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Biomedical subjects

D Nagel

Publications and source records attributed to D Nagel.

At least 19 recordsLinked to original sources
PubMed1992

Biochemical, hematological and endocrinological parameters during repeated intense short-term running in comparison to ultra-long-distance running.

In order to see the differences in the acute effects of two kinds of running on biochemical, hematological and hormonal parameters, we investigated in one 24 h race (same exterior conditions) two groups of runners (NR = nonstop runners; RR = relay runners). From each participant blood samples were taken before, 3 times during and after the race. In both groups the lipid parameters cholesterol, triglycerides and LDL-cholesterol declined significantly, triglycerides even to 40% of their initial value, whereas HDL-cholesterol increased significantly. Renal parameters showed similar increases in both groups except for uric acid, which rose by 73% in RR compared with only 23% increase in NR. A difference was also found in the lactate and glucose concentrations, showing a four-fold increase and a 34% increase at 4 h respectively in RR, whereas the NR remained constant. Changes in the hematological parameters were similar in both groups. Cortisol and prolactin showed similar alterations during the race but LH and testosterone declined to approximately half of their initial concentration (p greater than 0.05) in NR after 4 to 8 h, in contrast to RR, where the concentration of LH or testosterone remained constant or changed only moderately but insignificantly during the race. Our investigation indicates that in ultra-long-distance running and intense short-term exercise performed under the same exterior conditions, many parameters show similar changes but great differences can be found as well if certain hormones, glucose metabolism and renal parameters are considered.

Adolescent↗
PubMed1992

Removal of toxic metals and nonmetals from contaminated water.

The effects of the application of potassium ferrate to remove possible toxic compounds are presented. Potassium ferrate (K2FeO4) is shown in this work to be an effective means to remove toxic metals and nonmetals from aqueous solution. The toxic material present in water is precipitated from aqueous solution and readily removed. Potassium ferrate removes itself from solution. Discolored contaminated water may be made clear by utilizing potassium ferrate. In addition, turbidities of solutions induced by dissolved substances are eliminated by the action of potassium ferrate. The efficacy of potassium ferrate in cleaning contaminated water shows great potential in application to municipal and industrial waste water.

Chemical Precipitation↗
PubMed1992

Significance of bone alkaline phosphatase, CA 15-3 and CEA in the detection of bone metastases during the follow-up of patients suffering from breast carcinoma.

After the introduction (1, 2) and methodical evaluation (3, 4) of a new method for the quantitative measurement of the bone isoenzyme of alkaline phosphatase (test-combination bone alkaline phosphatase, Boehringer Mannheim), we started a retrospective clinical study for the follow-up investigations of breast cancer patients. Our aim was to establish the significance of the routinely used tumour markers, CEA and CA 15-3, in combination with bone alkaline phosphatase for the early detection of metastatic spread to the bone. We investigated 492 sera from 92 patients suffering from breast carcinoma, and we compared each date of investigation with the results of the clinical examination and with the results of medical imaging, if that had been performed. From a previous study involving skeleton scintigraphy (5) we knew that single examinations do not allow a differential diagnosis between benign and malignant disorders of the bone, so we based our calculations on differences between sequential investigations. We found that in follow-up investigations of patients with breast carcinoma the combined determination of CEA, CA 15-3 and bone alkaline phosphatase may be indicative for the localisation of metastatic disease. The determination of the bone alkaline phosphatase is easy to handle with a short assay time and good reproducibility; it can therefore be recommended.

Alkaline Phosphatase↗
PubMed1992

Cluster analysis in diagnosis.

The purpose of this paper is to survey the usefulness of cluster analysis in the special case of diagnoses. This complex topic is restricted, however, to the application on laboratory characteristics, separately or in connection with clinical data. The article is subdivided into three parts: (a) the fields of a possible use of cluster analysis, detection of diseases or subgroups of diseases, and data reduction by detection of structures; (b) a brief mathematical description of hierarchical and partitioning classification techniques (as a crucial point, the problems associated with these methods are discussed); (c) a critical review of 24 publications of the past 10 years concerning cluster analysis and diagnoses.

Clinical Laboratory Techniques↗
PubMed1991

Histologic, biochemical, and clinical parameters for monitoring multiple myeloma.

