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Biomedical subjects

N Sato

Publications and source records attributed to N Sato.

At least 325 records · Page 18Linked to original sources
PubMed2000

[Substance isolated from the kelp rhizoid identified as L-tryptophan shows high inhibition of breast cancer].

In general, the root of a seaweed is poorly developed as compared with its thallus and is called the rhizoid or holdfast. In Laminaria, belonging to Phaeophyceae, although the thallus is used for food, the rhizoid is considered an unuseful natural resource. We attempted to detect anti-breast cancer substances from that resource. As a result, a substance having a weak absorptivity to aluminium oxide and Sephadex G-25 was found. According to analysis of the FAB-MS spectra and 1H NMR spectra, the substance was identified as tryptophan, an amino acid. Finally, it was concluded by a chiral column-HPLC method that the tryptophan was the L-form.

Antineoplastic Agents↗
PubMed2000

[Preventive effect of chlormadinone acetate on flare-up phenomenon in advanced prostate cancer administered with a luteinizing hormone-releasing hormone analogue].

To investigate whether chlormadinone acetate (CMA) could prevent the flare-up phenomenon induced by a luteinizing hormone-releasing hormone analogue (LH-RHa), we treated 4 cases of stage C and 17 cases of stage D prostate cancer with CMA for 4 weeks and CMA plus monthly injection of LH-RHa for following 24 weeks. Serum LH, testosterone, and prostate-specific antigen (PSA) levels were closely monitored before and 3 days, 1-, 2-, and 4-weeks after LH-RHa injection. Subjective and objective responses were also investigated. Serum LH and testosterone levels significantly elevated 3 days after the initial injection of LH-RHa. However, they resumed 1 week after LH-RHa injection with fluctuation under the normal range. Out of 21 cases, 3 cases (14%) consisting of 2 poorly and 1 moderately differentiated adenocarcinoma showed increased serum PSA levels 1 week after LH-RHa injection in spite of suppressed serum testosterone levels. The objective response of these 2 poorly differentiated cases was progressive disease at 24 weeks. No cases indicated worsening of clinical symptoms concerning flare-up phenomenon. CMA seemed to be capable of preventing flare-up phenomenon in advanced prostate cancer.

Acute-Phase Reaction↗
PubMed2000

[Clinical usefulness of diffusion-weighted magnetic resonance imaging in patients with ischemic cerebrovascular disease].

Diffusion-weighted magnetic resonance imaging was performed to determine the detectability of ischemic changes in patients with ischemic cerebrovascular disease. We retrospectively reviewed 103 patients with symptoms suggestive of ischemic cerebrovascular disease. All patients underwent computed tomography, routine magnetic resonance imaging, and diffusion-weighted imaging. Of 103 patients, 18 were imaged within 3 hours after onset, 57 were imaged between 3 and 24 hours, and 29 were imaged between 24 and 144 hours. Eighty-eight patients were diagnosed as ischemic cerebrovascular disease. Magnetic resonance imaging was performed at a 1.0 Tesla clinical machine using single-shot spin-echo/echo-planar imaging sequence. In each case, three sets of DWI with motion-probing gradient pulses in the x, y, and z directions were taken. The detectability of ischemic changes of each imaging modality was compared. DWI detected ischemic changes in 83 of 88 cases with clinical diagnoses of cerebral ischemia(sensitivity; 94.3%). In contrast, DWI showed negative findings in 15 of the 15 patients with diagnoses other than cerebral ischemia(selectivity; 100.0%). DWI detected ischemic changes in 16 out of 18 patients(88.6%) within 3 hours after the onset. In contrast, T 2-weighted image did not detect any ischemic changes in the same period. These results suggest that DWI is considered to be highly useful for the early diagnosis of cerebral ischemia.

Adolescent↗
PubMed2000

[A case of cardiogenic cerebral embolism with successful recanalization: apparent diffusion coefficient analysis for prediction of reversible cerebral ischemia].

