Biomedical subjects

K Satoh

Publications and source records attributed to K Satoh.

At least 145 records · Page 8Linked to original sources

PubMed2001

Simvastatin and atorvastatin enhance hypotensive effect of diltiazem in rats.

Effects of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, simvastatin and atorvastatin, on diltiazem-induced hypotension were examined in anaesthetized rats and compared to that of pravastatin. Vehicle, 2 mg/kg/day simvastatin, 2 mg/kg/day atorvastatin, or 4 mg/kg/day pravastatin was administered orally for 4 days. Diltiazem at 3 mg/kg was given orally 2 hours after the final administration of the inhibitors. Arterial blood pressure was measured via a cannula introduced into the left carotid artery, and heart rate was counted from the pulse pressure. In all groups, diltiazem significantly decreased the mean arterial blood pressure without any changes in heart rate. Pretreatment with simvastatin and atorvastatin significantly enhanced the hypotensive effect of diltiazem, while that with pravastatin did not. Heart rate was not modified by pretreatment with the inhibitors. The results indicate that concomitant use of diltiazem with simvastatin or atorvastatin enhances diltiazem-induced hypotension, probably by competitive inhibition of diltiazem metabolism with simvastatin and atorvastatin metabolisms.

Animals↗

PubMed2001

Mechanism of atropine-resistant contraction induced by Dai-kenchu-to in guinea pig ileum.

To clarify the contractile mechanism of Dai-kenchu-to, the effects of hydroxy beta-sanshool (an ingredient of Zanthoxylum fruit), Zanthoxylum fruit (a constituent herb of Dai-kenchu-to) and Dai-kenchu-to were studied in mucosa-free longitudinal muscle of guinea pig ileum. Hydroxy beta-sanshool at 10(-7)-10(-5) g/ml induced dose-related contractions accompanied by autonomous contraction and produced an initial contraction at a concentration of 10(-4) g/ml or more. The contraction induced by hydroxy beta-sanshool (10(-5) g/ml) was significantly inhibited by tetrodotoxin or the capsaicin-receptor antagonist capsazepine. Although atropine or the substance P antagonist spantide tended to inhibit the contraction, a combination of atropine and spantide almost abolished the contraction by hydroxy beta-sanshool. The P2-purinoceptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid did not affect hydroxy beta-sanshool-induced contraction in the presence or absence of spantide. The tonic contractions by Zanthoxylum fruit (2 x 10(-4) g/ml) and Dai-kenchu-to (10(-3) g/ml) were significantly inhibited or tended to be inhibited by atropine, spantide, tetrodotoxin or capsazepine and were remarkably suppressed by the combination of atropine and spantide. These results suggested that acetylcholine release from intrinsic cholinergic nerves and tachykinins from sensory neurons are involved in the contractions induced by hydroxy beta-sanshool and that tachykinins may be involved in the atropine-resistant contraction by Dai-kenchu-to.

Animals↗

PubMed2001

CT assessment of subtypes of pulmonary emphysema in smokers.

OBJECTIVE: To determine the incidence of subtypes of pulmonary emphysema (PE) identified by CT imaging in male patients who have a significant smoking history. PATIENTS AND SETTING: We reviewed 945 subjects (619 men and 326 women) who had undergone CT scanning. However, only the data for male subjects were analyzed due to there being too few female subjects. The male subjects were divided into the following two age groups: group A (age, </= 50 years) and group B (> 50 years). There were two subtypes of PE found: centrilobular emphysema (CLE) and paraseptal emphysema (PSE). Based on these subtypes, PE was divided into the following three categories: I (CLE or CLE-predominant); II (CLE and PSE of equal extent); and III (PSE or PSE-predominant). RESULTS: PE was found in 270 of 516 male smokers (10 of 38 female smokers had PE). Among male subjects, in age group A there were 53 subjects with some degree of PE (category I, 12 subjects [22.6%]; category II, 7 subjects [13.2%]; and category III, 34 subjects [64.2%]). Among men in age group B, there were 217 subjects with some degree of PE (category I, 109 subjects [50.2%]; category II, 23 subjects [10.6%]; and category III, 85 subjects [39.2%]). CONCLUSION: In age group A, men < 50 years of age who were in category III (PSE or PSE-predominant PE) predominated (34 of 53 subjects; 64.2%). In age group B, men > 50 years of age who were in category I (CLE or CLE-predominant PE) predominated (109 of 217 subjects; 50.2%).

