Biomedical subjects

M Morikawa

Publications and source records attributed to M Morikawa.

At least 19 recordsLinked to original sources

PubMed2006

Two new reactive targets of 2,5-hexanedione in vitro - beta-alanine and glycine.

In this study, we found that two amino acids reacted with 2,5-hexanedione to form new reaction products in vitro, respectively. In the reaction of beta-alanine and 2,5-hexanedione, a reaction product was obtained and analyses of obtained results showed it was 3-(2,5-dimethyl-1H-pyrrol-1-yl)propanoic acid; in the reaction of glycine and 2,5-hexanedione, a reaction product was also obtained and analyses showed it was (2,5-dimethyl-1H-pyrrol-1-yl)acetic acid. Two reaction products were found to be oxidized easily; in addition, the latter was more easily to be oxidized than the former in the air. Our discoveries demonstrated that reactions between amino acids and 2,5-hexanedione could exist possibly in vitro. At present, it is clear that 2,5-hexanedione causes either axon atrophy or swelling, but the underlying molecular mechanism is still unclear. Since both beta-alanine and glycine are considered as neurotransmitter in the central nervous system, the reaction products remain to be identified in vivo.

Amino Acids↗

PubMed2006

Propofol sedation during endoscopic procedures: safe and effective administration by registered nurses supervised by endoscopists.

BACKGROUND AND STUDY AIMS: Propofol has several attractive properties, including a rapid onset of action and rapid recovery. However, the administration of propofol sedation in the absence of anesthesiologists remains controversial. This report describes the safety profile of propofol sedation for endoscopy when administered by registered nurses under the supervision of endoscopists. PATIENTS AND METHODS: The study was conducted in the endoscopic center of a Japanese private hospital. With assistance from an anesthesiologist, a protocol for administration of propofol by registered nurses was developed. Over the past 6 years, 27,500 patients received nurse-administered propofol sedation. The safety and patient satisfaction with this sedation procedure were evaluated. RESULTS: Among the participating patients, 6.7% developed hypoxemia (Sp(O2) < 90%); 6.2% required oxygen administration via a nasal cannula. Severe hypoxemia (Sp(O2) < 85%) occurred in 121 patients (0.62%) during upper gastrointestinal endoscopy and 20 patients (0.25%) during colonoscopy, but neither mask ventilation nor endotracheal intubation was necessary. A decline in blood pressure (systolic blood pressure < 90 mm Hg) was seen in 3.5% of the colonoscopy patients and 1.2% of the upper endoscopy patients. However, hypotension was corrected immediately using an intravenous saline solution. Patients who received propofol sedation expressed overall satisfaction on a 10-point visual analogue scale (with an average of 9.4 points). Among patients who had previously received a combination of midazolam and pethidine for colonoscopy, 85% preferred propofol sedation. The mean time from the end of the procedure to full recovery was 14.6 min. CONCLUSIONS: Administration of propofol by registered nurses under the supervision of endoscopists was safe, and resulted in high rates of patient satisfaction.

Adolescent↗

PubMed2006

Role of diffusion-weighted magnetic resonance imaging in diffuse axonal injury.

PURPOSE: To determine whether the signal changes on magnetic resonance imaging (MRI), including fluid attenuated inversion recovery (FLAIR), T2*-weighted gradient echo (GE) imaging, and diffusion-weighted imaging (DWI) in diffuse axonal injury (DAI) patients correlate with the clinical outcome. MATERIAL AND METHODS: We diagnosed patients with DAI based on the following criteria: 1) a loss of consciousness from the time of injury that persisted beyond 6 h; 2) no apparent hemorrhagic contusion on computed tomography (CT); 3) the presence of white matter injury on MRI. Twenty-one DAI patients were analyzed (19 M, 2 F, mean age 34 years) with MRI (FLAIR, T2*-weighted GE imaging, and DWI). RESULTS: 325 abnormalities were detected by MRI within a week after injury. The T2*-weighted GE imaging was significantly more sensitive than FLAIR and DWI in diagnosing DAI. DWI detected only 32% of all lesions, but could depict additional shearing injuries not visible on either T2*-weighted GE imaging or FLAIR. The mean number of lesions in brainstem detected by DWI in the favorable group (good recovery/moderately disabled) was significantly smaller than in the unfavorable group (severely disabled/vegetative survival/death). This trend was not observed on the T2*-weighted GE imaging and FLAIR findings. CONCLUSION: DWI cannot detect all DAI-related lesions, but is a potentially useful imaging modality for both diagnosing and assessing patients with DAI.

