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Biomedical subjects

R Stamm

Publications and source records attributed to R Stamm.

18 recordsLinked to original sources
PubMed2002

A possibility of systematisation of anthropometric data of girls aged 12-15.

The article describes an anthropometric cross-sectional study of 374 healthy schoolgirls aged 12-15 years from secondary schools of Tartu (Estonia). 29 body measurements and 9 skinfolds were measured. Mean skinfolds and 6 indices and ratios (including body mass index) were calculated. In each age group the data were systematized into 5 height-weight SD-classes according to the correspondence between body height and weight. The medium class lies between -0.5 SD and +0.5 SD of the respective age group mean (M +/- 0.5 SD); the other classes contain the respective outer values. All the subjects were assigned into one of the following five categories: three height/weight-concordant categories: I = small (small height-small weight), II = medium (medium height-medium weight), III = large (big height-big weight) and two height/weight-disconcordant categories: IV = so-called pyknomorphous, V = so-called leptomorphous. Categories IV and V thus contained three height/weight subclasses each. The body build categories differ significantly from each other within both groups (I-III and IV-V) in all age groups in all measured variables, except sternum length, abdomen length, trunk length, biacromial breadth, biiliocrystal breadth, femur breadth, ankle breadth, humerus breadth, wrist breadth, and head circumference for which no significant differences between pyknomorphous and leptomorphous categories were found. A multidimensional statistical model of body build might be used in girls going through puberty to systematize and compare morphological variables with other assessed characteristics in different applied studies, for example physiological, sociological, psychological, or nutritional.

Adolescent↗
PubMed2001

[Concepts of vulnerability of psychiatric diseases].

Despite intensive research in recent decades, the search for the aetiopathogenesis of psychiatric diseases is just as relevant as ever. In recent years, ideas of the aetiopathogenesis of psychotic diseases based on the concept of "vulnerability" in its diverse variations and developments have been gained increasingly ground. The publications of Zubin and associates above all have contributed to a "vulnerability model". According to this descriptive model, schizophrenic disturbances develop as a result of stimuli/irritants or stress factors under modulation of the social and physical environment as well as dependent on the premorbid personality. The increased vulnerability which gives rise to this is perceived as a threshold descensus of the individual towards stimuli/irritants (with a deficit counter--irritants impulses). Apart from that, multi-causality of vulnerability is assumed as the starting point, whereby there is the possibility of several therapy approaches. Moreover, contrary to the prevailing pessimistic view that schizophrenia is a process-type progressive disease, an episodic nature of schizophrenic psychoses is postulated with a prognosis that is indeed positive in the long term. In recent years, although often not explicitly stated, Zubin's concept of vulnerability was also indubitably subjected to various further developments (the vulnerability stress model by Nuechterlein and associates as also the integrative psycho-biological schizophrenia model by Ciompi may serve as examples). Worth mentioning are also various new concepts from system sciences (such as those from cybernetics, synergetics, the chaos theory, the communication theory, structure determinism etc.), which endeavour to clarify the problem of psychosis. The evaluation of central neurophysiological function deviations with schizophrenics and their relations has so far been oriented above all towards the vulnerability model of Zubin and Nuechterlein, which differentiates temporarily relatively stable trait markers with generally unaltered expressivity at the pre-, intra-, and post-psychotic stages as well as episode markers and intermediate markers. However, specific factors contributing to the pathogenesis of schizophrenic disturbances have not as yet been found, in addition, there is still a multitude of methodological problems and distinctive features to fulfill the expectation of a comprehensive concept with which the whole complexity of the occurrence, the progress, and the outcome of psychoses can be explained. Reintroduction of the concept of vulnerability experienced, as Schmidt-Degenhardt put it, "a renaissance in use that appeared almost inflationary and a completely dubious popularisation ... without reference to its historical implications...". Consequently, a critical view of the use of this term would appear to be necessary.

