Biomedical subjects

S Shimizu

Publications and source records attributed to S Shimizu.

At least 325 records · Page 18Linked to original sources

PubMed1998

Coil embolization of bleeding visceral pseudoaneurysms following pancreatectomy: the importance of early angiography.

OBJECTIVE: To evaluate the efficacy of early angiography in the diagnosis and treatment of delayed arterial hemorrhage as a significant complication following pancreatectomy. DESIGN: Retrospective case series. SETTING: University hospital; 6-year period between January 1992 and December 1997. PATIENTS AND INTERVENTION: Of a total of 81 patients undergoing pancreatic head resection, 10 (12%) developed massive arterial hemorrhage after surgery. All 10 patients underwent an emergency angiography and 8 of these were managed by transcatheter arterial embolization. RESULTS: Before onset of major bleeding, 9 patients (90%) had developed intra-abdominal abscess resulting from pancreatic fistula or other anastomotic leak, and all 10 patients had had preliminary minor bleeding. The angiogram demonstrated an exact site of bleeding as a pseudoaneurysm in all 10 patients. Transcatheter arterial embolization achieved temporary control of bleeding in all 8 patients for whom embolization was attempted and complete hemostasis in 5 of the 8 subsequently, yielding a success rate of 63%. Overall, 4 patients (40%) died of complications related directly to the major hemorrhage or the transcatheter arterial embolization technique. CONCLUSIONS: An emergency angiography should be considered in all patients who develop either a sentinel or massive gastrointestinal bleed following pancreatectomy irrespective of suspected intra-abdominal sepsis. Transcatheter arterial embolization allows temporary control of massive hemorrhage and hemodynamic stabilization in most cases, and prevents the need for high-risk emergency surgery.

Aged↗

PubMed1998

Significance of serum delta-bilirubin in patients with obstructive jaundice.

BACKGROUND: Delta-bilirubin is a bilirubin covalently bound with albumin, which is nontoxic and excreted neither in urine nor in bile. We previously reported that the percentage of delta-bilirubin increased after biliary drainage and that the rapidly excretable bilirubin fraction (total minus delta-bilirubin) was a better parameter to predict the effectiveness of biliary decompression in the dog model. The aim of the present study was to elucidate whether it is applicable to humans. MATERIALS AND METHODS: The serum bilirubin concentration was measured and its fractions were analyzed by high-performance liquid chromatography in 22 patients with obstructive jaundice before and after biliary drainage. In addition, the patients were subgrouped into good and poor drainage groups according to the decline index of serum bilirubin to examine the significance of delta-bilirubin. RESULTS: The concentration of total bilirubin decreased from 14.1 mg/dl before biliary drainage to 5.4 mg/dl 28 days after drainage. During this period, the percentage of conjugated bilirubin steeply declined from 47.1 to 8.8% and that of excretable bilirubin from 63.4 to 28.6%. In contrast, the proportion of serum delta-bilirubin increased from 36.6 to 71.4%. There was an inverse correlation between percentage of delta-bilirubin and total bilirubin concentration (r = -0.69, P < 0.01). In the good drainage group, the percentage of delta-bilirubin increased above 60% within 7 days after biliary drainage, but it did not reach 60% by 28 days in the poor drainage group. A decreasing rate of total bilirubin minus delta-bilirubin, the excretable bilirubin fraction, was a better index than that of total bilirubin to assess the efficacy of biliary drainage (P< 0.01). CONCLUSIONS: The increase in the percentage of serum delta-bilirubin indicates an effectiveness of biliary drainage in man. An analysis of serum delta-bilirubin for 7 days can distinguish the good drainage patients from the poor drainage patients.

Bilirubin↗

PubMed1998

Oxygen consumption and motility of mechanically unloaded myocardial slices.

