Pancreas divisum: thin-section CT

Twelve patients with known pancreas divisum underwent thin-section computed tomography (CT) to determine the capability of CT to depict this pancreatic anomaly. Focal pancreatic enlargement was present in five patients. Two distinct pancreatic moieties separated by a fat cleft were noted in three patients; a fourth patient had focal atrophy in the distribution of the dorsal pancreas. The two pancreatic moieties were identified at the same craniocaudal level in all four of these patients. The dorsal duct was depicted in all 12 patients, while the short ventral duct was seen in only five of the 12 patients. Failure of the ventral and dorsal pancreatic ducts to fuse was identified in all five patients in whom both ducts were seen. CT may not enable specific diagnosis of pancreas divisum in the majority of patients. If, however, distinct pancreatic moieties or unfused ductal systems are evident, the diagnosis may be confidently suggested.     

Self-limiting extravasation in the unused urinary bladder

Patients being evaluated as potential renal transplant recipients routinely undergo voiding cystourethrography. Eight patients were encountered in whom extraperitoneal extravasation was noted from the region of the ureterovesical junction during voiding (seven patients) or during filling (one patient). Extravasation was bilateral in six patients and unilateral in two. The patients neither experienced symptoms related to the extravasation, required treatment, nor had sequelae. Five of the eight patients have subsequently received renal transplants and their bladders were observed to be normal at surgery. Cystoscopy was also performed in two of these five patients and was unremarkable. After transplantation, these patients' bladders functioned normally and gave rise to no symptoms.     

Tuberculous joint disease in transplant patients.

Three patients with tuberculosis, all manifesting monarticular joint involvement, among 845 renal allograft recipients at the University of Minnesota are reported on. Clinical symptoms, methods of diagnosis, and optimal antibiotic regimes are discussed. The physician must suspect tuberculous joint disease when confronted with monarticular swelling and pain in the transplant recipient.     

Correlation between virus-cell receptor properties of alphavirusesin vitro and virulencein vivo

Summary Virulent and avirulent clones of Venezuelan, Western, and Eastern equine encephalitis viruses were examined for theirin vitro attachment characteristics to the surface of cultured cell monolayers. These attachment characteristics were correlated within vivo plasma clearance rates and virulence. For the clones investigated, avirulence correlatedin vitro with attachment pH optima close to physiologic pH andin vivo with a rapid clearance from plasma. Conversely, virulent clones had lowerin vitro attachment pH optima and low plasma clearancesin vivo.With 4 Figures     

The permeability of the blood-brain barrier in mice suffering from fatal lymphocytic choriomeningitis virus infection

Summary The ultrastructure and the blood-brain-barrier (BBB) permeability were studied in mice suffering from lymphocytic choriomeningitis (LCM). Brains and meninges from mice suffering from LCM virus-induced lymphocytic choriomeningitis were studied by investigating the BBB function and by electron and light microscopy.The cellular exudate in the leptomeninges was located in the subarachnoid space, in arachnoidea and pia, and it was dominated by proliferated pial cells and mononuclear cells, most of which were lymphocytes, while there were only a few neutrophil granulocytes. Many intravascular lymphocytes were seen adhering to as well as penetrating the vessel walls. Many of these lymphocytes were morphologically compatible with T cells. Lymphocytes and larger mononuclear cells were also accumulated in the choroid plexus, and lymphocytes were present in the ventricular system with a tendency to adhere to ependymal epithelial cells. Inspection of the ultrathin sections incubated for horseradish peroxidase (HRP)-activity revealed that the overwhelming part of the peroxidase activity was localized in the extracellular space of the meningeal vessel walls and especially in the abundant intercellular fluid which, like the inflammatory cells, was found in the subarachnoid space in arachnoidea and in pia. In the neuropil, only very small quantities of reaction product were seen intercellularly in the most superficial layers of the cortex. The tight junctions were always intact, but the possibility of a non-demonstrable opening is discussed. Evaluation of the BBB permeability for 2-amino[1-¹⁴C]isobutyric acid (AIB) was made by quantitative autoradiography, and it was demonstrated convincingly that AIB concentrations in the subpial and perichoroidal tissues were markedly increased in diseased animals as compared to the controls.Our results seem to contradict previous theories on the cause of death resulting from the LCM disease. The findings presented here do not speak in favor of a pronounced brain edema, just as results obtained by us and others do not speak for the possibility of the death being caused by convulsive seizures with subsequent brain anoxia. However, our observations are compatible with the hypothesis that cytotoxic T cells may interact in vivo with virus-infected targets, which are essential for the regulation of the composition of the cerebrospinal fluid. On the other hand, the dysfunction of the BBB demonstrated adds a new element to the pathologic mechanism in a model for the study of virus-induced meningitis.Supported by grants from the Danish Medical Research Council (nos. 12-3142, 12-3597) and from the Foundation of Consul Ehrenfried Owesen and spouse     

Augmented reality visualization using Image-Overlay for MR-guided interventions: system description, feasibility, and initial evaluation in a spine phantom

OBJECTIVE: The purpose of this article is to provide a preliminary user assessment of Image-Overlay, an augmented reality system for MRI-guided needle placement, in a spine phantom. CONCLUSION: Image-Overlay can be used to successfully target lumbar facet joints with high accuracy and minimal insertions. This is potentially useful for other interventional MRI applications. Additional clinical assessment is needed.