In a retrospective and prospective follow-up study from 1968 to 1989, bone marrow biopsy specimens, serum beta-2-microglobulin (SB2M) levels, and the clinical features of 251 patients with multiple myeloma (MM) and 28 patients with monoclonal gammopathy of undetermined significance (MGUS) were investigated. The main histologic variables (tumor cell type, tumor growth, tumor load, and fibrosis), SB2M level, serum thymidine kinase (STK) level, and various clinical parameters were analyzed to determine factors of value in monitoring the clinical phases of activity in MM. Our recently proposed prognostic strategy combining bone marrow histologic type, SB2M level, and signs of organ failure was tested for its ability to (1) diagnose the early and smoldering variants; (2) facilitate decisions on the time of initiation, the type and duration of initial induction therapy in the pretreatment phases (active and rapidly progressive phases); and (3) characterize variations in tumor regression and tumor-host interactions during chemotherapy (early treatment, plateau, relapse, transition, and refractory phases). The results indicate that this clinicopathologic monitoring combines information both on stage and aggressivity of MM and thus facilitates therapeutic decisions in the various clinical phases of MM.

Biomarkers, Tumor↗
PubMed1991

Serum androgens in intensive-care patients: correlations with clinical findings.

Serum androgen levels were studied in 100 patients (50 male) with varying degrees of severe illness, determined by Acute Physiological and Chronic Health Evaluation (APACHE). Comparison with normal subjects revealed the following changes: (1) Basal dehydroepiandrosterone sulphate (DHEAS) values were decreased in the ill female patients (P less than 0.001) as well as in the ill males (two groups, P less than 0.01; P less than 0.05). Androstenedione values did not differ from the controls in patients of either sex. Basal testosterone levels were decreased in ill male patients (P less than 0.001), but not in females. (2) The low testosterone concentrations in the severely ill male patients correlated inversely with the APACHE score; additionally, a dependence on diagnostic categories could be demonstrated in men, since the lowest values were found in patients suffering from sepsis or liver cirrhosis. Acutely ill males had a moderately decreased testosterone, whereas chronically ill males showed a marked reduction of testosterone compared to the controls. Lowered DHEAS and androstenedione levels could be measured in chronically ill males but not in ill females. (3) 17 alpha-OH-progesterone and 17 alpha-OH-pregnenolone levels in subgroups of the patients suggested a probable enzymatic block in the delta 5-pathway of androgen biosynthesis in severe illness. The ratio of 17 alpha-OH-pregnenolone to DHEAS was significantly higher in male patients and tended to be high in ill females, whereas the ratio of 17 alpha-OH-progesterone to androstenedione showed no difference between healthy and ill subjects.

17-alpha-Hydroxypregnenolone↗
PubMed1991

The kinetics of chemical reaction of activated nitrosamine with organic substrates.

The chemical reaction of tosylated N-nitrosobis (2-hydroxylpropyl) amine with aniline, 1-naphthol, pyridine, and hydroxylamine follows kinetics which can be described in a mixed order rate equation. This nitrosamine, considered an activated nitrosamine with a potential for alkylating a substrate, was seen to alkylate aniline, pyridine, 1-naphthol, and hydroxylamine. The presence of salts in the solution as well as an increase in solution pH increased the rate of reaction of the nitrosamine with substrates. The nitrosamine reacts quickly with water but will not react with solvents such as acetonitrile, dimethylsulfoxide, and methylene chloride.

Alkylating Agents↗
PubMed1991

Nitrosation of tertiary aromatic amines related to sunscreen ingredients.

Possible routes to the formation of the sunscreen contaminant, 2-ethylhexyl 4-N-methyl-N-nitrosoaminobenzoate, have been investigated in a study of the nitrosation chemistry of 2-ethylhexyl 4-N,N-dimethylaminobenzoate (Padimate-O) and related tertiary and secondary amines. Padimate-O and the corresponding ethyl ester nitrosate rapidly at 25 degrees C in either N2O3:ether or HNO2:HOAc to produce a mixture of alkyl 4-N-methyl-N-nitrosoaminobenzoate and alkyl 4-N,N-dimethylamino-3-nitrobenzoate, the former of which is the major product. The nitrosative dealkylation of these amines at this low temperature is unusual. Asymmetrical amines exhibit a preference for nitrosative demethylation (methyl versus ethyl or benzyl), but the cleavage ratios in N2O3:ether are time-dependent, suggesting competing mechanisms with different reactant kinetic orders. A radical cation route would explain the unusual reactivity, which may compete with the established nitrosative dealkylation mechanism. 2-Ethylhexyl 4-N-methyl-N-nitrosoaminobenzoate was mutagenic in two strains of Salmonella typhimurium in the Ames assay.

