Long-duration xenogeneic extracorporeal pig liver perfusion with human blood

Hepatic xenografts can tolerate hyperacute rejection owing to their lower susceptibility to humorally mediated injury. We investigated the possibility of long-duration xenoperfusion without immunologically controlling natural antibodies or complements. Pig livers were perfused for 9 h with human blood (Group 1) or pig blood (Group 2). Physiological conditioning and administration of prostaglandin E1 and insulin was characteristic of our system. The portal vein and hepatic artery pressure and bile production did not significantly differ between the two groups. Despite a gradual decrease throughout the perfusion, overall oxygen consumption was significantly higher in Group 1. Liver enzymes were released at higher levels in Group 1. Histological examination revealed intact hepatic architecture in Group 2, while in Group 1 interlobular morphology was severely damaged by endothelial disruption, although hepatic sinusoidal architecture was preserved. It is concluded that, despite biochemically and histologically confirmed tissue injury, graft viability was well-maintained in xenoperfusion even without immunological manipulations.

Dural arteriovenous fistula of the posterior fossa developing after surgical occlusion of the sigmoid sinus. Report of five cases

In this article, the authors present five cases of dural arteriovenous fistula (AVF) that developed in the transverse-sigmoid sinus 2 to 6 years after sacrifice of the sigmoid sinus because of tumor involvement. The original tumor was meningioma in two patients and neurinoma, glomus jugulare tumor, and ameloblastoma in one patient each. The involved sigmoid sinus was resected along with the tumor and ligated at the normal edge; all that remained of the sigmoid sinus was a small stump on the retrosigmoid portion. Serial angiography performed before and after tumor surgery revealed no abnormal arteriovenous communications or dural AVF in any of the cases. Although many reports have suggested that sinus thrombosis is a precipitating factor in the pathogenesis of dural AVFs, this has been difficult to verify because of the small number of cases in which serial angiography was performed before the development of a dural AVF. In all of the cases presented in this article, surgical resection of a dural AVF and histological examination were performed. Subintimal fibrous thickening was marked, and the sinus wall was found to contain many dural vessels. Organized thrombosis with neovascularization was seen in only two patients. These cases demonstrate that subintimal fibrous thickening a hypertrophied sinus wall secondary to increased intrasinus pressure or sinus thrombosis occurring after sinus occlusion can provoke the development of a dural AVF within the course of a lifetime. Maintenance of intrasinus blood flow may be very important to prevent this late postoperative complication.

ATP is required in platelet serotonin exocytosis for protein phosphorylation and priming of secretory vesicles docked on the plasma membrane

Calcium-evoked secretion generally requires the presence of millimolar concentrations of Mg-ATP. We investigated the role of Mg-ATP in the secretion of serotonin from electropermeabilized bovine platelets. The secretion of serotonin was lost within 5 minutes when the Mg-ATP concentration was diluted to less than 0.1 mM, but was maintained when ATP-gamma S (adenosine 5′-O-3-thiotriphosphate) was used instead of ATP. Okadaic acid, a potent inhibitor of protein phosphatase, could also maintain the exocytotic activity even when ATP was diluted. Decrease in the secretory activity was paralleled by a decrease in phosphorylation level of four proteins after dilution of ATP, but the activity was maintained when the thiophosphorylation level of these proteins was maintained. Two of these proteins were digested by a protease, calpain, which has been shown to lead to a loss in the exocytotic activity. Electron microscopic studies showed that calcium did not induce the formation of distinct bridge-like structures between the granule membrane and the plasma membrane in Mg-ATP-diluted cells, previously shown as the structure transiently formed prior to fusion of the two membranes. Anchorage of the secretory dense granules to the plasma membrane and the presence of the amorphous structures between the granules and the plasma membrane were unchanged by dilution of ATP. These results indicate that ATP is not required for the anchorage itself, but is required to prime anchored granules for calcium-triggered secretion. Maintenance of the phosphorylated state of proteins by ATP enables the calcium trigger to form the bridge-like structures preceding membrane fusion events.

Gastric remnant carcinoma after partial gastrectomy for benign and malignant gastric lesions

BACKGROUND

A retrospective study was designed to evaluate the clinicopathologic characteristics and prognosis of gastric stump carcinoma (GSC) after gastrectomy for gastric adenocarcinoma.

