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Biomedical subjects

K Hansen

Publications and source records attributed to K Hansen.

At least 199 records · Page 11Linked to original sources
PubMed1990

An unidentified macromolecular inhibitory constituent of calcium oxalate crystal growth in human urine.

We have detected and isolated a macromolecular constituent in normal human urine possessing calcium crystal growth inhibitory activity. The purification procedure consisted of two anion exchange chromatographies and one affinity chromatography. The crystal growth inhibitor was found to be heterogeneous in net charge as well as in size. It has not been identified. It is not an uronic acid-containing glycosaminoglycan, hitherto presumed to be responsible for the inhibitory activity. Whether an urinary fragment of inter-alpha-trypsin inhibitor is responsible has yet to be resolved.

Calcium Oxalate↗
PubMed1990

Long-term effects of the Herbst appliance on the craniomandibular system with special reference to the TMJ.

The purpose of this study was: (1) to analyse the long-term clinical implications of Herbst treatment on the masticatory system, and (2) to analyse the radiographic appearance of the temporomandibular joints at the time of follow-up using lateral tomography of the right and left TMJ. The sample consisted of 19 consecutive male subjects with a Class II, Division 1 malocclusion treated with the Herbst appliance for an average period of 7 months. The patients were reinvestigated at the end of the growth period (an average of 7.5 years after treatment). The anamnestic, clinical, and radiographic findings revealed that Herbst treatment did not seem to have any long-term adverse effects on the craniomandibular system.

Activator Appliances↗
PubMed1990

Oligoclonal Borrelia burgdorferi-specific IgG antibodies in cerebrospinal fluid in Lyme neuroborreliosis.

Cerebrospinal fluid (CSF) and serum from 45 patients with lymphocytic meningoradiculitis were examined by isoelectric focusing combined with immunoblotting to detect Borrelia burgdorferi-specific oligoclonal immunoglobulin G (IgG) bands. In pretreatment samples, 35 patients (78%) showed B. burgdorferi-specific oligoclonal IgG in CSF indicative of intrathecal antibody production. At 2, 3-6, and 6 weeks after onset, respectively, such bands were present in 5 (42%) of 12, 21 (88%) of 24, and in all of 9 patients (100%). Up to 1 year after therapy, specific oligoclonal bands in CSF tended to remain unchanged despite clinical recovery. B. burgdorferi-specific oligoclonal bands in serum were found in 7 patients. These bands had identical migration patterns as in CSF, but were fewer in number and in some patients showed a temporal evolution different from their CSF counterpart. Not all oligoclonal IgG in CSF reacted with B. burgdorferi. The 41-kDa flagellar antigen was shown to be a major antigen in the intrathecal immune response. The demonstration of B. burgdorferi-specific oligoclonal IgG in CSF is a sensitive and reliable indicator of Lyme neuroborreliosis.

Adolescent↗
PubMed1990

Cryptic osteoid osteoma of the cranium: case report.

Osteoid osteoma is an uncommon benign tumor of bone that rarely involves the cranium. If often causes local pain that is worse at night, characteristically relieved by aspirin, and does not correlate with the size of the lesion. The diagnosis depends on skull radiographs and computed tomography. This report describes a case in which radiographs showed nothing abnormal. The diagnosis and operative localization were accomplished with radionuclide bone scanning. Thus, the possibility of radiographically cryptic lesions must be considered in the evaluation of atypical head pain syndromes.

Adult↗
PubMed1990

The concentration of ouabain binding sites in biopsies of uterine muscle.

The concentration of Na, K-ATPase in biopsies of uterine muscle was determined by measurement of [3H]ouabain binding in the presence of vanadate. For this purpose a method previously described for skeletal muscle (Nørgaard et al. 1983) was modified. Biopsies were obtained from uterine muscle from pregnant women (during caesarian section), non-pregnant women (during hysterectomy) and from adult, non-pregnant guinea-pigs and rats. The ouabain binding site concentration in uterine muscle of the pregnant women averaged 72 +/- 2 pmol g-1 wet wt (n = 8), with an apparent dissociation constant (KD) for ouabain of 3 x 10(-9) mol l-1. The ouabain-binding capacity in uterine muscle of the non-pregnant women amounted to 83 +/- 9 pmol g-1 wet wt (n = 8). In uterine muscle of the guinea-pig, two populations of ouabain binding sites were observed: one with a maximum binding capacity of 230 pmol g-1 wet wt and an apparent KD of 1.6 x 10(-6) mol l-1, and one with a maximum capacity of 62 pmol g-1 wet wt and an apparent KD of 5 x 10(-8) mol l-1. Immediate freezing of the biopsies in liquid N2 and storage at -60 degrees C for up to 6 weeks caused no change in ouabain-binding capacity. The dry weight/wet weight ratio of the samples from different subjects showed values of around 20%. It is concluded that the concentration of Na-K pumps in human uterine muscle can be quantified by [3H]ouabain binding using samples weighing 5-10 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

A quantitative analysis of placental vasculature in the third-trimester fetus with autosomal trisomy.