4-Aminobenzoic Acid↗
PubMed1990

The mutation of V79 cells by N-nitrosobis(2-oxopropyl)amine activated by pancreas acinar and duct tissue from Syrian hamsters and MRC-Wistar rats.

The mutagenicity of N-nitrosobis(2-oxopropyl)amine was measured in the V79 assay using homogenates of acinar cells and duct tissue from the pancreases of Syrian hamsters and MRC-Wistar rats as the activating systems. Mutations at the sodium/potassium ATPase and hypoxanthine:guanine phosphoribosyltransferase loci were measured by resistance to ouabain and 6-thioguanine (TG). The order of effectiveness in generating mutagens from BOP was hamster duct, hamster acinar, rat duct, rat acinar. These data show extensive differences in BOP activation by hamster acinar and duct tissue.

Animals↗
PubMed1990

Ultra-long-distance running and the liver.

During an ultra-long-distance race (1000 km in 20 days) the influence of running was examined on the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), gamma-glutamyl-transferase (GGT), and glutamate dehydrogenase (GLDH) with regard to their release from the liver cells or their induction. Furthermore the liver synthetic capacity was assayed by measuring the enzyme activity of cholinesterase and the concentration of serum albumin during the race. Of the 110 participants, 55 finished the race and only the results of these runners were used in our study. AP increased continuously from day 0 (mean = 102 U/L) to day 19 (mean = 120 U/L). A fivefold increase of AST and a twentyfold increase of CK up to day 3 was followed by a significant decrease towards the end of the race. ALT rose as well up to day 6 from a mean value of 8 U/L to 24 U/L but remained at this level. Surprising was the individual increase of the enzymes GLDH (up to twentyfold) and GGT (up to sixfold) in more than half of the finishers on various days indicating liver cell injuries. The activity of CHE and the concentration of serum albumin decreased during the race, both were significantly correlated.

Adult↗
PubMed1990

The use of cluster analysis in clinical chemical diagnosis of liver diseases.

Diagnostic judgement is usually based on recognition of patterns. Unfortunately more than three quantitative data cannot be judged simultaneously without help of mathematical methods. Working on laboratory reports, a clinician usually goes linearly through the columns and reduces quantitative to qualitative data. Therefore the medical decision process should be improved if data reduction is performed with the aid of mathematical methods for pattern recognition. A total of 191 consecutive outpatients with a tentative or proven diagnosis of hepatobiliary disease were examined clinically, clinically chemically and partly histologically. Nineteen clinical chemical parameters were determined. Prior to pattern cognition, a principal component analysis was performed. Using six factors, accounting for 72.4% of total variance, cluster analysis was done, applying a hierarchical algorithm for ascertaining a starting partition, followed by the k-means algorithm. The validity of the solution was scrutinized, and a stable structure was found with nine clusters. Patients with a rejected suspect of liver disease were mainly located in clusters 1, 6 and 7. Cluster 1 also contains patients with compensated cirrhosis without inflammation, idiopathic hyperbilirubinaemia, focal nodular hyperplasia and haemangioma of the liver. In contrast, one third of cirrhoses, all with inflammatory activity were assigned to cluster 5. Patients with primary biliary disease were distributed among clusters 2, 3 and 4. All malignant neoplasias were assigned to cluster 9. More than 50% of fatty livers were classified to cluster 7. Cluster 2 and 8 contain only one patient with primary biliary cirrhosis (cluster 2) and fatty liver hepatitis (cluster 8). The follow-up of 66 patients also showed clinically meaningful changes of cluster assignment.

Cluster Analysis↗
PubMed1989

The activation of 3H-labeled N-nitrosobis(2-oxopropyl)amine by isolated hamster pancreas cells.

