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J K Platts

Publications and source records attributed to J K Platts.

5 recordsLinked to original sources
PubMed2000

The relation between tissue kallikrein excretion rate, aldosterone and glomerular filtration rate in human pregnancy.

The changes in renal kallikrein synthesis through normal pregnancy and its relation to aldosterone excretion and the glomerular filtration rate was investigated. Overnight urinary kallikrein and aldosterone excretion rates and glomerular filtration rate were measured at 18 weeks, 34 weeks, term and postpartum in normal human pregnancy. Kallikrein excretion was raised at 18 weeks compared with the nonpregnant state (P < 0 x 001) but was significantly reduced at term. The reduction in renal kallikrein was not due to falling aldosterone concentration, which increased in the third trimester, compared with 18 weeks (P = 0 x 002) and remained elevated at term compared with the nonpregnant state (P < 0 x 001). Glomerular filtration rate remained elevated at term despite the reduced kallikrein excretion rate. These data are consistent with the hypothesis that increased aldosterone production is one factor responsible for increased kallikrein synthesis which contributes to elevated glomerular filtration rate in early pregnancy. Other factors clearly inhibit renal kallikrein production at term. In the face of plasma volume expansion associated with increased mineralo-corticoid production, the effects of reduced kallikrein synthesis at term on glomerular perfusion and reabsorption of sodium by the distal tubule may predispose to blood pressure elevation in late pregnancy.

Aldosterone↗
PubMedDate not supplied

Death from phaeochromocytoma: lessons from a post-mortem survey.

Despite advances in biochemical assessment and imaging, phaeochromocytoma remains a difficult diagnosis. Using the names of patients whose death certificate listed phaeochromocytoma as a cause of death, a retrospective survey of 62 deaths from phaeochromocytoma (48 benign, 14 malignant) was carried out. All deaths occurred between 1981 and 1989, so the pitfalls uncovered reflect recent practice. A substantial proportion presented with abdominal pain and vomiting, dyspnoea, left ventricular failure or hypotension rather than the classical symptoms. These presentations were more common in this autopsy series than in prospective series of consecutive patients. Diagnosis in the presence of classical symptoms was often delayed but, once it was made, elective excision was relatively safe. A personal or family history of symptoms suggesting inherited diseases associated with phaeochromocytoma was not always given due weight. Biochemical tests, particularly 24 hour urinary vanillyl mandelic acid, often gave contradictory results; the limits of their predictive power should be better appreciated. Anaesthesia and surgery in the presence of undiagnosed phaeochromocytoma was the cause of death in 16 of 62 cases. Recommendations to improve the accuracy of diagnosis are made.

Adolescent↗