Growth disturbance in the trisomic fetus is believed to be primarily fetal in origin. There has been only sparse description of placental pathology in the third trimester in these fetuses, and therefore the placental role in their growth and development remains unexplored. We performed quantitative morphometric analysis on the placentas of 18 fetuses with trisomy and ten normal control fetuses. Doppler umbilical artery analysis was performed on ten abnormal fetuses and all controls. The placentas of trisomic fetuses exhibited a significant reduction in small muscular artery count and small muscular artery/villus ratio. Abnormal Doppler waveforms correlated closely with reduced small muscular artery counts. Undervascularization and increased vascular resistance of the placenta of trisomic fetuses may contribute to diminished fetal growth. The placenta appears to be another fetal organ whose structure and function are affected adversely by abnormal karyotype.

Arterioles↗
PubMed1989

Prevalence of antibodies to Borrelia burgdorferi in forestry workers and blood donors from the same region in Switzerland.

Sera from 259 forestry workers and 100 blood donors in the Canton of Solothurn, Switzerland, were tested for IgG antibodies to Borrelia burgdorferi in two EIAs using as antigen either sonic extract of whole organisms or purified flagella. Applying a 95% specific cut-off value based on results in the sera of 100 blood donors, 86 (33%) and 91 (35%) of the forestry workers respectively showed an elevated specific IgG level in the two EIAs. None of the 259 forestry workers had clinical signs of active infection at the time blood was taken, and only nine could recall experiencing erythema-migrans-like skin lesions within the last ten years. Thus, asymptomatic infections must be frequent. Elevated specific antibody levels increased significantly with the age of the forestry workers (p less than 0.0001) and the duration of occupational exposure to ticks (p = 0.0001). Thus serological results in individuals with high exposure to ticks must be interpreted with caution in view of the high a priori prevalence of antibodies to Borrelia burgdorferi in such persons. The prevalence of antibody to the Borrelia burgdorferi flagellum in a control population not selected for tick exposure, in this case blood donors, seems to be independent of geographical origin.

Adult↗
PubMed1989

Litigation against the emergency physician: common features in cases of missed myocardial infarction.

Adverse outcome data from two insurance companies were retrospectively studied to determine whether a constellation of clinical circumstances, data-gathering behaviors, or physician variables were common to cases of missed acute myocardial infarction (AMI) and, if so, to formulate quality assurance recommendations to decrease future occurrences of misdiagnosis. We studied AMI because missing this diagnosis accounts for the highest dollar losses in emergency department malpractice cases. Our study group consisted of 65 patients with undiagnosed AMI seen in EDs between 1982 and 1986. Univariate differences between undiagnosed cases and correctly diagnosed concurrent controls were analyzed using Student's t test and chi 2 analysis. Insurance losses for our cases averaged $113,806 +/- $178,330 (SD). Compared with concurrent controls, study patients were significantly younger, presented more atypically, and had fewer ECGs that were diagnostic of AMI. Undiagnosed patients were evaluated by physicians who documented less detailed histories, misread more ECGs, had less ED experience, and admitted fewer patients to the hospital. Preventive strategies are outlined.

Diagnostic Errors↗
PubMed1989

Class II correction in Herbst and Bass therapy.

The purpose of this study was to make a quantitative evaluation on lateral cephalograms of skeletal and dental changes contributing to Class II correction in Herbst and Bass appliance therapy. From two male patient samples treated with either the Herbst appliance (n = 72) or the Bass appliance (n = 32) 18 pairs of subjects were selected. The subjects within each pair had to be in the same growth period at the time of therapy and to exhibit a similar pretreatment sagittal (ANB angle) and vertical (ML/NSL angle) jaw base relationship. Lateral cephalograms in centric occlusion taken before treatment and after 6 months were analysed according to the method of Pancherz (1982a). After six months of treatment the Bass appliance seemed to have a greater influence on mandibular jaw base position than the Herbst appliance, although no statistical significant differences existed between the treatment groups. The correction in overjet and sagittal molar relationships was more complete in the Herbst than in the Bass patients. This was due to greater dental changes (distal movement of the maxillary molars, proclination of the mandibular incisors) taking place in the Herbst subjects.

Activator Appliances↗
PubMed1989

Serodiagnosis of erythema migrans and acrodermatitis chronica atrophicans by the Borrelia burgdorferi flagellum enzyme-linked immunosorbent assay.

