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Biomedical subjects

S Kitamura

Publications and source records attributed to S Kitamura.

At least 253 records · Page 14Linked to original sources
PubMed1998

Calphostin C induces expression of amphiregulin mRNA via reactive oxygen species in IEC-6 cells.

Calphostin C, a secondary metabolite of the fungus Cladosporium cladosporioides, is generally used as a specific inhibitor of protein kinase C. It is known that 12-O-tetradecanoyl-13-phorbol acetate (TPA), a protein kinase C activator, induces expression of mRNA for amphiregulin (AR), a member of EGF-related polypeptides, in mammalian epithelial cells. In this work, we determined the effect of calphostin C on AR mRNA expression in IEC-6 cells, a rat intestinal epithelial cell line, and unexpectedly found that this compound enhanced the TPA-induced expression of AR mRNA. Moreover, calphostin C alone induced expression of AR mRNA in a light-dependent manner, and this effect was abrogated by pretreatment with N-acetylcysteine. These results suggest that calphostin C can upregulate expression of AR mRNA via reactive oxygen species.

Acetylcysteine↗
PubMed1998

Multiple pseudoaneurysms of the aortic arch, right subclavian artery, and abdominal aorta in a patient with Behçet's disease.

A 38-year-old man presented with 2 months' history of a hoarseness and aphthous stomatitis. Image diagnosis showed that he had saccular-type aneurysms of the aortic arch, right subclavian artery, and infrarenal abdominal aorta. Simultaneous total arch replacement, including reconstruction of the right subclavian artery and replacement of the infrarenal abdominal aorta, was performed. Pathologic specimen of each aneurysmal wall revealed that intima and the majority of the medial layer were absent. Chronic inflammatory process was detected in the adventitia that was compatible with diagnosis of Behçet's disease.

Adult↗
PubMed1998

Expression of biologically active recombinant porcine GM-CSF by baculovirus gene expression system.

The full length porcine granulocyte/macrophage colony stimulating factor (GM-CSF) cDNA, including secretion signal peptide coding region was recloned into baculovirus transfer vector pAcYM1. The vector was then transfected with Autographica californica nuclear polyhedrosis virus (AcNPV) DNA into SF21AE cells and the recombinant virus AcPGM was recovered. Recombinant porcine GM-CSF (rpGM-CSF) was obtained from the serum-free culture medium of Tn5 cells infected with the AcPGM virus, and was shown to be a glycosylated 21 kDa protein as confirmed by tunicamycin treatment and [3H]-glucosamine uptake. The biological activities of rpGM-CSF in AcPGM-infected cell culture supernatants were demonstrated by porcine bone marrow cell proliferation and haematopoietic cell colony formation assays. The use of rpGM-CSF enabled us to culture porcine monocytes/macrophage and dendritic-like cells, derived from either porcine bone marrow or peripheral blood, for up to 4 months.

Amino Acid Sequence↗
PubMed1998

Reductive dechlorination of DDT to DDD by rat blood.

The present study provides evidence that the reductive dechlorination of DDT (p, p'-dichlorodiphenyltrichloroethane) to DDD (p, p'-dichlorodiphenyldichloroethane) mediated by rat blood proceeds in the presence of both a reduced pyridine nucleotide and a flavin. The reduction appears to proceed in two steps. The first step is reduction of a flavin such as FAD, FMN or riboflavin by NADPH or NADH, either enzymatically or nonenzymatically. The second step is nonenzymatic reductive dechlorination of DDT by the reduced flavin, catalyzed by the heme group of hemoglobin.

Animals↗
PubMed1998

Frequent expression of the vascular endothelial growth factor in human non-small-cell lung cancers.

BACKGROUND: Angiogenesis is an essential factor for progression and metastases in solid tumors. It has been reported that several angiogenic factors play a role in the regulation of angiogenesis. Vascular endothelial growth factor (VEGF) is one of the most important molecules in angiogenesis. We investigated expressions of VEGF in a series of lung carcinomas with regard to clinicopathological factors. METHOD: VEGF expression was investigated by use of immunohistochemical studies and Northern blot analysis, using 155 primary and 26 metastatic lung carcinomas for the immunohistochemical studies and 10 primary and two metastatic lung carcinomas for the Northern blot analysis. All lesions were resected at surgery. RESULTS: The frequencies for positive VEGF expression were 64 of 74 (86.5%) adenocarcinomas, 38 of 67 (56.7%) squamous cell carcinomas, four of four (100%) large cell carcinomas, two of three (66.7%) adenosquamous carcinomas and one of five (20%) small-cell carcinomas, the degree of positivity generally being greater in well differentiated tumors. The majority of metastatic foci from adenocarcinomas and squamous cell carcinomas at other sites were also positive (76.5 and 66.7%, respectively). VEGF expression did not correlate with clinicopathological factors such as tumor size or pathological stage, but pathological stage I adenocarcinoma cases positive for VEGF demonstrated a shorter disease-free period when followed up for 48 months than those cases expressing VEGF negatively. CONCLUSIONS: The results indicated that VEGF expression was frequently detected in non-small-cell lung cancers and suggested that VEGF might relate to the disease-free period of the patients with early adenocarcinomas.

