Biomedical subjects

M Kanai

Publications and source records attributed to M Kanai.

At least 91 records · Page 5Linked to original sources

PubMed1999

Dynamic light-scattering and preliminary crystallographic studies of the sensor domain of the haem-based oxygen sensor FixL from Rhizobium meliloti.

FixL is a transmitter protein in a two-component system which acts as an oxygen sensor when the symbiotic Rhizobia resides in root nodules of host plants. The oxygen-sensor domain of Rhizobium meliloti FixL (RmFixLH) was purified by His-tag affinity and isoelectronic focusing chromatographies, without the use of gel-filtration chromatography. Dynamic light-scattering measurements of RmFixLH thus obtained revealed it to be monodispersive and present as a homodimer in solution. A single crystal of RmFixLH in the met (Fe3+) form was grown in 100 mM acetic acid/NaOH buffer at pH 4.6 in the presence of 200 mM ammonium acetate, using 40%(w/v) PEG 4000 as a precipitant. A crystal of the ferrous CO form of RmFixLH was also prepared by reduction of the met crystal with Na2S2O4 in an atmosphere of CO. The crystals (0.2 x 0.05 x 0.01 mm) belong to the monoclinic system (C2) with unit-cell parameters a = 60.94, b = 37.44, c = 54.14 A, beta = 115.29 degrees and diffract X-rays to 1.7 A resolution at station BL44B2 of SPring-8, Japan. Bijvoet difference Patterson maps show a clear peak corresponding to the haem iron in RmFixLH.

Bacterial Proteins↗

PubMed1999

High incidence of glucose intolerance in Vogt-Koyanagi-Harada disease.

AIMS: To evaluate glucose tolerance of patients with Vogt-Koyanagi-Harada (VKH) disease before systemic corticosteroid therapy, and to assess changes brought on by treatment. METHODS: 20 VKH patients with acute bilateral panuveitis were studied. 20 healthy adults and 11 Behçet's disease patients with active uveoretinitis served as controls. A 75 g oral glucose tolerance test (OGTT) was given in the acute stage of ocular inflammation before systemic corticosteroid therapy. The OGTT was repeated in the convalescent stage of VKH disease in the patients with glucose intolerance before treatment. Insulin response was examined at the same time as the OGTT when possible. RESULTS: 55% of VKH patients (11/20) showed glucose intolerance but no apparent insulin secretion deficiency was detected. Four of seven patients in the convalescent stage showed improvement of glucose tolerance. None of the normal controls or disease controls showed glucose intolerance. CONCLUSION: A high incidence of glucose intolerance was found in the acute stage of VKH disease. However, glucose intolerance improved in most cases after systemic corticosteroid therapy. It is possible that glucose intolerance seen in VKH patients may be related to the autoimmune inflammatory process of this disease.

Adrenal Cortex Hormones↗

PubMed1999

Time course of changes in mu-opioid receptor mRNA levels in the periaqueductal gray of rat brain by a single or repeated injections of antisense oligodeoxynucleotides.

The effect of phosphorothioated antisense oligodeoxynucleotide (AS ODN) against the mu-opioid receptor (MOR) on MOR mRNA level in the periaqueductal gray (PAG) of rat brain was investigated. The MOR mRNA levels at 3, 6, 12, 24, 48 and 72 h after MOR AS ODN microinjection into the PAG were determined by reverse transcriptase-polymerase chain reaction. The MOR mRNA level was significantly decreased only at 12 h after the injection of 10 microg MOR AS ODN. When 10 microg MOR AS ODN was given three times at the interval of 48 h, MOR mRNA levels were significantly decreased at 6, 12 and 24 h after the last injection of the AS ODN. However, MOR mRNA levels were not significantly changed by three injections at 48-h interval of MOR sense ODN or AS ODNs against delta- and kappa-opioid receptors, although the two latter AS ODNs significantly reduced the respective targeted mRNA levels. In conclusion, the present results show that the selective decrease in MOR mRNA is at least one reason why the reported diminished effects of MOR agonists are produced in animals pretreated with MOR AS ODN, although they could be produced through several mechanisms in which MOR mRNA level does not change.

Animals↗

PubMed1999

[Treatment of recurrent cancer after surgery for biliary malignancies].

