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Biomedical subjects

Kenji Suzuki

Publications and source records attributed to Kenji Suzuki.

At least 145 records · Page 8Linked to original sources

Uncoupling protein 2 plays an important role in nitric oxide production of lipopolysaccharide-stimulated macrophages.

The expression of uncoupling protein 2 (UCP2) was reduced in macrophages after stimulation with lipopolysaccharide (LPS). The physiological consequence and the regulatory mechanisms of the UCP2 down-regulation by LPS were investigated in a macrophage cell line, RAW264 cells. UCP2 overexpression in RAW264 cells transfected with eukaryotic expression vector containing ucp2 cDNA markedly reduced the production of intracellular reactive oxygen species. Furthermore, in the UCP2 transfectant, nitric oxide (NO) synthesis, inducible NO synthase (NOS II) protein, NOS II mRNA, and NOS II promoter activity were definitely decreased after LPS stimulation compared with those in parental RAW264 or RAW264 cells transfected with the vector alone. Reporter assays suggested that an enhancer element was located in the region of intron 2 of the UCP2 gene and that the UCP2 expression was down-regulated not by the 7.3-kb promoter region but by the 5' region of the UCP2 gene containing two introns. Deletion of intron 2 resulted in the low transcriptional activities and abolishment of the LPS-associated negative regulation. In addition, the mRNA expression of transfected UCP2 was suppressed in RAW264 cells transfected with expression vector containing UCP2 genomic DNA, but was markedly increased in cells transfected with the vector containing UCP2 intronless cDNA. These findings suggest that the LPS-stimulated signals suppress UCP2 expression by interrupting the function of intronic enhancer, leading to an up-regulation of intracellular reactive oxygen species, which activate the signal transduction cascade of NOS II expression, probably to ensure rapid and sufficient cellular responses to a microbial attack.

Animals↗

Blockade of CXCL10 protects mice from acute colitis and enhances crypt cell survival.

Crypt cell renewal is essential for normal intestinal homeostasis as well as mucosal regeneration following injury. However, the factors regulating crypt cell growth in pathological conditions are not fully understood. We report here that the endogenously produced chemokine CXCL10 regulates crypt cell proliferation. CXCL10 was constitutively expressed by basal crypts in mouse colon, but the expression of CXCL10 as well as CXCR3 was enhanced in the epithelium in the proliferative zone after oral administration of dextran sulfate sodium. Neutralization of CXCL10 protected mice from epithelial ulceration by promoting crypt cell survival without evidence of altered immune cell infiltration. Furthermore, recombinant CXCL10 administration into mice inhibited intestinal epithelial cell proliferation. These findings suggest that CXCL10 regulates crypt cell growth to maintain intestinal homeostasis in an autocrine or paracrine fashion. Thus, CXCL10 can be a new therapeutic target for inflammatory bowel disease by controlling the dynamics of epithelial homeostasis.

Acute Disease↗

Lateral spread response elicited by double stimulation in patients with hemifacial spasm.

In patients with hemifacial spasm (HFS), a lateral spread response (or abnormal muscle response) is recorded from facial muscles after facial nerve stimulation. The origin of this response is not completely understood. We studied the lateral spread responses elicited by double stimulation in 12 patients with HFS during microvascular decompression. The response was recorded from the mentalis muscle by electrical stimulation of the temporal branch of the facial nerve or from the orbicularis oculi muscles by stimulation of the marginal mandibular branch. The interstimulus intervals (ISIs) of double stimulation ranged from 0.5 to 7.0 ms. R1 was defined as the response elicited by the first stimulus, and R2 as the response elicited by the second stimulus. R1 had a constant latency and amplitude regardless of the ISI, whereas R2 appeared after a fixed refractory period without facilitation or depression in a recovery curve of latency and amplitude. From these findings, we consider that the lateral spread response is due to cross-transmission of facial nerve fibers at the site of vascular compression rather than arising from facial nerve motor neurons.

Adult↗

Successful pulmonary resection of lung cancer in a patient with partial anomalous pulmonary venous connection: report of a case.

A rare case of the potentially grave combination of lung cancer and partial anomalous pulmonary venous connection (PAPVC) is described. PAPVC would cause many problems following major lung resection, even in a preoperatively asymptomatic patient, because of the inevitable development of right ventricular failure as a result of right ventricular volume overload caused by the left-to-right physiologic shunt. On the other hand, if a patient has primary lung cancer, anatomical resection should be done to achieve curative treatment. We successfully performed a left lower lobectomy for lung cancer in a patient with abnormal venous drainage in the left upper lobe, with simultaneous correction of a PAPVC.