Adolescent↗

PubMed2006

2D Thick-section MR digital subtraction angiography for the assessment of dural arteriovenous fistulas.

BACKGROUND AND PURPOSE: Although dynamic contrast-enhanced MR angiography studies for arteriovenous malformations (AVFs) and brain tumors have shown promising results, no formal attempt has yet been made to similarly evaluate dural AVFs. To assess the practical applicability of 2D thick-section contrast enhanced MR digital subtraction angiography (MRDSA) for the diagnosis and management of dural AVFs, MRDSA and intra-arterial digital subtraction angiography (IADSA) were comparatively evaluated. METHODS: We performed 80 consecutive MRDSA studies for 25 dural AVFs, including 11 cavenous sinuses, 9 sigmoid sinuses, 2 tentorial sinuses, one anterior condylar vein, one craniocervical junction, and one spine. MR images were continuously obtained following the initiation of a bolus injection of gadrinium chelates and subtraction images were constructed. We thereafter evaluated the imaging quality and hemodynamic information from all 46 MRDSA images performed in parallel with IADSA in either perioperative or follow-up studies. RESULTS: Most MRDSA images detected early venous filling, sinus occlusion, leptomeningeal venous drainage, and varices. It was difficult, however, to identify the feeding arteries because of both the partial volume effect and a low spatial resolution. Most important, MRDSA accurately detected aggressive lesions with leptomeningeal venous drainage and varices. CONCLUSION: Our MRDSA technique was found to have limited value for depicting all the anatomic details of dural AVFs, though it was able to identify important hemodynamic abnormalities related to the risk of hemorrhaging. MRDSA is therefore useful as a less invasive, dynamic angiographic tool, not only for perioperative studies but also for follow-up studies.

Adult↗

PubMed2005

Lesions identified on T2*-weighted gradient echo images in two patients with suspected diffuse axonal injury that resolved in less than ten days.

T2*-weighted gradient echo (GE) imaging is useful for detection of intracranial hemorrhage in the patients with diffusion axonal injury (DAI). However, the temporal changes in the DAI-related lesions on T2*-weighted GE images are not clear. We report two very rare cases with DAI in which lesions identified on T2*-weighted GE images resolved in less than ten days.

Adolescent↗

PubMed2005

Microbicidal efficacy of ozonated water against Candida albicans adhering to acrylic denture plates.

BACKGROUND/AIMS: Ozone is known to act as a strong antimicrobial agent against bacteria, fungi, and viruses. We examined the effect of ozonated water on Candida albicans on acrylic denture plate. METHODS: The heat-cured acrylic resins were cultured with C. albicans. After treatment of flowing ozonated water, the number of attached C. albicans was counted. In some experiments, the test samples were treated with ozonated water in combination with ultrasonication. RESULTS: After exposure to flowing ozonated water (2 or 4 mg/l) for 1 min, viable C. albicans cells were nearly nonexistent. The combination of ozonated water and ultrasonication had a strong effect on the viability of C. albicans adhering to the acrylic resin plates. There were no significant differences in antimicrobial activity against C. albicans between plates immersed in ozonated water with ultrasonication and those treated with commercially available denture cleaners. In addition, electron microscopic analysis revealed that small amounts of C. albicans remained on the plate after exposure to flowing ozonated water or immersion in ozonated water with ultrasonication. CONCLUSION: Our results suggest that application of ozonated water may be useful in reducing the number of C. albicans on denture plates.

