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Biomedical subjects

S Katoh

Publications and source records attributed to S Katoh.

At least 145 records · Page 8Linked to original sources
PubMed1996

Spinal deformity following surgery for spinal cord tumors and tumorous lesions: analysis based on an assessment of the spinal functional curve.

The mechanism of spinal deformity after surgical removal of a cervical spinal cord tumor or tumorous lesions was studied in 36 patients, based on the spinal functional curve prepared from the intersectional angle. The postoperative spinal deformity depends on the surgical level and the type of operation. In the laminectomy group, kyphosis of the upper cervical spine and compensatory increased lordosis of the lower cervical spine were observed in the C2 laminectomy patients. Localized kyphosis of the spine at the cervicothoracic junction and compensatory increased lordosis of the upper cervical vertebrae were noted in the C7 laminectomy patients. In the laminoplasty group, spinal deformities were less frequently observed, and when present the deformity was limited to a slight increase of lordosis, even in patients who had the facetectomy. These facts demonstrate the preventive effect of the laminoplasty regarding postoperative spinal deformity. Laminoplasty with reconstruction of the erector spinal muscles and the nuchal ligament is recommended for patients with a spinal cord tumor or a tumorous lesion. The spinal functional curve was significant in studying the biomechanics of the vertebral column with the advantage that both alignment and mobility of the spine are simultaneously, respectively and precisely visualized.

Adolescent↗
PubMed1996

Involvement of an intercellular adhesion molecule 1-dependent pathway in the pathogenesis of secondary changes after spinal cord injury in rats.

The intercellular adhesion molecule 1 (ICAM-1) plays an important role in immune responses by promoting infiltration of neutrophils into tissues; however, its implication in the secondary destructive pathomechanism after the initial mechanical injury to the spinal cord has not been clarified yet. This study was conducted to examine the role of ICAM-1 in this process after spinal cord injury (SCI) in rats. The expression of ICAM-1 mRNA was investigated by the reverse transcription-PCR method and the effect of monoclonal antibody (mAb) to ICAM-1 on SCI was evaluated by measuring various parameters. ICAM-1 mRNA expression correlated with the severity of injury and reached its maximum level 6 h after SCI. Intravenous injection of ICAM-1 mAb (1 mg/kg) 30 min after SCI reduced motor disturbance and enhanced recovery. Moreover, it significantly suppressed myeloperoxidase activity by 43.0% and spinal cord edema by 1.1% in the injured spinal cord tissue. The posttraumatic drop in spinal cord blood flow was also improved. These results suggest that ICAM-1 is deeply involved in the secondary self-destructive process after mechanical injury of the spinal cord and should be an effective target for developing a pharmacological treatment for SCI.

Animals↗
PubMed1996

Tetrahydrobiopterin biosynthesis enhanced by lipopolysaccharide stimulation in murine neuroblastoma cell line N1E-115.

We investigated for the first time the effect of lipopolysaccharide and the signal transduction pathway on the biosynthesis of tetrahydrobiopterin [(6R-L-erythro-1',2'-dihydroxypropyl) -2-amino-4-hydroxy-5,6,7,8-tetrahydropteridine], the cofactor for the enzymatic hydroxylation of the aromatic amino acids, in the murine neuroblastoma cell line N1E-115, which synthesizes tetrahydrobiopterin constitutively. Activation of N1E-115 cells with 1 microgram/ml lipopolysaccharide resulted in statistically significant increases in both intracellular tetrahydrobiopterin contents and the activity (Vmax) of GTP cyclohydrolase I, a rate-limiting enzyme in tetrahydrobiopterin de novo biosynthesis. Following simultaneous addition of the inhibitors of protein tyrosine kinases and GTP-binding proteins into serum-free culture media with lipopolysaccharide, we analyzed the transduction pathway of lipopolysaccharide signal toward the tetrahydrobiopterin biosynthetic system in N1E-115 cells. Our data indicate the following conclusions: (a) Protein tyrosine kinase systems are involved in mediating lipopoly-saccharide signal to tetrahydrobiopterin production, and (b) there may be a cross-talk between GTP-binding protein and the protein tyrosine kinase system in mediating lipopolysaccharide signal. These observations suggest that a neuronal cell such as N1E-115, which barely expresses CD14 on its cell surface, responds to lipopolysaccharide like macrophages and monocytes in the absence of soluble CD14.

