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Biomedical subjects

M Takagi

Publications and source records attributed to M Takagi.

At least 253 records · Page 14Linked to original sources
PubMed1999

Exercise four hour redistribution thallium-201 single photon emission computed tomography and exercise induced ST segment elevation in detecting the viable myocardium in patients with acute myocardial infarction.

OBJECTIVE: To investigate the specificity and sensitivity of the combination of redistribution in exercise thallium-201 single photon emission computed tomography (SPECT) and exercise induced ST elevation for detecting the viable myocardium in patients with acute myocardial infarction. DESIGN: 37 patients were studied within seven weeks of onset of Q wave myocardial infarction (anterior in 22, inferior in 15). All patients underwent exercise four hour redistribution thallium-201 SPECT and positron emission tomography using fluorine-18-fluorodeoxyglucose (FDG) and nitrogen-13 ammonia under fasting conditions. RESULTS: Sixteen patients showed exercise induced ST elevation >/= 1.5 mm, and 15 of these had increased FDG uptake in the infarct region. Eleven of 16 patients (10 of 11 patients with anterior infarctions) with irreversible thallium-201 defects and increased FDG uptake showed exercise induced ST elevation. The sensitivity, specificity, and predictive accuracy of redistribution, exercise induced ST segment elevation, or both for detecting increased FDG uptake were 82%, 75%, and 67% (94%, 75%, and 91% for anterior infarctions), respectively. CONCLUSIONS: In patients with acute Q wave myocardial infarction, the combination of redistribution in exercise thallium-201 SPECT and exercise induced ST elevation can detect the viable myocardium in the infarct region with high sensitivity and specificity, especially in patients with anterior infarctions.

Adult↗
PubMed1999

Increased activated protein C: protein C inhibitor complex and decreased protein C inhibitor levels in patients with chronic renal failure on maintenance hemodialysis.

Hemostatic abnormalities were examined in 55 patients during maintenance hemodialysis (HD). Before HD, plasma protein C and protein S antigens were almost within the normal range, while plasma thrombin-antithrombin III complex (TAT III) and plasmin-plasmin inhibitor complex (PPIC) levels in HD patients were increased slightly, and plasminogen activator inhibitor 1 level was significantly increased, compared to that in normal volunteers. Plasma activated protein C (APC) and protein C inhibitor (PCI) complex and APC alpha 1 antitrypsin (alpha 1AT) complex were not detected in normal volunteers; however, plasma APC-PCI complex was increased in 36 of the patients and plasma APC-alpha 1AT complex was increased in 25 patients. Plasma PCI levels in these patients before HD were significantly decreased. Plasma TAT, PPIC, and tissue type plasminogen activator levels were significantly higher before HD than after 1 hour HD and at the end of HD, while the changes in plasma protein C antigen, protein S antigen, PCI antigen, APC-PCI complex, and APC-alpha 1AT complex were not significant after 1 hour of HD or at the end of HD compared to levels before HD. Plasma PCI levels were correlated with APC-PCI complex, suggesting that decreased PCI levels might be caused by the activation of protein C.

Adult↗
PubMed1999

Pathologic findings of silent, small hyperintense foci in the basal ganglia and thalamus on MRI.

We analyzed the pathologic features of silent, small hyperintense foci in the basal ganglia and thalamus on MRI T2-weighted images (T2WI). Eight foci were histologically lacunar infarcts (LI), and 21 were dilated perivascular spaces (DPS). The foci with smooth margins were mostly DPS, whereas those with irregular margins were mostly LI (p = 0.018). Most putaminal foci were DPS, whereas most thalamic foci were LI (p = 0.001). The mean areas of LI and DPS overlapped below 19.6 mm2. The shape and site of hyperintense foci on T2WI are important for differentiating LI from DPS.

Aged↗
PubMed1999

Chmadrin: a novel Ki-67 antigen-related perichromosomal protein possibly implicated in higher order chromatin structure.

