Passenger lymphocyte thrombocytopenia due to human platelet antigen 3a antibodies: Case report and review of literature

We report a case of severe acute thrombocytopenia occurring within days after a cadaveric liver transplant, received from a female patient with aplastic anemia who died of intracranial bleeding. The donor, who was homozygous for the ITGA2B*002 (HPA-3b) gene, had developed human platelet antigen (HPA)-3a antibodies, whereas the recipient was homozygous for the ITGA2B*001 (HPA-3a) gene. Thrombocytopenia responded to an infusion of immunoglobulin G. This is the first report of a passenger lymphocyte syndrome manifesting with thrombocytopenia due to anti-HPA-3a. We review the literature on thrombocytopenia in the setting of PLS and discuss the differential diagnosis.

Isolation of transcripts from Diabrotica virgifera virgifera LeConte responsive to the Bacillus thuringiensis toxin Cry3Bb1

Crystal (Cry) proteins derived from Bacillus thuringiensis (Bt) have been widely used as a method of insect pest management for several decades. In recent years, a transgenic corn expressing the Cry3Bb1 toxin has been successfully used for protection against corn rootworm larvae (genus Diabrotica). The biological action of the Bt toxin in corn rootworms has not yet been clearly defined. Because development of resistance to Bt by corn rootworms will have huge economic and ecological costs, insight into larval response to Bt toxin is highly desirable. We identified 19 unique transcripts that are differentially expressed in D. virgifera virgifera larvae reared on corn transgenic for Cry3Bb1. Putative identities of these genes were consistent with impacts on metabolism and development. Analysis of highly modulated transcripts resulted in the characterization of genes coding for a member of a cysteine-rich secretory protein family and a glutamine-rich membrane protein. A third gene that was isolated encodes a nondescript 132 amino acid protein while a fourth highly modulated transcript could not be further characterized. Expression patterns of these four genes were strikingly different between susceptible and resistant western corn rootworm populations. These genes may provide useful targets for monitoring of Bt exposure patterns and resistance development in pest and non-target insect populations.

Liver haemorrhage in haemophilia--a case report and review of the literature

We present two patients with severe haemophilia A, who presented with haemorrhagic shock, secondary to a liver haematoma in the neonatal period. Both required emergency treatment and diagnosis of the hereditary coagulation defect. Major organ bleeding in severe haemophilia A in the newborn period is rare, and this unusual complication is not well recognized. Failure to recognize that the bleeding is due to a bleeding disorder, particularly in the absence of a family history, may lead to delay in appropriate management.

Early and pre-discharge aspirin administration among patients with acute myocardial infarction: current clinical practice and trends in the United States

OBJECTIVES

The purpose of our study was to determine the frequency of aspirin administration among patients with acute myocardial infarction (MI) as dictated by physicians practicing in the United States.

BACKGROUND

Aspirin (ASA), a widely available, inexpensive and generally well-tolerated platelet inhibitor, is recommended for patients with acute coronary syndromes, including acute MI. However, there is concern that aspirin is underutilized in daily clinical practice.

METHODS

Early (<24 hours) and predischarge ASA administration were determined among 220,171 patients with suspected acute MI enrolled in the Second National Registry of Myocardial Infarction (NRMI 2) between June, 1994 and April 30, 1996.

RESULTS

Overall, 165,122 (74.9%) of patients received ASA within 24 hours of hospital admission, whereas 55,049 patients did not. Early ASA recipients were younger, more often male, arrived at the hospital earlier, and were more likely to be classified as Killip Class II or less compared to those who did not receive ASA. Patients who received aspirin were also more likely to have chest pain, electrocardiographic ST segment elevation, and tended to arrive at the hospital earlier than those who did not receive ASA. However, over 20% of patients with ST segment elevation did not receive early ASA therapy. From the total cohort of early ASA recipients, only 69% received ASA at the time of hospital discharge. Trends in early and pre-discharge aspirin administration over a 2 year time period in all patients (72.6 to 75.1% and 71.5 to 74.6%, respectively; p < 0. 001) and in specific patient subsets were encouraging with a gradual but steady increase; however, utilization remained comparatively low in women and the elderly. By multivariable analysis, in-hospital recurrent MI (OR 0.90, 95% CI;.78-1.0, p = 0.04), stroke (OR 0.65, 95% CI,.52-.80, p < 0.001) and death (OR 0.24, 95% CI,.22-.26, p < 0. 001) occurred less frequently when ASA was administered within 24 hours of hospitalization.

CONCLUSION

Aspirin is currently underutilized in routine clinical practice as both primary and adjunctive forms of therapy in MI, especially among patients known to be at risk for recurrent cardiothrombotic events. The targeted and timely use of aspirin reduces early cardiovascular events and should remain a priority in national health care efforts.