Animals↗
PubMed1996

Effects of lecithinized superoxide dismutase on rat spinal cord injury.

Although superoxide dismutase (SOD) has been reported to promote functional recovery in ischemic spinal cord injury, it presents many difficulties in practical use primarily due to its short half-life in vivo and low tissue affinity. In this study, we investigated the effects of a new type of SOD, a lecithinized superoxide dismutase (PC-SOD), on motor disturbances, spinal cord edema, levels of myeloperoxidase (MPO), and spinal cord blood flow (SCBF) after spinal cord injury (SCI) in rats. PC-SOD is reported to show a delayed plasma disappearance in vivo in rats and has a higher affinity for vascular endothelium cells, neutrophils, and other cells than unmodified SOD. PC-SOD (4000 units/kg), unmodified SOD (4000 units/kg), or vehicle was injected intravenously 30 min after SCI. Four hours after SCI, SOD activities in spinal cord tissue and plasma were significantly higher in the PC-SOD group than in the unmodified SOD group. In the PC-SOD-treated rats, motor function was significantly better than in the other 2 groups of rats. PC-SOD significantly suppressed MPO activity, an indicator of neutrophils infiltration, in the spinal cord, at 4, 8, and 24 h after SCI, and spinal cord edema at 24 h after SCI. Moreover, the decrease of SCBF after SCI was less marked in the PC-SOD group. The present results suggest that lecithinization can improve the drug delivery of SOD to the spinal cord and PC-SOD may be an alternative pharmacological treatment for SCI.

Animals↗
PubMed1996

Surgical modulation of the natural course of collateral circulation in chronic ischemic patients.

The purpose of this study was to evaluate hemodynamic compromise in terms of baseline CBF and CRC in patients with chronic cerebral occlusive lesions and its modulation by a superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. The study subjects were 10 healthy volunteers and 49 chronic ischemic patients with stenosis or occlusion of the internal carotid artery (ICA) or middle cerebral artery (MCA). The hemodynamics were measured using stable xenon enhanced computed tomographic CBF measurement with the acetazolamide challenge. The compromised hemodynamics in patients with chronic steno-occlusive lesions did not improve during their natural course after two months. STA-MCA bypass modulated hemodynamic compromise in the ischemic patients. We recommend STA-MCA bypass for patients with reduced CRC, regardless of whether baseline CBF is reduced or normal. Hemodynamic classification using a combination of baseline CBF values and CRC values is useful for evaluating cerebral hemodynamics and for choosing the best treatment for cerebral ischemia with occlusive lesions.

Adult↗
PubMed1996

Regression of moyamoya vessels and hemodynamic changes after successful revascularization in childhood moyamoya disease.

Successful revascularization improves ischemic symptoms in the pediatric patients with moyamoya disease. However, it is not clear whether the revascularization prevents future intracranial hemorrhage from the residual moyamoya vessels. The purpose of this study is to investigate perioperative morphological and hemodynamic changes in the moyamoya vessels. Four pediatric patients (age < 15 years old) with bilateral moyamoya disease were selected for this study. To quantify the number of moyamoya vessels, T1-weighted transverse images at the level of the basal ganglia and the thalamus were selected and characteristic flow voids in the lentiform nucleus were counted. Resting CBF and cerebrovascular reserve capacity (CRC) were measured pre- and 1 year after surgery using Xenon-CT CBF method with acetazolamide test. The ratio of deep CBF/cortical CBF was calculated as an index of hemodynamic stress distribution. The one-year follow-up studies showed that 1) the number of moyamoya vessels decreased on the operative side, but did not change on the non-operative sides in all cases; 2) the ratio of deep CBF/cortical CBF decreased on the operative sides, but did not change in the non-operative sides; and 3) the CRC increased on both sides. This observation suggests the possibility that revascularization surgery may be effective for preventing the future risk intracranial hemorrhage.

