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Biomedical subjects

W Arnold

Publications and source records attributed to W Arnold.

At least 271 records · Page 15Linked to original sources
PubMed1985

[Hormone-producing (paracrine) cells in the human labyrinth].

Presence of immunoreactive somatostatin in the covering epithelial cells of the spiral prominence was demonstrated by immunohistochemical methods. The concentration of somatostatin increases from the basal turn to the apical turn of the cochlea. Ultrastructural investigations of these cells reveal secretory granules with a diameter of 250-350 nm. The findings promote the existence of a local paracrine system of the inner ear.

Adolescent↗
PubMed1985

[Immunopathology of the inner ear].

Immunologically mediated tissue lesions or functional disturbances can result from immune responses either to foreign antigens or autoantigenic constituents. Before a disease or a functional disorder can be called an (auto)immune disease, it must be established that immunological processes are involved in its etiology and/or pathogenesis. After reviewing the available data on immunology and on research on immunobiology of the inner ear, as well as clinical observations on disorders of the inner ear of possibly immunological origin, an attempt is made to determine whether (auto)immunopathology can be assumed in some patients with sensineural hearing loss. In patients with disorders presently recognized as autoimmune diseases, no hearing loss has been described so far. However, serum antibodies can be found via the indirect immunofluorescence method in some patients having functional disorders of the inner ear. These serum antibodies interact with normal human inner ear tissue. However, as long as immunopathological mechanisms have not been confirmed, these disorders should merely be called "diseases with autoimmune markers." It has been shown in animal experiments that the production of autoantibodies against inner ear components is associated with morphological and functional changes of the inner ear. The human endolymphatic sac releases secretory IgA into the lumen. Its epithelium contains (intraepithelial) lymphocytes, whereas lymphocytes, plasma cells (IgA, IgG) and macrophages occur in the perisaccular region. In this manner, the inner ear has its own immune system, which can possibly react independently of the systemic immune system.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

[Significance of electrocochleography within the scope of audiologic diagnosis].

Despite the extensive applicability of brainstem evoked response audiometry (= BERA), electrocochleography (= ECochG) occupies an undisputed place among audiological diagnostic methods. It is useful, among other things, in the early identification or confirmation of hearing defects in children, since it permits measurement of the auditory threshold and of the characteristics of the suprathreshold area, and may aid in excluding ambiguous findings resulting from subjective audiometric or other objective audiometric methods in certain cases. In this regard, it makes possible a valid early prescription of hearing aids to children with auditory defects; in addition, in certain cases it provides valuable additional information and can be employed in solving simulation and masking problems. The diagnostic validity of ECochG in Menière's disease requires continued investigation. To sum up, we can say that ECochG should be performed only at centres where the frequency of examinations guarantees the necessary expert knowledge.

Audiometry↗
PubMed1984

Determination of tenoxicam, and the isolation, identification and determination of Ro 17-6661, its major metabolite, in human urine.

A high-performance liquid chromatographic method for the determination of tenoxicam (Ro 12-0068, I) and the hydroxy metabolite Ro 17-6661 (II) in human urine has been developed. The parent drug and metabolite were extracted from acidified urine by means of an Extrelut column with chloroform. The evaporated eluate was analysed on a C18 reversed-phase column with methanol-phosphate buffer as the mobile phase and UV detection at 371 nm. The detection limit for both compounds in a 1-ml sample was 50 ng/ml (C.V. 7%). The inter- and intra-assay precision up to 20 micrograms/ml was 3-6%. The method was applied to the analysis of I and II in the urine of a human subject who had received a 40-mg oral dose of the drug. Approximately 36% of the dose was eliminated in the urine as II, and less than 0.5% as unchanged I. After enzymatic hydrolysis of the urine, an extra 2% of the dose was found as II. Compound II was isolated from human urine by preparative thin-layer chromatography and identified by comparison of its mass and proton resonance spectra with those of an authentic specimen.

Chromatography, High Pressure Liquid↗
PubMed1984

[Polycythemia in kidney cysts. A report on an unusual case].

A 43-year-old woman with a solitary renal cyst developed polycythaemia. 21 well documented cases of this type have been previously published. In the majority of them a causal connection could be assumed between the renal cyst and polycythaemia: in 13 of the 15 cases (as in the reported one), the polycythaemia disappeared after surgical removal of the cyst. Measurement of serum erythropoietin can help in the differential diagnosis, but exclusion of polycythaemia vera may be difficult in the individual case.

Adult↗
PubMed1984

[Systemic lupus erythematosus. Brown-Sequard syndrome, spinal ataxia and peripheral polyneuropathy as the sole manifestations].

Neurologic manifestations were the sole symptoms of disease in three patients with systemic lupus erythematodes (SLE): one case presented with Brown-Séquard's syndrome, a second with spinal ataxia and polyneuropathy, and a third with polyneuropathy. In all three patients there was a considerable delay in making the diagnosis after onset of neurological symptoms. The diagnosis was established either by demonstration of antinuclear antibodies in combination with antibodies against dsDNA or by the demonstration of antibodies against dsDNA alone. In two patients perivascular deposits of IgG and C3 were seen in skin-muscle biopsies from the calf region.

