Biomedical subjects

T Nakano

Publications and source records attributed to T Nakano.

At least 271 records · Page 15Linked to original sources

PubMed2000

Changes of hemostatic molecular markers after gynecological surgery.

The authors evaluated the hemostatic abnormalities occurring in the postoperative period of eight patients with malignant tumors and compared them with those occurring in the postoperative period of eight patients with benign tumors. Two of the patients with malignant tumor presented pulmonary embolism after operation. Plasma fibrinogen and fibrin degradation product levels in patients with malignant tumors were already high before operation and further increased significantly after operation. The plasma levels of D-dimer, thrombin-antithrombin complex, and free-tissue factor pathway inhibitor were increased in both groups after operation, but they were higher in patients with malignant tumors than in patients with benign tumors. The plasma levels of protein C and antithrombin were significantly decreased in both groups after operation. but they were significantly lower in patients with malignant tumors than in those with benign tumors. The decreased activity of protein C or antithrombin may be not only a risk factor of thrombotic disease, such as pulmonary embolism, but also the cause of thrombosis. In patients with malignant tumors, the operation time was significantly longer than that in patients with benign tumors. This long operative period might cause vascular endothelial cell injury which is reflected by the plasma levels of free-tissue factor pathway inhibitor, antithrombin, and protein C.

Adult↗

PubMed2000

Immunocytochemical localization of bovine serum albumin (BSA) in the liver and testis of rats injected with testosterone-BSA, hydrocortisone-BSA or corticosterone-BSA.

Through observations of colloidal gold with silver enhancement, we have demonstrated that 2-nm colloidal gold labeled-testosterone-bovine serum albumin (BSA) conjugate or hydrocortisone-BSA conjugate injected intravenously enters the hormone-target cell nuclei of rats (Nishimura and Ichihara, 1997; Nishimura and Nakano, 1997, 1999). To confirm immunocytochemically whether the nature of BSA in the steroid hormone-BSA conjugates (steroid-BSAs) remains intact in the hormone-target cell nuclei, testosterone-BSA, hydrocortisone-BSA or corticosterone-BSA was injected into the vascular system of rats, then the liver and testes of rats killed 2 h postinjection were reacted with FITC-conjugated anti-BSA antibody, and examined under fluorescence microscopy and confocal laser scanning microscopy. In the liver of rat injected with testosterone-BSA, the fluorescence was observed in the nuclei of endothelial cells, but not in the nuclei of hepatocytes, hepatic stellate cells and Kupffer cells. In the liver of rat injected with hydrocortisone-BSA, intense fluorescence was seen in the nuclei of hepatic stellate cells, but did not seem to be present in the nuclei of the other three kinds of cells. In the liver of rat injected with corticosterone-BSA, the fluorescence seemed to be in a few nuclei of hepatic stellate cells, and appeared as speckles in a few nuclei of the hepatocytes and Kupffer cells. In some seminiferous tubules of rat injected with testosterone-BSA, fluorescence was observed in the nuclei of spermatocytes and spermatids. These results suggest that BSA conjugated with steroid hormone can enter the hormone-target cell nuclei with its antigenicity kept intact, and that the fate of steroid-BSAs is decided at the cell membrane level.

Animals↗

PubMed2000

Shortening of conduction time over arborized atrioventricular accessory pathway with Mahaim fibers physiology just before interruption during radiofrequency ablation.

A 21-year-old woman had paroxysmal wide QRS tachycardia with a left bundle branch block configuration and a retrograde conducted P wave just behind the QRS complex. An electrophysiological study revealed antidromic atrioventricular tachycardia involving an atrioventricular connection with decremental conduction as the anterograde limb and normal atrioventricular node as the retrograde limb. During constant pacing from the high right atrium (HRA) at the cycle length (CL) of 600 ms, the QRS configurations were not identical to those during the wide QRS tachycardia or constant pacing at the CL of less than 500 ms. The process by which this arborized atrioventricular accessory pathway with the Mahaim fibers physiology was interrupted by radiofrequency catheter ablation is described. Radiofrequency energy was delivered to the site recording a Mahaim potential at the tricuspid annulus during constant pacing from the HRA at the CL of 429 ms. The stimulus-QRS interval gradually shortened as it reached the power plateau without changing the preexcited QRS configuration. Shortening of the conduction time over the Mahiam pathway might have resulted in changing of the propagation from a slow to fast conduction zone or acceleration in response to thermal effect in a node-like structure on the atrial insertion site.

