Atmospheric blocking as a traffic jam in the jet stream.

Atmospheric blocking due to anomalous, persistent meandering of the jet stream often causes weather extremes in the mid-latitudes. Despite the ubiquity of blocking, the onset mechanism is not well understood. Here we demonstrate a close analogy between blocking and traffic congestion on a highway by using meteorological data and show that blocking and traffic congestion can be described by a common mathematical theory. The theory predicts that the jet stream has a capacity for the flux of wave activity (a measure of meandering), just as the highway has traffic capacity, and when the capacity is exceeded, blocking manifests as congestion. Stationary waves modulate the jet stream's capacity for transient waves and localize block formation. Climate change likely affects blocking frequency by modifying the jet stream's proximity to capacity.

Oxygen isotope anomaly observed in water vapor from Alert, Canada and the implication for the stratosphere.

To identify the possible anomalous oxygen isotope signature in stratospheric water predicted by model studies, 25 water vapor samples were collected in 2003-2005 at Alert station, Canada (82°30'N), where there is downward transport of stratospheric air to the polar troposphere, and were analyzed for δ(17)O and δ(18)O relative to Chicago local precipitation (CLP). The latter was chosen as a reference because the relatively large evaporative moisture source should erase any possible oxygen isotope anomaly from the stratosphere. A mass-dependent fractionation coefficient for meteoric waters, λMDF(H2O) = 0.529 ± 0.003 [2σ standard error (SE)], was determined from 27 CLP samples collected in 2003-2005. An oxygen isotopic anomaly of Δ(17)O = 76 ± 16 ppm (2σ SE) was found in water vapor samples from Alert relative to CLP. We propose that the positive oxygen isotope anomalies observed at Alert originated from stratospheric ozone, were transferred to water in the stratosphere, and subsequently mixed with tropospheric water at high latitudes as the stratospheric air descended into the troposphere. On the basis of this ground signal, the average Δ(17)O in stratospheric water vapor predicted by a steady-state box model is ∼40‰. Seven ice core samples (1930-1991) from Dasuopu glacier (Himalayas, China) and Standard Light Antarctic Precipitation did not show an obvious oxygen isotope anomaly, and Vienna Standard Mean Ocean Water exhibited a negative Δ(17)O relative to CLP. Six Alert snow samples collected in March 2011 and measured at Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France, had (17)Oexcess of 45 ± 5 ppm (2σ SE) relative to Vienna Standard Mean Ocean Water.

Wind, waves, and wing loading: morphological specialization may limit range expansion of endangered albatrosses.

Among the varied adaptations for avian flight, the morphological traits allowing large-bodied albatrosses to capitalize on wind and wave energy for efficient long-distance flight are unparalleled. Consequently, the biogeographic distribution of most albatrosses is limited to the windiest oceanic regions on earth; however, exceptions exist. Species breeding in the North and Central Pacific Ocean (Phoebastria spp.) inhabit regions of lower wind speed and wave height than southern hemisphere genera, and have large intrageneric variation in body size and aerodynamic performance. Here, we test the hypothesis that regional wind and wave regimes explain observed differences in Phoebastria albatross morphology and we compare their aerodynamic performance to representatives from the other three genera of this globally distributed avian family. In the North and Central Pacific, two species (short-tailed P. albatrus and waved P. irrorata) are markedly larger, yet have the smallest breeding ranges near highly productive coastal upwelling systems. Short-tailed albatrosses, however, have 60% higher wing loading (weight per area of lift) compared to waved albatrosses. Indeed, calculated aerodynamic performance of waved albatrosses, the only tropical albatross species, is more similar to those of their smaller congeners (black-footed P. nigripes and Laysan P. immutabilis), which have relatively low wing loading and much larger foraging ranges that include central oceanic gyres of relatively low productivity. Globally, the aerodynamic performance of short-tailed and waved albatrosses are most anomalous for their body sizes, yet consistent with wind regimes within their breeding season foraging ranges. Our results are the first to integrate global wind and wave patterns with albatross aerodynamics, thereby identifying morphological specialization that may explain limited breeding ranges of two endangered albatross species. These results are further relevant to understanding past and potentially predicting future distributional limits of albatrosses globally, particularly with respect to climate change effects on basin-scale and regional wind fields.

Intrahepatic biliary strictures after liver transplantation.