Aged↗
PubMed1984

[Toxicologic survey of findings in putrefied corpses. Corpse putrefaction in air].

Autopsies were conducted on 234 putrefied corpses (exposed to the air, not buried) at the Institute for Forensic Medicine of the University of Hamburg from January 1979 to May 1983. Estimating the time it had taken to reach the respective degree of putrefaction was almost impossible. Only anamnestic clues provided evidence to ascertain the approximate time of death (between 3 days and 46 months ago). The cadavers were found in different locations: outdoors, inside heated or non-heated rooms. Some corpses wore clothes; others were naked; some were covered with blankets or other material. Chemicotoxicological analyses consisted of routine methods and additional modern sophisticated techniques: capillary gas chromatography, combined GC/MS, infrared spectrometry, radio- and enzyme-immunological tests. In organ specimens and body fluids of 47 corpses organic medicaments or poisons could be detected. Nearly all of these 47 forensic autopsies were carried out by request of the legal authorities to rule out legal intoxication as well as the influence of illegal drugs or medicaments. Unlike 20 years ago, today it is possible to detect and quantify organic drugs and poisons as well as their metabolic products, especially minor or major tranquilizers or barbiturates, in highly putrefied specimens. In spite of analytical progress, interpretation of some chemotoxicological results remains difficult. Poor anamnestic data provide insufficient clues. Therefore, pathologicoanatomical and histological results have special significance for the final conclusions. Good cooperation between the pathologist and toxicologist is one of the imperative prerequisites to come to a satisfying result.

Adolescent↗
PubMed1984

Active hepatitis B vaccination of dialysis patients and medical staff.

One hundred six patients with terminal renal insufficiency and 29 medical personnel were given three doses of hepatitis B vaccine at an interval of 0, 1, and 6 months (Merck, Sharp and Dohme, West Point, Pennsylvania, part of a joint study no. 649). Chronic hemodialysis patients (N = 99) received 40 micrograms vaccine (V) i.m. Uremic patients, who were just about to start chronic dialysis treatment (N = 7), were given 40 micrograms V, and at the first vaccination 3 ml hyperimmune globulin (HBIG) in addition. The medical personnel was alternately vaccinated with 20 micrograms V (N = 8), 40 micrograms (N = 11), 40 micrograms V, and 3 ml HBIG at the first vaccination (N = 10). After 12 months, 50% of the male dialysis patients, 66% of the female dialysis patients, and 95% of the medical staff developed anti-HBs antibodies. The anti-HBs titer of the dialysis patients was ten times lower than in the medical staff. The simultaneous passive immunization did not lead to any impairment of the anti-HBs titer in the dialysis patients and staff. The type of renal disease, length of time on dialysis, hematocrit, and immunoglobulin concentration did not influence the rate of immunization. After 12 months, 43 patients without antibody response were vaccinated a fourth time. Sixteen of these patients then developed anti-HBs, improving the immunization rate from 56.5 to 71.7%. A fifth vaccination only led to seroconversion, when brief or borderline anti-HBs could already be demonstrated previously. In dialysis patients who fail to develop anti-HBs after three doses of vaccine, a fourth vaccination is recommended after 12 months.

Antibodies, Viral↗
PubMed1984

[Serum antibodies against corneal and internal ear tissues in Cogan's syndrome].

Using the indirect immunofluorescence technique, IgG and IgA antibodies against human cornea and IgG antibodies against human inner ear tissue (stria vascularis, Reissner's membrane, spiral ligament, dark cell area) were demonstrated in the serum of a patient with cogan's syndrome. Sera of controls (healthy individuals) did not show positive reactions. Additionally the serum of two patients suffering from "idiopathic" progressive sensorineural hearing loss contained antibodies (IgG) which reacted with human inner ear tissue only but not with human cornea. A possible autoimmune mechanism in Cogan's syndrome is discussed.

Adolescent↗
PubMed1984

[Qualitative detection of immunoglobulins in the human endolymphatic sac].

Healthy human temporal bones and samples of the endolymphatic sac taken during surgery or from fresh cadavers were studied with regard to the presence of immunoglobulins. For demonstration of IgG, IgM, IgA and SIgA immunofluorescent methods and the immunoperoxidase-antiperoxidase method were used. Immunoglobulins are exclusively present within the endolymphatic sac whereas other structures of the healthy human inner ear do not show any positive reaction to the methods used for the demonstration of immunoglobulins.SIgA is clearly shown in epithelial cells of the rugosal part, whereas IgG predominantly is located in the flat endothelium--like cells of the extratemporal part. IgA and IgG further are detected within glycoproteins of the sac lumen and in plasma cells beneath the epithelium. Finally all subepithelial lymphatic spaces contain rich amounts of IgG. In one single temporal bone with tympanogenic labyrinthitis IgG and IgM wee present not only in all three layers of the round-window-membrane but also within the perilymphatic exudate. In this case IgM was found in the perisaccular tissue. The presence of free and local bound immunoglobulins exclusively in the region of the endolymphatic sac postulates and immunologic defense mechanism of this organ for the inner ear.

Antibody Formation↗