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Biomedical subjects

M Reichert

Publications and source records attributed to M Reichert.

At least 55 records · Page 3Linked to original sources
PubMed1997

Reduced concentration of serum growth hormone (GH)-binding protein in children with chronic renal failure: correlation with GH insensitivity. The European Study Group for Nutritional Treatment of Chronic Renal Failure in Childhood. The German Study Group for Growth Hormone Treatment in Chronic Renal Failure.

Growth retardation in children with chronic renal failure (CRF) despite normal or elevated GH levels indicates a peripheral insensitivity to the action of GH. One possible molecular mechanism is a reduced density of GH receptors in GH target organs. In humans, the circulating high affinity GH binding protein (GHBP) is thought to reflect GH receptor expression, because it is derived from the extra-cellular domain of the GH receptor by proteolytic cleavage. We, therefore, analyzed serum GHBP levels by ligand-mediated immunofunctional assay in 126 children with CRF compared to reference values obtained by analysis of 773 healthy children. In 77% of CRF patients, serum GHBP concentrations were below the mean for age- and gender-matched controls. The decrease in serum GHBP levels was related to the degree of renal dysfunction. In advanced CRF (glomerular filtration rate, < 35 mL/min.1.73 m2), mean age- and gender-adjusted GHBP levels were -1.40 +/- 0.18 SD score; 36% of patients had GHBP levels below the normal range (< -2 SD score). Children with end-stage renal disease (n = 26) had the lowest GHBP levels (-2.25 +/- 0.22 SD score). Multiple linear regression analysis revealed that body mass index, rather than glomerular filtration rate, is the prevailing determinant of serum GHBP levels in CRF. GHBP levels correlated with both the spontaneous growth rate ( r = 0.44; P < 0.0001) and the growth response to GH therapy (r = 0.48; P < 0.005), indicating decreased sensitivity to both endogenous and exogenous GH. Subcutaneous GH therapy did not consistently affect serum GHBP levels after 3 months of treatment. It is suggested that low GHBP levels in children with CRF represent a quantitative tissue GH receptor deficiency as one of the molecular mechanisms of GH insensitivity.

Adolescent↗
PubMed1995

Abrogation of p53-induced cell cycle arrest by c-Myc: evidence for an inhibitor of p21WAF1/CIP1/SDI1.

The tumor-suppressor p53 inhibits cell cycle progression by direct transactivation of the p21WAF1/CIP1/SDI1 gene, which encodes a universal inhibitor of cyclin dependent kinases (cdk). The proto-oncogene product c-Myc induces cell cycle progression and, in the absence of survival factors, apoptosis. However, a direct link between the cell cycle machinery and c-Myc has not yet been established. We show that c-Myc has not yet been established. We show that c-Myc abrogates a p53-induced G1-arrest without elevating the expression of cdks or cyclins involved in the G1/S-transition. Instead, the results suggest that c-Myc interferes with the inhibitory action of p21 on cdk/cyclin-complexes by inducing a heat-labile inhibitor of p21. The inactivation of p21 and related cdk-inhibitors may explain several of the oncogenic actions of c-Myc, including the induction of proliferation, immortalisation and the inhibition of differentiation. Modulation of cdk activity by the induction of an inhibitor of cdk-inhibitors represents a novel mechanism of cell cycle regulation in mammalian cells.

3T3 Cells↗
PubMed1994

Assay systems for the growth hormone-binding protein.

The first method used for detection of growth hormone-binding protein (GHBP) in biological fluids was based on the incubation of the sample with radiolabeled GH followed by separation of bound and free GH by gel exclusion chromatography. Recently, other methods have been developed which are faster and easier to use. These methods include variants of the original binding/column assay (e.g., separation of bound and free GH is obtained by immunoprecipitation, charcoal adsorption, ion exchange chromatography, or HPLC), and a ligand-mediated immunofunctional assay (LIFA), in which a monoclonal antibody is used to capture the GHBP on a microtiter plate; all binding sites are saturated with GH and an anti-GH antibody is used to detect the amount of GH (endogenous and exogenous) bound to the GHBP. To permit comparison of results obtained by different methods we have cross-validated the LIFA with two different binding assays: (i) the original long column assay (column assay), and (ii) an assay based on immunoprecipitation (RIPA) of the GH/GHBP complex with an anti-GHBP antibody.

Adolescent↗
PubMed1994

An integrated knowledge-based system to guide the physician during structured reporting.

A routinely used system for report generation, based on direct physician data entry, has been combined with a knowledge-based module. The knowledge-based system is operating in the background, and guides the user by dynamically suggesting diagnoses and generating hints regarding the actual and possible further diagnostic procedures. Hybrid technology with neural networks and rules is used. A laboratory evaluation has shown good agreement between diagnoses suggested by the system and confirmed diagnoses, with a kappa coefficient of 0.85 and an area under the ROC curve of 0.92. In a survey following a 14-day test period, physicians stated that the system was both sensible and helpful. The current application domain is ultrasound reporting.

Artificial Intelligence↗
PubMed1994

An infrastructure for cooperation and communication in an advanced clinical information system.

In a research project, organizational and technological requirements for an advanced clinical information system have been analysed, and a concept has been developed. From the application's perspective, medical personnel is more actively relieved from routine tasks by support of organizational tasks and by coordination of distributed activities. Program development is supported by a concept of simple and complex services with well-defined interfaces, and by the use of activity templates, i.e. pre-modeled activities describing possible sequences of services. The concept is based on an open systems approach, with a reliable and secure communication infrastructure. In addition, monitoring facilities are provided.

Computer Communication Networks↗
PubMed1994

[Clinical aspects and differential therapy of mild hypertension in pregnancy].

Pregnant patients with increases in blood pressure are often treated with medication, in our view inappropriately. We examined 222 pregnant women who were referred because of two blood pressure determinations > 140/90 mm Hg. The women were primarily treated by nonpharmacological means. Only 44 required medications to maintain a blood pressure < 140/90 mm Hg. Twenty-six additional pregnant women referred for hypertension were taught to measure their blood pressures at home. Fourteen underwent 24-h ambulatory blood pressure monitoring. Home and 24-h blood pressure measurements were both significantly lower than those obtained in the office and did not significantly differ from each other. We conclude that most pregnant women without proteinuria, who show mild to moderate blood pressures > 140/90 mm Hg are best treated conservatively without drugs. Those in whom home or 24-h blood pressures exceed 140/90 mm Hg and who do not respond to nonpharmacologic methods require medication. Finally, "white coat" hypertension is common in pregnant women.

Arousal↗
PubMed1993

Reusable laparoscopic instruments: continuous quality improvement.

Proactive management of processing activities is cost effective, fulfills the requirements of the Joint Commission for the Accreditation of Healthcare Organizations, and meets professional recommended practices. Controlling the variables is the key to producing an acceptable product each and every time. It may not be possible to completely eliminate variations, but they can be reduced to an acceptable level with product testing; simple, illustrated procedures with measurable outcomes; employee education; and adequate inventory. A cost-effective system approach can be developed to provide a high level of assurance that rigid laparoscopic instruments are clean, functional, and sterile each time they are used.

Humans↗