Biomedical subjects
Publications and source records attributed to M Kanai.
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BACKGROUND/AIMS: We previously reported that the populations of lymphocytes and the expression of activated antigens in human sinusoidal mononuclear cells were different from those in peripheral blood mononuclear cells. Attempts to culture these cells for further study failed because they died rapidly under standard culture conditions in vitro after isolation from the liver. In this study, we evaluated the characteristics of cell death and the effects of various culture conditions on the viability of these cells. METHODS: Sinusoidal mononuclear cells were isolated from University of Wisconsin solution that had been perfused through the portal veins of normal healthy human livers harvested for transplantation into living related recipients. RESULTS: 70% of sinusoidal mononuclear cells cultured in vitro were nonviable within 48 h after isolation, while only 10% of peripheral blood mononuclear cells died under the same conditions. Sinusoidal mononuclear cells showed DNA ladder formation of DNA on electrophoresis and characteristic morphological pattern on electron microscopic examination that suggested they had died in an apoptotic manner. The addition of human liver extracts or 2-mercaptoethanol and reduced glutathione to the cultures rescued the sinusoidal mononuclear cells from apoptosis. Furthermore, diamide, a sulfhydryl group specific oxidant, negated the effect of the liver extract. CONCLUSION: In comparison with peripheral blood mononuclear cells, human sinusoidal mononuclear cells were more subject to death by apoptosis ex vivo, which was reversed by exogenous agents producing reducing conditions. These results suggested that hepatic sinusoidal mononuclear cells might express a different sensitivity to redox environment than peripheral blood mononuclear cells.
We measured the concentration of hepatocyte growth factor (HGF) in bile obtained from patients after hepatectomy. The HGF concentrations in the bile samples were quantified using an enzyme-linked immunosorbent assay (ELISA). By immunoblotting, using a monoclonal antibody raised against the HGF alpha-subunit, the bile HGF, which was purified on a Heparin-Sepharose column, showed a band of the same size as the recombinant HGF alpha-subunit (69 kd). Bile samples were obtained from 24 patients with biliary tract disease before and after hepatectomy by means of biliary drainage. Before surgery, the bile HGF concentrations were minimal (0.8 +/- 0.1 ng/mL); however, after hepatectomy on postoperative day 1 in patients without posthepatectomy liver failure (20 of 24), they increased severalfold (4.1 +/- 0.4 ng/mL, P < .05). The patients with posthepatectomy liver failure (4 of 24) showed no significant increase in bile HGF after hepatectomy (less than 2 ng/mL on postoperative day 1). The volume of the remnant liver correlated positively with the bile HGF concentration. The bile HGF concentration on postoperative day 1 exhibited a significant negative correlation with the maximum concentration of serum total bilirubin after hepatectomy. The concentration of bile HGF was generally higher than that in serum (2.1-fold). Thus, the bile HGF concentration after hepatectomy may be useful for the early assessment of posthepatectomy liver function.
To study the role of apolipoprotein E (apoE) in vivo in deposits of amyloid beta protein (A beta), a major component of senile plaque amyloid in the brain of patients with Alzheimer disease, the transgenic mice were examined by apoE immunostaining. The mice were systemically overexpressing signal peptide and 99 amino acid residues of the carboxy-terminal fragment of human amyloid beta protein precursor (betaAPP) under control of the powerful cytomegalovirus enhancer/chicken beta-actin promotor. A beta deposits appeared at 4 months and increased with aging in the acinar cells of the transgenic pancreas. Similarly, apoE deposits appeared in the pancreatic acinar cells at 4 months old. The number and size of apoE deposits increased with aging and correlated with the progression of A beta deposits. Interstitial macrophages labeled by apoE immunostaining appeared at 8 months after birth and their number increased with aging. On serial section of the pancreata of 24-month-old mice, approximately 70% of A beta deposits were labeled with the apoE antiserum. ApoE was detected in the highly insoluble formic acid fraction of the transgenic pancreas by an immunoblot study. The Northern blot study revealed no increase in synthesis of endogenous apoE mRNA. These findings indicate that apoE is closely related to progression of A beta deposits with aging and suggest that A beta deposition in the transgenic pancreas is similar to that in the senile plaque of Alzheimer brains. Therefore, our experimental system using transgenic mice will provide a useful tool to analyze the molecular mechanism of A beta deposition in association with apoE in vivo.