A 54-year-old woman complaining of left hemiplegia was transferred to our hospital. Computed tomography on admission demonstrated normal. Electrocardiogram showed atrial fibrillation. Cerebral blood flow (CBF) was decreased in both the cortex and the perforator territory of the right middle cerebral artery (MCA), whereas the apparent diffusion coefficient (ADC) in the cortex was normal. Digital subtraction angiography (DSA) revealed an occlusion of the right MCA (M 1 proximal) with collateral flow from the right anterior cerebral artery (ACA) to the territory of the right MCA. After intra-arterial injection of tissue-plasminogen activator (t-PA), DSA showed partial recanalization, and the symptoms of the patient improved considerably. Five days after that, the patient deteriorated again and showed disturbance of consciousness and left hemiplegia. In this episode, both CBF and ADC in the cortex of the right MCA were decreased. DSA revealed an occlusion of the right internal carotid artery (ICA) and collateral flow from the right ACA to the territory of the right MCA disappeared. After intra-arterial injection of t-PA, DSA showed partial recanalization with collateral flow from the right ACA, and the symptoms of the patient improved. DSA 5 weeks after onset showed complete recanalization of both the right MCA and the ICA. The patient was diagnosed as both mitral and aortic stenosis and regurgitation (MSR + ASR) and underwent an operation for both mitral and aortic value replacement. She was discharged with no neurological deficit 4 months after onset. ADC analysis is especially useful for the prediction of reversible ischemic damage and the prevention of hemorrhagic transformation and fatal edema in acute ischemic stroke.

Angiography, Digital Subtraction↗
PubMed2000

Acute and chronic effect of alcohol on Ca2+ channels in hepatic stellate cells.

BACKGROUND: Hepatic stellate cells have been reported to play important roles in the regulation of hepatic microcirculation via cell contraction. Increase in intracellular calcium concentration is required to induce cell contraction. We have already reported the existence of L-type voltage-operated Ca2+ channels (VOCC), such as smooth muscle cells. On the other hand, alcohol has been known to disturb hepatic microcirculation. In this study, we evaluated the effect of acute and chronic treatment of alcohol on VOCC in rat hepatic stellate cells. METHODS: Stellate cells isolated from rats were cultured with or without 100 mM ethanol for up to 14 days. VOCC were detected by the patch clamp technique. Cells cultured for 14 days without ethanol were exposed to ethanol to investigate calcium current during membrane depolarization. alpha-Smooth muscle actin (alpha-SMA) was stained by indirect immunofluorescence. RESULTS: In the control model, VOCC were recognized in cells cultured for more than 7 days. Detection of VOCC increased from 9% on day 7 to 55% on day 14. On the other hand, VOCC in cells treated chronically with 100 mM ethanol appeared earlier than in the control and the incidences were significantly higher than those of the control accompanied with an early activation of cells. In contrast, simultaneous exposure to ethanol during the membrane depolarization inhibited Ca2+ current. CONCLUSIONS: The expression of Ca2+ channels in stellate cells were up-regulated by the chronic treatment of alcohol accompanied with the transformation to myofibroblast-like phenotype. However, alcohol itself inhibited Ca2+ current.

Actins↗
PubMed2000

Epithelial-mesenchymal interaction in gastric mucosal restoration.

In this review article we discuss the role of growth factors in gastric ulcer healing using an in vitro wound repair model with gastric epithelial and mesenchymal cells. Several growth factors accelerate gastric epithelial and mesenchymal wound healing in vitro with acceleration of cell migration and proliferation. Epidermal growth factor, transforming growth factor-alpha (TGFalpha), hepatocyte growth factor, and insulin accelerate predominantly gastric epithelial wound healing; and TGFbeta and basic fibroblast growth factor predominantly accelerate gastric mesenchymal wound healing. Platelet-derived growth factor-betabeta and insulin-like growth factor-1 (IGF-1) accelerate both significantly. Among these growth factors, IGF-1 produced from fibroblasts plays a key role in the gastric epithelial-mesenchymal interaction during the process of gastric wound healing.

Animals↗
PubMed2000

Alcohol enhances lipopolysaccharide-induced increases in nitric oxide production by Kupffer cells via mechanisms dependent on endotoxin.

