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Biomedical subjects

S G Jones

Publications and source records attributed to S G Jones.

At least 55 records · Page 3Linked to original sources
PubMed1986

Structural effects in the dithiocarbamate-enhanced biliary excretion of cadmium.

The dithiocarbamate enhancement of the biliary excretion of cadmium in rats loaded with cadmium (by either the oral or sc route) was found to be strongly dependent on the structure of the groups attached to the nitrogen atom of the dithiocarbamate moiety. Those dithiocarbamates containing hydroxyl-bearing attached groups were found to be capable of causing the greatest enhancement of the cadmium content of the bile. For the compounds of this type that were examined, this enhancement of biliary cadmium content varied from 30-fold to over 2000-fold. No enhancement of the biliary excretion of cadmium was found subsequent to the administration of sodium diethyldithiocarbamate, though this compound is known to cause a significant increase in the fecal excretion of cadmium.

Administration, Oral↗
PubMed1986

Effects of the mobilization of aged tissue cadmium by chelating agents.

An examination of the kidney and liver subsequent to the mobilization of aged cadmium deposits from them by the use of both dithiocarbamates and 1,2-dimercapto-1-propranolol (BAL) was carried out. No striking permanent effects due to cadmium mobilization were noted in the kidneys or livers for most of the chelating agents used. After the mobilization of part of the cadmium burden, the remaining cadmium gives evidence of undergoing a redistribution, leading to a renewed increase in both the kidney and liver levels of this element.

Animals↗
PubMed1984

Sodium N-methyl-D-glucamine dithiocarbamate and cadmium intoxication.

The sodium and ammonium salts of N-methyl-D-glucamine dithiocarbamate were prepared and their usefulness as antidotes for cadmium intoxication investigated. This chelating agent was found to be effective in both acute and repeated exposure cadmium poisoning. A single intraperitoneal injection of sodium N-methyl-D-glucamine dithiocarbamate (NaNMG-DTC), administered at a level greater than 1.1 mmol/kg body weight, protects against a normally lethal (greater than 95%) dose of cadmium chloride (10 mg CdCl2/kg body weight) and results in a subsequent dose-dependent decrease in the liver and kidney burdens of cadmium ion. In repeated exposure cadmium intoxication, repeated administration of NaNMG-DTC can result in substantial reductions in both the kidney (71%) and the liver (40%) levels of cadmium. The LD50 of the compound was not determined, but single injections of 26.6 mmol/kg body weight (injectate volume 1.0 ml) are well tolerated in mice.

Animals↗
PubMed1984

Structure-activity relationships among dithiocarbamate antidotes for acute cadmium chloride intoxication.

Eight sodium dithiocarbamates (NaS2CNR1R2) have been examined as antidotes for acute cadmium intoxication. While all of them possess an ability to increase survival when given to mice 2 hr after a lethal (greater than 99%) intraperitoneal injection of 10 mg/kg of CdCl2 X 2.5H2O, their effects on the organ distribution of cadmium vary considerably. It has been possible to show that the accumulation of cadmium in the brain and kidney as well as the survival rates can be correlated with a numerical measure of the polarity of the groups R1 and R2. Each factor has a different dependence on the polarity, but it is possible to construct a composite factor for antidotal efficacy which incorporates survival rate, brain cadmium levels and kidney cadmium levels. The factor constructed here exhibits an optimal value approximately in the middle of the polarity range studied. Compounds which have R1 = -CH2CH1OH and R2 = -CH2CH2OH, or -CH3 or -C2H5 appear to be the most effective antidotes of the compounds examined.

Acute Disease↗
PubMed1983

Mobilization of aged cadmium deposits by dithiocarbamates.

