibody titers ranged from nonreactive to 640. In 33 dogs (16.1%) titres were greater than or equal to 80, indicating exposure to B. burgdorferi. There were no significant differences in the prevalence rate of seropositive dogs due to place of residence, sex or age. The results indicate that dogs are exposed to tickborne B. burgdorferi in most areas of Denmark.

Age Factors↗
PubMed1988

Future trends in cervical cancer.

The identification of the close association of certain types of human papillomavirus with the development of cervical cancer should lead to an extensive revision of appropriate health policies. Having taken into account the drawbacks inherent in the existing data (stemming from the use of varying nomenclature, diagnostic methods and reliability, registration and screening practices) it is possible to conclude that the incidence of HPV infections, all premalignant and malignant stages of cervical cancer are, or will soon be, increasing in several countries. This rate of increase is fastest for the younger age groups and is despite the introduction of various forms of screening. These trends therefore indicate an urgent need to adopt policies to avert an unnecessary increase in fatalities due to cervical cancer. It is therefore recommended to: (1) establish a routine diagnostic method which can identify either the type of HPV present or the lesions which are progressing; (2) determine the incidence of HPV infections in the general population; (3) disseminate to medical personnel, teachers, and other members of society existing knowledge concerning the dangers associated with this virus and relevant to preventing its further spread; (4) introduce an effective population screening campaign for all sexually active women, preferably involving a yearly examination at a colposcopy clinic; (5) intensify basic and applied HPV research, especially that which could lead to a deeper understanding of viral transmission and infection, identification of cofactors which promote cervical lesion progression, or to the production of a vaccine.

Female↗
PubMed1988

In vitro toxicity of welding fumes and their constituents.

Welding fumes from a wide variety of processes and applications were assayed for toxicity with BHK21 cell line and SHE primary cells in culture. The most toxic fumes are those from the manual metal arc welding of stainless steel (MMA/SS) (LD50 = 7-14 microgram/ml), although all other welding fumes tested are toxic, with potencies lower by a factor of 10-200. The activity of MMA/SS is presumably due to the presence of high concentrations of Cr(VI) in the soluble fraction: For all other fumes the lowered activity (LD50 = 80-800 microgram/ml) is limited mostly to the insoluble fraction, and in part can be related to the presence of MnO2 and Fe3O4 which are toxic at such levels in these cell culture assays. Slight discrepancies between survival tests for the two cell lines, and between survival and lactate dehydrogenate release for BHK, indicate a differential response to certain constituents of these complex materials. These results suggest the need for a battery of different types of assays for use in an eventual ranking of exposures for the purpose of relative risk assessment.

Air Pollutants, Occupational↗
PubMed1988

Immunochemical characterization of and isolation of the gene for a Borrelia burgdorferi immunodominant 60-kilodalton antigen common to a wide range of bacteria.

By crossed immunoelectrophoresis and Western blotting (immunoblotting), it was shown that Borrelia burgdorferi expresses the 60-kilodalton Common Antigen (CA) that is cross-reactive with an equivalent antigen in a wide range of remotely related bacteria. B. burgdorferi CA is strongly immunogenic. A B. burgdorferi genomic library was constructed by using a plasmid cloning system. Escherichia coli recombinants were screened for expression of immunodominant B. burgdorferi antigens. One of the recombinant clones expressed the 60-kilodalton CA of B. burgdorferi. The DNA region encoding B. burgdorferi CA was localized on a 2.3-kilobase fragment of the plasmid pKH1. CA may have pathogenetic implications in Lyme borreliosis, since the CA of mycobacteria recently has been shown to play a role in the etiology of experimental autoimmune arthritis. The extensive cross-reactivity of this antigen may account for the low diagnostic specificity of the currently used serological tests in Lyme borreliosis.

Antigens, Bacterial↗
PubMed1988

Measurement of antibodies to the Borrelia burgdorferi flagellum improves serodiagnosis in Lyme disease.