Adenocarcinoma↗

"Early" peripheral lung cancer: prognostic significance of ground glass opacity on thin-section computed tomographic scan.

BACKGROUND: The number of peripherally located lung cancers with an excellent prognosis has been increasing, possibly due to the introduction of computed tomography for lung cancer screening in Japan. The concept of peripherally located "early lung cancer" remains controversial. METHODS: A retrospective study was conducted on 1,540 lung cancers resected at our institute between May 1992 and December 2000. The sizes of solid attenuation and ground glass opacity were evaluated radiologically and the relationships between radiologic findings and clinicopathologic features were investigated to define peripheral early lung cancer. RESULTS: Sixty-nine (4.4%) lung cancers showed a large ground glass opacity component on thin-section computed tomographic scan. The maximum tumor dimension ranged from 6 to 41 mm, and all tumors were clinical stage I. Forty-seven patients were diagnosed as having bronchioloalveolar carcinoma pathologically. None of the tumors showed lymph node involvement or lymphatic invasion. Only two showed vascular invasion, but all were pathologic stage I disease. Most of the lung cancers that showed pure ground glass opacity were bronchioloalveolar carcinoma. CONCLUSIONS: Peripheral lung nodules with a large ground glass opacity component on thin-section computed tomographic scan, which do not disappear during follow-up, tend to be bronchioloalveolar carcinomas or minimally invasive adenocarcinomas of the lung. These findings warrant a feasibility study of limited surgical resection for such lung tumors.

Adenocarcinoma↗

Mechanical vascular division in lung resection.

BACKGROUND: There is little information available regarding the relative advantage of stapling over ligation for major pulmonary vessels in lung resection. The thin and fragile structure of pulmonary vascular walls for their large luminal size might have made surgeons reluctant to use staplers. This study was intended to demonstrate the feasibility of pulmonary vascular division by staplers. METHODS: A total of 842 mechanical vascular divisions were performed for pulmonary artery (PA, n=376), pulmonary vein (PV, n=462), and azygos vein (AV, n=4) in 603 consecutive pulmonary resections from 1997 to 1999 at the National Cancer Center Hospital, Tokyo. In this series, 99.8% of mechanical vascular divisions were performed with endostaplers (840 vessels), and only 0.2% was performed with conventional TA-type staplers (two vessels). The prevalence of problems related to mechanical stapling (stapling failure) and postoperative bleeding was studied retrospectively. RESULTS: There was only one incidence of stapling failure, in which the superior pulmonary vein was divided without the formation of staples (overall stapling failure rate, 0.1%). The bleeding was controlled by ligation of each divided stump during thoracotomy. There was no stapling failure for PAs or AVs. In no case did postoperative bleeding require rethoracotomy at the stapled line of the vessels. CONCLUSIONS: Although temporary oozing was sometimes seen along the staple line, vascular division with endostaplers was highly reliable with only a 0.1% incidence of stapling failure for all kinds of vascular structures in the thorax.

Adolescent↗

An experimental study on Nd-YAG laser induced thermotherapy. Its possible application of the laser irradiation for therapy of hepatocellular carcinoma.

It has been reported that the local thermotherapy is useful in treatment of hepatocelluar carcinoma complicated with severe liver cirrhosis (LC). We studied the effect of laser beam generated by a newly developed Nd-YAG laser system on liver tissue of piglet. The system was composed of their quartz bare fiber with a cone-shaped tip. After liver was exposed by incision of abdomen under general anesthesia, the fiber was inserted into liver tissue and then the laser beam was generated. The power, duration and frequency of irradiation were varied. The coagulated area was inspected measured and examined histologically. The system produced an oval-shaped coagulated area in front of the needle tip. Furthermore, the volume of tissue coagulated was correlated with the total output of laser, enabling us to estimate the coagulated volume based on the laser output applied. Our findings indicated that Nd-YAG laser-induced thermotherapy would be successfully applied for the clinical treatment of HCC.

Journal Article↗

Tobacco plants were transformed by Agrobacterium rhizogenes infection during their evolution.