Acrylic Resins↗

PubMed2004

Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not involved in the risk of recurrent pregnancy loss.

The etiology of recurrent pregnancy loss (RPL) remains unclear, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We examined the relation between RPL and polymorphisms in four genes, human aryl hydrocarbon (Ah) receptor, cytochrome P450 (CYP) 1A1, CYP1A2 and CYP1B1, which are involved in the metabolism of a wide range of environmental toxins and carcinogens. All cases and controls were women resident in Sapporo, Japan and the surrounding area. The Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotypes were assessed in 113 Japanese women with recurrent pregnancy loss (RPL) and 203 ethnically matched women experiencing at least one live birth and no spontaneous abortion (control). No significant differences in Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotype frequencies were found between the women with RPL and the controls [Ah receptor: Arg/Arg (reference); Arg/Lys and Lys/Lys, odds ratio (OR)=0.67; 95% confidence interval (CI)=0.40-1.11, CYP1A1: m1m1 (reference); m1m2 and m2m2, OR = 0.86; 95% CI = 0.53-1.40, CYP1A2: C/C and C/A (reference); A/A, OR = 1.16; 95% CI = 0.71-1.88, CYP1B1: Leu/Leu (reference); Leu/Val and Val/Val, OR = 1.18; 95% CI = 0.68-2.02]. The present study suggests that the Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not major genetic regulators in RPL.

Abortion, Habitual↗

PubMed2004

Activation of WNT family expression and signaling in squamous cell carcinomas of the oral cavity.

The WNT family activates an oncogenic signaling mediated through beta-catenin and is up-regulated in a variety of malignant neoplasms. The signaling translocates beta-catenin into the nucleus and stimulates carcinoma cells in the epithelial-mesenchymal transition (EMT). However, WNT expression and signaling in oral carcinomas have not been examined. The present study focused on unveiling the involvement of WNTs in oral carcinomas, and showed that carcinoma cells express 11 of 19 WNT family members by reverse-transcription/PCR. WNT-expressing carcinoma cells exhibited increased beta-catenin levels in the cytoplasmic pool and translocation to the nucleus. The activation state of signaling correlated with the expression of membrane-type 1 matrix metalloproteinase, which degrades territorial matrices in carcinoma invasion. Immunohistochemistry disclosed that WNT3 expression and nuclear localization of beta-catenin were predominant in carcinoma cells at the invasive front. These results suggest that enhanced WNT expression and signaling accelerate the progression of carcinomas via activating EMTs and local invasiveness.

Carcinoma, Squamous Cell↗

PubMed2003

[Long-term results of atriopulmonary fontan connection for complex cardiac anomalies].

To evaluate the long-term results of atriopulmonary Fontan connection, we reviewed the outcome of 20 consecutive patients (single ventricle 8, double outlet right ventricle 8, tricuspid atresia 3, mitral atresia 1; mean age, 13 +/- 11) who underwent this operation between 1981 and 1997 at our institution. Glenn shunt preceded Fontan operation in 1 patient. Four patients had a concomitant bidirectional Glenn anastomosis at the time of the Fontan operation. Follow-up was 100% complete, and total cumulative follow-up of all patients was 241 patient-years (maximum, 20 years). Three hospital deaths and 5 late deaths were observed, resulting in 58 +/- 11% of cumulative survival at 20 years after the operation. Sudden death probably due to arrhythmias was the major cause of the late death, and occurred in 3 patients. Reoperation was required in 5 patients (2%/patient-year) at 1 to 17 years postoperatively. Re-closure of an atrioventricular valve was performed for failure of the valve closure in 3 patients at 1 to 6 years postoperatively. Reconstruction of the stenotic atriopulmonary connection (APC) was concomitantly required in 2 of the 3 patients. Pacemaker implantation was required for bradycardia with atrial fibrillation in 1 patient at 17 years. One patient with atrial flutter developed intraright atrial thrombosis at 12 years after the initial Fontan operation, and this patient underwent conversion to extracardiac conduit cavopulmonary connection with right atrial maze procedure. Atrial tachyarrhythmias are most common complications, and occurred in 12 patients (5.0%/patient-year), resulting in 40 +/- 13% of the cumulative free rate at 15 years after the operation. Thus, failure of the atrioventricular valve closure and stenosis of APC were important early to intermediate complications after the atriopulmonary Fontan connection. On the other hand, atrial tachyarrhythmias were inevitable, and were most common late complications leading to intra-right atrial thrombosis, which was successfully resolved by conversion of the conventional atriopulmonary Fontan anastomosis to extracardiac conduit cavopulmonary connection.