Our strategy for recurrent tumor after surgical resection for biliary malignancies, especially for hilar cholangiocarcinoma, is described. One hundred and thirty-three patients with hilar cholangiocarcinoma underwent curative resection in our department until November, 1998, and recurrent carcinomas have been pointed out in 73 patients (54.9%). The site of recurrence was peritoneum (21 cases), liver (16 cases), pre-caval and retro-duodenal space (15 cases), hepatic hilum (11 cases), lymph node (9 cases), bone (6 cases), sinus tract of percutaneous transhepatic biliary drainage (PTBD) (5 cases) and so on. Surgical resection was applied to recurrent carcinomas after careful evaluation, and 9 patients underwent surgical resection of the recurrent tumor: sinus tract of PTBD in the abdominal and/or chest wall (4 cases), lymph node (2 cases), liver (1 case), hepaticojejunostomy (1 case) and duodenum (1 case). There were three hospital death patients. Other six patients survived for 16 months on an average (11-20 months) after surgery for recurrent tumor. PTBD for recurrent cancer at the hepatic hilum and gastrojejunostomy for local recurrence around the duodenum improved quality of life of patients. Radiation therapy for bone metastasis or local recurrence at the hepatic hilum was sometimes very effective. Effect of systemic or transarterial chemotherapy is still unknown.

Adult↗

PubMed1999

[The effect of propofol as an anticonvulsant].

We observed that propofol was very effective for the refractory general convulsion after surgical operation of cerebral aneurysmal clipping in two patients. The first patient had suffered from asthma. Standard regimens except for thiopental were ineffective for the refractory general convulsion after the operation. So, we administered propofol to the patient, at the dosage of 1 mg.kg-1 intravenously and then, 1 mg.kg-1.hr-1 continuously i.v. Propofol suppressed the general convulsions completely. On the EEG, there were no convulsive spikes. Furthermore, patient's consciousness became clearer during the administration of propofol. The convulsion in the second patient not suffering from asthma, was intractable, too and diazepam, phenytoin, and phenobalbital were not effective. Then, we tried propofol in the same way, and good effect was obtained. Propofol may be an effective medicine for the refractory general convulsion.

Anticonvulsants↗

PubMed1999

Upward migration of the L-P shunt catheter into the cranial base.

A rare complication of upward migration of the L-P shunt catheter into the cranial base is reported. A 59-year-old female with hydrocephalus underwent L-P shunt with a one-piece catheter. The catheter was secured with a clip but migrataed up to the cranial base without the clip becoming detached from the catheter. We assume that the catheter slipped at the position of the clip as the result of a strong force produced by lumbar movements, and that the clip may have acted like an one-way valve to push the catheter into the spinal canal. To prevent such a complication, we should tighten the clip as firmly as possible and use more clips, or use another type of clip which prevents slipping of a one-piece catheter such as the one described by Imaizumi et al.

Cerebrospinal Fluid Shunts↗

PubMed1998

A Japanese family with adrenoleukodystrophy with a codon 291 deletion: a clinical, biochemical, pathological, and genetic report.

We report a Japanese family with adrenoleukodystrophy (ALD) with a three base pair deletion (delGAG 291) in the ALD gene. A variety of phenotypes were observed within this family. While the proband (patient 1) was classified as having a rare intermediate type of adult cerebral and cerebello-brain stem forms, his younger brother (patient 2) and nephew (patient 3) had a childhood ALD type. Another nephew (patient 4) of patient 1 was classified as having an adolescent form. The tau level in the cerebrospinal fluid (CSF) in patient 1 was as high as that of patients with Alzheimer's disease (AD). His brain magnetic resonance image (MRI) showed abnormalities in the bilateral cerebellar hemispheres and brain stem, but not in the cerebral white matter, where marked reductions of the cerebral blood flow and oxygen metabolism were clearly demonstrated by positron emission tomography (PET). In patients 2 and 3, the autopsy findings showed massive demyelination of the cerebral white matter with sparing of the U-fibers, compatible with the findings of childhood ALD. Oleic and erucic acids (Lorenzo's Oil) were administered to patients 1 and 4, but sufficient effectiveness was not obtained. The findings in this family suggest that delGAG291 is part of the cause of Japanese ALD with phenotypic variations. Moreover, although the scale of the study is limited, there is a possibility that PET can detect an insidious lesion which is undetectable by computed tomogram (CT) or MRI analysis, and that the higher level of tau reflects the process of neuronal degeneration in ALD. Lorenzo's Oil should be given in the early stage.