Adult↗

PubMed2000

Acute myocardial infarction in a patient with anomalous left coronary artery origin and primary antiphospholipid syndrome.

Anomalous left main coronary artery (LMCA) originating from the right coronary sinus and running between the aorta and pulmonary trunk is a rare congenital condition. Although this disease is known to be associated with myocardial infarction and sudden death, the precise mechanism is uncertain. A 14-year-old male with this anomaly developed myocardial infarction during exercise complicated by primary antiphospholipid syndrome. He was admitted to hospital with persistent chest pain and sudden cardiac collapse that occurred while he was running. Cardiac catheterization demonstrated a narrowed segment in the LMCA and impaired blood flow, prompting a diagnosis of extensive anterior myocardial infarction. Emergency bypass surgery was performed using a single saphenous vein graft to the left anterior descending artery. Postoperative angiography showed the presence of an anomalous LMCA arising from the right sinus of Valsalva and running between the great vessels. The aortic samples were pathologically normal. He was discovered to also have primary antiphospholipid syndrome and was discharged without symptoms after warfarin therapy. Complicated primary antiphospholipid syndrome may trigger myocardial infarction in asymptomatic patients with this type of coronary anomaly.

Acute Disease↗

PubMed2000

Aorto-coronary dissection during angioplasty in a patient with myxedema.

A 67-year-old man with overt hypothyroidism and medically controlled hypertension was admitted for coronary angiography because of exertional angina. His triiodothyronine (T3) and thyroxine (T4) levels had been low for 4 years. Although signs and symptoms of hypothyroidism were apparent, his hypercholesterolemia was mild. Coronary angiography revealed an eccentric stenosis in the distal portion of the right coronary artery and it was decided to perform angioplasty because his angina had continued in spite of medication. The dissection appeared at the lesion site after the first nominal inflation, and a subsequent image disclosed a spiral dissection from the dilated site to the aortic sinus and peripheral coronary artery. Although emergency stenting could not prevent the extension near the origin of the brachiocephalic artery, the false lumen thrombosed and then diminished with conservative therapy. Aorto-coronary dissection is potentially life-threatening and has been recently reported as a complication during cardiac catheterization procedures. Chronic hypothyroid insufficiency may be one of the risk factors for this complication.

Aged↗

PubMed2000

The pathway of dephosphorylation of myo-inositol hexakisphosphate by phytases from wheat bran of Triticum aestivum L. cv. Nourin #61.

Phytases are the primary enzymes responsible for the hydrolysis of phytic acid, myo-inositol-1, 2, 3, 4, 5, 6-hexakisphosphate (InsP6). The pathway of hydrolysis of InsP6 by phytase from wheat bran of Triticum aestivum L. cv. Nourin #61 is proved in this study. Structures of the intermediates were established by a variety of nuclear magnetic resonance techniques (1H-, two-dimensional 1H-1H coupling-correlation spectra and two-dimensional 31P-1H correlation spectra), gas chromatography, and bioassay. On the basis of the structures identified, initial hydrolysis of the phosphate ester occurs at the D/L-4 position of InsP6 to yield D/L-Ins (1, 2, 3, 5, 6) P5. After the dephosphorylation, the pathway of dephosphorylation is divided into two routes. The main route proceeds via D/L-Ins (1, 2, 5, 6) P4, D/L-Ins (1, 2, 6) P3 and D/L-Ins (1, 2) P2, while the minor route proceeds via D/L-Ins (1, 2, 3, 6) P4, Ins (1, 2, 3) P3 and D/L-Ins (1, 2) P2. D/L-Ins (1, 2) P2 is hydrolyzed at the D/L-1 or 2-position, and finally myo-inositol is produced.

6-Phytase↗

PubMed2000

In vitro proliferation potential of AC133 positive cells in peripheral blood.

