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Biomedical subjects

I Schmidt

Publications and source records attributed to I Schmidt.

At least 109 records · Page 6Linked to original sources
PubMed1987

Nucleotide sequence of the gene encoding the surface projection glycoprotein of coronavirus MHV-JHM.

Sequences encoding the surface projection glycoprotein of the coronavirus, murine hepatitis virus (MHV), strain JHM, have been cloned into pAT153 using cDNA produced by priming with specific oligonucleotides on infected cell RNA. The regions of three clones pJMS1010, pJS112 and pJS92, which together encompass the surface protein gene have been sequenced by the chain termination method. The sequence of the primary translation product, deduced from the DNA sequence, predicts a polypeptide of 1,235 amino acids with a molecular weight of 136,600. This polypeptide displays the features characteristic of a group 1 membrane protein; an amino-terminal signal sequence and carboxy-terminal membrane and cytoplasmic domains. There are 21 potential glycosylation sites in the polypeptide and a cysteine-rich region in the vicinity of the transmembrane domain. During maturation proteolytic processing of the polypeptide occurs and at positions 624 to 628 the sequence Arg-Arg-Ala-Arg-Arg is found, which is similar to a number of basic sequences involved in the cleavage of enveloped RNA virus glycoproteins. The fusogenic properties of the MHV surface protein do not appear to correlate with a strongly hydrophobic region at the putative amino terminus of the carboxy-terminal cleavage product.

Amino Acid Sequence↗
PubMed1987

Thermoregulation and diurnal rhythms in 1-week-old rat pups.

This paper reviews the ontogeny of thermoregulation and diurnal rhythmicity in rats. Additionally, original data are presented that indicate the emergence of an endogenous circadian core temperature rhythm during the first postnatal week. Despite neurological immaturity, newborn rats display autonomic and behavioral thermoregulatory responses within 24 h of birth. Their "biological clock" is already running before birth. The thermal environment of pups changes cyclically owing to diurnal variations in maternal behavior, but the core temperatures of 1-week-old pups huddling in the absence of the dam also show marked diurnal fluctuations. Five- to 8-day-old lean Zucker rat pups artificially reared in the absence of 24-h cycles of ambient temperature and food intake show diurnal changes in core temperature similar to those in huddling mother-reared pups. Diurnal core temperature changes, evident only when regulatory effectors are not overwhelmed, are one of the first self-maintained diurnal rhythms to appear. Because thermoregulation and circadian rhythmicity both appear before maturation of the neural networks believed to be critical for their control in adult animals, studying the immature rat might increase our understanding of the control of these processes in the more complex mature central nervous system.

Aging↗
PubMed1986

Cathepsin S. The cysteine proteinase from bovine lymphoid tissue is distinct from cathepsin L (EC 3.4.22.15).

Cathepsin S was purified from bovine spleen by acid autolysis, (NH4)2SO4 fractionation and chromatography on CM-Sephadex C-50, CM-cellulose and activated-thiol-Sepharose. Cathepsin L was isolated from lysosomal fractions of rat liver, rat kidney and bovine liver. Generally, cathepsin L was bound tightly to CM-Sephadex C-50. Preparations of cathepsin L from rat liver, rat kidney and bovine liver were shown to have kinetic constants for the substrate benzyloxycarbonyl-Phe-Arg-7-(4-methyl)coumarylamide in the same range (Km 2-3 microM). Benzyloxycarbonyl-Phe-Phe-diazomethane proved to be a sensitive irreversible inhibitor of cathepsin L from different species. Cathepsin S differed in all these characteristics from cathepsin L. A polyclonal antibody to cathepsin L from rat reacted with bovine cathepsin L but not with bovine cathepsin S.

Animals↗
PubMed1986

[Dyskinetic syndrome following the use of metoclopramide].

The relation to the wide use of metoclopramide side effects are rare. These concern the extrapyramidal-motor system among others in form of dyskinetic syndrome. At the instance of a 15-year-old boy the dramatic course with cramp-like increases of the muscle tonus and compulsive movements in head and shoulder region are described. The knowledge of these medicament-induced symptoms is of differential-diagnostic importance to avoid false diagnose and to act with a definite aim. In easier forms of a dyskinetic syndrome suffices the discontinuation of the metoclopramide medication, in more severe cases proves the use of antiparkinsonian agents.

Adolescent↗
PubMed1986

Detection of antibodies to HTLV-III in commercially available immunoglobulin preparations.

Samples of 96 polyvalent and virus-specific immunoglobulin batches commercially available in West-Germany were tested by enzyme-linked immunoassay and immunoblot for the presence of anti-HTLV-III antibodies. 37% of the polyvalent and 87% of the virus-specific batches were positive. It was concluded that these preparations are still safe and because of their reportedly low titer neutralizing antibodies possibly beneficial in certain cases, such as newborns of HTLV-III positive mothers or after accidental exposure to infectious material in clinics or laboratories.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Cold-rearing normalizes capacity for norepinephrine-stimulated thermogenesis but not body temperature in 16-day-old fatty Zucker rats.