We have recently established a new measurement system of myocardial O2 consumption per min (mVO2) of mechanically unloaded rat left ventricular (LV) slices (Yasuhara et al.: Am. J. Physiol. 270: H1063-H1070, 1996). Using this system, we have revealed that an increment in O2 consumption (delta mVO2) by electrical stimulation primarily represents mVO2 for Ca2+ handling in the excitation-contraction (E-C) coupling, though much smaller than that in the whole heart preparation. The much smaller delta mVO2 in the sliced myocardium than that in the whole heart is due to the much lower frequency of stimulation (60 bpm against 300 bpm). We consider that delta mVO2 does not contain mVO2 for residual crossbridge cycling from the results showing no effect of 2,3-butanedione monoxime on delta mVO2 despite the large decrease in mechanically unloaded contraction, which is expressed by the motility index. We also revealed that mVO2 without stimulation represents basal metabolism. The basal metabolism in rat myocardial slices, which is much higher than in other mammalian hearts, corresponds to that in the rat whole heart preparation. We finally obtained the results showing that sarcoplasmic reticulum (SR) Ca2+ pump blockers, thapsigargin and cyclopiazonic acid, did not reduce basal metabolic mVO2 but both of them reduced delta mVO2 maximally by 50-70% of control and markedly reduced the motility index. We conclude that myocardial O2 consumption (VO2) is composed of VO2 for E-C coupling and basal metabolism and does not contain VO2 for residual crossbridge cycling. Basal metabolic VO2 does not include VO2 for the SR Ca2+ pump, and at least two-thirds of VO2 for E-C coupling represents VO2 for the SR Ca2+ pump.

Animals↗

PubMed1998

Light-dependent fragmentation of the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase in chloroplasts isolated from wheat leaves.

The large subunit (LSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39) is degraded into an N-terminal side fragment of 37 kDa and a C-terminal side fragment of 16 kDa by the hydroxyl radical in the lysates of chloroplasts in light (H. Ishida et al. 1997, Plant Cell Physiol 38: 471-479). In the present study, we demonstrate that this fragmentation of the LSU also occurs in the same manner in intact chloroplasts, and discuss the mechanisms of the fragmentation. The fragmentation of the LSU was observed when intact chloroplasts from wheat leaves were incubated under illumination in the presence of KCN or NaN3, which is a potent inhibitor of active oxygenscavenging enzyme(s). The properties, such as molecular masses and cross-reactivities against the site-specific anti-LSU antibodies, of the fragments found in the chloroplasts were the same as those found in the lysates. These results indicate that, as in the lysates, the fragmentation of the LSU in the intact chloroplasts was also caused by the hydroxyl radical generated in light. The fragmentation of the LSU was completely inhibited by 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU), and only partially inhibited by methyl viologen in the lysates. The addition of hydrogen peroxide to the lysates stimulated LSU fragmentation in light, but did not induce any fragmentation in darkness. Thus, we conclude that both production of hydrogen peroxide and generation of the reducing power at thylakoid membranes in light are essential requirements for fragmentation of the LSU.

Antibodies↗

PubMed1998

Laparoscopic treatment of congenital choledochal cyst.

We describe the laparoscopic treatment of a patient presenting with congenital choledochal cyst. Our patient was a 19-year-old man with a complaint of recurrent abdominal pain due to pancreatitis. The choledochal cyst was type I and had a common channel of pancreatobiliary duct, as revealed by endoscopic retrograde cholangiopancreatography. Under laparoscopic guidance, the dilated bile duct and the gallbladder were excised, and a Roux-en-Y anastomosis was constructed with an endo-EEA. Finally, end-to-side anastomosis was carried out by the continuous suture method, aided by an Endostitch between the stump of the hepatic duct and the Roux-en-Y limb. After the operation, slight hyperamylasemia was observed for several days but further treatment was not necessary. Postoperative symptoms were minimal, and the patient was discharged on the 11th day after the procedure. Although it is difficult and time-consuming, laparoscopic operation is highly beneficial for the patient. The use of such instruments as the endostapler and Endostitch may help to simplify this complex intracorporeal procedure involving division and anastomosis of the digestive tract.

Adult↗

PubMed1998

Carcinoma of the pancreas associated with anomalous junction of pancreaticobiliary tracts: report of two cases and review of the literature.

