Biliary complications in living related liver transplantation

BACKGROUND

Biliary tract reconstruction has long been considered the Achilles' heel of liver transplantation as biliary complications can increase morbidity and mortality especially in partial liver graft transplantation.

METHODS

Thirty-four living related liver transplants were performed at Chang Gung Memorial Hospital in Kaohsiung for 33 children and 1 adolescent during a 5.5-year period. All potential donors underwent a detailed preoperative imaging study of the vascular and biliary anatomy, including three-dimensional helical computed tomographic cholangiography (n = 20), magnetic resonance cholangiography (n = 14), and intra-operative cholangiography (n = 31) before graft retrieval. All hepatic artery anastomoses were performed in the standard microsurgery fashion and their patency was confirmed intra-operatively using Doppler ultrasound.

RESULTS

The biliary complication rate was 8.8% (3/34), including multiple intrahepatic biliary stenosis of unknown origin (n = 1), bile leakage from the Roux-en-Y loop (n = 1), and a missed biliary radicle (n = 1) which were treated via interventional radiological and surgical procedures. The overall graft and patient survival rates were 100%.

CONCLUSION

The biliary complication rate in this series was low compared to those of other experienced centers. Complete study of the variations of intrahepatic duct ramification pre-and-intra-operatively provided adequate information on the appropriate transection plane. Furthermore, intra-operative Doppler ultrasound verification of vessel patency helps prevent vascular complications, which has been identified as a cause of biliary complications.

The correlations between the difficult temperament and subjective psychiatric symptoms in Chinese early adolescents

This study was designed to assess the intercorrelations between difficult temperament factors and self-rating psychiatric symptoms in Chinese early adolescents. The study subjects completed the Chinese Adolescent Temperament Self-Rating Questionnaire and Brief Psychiatric Symptom Rating Scale. Results revealed that the group of subjects with two or more difficult temperament factors showed significantly higher scores in some of self-rating psychiatric symptoms. In addition to difficult temperament factors, low score of task orientation and tactile threshold also appeared to be risk factors for self perceived psychiatric symptoms in the Chinese adolescents.

Analgesic effect of electric stimulation of peripheral nerves with different electric frequencies using the formalin test

Although electroacupuncture (EA) has been widely used to treat pain, the optimal frequency of EA therapy remains unclear. The study sought to determine the effect of different EA frequencies in a Sprague-Dawley (SD) rat model of pain. Electric stimulation (ES) at frequencies of 2 Hz, 15 Hz or 100 Hz was applied to the ipsilateral or contralateral sciatic nerve of the injected hindpaw of SD rats. Formalin (50 microl, 5%) was subcutaneously injected into the plantar surface of the left hindpaw to induce a nociceptive response. Behavior, including licking and biting, was observed to have two distinct periods, an early phase during the first 5 mins and a late phase from 21-35 mins after injection. The total biting or licking count served as an Indicator of nociceptive response. Our results indicate that ES of the ipsilateral sciatic nerve at a frequency of 2 Hz or 15 Hz reduced the nociceptive responses in both the early and the late phases of the formalin test, whereas ES at 2 Hz had greater antinociceptive effect than ES at 15 Hz in the early phase. No similar analgesic effect in the early phase was observed for ES at 100 Hz. Both pretreatment with ES at 2 Hz and naloxone (3 mg/kg, s.c.) produced a greater antinociceptive response in the late phase than when ES at 2 Hz was delivered immediately after formalin administration. In addition, ES of the neck muscle or contralateral sciatic nerve at a frequency of 2 Hz also decreased licking and biting activity in both phases. The results of this study indicate that different analgesic mechanisms are involved in the response to ES at frequencies of 2 Hz, 15 Hz and 100 Hz, and that ES at 2 Hz has a greater analgesic effect on formalin-induced nociceptive response, especially when it is delivered prior to the onset of pain. The analgesic effect of ES may be mediated via a central origin in the supraspinal level. These findings suggest that 2 Hz may be a good frequency selection for clinical EA applications in analgesia, and that pretreatment with EA at 2 Hz may be an effective method to treat post-operative pain.

Fast block matching algorithm based on the winner-update strategy

Block matching is a widely used method for stereo vision, visual tracking, and video compression. Many fast algorithms for block matching have been proposed in the past, but most of them do not guarantee that the match found is the globally optimal match in a search range. This paper presents a new fast algorithm based on the winner-update strategy which utilizes an ascending lower bound list of the matching error to determine the temporary winner. Two lower bound lists derived by using partial distance and by using Minkowski's inequality are described. The basic idea of the winner-update strategy is to avoid, at each search position, the costly computation of the matching error when there exists a lower bound larger than the global minimum matching error. The proposed algorithm can significantly speed up the computation of the block matching because: 1) computational cost of the lower bound we use is less than that of the matching error itself; 2) an element in the ascending lower bound list will be calculated only when its preceding element has already been smaller than the minimum matching error computed so far; 3) for many search positions, only the first several lower bounds in the list need to be calculated. Our experiments have shown that, when applying to motion vector estimation for several widely-used test videos, 92% to 98% of operations can be saved while still guaranteeing the global optimality. Moreover, the proposed algorithm can be easily modified either to meet the limited time requirement or to provide an ordered list of best candidate matches. Our source codes of the proposed algorithm are available at http://smart.iis.sinica.edu.tw/html/winup.html.

