PubMed Health⌕ Search

Biomedical subjects

J Erickson

Publications and source records attributed to J Erickson.

At least 91 records · Page 5Linked to original sources
PubMed1976

Tumorigenicity of tetramethylhydrazine hydrochloride in Swiss mice.

Tetramethylhydrazine hydrochloride (TEMH) was administered in drinking water as a 0.125% solution to randomly bred Swiss mice for life beginning at 6 weeks of age. As a result of treatment, the incidence of blood vessel tumors rose from 5 to 96% in females and from 6 to 88% in males, while that of lung tumors increased from 21 to 36% in females and from 23 to 28% in males, as compared with untreated controls. The increased incidence of blood vessel tumors, but not of lung neoplasms, was statistically significant. Histopathologically, the tumors exhibited the characteristics of angiomas and angiosarcomas of blood vessels and adenomas of the lung. The investigation proved for the first time the tumorigenicity of TEMH. The possible role of increased methyl substitution on hydrazine in tumorigenesis was also discussed, as well as hydrazine derivatives as a tumor-producing class.

Adenoma↗
PubMed1976

Cytogenetic analysis of homozygous segregation distorter males of Drosophila melanogaster.

Certain homozygous SD males are nearly sterile. Sterility is not due to aneuploid gametes--no significant second chromosome nondisjunction was found in matings to attached-2 and mei-S332 females. Some fourth chromosome aneuploidy was observed here, and in the cytological work. Otherwise, cytology of the meiotic divisions was essentially normal. Early spermatid bundles are normal, sperm head counts approximating the normal 64. In the later, coiled bundle stage, one observes less than 30 heads many of which are grossly abnormal: twisted, club-like, or globular. In double mating experiments, SD/SD sperm did not displace normal sperm introduced first. In the reverse experiment, sperm (or fluid) from SD/SD males markedly reduced capacity of the females to store and utilize sperm from normal males, as scored from progeny and by counts of stored sperm. No sperm were seen in the storage organs of females imseminated first by SD/SD then by normal males. Many females refuse such a second mating. Our observations are quantitatively different from those with heterozygous SD males, but qualitatively similar, supporting the view that the near sterility of homozygous SD males arises from a mechanism of sperm dysfunction like that in SD/+ males.

Animals↗
PubMed1975

Sex dependent toxicity of four chemicals.

Toxicity investigations were conducted with 4 chemicals: hydrazine, 1,2-dimethylhydrazine di HCl, phenylhydrazine HCl and Beta-N-(gamma-L(+)-glutamyl)-4-hydroxymethylphenylhydrazine in Swiss mice. Hydrazine and phenylhydrazine HCl were administered daily in drinking water, the former at 0.01% and the latter at 0.001% concentrations. The 1,2-dimethylhydrazine di HCl and Beta-N-(gamma-L(+)-glutamyl)-4-hydroxymethylphenylhydrazine were given as a single subcutaneous injection at 45 mug and 100 mug/gr. body weight basis, respectively. The findings clearly showed that all four chemicals exerted a stronger toxic effect in male than in female mice. It is, therefore, recommended in similar situations to use different doses of chemicals for each sex in the long-term tumorigenesis studies.

Animals↗
PubMedDate not supplied

Maneuverability and usability analysis of three knee-extension propelled wheelchairs.

PURPOSE: The purpose of this study was to evaluate the maneuverability and usability of three knee-extension propelled wheelchairs. METHOD: The maneuverability of the knee-extension propelled wheelchairs was determined in a controlled test representing five standard wheelchair activities. The usability of the wheelchairs was evaluated in a field test with elderly residents of an extended care facility in Salt Lake City. RESULTS: The results indicate that the wheelchair designs using a swinging (four-bar linkage) or sliding belt mechanism are preferred to a sliding plate design. CONCLUSIONS: The use of knee-extension propelled wheelchairs is a feasible alternative to hand propelled wheelchairs. Further development and research is needed to address power requirements, maneuverability, and entrance/egress from the chairs.

Aged↗