Adult↗

PubMed2001

Amebiasis in Japanese homosexual men with human immunodeficiency virus infection.

We report cases of amebiasis in 6 human immunodeficiency virus (HIV)-positive male patients. Five were confirmed homosexuals while one was suspected. Three patients had liver abscess and 5 had colitis with duration of 10 days to months. The patients with liver abscess showed a lower incidence of abdominal pain but a higher incidence of concomitant diarrhea. Drainage therapy was effective for rapid afebrile results. Two invasive colitis cases died from perforation. This may have been due to delayed diagnosis. Invasive amebiasis is not common even in HIV-infected individuals. Among Japanese homosexual men, however, it may cause symptomatic diseases.

AIDS-Related Opportunistic Infections↗

PubMed2001

Anterior ischemic optic neuropathy after combined ophthalmic artery embolization and craniofacial surgery--case report.

A 57-year-old man developed visual loss following craniofacial surgery for an inflammatory ethmoidal sinus mass. Surgery was preceded by endovascular occlusion of the ophthalmic artery distal to central retinal artery (CRA). Routine angiography obtained immediately after endovascular ophthalmic artery occlusion showed patency of the CRA. He complained of visual loss one day after craniofacial surgery (2 days after embolization). Repeat emergency angiography confirmed the patent CRA. Ophthalmic examination and fluorescein angiography showed that the visual loss was due to anterior ischemic optic neuropathy (AION). Preservation of the CRA is critical during ophthalmic artery embolization to avoid visual complications. Neurosurgeons should be aware of the possibility of AION as a complication of ophthalmic artery embolization.

Embolization, Therapeutic↗

PubMed2001

Cerebellar hemorrhage caused by dural arteriovenous fistula: a review of five cases.

OBJECT: In this study the authors performed a retrospective analysis of five cases in which the patients (three women and two men) were treated for intracranial dural arteriovenous fistulas (AVFs) associated with cerebellar hemorrhage. On the basis of their findings, the authors evaluated the characteristics of this unusual symptom. METHODS: The dural AVFs were located in the right cavernous sinus in one patient, the left transverse-sigmoid sinus in three patients, and the right superior petrosal sinus (SPS) in one patient. All patients presented with severe headache and/or loss of consciousness. Computerized tomography scans revealed a small cerebellar hemorrhage near the fourth ventricle and hydrocephalus in four cases, and a massive hemispheric cerebellar hemorrhage in the remaining case. The four patients with small hemorrhages underwent ventriculostomy and endovascular treatment; all recovered. The patient suffering from a massive hemorrhage because of a dural AVF in the SPS was treated by suboccipital craniectomy, hematoma evacuation, and removal of the vascular anomaly. This patient remains in a persistent vegetative state. In four cases, results of angiography demonstrated retrograde leptomeningeal venous drainage through the SPS to the anastomotic lateral mesencephalic vein (ALMV) and/or to the vein of the lateral recess of the fourth ventricle (VLR4V). Retrograde leptomeningeal venous drainage to the ALMV and/or VLR4V was responsible for cerebellar hemorrhage in these cases. CONCLUSIONS: Thus, it is important to consider dural AVF in cases in which there is even a small hemorrhage near the fourth ventricle accompanied by intraventricular perforation and a decreased level of consciousness.

Aged↗

PubMed2001

Hyperperfusion phenomenon after percutaneous transluminal angioplasty for atherosclerotic stenosis of the intracranial vertebral artery. Case report.

The authors report on a patient who underwent percutaneous transluminal angioplasty (PTA) for stenosis of the intracranial vertebral artery (VA). This 67-year-old man's dizziness while walking was caused by infarction of the left cerebellar peduncle. On angiograms, his left VA manifested 90% stenosis at the intracranial portion and his right VA ended at the posterior inferior cerebellar artery. Because single-photon emission computerized tomography (SPECT) showed low perfusion and poor perfusion reserve in the posterior circulation, the authors performed PTA of the left VA, which was only 35% dilated due to stenosis. Although the patient's postoperative course was uneventful, postoperative hemodynamic studies (SPECT and transcranial Doppler [TCD] ultrasonography) revealed the hyperperfusion phenomenon. A 100% increase of regional cerebral blood flow in the posterior circulation was demonstrated on SPECT studies and TCD ultrasonography revealed a doubling of blood flow velocity in the VA compared with preoperative values. Careful control of the patient's blood pressure resulted in resolution of the hyperperfusion phenomenon within I week post-PTA. Although hyperperfusion syndrome following carotid endarterectomy is not rare, it is seldom seen after reconstruction of the posterior circulation, and the possibility of its occurrence must be kept in mind when the posterior circulation is reconstructed.