Adenocarcinoma↗
PubMed1998

Surgical treatment for aortic regurgitation caused by Takayasu's arteritis.

Aortic regurgitation (AR) caused by Takayasu's arteritis is relatively rare. We investigated the surgical results in patients with AR caused by Takayasu's arteritis. Between 1978 and December 1997, 65 patients (5 males, 60 females) with AR secondary to Takayasu's arteritis underwent surgery. The patients' ages ranged from 19 to 70 years (mean, 48 years). Takayasu's arteritis was diagnosed by clinical examination confirmed by intraoperative pathological examination of the aortic wall. The surgical procedures for AR were aortic valve replacement in 45 patients, Bentall-type operation in 19, and remodeling in 1. Four (6.2%) patients died during the hospital stay. The follow-up period ranged from 3 to 227 months (mean, 111 months). Eleven patients died during the follow-up period, and the actuarial survival rate was 87% at 5 years and 75% at 10 years. The incidence of prosthetic valve detachment was 4.6% (3/65). Three patients required a composite graft replacement. No prosthetic valve detachment was noted in 96% of the patients at 5 years and in 94% at 10 years. Preoperative steroid administration to treat inflammation and its postoperative use to control inflammation may be important in the treatment of these patients.

Adult↗
PubMed1998

Bilateral representation of language function. Agenesis of corpus callosum by Wada and PET activation.

A 33-year-old right-handed man with intermittent headache was found to have agenesis of the corpus callosum. He underwent magnetic resonance imaging, positron emission tomography (PET), and detailed neuropsychologic tests, including a Wada test. There was bilateral representation of language, and a PET activation study with word repetition revealed bilateral areas of activation that were not completely symmetric. These findings and the literature concerning agenesis of the corpus callosum are discussed as is the possible compensatory mechanism for absence of the corpus callosum, which is important for cross-communication.

Adult↗
PubMed1998

High Fas ligand expression on lymphocytes in lesions of ulcerative colitis.

BACKGROUND: The pathogenesis of ulcerative colitis is unclear, but cytotoxic T lymphocytes infiltrating the mucosa have been implicated in mucosal damage. The Fas ligand (FasL), expressed on cytotoxic T lymphocytes, induces apoptosis in cells expressing Fas. AIM: To analyse FasL expression in affected colonic mucosa to ascertain Fas-FasL interaction in ulcerative colitis. METHODS: FasL mRNA was quantified in colonic mucosal specimens from healthy subjects and patients with ulcerative colitis or Crohn's disease, using the competitive reverse transcription polymerase chain reaction. FasL mRNA localisation was determined by in situ hybridisation. Expression of Fas in colonic mucosa was analysed immunohistochemically. Phenotypes of lamina propria lymphocytes that expressed FasL were analysed by flow cytometry. RESULTS: FasL mRNA was strongly expressed in active ulcerative colitis lesions, but not in those associated with active Crohn's disease or active proctitis-type ulcerative colitis. In situ hybridisation showed that FasL mRNA expression occurred in mononuclear cells infiltrating lesions. Fas was expressed in epithelial cells in ulcerative colitis and Crohn's disease, and in normal subjects. Cytometry showed that FasL was expressed in CD3 lymphocytes infiltrating the lamina propria in active lesions. CONCLUSIONS: FasL is expressed in CD3 lymphocytes infiltrating into ulcerative colitis but not Crohn's disease lesions, suggesting that Fas-FasL induced apoptosis participates in the mucosal damage of ulcerative colitis.

Acute Disease↗
PubMed1998

Effects of inhalation of nitroglycerin on hypoxic pulmonary vasoconstriction.