We discovered that the origin of cT-DNA in the genome of wild-type Nicotiana glauca is the T-DNA of the mikimopine-type Ri plasmid (pRi) harbored in Agrobacterium rhizogenes. The cT-DNA was inserted into the genomic DNA of N. glauca from the position corresponding to the right border of mikimopine-type pRi. The cT-DNA contained two mikimopine synthase gene (mis) homologs, NgmisL and NgmisR, both of which were transcribed at low level in all N. glauca organs. NgMisR protein expressed in Escherichia coli has preserved Mis activity, which converts l-histidine and alpha-ketoglutaric acid to mikimopine. The mis homolog was also found in the genome of three other Nicotiana species: N. tomentosa, N. tomentosiformis, and N. tabacum; however, the site of insertion differed from that in N. glauca, suggesting that A. rhizogenes harboring mikimopine-type pRi independently infected the ancestors of some Nicotiana plants. This is the first clear evidence of a host-parasite relationship during the early evolution of Nicotiana plants. We propose that a new phylogenetic approach using opine type cT-DNA is applicable for presuming divergence in the genus Nicotiana.

Amino Acid Sequence↗

Large cell neuroendocrine carcinoma of the lung: a clinicopathologic study of eighty-seven cases.

OBJECTIVE: Large cell neuroendocrine carcinoma of the lung is a newly recognized clinicopathologic entity. The clinical characteristics and optimal treatment of patients with large cell carcinomas are not yet established. The aim of this study was to define the clinicopathologic characteristics of large cell neuroendocrine carcinoma. METHODS: The histologic characteristics of the patients receiving an initial diagnosis of poorly differentiated non-small cell lung carcinoma (n = 484), small cell carcinoma (n = 55), carcinoid (n = 31), and large cell neuroendocrine carcinoma (n = 12) were retrospectively reviewed according to World Health Organization criteria. Immunohistochemistry was performed to confirm the neuroendocrine phenotype. The outcomes and other clinical characteristics of those patients with large cell neuroendocrine carcinoma were retrospectively analyzed and compared with those of patients with poorly differentiated carcinoma of other histologic types. RESULTS: A total of 87 patients were given a diagnosis of large cell neuroendocrine carcinoma after the histologic review. These patients comprised 3.1% of all patients undergoing resection for primary lung cancer during the same period. The overall 5-year survival was 57%. The 5-year survivals of patients with stage I, II, III, and IV disease were 67%, 75%, 45%, and 0%, respectively. There was no statistically significant difference between the overall survival of patients with large cell neuroendocrine carcinoma and those with other non-small cell lung cancers. There was a significant difference between the survival of patients with stage I large cell neuroendocrine carcinoma and that of patients with the same stage of other non-small cell lung carcinomas. The site of the first documented recurrence was locoregional in 12 patients (34%), distant metastases in 20 patients (57%), and both simultaneously in 3 patients. Locoregional lymph node recurrences were observed frequently. More than 80% of recurrences were found within 1 year after the operation. CONCLUSION: In terms of prognosis, large cell neuroendocrine carcinoma is distinctly different from other non-small cell lung cancers. The prognosis of large cell neuroendocrine carcinoma was poor, even for early stage disease; the prognosis of the stage I disease of large cell neuroendocrine carcinoma was poorer than that of the same stage of other non-small cell lung cancers. Because of its aggressive clinical behavior and poor prognosis, large cell neuroendocrine carcinoma should be recognized as one of the poorest prognostic subgroups among primary lung cancers, and therefore novel therapeutic approaches should be established.

Adult↗

The X-ray crystallographic study of long chain left handed Z-DNA and polyamine complex and structural chemistry study of effection by polyamine for the Z-DNA.

We cleared the stabilization mechanism of Z-DNA by using the molecular dynamics calculation and the grid map simulated annealing docking method. Then, we clarified Z-DNA was stabilized by the metal counter ions whose electrical charge and the number of electrons are too many and by polyamine to go into the minor groove. We succeeded in stabilizing Z-DNA of the long chain by using these methods, and succeeded in the crystallization and the data collection up to 1.7 A resolution.

Crystallography, X-Ray↗

White blood cell count as a risk factor for hypertension; a study of Japanese male office workers.

OBJECTIVE: To investigate the association of white blood cell (WBC) count with risk of hypertension. DESIGN: Cross-sectional and longitudinal studies. SETTING: A work site in Japan. PARTICIPANTS: A total of 3776 Japanese male office workers aged 23-49 years were enrolled in this study; 2900 hypertension-free [systolic blood pressure (SBP) < 140 mm Hg, diastolic blood pressure (DBP) < 90 mm Hg, no medication for hypertension, and no past history of hypertension] men were followed up over a 4-year period. MAIN OUTCOME MEASURES: Blood pressure levels and the incidence of hypertension (SBP > or = 140 mm Hg and/or DBP > or = 90 mm Hg or medication for hypertension) according to WBC count at study entry. RESULTS: After controlling for potential predictors of hypertension, SBP and DBP levels increased in a dose-dependent manner among both never-smokers and ex-smokers as WBC count increased. Among current smokers, only SBP level increased progressively with WBC count level. The multivariate-adjusted relative risk for development of hypertension compared with the first WBC count quintile was 1.29, 1.21, 1.67, and 1.92 among never-smokers (P for trend = 0.002): and 1.34, 1.46, 1.84, and 1.97 among ex-smokers (P for trend = 0.030) with the second, third, fourth, and fifth quintiles, respectively. Among current smokers, the respective multivariate-adjusted relative risks for hypertension relative to the first WBC count quintile were 0.91, 0.97, 1.08, and 0.84 (P for trend = 0.999). CONCLUSIONS: WBC count is an important risk factor for hypertension, and the increased risk for hypertension associated with WBC count is more pronounced in non-smokers.

