Occupational pesticide exposure and screening tests for neurodegenerative disease among an elderly population in Costa Rica.

BACKGROUND: Pesticides have been associated with Parkinson's disease (PD) in many studies, and with Alzheimer's disease (AD) in a few. METHODS: We conducted screening tests for neurologic disease and occupational pesticide use in a population-based sample of 400 elderly subjects at two government-run clinics in Costa Rica; 361 subjects who failed the initial screen were given both the mini-mental states exam (MMSE) and a modified version of a 10-item united Parkinson's disease rating motor subscale (UPDRS). Among subjects who failed either test, 144 were then examined by a neurologist. RESULTS: Past occupational pesticide exposure was reported by 18% of subjects. Exposed subjects performed worse on the MMSE than the non-exposed (mean 24.5 versus 25.9, p=0.01, adjusted for age, sex, and education). The exposed had significantly elevated risks of abnormal scores on two UPDRS items, tremor-at-rest (OR 2.58, 1.28-5.23), and finger-tapping (OR=2.94, 95% CI 1.03-8.41). Thirty-three (23%) of those examined by the neurologist were diagnosed with possible/probable PD, 3-4 times the expected based on international data; 85% of these cases had not been previously diagnosed. Among subjects who took the UPDRS, the exposed had an increased risk of PD (OR=2.57, 95% CI 0.91-7.26). No excess risk was found for a diagnosis of AD or mild cognitive impairment. CONCLUSIONS: Elderly subjects with past occupational pesticide exposure performed significantly worse on screening tests for dementia and PD, and had an increased risk of an eventual PD diagnosis. Screening may be particularly appropriate among elderly subjects with past pesticide exposure.

Monitoring intracellular melatonin levels in human prostate normal and cancer cells by HPLC.

Melatonin (N-acetyl-5-methoxytryptamine) is a potent endogenous antioxidant and free radical scavenger that has attracted much attention as a consequence of its multiple biological functions. In addition to other physiological properties, it has clear antiproliferative activity in several types of cancer cell. The concentration of melatonin necessary to inhibit cell growth is much higher than its blood physiological concentrations in some tumor types. For years its indolic nature has impeded proper monitoring, by molecular or immunological techniques, of its uptake by cancer cells. In this work we developed a simple, rapid, and validated analytical method for detection and quantification of MEL inside normal and cancer cells. For this purpose we performed high-performance liquid chromatographic analysis after liquid-liquid extraction of the indole from biological samples. The method was validated, and the correlation coefficient for amounts from 0.125 to 1.25 microg was higher than 0.999, with a range of recovery near 100%. Precision was evaluated as repeatability, and for intermediate precision, the relative standard deviation was less than 5%. The method was used to study the stability of the indole in solution and to determine intracellular melatonin concentrations in normal (PNT1A) and several cancer (LNCaP, DU-145, PC-3) prostate cell lines. Intracellular LOQ/LOD were 7.23/2.83, 23.17/9.07, 4.03/1.83, and 6.51/2.53 nmol L(-1), or 1.82/4.66, 0.56/1.45, 3.26/8.34, and 2.02/5.17 attogram in each cell in PNT1A, LNCaP, DU145, and PC-3 cells, respectively. Because there was no information about intracellular levels of melatonin inside normal or tumor prostate cells after treatment with the indole, nor a relationship between its antiproliferative activity and its intracellular concentration, this is the first time that, by using an analytical method combined with measurement of cellular volume by flow cytometry, the intracellular concentration of MEL has been estimated. Also, data obtained here explain why the antiproliferative properties of MEL vary in different cell types. This is, moreover, the first time that by increasing the intracellular concentration of melatonin, its antitumor properties have been promoted in prostate cancer cells. This process can be monitored by the method developed here.

Development and validation of new methods for the determination of melatonin and its oxidative metabolites by high performance liquid chromatography and capillary electrophoresis, using multivariate optimization.

Melatonin (N-acetyl-5-metoxytriptamine, MEL) has focused a lot of attention as consequence of its multiple functions. MEL is a potent endogenous antioxidant and a free radical scavenger that reacts with several sort of radicals generating various metabolites. Two of them are N1-acetyl-N2-formyl-5-methoxykynurenine (AFMK) and N1-acetyl-5-methoxykynurenine (AMK). These compounds are important because they have also antioxidant actions as well as other important biological properties. In the present work, we develop two methods to detect and quantify these compounds (MEL, AFMK and AMK) in the same sample. For this purpose we used an experimental design, and utilized high performance liquid chromatography (HPLC-DAD) and micellar electrokinetic chromatography (MEKC) techniques with diode array detector in both of them. The limit of detection/quantification for MEL, AFMK and AMK were respectively 44/94, 18/38 and 23/51 ng mL(-1) by using HPLC and 13/44, 37/124 and 47/156 ng mL(-1) by using MEKC. This is the first time that these compounds have been separated in the same chromatogram or electroferogram. The time of analysis was faster using MEKC. Furthermore, this technique showed better resolution but HPLC offered better limit of detection and quantification for metabolites. Both methods were validated and correlation coefficients were higher than 0.999 and the range of recovery of those methods were 99.6-103.7%. Precision was evaluated as repeatability and intermediate precision with relative standard derivation <5%. When a 5 microg mL(-1) solution of these compounds were analyzed with both methods we do not observed any statistically significance differences. Moreover, we analyzed 3COHM (cyclic-3-hydroximelatonin), another known metabolite of melatonin, by using the same methods. The employment of these methods will offer a useful tool to contribute to answer the role of MEL, AFMK and AMK in biological system and both methods can be used in routine analysis for these compounds.

Rotura hepática espontánea en el embarazo sin asociación con preeclampsia / Spontaneous liver hematoma in pregnancy without associated preeclampsia

Presentamos un caso de rotura hepática espontánea con formación de un gran hematoma que afectaba a los dos lóbulos hepáticos, de aparición durante el trabajo de parto, sin relación con la hipertensión inducida por la gestación ni con ninguna otra alteración hepática de base. Los resultados perinatales y maternos han sido excelentes (AU)

Acute mercury vapour intoxication: report of six cases.

In a group of six workers acutely exposed to metallic mercury vapour in a confined space, one patient had acute renal and respiratory failure which required daily haemodialysis and mechanical ventilation, another had acute bilateral pneumonitis with respiratory insufficiency, and the other four had corrosive oropharyngeal mucositis with a 'flu-like syndrome. Serum and urinary mercury showed an obvious correlation with the clinical picture. After removal from the source of exposure and the institution support measures (including chelant therapy in the first two patients), all recovered without evidence of residual damage.

Ultrastructure of gland cells associated with the chaetal follicles in the clitellar region of Lumbricus friendi Cognetti, 1904 (Oligochaeta).

The ultrastructure of the gland cells associated with the chaetal follicles of the ventral clitellar epithelium is described in the earthworm Lumbricus friendi. Regarding their secretory granules, two cell types (GS1 and GS2) have been identified. Secretory granules of both cell types show a large, electron-dense core which is homogeneous in the GS1 type and irregularly shaped in the GS2 type. Crystalline inclusions embedded in the GS1 granule matrix is characteristic of the GS1 cell type. Both types of secretory granules are directly extruded by exocytosis into the chaetal follicle lumen. The basal regions show the typical cytological features of cells which are capable of synthesis of both protein and complex carbohydrates. The results and the functional significance of the two cell types studied are discussed and compared with that is known in other lumbricids.