Recent studies suggest that nitric oxide (NO) may play an important role in the pathophysiology of pulmonary hypertension. Nitroglycerin is metabolized to NO, which is a potent vascular smooth muscle relaxant. The aim of the present study was to compare the effects of inhaled and infused nitroglycerin on pulmonary hemodynamics and gas exchange in anesthetized, artificially ventilated dogs. Nitroglycerin was administrated either by inhalation or by infusion. Systemic blood pressure (SBP), pulmonary arterial pressure (PAP), and pulmonary capillary wedge pressure (PCWP) were measured, and cardiac output was estimated by an electromagnetic flowmeter. Blood gas measurements were performed during hypoxic gas exposure (FiO2; 0.1) with a continuous inhalation or infusion of nitroglycerin (1, 2.5 micrograms/kg/min). Inhaled (n = 4) and infused (n = 4) nitroglycerin (1 microgram/kg/min) did not produce any detectable effects on the hemodynamics. Inhaled nitroglycerin (2.5 micrograms/kg/min) reduced SBP, PAP and calculated pulmonary vascular resistance (PVR) in all dogs. Cardiac output did not change. In addition, inhaled nitroglycerin increased PaO2. In contrast, the continuous infusion of nitroglycerin (2.5 micrograms/kg/min) did not change in PAP, whereas infused nitroglycerin decreased the mean SBP. Infused nitroglycerin did not alter cardiac output and calculated PVR. A decreased PaO2 was noted in 2 dogs on nitroglycerin infusion. These findings indicate that inhaled nitroglycerin effects the pulmonary circulation relatively more than infused nitroglycerin, which tends to have more of a general effect on the systemic circulation. The effects of inhaled nitroglycerin may thus be comparable to the effects of NO inhalation.

Administration, Inhalation↗
PubMed1998

Quinone-dependent tertiary amine N-oxide reduction in rat blood.

Rat blood exhibited a significant quinone-dependent N-oxide reductase activity towards imipramine N-oxide. The reduction mediated by the blood proceeded in the presence of both NAD(P)H and menadione under anaerobic conditions. When menadione was replaced with 1,4-naphthoquinone or 9,10-phenanthrenequinone, similar results were obtained. The reduction was also mediated by the combination of rat erythrocytes and plasma. The reducing activity was inhibited by dicumarol and carbon monoxide. When boiled plasma was combined with untreated erythrocytes, the N-oxide reducing activity was abolished. In contrast, when boiled erythrocytes were combined with untreated plasma, the activity was unchanged. These results suggest that the activity is caused by the heme of hemoglobin in erythrocytes and quinone reductase in plasma. In fact, erythrocytes and hemoglobin have the ability to reduce the N-oxide when supplemented with DT-diaphorase purified from rat liver in the presence of both NAD(P)H and menadione. Hemoglobin also exhibits N-oxide reductase activity with reduced menadione (menadiol). Furthermore, hematin exhibits a significant reducing activity in the presence of menadiol. The reduction appears to proceed in two steps. The first step is enzymatic reduction of quinones to dihydroquinones by quinone reductase(s) with NADPH or NADH in plasma. The second step is nonenzymatic reduction of imipramine N-oxide to imipramine by the dihydroquinones, catalyzed by the heme group of hemoglobin in erythrocytes. Cyclobenzaprine N-oxide and brucine N-oxide are similarly transformed to the corresponding amines by the above reducing system in blood. These results suggest that blood plays an important role in the reduction of tertiary amine N-oxides to tertiary amines.

Animals↗
PubMed1998

Impact of percutaneous transluminal coronary angioplasty on coronary bypass surgery--changes in the patient profile during the past decade.

As percutaneous transluminal coronary angioplasty has become an increasingly common procedure replacing coronary artery bypass grafting (CABG), the clinical profile of the patients referred for CABG has changed markedly. A retrospective study of the changes in the clinical profile and surgical outcome of patients who underwent CABG during the past 10 years was conducted. Between March 1982 and February 1996, 1010 patients underwent isolated CABG at Nara Medical University. The first 100 consecutive patients who underwent CABG in 1984-85 (group 1) were compared with the first 100 consecutive patients who underwent CABG in 1994-95 (group 2). Preoperative risk increased significantly during the decade with respect to patient age (p<0.001), the presence of diabetes mellitus (p=0.048), the number of diseased vessels (p<0.001), left main trunk disease (p=0.008), the presence of aortic or peripheral vascular disease (p=0.032),and the need for emergency surgery (p=0.013). Operative procedures have become more complicated with respect to the number of total and arterial grafts, duration of the aortic cross-clamp and cardiopulmonary bypass. Hospital mortality for elective CABG has not changed (2%) and the overall mortality has not increased significantly (from 2% to 3%) during the decade. In conclusion, although the preoperative risks have increased and more complicated procedures are required, CABG continues to be performed safely with low mortality rates.