Adult↗

Relationship of light to moderate alcohol consumption and risk of hypertension in Japanese male office workers.

BACKGROUND: A close relationship between alcohol consumption and hypertension has been established, but the effect of light to moderate alcohol consumption on blood pressure (BP) remains unclear. METHODS: A total of 5275 Japanese male office workers aged 23 to 59 years partook in a survey. Subjects were classified as nondrinkers or current drinkers who averaged less than 12, 12 to 22, 23 to 45, or > or =46 g/day of ethanol. BPs were measured at annual health examinations from May 1996 through May 2000. A total of 3784 hypertension-free (systolic BP <140 mm Hg, diastolic BP <90 mm Hg, no medication for hypertension, and no history of hypertension) men were observed for 4 years. Men in whom hypertension (systolic BP > or =140 mm Hg, diastolic BP > or =90 mm Hg, or both or receipt of antihypertensive medication) was found during repeated surveys were defined as incident cases of hypertension. RESULTS: After controlling for potential predictors of hypertension, systolic and diastolic BP levels and the incidence of hypertension were lowest in nondrinkers in all three age ranges (23-35, 36-47, and 45-59 years) and increased in a dose-dependent manner as alcohol consumption increased. For individuals aged 23 to 35 years, systolic and diastolic BP levels and the incidence of hypertension were significantly higher among those who drank an average of > or =23 g/day of ethanol than among nondrinkers. For those aged 36 to 59, the diastolic BP level was significantly higher among those who drank any alcohol at all than among nondrinkers, and the systolic BP level and the incidence of hypertension were significantly higher among those who drank an average of > or =12 g/day of ethanol than among nondrinkers. CONCLUSIONS: Light to moderate alcohol consumption seems to have an important influence on BP in both young and middle-aged Japanese men.

Adult↗

Co-occurrence of obsessive-compulsive personality traits in young and middle-aged Japanese alcohol-dependent men.

BACKGROUND: Previous studies may have underestimated the potential importance of the prevalence of obsessive-compulsive traits among persons with alcoholism. Although many studies have examined the characteristics of young alcoholics compared with middle-aged alcoholics, none has compared the prevalence of obsessive-compulsive traits in young and middle-aged alcoholics. METHODS: This study compared the prevalence of obsessive-compulsive traits (Leyton Obsessional Inventory) and depressive symptoms (Zung Self-Rating Depression Scale) among young (n=41) and middle-aged (n=34) hospitalized Japanese male alcoholics and in young (n=28) and middle-aged (n=25) nonalcoholic subjects. RESULTS: Both young and middle-aged male alcoholics reported more obsessive-compulsive personality traits and depressive symptoms than their comparison groups. However, the alcoholic subjects' obsessive-compulsive personality traits were not related to their level of depressive symptoms. CONCLUSIONS: Young and middle-aged male Japanese alcoholics have more obsessive-compulsive personality traits than nonalcoholic males of similar ages. Their alcohol-related psychological and behavioral characteristics may derive, in part, from their obsessive-compulsive symptoms.

Adult↗

Associations between white blood cell count and features of the metabolic syndrome in Japanese male office workers.

We assessed the association of white blood cell (WBC) count with different components of the metabolic syndrome (MS) in 5275 Japanese male office workers aged 23-59 years. There was a significantly crude correlation between WBC count and body mass index, systolic and diastolic blood pressures, total cholesterol, high-density lipoprotein cholesterol (negative), triglycerides, fasting plasma glucose, and uric acid (all P<0.001). After controlling for potential confounding factors, the adjusted means of WBC count were significantly higher in subjects with each feature of the MS (obesity, hypertension, hypercholesterolemia, low high-density lipoprotein cholesterol levels, hypertriglyceridemia, high fasting plasma glucose levels, and hyperuricemia) (all P<0.005). The adjusted WBC count increments in subjects with 1, 2, 3, 4, and > or = 5 features of the MS were 0.28, 0.45, 0.68, 0.76, and 1.40 x 10(9) cells/l, respectively, compared with the subjects without features of the MS (P for trend<0.001). The adjusted means of WBC count increased significantly with the increasing number of features of the MS in both non-smokers and smokers (both P<0.001). These data indicate a strong association between WBC count and a number of disorders characterizing the MS independent of cigarette smoking among Japanese men.

