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Biomedical subjects

K Hansen

Publications and source records attributed to K Hansen.

At least 235 records · Page 13Linked to original sources
PubMed1986

The type of human papillomavirus present in cervical infections can be determined by the occurrence of specific marker proteins.

Four different proteins have been identified on high resolution two dimensional gels of [35S] methionine labelled human cervical biopsies whose expression correlates with the presence of papillomavirus. They are all basic proteins having molecular weights in the region of 48 to 50 kd and are normally expressed individually in different lesions unless the lesion results from a co-infection of two virus types. Comparison of the occurrence of these marker proteins with the actual HPV type present, determined by in situ filter hybridisation, has shown that two are found exclusively with HPV types 6/11 while the other two are found with types 16/18.

Antigens, Viral↗
PubMed1986

A placebo-controlled, double-blind, cross-over trial of flunarizine in common migraine.

After four weeks of medication-free baseline observation, 29 patients with common migraine randomly received flunarizine (10 mg daily) or placebo for a 16-week period. After four weeks wash-out they crossed treatments for another 16 weeks; 27 patients completed the trial. Compared with placebo, flunarizine significantly reduced the frequency of migraine attacks and the derived headache indices, but the duration and severity of single attacks remained unchanged (Mann-Whitney U-test). The effect of flunarizine increased during the 16-week treatment period and during the last four weeks the number of migraine attacks reduced to 50% compared to the wash-out period. The only side-effect of flunarizine was mild daytime sedation in three patients. It is concluded that flunarizine is a valuable new prophylactic agent for common migraine.

Adolescent↗
PubMed1986

Some factors affecting bubble formation with catheter-mediated defibrillator pulses.

Factors affecting bubble formation during delivery of defibrillator pulses to arrhythmogenic cardiac tissue via a catheter are unknown. We investigated the role of energy, electrode surface area, interelectrode distance, and electrode polarity on bubble formation and on current and voltage waveforms during delivery of damped sinusoidal discharges from a standard defibrillator to anticoagulated bovine blood. Gas composition was studied with mass spectrometry. Defibrillator energy settings were varied between 5 and 360 J. The principal catheter used for study was a Medtronic 6992A lead. Additional electrodes tested included 2, 5, and 10 mm long No. 6F, 7F, and 8F copper electrodes. Interelectrode distances used to assess the effect of anode-cathode spacing were 1, 5, 10, and 20 cm. Bubble volume increased linearly from 0.043 to 0.134 ml per cathodal pulse and from 0.030 to 3.50 ml per anodal pulse as energy settings were increased from 5 to 360 J (r = .99). Typical smooth waveforms for both current and voltage were seen only in the absence of bubbles. The voltage waveform was distorted for each cathodal pulse of 100 J or more and for each anodal pulse of 10 J or more only if bubbles were present. The effect of electrode surface area on bubble formation was tested at a 200 J energy setting and at a 10 cm interelectrode distance with the use of cathodal pulses. Bubble formation varied inversely with electrode surface area (r = .876). Bubble formation, however, varied minimally as interelectrode spacing was changed from 1 to 20 cm. The effect of polarity on bubble formation when the Medtronic 6992A distal electrode and an 8.5 cm disk electrode separated by 10 cm were used was highly significant. For a 200 J pulse, bubble formation with the catheter as anode was 3.30 +/- 0.10 ml and with the catheter as cathode it was 0.070 +/- 0.002 ml (p less than .001). Mass spectrometry of both anodal and cathodal gas samples demonstrated the constituents of the gas bubble to include a variety of gases, which is inconsistent with simple electrolytic production of the bubbles observed. The predominance of nitrogen in either polarity sample suggested that the principal source of the bubble was dissolved air. In summary, bubble formation at an electrode receiving damped sinusoidal outputs from a standard defibrillator does not vary significantly with varying interelectrode distance. However, it is directly proportional to energy and inversely proportional to electrode surface area. Anodal catheter discharges produce considerably more bubbles than do cathodal discharges.(ABSTRACT TRUNCATED AT 400 WORDS)

Catheterization↗
PubMed1986

Duration of morning stiffness in rheumatic patients after medication with enteric-coated and plain naproxen tablets.

Twenty-nine adult rheumatic patients who were taking 500 mg naproxen at bedtime and had a certain degree of morning stiffness despite this medication took part in a randomized double-blind cross-over study in which the duration of morning stiffness after evening doses of 500 mg enteric-coated naproxen tablets was compared with that after identical doses of plain naproxen tablets. The duration of morning stiffness was significantly shorter after taking enteric-coated tablets (p less than 0.01), and the mean plasma naproxen morning concentration was 34% higher (p = 0.01). Since the results were unambiguous in such a small group of patients, they are judged to be of considerable clinical value.