Mice with chronic cadmium intoxication were given low levels (0.6 mm/kg) of several dithiocarbamates (parent compounds: dihydroxyethylamine, iminodiacetic acid, methylhydroxyethylamine and sarcosine) in an attempt to reduce the cadmium present in the liver and kidney. Comparing the results with those obtained with the less polar sodium diethyldithiocarbamate (NaDDTC), only ammonium di(hydroxyethyl)dithiocarbamate (NH4DHE-DTC) possessed a similar ability to reduce kidney cadmium levels. Under the experimental conditions employed, the reduction obtained with NH4DHE-DTC was less than that effected by a comparable dose of NaDDTC. A subsequent dose-dependence study showed, however, that sodium di(hydroxyethyl)dithiocarbamate (NaDHE-DTC) is quite effective at higher dosage levels (up to 5.5 mmoles/kg) where substantial reductions in both kidney (89% mobilization) and liver (38% mobilization) stores of cadmium were observed. High doses of the NaDHE-DTC are well tolerated as the LD50 of this compound in mice is greater than 19.8 mmoles/kg.

Animals↗
PubMed1982

A comparison of diethyldithiocarbamate and EDTA as antidotes for acute cadmium intoxication.

For mice which have been given the cadmium equivalent of CdCl2 X 2 1/2H2O at a level of 10 mg/kg, diethyldithiocarbamate (DDTC) administration at 500 mg/kg leads to a higher survival rate than is found with Na2CaEDTA under identical conditions. This occurs when the interval between administration of the cadmium salt and the antidote is either one or two hours. The surviving animals, however, are found to have appreciable levels of cadmium in their brain, liver and kidney when they were treated with DDTC, though their behavior appeared to be normal. The use of 50 mg/kg of DDTC after 2 hr in such cadmium poisoned mice also leads to a higher survival rate and reduced amounts of cadmium retained in the brain, liver and kidney. Unlike the other chelating agents which have been reported as useful in acute cadmium intoxication, DDTC appears to act by forming a lipid soluble complex which is largely immobilized in lipid containing tissues of the animal's body.

Acute Disease↗
PubMed1978

Correlations between chromosome segments and fitness in Drosophila melanogaster III. Differential genetic responses to zinc sulfate and selenocystine.

Genetic X environmental interactions are examined at an intrachromosomal level in Drosophila melanogaster. With respect to two fitness components, egg production and egg-to-adult viability, evidence is provided that different segments of the X chromosome are affected differently by each of the chemical substances, zinc sulfate and selenocystine. The extent of a segment's effect on a trait is not always parallelled by the extent of its association with that trait's sensitivity to chemical treatment. Both attributes are functions of the genetical background. The degree of dominance of each segment is not always greater in the chemical environments, a finding inconsistent with Parson's concept of "extreme-environment heterosis".

Animals↗
PubMedDate not supplied

Continuous quality improvement project: decreasing the potential for the development in the inpatient setting of drug resistance by improving nursing practice for HAART administration.

HIV/AIDS patients' dissatisfaction with highly active antiretroviral therapy (HAART) medication administration in the inpatient setting was the impetus for a continuous quality improvement (CQI) project. The purpose of the CQI project was to initiate a change in nursing practice for HAART medication administration. The goal of the project was to decrease the potential for development of drug resistance in the inpatient setting related to nonadherence with food requirements for drug administration and to incomplete or "missed" doses of prescribed HAART. A secondary goal was to increase the provision of patient education on HAART medications by nurses. The interdisciplinary CQI team found that medication administration in the inpatient setting involved more than nurses simply "passing meds." Inpatient medication administration was a complex process involving a variety of hospital systems, departments, and traditions, all of which had an impact on patient care. The article describes the CQI methodology that was used for the project and how each step of the project was planned and implemented. Specific problems related to administering HAART in the hospital setting are listed as areas for needed nursing research.

Anti-HIV Agents↗
PubMedDate not supplied

Implementing a multidisciplinary HIV diarrhea critical pathway in the acute care setting.

Clinical pathways are the new strategy for managing hospital length of stay and cost in the changing, dollar-driven arena of health care. For patients with AIDS, HIV-related diarrhea is a potential source of increased morbidity that results in increased hospitalization and health care costs. This article describes the development and implementation of a multidisciplinary HIV Diarrhea Critical Pathway at Mount Sinai Medical Center of Greater Miami in South Florida. The focus of this article is on the nursing issues that arose during the piloting of the Diarrhea Critical Pathway and on the "how-tos" of its use. Initial evaluation of the first 3 years of using the diarrhea pathway is reported.