OBJECTIVE: Previous reports about changes in cerebral blood flow (CBF) in transient global amnesia disclosed decreased flow in some parts of the brain. However, CBF analyses in most reports were qualitative but not quantitative. The purpose of this study was to determine changes in CBF in transient global amnesia. METHODS: The CBF was measured and the vasoreactive response to acetazolamide was evaluated in six patients with transient global amnesia using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT). The CBF was measured during an attack in two patients and soon after an attack in the other four. About one month later, CBF was re-evaluated in each patient. RESULTS: Two patients examined during an attack and one patient examined five hours after an attack had increased blood flow in the occipital cortex and cerebellum. Three patients examined at six to 10 hours after an attack had decreased blood flow in the thalamus, cerebellum, or putamen. These abnormalities of blood flow almost disappeared in all patients one month after onset. The vasodilatory response to acetazolamide, which was evaluated initially using SPECT, was poor in areas of increased blood flow. By the second evaluation of CBF with acetazolamide, the vasodilatory response had returned to normal. CONCLUSIONS: In a patient with transient global amnesia, CBF increased in the vertebrobasilar territory during the attack and decreased afterwards. The vasodilatory response to acetazolamide may be impaired in the parts of the brain with increased blood flow. It is suggested that transient global amnesia is distinct from migraine but may share the same underlying mechanism.
Proliferation and function of the intestinal epithelium is modulated by a range of regulatory peptides, including cytokines and peptide growth factors. To define mechanisms integrating these regulatory systems, the effects of growth factors and cytokines on the expression of the fibroblast growth factor (FGF) receptor 3 (FGFR3) IIIb expressed on intestinal epithelial cells were examined in Caco-2 cells. Regulated expression of FGFR3 IIIb was associated with acquisition of the differentiated state. Keratinocyte growth factor (KGF), a ligand of another member of the FGF receptor family, enhanced expression of FGFR3 IIIb, but acidic FGF, the ligand for FGFR3 IIIb itself, had no effect. Epidermal growth factor and transforming growth factor-beta also markedly enhanced FGFR3 IIIb expression in a different temporal pattern. In addition, FGFR3 IIIb expression was increased 10-fold by the cytokine interleukin-2. These studies demonstrate integration between cytokines and growth factor ligand-receptor systems in intestinal epithelial cells.
Epithelial cell kinase (Eck) is a member of a large family of receptor tyrosine kinases whose functions remain largely unknown. Expression and regulation of Eck and its cognate ligand B61 were analyzed in the human colonic adenocarcinoma cell line Caco-2. Immunocytochemical staining demonstrated coexpression of Eck and B61 in the same cells, suggestive of an autocrine loop. Eck levels were maximal in preconfluent cells. In contrast, B61 levels were barely detectable in preconfluent cells and increased progressively after the cells reached confluence. Caco-2 cells cultured in the presence of added B61 showed a significant reduction in the levels of dipeptidyl peptidase and sucrase-isomaltase mRNA, markers of Caco-2 cell differentiation. Cytokines interleukin-1beta (IL-1beta), basic fibroblast growth factor, IL-2, epidermal growth factor, and transforming growth factor-beta modulated steady-state levels of Eck and B61 mRNA and regulated Eck activation as assessed by tyrosine phosphorylation. Functionally, stimulation of Eck by B61 resulted in increased proliferation, enhanced barrier function, and enhanced restitution of injured epithelial monolayers. These results suggest that the Eck-B61 interaction, a target of regulatory peptides, plays a role in intestinal epithelial cell development, migration, and barrier function, contributing to homeostasis and preservation of continuity of the epithelial barrier.
Some patients with familial Alzheimer's disease (FAD) have mutations in the presenilin-1 (PS-1) gene on chromosome 14. We report a Japanese family with AD and an Ala285Val substitution in exon 8 of the PS-1 gene. FAD in this family was characterized by relatively late onset (mean age, 50 years) and absence of myoclonus, seizures, or paratonia. Levels of tau were markedly elevated in CSF whereas CSF levels of amyloid beta protein were normal. MRI of the cranium showed marked linear signal abnormalities within white matter in the parieto-occipital lobes, consistent with cortical amyloid angiopathy of the type encountered in patients with the PS-1 gene mutation.
