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Biomedical subjects

H Meier

Publications and source records attributed to H Meier.

At least 109 records · Page 6Linked to original sources
PubMed1976

Carcinogenic effects of a single dose of diethylnitrosamine in three unrelated strains of mice: genetic dependence of the induced tumor types and incidence.

The carcinogenic effects of a single dose of diethylnitrosamine (DEN) were studied in three inbred strains of mice. The most predominant tumors observed were lung adenomas, leukemia, and liver tumors. Mice of strain AKR/J developed both leukemia and lung tumors; SWR/J mice were most susceptible to lung tumor development; and in C57BL/6J mice liver lesions including liver tumors occurred. The influence of the genetic background on the organ susceptibility to DEN-carcinogenesis is discussed.

Animals↗
PubMed1976

Effect of allelic substitutions at the hairless locus on endogenous ecotropic murine leukemia virus titers and leukemogenesis.

Leukemia-prone hairless (HRS/J; hr/hr) mice had significantly higher leukemia virus titers than did the leukemia-resistant nonmutants (hr/ + and +/+). This difference was ascribed to the allelic substitution at a single gene locus; at 6 months of age it averaged 13-fold, immediately preceding the large divergence in leukemia incidence between the mutant and nonmutant mice.

Alleles↗
PubMed1976

Comparison of dy and dy2J, two alleles expressing forms of muscular dystrophy in the mouse.

The muscular dystrophies caused by dy and dy2J on a C57BL/6J genetic background are similar in quality. At 1 month, slight differences occur in distribution of the muscle lesions, diffuse and focal, respectively, but at 3 months little, if any, differences exist. The dy dystrophy appears the same histologically on either the C57BL/6J or original 129/ReJ and 129B6F backgrounds.

Age Factors↗
PubMed1976

Evidence for a particle-associated RNA-directed DNA polymerase in rabbit placental and uterine tissues.

A RNA-directed DNA polymerase associated with particles that band at a density characteristic of type C RNA viruses was found in normal rabbit placental and uterine tissues taken during the early stages of gestation. That the rabbit RNA-directed DNA polymerase is distinct from the known cellular DNA polymerases and similar to the RNA-directed DNA polymerase of mammalian type C RNA viruses is shown by column chromatographic characteristics, template primer preferences, molecular weight determination, and an absolute requirement for the divalent cations.

Animals↗
PubMed1976

Presence of a high-molecular-weight RNA and RNA-directed DNA polymerase in rabbit hereditary lymphosarcoma.

Rabbit lymphosarcoma tissues contain 70 S RNA and RNA-directed DNA polymerase encapsulated in particulate components that band in the density region of type C RNA viruses. RNA-directed DNA polymerase associated with the particles could be distinguished from cellular DNA polymerases by salt elution from phosphocellulose. The enzyme preferred the template primers poly(rA)-(dT)12-18 and poly(rC)-(dG)12-18 over other synthetic template primers and also utilized viral 70 S RNA as template; these properties are not observed with the known cellular DNA polymerases.

Animals↗
PubMed1975

Alterations in the accumulation patterns of polyamines in brains of myelin-deficient mice.

Quaking mutants and jimpy mutants of mice have known deficiencies of myelination of the central nervous system, as well as lesser involvement of the peripheral nervous system. Both mutants also have altered polyamine synthesis and accumulation, particularly in the hindbrain and spinal column. The ratio of spermidine/spermine, which generally is higher in tissues with high rates of biosynthetic activity, was significantly lower in the mutants as compared to their normal siblings. In quaking mutants, 5 months of age, the spermidine concentration of hindbrain and spinal column was 60% that of controls. In contrast, the decreased spermidine/spermine ratio in jimpy mutants resulted from a marked increase in the spermine concentration in both forebrain and hindbrain. Alterations in the spermidine/spermine ratio could lead to reductions in the biosynthetic potential of the brain during development.

Adenosylmethionine Decarboxylase↗
PubMed1975

[Influence of mechanical and thermal treatment of animal feed on the true digestibility of amino acids. 2. True digestibility of amino acids in treated horse beans].

Trials were performed to investigate in which way mechanical and/or thermal treatment of horse beans would have an effect on the harmful components that were shown to be present in horse beans. In the course of these trials amino acids from heat-treated horse beans (variety Fribo) were analyzed for their true digestibility. Apart from heat-treated horse beans the investigation included undecorticated and decorticated beans and a mixture of horse beans with spring barley.

