Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A subgroup of workers from a secondary lead smelter was defined to include those with blood lead levels not exceeding 80 microgram/100 ml and with no past history of elevated blood lead. Central nervous system symptoms (tiredness, sleeplessness, irritability, headache) were reported by 55% of the group and muscle and joint pain by 39%. Zinc protoporphyrin (ZPP) levels were elevated in 71% of cases. Low hemoglobin levels (less than 14 gm/100 ml) were found in more than a third of the workers. While BUN and creatinine were mostly in the normal range, there was nevertheless a correlation between ZPP and both BUN and creatinine. Reduced nerve-conduction velocities were present in 25% of the group; this was not significantly different from findings in a control group. The data indicate that a blood level of 80 microgram/100 ml is an inappropriate biological guide in the prevention of lead disease.
 ...
PMID:Lead effects among secondary lead smelter workers with blood lead levels below 80 microgram/100 ml. 93 40

The prevalence of lead induced subjective symptoms was evaluated by a standardised questionnaire in a group of 96 workers employed between nine and 45 years in a secondary lead smelting works. A control group of 96 non-lead exposed subjects, matched for age and sex, were chosen from the Glostrup population study. Blood lead concentrations were in excess of 60 micrograms/100 ml in about 30% of the lead workers. Zinc protoporphyrin levels were found to be higher than 500 mumol/Hb in nearly 18% of the lead workers. The prevalence of fatigue, headache, sleep disturbance, and digestive symptoms (constipation and colic) were not higher in the lead exposed group. The body weight showed no significant difference in the two groups. Nervousness was four times more frequent in the control group. The results indicate that subjective symptoms are useless as indicators of incipient lead poisoning.
 ...
PMID:Subjective symptoms after long term lead exposure in secondary lead smelting workers. 687 Nov 20

The association between lead absorption and objective psychological performance tests in five groups with different levels of lead absorption was studied in the following groups: (1) a control, non-lead-exposed group; (2) cable splicers, (3) cable manufactures, and (4) secondary lead smelter workers. The following performance tests were used: Block Design, Digit Symbol, and Embedded Figures. Age-corrected performance test scores and the average of three test scores (INDEX) were used throughout. A significant association between performance tests scores and increased lead absorption was found. Zinc protoporphyrin level was a more "powerful" (in the statistical sense) indicator of lead-induced CNS effects than blood lead levels. This study provides additional evidence that neurotoxic effects associated with occupational exposure to lead can be demonstrated by means of performance tests. It has been known and widely accepted that increased lead absorption is associated with "non-specific" subjective symptoms: tiredness, sleep disturbance, irritability, etc. Psychometric techniques (including an appropriate statistical analysis strategy) are highly sensitive for the early detection of CNS neurotoxicity, such as metal toxicity. Moreover, even in lead-exposed but asymptomatic individuals, a significant correlation (negative) between test scores and levels of lead absorption could be detected. It is concluded that workers exposed to lead at levels considered "safe" might be at risk of developing brain dysfunction with long term exposure.
 ...
PMID:Lead exposure and behavioral changes: comparisons of four occupational groups with different levels of lead absorption. 734 80