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Biomedical subjects

W Arnold

Publications and source records attributed to W Arnold.

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

[Alcohol-induced liver diseases].

This review article is mainly concerned with the incidence and pathogenesis of alcohol-induced liver diseases. Clinically the most relevant symptom is a hepatomegaly. During the course of the disease there is to state progression to alcoholic hepatitis with increasing jaundice. The laboratory values show different patterns; severe courses develop progression to a fulminant hepatitis. The diagnostic approach includes exact patient's medical history, clinical and laboratory investigations, followed by a step-wise diagnostic procedure including histology. Therapeutically the main approach is a diet, in case of malnutrition substitution of vitamins and only rarely the need of corticosteroids and/or anabolic steroids. Prognosis and long-term course of alcoholic-induced liver disease depend mainly on the severity of the disease and the consequent alcohol-free diet.

Alcoholism↗
PubMed1989

[Auditory and communication learning in patients with cochlear implants].

Nowadays the cochlear implant (CI) offers a new method of hearing, especially for deaf patients who do not benefit from conventional hearing aids. However, it may be difficult to get used to this kind of hearing advice. CI users have special problems in interpreting strange acoustic sensations and relating them to auditory features of language and noise they knew before the onset of deafness. An interdisciplinary approach is very important for rehabilitation. Beside otological examination and the surgical implantation, audiological assessment is needed for the correct adjustment of the speech processor and for measurement of performance. Also auditory management and counselling of deaf patients is an important part of CI rehabilitation. A learning programme in hearing and communicating ("hearing training") is offered to CI users that takes account of different linguistic levels. Auditory learning by the use of CI is based on different abilities of the deaf patient, of which the most important are speech skills and learning capacity. Although success rates vary, it certainly improves speech intelligibility during lip reading, communication behaviour, and recognition of environmental noise. The latter ability improves orientation in the acoustic surroundings. CI rehabilitation may improve the psychosocial attitude of the deaf.

Cochlear Implants↗
PubMed1989

[Otosclerosis. A paramyxovirus-induced inflammatory reaction].

Despite intensive investigation the cause of otosclerosis remains unknown. Recent immunohistochemical and electron microscopic studies of otosclerotic stapes have revealed a possible viral aetiology. Therefore we investigated the histology, ultrastructure and immunohistochemistry of fragments of otosclerotic footplates. Immunoglobulins G (IgG) and A (IgA) were found in plasma cells, oseocytes, chondrocytes and connective tissue of the active lesions. Polyclonal and monoclonal antibodies against paramyxovirus and rubella virus antigens produced reproducible reactions with these antigens at different sites of otosclerotic stapes, especially in the epithelial cells of the overlying middle ear mucosa. Using specific T-lymphocyte and B-lymphocyte markers about 80% of the lymphocytes present in the otosclerotic footplate proved to be T-lymphocytes. There was neither deposition of immunoglobulins nor any expression of viral antigens in non-otosclerotic footplates which were investigated as controls. Our results indicate that otosclerosis is an inflammatory reaction of the otic capsule initiated or caused by paramyxovirus and/or rubella virus. The silent progress of the disease and its onset under certain conditions, e.g. endocrine upsets, show similarity to slow viral infections.

Adult↗
PubMed1989

[Fourier transformation infrared spectrometry--a new (old) method of detection in forensic chemistry and criminal investigation].

The Fourier-Transform-Infrared spectrometry (FTIR) is a very valuable technique for identifying organic substances. FTIR is more versatile in comparison to disperse infrared spectrometry, as it combines speed and sensitivity. FTIR is even superior to GC/MS: 1. Easy differentiation between isomers is possible. 2. Functional group information can be achieved instead of mass fragments. 3. GC fractions can be saved for further analysis. The FTIR instrument has no prisma or grating. It is equipped with a Michelson interferometer, which gives much more beam energy on the examination object. Most beneficial is the use of a broadband beam source, which impinges simultaneously all frequencies on the sample and on the detector. All these qualities allow the registration of fast chemical and biological processes or the observation of all reactions by volatizing and evaporation at high temperatures. IR spectrometer can run high quality infrared spectra in short time (almost 100/second) with high sensitivity. This is the basic requirement for the "on line" coupling of the IR-system with a GC. The GC peaks are analysed by IR beams with the help of a "light pipe". It is possible to examine all kinds of substances with diffuse and attenuated total reflectance methods. In special cases the change for binding of proteins and kinetic and structural processes in the flowing blood can be measured in vivo. Another use of FTIR-techniques is possible in combination with a microscope. Samples with a square aera of 8 microns can be examined. In criminalistics and forensic toxicology little particles as hairs, fibers, foams, adherents of powder in clothes, splinters of lacquer and paints etc. can be detected and identified by transmission or reflection. In conclusion, the FTIR spectrometry offers a versatility to some measurement problems that is often superior, faster and easier than other techniques such as NMR and MS.

