Soluble thrombomodulin antigen as a marker for endothelial damage during liver transplantation.
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Adolescent↗
Biomedical subjects
Y C Chiang
Publications and source records attributed to Y C Chiang.
Repeated hypotensive episodes due to hepatic outflow obstruction during liver transplantation in adult patients.
We report two cases of unusual repeated hypotension, decreased cardiac output, decreased mixed venous oxygen saturation, decreased central venous pressure, pulmonary artery pressure, and pulmonary wedge pressure after the completion of all vascular anastamoses of liver transplantation. These unstable hemodynamics appear to reflect a clinically relevant picture of hypovolemia. However, the real cause was partial hepatic outflow obstruction. The obstruction was suspected because hypotension was alleviated by elevating the full-sized liver graft ventrally and to the left. Doppler ultrasound examination confirmed that the flow velocity of the hepatic vein outflow was insufficient when the liver fell to its resting position in the right hepatic fossa. An additional side-to-side cavo-caval anastomosis resolved the problem in one patient, whereas the other required not only the additional anastomosis, but also application of a tissue expander filled with 770 mL normal saline beneath the liver to eliminate the obstruction. We emphasize that obstruction of the hepatic outflow causes only temporal hypovolemia because of a decrease of venous return and that treatment of this complication should be surgical intervention to relieve the obstruction. Blind resuscitation with fluids will not solve the problem and, in fact, may result in fluid overload with subsequent complications.
Adult↗
Clusterin may be involved in rat liver allograft tolerance.
Little is known about the possible role of complement inhibitors on tolerance induced by liver allografts. Clusterin, which is a plasma glycoprotein, inhibits cytolytic membrane attack complex (MAC) of complement by binding to soluble C5b-7 complex. The role of clusterin in relation to the naturally achieved tolerance in a rat orthotopic liver transplantation (OLT) has not been investigated before. Here we determined the kinetics of clusterin expression at different post-transplantation time points in a tolerogenic model (DA-PVG) where rejection was naturally overcome without any immunosuppressive drugs in comparison with the syngenic OLT model (DA-DA). Peripheral blood and liver tissues were taken from OLT at various post-operative time points. A strong expression of soluble clusterin was observed on post-transplantation day 7, which occurred at the peak of the rejection in this tolerogenic OLT model. The expression of clusterin remained strong even after tolerance was achieved. The intensity of clusterin expression was much stronger when compared with the syngenic OLT (DA-DA) model after OLT. A strong expression of clusterin mRNA was also observed in the tolerogenic model on post-OLT day (POD) 7 and the expression persisted when compared with the syngenic model on post-OLT day 60. Our data have shown that the strongest levels of clusterin during the reaction phase in tolerogenic OLT may be involved in tolerance induction.
Animals↗
International sharing of split liver grafts in Asia: initial experience.
The donor shortage problem is particularly serious in Asia and has markedly limited progress in liver transplantation. The increasing demand has, in fact, made it necessary to resort to living donor liver transplantation in both pediatric and adult recipients. Nevertheless, expanding the use of split liver allografts is yet another option to increase the supply. This has a wide potential application on a regional level because most liver transplant programs are still small and may have limited resources in terms of being able to do two transplants in one sitting. The first experience of overseas sharing of split liver grafts in Asia took place in January 1999. The graft was from a 35-yr-old donor from Kaohsiung, Taiwan, who sustained irreversible brain damage in a vehicular accident and had optimal conditions for multiorgan donation. The liver was split ex vivo and the left lateral segment was given to a 3-yr-old girl with biliary atresia at the Chang Gung Memorial Hospital. The extended right lobe split graft was transported to Hong Kong and transplanted into a 51-yr-old male patient with end-stage hepatitis C cirrhosis who was then in a state of acute failure with hepatorenal syndrome. Graft function was excellent in both recipients and the patient from Taiwan was discharged without any complications. Unfortunately, the Hong Kong recipient developed a cerebrovascular accident and required a reoperation for bile leakage from the cut surface of the liver in the early postoperative period. He has made a steady recovery since then; graft function has remained good and his kidneys have recovered. Both patients are currently alive and well 11 months post-transplant. This initial experience of overseas sharing of split liver grafts in Asia demonstrates its feasibility. It has a potentially wide applicability and could lead to the establishment of a formal organ-sharing network in the region. Established competence and mutual trust among the participating liver transplant teams would be essential in perpetuating such a graft-multiplying strategy on an organized basis.
