In situ flow cell platform for examining calcium oxalate and calcium phosphate crystallization on films of basement membrane extract in the presence of urinary ‘inhibitors’

The development of a flow-cell platform is reported that utilizes basement membrane extract as a biologically relevant crystallization substrate to study the effect of urinary inhibitors on the in situ formation of calcium oxalate/phosphate.

Effect of Age, Sex and Pregnancy on Levels of Urinary Inhibitors of mineralization in Human Beings

Background: Based upon the differences observed in the level of urinary inhibitors between adult normal subjects of both sexes and kidney stone patients of identical sex, it has been postulated that urinary inhibitors play an important role in the control of pathological mineralization. Review of literature revealed that corresponding studies on the level of urinary inhibitors in children of both sexes and during various stages of pregnancy are not available. These studies, so important to investigate the role of inhibitors in physiological mineralization, formed the objective of the present study. Materials and Methods: Homogenous system of In vitro mineralization was employed to study not only the extend of mineralization and the effect of various urine samples obtained from normal subjects of both sexes and pregnant females at various trimesters of pregnancy on extend of mineralization but also to quantify the level of the inhibitors. Results: Using in vitro system of mineralization (precipitation of Ca2+ or HPO4 2- ions as mineral phase), it has been shown that in contrast to the adult human beings, in children of less than 13 years of age no significant differences exists in the level of the urinary inhibitors between males and females children provided experimental support to the epidemiological studies on the occurrence of the renal calculosis problem in both sexes of children and adult human beings. The findings that the level of the urinary inhibitors of mineralization in both sexes of children is as high as present in adult females and that a highly significant decrease in their levels occurs during the 3rd trimester of pregnancy strongly suggests that hormones may be playing an important role in regulating their levels. Conclusion: Inhibitors of mineralization excreted in urine of normal healthy subjects of both sexes of Children (<13 years), adults (>20 years), kidney stone patients at these ages, non pregnant and pregnant females (during various trimesters of pregnancy) have been postulated to play an important role in the control of both physiological and pathological mineralization.DOI: http://dx.doi.org/10.3126/nje.v4i4.11360 Nepal Journal of Epidemiology 2014; 4(4):399-404