The diagnostic performance of an enzyme-linked immunosorbent assay (ELISA) using purified Borrelia burgdorferi flagella as test antigen was compared with that of a B. burgdorferi sonic extract ELISA. We tested sera from 200 healthy controls, 107 patients with erythema migrans (EM), 50 patients with acrodermatitis chronica atrophicans (ACA), and 98 patients with various dermatological disorders without clinical evidence of active Lyme borreliosis. The flagellum ELISA was significantly more sensitive than the sonic extract ELISA. With sera from patients with EM, the diagnostic sensitivity for immunoglobulin G (IgG) antibody detection increased from 11.2 to 35.5% (P less than 0.001) and for IgM antibody detection it increased from 16.6 to 44.8% (P less than 0.001). In the flagellum ELISA, the number of positive tests increased significantly (P less than 0.005) when the duration of EM exceeded 1 month, but still only about 50% of patients with longstanding (1 to 12 months) untreated EM were IgG seropositive. Concomitant general symptoms did not affect the antibody level, whereas patients with multiple erythema were more frequently seropositive. All sera from patients with EM which were positive in the sonic extract ELISA were also positive in the flagellum ELISA. Not only did the overall number of positive tests increase, but the flagellum ELISA yielded a significantly better quantitative discrimination between seropositive patients and controls (P less than 0.002). IgG antibodies to the B. burgdorferi flagellum were found in all sera from patients with ACA, indicating persistence of an antiflagellum immune response in late stages of Lyme borreliosis. IgM reactivity in sera from patients with ACA was shown to be unspecific and the result IgM rheumatoid factor. A rheumatoid factor was detected in sera from 32% of patients with ACA, compared with 7.5% of patients with EM. The improved diagnostic performance, the ease of standardization of the flagellum antigen, and the lack of strain variation make the B. burgdorferi flagellum a needed reference antigen for growing routine serology in Lyme borreliosis.

Absorption↗
PubMed1989

Recovery of human immunodeficiency virus type 1 from supernatant fluid of routine viral cultures.

Peripheral blood mononuclear cell samples from human immunodeficiency virus (HIV) antibody-positive subjects were inoculated into cell cultures used for routine viral isolation to determine if HIV could survive in them. HIV was recovered from 5 (19%) of 26 day 1 supernatants and from four of the five samples in all three types of cell cultures. We conclude that HIV may survive for at least 24 h in standard virology cell culture systems and therefore is a potential risk for laboratory personnel.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Mechanisms of fibre-induced superoxide release from alveolar macrophages and induction of superoxide dismutase in the lungs of rats inhaling crocidolite.

Asbestos resembles the phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA), in its ability to elicit release of superoxide (O2-.) from rodent alveolar macrophages (AM) in vitro. In addition, superoxide dismutase (SOD), the antioxidant enzyme scavenging O2-, is increased in cultures of tracheobronchial epithelial cells and lung fibroblasts after exposure to either crocidolite or chrysotile asbestos. Our objectives here were to determine: (1) the chemical and physical properties of asbestos important in the generation of O2- from rat AM; and (2) the effects of O2- in comparison with asbestos on biosyntheses of collagen and non-collagen protein in rat lung fibroblasts in vitro. We were also interested in whether increased production of SOD occurred in the lungs of rats after inhalation of crocidolite asbestos. To determine whether O2- was elicited in response to a variety of asbestiform fibres, AM lavaged from Fischer 344 rat lungs were exposed in vitro to equivalent non-toxic amounts of crocidolite asbestos, erionite, Code 100 fibreglass, sepiolite, and their non-fibrous analogues, riebeckite, mordenite and glass particles. In addition, sized preparations of long (greater than 10 microns) and short (less than 2 microns) asbestos were introduced at identical concentrations to determine whether length of fibres is critical in O2- release. The amount of O2- released from AM in response to dusts was then determined by measuring SOD-inhibitable reduction of cytochrome C. All asbestiform fibres caused a significant (p less than 0.05) increase in generation of O2- from epithelial cells, whereas non-fibrous particles were less active at comparable concentrations. Experiments with long (greater than 10 microns) versus short (less than 2 microns) chrysotile showed that long fibres caused a more striking, dosage-dependent release of O2-. To determine whether O2- plays a role in the causation of fibrotic lung disease, rat lung fibroblasts were exposed to a biochemical generation system (xanthine-xanthine oxidase) for O2- before quantitation of cell-associated collagen and non-collagen protein at 24, 48 and 72 h thereafter. At the latter time periods, significant increases in total collagen per ng DNA were observed. In comparison with controls, the generation system for O2- also caused an initial decrease in synthesis of non-collagen protein followed by increases in synthesis of non-collagen protein at 48 and 72 h.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Antibodies to the Borrelia burgdorferi flagellum in patients with scleroderma, granuloma annulare and porphyria cutanea tarda.

It is generally accepted that cutaneous Lyme borreliosis comprises erythema chronicum migrans, lymphadenosis benigna cutis, and acrodermatitis chronica atrophicans. In recent years the tick-borne spirochete Borrelia burgdorferi has been associated with a number of other cutaneous disorders. We therefore investigated sera from 175 patients with localized scleroderma (morphea) (n = 64), systemic sclerosis (n = 74), granuloma annulare (n = 16) and porphyria cutanea tarda (n = 21) with the new, highly sensitive and specific Borrelia burgdorferi flagellum ELISA assay. As controls (n = 297) served normal healthy volunteers and patients with other skin diseases. It was found that the distribution of individual antibody values and the median antibody levels were identical in controls and in patients with scleroderma, granuloma annulare and porphyria cutanea tarda. These data do not support the hypothesis of an etiological association between Borrelia burgdorferi infection and scleroderma, granuloma annulare or porphyria cutanea tarda.

Adolescent↗