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Biomedical subjects

C Witting

Publications and source records attributed to C Witting.

At least 19 recordsLinked to original sources
PubMed1999

[Confusing tissue samples: causes, consequences, prevention].

The rising numbers of tissue samples for securing a diagnosis has led to a multitude of tissue samples in pathology institutes. Criteria and measures for ensuring the quality of histological diagnosis have been developed. Corresponding rules for the organization of the tissue sampling up to their processing do not yet exist. Suspicion of interchanged samples occurs much more often than it actually happens; however, it is important to be aware of the possibility so as to inform the clinician and to eliminate any possible causes of the confusion. The civil and penal consequences of such an interchanging, the subsequent "incorrect" diagnosis and the therapeutic measures are secondary compared to the potentially dramatic consequences for the patient. Important causes for an interchanging and possible preventive measures are presented.

Clinical Laboratory Techniques↗
PubMed1996

[An example for stepwise reduction of work site-induced formaldehyde exposure in pathology].

Occupational formaldehyde exposure in pathology depends on the efficiency of the ventilation system in use and may reach concentrations considerably above the current threshold limit values. The reduction of formaldehyde exposure by stepwise improvement of the ventilation system at a pathologist's workplace is presented as an example in this paper. Assessment of formaldehyde concentration by personal air sampling at a workplace originally equipped with a hood ventilation system resulted in values of up to 4 ml/m3 in the pathologist's breathing zone. Lowering the ventilation inlet to the working level by connecting the hood to a suction unit via a flexible hose resulted in an effective reduction of formaldehyde exposure to values of about 0.5 ml/m3. This simple and low-cost technical improvement had some uncomfortable side effects, such as current noise and wind chill, which could only be overcome by installing ventilated work tables according to modern technical standards.

Air Pollutants, Occupational↗
PubMed1996

Double-phase Tc-99m MIBI scintigraphy in secondary hyperparathyroidism relapsing after parathyroidectomy and removal of a parathyroid autograft.

A 53-year-old woman with chronic renal failure had secondary hyperparathyroidism relapsing after undergoing a second parathyroidectomy and excision of an autologous parathyroid graft that had been implanted after her first parathyroidectomy. Double-phase scintigraphy with Tc-99m MIBI disclosed pathologic MIBI uptake in the right anterior thorax where the parathyroid transplant had been placed. Histopathologic examination of three nodules excised from this region yielded hyperplastic parathyroid tissue. This case report further illustrates the value of double-phase Tc-99m MIBI scintigraphy in atypical cases of hyperparathyroidism.

Diagnosis, Differential↗
PubMed1992

Zinc concentrations in human tissues. Liver zinc in carcinoma and severe liver disease.

In 58 unselected necropsies, zinc (Zn) in specimens of liver (mean +/- s = 280 +/- 178 micrograms/g d.w./4.28 +/- 2.72 mumol/g d.w.), kidney (170 +/- 57 micrograms/g d.w./2.60 +/- 0.87 mumol/g d.w.), spleen (69 +/- 13 micrograms/g d.w./1.05 +/- 0.20 mumol/g d.w.), and lung (64 +/- 16 micrograms/g d.w./0.98 +/- 0.24 mumol/g d.w.) were analysed by means of flameless atomic absorption spectrometry. In the examined range from 25 to 92 years of age, the Zn concentrations in all tissues measured did not show age or sex-dependency. There was a high correlation between the tissue concentration of Zn and Mg in lung, liver, and spleen, between Zn, Mg, and Pb in liver as well as between Zn and Pb and Zn and Cd in kidney. All hepatic cirrhosis cases had very low Zn conc. in liver tissue, the tumor cases generally increasing Zn conc. in liver tissue with progressive stage of regional invasion and distant metastasis.

Adult↗
PubMed1989

[Late metastasis of an extragonadal Leydig cell tumor].

The case of a 36-year-old patient who underwent extirpation of a Leydig cell tumor of the epididymis is presented. Five years later a retroperitoneal mass was removed, which was found to be a metastatic Leydig cell carcinoma. The literature conrains reports of only 32 cases of metastatic Leydig cell tumors, all of which had originated in the testis and not extragonadally. The symptoms, treatment and prognosis are discussed with reference to the literature.

Adult↗
PubMed1988

Investigations on metabolism and carcinogenicity of 1,1,2-trichloroethane.

Two groups of male and female Sprague-Dawley rats (50 animals/group per sex) were treated with either 15.37 or 46.77 mumole of 1,1,2-TCE in DMSO/rat for 2 years. The animals were treated once a week by s.c. injection of test compound in the skin of neck. Two groups of controls received either DMSO or no treatment at all. The incidence of benign mesenchymal and epithelial tumors was not significant when compared with either DMSO-treated or untreated controls. The animals treated with 46.77 mumole 1,1,2-TCE significantly developed sarcomas when compared with the untreated controls. In a further experiment, either 40 mumole or 160 mumole 1,1,2-TCE was injected into male Wistar rats and the metabolites, TdGA and HEMA, were determined in 24-h urine samples. Comparative studies were carried out giving equimolar amounts of chloroethanol and 2-chloroacetaldehyde diethyl acetal. Analysis of the metabolites showed that no detectable HEMA was excreted in urine after treatment of rats with 1,1,2-TCE or chloroethanol. TdGA was excreted in urine much more among chloroacetaldehyde-treated animals than among 1,1,2-TCE- or chloroethanol-treated rats.