A novel perichromosomal protein, which we have named chmadrin, was identified from rat kangaroo PtK2 cells. The deduced amino acid sequence revealed structural homologies in several limited regions to the Ki-67 antigen (pKi-67). The subcellular localization of chmadrin was found to be similar to that of pKi-67 throughout the cell cycle, that is, predominantly nucleolar during interphase and perichromosomal in the mitotic phase. In addition, a certain population of the protein was found to be localized in heterochromatic foci in interphase nuclei. Transient expression analysis of the truncated proteins corresponding to the conserved regions clearly demonstrated the structural basis for the characteristic cellular localization. Residues 494-778, which show extensive similarity to the corresponding region of pKi-67, were efficiently targeted to nucleoli, whereas a repetitive structure found at the C-terminal portion, whose similarity to pKi-67 is weak, was localized precisely to mitotic chromosomes. The C-terminal portion was designated the 'LR domain' since several LR (leucine and arginine) pairs commonly appear in chmadrin and pKi-67. When overproduced in the interphase nuclei, the LR domain induced the formation of aberrant heterochromatin as a structural constituent. These are the first empirical data suggesting the involvement of perichromosomal proteins in the organization of chromatin structure.

Amino Acid Sequence↗
PubMed1999

Production of recombinant Der fI (a major mite allergen) by Aspergillus oryzae.

Der fI is a major mite allergen. To produce Der fI by Aspergillus oryzae, we placed a DNA fragment encoding precursor-type recombinant Der fI E(-1)K (reDer fI E(-1) K), which had the C-terminal amino acid of the pro-sequence (Glu) changed to Lys, downstream of the glaA gene promoter and introduced it into Aspergillus oryzae. In liquid culture, most of the reDer fI E(-1)K produced by the transformants was degraded when culture was shaken vigorously. However, the degradation of reDer fI E(-1)K was suppressed when it was shaken gently. The processed reDer fI E(-1)K could be obtained after lysylendopeptidase and endoglycosidase Hf (Endo Hf) treatment. The yield of processed reDer fI E(-1)K was 8 mg/l. When the transformant was grown on a wheat bran culture, the yield of processed reDer fI E(-1)K reached 48 mg/kg. Because processed reDer fI E(-1)Ks obtained from both cultures had almost the same IgE-binding activity and elicited the same skin reaction as native Der fI, they could be very useful for diagnostic purposes or immunotherapy.

Allergens↗
PubMed1999

Transforming and epidermal growth factors in degenerated intervertebral discs.

We studied the presence of anabolic growth factors in human herniated intervertebral discs (IVD) using a reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. Messenger RNA (mRNA) was isolated from the nucleus pulposus using oligo (dT)25 superparamagnetic beads and probing with gene-specific primers in RT-PCR. mRNA coding for TGF-alpha (3/10), EGF (0/10), TGF-beta1 (0/10) and TGF-beta3 (2/10) or the EGF receptor (EGF-R; 0/10) and TGF-beta type-II receptor (0/10) was found only occasionally. Beta-actin was always present and positive sample controls confirmed the validity of the RT-PCR assay. These RT-PCR findings were confirmed using immunohistochemical staining of EGF and TFG-beta, whereas TGF-alpha protein was always found associated with discocytes. We conclude that the nucleus pulposus of the herniated IVD is vulnerable to proteolytic degradation and depletion of proteoglycans due to the lack and/or low production of anabolic growth factors/receptors which could increase the local synthesis of the extracellular matrix.

Actins↗
PubMed1999

Osmoregulation of vasopressin secretion in patients with the syndrome of inappropriate antidiuresis associated with central nervous system disorders.

