Protective role of nitric oxide in ischemia and reperfusion injury of the liver

BACKGROUND

The suppressed production of nitric oxide (NO), associated with endothelial dysfunction, is thought to be a cause of ischemia and reperfusion injury of the liver. But findings of the salutary effects of NO enhancement on such injury have been conflicting. In this study, we tested our hypothesis that NO enhancement would attenuate ischemic liver injury. For this purpose, an NO precursor, L-arginine, and a novel NO donor, FK409, were applied to a 2-hour total hepatic vascular exclusion model in dogs.

STUDY DESIGN

L-arginine was administered IV at a dose of 100 mg/kg twice (n = 5), while 300 mg/kg twice of FK409 was infused continuously into the portal vein (n = 5). The drugs were given to the animals for 30 and 60 minutes before and after ischemia, respectively. Non-treated animals were used as the control (n = 10). Two-week survival, systemic and hepatic hemodynamics indices, liver function tests, energy metabolism, and histopathology were analyzed.

RESULTS

Both treatments comparably augmented hepatic tissue blood flow, decreased liver enzyme release, and increased high-energy phosphate restoration during the reperfusion period, all of which contributed to rescuing all of the treated animals from the 2-hour total hepatic ischemia. In contrast, ischemia caused 70% mortality in the control group. Histologically, structural abnormality and neutrophil infiltration were markedly attenuated by the treatments. Systemic hypotension was observed in the animals treated with FK409, however.

CONCLUSIONS

Our data demonstrate that NO enhancement alleviates the liver injury caused by ischemia and reperfusion. The supplementation of L-arginine, rather than FK409, is considered more applicable to clinical use because of the absence of systemic adverse effects.

Preparation of a novel functional hydrogel consisting of sulfated glucoside-bearing polymer: activation of basic fibroblast growth factor

Sulfated poly(glucosyloxyethyl methacrylate) [poly(GEMA)-sulfate] and its hydrogel were synthesized and evaluated to develop novel tissue regeneration assist devices. The poly(GEMA)-sulfate hydrogel was obtained by gamma-ray irradiation. Basic fibroblast growth factor (bFGF) was expected to be subsequently incorporated with hydrogel matrices and activated or released from the matrices. A sustained release of bFGF from the poly(GEMA)-sulfate hydrogel was not realized; however, bFGF from poly(GEMA)-sulfate hydrogel was effectively activated. Poly(GEMA)-sulfate hydrogels are thought to be potential component materials for a tissue engineering matrix.

Evaluation of biological responses to polymeric biomaterials by RT-PCR analysis III: study of HSP 70, 90 and 47 mRNA expression

In this study, in order to analyze how cells recognize biomaterials, mRNA was evaluated on various substrates as shown in the attached HeLa S3 cells. The expressed Heat-Shock Protein (HSP) 70A, 70B, 90 and 47 mRNA were isolated and detected using the RT-PCR method. As a result, 70B, 90 and 47 mRNA expressions varied with differences in the hydrophilicity hydrophobicity of the substrates. HSP mRNAs outcome was induced significantly in the HeLa S3 cells that had adhered onto the hydrophilic surfaces. On the other hand, in the cells that had adhered to the hydrophobic surfaces, HSP mRNAs expressions were low. In the non-adhered HeLa S3 cells the tendency found in HSP 70B and HSP 47 mRNA's expressions was the same as that found in adhered cells, while there were no significant differences in the HSP 90 mRNA expression among either of the samples. We have concluded that HSP mRNAs expression is an important marker in the study of cell-polymer interactions.

The application of radio-opaque markers prior to ileostomy in an infant with chronic intestinal pseudo-obstruction: report of a case

We report the case of a 6-month-old boy who developed chronic intestinal pseudo-obstruction soon after birth. A rectal biopsy demonstrated immaturity of the neuronal cells in the enteral ganglion. His clinical course was stressful, with remission and exacerbation despite conservative treatment with daily bowel irrigation, prokinetic agents, and parenteral nutrition. Since the infant developed serious enterocolitis associated with the increased severity of his bowel obstruction, and no substantial gain in body weight was observed, a loop-ileostomy was performed based on X-ray findings with radio-opaque markers, which were employed to evaluate the whole gut transit time. The radio-opaque markers proved extremely useful for determining which loop of the ileum should be utilized for the ileostomy.

