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Biomedical subjects

H A Schmidt

Publications and source records attributed to H A Schmidt.

At least 19 recordsLinked to original sources
PubMed2000

Axeldb: a Xenopus laevis database focusing on gene expression.

Axeldb is a database storing and integrating gene expression patterns and DNA sequences identified in a large-scale in situ hybridization study in Xenopus laevis embryos. The data are organised in a format appropriate for comprehensive analysis, and enable comparison of images of expression pattern for any given set of genes. Information on literature, cDNA clones and their availability, nucleotide sequences, expression pattern and accompanying pictures are available. Current developments are aimed toward the interconnection with other databases and the integration of data from the literature. Axeldb is implemented using an ACEDB database system, and available through the web at http://www.dkfz-heidelberg.de/abt0135/axeldb.htm

Animals↗
PubMed2000

In silico analysis of gene expression patterns during early development of Xenopus laevis.

The information as to where and when a mRNA is present in a given cell is essential to bridge the gap between the DNA sequence of a gene and its physiological function. Therefore, a major component of functional genomics is to characterize the levels and the spatio-temporal domains of gene expression. Currently, there is just a few specialised public databases available storing the data on gene expression while they are needed as a resource for the field. Moreover, there is a need to develop and assess computational tools to compare and analyse expression profiles in a suitable way for biological interpretation. Here we describe our recent work on developing a database on gene expression for the frog Xenopus laevis, and on setting up and using new tools for the analysis and comparison of gene expression patterns. We used histogram clustering to compare expression profiles at both gene and tissue levels using a set of data coming from the characterization of the expression of genes during early development of Xenopus. This enabled us to draw a tree of tissue relatedness and to identify coexpressed genes by in silico analysis.

Animals↗
PubMed1989

Oxandrolone in constitutionally delayed growth, a longitudinal study up to final height.

Twenty-seven prepubertal boys and 9 prepubertal girls with constitutionally delayed growth were treated with the anabolic steroid oxandrolone for 12 months and followed until they reached final height. Sixteen boys were treated with a mean dose of 0.12 mg/kg.day [low dose (LD)] and 11 boys with a mean dose of 0.22 mg/kg.day [high dose (HD)]. The girls were treated with a mean dose of 0.1 mg/kg.day. Thirteen boys and 9 girls served as controls. On oxandrolone the mean height velocity increased from 4.0 to 8.6 (boys, LD), from 4.3 to 8.9 (boys, HD), and from 4.3 to 8.3 cm/yr (girls). The immediate posttreatment height velocity was significantly higher than the pretreatment height velocity (P less than 0.05), regardless of whether the patients had entered puberty. On oxandrolone the mean ratios of change in bone age/change in chronological age were 2.0 (boys, LD), 2.3 (boys, HD), and 2.0 yr/yr (girls) and continued to be accelerated during the 6 months after treatment. Height predictions at the onset of treatment and after 6 months off treatment were calculated by three different methods: Bayley-Pinneau (BP), Roche-Wainer-Thissen (RWT), and Tanner Mark II (T II). In the boys (LD) mean height predictions increased significantly by the methods of BP (3.3 cm) and RWT (2.9 cm), but not by the method of T II (0.6 cm). In the boys (HD) no significant change in height predictions was noted. In the girls mean height predictions remained unchanged by BP and RWT, but decreased significantly by T II (-2.5 cm). The difference between final height and initial height prediction was taken as a measure of the influence of the treatment on adult height. In all three treatment groups the difference between final height and initial height prediction, calculated with all three methods, did not differ from the control group. We conclude that oxandrolone treatment for 1 yr has no effect on adult height. In spite of this, the use of an anabolic steroid such as oxandrolone may still have value, as an increase in height velocity and an earlier onset of puberty may benefit short children suffering from psychological problems due to delay of growth and development.

Body Height↗
PubMed1986

[Evaluation of ventilation using 133Xe for improved nuclear medicine lung diagnosis].