Adolescent↗

PubMed2003

[Congenital tracheal stenosis due to complete cartilage rings with right pulmonary agenesis].

A 2-month-old male infant with severe dyspnea was diagnosed as having right pulmonary agenesis at birth and was admitted to our hospital after tracheal intubation with an endotracheal tube of 3 mm in diameter. However, the trachea was too stenotic to place the tube in the proper position. Chest X-ray on admission showed pneumonia of the left lung. Preoperative chest computed tomography (CT) scan and bronchoscopy showed that from the level of 12 mm beneath the coricoid cartilage, the trachea tapered and continuing to the tracheal carina and that the smallest tracheal level was located 18 mm distal from the coricoid cartilage, the area of which was 4 mm2. His respiratory condition rapidly deteriorated in spite of intravenous administration of antibiotics and mechanical ventilation. Percutaneous cardiopulmonary support (PCPS) was used to maintain his pulmonary function, and pericardial tracheoplasty was performed. Chest X-ray immediately after the operation did not show left lung reexpansion due to severe pulmonary edema. High-dose steroid pulse therapy was performed, but it was not effective. He died from acute respiratory failure due to infantile respiratory distress syndrome (IRDS) on postoperative day 3. The outcome in this case shows that it is very risky to repair tracheal stenosis in a patient with pneumonia using PCPS.

Cardiopulmonary Bypass↗

PubMed2003

[Reoperation for double-outlet right ventricle (SDL type) following the Rastelli procedure: report of a case].

The relationship of the conduit to the sternum is crucial in the Rastelli operation. Right-sided conduits are more greatly affected by sternal compression than left, since the position of the right ventricular infundibulum is more anterior. A 37-year-old woman developed right ventricular outflow tract obstruction, left ventricular outflow tract obstruction, and aortic valve regurgitation secondary to infective endocarditis 15 years after Rastelli repair for double-outlet right ventricle (SDL). We enlarged the ventricular septal defect, performed intraventricular rerouting and aortic valve replacement, and reconstructed the valved conduit using a Carpentier-Edwards conduit. The old conduit was densely adherent to the sternum. Subaortic stenosis was caused by a narrow fibromuscular ridge associated with a bulge of the underlying septal muscle. The patient's recovery was uneventful. She is alive and well without any complaints 1 year after surgery.

Adult↗

PubMed2002

Three-dimensional fast recovery fast spin-echo imaging of the inner ear and the vestibulocochlear nerve.

The aim of this study was to assess the performance of three-dimensional fast recovery fast spin-echo (3DFRFSE) for imaging of the inner ear as well as the facial and vestibulocochlear nerves. We evaluated 3DFRFSE sequences, comparing it with 3D fast spin-echo (3DFSE) in a water phantom and in 12 normal volunteers. We also examined 66 patients using 3DFRFSE sequence and assessed the visualization of their pathologies. In a water phantom study, signal intensity (SI) on 3DFRFSE was higher than that on 3DFSE at the same TR ranging from 1,500 to 6,000 ms. In normal volunteers, 3DFRFSE with TR of 2,800 ms showed comparable SI, and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) superior to those on 3DFSE with TR of 5,000 ms. In clinical setting, 3DFRFSE was useful in demonstrating anatomic details in the labyrinth and pathologic findings of inner ear. The 3DFRFSE can provide high-resolution heavily T2-weighted images (T2WI) with shorter scan time than 3DFSE without significant disadvantage. The 3DFRFSE is a beneficial technique for evaluation of lesions in the inner ear as well as the facial and vestibulocochlear nerves.