Adolescent↗
PubMed1996

Yellow marking and pteridine contents in the integument of albino Armadillidium vulgare.

The albino mutant strain in the woodlice, Armadillidium vulgare, was investigated with respect to the yellow patterns on the dorsal integument. Pigment cells were observed with electron microscope in order to determine the cell types of yellow markings. Quantitative analyses of pteridines in the albino were carried out by HPLC. The result indicated that the albino integument contain sepiapterin, biopterin, pterin, isoxanthopterin as in the wild type and the red mutant strain. The total amount of the four pteridines in the albino was about half as much as that in the red phenotype for both males and females, respectively. Males and females showed almost the same totals and ratios of the four pteridines in the albino and red phenotypes. Therefore, pteridine contents in both phenotypes of A. vulgare may not be related to the activity of androgenic gland hormone. Yellow chromatophores of the albino and red phenotypes were morphologically identical, emitting a yellow fluorescence. These cells contained numerous electron-lucent pigment organelles which were similar to pteridine granules of the wild type.

Animals↗
PubMed1996

Sphenoethmoidal mucoceles with intracranial extension--three case reports.

Three unusual cases of sphenoethmoidal mucoceles with rare intracranial extension are reported. A 64-year-old female presented with a 7-month history of right visual disturbance. Computed tomography (CT) and magnetic resonance (MR) imaging demonstrated a huge mass in the right middle fossa. She underwent right frontotemporal craniotomy. Postoperatively, her proptosis and cranial nerve dysfunction had improved markedly. A 53-year-old female complained of headache, nausea, and dizziness. CT and MR imaging revealed a cystic mass filling the right sphenoid sinus. The cystic lesion was evacuated through the transnasal approach. She was doing well postoperatively and has been asymptomatic. A 39-year-old male complained of headache, vomiting, and right visual disturbance. CT and MR imaging demonstrated a homogeneous mass occupying the sphenoid sinus. Sphenoidotomy exposed the cyst extending superiorly into the anterior cranial fossa. He recovered from the visual disturbances and has been asymptomatic since. MR imaging provides confirmation of the diagnosis of sphenoethmoidal mucocele and is important for preoperative evaluation.

Adult↗
PubMed1996

[Prevention of MRSA spread in the neurosurgical field].

We investigated the distribution of MRSA (methicillin-resistant Staphylococcus aureus) on and around six patients with MRSA infection in our neurosurgical ward. All patients had a disturbance of consciousness and had sputum colonization of MRSA. Samples were obtained from 11 sites (patients' hands, attendances' hands, floors, sidetables, bedclothes, chairs, walls, curtains, door knobs, faucets and disposable gloves) in the patients' rooms by the wiping method. High counts of MRSA were detected on horizontal planes such as floors, sidetables and chairs, but MRSA was not detected on vertical planes such as curtains and walls. The reason why MRSA was detected on the horizontal planes was due to a fall of MRSA spread from sputum in the air. These findings indicate that the disinfection of horizontal planes is important for preventing the spread of MRSA. We also evaluated what disinfectant was useful for floor disinfection and concluded that 0.5% chlorhexidine digluconate (Hibitane) and 0.5% benzalkonium chloride (Osvan) were more effective than the other usually-used disinfectants such as alkyldiaminoethyl glycine (Tego-51).

Adult↗
PubMed1996

[Nephrotic syndrome related to chronic graft versus host disease after allogeneic bone marrow transplantation in a patient with malignant lymphoma].

A 13-yr-old boy was diagnosed as T cell lymphoma. After the second remission, he underwent BMT from an HLA-identical, MLC negative sibling donor. After BMT, he developed grade II acute GVHD. GVHD was improved by pulsed steroid therapy using prednisolone. About 12 months after BMT, he developed bronchiolitis obliterans, sicca syndrome, and leukoderma, which were related to chronic GVHD. Pulsed steroid therapy was carried out twice, and his condition improved. Twenty-seven months after BMT, he developed nephrotic syndrome. A renal biopsy was performed, and the diagnosis was histologically membranous nephropathy and focal glomerular sclerosis. The response to steroids was not satisfactory. After 5 weeks, dipyridamole was added, but proteinuria persisted. Proteinuria disappeared 8 weeks after the addition of cyclosporine. The second biopsy after 5 months of treatment revealed an improvement in the renal lesions. The patient showed a low T4 to T8 ratio of T-lymphocytes at the onset of nephrotic syndrome. However after treatment with cyclosporine, the ratio gradually increased. These findings suggested the nephrotic syndrome in this patient was related to renal involvement in the course of chronic GVHD.