In 101 patients a combined examination of ventilation with 133Xe and of perfusion with 99mTc-HAM was performed. By using the device 101 (Veenstra) the wash-in, equilibrium and wash-out could be evaluated in one examination, the total time needed for one patient was about 10 min. In suspected lung embolism the specificity could be increased to 100% whereas the sensitivity remained constant at 93%. In patients with central obstruction, specificity could be increased from 60% to 87% and sensitivity from 54% to 70%. In the diagnosis of lung embolism, the additional examination of ventilation should be used in any case, in the diagnosis of central obstruction it is recommended.

Adult↗
PubMed1983

[Advantages of the combined use of nuclear medicine procedures in the diagnosis of coronary disease].

Investigations on 106 patients with coronary artery disease were performed to improve the diagnosis of myocardial ischemia by combining myocardial scintigraphy and gated blood studies. The results show that it is possible to enhance the detection of coronary artery disease and to classify haemodynamic efficiency. In addition we found that in investigations performed on patients with arrhythmia and under stress conditions the "hybrid-technique" is superior to the framemode acquisition method.

Adult↗
PubMed1978

[Comparative studies of commercially available T4-RIA-kits (author's transl)].

The investigation of 4 commercially available T4-RIA-Kits with 350 patient sera have shown that: The separation of hypo-, eu- and hyperthyroid values is easier with kit a) and d) than with b) and c), though all kits give acceptable values under routine conditions. For the determination of the "normal range" not less than 100 patient sera are necessary. The time needed for 100 determinations is 2 to 3 hr. A general recommendation for one of the tested T4-RIA-Kits cannot be made since the choice depends also on local circumstances.

Humans↗
PubMed1978

[Comparative studies of commercially available T4-RIA-Kits (author's transl)].

The investigation of the tested commercially available T4-RIA-Kits have shown that: The separation of hypo-, eu- and hyperthyroid values is better with kits a) and f) than with b),c),d) and e), though all kits give acceptable values under routine operating conditions, kit b) takes less time and work than the other tested kits, depending on the kit used, the time needed for 100 determinations varies between 1,5 and 4 hr. A general recommendation for one of the tested T4-RIA-Kits cannot be made since the choice of a kit depends not only on the criteria discussed but also on local circumstances.

Humans↗
PubMed1976

The entity of non occlusive mesenteric ischemia: strophanthin effect on mesenteric blood flow in experimental animals.

Digitalis glycosides have the well known positive inotropic effect on the heart. Their effect on extracardiac vascular smooth muscle receives increasing attention. In experimental animals a significant decrease in mesenteric blood flow and an increase in mesenteric vascular resistance could be shown. Angiography of main mesenteric arteries, smaller arteries, and arterioles reveal typical vasoconstriction. Angiomorphometric measurements show good correlation between the decrease in vascular diameter and the increase in vascular resistance.

Animals↗
PubMed1975

[Nuclear medical diagnostic--pancreatic carcinoma (author's transl)].

Of the procedures available for diagnosis of pancreatic carcinoma, particular significance can be attributed to scintigraphy. The method is based upon the accumulation of a labeled amino acid in the glandular tissue. The scanning technique delineates functionable tissue. The diagnosis of carcinoma of the pancreas cannot be deduced from the scintigraphic picture alone, however, because functional deficiency of a different origin could result in the same picture. In these cases, carefully planned exploratory surgery is indicated. The limited expense in terms of time and personnel and the modest stress to the patient make pancreatic scintigraphy a method that can reasonably-together with internal procedures-be applied right at the beginning of the process of diagnosis.

Diagnosis, Differential↗
PubMed1975

[Effect of strophanthin on intestinal blood flow. A contribution to the physiopathology of hemorrhagic enteropathy].

The purpose of the present study was to compare in canine experiments hemodynamic and angiographic effects on mesenteric circulation. I. v. administration of strophanthin is leading to an increase of arterial pressure and a decrease of mesenteric blood flow. Most consistent angiographic changes are attenuation and local vasoconstriction of peripheral vessels. The relationship between digitalis administration and mesenteric underperfusion leading to non-occlusive mesenteric ischemia is discussed.

Animals↗