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Biomedical subjects

K Kubota

Publications and source records attributed to K Kubota.

At least 109 records · Page 6Linked to original sources
PubMed2000

Monoclonal antibodies generated against an affinity-labeled immune complex of an anti-bile acid metabolite antibody: an approach to noncompetitive hapten immunoassays based on anti-idiotype or anti-metatype antibodies.

Conventional immunoassays for haptens such as steroids and synthetic drugs are dependent on the competitive reaction between an unlabeled antigen (analyte) and a labeled antigen against a limited amount of anti-hapten antibody. Although noncompetitive immunoassay procedures such as two-site immunometric assays offer a much higher sensitivity, direct application of this principle to haptens has been difficult due to their small molecular mass precluding simultaneous binding by two antibody molecules. Here, we have attempted to develop a noncompetitive immunoassay system based on anti-idiotype or anti-metatype antibodies. Ursodeoxycholic acid 7-N-acetylglucosaminide (UDCA 7-NAG), which is a bile acid metabolite (molecular weight, 595.8), was selected as the model hapten. A/J mice were immunized with a monoclonal antibody against UDCA 7-NAG, which had been affinity-labeled with a relevant hapten derivative. The fusion between the immune spleen cells and P3/NS1/1-Ag4-1 myeloma cells yielded four kinds of alpha-type and two kinds of beta-type monoclonal anti-idiotype antibodies, each recognizing the framework region and paratope of the anti-hapten antibody. The use of a selected combination between alpha-type and beta-type antibodies together with the anti-hapten antibody provided a noncompetitive assay system with a subfemtomole order sensitivity (detection limit, 118 amol) and a practical specificity.

Acetylglucosamine↗
PubMed2000

A rare case of multiple carcinoids and endocrine cell micronests in a patient with chronic duodenitis.

BACKGROUND: To the authors' knowledge, multiple carcinoid tumors of the duodenum have not been reported previously. However, multiple carcinoids in the stomach, ileum, and rectum, which were accompanied by the proliferation of endocrine cells, have been reported in the published literature. METHODS: A patient with multiple carcinoids including argyrophilic cell hyperplasia of the duodenum and hypergastrinemia underwent surgery. The resected stomach and duodenum were analyzed histopathologically. RESULTS: There were 11 carcinoid lesions, each of which was accompanied by peripheral endocrine cell micronests (ECMs). Increasing gastrin positive cells in the antral region and chronic duodenitis in the duodenal bulb also were observed. The peripheral ECMs usually were adjacent to proliferating argyrophilic cells in the Brunner gland ducts or the crypts of Lieberkühn, which showed focal pyloric gland metaplasia. CONCLUSIONS: In the case presented in the current study, the development of the multiple carcinoid lesions may be strongly related to the presence of multifocal pyloric gland metaplasia, as well as to the trophic action of gastrin, which is present at high levels in the setting of chronic duodenitis.

Carcinoid Tumor↗
PubMed2000

Peri-operative blood lactate levels in recipients of living-related liver transplantation.

BACKGROUND: The role of changes in peri-operative blood lactate levels in recipients of living-related liver transplants has not yet been clarified. METHODS: Forty-three recipients were included in this study. Blood lactate, plasma total bilirubin, aminotransferase, body temperature, and gastric mucosal PCO2 levels were measured at six time points during surgery: just before the initiation of surgery, just after dissection of the hepatic vasculature, at the end of the anhepatic phase, and 30, 60, and 120 min after reperfusion. We calculated the rate of lactate accumulation during the pre-anhepatic and anhepatic phases and the elimination rate during reperfusion (neohepatic phase), and examined the correlation between these results and the clinical findings. RESULTS: The rate of lactate elimination during the neohepatic phase was correlated with the ratio of graft weight to standard liver volume (P<0.0001). There was also a significant correlation between the rate of lactate accumulation during the pre-anhepatic phase and the preoperative total bilirubin levels (P=0.0008). CONCLUSIONS: Each pre-anhepatic, anhepatic, and neohepatic phase had a characteristic blood lactate profile. The graft size strongly affected lactate levels during the early neohepatic phase.

Adult↗
PubMed2000

Left hemihepatectomy in living donors with a thick middle hepatic vein draining the caudal half of the right liver.