BACKGROUND: Ethanol causes both tolerance and sensitization of Kupffer cells. Accordingly, this study examines the effect of acute ethanol consumption on nitric oxide (NO) production from Kupffer cells with or without lipopolysaccharide (LPS) treatment. METHODS: Rats were given ethanol (4 g/kg body weight) intragastrically, and Kupffer cells were isolated 2 and 24 hr later. Some rats were treated for 4 days with 150 mg/kg/day of polymyxin B and 450 mg/kg/day of neomycin to prevent growth of intestinal bacteria, the primary source of endotoxin in the gastrointestinal tract. After addition of LPS, NO was measured by the Griess reaction. RESULTS: Two hours after ethanol administration, LPS-induced NO production by Kupffer cells was diminished by 50% but was enhanced 2-fold at 24 hr. Sterilization of the gut with antibiotics blocked this enhancement. CONCLUSIONS: Kupffer cells isolated from rats early after ethanol exhibited tolerance to LPS, whereas sensitization was observed later. It is likely that sensitization to Kupffer cell is caused by gut-derived endotoxin.

Animals↗
PubMed2000

[Antimicrobial susceptibility testing for Mycobacterium tuberculosis by the bioluminescence assay of mycobacterial ATP using filamentous cell treatment].

The antimicrobial susceptibility testing for Mycobacterium tuberculosis by the bioluminescence assay of adenosine triphosphate(ATP) derived from living mycobacteria was improved introducing filamentous cell treatment(FCT) reported for beta-lactam susceptibility test of Pseudomonas aeruginosa by Hattori. Before ATP extraction, bacterial cells were treated with the FCT reagent for 30 minutes at room temperature. Adenosine phosphate deaminase in the FCT reagent simultaneously digested the extracted ATP and released ATP in a liquid culture of M. tuberculosis H37Rv and the RLU level was decreased markedly. Using this improved ATP method, we determined the ATP contents of M. tuberculosis inoculated into Middle-brook 7H9 broth medium with or without drugs. In ethambutol(EB) susceptibility, the ATP method reported previously, showed false-resistance when judged within 7 days. To eliminate false-resistance in EB susceptibility we applied the modified ATP method with FCT treatment to strains determined EB susceptible by reference methods. Using this modified ATP method, we could judge EB susceptibility of 5 ATCC reference strains within 3 days, and these of 15 clinical isolates of M. tuberculosis within 5 days. And all the results obtained were coincident between the ATP method and the reference methods. The reproducibility of this modified ATP method was evaluated with six ATCC reference strains at the concentrations of 0.1 microgram/ml of isoniazid(INH), 2.0 micrograms/ml of rifampicin(RFP), 2.5 micrograms/ml of EB, 2.0 micrograms/ml of streptomycin(SM), and 5.0 micrograms/ml of kanamycin(KM). The test was repeated six times. Reduction of ATP contents were observed in susceptible strains but not in resistant ones within 3 days of cultivation and susceptibilities to drugs could be determined within 3 days at every time when combined FCT to the ATP method. And highly reproducible results were obtained. It is strongly suggested that this modified method is simple, rapid, highly reproducible and nonradiometric, and could be used for the assessment of drug susceptibility for M. tuberculosis.

Adenosine Triphosphate↗
PubMed2000

[SIRS in surgical stress].

It has been suggested that SIRS are triggered by superfluous pro-inflammatory cytokine production, and that organ injury is caused by uncontrolled inflammatory responses. However, the results of clinical studies, on the usefulness of specific cytokine antagonists and anti-TNF antibodies for the treatment of septic shock, have been unsatisfactory. The reason for this might have been that when uncontrolled inflammatory reactions progressed locally, anti-inflammatory reactions were elevated in the circulated blood by way of CARS, thus the timing of administration and pharmacokinetics did not match clinical course. Recent research has shown that SIRS is always accompanied by CARS, and since it seems to do the amplitude of SIRS and CARS to each other so that there may be a deep valley, if there is a high mountain. We introduce the recent knowledge which indicates that SIRS is a preliminary alert for not only organ dysfunction but also immunosuppression after severe injury or major surgery.

Cytokines↗
PubMed2000

Aldose reductase mRNA expression is associated with rapid development of diabetic microangiopathy in Japanese Type 2 diabetic (T2DM) patients.

