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Biomedical subjects

Mitsuo Iida

Publications and source records attributed to Mitsuo Iida.

At least 19 recordsLinked to original sources
PubMed2007

A nonsynonymous SNP in PRKCH (protein kinase C eta) increases the risk of cerebral infarction.

Cerebral infarction is the most common type of stroke and often causes long-term disability. To investigate the genetic contribution to cerebral infarction, we conducted a case-control study using 52,608 gene-based tag SNPs selected from the JSNP database. Here we report that a nonsynonymous SNP in a member of protein kinase C (PKC) family, PRKCH, was significantly associated with lacunar infarction in two independent Japanese samples (P = 5.1 x 10(-7), crude odds ratio of 1.40). This SNP is likely to affect PKC activity. Furthermore, a 14-year follow-up cohort study in Hisayama (Fukuoka, Japan) supported involvement of this SNP in the development of cerebral infarction (P = 0.03, age- and sex-adjusted hazard ratio of 2.83). We also found that PKCeta was expressed mainly in vascular endothelial cells and foamy macrophages in human atherosclerotic lesions, and its expression increased as the lesion type progressed. Our results support a role for PRKCH in the pathogenesis of cerebral infarction.

Case-Control Studies↗
PubMed2007

Role of substantia innominata in cerebral blood flow autoregulation.

Ascending projections from the substantia innominata (SI) may have an important role in the regulation of cerebral blood flow (CBF). However, several reports have suggested that unilateral lesion of the SI does not affect CBF autoregulation. On the other hand, it is also reported that several cortical and subcortical functions may be regulated not only by ipsilateral SI, but also by contralateral SI. Thus, the objective of this study is to test the hypothesis that bilateral lesions of the SI affect CBF autoregulation. Experiments were performed on anesthetized male Sprague-Dawley rats. Ibotenic acid or physiological saline was microinjected into bilateral SI. Rats were classified into four groups as follows: bilateral SI lesion rats (ibotenic acid was injected bilaterally), left or right SI lesion rats (ibotenic acid was injected into the unilateral SI and saline into the contralateral SI), and control rats (saline was injected bilaterally). Ten days after injection, CBF in the left frontal cortex was measured by laser-Doppler flowmetry during stepwise controlled hemorrhagic hypotension. In bilateral SI lesion rats, CBF was started to decrease significantly at 80 mm Hg (p<0.01). In the other three groups, CBF was well maintained until 50 mm Hg. Changes in CBF through stepwise hypotension in bilateral SI lesion rats were significantly different from the other groups (p<0.01). These results suggest that bilateral SI regulates cortical vasodilator mechanisms during hemorrhagic hypotension. Under unilateral SI lesion, some compensatory effects from the contralateral SI may maintain CBF autoregulation.

Analysis of Variance↗
PubMed2007

Impact of Phospholipase A2 group IIa gene polymorphism on phenotypic features of patients with familial adenomatous polyposis.

PURPOSE: Phospholipase A2 Group IIa has been suggested to be a possible disease modifier gene in familial adenomatous polyposis. This investigation was designed to elucidate possible association between phospholipase A2 Group IIa polymorphism and phenotypes of patients with familial adenomatous polyposis. METHODS: Phospholipase A2 Group IIa was examined by polymerase chain reaction-based single strand conformation polymorphism and direct sequencing in 55 patients from 45 families with familial adenomatous polyposis. The patients were examined by gastroduodenoscopy plus biopsy with respect to fundic gland polyposis and gastroduodenal adenomas. Helicobacter pylori status was determined by rapid urease test. Contributions of genetic alteration and Helicobacter pylori infection to intestinal and extraintestinal lesions were investigated. RESULTS: Four types of single nucleotide polymorphism were found in exon 3 of phospholipase A2 Group IIa, among which single nucleotide polymorphism in codon 32 was the most frequent. The prevalence of fundic gland polyposis was higher in patients positive for single nucleotide polymorphism of phospholipase A2 Group IIa than those negative for single nucleotide polymorphism (61 vs. 33 percent; P < 0.05). In contrast, positive rate of Helicobacter pylori infection was lower in the former than in the latter (22 vs. 52 percent; P < 0.05). The prevalence of the other phenotypes was not different significantly. Logistic regression analysis revealed a possibility toward single nucleotide polymorphism of phospholipase A2 Group IIa as an independent risk factor for fundic gland polyposis (95 percent confidence interval, 00.9-14.3; P = 0.06). CONCLUSIONS: Phospholipase A2 Group IIa may be a modifier gene for fundic gland polyposis in patients with familial adenomatous polyposis.

