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Biomedical subjects

R Kraus

Publications and source records attributed to R Kraus.

At least 19 recordsLinked to original sources

32P-postlabeling analysis of DNA adducts in different populations.

Blood samples were obtained from different populations exposed occupationally or by lifestyle habits to polycyclic aromatic hydrocarbons (PAH). DNA adducts were determined by 32P-postlabeling assay either in white blood cells (WBC) or lymphocytes. The level of DNA adducts ranged from 1.5 per 10(9) nucleotides in one of the control groups up to 7.1 per 10(9) nucleotides in one group of PAH-exposed workers. Comparison of the adduct thin layer chromatography (TLC) profiles revealed individual variation in both pattern and level of DNA adducts. Significant differences of adduct levels were detected between one group of PAH-exposed coke-oven workers and the corresponding control group. Only a weak influence of the smoking habits on the amount of adducts was detectable in occupationally exposed or unexposed individuals.

Adult

Sister chromatid exchange frequencies in lymphocytes of oral cancer patients seem to be influenced by drinking habits.

Sister chromatid exchange (SCE) values were determined in the lymphocytes of 24 oral cancer patients before therapy and in the lymphocytes of 24 control persons standardized with respect to sex, age and smoking habits. Oral cancer patients showed significantly elevated SCE values (mean 7.82 versus 6.42). In both groups the highest SCE values were found in the subgroups with the highest alcohol consumption. A significant correlation between SCE and gamma-glutamyltranspeptidase (GGT) values by Spearman correlation analysis was detected in the combined group (cancer patients and control persons) (n = 32, r = 0.40, P = 0.023). The SCE values in the oral cancer patients were weakly correlated (Pearson) to DNA adduct levels (n = 22, r = 0.39, P = 0.068) and DNA single-strand breakage frequencies (n = 12, r = 0.56, P = 0.054) in lymphocytes. The correlation (Pearson) between SCE values and DNA strand breakage values in lymphocytes was significant (n = 10, r = 0.67, P = 0.036) in smoking cancer patients. The increase of SCE values with respect to alcohol drinking habits underlines epidemiologic findings that alcohol is an important co-carcinogen in many cancers, especially in oral cancers. Because of the influences on SCE and adduct levels in lymphocytes, alcohol drinking habits should be controlled as broadly as possible in biomarker studies.

Adult

[Functional studies of the spinal cord in chronic stenosing diseases of the cervical spine using somatosensory evoked potentials].

Report about 35 persons with chronic stenosing diseases of cervical spine which was investigated through somatosensory evoked potentials (SSEP) after stimulation of the median (M-SSEP), ulnar (U-SSEP) and tibial (T-SSEP) nerve. The examinations were always performed in extreme possible cervical ante and retroflexion. The majority of patients (n = 17) presented with a bony spinal stenosis. Less often were cervical disc prolaps (n = 8) or a atlanto-axial dislocation in primary chronic polyarthritis (n = 7) the cause of the illness. The rest of the patients (n = 3) had still different sources of stenoses of the spine. In 23 of 35 patients a change of the SSEP occurred during measurement while in this extreme cervical ante-and retroflexion. In 15 of these cases the initially pathological SSEP deteriorated, while in 8 patients an initially normal SSEP turned pathological in the functional position. Most often changes of the so-called "Functional SSEP" occurred in multisegmental bony cervical stenosis. In most cases a change in the T-SSEP obtained, independently of the main localisation of the radiologically verified spinal stenosis. The SSEP changes are illustrated through typical examples. The determination of SSEP in extreme positions of the cervical spine appears, therefore, as a suitable method to discover transient dysfunctions or the increase of dysfunctions of the cervical spinal cord. They can also serve as a preoperative screening method of dysfunctions of the cervical spinal cord in operations of planned long duration with unfavourable positioning of the cervical spine (extreme antiflexion, twisting, or retroflexion).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

DNA strand breakage and DNA adducts in lymphocytes of oral cancer patients.