STUDY DESIGN

A comparison of the clinicopathologic features was made between 12 cases of GSC and 27 cases of remnant carcinoma (RC) following gastrectomy for adenocarcinoma. The various factors influencing survival of both groups of patients were evaluated separately and by multivariate analysis.

RESULTS

Gastric stump carcinoma emerges late after initial gastrectomy and has a significant tendency toward lymph node metastasis. No difference was observed between the survival curves for patients with GSC or RC after gastrectomy for malignancy. Serosal invasion was the factor most affecting survival.

CONCLUSIONS

Early diagnosis is most important for management of the disease, and only patients with T2 staged GSC according to the Union Internationale Contre le Cancer classification system might benefit from extensive lymphadenectomies.

Characterization of fibroblast growth factor-2 binding to ribosomes

We have examined the binding of FGF-2 to ribosomes and have found that in NIH 3T3 cells that synthesize high amounts of all FGF-2 forms, both 18 kDa and HMW forms of FGF-2 bind to ribosomes. Ribosomes purified from these cells were treated with RNase or puromycin to identify the binding site of FGF-2 on the ribosome. Neither RNase nor puromycin treatment affected the in vivo binding of FGF-2 to ribosomes suggesting that FGF-2 binds ribosomal protein or rRNA, but not mRNA. The stoichiometry of binding in these cells was approximately 1 FGF-2 molecule bound per 1 ribosome. Binding was unaffected by high salt treatment indicating that FGF-2 tightly associates with polysomes. An in vitro binding experiment performed with purified ribosomes and recombinant FGF-2 suggested that the binding site is saturable. HBNF, a protein with similar charge and size to FGF-2, bound 15-fold less than FGF-2 to purified ribosomes. These results indicate that the binding of FGF-2 to ribosomes is specific.

Electrical properties of extracted rat liver tissue

We attempted to investigate the process of ischemia-induced disturbances in the rat liver, employing the electrical bio-impedance technique. The electrical bio-impedance was measured continuously over 6 h by the 4-electrode method, at various incubation temperatures, in six liver samples extracted from male Wistar rats. The electrical properties of biological tissues can be expressed in terms of three parameters: extracellular resistance (Re), intracellular resistance (Ri) and cell membrane capacitance (Cm). These three parameters were calculated from the measured values of the electrical impedance by the curve-fitting technique, using a computer program. The Re value increased rapidly after the rat livers were extracted, and then decreased slowly. The Re value reached a peak after about 13 min at 36 degrees C, and then decreased slowly, becoming constant after 3 h. There was a negative correlation between the Tmax of Re (the time when Re reached a maximum) and the incubation temperature (R = -0.973, P < 0.001). The Ri value decreased once in the early stage after extraction, followed by almost no change and then an increase after 4 h at 36 degrees C. The Cm showed a similar pattern of change to the Re value, and a negative correlation was also found between the Tmax of Cm and the incubation temperature (R = -0.969, P < 0.001). The increase in the Re and Cm values, and the decrease in the Ri value for quite long periods after the blood flow has stopped, suggest an increase in the resistance of extracellular fluid due to a decrease in its volume, an increase in cell membrane capacitance due to cell swelling, and a decrease in cellular fluid resistance due to an increase in its volume. The time when the Cm value decreases rapidly after an initial gradual decrease after the peak corresponds well with the time when the Ri value begins to increase, from which it is estimated that cell lysis proceeds and that the flow of extracellular fluid into the cell begins at this time. The findings of this study suggest the possibility of estimating the changes in liver tissue or the tissue structure due to ischemia.

High positive rate of pS2 expression in forefront intraductal cancerous area in breast cancer

Multiple sections of 40 consecutive cases with invasive ductal carcinoma of the breast, all of which bad wide intraductal cancerous extension, were examined by immunohistochemical analysis for evaluation of hormone dependency in several areas of breast cancer tissues. In this study, we examined the expression of pS2 protein in the central invasive area (CIV), central intraductal cancerous area (CDC) and forefront intraductal cancerous area (FDC). pS2 staining was positive in 52.5% (21/40) of CIV and a significant correlation was found between pS2 expression in CIV and the estrogen receptor status (ER). pS2 staining was positive in 77.5% of CDC and 85.0% of FDC, respectively. A majority (68.4%) of the cases that were negative pS2 in CIV were positive for pS2 in FDC. Moreover, the cases with noncomedo intraductal carcinoma in premenopausal status showed a higher positivity of pS2 expression in FDC than the cases with comedo-carcinoma, though the number of cases of comedo-carcinoma was limited. These findings suggest that endocrine therapy may be useful after breast conserving treatment regardless of the ER status of the primary tumor.