Animal Feed↗
PubMed1975

[Studies on the additive character of amino-acid absorption data obtained from pigs. 2. Studies using regression technic].

The first communication in this series (MEIER et al. 1973) reported the results of studies on the additive character of amino acid absorption data from pigs which were based on the use of the classics technique. In order to verify these results the studies were repeated, partly with the same components using regression techniques. The present studies on the additive character of amino acid absorption data showed that the additive character of these data can also be established in pigs. Moreover, the results of these investigations indicated that studies on the additive character of amino acid absorption values may be carried out by using the classical method. In performing studies of this kind attention should be paid to the fact that the rations tested should be such as to meet or nearly meet the maintenance needs of the animals.

Amino Acids↗
PubMed1975

Transplacental induction of primary renal tumors in rabbits treated with 1-ethyl-1-nitrosourea.

Pregnant rabbits of the two partially inbred strains III and WH were given ip injections of a single dose of 1-ethyl-1-nitrosourea (ENU) (60 mg/kg) in trioctanoin on day 18 of gestation. Controls were treated on the same day with solvent alone. Fourteen of 15 strain III progeny that survived more than 8 weeks developed primary renal tumors at a mean age of 3.3 months. Five other treated strain III progeny died at an early age due to other causes. In contrast, only 3 of 7 strain WH offspring surviving more than 8 weeks developed renal tumors; they had about the same latency period (3.9 months). In each strain, either renal tubular cystadenomas or mixed nephroblastomas appeared to develop within small renal cortical cysts. In strain III, the presence of these cysts may have been due to a high frequency of a recessive gene (rc) for renal cysts, but in strain WH they were induced by ENU. The differential strain incidence suggests that susceptibility to renal tumor inducibility by ENU is increased by the presence of the rc/rc genotype for cyst formation.

Animals↗
PubMed1975

Isolation of an endogenous C-type RNA virus from Mus musculus molossinus.

We isolated a type-C RNA virus from the Japanese field mouse, Mus musculus molossinus. M. musculus musculus and M. musculus molossinus are two different subspecies of Mus and thus only distantly related. The virus grew only on cells foreign to the host, was xenotropic, and readily rescued the murine sarcoma (MuSV) genome from a normal rat kidney cell line transformed nonproductively by the Harvey strain of MuSV. The virus banded at a density of 1.16 g/ml and contained an RNA-dependent DNA polymerase.

Animals↗
PubMed1975

[Genetic relationship of two mutant genes which producing three different syndromes in the mouse (author's transl)].

We determined that leaner gene (la) is located in the linkage group XVIII and closely linked to Es-1, which is known to be located closely to tottering gene (tg). Double heterozygote (la/tg) produced by mating between la heterozygote and tg heterozygote showed an intermediate syndrome between those seen in tottering (tg/tg) and leaner (la/la) mice. Both leaner and tottering mice showed neuromuscular disorders, but their clinical and pathological characteristics were different. Leaner mice were found to represent a so-called cerebellar mutant having the reduced size of cerebellum and severe cytoarchitectonic abnormalities with focal losses of Purkinje and granular layer cells. Tottering was, however, another mutation having epileptiform seizures, and it was characterized pathologically by cellular losses and shrinkage as well as vesiculations of cytoplasmic membranous structures in the cerebellum. The double heterozygote was shown to have both pathologic characteristics seen in each homozygote, and also showed shrinkage of Purkinje cells and vesiculation of the endoplasmic reticulum and Golgi apparatus. These clinical and pathological findings supported the genetic data suggesting that la and tg constitute an allele.

Alleles↗
PubMed1975

Strain differences in aryl hydrocarbon hydroxylase induction by 3-methylcholanthrene in rabbits.

We determined both basal and induced AHH activity in livers of six partially inbred strains of rabbits. Strain III rabbits had the highest enzyme activity upon induction by 3-MCA, i.e., four to five times that in strain WH (noninducible), which has the lowest enzyme activity. AHH induction was also "low" in strains X, OS, ACEP, and AC. F1 hybrids between strains III and WH revealed a differential response to the induction of liver AHH activity by MCA: the levels of induced hydroxylase activity were consistently higher in (III X WH)F1 rabbits than in the reciprocal (WH X III)F1 hybrids. All possible crosses between these two "extreme" strains are now being analyzed to estimate the number of genes involved in their response difference to MCA.

Animals↗