In lymphocytes of 12 oral cancer patients (and two control groups) the frequencies of DNA single-strand breaks and DNA-protein cross-linking were determined by alkaline filter elution. We found elevated DNA elution rates, which must be interpreted as an increased strand breakage frequency. There were significant correlations between the DNA strand breakage frequency and smoking habits. Using the 32P-postlabelling assay we determined the DNA adduct level in lymphocytes of 23 oral cancer patients (and two control groups). No significant influence of smoking habit on the DNA adduct level could be detected. There was a significant correlation between the DNA adduct level and the gamma-glutamyltranspeptidase (GGT) value, suggesting systemic influences of alcohol drinking habits on the adduct level.

Adult

[Polychlorinated biphenyls (PCBs) and reproduction disturbances].

A review of the impact of chlorinated biphenyls (PCBs) on reproduction is presented. PCBs are able to pass the placenta; accumulation in offspring is mainly achieved by breast feeding. Disturbances of fertility and embryotoxicity were detected in animals; teratogenicity without maternal toxicity was only observed in mice. In animal experiments disturbances of fetal and postnatal development were detected as well as in human studies. Neurotoxicity was observed even at low-level exposures in monkeys, which are most comparable to humans because of the development of the same clinical symptoms. Technical PCBs which are dominating in occupational and environmental exposure until now must be judged as toxic for reproduction: dermal exposure (especially in accidents) should be considered as an important route of exposure beside inhalation. Work to list possible PCB exposure risks and to develop ways to reduce these risks are necessary now.

Abnormalities, Drug-Induced

Activity testing of alveolar macrophages and changes in surfactant phospholipids after irradiation in bronchoalveolar lavage: experimental and clinical data.

This study presents results of bronchoalveolar lavage (BAL) after irradiation to the lungs in mice as well as clinical data. The number of BAL cells, mainly macrophages, lymphocytes, and granulocytes, changed in a time-dependent manner. The phagocytic activity of the macrophages measured as the phagocytosis of microbeads and measured as the esterase activity also showed a strong time-dependent increase during the acute phase up to 21 days after irradiation. The contents of surfactant phospholipids (SF) and sphingomyelin (SPH; as a parameter for cell death) were quantified by HPLC. Both were significantly changed between day 2 and 21 after irradiation. Three BALs of a patient with idiopathic interstitial pneumonitis, who had received an allogenic bone marrow graft after total body irradiation with 10 Gy, showed similar effects in the cellular and surfactant parameters. These data indicate that there are positive interactions between the number of different BAL cells, macrophage activity, and SF and SPH content in the preclinical model of the mouse as well as in the clinical situation after lung irradiation.

Animals

Radiation-induced changes in lung tissue and development of fibrosis determined by quantitative morphometric methods.

This study presents results of morphometric investigations of mouse lungs after single irradiation. An automatic image analyser was used to monitor pathological changes in morphological structure, especially the size and distribution of collagen fibres, the thickness of the septa and the diameters of alveoli in the lung. Radiation-induced changes in the area of alveoli and septa as well as collagen content were seen 11 weeks after irradiation. A dose-dependent increase in tissue and decrease in alveolar surface as well as a quantifiable increase in radiation oedema were seen. The septa were thickened and the total collagen content increased in a dose-dependent manner. The morphometric methods used here are suitable for determining changes in lung structure, particularly those in collagen content in the early phase of a pathological response after thorax or total body irradiation for conditioning in bone marrow transplantation.

Animals

Sonography of neck masses in children.