Aged↗

PubMed2001

Identification of the carotid artery dural ring by using three-dimensional computerized tomography angiography. Technical note.

The carotid artery (CA) dural ring is an important structure in aneurysm surgery of the paraclinoid region. The authors used three-dimensional computerized tomography (3D-CT) angiography to study the CA dural ring. Three-dimensional computerized tomography angiography was performed in patients with cerebral aneurysms and other cerebrovascular diseases. The paraclinoid segment of the internal carotid artery (ICA) was examined by the shaded surface reconstruction method on targeted 3D-CT angiography. The concavity was recognized in the paraclinoid segment of the ICA. The relationship between the concavity and the dural ring was investigated with anatomical studies and surgical findings. In anatomical studies, the concavity in the paraclinoid segment of the ICA on 3D-CT angiography coincided with the level of attachment of the dural ring. Using 3D-CT angiography, it is possible to identify the location of the dural ring in patients being considered for aneurysm surgery.

Carotid Artery Diseases↗

PubMed2001

[A case of lung cancer underwent carinal resection with right upper lobectomy and carinal reconstruction with double-barreled anastomosis].

A 70-year-old male complaining cough was admitted to our hospital. Bronchoscopic examination revealed a tumor mass which occluded the orifice of the right upper lobe. Chest computed tomographic (CT) scans gave the image of tumor invasion at the carina. The pathological diagnosis of the tumor was squamous cell carcinoma. Operation was accomplished by right posterolateral thoracotomy approach through the fifth rib bed. The carinal resection with right upper lobectomy was followed by a double-barreled anastomosis of the right intermediate trunk and left main-stem bronchus into the carina. The operation was successfully performed and was considered curative. The length of resected airway measured 4.0 cm from tracheal line of resection to the divided the right intermediate trunk. Reinforcement of the anastomosis was not performed in this case. No postoperative complication occurred but mild ischemia of the anastomosis. The patient died of recurrent tumor in a year and 2 months after operation.

Aged↗

PubMed2001

[Patient compliance and the quality of life are well maintained in weekly paclitaxel and carboplatin therapy for advanced gynecologic cancers in Japanese women].

OBJECTIVES: To assess patient compliance and efficacy of a combination chemotherapy consisting of weekly administration of paclitaxel and carboplatin for gynecologic malignancy in Japanese women. METHODS: Fourteen ovarian and three uterine cancer patients received 80 mg/m2 of paclitaxel (paclitaxel) and AUC 1.5 to 2.0 of carboplatin weekly. The toxicity was evaluated and patients' QOL was tested. RESULTS: Neutropenia higher than grade 3 were observed in 29.4%. Four patients received G-CSF support. Grade 1 neurotoxicity was seen in 76.5% of patients. Evaluation of QOL by EORTC-QLQC30 showed significantly better tolerance of a weekly than monthly regimen. Three out of four patients with lung metastasis showed complete disappearance of the lesions. One patient with stage IIIb cervical cancer underwent postchemotherapy-hysterectomy and a complete pathological response was confirmed. The overall response rate was 64.7% including patients previously treated with platinum based multidrug regimens. CONCLUSIONS: A weekly paclitaxel and carboplatin regimen was well tolerated by Japanese women. The regimen was active in over 60% of cases and it also appeared active in multidrug resistant cases.

Aged↗

PubMed2001

Expression of vascular endothelial growth factor in human monocyte/macrophages stimulated with lipopolysaccharide.

Vascular endothelial growth factor (VEGF) is a mitogen for endothelial cells. We have studied the production of VEGF by human macrophages in response to lipopolysaccharide (LPS). Macrophages stimulated with LPS expressed VEGF mRNA and protein in concentration- and time-dependent manners. The LPS-induced expression of VEGF was inhibited by cycloheximide pretreatment, which suggested that synthesis of certain factor(s) is required for the LPS activity. The induction of VEGF was also suppressed by SB203580, an inhibitor of p38 mitogen-activated protein (MAP) kinase. These results suggest that the LPS-induced VEGF expression depends on the p38-mediated expression of c-Jun, which constitutes the AP-1 complex and binds to the AP-1 site in the VEGF promoter. Pretreatment of the cells with dexamethasone did not affect the LPS-induced upregulation of VEGF mRNA but strongly inhibited VEGF protein production, and the involvement of posttranscriptional regulation on VEGF expression by dexamethasone was suggested. The conditioned medium of LPS-stimulated macrophages enhanced the growth of cultured endothelial cells and it was inhibited by an antibody against VEGF. We conclude that macrophages produce VEGF in response to the stimulation with LPS, which may be partly mediated by the p38 MAP kinase pathway.