The isolation of Borrelia burgdorferi flagella and an enzyme-linked immunosorbent assay (ELISA) for detection of immunoglobulin G (IgG) and IgM to the B. burgdorferi flagellum are described. The diagnostic performance of the flagellum ELISA for serodiagnosis of Lyme disease was compared with the performance of a traditional whole cell B. burgdorferi sonic extract ELISA. We examined sera and cerebrospinal fluid (CSF) from 56 patients with lymphocytic meningoradiculitis (Bannwarth's syndrome), the most frequent secondary-stage manifestation of Lyme disease in Europe. Two hundred healthy individuals and patients with aseptic meningitis, encephalitis, Guillain-Barré syndrome, and syphilis served as controls. The flagellum ELISA was significantly more sensitive than the sonic extract ELISA. The diagnostic sensitivities were increased from 41.1 to 76.8% (P less than 0.01) for IgG and from 35.7 to 67.9% (P less than 0.05) for IgM detection in serum. The increase in sensitivity was most pronounced in patients with a short duration of disease (less than 20 days after onset). The diagnostic specificity increased for IgG detection but was almost unaltered for IgM. The flagellum ELISA did not improve the diagnostic sensitivity of measuring antibodies to borreliae in CSF, most likely owing to the low level of unspecific antibodies in CSF compared with serum. The cross-reactivity of sera and CSF from patients with syphilis decreased significantly. The flagellum antigen of B. burgdorferi shows no strain variation, is easy to purify in sufficient quantity, and is therefore a suitable reference antigen for routine serodiagnosis of Lyme disease.

Adolescent↗
PubMed1988

Pyridoxine in the treatment of premenstrual syndrome: a retrospective survey in 630 patients.

We present a survey summarising the retrospective reports of the therapeutic effect of pyridoxine (vitamin B6) in 630 women suffering from premenstrual syndrome (PMS) who attended a PMS clinic during the period 1976-1983. The daily doses of pyridoxine hydrochloride varied from 40 to 100 mg early in the study and from 120 to 200 mg in the later period of the investigations. The response to treatment was recorded as good (no significant residual complaints) in 40 per cent or more of patients taking 100-150 mg pyridoxine daily and in 60 per cent of patients treated with 160-200 mg daily. Together with partial response (useful benefit but still some significant complaints), the positive effect of the treatment increased to 65-68 per cent and 70-88 per cent respectively. No symptoms consistent with a diagnosis of peripheral neuropathy were reported.

Adolescent↗
PubMed1987

Generation of superoxide (O2-.) from alveolar macrophages exposed to asbestiform and nonfibrous particles.

Active oxygen species are implicated causally in tumor promotion by 12-O-tetradecanoylphorbol-13-acetate and in cell damage by asbestos, a putative tumor promoter of the respiratory tract. To determine the properties of asbestos important in generation of the oxygen free radical, superoxide (O2-.), hamster and rat alveolar macrophages were exposed in vitro to nontoxic concentrations of fibrous (crocidolite, erionite, Code 100 fiberglass, sepiolite) and nonfibrous (riebeckite, mordenite, glass) particulates. The amount of O2-. released by cells in response to dusts was determined by measuring the reduction of cytochrome c in the presence and absence of superoxide dismutase. Results showed that all fibrous (defined as a greater than 3:1 length:diameter ratio) dusts caused a significant increase in both release of O2-. from rat macrophages and enhancement of zymosan-triggered O2-. from hamster macrophages. Nonfibrous particles were less active than fibers at comparable concentrations. These results suggest that the geometry of particulates is of critical importance in the generation of O2-. from cells of the respiratory tract.

Animals↗
PubMed1987

An enzyme labelled nuclear antigen immunoassay for detection of cytomegalovirus IgM antibodies in human serum: specific and non-specific reactions.

