Accuracy of Ultrasound Imaging for Etiology of New-Onset Painless Jaundice.

PURPOSE: Ultrasound (US) is considered a first-line study for painless jaundice. However, in our hospital system, patients with new-onset painless jaundice often have a contrast-enhanced computed tomography (CECT) or magnetic resonance cholangiopancreatography (MRCP) regardless of the sonographic findings. Thus, we investigated the accuracy of US for detection of biliary dilatation in patients with new-onset painless jaundice. METHODS: Our electronic medical record was searched from January 1, 2012, to January 1, 2020, for adult patients with new-onset painless jaundice. Presenting complaint/setting, laboratory values, imaging studies/findings, and final diagnoses were recorded. Patients with pain or known liver disease were excluded. A gastrointestinal physician reviewed the laboratory values/chart to classify the type of suspected obstruction. Two radiologists blindly re-reviewed the US scans, and κ between the radiologists was calculated. Fisher exact test and the 2-sample t test were used for statistical analysis. RESULTS: Three hundred sixty patients presented with jaundice (>3 mg/dL), of whom 68 met the inclusion criteria (no pain and no known liver disease). Laboratory values had an overall accuracy of 54%, but were accurate in 87.5% and 85% for obstructing stones/pancreaticobiliary cancer. Ultrasound demonstrated overall accuracy of 78%, but only 69% for pancreaticobiliary cancer and 12.5% for common bile duct stone. Seventy-five percent of the patients underwent follow-up CECT or MRCP regardless of presenting setting. In the emergency department or inpatient setting, 92% of the patients underwent CECT or MRCP regardless of US, and 81% had follow-up CECT or MRCP within 24 hours. CONCLUSION: A US-first strategy in the setting of new-onset painless jaundice is accurate only 78% of the time. In practice, US was almost never a stand-alone imaging examination in patients presenting to the emergency department or inpatient setting with new-onset painless jaundice, no matter the suspected diagnosis based on clinical and laboratory grounds or on the US findings themselves. However, for milder elevations of unconjugated bilirubin (suspicious for Gilbert disease) in the outpatient setting, a US demonstrating lack of biliary dilatation was often a definitive study for exclusion of pathology.

State of the Art: Role of the Dendritic Cell in Induction of Allograft Tolerance.

Despite decades of research, the induction and maintenance of long-term allograft tolerance without immunosuppression remains an elusive goal in the field of solid organ and cell transplantation. Immunosuppressive medications frequently prevent or minimize acute cellular rejection but have failed to halt antidonor antibody production and chronic organ rejection. Past efforts aimed at promoting lasting allograft tolerance have focused primarily on peripheral T-cell depletion, augmentation of regulatory T cells, or induction via simultaneous hematopoietic stem cell transplantation and facilitation of donor chimerism. So far, none of these methods have led to consistently safe, feasible and long lasting donor organ acceptance. Over the course of the past 4 decades, the study of a unique population of antigen-presenting cells known as dendritic cells has shown promise for breaking new ground in achieving indefinite allograft survival without immunosuppression and its associated adverse effects. In this review, we discuss the discovery and early investigations of dendritic cells and chronicle some of the key studies demonstrating their role in transplantation, particularly in indirect allorecognition, the immunologic pathway thought to drive chronic rejection and perhaps tolerance induction.

Laparoscopic distal pancreatectomy offers shorter hospital stays with fewer complications.

BACKGROUND: Laparoscopic distal pancreatectomy (LDP) is increasingly performed for lesions of the body and tail of the pancreas. The aim of this study was to investigate short-term outcomes after LDP compared to open distal pancreatectomy (ODP) at a single, high-volume institution. METHODS: We reviewed records of patients who underwent distal pancreatectomy (DP) and compared perioperative data between LDP and ODP. Continuous variables were compared using Student's t or Wilcoxon rank-sum tests. Categorical variables were compared using chi-square or Fisher's exact test. RESULTS: A total of 360 patients underwent DP. Beginning in 2001, 95 were attempted, and 71 were completed laparoscopically with a 25.3% conversion rate. Compared to ODP, LDP had similar rates of splenic preservation, pancreatic fistula, and mortality. LDP had lower blood loss (150 vs. 900 mL, p < 0.01), smaller tumor size (2.5 vs. 3.6 cm, p < 0.01), and shorter length of resected pancreas (7.7 vs. 10.0 cm, p < 0.01). LDP had fewer complications (28.2% vs. 43.8%, p = 0.02) as well as shorter hospital stays (5 vs. 6 days, p < 0.01). CONCLUSIONS: LDP can be performed safely and effectively in patients with benign or low-grade malignant neoplasms of the distal pancreas. When feasible in selected patients, LDP offers fewer complications and shorter hospital stays.

Heterogeneous reactions of gaseous HNO3 and NO2 on the clay minerals kaolinite and pyrophyllite.

Airborne clay mineral particles have long atmospheric lifetimes due to their relatively small size. To assess their impact on trace atmospheric gases, we investigated heterogeneous reactions on prototype clay minerals. Diffuse reflectance infrared spectroscopy identified surface-adsorbed products formed from the uptake of gaseous nitric acid and nitrogen dioxide on kaolinite and pyrophyllite. For kaolinite, a 1:1 phyllosilicate, HNO3 molecularly adsorbed onto the octahedral aluminum hydroxide and tetrahedral silicon oxide surfaces. Also detected on the aluminum hydroxide surface were irreversibly adsorbed monodentate, bidentate, bridged, and water-coordinated nitrate species as well as surface-adsorbed water. Similar adsorbed products formed during the uptake of NO2 on kaolinite at relative humidity (RH) of 0%, and the reaction was second order with respect to reactive surface sites and 1.5 +/- 0.1 for NO2. Reactive uptake coefficients, calculated using Brunauer, Emmett, and Teller surface areas, increased from (8.0 +/- 0.2) x 10(-8) to (2.3 +/- 0.4) x 10(-7) for NO2 concentrations ranging from 0.56 x 10(13) to 8.8 x 10(13) molecules cm(-3). UV-visible spectroscopy detected gaseous HONO as a product for the reaction of NO2 on wet kaolinite. The uptake of HNO3 on pyrophyllite, a 2:1 phyllosilicate, resulted in stronger signal for nitric acid molecularly adsorbed on the silicon oxide surface compared to kaolinite. Monodentate, bridged, and water-coordinated nitrate species bound to aluminum sites also formed during this reaction indicating that reactive sites on edge facets are important for this system. The uptake of NO2 on pyrophyllite, gammaBET = (7 +/- 1) x 10(-9), was significantly lower than kaolinite because NO2 did not react with the dominant tetrahedral silicon oxide surface. These results highlight general trends regarding the reactivity of tetrahedral silicon oxide and octahedral aluminum hydroxide clay surfaces and indicate that the heterogeneous chemistry of clay aerosols varies with mineralogy and cannot be predicted by elemental analysis.