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Biomedical subjects

T Kojima

Publications and source records attributed to T Kojima.

At least 19 recordsLinked to original sources
PubMed1992

EEG coherence in unmedicated schizophrenic patients: topographical study of predominantly never medicated cases.

Electroencephalographic (EEG) power and coherence were compared in 11 unmedicated schizophrenics (including 9 never mediated patients) and in 15 normal controls. There was no significant difference in power between the two groups. However, interhemispheric coherence between O1-O2 was higher in the schizophrenics in the delta and beta bands, and interhemispheric coherence between T5-T6 was higher in the delta band. These results suggest that coherence is more sensitive than power for comparison of these two groups, and that cerebral function is less lateralized in schizophrenics.

Adult↗
PubMed1992

Topographical changes in alpha power in medicated and unmedicated schizophrenics during digits span reverse matching test.

The topographical distribution of alpha power reduction was compared in nine unmedicated schizophrenics (predominantly never-treated), 17 medicated schizophrenics, and 15 normal controls. The task involved four procedures: (1) listening to signal sound, (2) listening to digits for memorization, (3) after listening, and (4) listening to digits for recognition. The electroencephalograms (EEGs) during each procedure were analyzed with Fast Fourier Transformation and compared with EEGs at rest. While listening to the digits, medicated schizophrenics showed less alpha power reduction than normal controls and unmedicated schizophrenics. In addition, there were correlations found between the degree of alpha power reduction and medication dose, and score of chronic symptoms. These suggest that patients with different clinical backgrounds have differing cerebral activity.

Adult↗
PubMed1992

Improvement in the heterogeneous N-termini and the defective N-glycosylation of human interleukin-6 by genetic engineering.

Recombinant human interleukin-6 (IL-6), expressed in Chinese hamster ovary cells, has heterogeneous N-termini of Ala1 and Val3, as does naturally occurring IL-6. This heterogeneity is thought to be caused by difficulty in cleavage of the signal sequence. To obtain homogeneous IL-6, Pro at -1 was exchanged for Ala by site-directed mutagenesis. Alternatively, the signal sequence was replaced with that of human granulocyte-colony-stimulating factor. In both cases, the IL-6 designed to start with Ala1 was still heterogeneous, while the IL-6 designed to start with Val3 showed a homogeneous N-terminus. It is suggested that the heterogeneity of the N-terminus is caused not only by the signal sequence, but also by the succeeding sequences of the mature protein. Only a portion of recombinant human IL-6 is N-glycosylated. Asn46, being exchanged for Gln by site-directed mutagenesis, was confirmed to be partially N-glycosylated. The defective N-glycosylation was assumed to be caused by interference or tension from a disulfide bond near the N-glycosylation site. To verify this hypothesis, the Cys45 and Cys51 forming the disulfide bond were exchanged for Ser. The N-glycosylated species became predominant upon this substitution, suggesting that formation of the disulfide bond is a cause of the defective N-glycosylation.

Amino Acid Sequence↗
PubMed1992

Interpretation of the thiobarbituric acid reactivity of rat liver and brain homogenates in the presence of ferric ion and ethylenediaminetetraacetic acid.

The thiobarbituric acid (TBA) reactivity of rat liver and brain homogenates was characterized to elucidate what kinds of aldehyde species contributed to the reactivity. Characteristic pH dependence of the reactivity with a maximum at around pH 3 and marked enhancement of the reactivity by t-butyl hydroperoxide (t-BuOOH) and ferric ion were similar to those of alkadienals. The amounts of aldehyde species, including alkadienals determined as 2,4-dinitrophenylhydrazones, were high enough to account for the enhanced reactivity. The reactivity was inhibited by ethylenediaminetetraacetic acid (EDTA) but not completely, suggesting the presence of malonaldehyde whose reactivity was not affected by EDTA. The amounts of malonaldehyde determined as 1-(2,4-dinitrophenyl)pyrazole could account for a part of the reactivity in the presence of EDTA. Hence, the TBA reactivity of liver and brain homogenates at around pH 3 in the presence of t-BuOOH and ferric ion may be accounted for by alkadienals and malonaldehyde and that in the presence of EDTA by malonaldehyde.

Animals↗
PubMed1992

Isolation and characterization of heparan sulfate proteoglycans produced by cloned rat microvascular endothelial cells.