AC133 antigen is a novel marker for human hematopoietic stem/progenitor cells. In this study, we examined the expression and proliferation potential of AC133(+) cells obtained from steady-state peripheral blood (PB). The proportion of AC133(+) cells in the CD34(+) subpopulation of steady-state PB was significantly lower than that of cord blood (CB), although that of cytokine-mobilized PB was higher than that of CB. The proliferation potential of AC133(+)CD34(+) and AC133(-)CD34(+) cells was examined by colony-forming analysis and analysis of long-term culture-initiating cells (LTC-IC). Although the total number of colony-forming cells was essentially the same in the AC133(+)CD34(+) fraction as in the AC133(-)CD34(+) fraction, the proportion of LTC-IC was much higher in the AC133(+)CD34(+) fraction. Virtually no LTC-IC were detected in the AC133(-)CD34(+) fraction. In addition, the features of the colonies grown from these two fractions were quite different. Approximately 70% of the colonies derived from the AC133(+)CD34(+) fraction were granulocyte-macrophage colonies, whereas more than 90% of the colonies derived from the AC133(-)CD34(+) fraction were erythroid colonies. Furthermore, an ex vivo expansion study observed expansion of colony-forming cells only in the AC133(+)CD34(+) population, and not in the AC133(-)CD34(+) population. These findings suggest that to isolate primitive hematopoietic cells from steady-state PB, selection by AC133 expression is better than selection by CD34 expression.

AC133 Antigen↗

PubMed2000

Predictive value of remnant-like particle cholesterol as an indicator of coronary artery stenosis in patients with normal serum triglyceride levels.

OBJECTIVE: We designed the present study to evaluate the association of various lipid and fibrinolytic components with coronary artery stenosis with respect to the triglyceride (TG) level. METHODS: Levels of TG, remnant-like particle cholesterol (RLP-C), total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), lipoprotein-(a), uric acid, blood glucose, tissue plasminogen activator (t-PA), t-PA inhibitor type 1, antithrombin III, and protein C were measured in 208 patients who underwent diagnostic coronary angiograms. PATIENTS: Of these 208 patients, 59 were hypertriglyceridemic (150 mg/dl or higher) and 149 were normotriglyceridemic. RESULTS: Both LDL-C and HDL-C showed significant differences between patients with and those without coronary artery stenosis in both hypertriglyceridemic and normotriglyceridemic patient subgroups. However, RLP-C showed a significant difference in the normotriglyceridemic patient subgroup (p=0.012) but not in the hypertriglyceridemic patient subgroup (p=0.736). CONCLUSION: Our current retrospective study disclosed that RLP-C levels are closely associated with coronary artery stenosis in patients with normal TG levels.

Aged↗

PubMed2000

Long-term results of inferior vena cava filters: experiences in a Japanese population.

OBJECTIVE: In this prospective, non-controlled observational study, we evaluated the middle- to long-term results of placement of inferior vena cava (IVC) filter devices in Japanese patients. METHODS AND RESULTS: In 42 Japanese patients with deep vein thrombosis (DVT) or pulmonary thromboembolism (PTE) who underwent percutaneous insertion of IVC filters, follow-up examinations at fixed intervals of 2 years were performed, and the data was evaluated including complications. There were no fatal complications during IVC filter implantation. About 5% of patients with an inserted IVC filter developed symptomatic PTE, another 5% developed asymptomatic PTE. The trapped thrombus was demonstrated in about 22% of the inserted IVC filters. Lower rates of PTE development, occlusion of IVC, and captured thrombus were found in the cases where concurrent use of anticoagulation therapy with filters was used. Trapped thrombi were found in half of IVC filters inserted prophylactically for proximal femoral venous thrombosis. CONCLUSION: These experiences with IVC filters suggest that they are safe and effective for the prevention of PTE in the Japanese population.

Adult↗

PubMed2000

Postischemic reperfusion in the eyes of young and aged rats.