Adult↗
PubMed1986

Lymphocyte malignancy and chromosome 14: structural aberrations involving band q11.

Five patients with lymphocytic malignancies were found to have structural aberrations of chromosome 14, all involving band q11. The malignant cells of all five cases were analyzed by immunofluorescence to establish immunologic phenotypes. Three patients had T lymphoblastic lymphoma/leukemia with mediastinal masses (cases 1, 2, and 3); one patient had peripheral T cell lymphoma (case 4); and one patient had acute lymphocytic leukemia, common acute lymphoblastic leukemia antigen positive (case 5). Although aberrations of chromosome 14 frequently are associated with lymphocytic malignancies, these abnormalities most often result in extra material on the long arm, 14q+. However, none of the five patients reported here had a 14q+. Cases 1 and 2 had t(9;14)(q34;q11) and t(11;14)(p11 or 13;q11), respectively. Case 3 showed del(14)(q11), and cases 4 and 5 showed inv(14)(q11q32). Structural aberrations resulting in 14q- and inv(14) appear to occur infrequently. The five cases in this report, in conjunction with those found in the literature, indicate a strong association between breaks at 14q11 and T lymphocytic malignancies.

Adult↗
PubMed1986

Sex pheromones of two Asian moths (Creatonotos transiens, C. gangis; Lepidoptera--Arctiidae): behavior, morphology, chemistry and electrophysiology.

Two sympatric species of Asian arctiid moths (Creatonotos spp.) use a sequential, dual luring and mating system. After sunset males pneumatically expand their coremata from a cavity between the abdominal sternites 7 and 8 and release their pheromone. They attract other males and thus, scent-emitting male groups may develop. About 30 min later females are attracted to the calling males. Upon contact with a female the male's corema deflates and mating follows. After 1-2 h the male calling subsides and now the remaining virgin females continue to emit their pheromone bouquet from internal, tubular glands located in the dorsal part of the abdomen, rostrad from tergite 8/9. This attracts males and further matings occur.- The coremata are huge, pneumatically eversible organs composed of two pairs of tubes, up to 37 mm long, each covered by ca. 3000 scent hairs (scales). There is a giant epidermal (trichogen) gland cell at the base of each hair. One large corema may contain up to 0.5 mg of the pheromone, hydroxydanaidal. The internal, tubular female glands are antler shaped; their air-filled lumen is ventilated by abdominal pumping. The major components of the female attractant are (Z,Z,Z)-3,6,9-heneicosatriene and (Z,Z)-2 (2,5-octadienyl)-3-undecyloxirane with different ratios in the two species. One of the minor components, common to both species, is (Z,Z,Z)-3,6,9-tricosatriene. Only the male antennae possess specialized receptor cells for the female attractants; other antennal cells of both sexes respond to the male pheromone.

Animals↗
PubMed1985

Structure of a novel phosphoglycolipid from Deinococcus radiodurans.

The chemical structure of a major phosphoglycolipid from Deinococcus radiodurans has been shown to be 2'-O-(1,2-diacyl-sn-glycero-3-phospho)-3'-O-(alpha-galactosyl)-N-D-gl yceroyl alkylamine. By infrared spectroscopy, the lipid was shown to contain both carbonyl ester and amide linkages. Chemical analysis demonstrated a molar ratio of fatty acid, carbohydrate, and phosphorus of 2:1:1. The lipid was shown to contain an sn-3-phosphatidic acid backbone by digestion with phospholipase A2. Phosphodiester bond cleavage of the lipid with hydrofluoric acid liberated a component which contained galactose, glyceric acid, and alkylamines. Using NMR and permethylation/hydrolysis procedures, galactose was shown to be linked alpha-glycosidically to the 3-O-position of glyceric acid.

Chemical Phenomena↗
PubMed1985

Secretion of phospholipase A1 by bone marrow-derived macrophages.

Bone marrow-derived macrophages contain phospholipase activity of the A1 and A2 types, active at acid or neutral pH and with different specificities for the fatty acid to be liberated. In contrast to this variety, only one single phospholipase could be detected in extracellular fluids of these cells. Surprisingly, this phospholipase was of the A1 type and active at about pH 8. It exhibited a restricted substrate specificity in that, of the various substrates tested, only phosphatidylcholine containing palmitic acid in position 2 was degraded. This total restriction was not detected with phosphatidylethanolamine substrates. In addition to phospholipase A1, extracellular fluids exhibited lipase activity. A modulation of enzyme secretion could not be achieved by lymphokines or phorbol esters. However, release could be blocked by treating cells with cycloheximide (5 micrograms/ml) or tunicamycin (0.5 micrograms/ml). Phospholipase A1 was also released by thioglycollate-induced peritoneal macrophages.