Cells, Cultured↗

PubMed2001

[Causal relationship between Helicobacter pylori infection and upper gastroduodenal diseases].

Helicobacter pylori infection causes chronic gastritis (nonatrophic gastritis), which progresses to atrophic gastritis and intestinal metaplasia over a period of decades. Atrophy may result from inflammation and apoptosis caused by H. pylori infection. H. pylori is an important risk factor for peptic ulcer disease. Duodenitis in the gastric metaplasia of the duodenum, hypergastrinemia, and impaired proximal duodenal mucosal bicarbonate secretion are considered causal factors for duodenal ulcer disease. Low-grade B-cell gastric lymphoma of mucosa-associated lymphoid tissue (MALT) develops in response to H. pylori infection. Studies of Mongolian gerbil model demonstrated that H. pylori had an initiator or promoter effect on gastric carcinogenesis.

Chronic Disease↗

PubMed2001

[Antimicrobial resistant test of H. pylori].

The resistance of Helicobacter pylori (H. pylori) to antibiotics leaves great influence on treatment outcome. Agar and broth dilution techniques are difficult to perform and not practical. E-test has the advantage of allowing visualization of resistant subpopulations of bacteria within zones of inhibitions. We studied point mutation of 23s-rRNA gene for H. pylori strains. (74 clarithromycin (CAM)-resistant, 6 CAM-susceptible) The results of these assays were well correlated with these of E-test. The cure rate of triple therapy with metoronidazole (MTZ) for CAM-resistant H. pylori is 100%(11/11), and that with CAM for MTZ-resistant H. pylori is 94.4% (17/18). It is very difficult to eradicate CAM and MTZ-resistant H. pylori.

Clarithromycin↗

PubMed2001

Preventive effect of FK143, a 5alpha-reductase inhibitor, on chemical hepatocarcinogenesis in rats.

The incidence of hepatocellular carcinoma (HCC) is more prevalent in males than in females. 5alpha-Dihydrotestosterone is the most potent form of androgen and is converted from testosterone by 5alpha-reductase. The antitumor effect of a 5alpha-reductase inhibitor (FK143) was evaluated in a rat chemical hepatocarcinogenesis model (Solt-Farber). Male Fischer 344 rats were used in three groups: (a) control group; (b) low-dose FK143 (FKL) group (20 ppm FK143); and (c) high-dose FK143 (FKH) group (200 ppm FK143). The numbers of both glutathione S-transferase placental form-positive foci (P < 0.05) and hyperplastic nodules (HNs; P < 0.01) in the liver were significantly lower in the FKL group than in the control group. The numbers (P < 0.05) and tumor volume (P < 0.01) of HCCs per liver were significantly lower in the FKL group when compared with the control group. All HCCs were well differentiated in the FKL group, whereas 38% and 36% of HCCs were moderate to poorly differentiated in the control group and the FKH group, respectively. The proliferating cell nuclear antigen labeling index:apoptotic index ratios of enzyme-altered foci, HNs, and HCCs were significantly lower in the FKL group than in the control group. Serum 5alpha-dihydrotestosterone was significantly lower in both the FKL and FKH groups. However, a high dose of FK143 (200 ppm) provided no protection against hepatocarcinogenesis, and the level of serum testosterone was elevated in this group when compared with that in the control group. The low dose of FK143 significantly suppressed the formation of enzyme-altered foci, HNs, and HCCs in rat hepatocarcinogenesis. This may indicate that 5alpha-dihydrotestosterone enhances hepatocarcinogenesis. We conclude that an optimal dose of FK143 may have a suppressive effect on hepatocarcinogenesis.

5-alpha Reductase Inhibitors↗

PubMed2001

[A case of ectopic pulmonary calcification appearing as diffuse ground-glass attenuation on HRCT].