Adult↗
Functional interaction of CCR4-NOT proteins with TATAA-binding protein (TBP) and its associated factors in yeast.
The CCR4-NOT transcriptional regulatory complex affects expression of a number of genes both positively and negatively. We report here that components of the CCR4-NOT complex functionally and physically interact with TBP and TBP-associated factors. First, mutations in CCR4-NOT components suppressed the his4-912delta insertion in a manner similar to that observed for the defective TBP allele spt15-122. Second, using modified HIS3 promoter derivatives containing specific mutations within the TATA sequence, we found that the NOT proteins were general repressors that disrupt TBP function irrespective of the DNA sequence. Third, increasing the dosage of NOT1 specifically inhibited the ability of spt15-122 to suppress the his4-912delta insertion but did not affect the Spt- phenotype of spt3 or spt10 at this locus. Fourth, spt3, spt8, and spt15-21 alleles (all involved in affecting interaction of SPT3 with TBP) suppressed ccr4 and caf1 defects. Finally, we show that NOT2 and NOT5 can be immunoprecipitated by TBP. NOT5 was subsequently shown to associate with TBP and TAFs and this association was dependent on the integrity of TFIID. These genetic and physical interactions indicate that one role of the CCR4-NOT proteins is to inhibit functional TBP-DNA interactions, perhaps by interacting with and modulating the function of TFIID.
Alcohol Oxidoreductases↗
Combined microvascular anastomosis: experimental and clinical experience.
A short operative time and a high successful rate of microvascular anastomosis are the goals of many plastic surgeons. The authors present their experimental and clinical experience in microvascular anastomoses with the use of a combination of continuous suture and interrupted tie. Twenty rats were divided into two groups. The aorta and inferior vena cava were used for microvascular anastomoses. The vessels of 10 rats were repaired with conventional interrupted suture, and the vessels of the other 10 rats were repaired with combined anastomoses. A total of 150 clinical microvascular surgeries during the past 2 years are also presented, all of which were performed using the combined method. Microvascular anastomoses with the combined method were completed faster than when using the conventional interrupted method in experimental studies. Clinically, no direct microvascular anastomosis failed with the use of combined method. Microvascular anastomosis with the use of the combined continuous suture and interrupted tie resulted in satisfactory outcomes. This technique has the advantages of both interrupted and continuous methods, but not their shortcomings.
Animals↗
Plasma selenium levels and risk of hepatocellular carcinoma among men with chronic hepatitis virus infection.
Both experimental and epidemiologic studies have linked a low dietary intake of selenium with an increased risk of cancer. The authors examined the association between plasma selenium levels and risk of hepatocellular carcinoma (HCC) among chronic carriers of hepatitis B and/or C virus in a cohort of 7,342 men in Taiwan who were recruited by personal interview and blood draw during 1988-1992. After these men were followed up for an average of 5.3 years, selenium levels in the stored plasma were measured by using hydride atomic absorption spectrometry for 69 incident HCC cases who were positive for hepatitis B surface antigen (HBsAg) and/or antibodies against hepatitis C virus (mostly HBsAg positive) and 139 matched, healthy controls who were HBsAg positive. Mean selenium levels were significantly lower in the HCC cases than in the HBsAg-positive controls (p = 0.01). Adjusted odds ratios of HCC for subjects in increasing quintiles of plasma selenium were 1.00, 0.52, 0.32, 0.19, and 0.62, respectively. The inverse association between plasma selenium levels and HCC was most striking among cigarette smokers and among subjects with low plasma levels of retinol or various carotenoids. There was no clear evidence for an interaction between selenium and alpha-tocopherol in relation to HCC risk.
