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Biomedical subjects

M Takao

Publications and source records attributed to M Takao.

At least 55 records · Page 3Linked to original sources
PubMed2000

Biocompatibility of silicone-coated oxygenator in cardiopulmonary bypass.

BACKGROUND: This study was designed to analyze the biocompatibility of silicone-coated oxygenators using inflammatory response as the outcome measure, and to investigate whether the silicone-coated oxygenators perform better in terms of postoperative organ dysfunction. METHODS: The 32 patients who underwent cardiopulmonary bypass (CPB) were divided into 3 groups: group A (n = 10), heparin-coated circuit with silicone-coated oxygenator; group B (n = 11), whole heparin-coated circuit; and group C (n = 11), whole untreated circuit. The plasma concentrations of the proinflammatory markers, made of inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, interleukin-8), terminal complement complex (C5b-9), and polymorphonuclear elastase (PMN-E), were measured by enzyme-linked immunosorbant assay. RESULTS: All proinflammatory markers were significantly lower in groups A and B than in group C, especially C5b-9 and PMN-E concentrations, which were significantly lower in group A than in group B. The alveolar-arterial oxygen gradients (A-aDO2) and the respiratory index were significantly better in group A than in group C. In group B, however, only the A-aDO2 was significantly better than in group C. The duration of intubation and the length of stay in the intensive care unit stay were significantly shorter in groups A and B than in group C. CONCLUSIONS: Silicone-coated oxygenators are biocompatible and prevent postoperative organ dysfunction.

Anticoagulants↗
PubMed2000

Impaired behavioral suppression by light in metabotropic glutamate receptor subtype 6-deficient mice.

The metabotropic glutamate receptor subtype 6 is localized on the dendrites of ON bipolar cells in mammalian retina, and is responsible for synaptic transmission from photoreceptors to ON bipolar cells. We have previously provided electrophysiological evidence that metabotropic glutmate receptor subtype 6-deficient mice have an impairment in the ON visual pathway. In this study, we compared, between metabotropic glutamate receptor subtype 6-deficient (n=9) and wild-type mice (n=7), their daily wheel-running activity in constant dark and light-dark cycle environments. There was no difference in their free-running rhythmicity in a constant dark environment nor in their ability to entrain their active/rest phase to the phase-shifted light-dark cycle environment, indicating that the circadian system in mutant mice was functioning normally. However, the wheel-running activity was suppressed immediately after light onset of the light-dark cycle in wild-type mice (suppressive effect), whereas that of mutant mice was prolonged for several hours in spite of light onset (very weak suppressive effect). The suppression of activity in wild-type mice is a "masking effect" of the endogenous circadian rhythm in response to light stimuli. The results indicate that the failure of mutant mice to suppress their activity upon light onset is not due to abnormality in their circadian system, but to their lack of response to light stimuli. This study clearly demonstrates that the dysfunction of the ON visual pathway in metabotropic glutamate receptor subtype 6-deficient mice impairs their behavioral responsiveness to light and yet preserves their circadian system.

Animals↗
PubMed2000

Neuroserpin mutation S52R causes neuroserpin accumulation in neurons and is associated with progressive myoclonus epilepsy.

Mutations in the Neuroserpin gene have been reported to cause familial presenile dementia. We describe a new family in which the S52R Neuroserpin mutation is associated with progressive myoclonus epilepsy in 2 siblings. The proband presented myoclonus and epilepsy at age 24, his brother and mother presented a similar disorder when they were 25. A clinical diagnosis of progressive myoclonus epilepsy was made on the proband and his brother. Skin and liver biopsies did not reveal the presence of cytological alterations in the proband. His neurological status worsened over the subsequent 19 yr during which he became demented and had uncontrollable seizures. He died at 43 yr of age from aspiration pneumonia. Neuropathologically, eosinophilic bodies, which were positive for periodic acid-Schiff and immunoreactive with antibodies against human neuroserpin, were present in the perikarya and cell processes of the neurons. They were found in large numbers in the cerebral cortex and substantia nigra and to a lesser extent, in most subcortical gray areas, spinal cord, and dorsal root ganglia. By electron microscopy, the intracytoplasmic bodies were contained within the membranes of the rough endoplasmic reticulum. Occasionally neuroserpin immunopositivity was seen throughout the cytoplasm, even without the presence of well-defined bodies. Our study characterizes for the first time the neuropathologic phenotype associated with hereditary progressive myoclonus epilepsy caused by the S52R Neuroserpin mutation.

