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Biomedical subjects

S Harata

Publications and source records attributed to S Harata.

33 records · Page 2Linked to original sources
PubMed1998

Proteoglycans in the nucleus pulposus of canine intervertebral discs after chondroitinase ABC treatment.

Experimental chemonucleolysis of the canine intervertebral disc with chondroitinase ABC and chymopapain was compared during a 52-week period. Roentgenograms and magnetic resonance imaging were used to examine changes in disc space and water content, respectively. Disc space narrowing and reductions in disc water content after chondroitinase ABC treatment were less than that after chymopapain. High-performance liquid chromatography was performed to measure changes in proteoglycans. Similarly to chymopapain, chondroitinase ABC degrades proteoglycans in the nucleus pulposus and decreases their quantity. However, large differences in the molecular weight and acidity of the resynthesized proteoglycans and in the chain length of the resynthesized glycosaminoglycans were observed between the two enzymes. The difference in disc space narrowing and the changes in disc water content between the two enzymes might result from differences in the characteristics of the resynthesized proteoglycans.

Acids↗
PubMed1996

The prognosis and the treatment of patients with a C3/4 spinal cord injury.

Twenty patients with a C3/4 spinal cord injury have been treated in our hospital since 1974. There were 15 new patients. The average follow up period was 68 months, ranging from 7 to 162 months. The 15 new cases were classified as Frankel A in nine cases, B in one, and C in five. Frankel A or B were usually accompanied by either an unstable spinal fracture or by spinal canal stenosis at the C3/4 level. Twelve patients received surgery. At the most recent follow up, eight of the 15 patients (53.3%) had improved according to Frankel's classification. Five, all Frankel A on remission, have died between 2 and 156 months after injury. Seven patients required tracheotomy on account of severe respiratory disturbance.

Adult↗
PubMed1996

Isolation and characterization of mumps virus strains in a mumps outbreak with a high incidence of aseptic meningitis.

In 1993, mumps with a high incidence of aseptic meningitis became prevalent in Akita prefecture, Japan. Three mumps virus isolates obtained from the nonvaccine-associated cases lacked the BamHI restriction cleavage site of the P gene, like the Urabe strain (Yamada, A. et al, Vaccine 8: 553-557). However, four additional nucleotide substitutions were found in the determined region of 157 bp. Fourteen of 19 cases from which mumps virus showing the Urabe-like RFLP profile was detected were complicated with symptomatic meningitis, whereas there were only four cases of meningitis among 23 individuals infected with the wild type showing no Urabe-like RFLP profile (non-"Urabe-like" wild-type). The incidence of meningitis was over 70% among patients infected with the "Urabe-like" wild-type virus. The "Urabe-like" wild-type. disappeared after February 1994 in the epidemic area and was replaced by the non-"Urabe-like" wild-type. Patients infected with the "Urabe-like" wild-type lived in a closed colony, in which there were two instances of transmission between siblings. Thus this outbreak was transient and narrowly localized.

Base Sequence↗
PubMed1995

Identification of glycosaminoglycans using high-performance liquid chromatography on a hydroxyapatite column.

Glycosaminoglycans (heparin, heparan sulfate, dermatan sulfate, chondroitin sulfate, and hyaluronic acid) were labeled with a fluorescent reagent, 2-aminopyridine. The fluoro-labeled glycosaminoglycans were subjected to high-performance liquid chromatography on a hydroxyapatite column. The binding property of each glycosaminoglycan to hydroxyapatite was different. The structural properties of glycosaminoglycans bound to hydroxyapatite were then investigated using chemical desulfated or enzymic depolymerized glycosaminoglycans. This revealed that the sulfate content and molecular weight of the glycosaminoglycans correlated with their binding properties to hydroxyapatite. Desulfated dermatan sulfate but not desulfated chondroitin 6-sulfate bound to the hydroxyapatite. These data indicate that iduronic acid residues of glycosaminoglycans are important for the binding property. The method described which uses hydroxyapatite columns facilitates rapid separation and microanalysis of the glycosaminoglycans, especially dermatan sulfate and chondroitin sulfate.