Risk for intracranial hemorrhage after tissue plasminogen activator treatment for acute myocardial infarction. Participants in the National Registry of Myocardial Infarction 2

BACKGROUND

The efficacy of thrombolytic therapy in reducing mortality from acute myocardial infarction has been unequivocally shown. However, thrombolysis is related to bleeding complications, including intracranial hemorrhage.

OBJECTIVE

To determine the frequency of and risk factors for intracranial hemorrhage after recombinant tissue-type plasminogen activator (tPA) given for acute myocardial infarction in patients receiving usual care.

DESIGN

Large national registry of patients who have had acute myocardial infarction.

SETTING

1484 U.S. hospitals.

PATIENTS

71073 patients who had had acute myocardial infarction from 1 June 1994 to 30 September 1996, received tPA as the initial reperfusion strategy, and did not receive a second dose of any thrombolytic agent.

MEASUREMENT

Intracranial hemorrhage confirmed by computed tomography or magnetic resonance imaging.

RESULTS

673 patients (0.95%) were reported to have had intracranial hemorrhage during hospitalization for acute myocardial infarction; 625 patients (0.88%) had the event confirmed by computed tomography or magnetic resonance imaging. Of the 625 patients with confirmed intracranial hemorrhage, 331 (53%) died during hospitalization. An additional 158 patients (25.3%) who survived to hospital discharge had residual neurologic deficit. In multivariable models for the main effects of candidate risk factors, older age, female sex, black ethnicity, systolic blood pressure of 140 mm Hg or more, diastolic blood pressure of 100 mm Hg or more, history of stroke, tPA dose more than 1.5 mg/kg, and lower body weight were significantly associated with intracranial hemorrhage.

CONCLUSIONS

Intracranial hemorrhage is a rare but serious complication of tPA in patients with acute myocardial infarction. Appropriate drug dosing may reduce the risk for this complication. Other therapies, such as primary coronary angioplasty, may be preferable in patients with acute myocardial infarction who have a history of stroke.

Early assessment and in-hospital management of patients with acute myocardial infarction at increased risk for adverse outcomes: a nationwide perspective of current clinical practice. The National Registry of Myocardial Infarction (NRMI-2) Participants

BACKGROUND

Therapeutic decision making in critically ill patients requires both prompt and comprehensive analysis of available information. Data derived from randomized clinical trials provide a powerful tool for risk assessment in the setting of acute myocardial infarction (MI); however, timely and appropriate use of existing therapies and resources are the key determinants of outcome among high-risk patients.

METHODS

Demographic, procedural, and outcome data from patients with MI were collected at 1073 U.S. hospitals collaborating in the National Registry of MI (NRMI 2). Patients were classified on hospital arrival as either "low risk" or "high risk" according to a modified Thrombolysis in Myocardial Infarction II Risk Scale based on predetermined demographic, electrocardiographic, and clinical features.

RESULTS

Among the 170,143 patients enrolled, 115,222 (67.5%) were classified as low risk and 55,521 (32.5%) as high risk for in-hospital death, recurrent ischemia, recurrent MI, congestive heart failure, and stroke. Using a composite unsatisfactory outcome measure, in-hospital adverse events were had by a greater proportion of patients initially classified as high risk compared with those classified as low risk. By multivariate analysis, age >70 years, prior MI, Killip class >1, anterior site of infarction, and the combination of hypotension and tachycardia were independent predictions of poor outcome in patients with or without ST-segment elevation on the presenting electrocardiogram. High-risk patients with ST-segment elevation were treated with thrombolytics (47.5%) or alternative forms of reperfusion therapy (9.3%) within 62 minutes and 226 minutes of hospital arrival, respectively. High-risk patients offered reperfusion therapy were also more likely to receive aspirin, beta-blockers (intravenous, oral) and angiotensin-converting enzyme inhibitors within 24 hours of infarction (all p < 0.0001), survive their event (8.4% versus 21.4% p < 0.0001), and leave the hospital sooner than those not reperfused.

CONCLUSIONS

This large registry experience included more than 150,000 nonselected patients with MI and suggests that high-risk patients can be identified on initial hospital presentation. The current use of reperfusion and adjunctive therapies among high-risk patients is suboptimal and may directly influence outcome. Randomized trials designed to test the impact of specific management strategies on outcome according to initial risk classification are warranted.