Acetaldehyde↗
PubMed1987

[Spontaneous intra-antral rhinolith. A case study].

Rhinoliths of the paranasal sinuses have often been reported and are generally due to trauma and surgery of these cavities and to retained foreign bodies. In the present case, an unilateral chronic rhinosinusitis had been treated by antiinflammatory agents only, but never underwent surgery or trauma. Tomography revealed a high density concretion. A solid rhinolith was removed by a Caldwell-Luc procedure and was then submitted to spectrographic and electron microscopic investigations.

Calcium Phosphates↗
PubMed1986

Investigations on metabolism, genotoxic effects and carcinogenicity of 2,2'-dichlorodiethylether.

Either 40 mumole or 160 mumole 2,2'-DDE was injected into male Wistar rats and the metabolites, TdGA and HEMA, were determined in the 24-h urine specimens. Comparative investigations were carried out giving equimolar amounts of chloroethanol and 2-chloroacetaldehyde diethyl acetal. In a further step, inhalation experiments were performed to determine urinary excretion of the two metabolites after an 8-h exposure of male Wistar rats to 10, 50, 100, and 500 ppm 2,2'-DDE and to 50, 200, und 1,000 ppm vinyl chloride. A long-term study was conducted to investigate the possible carcinogenicity of 2,2'-DDE in male and female Sprague-Dawley rats following s.c. injections of 4.36 mumole and 13.1 mumole 2,2'-DDE in DMSO per week. The evaluation of tumor development in treated groups and controls were based on macroscopic inspection and histological examinations of the suspect organs and tissues. Analysis of the metabolites showed that HEMA excretion was much lower than the excretion of TdGA following the uptake of 2,2'-DDE, 2-chloroethanol and 2-chloroacetaldehyde diethyl acetal. Contrary to these, vinyl chloride uptake resulted in a higher urinary excretion of HEMA than TdGA. There was no appreciable increase in the number of tumors detected in 2,2'-DDE-treated animals when compared with untreated or DMSO-treated groups. Since irradiation of 2,2'-DDE with UV did not elevate mutagenic activity of the compound against Salmonella typhimurium TA100, the high mutagenicity of the compound found in a desiccator cannot be due to the liberation of mutagenic compounds produced under the influence of UV light.

Acetaldehyde↗
PubMed1985

Increased chromium and nickel content in lung tissue.

In random autopsies chromium (n = 23) and nickel (n = 16) together with various other metals, were determined in lung tissue by means of flameless atomic absorption spectrometry. With increasing age a significant increase in concentration of both chromium and nickel was found. This is evaluated as an indicator for a corresponding exposure, which is marked by a local (workplace) and regional (environment) share of a clear increase in the total chromium/nickel load and by a life-long duration. The question arises, whether the selective concentration (long half-life) of the inhaled chromium and nickel particles/compounds in the lung are to be regarded as a stochastic lung cancer risk.

Adult↗
PubMed1983

Active immunization with follicle-stimulating hormone for fertility control: a 4 1/2-year study in male rhesus monkeys.

Active immunization of four adult rhesus monkeys with highly purified ovine follicle-stimulating hormone (FSH) over 4 1/2 years resulted in the production of specific FSH antibodies. While luteinizing hormone and testosterone secretion were not affected, sperm counts were in most instances reduced to or below the lower normal range. On a few occasions, azoospermia or high sperm counts were observed. Although the antibodies produced neutralized the biologic activity of FSH throughout, spermatogenesis gradually returned, as evidenced by testicular histologic characteristics. However, the diameter of the seminiferous tubules remained decreased, and the germinal epithelium was depleted. No adverse side effects could be demonstrated in the immunized animals, e.g., immune complexes in either serum or tissues and resultant tissue damage. These results show that although active immunization with FSH may not result in an effective method of male fertility control, long-term immunization against a circulating hormone may not result in deleterious side effects.

Animals↗
PubMed1982

The tumor-protective effect of selenium in an experimental model.

The possibility of a tumor-protective effect of selenium on the growth of benzpyrene-induced sarcoma was studied in an assay with Balb/c mice. The animals received 4 parts/10(6) selenium in their drinking water for 12 months prior to subcutaneous injection of benzpyrene to induce sarcomas. In contrast to unpretreated controls, the selenium-exposed animals developed significantly less and smaller tumors in a given time. These results are compared to those of other authors. Several mechanisms for selenium influence on benzpyrene metabolism are discussed.

Animals↗
PubMed1981

[Wallenberg's syndrome (author's transl)].

Wallenberg's syndrome includes a series of symptoms caused by obliteration of small arteries supplying the medulla oblongata. In the differential diagnosis it must be separated from lesions of the pons. Cause of the arterial block was first considered to be an embolus, inflammatory processes were later also incriminated. The course of the disease and autopsy findings in a 57-year-old man who had arterial hypertension for 20 years show that Wallenberg's syndrome can be a typical complication of chronic hypertension.

Autopsy↗