Differences in portal hemodynamics between whole liver transplantation and living donor liver transplantation

The aim of this study was to investigate the differences in portal hemodynamics between whole liver transplantation and living donor liver transplantation (LDLT). Twenty patients who underwent LDLT (the L group) and 42 patients who underwent whole liver transplantation (the W group) were enrolled, and colored Doppler ultrasonography was performed preoperatively and on postoperative days (PODs) 1, 3, 5, 7, 30, and 90. The changes in the portal blood flow velocity (PBV) and portal blood flow volume (PBF) were monitored. The graft and spleen sizes were measured with angiographic computed tomography, and upper endoscopy was used to measure esophageal varices on PODs 14, 30, and 90. Although the portal venous pressure (PVP) decreased after graft implantation, it was higher in the L group with a smaller graft size ratio (25.7 ± 5.1 cm H₂O for the L group and 18.5 ± 4.6 cm H₂O for the W group, P < 0.05). PBF and PBV increased in both the W and L groups on POD 1 after transplantation; however, the PBF and PBV peaks were significantly higher in the W group. The postoperative PVP and graft volume were greatly related to PBF on POD 1. Grafts in the L group regenerated rapidly after the operation, and the volume increased from 704 ± 115 to 1524 ± 281 mL as early as 1 month after transplantation. A rapid improvement in splenomegaly was observed in both groups. An improvement in esophageal varices was observed in the W group on POD 14 after transplantation, whereas no change was observed in the L group. The portal venous flow in patients with portal hypertension showed a high perfusion state after LDLT, but in contrast to whole liver transplantation, the PVP elevation after LDLT postponed the closing time of the collateral circulation and affected the recovery from splenomegaly.

Role of splanchnic hemodynamics in liver regeneration after living donor liver transplantation

The aim of this study was to investigate the changes in splanchnic hemodynamics after LDLT and their relationship with graft regeneration. Eighteen patients with LDLT December 2006 and June 2008 were enrolled, and color Doppler ultrasonography was performed preoperatively and on postoperative days (PODs) 1, 3, 5, 7, 30, and 90 after transplantation. The changes in the portal blood flow mean velocity (PBV) and portal blood flow volume (PBF) were monitored, and their effects on hepatic function were observed simultaneously. Graft sizes were measured on PODs 7, 30, and 90 after the operation. The regeneration rates of grafts were calculated. PBF increased in the recipient group from 1081.17 +/- 277.50 to 2171.44 +/- 613.15 mL/minute, and PBV increased from 15.01 +/- 5.67 to 56.00 +/- 22.11 cm/s; they were both significantly higher than those in the donor group (P < 0.01). On POD 1, serum aspartic aminotransferase, alanine aminotransferase, and total bilirubin all peaked; however, these indices in patients with PBF/graft weight (GW) > 300 mL/minute . 100 g were significantly higher than those in patients with PBF/GW < 300 mL/minute . 100 g. Livers in the recipient group regenerated rapidly. The graft regeneration rate reached 119.40% +/- 28.21% as early as 1 month post-transplantation. PBF and PBV on PODs 1 and 3 were greatly related to liver regeneration at 30 days. The portal venous flow in patients with portal hypertension after LDLT showed a high perfusion state, which could promote graft regeneration, but PBF/GW after the operation should be controlled below 300 mL/minute . 100 g in order to protect grafts from hyperperfusion injury.

[Effects of androgen on microstructure and mechanics nature of bone in orchiechtomied male rats]

OBJECTIVE

To investigate the effect of androgen on microstructure and mechanics nature of bone in orchiechtomied (ORX) male rats and reveal its mechanism by using the Micro CT analysis, bone biomechanics test, bone histomorphometric parameter test, and total body bone mineral density (BMD) measured by dual-energy X-ray absorptiomery (DXA).

METHODS

Thirty 12-month-old male Wister rats were randomly divided into three groups including ORX, sham-operated (Sham) and androgen (AD) group, ten rats in every group. Total body BMD was measured by DXA. Femurs and vertebrae were then harvested at the 12 th week after ORX for micro-computed tomography (Micro CT), histology and biomechanical were tested.

RESULTS

The administration of testosterone may reverse the decreasing BMD of total body and may prevent the decreasing weight. The biomechanical values of Maximum load, Enery, Maximum stress, Elastic Modulus of AD group significantly enhanced compared with ORX group (P < 0.05). The results of histomorphometric parameters showed that cancellous bone volume, osteoblast-osteoid interface, linear extent of bone formation, mineralizing surfaces, mineral apposition rate increased in the therapy group.