The hemodynamic changes during postischemic reperfusion were investigated in the eyes of young (4 months) and aged (more than 18 months) rats using laser Doppler flowmetry, and histological changes in the retina were examined 6 h after the cessation of ischemia. During exposure to 80 mmHg of intraocular pressure, choroidal blood flow (ChBF) decreased to 40-50% of the baseline value. Marked hyperperfusion (186 +/- 9%) was observed 1 min after cessation of 30-min ischemia in young rats. The hyperperfusion was less (111 +/- 3%) after 120-min ischemia. Delayed hypoperfusion was not observed during 6 h of reperfusion after 120-min ischemia. In aged rats, the hyperperfusion after 30-min ischemia was less (130 +/- 17%) than that in young rats, and the ChBF decreased to 80% of the baseline value during 6 h of reperfusion after 120-min ischemia. Histological examination of the retina showed that exposure to 120-min ischemia caused microvacuolation in the inner and outer plexiform layers and vacuolar changes in the cytoplasms in the inner nuclear layer of both young and aged rats, suggesting edema formation in the retina. The thickness of the outer layers of the retina tended to increase after 120-min ischemia in young rats, whereas it decreased significantly in aged rats. These results suggest that 120-min ischemia with 40-50% of normal choroidal blood flow causes more severe damage than 30-min ischemia, and that the hemodynamic changes during reperfusion in aged rats are different from those in young rats.

Aging↗

PubMed2000

Dissecting aneurysm of the anterior cerebral artery requiring surgical treatment--case report.

A 45-year-old male presented with spontaneous dissecting aneurysm in the anterior cerebral artery manifesting as headache persisting for several days and speech disturbance. Neurological and laboratory examinations showed no abnormalities. Magnetic resonance imaging revealed infarction in the right cingulate gyrus. Angiography revealed occlusion of the right A2. Repeat angiography 8 months later showed a saccular aneurysm had developed. The interhemispheric approach exposed the aneurysm at the junction between the right frontopolar artery and the pericallosal artery. The aneurysm was fusiform due to the right A2 dissection. The aneurysm was trapped and resected. One month after the operation, the patient was discharged without neurological deficits. Cases of dissecting aneurysms in the anterior cerebral artery with ischemic onset are usually treated conservatively. Cases requiring surgery include those due to trauma, growing aneurysms, giant aneurysms, and uncontrolled hypertension. Some dissecting aneurysms of the distal anterior cerebral artery require only resection without bypass surgery.

Aortic Dissection↗

PubMed2000

Immunohistochemical demonstration of inducible nitric oxide and nuclear factor-kappa B with reference to age-related changes in the mouse spiral and vestibular ganglion.

The morphology and immunohistochemistry of inducible nitric oxide synthase (iNOS) and nuclear factor-kappa B (NF-kappa B) were studied on the spiral and vestibular ganglion of young and old ddy mice. The significant decrease in the number of the spiral ganglion cells and a significant expression of iNOS and NF-kappa B were observed in old mice. In contrast, in the vestibular ganglion of all animals examined, decrease in the number of the ganglion cells or expression of iNOS and NF-kappa B were not observed. Although the relevance of enzymatic systems for the protection of vestibular ganglion cells in old individuals from harmful oxidative stress increased with aging should be further clarified, lack of harmful stress due to nitric oxide (NO) may be one of the plausible reasons for that the vestibular ganglion cells were not decreased in number with aging, since iNOS was not detected in the vestibular ganglion cells in the animals tested in the present study.

Aging↗

PubMed2000

Lack of integrated TT virus (TTV) genomes in cellular DNA in infected human hematopoietic cells.

TT virus (TTV) isolated from the serum of a patient with posttransfusion hepatitis has been characterized as a member of the Circoviridae, a family of small DNA viruses with single-stranded circular genomes. TTV appeared to infect not only the serum and liver, but also the peripheral blood mononuclear cells (PBMC). We investigated the prevalence of TTV DNA in human hematopoietic cells, based on 84 mononuclear cell samples obtained from the bone marrow or lymph nodes of patients with hematopoietic malignancies including leukemia, malignant lymphoma and aplastic anemia. Forty-nine (58.3%) out of the 84 samples were positive for TTV DNA with polymerase chain reaction analysis, which was almost similar to the frequency found in the patients' serum. Southern blot analyses using a 3.2-kb fragment derived from the TTV DNA, however, showed no evidence supporting the fact that the TTV genomes are integrated into the human hematopoietic cell genomes, thus suggesting their existence as episomal forms.