There appears to be an obvious difference in the susceptibility to diabetic microangiopathy among Type 2 diabetic (T2DM) patients. We examined the hypothesis that aldose reductase (AR) messenger ribonucleic acid (mRNA) expression may be enhanced in diabetic patients susceptible to diabetic microangiopathy by measuring AR mRNA expression in the polymorphonuclear leukocytes (PMNs) obtained from T2DM patients. The AR mRNA and beta-actin mRNA expressions were measured by reverse transcription-polymerase chain reaction method. The relative AR mRNA expression to beta-actin mRNA expression significantly increased in the PMNs of T2DM patients, compared to normal healthy controls. The relative AR mRNA expression tended to increase with an increase of glycosylated haemoglobin A1c (HbA1c) levels. The patients who showed both progressive diabetic retinopathy and diabetic neuropathy within 10 years after the diagnosis of T2DM (Group I) showed significantly 1.6 times higher AR mRNA expressions than those who have not shown both complications over 10 years after diagnosis (Group II), in spite of no obvious difference in glycaemic control between both groups. The present data indicate that the AR mRNA expression increased in the PMNs of T2DM patients and there is an obvious difference in the PMNs AR mRNA expression between T2DM patients susceptible and relatively resistant to the development of diabetic microangiopathy.

Aged↗
PubMed2000

[Activities of antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. Levofloxacin--Surveillance Group].

The surveillance study was conducted to determine the antimicrobial activity of fluoroquinolones (ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin) and other 20 antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. The resistance to fluoroquinolones was remarkable in Enterococci, methicillin-resistant staphylococci and Pseudomonas aeruginosa from UTI. However, many of the common pathogens such as Streptococcus pneumoniae including penicillin-resistant isolates, methicillin-susceptible Stahylococcus aureus, Moraxella catarrhalis, the family of Enterobacteriaceae, Haemophilus influenzae including ampicillin-resistant isolates have been kept to be susceptible to fluoroquinolones. About 90% of P. aeruginosa isolates from RTI were susceptible to fluoroquinolones. In conclusion, the results from this surveillance study suggest that fluoroquinolones are useful in the treatment of various bacterial infections including respiratory infections.

Anti-Infective Agents↗
PubMed2000

[Effect of radiofrequency catheter ablation on autonomic tone in patients with common atrial flutter: difference depending on the site of ablation].

OBJECTIVES: Radiofrequency catheter ablation (RFCA) of the inferior vena cava-tricuspid annulus isthmus has become an effective procedure for radical treatment of common atrial flutter. This site is close to the right atrial posteroseptal region, so vagal denervation after slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia can also occur after the procedure. To confirm this hypothesis, we tested whether autonomic disturbance can occur after RFCA in 16 patients with common atrial flutter. METHODS: Parameters of the autonomic function were measured using several components of the time domain analyses and power spectra of heart rate variability calculated from Holter recordings and the baroreflex sensitivity. Patients were divided into 2 groups based on the location of the ablated area: the isthmus group (9 patients) with the ablated area of the exact isthmus, and the posteroseptal group (7 patients) with the ablated area slightly shifted toward the right atrial posteroseptal position. All values after RFCA were compared with those before RFCA, and the ratio (after/before) was compared between the groups. The correlation between the ratio and cumulative delivered energy was also studied for each parameter. RESULTS: After RFCA, the heart rate increased, and the SD, rMSSD and pNN50 decreased significantly in the posteroseptal group, whereas no significant changes occurred in the isthmus group. The high frequency of the power spectra decreased after RFCA only in the posteroseptal group, and the ratio was significantly smaller in the posteroseptal group compared to the isthmus group. A significant reverse correlation between the ratio of the high frequency and cumulative energy was observed only in the posteroseptal group. The baroreflex sensitivity tended to be diminished after RFCA only in the posteroseptal group. CONCLUSIONS: Vagal denervation can occur after RFCA of common atrial flutter when the ablation site is shifted toward the right atrial posteroseptal region.

Atrial Flutter↗
PubMed2000

Enhanced mRNA expression of Th1 cytokines and IL-12 in active pulmonary sarcoidosis.

