PubMed Health⌕ Search

Biomedical subjects

S Ko

Publications and source records attributed to S Ko.

At least 55 records · Page 3Linked to original sources
PubMed1998

Batch foam recovery of sporamin from sweet potato.

The major sweet potato root protein, sporamin (which comprises about 80-90% of the total protein mass in the sweet potato) easily foams in a bubble/foam-fractionation column using air as the carrier gas. Control of that foam fractionation process is readily achieved by adjusting two variables: bulk solution pH and gas superficial velocity. Varying these parameters has an important role in the recovery of sporamin in the foam. Changes in the pH of the bulk solution can control the partitioning of sporamin in the foam phase from that in the bulk phase. A change in pH will also affect the amount of foam generated. The pH varied between 2.0 and 10.0 and the air superficial velocities (V0) ranged between 1.5 and 4.3 cm/s. It was observed in these ranges that, as the pH increased, the total foamate volume decreased, but the foamate protein (mainly sporamin) concentration increased. On the other hand, the total foamate volume increased significantly as the air superficial velocity increased, but the foamate concentration decreased slightly. The minimum residual protein concentration occurred at pH 3.0 and V0 = 1.5 cm/s. On the other hand, the maximum protein mass recovery occurred at pH 3.0 and at V0 = 4.3 cm/s.

Chemical Fractionation↗
PubMed1998

Comparison of hemodynamic changes in two veno-venous bypass techniques modified at the portal cannulation site.

Veno-venous bypass under total vascular exclusion is a useful technique to permit safer resection of hepatic malignancy. We describe here a retrospective study of two modified venous bypass techniques as alternatives to the conventional end-on portal cannulation technique. Portal decompression via inferior mesenteric vein access was performed in eight patients (group A), and portal decompression via a passive shunt between a branch of the mesenteric vein and the right saphenous vein was performed in a second group (group B; n = 8). Both techniques were used in hepatic resection for malignancy under total vascular exclusion. To assess the efficacy of these bypass techniques, we compared the hemodynamic changes in the two groups. There were no differences in the bypass flow between the two groups. Neither group showed any significant changes in hemodynamic parameters (including mean arterial pressure, cardiac index, systemic vascular resistance index, and pulmonary artery pressure) between the pre-bypass and bypass phases. The heart rate in the bypass phase was significantly increased compared to that in the pre-bypass phase in both groups. All hemodynamic parameters in each phase were similar in the two groups. We conclude that both techniques maintained adequate venous return and stabilized the hemodynamic changes during hepatic resection under total vascular exclusion, and that either technique can be selected according to the intraoperative situation.

Aged↗
PubMed1998

Comparative, general pharmacology of SDZ NKT 343, a novel, selective NK1 receptor antagonist.

1. The in vitro and in vivo pharmacology of SDZ NKT 343 (2-nitrophenyl-carbamoyl-(S)-prolyl-(S)-3-(2-naphthyl)alanyl-N-benzyl-N- methylamide), a novel tachykinin NK1 receptor antagonist was investigated. 2. SDZ NKT 343 inhibited [3H]-substance P binding to the human NK1 receptor in transfected Cos-7 cell membranes (IC50 = 0.62+/-0.11 nM). In comparison, in the same assay Ki values for FK888, CP 99,994, SR 140,333 and RPR 100,893 were 2.13+/-0.04 nM, 0.96+/-0.20 nM, 0.15+/-0.06 nM and 1.77+/-0.41 nM, respectively. SDZ NKT 343 showed a markedly lower affinity at rat NK1 receptors in whole forebrain membranes (IC50 = 451+/-139 nM). 3. SDZ NKT 343 caused an increase in EC50 as well as reduction in the number of binding sites (Bmax) determined for [3H]-substance P, suggesting a non-competitive interaction at the human NK1 receptor. SDZ NKT 343 also caused a reduction in the maximum elevation of [Ca2+]i evoked by substance P (SP) in human U373MG cells and depressed the maximum [Sar9]SP sulphone-induced contraction of the guinea-pig isolated ileum. The antagonism of SP effects on U373MG cells by SDZ NKT 343 was reversible. 4. SDZ NKT 343 showed weak affinity to human NK2 and NK3 receptors in transfected Cos-7 cells (Ki of 0.52+/-0.04 microM and 3.4+/-1.2 microM, respectively). SDZ NKT 343 was inactive in a broad array of binding assays including the bradykinin B2 receptor the histamine H1 receptor, opiate receptors and adrenoceptors. SDZ NKT 343 only weakly inhibited the voltage-activated Ca2+ and Na+ currents in guinea-pig dorsal root ganglion neurones. The enantiomer of SDZ NKT 343, (R,R)-SDZ NKT 343 was about 1000 times less active at human NK1 receptors expressed in Cos-7 cell membranes. 5. Contractions of the guinea-pig ileum by [Sar9]SP sulphone were inhibited by SDZ NKT 343 in a concentration-dependent manner, with an IC50 = 1.60+/-0.94 nM, while the enantiomer (R,R)-SDZ NKT 343 was 100 times less active (IC50 = 162+/-26 nM). In comparison, in the same assay IC50 values for other NK1 receptor antagonists CP 99,994, SR 140,333, RPR 100,893 and FK 888 were 2.90+/-07 nM, 0.14+/-0.02 nM, 11.4+/-2.9 nM and 2.4+/-0.83 nM, respectively. 6. In anaesthetized guinea-pigs i.v. administered SDZ NKT 343 antagonized [Sar9]SP sulphone-evoked bronchoconstriction (70% reduction at 0.4 mg kg(-1), i.v.). Basal airway resistance, mean arterial blood pressure and heart rate were not affected. 7. In conclusion, SDZ NKT 343 is a highly selective NK1 receptor antagonist with high potency at the human and guinea-pig receptors. SDZ NKT 343 may be used as a potential novel therapeutic agent in human diseases where NK1 receptor hyperfunction is involved.