Ear, Inner↗

PubMed2002

Distribution and partial characterisation of IgG Fc binding protein in various mucin producing cells and body fluids.

BACKGROUND AND AIMS: Mucus released from goblet cells is important in intestinal mucosal defence, and mucin glycoproteins are thought to be major components of mucus. Recently, we identified and cloned another component of human colonic mucus, IgG Fc binding protein (Fc gamma BP). Fc gamma BP is immunologically distinct from known Fc gamma receptors and its structure contains repeated cysteine rich unit sequences resembling those present in mucins. In this work, we assessed the tissue distribution of Fc gamma BP, its binding activity in various body fluids, and its ability to inhibit complement mediated haemolysis. METHODS: Immunohistochemical localisation of Fc gamma BP, using monoclonal antibodies against Fc gamma BP (K9 or K17) and labelled IgG, was conducted in various mucin producing tissues: colon, small intestine, stomach, gall bladder, cystic duct, choledochus, bronchus, submandibular gland, conjunctiva, and cervix uteri. The binding activity of Fc gamma BP in mucus extracted from colon, gastric juice, bile, nasal discharges, saliva, sputum, and tears was also examined by immunodotblot and immunoprecipitation using these monoclonal antibodies. Inhibition of complement mediated haemolysis by Fc gamma BP was investigated using sheep red blood cells (SRBC) and anti-SRBC IgG. RESULTS: The immunohistochemical study revealed that mucin secreting cells in the colon, small intestine, gall bladder, cystic duct, choledochus, bronchus, submandibular gland, and cervix uteri contained Fc gamma BP, and immunodotblot and immunoprecipitation analysis using IgG and monoclonal antibodies demonstrated that the fluids secreted by these cells were capable of binding IgG. Mucin producing cells of the conjunctiva did not express Fc gamma BP molecules or bind to IgG. The surface mucus cells in the stomach were variably positive for Fc gamma BP. Perhaps because of proteolytic degradation, Fc gamma BP in gut lavage fluid did not have IgG binding activity, although this activity was present in the mucus covering the colon. Fc gamma BP suppressed complement mediated haemolysis of SRBC. CONCLUSIONS: Fc gamma BP is widely expressed on mucosal surfaces and in external secretions. It is functionally intact in several fluids. These findings lend support to the concept that Fc gamma BP is an important component of mucosal immunological defences.

Animals↗

PubMed2002

[Esophageal rupture just after the graft replacement of thoracoabdominal aorta for chronic aortic dissection].

A 51-year-old man with thoracoabdominal aortic aneurysm (DeBakey IIIb type chronic aortic dissection) first underwent the graft replacement of thoracic aorta with elephant trunk technique. Postoperatively, the residual false lumen just distal to the inserted graft as an elephant trunk enlarged in a short period, and it compressed the esophagus. He underwent the second graft replacement of thoracoabdominal aorta 2 months after the first surgery. Just after the second surgery, he had the esophageal rupture probably because of direct damage due to the enlarged aneurysm and loss of the arterial blood supply due to the graft replacement. He died of bleeding from the distal anastomosis because of the uncontrolled graft infection. It may have to be kept in mind that the esophageal rupture after the graft replacement could be one of the reason of the graft infection when the aortic aneurysm severely compressed the esophagus preoperatively.

Aortic Dissection↗

PubMed2001

Detection of Fcgamma binding protein antigen in human sera and its relation with autoimmune diseases.