Donor safety is the first consideration in living related liver transplantation. Left hemihepatectomy including the middle hepatic vein is a reasonable donor procedure for obtaining a large graft for living related liver transplantation. This procedure, however, needs to be modified in donors with hepatic venous variation. While carrying out donor hepatectomy, we encountered two cases showing a variant form of hepatic venous drainage comprising a thick middle hepatic vein draining segment 6 of the liver. This variation made it necessary to preserve the middle hepatic vein in the donor liver remnant. Failure to recognize such a variant would result in congestion in the remaining right liver of the donor. To guarantee donor safety, evaluation of the drainage area of the corresponding hepatic vein is a matter of great importance in donor hepatectomy.

Adolescent↗
PubMed2000

Separation of lipooligosaccharides by linear gradient gel electrophoresis.

Lipooligosaccharides (LOSs) are one of the major antigenic and immunogenic components on the outer membrane of mucosal Gram-negative bacteria. These glycolipid antigens are in the M(r) range of 3-7 kDa, and SDS/PAGE has been used as an analytical tool. Although we are able to separate relatively higher M(r) LOS components by mini-PAGE, we encounter difficulties in resolving LOS components below 3.6 kDa present in heterogeneous LOS preparations. In the present study, we selected PID2 LOS consisting of six LOS components of 3.0-5.1 kDa as a model LOS and examined mini-PAGE conditions not only to resolve smaller M(r) LOS components but also to retain resolving capability of higher LOS components. We found that mini-PAGE with stepwise and linear gradient gels (glycine-SDS) resolved smaller M(r) LOS components. Mini-PAGE with linear gradient gels gave the best resolution, and LOS components of 3.0-5.1 kDa were separated as tight and even bands. Because of the resolution, LOS components were stained chemically and immunochemically much better than those on continuous or stepwise gradient gels. Our study also showed that preformed tricine-SDS (TSDS) minigels such as 16.5 and 10-20% (linear gradient) did not resolve PID2 LOS, which indicated that heterogeneous LOS preparations may not be fully analyzed by using these TSDS minigels. By using glycine-SDS linear gradient mini-PAGE, we should be able not only to screen expression of LOSs but also to characterize smaller M(r) LOS components present in heterogeneous LOS preparations whose identities may have been neglected in the past.

Antigens, Bacterial↗
PubMed2000

Randomized trial of the usefulness of a bile leakage test during hepatic resection.

HYPOTHESIS: An intraoperative bile leakage test will assist in decreasing postoperative bile leakage in patients undergoing hepatic resection. DESIGN: Randomized controlled trial. SETTING: University hospital. PATIENTS: One hundred three consecutive patients who were scheduled for hepatic resection without biliary reconstruction. Associated cirrhosis was present in 49 patients (48%), and only 24 (23%) had normal livers. Patients were randomized to undergo (n = 51) or to not undergo (n = 52) a bile leakage test, according to age, liver function, and hepatectomy method. The 2 groups were similar in baseline demographics. INTERVENTION: A bile leakage test was carried out by injecting isotonic sodium chloride solution through the cystic duct, and interrupted suturing was taken for a bile leak on the transected liver surface. MAIN OUTCOME MEASURES: The incidence of postoperative bile leakage and the length of the postoperative hospital stay. Bile leakage was defined as continuous drainage, with a bilirubin level of 86 micromol/L or more (> or =5 mg/dL), beyond 1 week. RESULTS: Twenty-one patients (41%) in the test group showed a bile leak, and a median of 1 site (range, 1-6 sites) was closed during the test. Postoperative bile leakage was observed in 3 patients (6%) in the test group and in 2 (4%) in the control group (P = .99). The odds ratio of the event was 1.53 (95% confidence interval, 0.25-9.44). The median postoperative hospital stay lasted 17 (range, 13-47) and 18 (range, 12-41) days for the test and control groups, respectively (P =.98). CONCLUSION: This randomized trial suggested no advantage in using a bile leakage test during hepatic resection.

Adult↗
PubMed2000

Reconstruction of small and fragile bile ducts without mucosa-to-mucosa anastomosis.