Adolescent↗
PubMed1995

Intradural extramedullary ependymoma. A case report.

STUDY DESIGN: The present study illustrates a rare case of ependymoma of the spinal cord. OBJECTIVES: An encapsulated intradural extramedullary ependymoma of the cervicothoracic spinal cord in a 24-year old woman is reported. SUMMARY OF BACKGROUND DATA: Ependymoma is a glial tumor arising in the central nervous system. Intradural extramedullary ependymoma of the spinal cord is rare, and two cases were reported previously. METHODS: The woman presented with myelopathy below C6. Magnetic resonance imaging showed an intradural tumor from C4 to T3 and no other lesion in the central nervous system. At surgery, the extramedullary tumor apparently was not attracted to the spinal cord or dura mater. Gross total removal was easily achieved under the operating microscope. RESULTS: Histologic examination revealed the encapsulated tumor as an anaplastic ependymoma. Almost complete neurologic recovery was obtained. CONCLUSION: The encapsulated appearance, lack of an apparent attachment to the central nervous system, and absence of signs of the primary neoplastic process within the brain or spinal cord suggested that the tumor arose from ectopic ependymal cells.

Adult↗
PubMed1995

Glycosylation of CD44 negatively regulates its recognition of hyaluronan.

Although CD44 is expressed on a wide variety of cell types, few of them use it to recognize the ligand hyaluronan (HA). A glycosylation-defective clone of Chinese hamster ovary cells (Lec 8) bound HA, demonstrating that complete processing of glycoproteins with addition of a full complement of sialic acid is not required. On the contrary, subsequent findings revealed that complex sugars on CD44 can actually inhibit ligand recognition. Two subclones of wild-type Chinese hamster ovary cells with similar amounts of surface CD44 were isolated on the basis of HA binding and found to differ with respect to CD44 size as well as staining with fluorescent lectins. Treatment of the nonbinding clone with tunicamycin reduced the size of the protein and allowed the cells to recognize HA via CD44. This function was also induced by treatment with deglycosylating enzymes (either a mixture of endoglycosidase F and N-glycosidase F or neuraminidase alone). A possible role for glycosylation in regulation of adhesion was then sought with a series of normal and transformed murine cells. Disruption of glycosylation or treatment with deglycosylating enzymes did not induce ligand binding in an interleukin 7-dependent pre-B cell line, and splenic B cells also appeared to be in an inactive state. Some normal B cells acquired the ability to recognize HA after stimulation with lipopolysaccharide or interleukin 5 and had distinctive surface characteristics (loss of immunoglobulin D and acquisition of CD43). An additional subset of activated cells might have been in a transitional state, because the cells bound ligand after neuraminidase treatment. The ligand-binding ability of a purified CD44-immunoglobulin fusion protein dramatically increased after neuraminidase treatment. Thus, differential glycosylation of this molecule is sufficient to influence its recognition function. Cell adhesion involving HA can be regulated by multiple mechanisms, one of which involves variable glycosylation of CD44.

Animals↗
PubMed1995

Characterization of rice alpha-amylase isozymes expressed by Saccharomyces cerevisiae.

Two rice alpha-amylase isozymes, AmylA and Amy3D, were produced by secretion from genetically engineered strains of Saccharomyces cerevisiae. They have distinct differences in enzymatic characteristics that can be related to the physiology of the germinating rice seed. The rice isozymes were purified with immunoaffinity chromatography. The pH optima for Amy3D (pH optimum 5.5) and Amy1A (pH optimum 4.2) correlate with the pH of the endosperm tissue at the times in rice seedling development when these isozymes are produced. Amy3D showed 10-14 times higher reactivity to oligosaccharides than Amy1A. Amy1A, on the other hand, showed higher reactivity to soluble starch and starch granules than Amy3D. These results suggest that the isozyme Amy3D, which is expressed at an early stage of germination, produces sugars from soluble starch during the early stage of seed germination and that the isozyme Amy1A works to initiate hydrolysis of the starch granules.