Biliary complication has been one of the most common complications after liver transplantation. Nonanastomotic strictures and dilatations involving the intrahepatic biliary tree have been recognized as biliary complications. These lesions were reported to be associated with hepatic artery thrombosis; prolonged preservation time; ABO-incompatible organs; and immunological injury, including injuries to vascular endothelial cells (chronic rejection) and the bile duct (primary sclerosing cholangitis). However, the etiology of these lesions appeared to be mostly related to ischemic injury. Anatomical research on the arterial supply of the bile duct has provided further insights into bile duct blood supply and its surgical implications. The biliary tract is supplied with arterial blood by a vasculature called the peribiliary vascular plexus. Any injury to the peribiliary vascular plexus may contribute to ischemic death of the biliary system mucosa. At many points, the process of liver transplantation exposes the endothelial cells and peribiliary vascular plexus to ischemic injury. The majority of intrahepatic biliary strictures (IHBS) are diffuse or bilateral. A percutaneous or an endoscopic approach has been used as the initial treatment. However, a low threshold for surgical intervention (retransplantation) should be adopted, because these patients demonstrate high mortality. The aim of this article is to review the anatomy, etiology, clinical picture, diagnosis, management, and prognosis of IHBS after liver transplantation.

Porcine model of auxiliary partial orthotopic liver transplantation for acute liver failure.

BACKGROUND: Auxiliary partial orthotopic liver transplantation (APOLT) has been an effective alternative in acute liver failure (ALF), but clinically several problems remain to be resolved. Thus, we attempt to establish an APOLT model for ALF using a large animal and demonstrate the validity of our model. METHODS: In experiment 1, we created an animal model of ALF using pig. ALF was induced by resection of 70% of the whole liver under total hepatic vascular exclusion (THVE). The duration of ischemia was 90 minutes. In experiment 2, we tried to make an APOLT model by using this ALF model as a recipient. That is, during 90 minutes of THVE, 70% hepatectomy and subsequent partial orthotopic transplantation was completed. RESULTS: In experiment 1, six of seven pigs died within three days with jaundice and massive ascites. Based on microcirculatory disturbance of the remnant liver and hepatocellular necrosis, 70% hepatectomy with 90 minutes of THVE was considered a proper model of ALF. In experiment 2, six out of seven APOLT model animals survived more than four days. T. Bil levels in the APOLT model remained consistently within the normal range throughout the observation period. In immunohistochemistry, several labeled nuclei stained with Ki67 were identified in native liver of the APOLT model. CONCLUSIONS: This APOLT procedure provided temporary liver function support and enabled the recipient to survive until the failing native liver had regenerated. Our APOLT model could be suitable and useful for understanding the role of APOLT in ALF.

First detection of Rickettsia in soft-bodied ticks associated with seabirds, Japan.

Rickettsia was first detected in seabird soft-bodied ticks, Carios capensis and C. sawaii in Japan. According to sequence analysis, Rickettsia in Japan was identical to Rickettsia scc31 in C. capensis in the U.S.A. This suggested that an environmental circulation had consisted among microorganisms, ticks and long distance migratory seabirds around the Pacific Ocean.

99mTc-DTPA-galactosyl-human-serum-albumin liver scintigraphy for evaluating hepatic functional reserve before hepatectomy in a patient with indocyanine green excretory defect: report of a case.

A 78-year-old woman with indocyanine green (ICG) excretory defect underwent left hepatectomy for cystadenocarcinoma. The retention rate of ICG at 15 min (ICGR(15)) was high, at 79.3%, despite all other liver function tests showing normal values. Conversely, 99mTc-DTPA-galactosyl-human-serum-albumin (GSA) liver scintigraphy showed a reduced accumulation of GSA in the left lateral lobe, the hepatic uptake ratio of the GSA scintigraphy was 0.96, and the arterial ketone body ratio was 1.67. Based on these results, we judged that the hepatic functional reserve of this patient was adequate for left hepatectomy, which was subsequently performed uneventfully. Histopathological examination of the resected liver showed neither fibrosis nor inflammatory cell infiltration. Thus, we consider that GSA liver scintigraphy is the best diagnostic modality for evaluating hepatic functional reserve in a patient with ICG excretory defect.

Piggyback technique in adult orthotopic liver transplantation: an analysis of 1067 liver transplants at a single center.