Animals↗
PubMed1997

Radical esophagogastrectomy for unshuntable extrahepatic portal hypertension with bleeding varices: report of a case.

A 29-year-old woman with idiopathic portal hypertension was referred to our department for the surgical management of repetitive bleeding from esophageal and gastric varices. At the age of 16 years she had undergone a splenectomy with esophageal transection followed by endoscopic sclerotherapy which had been performed a total of 24 times. Although vericeal hemorrhage was prevented for several months, bleeding from gastric varices and portal hypertensive gastropathy was not able to be controlled readily by endoscopic sclerotherapy from when she was 26 years old. On admission, angiographic studies showed a complete obstruction of the portal vein; however, a portosystemic shunt operation was not able to be performed due to her previous splenectomy. To control her repetitive bleeding, we decided to perform a total gastrectomy and distal esophagectomy with reconstruction by a Roux-en-Y esophagojejunostomy. Her postoperative course was uneventful, and no episodes of recurrent bleeding or other complications have developed, indicating that her quality of life has dramatically improved. Thus, we conclude that distal esophagectomy and total gastrectomy constitute an effective surgical treatment for unshuntable extrahepatic portal hypertension.

Adult↗
PubMed1997

Transthoracic transdiaphragmatic approach for hepatectomy of Couinaud's segments VII and VIII.

For hepatectomy of Couinaud's segment VII or VIII, severe compression and mobilization of the liver is required to establish the operative field via the usual transabdominal approach. Compression of the cirrhotic liver impairs hepatic and systemic blood circulation, which may cause liver dysfunction. We adopted a transthoracic transdiaphragmatic approach for hepatectomy of segment VII or VIII in cirrhotic patients to establish a good operative field without compressing the liver. The aim of this study was to evaluate the benefits of this approach. Forty-four patients with hepatocellular carcinoma (HCC) complicating liver cirrhosis who underwent limited hepatectomy of Couinaud's segment VII or VIII were studied. The patients were randomized to two groups preoperatively: group I (n = 22), transabdominal approach; group II (n = 22), transthoracic transdiaphragmatic approach. There were no differences in preoperative liver function tests, hepatic functional reserve, or extent of tumor between the two groups. The operative time in group II was significantly shorter than that in group I (243 +/- 50 versus 313 +/- 80 minutes;p < 0.01). Operative blood loss in group II was also significantly smaller than that in group I (1190 +/- 1098 versus 2679 +/- 2267 g;p < 0.01). Serum lactate dehydrogenase levels on postoperative day 1 in group II were significantly lower than those in group I (587 +/- 154 versus 791 +/- 383 IU/L;p < 0.05). Major postoperative complications were significantly fewer in group II. It was concluded that the transthoracic transdiaphragmatic approach is a useful method for hepatectomy of segments VII and VIII in cirrhotic patients.

Chi-Square Distribution↗
PubMed1997

Studies on kochiae fructus. III. Antinociceptive and antiinflammatory effects of 70% ethanol extract and its component, momordin Ic from dried fruits of Kochia scoparia L.

The 70% ethanol extract (KS-ext) from Kochiae Fructus (dried fruits of Kochia scoparia L.) was screened for its activity on nociceptive and inflammatory responses in experimental animals. Although KS-ext at an oral administration of 500 mg/kg had an antinociceptive effect on writhing responses induced by acetic acid, it was ineffective on nociceptive response in the hot plate test. Oleanolic acid oligoglycoside, momordin Ic isolated from Kochiae Fructus significantly decreased the frequency of licking behavior within a unit of time at the late phase without affecting that of the early phase in the formalin test. Also, KS-ext inhibited the rise of vascular permeability induced by acetic acid, the increase of paw edema induced by carrageenin, histamine, serotonin or bradykinin and ear swelling induced by arachidonic acid. Momordin Ic also exhibited an inhibitory effect on carrageenin-induced edema. These results indicated that Kochiae Fructus has a peripheral antinociceptive effect mediated by antiinflammatory action, and that its active component can be partially attributed to momordin Ic.