Aged↗
PubMed1998

[Cerebral blood flow of patients with age-associated memory impairment and the early stage of Alzheimer's disease. A study by SPECT using the ARG method].

In order to further understand the pathology of Alzheimer's disease (AD), we have utilized image analysis in diagnosing the early stages of AD in patients with cognitive disorders. CT and MRI, however, have not been feasible since only atrophy is seen and it is difficult to differentiate the changes in AD from age associated changes. In this study we tried to determine whether regional cerebral blood flow (rCBF) measurements using single photon emission CT (SPECT) are feasible for the early diagnosis of AD. Regional CBF (rCBF) was measured using SPECT in three subject groups: Age-associated memory impairment (AAMI. n = 9), mild AD (n = 16), and normal aged patients (mean age = 68.3; n = 20). The subjects were then observed for three years. The region of interest (ROI) for the medial temporal lobe was set at OM-30 degrees to cover the maximum area of the hippocampus. The absolute values of rCBF in the frontal, temporal, and parietal lobes and the cerebellum were significantly lower in the mild AD subjects than in the normal aged subjects. A significant decrease in rCBF was also seen in the medial temporal lobe in both the AD and the AAMI subjects compared to the normal controls. During the three years of follow up, no cases of dementia were seen in the AAMI subjects. However, there were two patients who appeared to have difficulty in adapting to daily life due to amnesia, one with a decrease in rCBF of the medial temporal lobe on the second SPECT, and the other showing a low rCBF the first time. This study suggests that AAMI subjects may comprise both AD and normal subjects. Therefore a more prospective study is needed.

Aged↗
PubMed1998

[Brain water diffusion coefficients and diffusion anisotropy in non-demented patients with diffuse leuko-araiosis].

PURPOSE: To investigate changes in both water diffusion coefficients and diffusion anisotropy in white matter of non-demented patients with leuko-araiosis using diffusion-weighted MRI. METHODS: Diffusion mapping was performed on 8 non-demented patients with leuko-araiosis, 6 patients with chronic cerebral infarction and 6 healthy volunteers, using a spin-echo sequence with motion probing gradient applied sequentially at two gradient strength settings in three orthogonal directions. The apparent diffusion coefficients (ADC) were calculated from 4 regions of interest located within the frontal and parietal subcortical white matter. The index of diffusion anisotropy (IDA) was calculated from the ADC in three orthogonal directions. (IDA = ADCmax-min/ADCmean x 100). RESULTS: Significantly larger ADC were found within the frontal and parietal subcortical white matter in the non-demented patients with leuko-araiosis (mean = 1.51 +/- 0.36 x 10(-3) mm2/s) and the were also significantly larger in patients with cerebral infarction (mean = 2.12 +/- 0.46 x 10(-3) mm2/s) than in the control group (mean = 1.01 +/- 0.33 x 10(-3) mm2/s). But no significant differences were found in the IDA between the non-demented patients with leuko-araiosis (mean = 43.1 +/- 29.2) and the control group (mean = 46.5 +/- 32.5). CONCLUSION: An increase in extracellular space caused by the loss of axonal fibers and myelin is probably the cause of the higher ADC in periventricular hyperintensity lesions. However, the remaining nerve fibers maintain the anisotropy in the lesions in non-demented patients with leuko-araiosis.

Aged↗
PubMed1998

[Remote effect in patients with thalamic stroke. A study using positron emission tomography].

The purpose of this study was to investigate the functional relation between the thalamus and other cortical regions in patients with thalamic stroke from the view of cerebral blood flow (CBF) and the cerebral metabolic rate of oxygen (CMRO2) using positron emission tomography (PET). Twenty patients with thalamic stroke (right lesion = 8, left lesion = 12) and 7 normal controls were studied. Five patients were diagnosed as having thalamic infarction, and 15 (patients were diagnosed) as having thalamic hemorrhage by X-CT and/or MRI scan. Regional cerebral blood flow and cerebral metabolic rate of oxygen were measured by PET using C15O2 and 15O2 steady state inhalation technique. In the left thalamic stroke group, CMRO2 was significantly decreased in the left cingulate, superior frontal, superior temporal, middle temporal, medial occipital, and thalamic regions, compared with the normal control group. In the right thalamic stroke group, CMRO2 was decreased in the left cingulate, medial occipital, right hippocampal, thalamic, and the bilateral cerebellar regions, compared with the normal control group. In the left thalamic stroke group. CBF was decreased significantly in the left cingulate, middle temporal, hippocampal, thalamic, and right cerebellar regions, compared with the normal control group. In the right thalamic stroke group, CBF was significantly decreased in the right hippocampal, thalamic and left cerebellar regions compared with the normal control group. These results indicate that CBF and CMRO2 decrease in some distant regions from thalamic lesions, perhaps due to a disconnection of neuronal fiber. Especially in the left thalamic stroke group, CMRO2 was decreased in the ipsilateral temporal regions. This result suggests that there are more intimate functional fiber connections between the thalamus and temporal cortex in the left hemisphere than in the right hemisphere.