Adrenoleukodystrophy↗

PubMed1998

Combination assay of CSF tau, A beta 1-40 and A beta 1-42(43) as a biochemical marker of Alzheimer's disease.

Cerebrospinal fluid samples from a total of 157 subjects consisting of 55 patients with sporadic Alzheimer's disease (AD), 34 normal controls, 23 patients with non-AD dementia, and 45 with other neurological diseases were examined by ELISA of tau, A beta 1-40, and A beta 1-42(43). The AD group had a significantly higher level of tau than the normal control group (P < 0.001), and the diagnostic sensitivity was 31% and specificity was 94%. CSF A beta 1-40 levels did not show any significant differences. Although the level of A beta 1-42(43) was decreased significantly in the AD group compared to the control group (P < 0.005), the overlap of A beta 1-42(43) levels among all groups meant that none of the AD samples exceeded the cut-off value, the mean 2SD of normal control subjects. Reduction of A beta 1-42(43) levels in AD resulted in a significant increase in the ratio of A beta 1-40 to A beta 1-42(43) (A beta ratio) as an improved marker. The diagnostic sensitivity and specificity of A beta ratio were 51% and 82% respectively. The three indexes, using the tau level and A beta ratio (tau or A beta ratio, deviation score and tau x A beta ratio), showed better sensitivity (58%, 67%, 69%) and specificity (82%, 86%, 88%) than previously reported methods. Combination assay for CSF tau, A beta 1-40 and A beta 1-42(43) in CSF is a biological marker of AD and may be useful to biochemically monitor subjects under treatment.

Adult↗

PubMed1998

Immunohistochemical detection of sex steroid receptors, cyclins, and cyclin-dependent kinases in the normal and neoplastic squamous epithelia of the uterine cervix.

BACKGROUND: Malignant transformation of sex steroid-dependent tissues has been reported to be associated with abnormal expression of sex steroid receptors. In addition, abnormalities of cell cycle-related molecules have been demonstrated in various malignancies. However, expression of steroid receptors and cell cycle-related molecules in the process of malignant transformation of the ectocervical squamous epithelium, which also is a sex steroid-dependent tissue, has not been elucidated fully. METHODS: Immunohistochemical staining was performed on formalin fixed, paraffin embedded tissue sections of normal squamous epithelia (30 cases), cervical intraepithelial neoplasia (CIN) (21 cases), and invasive squamous carcinoma (SCC) (33 cases), using antibodies against estrogen receptors (ER), progesterone receptors (PR), cyclins (E, A, and B1), cyclin-dependent kinases (cdk2 and cdc2), and p53 protein. In addition, growth activity of SCC was evaluated by Ki-67 labeling. RESULTS: In the normal epithelia, diffuse proportionate to regional expression of ER/PR and sporadic expression of cyclins/cdks were observed mainly in the parabasal cells irrespective of the menstrual cycle. In the neoplastic lesions, the expression of ER markedly decreased; however, the expression of PR increased. The expression of cyclins, cdks, and p53 was increased in a considerable number of these neoplastic cases. In addition, cyclin A positive SCC had elevated Ki-67 labeling, whereas cyclin E positive SCC cases had lower Ki-67 labeling. CONCLUSIONS: These findings suggest that malignant transformation of ectocervical epithelia is associated with loss of normal growth control by steroid hormones as well as with the acquisition of abnormal cell cycle regulatory mechanisms.

Adult↗

PubMed1998

The C-terminal conserved domain of MARCKS is phosphorylated in vivo by proline-directed protein kinase. Application of ion trap mass spectrometry to the determination of protein phosphorylation sites.

