Association between Spirometric Parameters and Depressive Symptoms in New Mexico Uranium Workers.

BACKGROUND: Uranium workers are at risk of developing lung disease, characterized by low forced expiratory volume in one second (FEV1) and/or forced vital capacity (FVC). Previous studies have found an association between decreased lung function and depressive symptoms in patients with pulmonary pathologies, but this association has not been well examined in occupational cohorts, especially uranium workers. METHODS: This cross-sectional study evaluated the association between spirometric measures and depressive symptoms in a sample of elderly former uranium workers screened by the New Mexico Radiation Exposure Screening & Education Program (NM-RESEP). Race- and ethnicity-specific reference equations were used to determine predicted spirometric indices (predictor variable). At least one depressive symptom [depressed mood and/or anhedonia, as determined by a modified Patient Health Questionnaire-2 (PHQ-2)], was the outcome variables. Chi-square tests and multivariable logistic regression models were used for statistical analyses. RESULTS: At least one depressive symptom was self-reported by 7.6% of uranium workers. Depressed mood was reported over twice as much as anhedonia (7.2% versus 3.3%). Abnormal FVC was associated with at least one depressive symptom after adjustment for covariates. There was no significant interaction between race/ethnicity and spirometric indices on depressive symptoms. CONCLUSIONS: Although depressive symptoms are uncommonly reported in uranium workers, they are an important comorbidity due to their overall clinical impact. Abnormal FVC was associated with depressive symptoms. Race/ethnicity was not found to be an effect modifier for the association between abnormal FVC and depressive symptoms. To better understand the mechanism underlying this association and determine if a causal relationship exists between spirometric indices and depressive symptoms in occupational populations at risk for developing lung disease, larger longitudinal studies are required. We recommend screening for depressive symptoms for current and former uranium workers as part of routine health surveillance of this occupational cohort. Such screening may help overcome workers' reluctance to self-report and seek treatment for depression and may avoid negative consequences to health and safety from missed diagnoses.

Association Between Self-Reported Dyspnea and Depressive Symptoms in New Mexico Uranium Workers.

New Mexico has the largest number of former uranium workers, mostly racial/ethnic minorities. Uranium workers are at risk for dyspnea secondary to mine dust exposure. The association between dyspnea and depressive symptoms has not been well examined in occupational minority cohorts. This study evaluated the associations between dyspnea (measured by the modified Medical Research Council Questionnaire) and depressive symptoms (measured by the Patient Health Questionnaire-2) in former uranium workers screened by the New Mexico Radiation Exposure Screening & Education Program. The subjects were mostly elderly, rural-residing, minority males. Dyspnea was commonly reported; however, depressive symptoms were uncommon. At baseline, former workers experiencing higher levels of dyspnea were more than 3 times likely to endorse depressive symptoms than those with no or mild dyspnea. Longitudinal analysis failed to determine an association between change in dyspnea and concomitant change in depressive symptoms. Dyspnea and depressive symptoms were associated cross-sectionally in former uranium workers.

Changes of peripheral-type benzodiazepine receptors in the penumbra area after cerebral ischemia-reperfusion injury and effects of astragaloside IV on rats.

This study investigated the changes in peripheral benzodiazepine receptors (PBRs) in the penumbra after cerebral ischemia-reperfusion injury, and examined the effects of astragaloside IV (AST) on PBRs in rats. Sixty Sprague-Dawley rats were divided into a sham operation group, a model group, and three AST treatment groups. Cerebral ischemic models were induced by the clue-blocked method. Neurological deficits were examined. The animals were sacrificed after 2 h of ischemia and 24 h of reperfusion, and mitochondria from the penumbra were purified. PBR density (Bmax) and affinity were measured by radioligand assays. Mitochondrial [(3)H]PK11195 binding was correlated with neurological deficits in rats. Compared to the model group, the 10 mg/kg AST group, 40 mg/kg AST group, and 100 mg/kg AST group had fewer neurological deficits. The effects in the 40 mg/ kg group did not significantly differ from the effects in the 100 mg/ kg group. Compared to the model group, the 10 mg/kg AST group, 40 mg/kg group, and 100 mg/kg group had a decreased Bmax in the penumbra. The Bmax decreased in the 40 mg/kg AST group and in the 100 mg/kg AST group compared with the 10 mg/kg group. The Bmax and neurological deficits in the 40 mg/kg did not significantly differ from those in the 100 mg/kg group. By contrast, the AST-treated rats showed no significant changes in the binding parameter equilibrium dissociation constant compared with those in the sham operation group and the model group. AST protects ischemic brain tissue by inhibiting PBR expression after cerebral ischemia.