We report two cases of carcinoma of the pancreas with anomalous junction of the pancreaticobiliary tracts. A 71-year-old Japanese woman had obstructive jaundice. Ultrasonography showed a hypoechoic mass in the pancreatic head and computed tomography demonstrated a low-density nodule in the pancreatic head. Endoscopic retrograde cholangiopancreatography displayed a double duct sign and an anomalous junction of the pancreaticobiliary tracts. The patient underwent a pancreatoduodenectomy. The histopathologic diagnosis of the resected specimen was adenocarcinoma of the pancreatic head. A 56-year-old Japanese man also developed obstructive jaundice. Ultrasonography and computed tomography showed a huge mass almost replacing the whole pancreas and involving the superior mesenteric artery, splenic artery, splenic vein, and portal vein. Multiple hepatic metastases and peritoneal dissemination were present. Endoscopic retrograde cholangiopancreatography demonstrated an anomalous junction of the pancreaticobiliary tracts. The patient died of hemorrhage from esophageal varices. We discuss the relationship between the anomalous junction of the pancreaticobiliary tracts and pancreatic carcinoma.

Adenocarcinoma↗

PubMed1998

Chronic asymptomatic pseudocyst with sludge aggregates masquerading as mucinous cystic neoplasm of the pancreas.

Pseudocyst of the pancreas is sometimes difficult to distinguish from mucinous cystic neoplasm of the pancreas. A 37-year-old asymptomatic Japanese man was diagnosed with hypertension. He had a 20-years history of habitual drinking of alcohol, but no history of pancreatitis or abdominal trauma. During examinations to ascertain the cause of hypertension, ultrasonography and computed tomography incidentally demonstrated a huge cyst in the head of the pancreas. Laboratory data were within normal limits, including serum levels of amylase, carcinoembryonic antigen, and carbohydrate antigen 19-9. Imaging studies showed a huge unilocular cyst, measuring 7 cm, in the head-to-body of the pancreas, and two small unilocular cysts, measuring 1.4 and 1.5 cm, in the tail and head of the pancreas, respectively. A mural nodule was suspected in the largest cyst. Endoscopic retrograde cholangiopancreatography demonstrated communication of the main pancreatic duct with the two small cysts in the head and tail of the pancreas but not with the huge cyst. There were no ductal changes suggesting chronic pancreatitis. Laparotomy was performed under the tentative diagnosis of potentially malignant mucinous cystic neoplasms of the pancreas. However, inflammatory adhesion was dense around the pancreas and the mural nodule suspected preoperatively was found to be sludge aggregates in a pseudocyst. The diagnosis of an intraoperative frozen section of the cyst wall was pseudocyst of the pancreas. Cystojejunostomy was performed. We report this case because the preoperative diagnosis was mucinous cystic neoplasm of the pancreas, but the diagnosis changed with careful intraoperative examinations, to pseudocyst of the pancreas. We discuss the differential diagnosis of the two conditions.

Adult↗

PubMed1998

Comparison of endoscopic retrograde and magnetic resonance cholangiopancreatography in the surgical diagnosis of pancreatic diseases.

BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) is a newly developing noninvasive examination of the biliopancreatic trees. Roles of MRCP in the diagnosis of pancreatic diseases have not been scrutinized. METHODS: Endoscopic retrograde cholangiopancreatography (ERCP) and MRCP were reviewed in 52 Japanese patients with various pancreatic diseases and 6 patients with normal pancreas to compare their diagnostic usefulness and limitation. RESULTS: In those with normal pancreas, only the main pancreatic duct was visualized by MRCP, while both the main pancreatic and branch ducts were clearly delineated by ERCP. In 3 patients with serous cystadenoma, the tumor was not visualized by ERCP, whereas it was visible as a high-intensity mass on MRCP. Of 18 patients with a "mucin hypersecreting" tumor of the branch type, MRCP demonstrated cystically dilated branch ducts in all, while ERCP failed to visualize the dilated ducts in 6 patients. However, the details of the cystic lesions (mural nodule, communication with the main pancreatic duct) were more exactly demonstrated by ERCP than MRCP. In 5 patients with a mucin hypersecreting tumor of the main pancreatic duct type, the dilated main pancreatic duct and the presence of mural nodules were similarly demonstrated both by ERCP and MRCP. In 12 patients with pancreatic adenocarcinoma, indirect findings were similarly demonstrated both by ERCP and MRCP, ie, stenosis (4 patients) and obstruction (8) together with dilation of the main pancreatic duct (9). In 3 patients, the center of the mass showed high intensity on MRCP, suggesting the secondary change of pancreatic carcinoma. In 8 patients with obstruction of the main pancreatic duct due to carcinoma, the distal pancreatic duct was visualized by MRCP but not by ERCP. In 9 patients who had undergone pylorus-preserving or standard pancreatoduodenectomy, follow-up MRCP was obtainable in all examined and displayed the main pancreatic duct. CONCLUSIONS: MRCP plays a complementary role in the surgical diagnosis of pancreatic disorders and is especially useful to examine the pancreatic duct after pancreatoduodenectomy.