To clarify the characteristics of vasopressin (AVP) secretion in patients with the syndrome of inappropriate antidiuresis (SIAD) related to central nervous system disorders, we examined the response of AVP secretion to osmotic stimulus by hypertonic saline infusion and analyzed the possible causative factors in six patients with SIAD associated with head trauma or cerebral infarction. Hyponatremia developed after head trauma in four patients and cerebral infarction in two patients. In all patients the clinical state and laboratory findings fulfilled the criteria for SIAD, which was supported by either nonsuppressible plasma AVP levels or effectiveness of treatments with water restriction, demeclocycline, nonpeptide V2 AVP antagonist or diphenylhydantoin. Although patterns of plasma AVP response to the osmotic stimulus varied, plasma AVP concentrations neither increased nor decreased to undetectable levels with a rise in plasma osmolality. In one patient, plasma AVP levels responded to increasing plasma osmolality when plasma osmolality normalized; in which the threshold and the sensitivity of osmostat were normal. In two other patients, AVP secretion responded to plasma osmolality after the treatment. The changes in AVP secretion were not due to nonosmotic stimuli for AVP release. In conclusion, this study shows that patients with SIAD and central nervous system disorders may have persistent AVP secretion with a loss of hypotonic suppression such as found in patients with adrenal insufficiency or depletional hyponatremia in central nervous system disorders, indicating that careful evaluation is necessary to determine the relationship between persistent AVP secretion and the pathogenesis of hyponatremic disorders.

Aged↗
PubMed1999

Increased expression of EMMPRIN in the tissue around loosened hip prostheses.

Matrix metalloproteinases (MMPs) have been shown to play a role in aseptic loosening of total hip replacement (THR). Extracellular matrix metalloproteinase inducer (EMMPRIN) can upregulate expression of several MMPs but has little effect on their tissue inhibitor (TIMP). Using the avidin-biotin-peroxidase complex immunostaining method, we detected strong immunoreactivity of EMMPRIN in the lining-like layers, sublining area and vascular endothelium of synovial membrane-like interface tissue around loosened prostheses. In contrast, EMMPRIN staining was very weak in the synovial samples from patients with hip arthrosis. Double immunofluorescence labeling revealed EMMPRIN/MMP-1 double-positive cells in lining-like layers and the sublining area of interface tissue. Our findings indicate that EMMPRIN expression is upregulated in interface tissue, and that locally accumulated EMMPRIN may modulate MMP-1 expression. An imbalance in the activity of MMPs and TIMP may lead to tissue destruction and periprosthetic osteolysis. These biological responses, combined with mechanical stress caused by micromotion and oscillating fluid pressure, may eventually cause aseptic loosening of THR.

Adult↗
PubMed1999

Lipid alterations in the liver and serum of rats in histidine-excess and copper deficiency.

To obtain further information on lipid metabolism in the histidine-excess and copper-deficiency, rats were fed basal, histidine-excess (the addition of 50 g L-histidine/kg diet) or copper-deficient diets for 0, 7, 21 and 42 d ad libitum. Liver triacylglycerol accumulated and the serum triacylglycerol level decreased after feeding of the histidine-excess diet for 21 or 42 d, but not after feeding of the copper-deficient diet. Serum cholesterol level increased in rats fed the histidine-excess diet for 7, 21 and 42 d, but not in rats fed the copper-deficient diet. Copper content in the liver and serum significantly decreased in rats fed the histidine-excess diet. Copper content in the liver and serum was markedly decreased in rats fed the copper-deficient diet. Liver zinc content was constant, but the serum zinc level decreased in rats fed the histidine-excess diet. Feeding of the copper-deficient diet hardly affected zinc content in the liver and serum. Urinary copper and zinc increased in rats fed the histidine-excess diet, and decreased or showed a decreasing tendency in rats fed the copper-deficient diet. Overall results indicated that feeding the histidine-excess diet caused copper deficiency, whereas hypercholesterolemia was not shown in rats fed the copper-deficient diet although the livers of rats fed the copper-deficient diet contained less copper than those of rats fed the histidine-excess diet. Thus, the responses on liver triacylglycerol and serum cholesterol to copper deficiency induced by the feeding of a histidine-excess diet are different from those to copper deficiency induced by feeding of a copper-deficient diet.

