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Biomedical subjects

K Müller

Publications and source records attributed to K Müller.

At least 253 records · Page 14Linked to original sources
PubMed1991

[Systemic lupus erythematosus. 1. Disease manifestations, infections, thrombotic episodes, causes of death and survival in a case load of 173 patients followed for 13.9 years].

One hundred and seventy-three patients had systemic lupus erythematosus according to the 1982-ARA-criteria. The mean disease duration at the time of the study was 16.4 years, and the patients were followed by three Copenhagen clinics for a mean of 13.9 years until 1987/88 or death. Half of the patients had nephropathy, 61 patients developed severe infections, and 39 patients had thrombotic episodes. Fifty-six patients died during the observation period, 24 due to active lupus (12 of kidney failure), 12 because of infections, and 11 because of atherosclerotic cardio-vascular disease. The patients had 10-, 15- and 20-year survival rates of 80, 65 and 48 per cent. The deaths were evenly distributed throughout the observation period.

Adult↗
PubMed1991

[Systemic lupus erythematosus. 2. Factors of predictive significance for survival].

Sixty-one of 173 patients with systemic lupus erythematosus followed for a mean of 13.9 years had severe infections which influenced their survival more than could be accounted for by the mortality (20 per cent) caused by the infections. Patients with infections had more SLE manifestations than patients without infections, and they died of lupus manifestations more often than patients without infections. Patients who went into a permanent remission and patients who died of lupus differed most markedly by the rates of infection. The rate of infection was increased more than tenfold in patients treated with high dosages of glucocorticoid compared with patients who received low dosages. Treatment with cytostatics influenced the rate of infections to a moderate degree. Nephropathy also influenced survival but half of the patients with nephropathy maintained a normal plasma creatinine in spite of the long observation period. 16 per cent of the patients with nephropathy died of kidney failure or are receiving chronic hemodialysis.

Adult↗
PubMed1991

The alkaline phosphatase from bone: transphosphorylating activity and kinetic mechanism.

For the purified alkaline phosphatase from bone, the ability to catalyze a phosphate transfer reaction from p-nitrophenyl phosphate to two different hydroxy acceptor compounds, ethanolamine and glycerol, was established by identification of the formed phosphorylated products, phosphoethanolamine and glycerol 3-phosphate, respectively. In addition, a steady-state kinetic analysis of the hydrolysis of p-nitrophenyl phosphate in the presence of an added nucleophile, diethanolamine, gave rise to the proposal of a simple model for the kinetic mechanism of the enzyme. This mechanism includes a covalent phosphoryl enzyme intermediate, the dephosphorylation of which by water (k3) or a nucleophile (k4) is rate-determining. According to this model, in the presence of diethanolamine, k3 and k4 were determined to be 4.44 s-1 M-1 and 1000 s-1 M-1, respectively. Therefore, in vitro a suitable nucleophile, such as diethanolamine, seems to be a better phosphate acceptor than water. These results may suggest that alkaline phosphatase from bone could be well suited for catalyzing phosphate transfer reactions in vivo as well.

Alkaline Phosphatase↗
PubMed1991

[The use of diagnostic imaging methods in reptiles].

Useful methods of clinical imaging in reptiles are described using examples. Most important in reptiles is radiography with or without contrast media. Invasive diagnostic methods often used are endoscopy and laparoscopy. Ultra sound scanning in reptiles is established for controlling ovary function.

Animals↗
PubMed1991

Maturation of lower extremity EMG responses to postural perturbations: relationship of response-latencies to development of fastest central and peripheral efferents.