BACKGROUND: Orthotopic liver transplantation (OLT) in adult patients has traditionally been performed using conventional caval reconstruction technique (CV) with veno-venous bypass. Recently, the piggyback technique (PB) without veno-venous bypass has begun to be widely used. The aim of this study was to assess the effect of routine use of PB on OLTs in adult patients. PATIENTS AND METHODS: A retrospective analysis was undertaken of 1067 orthotopic cadaveric whole liver transplantations in adult patients treated between June 1994 and July 2001. PB was used as the routine procedure. Patient demographics, factors including cold ischemia time (CIT), warm ischemia time (WIT), operative time, transfusions, blood loss, and postoperative results were assessed. The effects of clinical factors on graft survival were assessed by univariate and multivariate analyses.In all, 918 transplantations (86%) were performed with PB. Blood transfusion, WIT, and usage of veno-venous bypass were less with PB. Seventy-five (8.3%) cases with PB had refractory ascites following OLT (p=NS). Five venous outflow stenosis cases (0.54%) with PB were noted (p=NS). The liver and renal function during the postoperative periods was similar. Overall 1-, 3-, and 5-year patient survival rates were 85%, 78%, and 72% with PB. Univariate analysis showed that cava reconstruction method, CIT, WIT, amount of transfusion, length of hospital stay, donor age, and tumor presence were significant factors influencing graft survival. Multivariate analysis further reinforced the fact that CIT, donor age, amount of transfusion, and hospital stay were prognostic factors for graft survival. CONCLUSIONS: PB can be performed safely in the majority of adult OLTs. Results of OLT with PB are as same as for CV. Liver function, renal function, morbidity, mortality, and patient and graft survival are similar to CV. However, amount of transfusion, WIT, and use of veno-venous bypass are less with PB.

Metastasis of uterine leiomyosarcoma to the pancreas.

BACKGROUND: Metastasis of uterine leiomyosarcoma to the pancreas is extremely rare. CASE: A 46-year-old woman presented with hypermenorrhea and dysmenorrhea and underwent surgery. The histologic and immunohistochemical diagnosis was uterine leiomyosarcoma stage I with no metastasis to the ovaries or the pelvic lymph nodes. The mitotic count was very high. Thereafter, recurrences in the lung and subsequently in the pancreas were detected. The lesions in the lung and pancreas were resected and diagnosed as metastases of uterine leiomyosarcoma based on histology and immunohistochemistry. CONCLUSION: We report an extraordinarily rare case of uterine leiomyosarcoma with metastasis to the pancreas following initial metastasis to the lung, both of which were diagnosed using histology and immunohistochemistry of the specimens obtained at surgery.

Carcinosarcoma of the extrahepatic bile duct.

A rare case of a carcinosarcoma of the extrahepatic bile duct demonstrating interesting features is described. A 75-year-old woman with a history of choledocholithotomy presented with acute obstructive suppurative cholangitis. Ultrasonography and computed tomography showed a thickened choledochal wall, with calcification. Percutaneous transhepatic and endoscopic retrograde cholangiography revealed a round filling defect accompanied by an irregular obstruction in the common bile duct. Carcinosarcoma was diagnosed from a protruding lesion in the common bile duct obtained by intraoperative frozen sectioning, and pylorus-preserving pancreatoduodenectomy was performed. Histological examination by light microscopy showed a transition between the carcinomatous and sarcomatous components and positive immunoreactivity for epithelial markers in the sarcomatous component. The patient died of a local recurrence 2 years after the surgery. Polypoid growth and ossification in the tumor could be representative features of carcinosarcoma of the extrahepatic bile duct.

Intrahepatic biliary strictures without hepatic artery thrombosis after liver transplantation: an analysis of 1,113 liver transplantations at a single center.

BACKGROUND: Intrahepatic biliary strictures (IHBS) without hepatic artery thrombosis (HAT) is a serious complication and known to increase the risk of graft failure after liver transplantation. This manuscript describes the incidence, risk factors, clinical pictures, management, and outcomes. METHODS: Between 1994 and 2002, 1,113 liver transplantations were performed in 974 adult patients. Data was retrospectively analyzed in terms of incidence, risk factors, clinical pictures (type of strictures), management (radiologic, surgical management), and outcomes. RESULTS: Sixteen (1.4%) grafts had IHBS without HAT. Specific risk factors were not identified from donors or recipients. However, ischemic factors from the donors were suspected from non-heart-beating donors (n=1) and cardiac-arrest donors (n=2). Three types of IHBS were identified: (1) diffuse type (n=7), (2) bilateral proximal type (n=7), and (3) unilateral type (n=2). Overall success rate of radiologic interventions was 31.3% (5/16). Of the 11 patients who did not improve, 6 died: diffuse type (3/7, 42.9%), bilateral type (3/7, 42.9%), and unilateral (0/2, 0%). Three patients had retransplantation, and two patients are waiting retransplantation. The majority of the IHBS were diffuse or bilateral (14/16, 87.5%), and rate of the graft failure was high (10/14, 71.4 %). Overall graft survival of IHBS was lower than that without IHBS (P=0.025). CONCLUSIONS: The majority of the IHBS without HAT were of a diffuse or bilateral proximal type. Patients with diffuse or bilateral proximal type have a low success rate from radiologic intervention and may benefit from early retransplantation.