MARCKS, the major protein kinase C substrate in various cells and tissues, binds to calmodulin, acidic membrane phospholipids, and actin filaments, and these interactions are regulated by protein phosphorylation. We have previously shown that MARCKS purified from bovine brain is phosphorylated not only by protein kinase C but also by so-called proline-directed protein kinases in the well conserved N-terminal half of the molecule (Taniguchi, H., Manenti, S., Suzuki, M., and Titani, K. (1994) J. Biol. Chem. 269, 18299-18302). Although the presence of other phosphorylation sites in the C-terminal peptide was also noticed, the ambiguity in the C-terminal domain of the bovine protein hampered a more detailed analysis. In the present study, we analyzed MARCKS purified from rat brain by electrospray ionization/ion trap mass spectrometry. The results obtained revealed two additional novel phosphorylation sites in the C-terminal region. Both phosphorylation sites (Ser291 and Ser299) are immediately followed by proline, suggesting that these sites are also phosphorylated by the proline-directed protein kinase(s). Since Ser299 is within the C-terminal domain, which is well conserved among various species, the function of the domain, whatever it is, seems to be controlled by phosphorylation.

Amino Acid Sequence↗

PubMed1998

Dipeptidyl peptidase III is a zinc metallo-exopeptidase. Molecular cloning and expression.

We have purified dipeptidyl peptidase III (EC 3.4.14.4) from human placenta. It had a pH optimum of 8.8 and readily hydrolysed Arg-Arg-beta-naphthylamide. Monoamino acid-, Gly-Phe-, Gly-Pro- and Bz-Arg-beta-naphthylamides were not hydrolysed at all. The enzyme was inhibited by p-chloromercuriphenylsulphonic acid, metal chelators and 3,4-dichloroisocoumarin and contained 1 mol of zinc per mol of enzyme. The zinc dissociation constant was 250 fM at pH 7. 4 as determined by the zinc binding study. We isolated, by immunological screening of a Uni-ZAP XR cDNA library constructed from rat liver mRNA species, a cDNA clone with 2633 bp encoding the rat enzyme. The longest open reading frame encodes a 827-residue protein with a theoretical molecular mass of 92790 Da. Escherichia coli SOLR cells were infected with the pBluescript phagemid containing the cloned cDNA and established the overexpression of a protein that hydrolysed Arg-Arg-beta-naphthylamide. The recombinant protein was purified and the amino acid sequence of the protein was confirmed. We presumed that the putative zinc-binding domain involved in catalysis was present in the recombinant enzyme. It was a novel zinc-binding motif in that one amino acid residue was inserted into the conserved HEXXH motif characteristic of the metalloproteinases.

Amino Acid Sequence↗

PubMed1998

Intestinal trefoil factor induces inactivation of extracellular signal-regulated protein kinase in intestinal epithelial cells.

Intestinal trefoil factor (ITF), a small, compact protease-resistant peptide, is abundantly expressed in goblet cells of large and small intestine. Although several biological activities of ITF have been identified, including promotion of wound healing, stimulation of epithelial cell migration, and protection of intestinal epithelial barrier, little is known about signaling events through which ITF mediates its physiological function. In this study, the effects of exogenous ITF on mitogen-activated protein kinase (MAPK) signaling cascades were examined in IEC-6 cells, a nontransformed intestinal epithelial cell line that does not express endogenous trefoil peptides. Stimulation with ITF resulted in rapid decrease in extracellular signal-related protein kinase (ERK) activity and concomitant reduced ERK tyrosine phosphorylation. ITF also decreased activation of ERK activity induced by either transforming growth factor-alpha, which links extracellular stimuli to the Ras/Raf/MEK/ERK pathway via the epidermal growth factor receptor, or phorbol 12-myristate 13-acetate, which activates Raf through protein kinase C. ITF-induced inhibition of ERK activity was blocked by an inhibitor of tyrosine and dual-specific phosphatases, sodium orthovanadate. In summary, ITF leads to inhibition of ERK and the MAPK pathway through activation of tyrosine or dual-specific phosphatase.

Calcium-Calmodulin-Dependent Protein Kinases↗

PubMed1998

Longitudinal study of cerebrospinal fluid levels of tau, A beta1-40, and A beta1-42(43) in Alzheimer's disease: a study in Japan.