Adult↗
PubMed2000

Crystallization and preliminary X-ray analysis of endopolygalacturonase SE1 from Trichosporon penicillatum.

Endopolygalacturonase SE1 from Trichosporon penicillatum has been crystallized by the hanging-drop method of vapour diffusion using ammonium sulfate as a precipitant. The crystals belong to the hexagonal space group P6(1) or P6(5), with unit-cell parameters a = b = 135.0, c = 70.7 A, gamma = 120 degrees. The calculated V(M) based on one molecule per asymmetric unit is 3.09 A(3) Da(-1). A native data set from a crystal has been collected to 2.0 A resolution on a Cu Kalpha rotating-anode X-ray source.

Crystallography, X-Ray↗
PubMed2000

Purification and characterization of thermostable pectate lyase with protopectinase activity from thermophilic Bacillus sp. TS 47.

A strain of thermophilic bacterium, Bacillus sp., with pectolytic activity has been isolated. It produced an extracellular endo-polygalacturonate trans-eliminase (PL, EC 4.2.2.1) when grown at 60 degrees C on a medium containing polygalacturonate (PGA). The PL was purified by hydrophobic, cation exchange, and size exclusion column chromatographies. The molecular mass of the enzyme was 50 kDa by SDS-PAGE. The isoelectric point of the enzyme was pH 5.3. The enzyme had a half-life of 13 and 1 h at 65 and 70 degrees C, respectively, and showed optimal activity around at 70 degrees C and pH 8.0. It had protopectinase activity, besides PL activity, on lemon protopectin and cotton fibers. The first 20 amino acids sequence of the enzyme had significant similarity with that of PL from methophilic Bacillus subtilis, with 50% identity.

Amino Acid Sequence↗
PubMed2000

[A case of malignant fibrous histiocytoma of the chest wall].

A case of malignant fibrous histiocytoma of the chest wall. A 56-year old man was admitted to the hospital with a complaint of showing abnormal shadow on chest X-ray. Chest X-ray and chest CT scan showed a calcified tumor of the chest wall. Histological diagnosis could not be made prior to the operation. Wide resection of the right chest wall containing the tumor and partial resection of the right lung were done. Malignant fibrous histiocytoma (MFH) showing a striform-pleomorfic pattern was recognized histologically with resected specimen. MFH commonly arises in the soft tissues of the extremities, but rarely in those of the chest. This paper also presents a review of 38 reported cases of MFH originated from the chest wall.

Histiocytoma, Benign Fibrous↗
PubMed2000

[A case of advanced rectal cancer with unresectable liver metastasis for which chemotherapy was markedly effective].

We report a case of advanced rectal cancer accompanied by unresectable liver metastasis in which remission has been achieved for 7 years. The patient was a 64-year-old woman, and her chief complaints were a feeling of abdominal distention and melena. After low anterior resection (D3), oral administration of 600 mg/day of UFT-E and chemotherapy against the liver metastasis by hepatic arterial injection via a reservoir were started. Since the arterial injection via a reservoir became impossible due to infection, her clinical course was observed solely with oral administration of UFT-E. As a result, complete remission was achieved 7 months postoperatively, and the patient is still alive in good health without recurrences at present (7 years postoperatively). The reason why a favorable outcome has been achieved is probably that, although the initial operation resulted is non-curative resection, measures sufficient to enable the patient to lead an ordinary social life were taken at the beginning, and efforts to achieve a long-term survival were made while respecting the quality of life of the patient so that the patient would be able to coexist with the cancer.

