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Biomedical subjects

W J Washington

Publications and source records attributed to W J Washington.

8 recordsLinked to original sources
PubMed1999

Three pathways between the sacroiliac joint and neural structures.

BACKGROUND AND PURPOSE: Despite ongoing clinical suspicion regarding the relationship between sacroiliac joint (SIJ) dysfunction and lower extremity symptoms, there is a paucity of scientific literature addressing this topic. The purpose of this study was to describe patterns of contrast extravasation during SIJ arthrography and postarthrography CT in patients with lower back pain and to determine whether there are pathways of communication between the SIJ and nearby neural structures. METHODS: Fluoroscopically guided SIJ arthrography was performed on 76 SIJs. After the injection of contrast medium, anteroposterior, lateral, and oblique radiographs as well as 5-mm contiguous axial and direct coronal CT images were obtained. Contrast extravasation patterns were recorded for each joint. These observations included a search for contrast extravasation from the SIJ that contacted nearby lumbosacral nerve roots or structures of the plexus. RESULTS: Sixty-one percent of all joints studied revealed one of five contrast extravasation patterns. Three of these observed patterns show a pathway of communication between the SIJ and nearby neural structures. These included posterior extravasation into the dorsal sacral foramina, superior recess extravasation at the sacral alar level to the fifth lumbar epiradicular sheath, and ventral extravasation to the lumbosacral plexus. CONCLUSION: Three pathways between the SIJ and neural structures exist.

Adult↗
PubMed1989

Age-dependent modulation of tissue-specific repair activity for 3-methyladenine and O6-methylguanine in DNA in inbred mice.

3-Methyladenine-DNA N-glycosylase (MAG) and O6-methylguanine-DNA methyltransferase (MGMT) activities were assayed in liver, lungs, brain and ovaries of female mice of two inbred stocks, C3Hf and C57BL/E, as a function of age. In addition to differences in the enzyme levels between the two stocks for each organ, the suckling animals (9-day-old) have consistently lower levels of both MAG and MGMT than young adults (7- or 8-week-old). While the MGMT levels in adults did not decrease with age, the MAG levels in 15- to 17-month-old animals were, in general, significantly lower than those in young adults. These results raise the possibility that the older animals are at a higher risk than young adults following exposure to alkylating mutagens.

Age Factors↗
PubMed1985

Ethanol-induced late fetal death in mice exposed around the time of fertilization.

In the mouse, all autosomal monosomies and trisomies are lethal by the time of birth (Searle, 1981). To test whether ethanol ingested by females shortly after mating induces nondisjunction, as reported by Kaufman (1983) on the basis of cytological evidence, we attempted to determine whether the incidence of intrauterine death was affected by this treatment. The incidence of late death (day 11 postconception or later) was found to be significantly increased when ethanol was administered 2 h following a 30-min mating period, but not when the interval was shorter. Measurements of early death were not sensitive enough (because of the high control frequency) to show an effect of ethanol treatment. Limited cytological data showed an induced incidence of trisomy in line with the excess frequency of late death, but the trisomy incidence by itself was not significantly different from control. The overall level of effect in the present experiment was lower than that reported by Kaufman.

Animals↗
PubMed1984

Pseudo dominant-lethal response in female mice treated with plant oils.

Corn oil, sesame oil, peanut oil, or olive oil, injected intraperitoneally to female mice prior to insemination, increased the number of deciduomata. In many plant oil-treated females the number of implantation sites was markedly higher than corpora lutea count. These effects were not observed among females that were treated similarly with mineral oil or among females that were given corn oil via oral administration. Evidence indicates that these effects did not arise from induced dominant-lethal mutations but from decidual responses resulting from traces of oil reaching the uterine lumen.

Animals↗
PubMed1983

Induction of morphologically abnormal sperm in rats exposed to O-Xylene.

An analysis of sperm abnormalities can be used as a rapid method to determine the mutagenic potential of chemical agents as well as the toxic potential of chemicals on the whole animal. O-Xylene was investigated for its potential mutagenicity by the sperm abnormality assay. Sprague Dawley rats 10-16 weeks old were injected intraperitoneally (ip) with 0.5 and 1.5 ml/kg body weight of o-xylene in corn oil. Five weeks after treatment, animals were sacrificed and sperm examined for morphological abnormalities. Several morphologically abnormal sperm types were observed; among these were those with amorphous heads, and banana-like heads. Animals housed at room temperatures of 20-24 degrees C showed no significant increase in abnormal sperm over the control. Rats housed at temperatures between 24 and 30 degrees C after ip injection with 0.5 ml/kg o-xylene showed a significant increase in abnormal sperm.

Animals↗
PubMedDate not supplied

Tissue-specific variation in repair activity for 3-methyladenine in DNA in two stocks of mice.

Two stocks of mice, hybrid (C3H X 101)F1 and inbred SEC/R1, were compared for 3-methyladenine-DNA N-glycosylase activity which is involved in removal of 3-methyladenine, 7-methylguanine and some other N-methylpurines in DNA, in cell-free extracts of different tissues. Based on activity measured both per unit weight of tissue and per mass DNA, there is a significant organ-specific and stock-specific difference in N-glycosylase activity over a range of 0.5-8.7 fmoles of 3-methyladenine released per h at 37 degrees C per micrograms DNA of tissue extract. On a per cell basis, the repair activity for 3-methyladenine is the highest in stomach in both stocks. The tissue can be arranged in order of decreasing activity of glycolytic removal as stomach greater than kidney greater than lung greater than liver greater than spleen greater than brain greater than ovary for SEC/R1 mice and stomach greater than kidney greater than ovary greater than spleen, lung and brain greater than liver for the hybrid mice. For all tissues except ovary, SEC/R1 mice have 1.5-4-fold higher specific N-glycosylase activity than (C3H X 101)F1 mice. In contrast, the ovary of SEC/R1 stock has about half as much enzyme activity as that of the hybrid stock.

Adenine↗