Base-specific separation of oligodeoxynucleotides by capillary affinity gel electrophoresis

Capillary affinity gel electrophoresis was applied to sequence-specific and base composition-specific recognition of oligodeoxynucleotides, utilizing the formation of heteroduplexes between a nucleic acid analogue immobilized into the capillary gel and soluble oligodeoxynucleotides with different sequences. Capillary affinity gel electrophoresis using capillaries filled with a conjugated gel of polyacrylamide and a synthetic nucleic acid analogue [poly(9-vinyladenine)] was effective for the selective separation of hexathymidylic acid from a mixture of four homopolymers of A6, C6, G6, and T6 and for the complete resolution of five heteropolymers of hexadeoxynucleotides (TAAAAA, TTAAAA, TTTAAA, TTTTAA, TTTTTA). We also demonstrated that capillary affinity gel electrophoresis was useful for the selective and the sensitive sequence-specific recognition of sequence isomers of DNA (TTTTAA, TTTTAAT, TTTATA, and TTTTAA).

Manual reduction with the index finger for infantile intussusception. A modification of Hutchinson's maneuver

Manual reduction with the index finger (modified Hutchinson's maneuver) enabling simple and safe manual reduction of infantile intussusception is described. The procedure was used in four patients, two boys and two girls, ranging in age from 2 to 15 months, as greater than normal compression was necessary and/or serosal splitting occurred during conventional reduction. The technique is as follows: in addition to the proximal bowel compression with Hutchinson's maneuver, the surgeon inserts his index finger into the intussusceptum via its neck. The finger enables the surgeon to sound a wider space between the intussusceptum and intussuscipiens, which is most likely to be responsive to bowel compression. Although the intussusceptions in the four patients were categorized as ileo-ileo-colic (three cases) and ileo-ileal (one case) types, this manual reduction technique was successful in all cases, no bowel rupture occurred, and hospitalization was no longer than with the conventional procedure. We conclude that this modified Hutchinson's maneuver may contribute to successful surgical reduction of infantile intussusception.

Efficacy of prostaglandin I2 analog on liver grafts subjected to 30 minutes of warm ischemia

Due to the fact that no effective conditioning agent for hemodynamically unstable donors exists, the number of suitable donors is limited. The efficacy of OP-41483, a stable analog of prostaglandin I2, as a conditioning agent of the liver was investigated in this study using pigs. OP-41483 was administered via the portal tributary for 10 min before 30 min of warm ischemia. Graft livers were procured after perfusion with OP-41483 in cold normal saline, then flushed with OP-41483 in Euro-Collins solution and placed in cold storage prior to orthotopic transplantation. OP-41483 was also administered intraportally for 120 min after reperfusion. Biochemical and histological studies, and survival rates were compared with a control group not given OP-41483 in an otherwise similar experimental protocol. The graft function recovered better in the OP group than in the control group, shown by the lactate values and lactate-to-pyruvate ratios. The marked congestion noted in the parenchyma of the control group livers was minimal in the OP group, verifying the microcirculatory effect of prostaglandin I2 by its vasodilatory and antithrombotic actions. These findings suggest that OP-41483 has some protective effect as a conditioning agent in liver transplantation, with timing of administration being crucial.

Evaluation of biological responses to polymeric biomaterials by RT-PCR analysis. II: Study of HSP 70 mRNA expression

In order to investigate how cells recognize biomaterials, mRNA that was expressed in attached HeLa S3 cells on various substrates was evaluated. As culture substrates, cellulose, ethylene-vinyl alcohol copolymer (EVAL), nylon, tissue culture polystyrene (TCPS), high-density polyethylene (PE), silicone rubber, and tetrafluoroethylene-hexafluoropropylene copolymer (6F) were used. HeLa S3 cells were cultured on these substrates for 24 h. The expressed HSP 70s mRNA was then isolated and detected using the RT-PCR method. As a result, the expression of HSP 70B mRNA was largely induced in cells that adhered to hydrophilic surfaces. On the other hand, on hydrophobic surfaces, the HSP 70B mRNA expression was low. It is concluded that HSP 70B mRNA expression is sensitive to differences in the hydrophilicity-hydrophobicity of the substrates.

Three-dimensional helical computed tomography with intravenous cholangiography for sclerosing cholangitis manifested as postcholecystectomy symptom

A 46-year-old woman who had upper abdominal pain 10 years after cholecystectomy, and who had incidental sclerosing cholangitis (SC), was investigated by three-dimensional helical computed tomographic (3-DHCT) cholangiography with contrast medium, because endoscopic retrograde cholangiography (ERC) was unsuccessful and a second ERC was not permitted by the patient. The cholangiogram demonstrated annular strictures of the bilateral hepatic duct at the confluence of the common hepatic duct, and dilatation of the left intrahepatic biliary duct. Although we could not clarify the cause of the biliary tract deformity at the time of the 3-DHCT, the tentative diagnosis of postcholecystectomy deformity of the biliary tree led to successful treatment by right liver lobectomy and hepaticojejunostomy. Histologic findings were compatible with SC. From this experience and the literature, we suggest that 3-DHCT cholangiography with contrast medium can contribute to the preoperative diagnosis of morphological changes in the biliary tree in patients with postcholecystectomy symptoms.