We describe a simple and easy technique for performing choledochojejunostomy without the need to suture the full thickness of the ductal and intestinal walls for patients in whom standard choledochojejunostomy is difficult because the stumps of the residual bile ducts are small and fragile. This technique is useful in partial liver transplantation or after hepatectomy that includes removal of the extrahepatic bile ducts. The procedure involves the placing of external biliary drainage tubes through a Roux-en-Y jejunal loop, positioned transanastomotically, and the use of an external jejunostomy to decompress the loop. The tubes are fixed to the jejunal loop by a purse-string suture and to the duct by simple ligation or a purse-string suture. Anastomosis is performed by suturing the connective tissue and liver parenchyma around the ductal stump to the seromuscular layer of the intestine. Choledochojejunostomy according to this method was performed in 5 cases; the biliary drainage tubes were removed 1 to 4 months after surgery. The only complications were cerebellar infarction and cholangitis, both of which resolved with conservative treatment. We consider that this technique will be helpful as a last-ditch measure when standard choledochojejunostomy, with suturing of the full thickness of the walls of the duct and intestine to secure mucosa-to-mucosa apposition, is impossible because of small and fragile bile ducts.

Anastomosis, Surgical↗
PubMed2000

Glucose uptake by individual skeletal muscles during running using whole-body positron emission tomography.

The purpose of this study was to examine, by positron emission tomography (PET), the distribution of [18F]fluoro-deoxy-glucose ([18F]FDG) uptake by human muscles during 35 min of running. Thirteen healthy male subjects were studied, seven of whom participated in the exercise study. Running intensity was kept constant such that the subjects' heart rates were maintained at between 140 and 150 beats per minute. [18F]FDG [62.9 (14.8) MBq, mean (SD)] was injected after 15 min of running. PET imaging was started immediately after the running ended. The ratio of [18F]FDG uptake by muscles in runners to that in control subjects (r-c ratio) varied from three to six for the muscles of the foot and leg below the knee joint. The r-c ratio of the medial head of the gastrocnemius (MG) was higher than that of its lateral head (LG). The r-c ratio of the rectus femoris (RF) was lower than that of the other three muscles of the quadriceps femoris (QF). The r-c ratio of inactive muscles located above the waist was approximately 0.7. These results suggest that, during the moderate running of this study: (1) glucose uptake by muscles of the foot and leg below the knee joint clearly increases, (2) the r-c ratio differs significantly among the skeletal muscles, which act synergistically, and (3) glucose uptake by inactive skeletal muscles decreases.

Fluorodeoxyglucose F18↗
PubMed2000

Anomalies of inferior vena cava and left renal vein: risks in aortic surgery.

Although most aortic surgery is now routinely performed without incident, major venous anomalies can cause unexpected bleeding. In the last 6 years, 4 of 166 patients undergoing abdominal aortic surgery at our institution were found to have a major venous anomaly, including a double inferior vena cava (2), a preaortic iliac vein confluence (1), and a circumaortic renal collar (1). The 3 men and 1 woman had a mean age of 62.3 years (range, 56 to 68 years). All four patients underwent surgery for an abdominal aortic aneurysm. Preoperative imaging revealed all of the venous anomalies except for the renal collar. Unexpected venous injuries complicated the operation in one patient who had a double inferior vena cava and an inflammatory abdominal aortic aneurysm and in the patient with the circumaortic renal collar. Major venous anomalies are rarely encountered in patients undergoing aortic surgery. Preoperative assessment and intraoperative awareness are important to prevent unexpected venous injuries. Patients with an anomaly of the left renal vein and an inflammatory abdominal aortic aneurysm are at a particularly high risk.

Aged↗
PubMed2000

Possible existence of platelet activation before the onset of cerebral infarction.

To study the existence of platelet activation before the onset of cerebral infarction, the ultrastructural features of platelets (7-day survival) and coagulation-fibrinolytic markers (70-100-min life span) were measured 2-12 h (acute phase), 7 days (subacute phase) and 6 months (chronic phase) after onset in 18 patients with cerebral infarction. Seven patients with atherosclerosis but without cerebral infarction and eight healthy subjects were studied as controls. Ultrastructural study included folds, pseudopods, vacuoles and centralization in addition to immunochemical staining such as platelet peroxidase and fibrinogen. Furthermore, beta-thromboglobulin, platelet factor-4, thrombin antithrombin complex and alpha(2)-plasmin inhibitor plasmin complex were examined as coagulation-fibrinolytic markers. Ultrastructural study of circulating platelets demonstrated no difference between acute and chronic phases and little difference between cerebral infarction and atherosclerosis, although plasma coagulation-fibrinolytic markers showed an increase in cerebral infarction at the acute phase but no difference among the chronic phase of cerebral infarction, atherosclerosis and normal healthy subjects. It is considered that shape change in circulating platelets was caused by pre-existed atherosclerosis rather than the thrombotic event itself though coagulation-fibrinolytic markers were derived from the thrombotic event.

Aged↗