Density and function of inward currents in right atrial cells from chronically fibrillating canine atria

OBJECTIVE: To determine whether I(Na) and I(CaL) are altered in function/density in right atrial (RA) cells from dogs with chronic atrial fibrillation (cAF dogs, episodes lasting at least 6 days) and whether the changes that occur differ from those in dogs with nonsustained or brief episodes of fibrillation (nAF dogs). METHODS: Using whole cell voltage clamp, sodium and calcium current density and function were determined in disaggregated RA cells from nAF, cAF and control atria (Con). Ca(2+) currents were studied with either Ca(2+) or Ba(2+) as charge carrier, as well as with either EGTA or BAPTA as the internal solution Ca(2+) chelator. RESULTS: After rapid atrial pacing, dogs can either fibrillate for short periods of time (nAF) or longer, more sustained periods (cAF). Both the Na(+) and Ca(2+) current decrease in cells of the nAF atria. Na(+) current density remains reduced in cAF cells with some slowing of recovery kinetics. Ca(2+) current density does not further decrease with persistent atrial fibrillation (cAF cells) remaining significantly different from Con cells. However, the difference in density of Ca(2+) currents between nAF and Con cells is negligible when Ba(2+) is charge carrier and when Ca(i) is quickly and effectively chelated with BAPTA. On the contrary, cAF I(BaL) densities remain significantly reduced compared to Con and nAF values when Ba(2+)/BAPTA conditions are used. CONCLUSIONS: Na(+) current density/function does not recover to Con values in cAF. Further these enhanced Ca(2+)-dependent inactivation processes contribute significantly to the reduction of I(CaL) density observed in nAF cells while reduction of Ca(2+) currents in cAF atria is probably by another mechanism     

Successful living domino liver transplantation in a child with protein C deficiency

PC is produced in the liver and inhibits blood coagulation by catalyzing active factors V and VIII. PC deficiency causes abnormal blood clotting that is difficult to regulate by anticoagulative treatments. Four reports of PC deficiency treated with LTx have been published; however, no report of DLT as a therapy for PC deficiency is available. We describe a case of a 23‐month‐old girl who received DLT for compound heterozygous PC deficiency. Her PC activity was below 5%. She developed intracranial lesion and frequent refractory purpura fulminans. Both her parents had heterozygous mutations of PC genes and were excluded as living donors. Furthermore, she was a low priority on the waiting list of deceased‐donor transplantation. We performed living DLT using the liver from a patient with MSUD. Activated PC concentrate safely supported the perioperative period. After DLT, she maintained normal PC activities and BCAA levels. This is the first case of PC deficiency successfully treated by living DLT with MSUD. We propose that DLT using liver from patients with MSUD is a treatment option for PC deficiency.     

Whole-genome copy number and immunohistochemical analyses on surgically resected intracholecystic papillary neoplasms

Intracholecystic papillary neoplasms are newly defined precancerous lesions. According to Classification of the World Health Organization, they have four histological morphologies, which are biliary, gastric, intestinal, and oncocytic. This study evaluated 17 patients with resected intracholecystic papillary neoplasms in terms of histological, immunohistochemical, and copy number variation (CNV). The histological subtypes included 5 cases of low-grade (5 gastric) and 12 cases of high-grade (6 gastric and 6 biliary) neoplasms. Most cases showed high expression of MUC1, MUC5AC, and CK7, moderate expression of MUC6 and Ki-67, and low expression of CK20, MUC2, and CDX2. The CNV profile identified gain of 7q in 12%, and loss of 1p (18%), 5q (29%), 9p (35%), 12p (17%), 17p (24%), and 19p (18%). No CNVs were observed in low-grade neoplasms, whereas high-grade ones had increasing abnormalities. β-catenin was often expressed in the nucleus of neoplasms with gastric morphology, suggesting the involvement of the Wnt/β-catenin pathway. However, it was not expressed among those with biliary morphology, which instead exhibited high p53 expression. Neoplasms with biliary morphology showed more CNV changes (9p, 17p, 19p losses). Distinct immunological and CNV patterns were seen in both morphologies, suggesting differences in their pathogenesis. More CNVs accumulated with tumor progression.     

Evaluation of an artificial intelligence system for detecting vertical root fracture on panoramic radiography

Objectives

The aim of this study was to evaluate the use of a convolutional neural network (CNN) system for detecting vertical root fracture (VRF) on panoramic radiography.

Methods

Three hundred panoramic images containing a total of 330 VRF teeth with clearly visible fracture lines were selected from our hospital imaging database. Confirmation of VRF lines was performed by two radiologists and one endodontist. Eighty percent (240 images) of the 300 images were assigned to a training set and 20% (60 images) to a test set. A CNN-based deep learning model for the detection of VRFs was built using DetectNet with DIGITS version 5.0. To defend test data selection bias and increase reliability, fivefold cross-validation was performed. Diagnostic performance was evaluated using recall, precision, and F measure.

Results

Of the 330 VRFs, 267 were detected. Twenty teeth without fractures were falsely detected. Recall was 0.75, precision 0.93, and F measure 0.83.

Conclusions

The CNN learning model has shown promise as a tool to detect VRFs on panoramic images and to function as a CAD tool.