The effects of a lowered rearing temperature on body weight, core temperature (Tc) and norepinephrine(NE)-stimulated thermogenesis were investigated in 16- to 17-day-old Zucker rat pups. 16-day-old fatty pups were significantly heavier (9%) than lean littermates in litters reared at 18 degrees C ("cold-reared") but not in litters reared at 25 degrees C ("normally-reared"). After 2 h isolation at 25 degrees C, Tc of lean pups was slightly higher (37.1 degrees C) in cold-reared litters than in normally-reared litters (36.4 degrees C), while fatty pups reared at either temperature were severely hypothermic (Tc = 33 - 34 degrees C). At an ambient temperature of 25 degrees C Tc in fatty and lean cold-reared pups increased to 39.5 degrees C after subcutaneous injection of 800 micrograms/kg NE. Normally-reared lean pups reached the same peak Tc after NE injection, while their fatty littermates reached a significantly lower peak Tc of 38.4 degrees C. The hypothermia associated with the onset of excess fat deposition in suckling fatty Zucker rats is not caused by a reduced capacity for NE-stimulated thermogenesis.

Adipose Tissue, Brown↗
PubMed1986

Diurnal cycle of core temperature in huddling, week-old rat pups.

Lean Zucker rat pups were reared at 25 degrees C on four staggered 12:12 light:dark cycles with lights on at 0100, 0700, 1300 or 1900 hr. Core temperature (Tc) of 5- to 8-day-old pups was measured repeatedly at the rearing temperature of 25 degrees C between 0700 and 1900 hr using a procedure that minimally interfered with spontaneous nursing cycles and huddling of the pups. Tc of litters measured 30 to 60 min after the mother spontaneously left the nest was low and variable (32.2-35.4 degrees C) during the first few hours after lights-on, but was uniformly high and much less variable (35.5-36.5 degrees C) around the time of lights-off. Pup Tc was phase-advanced to the nocturnal elevation of maternal Tc, and lagged several hours behind the diurnal elevation of nursing activity. Cyclic variations in Tc of pups huddling in the nest thus reflect a diurnal rhythm in the ability and/or drive for body temperature defense that is independent of heat derived from the mother during nursing.

Animals↗
PubMed1986

Are there species differences amongst the lysosomal cysteine proteinases?

Kinetic constants for the hydrolysis of synthetic substrates by cathepsin B, cathepsin L or cathepsin H show only small variations between various species. The species variants purified from human, beef and rabbit reacted with antisera raised against the enzymes from rat. With regard to these criteria we could show that cathepsin I from rabbit lung is a species variant of cathepsin H, whereas cathepsin S is a separate enzyme from cathepsin L.

Animals↗
PubMed1986

Acceleration of p-aminohippurate excretion in immature rats by dexamethasone treatment.

In 5-, 10- and 15-day-old rats repeated administration of dexamethasone caused a dose-dependent increase of p-aminohippurate (PAH) excretion. Remarkably, dexamethasone has no influence on PAH excretion in adult rats. The effect of treatment in young rats cannot be explained by an increase in the glomerular filtration rate. In 10-day-old rats GFR shows a tendency to increase. In renal cortical slices from 5-day-old rats PAH transport is increased following dexamethasone treatment, whereas in 10- and 15-day-old rats an increase of kidney mass seems to be responsible for acceleration of renal excretion of PAH after administration of dexamethasone. In 5-day-old rats only the protein content is statistically significantly increased after dexamethasone treatment.

Aging↗
PubMed1985

Maturation of thermoregulation in Zucker rats.

We compared the development of thermoregulatory abilities of fatty (fa/fa) and lean (Fa/-) Zucker rats as they grew from two weeks to eight months of age. The rectal temperature of lightly restrained littermates was continuously recorded for 2-6 h, and at ages before body weights of fatty and lean pups became significantly different, oxygen consumption was simultaneously measured. At the rearing temperature of 25 degrees C, hypothermia with a 30 percent lower oxygen consumption was apparent in fatty pups at 16 but not at 24 days. At 5 degrees C on day 25 fatty pups became hypothermic with a metabolic rate only 10-15 percent lower than lean pups. Three-month old fatty and lean rats defended the same core temperature not only at 25 degrees C, but even during 6 h without food at 5 degrees C. The core temperature of 5-8 month old fatty rats fell slightly but significantly below that of lean rats only during the sixth hour at 25 degrees C, but not during 6 h at 5 degrees C. If the capacity for thermogenesis in brown adipose tissue of fatty rats is less than in lean rats, its decreased contribution to cold defense must be completely made up in 25 degrees C-acclimated adults by more insulation and/or shivering.

Aging↗
PubMed1984

Body temperature of huddling newborn Zucker rats.

Daily mean core temperature (Tc) in huddling Zucker rat pups reared at 25 degrees C revealed the onset of a significantly lower Tc in fa/fa pups on day 6. The difference between any pup's Tc and the mean Tc of that half of the litter with the highest Tc on any given day was an early marker for genotype. Calculating the mean difference for any 2 consecutive days from day 6 onwards gave values for each fa/fa pup that were outside the 99% confidence limits for the individual observations in the Fa/- pups.

Animals↗
PubMed1984

[Neutralizing virus antibodies in human immunoglobulins for intravenous use].

Neutralizing antibodies against measles, poliomyelitis, rubella, herpes simplex, influenza and vaccinia viruses were measured in batches of a representative selection of human immunoglobulins for intravenous use licensed in the Federal Republic of Germany. Rubella antibodies were also examined by haemagglutination-inhibition tests. Where available, reference preparations were used, and antibody levels expressed in I. U. All preparations contained significant amounts of the examined antibodies, with relatively low variation from one batch to the other. In most cases activity data specified by the manufacturers could be confirmed. However, differences between the various preparations were sometimes important, some of them relating mainly to individual antibodies, others more or less to the whole range. Some striking findings are emphasized with consideration of manufacturing and control problems.

Antibodies, Viral↗