Adenocarcinoma↗
PubMed2000

The role of cyclosporine A and interleukin-2 in obliterative airway disease in a rat tracheal transplant model.

The pathogenesis of obliterative bronchiolitis (OB) following lung and heart-lung transplantation remains unclear. We evaluated the role of CsA and IL-2 on the development of obliterative airway disease (OAD) by administrating exogenous IL-2 in a CsA-treated rat tracheal transplant model. Tracheal grafts were implanted into the peritoneal cavity from Brown Norway (BN) to BN rats or to Lewis (LEW) rats. Allotransplant: No treatment was given in group 1. Short-term CsA (25 mg/kg, i.m. on POD 2 and 3) was used in group 2. Group 3 was treated with long-term CsA (25 mg/kg, i.m. on POD 2 and 3, followed by 5 mg/kg on POD 4 to 27). Administration of IL-2 (300, 000 IU/kg, i.p. on POD 15 to 19 and 22 to 26) was performed to long-term CsA treated rats in group 4. Isotransplant: No treatment was given to group 5, group 6 was treated with IL-2 (same regimen as in group 4). Grafts were harvested at different time points after Tx for histological assessment. No luminal obliteration was observed in group 5 and 6. Complete luminal obliteration was noted 4 weeks after Tx in group 1. In group 2 and 3, obliterative lesion occurred 4-6 weeks after CsA withdrawal. IL-2 increased epithelial loss, lymphocytic infiltration, and obliterative changes in group 4. Our results suggest that OAD is an immune mediated disorder. Furthermore, administration of exogenous IL-2 might be able to abrogate the protection from OAD by CsA therapy.

Animals↗
PubMed1999

Differential subcellular localization of human MutY homolog (hMYH) and the functional activity of adenine:8-oxoguanine DNA glycosylase.

The post-replicative adenine:8-oxo-7,8-dihydroguanine (GO) mismatch is crucial for G:C to T:A transversion. This mismatch is corrected by Escherichia coli MutY which excises the adenine from A:GO. A candidate gene coding for the human counterpart of MutY has been cloned as hMYH. However, the function and enzyme activities of the gene product have not been identified. We previously demonstrated that an epitope-tagged hMYH protein behaves as a mitochondrial protein. In the present study, we have identified an alternative hMYH transcript, termed type 2, which differs in the exon 1 sequence of the known transcript (type 1). A nuclear localization for the type 2 protein was revealed by detection of epitope-tagged protein in COS-7 cells. Expression of both type 1 and type 2 transcripts was reduced in post-mitotic tissues. hMYH cDNA suppressed the mutator phenotype of E.coli mutY. In vitro expressed hMYH showed adenine DNA glycosylase activity toward the A:GO substrate. The protein can bind to A:GO, and to T:GO and G:GO without apparent catalysis. These results represent the first demonstration of the function of the hMYH gene product which is differentially transported into the nucleus or the mitochondria by alternative splicing

Adenine↗
PubMed1999

Pathologic findings of silent hyperintense white matter lesions on MRI.

The pathologic features of silent hyperintense white matter lesions in T2-weighted images on MRI were studied in patients with no neurologic signs or symptoms. The small patchy hyperintense white matter lesions represented myelin pallor associated with vessels showing hypertension and arteriosclerotic changes. 'Caps' also showed myelin pallor with dilated perivascular spaces. There were no lacunar infarcts in these lesions. Some of 'caps' was shown to be elongated normal lateral ventricle. 'Rims' of early stage revealed subependymal gliosis that was a part of normal aging processes.

Aged↗
PubMed1999

Repair of apurinic/apyrimidinic sites by UV damage endonuclease; a repair protein for UV and oxidative damage.