Lactic acidosis as a facilitator of oxyhemoglobin dissociation during exercise

The slow rise in O2 uptake (VO2), which has been shown to be linearly correlated with the increase in lactate concentration during heavy constant work rate exercise, led us to investigate the role of H+ from lactic acid in facilitating oxyhemoglobin (O2Hb) dissociation. We measured femoral venous PO2, O2Hb saturation, pH, PCO2, lactate, and standard HCO3- during increasing work rate and two constant work rate cycle ergometer exercise tests [below and above the lactic acidosis threshold (LAT)] in two groups of five healthy subjects. Mean end-exercise femoral vein blood and VO2 values for the below- and above-LAT square waves and the increasing work rate protocol were, respectively, PO2 of 19.8 +/- 2.1 (SD), 18.8 +/- 4.7, and 19.8 +/- 3.3 Torr; O2 saturation of 22.5 +/- 4.1, 13.8 +/- 4.2, and 18.5 +/- 6.3%; pH of 7.26 +/- 0.01, 7.02 +/- 0.11, and 7.09 +/- 0.07; lactate of 1.9 +/- 0.9, 11.0 +/- 3.8, and 8.3 +/- 2.9 mmol/l; and VO2 of 1.77 +/- 0.24, 3.36 +/- 0.4, and 3.91 +/- 0.68 l/min. End-exercise femoral vein PO2 did not differ statistically for the three protocols, whereas O2Hb saturation continued to decrease for work rates above LAT. We conclude that decreasing capillary PO2 accounted for most of the O2Hb dissociation during below-LAT exercise and that acidification of muscle capillary blood due to lactic acidosis accounted for virtually all of the O2Hb dissociation above LAT.

Reproducibility of digital subtraction fluoroscopic readings for coronary artery calcification

RATIONALE AND OBJECTIVES

Digital subtraction fluoroscopy, an inexpensive screening test for coronary atherosclerosis, is highly sensitive in detecting coronary calcifications. However, no previous study has reported interobserver agreement for this test.

METHODS

Six hundred and thirty-one subjects underwent digital subtraction fluoroscopy in the 60 degrees left anterior oblique projection. Images were acquired with pulsed fluoroscopy at 15 frames per second. An averaged mask was subtracted from successive images. These fluoroscopic images were stored on a digital disk and replayed in cine loop format. An observer, blinded to clinical information, read the fluoroscopic studies for the presence of calcium in the left main-left anterior descending artery, circumflex artery, and right coronary artery. The images were then stored on digital tape and reread by a second blinded observer.

RESULTS

The percentages of interobserver agreement regarding the presence and absence of calcium in left main-left anterior descending, circumflex, and right coronary arteries, were 91.9%, 92.9%, and 92.2%, respectively. The overall kappa values, which are 0.85, 0.77, and 0.82 in left main-left anterior descending, circumflex, and right coronary arteries, respectively, show a highly significant level of agreement (P < .0001).

CONCLUSION

Digital subtraction fluoroscopy is a reliable screening test for coronary calcifications.

Prolonged ambulatory monitoring of colonic motor activity in the pig

The aim of this study was to develop a chronic model suitable for repeated, long-term studies of the interaction of behavior and colonic function in unrestrained pigs. Cecostomies were created in three 20-30 kg micropigs under general anesthesia. Fistulas were created by suturing the bowel to the abdominal wall. Recordings were made by passing a small (8F) solid-state pressure transducer through the fistula into the proximal bowel and connecting it to a battery-operated data logger worn in a vest on the pig's back. Cecostomies have remained patent and trouble-free for over 18 months. No serious infections have occurred. Preliminary data from a total of thirteen 24-h recording sessions showed 54% of all contractile activity to be in the 2-4 cpm frequency range. Increased motility was seen following meals and upon morning awakening. Motility was minimal during the night. Infrequent (10.31 +/- 2.05/24 h; mean +/- SD) propagated contractions were also noted. These contractions were generally of low amplitude (33.24 +/- 3.81 mmHg). These techniques allow prolonged, intraluminal recordings to be made from the colon of the unrestrained pig.

Fatal left ventricular perforation during mitral balloon valvoplasty

Percutaneous balloon dilation of left-sided cardiac valves is being performed with increasing frequency. We describe and document the mechanism of injury of left ventricular perforation during mitral balloon valvoplasty. Despite a technically successful surgical repair with hemodynamic restoration, the patient was brain dead. We emphasize (1) the risk and the potentially catastrophic nature of left ventricular perforation during mitral balloon valvoplasty and (2) the need for surgical standby and rapid operative decompression for this complication.

Louisiana's ventilator assisted care program: case management services to link tertiary with community-based care

The Ventilator Assisted Care Program has provided case management services to 36 youths and their families throughout Louisiana. It has served to link tertiary care centers with community-based service systems for the comprehensive care management of children and adolescents who use ventilators. The hospital-based, state-licensed service has been funded by Louisiana's Medicaid and Handicapped Children's Services Programs on a fee for service basis. It was originally funded by a grant from the Bureau of Maternal and Child Health. The service planning, coordination, and monitoring activities for individual families have usually begun predischarge and have been continued throughout the home care experience. The child and family have been considered to be the center of the care matrix, actively directing the service systems as well as service development.

