Biomedical subjects

G Gallegos

Publications and source records attributed to G Gallegos.

10 recordsLinked to original sources

PubMed1995

Surveillance monitoring of soils for radioactivity: Lawrence Livermore National Laboratory 1976 to 1992.

Environmental monitoring of soils at the U.S. Department of Energy's Lawrence Livermore National Laboratory in California has been conducted for more than 20 years. The purposes of the program are to determine the effects, if any, of LLNL's operations on the surrounding areas near its two separate sites and to determine if there are any long-term trends. Data from 1976 to 1992 were analyzed to determine their appropriate statistical distribution, and differences among locations and changes with time were evaluated. The data generally followed lognormal distributions, and results for 239 + 240Pu and 137Cs data were consistent with previously reported values for world-wide fallout. Although all values for 239 + 240Pu were small, 239 + 240Pu data for locations downwind from the Livermore site were found to be statistically significantly higher than for upwind locations. Results for 238U at Site 300 locations near where 238U is used were significantly higher than background locations. Results for 137Cs and 40K were not significantly different between sites, whereas results for 232Th were significantly higher for Site 300 than for the Livermore site. Doses for all radionuclides were below acceptable levels, and doses for most radionuclides were negligible. Evaluation of trends with time yielded small or statistically insignificant changes for all radionuclides.

Cesium Radioisotopes↗

PubMed1992

Characterization of photosystem 1 chlorophyll a/b-binding apoprotein accumulation in developing soybean using type-specific antibodies.

The structure and supramolecular assembly of the soybean photosystem 1 (PS 1) chlorophyll a/b-binding antenna (LHC 1) was examined. We identified the subunit composition of LHC 1 in soybean and followed the accumulation of individual subunits during light-induced assembly. We observed four LHC 1 subunits, at 23, 22, 21 and 20.5 kDa, obtained partial sequence information by amino-terminal sequence analysis, and classified the 20.5, 22, and 21 kDa subunits as being encoded by type I, II, and IV chlorophyll a/b binding protein genes, respectively. Antisera against LHC 1 subunits were used to follow the accumulation of individual subunits during the light-initiated transition from etioplast to chloroplast. Several points are noteworthy. First, monospecific antibody against the 22 kDa subunit decorated a 25 kDa peptide in etiolated tissue, which declined during maturation. This decline correlated with the light-induced appearance of mature 22 kDa peptide, suggesting a precursor/product relationship. Second, the same antibody identified a 22 kDa protein in mature corn, but not a larger band in etiolated corn, suggesting that LHC 1 accumulation is regulated differently between species before the onset of chlorophyll biosynthesis. Third, the mature 22 kDa subunit appeared somewhat later than the other LHC 1 peptides during greening, implying that this subunit is less intimately associated with the PS1 core than are the subunits appearing earlier in development.

Antibodies↗

PubMed1990

Simple disturbance of the dam in the neonatal period can alter haloperidol-induced catalepsy in the adult offspring.

Three experiments were performed to determine whether apparently minimal disturbances of dams and litters would influence haloperidol-induced akinesia. In Experiment I, Long-Evans hooded rats (a) were left unmanipulated, (b) received nestcage relocation and observation, (c) received nestcage relocation/observation and maternal separation, or (d) received nestcage relocation/observation and pup handling. The male adult offspring received open-field testing and later received forepaw-on-dowel catalepsy testing following saline, morphine (20 mg/kg), or haloperidol (2 mg/kg). In Experiment II, hooded rats received (a) no manipulation, (b) nestcage relocation, (c) maternal separation, or (d) pup handling. At weaning, dams were tested in the open-field. Activity wheel locomotion of the offspring was assessed following saline or haloperidol for 3 days/week for 3 weeks; then, 5 and 7 days later, rats received haloperidol (0.5 mg/kg) and catalepsy testing. In both experiments, manipulations involving the dam reduced the offsprings' haloperidol-induced catalepsy, but, in Experiment II, a history of haloperidol administration distinguished between the effects of nestcage relocation and maternal separation. In Experiment III, Swiss albino mice received (a) no treatment, (b) nestcage relocation and maternal separation, (c) relocation/separation and mild cold stress of pups, (d) relocation/separation and pup handling, or (e) relocation/separation and severe cold stress of pups. Adult male mice received saline or haloperidol (2.5 mg/kg) and inclined grid catalepsy testing. Mice receiving relocation/separation and mice receiving relocation/separation and severe cold stress showed enhanced catalepsy versus control mice. Thus, it was concluded that seemingly innocuous events in infancy can influence the intensity of extrapyramidal side effects of neuroleptics in adulthood.

Animals↗

PubMed1983