EMG responses to toe-up tilt perturbations on a movable platform system were analysed in 86 children between the age of 12 months and 13 years. To assess the relative contribution of peripheral and central nerve conduction properties, a concomitant recording of the fastest efferent pathways in the central and peripheral motor system was made using non-invasive transcranial magnetic stimulation of motor cortex and peripheral nerve roots. This allowed the determination of the fastest downstream efferent connection times from motor cortex to lumbar motor neuron pools and to measure the fastest efferent conduction from these motor neuron pools to effector muscles in the lower leg. The sequence observed for stance stabilizing EMG responses was similar to that obtained in earlier studies with short latency (SL) and middle latency (ML) companents occurring in the stretched triceps surae muscle and long latency (LL) responses occurring in the non-stretched tibialis anterior muscle. Homologous responses were also obtained in upper leg muscles, being recruited consistently later than those in lower leg muscles across all age groups. In the short latency range two different SL1- and SL2-responses were obtained in children of all age groups as well as in adult controls. Both the SL1- and the SL2-responses showed a flat developmental profile, reaching adult values between 20 and 30 months of age which correlated with that of the fastest efferents from lumbar motor neuron pools to leg muscles, i.e. the final motor path. ML-responses showed a steeper developmental profile.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Bone tumor induction after incorporation of short-lived radionuclides.

Temporally-limited internal irradiation after incorporation of short-lived bone-seeking radionuclides is a useful experimental tool for the investigation of extrinsic and intrinsic factors which modify the dose dependence of bone tumor risk. Here we describe some of the results obtained in experiments with female mice (mainly NMRI). The future aim of such experiments should be the prediction of risk of late effects using early molecular-biological changes. Molecular-biological descriptions in our model are at present very limited.

Animals↗
PubMed1991

Failure to obtain drug-resistant variants of influenza virus after treatment with inhibiting doses of 3-deazaadenosine and H7.

3-Deazaadenosine and H7 specifically inhibit influenza virus replication under conditions at which they have no effect on other tested RNA viruses. This effect can be significantly potentiated by concomitant application of both compounds. Even under the most stringent conditions we failed to obtain any drug resistant variants. A possible explanation for this failure is that these compounds presumably do not act on a viral component like amantadine which was used as a control, but they interfere with cellular enzymes (factors) absolutely essential for influenza virus replication but more or less dispensable for the survival of the cell.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

Benefit of Bonefit implant system.

The International Team for Oral Implantology (ITI) Bonefit system has been introduced as an extended and improved system with respect to titanium plasma-sprayed screws and the F-type implant. The clinical results of the Bonefit implant system were at least as good as those of the F-type implant. The Bonefit system, however, offers more indications and applications, especially in crowns and bridgework. Furthermore, the ITI Bonefit system appears to eliminate some of the reported shortcomings of the F-type implant.

Adolescent↗
PubMed1991

Mutants and revertants of an avian influenza A virus with temperature-sensitive defects in the nucleoprotein and PB2.

ts19 is a temperature-sensitive (ts) mutant of the influenza A fowl plague virus with a defect in the nucleoprotein (NP). In ts19-infected chicken embryo cells all viral components are synthesized in normal yields at the nonpermissive temperature, but infectious virus is not formed. Under these conditions the migration of the NP and M of ts19 from the cell nucleus to the cytoplasm is affected. This ts defect is due to a single amino acid replacement (R162K) in a completely conserved region of the NP. Another mutant with a different defect in the NP is ts81. After infection with ts81 at 40 degrees no vRNA is being synthesized. By backcross of a revertant derived from ts81 many isolates with a ts defect in the PB2 protein were obtained. This ts defect seems to extragenically suppress the ts defect in the NP gene and to be dominant in a wild-type background.

Amino Acid Sequence↗
PubMed1991

Inhibition of production and function of interleukin-6 by 1,25-dihydroxyvitamin D3.

1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3) has been shown to interfere with immunoglobulin production and lymphocyte proliferation in vitro. These lymphocyte functions are influenced by interleukin (IL)-6 produced by antigen presenting cells. Hence, the ability of 1,25-(OH)2D3 to interfere with the production and function of IL-6 was investigated. 1,25-(OH)2D3 and the analogue MC 903 inhibited IL-6 production by LPS-stimulated human mononuclear cells. The precursor 25-OH D3 was ineffective. Likewise, 1,25-(OH)2D3 but not 25-OH D3 inhibited rIL-6-driven as well as rIL-1 alpha/beta-driven proliferation of murine thymocytes. This effect of 1,25-(OH)2D3 was partially or totally overcome by larger concentrations of rIL-6 as well as by rIL-2 and ionomycin. Consistently, the production of IL-6 and IL-2 in rIL-1 driven thymocyte cultures were found to be reduced by 1,25-(OH)2D3. Inhibition of production and function of IL-6 may therefore be involved in 1,25-(OH)2D3-mediated regulation of lymphocyte functions in vitro.