Intestinal goblet cells of patients with ulcerative colitis and Crohn's disease highly express a binding protein of the Fc portion of IgG (FcgammaBP), which is entirely different from the Fcgamma receptors I,II, and III on neutrophils and macrophages. In this study, we proved the qualitative existence of FcgammaBP antigen in the sera of patients with rheumatoid arthritis and systemic lupus erythematosus, and, further, established a highly sensitive and quantitatively reproducible assay for FcgammaBP antigen in order to prevent the cross-reactivity of FcgammaBP with von Willebrand factor which has about 30% homology. This assay revealed a higher level of FcgammaBP antigen in the blood stream of patients with autoimmune diseases, especially progressive systemic sclerosis. This would suggest that abnormal production of autoantibodies reflects increased generation of FcgammaBP in goblet cells and its secretion into the circulation by an unknown mechanism.

Animals↗

PubMed2001

Ca(2+)-induced folding of a family I.3 lipase with repetitive Ca(2+) binding motifs at the C-terminus.

In order to understand a role of the Ca(2+) ion on the structure and function of a Ca(2+)-dependent family I.3 lipase from Pseudomonas sp. MIS38, apo-PML, holo-PML, holo-PML*, and the N-terminal domain alone (N-fragment) were prepared and biochemically characterized. Apo-PML and holo-PML represent refolded proteins in the absence and presence of the Ca(2+) ion, respectively. Holo-PML* represents a holo-PML dialyzed against 20 mM Tris-HCl (pH 7.5). The results suggest that the C-terminal domain of PML is almost fully unfolded in the apo-form and its folding is induced by Ca(2+) binding. The folding of this C-terminal domain may be required to make a conformation of the N-terminal catalytic domain functional.

Amino Acid Motifs↗

PubMed2001

Origin of scaling structure and non-Gaussian velocity distribution in a self-gravitating ring model.

Fractal structures and non-Gaussian velocity distributions are characteristic properties commonly observed in virialized self-gravitating systems, such as galaxies and interstellar molecular clouds. We study the origin of these properties using a one-dimensional ring model that we propose in this paper. In this simple model, N particles are moving, on a circular ring fixed in three-dimensional space, with mutual interaction of gravity. This model is suitable for the accurate symplectic integration method by which we argue the phase transition in this system. Especially, in between the extended phase and the collapsed phase, we find an interesting phase (halo phase) that has negative specific heat at the intermediate energy scale. Moreover, in this phase, there appear scaling properties and nonthermal and non-Gaussian velocity distributions. In contrast, these peculiar properties are never observed in other gas and core phases. Particles in each phase have a typical time scale of motions determined by the cutoff length xi, the ring radius R, and the total energy E. Thus all relaxation patterns of the system are determined by these three time scales.

Journal Article↗

PubMed2001

Prolonged inhibition of obliterative airway disease in murine tracheal allografts by brief treatment with anti-leukocyte function-associated antigen-1 (CD11a) monoclonal antibody.

BACKGROUND: We have previously shown that anti-leukocyte function-associated antigen (LFA)-1 (CD11a) monoclonal antibody (mAb) prevents acute rejection and produces donor-specific unresponsiveness in murine recipients of heterotopic heart allografts. Here, we investigate the ability of this mAb to prevent the development of obliterative airway disease (OAD) in murine recipients of tracheal allografts. METHODS AND RESULTS: BALB/c tracheae were heterotopically transplanted into C3H mice. OAD developed by day 28 after transplantation and was characterized histologically by a loss of epithelial cell coverage and luminal obliteration of the tracheal allograft with a proliferation of fibrogenic mesenchymal cells, which is a lesion comparable to obliterative bronchiolitis in human lung transplant recipients. Monotherapy with anti-LFA-1 mAb preserved graft epithelium, prevented the development of OAD, and maintained unresponsiveness to donor antigen for more than 42 days after the final mAb administration. CONCLUSION: These findings suggest the potential for anti-LFA-1 mAb therapy to suppress both acute and chronic rejection in clinical lung transplantation.

Animals↗