Aminopyridines↗
PubMed1994

Cloning and characterization of the cDNA encoding the HA protein of a hemagglutination-defective measles virus strain.

cDNA clones corresponding to the mRNA for the hemagglutinin of the hemagglutination-defective strain AK-1 of measles virus were isolated and characterized. Compared with the prototype Edmonston strain, 60 nucleotide substitutions that resulted in 18 amino acid changes were detected. An additional potential N-linked glycosylation site was added by point mutation, which was supported by the observation that the hemagglutinin of the AK-1 strain was stained more heavily after NaDodSO4-PAGE and periodic acid-Schiff (PAS) staining than the Edmonston strain. Computer-assisted analysis revealed that three reverse turns in the secondary structure had disappeared in the hemagglutinin of the AK-1 strain. Moreover, one of these structural changes occurred in the closely glycosylated region at amino acid residues 168-240, which appeared to be a biologically important functional domain. The isoelectric point calculated from the predicted amino acid sequence became about 1 pH unit more basic in the AK-1 strain than the Edmonston strain. This present study is the first sequence analysis of the hemagglutinin gene in a hemagglutination-defective strain of the measles virus.

Amino Acid Sequence↗
PubMed1993

Age-related changes in proteoglycans of human ligamentum flavum.

Age-related changes in proteoglycans of human ligamentum flavum were studied using specimens obtained from patients divided into four age groups. The proteoglycans were purified by ion-exchange and gel-filtration chromatography. A low-molecular-weight proteoglycan with the same molecular size was present in all each age groups. Conversely, high-molecular-weight proteoglycan increased with advancing age. Properties of the sugar chains, glycosaminoglycans, in these proteoglycans were studied using cellulose acetate membrane electrophoresis and chondroitinase digestion. It was found that the high-molecular-weight proteoglycan consisted mainly of chondroitin 6-sulfate, whereas the low-molecular-weight proteoglycan consisted mainly of dermatan sulfate, although the ratio of chondroitin 6-sulfate increased with age. These results indicate that proteoglycans of human ligamentum flavum show changes in amount and composition with age.

Adolescent↗
PubMed1992

Spinous process-splitting laminoplasty using hydroxyapatite spinous process spacer.

Between February 1986 and August 1989, 45 patients with cervical myelopathy were treated by spinous process-splitting laminoplasty. Hydroxyapatite intraspinous spacers were used to maintain the enlargement of the cervical spinal canal. The shape of this spacer is trapezoidal. After sagittal splitting of the spinous process, the spacer was inserted between the two halves and affixed with the wire. Histologic study showed there was good fusion between the spacer and bone. In all cases, good enlargement of the cervical spinal canal was achieved. Spacer displacement, wire breakage, and postoperative infection were not seen. There was no postoperative neurologic deterioration. Computed tomography showed that the width of the cervical spinal canal was maintained.

Animals↗
PubMed1991

Influence of the ultrasonic surgical aspirator on the dura and spinal cord. An electrohistologic study.

The influence of the ultrasonic surgical aspirator on the dura and underlying spinal cord was examined. Spinal-cord-evoked potential was simultaneously recorded. In a test of identical time, the degree of influence on the dura, the pia mater, and the spinal cord increased according to the increase of energy of the ultrasonic surgical aspirator. With 60% energy at 20 seconds and 80% energy at both 10 and 20 seconds, spinal-cord-evoked potential showed wave changes. In light of these results, it is suggested that in using the ultrasonic surgical aspirator on the dura, the electrohistologic safety limit be set at 60% energy and the maximum time duration at one point less than 10 seconds.

Aged↗
PubMed1988

Dual vascularized fibula transfer on a single vascular pedicle: a useful technique in long bone reconstruction.

The use of dual vascularized fibula transfer on a single vascular pedicle for reconstruction of long bone defect is described. This technique involves dividing one length of donor vascularized fibula into two segments, without cutting the vessels. The vessels are then folded, thereby supplying blood circulation to both bones. Since 1985 the authors have treated six cases of bone reconstruction using this method. Two of these six cases are reported, with follow-up periods of over one year.

Adult↗
PubMed1988

Degradation and biosynthesis of proteoglycans in the nucleus pulposus of canine intervertebral disc after chymopapain treatment.