The sonograms and medical records of 49 patients were reviewed to determine if there is a characteristic sonographic appearance for certain neck masses. Neck masses included: inflammatory masses (12), noninflammatory masses (23), and thyroid masses (14). Four entities including thyroglossal duct cyst, fibromatosis colli, cystic hygroma, and multiple lymphadenopathy showed characteristic sonographic appearance. Thyroglossal duct cysts were seen as midline or slightly off midline cystic masses. A sinus tract extending superiorly was nicely demonstrated in one patient. The mass in fibromatosis colli (neonatal torticollis) appeared as a well defined mass clearly within the sternocleidomastoid muscle, uniformly echogenic, but less echogenic than the normal surrounding muscle, without good through-transmission. A cystic or primarily cystic mass with linear septations was the characteristic finding of the cystic hygroma. Multiple lymphadenopathy demonstrated multiple discrete, oval, relatively hypoechoic masses along the cervical lymphatic chain. The sonographic appearance of inflammatory masses was variable, being either inhomogeneously echogenic or of mixed echogenicity. Hemangiomas were either echogenic with cystic vascular spaces or linear septations or relatively homogeneously echogenic. Intrinsic thyroid masses could be distinguished from extrinsic masses in most cases. The demonstration of calcification in a mass was useful in narrowing the differential diagnosis. Although it is not a specific finding, the presence of calcification highly suggests a neoplastic lesion, particularly neuroblastoma or teratoma. Not only can the location, extent, and internal characteristics of a mass be determined, but in certain entities, the sonographic appearance is characteristic and an accurate diagnosis can be made.

Adolescent

[Tomography in veterinary medicine. Possibilities for the application of this x-ray technic demonstrated on the spinal column of a dog].

After a short introduction of theoretical principles of tomography, the advantages of this technique--especially the representation of the dog's spinal column--are discussed with five case histories. This technique allows to produce isolated pictures of special parts of the spinal column which may be superpositioned by other body parts like: atlantooccipitalregion (especially dens axis), caudal cervical spine, thoracical spine and lumbosacral region. Particularly the evaluation of the intervertebral spaces, the small vertebral joints and the contours and structures of the vertebrae is enhanced, which is important in tumorous and infectious processes, as well as in fractures and luxations of the vertebrae. Besides the spatial association of certain structures is possible if their localization with conventional x-ray methods and even with exposures in two planes is unsuccessful.

Animals

Comparison of cardiovascular response to combined static-dynamic effort, postprandial dynamic effort and dynamic effort alone in patients with chronic ischemic heart disease.

The cardiovascular responses to combined static-dynamic effort, postprandial dynamic effort and dynamic effort alone were evaluated by upright bicycle ergometry during equilibrium-gated blood pool scintigraphy in 24 men, mean age 59 +/- 8 years, with chronic ischemic heart disease. Combined static-dynamic effort and the postprandial state elicited a peak cardiovascular response similar to that of dynamic effort alone; work load 643 +/- 156 and 638 +/- 161 vs 650 +/- 153 kg-m/min, respectively; heart rate 147 +/- 14 and 145 +/- 14 vs 143 +/- 17 beats/min; systolic pressure 195 +/- 26 and 200 +/- 25 vs 197 +/- 25 mm Hg; and rate-pressure product 286 +/- 48 and 292 +/- 55 vs 282 +/- 52. Heart rate, intraarterial systolic and diastolic pressures, rate-pressure product and ejection fraction were similar for the three test conditions at the onset of ischemia and at peak effort. The prevalence and extent of exercise-induced ischemic left ventricular dysfunction, ST-segment depression, angina pectoris and ventricular ectopic activity were also similar during the three test conditions. Direct and indirect measurements of systolic and diastolic blood pressure were highly correlated. The onset of ischemic ST-segment depression and angina pectoris correlated as strongly with heart rate alone as with the rate-pressure product during all three test conditions. The cardiovascular response to combined static-dynamic effort and to postprandial dynamic effort becomes more similar to that of dynamic effort alone as dynamic effort reaches a symptom limit. If significant ischemic and arrhythmic abnormalities are absent during symptom-limited dynamic exercise testing, they are unlikely to appear during combined static-dynamic or postprandial dynamic effort. This simplifies, the task of formulating guidelines for physical effort in patients with chronic ischemic heart disease, especially in providing "clearance" to perform avocational and vocational tasks involving combined static-dynamic and postprandial dynamic effort.

Aged