Scintigraphic diagnosis of tricuspid regurgitation

The authors describe a simple technique for diagnosis of tricuspid regurgitation. Red blood cells were labeled in vivo with 99mTc and 22 patients were studied with ECG-gated blood-pool imaging of the liver. A single region of interest was manually drawn around the liver and a time-activity curve obtained. The per cent change in liver counts during the cardiac cycle was found to be significantly higher in the 12 patients with tricuspid regurgitation (Group I) (mean, 4.04 +/- 1.6%; range, 1.3-21.4%) compared with the 10 controls (Group II) (mean, 0.35 +/- 0.16%; range, 0.013-1.3%) (p less than 0.05). Using a 1% change in liver counts as the criterion of a positive study, all 12 cases in Group I were diagnosed correctly, but there was one false positive in Group II; thus the sensitivity was 100% and the specificity 90%.     

Rat foetal endocrine pancreas in experimental diabetes.

The endocrine pancreas of foetuses and newborn rats of experimental diabetic mothers showed morphological and ultrastructural changes. Islet hypertrophy and beta cell hyperplasia were constantly present, but the beta cells of foetuses of severely diabetic mothers were degranulated. The ultrastructural changes indicated hyperfunction in the beta cells of foetuses of experimental diabetic mothers. The morphological changes mentioned were similar to those seen in human diabetic pregnancy.     

Direct binding of respiratory syncytial virus to pneumococci: a phenomenon that enhances both pneumococcal adherence to human epithelial cells and pneumococcal invasiveness in a murine model

In a previous study we showed that pneumococcal adherence to epithelial cells was enhanced by a preceding respiratory syncytial virus (RSV) infection. RSV-glycoproteins, expressed on the infected cell surface, may play a role in this enhanced pneumococcal binding, by acting as bacterial receptors. In the current study, it was attempted to analyze the capacity of pneumococci to interact directly with RSV virions. By flow-cytometry, a direct interaction between RSV and pneumococci could be detected. Heparin, an inhibitor of RSV infectivity that interacts with RSV protein-G, blocked RSV-pneumococcal binding, indicating that the latter interaction is indeed mediated by protein-G. RSV-pneumococcal complexes showed enhanced adherence to uninfected human epithelial cells, compared with pneumococcal adherence without bound RSV, and this enhancement was also blocked by heparin. In addition, the significance of these findings in vitro was explored in vivo in a murine model. Both mice that were pretreated with RSV at day 4 before pneumococcal challenge and mice infected with both agents simultaneously showed significantly higher levels of bacteraemia than controls. Simultaneous infection with both agents enhanced the development of pneumococcal bacteraemia most strongly. It was hypothesized that direct viral binding is another mechanism by which RSV can induce enhanced pneumococcal binding to epithelial cells, a phenomenon that is translated in vivo by a higher invasiveness of pneumococci when administered simultaneously with RSV to mice. Apparently, RSV acts in this process as a direct coupling particle between bacteria and uninfected epithelial cells, thereby increasing colonization by and enhancing invasiveness of pneumococci.     

Convection perfusion of glucocerebrosidase for neuronopathic Gaucher's disease

Systemic enzyme replacement for Gaucher's disease has not prevented premature death or severe morbidity in patients with a neuronopathic phenotype, because the enzyme does not cross the blood-brain barrier. We used convection-enhanced delivery for regional distribution of glucocerebrosidase in rat and primate brains and examined its safety and feasibility for neuronopathic Gaucher's disease. Rats underwent intrastriatal infusion and were observed and then sacrificed at 14 hours, 4 days, or 6 weeks. Primates underwent serial magnetic resonance imaging during enzyme perfusion of the right frontal lobe or brainstem, were observed and then sacrificed after infusion completion. Animals underwent histologic and enzymatic tissue analyses. Magnetic resonance imaging revealed perfusion of the primate right frontal lobe or pons with infusate. Enzyme activity was substantially and significantly (p < 0.05) increased in cortex and white matter of the infused frontal lobe and pons compared to control. Immunohistochemistry demonstrated intraneuronal glucocerebrosidase. There was no toxicity. Convection-enhanced delivery can be used to safely perfuse large regions of the brain and brainstem with therapeutic levels of glucocerebrosidase. Patients with neuronopathic Gaucher's disease and similar central nervous system disorders may benefit from this treatment.     

