An increased frequency of kidney stone formation is reported in patients with inflammatory bowel disease. In order to investigate its pathogenesis, the concentrations of factors known to enhance calcium oxalate stone formation (oxalate, calcium, uric acid) as well as of inhibitory factors for nephrolithiasis (magnesium, citrate) were determined in the urine of 86 patients with Crohn's disease and compared with those of 53 metabolically healthy controls. Six patients with Crohn's disease already had experienced calcium oxalate nephrolithiasis. Patients with Crohn's disease had significantly higher urinary oxalate and lower magnesium and citrate concentrations. Among all patients magnesium and citrate were significantly lower in those with a positive history of kidney stones. Our results demonstrate that the increased propensity for renal stone formation in patients with Crohn's disease is a result not only of increased urinary oxalate, but also of decreased urinary magnesium and citrate concentrations.

In five patients with benign transient hyperphosphatasaemia (THP), high activities of so-called "atypical" alkaline phosphatase or fragment isoenzymes were detected. One case occurred after rotavirus infection. Incubation with neuraminidase suggested that "atypical" alkaline phosphatase originated from highly glycosylated bone and liver isoenzymes. This may have been due to virus-induced low isoenzyme clearance from serum. The course of isoenzyme activities in THP following rotavirus infection was followed. Determination of atypical alkaline phosphatase may be useful in the diagnosis of THP.

A new method for the Separation of alkaline phosphatase isoenzymes by means of high performance liquid chromatography (HPLC) is presented. One isoenzyme was identified in homogenate of small intestine, two were identified in bone, and two in liver, and fragment and biliary isoenzymes were identified in bile. Sera from 32 patients with different diseases of the skeletal System or the liver were analysed. High activities of the bone isoenzymes were detected in bone diseases, of the second liver isoenzyme in acute hepatitis and of the first liver and biliary isoenzymes in biliary obstruction. There are indications that the first liver isoenzyme is derived from the cell membrane and the second liver isoenzyme from the cytosol. The biliary isoenzyme is considered to be a highly sensitive and specific indicator for cholestasis.

Department o f P a e d i a t r i c Nephrology, I n s t i t u t e of Child H e a l t h , London, UK. Hypertension may be due t o volume o v e r l o a d , t h e p r e s s o r e f f e c t o f c i r c u l a t i n g a g e n t s such a s r e n i n o r , t h e o r e t i c a l l y , t o reduced l e v e l s o f c i r c u l a t i n g v a s o d i l a t o r a g e n t s . C e r t a i n p r o s t a g l a n d i n s , e.8. PGE a r e known v a s o d i l a t o r s .The r e n a l medulla is known t o be a s o u r c e o?PGE , kidney damage could t h e r e f o r e r e s u l t i n reduced production and henge c o n t r i b u t e t o t h e development of h y p e r t e n s i o n . Experimental work s u g g e s t s t h a t t h e r e is decreased p r o d u c t i o n o f PGE i n a r e a s o f induced r e n a l s c a r r i n g . W e have p r e v i o u s l y e s t a b l i s h e d 2 a normal r a n g f o r t h e 24 hour u r i n a r y e x c r e t i o n o f PGE , PGF , 6 k e t o PGF and thromboxane B (TXB ) and have shown t h a z rela$?ng t h e v a l u e s l a o b t a i n e d t o u $ i n a r y 2 c r e a t i n i n e ( C r ) is t h e most u s e f u l index of PG e x c r e t i o n . We t h e r e f o r e s t u d i e d a group of c h i l d r e n w i t h secondary h y p e r t e n s i o n (due t o r e f l u x nephropathy o r r e n o v a s c u l a r d i s e a s e ) and compared them w i t h normal c h i l d r e n and with c h i l d r e n with primary hypertension.24 hour u r i n e c o l l e c t i o n s were obtained from hypert e n s i v e c h i l d r e n a t d i a g n o s i s , and random u r i n e specimens c o l l e c t e d a t follow-up c l i n i c v i s i t s . No d i f f e r e n c e s were found between hypert e n s i v e s and normals i n t h e PG:Cr r a t i o s f o r PGF , 6 k e t o PGF and TXB2 ,However, PGE :Cr r a t i o s were s u b s t a n t % l y reduced iff c h i l d r e n wlth secondary2hypertension when compared with normal (7.7 vs 17.5 nglmmol C r ) . Children with e s s e n t i a l h y p e r t e n s i o n had PGE .Cr r a t i o s a t t h e lower end of t h e normal range. Our d a t a 2 ' demonstrate reduced PGE e x c r e t i o n i n secondary h y p e r t e n s i o n , which may be a c o n t r i b u t o r y f g c t o r j n i t s development,, plasma dopmlne, noradrenallne, adrenaline and renln-activity were measured I n 39 subJects r l t h stable m l l d hypertenslon (mean age 23.9 years, 34 males), and I n 39 ag-matched normotenslve controls f r m the same opengopulatlon. Mean s l t t l n g b l m d pressure I n hypertenslves was 142/82 mug. I n normotenslves average blood pressure ras 125/74 mug. Plasma catecholmlnes were measured r l t h a CCMT radloenrymatlc assay. plasma dopmlne r a s s l g n l f l c a n t i y higher I n hypertenslves (72 + SE 7 pg/rnl) than I n normotenslves (46 + SE 4 pg/ml; p<0.01 I. The sane Tas t r u e f o r naadrenallne (302 + SE T 3 pglnl I n hypertenslves, and 157 + SE 9 pg/ml I n nwmoten?ives; p<0.0011, and for sdrenal lne (91 + SE l y p g / m l I n hypertenslves and 38 + SE 4 pg/ml I n nwmotenslves; -p'0.0...

15 male rabbits were divided into three groups. The animals in group 1 were splenectomized. In group 2 pulpa tissue from the cut surface of the spleen was left in the abdominal cavity. Group 3 was sham operated. After 15 months all animals from group 2 showed particles of histologically intact splenic tissue mainly on the parietal peritoneum of the abdominal wall. The implications of the autoimplantation of splenic tissue during splenectomy are discussed.