Combined contrast echocardiographic and radionuclide diagnosis of atrial septal defect: accuracy of the technique and analysis of erroneous diagnoses

The utility of combined peripheral vein contrast 2-dimensional echocardiography (2-D echo) and radionuclide shunt detection was evaluated in 25 patients with suspected atrial septal defect (ASD) in whom the diagnosis was confirmed at cardiac catheterization: 14 patients had ASD and 11 had no intracardiac shunt. Contrast 2-D echo correctly diagnosed 13 of 14 patients with ASD, but there were 2 false-positive diagnoses in the 11 patients without ASD. Radionuclide shunt studies correctly identified all 14 patients with ASD, but yielded 5 false-positives results among the 11 without ASD. After altering the radionuclide processing technique, there were only 2 of 11 false-positive shunt studies, and the correlation of radionuclide shunt magnitude with cardiac catheterization improved (r = 0.49, p less than 0.025 to r = 0.75, p less than 0.001). Thus, the improved processing method improved both the qualitative and quantitative accuracy of radionuclide shunt detection. The combination of contrast 2-D echo and radionuclide shunt detection led to a proper diagnostic and therapeutic decision in 24 of 25 patients. Therefore, these combined modalities are clinically useful in the evaluation of patients with suspected ASD.

Contrasting cardiovascular and respiratory responses to exercise in mitral valve and chronic obstructive pulmonary diseases

The role of cardiovascular and pulmonary limitation in performing maximal exercise is contrasted in patients with mitral valve disease (MVD) and chronic obstructive pulmonary disease (COPD). The ventilatory (VE) gas exchange (VO2 and VCO2) and heart rate (HR) responses to an incremental cycle ergometer exercise were measured in six patients with MVD, seven patients with COPD, and six normal subjects. The VE requirement for the work (VE-VO2 relationship) was increased in both COPD and MVD groups compared with control subjects, but the breathing reserve was significantly lower in COPD (13 percent) compared with MVD (49 percent) and control groups (44 percent). In contrast, the VO2 at the anaerobic threshold was significantly lower in MVD (12.2 +/- .5 ml/kg) compared with COPD (15.7 +/- 1.2 ml/kg) and control subjects (16.6 +/- .9 ml/kg). Also, the heart rate reserve and the VO2-HR slope were significantly reduced in MVD (9 +/- 6 percent and 6.9 +/- 1.0 ml/min/beat, respectively) compared with COPD patients (44 +/- 7 percent and 2.0 ml/min/beat, respectively). Both patient groups experienced an acidosis in their terminal work rate, but the acidosis was primarily respiratory in the COPD and totally metabolic in the MVD group. These studies indicate that at maximal work rate, MVD but not COPD patients, manifest compromised O2 delivery to the muscles, while COPD but not MVD patients were unable to increase VE sufficiently to match the exercise-induced CO2 production.

Ventilatory responses to cardiac output changes in patients with pacemakers

Cardiac output changes were induced by step changes of heart rate (HR) in six patients with cardiac pacemakers during monitoring of ventilation and gas exchange, breath-by-breath. Mean low HR was 48 beats/min; mean high HR was 82 beats/min. The change of oxygen uptake immediately after the HR change was used as an index of altered cardiac output. After HR increase, oxygen uptake (V02) rose by 34 +/- 20% (SD), and after HR decrease, Vo2 fell by 24 +/- 11%. There was no change in arterial blood pressure. After HR increase, ventilation increased, after a mean delay of 19 +/- 4 s; after HR reduction, ventilation fell, after a mean delay of 29 +/- 7 s. In the period between HR increase and the resulting increase in ventilation, end-tidal PCO2 (PETCO2) rose by 2.6 +/- 2.0 Torr, and in the period between HR decreases and the fall in ventilation, PETCO2 dropped by 2.9 +/- 2.2 Torr. The response time and end-tidal gas tension changes implicate the chemoreceptors in the reflex correction of blood gas disturbances that may result from imbalances between cardiac output and ventilation.

High output heart failure associated with pulmonary edema complicating hydatidiform mole

Detailed hemodynamic, metabolic and blood volume studies were performed in a patient with hydatidiform mole who developed pulmonary edema associated with a high cardiac output. Several factors including hyperthyroidism, hypervolemia, and the molar state probably contributed to the left ventricular failure in this patient. results of these studies suggest that patients with hydatidiform mole and pulmonary edema need correction of the hypervolemia as well as removal of the molar tissue.