The effects of chymopapain treatment of the canine intervertebral disc were studied in vivo by monitoring proteoglycan in the nucleus pulposus. Analysis of proteoglycan was carried out by Sepharose CL-4B (Pharmacia Fine Chemicals AB, Stockholm, Sweden) chromatography and electrophoresis. The proteoglycan was degraded to glycosaminoglycans within 1 week after chymopapain treatment. Two weeks later, a proteoglycan smaller than the original appeared in the nucleus pulposus. At 8 weeks after injection, the amount of the newly synthesized proteoglycan, similar in molecular weight to the original, had recovered to about half that of the original, although the new proteoglycan fraction was rich in hyaluronic acid. It was concluded that, following chemonucleolysis with chymopapain, the water-binding capacity of the nucleus pulposus recovered, but that the regenerated nucleus pulposus differed biochemically from the original.

Animals↗
PubMed1981

Osteoarthritis of the alanto-axial joint.

Thirty-one patients suffering from osteoarthritis of the atlanto-axial joint are described, suggesting that this disease is not particularly uncommon. The most characteristic radiological signs are narrowing of the joint space from loss of articular cartilage, marginal cortical thickening and osteophyte formation. Histological examination in the cadaver has shown thinning and fibrillation of articular cartilage and intra-cartilaginous ossification. The radiological appearances of the atlanto-axial joint are classified in three types, lateral atlanto-axial, atlanto-odontoid and mixed. Peak age distribution occurs between 50 and 69 years of age. Patients complain of occipital pain, a stiff shoulder and paraesthesia of the fingers. Treatment was conservative in all cases except one, a 63-year-old woman with severe occipital pain. A transoral atlanto-axial fusion was performed in this case with marked improvement. The transoral approach allows fixation and curettage of the degenerative lesions.

Adult↗
PubMedDate not supplied

Anterior cervical fusion using porous hydroxyapatite ceramics for cervical disc herniation. a two-year follow-up.

BACKGROUND CONTEXT: The Smith-Robinson Method (SR), which employs autogenous bone, is the current standard for anterior cervical fusion (AF) surgery. However, autogenous bone has graft-related complications and morbidity, and harvesting it increases trauma and risk to the patient. The use of hydroxyapatite ceramic (HAP) inserts may provide a superior alternative. PURPOSE: To determine the efficacy of using HAP in AF. STUDY DESIGN/SETTING: A retrospective study of patients who had AF surgery with wide decompression and porous HAP inserts used to treat cervical disc herniation (CHD). PATIENT SAMPLE: We evaluated 36 patients who had single-level AF using HAP for CHD, without internal fixations, clinically and radiographically with a minimum follow-up of 2 years. There were 25 men and 11 women, with an average age of 49 years (age range, 24-78 years). Preoperative diagnosis included 25 cases with myelopathy and 11 cases with radiculopathy. OUTCOME MEASURES: We established four grades to classify the degree of bony fusion between the HAP and vertebra, based on any motion at the fused segment, any radiolucent zones (RZ) between vertebral bodies and the grafted HAP, and anterior or posterior bone formations on grafted HAPs. We evaluated the severity of myelopathy by applying the Japan Orthopaedic Association (JOA) scoring system. We evaluated the surgical outcome of the myelopathy patients using the Hirabayashi recovery rating, and for the radiculopathy patients, we used the Herkowitz criteria. METHODS: We retrospectively reviewed the radiographic and clinical records of all 36 patients from surgery up to periods ranging from 2 to 7 years after surgery, with the average period of follow-up being 4.5 years. We systematically classified the degree of bony fusion into four grades ranging from Grade 1 nonunion to Grade 4 complete union. RESULTS: None of the subjects showed Grades 1 and 2 fusion. Eleven percent of the cases showed Grade 3 and 89% showed Grade 4. Loss of height of the fused segment was observed in 29 cases with an average of 1.6 mm. A decrease of lordotic angle of the fused segment was observed in six cases with an average of 2.3 degrees. Four cases revealed cracked HAP inserts but achieved Grade 4 bone fusion. There was no evidence of collapse or displacement of HAPs. The results of the 11 radiculopathy patients were excellent in 10 cases and good in the remaining case. The recovery rate of the 25 myelopathy patients was 73.0%. CONCLUSIONS: Our method of anterior cervical fusion surgery using porous HAP inserted into resected end plates, combined with a wide decompression procedure, had clinical and radiographic results so satisfactory that we conclude that it can effectively replace the use of autogenous bone for treating cervical disc herniation.

Adult↗