Humans↗
PubMed2001

MEGA-database: one million data since 1972.

MEGA is the chemical workplace exposure database of the Institute for Occupational Safety (BIA) of the German Berufsgenossenschaften (BG) (statutory accident institutions for insurance and prevention). On the legal basis of the social insurance law the inspectorates of the BGs conduct workplace measurements of chemical and biological agents. The BGs have cooperated with BIA within the Berufsgenossenschaftliches Messsystem Gefahrstoffe--BGMG since 1972: measurements are done by the BGs, analyses and data processing are the tasks of BIA. In 1999 31,000 measurements with 68,000 analyses were taken in 4,000 enterprises. All data are stored in the MEGA-database with up to 150 pieces of information (describing type of workplace, working conditions, measured substances, sampling strategy, sampling duration, sampling and analytical method etc.), for each result. MEGA contains today about 1,000,000 measurements of more than 400 substances starting in 1972. MEGA is used by BIA and the BGs for the following purposes: prevention (e.g., identification of hazards, efficiency of exposure reducing measures, determination of technical criteria for exposure limit values), epidemiological questions, and investigations of occupational diseases. In the framework of the measuring and inspection activities and tasks of the inspectorates of the BGs the locations for measurements are not randomly selected, but are based on criteria such as supposed critical exposure situations or testing the efficiency of exposure reducing measures. Nevertheless, a statistical appraisal of the data is possible for different purposes considering the specific determinants of the results, as, for example, classification of enterprises (sectors), workplaces (activities, tasks), used materials, and products. The MEGA-database will be further developed into a multifactorial exposure database with additional data on biological exposure to bacteria and funghi, but also noise and other data.

Databases, Factual↗
PubMed1990

Essential problems in quantification of proteins following colloidal staining with coomassie brilliant blue dyes in polyacrylamide gels, and their solution.

Quantitative determination of stained proteins following polyacrylamide gel electrophoresis (PAGE) is of increasing interest especially since computer-aided densitometers have become available as well as recipes for sensitive and background-free staining with Coomassie Brilliant Blue dyes. However, avoidance of separation artifacts is not the only essential prerequisite for quantitative evaluation. The local particle density of a protein in a given gel is of critical importance since it determines its stainability. Depending on local protein concentration, the dye binding to the same amount of a given protein differs considerably. Since the stainability of proteins using colloidal staining procedures, as with Coomassie Brilliant Blue dyes, is time-dependent and, in addition, also dependent on the pore size of a given polyacrylamide gel used for PAGE, calibration curves for quantitative determinations have to be prepared in polyacrylamide gels of the same composition as used for PAGE. Staining conditions also have to be identical for calibration gels and gels under analysis. If, however, a set of calibration curves is prepared for different staining times, it is possible to calculate a generalized calibration curve, allowing for quantitative evaluation with flexible staining time. Furthermore, and in consequence of the implications due to particle density, quantitative determination via densitometry is only possible by determining the protein amount of each single measuring point (pixel) via its absorbance on the basis of a calibration curve. Since the particle density is inherent in a calibration curve, the final summation of the protein amount per pixel will give values close to reality.

Calibration↗
PubMed1982

Increased accumulation of 2-deoxy-2-[18F]Fluoro-D-glucose in liver metastases from colon carcinoma.

Three patients with liver metastases from colon carcinoma were studied with 2-deoxy-2-[F-18]fluoro-d-glucose (F-18-FDG) using positron emission tomography. The radioactivity in the metastatic tumor increased continuously following the injection of F-18-FDG, whereas it decreased in normal liver tissue. This resulted in the tumor to normal-liver ratio of 3.3-4.7 at 50 min after injection. The liver tumor was visualized as an increased accumulation of radioactivity in all patients, with the central area of the tumor showing less activity. These preliminary results suggest that F-18-FDG may be useful as a positive imaging agent for the detection and characterization of liver tumors.

Adenocarcinoma↗