Animals↗
PubMed1996

Influence of associated viral hepatitis status on recurrence of hepatocellular carcinoma after hepatectomy.

The purpose of this study was to investigate the relation between the recurrence of hepatocellular carcinoma (HCC) and the histologic status of underlying chronic liver disease from a viewpoint of multicentric hepatocarcinogenesis. Sixty-eight patients who underwent curative resection of HCC and have been followed for more than 2 years are reported. Based on the microscopic findings of the noncancerous part of the liver, the patients were divided into normal liver (N,n = 2), chronic persistent hepatitis (CPH,n = 6), chronic aggressive hepatitis (CAH,n = 31), and liver cirrhosis (LC,n = 29) according to a classification by the European Association for the Study of the Liver. Background data for the groups showed no significant differences. Recurrence was observed in none of the patients in the N and CPH groups, 26 (83.9%) of the patients in the CAH group, and 12 (41.4%) of the patients in the LC group. The cumulative disease-free survival rate of the CAH group was significantly lower than that of the CPH group (p < 0.05) and LC group (p < 0.01). This study revealed that the histologic status of the underlying chronic liver disease influenced the recurrence rate in patients with HCC. CAH was considered to be a risk factor for recurrence after resection of HCC.

Aged↗
PubMed1996

Significant influence of accompanying chronic hepatitis status on recurrence of hepatocellular carcinoma after hepatectomy. Result of multivariate analysis.

OBJECTIVE: The aim of this study was to evaluate the correlation between the histologic status of accompanying chronic hepatitis and the recurrence rate of hepatocellular carcinoma (HCC) after hepatectomy by multivariate analysis. SUMMARY BACKGROUND DATA: Recent studies have suggested that a considerable number of intrahepatic recurrence of HCC after hepatectomy might be the results of metachronous multicentric hepatocarcinogenesis. The authors hypothesized that the incidence of recurrence due to metachronous multicentric hepatocarcinogenesis would depend on the histologic status of accompanying chronic viral liver disease, which is a main promoter of HCC. METHODS: One hundred ten patients with HCC who underwent curative resection were studied. Histologic status of accompanying chronic hepatitis was classified into the three categories: 1) normal liver or chronic persistent hepatitis (CPH, n = 13), 2) chronic aggressive hepatitis (CAH, n = 50), and 3) liver cirrhosis (LC, n = 47). RESULTS: The Cox multivariate proportional hazard model showed that the accompanying chronic viral hepatitis status (p = 0.0133), extent of hepatectomy (p = 0.0078), and number of tumors (p = 0.0475) were significantly predictive variables for recurrence-free survival. By the log-rank test, recurrence-free survival rate in patients with CPH was significantly higher than those in patients with CAH (p = 0.0005) and LC (p = 0.0075). Patients with CAH had the lowest recurrence-free survival rate (vs. LC, p = 0.028). CONCLUSIONS: The results of this study indicated the significant influence of histologic activity of hepatitis on recurrence of HCC. This might support the concept of significant contribution of multicentric hepatocarcinogenesis to recurrence of HCC after hepatectomy.

Adult↗
PubMed1996

Shortened telomere length in hepatocellular carcinomas and corresponding background liver tissues of patients infected with hepatitis virus.

The telomere length in 20 surgically resected human hepatocellular carcinomas (HCCs) and adjacent non-cancerous livers with hepatitis virus infection were investigated. All the HCC samples examined demonstrated shorter telomere length than the corresponding non-cancerous liver tissues, the respective average values being 5.4 kbp and 8.8 kbp (P < 0.001). The shortening of telomere length was most prominent in HCCs larger than 30 mm in diameter, and in both tumors and non-cancerous livers it was more marked with hepatitis B virus as compared with hepatitis C virus infection. These results indicate that telomere shortening is associated with not only progression, but also development of HCC, and there is a possible difference in the nature of the association in patients with hepatitis viruses of B and C types.

Adult↗
PubMed1996

Different immunosuppressive effects of liposomal FK506 in liver and kidney transplantation.

The efficacy of liposomal FK506 was compared between a canine liver transplantation model and a canine kidney transplantation model. The present study revealed that liposomal FK506 increased immunosuppressive efficacy of FK506 in liver transplantation but decreased in kidney transplantation. Because liposomal FK506 increased FK506 levels in the liver and spleen, and decreased FK506 levels in the kidney, it was suggested that enhanced immunosuppressive efficacy in liver transplantation should be attributed to the local immunosuppressive effects in the hepatic allograft rather than effective suppression of splenocyte activity.