BACKGROUND AND AIM OF THE WORK: Active sarcoidosis is considered to be a Th1 dominant condition. We examined whether Th1 cytokines are highly expressed at inflammed lesions of Japanese patients with sarcoidosis. METHODS: To investigate the mRNA expression of Th1 cytokines and IL-12 in sarcoid BAL cells, we used semiquantitative reverse transcription--polymerase chain reaction method. RESULTS: The mRNA expressions of Th1 cytokines (IFN-gamma and IL-2) in active sarcoid BAL cells were significantly elevated as compared with those in healthy volunteers. The proportion of positive IL-4 mRNA expression in sarcoid BAL cells was not significantly higher than that in healthy volunteers. Further, there was no significant difference in IFN-gamma mRNA levels between the groups positive and negative for IL-4 mRNA expression. Although the proportion of positive expression of IL-12 mRNA in active sarcoid BAL cells was not significantly higher than that in healthy volunteers, the group positive for IL-12 mRNA expression had significantly elevated levels of IFN-gamma mRNA than did the negative group. CONCLUSIONS: These results may indicate that IL-12 induces IFN-gamma expression and subsequent Th1 dominant condition in Japanese patients with sarcoidosis.

Adult↗
PubMed2000

[Diffuse Lewy body disease searched out from 114 patients with parkinsonism].

From 114 patients who had been previously diagnosed as Parkinson's disease, we diagnosed six cases as clinically definite "diffuse Lewy body disease (DLBD)" according to McKeith's criteria with more strict modifications. Besides a central feature, dementia, and core features including parkinsonism, fluctuating cognition, and recurrent visual hallucinations, the patients presented some of supportive features, that is, repeated falls (4 cases), syncope (5 cases), and transient loss of consciousness (all cases). Autopsy, which was performed in 2 of the cases, revealed Lewy bodies in various nervous tissues including autonomic nervous systems in both cases. 7 cases of probable DLBD and 8 cases of possible DLBD, which lacked fluctuating cognition and/or visual hallucinations, demonstrated neither of repeated falls, syncope, nor transient loss of consciousness. Episodes of these supportive features, which seem to be associated with autonomic dysfunctions and/or fluctuating cognition, should be important in the differential diagnosis of DLBD.

Adult↗
PubMed2000

[CD8-positive diffuse large B-cell lymphoma].

In May, 1998, a 63-year-old woman was admitted for treatment of relapsed malignant lymphoma. In March 1997, a diagnosis of diffuse large B-cell lymphoma(DLBL), clinical stage IIISE A, was made from a biopsy specimen of the tumor in the left buccal mucosa. Six cycles of CHOP regimen were given, and complete remission was achieved. However, relapse of the lymphoma was suspected, and the patient was transferred to our hospital. On admission, a right tosillar mass, 8 mm in diameter, was found, and a biopsy showed DLBL. The immunophenotype of the lymphoma cells was CD3- CD4- CD5- CD8+ CD10- CD19+ CD20+ CD23- CD25+ IgL (lambda)+, and dual staining confirmed that the cells were CD8+ and CD19+. The patient was an HTLV-1 carrier, but monoclonal integration of HTLV-1 proviral DNA into the lymphoma cells was not detected. She was diagnosed as having CD8+ DLBL, clinical stage IA. Because she responded to salvage chemotherapy, autologous peripheral blood stem cell transplantation was performed and complete remission was obtained. To our knowledge, this is the first report of CD8+ DLBL.

CD8 Antigens↗
PubMed2000

[Two cases of the epidermoid on the petrous bone].

Epidermoids known as cholesteatomas, are congenital benign tumors and originate in the embryonic ectoderm. They account for 1.3% of all intracranial tumors. They are often found in the cerebellopontine angle and the paraseller region, but rarely in the petrous portion of the temporal bone. Epidermoids of the petrous bone tend to slowly present progressive facial palsy and hearing disturbance. In this article, two cases of epidermoids involving the petrous bone are reported. A 55-year-old male presented left facial palsy, left hearing disturbance and decreased gustation in the left side of the tongue. MRI revealed a non-enhanced mass on the petrous portion of the left temporal bone, and bone-window CT showed bone destruction in the same region (Case 1). A 71-year-old female was aware of left facial palsy and left hearing loss for 15 years. MRI showed a non-enhanced mass on the petrous bone, and bone-window CT demonstrated extensive bone erosion of the petrous bone and the middle cranial fossa (Case 2). In both cases, total removal was performed via the middle cranial fossa approach. Both tumors existed extradurally and had pressed against the genicurate ganglion of the facial nerve. The facial palsy of the former case recovered 12 months after surgery. We discuss the problems of diagnosis and treatment of epidermoids of the petrous bone.

Aged↗