Coronary venous blood flow in patients with acute myocardial infarction

In 94 patients with large myocardial infarction, their coronary venous blood flow was studied in the acute period of the disease by continuous coronary sinus thermodilution. No relationship was established between the coronary venous blood flow and the duration of coronary heart disease. The patients with anterior myocardial infarction had a significantly less blood flow in the vena cordis magna than those with posterolateral infarction. No correlation was found between the blood flow and precordial mapping parameters. Thus, continuous coronary sinus thermodilution cannot be used for indirect identification of the site of myocardial infarction and for prediction of its progression severity.     

Effects of a holmium-166 incorporated covered stent placement in normal canine common bile ducts

PURPOSE: A specially designed self-expandable covered metallic stent incorporated with beta-emitting radioisotope, Holmium-166 (Ho-166), was developed for delivering intraluminal brachytherapy as well as for internal bile drainage in malignant biliary stricture. The purpose of the study was to demonstrate the safety and tissue response of the radioactive metallic stent on the normal canine common bile duct (CBD) prior to the clinical application. MATERIALS AND METHODS: Nitinol self-expandable stents (diameter; 4 mm, length; 20 mm) were covered with polyurethane membrane (50 microm thick) containing 21 to 135 muCi of Ho-166 (mean, 77.9 microCi). To prevent migration of stent, the membrane covered only the middle 1 cm of the stent and the ends of the stent were left uncovered. The stents were placed in the CBD of 20 healthy beagle dogs. For control, non-radioactive covered stents were placed in another three dogs. The dogs were killed 3 to 6 months after stent insertion and histopathologic examination of CBD was performed. RESULTS: There was no stent migration in all cases. Varying degrees of papillary mucosal hyperplasia leading to significant narrowing of the lumen was observed within the lumen of the bare portion and under the mucosal surface of the non-radioactive covered stents. However, fibrosis was noted in Ho-166 coated area, instead of mucosal hyperplasia. Severity of fibrosis was correlated with estimated radiation dose. Despite high dose, there was no perforation of CBD wall. The membrane of Ho-166 coat was disrupted in some cases of 6 months follow-up. CONCLUSIONS: Holmium-166 incorporated covered stents demonstrated fibrosis of CBD wall and inhibition of ingrowth of mucosal hyperplasia without serious complication such as perforation, while control group showed severe mucosal hyperplasia.     

Plastic reorganization of hippocampal and neocortical circuitry in experimental traumatic brain injury in the immature rat

The reorganization of circuitry in the immature forebrain resulting from controlled cortical impact was examined with viral transneuronal tracing. Animals injured on postnatal day (PND) 17 and sham controls from the same litters received an intracerebral injection of a recombinant strain of pseudorabies virus (PRV) into the entorhinal cortex on PND 45. Fifty hours following injection of virus the animals were perfused and infected neurons were localized immunohistochemically with antisera specific for PRV. Prior studies have demonstrated that the PRV recombinant used in this analysis moves exclusively in the retrograde direction through synaptically linked neurons. CCI induced a necrotic loss of cortex at the site of impact and variable damage to the underlying corpus callosum and rostral (dorsal) hippocampus that was not present in sham controls. Analysis of viral transport in sham controls revealed retrograde transport of virus through hippocampal and neocortical circuitry in a pattern consistent with established patterns of connectivity and topography. Injured animals exhibited preservation of topographically organized connections in both the hippocampus and neocortex. However, the magnitude of labeling in the injured hemisphere was significantly increased relative to control animals and correlated with the magnitude of the injury. The distribution of infected neurons in the contralateral uninjured hemisphere also conformed to known connections. However differences in the involvement of the corpus callosum in the injury resulted in greater variability in the number of infected neurons among cases. These data provide novel insights into trauma induced reorganization of the developing brain and add to the experimental tools that can be used to assess the basis for functional recovery in animal models of developmental traumatic brain injury.     

Metabolic abnormalities with hematologic manifestation

These are unusual diseases in pediatric pathology. We present the morphologic aspects of peripheral blood smear and bone marrow smear of nine storage disease cases.     

Decrease of kappa-opioid receptor mRNA level in ventral tegmental area of male mice after repeated experience of aggression

Brain opioid systems have been implicated in the regulation of social interaction, including agonistic behaviour. kappa-Opioid receptor B and C mRNA levels were decreased in the ventral tegmental area but not in the nucleus accumbens in male mice with repeated experience of social victories (winners), but not in mice after social defeats (losers) after 10 but not 20 days of confrontations. mu-Opioid receptor mRNA levels were not changed.     

Hyperpolarized helium-3 MR imaging of pulmonary function

Recent advances in HP MR imaging contrast agents have led to novel tests of pulmonary function. Many of these tests show promise in the clinical arena.