We have isolated heparan sulfate proteoglycans (HSPGs) from cloned rat microvascular endothelial cells using a combination of ion-exchange chromatography, affinity fractionation with antithrombin III (AT III), and gel filtration in denaturing solvents. The anticoagulantly active heparan sulfate proteoglycans (HSPGact) which bind tightly to AT III bear mainly anticoagulantly active heparan sulfate (HSact) whereas the anticoagulantly inactive heparan sulfate proteoglycans (HSPGinact) possess mainly anticoagulantly inactive heparan sulfate (HSinact). HSact and HSinact were also isolated by a combination of ion-exchange chromatography, treatment with protease and chondroitin ABC lyase, and affinity fractionation with AT III. HSact and HSinact have molecular sizes of about 25-30 kDa with the same overall composition of monosaccharides except that HSact exhibits about nine glucuronsyl 3-O-sulfated glucosamines/chain whereas HSinact possesses about three glucuronsyl 3-O-sulfated glucosamines/chain. Direct isolation of the AT III-binding site of HSact by exposing carbohydrate chains to Flavobacterium heparitinase in the presence of protease inhibitor revealed only a single interaction site which contained two to three glucuronsyl 3-O-sulfated glucosamine residues. The core proteins of HSPGact and HSPGinact were isolated by treatment with Flavobacterium heparitinase and purification by ion-exchange chromatography. The molecular sizes of the core proteins were established by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and their primary structures were examined by cleavage with trypsin or endopeptidase Glu-C as well as separation of peptides by reverse-phase high performance liquid chromatography. The results showed that both sets of core proteins exhibited three major components with molecular sizes of 50, 30, and 25 kDa, respectively. The 25-kDa species appears to be a proteolytic degradation product of the 30-kDa species. The peptide mapping revealed that HSPGact and HSPGinact possess extremely similar core proteins.

Animals↗
PubMed1992

Molecular cloning and expression of two distinct cDNA-encoding heparan sulfate proteoglycan core proteins from a rat endothelial cell line.

The cloned rat fat pad endothelial cell (RFP-EC) line synthesizes anticoagulantly active heparan sulfate proteoglycans (HSPGact) and anticoagulantly inactive heparan sulfate proteoglycans (HSPGinact), both of which exhibit 25-, 30-, and 50-kDa core proteins of extremely similar structure. The primary sequences of internal peptides obtained from HSPGinact core proteins and the NH2-terminal sequence analyses of the 25-kDa component from the HSPGinact core proteins demonstrate that the 30-kDa component is a previously unidentified species, designated as ryudocan, with the 25-kDa component representing a proteolytic degradation product, while the 50-kDa component is the rat homolog of syndecan (Saunders, S. Jalkanen, M., O'Farrell, S., and Bernfield, M. (1989) J. Cell Biol. 108, 1547-1556). Specific oligonucleotide probes were obtained for ryudocan and syndecan by polymerase chain reaction, and the corresponding cDNAs were isolated from a RFP-EC library. The cDNAs encode type I integral membrane proteins of 202 and 313 amino acids, respectively, which have homologous transmembrane and intracellular domains but very distinct extracellular regions. In particular, ryudocan exhibits only three potential glycosaminoglycan attachment sites within the extracellular region while syndecan has five glycosaminoglycan attachment sites within the same domain. Both species are expressed in RFP-EC lines, primary rat aortic smooth muscle cells and primary rat skin fibroblast cells. The levels of ryudocan and syndecan mRNA were measured by quantitative polymerase chain reaction in primary microvascular endothelial cells and closely associated non-endothelial cells isolated by cell sorting. Ryudocan and syndecan mRNAs were abundantly expressed in both populations representing about 0.1-0.5% of mRNA.

Amino Acid Sequence↗
PubMed1992

Microsurgical use of polydioxanone (PDS) suture: an experimental report.

Although many technological advances have been made in surgical materials, nylon is still the main suture material use for microvascular surgery. This study sought to evaluate polydioxanone (PDS) sutures for use in microvascular anastomoses. Twenty-eight male Sprague-Dawley rats were used in this experiment. Spatula-type needles with 9-0 PDS suture were used to anastomose the right femoral arteries, with 9-0 nylon used on the left side. The arteries were observed for 1, 2, 3, 4, 8, 12, and 16 weeks after surgery to determine arterial patency and to evaluate vascular pathology. Results were comparable between PDS and nylon. We suggest that if the suture material is redesigned to allow smooth passage through the tissue, and if the needle used in conjunction with the suture is improved, PDS may offer an excellent material for microvascular anastomosis.

Anastomosis, Surgical↗
PubMed1992

Ossification of the ligamentum flavum in the thoracolumbar spine of young adults report of two cases.