Gastro-intestinal stromal tumour of the duodenum: extreme presentation in two cases

Gastro-intestinal stromal tumours (GIST) are primary mesenchymal tumours arising from the gastro-intestinal tract. They are uncommon visceral tumours, preferentially located in the stomach and small intestine. The present paper will discuss the clinical presentation of GIST in a 32-year-old female (Case 1) and in a 72-year-old female (Case 2). In both cases the tumour is located in the duodenum which appears to be a rather unusual location (4%) for GIST. This work will illustrate that duodenal GIST can occur in extreme presentations, diverging from vague complaints to directly life threatening symptoms.     

alpha-Galactosidase A deficiency in Dutch patients on dialysis: a critical appraisal of screening for Fabry disease.

INTRODUCTION: Fabry disease or alpha-galactosidase A (alpha-Gal A) deficiency is an X-linked lysosomal storage disorder that often leads to renal insufficiency in males and occasionally in females. The disease is rare, but its prevalence may be underestimated due to its variable clinical picture. Enzyme supplementation therapy with rHu-alphaGal A is currently available. Limited experience has so far shown that therapy may at best stabilize renal function. Despite these preliminary findings, much effort is being put into screening high-risk groups for undiagnosed alpha-Gal A deficiency. We studied the prevalence of alpha-Gal A deficiency in a Dutch dialysis cohort to establish possible underdiagnosis. We discuss the benefits of screening for Fabry disease. METHODS: Activity of alpha-Gal A in whole blood was measured in a group of 508 male Dutch dialysis patients. RESULTS: Of the 508 patients studied only one patient, already known with Fabry disease, had a alpha-Gal A deficiency, a prevalence of 0.22% (95 CI 0-1.1%). CONCLUSIONS: No undiagnosed Fabry patients were found, indicating that in our studied cohort there is no large-scale underestimation of its prevalence. Even though screening of dialysis patients for Fabry disease might identify patients who remain otherwise unrecognized, screening of high-risk populations for alpha-Gal A deficiency should be carried out with caution since long-term efficacy of treatment is currently unknown.     

Emergency room retrograde transbrachial arteriography for the management of axillosubclavian vascular injuries

BACKGROUND: Our purpose was to determine the accuracy of single-injection, retrograde transbrachial arteriography (RTBA), performed in the emergency room, for suspected axillosubclavian injuries. METHODS: Thirty-three patients were prospectively assigned for RTBA. Clinical indications for RTBA included high-risk mechanism of injury, decreased (n = 19) or absent (n = 5) brachial pulse, neurologic deficits (n = 11), external or intrathoracic bleeding (n = 4), and bruit (n = 2). Brachial artery was cannulated with an 18-gauge catheter. A sphygmomanometer cuff was placed at the forearm and inflated to 250 mm Hg. Twenty milliliters of nonionic contrast media was injected countercurrent and a single anteroposterior chest radiograph was obtained. Small intimal flaps were followed by serial ultrasound. Surgical findings were used to establish RTBA accuracy. RESULTS: RTBA was successfully performed in all cases. Arterial lesions were detected in 28 (84.8%) patients, including thrombosis (n = 8), arteriovenous fistula (n = 8), and false aneurysm (n = 7) as the most frequent lesions. A sensitivity of 96.5%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 80% were observed with RTBA. CONCLUSION: We conclude that RTBA is a safe and accurate technique to be used in the emergency room for the rapid detection of axillosubclavian arterial injuries.