Adenomatous Polyposis Coli↗
PubMed2006

Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma: a clinicopathologic and molecular study with reference to antibiotic treatment.

BACKGROUND: The majority of gastric mucosa-associated lymphoid tissue (MALT) lymphoma develops in Helicobacter pylori-associated chronic gastritis. Little is still known regarding the clinicopathologic features of gastric MALT lymphoma not associated with H. pylori infection. METHODS: One hundred thirty-seven patients with gastric MALT lymphoma, in whom H. pylori status was evaluated using at least both serology and histology, were enrolled. Clinical, histopathologic, and molecular findings were compared between H. pylori-negative group (n = 12; 9%) and H. pylori-positive group (n = 125; 91%). t(11;18)(q21;q21) was investigated by reverse-transcription polymerase chain reaction and interphase fluorescence in situ hybridization. RESULTS: In cases without diffuse large B-cell lymphoma (DLBCL) component, H. pylori-negative lymphomas located more frequently in the proximal stomach (70%), less frequently appeared as superficial type (40%), and frequently invaded the submucosa or beyond (70%). Histologically, lymphoepithelial lesions (57%), lymphoid follicles (43%), and background mucosal atrophy (50%) in the H. pylori-negative group were less frequent than in the H. pylori-positive group (91%, 93%, and 100%, respectively). The frequencies of t(11;18)(q21;q21) (100%) and BCL10 nuclear expression (100%) in the H. pylori-negative group were significantly higher than in the H. pylori-positive group (2% and 27%, respectively). Response to antibiotic treatment was observed not only in the H. pylori-positive group (75%), but also in the H. pylori-negative group (2 of 7 patients, 29%). In cases with a DLBCL component, such differences were not observed between the 2 groups. CONCLUSIONS: H. pylori-negative gastric MALT lymphoma is characterized by frequent t(11;18)(q21;q21). Antibiotic treatment should be considered also for this disease, although cases with t(11;18)(q21;q21) may need additional strategies.

Adolescent↗
PubMed2006

Overt diabetes mellitus in a patient with combined primary aldosteronism and Cushing's syndrome.

Although there are some case reports of combined aldosterone and cortisol producing adrenal tumor, overt diabetes mellitus has been rarely described. A 55-year-old hypertensive woman had hypokalemia and overt hyperglycemia without Cushingoid clinical features. The body mass index was 18.2 kg/m2, fasting blood glucose was 302 mg/dl and hemoglobin A1c was 11.6%. Endogenous insulin secretion was well preserved, whereas insulin sensitivity measured by short insulin tolerance test was markedly impaired. A solitary left aldosterone- and cortisol-producing adrenal tumor was diagnosed. We described a rare case of overt diabetes mellitus in a patient with combined primary aldosteronism and Cushing's syndrome.

Adrenal Gland Neoplasms↗
PubMed2006

Postischemic gene transfer of soluble Flt-1 protects against brain ischemia with marked attenuation of blood-brain barrier permeability.