Animals↗
PubMed1996

Liver transplantation for hepatocellular carcinoma: consideration from the findings on autopsy.

Extrahepatic spread of hepatocellular carcinoma was investigated in twenty autopsy cases with unresected hepatocellular carcinoma to define the appropriate patient selection criteria for liver transplantation. Diagnosis of extrahepatic spread of cancer by diagnostic imaging was not easy, and unsatisfactory prognosis after liver transplantation in patients with hepatocellular carcinoma might have been attributed to the high incidence of extrahepatic occult foci of cancer. All patients with multiple nodular, massive and diffuse tumor had extrahepatic spread of cancer. Only patients with a single nodular type tumor, no larger than 30 mm in diameter, had no extrahepatic metastasis, and these patients are the preferred candidates for liver transplantation.

Aged↗
PubMed1995

The enhanced immunosuppressive efficacy of newly developed liposomal FK506 in canine liver transplantation.

Local delivery of immunosuppressants to the graft and lymphatic tissue is a potential appraoch to enhance the immunosuppressive efficacy and to alleviate systemic adverse effects simultaneously. By taking advantage of this method, we developed liposomal FK506. Previous pharmacokinetic study of liposomal FK506 indicated increased FK506 levels in the liver and spleen. Because the liver is the site of the allograft in liver transplantation and the spleen is a major lymphoid tissue, we hypothesized that liposomal FK506 would increase immunosuppressive efficacy in liver transplantation. We evaluated this hypothesis in a canine model. Orthotopic liver transplantation was performed using beagle dogs, and the recipients were divided into the following groups: group I, no immunosuppression (n = 5); group II, 0.05 mg/kg/day of FK506 i.v. in a commercially available i.v. formulation for 14 days (n = 5); and group III, 0.05 mg/kg/day of FK506 i.v. in a liposomal formulation for 14 days (n = 5). All recipients in group I died within 2 weeks. Recipients in group II died within 33 days. In contrast, three recipients in group III survived for more than 200 days (P < 0.05 versus group I or group II). In DNA analysis, splenocyte proliferation activity in group III was significantly suppressed in comparison with group II. These results suggest that liposomal FK506 markedly increase the immunosuppressive efficacy of FK506 in liver transplantation. A local immunosuppressive effect in the grafted liver and significant suppression of splenocyte proliferation might contribute to enhancement of the immunosuppressive efficacy of liposomal FK506.

Animals↗
PubMed1995

Successful management of portal hypertension following artificial arterioportal shunting: report of a case.

A 63-year-old woman diagnosed as having hepatic hilar cancer underwent an extended left lobectomy of the liver with excision of the right hepatic artery which was involved by the tumor. Because the hepatic artery could not be reconstructed by direct anastomosis, an artificial arterioportal (A-P) shunt was constructed between the common hepatic artery and the portal vein. However, 4 weeks after the operation, portal hypertension with severe esophageal varices developed. Under the diagnosis of portal hypertension caused by excessive blood flow from the A-P shunt, coil embolization of the common hepatic artery was performed using an angiographic technique, following which the esophageal varices completely disappeared. This case demonstrates that portal hypertension after A-P shunting can be effectively treated with coil embolization.

Angiography↗
PubMed1995

Ki-ras mutations and p53 protein expressions in intrahepatic cholangiocarcinomas: relation to gross tumor morphology.

BACKGROUND & AIMS: We previously reported that intrahepatic cholangiocarcinomas (ICCs) can be divided into three categories according to their gross appearance with possible links to biological behavior. Ki-ras and p53 gene alterations are thought to be involved in early and late phases of carcinogenesis, respectively. This study was performed to investigate the relationship between the gross appearance and genetic alterations of ICC. METHODS: We examined 21 patients with ICC. Ki-ras point mutations were assessed by polymerase chain reaction/single-strand conformation polymorphism methods followed by direct DNA sequencing. Expressions of p53 protein were immunohistochemically assessed. RESULTS: Ki-ras point mutations were found in 10 patients (48%), and expressions of p53 protein were detected in 4 (19%). Applying the gross classification that we previously proposed, Ki-ras mutations were prominent in the periductal extension type (4 of 6; 67%) and the spicula-forming type (6 of 10; 60%). On the other hand, none of the five mass-forming-type tumors harbored Ki-ras mutations. Expressions of p53 protein did not show any clear association with gross appearance. CONCLUSIONS: Ki-ras gene alterations may be involved in the cholangiocarcinogenesis of periductal extension and spicula-forming but not mass-forming types, suggesting that the underlying processes of development are different.

Adult↗