Adenocarcinoma↗

PubMed1998

Litmus paper helps detect potential pancreatoenterostomy leakage.

BACKGROUND: Leakage of pancreatoenterostomy remains as a serious and fatal complication after pancreatectomy. Several risk factors have been reported, ie, normal pancreatic parenchyma, small pancreatic duct, a large amount of intraoperative blood loss, management of the cut surface of the pancreas, and the presence of preoperative jaundice. Transected pancreatic ductules on the cut surface of the pancreas that are not drained into the main pancreatic duct after pancreatectomy are one of the risks. The pancreatic juice is alkaline and turns red litmus to blue. METHODS: In order to detect the transected pancreatic ductules on the cut surface of the pancreas, red litmus paper is applied to the cutting surface of the pancreas after stimulation of secretin. RESULTS: Nondrained, transected pancreatic ductules on the cut surface of the pancreas can be detected as blue spots on the red litmus paper. The corresponding areas to the blue spots can be transfixed with sutures to close the nondrained and transected pancreatic ductules. CONCLUSION: Litmus paper can be expected to detect pancreatoenterostomy leakage after pancreatectomy.

Humans↗

PubMed1998

Changes in pancreatic function after pancreatoduodenectomy.

BACKGROUND: The objective of this study was to compare the alterations in pancreatic function after pancreatoduodenectomy between malignant and benign diseases. METHODS: In 34 patients who underwent pancreatoduodenectomy for pariampullary cancer (malignant group; n = 18) and benign pancreatic disorders (benign group; n = 16), exocrine and endocrine functions were analyzed before surgery, at a short-term period (< or = 2 months), and at a long-term period (>12 months) after surgery. Assessment was based on the BT-PABA excretion test, fasting blood sugar level, and oral glucose tolerance test. RESULTS: Compared with the preoperative level, urinary PABA excretion rate in the malignant group significantly decreased on short-term follow-up but recovered on long-term follow-up. However, that in the benign group increased on long-term follow-up without showing a short-term decline. Diabetes mellitus was present in 11 (61%) of the 18 patients in the malignant group and 6 (38%) of the 16 in the benign group before surgery. Glucose tolerance improved in 6 (55%) of the 11 patients in the malignant group but in only 1 (17%) of the 6 in the benign group shortly after surgery. In the benign group, 3 (30%) of 10 patients with normal preoperative glucose tolerance became diabetic after surgery, while no patient in the malignant group developed diabetes on short-term follow-up. CONCLUSIONS: Surgeons should pay attention to exocrine pancreatic function in patients with a periampullary cancer and to glucose metabolism in patients with benign disease over the short-term period after pancreatoduodenectomy.

4-Aminobenzoic Acid↗

PubMed1998

Unilateral absence of pulmonary artery and ventricular septal defect in an infant.

A 2-month-old boy was diagnosed as having a rare combination of absence of left pulmonary artery and ventricular septal defect. He underwent intracardiac repair at the age of 8 months. Reconstruction of the left pulmonary artery was impossible because it could not be visualized through a median sternotomy. Although his early postoperative course was uneventful, he needed ipsilateral pneumonectomy 3 months later because of unremitting hemoptysis. Hilar left pulmonary artery, which used to exist, was not found even by histologic examination.

Aorta, Thoracic↗

PubMed1998

Conotruncal repair for tetralogy of Fallot: midterm results.