Forensic Medicine↗
PubMed1988

Nucleotide sequence of the phosphinothricin N-acetyltransferase gene from Streptomyces viridochromogenes Tü494 and its expression in Nicotiana tabacum.

The phosphinothricin (Pt) N-acetyltransferase gene (pat) of Streptomyces viridochromogenes Tü494 is located on a 0.8-kb BglII fragment [Strauch et al., Gene 63 (1988) 65-74]. By sequencing a 1.3-kb BglII-SstII fragment, an open reading frame representing the pat gene was found. It encodes a polypeptide of 183 amino acids with an Mr of 20,621. The base composition of the pat gene is typical for Streptomyces [70.1 mol% (G + C) in total and 93.5 mol% (G + C) in the third position]. Translation of pat is initiated by a GTG codon which was identified by frameshift mutations in Escherichia coli as well as in Streptomyces lividans. Significant homology of the pat gene was found to the bialaphos-resistance gene (bar) of Streptomyces hygroscopicus [Thompson et al., EMBO J. 9 (1987) 2519-2523]. However, variations were detected in the 5'-noncoding region of the two resistance genes which may reflect differences in regulation. Since Pt is a potent herbicide, the pat gene was modified and introduced into Nicotiana tabacum by Agrobacterium-mediated leaf-disc transformation. The GTG start codon of pat was replaced by ATG. Subsequently the modified pat-coding region was fused to the 35S promoter of the cauliflower mosaic virus. Transgenic plants could directly be selected on Pt-containing medium.

Acetyltransferases↗
PubMed1988

A family of high-copy-number plasmid vectors with single end-label sites for rapid nucleotide sequencing.

A set of plasmid vectors was developed which allows fast sequencing by the chemical degradation method. These high-copy-number vectors are derivatives of the plasmid pUC8 containing different multiple-purpose cloning sites flanked by unique recognition sequences for the restriction enzymes BstEII, Tth111I and Eco81I as sites for end-labelling DNA. Due to their partially asymmetric recognition sequences, each of these three restriction sites can be singly end-labelled by a filling-in reaction with selected nucleotides. This allows easy single end-labelling of any cloned DNA fragment for sequencing by the chemical degradation method without any isolation and purification step after the labelling reaction. In addition, the nucleotide sequence of the complementary strand from the same end can be determined by the dideoxy chain termination procedure using the universal M13 primers. In most of the new vectors, the reading frame of the lacZ' gene is retained, allowing identification of cloned fragments.

Base Sequence↗
PubMed1988

Nucleotide sequence of a 24,206-base-pair DNA fragment carrying the entire nitrogen fixation gene cluster of Klebsiella pneumoniae.

The complete nucleotide sequence (24,206 base-pairs) of the Klebsiella pneumoniae gene region for nitrogen fixation (nif) is presented. Coding regions corresponding to the 19 known nif genes (including nifW and nifZ) could be identified. An additional open reading frame of 216 base-pairs, called nifT, was detected between nifK and nifY. Search for transcriptional signal structures revealed some unusual features: (1) several possible NifA-binding motifs are present in the intergenic regions between nifJ and nifH as well as between nifX and nifU; (2) a perfect NifA-binding motif, preceding the nifENX promoter, is located within an inverted repeat structure; (3) structures resembling the consensus nif promoter are found within the coding regions of nifW and nifZ and, together with a NifA-binding motif, in nifN. Typical rho-independent termination structures were detected only downstream from the nifHDKTY and the nifBQ operons. Analysis of the deduced amino acid sequences revealed the presence of two Cys-X2-Cys-X2-Cys-X3-Cys-Pro clusters in the pyruvate-flavodoxin oxidoreductase NifJ. This arrangement of cysteine residues is normally present only in ferredoxins. A high degree of homology between the two gene products (NifE and NifN) involved in iron-molybdenum cofactor biosynthesis and the two nitrogenase component I structural proteins (NifD and NifK) was found. All four proteins are characterized by the conserved motif His-Gly-X2-Gly-Cys, which may play a role in binding the iron-molybdenum cofactor.