Brain edema is a major and often mortal complication of brain ischemia. Vascular endothelial growth factor (VEGF) is also known as a potent vascular permeability factor and may play detrimental roles at the acute stage of brain infarction. Our goal in this study was to explore protective effects of gene transfer of soluble flt-1 (sFlt-1), a natural inhibitor of VEGF, on focal brain ischemia. Adenoviral vector encoding sFlt-1 or beta-galactosidase as control was injected into the lateral ventricle 90 mins after photochemical distal middle cerebral artery occlusion in male spontaneously hypertensive rats. The transduced sFlt-1 was released to the cerebrospinal fluid from the ventricular wall and significantly increased 6 h, 1 and 7 days after sFlt-1 transfection. One day after brain ischemia, sFlt-1 gene transfer significantly reduced infarct volume (by 35%), brain edema (by 35%), and blood-brain barrier permeability (Evans blue extravasation; by 69%) with diminished phosphorylation of focal adhesion kinase (FAKtyr397 and FAKtyr861) in the ischemic vessels. Seven days after ischemia, sFlt-1 gene transfer also significantly attenuated infarct volume (by 29%) and monocyte/macrophage infiltration (by 27%), although there were no reductions in angiogenesis by sFlt-1 overexpression. These results suggest that sFlt-1 gene therapy targeting brain edema in acute stage of brain ischemia may be useful for brain infarction.

Animals↗
PubMed2006

Intramucosal gastric adenocarcinoma of poorly differentiated type in the young is characterized by Helicobacter pylori infection and antral lymphoid hyperplasia.

The aim of this investigation was to clarify the histological characteristics of gastric cancer in the young. Twenty-three surgically resected specimens of young patients (under 30 years of age; young group) with intramucosal cancer of poorly differentiated type and 42 surgically resected specimens of elderly patients (more than 40 years of age; elderly group) with tumors of the identical depth and histological type were examined. The degree of gastritis and Helicobacter pylori (H. pylori) infection was evaluated according to the updated Sydney system. The incidence of H. pylori infection was significantly higher in the young group than in the elderly group (96 vs 36%, P<0.05). Within the background mucosa, antral chronic inflammatory infiltrates with lymphoid-follicle hyperplasia were more severe, and intestinal metaplasia was less frequent in the young group than in the elderly group. Glandular atrophy was not different between the two groups. Intramucosal gastric adenocarcinomas of poorly differentiated type in the young may be associated with H. pylori infection with antral chronic inflammation with lymphoid-follicle hyperplasia, regardless of the existence of intestinal metaplasia within the background gastric mucosa.

Adenocarcinoma↗
PubMed2006

Role of amyloidosis in determining the prognosis of dialyzed patients with rheumatoid arthritis.

The role of secondary amyloidosis in determining the prognosis of dialyzed patients with rheumatoid arthritis (RA) was examined in 22 patients with a mean age of 60.1 years included 21 renal amyloidosis. RA duration until the start of dialysis was 19.5 +/- 7.2 years and the observation period after introduction 27.1 +/- 26.4 months. Of the 14 dead cases, four died due to sepsis, three due to gastrointestinal tract bleeding, two due to congestive heart failure, and eight cases died within 5 months after starting dialysis. When comparing the eight survivors and the nine non-survivors who died within 2 years after the start of dialysis, the former patients showed significantly higher serum albumin, and lower electrocardiogram score and cardiothoracic ratios at the time of introduction to dialysis. The careful prevention and treatment of infection, cerebrovascular and/or gastrointestinal tract complications seem to be necessary to improve the prognosis of RA patients after the initiation of renal replacement therapy.

Aged↗
PubMed2006

Expression of isoforms of NADPH oxidase components in rat pancreatic islets.

