A major assumption of the biometric analysis of infant mortality as developed by Bourgeois-Pichat is that the age structure of infant deaths after the first month of life is virtually constant across time and cultures. Reanalysis of results from studies which compare the mortality of infants according to the type of feeding indicated that the relationship between mortality and age within the first year of life followed different patterns for breast fed and artificially fed infants. Historical data for populations with different breast feeding customs reveal similar differences in the age pattern of infant mortality. In populations where breast feeding was uncommon or of very short duration, infant mortality rises particularly steeply during the early months of the first year of life. The age structure of infant mortality in less developed countries where breast feeding is decreasing rapidly may bsimilarly affected. When substantial deviations from the linear relationship are evident, particular caution is required in applying the biometric technique, since in such situations the estimated endogenous mortality is very much affected by the particular set of data points within the first year of life which are chosen for the basis of the estimates.

Prostaglandin E2 , which is known to contribute to cancer progression, is inactivated by the catabolic enzyme, 15-hydroxyprostaglandin dehydrogenase (PGDH), which has tumor-suppressor activity in lung, colon, breast, and gastric cancers. Therefore, we evaluated the expression of PGDH in human bladder cancer tissue specimens and cell lines. Immunoperoxidase staining of bladder cancer tissues demonstrated that (1) PGDH is highly expressed by normal urothelial cells but (2) reduced in many low stage (Ta/Tis) bladder cancers, and (3) PGDH is completely lost in most invasive bladder cancers. Of eight cancer cell lines tested, only two relatively well-differentiated bladder cancer cell lines, RT4 and UM-UC9, expressed PGDH. Moreover, inhibition of PGDH expression in well-differentiated RT4 cells using small inhibitory RNA or short hairpin RNA resulted in a more aggressive phenotype with increased motility and anchorage-independent growth. Additionally, PGDH knockdown affected prostaglandin E2 signaling as measured by cAMP generation. These data indicate that loss of PGDH expression contributes to a more malignant bladder cancer phenotype and may be necessary for bladder cancer development and/or progression. (Am J

This article describes trends and regional differences in breastfeeding within Germany from 1870 to 1937. Sharp regional differences in both the incidence and duration of breastfeeding are present around 1910. There is a complex pattern of trends in infant-feeding practices. Breastfeeding declined in urban areas between the late nineteenth century and the first World War. A strong nationwide resurgence in the incidence of breastfeeding occurred between the two world wars, accompanied by a decline in the average duration of breastfeeding. By 1937, the formerly great regional differences in breastfeeding had nearly disappeared. The article also discusses social, economic, cultural, and historical variables affecting infant-feeding practices, including local breastfeeding customs, a national infant welfare campaign, and allowances to nursing mothers.

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