Adult↗
Magnetic resonance of the hepatic veins with angular reconstruction: application in living-related liver transplantation.
BACKGROUND: Preoperative mapping of the hepatic venous system of the partial liver graft is indispensable to the success of living-related liver transplantation. We assessed the accuracy of magnetic resonance (MR) venography with angular reconstruction in depicting the tributaries of the middle hepatic vein and left hepatic vein in the donors, which was essential in graft retrieval and venoplasty. METHODS: Nineteen living-related liver transplantation donors underwent a pretransplantation survey, including sonography and MRI for hepatic venous evaluation. T1-weighted images were reconstructed manually, using the inferior vena cava as a fixed point for tilting to produce an oblique plane image where both the middle hepatic vein and left hepatic vein could be demonstrated draining into the inferior vena cava. The reconstructed images of the hepatic veins were compared with preoperative sonography, intraoperative sonography, and operative findings. RESULTS: Preoperative sonography and MR findings correlated well with the operative findings in the major hepatic veins. The MR venography of the ramification of the hepatic veins has an accuracy of 93%, the sonography, 84%. Sonography is slightly inferior in the evaluation of the hepatic vein in segment 4 and the left superior hepatic vein, with an accuracy of 73% and 67%, respectively. CONCLUSION: MR venography with angular reconstruction is accurate in depicting the complex distribution of the hepatic veins of the left liver, providing important information for decision making as to the cutting plane during graft retrieval and the method of venoplasty and anastomosis. Thus, unnecessary blood loss could be avoided and vascular complications could be prevented, as these conditions would be unacceptable for a healthy living donor. We propose that MR venography, a rapid and reliable technique, is an appropriate alternative examination or complementary modality to sonography in the pretransplantation evaluation of the living donor.
Adult↗
Plasma carotenoids, glutathione S-transferase M1 and T1 genetic polymorphisms, and risk of hepatocellular carcinoma: independent and interactive effects.
This study was conducted to assess the role of carotenoid and glutathione S-transferase (GST) M1 and T1 genetic polymorphisms in the development of hepatocellular carcinoma (HCC). A total of 84 incident cases of HCC and 375 matched controls selected from a cohort of 7,342 men (4,841 chronic hepatitis B carriers and 2,501 noncarriers) who were recruited between 1988 and 1992 in Taiwan were studied. Neither GST M1/T1 polymorphisms nor plasma levels of various carotenoids were independently associated with HCC, but they modulated smoking- and/or drinking-related HCC risk. Cumulative exposure to tobacco smoke significantly increased HCC risk in a dose-dependent manner among subjects with low plasma beta-carotene levels (p for trend = 0.047) but not among those with high levels. A statistically significant effect of habitual alcohol drinking on HCC risk was observed only for those with low plasma levels of beta-carotene, alpha-carotene, or lycopene and for GST M1 null subjects. There was evidence suggesting an interaction between the GST M1/T1 genotype and certain carotenoids in HCC associated with smoking and drinking. The strongest effect of smoking and drinking was noted among GST M1 null subjects with low plasma levels of beta-carotene (smoking: adjusted odds ratio (OR) = 3.54, 95% confidence interval (CI) 1.06-11.83; drinking: OR = 8.28, 95% CI 2.40-28.61).
Adult↗
A p53 genetic polymorphism as a modulator of hepatocellular carcinoma risk in relation to chronic liver disease, familial tendency, and cigarette smoking in hepatitis B carriers.