OBJECTIVE: Because of the left-sided location of the main atrioventricular conduction axis, the membranous flap can be safely used for closure of the ventricular septal defect in tetralogy of Fallot. METHODS: Conotruncal repair consists of (1) precise closure of the defect using the membranous flap and (2) outflow reconstruction of the right ventricle by a wide monocusp patch. This method has been followed in 233 patients from October 1985 to March 1997. The age of patients ranged from 2 months to 53 years, with a mean of 4.6 years; 44% were younger than 2 years of age, and 11% were less than 12 months of age. RESULTS: A membranous flap was present in 86%, 12% had a muscle bar between the defect and the tricuspid valve, and only 2% had neither a membranous flap nor a muscle bar. There was no early death; two late deaths occurred over a mean follow-up period of 7.3 years. The actuarial survival was 99.1%. No patients required reoperation except for two with residual anomalously connecting pulmonary veins. All 233 patients were in sinus rhythm postoperatively. No patient has had a significant residual defect. The mobility of the polytetrafluoroethylene monocusp was echocardiographically detected in 85% and pulmonary regurgitation was less than mild in 82% at the late phase. The late right and left ventricular pressure ratio was 0.40 +/- 0.14 (n = 30) and the late central venous pressure was 5.6 +/- 2.2 mm Hg (n = 30). CONCLUSION: Conotruncal repair has provided good midterm results with a low central venous pressure, well-reconstructed outflow tract of the right ventricle, no residual defect, and no heart block.

Actuarial Analysis↗

PubMed1998

Protective effects of tetrahydrobiopterin against nitric oxide-induced endothelial cell death.

The purpose of this study was to examine whether tetrahydrobiopterin (BH4), one of the cofactors of nitric oxide (NO) synthase, attenuates NO-induced endothelial cell death. S-Nitroso-N-acetyl-DL-penicillamine (SNAP) was used as a NO donor. Endothelial cell death was assessed by the leakage of intracellular lactate dehydrogenase (LDH). Addition of SNAP to endothelial cells time- and concentration-dependently induced endothelial cell death. The SNAP-induced endothelial cell death was strongly reduced by the treatment with carboxy-PTIO, a NO scavenger, or catalase, but not with superoxide dismutase (SOD). Moreover, pretreatment with sepiapterin, a precursor of BH4, increased intracellular BH4 content, and strongly reduced the SNAP-induced endothelial cell death. Both the increase in BH4 content and the protective effects of sepiapterin were prevented by co-pretreatment with N-acetylserotonin (NAS), an inhibitor of BH4 synthesis. These findings suggest that the cytotoxicity of NO released from SNAP involves H2O2 production, and increase in intracellular BH4 content attenuates NO-induced endothelial cell death. Scavenging of H2O2 by BH4 may be at least one of the mechanisms by which BH4 reduces NO-induced endothelial cell death.

Animals↗

PubMed1998

Effect of glucose on ureagenesis during exercise in amino acid-infused dogs.

The purpose of this study was to investigate the effect of glucose administered with amino acids before and during exercise on hepatic ureagenesis. Eight mongrel dogs subjected to treadmill running for 150 minutes at 10 km/h on a 12% incline were intravenously infused with either a mixture of amino acids and glucose (AAG) or amino acids alone (AA). The infusion was started 60 minutes before exercise and continued until the end of exercise. The rate of urinary urea excretion increased after infusion of both AAG and AA. However, the rate of urinary urea excretion was significantly lower in the AAG group versus the AA group during the first 1.5 hours of the recovery period ([R0 to R90] 514+/-24 v 637+/-24 mg/h, mean+/-SE, P < .05). Moreover, hepatic urea output was decreased during AAG versus AA infusion (229+/-62 v 367+/-55 microg/kg/min, P < .05). Hepatic glucose production during exercise was also significantly lower in AAG versus AA infusion (354+/-54 v 589+/-56 mg/kg, P < .05). On the other hand, no difference was observed in hepatic total amino acid uptake between the groups. Thus, these results indicate that AAG administered before and during exercise appears to reduce hepatic ureagenesis due to reduced hepatic gluconeogenesis as compared with administration of AA alone. These findings also suggest that nitrogen retention is enhanced by glucose administered during exercise.

Amino Acids↗

PubMed1998

Dissemination of Epstein-Barr virus associated B-cell lymphoma of the brain after development of immunological incompetence with Evans syndrome.

