Diabetes is associated with a higher risk of mortality among women in a middle-income country: Results form the Mexican Teacher's cohort study.

AIMS: In Mexico City, the mortality rate among patients with diabetes appears to be four times that of people without diabetes. Our study aimed to refine analyses of the impact of diabetes on mortality in a large cohort of women from different areas in Mexico with healthcare insurance. METHODS: Our study followed 111,299 women with comprehensive healthcare coverage from the Mexican Teachers' Cohort. After a median follow-up of 7.8years, 5514 (5%) prevalent self-reported diabetes cases and 4023 incident cases were identified, while deaths were identified through employers' databases and next-of-kin reports, with dates and causes of death for 1121 women obtained from mortality databases. Hazard ratios (HRs) for total and cause-specific mortality were estimated by Cox regression models, using follow-up time as the time scale and allowing for time-variable diabetes status after adjusting for age, socioeconomic status, use of health services, and anthropometric and lifestyle variables. RESULTS: In multivariable-adjusted models, the HR for all-cause mortality was 3.28 (95% CI: 2.86-3.75) in women with vs. without diabetes. The impact of diabetes on mortality was higher in rural vs. urban areas (HR: 4.72 vs. 2.98, respectively). HRs were 1.57 and 23.44 for cancer and renal disease mortality, respectively. CONCLUSION: In women with healthcare coverage in Mexico, the magnitude of the association between diabetes and all-cause mortality was higher than that observed in high-income countries, but less than what has previously been reported for Mexico. Such elevated mortality suggests a lack of adequate access to quality diabetes care in the population despite comprehensive healthcare coverage.

Plasmodium vivax: ookinete destruction and oocyst development arrest are responsible for Anopheles albimanus resistance to circumsporozoite phenotype VK247 parasites.

Anopheles albimanus and An. pseudopunctipennis differ in their susceptibilities to Plasmodium vivax circumsporozoite phenotypes. An. pseudopunctipennis is susceptible to phenotype VK247 but almost refractory to VK210. In contrast, An. albimanus is almost refractory to VK247 but susceptible to VK210. To investigate the site in the mosquito and the parasite stage at which resistance mechanisms affect VK247 development in An. albimanus, parasite development was followed in a series of experiments in which both mosquitoes species were simultaneously infected with blood from patients. Parasite phenotype was determined in mature oocysts and salivary gland sporozoites by use of immunofluorescence and Western blot assays and/or gene identification. Ookinete maturation and their densities within the bloodmeal bolus were similar in both mosquito species. Ookinete densities on the internal midgut surface of An. albimanus were 4.7 times higher than those in An. pseudopunctipennis; however, the densities of developing oocysts on the external midgut surface were 6.12 times higher in the latter species. Electron microscopy observation of ookinetes in An. albimanus midgut epithelium indicated severe parasite damage. These results indicate that P. vivax VK247 parasites are destroyed at different parasite stages during migration in An. albimanus midguts. A portion, accumulated on the internal midgut surface, is probably destroyed by the mosquito's digestive enzymes and another portion is most likely destroyed by mosquito defense molecules within the midgut epithelium. A third group, reaching the external midgut surface, initiates oocyst development, but over 90% of them interrupt their development and die. The identification of mechanisms that participate in parasite destruction could provide new elements to construct transgenic mosquitoes resistant to malaria parasites.

Description and morphometric analysis of the eggs of Anopheles (Anopheles) vestitipennis (Diptera: Culcidae) from southern Mexico.

Light and scanning electron microscopy were used to compare the eggs of Anopheles vestitipennis Dyar & Knab females collected from human and animal baits in 9 villages of southern Mexico. An. vestitipennis eggs are boat-shaped, with lateral floats extending the length of the egg. Both the deck and dorsal surface are covered with hexagonal and pentagonal chorionic cells that contain round tubercles in the cell field. Crowns that enclose 3-5 lobed tubercles are present at both egg poles. By light microscopy, the mean length/width ratio of eggs of females caught at human bait were statistically different from those of females caught in horse-baited animal traps. In a regression tree model that included 19 egg attributes, the same egg groups could be separated by their posterior crown length/width ratio and mean anterior cell deck form factor (an index of their roundness). These findings support of the possible existence of 2 An. vestitipennis subpopulations with different host preferences in southern Mexico.