To clarify the alterations of tau, amyloid beta protein (A beta) 1-40 and A beta1-42(43) in the cerebrospinal fluid (CSF) that accompany normal aging and the progression of Alzheimer's disease (AD), CSF samples of 93 AD patients, 32 longitudinal subjects among these 93 AD patients, 33 patients with non-AD dementia, 56 with other neurological diseases, and 54 normal control subjects from three independent institutes were analyzed by sensitive enzyme-linked immunosorbent assays. Although the tau levels increased with aging, a significant elevation of tau and a correlation between the tau levels and the clinical progression were observed in the AD patients. A significant decrease of the A beta1-42(43) levels and a significant increase of the ratio of A beta1-40 to A beta1-42(43) were observed in the AD patients. The longitudinal AD study showed continuous low A beta1-42(43) levels and an increase of the ratio of A beta1-40 to A beta1-42(43) before the onset of AD. These findings suggest that CSF tau may increase with the clinical progression of dementia and that the alteration of the CSF level of A beta1-42(43) and the ratio of A beta1-40 to A beta1-42(43) may start at early stages in AD. The assays of CSF tau, A beta1-40, and A beta1-42(43) provided efficient diagnostic sensitivity (71%) and specificity (83%) by using the production of tau levels and the ratio of A beta1-40 to A beta1-42(43), and an improvement in sensitivity (to 91%) was obtained in the longitudinal evaluation.

Aged↗

PubMed1998

Effects of three peptidase inhibitors, amastatin, captopril and phosphoramidon, on the hydrolysis of [Met5]-enkephalin-Arg6-Phe7 and other opioid peptides.

The contents of [Met5]-enkephalin-Arg6-Phe7 (met-enk-RF) and its six hydrolysis products: Y, YG, YGG, YGGF, YGGFM, and YGGFMR were estimated after incubating met-enk-RF with either a guinea-pig ileal or striatal membrane fraction for various times at 37 degrees C. After 45 min incubation with either ileal or striatal membranes, met-enk-RF was completely hydrolyzed, yielding Y as the major product. Incubation with either membrane preparation for 60 min in the presence of the aminopeptidase inhibitor amastatin hydrolyzed 90 or 92% of met-enk-RF, respectively, with YGG being the major product. If the dipeptidyl carboxypeptidase I inhibitor captopril is also included in the incubation, met-enk-RF hydrolysis decreases by about half for both membranes, with YGG remaining the major product. Inclusion of three peptidase inhibitors, amastatin, captopril, and phosphoramidon (inhibition of endopeptidase-24.11) further reduced met-enk-hydrolysis, with 87% or more remaining intact. This shows that met-enk-RF was mainly hydrolyzed by three enzymes, amastatin-sensitive aminopeptidase, captopril-sensitive dipeptidyl carboxypeptidase I and phosphoramidon-sensitive endopeptidase-24.11, in both ileal and striatal membranes. Additionally, estimations of [Leu5]-enkephalin (leu-enk), alpha- and beta-neoendorphins (alpha- and beta-neoends), and dynorphin B (dyn B) contents after incubating the individual peptides with striatal membrane for 60 min in the presence of the three peptidase inhibitors showed that 98, 32, 5, and 23%, respectively, remained intact. Our previous studies together with the data obtained here show that one group of endogenous opioid peptides: met-enk, leu-enk, met-enk-RF, met-enk-RGL, and dyn A-(1-8) are largely or almost exclusively hydrolyzed by the three enzymes, amastatin-sensitive aminopeptidase, captopril-sensitive dipeptidyl carboxypeptidase I, and phosphoramidon-sensitive endopeptidase-24.11, and indicate that an unidentified fourth enzyme(s) is involved in the hydrolysis of another group of peptides: alpha-neoend, beta-neoend, and dyn B.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1998

Aggressive surgical treatment of hilar cholangiocarcinoma.

Recent progress in surgical techniques for and the perioperative management of hilar cholangiocarcinoma has led to improved outcomes for aggressive liver and bile duct resections, which, however, still show considerable morbidity and mortality. In this article, the results of pioneers' attempts in hepatobiliary surgery for difficult hilar cholangiocarcinomas are reviewed. It is recommended that curative hepatobiliary resection should be performed for hilar cholangiocarcinoma, with careful preoperative management of patients complicated with several difficult conditions.

Bile Duct Neoplasms↗

PubMed1998

A new method to prevent wound infection: a controlled clinical trial in patients with combined liver and bile duct resection.

