Thrombocytosis in Whipple's disease.

Three men with Whipple's disease had platelet counts of 729,000-1,142,000 per mm3, which fell to normal as their illness responded to antibiotic therapy. Reports on Whipple's disease and hospital charts from the largest published series reveal thrombocytosis in 11 of the 24 patients whose counts were recorded. The prevalence of anemia, marrow infiltration, and classic manifestations of Whipple's disease did not differ between patients with and without thrombocytosis. The thrombocytosis of Whipple's disease is similar to that of celiac sprue, Crohn's disease, and ulcerative colitis.

Liver arginase activity and plasma urea-nitrogen in steers fed diets containing different levels of protein.

Seventeen Charolais-Hereford crossbred steers averaging 220.0 kg in weight initially were randomly allotted to three treatments and fed diets containing (A) 9%, (B) 11%, or (C) 13% protein ad libitum in individual pens for 238 days. Liver samples were taken by aspiration biopsy on days 47 (sampling I) and 238 (sampling II) for arginase assay. Blood samples were taken by jugular puncture at these same times for plasma urea-nitrogen analysis. Mean hepatic arginase activities (mumole urea/mg protein/hr) of steers fed the three diets at sampling I were: (A) 224.8, (B) 327.8 and (C) 333.3. The activities of B and C were significantly (P less than .05) higher than A. Plasma urea-N levels at this same time averaged: (A) 4.44, (B) 8.55 and (C) 12.22 mg/100 ml, and were significantly different (P less than .01) from each other. Arginase activities at sampling II were: (A) 240.6, (B) 305.2 and (C) 353.0. A differed significantly (P less than .05) from C. Plasma urea-N at this time averaged: (A) 8.69, (B) 10.72 and (C) 15.00 mg/100 ml, and C was significantly (P less than 5.0) higher than A and B. These data suggest that in the bovine hepatic arginase activity levels increase with increases in dietary protein and that similar patterns in activity are maintained after feeding for an extended period of time. The increased arginase activity was accompanied by increased plasma urea-nitrogen.

Urea cycle enzyme activity in lambs fed different nitrogen levels at low dietary intakes.

Eleven Southdown male lambs averaging 19.8 kg were randomly allotted to two groups and fed diets containing 7.7% (low-N) or 15.8% (high-N) crude protein. All of the supplemental nitrogen in the high-N diet was supplied as urea. Intake of the low-N and high-N diets averaged 372.3 g and 340.5 g/day, respectively. Findings at the end of the thirty-day trial were: (1) mean body weights unchanged for the two groups; (2) plasma urea nitrogen three-fold higher in the high-N (19.07 mg/100 ml) than the low-N (6.57) animals; (3) similar hepatic activity levels of three urea cycle enzymes (ornithine transcarbamylase, argininosuccinase, arginase) in the two groups, and (4) similar liver weights and liver protein concentration. The absence of adaptive change in enzyme levels suggests the hypothesis that addition of non-protein nitrogen to maintenance diets may cause ammonia intoxication by exceeding the liver's reserve capacity for urea synthesis.

Effect of age on activities of urea cycle enzymes in the bovine.

Eighteen Hereford cows averaging 429.6 +/- 14.5 kg in weight, ranging from 3.33 to 12.12 years of age and consuming 18.2 kg corn silage/animal/day were used to observe the effect of age on activities of the liver enzymes of urea synthesis. Liver samples were taken by aspiration biopsy and homogenized in water for enzyme assay. Plasma urea-nitrogen of all cows averaged 4.20 mg per 100 ml. The enzymes measured were: carbamyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), argininosuccinate synthetase (AS), argininosuccinase (AL) and arginase (A). Mean enzyme activities of the cows were: CPS 1.57, OTC 44.4, AS 0.61, AL 1.05 and A 203.9 mum product/mg protein/hr. Regression coefficients (b) of enzyme activity (units) on age (years) were 0.021 +/- .018, 0.713 +/- .379, 0.016 +/- .016, 0.032 +/- .014 and 6.73 +/- 5.09 units for the five enzymes, respectively. Age (3.3 to 12.1 years) did not significantly (P less than .05) affect activities of the urea cycle enzymes (per mg protein, per g liver or per W-75 kg/hr) or plasma urea-nitrogen levels in the adult Hereford female at the level of dietary protein fed in this study.

Urea cycle enzyme adaptation to dietary protein in primates.

Activities of the five hepatic enzymes of the urea cycle increased two- to threefold in monkeys on a 60 percent protein diet compared with levels in monkeys on an isocaloric 6 percent protein diet. Equal adaptation occurred in rats on the same diets. These enzyme activities in adult humans approximate those of monkeys on a similar protein intake.