A 50-year-old man was admitted to undergo an operation for aortic stenosis and insufficiency. Chest high-resolution CT (HRCT) showed diffuse areas with ground-glass attenuation in both lung fields. The shadows were not seen in the periseptal zones. A transbronchial lung biopsy specimen revealed ectopic interstitial calcification. Differential diagnosis upon observation of diffuse areas with ground-glass attenuation on HRCT included hypersensitivity pneumonitis and bronchopneumonia. In the peripheral region of the secondary pulmonary lobules, the microchemical environment of the alveoli tended to become alkalosed in comparison with the central area, the characteristic distribution of the areas of ground-glass attenuation may be explained by the differentiation of the acid-base balance between the peripheral and central regions of the secondary pulmonary lobules.

Calcinosis↗

PubMed2001

[Comparison of 133Xe gas dynamic SPECT and thin-section CT in patients with pulmonary emphysema].

PURPOSE: We assessed 133Xe gas dynamic single photon emission computed tomography (SPECT) by comparing washout axial images with thin-section CT (TSCT) in patients with pulmonary emphysema. METHODS: Twenty-three patients were studied. All patients were diagnosed as having pulmonary emphysema on the basis of TSCT. We compared TSCT of upper, middle and lower lung fields with 133Xe gas dynamic SPECT axial images at the corresponding levels during the 3 to 4 minutes of washout phase. If the degree of 133Xe gas retention or TSCT finding of ventral and dorsal parts was not the same, the images were divided into two parts. RESULTS: A total of 174 lesions in 23 cases were examined, but 3 lesions having no retention of 133Xe gas at equilibrium phase were excluded. The results showed that: there were 37 lesions (21.6%) with equivalent severity on both images; there were 42 lesions (24.5%) with more severity on 133Xe gas dynamic SPECT than on TSCT; and there were 92 lesions (53.8%) with more severity on TSCT than on 133Xe gas dynamic SPECT. The severity on 133Xe gas dynamic SPECT and TSCT was not always compatible. One of the reasons for the variable 133Xe gas retention even when the lesion had the same severity on TSCT, may be bronchial stricture which cannot be seen on TSCT. CONCLUSION: By comparison of axial images of 133Xe gas dynamic SPECT with CT images, we could recognize the areas of 133Xe gas retention in detail. Results suggest that 133Xe gas dynamic SPECT can be useful to identify ventilation impairment in pulmonary emphysema.

Aged↗

PubMed2001

Progress with inactivated poliovirus vaccines derived from the Sabin strains.

To produce a safe and effective inactivated poliovirus vaccine (IPV), we have developed S-IPV using Vero cells infected with the Sabin strains in a semi-production scale. All production steps including virus culture on microcarrier beads were highly reproducible. Mean recovery percents of infectious viruses or D-antigens during all processes for concentration, purification and inactivation were 30-50% in the three types. The S-IPV potency was adjusted for D-antigen content as determined by in-house ELISA and was comparable to WHO reference IPV derived from the virulent strains in immunogenicity tests in rats. Antibody development in more than 30 seronegative infant volunteers after two shots of S-IPV at four-week interval were 100% without notable adverse reactions. The mean antibody titres (log2) to Sabin 1, 2 and 3 viruses were 11.1, 8.3 and 8.9, respectively. The antibodies neutralized the Mahoney, MEF-1, and Saukett virulent strains with slightly inferior titres to those of the Sabin strains. D-antigens for each type of S-IPV were stable at 4 degrees C without any significant decrease over more than two years.

Adult↗

PubMed2000

Lipopolysaccharide induces the expression of cellular inhibitor of apoptosis protein-2 in human macrophages.

Apoptosis is an important process in normal animal development as well as in diseases, and inhibitor of apoptosis protein (IAP) is one of the important factors that regulate apoptotic cell death. We found that lipopolysaccharide (LPS) enhances the expression of mRNA and protein of cellular IAP-2 (cIAP2) in human monoblastic U937 cells differentiated by phorbol ester pretreatment. cIAP2 mRNA was not detected in undifferentiated U937 cells. mRNAs of cIAP1 and X-chromosome-linked IAP (XIAP) were expressed constitutively and not affected by LPS in both undifferentiated and differentiated cells. LPS stimulated the expression of cIAP2 mRNA and protein in time- and concentration-dependent manners. LPS enhanced the expression of cIAP2 mRNA and protein in human monocyte-derived macrophages, which was associated with the inhibition of the caspase-3 activation, i.e., decrease in active p17 fragment of caspase-3 with simultaneous accumulation of precursor p20 fragment. We conclude that LPS may inhibit apoptosis of macrophages, at least in part, through the induction of cIAP2.

Apoptosis↗