Comparison of serum parathyroid hormone and ionized calcium and magnesium concentrations and fractional urinary clearance of calcium and phosphorus in healthy horses and horses with enterocolitis.

OBJECTIVE: To evaluate calcium balance and parathyroid gland function in healthy horses and horses with enterocolitis and compare results of an immunochemiluminometric assay (ICMA) with those of an immunoradiometric assay (IRMA) for determination of serum intact parathyroid hormone (PTH) concentrations in horses. ANIMALS: 64 horses with enterocolitis and 62 healthy horses. PROCEDURES: Blood and urine samples were collected for determination of serum total calcium, ionized calcium (Ca2+) and magnesium (Mg2+), phosphorus, BUN, total protein, creatinine, albumin, and PTH concentrations, venous blood gases, and fractional urinary clearance of calcium (FCa) and phosphorus (FP). Serum concentrations of PTH were measured in 40 horses by use of both the IRMA and ICMA. RESULTS: Most (48/64; 75%) horses with enterocolitis had decreased serum total calcium, Ca2+, and Mg2+ concentrations and increased phosphorus concentrations, compared with healthy horses. Serum PTH concentration was increased in most (36/51; 70.6%) horses with hypocalcemia. In addition, FCa was significantly decreased and FP significantly increased in horses with enterocolitis, compared with healthy horses. Results of ICMA were in agreement with results of IRMA. CONCLUSIONS AND CLINICAL RELEVANCE: Enterocolitis in horses is often associated with hypocalcemia; 79.7% of affected horses had ionized hypocalcemia. Because FCa was low, it is unlikely that renal calcium loss was the cause of hypocalcemia. Serum PTH concentrations varied in horses with enterocolitis and concomitant hypocalcemia. However, we believe low PTH concentration in some hypocalcemic horses may be the result of impaired parathyroid gland function.

Nitric oxide end products in patients hospitalized for diarrhoea.

OBJECTIVE: Increased nitric oxide (NO) has been demonstrated in inflammatory bowel diseases (IBD). Plasma and urinary nitrite and nitrate are usually considered to reflect global NO generation. Recently it has been suggested that plasma nitrate may be a discriminant indicator between infectious enterocolitis (IC) and IBD. To investigate this hypothesis we compared plasma and 24 h urinary nitrite and nitrate in 13 healthy controls, 44 patients with IBD [Crohn's disease (CD) n = 30; ulcerative colitis (UC) n = 14], 16 patients presenting with IC and seven chronic radiation enterocolitis (RE) patients. RESULTS: Despite a trend towards higher plasma nitrate in IC (54.6+/-11.4 micromol/l) than in the other groups (CD: 38.4+/-4.8, UC: 34.8+/-8.4, RE: 34.7+/-7.5, controls: 31.1+/-5.2), this difference was not statistically significant. Urinary nitrate was higher in IBD, IC and RE than in controls, with no difference between these groups. Nitrite concentrations were not different. Nitrate levels were positively correlated with blood and 24 h urinary neopterin (e.g. plasma nitrate and blood neopterin: r = 0.54, P<0.0001), and in some cases, to C-reactive protein. CONCLUSIONS: High nitrate (in our case only urinary nitrate) appears to be secondary to the magnitude of the inflammation rather than the aetiology of the diarrhoea. It should therefore more likely be considered as a marker of the severity of the inflammatory response rather than used as a discriminant indicator between IC and IBD patients.

Neutropenic enterocolitis associated with autologous bone marrow transplantation.

Fatal neutropenic enterocolitis was seen in a patient undergoing autologous bone marrow transplantation for non-Hodgkin's lymphoma. Excessive drug action due to a mildly diminished creatinine clearance could have contributed to the pathogenesis. Computed tomographic scanning and ultrasonography demonstrated pneumatosis of the gastrointestinal tract, but the disease had become extensive by then. Necrotizing enterocolitis should be suspected early in a granulocytopenic patient with abdominal pain and diarrhea or vomiting. Aggressive surgical or medical management may avoid a fatal outcome.