Amino Acid Sequence↗
PubMed1988

A monoclonal antibody to the Ca2+-ATPase of cardiac sarcoplasmic reticulum cross-reacts with slow type I but not with fast type II canine skeletal muscle fibers: an immunocytochemical and immunochemical study.

Ca2+-ATPase of the sarcoplasmic reticulum was localized in cryostat sections from three different adult canine skeletal muscles (gracilis, extensor carpi radialis, and superficial digitalis flexor) by immunofluorescence labeling with monoclonal antibodies to the Ca2+-ATPase. Type I (slow) myofibers were strongly labeled for the Ca2+-ATPase with a monoclonal antibody (II D8) to the Ca2+-ATPase of canine cardiac sarcoplasmic reticulum; the type II (fast) myofibers were labeled at the level of the background with monoclonal antibody II D8. By contrast, type II (fast) myofibers were strongly labeled for Ca2+-ATPase of rabbit skeletal sarcoplasmic reticulum. The subcellular distribution of the immunolabeling in type I (slow) myofibers with monoclonal antibody II D8 corresponded to that of the sarcoplasmic reticulum as previously determined by electron microscopy. The structural similarity between the canine cardiac Ca2+-ATPase present in the sarcoplasmic reticulum of the canine slow skeletal muscle fibers was demonstrated by immunoblotting. Monoclonal antibody (II D8) to the cardiac Ca2+-ATPase binds to only one protein band present in the extract from either cardiac or type I (slow) skeletal muscle tissue. By contrast, monoclonal antibody (II H11) to the skeletal type II (fast) Ca2+-ATPase binds only one protein band in the extract from type II (fast) skeletal muscle tissue. These immunopositive proteins coelectrophoresed with the Ca2+-ATPase of the canine cardiac sarcoplasmic reticulum and showed an apparent Mr of 115,000. It is concluded that the Ca2+-ATPase of cardiac and type I (slow) skeletal sarcoplasmic reticulum have at least one epitope in common, which is not present on the Ca2+-ATPase of sarcoplasmic reticulum in type II (fast) skeletal myofibers. It is possible that this site is related to the assumed necessity of the Ca2+-ATPase of the sarcoplasmic reticulum in cardiac and type I (slow) skeletal myofibers to interact with phosphorylated phospholamban and thereby enhance the accumulation of Ca2+ in the lumen of the sarcoplasmic reticulum following beta-adrenergic stimulation.

Animals↗
PubMed1988

Social thermoregulation during hibernation in alpine marmots (Marmota marmota).

Body temperature (Tb) of socially hibernating alpine marmots, a pair and two family groups, was monitored continuously from October to March with implanted temperature-sensitive radiotransmitters. At the same time, the animals' behaviour was observed. The recurrent entrances into and arousals from hibernation were highly synchronised within groups. Group members always lay huddled together when euthermic and also when torpid with a few exceptions at higher ambient temperatures (Ta). Body contact with euthermic nestmates warmed torpid marmots passively. The Tb of animals reentering hibernation did not fall to values close to Ta as long as euthermic group members were present. Although animals presumably save energy through social thermoregulation, especially when euthermic, these benefits are not necessarily mutual among group members. Differences in thermoregulatory behaviour of individuals described in this study could be responsible for differential weight losses during winter as found in the natural habitat (Arnold 1986).

Animals↗
PubMed1988

Otosclerosis--an inflammatory disease of the otic capsule of viral aetiology?