The effects of repetitive myocardial ischemia on collateral circulation, ST deviation and epicardial wall motion were examined in 12 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) for single left anterior descending artery disease. Rentrop collateral filling grade was assessed using contrast injection to the contralateral artery during the first and final episodes of coronary occlusion. ST deviation was measured by intracoronary electrocardiography. Epicardial wall motion (%pre PTCA) was measured by guide wire motion analysis according to the centerline method. Collateral filling grade was assessed 30 sec after balloon inflation. The ST segment and the epicardial wall motion were measured 60 sec after balloon inflation and deflation, respectively. There was no change in the collateral filling grade between the first and final episode of coronary occlusion. Patients with collateral filling grade I (R-I group, n = 4), II (R-II group, n = 3) and III (R-III group, n = 5) during coronary occlusion showed mean ST segment shifts of 13.2, 9.4, and 0.9 mm, respectively, and mean epicardial wall motion of 41.4%, 67.2%, and 78.5%, respectively. The collateral filling grade correlated with ST deviation and epicardial wall motion, and there was a significant correlation between epicardial wall motion and ST deviation (r = -0.67). Comparison of the R-I group or severe ischemia (n = 4) and the R-III group or slight ischemia (n = 4) during coronary occlusion for the fourth time showed the effect of preconditioning was obtained in R-I group. More R-III group patients than R-I group had hyperkinetic epicardial wall motion during coronary reperfusion. Stunned myocardium was demonstrated in both R-I group and R-III group patients. Epicardial wall motion was poorer in the R-I group than R-III group. We concluded the following: There is no change in the grade of collaterals during repetitive coronary occlusion, and there is a relationship between the grade of collateral and degree of myocardial protection; there is good correlation between ST segment and epicardial wall motion; ischemic preconditioning is obtained during repetitive severe myocardial ischemia; recovery from brief episodes of slight myocardial ischemia is associated with hyperkinesia of epicardial wall motion; the reduction of stunned myocardium is related to the degree of premyocardial ischemia; preconditioning is sufficient to cause myocardial stunning, but myocardial stunning is insufficient to cause preconditioning.
We describe a 40-yr-old woman with a giant hepatic hemangioma and consumption coagulopathy who underwent transcatheter arterial embolization (TAE) prior to liver resection. Post-contrast computed tomography showed a large mass in the right hepatic lobe with a peripheral, nodular enhancement pattern that enlarged on delayed-phase images. There was a low fibrinogen concentration and decreased platelet count. The patient received i.v. nafamostat mesilate and underwent selective embolization of the arteries feeding the hemangioma; consequently, the plasma fibrinogen concentration increased to 1.6-fold before surgery. Right hepatic lobectomy with partial resection of the caudate lobe was performed. The intraoperative blood loss was only 1380 g. This patient illustrates the usefulness of preoperative TAE for hepatic hemangioma with consumption coagulopathy; TAE appears to improve coagulopathy and increase the safety of surgery.
From the therapeutic and diagnostic viewpoints, percutaneous transhepatic biliary drainage (PTBD) is crucial for the preoperative management of hilar cholangiocarcinoma. Pertinent multiple catheterizations using PTBD produce effective relief of jaundice and accurate diagnosis of cancer extent. Endoscopic retrograde biliary drainage is contraindicated for preoperative biliary decompression. To reduce posthepatectomy liver failure, an accurate preoperative assessment of hepatic functional reserve is essential. Indocyanine green test has been used conventionally. Although this test underestimates liver function under conditions of jaundice, it is still the most practical and reliable. Preoperative portal vein embolization is an effective method for preventing posthepatectomy liver failure and extending an indication of extensive liver resection. Liver resection for hilar cholangiocarcinoma is now popular in Japan, and combined en bloc resection of the caudate lobe has become general. However, the procedure of and indication for hepatectomy is not yet standardized. Further investigations are needed to produce more rational surgical procedure for hilar cholangiocarcinoma.
We report a case of foramen magnum meningioma in which case enhanced three-dimensional CT scan was valuable for preoperative evaluation of the surgical approach. A 53-year-old woman had suffered from stiffness and pain in the left occipital region and numbness of the left side of the face for about 2 years before admission. She had also weakness and numbness of the left side of her body for about 2 months before admission, and dysphagia and pain in the occipital region and in the posterior region of the neck produced by straining for about 1 month before admission. Neurological examination revealed left hemiparesis, and hypalgesia and tactile hypesthesia of the left side of the body, including the face. Plain X-P was normal. Enhanced CT scan and gadolinium enhanced MRI revealed a well-enhanced mass attached to the left anterolateral part of the foramen magnum. The left occipital condyle was observed at the lateral side of the attachment part of this mass. Angiography revealed tumor feeders from the meningeal branches of the left vertebral artery and the left ascending pharyngeal artery. Enhanced three-dimensional CT scan clearly showed that the tumor was attached to the left anterolateral part of the foramen magnum, that the left occipital condyle was at the lateral side of the attachment part of this mass and that the jugular foramen and jugular tubercle were situated superolateral to the attachment part of this mass. Considering these factors, we decided that removal of the posterior part of the left occipital condyle was necessary, but removal of the left jugular tubercle was not necessary for a good operative view from the left posterior lateral direction. The tumor was totally removed successfully and good results were obtained by the transcondylar approach without removal of the jugular tubercle. Histology of the tumor revealed meningothelial meningioma. In this case, preoperative evaluation with enhanced three-dimensional CT scan was helpful for deciding the surgical approach. With enhanced three-dimensional CT scan, it is easy to judge whether removal of the posterior part of the occipital condyle and/or the jugular tubercle is necessary for a good operative view, and we can get good images revealing the relationships between the tumor and surrounding structures. Preoperative evaluation with enhanced three-dimensional CT scan is very useful especially in this kind of situation.