Outflow tract reconstruction in living donor liver transplantation

BACKGROUND

Hepatic venous reconstruction is critical in living donor liver transplantation because outflow obstruction may lead to graft dysfunction or loss. We describe our experience and analyze outcomes with a technique of creating a single outflow tract using venoplasties of the graft and recipient hepatic veins.

PATIENTS AND METHODS

A retrospective study was done on 38 consecutive living donor liver transplants performed from June 1994 to March 2000. The grafts included 36 left-side grafts and 2 right-side grafts. Nine grafts had multiple hepatic veins and required a venoplasty of two or three hepatic veins to create a single outflow orifice. Triple recipient hepatic venoplasty was performed in 32 patients, double venoplasty in 5 and none in 1.

RESULTS

There were four cases of outflow obstruction, three occurring in patients with a double recipient venoplasty. Two of the problems were remedied intraoperatively by adjusting the position of the graft although two were structural in nature and required the insertion of expandable metallic vascular stents. All donors and recipients with their original grafts are alive at a mean follow-up period of 27 months.

CONCLUSION

A triple recipient venoplasty with a matching venoplasty of multiple graft hepatic veins to create a single wide outflow orifice is recommended in living donor liver transplantation using left side grafts.

Aging and external ear resonance

External ear resonance was measured in elderly people using a probe-tube microphone system. Resonance frequency, amplitude, and bandwidth as well as ear canal volume were compared across age groups and genders. No significant age group trends were observed in external ear resonant frequency. Also, the amplitude and bandwidth of the resonance peaks across ages were not significantly different. For the gender effect, the mean external ear resonant frequencies are generally higher for females than for males in all age groups, but the differences are not statistically significant. The mean amplitudes of the resonant frequency are larger for men than for women. But the difference is also small. For the ear canal volume, no significant age trend was found. However, the mean ear canal volume was significantly larger for males than for females.

Expression and sequence analysis of the mouse adenine nucleotide translocase 1 and 2 genes

Only two isoforms of the adenine nucleotide translocase (Ant) protein have been identified in mouse, as opposed to the three in humans. To determine whether the homologous mouse and human proteins share similar patterns of expression, Northern and Western analyses were performed on several mouse tissues. Mouse Ant1 is expressed at high levels in skeletal muscle and heart, similar to human ANT1. Mouse Ant2 is strongly expressed in all tissues but muscle, in marked contrast to human ANT2. To investigate the molecular basis of these differences, we cloned and sequenced the genomic loci of mouse Ant1 and Ant2, and compared them to the three human ANT loci. The mouse and human ANT1 and ANT2 genes showed substantial homology starting about 300 base pairs (bp) 5' to the coding region and continuing through the 3' untranslated region (UTR). Repeats constituted 32% of 15kb of Ant1 sequence and 36% of the 27kb of Ant2 sequence and included SINEs, LINEs and LTR elements. The core promoters of the mouse and human ANT1 and ANT2 genes are very similar. However, the mouse Ant1 gene lacks the upstream OXBOX and REBOX elements found in human ANT1 genes, thought to be important for muscle-specific expression. The mouse Ant2 gene, like human ANT2, has an upstream GRBOX, yet this element is not associated with suppression of transcription, as hypothesized for human ANT2. These discrepancies indicate that additional studies will be required to fully understand the transcriptional regulation of both Ant1 and Ant2.

Two-hybrid system for characterization of protein-protein interactions in E. coli

The yeast two-hybrid system has been used to characterize many protein-protein interactions. A two-hybrid system for E. coli was constructed in which one hybrid protein bound to a specific DNA site recruits another to an adjacent DNA binding site. The first hybrid comprises a test protein, the bait, fused to a chimeric protein containing the 434 repressor DNA binding domain. In the second hybrid, a second test protein, the prey, is fused downstream of a chimeric protein with the DNA binding specificity of the lambda repressor. Reporters were designed to express cat and lacZ under the control of a low-affinity lambda operator. At low expression levels, lambda repressor hybrids weakly repress the reporter genes. A high-affinity operator recognized by 434 repressor was placed nearby, in a position that does not yield repression by 434 repressor alone. If the test proteins interact, the 434 hybrid bound to the 434 operator stabilizes the binding of the lambda repressor hybrid to the lambda operator, causing increased repression of the reporter genes. Reconstruction experiments with the fos and jun leucine zippers detected protein-protein interactions between either homodimeric or heterodimeric leucine zippers.

Peripheral nerve regeneration using silicone rubber chambers filled with collagen, laminin and fibronectin

A 10 mm gap of rat sciatic nerve was created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes filled with an extracellular gel containing collagen, laminin and fibronectin. Empty silicone rubber tubes were used as controls. Six weeks after implantation, all extracellular elements were completely degraded and absorbed, and 90% of the animals from the extracellular gel group exhibited regeneration across the nerve gaps, whereas only 60% in the control group. Both qualitative and quantitative histology of the regenerated nerves revealed a more mature ultrastructural organization with 28% larger cross-sectional area and 28% higher number of myelinated axons in the extracellular gel group than the controls. These results showed that the gel mixture of collagen, laminin and fibronectin could offer a suitable growth medium for the regeneration of axons.