Ossification of the ligamentum flavum in the thoracolumbar spine is rare in young adults. We report two cases in 22 year old males who required surgical treatment. The first patient was obese and hyperinsulinaemic. He had a compression myelopathy below T11 due to extensive posterior ossification. The second patient had an osteoid osteoma of the right pedicle of T11 with ossification of the adjacent ligamenta flava. Both patients benefited from surgical decompression of the spine.

Adult↗
PubMed1992

Plasma endothelin-1 like immunoreactivity levels in neonates.

We attempted to determine the plasma endothelin-1-like immunoreactivity (ET-1) levels and to evaluate its physiological significance in 29 neonates: 5 with respiratory distress syndrome (RDS), 3 with transient tachypnoea of the newborn (TTN), 4 with neonatal asphyxia, 5 with bronchopulmonary dysplasia (BPD) following RDS, 7 healthy preterm infants and 5 healthy full-term infants. Plasma ET-1 levels in infants with RDS were significantly higher than those in healthy full-term infants through the 1st week of life. Plasma ET-1 levels in infants with neonatal asphyxia were high on the first 2 days of life and then gradually decreased to those of healthy full-term infants. Plasma levels in infants with TTN were the same as those in healthy full-term infants. Plasma ET-1 levels in infants with BPD were high when compared with those in healthy preterm infants during the first 2 months of life. This study showed that plasma levels were markedly elevated for a long time in the infants with respiratory distress. We speculate that plasma ET-1 may be a specific marker for pulmonary endothelium injury in infants with respiratory distress.

Asphyxia Neonatorum↗
PubMed1992

Exploratory eye movements in schizophrenic patients and patients with frontal lobe lesions.

Exploratory eye movements in 20 schizophrenics, 18 patients with frontal lobe lesions (9 right-sided and 9 left-sided) and 20 normal controls were examined with an eye mark recorder while they viewed stationary S-shaped figures. The eye movements made during the subject's first 15-s viewing of an original figure were analyzed. Patients with right frontal lobe lesions (RF) and schizophrenics (S) had lower scores than normal controls (NC) for the number of eye fixations, total eye scanning length and mean eye scanning length. Each subject was then shown two other figures slightly different from the original and was requested to compare them with the original. After comparing them, the subject was asked the question, "Are there any other differences?" The eye movements made over the ensuing 5 s in response to this question were scored using the responsive search score (RSS). The RSS was low only in the S group. The subject was also asked to reproduce the original figure before and after making comparisons between the figures. The RF and S groups were poorer at reproduction than the NC group. These findings suggest that there is disordered function of the right frontal lobe in schizophrenia, and that schizophrenia is due not only to localized damage to one part of the brain but to more widespread damage.

Adult↗
PubMed1992

Interpretation of COHb concentrations in the left and right heart blood of cadavers.

Carbon monoxide hemoglobin (COHb) concentrations in left and right heart blood samples from cadavers both exposed and not exposed to fire or CO gas were analyzed by the gas chromatographic method. The COHb concentration ratio between samples of left and right heart blood (L/R ratio) does not appear to be useful for establishing whether death has occurred before or after exposure to fire with the exception of cases where no soot can be detected in the airways by the naked eye and the COHb concentration in the blood sample is within the level considered normal for tobacco smokers.

Adolescent↗
PubMed1992

Clinical characteristics of vascular leiomyoma of the upper extremity: report of 11 cases.

Clinical features of vascular leiomyoma of the upper extremity which have not been described or have been described incorrectly are documented with a report of 11 consecutive cases seen within the past 11 years. All patients were followed without recurrence or surgical morbidity. Vascular leiomyoma has been described as a painful nodule found more frequently on the extensor surfaces, but in our experience spontaneous or paroxysmal pain is exceptional and the tumour tends to be located on the volar surface when it is in the hand. In the digit, they tend to be found at the base away from the midline, and not seen distal to the DIP joint.

Adolescent↗
PubMed1992

In vitro fertilization and development of frozen-thawed bovine oocytes.

