PubMed Health⌕ Search

Biomedical subjects

R D Masters

Publications and source records attributed to R D Masters.

6 recordsLinked to original sources
PubMed2000

Association of silicofluoride treated water with elevated blood lead.

UNLABELLED: Previous epidemiological studies have associated silicofluoride-treated community water with enhanced child blood lead parameters. Chronic, low-level dosage of silicofluoride (SiF) has never been adequately tested for health effects in humans. We report here on a statistical study of 151,225 venous blood lead (VBL) tests taken from children ages 0-6 inclusive, living in 105 communities of populations from 15,000 to 75,000. The tests are part of a sample collected by the New York State Department of Children's Health, mostly from 1994-1998. Community fluoridation status was determined from the CDC 1992 Fluoridation Census. Covariates were assigned to each community using the 1990 U.S. Census. Blood lead measures were divided into groups based on race and age. Logistic regressions were carried out for each race/age group, as well as above and below the median of 7 covariates to test the relationship between known risk factors for lead uptake, exposure to SiF-treated water, and VBL >10 microg/dL. RESULTS: For every age/race group, there was a consistently significant association of SiF treated community water and elevated blood lead. Logistic regressions above and below the median value of seven covariates show an effect of silicofluoride on blood lead independent of those covariates. The highest likelihood of children having VBL> 10 microg/dL occurs when they are both exposed to SiF treated water and likely to be subject to another risk factor known to be associated with high blood lead (e.g., old housing). Results are consistent with prior analyses of surveys of children's blood lead in Massachusetts and NHANES III. These data contradict the null hypothesis that there is no difference between the toxic effects of SiF and sodium fluoride, pointing to the need for chemical studies and comprehensive animal testing of water treated with commercial grade silicofluorides.

Black or African American↗
PubMed1995

Superficial and deep cervical plexus block: technical considerations.

Regional anesthetic block of the cervical plexus is a safe and useful alternative to general endotracheal anesthesia for surgery of the neck, upper shoulder, and occipital scalp area. The sensory component of the cervical plexus can be blocked separately and easily by a superficial cervical plexus block. Both motor and sensory block can be obtained by deep cervical plexus block. Minor transient side effects are common to deep cervical plexus blocks, but they are rarely of any consequence. Recent years have seen an increase in interest in the use of the cervical plexus block, because its popularity for surgical procedures such as carotid endarterectomies has grown. An understanding of the anatomy and principles of this anesthetic technique will enable the clinician to offer the patient and surgeon an important anesthetic option.

Cervical Plexus↗
PubMed1994

Incidence and clinical significance of hemidiaphragmatic paresis in patients undergoing carotid endarterectomy during cervical plexus block anesthesia.

This study was designed to investigate the incidence and clinical consequences of hemidiaphragmatic paresis in patients undergoing carotid endarterectomy using cervical plexus block anesthesia. In 28 patients, diaphragmatic motion was evaluated by fluoroscopy 20 min after cervical plexus block with 1% mepivacaine. In 61% of the patients abnormalities of diaphragmatic motion were detected. These motion anomalies were associated with a statistically significant elevation of PaCO2. Gender, age, and whether the block was on the left or right side did not appear to affect the incidence of motion abnormalities after cervical plexus block anesthesia.

Aged↗
PubMed1982

Is sociobiology reactionary? The political implications of inclusive-fitness theory.

Is inclusive fitness theory, popularly called "sociobiology," necessarily conservative or reactionary? While this criticism is usually focused on the extension of evolutionary reasoning to human behavior, it implies that contemporary biological theory is ideologically biased. Historical, logical, and empirical evidence shows, however, that models of natural selection based on reproductive success--particularly when redefined in terms of inclusive fitness--are not incompatible with scientific objectivity. This approach is a cost-benefit analysis of social behavior, akin to "rational actor" models in economics, game theory, and public-choice theory. Derived from the "social-contract" tradition in Western political philosophy, epitomized by such varied thinkers as Thrasymachus, Hobbes, and Rousseau, such a calculus of individual advantage has had as broad a range of ideological overtones as the contrasting "'sociological" tradition of Aristotle, Marx, and Durkheim. Previous evolutionary explanations of human society have likewise suggested diverse political conclusions. Indeed, if inclusive-fitness models do have political implications, they could well challenge existing sociopolitical beliefs and institutions rather than support them.

Altruism↗