Blotting, Southern↗

PubMed2000

Effect of segmental transcatheter arterial chemoembolization on branched chain amino acids and tyrosine ratio in patients with hepatocellular carcinoma.

The effect of segmental transcatheter arterial chemoembolization (TAE) on serum amino acid levels and liver function were studied in 23 patients with HCC associated with hepatitis virus C (22 patients) or alcoholism (1 patient), with compensated liver cirrhosis (Child A 18 patients, Child B 5 patients). Serum levels of branched-chain amino acids (BCAA), tyrosine, branched-chain amino acids to tyrosine ratio (BTR), ammonia, total bilirubin and albumin, and prothrombin times were measured before and after TAE (24 h, 7 and 14 days). The BTR was increased significantly 24 h after TAE (p<0.001) and gradually decreased to pre-TAE levels. Serum tyrosine levels decreased at 24 h after TAE (p<0.005) and later increased. Serum BCAA levels increased slightly at 7days after TAE and were decreased at 14 days after TAE. This results indicated that the increased BTR was due primarily to the decreased tyrosine level at 24 h after TAE. Serum ammonia levels gradually decreased after TAE and the prothrombin time and serum levels of total bilirubin and albumin were not significantly changed. In this study, segmental TAE had little influence on liver function, and the BTR unexpectedly increased at 24 h after TAE. These results suggest that segmental TAE has minimal side effects and may have a beneficial effect on amino acid metabolism.

Adult↗

PubMed2000

[Second reconstructions after failure of free-tissue transfer in the head and neck region].

A retrospective study was performed on 74 patients seen in our hospital between 1990 and 1999 who underwent head and neck reconstructive surgery involving a free flap. Reconstructive surgery was unsuccessful in 5 cases (6.8%). A pedicled myocutaneus flap was used in two cases for the second reconstruction attempt, while a second free flap (jejunum) was used in two other patients. In these cases, a bilateral neck dissection was performed prior to the second free flap reconstruction and neck infection was found. The head and neck artery and vein were unsuitable as recipient vessels in the second operation. Instead, the cephalic vein was used as a source of vein grafts and as a recipient vein.

Adult↗

PubMed2000

Adxanthromycins A and B, new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule from Streptomyces sp. NA-148. I. Taxonomy, production, isolation and biological activities.

Two new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule, adxanthromycins A and B were isolated from the cultured broth of a streptomycete strain. The strain was identified as Streptomyces sp. NA-148 from its morphological and physiological characteristics. Adxanthromycins A and B inhibited the formation of the JY cell aggregates from 1.5 microg/ml, respectively, in a dose dependent manner. Components A and B also inhibited a human T cell leukemia cell line SKW-3 adhesion to soluble ICAM-1 in a dose-dependent manner with an IC50 of 18.8 microg/ml and 25.0 microg/ml, respectively.

Anti-Bacterial Agents↗

PubMed2000

Adxanthromycins A and B, new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule from Streptomyces sp. NA-148. II. Physico-chemical properties and structure elucidation.

Adxanthromycins A and B are new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule isolated from the fermentation broth of Streptomyces sp. NA-148. The molecular formula of adxanthromycins A and B were determined as C42H40O17 and C48H50O22, respectively by FAB-MS and NMR spectral analyses, and the structures of both compounds were elucidated to be a dimeric anthrone peroxide skeleton containing alpha-D-galactose by various NMR spectral analyses and chemical degradation.

Anti-Bacterial Agents↗

PubMed2000

[Cardiovascular effects of the thiazolidinedione troglitazone].

Troglitazone, a newly introduced insulin sensitizer, has been implicated in prevention and treatment of atherosclerotic cardiovascular disease especially associated with type 2 diabetes mellitus and insulin resistance. Beneficial effects of troglitazone on multiple risk factor syndrome have been reported in terms of blood pressure lowering effect and ameliorations of dyslipidemia and hyperinsulinemia. Moreover, in vitro and in vivo studies have shown vasodilating and antiatherogenic effects as well as cardioprotective action of this compound. Thus, troglitazone may have potential to prevent and delay diabetic heart disease and large vessel complications.

Animals↗