Adult↗

Distribution and cardiovascular risk correlates of serum triglycerides in young Japanese adults.

To examine the distribution and cardiovascular risk correlates of serum triglycerides, a cross-sectional population study based on annual health examinations at the workplace was performed in 2199 young Japanese adults aged 23 to 37 years. Triglyceride levels showed significant sex (male > female) differences, and the percentages of those with high triglycerides (> or = 150 mg/dl) were 9.4% for males and 0.8% for females. In terms of conjoint trait of dyslipidemia, 86.1% of males displayed normal levels of both triglycerides (< 150 mg/dl) and high-density lipoprotein (HDL) cholesterol (> or = 40 mg/dl), while 98.7% of females had normal values. Age- and sex-specific triglyceride levels above the 75th percentile (equivalent to 82-116 mg/dl for males and 56-63 mg/dl for females) increased the risk (odds ratio (OR)) for having obesity, hypertension, and hyperuricemia by 2.9 (95% confidence interval (CI)=2.0-4.3),1.7 (CI=1.1-2.9), and 3.0 (CI=1.6-5.9), respectively. The respective ORs for triglyceride levels above the 75th percentile and HDL cholesterol below the 25th percentile (equivalent to 45-49 mg/dl for males and 58-63 mg/dl for females), compared with triglyceride levels the 75th percentile or less and HDL cholesterol levels the 25th percentile or more, were 8.7 (CI=5.8-12.9), 2.2 (CI=1.5-3.3), and 6.0 (CI=3.2-11.5). Our results suggest a threshold effect of triglyceride levels considered as normal on enhanced cardiovascular risk in young Japanese adults, especially in those with low HDL cholesterol levels.

Adult↗

Acute aneurysm surgery using three-dimensional CT angiogrphy without conventional catheter angiography.

The object of this study is to assess whether aneurysm surgery can be performed in patients with ruptured cerebral aneurysms by using three-dimensional computerized tomography angiography (3D-CTA) alone, without conventional catheter angiography (CCA). Between May 1994 and November 1996, a consecutive series of 60 cases of ruptured cerebral aneurysms was evaluated by both 3D-CTA and CCA prospectively and compared the detectability of cerebral aneurysms. Both 3D-CTA and CCA demonstrated a 100% diagnostic accuracy of ruptured cerebral aneurysms. In the associated unruptured cerebral aneurysms, the diagnostic accuracies of 3D-CTA and CCA were 96% and 92%, respectively. Based on the results, we have operated on 128 consecutive patients with ruptured aneurysms in the acute stage based on 3D-CTA findings since December 1996. One hundred twenty eight ruptured aneurysms including 50 associated unruptured aneurysms were detected by 3D-CTA. In seven of 128 ruptured aneurysms, which included four dissecting vertebral artery aneurysms, two basilar artery (BA) tip aneurysms, and one BA-superior cerebellar artery (SCA) aneurysm, 3D-CTA was followed by CCA to obtain diagnostic confirmation or information concerning the vein of Labbé, which was needed to guide the surgical approach for BA tip aneurysms. All of the ruptured aneurysms were confirmed at surgery and treated successfully. One hundred twenty one patients who underwent surgery with 3D-CTA findings only had no complications related to the lack of information of CCA. The authors considered that 3D-CTA could replace CCA in the diagnosis of ruptured aneurysms and that surgery could be performed in almost all acutely ruptured aneurysms by using only 3D-CTA without CCA.

Acute Disease↗

[Line scan diffusion weighted imaging (LSDI) on 0.2 Tesla MRI of the normal cervical cord in vivo: preliminary study].

Diffusion weighted imaging(DWI) has been widely performed in the brain. However, DWI of the spinal cord is rarely performed because of technical and physiologic problems. Line scan diffusion weighted imaging(LSDI) is spin-echo based and relatively insensitive to susceptibility artifacts. We calculated the apparent diffusion coefficient(ADC) values of the normal cervical spinal cord by LSDI on a 0.2 Tesla MR imager and compared the ADC values with those from 1.5 Tesla MRI previously reported in the literature. The ADC values were adequate, and LSDI on 0.2 Tesla MRI is expected to become a useful tool for clinical application.

Adult↗