Increased oxidative stress plays a role in the pathogenesis of beta-cell dysfunction and death. We studied isoforms of NADPH oxidase components in islets of Langerhans isolated from rat pancreas and tumoral rat beta-cell line RINm5F cells by RT-PCR and sequencing of its products. RT-PCR revealed that isolated islets constitutively expressed mRNA of NADPH oxidase components, Nox1, Nox2, Nox4 and p22(phox) as membrane-associated components and p47(phox), Noxo1 (homologue of p47(phox)), Noxa1 (homologue of p67(phox)), and p40(phox) as cytosolic components. RINm5F cells showed a similar pattern of expression but Nox2 mRNA was not detected. Expression of Nox1, Nox4, Noxo1 and Noxa1 was confirmed by sequencing the PCR products. Immunohistochemistry revealed the expression of NADPH oxidase component in beta-cells of rat pancreatic islets. Glucose-stimulated insulin secretion from isolated islets was suppressed by diphenyleneiodonium, a flavocytochrome inhibitor, but not by apocynin, an inhibitor of p47(phox) translocation to membranes. Our results suggest that the functional significance of NADPH oxidase in insulin secretion may merit further investigation.

Animals↗
PubMed2006

Blood pressure changes during the initial week after different subtypes of ischemic stroke.

BACKGROUND AND PURPOSE: The purpose of this study was to clarify the differences in the acute blood pressure course among different ischemic stroke subtypes. METHODS: We divided 588 consecutive patients with acute brain infarction into four clinical subgroups to study the blood pressure levels during the initial 6 hospital days. RESULTS: During the 6 days, systolic blood pressure of lacunar and atherothrombotic patients was higher (P=0.0001) and diastolic blood pressure of lacunar patients was higher (P=0.0371) than of patients with the other subtypes. Preexisting hypertension was associated with elevated acute systolic blood pressure in all patients and in each subtype and with elevated acute diastolic blood pressure in all patients, cardioembolic patients, and patients with stroke of other etiology. After adjustment by preexisting hypertension, diabetes mellitus with a hemoglobin A1c >7.0% was associated with elevated systolic blood pressure in all, lacunar, and cardioembolic patients and with diastolic blood pressure in all patients. CONCLUSIONS: Blood pressure course of patients sustaining acute stroke varied widely according to stroke subtypes. Poorly controlled diabetes mellitus, as well as preexisting hypertension, appeared to influence blood pressure during the initial week of stroke.

Acute Disease↗
PubMed2006

Late-onset life threatening hemorrhage of omeprazole-resistant duodenal ulcer managed by interventional radiology: report of a case.

A 67-year-old diabetic man was emergently hospitalized in our department because of a huge duodenal ulcer without visible vessels. Despite of intravenous administration of 40 mg omeprazole and fasting with intravenous nutritional support, endoscopically unmanageable massive bleeding occurred on the 8th hospital day. Emergent angiography showed extravasation of contrast media from a duodenal branch of the proper hepatic artery, and superselective arterial embolization was successfully achieved. The patient recovered from the hemorrhagic shock and underwent subsequent successful surgery. Analysis of CYP2C19 enzyme genotype indicated the patient was a homozygous extensive metabolizer, considered a poor responder for omeprazole treatment.

Aged↗
PubMed2006

Endoscopic features of chronic nonspecific multiple ulcers of the small intestine: comparison with nonsteroidal anti-inflammatory drug-induced enteropathy.

Chronic nonspecific multiple ulcers of the small intestine (CNSU) and nonsteroidal anti-inflammatory drug-induced enteropathy (NSAID-enteropathy) share common clinicopathologic features characterized by histologically nonspecific ulcers and persistent blood loss. The aim was to compare enteroscopic findings between CNSU and NSAID-enteropathy. Four patients with CNSU and five patients with NSAID-enteropathy were examined by enteroscopies. The site of involvement was heterogeneous in NSAID-enteropathy, while the ileum was the predominant site in CNSU. Three patients with NSAID-enteropathy and all four patients with CNSU had concentric stenosis. Circular ulcers were found in all five patients with NSAID-enteropathy and in three patients with CNSU. Active ulcer was seen in only two patients with NSAID-enteropathy. In contrast, all four patients with CNSU had active ulcer. These findings suggest that in patients with persistent GI bleeding and enteroscopically active small intestinal ulcers, CNSU, as well as NSAID-enteropathy, should be considered.

Adolescent↗
PubMed2006

A prospective study of dietary salt intake and gastric cancer incidence in a defined Japanese population: the Hisayama study.