Animals↗
PubMed1991

Magnetic stimulation of motor cortex and nerve roots in children. Maturation of cortico-motoneuronal projections.

Magnetoelectrical stimulation of motor cortex and peripheral nerve roots was used to establish the maturational profiles of central and peripheral nervous system conduction times in normal children in upper and lower extremity muscles. To obtain true central conduction times, not contaminated by variation due to different preinnervational levels, a protocol using stimulation under full muscular relaxation was used. With this protocol clear responses of the upper extremity could be obtained after the first year of life, whereas in the lower extremity they could not be obtained before the fourth year of life. The developmental profile of central conduction times to upper and lower extremity muscles showed an age-dependent acceleration with adult values not being reached before the age of about 10 years. In contrast, peripheral conduction times obtained after cervical or lumbar root stimulation to upper and lower extremities showed a much faster maturational profile, with adult values being reached at about the age of 3 years. The data are discussed in relation to the available literature on neuromorphological development and provide normative values for the understanding of normal development of motor control in children as well as for application of this technique in children with motor disturbances.

Adolescent↗
PubMed1991

Down-regulation of monocyte functions by treatment of healthy adults with 1 alpha,25 dihydroxyvitamin D3.

A number of in vitro studies suggest an immunoregulatory role of 1 alpha,25 Dihydroxyvitamin D3 (1,25-(OH)2D3). The hormone inhibits production of interleukin-2 and immunoglobulin, and it blocks lymphocyte proliferation. Diverse effects on monocyte functions have been reported. However, immunological effects of 1,25-(OH)2D3 have not been substantiated in vivo. Six healthy male volunteers, aged 28-45 yr, were treated orally with 1,25-(OH)2D3 (tabl. Rocaltrol), 1 microgram twice daily for 7 days. Blood and urine samples were collected before and 7 days after initiation of treatment. Blood mononuclear cells from individuals treated with 1,25-(OH)2D3 showed a significantly reduced production of both interleukin-1 alpha (45%) and tumor necrosis factor-alpha (58%) (both measured by ELISA). Interleukin-6, production, measured by the B9 cell assay, was reduced in five individuals (78%), and unchanged in one. There was no effect on the release of interleukin-1 beta. There was no measurable effect on interleukin-2, interferon gamma or immunoglobulin production, or on mitogen-induced proliferation of blood mononuclear cells. Serum-osteocalcin and urine excretion of calcium were increased to 131 and 173%, respectively. The serum-calcium and serum-phosphate levels were unchanged.

Administration, Oral↗
PubMed1991

Cytokine secretion by peripheral blood monocytes from human immunodeficiency virus-infected patients is normal.

We have measured the production of interleukin 1 (IL 1), interleukin 6 (IL 6), and tumor necrosis factor alpha (TNF alpha) by unstimulated monocytes and monocytes stimulated with lipopolysaccharide (LPS) isolated from the peripheral blood of patients infected with human immunodeficiency virus 1 (HIV-1) and healthy controls. Spontaneous and LPS-induced cytokine production were not significantly different between patients and controls. Median lipopolysaccharide-stimulated cytokine secretion for patients and controls was 1.7 and 4.3 U/ml for IL 1, 475 and 625 U/ml for IL 6, and 468 and 580 pg/ml for TNF alpha. Cytokine levels were not related to stage of disease. We conclude that in vivo HIV infection itself does not alter peripheral blood monocyte cytokine secretion.

Adolescent↗
PubMed1991

[Multiple tics and Gilles de la Tourette syndrome].

Tic disorders are frequent in childhood, varying from transient motor tics over multiple chronic tic disorders to full-blown Gilles de la Tourette syndrome (GTS). GTS is genetically determined. In affected families, relatives of the patient(s) with GTS may show minor symptoms only. The clinical picture is extremely variable, extending from the well known motor tics over complex compulsive obsessive behavior to purely sensory tics. The optimal treatment today is the use of dopamine antagonists.

Antipsychotic Agents↗