Intestinal and multivisceral transplantation after abdominal trauma.

SUMMARY: BACKGROUND Some trauma victims who survive acute illness develop lingering, debilitating syndromes that are incompatible with any semblance of normalcy. Intestinal failure, in particular, exacts a high price in terms of quality of life. Total parenteral nutrition (TPN) has served these patients well, but complications limit its long-term therapeutic effect. Consequently, transplantation is emerging as a life-saving therapy for some patients with the short gut syndrome. METHODS We reviewed eight adult and two pediatric recipients of intestinal and multivisceral transplants after severe abdominal trauma. Background demographics, type of abdominal trauma, transplant procedure, postoperative complications, and survival rates were appraised. This group was also compared with 47 nontrauma recipients of intestinal transplants performed during the same period. RESULTS Four patients (40%) died postoperatively (postoperative days 7, 53, 87, and 91) as a result of multiple organ failure after graft pancreatitis (n = 1), viral encephalitis (n = 1), and sepsis after severe rejection (n = 2). Six patients (60%) are alive (postoperative days 52-1,783). All are off TPN. The 4-year patient survival was 58%, with no significant difference between trauma and nontrauma patients.CONCLUSION Intestinal and multivisceral transplantation are viable options for the treatment of irreversible intestinal failure associated with severe trauma. Surviving patients are TPN independent and have a satisfactory quality of life.

Use of older controlled non-heart-beating donors for liver transplantation.

BACKGROUND: Use of liver grafts from non-heart-beating donors (NHBDs) warrants consideration so to expand the donor pool. Because the results of controlled NHBDs (CNHBDs) were acceptable, we have recently tried to expand the criteria to older CNHBDs. Here, we report our experience using liver grafts from older CNHBDs. METHODS: We retrospectively studied our donor records from June 1994 through December 2001. CNHBDs were divided into two groups by age: older donors (O) were more than or equal to 55 years old, and younger donors (Y) were less than 55 years old. We compared donor and recipient demographics and peak laboratory values during the first postoperative week. RESULTS: Twenty-five grafts from CNHBDs were transplanted in our center. Five livers were harvested from O (63+/-6 years) and 20 were from Y (32+/-15 years). No differences other than age in donor characteristics were noted between O and Y. Mean age of recipients was 50 years in both groups. Mean cold ischemic time (CIT) was 5.4 hours in O and 7.3 hours in Y (P<.05). Peak glutamic oxaloacetic transaminase (U/L), glutamic pyruvic transaminase (U/L), bilirubin (mg/dL), and prothrombin time (sec) during the first postoperative week were 611, 500, 3.9, and 16 in O and 846, 593, 5.9, and 17 in Y. There were no significant differences between the two groups. The graft survival at 1 year was 80% in O and 70% in Y. CONCLUSIONS: In our preliminary experience, recipients of liver grafts from older CNHBDs had an outcome equivalent to that of younger CNHBDs. With the strict evaluation of the donors and brief CIT, liver grafts from older CNHBDs may be used to expand the donor pool.

Serotonin activity and liver dysfunction following hepatic ischemia and reperfusion.

Serotonin (5-hydroxytriptamine; 5-HT), which is stored in platelets, is known to induce vasoconstriction and promote platelet aggregation. More recent studies suggest that serotonin also plays a role in organ injury after ischemia and reperfusion. The purpose of this study was to characterize the role of 5-HT and platelet function in the pathogenesis of hepatic ischemia-reperfusion injury. Under the portocaval shunt, 60 or 90 min of complete warm ischemia of canine liver was induced by Pringle's maneuver, followed by reperfusion for 120 min. Time-matched, sham-operated animals served as controls. Hepatic tissue blood flow and various parameters of hepatic vein blood (ALT, LDH, platelet count and platelet aggregation) were measured before and after reperfusion. 5-HT levels in portal vein and hepatic vein were also assayed. Hepatic ischemia and reperfusion resulted in liver hypoperfusion, hepatocellular dysfunction, increased platelet aggregation, increased 5-HT levels, and hepatic microcirculation injury. These results suggest that the endogenous 5-HT released from platelet may contribute to liver tissue hypoperfusion following hepatic ischemia-reperfusion.