INTRODUCTION: Despite advances in antibiotic prophylaxis, postoperative wound infection remains a major source of morbidity after digestive surgery. Its prevention is a challenging problem, especially in high-risk patients. The authors introduced a new method to prevent surgical wound infections and evaluated its efficacy in a prospective, randomized trial in markedly high-risk patients. METHODS: Patients with biliary tract carcinoma who were scheduled to undergo combined liver and extrahepatic bile duct resection with biliary reconstruction were randomly assigned to one of two groups, well matched in terms of clinical characteristics at baseline. In one group the new treatment was employed (sealed group, n=31), and in the other the wound was treated in the usual fashion (open group, n=28). In the sealed group, povidone-iodine gel was administered to the subcutaneous tissue, and the skin and peritoneum were approximated with a continuous suture. Wound infection was registered up to 30 days after surgery. RESULTS: Wound infection occurred in 18 patients: 5 (16%) patients in the sealed group and 13 (46%) in the open group (P<0.05). All 18 underwent preoperative percutaneous transhepatic biliary drainage and had positive bile culture findings. In 13 of these 18 patients (72%) the microorganisms isolated from the infected wound were identical to those in the bile. CONCLUSIONS: Our results confirm the close association between infected bile and wound infection in hepatobiliary surgery. Our new method, "direct wound sealing," is simple, easy to perform, virtually cost-free, and has the potential to prevent wound infections even in markedly high-risk patients.

Anti-Infective Agents, Local↗

PubMed1998

Preventive effects of an antiallergic drug, pemirolast potassium, on restenosis after percutaneous transluminal coronary angioplasty.

BACKGROUND: We recently confirmed that pemirolast potassium, an antiallergic agent, markedly inhibits migration and proliferation of vascular smooth muscle cells. It has also been reported that pemirolast inhibits intimal hyperplasia in animal experiments. METHODS AND RESULTS: To elucidate the preventive effects of pemirolast on restenosis after percutaneous transluminal coronary angioplasty (PTCA), 227 patients were enrolled in this prospective, randomized trial. A total of 205 patients who were compatible with the protocol were analyzed (pemirolast group, 104 patients with 140 lesions; control group, 101 patients with 133 lesions). Patients in the pemirolast group received 20 mg/d of pemirolast from 1 week before PTCA until the time of follow-up angiography (4 months after PTCA). Angiographic restenosis was defined as diameter stenosis >/=50% at follow-up. Restenosis rates were significantly lower in the pemirolast group than in the control group (24.0% vs 46.5% of patients, 18.6% vs 35.3% of lesions, P <.01, respectively). During 8 months of follow-up, there were no coronary events (death, myocardial infarction, coronary artery bypass surgery, or repeated PTCA) in 81.7% of the pemirolast group and in 63.4% of the control group (P =.013). CONCLUSIONS: This study suggested that pemirolast would be useful in the clinical setting to prevent restenosis after PTCA.

Aged↗

PubMed1998

Rapid mitogen-activated protein kinase activation by transforming growth factor alpha in wounded rat intestinal epithelial cells.

BACKGROUND & AIMS: To define signaling events initiating healing after intestinal epithelial injury, activation of mitogen-activated protein kinase (MAPK) pathways was assessed after wounding using an in vitro model. METHODS: Proteins isolated from wounded monolayers of nontransformed intestinal epithelial cells (IEC-6) were analyzed for tyrosine phosphorylation and MAPK expression by Western blot. Extracellular signal-regulated kinase (ERK) 1, ERK2, and Raf-1 activities were assessed by immune complex kinase assays. RESULTS: Tyrosine phosphorylation of several proteins including ERK1 was substantially increased 5 minutes after injury. Another MAPK, c-Jun-N-terminal protein kinase (JNK), was also activated after wounding. Conditioned medium from wounded but not intact IEC-6 monolayers resulted in increased activity of ERK1, ERK2, and Raf-1 kinase. Wound-conditioned medium stimulated proliferation of subconfluent IEC-6 cells compared with conditioned medium from intact IEC-6 cultures and contained higher amounts of transforming growth factor (TGF)-alpha than supernatants of confluent IEC-6 cultures. Activation of ERK1 and ERK2 was partially inhibited by neutralizing anti-TGF-alpha. CONCLUSIONS: Wounding of intestinal epithelial cells results in activation of Raf-1, ERK1, ERK2, and JNK1 MAPKs and subsequent cell proliferation in vitro. Activation of ERK1 and ERK2 is mediated in part by TGF-alpha.

Animals↗