A mu-capture enzyme linked immunosorbent assay was developed for detection of IgM antibody to cytomegalovirus (CMV). Virus-specific IgM was detected using horseradish peroxidase labelled nuclear CMV antigen (CMV-ELA). False-positive reactions caused by Paul-Bunnell-Davidsohn (PBD) positive sera and antinuclear antibody (ANA) positive sera were identified in a combination assay employing enzyme labelled nuclear control antigen (CO-ELA) in parallel to the CMV-ELA. Four of five PBD positive and 30 of 31 ANA positive sera reactive with the CMV-ELA were identified as false positive reactions in the combined ELA-assay. The reactivity in PBD-positive sera could not be explained by antigenic cross reactivity between CMV and Epstein-Barr virus, and the results further suggested that different cell specified components of the CMV-ELA were responsible for the reactivity of PBD-positive as compared to ANA-positive sera. One of 314 healthy blood donors, 12 of 12 patients with primary CMV infection, and 11 of 15 patients with secondary CMV infection had detectable CMV IgM antibodies. Comparison of different CMV-ELAs revealed that pronounced differences in specificity as well as sensitivity may exist.

Antibodies, Antinuclear↗
PubMed1987

Absence of hydrocephalus in spite of impaired cerebrospinal fluid absorption and severe intracranial hypertension.

Four patients are described presenting papilloedema, increased pressure and reduced CSF absorption--caused by either spinal tumours, leptomeningeal carcinomatosis or encephalitis. Remarkably they all had a normal CT without signs of hydrocephalus. A 24-hour intracranial pressure monitoring showed a mean pressure of 30-35 mm Hg, recurrent plateau waves and high occurrence of B waves. Conductance to CSF outflow studied by a constant perfusion test was severely reduced 0.010-0.026 ml min-1 mm Hg-1 (normal greater than 0.12 ml mm Hg-1 min-1). Despite these findings no ventricular enlargement was seen on serial CT scans. The reason therefore remains unknown. Disappearance of papilloedema and a variable clinical improvement followed shunt-insertion.

Absorption↗
PubMed1987

A biotin-avidin-amplified inhibition enzyme immunoassay for detection of CMV antibodies in human serum.

In this inhibition immunoassay undiluted serum reacts in solution with crude cellular CMV antigen in wells of microtestplates coated with hyperimmune CMV-reactive monkey IgG. CMV antibodies in the serum under test block (completely or partial) the fixation of antigen to the capture layer. Unblocked antigenic activity is in subsequent steps measured by the use of biotinylated CMV-reactive monkey IgG and peroxidase-conjugated avidin. The assay was evaluated in comparison with the CF test and was found superior both in terms of qualitative and quantitative detection of CMV antibodies. The results were uninfluenced by the presence in the sera of rheumatoid factor or autoantibodies (antinuclear antibodies). A characteristic feature of this inhibition immunoassay was the absence of equivocal results as demonstrated by analysis of 500 donor sera which were classified in two distinct separate groups: reactive and nonreactive. The assay is simple and reproducible and provides for a good reagent economy. Crude antigen can be used without sacrifice of specificity. Antigen from one Roux bottle proved sufficient for 25,000 duplicate tests.

Animals↗
PubMed1987

Borrelia meningitis in Denmark.

We studied 23 patients with borrelia meningitis, a tick-borne spirochetosis increasingly recognized in Denmark. The disease showed a seasonal incidence from June to December. Twenty one patients experienced a painful sensory radiculitis, in 17 cases followed by a predominantly cranial mononeuritis multiplex mainly affecting the facial nerve (Bannwarth's syndrome). Three patients had focal CNS involvement in the form of a transverse myelitis, a focal encephalitis and a disseminated leucoencephalopathy, respectively. The CSF showed invariably lymphocytic pleocytosis and elevated spinal protein concentration. Measuring borrelia antibodies in the CSF seemed of higher diagnostic sensitivity than in serum. Penicillin therapy was effective even in cases with focal CNS lesions.

Adolescent↗
PubMed1986

Acute promyelocytic leukemia: report of a variant translocation, t(1;17).

A 4-year-old female with acute promyelocytic leukemia (APL) was found to have a variant form of the 15;17 translocation, which is diagnostic of APL. The karyotype of the malignant cells was 47,XX,t(1;11)(q25;q21),t(1;17)(p36;q21), + 8. This case is additional evidence that the breakpoint of #17 at q21 is the characteristic chromosomal aberration of APL. The present case is also unusual because of the young age of the patient.

Child, Preschool↗