Lithogenic risk factors in the urine of black and white subjects.

OBJECTIVE: To identify biochemical and dietary factors which may play a role in the low incidence of stone formation in the black South African population. SUBJECTS AND METHODS: The study included 31 semiurbanized black and 29 urbanized white subjects. The protocol and modern laboratory techniques used to assess recurrent stone formers were followed. Urinary sodium, potassium, creatinine, calcium, phosphate and urate levels were measured, and urinary citrate, oxalate and cystine assessed. RESULTS: Black subjects ate a diet significantly higher in sodium (P < 0.04); there was no difference in serum levels but urinary sodium was significantly higher (P < 0.001) in black than in white subjects. Urinary potassium, calcium, citrate, phosphate and cystine were all significantly lower in black than in white subjects (P < 0.001 for the first four and P < 0.03 for cystine). CONCLUSION: Certain intrinsic factors in South African black subjects may account for their lower frequency of stone formation than in white subjects. Of these, the very low urinary calcium, decreased urinary cystine and different interactions between sodium and calcium/cystine are probably important.

Large-vein, thrombotic, hepatic venous outflow obstruction (Budd-Chiari syndrome). A case report.

A patient with Budd-Chiari syndrome caused by large-vein, thrombotic, hepatic venous outflow obstruction, who was initially treated conservatively, is presented. The hazards of this approach are emphasised. Accurate classification of Budd-Chiari syndrome and active treatment tailored to the site and nature of the hepatic venous outflow obstruction are indicated to prevent progressive hepatic damage leading to chronic liver failure, portal hypertension and eventual death.

Anal canal adenocarcinoma. A report of 4 cases.

Although rare, adenocarcinoma of the anal canal may be more common than previously thought in populations with a high incidence of peri-anal sepsis. Four such cases are presented and published reports reviewed. To avoid unnecessary delays in diagnosis, the clinician must adopt a high index of suspicion when dealing with chronic peri-anal disease. More regular follow-up examinations and biopsies of suspicious lesions are necessary. Since the origin and histological appearance of these tumours are often not clear cut, both clinician and pathologist must work closely together when correlating their findings. Until recently, the vast majority of cases have been managed surgically, and a concerted effort needs to be made to evaluate the role of chemoradiotherapy and preoperative radiotherapy as therapeutic modalities.