Aged↗
PubMed1998

[Assessment of regional cerebral blood flow in subcortical infarction with aphasia].

We assessed the regional cerebral blood flow (rCBF) in 8 patients with subcortical aphasia and 8 patients with subcortical infarction without aphasia using the N-isopropyl-P-[123I]-iodoamphetamine autoradiography (123I-IMP ARG) method. In this study, we evaluated vermis to left cortex ratio of CBF. In cases of Broca's aphasia (N = 2), CBF was lower in the posterior frontal regions including Broca's area, and more hypoperfused in the posterior frontal and in the posterior temporal regions, including Wernicke's area of total aphasia (N = 2). But, it was not significantly hypoperfused in those regions in the cases of Wernicke's (N = 2) and amnestic aphasia (N = 2). In the subcortical aphasia, global CBF in the left cerebral cortex was lower than that in the right cerebral cortex. However, in the subcortical infarction group without aphasia there was no difference between CBF in the left cerebral cortex and the right cerebral cortex. We conclude that hypoperfusion in the left cerebral cortex was greater than that in the right cerebral cortex and it was probably due to dysfunction of the left cerebral cortex when subcortical infarction occurred with aphasia. Though some types of aphasia were not relative to the dysfunction of the left cerebral cortex.

Aged↗
PubMed1998

Recovery and limitation of exercise capacity after lung resection for lung cancer.

OBJECTIVE: To assess the effects of pulmonary resection for lung cancer on postoperative recovery and limitation of exercise capacity. METHODS: Eighty-two patients (20 pneumonectomies, 62 lobectomies) underwent spirometric pulmonary tests and exercise capacity tests preoperatively, and at 3 months and more than 6 months after the operation. RESULTS: In the lobectomy group, FEV1 vital capacity (VC), and maximum oxygen consumption (VO2max) decreased significantly 3 months after the operation and improved after more than 6 months, but did not reach the preoperative values. In the pneumonectomy group, FEV1 VC, and VO2max decreased 3 months after the surgery and the values did not recover thereafter. In comparison with preoperative values, the functional percentage losses after more than 6 months for lobectomies and pneumonectomies were 11.2% and 36.1% for FEV1, 11.6% and 40.1% for VC, and 13.3% and 28.1% for VO2max, respectively. Postoperatively, maximal minute ventilation (VEmax), the maximal heart rate percentage, and maximal O2 pulse during the exercise test significantly decreased in both the lobectomy and pneumonectomy groups. Nevertheless, VEmax and O2 pulse improved more than 6 months after lobectomy compared with the value at 3 months, but not after pneumonectomy. Breathing reserve did not differ before and after surgery in the lobectomy group, although it decreased significantly after surgery in the pneumonectomy group. Subjectively, postoperative exercise after lobectomy was limited by leg discomfort (64% at more than 6 months after surgery); after pneumonectomy, exercise was limited by dyspnea (60%). CONCLUSIONS: These results suggest that there are differences between lobectomy and pneumonectomy for lung cancer in terms of recovery and limitation of exercise capacity.

Exercise Test↗
PubMed1998

Multiple pulmonary metastases with cavitation from gallbladder cancer.

We report a rare case of multiple pulmonary metastases with cavitation from gallbladder cancer. A 77-year-old woman was admitted to our hospital complaining of productive cough and exertional dyspnea. Chest X-ray film showed multiple nodular shadows with some cavitation. Computed tomography showed multiple cavities, up to 2 cm in diameter, as well as nodules, in bilateral lung fields. Under a survey of primary focus, the ultrasonographic test of the abdomen revealed a hypoechoic mass in the hepatic hilum. The patient died of respiratory failure. Autopsy findings revealed that that multiple lung tumors had metastasized from papillary adenocarcinoma of the gallbladder and that cavitation of the lung was formed by bronchioloectasis.

Adenocarcinoma, Papillary↗