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Biomedical subjects

R G Rice

Publications and source records attributed to R G Rice.

16 recordsLinked to original sources
PubMed1986

Occurrence of by-products of strong oxidants reacting with drinking water contaminants--scope of the problem.

This paper describes results of a detailed literature review of the organic and inorganic by-products that have been identified as being formed in aqueous solution with four of the strong oxidizing/disinfecting agents commonly employed in drinking water treatment. These agents are: chlorine, chlorine dioxide, chloramine, and ozone. Significant findings include the production of similar nonchlorinated organic oxidation products from chlorine, chlorine dioxide, and ozone. In addition, all three chlorinous oxidants/disinfectants can produce chlorinated by-products under certain conditions. The presence of chloronitrile compounds in drinking waters is indicated to arise from reactions of chlorine or chloramine to amine/amide functions in amino acids or proteinaceous materials, followed by dehydrohalogenation. These nitriles could hydrolyze to produce the corresponding chloroacetic acids. It is concluded that to minimize the presence of oxidation by-products in drinking waters, the concentrations of oxidizable organic/inorganic impurities should be lowered before any oxidizing agent is added.

Chemical Phenomena↗
PubMed1985

Multiple extractions of hormone receptors from mixed human breast tumors.

Multiple extractions of hormone receptors from mixed human breast tumors revealed a considerable amount of ER and PgR activity remaining in the second and third cytosol fractions extracted by the same tris buffer system (TEDG, pH 7.4, containing 10 mM tris, 1.5 mM EDTA, 2.0 mM dithiothreitol, and 10% glycerol). The incomplete and inefficient extraction of tumors with tris buffer system after only one homogenization and centrifugation is a serious concern in efforts to achieve accurate determinations of receptor concentrations which permit the accurate prediction of hormone responsiveness of breast cancers.

Breast Neoplasms↗
PubMed1979

Synchronous primary mucinous adenocarcinomas in the descending colon and perianal glands.

The descending colon is a relatively rare site for mucinous adenocarcinoma. Anal ductal malignancy and multiple primary coloperianal mucinous adenocarcinomas are also rare. We have described the unusual finding of multiple primary synchronous mucinous adenocarcinomas in the descending colon and perianal glands. There was no evidence of any metastasis from the Dukes B lesion in the descending colon.

Adenocarcinoma, Mucinous↗
PubMed1976

EPSDT- one quarter million screenings in Michigan.

Since the spring of 1973, Michigan's EPSDT program has screened more than 300,000 children. The Department of Social Services contracted with the Department of Public Health to design the screening and referral parts of the program; in turn the Department of Public Health contracts with local health departments to do screening with one or more teams composed of a nurse, two technicians, and a clerk. The 72 teams screen 10,000 clients each month. More than one-half of these clients are referred for diagnosis and treatment. The highest percentage (27 per cent) of referral is for dental care; the second highest (26 per cent) is for immunization. Participation in the program of state and local social services departments, local health departments, and all groups of health providers has been excellent. There continues to be a high no-show for screening and a moderate no-show rate to providers for diagnosis and treatment. Evaluation of the program elements is needed.

Adolescent↗
PubMedDate not supplied

Multiple extractions of hormone receptor from rabbit uteri and human breast tumors.

The cytosol hormone receptors were extracted from rabbit uteri and human tumors with tris buffer systems for three consecutive homogenization and centrifugation processes to obtain three cytosols C-1, C-2, and C-3. The assay results evaluated revealed that minimal to tremendous amounts of receptor activities were present in C-2 and/or C-3 fractions. The essential experimental conditions and some speculative mechanisms have been discussed in detail.

Animals↗
PubMedDate not supplied

Efficacy of extraction and incubation of ER and PgR with different solvent systems from rabbit uterus.

Methods for improving the estrogen receptor (ER) and progestin receptor (PgR) assay were studied. Using DCC procedure as the basis, the extraction and incubation of ER and PgR is more efficiently achieved by phosphate buffer as compared with water, tris and veronal buffers. The multiple extractions of hormone receptors by any solvent system used is more complete than a single operation of homogenization and centrifugation. The utilization of combined extraction first with water and then phosphate buffer, followed by incubation of the cytosol in phosphate buffer with hormone is also an efficient procedure for the assay of both ER and PgR.

Animals↗
PubMedDate not supplied

The effect of dithiothreitol on the estrogen receptor.

The effects of Dithiothreitol (DTT) on the estrogen receptor molecule were studied. DTT was evaluated for its potential abilities to preserve the integrity of the estrogen receptor. Storage at various extremes of pH was also considered for its possible adverse or positive effect. Cytosol was prepared utilizing rabbit uterus. Six aliquots of the cytosol were stored at 4 degrees C for 15 days. Two samples were adjusted to each pH, 6.0, 7.0, and 8.0, and to one sample of each pH was added DTT, 0.154 mg/ml. Aliquots of stored cytosols were analyzed for estrogen receptor (ER) on day 1, 3, 7, and 15 after adjusting the aliquots to pH 7.4. There was degradation of ER with time; degradation was less with DTT. The degradation also increases with the lower pH. The cytosol stored at 4 degrees C and pH 8.0 with DTT was the best environment in these experiments for stability of ER.

Animals↗