Carbohydrate Metabolism↗
PubMed1995

Purification of recombinant alpha-amylase by immunoaffinity chromatography with anti-peptide antibody.

Adsorption characteristics of an anti-peptide antibody, obtained by immunization of eight amino acids in the C-terminal region of chimeric alpha-amylase of rice alpha-amylase isozymes, were studied by use of the chimeric enzyme and the peptide used for immunization. This anti-peptide antibody adsorbed the enzyme, as well as the peptide antigen, with sufficient affinity for immunoaffinity purification and was used for purification of the enzyme secreted from yeast cells. Chimeric alpha-amylase was purified by immunoaffinity chromatography to high purity in one step from the fermentation broth. One-third of the secreted enzyme was not adsorbed by the column of anti-peptide antibody because of processing in the C-terminal region.

Amino Acid Sequence↗
PubMed1995

Motor recovery of patients presenting with motor paralysis and sensory sparing following cervical spinal cord injuries.

We studied the neurological progress of 21 consecutive patients with cervical spinal cord injuries, presenting with sensory sparing but with complete motor paralysis below the level of their injury (Frankel B). All patients were admitted within 48 h of injury and treated conservatively with 6 weeks of bedrest and traction, followed by 6 weeks of bracing. The follow-up period was more than 1 year (49.6 months on average). Despite the initial absence of motor power in the lower limbs, seven patients recovered significant motor power and were able to walk. The preservation of pinprick sensation between the level of the injury and the sacral dermatomes was the best prognostic indicator for useful motor recovery with 75% of the patients regaining the ability to walk. This pattern of sensory sparing predicted a statistically significant better motor outcome than other patterns of sensory sparing. Although 50% of patients with no sacral sensation and/or with anal sensation on rectal examination recovered motor power, this recovery was functional in only one out of eight patients.

Adolescent↗
PubMed1995

A nationwide epidemiological survey of spinal cord injuries in Japan from January 1990 to December 1992.

This survey of traumatic spinal cord injuries in Japan from January 1990 to December 1992 was carried out by a statistical method of the nationwide epidemiological study. The number of the registered patients during these 3 years was 9752 and the mean response rate of every of the 47 prefectures was 51.4%. The registered patients with neurological deficits (Frankel A-D) were 7471 and the annual spinal cord injury incidence was 40.2 per million. The ratio of cervical cord injuries to more caudal SCI was 3:1. The age distribution and the causes of spinal cord injuries are presented in detail. From the results of this study, the prevention campaign should be focused mainly on the following topics: sports and motorcycle accidents involving young people; traffic accidents involving adults; falling accidents involving aged people.

Accidents, Occupational↗
PubMed1995

Influence of minor trauma to the neck on the neurological outcome in patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine.

The influence of minor trauma to the neck on the neurological outcome in patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine was evaluated retrospectively. Out of 118 patients treated in our clinic for cervical OPLL between 1976 and 1992, 27 had sustained minor trauma to the cervical spine. Of these 27 patients, 13 developed myelopathy, seven showed deterioration of preexisting myelopathy, and no neurological change was observed in seven patients. Regarding the relationship between the diameter of the residual spinal canal and the neurological outcome in these 27 patients, 18 out of the 19 patients with a narrow residual spinal canal (< 10 mm) developed neurological deterioration, whereas that occurred in only two of the eight patients with a wider spinal canal (> or = 10 mm). Although the severity of myelopathy and the transverse area of the spinal cord measured from T1-weighted magnetic resonance images, in patients who had sustained minor trauma was not statistically different from patients without trauma, neurological recovery after surgical treatment was poorer in the former group than in the latter. These results indicate that even indirect minor trauma to the neck can cause irreversible changes in the spinal cord if there is marked stenosis of the cervical spinal canal; such patients who are at risk, must be educated, and should be told to avoid even minor injuries at any cost.

Adult↗