The results of prospective studies of the association between dietary salt intake and gastric cancer occurrence remain controversial. To examine this issue in a cohort study of a general population, 2,476 subjects aged 40 years or older were stratified into 4 groups according to the amount of daily salt intake: namely, <10.0, 10.0-12.9, 13.0-15.9, and > or = 16.0 per day and were followed up prospectively for 14 years. During the follow-up period, 93 subjects developed gastric cancer. The age- and sex-adjusted incidence was significantly higher in the second to fourth groups than in the first group (age- and sex-adjusted hazard ratio [95% confidence interval], 2.42 [1.24-4.71] for the second group; 2.10 [1.03-4.30] for the third group; 2.98 [1.53-5.82] for the fourth group). This association remained substantially unchanged even after adjusting for other confounding factors such as age, sex, Helicobacter pylori infection, atrophic gastritis, medical history of peptic ulcer, family history of cancer, body mass index, diabetes, total cholesterol, physical activity, alcohol intake, smoking habit and other dietary factors. In the stratified analysis, a significant salt-cancer association was observed only in subjects who had both Helicobacter pylori infection and atrophic gastritis (age- and sex-adjusted hazard ratio, 2.87 [1.14-7.24]). Our findings suggest that high dietary salt intake is a significant risk factor for gastric cancer; moreover, this association was found to be strong in the presence of Helicobacter pylori infection with atrophic gastritis.

Adult↗
PubMed2006

Accuracy of conventional plus transoral carotid ultrasonography in distinguishing pseudo-occlusion from total occlusion of the internal carotid artery.

BACKGROUND: To investigate the accuracy of conventional carotid ultrasonography (CCU) combined with transoral carotid ultrasonography (TOCU) for distinguishing pseudo-occlusion from total occlusion of the internal carotid artery (ICA). METHODS: This study included 95 patients who were suspected of having an occlusion of the ICA on magnetic resonance angiography (MRA) and underwent both CCU and conventional digital subtraction angiography (DSA) in order to confirm the diagnosis. TOCU was also performed to observe the cervical portion of the ICA distal to the stenosis. We compared the ultrasonographic findings with the DSA findings. RESULTS: Twelve of the 95 patients were defined as having an ICA pseudo-occlusion on DSA. On B-mode images with CCU color Doppler, slight residual flow signals in the ICA lumen were shown in 20 patients. Among them, 2 patients had a pulsed Doppler waveform of the distal ICA occlusion pattern. Among the remaining 18 patients, 4 had a pulsed Doppler waveform of the to and fro flow pattern, and 14 had a weak antegrade flow pattern in the ICA lumen. The conventional ultrasonographic method showed 100% sensitivity with 93% specificity for diagnosing an ICA pseudo-occlusion. The addition of TOCU findings increased the specificity to 98%. In 2 patients, who were overdiagnosed as having an ICA pseudo-occlusion even using TOCU, DSA revealed an occlusion of the ICA distal to the ophthalmic artery with a severe stenosis of the proximal ICA. CONCLUSIONS: Using conventional and transoral carotid ultrasonography, an ICA pseudo-occlusion can be diagnosed with higher accuracy.

Aged↗
PubMed2006

Changes in brain volume 2 years after extracranial-intracranial bypass surgery: A preliminary subanalysis of the Japanese EC-IC trial.

BACKGROUND AND METHODS: We studied changes in brain volume on magnetic resonance imaging in 10 patients with and without extracranial-intracranial (EC-IC) bypass surgery who met the inclusion criteria for the Japanese EC-IC Bypass Trial, a multicenter, randomized, prospective study of patients with hemodynamic brain ischemia due to cerebral artery occlusive disease. We also examined the association of cerebral hemodynamics on single-photon emission computed tomography with the changes in brain volume. RESULTS: The affected/unaffected ratio of the percent brain volume declined in patients without EC-IC bypass surgery (p < 0.02, n = 4), and the affected/unaffected percent regional cerebral blood flow ratio increased in patients with the surgery (p < 0.03, n = 6). Acetazolamide reactivity increased in the affected hemisphere of patients with surgery (p < 0.01). Two-year increase (decrease) in acetazolamide reactivity of the affected hemisphere showed a significant positive correlation with 2-year changes in the affected/unaffected percent brain volume ratio (R2 = 0.737, p = 0.0007). CONCLUSIONS: Change in acetazolamide reactivity might be a good predictor for brain atrophy in cerebral artery occlusive disease.

