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Biomedical subjects

R Gassmann

Publications and source records attributed to R Gassmann.

At least 19 recordsLinked to original sources
PubMed2000

Adaptive response of the rat pancreas to dietary substrates: parallel regulation of trypsinogen and pancreatic secretory trypsin inhibitor.

Chronic pancreatitis has been associated with malnutrition in alcoholic patients and malnourished juveniles. The composition of the diet, especially the protein content, regulates the synthesis of secretory proteins in the rat pancreas. Adaptive responses of the pancreas have shown that anionic proteases (e.g., trypsinogen) are upregulated during protein deprivation. We hypothesize that the (cationic) pancreatic secretory trypsin inhibitor (PSTI) is down-regulated after a protein-deficient diet. Low PSTI levels might cause a lack of protection from prematurely activated trypsin and therefore enhance the risk for pancreatic inflammation. Over a period of 1 month, rats were fed one of four isocaloric diets with a casein content varying from 0 to 82%. PSTI and trypsinogen mRNA remained fairly constant, irrespective of the diet composition. Trypsinogen and elastase secreted into pancreatic juice were upregulated after a protein-deficient diet relative to a control diet. Contrary to our hypothesis, PSTI was also upregulated. Parallel secretion of trypsinogen and PSTI appears to ensure protection against premature activation even under extreme dietary conditions.

Adaptation, Physiological↗
PubMed1996

Special considerations concerning regulatory requirements and drug development for peptides and biotech products in the EU.

The marketing authorization for a new medicinal product is based on the scientific assessment of its quality, safety and efficacy. The marketing authorization application (MAA) which covers all the relevant documentation can be filed in the EU via different application procedures. For peptides and biological products special issues have to be taken into consideration during drug development. Due to special production procedures and the complexity of the active substance itself, peptides and biotech products are subject to specific regulatory requirements. This leads to the necessity to discuss the development program of a new peptide or biotech product with the health authorities on a case by case basis. This article will focus on the special regulatory requirements for peptides and biotech products including the registration procedures as well as technical, preclinical and clinical issues.

Biotechnology↗
PubMed1976

A morphological study of antibody transport in the transparent fluid flowing form the lymph-folds of the copulatory organ into the cloacal lumen of the cock (Gallus domesticus).

The lymph of the copulatory organ of the cock is produced mainly in the lymphobulbus phalli. The lymph fluid passes the secretory duct with its branching lymph capillaries and discharges into the lymph-fold. From here, it is released into the interstitial tissue through gaps of the lymph capillaries but also through the intercellular spaces between the endothelial cells of the lymph capillaries. A minor portion of the lymph is produced also in the lymph-fold from where it is transported in the interstitial tissue either by transfer vesicles of the circulatory blood capillaries or by pores and fenestrae of the transudatory blood capillaries. During the erection of the copulatory organ the lymph is pressed through the intercellular spaces of the epithelial covering the lymph-fold which is cylindrical and multistratified in shape. From here, it reaches the cloacal lumen in the form of transparent fluid (TF). TF was collected by different methods. It contains immunoglobulins which arise from plasma cells of the lymph-fold. Juxtaluminally, the lymph passage takes place via zonulae pseudooccludentes. The epithelial covering secretes a mucoid substance which is added to the TF prior to its following the spermatic phase as the final fraction of the ejaculate. Plasma cells and lymphocytes migrate along the lymph flow in the intercellular spaces of the epithelial covering of the lymph-fold. After an experimental application of antigen the sub- and intraepithelial cells and lymphocytes increase in number with their portion of active cells exceeding the less active ones. The increase coincides with the increase in antibodies detected in the TF where they may cause a local immunisation.

Animals↗