Biomedical subjects

Stanley Berent

Publications and source records attributed to Stanley Berent.

4 recordsLinked to original sources

PubMed2005

Face emotion perception and executive functioning deficits in depression.

Frontal, limbic and temporal regions of the brain important in emotion perception and executive functioning also have been implicated in the etiology and maintenance of depression; yet, the relationships among these topics remain poorly understood. The present study evaluated emotion perception and executive functioning among 21 depressed women and 20 nondepressed women controls. Depressed women performed significantly worse than controls in emotion perception accuracy and in inhibitory control, an aspect of executive functioning, whereas the groups did not differ in other cognitive tests assessing memory, visual-spatial, motor, and attention skills. The findings suggest that emotion perception and executive functioning are disproportionately negatively affected relative to other cognitive functions, even in a high-functioning group of mildly depressed women. Measures of emotion perception and executive functioning may be of assistance in objectively measuring functional capability of the ventral and dorsal neural systems, respectively, as well as in the diagnosis of depression.

Adolescent↗

PubMed2005

The potential adverse health effects of dental amalgam.

There is significant public concern about the potential health effects of exposure to mercury vapour (Hg(0)) released from dental amalgam restorations. The purpose of this article is to provide information about the toxicokinetics of Hg(0), evaluate the findings from the recent scientific and medical literature, and identify research gaps that when filled may definitively support or refute the hypothesis that dental amalgam causes adverse health effects. Dental amalgam is a widely used restorative dental material that was introduced over 150 years ago. Most standard dental amalgam formulations contain approximately 50% elemental mercury. Experimental evidence consistently demonstrates that Hg(0) is released from dental amalgam restorations and is absorbed by the human body. Numerous studies report positive correlations between the number of dental amalgam restorations or surfaces and urine mercury concentrations in non-occupationally exposed individuals. Although of public concern, it is currently unclear what adverse health effects are caused by the levels of Hg(0) released from this restoration material. Historically, studies of occupationally exposed individuals have provided consistent information about the relationship between exposure to Hg(0) and adverse effects reflecting both nervous system and renal dysfunction. Workers are usually exposed to substantially higher Hg(0) levels than individuals with dental amalgam restorations and are typically exposed 8 hours per day for 20-30 years, whereas persons with dental amalgam restorations are exposed 24 hours per day over some portion of a lifetime. This review has uncovered no convincing evidence pointing to any adverse health effects that are attributable to dental amalgam restorations besides hypersensitivity in some individuals.

Dental Amalgam↗

PubMed2004

Absence of sensory neuropathy among workers with occupational exposure to chlorpyrifos.

Several studies have reported the occurrence of sensory neuropathy with exposure to chlorpyrifos and other organophosphorus insecticides, at levels not associated with overt toxicity. We evaluated 113 chemical workers, including 53 of 66 (80%) eligible chlorpyrifos workers and 60 of 74 (81%) randomly selected referent workers, to identify evidence of sensory neuropathy or subclinical neuropathy. Compared to referents, chlorpyrifos subjects had significantly longer duration of work in chlorpyrifos-exposed areas (9.72 vs. 0.01 years; P < 0.0001), greater cumulative chlorpyrifos exposure (64.16 vs. 0.69 mg/m(3). day; P < 0.0001), higher urine 3,5,6-trichloro-2-pyridinol (TCP) excretion (108.6 vs. 4.3 microg/g creatinine; P < 0.0001), and lower plasma butyrylcholinesterase (BuChE) activity (7281 vs. 8176 mU/ml; P = 0.003). Despite exposures among chlorpyrifos subjects to levels at which well-described physiological effects on B-esterases exist, the frequency of symptoms or signs of neuropathy did not differ significantly between groups, and the only 2 subjects fulfilling criteria for confirmed neuropathy were both in the referent group. Mean nerve conduction study results were comparable to established control values and did not differ significantly between groups. We found no evidence of sensory neuropathy or isolated peripheral abnormalities among subjects with long-term chlorpyrifos exposure at levels known to be associated with the manufacturing process.

Adolescent↗

PubMed2004

The effects of occupational exposure to chlorpyrifos on the neurologic examination of central nervous system function: a prospective cohort study.

Questions persist about adverse effects such as impaired cognition and attention, incoordination, spasticity, or parkinsonism from chronic, low-level exposures to organophosphate (OP) compounds. In a prospective cohort study, we evaluated chlorpyrifos-manufacturing workers and a referent group on 2 occasions, 1 year apart, to determine whether occupational exposure to chlorpyrifos produced clinically evident central nervous system (CNS) dysfunction. Chlorpyrifos subjects had significantly higher TCP excretion and lower average BuChE activity than referents in a range in which physiological effects on B-esterases exist. Few subjects had neurologic symptoms or signs, and there were no significant group differences in terms of signs at baseline or second examinations. Chronic chlorpyrifos exposure produced no clinical evidence of cortical, pyramidal tract, extrapyramidal, or other CNS dysfunction among chlorpyrifos subjects compared with referents, either at baseline or after 1 year of additional chlorpyrifos exposure.

Adult↗