Fragments of otospongiotic and otosclerotic footplates were investigated by immunohistochemical methods. Antibodies IgG, IgA, IgM were found to be bound to the vascular connective tissue of the resorption lacunae, IgG also to osteocytes. The application of antibodies against mumps, measles and rubella antigens showed the expression of the relevant viral antigens in the large cells of the resorption lacunae, in the vascular connective tissue, and in osteocytes, osteoclasts and chondrocytes, present in or around the otospongiotic areas. In the sclerotic stage only the perivascular connective tissue and chondrocytes have expressed viral antigens whereas IgG was restricted to the osteocytes of the sclerotic focus and to the residual perivascular tissue. Two footplates with postinflammatory sclerosis serving as controls revealed only IgG in some chondrocytes. Healthy footplates showed neither a deposition of antibodies nor any expression of viral antigens. These results favour a viral aetiology of otosclerosis as an inflammatory vascular reaction of the otic capsule initiated or caused by the viruses of measles, rubella and mumps.

Adult↗
PubMed1988

Psychophenomenon of paradoxical rotation provoked by acoustic and tactile stimuli.

Two groups of healthy persons were examined during rotation at a constant speed. In the first group (10 subjects), a narrow band noise (500 Hz, 70 dB SPL) from a fixed loudspeaker was applied during the 120 degrees/s rotation. In the second group (20 subjects), a mild tactile stimulus was applied to the subject's head. All individuals from both groups were convinced that it was not the chair they were sitting in, but the sound source and the tactile stimuli which were rotating.

Acoustic Stimulation↗
PubMed1988

[Quantitative and qualitative findings of hepatitis B virus-associated antigens, receptors and antibodies in the course of the acute phase of hepatitis B infection].

UNLABELLED: Receptors for pHSA may be the links between HBV and hepatocytes. Therefore, we evaluated the correlation between serum binding activity for pHSA during the acute phase of hepatitis B in relation to the decrease of surface antigen concentration. METHODS: 130 sera from 22 patients with acute (HBeAg-positive) hepatitis B were obtained weekly during an average interval of 7 weeks after the onset of the disease. R-pHSA were tested by RIA in 4 titre steps (1:50, 1:500, 1:5000, 1:50,000). HBsAg was analysed quantitatively by RIA according to the standard serum of the Paul-Ehrlich-Institute.

Acute Disease↗
PubMed1988

Analysis of hamster lymphomas for the presence of hamster papovavirus DNA.

The hamster papovavirus (HaPV) is a polyomavirus isolated from skin epitheliomas arising spontaneously in young Syrian hamsters. It can induce lymphomas and leukaemias in newborn hamsters. Although no virus particles are detectable by electron microscopy, high amounts of monomeric and oligomeric forms of extrachromosomal HaPV DNA molecules are found in the lymphoma cells. These molecules display deletions of about 300 nucleotides in length. Their role in the lymphoma induction is discussed.

Animals↗
PubMed1988

[The diagnostic value of immunologic findings in the differentiation of chronic liver diseases].

Various types of virus induced and non-virus induced chronic active hepatitis (CAH) as well as chronic non-suppurative destructive cholangitis (PBC) and primary sclerosing cholangitis have to be distinguished. Classical autoimmune type "lupoid" CAH is characterized by antinuclear antibodies (ANA), liver membrane antibodies (LMA) and smooth muscle antibodies (SMA). A second subgroup of autoimmune type CAH is characterized by anti liver kidney-microsomal antibodies (LKM) which are directed against a specific cytochrome p-450 isoenzyme. A third subgroup of autoimmune type CAH is identified by auto-antibodies to a soluble cytoplasmic liver antigen (SLA). Autoimmune type CAH profits from immuno-suppressive therapy, i.e. corticosteroids alone or in combination with azathioprin. Chronic hepatitis B virus infection is nowadays treated with Interferon when HBV-DNA is detectable in serum, duration of liver disease is less than 5 years and superinfection with HDV and HIV can be excluded. PBC is diagnosed through the detection of antimitochondrial antibodies (AMA) and its PBC specific subtypes anti p 62 (M2) and anti p 48. Aetiology and pathogenesis of PBC are still unknown. Liver transplantation is an established therapy for endstage PBC. This is also true for primary sclerosing cholangitis (PSC).

Antigens, Viral↗