Accidental monensin poisoning in goats.

Sodium monensin is the most frequently used ionophore as a growth promoter in ruminant diets. It has numerous benefits; however its toxic effects have also been observed in several animal species. Naturally occurring cases have not yet been reported in goats. This study describes an outbreak of accidental poisoning, characterizing its clinical, laboratory and pathological findings. Thirty-seven of 40 Anglo Nubian goat kids became intoxicated after receiving a diet that was erroneously supplemented with sodium monensin. They ingested an estimated toxic dose between 25 and 39 mg/kg BW. Clinical evolution was monitored (n = 27), followed by serum creatine kinase (CK) and aspartate aminotransferase (AST) activities measurements, and blood gas analysis. Postmortem examinations were performed between 1 and 8 days of evolution (n = 14). Clinical signs began 5 h after ingestion and included reticuloruminal hypomotility, lethargy, anorexia, tachycardia, cardiac arrhythmia, wet cough, pulmonary and tracheal crackles, and serous nasal discharge. The morbidity and lethality rates were 92.5 and 62.1%, respectively. CK and AST activities increased, reaching median values of 10,860 and 1596 U/L, respectively; the hyperchloremic metabolic acidosis was mild. The lesions were characterized by degeneration and necrosis of the cardiac and skeletal muscles, pulmonary congestion and edema, and passive liver congestion. The kids essentially developed cardiomyopathy with left and right congestive heart failures. Unlike in other ruminant species, skeletal muscle functional disability was infrequent. It can be concluded that monensin is toxic to goats and should be used with caution in their diet.

A semiquantitative approach to the evaluation of acute cardiac allograft rejection at endomyocardial biopsy.

BACKGROUND: Histopathologic criteria for grading of acute cardiac allograft rejection are focused on the most severe lesion that is recognized among the myocardial fragments provided by each endomyocardial biopsy specimen. Considering the distribution of rejection lesions among all the fragments improved the accuracy in characterizing the severity of rejection in pathologic studies. This study was undertaken to verify the usefulness of a semiquantitative evaluation of endomyocardial biopsy specimens, consisting of the calculation of the proportion of fragments showing rejection in the clinical setting. METHODS: Of the 2386 biopsy specimens obtained during the first posttransplantation year in 168 consecutive cardiac allograft recipients, 290 biopsy specimens constituted by > or = 3 adequate fragments and showing rejection not followed by treatment (n = 159) or being the first biopsy specimen prompting treatment with augmented immunosuppression for that rejection episode (n = 131) were selected. These biopsy specimens (index biopsy specimens) were grouped according to whether rejection was present in < or = 33%, > 33% to < or = 67%, and > 67% of the fragments. The rejection grade (according to the standardized grading system) and the proportion of fragments positive for rejection were correlated with the occurrence of clinical symptoms and signs of rejection at index biopsy and with the results of the next biopsy. RESULTS: Rejections graded > or = 3A were more frequently symptomatic (36% vs 9% for those graded < 3, p < 0.0001), as were those involving increasing proportions of fragments (< or = 33%: 5 of 124, 4%; > 33 to < or = 67%: 13 of 99, 13%; > 67%: 19 of 67, 28% [p < 0.0001]). Spontaneous resolution after untreated biopsies was more frequent in focal (grade 1A and 2) than in diffuse mild (1B) rejections (68% vs 38% [p < 0.04]), whereas progression to grade 3A or greater was less frequent (4% vs 27% [p < 0.01]). Increasing proportions of positive fragments were associated with lower frequencies of spontaneous resolution (p < 0.05) and higher frequencies of worsening (9%, 22%, 43% [p < 0.009]) or progression to grade 3A or greater (2%, 6%, 28% [p < 0.005]). Complete resolution after treatment was less frequent for increasing proportions of positive fragments at index biopsy (80%, 66%, 49% [p < 0.05]). CONCLUSIONS: Diffuse versus focal rejection pattern and the proportion of positive fragments seem to be clinically relevant in terms of occurrence of symptoms, spontaneous evolution, and response to treatment.

Significance of pericardial effusion after heart transplantation.

The aim of this study was to evaluate the clinical significance of pericardial effusion after heart transplantation and to assess its correlation with acute rejection. One hundred fifty transplanted patients were followed up for the first year: serial echocardiographic studies were performed on the same day as were the endomyocardial biopsies; hemodynamic studies and coronary angiographies were performed 1 year after transplant. Ten days after surgery, pericardial effusion was absent in 77 patients, small in 52, moderate in 14, and large in 7, and was significantly related to severe postoperative bleeding (p < 0.001). Patients were classified according to the presence and the course of pericardial effusion in group A (absence or disappearance of previous pericardial effusion within 1 month, 107 patients) and in group B (onset, persistence, or increase in pericardial effusion, 43 patients). One hundred nineteen patients experienced > or = 1 acute rejection episode. The evolution of pericardial effusion was different (p < 0.0001) according to the number of acute rejection episodes and biopsy specimens showing acute rejection, histologic grading and time of the first episode, and histologic grading of the most severe acute rejection episode. Furthermore, there was a significant correlation with the cumulative duration of acute rejection episodes (p < 0.005) and the presence of previous cardiac surgical history (p < 0.007), but no correlation with cardiac transplant vasculopathy or with a positive weight mismatch. This study suggests that pericardial effusion in transplant recipients is associated with a higher incidence and more severe histologic grading of acute rejection episodes; its presence indicates the need for stricter monitoring of acute rejection.

Acute rejection after heart transplantation: noninvasive echocardiographic evaluation.

OBJECTIVES: The purpose of this study was to assess the reliability of echocardiography in the noninvasive diagnosis of acute rejection in heart transplant recipients. BACKGROUND: Although echocardiographic results seem to correlate well with allograft rejection, published data are limited and contradictory. METHODS: In 130 transplant recipients, 1,400 serial echocardiograms were recorded within 24 h of endomyocardial biopsy. Increased wall thickness, myocardial echogenicity, pericardial effusion, shorter pressure half-time, isovolumetric relaxation time and a decrease in left ventricular ejection fraction were considered markers of rejection. RESULTS: The distribution of echocardiographic markers revealed highly significant differences between bioptically graded moderate, mild and no rejection and between untreated and treated rejection episodes (both chi-square test, p < 0.0001). Specificity was 98.6% for two markers, but sensitivity was good (80%) for only moderate rejection because of the large number of false negatives in untreated patients with mild rejection. In untreated patients, there was a highly significant difference in the number of echocardiographic criteria between a benign and nonbenign outcome (chi-square test, p < 0.0001). In treated patients, the significant difference in the variation in echocardiographic criteria between favorable and unfavorable responses after 1 week was more pronounced after 2 weeks (t test, p < 0.01 vs. < 0.001). Diastolic indexes and pericardial effusion at 2 weeks seemed to be predictive of therapeutic response. CONCLUSIONS: Poor sensitivity to mild rejection indicates that serial echocardiography cannot supplant endomyocardial biopsy in the early diagnosis of acute rejection, but it seems to be a reliable noninvasive means of identifying acute rejection requiring intensified immunosuppressive therapy and of evaluating outcome.