Presence Of Multiple Defects Research Articles

Completeness of the Discharge Diagnoses as a Measure of Birth Defects Recorded in the Hospital Birth Record

Licensed hospitals usually maintain a discharge diagnoses index, which provides an inexpensive tool for the surveillance of birth defects diagnosed shortly after birth. Government agencies in several states routinely use discharge diagnoses for this purpose. To evaluate the completeness of the discharge diagnoses, the authors compared birth defects noted in the discharge diagnoses with those noted anywhere in the hospital birth record in a cohort of 3,421 infants born to US Army veterans from 1966 to 1986. In this cohort, 237 birth defect cases were documented in hospital birth records, and 49% of those cases were missed in the discharge diagnoses (28% of major defect cases and 66% of minor defect cases). The extent of missed defects varied greatly by organ system and by specific defect. Significant predictors of a missed defect were the presence of multiple defects, female sex, and western region of birth. The underascertainment of defects in the discharge diagnoses should be considered in the development and operation of surveillance systems using this source of data.

Water balance in the Brattleboro rat: single or multiple defects?

The total restoration of urinary concentrating ability of the DI rat given daily injections of vasopressin takes several weeks, although complete osmotic equilibrium across the collecting duct is manifest within hours. This suggests that there may be other deficiencies of the renal concentrating mechanism that, if corrected by vasopressin treatment, are corrected more slowly. I have focussed on just three possibilities. First, the morphology of the medullary interstitium is different from normal rats. Perhaps associated with this finding are alterations in the levels of medullary glycosaminoglycans which may have a role to play in water balance. Functional and morphological changes in the juxtamedullary nephrons are also evident. Second, the possibility exists that the countercurrent multiplier of the DI rat operates less efficiently than in the normal animal. Finally, reduced synthesis of PGs in the renal medulla of DI rats may also influence the concentrating mechanism, although in a favorable direction. While most (if not all) of these differences are secondary to the lack of vasopressin, in some instances it appears that it is the high water turnover (possibly the altered chemical composition of the medullary interstitium) that is the primary culprit. While the DI rat remains an excellent model for the study of water balance and the action of vasopressin, the presence of multiple defects within the system should be borne in mind. This is particularly true when comparing data obtained following acute treatment with vasopressin versus that following chronic treatment.