Acetazolamide↗
PubMed2006

Expression of synaptopodin and GLEPP1 as markers of steroid responsiveness in primary focal segmental glomerulosclerosis.

The crucial involvement of podocyte failure in the development of hereditary focal segmental glomerulosclerosis (FSGS) indicates that specific podocyte proteins are closely related to podocyte function and biology. We hypothesized that podocyte failure, reflected by alteration of these proteins, leads not only to FSGS but also to resistance to steroid therapy. We investigated the association between expression of synaptopodin and glomerular epithelial protein 1 (GLEPP1) and response to corticosteroid therapy in primary FSGS. The subjects of this retrospective study were 17 adult patients with primary FSGS with nephrotic syndrome (NS) seen at Fukuoka Red Cross Hospital between 1979 and 2001. They were divided into two groups according to the response to steroid therapy at 6months: responders (n=10) and non-responders (persistence of nephrotic-range proteinuria, n=7). Expression levels of synaptopodin and GLEPP1 were examined immunohistochemically using image analysis software. Low expression levels of both proteins were associated with poor steroid responsiveness in FSGS. The average gray values for synaptopodin and GLEPP1 expression in responders vs. non-responders were 9.0+/-0.7 (mean+/-S.E.M.) vs. 6.3+/-0.9 (P=0.04) and 9.6+/-1.2 vs. 6.0+/-1.0 (P=0.04), respectively. The percentages of glomerular area staining for synaptopodin and GLEPP1 in responders vs. non-responders were 15.4+/-2.7% vs. 8.1+/-1.2% (P=0.045) and 11.9+/-1.6% vs. 6.0+/-1.3% (P=0.02), respectively. Synaptopodin expression correlated with the severity of proteinuria and with GLEPP1 expression. Reduced expression of both synaptopodin and GLEPP1 is associated with poor response to steroid therapy in primary FSGS.

Adult↗
PubMed2006

Rapid intracellular acidification and cell death by H2O2 and alloxan in pancreatic beta cells.

Pancreatic beta-cell death induced by oxidative stress plays an important role in the pathogenesis of diabetes mellitus. We studied the relation between rapid intracellular acidification and cell death of pancreatic beta-cell line NIT-1 cells exposed to H2O2 or alloxan. Intracellular pH was measured by a pH-sensitive dye, and cell damage by double staining with Annexin-V and propidium iodide using flow cytometry. H2O2 and alloxan caused a rapid fall in intracellular pH and suppressed Na+/H+ exchanger activity in the NH4Cl prepulse method. H2O2 induced necrotic cell death, which shifted to apoptotic cell death when initial acidification was prevented by pH clamping to 7.4 using nigericin (unclamped cells vs clamped cells, necrosis 43.8 +/- 5.8% vs 21.1 +/- 10.6%, P < 0.05; apoptosis 8.0 +/- 1.9% vs 44.5 +/- 5.0%, P < 0.01). pH-clamped cells showed enhanced caspase 3 activity and proapoptotic Bax expression. On the other hand, NIT-1 cells were resistant to alloxan toxicity, but treatment with alloxan and nigericin strikingly enhanced the cytotoxicity. Antioxidants partly prevented cell death, although intracellular pH remained similarly acidic. The rapid intracellular acidification was not the cause of cell death but a significant determinant of the mode of death of H2O2 -treated beta cells, whereas no link between cell death and acidification was demonstrated in alloxan toxicity.

Animals↗