A statistic survey was made on the clinical results of living and cadaveric renal transplantations performed at our department between October 1980 and June 1996. A total of 38 patients received 6 living and 32 cadaveric renal transplants. The graft and patient survival rates of a living renal transplantation were 83.3% and 100% at 3 years, respectively. The graft survival rate of cadaveric renal transplantation was 66.3% at 3 years and 56.0% at 5 years. In a cadaveric renal transplantation, patients with episodes of acute rejection within 12 months showed a significantly worse graft survival rate. This clinical parameter seems to be a prognostic factor for a long-term graft survival.
A 54-year-old woman presented with jaundice. Percutaneous transhepatic biliary drainage, cholangiography via a percutaneous transhepatic biliary, drainage catheter, and percutaneous transhepatic cholangioscopy were performed to alleviate the jaundice and to evaluate her biliary system. A diffuse-type tumor was detected in the common bile duct. The tumor had spread superficially up to the right anterior segmental duct and the left hepatic duct and involved the caudate branches. Curative surgery, which included a right anterior segmentectomy, total caudate lobectomy, and pylorus-preserving pancreatoduodenectomy, was performed. The histopathologic diagnosis was moderately differentiated tubular adenocarcinoma originating at the common bile duct. The extent of the superficial spread of the tumor corresponded to our preoperative determination. Her postoperative recovery was uneventful. In this case report, we discuss the accurate preoperative diagnosis and rational surgical treatment of bile duct carcinoma with superficial spread.
We report a case of xanthogranuloma of the bladder following herniorrhaphy. The patient complained of urinary frequency, residual feeling, and presented with a solid mass located on the dome of the bladder. He had undergone previous inguinal herniorrhaphy. Transurethral biopsy revealed an inflammatory change. Partial cystectomy was carried out for en bloc removal of the tumor. The histological diagnosis was xanthogranuloma of the bladder. Postoperatively, the symptoms disappeared. This is the sixth case report of xanthogranuloma of the urinary bladder and the first case following herniorrhaphy in the Japanese literature.
A 67-year-old woman was admitted with aching pain in her left flank and nausea. Bilateral renal infarctions were noticed by CT scan and arteriography. Selective intra-arterial thrombolytic therapy was performed. Urokinase (UK) was administered through a balloon catheter embedded into the occlusive segment of the left renal artery selectively. UK (20,000 units/hour) was continuously infused after short-term high dose UK (360,000) infusion. In spite of recanalization of the occluded artery, CT scan and renoscintigraphy image did not suggest recovery of renal function. Conservative intra-arterial thrombolytic therapy is considered to be the most effective treatment for renal infarction.
S-Ribonucleases (S-RNases) that cosegregate with S-alleles in the styles of solanaceous and rosaceous plants are associated with gametophytic self-incompatibility (GSI). The amino acid sequences of many S-RNases have been derived from cDNA sequences, but the state of half-cystines has not been clarified. We report the locations of the two free cysteine residues and four disulfide bridges of tobacco S6-RNase and of the four disulfide bridge of Japanese pear S4-RNase. The protein was first S-pyridylethylated at a low pH to selectively modify the free cysteines without thiol-disulfide exchange. The S-pyridylethylated protein (PE-protein) was digested with Achromobacter protease I (API) at pH 6.5 then analyzed by liquid chromatography/electrospray-ionization mass spectrometry (LC/ESI-MS). This analysis showed that tobacco S6-RNase has two free cysteine residues, Cys77 and Cys95, and four disulfide bonds at Cys16-Cys21, Cys45-Cys94, Cys153-Cys182 and Cys165-Cys176. Similarly, four disulfide bonds were identified for pear S4-RNase, which bears no free cysteine, at Cys15-Cys22, Cys48-Cys92, Cys156-Cys195 and Cys172-Cys183. The eight cysteines forming these four disulfide bonds are conserved in all the known S-RNases, indicative that these cross-links are important in stabilizing the tertiary structures of the self-incompatibility-associated glycoproteins in the solanaceous and rosaceous families. The LC/ ESI-MS analysis also provided some structural informations regarding sugar chains attached to the S-RNases.