Bovine oocytes were vitrified (V-oocytes) or frozen slowly (S-oocytes) at the germinal vesicle (GV) stage or after maturation in vitro (IVM) and their survival assessed morphologically and also by in vitro fertilization (IVF) and culture. The morphological survival of S-oocytes was 30.7% after freezing at the GV stage and 53.3% after IVM. The corresponding survival rates of V-oocytes were significantly lower, viz. 14.6 and 14.0%, respectively. The fertilization rate of S-oocytes frozen after IVM (51.0%) was lower than that of unfrozen controls (75.8%), but higher than after other treatments. Development continued in 16.0% of the fertilized S-oocytes, compared to 39.4% of control IVF zygotes and 1.6% developed into morulae or blastocysts (4.5% in controls). Only 0.8% of frozen-thawed GV stage oocytes and 4.6% of post-IVM V-oocytes cleaved after IVF and none formed morulae or blastocysts. Transfer of four embryos (two morulae and two blastocysts) derived from post-IVM S-oocytes into a recipient heifer resulted in pregnancy and the birth of twin calves.

Animals↗
PubMed1992

Alpha-fetoprotein-producing acinar cell carcinoma of the pancreas.

A pancreatic carcinoma and liver metastases associated with marked elevation of the serum alpha-fetoprotein (AFP) level were resected from a 57-year-old man. On microscopic examination, the tumor cells showed a predominantly acinar arrangement, with tubular and trabecular structures; in some foci it had features of a medullary pattern. Alpha-fetoprotein, lipase, trypsin, chymotrypsin, and alpha 1-antitrypsin were strongly demonstrated in tumor tissue by immunohistochemical techniques. A biochemical analysis of AFP on affinity sepharose columns revealed that the AFP derived from the tumor tissues was similar to that of hepatocellular carcinoma. Ultrastructural study showed that most of the tumor cells had abundant rough endoplastic reticulum and numerous zymogen granules. No squamoid corpuscles, neuroendocrine granules, bile production, or bile canaliculi were recognized. These findings suggest that this unique tumor originated from acinar cells.

Carcinoma↗
PubMed1992

Treatment of tardive dyskinesia with ceruletide: a double-blind, placebo-controlled study.

The effectiveness of a once-weekly i.m. injection of ceruletide (0.8 microgram/kg) in suppressing the symptoms of neuroleptic-induced tardive dyskinesia (TD) was evaluated in a double-blind, placebo-controlled, matched-pairs study. Global evaluation of the severity of TD symptoms over the 8-week study period revealed a significant improvement with ceruletide as compared with placebo. Analysis of the therapeutic response to ceruletide over the course of treatment revealed a slow, but long-lasting improvement of TD symptoms. Side effects, which were mild and transient, consisted mainly of nausea and epigastric discomfort. The incidence of side effects did not differ between the ceruletide- and placebo-treated groups. Ceruletide appears to be a novel and practical treatment that can substantially alleviate the symptoms of dyskinesia.

Adult↗
PubMed1992

Chromosome rearrangements at 12q13 in two cases of chondrosarcomas.

We analyzed the karyotypes of two moderately differentiated (grade 2) chondrosarcomas. Case 1 had a reciprocal translocation between chromosomes 6 and 12, t(6;12)(q25;q13) in most of the cells analyzed, as well as trisomies of chromosomes 7, 8, 11, 17, 19, and 21 and tetrasomy of chromosome 19. A reciprocal translocation involving chromosomes 12 and 19, t(12;19)(q13;q13), was noted as a highly clonal abnormality in the other case. Some cells had t(12;19) as the sole chromosome abnormality. Thus, chromosome rearrangements involving the long arm of chromosome 12 at the same region (q13) were commonly identified in the two tumors. These findings suggest that the rearrangements at 12q13 are nonrandom acquired changes that characterize a subgroup of chondrosarcomas.

Adult↗
PubMed1992

Vascular anatomy of the finger dorsum and a new idea for coverage of the finger pulp defect that restores sensation.

The cutaneous vascular anatomy of the finger dorsum was studied by dissection under loupe magnification of 71 fingers from 19 preserved cadaver hands. All specimens were injected with red latex or epoxy resin through a cannula in the brachial artery to identify the small vessels. The finger dorsum was supplied by the terminal branches from the dorsal metacarpal artery around the metacarpophalangeal joint. Other areas were nourished by the dorsal cutaneous branch from the proper palmar digital artery. There were two or three dorsal branches in the proximal phalangeal region and two in the middle phalangeal region. On the basis of these findings, we have developed a new method for one-stage reconstruction of finger pulp defect that restores sensation. Our innervated reverse vascular pedicle digital island flap includes the dorsal digital nerve and the proper palmar digital artery as a retrograde vascular pedicle. We have used the technique in three patients, with excellent results. The advantage of this procedure is that it provides a one-stage reconstruction of the pulp defect and restores sensation. The disadvantage is that the procedure requires neurorrhaphy.

Adult↗