UV damage endonuclease (UVDE) initiates a novel form of excision repair by introducing a nick imme-diately 5" to UV-induced cyclobutane pyrimidine dimers or 6-4 photoproducts. Here, we report that apurinic/apyrimidinic (AP) sites are also nicked by Neurospora crassa and Schizosaccharomyces pombe UVDE. UVDE introduces a nick immediately 5" to the AP site leaving a 3"-OH and a 5"-phosphate AP. Apyrimidinic sites are more effectively nicked by UVDE than apurinic sites. UVDE also possesses 3"-repair activities for AP sites nicked by AP lyase and for 3"-phosphoglycolate produced by bleomycin. The Uvde gene introduced into Escherichia coli cells lacking two types of AP endonuclease, Exo III and Endo IV, gave the host cells resistance to methylmethane sulfonate and t-butyl hydroperoxide. We identified two AP endonuclease activities in S.pombe cell extracts. Besides cyclobutane pyrimidine dimers and 6-4 photoproducts, N. crassa UVDE also nicks Dewar photoproducts. Thus, UVDE is able to repair both of the major forms of DNA damage in living organisms: UV-induced DNA lesions and AP sites.

Apurinic Acid↗
PubMed1999

Transient vasodilatory effects of adrenomedullin on cerebral parenchymal microvessels in cats.

We studied the effects of adrenomedullin, structural homology of calcitonin gene-related peptide (CGRP), on the cerebral parenchymal microvessels in cats by our photoelectric method. Adrenomedullin significantly increased cerebral blood volume (CBV) at 0.5 and 1 min after intracarotid injection (0.01-1 nmol/kg, maximum; +0.71 vol% for 0.1 nmol/kg adrenomedullin). Adrenomedullin antagonist, adrenomedullin22-62 (0.01-10 nmol/kg), caused no significant changes in CBV and mean arterial blood pressure. Preinjection of 10 nmol/kg adrenomedullin22-52 blocked the vasodilatory effect of 0.01 nmol/kg adrenomedullin (P < 0.05). Pretreatment of 1 nmol/kg CGRP8-37, which has antagonistic activity against CGRP, also inhibited the vasodilatation of adrenomedullin. The degree of CBV reduction after adrenomedullin22-52 injection was greater than that after CGRP8-37 injection. Adrenomedullin has no major role in the maintenance of resting tone of intracerebral parenchymal vessels. Intravascularly administered adrenomedullin dilates cortical microvessels mainly through the specific adrenomedullin receptor.

Adrenomedullin↗
PubMed1999

Occurrence and distribution of substance P receptors in the cerebral blood vessels of the rat.

The distribution of immunoreactivity to the receptor for substance P was examined in the cerebral blood vessels of the rat. Substance P immunoreactivity has been demonstrated in the nerve fibers of the cerebral blood vessels. Recently, the production of substance P receptor specific antibody has enabled the detection of localization of the substance P receptor in the central nervous system. In this study, we examined the existence of nerve fibers with substance P receptor immunoreactivity in the cerebral blood vessels and the cranial ganglia innervating the cerebral blood vessels. Sprague-Dawley rats were perfused with fixative and the pial arteries and the cranial ganglia known to innervate the cerebral blood vessels, i.e., trigeminal, sphenopalatine, internal carotid, otic and superior cervical ganglia, were dissected. All specimens were incubated with anti-substance P receptor IgG, then stained by the avidin-biotin-peroxidase complex method. Numerous nerve fibers with varicosities forming plexuses, with substance P receptor immunoreactivity were observed on the walls of the major extracerebral arteries forming the circle of Willis and its branches. Substance P receptor immunoreactivity was also detected in the endothelium of the cerebral arteries. Substance P receptor immunoreactivity was positive in many neurons of the sphenopalatine ganglion, otic ganglion, trigeminal ganglion, superior cervical ganglion and internal carotid ganglion. The present study demonstrated the existence of nerve fibers with substance P receptor immunoreactivity in the cerebral blood vessels and the cranial ganglia that innervate the cerebral blood vessels. These findings are important in understanding the responsiveness of the cerebral blood vessels to substance P.

Absorption↗
PubMed1999

Mammalian Cry1 and Cry2 are essential for maintenance of circadian rhythms.

