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Biomedical subjects

H Schubert

Publications and source records attributed to H Schubert.

At least 109 records · Page 6Linked to original sources
PubMed1989

Congenital fascial dystrophy: stiff skin syndrome--a human counterpart of the tight-skin mouse.

Four patients are described with stony-hard induration of the skin and deeper tissues, most pronounced on the buttocks, thighs, and legs, and with limitation of joint mobility and contractures of the lower limbs. Two patients were siblings and one was the product of a consanguineous marriage. The disorder appears to be genetically determined, but the mode of inheritance has not been established. The disease was noticed in the patients' early infancy and was not progressive. Except for functional impairment of the lungs caused by an underdeveloped thorax that resulted from pressure of the thickened thoracic fascia, there was no involvement of the viscera or muscles and no immunologic abnormalities. The most important finding was markedly thickened fascia. This hereditary connective tissue disorder has all the characteristics of the tight-skin mouse.

Adult↗
PubMed1989

[Bernardino Ramazzini (1633-1714). On the 275th anniversary of the death of the founder of occupational dermatology].

Ramazzini is not only reputed to be the father of industrial hygiene, but must be thought to be the founder of occupational dermatology too. In his famous book about diseases of artists and craftsmen (De morbis artificium diatriba) he shows us numerous job-caused dermatoses, their occupational background, and makes proposals for their treatment and prophylaxis. The medical inspection of the work place and asking for the occupational history of the patient are tracing back to him too. His life is described.

Dermatitis, Occupational↗
PubMed1989

Semiconductor diode laser endophotocoagulation.

We successfully used a semiconductor diode laser to deliver endophotocoagulation burns to the retina of a rabbit. The diode laser employed emits light at a wavelength of 817 nm (near infrared). It has a power output of up to 1.0 W in the continuous-wave mode, equivalent to the capability of current argon laser endophotocoagulators. A standard, commercially available fiberoptic endophotocoagulation probe was used to deliver the laser burns. We used power settings ranging from 300 mW to 400 mW and exposure times of 0.1 to 0.2 seconds to produce chorioretinal burns that appeared clinically and histopathologically indistinguishable from those induced with conventional wavelengths. This new laser system has the decided advantages over traditional endophotocoagulators of being much smaller, less costly, and requiring no water cooling, without sacrificing power output or ease of delivery.

Animals↗
PubMed1989

[Photochemotherapy of experimental tumors in animals using various photosensitizers].

Different colouring matters with high molar extinction coefficient were tested at the Friedrich Schiller University with regard to their photodynamic efficacy. Test system was the rapid-growing solid Ehrlich carcinoma. Methylen-blue, hematoporphyrin derivative Halle and chlorophyllin produce a markedly reduction of the tumor weight. In the presence of hypoxic areas an additional application of nitroimidazols is possible. A pilot laser unit for photochemotherapy of urinary bladder tumors is presented.

Animals↗
PubMed1989

[A comparison between high-frequency jet ventilation (HFJV) and conventional positive end-expiratory pressure ventilation (CPPV)--an experimental study on dogs with acute lung damage].

In a controlled study on 24 dogs with severe damage to the lungs HFJV was compared to CPPV on the basis of selected cardiorespiratory parameters. The pulmonary damage was produced by injection of oleic acid (OA) into the right atrium under conventional mechanical ventilation (IPPV). After the damage, the dogs were randomly allotted into one of two groups. Twelve dogs (group I) were ventilated for 5 hours with a PEEP of 10 cm H2O (1 kPA), 12 animals (group II) for 5 hours with HFJV. The oleic-acid-induced damage results in the known hypoxaemia with an increase in the intrapulmonary shunt. After changing to CPPV, the PaO2, which fell from 27.2 +/- 3 kPa to 10.8 +/- 2.9 kPa, rises to 20.3 +/- 7.7 kPa, but shows no further significant alteration until the end of the experiment. In contrast to the clearly improved oxygenation, essential cardiocirculatory parameters (CI, SVI, RVSWI, LVSWI, TCO2) are partially reduced by more than 50% of the initial values. PAP, PCWP, HR, TPR and PVR increase significantly, MAP remaining nearly unchanged. After changeover to HFJV, there is first a further fall of PaO2 from 11.1. +/- 3.0 kPa to 9.1 +/- 1.4 kPa following OA, then, however, until the end of the experiment, a continuous elevation to 15.6 +/- 2.4 kPa with a mean airway pressure that is by 75% lower. The haemodynamic parameters show no significant changes as compared to the initial values, overall, however, they lie significantly below or above those of group I. The results from our investigations allow to draw the conclusion that, despite haemodynamic advantages, HFJV in consequence of deterioration of the arterial oxygenation currently is no alternative superior to CPPV in ventilating the severely damaged lung.

Animals↗
PubMed1989

In vivo autofluorescence investigations on animal tumors.

The in vivo fluorescence behavior of unmarked tissue (autofluorescence) of tumor-bearing mice was investigated. An argon-ion laser was used as the excitation source emitting radiation at 351 nm and 364 nn. Fluorescence bands in the red spectral range were recorded. The spectral distribution of the fluorescence of the solid Ehrlich carcinoma was different from that of the neighboring tissue.