CONCLUSION

Androgen can accelerate cancellous bone formation and bone turnover, improve bone microstructure and enhance bone intensity and BMD.

Molecular characterization of Streptococcus pneumoniae type 4, 6B, 8, and 18C capsular polysaccharide gene clusters

Capsular polysaccharide (CPS) is a major virulence factor in Streptococcus pneumoniae. CPS gene clusters of S. pneumoniae types 4, 6B, 8, and 18C were sequenced and compared with those of CPS types 1, 2, 14, 19F, 19A, 23F, and 33F. All have the same four genes at the 5' end, encoding proteins thought to be involved in regulation and export. Sequences of these genes can be divided into two classes, and evidence of recombination between them was observed. Next is the gene encoding the transferase for the first step in the synthesis of CPS. The predicted amino acid sequences of these first sugar transferases have multiple transmembrane segments, a feature lacking in other transferases. Sugar pathway genes are located at the 3' end of the gene cluster. Comparison of the four dTDP-L-rhamnose pathway genes (rml genes) of CPS types 1, 2, 6B, 18C, 19F, 19A, and 23F shows that they have the same gene order and are highly conserved. There is a gradient in the nature of the variation of rml genes, the average pairwise difference for those close to the central region being higher than that for those close to the end of the gene cluster and, again, recombination sites can be observed in these genes. This is similar to the situation we observed for rml genes of O-antigen gene clusters of Salmonella enterica. Our data indicate that the conserved first four genes at the 5' ends and the relatively conserved rml genes at the 3' ends of the CPS gene clusters were sites for recombination events involved in forming new forms of CPS. We have also identified wzx and wzy genes for all sequenced CPS gene clusters by use of motifs.

Elevated activity of N-acetylglucosaminyltransferase V in human hepatocellular carcinoma

Cell-surface glycoproteins are regarded as candidates for involvement in the spread of tumor cells. N-linked beta1-6 branched oligosaccharides may contribute directly to the malignant or metastatic phenotypes of tumor cells. Increased beta1-6 branching has been associated with an increased level of N-acetylglucosaminyltransferase V (GlcNAc transferase V), the glycosyltransferase that initiates the beta1-6 branching. In this report, 33 pathologically verified hepatocellular carcinoma (HCC) specimens, six non-cancerous tissues surrounding HCC and five normal liver specimens have been studied. We have quantified N-linked beta1-6 branched oligosaccharides indirectly by measuring GlcNac transferase V activity. The average GlcNac transferase V activities in hepatocellular carcinoma (HCC), noncancerous tissues surrounding HCC and normal liver tissues were 324.2 +/- 269.8, 84.8 +/- 20.7 and 7.0 +/- 6.2 pmol product h(-1) mg protein(-1) (P < 0.05) respectively. In addition, the activity was correlated with the TNM classification of HCC. The average activities of GlcNAc transferase V in stages T1, T2-3 and T4 were 77.6 +/- 57.8, 369.0 +/- 294.7 and 329.9 +/- 205.9 pmol product h(-1) mg protein h(-1) respectively (P < 0.05), showing that the activity of the enzyme in advanced HCC was higher than that in early HCC. Our preliminary results indicated that GlcNAc transferase V activity increased in human HCC and was correlated with its progression.

Peritoneal reflections of left perihepatic region: radiologic-anatomic study

To clarify the anatomy of the peritoneal reflections of the left perihepatic region, the authors examined 95 cadavers. Thirty-eight were studied radiographically, 37 with sagittal dissection, and 20 with transverse dissection. In over 80% of the cadavers, the left triangular ligament of the liver separated the left suprahepatic space into anterior and posterior sections. The lesser omentum extended to the diaphragm, where its anterior layer reflected and continued as the posterior layer of the left triangular ligament. Thus, the posterior left suprahepatic space and the lesser sac were clearly separated by the lesser omentum and the stomach and over-lapped each other in three dimensions. The posterior left suprahepatic space was located anterosuperior to the lesser sac and in turn was continuous with the gastrohepatic space inferiorly. Carefully researched diagrams of both the midline sagittal and left parasagittal perihepatic spaces were developed. This information has clinical value when the radiologist is called on to drain a left perihepatic abscess.