Incidence, diagnosis and significance of multiple gastric cancer

Of 2790 patients with gastric cancer undergoing surgery between January 1978 and December 1993, 160 (with 356 neoplastic lesions) had synchronous multiple cancer. Of these lesions 271 (76 percent) were early cancers. Only 85 (53 percent) of the 160 patients were diagnosed before operation as having multiple cancer; 69 further patients (43 percent) were diagnosed during the course of the operation. Small flat (IIb) and depressed (IIc) type lesions had a propensity to be missed before operation. The incidence of multiple cancer was relatively low, indicating that several microscopic lesions might have been overlooked in this series. There has, however, only been one patient (1 percent) with subsequent cancer of the gastric remnant of 126 with multiple cancer and postoperative gastric remnants over the past 16 years. This might be because of co-resection of unrecognized lesions by distal gastrectomy in 68 percent of the patients. Alternatively some microscopic cancers might not invariably be destined to grow into clinically significant lesions over 10 or more years.

Anti-tumour-promoting glyceroglycolipids from the green alga, Chlorella vulgaris

Two new monogalactosyl diacylglycerols were isolated from the freshwater green alga, Chlorella vulgaris, as anti-tumour promoters, together with three monogalactosyl diacylglycerols and two digalactosyl diacylglycerols. The new monogalactosyl diacylglycerol containing (7Z,10Z)-hexadecadienoic acid showed a more potent inhibitory effect toward tumour promotion than the other glycerolipids isolated.

[Relationship between catecholamine levels in amniotic fluid and fetal blood flow in fetal distress]

Eighteen cases of complicated pregnancy with fetal distress and/or pregnancy toxemia who underwent Cesarean section (CS) before onset of labor were studied. The resistance indexes (RI) of the umbilical artery (UA) and fetal middle cerebral artery (MCA) were measured by Doppler echography prior to CS. UA blood and amniotic fluid (AF) were obtained during CS and the pH value for the UA and the concentrations of norepinephrine (NE) and epinephrine (E) in AF were measured. A significant correlation between the pH value, MCA-RI/UA-RI ratio and the levels of NE and E in amniotic fluid was obtained. NE and E concentrations in AF obtained from the patients with fetal distress before the onset of labor were 1.92 +/- 0.54 and 1.48 +/- 0.28ng/ml and these concentrations were significantly higher then those from elective CS. The deviations (delta SD) of RI from the normal mean for corresponding gestational age in fetal distress were -4.21 +/- 0.94 in MCA and 1.31 +/- 0.48 in UA. A negative correlation between the pH value and delta SD (UA) was observed but the pH value correlated positively with delta SD (MCA). Furthermore, the MCA-RI/UA-RI ratio showed a significant negative correlation with the NE and E levels in AF. These results suggest that fetal catecholamine affects fetal blood flow in fetal distress.

Interleukin-6 induces proteolysis by activating intracellular proteases (cathepsins B and L, proteasome) in C2C12 myotubes

1. A cell culture system of C2C12 myotubes was established as a model of the muscle. With the aid of this model, the half-lives of intracellular proteins as well as the activities and mRNA levels of proteasomes (26S and 20S) and cathepsins (B, L, and H) were examined in the presence of various amounts of cytokines. 2. It was found that 100 units/ml recombinant human interleukin-6 somewhat shortened the half-life of long-lived proteins to 23.79 +/- 1.55 h (control: 25.60 +/- 1.87 h). When 1% fetal bovine serum contained in the culture medium was replaced by 0.5 mg/ml bovine serum albumin, interleukin-6 was more effective since 10 units/ml of interleukin-6 shortened the half-life to 19.09 +/- 2.87 h (control: 22.26 +/- 321 h). Interleukin-6 (100 units/ml) increased the activity of 26S proteasome by 31.5%, of cathepsin B by 53.5% and of cathepsin B+L by 21.3%. These increases occurred in association with an increase in their transcription. 3. On the other hand, 1000 units/ml of recombinant human tumour necrosis factor alpha prolonged the half-life of long-lived proteins while reducing the protease activities of 20S proteasome (-27.1%), cathepsins B (-64.6%) and B+L (-54.9%). 4. These results suggest that interleukin-6 induces degradation of long-lived intracellular proteins by activating both the non-lysosomal (proteasomes) and lysosomal (cathepsins) proteolytic pathways. It is therefore concluded that interleukin-6 is a candidate for a proteolysis-inducing factor in myotubes and may play an important role in the progression of muscle degradation in systemic inflammatory responses induced by sepsis or severe injury.

