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Biomedical subjects

H Meisel

Publications and source records attributed to H Meisel.

122 records · Page 7Linked to original sources

Chimaeric HBV core particles carrying a defined segment of Puumala hantavirus nucleocapsid protein evoke protective immunity in an animal model.

Hantaviruses are rodent-born agents which are pathogenic in humans causing haemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. To induce a protective immunity against a European hantavirus (Puumala) we constructed chimaeric hepatitis B virus (HBV) core particles carrying defined fragments of the Puumala virus nucleocapsid protein. After immunisation of bank voles, the natural host of Puumala virus, with core particles possessing an insertion of the N-terminal part of Puumala virus nucleocapsid protein, four of five animals were protected against subsequent virus challenge. The results show that the major protective region of the nucleocapsid protein is located between amino acids 1 and 45 and that chimaeric HBV core-like particles are useful carriers of foreign protective epitopes.

Animals↗

[Maternal hepatitis B infection as the cause of nonimmunologic hydrops fetalis].

A 16-year-old primigravida was referred to our department at 22 weeks gestation because of a nonimmune hydrops fetalis. Sonography revealed an isolated fetal ascites. Cordocentesis was performed to rule out anaemia, infection and chromosomale abnormalities, followed subsequently by intrauterine transfusion because of fetal anaemia (hemoglobin-concentration of 8.4 g/dl). It was found that the pregnant suffered from an acute hepatitis-B-virus-infection with positive HBsAg, positive HBeAg and HBc-IgM antibodies, confirmed by serological tests. In a second cordocentesis the cordblood specimen was found to be HBsAg positive as well. The fetus was intramusculary given hyperimmune-globulin under ultrasound guidance. In the further course of pregnancy signs of meconium-peritonitis were observed. Postnatally a distal ileal perforation was detected and the newborn underwent laparotomy for distal ileal perforation. In this case report we discuss the connection with nonimmune hydrops fetalis and the maternal and fetal hepatitis-B-virus-infection.

Adolescent↗

Bioactive peptides encrypted in milk proteins: proteolytic activation and thropho-functional properties.

The bioactivities of peptides encrypted in major milk proteins are latent until released and activated by enzymatic proteolysis, e.g. during gastrointestinal digestion or food processing. The proteolytic system of lactic acid bacteria can contribute to the liberation of bioactive peptides. In vitro, the purified cell wall proteinase of Lactococcus lactis was shown to liberate oligopeptides from beta- and alpha-caseins which contain amino acid sequences present in casomorphins, casokinines, and immunopeptides. The further degradation of these peptides by endopeptidases and exopeptidases of lactic acid bacteria could lead to the liberation of bioactive peptides in fermented milk products. However, the sequences of practically all known biologically active peptides can also be cleaved by peptidases from lactic acid bacteria. Activated peptides are potential modulators of various regulatory processes in the body: Opioid peptides are opioid receptor ligands which can modulate absorption processes in the intestinal tract, angiotensin-I-converting enzyme (ACE)-inhibitory peptides are hemodynamic regulators and exert an antihypertensive effect, immunomodulating casein peptides stimulate the activities of cells of the immune system, antimicrobial peptides kill sensitive microorganisms, antithrombotic peptides inhibit aggregation of platelets and caseinophosphopeptides may function as carriers for different minerals, especially calcium. Bioactive peptides can interact with target sites at the luminal side of the intestinal tract. Furthermore, they can be absorbed and then reach peripheral organs. Food-derived bioactive peptides are claimed to be health enhancing components which can be used for functional food and pharmaceutical preparations.

Amino Acid Sequence↗