Biomedical subjects

Kenneth Ward

Publications and source records attributed to Kenneth Ward.

22 records · Page 2Linked to original sources

PubMed2002

Effects of dietary sodium and genetic background on angiotensinogen and Renin in mouse.

Elements of a renin-angiotensin system expressed along the entire nephron, including angiotensinogen secreted by proximal tubule and renin expressed in connecting tubule, may participate in the regulation of sodium reabsorption at multiple sites of the nephron. The response of this tubular renin-angiotensin system to stepwise changes in dietary sodium was investigated in 2 mouse strains, the sodium-sensitive inbred C57BL/6 and the sodium-resistant CD1 outbred. Plasma angiotensinogen was not affected by sodium regimen, whereas plasma renin increased 2-fold under low sodium. In both strains, the variation in urinary parameters did not parallel the changes observed in plasma. Angiotensinogen and renin excretion were significantly higher under high sodium than under low sodium. Water deprivation, by contrast, induced significant activation in the tubular expression of angiotensinogen and renin. C57BL/6 exhibited significantly higher urinary excretion of angiotensinogen than did CD1 animals under both conditions of sodium intake. The extent to which these urinary parameters reflect systemic or tubular responses to challenges of sodium homeostasis may depend on the relative contribution of sodium restriction and volume depletion.

Aldosterone↗

PubMed2001

Angiotensinogen in essential hypertension: from genetics to nephrology.

There is general consensus that genetic variation accounts in part for individual susceptibilities to essential hypertension. In marked contrast to classic mendelian disorders, in which genetic alterations produce a gain or loss of function, genetic determinants of essential hypertension, high blood pressure of unknown cause, are expected to be small, achieving significance through the cumulative effects of environmental exposure over the course of a lifetime. Whether and how genetic factors that contribute to common diseases can be identified remain unclear. Research on a link between angiotensinogen and essential hypertension illustrates a path that began in genetics and is now leading toward nephrology. Various challenges encountered along the way may prove to be characteristic features of genetic investigations of the pathogenesis of common diseases. The implication of a gene by statistical analysis is only the beginning of a protracted process of functional analysis at increasing levels of biologic integration. The ultimate goal is to develop an understanding of the manner in which genetic variation at a locus can affect a physiologic parameter and to extract from this inference new knowledge of significance for the prevention or treatment of disease.

Alleles↗

PubMedDate not supplied

Renal hypertrophic infundibular stenosis.

Bilateral hydrocalycosis secondary to radiographically demonstrated bilateral infundibular stenosis required a left nephrectomy in an 18-year-old young man. The infundibular narrowing was due to marked hyperplasia of the submucosal smooth muscle. Scattered within the hypertrophic smooth muscle were rare spindled CD117-positive interstitial cells, similar to the cells responsible for peristaltic pacemaker activity within the gastrointestinal tract. The admixture of CD117 cells suggests this is a true muscular hyperplasia rather than a leiomyomatosis. The stimulus to the hyperplasia is unknown.

Adolescent↗

PubMedDate not supplied

Congenital subcutaneous dendritic cell rich lymphoepithelial hamartoma.

We present the clinical, radiologic, histologic, immunohistochemical, and ultrastructural characteristics of a congenital pretibial subcutaneous lesion composed of a mixture of T and B cells, epithelial cells, and dendritic cells, probably representing a hamartoma. After total removal, there has been no recurrence. The prominent dendritic component of this lesion, demonstrated immunohistochemically and ultrastructurally, separates the lesion from cutaneous lymphadenoma and other adnexal tumors.

B-Lymphocytes↗