This study evaluated whether the codon 72 p53 polymorphism was related to hepatocellular carcinoma (HCC). Genotypes of p53 were determined in 80 incident cases of HCC and 328 controls nested in a cohort study of 4,841 male chronic hepatitis B carriers. No overall increase in HCC risk with the Pro variant allele of the p53 polymorphism was apparent. However, there were synergistic effects on HCC development for the Pro allele with chronic liver disease and family history of HCC in first-degree relatives. Compared with subjects without the Pro allele and chronic liver disease, the increase in HCC risk associated with chronic liver disease among those without the Pro allele was only threefold. Subjects with both chronic liver disease and the Pro allele were at an increased risk of 7.60 (95% CI = 2.28-25.31). When subjects without family history of HCC and the Pro allele were considered as the reference group, there was no apparent increased risk of HCC for those without the Pro allele who had family history of HCC. Among those with both factors, there was a significantly increased risk of 3.29 (95% CI = 1.10-9.85). Both cigarette smoking and glutathione S-transferase M1 genotype modified the risk of HCC associated with the p53 polymorphism. Significantly increased risk associated with the p53 genotype was observed only among smokers who were glutathione S-transferase-null (Pro/Pro vs. Arg/Arg: odds ratio = 6.46; 95% CI = 1.55-26.94). The p53 polymorphism also interacted with the cytochrome P450 1A1 and carotenoid levels in smoking-related hepatocarcinogenesis.
Adult↗
Contact leukomelanosis induced by the leaves of Piper betle L. (Piperaceae): a clinical and histopathologic survey.
BACKGROUND: In April 1997, an unusual pigmentary disorder was noticed by dermatologists in Taiwan. All patients had a history of using facial dressings with steamed leaves of Piper betle L. (Piperaceae). OBJECTIVE: Our purpose was to clarify the evolution and the origin of this unique leukomelanosis. METHODS: Fifteen patients with an unusual pigmentary disorder, who visited our clinic in September and October 1997, were asked to complete a questionnaire designed to elicit the history related to the disorder. Eight of these 15 patients underwent skin biopsies: 6 on the mottled hyperpigmented area (group A) and 2 on the hypopigmented area (group B). All 8 specimens were prepared with hematoxylin-eosin, Masson-Fontana, and S-100 stains. RESULTS: The results of the questionnaire revealed that these patients had all experienced a temporary erythematous reaction in the first few days of the use of the facial dressing, and 9 of them also complained of an accompanying stinging sensation. A bleaching effect became noticeable approximately 1 week to 1 month later. Eight patients reported that the hyperpigmentation and confetti-like hypopigmentation occurred after overexposure to the sun. In both groups, histopathologic examination revealed some melanophages in the dermis. Masson-Fontana staining of specimens from group A showed local interspersed depigmentation and hyperpigmentation in the basal epidermis and pigmentary incontinence in the dermis. This picture was different from the homogeneous depigmentation within basal epidermis in specimens from group B. In both groups, S-100 staining was negative for melanocytes in the depigmented area. CONCLUSION: The clinical course and histopathologic findings suggest that the evolution of this pigmentary disorder can be divided into 3 stages. The first stage is the immediate bleaching stage, when an irritant reaction is usually conspicuous. The second stage consists of prominent hyperpigmentation visible both grossly and microscopically. The final stage is characterized by confetti-like depigmentation. It may be induced by chemicals in the betel leaves such as phenol, catechol, and benzene derivatives, perhaps through inhibition of melanin synthesis or melanocytotoxicity.
Adult↗
Jaw electromyographic activity induced by the application of algesic chemicals to the rat tooth pulp.
The aim of this study was to determine if the application of mustard oil (MO), a small-fiber excitant and inflammatory irritant, or other algesic chemicals (capsaicin, CAP, and bradykinin, BK) to the rat maxillary molar tooth pulp induces electromyographic (EMG) activity of the masseter and digastric muscles, and also to determine if endogenous opioid mechanisms may be involved in any documented EMG changes. Application of MO to the tooth pulp induced a significant increase in EMG activity of the ipsilateral masseter up to 30 min. The application of mineral oil to the pulp or MO application to the pulp-extirpated tooth did not induce any significant EMG increases. The application of CAP or BK to the pulp in contrast had much weaker effects on EMG activity of the jaw muscles. CAP produced a small but prolonged increase in masseter EMG activity, and BK induced a short-lasting increase in digastric EMG activity. The systemic administration of the opiate antagonist naloxone significantly reactivated (i.e. rekindled) the EMG response evoked by MO application to the pulp. Naloxone did not produce any such significant rekindling effect on EMG activity following CAP, BK or mineral oil application to the pulp or following MO application to the pulp-extirpated tooth. The MO, BK and especially CAP groups showed histological evidence of vasodilatation and polymorphonuclear leukocyte infiltration in the pulp tissue and a significant increase in plasma extravasation of Evans Blue dye, whereas mineral oil did not induce these changes. These findings suggest that pulp afferent inputs to the central nervous system evoked by BK. CAP and especially MO may induce enhanced jaw muscle activity. In addition, the naloxone data suggest that an opioid suppresive mechanism may be induced by the pulpal afferent inputs evoked by MO, and may serve to limit the jaw muscle activity elicited by these inputs.