Donor intracaval thrombus formation and pulmonary embolism after simultaneous piggyback liver transplantation and aortic valve replacement.

Pulmonary embolism (PE) is a well known and serious complication that may develop after abdominal surgery. Liver transplant recipients are not immune to PE and tend to share many of the same risk factors with surgical patients who are stricken with this potential fatal complication. Liver transplantation using the piggyback (PB) technique is widely accepted, although there are reports of technique-specific-related vascular complications. We present a case of a 49-yr-old male liver transplant recipient who received his graft using the PB while simultaneously undergoing aortic valve replacement. His post-operative course was complicated by a PE 15 d after his surgery and was the result of an intracaval thrombus of the graft liver. The current case should alert clinicians to think of a donor intracaval thrombus as a complication of PB liver transplantation and a possible source of PE.

Effect of protocol Doppler ultrasonography and urgent revascularization on early hepatic artery thrombosis after pediatric liver transplantation.

HYPOTHESIS: Protocol Doppler ultrasonography of the liver (DUSL) is useful for detecting early hepatic artery thrombosis (HAT). Urgent exploration based on DUSL findings and immediate revascularization of the liver may avoid HAT-related sequelae, namely, biliary complications and retransplantation after pediatric liver transplantation. DESIGN: Case-control study. SETTING: University hospital. PATIENTS: Group 1 included 96 liver transplantations performed in 75 pediatric patients from June 1, 1994, to August 31, 1999. Group 2 included 43 liver transplantations performed in 39 pediatric patients from September 1, 1999, to September 30, 2001. INTERVENTION: In group 1, DUSL was performed on the first posttransplantation day or on request. Angiographic confirmation of suggested HAT was treated with thrombolysis, angioplasty, or thrombectomy. In group 2, protocol DUSL was performed every 12 hours in the first week and every 24 hours in the second week. The suspicion of HAT warranted urgent surgery without the patient undergoing angiography. MAIN OUTCOME MEASURES: Incidence of HAT, biliary complications, and retransplantation. Graft and patient survival. Hospital stay, and number of admissions and operations after undergoing HAT. RESULTS: The incidence of HAT was 10.4% (10 of 96 transplantations) in group 1 and 7.0% (3 of 43 transplantations) in group 2. The incidence of biliary complications after HAT was 100% in group 1 and 0% in group 2 (P=.02). The incidence of retransplantation after HAT was 90.0% (9 of 10 patients) in group 1 and 0% in group 2 (P=.01). Of the 10 patients who experienced HAT in group 1, 5 patients underwent early retransplantation (mean length of time, 13.2 days). All 5 patients who did not undergo early retransplantation had biliary complications. Four of these 5 patients underwent retrasplantation at a later time (mean length of time, 687 days). In group 2, DUSL identified early HAT in 3 patients (7.0%). Emergent thrombectomy and arterial reconstruction were undertaken. All 3 (100%) have their original graft and are alive. None experienced biliary complications. One-year graft and patient survival is 72.0% and 84.0%, respectively, in group 1 and 80.0% and 85.0%, respectively, in group 2. Shorter hospital stay, fewer readmissions, and surgery after HAT were noted in group 2. CONCLUSIONS: Protocol DUSL detects early HAT and urgent revascularization based on DUSL can significantly reduce the incidence of biliary complication and graft loss requiring retransplantation in pediatric liver transplantation.

Chlorine isotope fractionation during reductive dechlorination of chlorinated ethenes by anaerobic bacteria.

Chlorine isotope fractionation during reductive dechlorination of trichloroethene (TCE) and tetrachloroethene (PCE) to cis-1,2-dichloroethene (cDCE) by anaerobic bacteria was investigated. The changes in the 37Cl/35Cl ratio observed during the one-step reaction (TCE to cDCE) can be explained by the regioselective elimination of chlorine accompanied by the Rayleigh fractionation. The fractionation factors (alpha) of the TCE dechlorination by three kinds of anaerobic cultures were approximately 0.994-0.995 at 30 degrees C. The enrichment of 37Cl in the organic chlorine during the two-step reaction (PCE to cDCE) can be explained by the random elimination of one chlorine atom in the PCE molecule followed by the regioselective elimination of one chlorine atom in the TCE molecule. The fractionation factors for the first step of the PCE dechlorination with three kinds of anaerobic cultures were estimated to be 0.987-0.991 at 30 degrees C using a mathematical model. Isotope fractionation during the first step would be the primary factor for the chlorine isotope fractionation during the PCE dechorination to cDCE. The developed models can be utilized to evaluate the fractionation factors of regioselective and multistep reactions.