Animals↗
PubMed1989

[Electrophysiologic and histomorphological studies on the nervus ischiadicus of rats. I. The uninjured nerves].

We report in the model described above on measurements of striking features of the normal sciatic nerve of adult male Wistarrats (250-300 g). Electrophysiological parameters were measured by means of an Electromyoneurograph (needle stimulation). The calculation of the maximum motor nerve conduction velocity results in a mean value of 59.6 ms-1. The mean compound action potentials of the foot muscle are 9.2 mV (proximal stimulated) and 10.1 mV (distal stimulated). Counting out 10011 nerve fibres in Light Microscoping Findings for histological studies we got a nearly Normal distribution of the fibre diameters with a mean fibre diameter of 7.09 microns. The corresponding density of nerve fibres is 8700.4 mm-2. The calculated percentage of neural tissue, related to the surrounding connective tissue is about 36.32%.

Action Potentials↗
PubMed1989

Photodynamic therapy with haematoporphyrin derivative on mice with solid Ehrlich carcinomas.

The tumor-toxic effect of the photosensitizer HpD/Halle activated by laser radiation was demonstrated. Solid Ehrlich carcinoma was used as model. Investigations into the tumor growth, the HpD-distribution after different kinds of drug administration by means of fluorescence measurements, the phototoxicity and the reduction of tumor masses after HpD application and laser irradiation were carried out.

Animals↗
PubMed1988

Thioacetamide-induced cirrhosis-like liver lesions in rats--usefulness and reliability of this animal model.

Long term administration of thioacetamide (0.03% in tap water) results in a characteristic lesion in rat liver, which corresponds to cirrhosis-like patterns of micronodular cirrhosis type after treatment over 3 months. During its development a reproducible temporal course of biochemical and morphological changes can be recognized. After withdrawal of the toxic agent this lesion persists for about 2 months. Then the cirrhosis-like alterations recede and a proliferation of bile ducts predominates, which is associated with increasing portal fibrosis altering the pattern and relatively enhancing the total collagen content of the liver. Considering these peculiarities, the TAA-model is suitable for investigations into connective tissue metabolism in the fibrotic liver and cirrhosis-like patterns. Search for and test of therapeutic principles should be done during TAA-administration (prophylactic agents) or within 2 months after withdrawal of toxic agents (therapeutics).

Acetamides↗
PubMed1988

Epidemiology of nickel allergy: results of a follow-up analysis of patients with positive patch tests to nickel.

In a previous paper, we reported on nickel sensitivity in 2400 consecutive patients in 5 countries. 3 years later, we reassessed 104 of the 157 nickel-positive patients of this former study and found 13 now to be negative to nickel sulphate. Nearly all the others can no longer tolerate nickel contact. 68 patients were free from nickel dermatitis, 16 showed a very mild eczema or dyshidrosis, and 13 were suffering from chronic hand dermatitis. 42 of 104 patients had changed their occupation, 36 successfully, with clearance of skin lesions. Rehabilitation by avoidance of nickel-containing costume jewelry, wrist-watches and clothing buckles, and by change of occupation, is possible and necessary.

Dermatitis, Contact↗
PubMed1988

[Experimental studies in animals of the regeneration of peripheral nerves].

In bridging nerve gaps and studying the process of nerve regeneration the method of "tubulation" becomes of new worldwide importance during the last years. In this technique the both stumps are introduced in a preformed tube without tension, the further healing process is left to the neuron's potency for self-repair. Although until now the experimental results confirm the possibility of this management it is often impossible to compare the findings because of the insufficient quantitative analyses. In this paper the own results of bridging a 4-6 mm defect in rat sciatic nerves with a connective tissue-teflon-tube are presented including an extensive quantitative analysis with methods of computer-based multivariate data analysis. The theoretic advantages of this technique are discussed in relation to the autologous interfascicular nerve transplantation.

Animals↗
PubMed1987

Photochemotherapy of animal tumors with the photosensitizer methylene blue using a krypton laser.

The cytotoxic effect of the photosensitizer Methylene Blue activated with long wavelength laser radiation has been investigated using mice with solid Ehrlich carcinomas. A krypton laser was used as a light source emitting laser radiation at 647 nm and 676 nm. The red spectral range is important for photochemotherapy because it is easily transmitted through tissue. A significant tumor reduction, including complete tumor destruction, has been achieved.

Animals↗
PubMed1987

Epidemiology of nickel allergy.

In 2400 consecutive patients at 8 clinics in 5 countries, nickel hypersensitivity was found in 176 cases (7.3%), 19 male (2.1%) and 157 female (10.5%). The incidence ranged from 15 to 38 cases in 300 patients of every department (5.0% Sofia to 12.7% Erfurt). 60.6% of the nickel positives were schoolgirls or younger than 25 years. The exposure time was 3 years, in 49% 1 year or shorter. Most cases (75%) are not occupationally acquired, but due to costume jewelry (31.8%), wrist watches (23.3%), metal clothing buckles (3.4%) including jeans buttons. Job dependent nickel dermatitis is often (36/51 cases) linked with wet work. Atopic dermatitis was found in 8.3% of female nickel allergy. Nickel positivity without a dermatitis history was seen in 9/176 cases (5%). Nickel allergy will become a sex-indifferent phenomenon in Europe, because of the changing customs of adornment.

Dermatitis, Contact↗