Animals↗
The CCR4 and CAF1 proteins of the CCR4-NOT complex are physically and functionally separated from NOT2, NOT4, and NOT5.
The CCR4-NOT complex (1 mDa in size), consisting of the proteins CCR4, CAF1, and NOT1 to NOT5, regulates gene expression both positively and negatively and is distinct from other large transcriptional complexes in Saccharomyces cerevisiae such as SNF/SWI, TFIID, SAGA, and RNA polymerase II holoenzyme. The physical and genetic interactions between the components of the CCR4-NOT complex were investigated in order to gain insight into how this complex affects the expression of diverse genes and processes. The CAF1 protein was found to be absolutely required for CCR4 association with the NOT proteins, and CCR4 and CAF1, in turn, physically interacted with NOT1 through its central amino acid region from positions 667 to 1152. The NOT3, NOT4, and NOT5 proteins had no significant effect on the association of CCR4, CAF1, and NOT1 with each other. In contrast, the NOT2, NOT4, and NOT5 interacted with the C-terminal region (residues 1490 to 2108) of NOT1 in which NOT2 and NOT5 physically associated in the absence of CAF1, NOT3, and NOT4. These and other data indicate that the physical ordering of these proteins in the complex is CCR4-CAF1-NOT1-(NOT2, NOT5), with NOT4 and NOT3 more peripheral to NOT2 and NOT5. The physical separation of CCR4 and CAF1 from other components of the CCR4-NOT complex correlated with genetic analysis indicating partially separate functions for these two groups of proteins. ccr4 or caf1 deletion suppressed the increased 3-aminotriazole resistance phenotype conferred by not mutations, resulted in opposite effects on gene expression as compared to several not mutations, and resulted in a number of synthetic phenotypes in combination with not mutations. These results define the CCR4-NOT complex as consisting of at least two physically and functionally separated groups of proteins.
Binding Sites↗
Within- and between-individual length heterogeneity of the rDNA-IGS in Miscanthus sinensis var. glaber (Poaceae): phylogenetic analyses.
The variability in the intergenic spacer (IGS) region between 17S and 25S rRNA genes of ribosomal DNA (rDNA) gene family was surveyed in Miscanthus sinensis var. glaber. Length heterogeneity, with sizes from 1782 to 2212 base pairs, of the IGS resulted from the variation of copy numbers of the A and B subrepeats. These repeated elements were located upstream of the presumptive polymeraseII promoter, which was the region corresponding to the nontranscribed spacer (NTS). Length heterogeneity was detected both within and between individuals of Miscanthus sinensis var. glaber. Neighbor-joining analyses of repetitive A elements indicated that both unequal crossing-over and preferential conversion may have affected the hot-spot regions of the IGS in concert. Within-individual polymorphism and the reconstructed phylogeny suggested that interspecific hybridization has also contributed to length heterogeneity.
Base Sequence↗
Plastic surgery in liver transplantation.
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Adolescent↗
Experience with liver transplantation in Taiwan.
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Cadaver↗
Radiologic anatomy in split liver transplantation.
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Bile Ducts, Intrahepatic↗
Portal hemodynamics in living-related liver transplantation: quantitative measurement by Doppler ultrasound.
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Adult↗