Cost Control↗
PubMedDate not supplied

Nursing practice for HIV/AIDS fever care: a descriptive study.

Nurses often perceive fever in relation to the impact it has on specific patient populations. Fever in HIV/AIDS patients is a common symptom. This descriptive study explored how nurses in AIDS care defined and described fever in HIV/AIDS patients and used nursing interventions for fever management. Seventy-five registered nurses, nurse practitioners, and LPNs employed in AIDS care throughout Florida were surveyed concerning interventions for AIDS-related fever. The study revealed that nurses in AIDS care treat fever by providing patient comfort, initiating nursing interventions for low-grade to moderate fever, and notifying the primary care provider if nursing interventions do not keep the temperature below 100.9 degrees F. The sample provided a variety of nursing interventions to make the patient more comfortable. In addition, the study also revealed a unique perspective for fever care, which influences the practice of nurses in AIDS care and might differentiate nursing practice in AIDS care from other nursing specialties. However, some interventions differed from fever nursing management strategies published by the Association of Nurses in AIDS Care. Further research needs to explore the efficacy of these interventions.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Use of the Topliss scheme for the design of more effective chelating agents for cadmium decorporation.

The Topliss scheme, which designates a special series of substituents for use in sequence in the search for suitably substituted aromatic compounds with biological properties superior to the parent unsubstituted aromatic compound, has been applied to the design of new chelating agents for the decorporation of cadmium from its deposits in vivo. Substituted benzylamines have been used in the syntheses of the corresponding substituted sodium N-benzyl-D-glucamine-N-carbodithioates, i.e., RC6H4CH2N(CS2Na)CH2(CHOH)4CH2OH (or RBGDTC): CF3BGDTC, R = 3-CF3; MeBGDTC, R = 4-CH3; MeOBGDTC, R = 4-OCH3; ClBGDTC, R = 4-Cl. Examination of the behavior of these compounds as agents for the mobilization of cadmium from its deposits in vivo shows that such substitution can have an appreciable effect on the organ selectivity for cadmium removal, as well as the efficacy. Of the four compounds suggested by the Topliss scheme for pilot studies, two were much more effective than the parent compound (BGDTC), and of these the best one, sodium N-(4-methoxybenzyl)-D-glucamine-N-carbodithioate (MeOBGDTC) reduced kidney cadmium levels to 30% and liver cadmium levels to 50% of those obtained with the parent compound. Sodium N-[3-(trifluoromethyl)benzyl]-D-glucamine-N-carbodithioate (CF3BGDTC) was also found to be superior to the parent compound in reducing the liver cadmium levels, though it was equivalent in reducing renal cadmium levels.

Animals↗
PubMedDate not supplied

Optimization of chelating agent structure for the mobilization of aged renal and hepatic cadmium deposits: sodium N-benzyl-4-O-(beta-D-galactopyranosyl)-D-glucamine-N-carbodithioate.

An examination of the structure-activity relationships for the mobilization of intracellular cadmium by previously synthesized dithiocarbamates indicates that superior compounds can be prepared by increasing the molecular weight by using bulky polar but nonionic substituents. This suggested the synthesis and characterization of sodium N-benzyl-4-O-(beta-D-galactopyranosyl)-D-glucamine-N-carbodithioate++ +. The preparation of this compound and its characterization as an agent for the mobilization of aged renal and hepatic cadmium deposits in mice show it to be superior to the compounds reported earlier which have been used for this purpose. Five ip injections at 0.40 mmol/kg reduced hepatic cadmium levels to 35% of their initial level and renal cadmium levels to 37%. The nature of the structural factors responsible for the efficacy of such agents is outlined as well as the relationship of these to the toxicity of the compounds and their cadmium complexes. These factors indicate clearly the differences in the molecular requirements for the mobilization of extracellular and intracellular toxic metal ions. The requirement that intracellular toxic metals be mobilized places several constraints on the structures of potentially efficacious compounds in addition to the thermodynamic and kinetic restrictions imposed by the requirements for extracellular efficacy.

Animals↗