Animals↗
PubMed1985

Multiple congenital anomalies, mental retardation and hypogonadotropic hypogonadism in a boy with small marker chromosomes.

We report on a mentally retarded boy with hypogonadotropic hypogonadism. He also had a hypoplastic right kidney and right vesicoureteral reflux, blunted calyses of the left kidney, spina bifida occulta, stiff metacarpophalangeal joints, and cataract of the left eye. Chromosome studies showed two marker chromosomes, the larger of which appeared to be a ring chromosome varying greatly in size, while the smaller one remained constant in size. Chromosome abnormalities may be associated with several forms of hypogonadotropic hypogonadism.

Abnormalities, Multiple↗
PubMed1985

Welding fumes and chromium compounds in cell transformation assays.

Fumes generated from mild steel and stainless steel welding were collected on paper filters and tested in the BHK and SHE cell transformation assays. Fumes from the manual metal arc welding of stainless steel (MMA/SS) had a toxic and transforming effect attributable to their Cr(VI) content. The fumes from metal inert gas stainless steel (MIG/SS) welding also had a toxic effect but this was 2-3 times greater than that expected from their soluble Cr(VI) content based on the activity of soluble Cr(VI) from pure chromium compounds. When collected in an impinger, the fumes from MIG/SS were found to contain approximately 10 times the soluble Cr(VI) content of samples collected on filters. This additional Cr(VI), when collected in a water impinger, also exhibited a greater toxicity compared with that found for the additional Cr(VI) collected in an impinger filled with growth medium. This comparison implies the presence of a short-lived biologically active Cr(VI) species usually lost in conventional sampling techniques. It also implies that there is a detoxification step associated with the formation of Cr(VI) organic complexes. Relatively insoluble Cr(VI) compounds showed a higher toxic and transforming effect in the BHK assay than could be ascribed to the soluble Cr(VI) content of the medium, indicating the importance of phagocytosis as a pathway for the uptake of Cr(VI) and other toxic substances from particulates.

Animals↗
PubMed1985

Enhanced functional recovery with venting during cardioplegic arrest in chronically damaged hearts.

Thirty dogs with experimental myocardial infarction underwent cardiopulmonary bypass, hypothermic asanguineous K+ cardioplegia (1 hour), and reperfusion (30 minutes). Ten hearts were vented throughout, 5 only during arrest, and 5 only during reperfusion; 10 were not vented. Left ventricular (LV) performance and compliance were assessed by isovolumic (LV balloon) indexes before bypass and after reperfusion. Vented hearts recovered 116 +/- 8.3% of prearrest developed LV systolic pressure (DLVSP) and 131 +/- 13.6% of prearrest rate of rise of LV pressure (dP/dt). Nonvented hearts allowed to develop pressure during arrest (11.6 +/- 1.6 mm Hg) and reperfusion (65 +/- 4 mm Hg) recovered 50 +/- 3.9% of prearrest DLVSP and 55 +/- 5% of prearrest dP/dt (p less than 0.05). Reduction in LV compliance was comparable in both groups. Mitochondrial architecture (electron microscopy) was preserved in vented hearts, but was modestly disrupted in nonvented hearts, thus suggesting slight metabolic impairment. Functional recovery was nearly complete in hearts vented only during reperfusion (DLVSP, 94 +/- 10.4%; dP/dt, 89 +/- 12.6%), but venting only during arrest led to functional depression (DLVSP, 50 +/- 6.6%; dP/dt, 51 +/- 8%; p = 0.01). We conclude that venting chronically infarcted hearts during cardiac operations affords better myocardial protection by avoiding the damage that occurs during nonvented reperfusion.

Animals↗
PubMed1985

Human placental lactogen and dU-estrogen levels in normal twin pregnancies.

Reference intervals for human placental lactogen (hPL) and dU-estrogens (dU-E) in uncomplicated twin pregnancies are found to be higher than singleton pregnancies and considerably wider. Significantly more monozygotic than dizygotic pregnancies, and significantly more monoplacental than diplacental pregnancies showed hPL values below the median on the normal range curve. The same was not found for dU-E. Significantly more growth-retarded fetuses were found in monoplacental than diplacental pregnancies. The benefit of measuring the two parameters in order to identify the intrauterine growth retarded fetuses were evaluated in terms of sensitivity and specificity. Both parameters were found less suitable for the purpose.

Birth Weight↗