The activation of 3H-labeled N-nitrosobis(2-oxopropyl)amine [( 3H]BOP) by pancreas acinar and duct tissue from Syrian hamsters and MRC-Wistar rats in vitro was measured as DNA alkylation. Hamster tissue was incubated with [3H]BOP (0.1 mM; 20 microCi/ml) for 2 h. Initial levels of alkylation were similar, 41.7 +/- 3.7 (acinar) and 51.5 +/- 7.8 (duct) dpm/micrograms DNA. Alkylation persisted for longer in duct (t/2 greater than 46 h) than in acinar tissue (t/2 = 6 h). The faster repair of alkylation in acinar tissue was not due to acinar cell death. In rat duct tissue the level of alkylation 2 h after incubation (38.9 +/- 4.5 dpm/micrograms DNA) was similar to that in hamster ducts but declined more rapidly (t/2 = 27 h). Hamster and rat acinar and duct tissue was incubated with BOP followed by [3H]thymidine to measure DNA synthesis. BOP stimulated DNA synthesis in hamster but not in rat duct tissue or hamster acinar tissue. These data support the hypothesis that the duct tissue is the target tissue for BOP in Syrian hamsters.

Alkylation↗
PubMed1989

Effects of an ultra-long-distance (1000 km) race on lipid metabolism.

The influence was examined of ultra-long-distance running (1000 km race lasting 20 days) on changes in serum lipids. The 110 participants received two types of diet, a conventional Western diet and a wholesome vegetarian diet. Of the 55 finishers the serum concentration of total cholesterol, low density lipoprotein (LDL)-cholesterol, apolipoprotein B and triglycerides decreased significantly during the first 8 days of the run, but rose again towards the end of the race without reaching pre-race levels. The high density lipoprotein (HDL)-cholesterol increased initially but decreased in the final days of the run. The values for apolipoprotein A-I were not correlated with HDL-cholesterol. The free fatty acids and free glycerol showed marked increases (five times the prerace concentration), falling towards the end of the run. Changes in serum lipids showed no correlation with changes in body mass. Similar changes were observed in both dietary groups.

Adult↗
PubMed1989

Effects of long-distance running on iron metabolism and hematological parameters.

In 110 well-trained participants of a 1000-km running competition lasting for 20 days hematological parameters, iron metabolism, and their respective changes during the race were investigated. Thirty-nine men and 11 women were accustomed to wholesome vegetarian food (lacto-ovovegetarian), 52 men and 8 women consumed a conventional western diet. In each group 50% of the runners finished the race. Before the competition started red blood cell count, hematocrit, and hemoglobin were on average below the values observed in the normal population in all groups. Both male and female runners consuming the wholesome diet showed significantly lower ferritin values than those on a western diet. During the first days of the competition hemolysis occurred leading to increased serum concentrations of bilirubin and iron and decreased haptoglobin levels. Hb concentrations showed a constant decrease during the race. Serum ferritin concentration rose about twofold within the first days and then decreased again without reaching pre-race levels. Serum iron concentrations showed a significant decrease between days 3 and 6. Iron loss was caused by hematuria (25% of all urines tested), gastrointestinal blood loss (10% of all stool specimens tested), and by sweating (4.5 micrograms iron/dl sweat). Our results suggest that especially in female long-distance runners it may be difficult to supply sufficient quantities of iron with the diet.

Adult↗
PubMed1989

[Epidemiologic studies of tinnitus aurium].

The prevalence of tinnitus was examined in a group of 270 persons from an average cross-section of the population of Ulm. For statistical reasons we selected eight groups aged exactly 10, 20, 30, 40, 50, 60, 70, and 80 years. Thirty-one percent of those examined have already noted the presence of tinnitus at some point in time. Temporary tinnitus lasting not longer than 5 min. was reported in 19.5% and longer lasting tinnitus in 11.5% of cases. The highest incidence of 55% was found at the age of 20. The previously assumed age dependent increase in the incidence of tinnitus was seen only in the longer lasting type (5 min). The age dependent incidence of tinnitus was statistically correlated to audiogram, blood pressure, grade of physical activity, noise stress, and vertigo. The low incidence of tinnitus in presbyacusis (11%) differs from previous studies. Hypertension was associated with a lower incidence of tinnitus than normotension or hypotension.

Adult↗