A 54-year-old female with Epstein-Barr virus (EBV)-associated B-cell lymphoma of the brain and Evans syndrome is presented. After treatment of the lymphoma with irradiation to the brain and chemotherapy she developed Evans syndrome with autoimmune hemolytic anemia and thrombocytopenia. Further immunosuppressive treatment for Evans syndrome caused the dissemination of EBV-associated B-cell lymphoma. The dissemination of EBV-associated B-cell lymphoma was confirmed by in situ hybridization with EBV encoded small RNAs (EBER), polymerase chain reaction with Bam HI-W fragment of EBV and lymphocyte determined membrane antigen (LYDMA) and immunohistochemistry with latent membrane protein (LMP). Since only a few cases of lymphomas associated with EBV occurring during autoimmune diseases have been reported, this is an illustrative case.

Autoimmune Diseases↗

PubMed1998

Genetic polymorphism of the angiotensin-converting enzyme (ACE) in asthmatic patients.

Angiotensin-converting enzyme (ACE) inactivates bradykinin, substance P and neurokinin A, which are believed to play important roles in the pathogenesis of asthma, especially in neurogenic inflammation. It has recently been shown that an insertion (I)/deletion (D) polymorphism in the ACE gene accounts for variation in serum ACE levels. There are thus three genotypes (insertion homozygote, II; deletion homozygote, DD; heterozygotes, DI). The serum ACE level with the DD type is reported to be about double that of the II type and intermediate in the DI case. In the present study, we examined whether asthma is linked with this ACE gene polymorphism. Seventy-one patients with asthma (27 males and 44 females) and 142 sex- and age-matched healthy controls were determined for their genotype by the polymerase chain reaction (PCR) method. Twenty-five asthmatics demonstrated the II type (35.2%), 37 the DI type (52.1%), and nine the DD type (12.7%). There were no significant differences in the distributions of genotypes and serum ACE levels between healthy controls and patients. No significant differences were evident in serum IgE levels, age at onset, proportion of atopic type patients and severity of asthma among the three genotypes. We did not find any association between asthma and the ACE gene polymorphism in this study.

Asthma↗

PubMed1998

Short-term and long-term pancreatic exocrine and endocrine functions after pancreatectomy.

Exocrine and endocrine functions of the pancreas were assessed in 44 Japanese patients who underwent pancreatic head resection. Functions were analyzed comparing levels before surgery, at a short-term follow-up (<2 months), and at a long-term follow-up (12-31 months). The N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA) excretion test, fasting blood sugar (FBS) level, and oral glucose tolerance test (OGTT) were used to determine pancreatic function. The patients were divided into three groups according to the size of the main pancreatic duct: group 1, 15 patients with a normal sized duct (< or =3 mm); group 2, 20 with a moderately dilated duct (>3 mm, <10 mm); and group 3, 9 with a markedly dilated duct (> or =10 mm). The mean BT-PABA value (6-hr urinary PABA recovery rate) in group 1 showed no change during the postoperative period. In contrast, the BT-PABA values in groups 2 and 3 had dropped by the short-term follow-up and returned to the preoperative level by the long-term examination. FBS and 120-min OGTT levels were not different between the three groups preoperatively. Although these values showed no change in all the three groups at the short-term measurements, the FBS in group 3 and 120-min levels in all the three groups had increased at the long-term. These findings suggest that exocrine pancreatic function shows a short-term deterioration in patients with a dilated pancreatic duct but recovers to the preoperative level over the long term after pancreatic head resection. Endocrine insufficiency, however, may occur at a long-term point after surgery irrespective of the preoperative pancreatic ductal dilatation.

4-Aminobenzoic Acid↗

PubMed1998

Metalloenzyme nitrile hydratase: structure, regulation, and application to biotechnology.

Nitrile hydratase (NHase), which catalyzes the hydration of nitriles to amides, has been used in the industrial production of acrylamide and nicotinamide. Recent studies on NHases, which are roughly classified into iron and cobalt types according to the metal involved, have clarified the photoactivation mechanism, the novel ligand structure of the metal-binding sites, the unique mechanism of the enzyme hyper-induction, and the occurrence of an accessory gene involved in cobalt-containing NHase formation. These detailed analyses have led to the development of biotechnological applications of NHase, including biotransformation and bioremediation.

Acrylamide↗