Animals↗
PubMed1999

Japanese encephalitis vaccine (inactivated, BIKEN) in U.S. soldiers: immunogenicity and safety of vaccine administered in two dosing regimens.

The safety and immunogenicity of Japanese encephalitis (JE) vaccine (Nakayama strain, monovalent / BIKEN) was studied in 538 U.S. soldiers in 1990. Three doses of vaccine from three consecutively manufactured lots were given on days 0, 7, and either 14 or 30. Serum for antibody determination was drawn at months 0, 2, and 6. Japanese encephalitis plaque reduction neutralization tests were performed by three laboratories on each specimen. Five hundred twenty-eight (98%) participants completed the immunization series. All recipients without antibody before immunization developed neutralizing antibody against JE virus. There were no differences in geometric mean titer among the three test lots at months 2 and 6. Soldiers who received the third dose on day 30 had higher titers at both time points. Antibody to yellow fever had no significant effect on immune response to vaccine. Conclusions drawn from analysis of serologic data from the three labs were nearly identical. Symptoms were generally limited to mild local effects and were reduced in frequency with each subsequent does in the series (21% to 11%; P < 0.0001). Generalized symptoms were rare (e.g., fever = 5%) with no reported cases of anaphylaxis.

Adult↗
PubMed1999

[Multifocal electroretinograms in patients with branch retinal artery occlusion].

PURPOSE: We recorded multifocal electroretinograms (m-ERGs) in patients with branch retinal artery occlusion (BRAO) and compared the waveform in the area of retinal artery occlusion with that in the normal area, to evaluate the influence of the damage of the inner retina on the m-ERG. SUBJECTS AND METHODS: Three patients who had normal visual acuity and visual field loss of more than one quadrant due to BRAO were examined. The waveform of first-order and second-order kernel responses of m-ERG in the area of retinal artery occlusion were compared with those of the vertically symmetrical, normally perfused area of the same eye. RESULTS: Prolongation of latency and decrease of amplitude were noted for the first negative wave (N 1), the first positive wave (P1), and the second negative wave (N2) in the first-order kernel responses in the area of retinal artery occlusion in comparison with the normally perfused area. Second-order kernel responses were not detected in the area of retinal artery occlusion. CONCLUSIONS: The damage to the inner retina affected portions N1, P1, and N2 of the first-order kernel responses, and N2 was the most seriously affected. Second-order kernel responses appear to reflect more strongly the function of the inner retina.

Child↗
PubMed1999

[Long-term follow-up study on sequelae of carbon monoxide poisoning; serial investigation 33 years after poisoning].