Protective effect of heat shock pretreatment with heat shock protein induction before hepatic warm ischemic injury caused by Pringle's maneuver

BACKGROUND

Induction of heat shock proteins is thought to have a > cytoprotective effect against environmental stress and to result in a better ischemic tolerance. The protective ability of heat exposure and heat shock protein 72 (HSP 72) induction before warm ischemia caused by Pringle's maneuver was evaluated in rats.

METHODS

Heat exposed rats (HS) were compared with control animals (C). The gene expression (messenger RNA) of HSP 72 and HSP 72 were detected by Northern and Western blot analyses. During 40 minutes of in situ reperfusion, liver energy metabolism and levels of standard liver enzymes were evaluated. The survival rate was determined after postoperative day 7.

RESULTS

After heat exposure and recovery, messenger RNA of HSP 72 and HSP 72 can be detected strongly in HS group but not in C group. During reperfusion HS group exhibited a significantly (p < 0.01) improved energy metabolism, and the release of liver enzymes was significantly (p < 0.001) reduced compared with C group. Seven-day survival rate was 100% in HS group but at 50% was significantly impaired (p < 0.05) in C group.

CONCLUSIONS

Heat exposure associated with HSP induction has a significant protective effect against warm ischemic liver injury, which results in a relevant improvement of survival rate.

Calcium-dependent transmitter secretion from fibroblasts: modulation by synaptotagmin I

Following endocytic uptake of acetylcholine (ACh), CHO fibroblasts exhibit Ca(2+)-dependent spontaneous quantal ACh release and depolarization-evoked ACh release, as detected by a whole-cell voltage-clamped myocyte in contact with the fibroblast. CHO fibroblasts transfected with synaptotagmin I, an integral membrane protein of synaptic vesicles, showed a reduced spontaneous quantal ACh release and an enhanced Ca(2+)-evoked ACh release, as compared with control cells. Biochemical and ultrastructural studies of endocytic activity using horseradish peroxidase as a marker further confirmed the inhibitory action of synaptotagmin I on spontaneous vesicular exocytosis and on elevated exocytosis induced by Ca2+. Through inhibition of exocytosis at the resting intracellular concentration of Ca2+ and removal of the inhibition upon depolarization-induced Ca2+ entry, synaptotagmin I could enhance the efficiency of excitation-secretion coupling.

Neural activity of chorda tympani mechanosensitive fibers during licking behavior in rats

The chorda tympani nerve, supplying the anterior two-thirds of the tongue, contains gustatory and mechanosensitive afferent fibers. We have analyzed discharge patterns in rats of various fibers recorded from dissected nerve filaments during licking behavior of which 4 were taste-sensitive and 12 mechanosensitive. The incidence of these two types were estimated electrophysiologically under anesthesia and their conduction velocity measured. Recordings in freely moving animals showed that the mechanosensitive fibers innervating the dorsal part of the tongue gave two burst discharges per lick, suggesting that contact of the tongue with the upper incisors and/or lip occurred during tongue protrusion and retraction. The fibers from the tip of the tongue showed one burst discharge per lick, which was the response to contact with a drinking spout. No rhythmical discharges synchronized with lick signals were observed in the fibers from the lateral part of the tongue or the taste-sensitive fibers. Such mechanoreceptor discharges were difficult to detect in recordings from the whole chorda tympani nerve. This masking of responses was due mainly to activation of a small number of mechanosensitive fibers by licking-induced mechanical stimulation. The lubricating action of saliva also decreased mechanoreceptor sensitivity. Despite their small number, the mechanosensitive fibers had axons with faster conduction velocities (larger diameter) than the taste-sensitive fibers. This was probably the reason why dissected nerve bundles more frequently showed mechanical than taste responses in conscious rats.