Many biochemical, physiological and behavioural processes show circadian rhythms which are generated by an internal time-keeping mechanism referred to as the biological clock. According to rapidly developing models, the core oscillator driving this clock is composed of an autoregulatory transcription-(post) translation-based feedback loop involving a set of 'dock' genes. Molecular clocks do not oscillate with an exact 24-hour rhythmicity but are entrained to solar day/night rhythms by light. The mammalian proteins Cryl and Cry2, which are members of the family of plant blue-light receptors (cryptochromes) and photolyases, have been proposed as candidate light receptors for photoentrainment of the biological clock. Here we show that mice lacking the Cryl or Cry2 protein display accelerated and delayed free-running periodicity of locomotor activity, respectively. Strikingly, in the absence of both proteins, an instantaneous and complete loss of free-running rhythmicity is observed. This suggests that, in addition to a possible photoreceptor and antagonistic clock-adjusting function, both proteins are essential for the maintenance of circadian rhythmicity.

Animals↗
PubMed1999

Processing of UV damage in vitro by FEN-1 proteins as part of an alternative DNA excision repair pathway.

Ultraviolet (UV) irradiation induces predominantly cyclobutane and (6-4) pyrimidine dimer photoproducts in DNA. Several mechanisms for repairing these mutagenic UV-induced DNA lesions have been identified. Nucleotide excision repair is a major pathway, but mechanisms involving photolyases and DNA glycosylases have also been characterized. Recently, a novel UV damage endonuclease (UVDE) was identified that initiates an excision repair pathway different from previously established repair mechanisms. Homologues of UVDE have been found in eukaryotes as well as in bacteria. In this report, we have used oligonucleotide substrates containing site-specific cyclobutane pyrimidine dimers and (6-4) photoproducts for the characterization of this UV damage repair pathway. After introduction of single-strand breaks at the 5' sides of the photolesions by UVDE, these intermediates became substrates for cleavage by flap endonucleases (FEN-1 proteins). FEN-1 homologues from humans, Saccharomyces cerevisiae, and Schizosaccharomyces pombe all cleaved the UVDE-nicked substrates at similar positions 3' to the photolesions. T4 endonuclease V-incised DNA was processed in the same way. Both nicked and flapped DNA substrates with photolesions (the latter may be intermediates in DNA polymerase-catalyzed strand displacement synthesis) were cleaved by FEN-1. The data suggest that the two enzymatic activities, UVDE and FEN-1, are part of an alternative excision repair pathway for repair of UV photoproducts.

Base Sequence↗
PubMed1999

Localized hypertrophic mononeuropathy involving the femoral nerve.

The authors report a case of localized hypertrophic mononeuropathy involving the femoral nerve in a 20-year-old woman referred because of progressive weakness and atrophy of the left thigh. MRI showed an enlarged femoral nerve and biopsies of fascicles displayed a concentric pattern of cells resembling an onion bulb. These cells were positive for epithelial membrane antigen immunostaining and had an incomplete basal lamina.

Adipose Tissue↗
PubMed1999

Cloning of soluble alkaline phosphatase cDNA and molecular basis of the polymorphic nature in alkaline phosphatase isozymes of Bombyx mori midgut.

A cDNA coding for soluble type alkaline phosphatase (sALP) of Bombyx mori was isolated. Deduced amino acid sequence showed high identities to various ALPs and partial similarities to ATPase of Manduca sexta. Using this cDNA sequence as a probe, the molecular basis of electrophoretic polymorphism in sALP and membrane-bound type ALP (mALP) was studied. As for mALP, the result suggested that post-translational modification was important for the proteins to express activity and to represent their extensive polymorphic nature, whereas the magnitude of activities was mainly regulated by transcription. On the other hand, sALP zymogram showed poor polymorphism, but one exception was the null mutant, in which the sALP gene was largely lost. Interestingly, the sALP gene was shown to be transcribed into two mRNAs of different sizes, 2.0 and 2.4 Kb. In addition to the null mutant of sALP, we found a null mutant for mALP. Both of these mutants seem phenotypically silent, suggesting that the functional differentiation between these isozymes is not perfect, so that they can still work mutually and complement each other as an indispensable enzyme for B. mori.

Alkaline Phosphatase↗