1. We examined 156 patients 33 years after CO poisoning occurred at the Miike Mikawa Mine, Fukuoka, Japan. The subjects were classified according to age as follows: between 55 and 59 years (n = 14), 60 and 69 years (n = 62), 70 and 79 years (n = 60), and 80 and 87 years (n = 18). The mean age was 69.2 years old. Concerning the duration of coma that occurred soon after the accident, 64 remained comatose from 0 to 6 hours, 46 from 6 to 12 hours and 46 from 12 to 48 hours. 2. Subjective symptoms were observed in 96.8% of the patients. Among them, forgetfulness was noted in 89.7%, followed by irritability in 66.7%, headache in 59.6%, insomnia in 55.8%, limb pain in 46.8%, dull head feeling in 42.9% and dizziness in 36.5%. 3. Intellectual disturbances were observed in 68.6% of the patients, including impression disturbance in 58.3%, memory disturbance in 51.9%, calculation disturbance in 63.5%, thinking disturbance in 61.5% and disorientation in 14.1%. 4. Apathy and disorder of volition and interest which were found in 72.4% were included in personality change because all symptoms persisted for many years. Personality change was classified as follows: weakness of emotion and will (hypobulia) in 54.4%, infantilism in 35.2%, hyperactive, talkactive and lack of inhibition in 18.5%, lack of self-possession and unstable temper in 9.6%, depression in 15.3%, neurosis in 7.6% and schizophrenic state in 2.5%. Among these symptoms of personality change, weakness of emotion and will and infantilism were conspicuous among the patients who remained in a coma for more than 6 hours soon after the accident but showed no relationship with age. 5. Neurological symptoms that were found in 48.7% of the patients were classified as sensory disturbance in 25.6%, peripheral nerve symptoms in 16.0%, pyramidal symptoms in 14.1%, ataxia and cranial nerve symptoms in 7.1%, paroxysmal symptoms in 6.4% and focal symptoms in 4.5%, extrapyramidal symptoms in 21.8% (Parkinsonism in 4.5%, tremor in 10.9% and muscle rigidity in 16.0%) and vegetative symptoms in 37.2%. 6. At the time of investigation, 5 CO poisoning patients were classified as serious cases (3.2%), 20 as comparatively serious (12.8%) medium-degree cases, 28 as comparatively mild (17.9%) medium-degree cases, 37 as comparatively serious (23.7%) mild cases, 42 as comparatively mild (26.9%) mild cases, 24 (15.4%) as having symptoms which were not problematic, and 24 (15.4%) as having symptoms that markedly worsened due to complication. 7. A total of 138 (88.4%) cases had complications were classified as follows: 78 cases (50.0%) of hypertension, 62 cases (39.7%) of cerebral infarction, 24 cases (15.4%) of cardiac disturbance, 21 cases (13.5%) of diabetes mellitus, 14 cases (9.0%) of hepatic disturbance and six cases of silicosis (3.8%). 8. Cranial MRI was carried out for 129 cases (82.7%). Of the abnormal findings identified, cerebral atrophy accounted for 72.0% (93 cases), including moderate and severe cases in 47.2% (61 cases), pallidum lesion for 37.9% (49 cases), lacunar infarction (including cerebral infarction) for 52.7% (68 cases), and hippocampal atrophy for 18.6% (24 cases). Many cases of cerebral atrophy and hippocampal atrophy were observed in patients who remained in the initial coma for more than 12 hours and were 80 years of age or old. The cases of pallidum lesion were observed in patients who remained in the initial coma for more than 6 hours, and no relationship with age was found. The other findings, cerebral atrophy and lacunar infarction showed a slight relationship with age. 9. Among the moderate and serious cases of intellectual disturbance, cerebral atrophy constituted to 62.5%, lacunar infarction 68.7% and pallidum lesion 50.0%. Among the moderate and serious cases of personality change, cerebral atrophy constituted 78.5%, lacunar infarction 35.0% and pallidum lesion 50.0%. Moreover, among extrapyramidal symptoms, pallidum lesion constituted 58.6%, cerebral atrophy 55.1% and lacun

Accidents, Occupational↗
PubMed1999

Studies of host response to orthopedic implants and biomaterials.

The use of implanted biomaterials in orthopedic surgery has increased rapidly during the past two decades. Total joint replacement of the hip or knee joint has become common treatment; at the same time, an increasing number of fractures are treated with osteosynthesis. The original Charnley low-friction arthroplasty of the hip is still widely used and gives in large series excellent results. Aseptic loosening of this arthroplasty has been thought to be due to wear debris of the methylmethacrylate used for fixation of the implants, or to debris generated from wear of the polyethylene socket. To date, many different materials have been tried in order to reduce wear and generation of macrophage irritating submicron sized particles, or to provide more biocompatible components. However, trials to improve the methylmethacrylate cement or to invent better polyethylenes have often failed. Diamond coating of the metallic components seems promising: there is less wear and diamond is very biocompatible in bulk and small particulate form. Biodegradable implants have also been found useful in treating fractures. Bioactive bioabsorbable materials may also make possible a tissue engineering approach and can be used as carriers for selected drugs and cytokines. Because many promising materials and designs have failed in clinical use, extensive theoretical and experimental testing is mandatory before introducing new materials and implants in a clinical setting.

Biocompatible Materials↗