Difference in thymidylate synthetase activity in involved nodes compared with primary tumor in breast cancer patients

Thymidylate synthetase (TS) is a key enzyme as a methyl donor in the methylation reaction from dUMP to dTMP. TS activity was assessed in various tissue of mammary disorders. The descending order of TS activity was as follows: cancer-positive nodes, primary cancers, cancer-negative nodes, benign lesions, and normal parenchyma. Significant differences in TS activity were found between the positive nodes and each of the other tissues (p < 0.01). In node-positive cases, a significant correlation in TS activity was found between the primary cancers and positive nodes (r = 0.616, p = 0.033). There was no correlation between the nodal status and the TS activity in primary cancers. In 11 of 12 cases, the TS activity of positive nodes was higher than the 'calculated' TS activity of the primary cancer, which was defined as the TS activity per unit weight of cancer cells. A significant correlation was found between the calculated TS activity and the mitotic frequency in primary cancers (r = 0.697, p = 0.0001). On the other hand, a significant correlation could not be found between the TS activity and the mitotic frequency in positive nodes (r = 0.364, p = 0.244).

Involvement of HPC-1/syntaxin-1A antigen in transmitter release from PC12h cells

We examined the effect of antiserum against HPC-1/Syntaxin-1A on the norepinephrine release from digitonin-permeabilized PC12h cells. PC12h cells were permeabilized with digitonin and preincubated with nonimmunized serum or antiserum against HPC-1. The release of norepinephrine was measured in the presence or absence of calcium. The calcium-dependent norepinephrine release was increased in the cells preincubated with anti HPC-1 antiserum. However, with a higher concentration of anti HPC-1 antiserum, the calcium-dependent norepinephrine release was decreased, possibly because of a nonspecific effect. In the case of purified IgG, the same results were obtained. These findings suggested that HPC-1 plays an important role in the exocytosis of transmitter presumably by suppressing the membrane fusion process between the synaptic vesicle and presynaptic membrane.

Prognostic implications of the response of arterial ketone body ratio and insulin secretion to glucose load in major hepatectomy

Impaired glucose tolerance is a serious obstacle to major hepatic resection. To assess the predictability of surgical risk in major hepatectomy for patients with chronic liver diseases from the viewpoint of glucose metabolism, we evaluated the insulinogenic index (II) and redox tolerance index (RTI) in 48 patients who underwent major hepatectomy at our university hospital due to hepatocellular carcinoma. Patients with low II and low RTI fell into the high risk group. Based on this finding, the Z score was developed as an index of patient risk for major hepatectomy: Z = 3.11 x [II] + 1.43 x [RTI] - 2.27. When the Z score was negative, mortality reached 33.3%, but when it was positive the mortality was only 3.2%. Intraportal insulin supplementation after hepatectomy to patients with a negative Z score could reduce mortality. Preoperative evaluation of surgical risk by Z score seems to be useful for predicting patient prognosis after hepatectomy.

The frequency of 4977 base pair deletion of mitochondrial DNA in various types of liver disease and in normal liver

Using a polymerase chain reaction (PCR) method, we tested for the hepatic mitochondrial DNA (mtDNA) deletion in 40 hepatic tumors (28 hepatocellular carcinomas [HCCs], 9 other malignant tumors, and 3 benign tumors) and in the livers of 71 patients, including 16 pediatric patients with end-stage liver disease who underwent living related donor liver transplantation and 16 liver donors. A 4977 base pair (bp) deletion of mtDNA was detected in 36 of 55 specimens of non-tumor portions of adult liver (65.5%). However, none of the specimens obtained from cirrhotic livers of the 16 pediatric patients younger than 13 years of age had the 4977 bp deletion. The frequency of mtDNA deletion was significantly decreased compared with normal liver in HCCs (7 of 28) and other malignant liver tumors (2 of 9). The frequency of this deletion was unrelated to the presence of liver cirrhosis, patient's gender, hepatitis B virus surface antigen status, and hepatitis C virus antibody status.