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Biomedical subjects

Masahiro Yoshida

Publications and source records attributed to Masahiro Yoshida.

At least 37 records · Page 2Linked to original sources
PubMed2005

Inhaled nitric oxide therapy after Fontan-type operations.

PURPOSE: Inhaled nitric oxide (NO) therapy is a newly developed strategy designed to reduce pulmonary vascular resistance after the Fontan-type operation. We reviewed our experience to evaluate its efficacy and true indications. METHODS: We retrospectively examined 47 children who received inhaled NO therapy after the Fontan-type operation between August 1996 and December 2002. The maximal dose of NO ranged from 5 to 30 ppm (median 10 ppm), and the duration of inhaled NO therapy ranged from 5 h to 52 days (median 2 days). RESULTS: Inhaled NO significantly decreased the central venous pressure (CVP), from 16.2 +/- 2.2 to 14.6 +/- 2.2 mmHg (P < 0.0001), and the transpulmonary pressure gradient between the CVP and left atrial pressure, from 9.9 +/- 2.9 to 8.4 +/- 2.7 mmHg (P < 0.0001). It also increased the systolic systemic arterial pressure from 71.9 +/- 15.2 to 76.8 +/- 14.5 mmHg (P < 0.05). In 26 patients with additional fenestration, inhaled NO led to a significant improvement in SaO(2) from 90.1% +/- 9.6% to 93.3% +/- 7.9% (P < 0.01). However, patients with a CVP <15 mmHg or a transpulmonary pressure gradient <8 mmHg, or both, after the Fontan-type operation, showed no significant changes in hemodynamics during inhaled NO therapy. CONCLUSIONS: We propose that a CVP >/=15 mmHg or a transpulmonary pressure gradient >/=8 mmHg, or both, after Fontan-type operations are appropriate indications for inhaled NO therapy.

Administration, Inhalation↗
PubMed2005

Appropriate additional pulmonary blood flow at the bidirectional Glenn procedure is useful for completion of total cavopulmonary connection.

BACKGROUND: The role and effect of additional pulmonary blood flow at the time of bidirectional Glenn procedure (BDG) is controversial. We assessed our experiences to clarify the effects of controlled additional pulmonary blood flow on outcomes after BDG. METHODS: Thirty-eight patients who underwent BDG (2.1 +/- 2.1 years of age) were enrolled in this study. In group A (n = 29) additional pulmonary blood flow was controlled by the banding of the pulmonary trunk, or the previously created Blalock-Taussig shunt, to keep the central venous pressure equal to or less than 16 mm Hg at BDG. In group B (n = 9), BDG was the only source of pulmonary blood flow. RESULTS: One operative death occurred in group B. In group A, 24 patients underwent total cavopulmonary connection (TCPC) 14 +/- 6 months after BDG, and the remaining 5 patients are waiting for TCPC in good condition. In group B, 6 patients underwent TCPC 8 +/- 7 months after BDG. One patient is awaiting TCPC and the remaining patient is considered unsuitable for TCPC. Cardiac catheterization performed in 32 patients showed significant decrease of pulmonary artery (Nakata) index from 307 +/- 73 to 215 +/- 45 mm2/m2 after BDG in group B (p < 0.05). On the other hand, the Nakata index stayed in higher range from 316 +/- 115 to 287 +/- 74 mm2/m2 in group A, and there was a significant correlation between the Nakata index and the percentage of its difference (Y = 40.823 - 0.144 X; n = 26, R = 0.740, p < 0.0001). CONCLUSIONS: Appropriate additional pulmonary blood flow is useful for the completion of TCPC by means of suppressing the decrease in the size of the pulmonary artery, especially in patients with underdeveloped pulmonary arteries.

Cardiac Output↗
PubMed2005

Hemodynamic changes of splenogastric circulation after spleen-preserving pancreatectomy with excision of splenic artery and vein.

BACKGROUND: The safety of spleen conservation without preservation of the splenic artery and vein was proved on the basis of short-term observation, but the long-term results of this procedure have been uncertain. To clarify the hemodynamic changes of splenogastric circulation of patients undergoing spleen-preserving pancreatectomy with excision of the splenic artery and vein, we retrospectively analyzed patient outcome with particular reference to the assessment of hemodynamic changes of splenogastric circulation. METHODS: Ten patients who had undergone spleen-preserving pancreatectomy with excision of the splenic artery and vein were retrospectively analyzed. In all patients both the short gastric and left gastroepiploic arteries and veins were preserved. All patients were observed for a minimum of 52 months. Collateral venous pathways were evaluated by computed tomography and endoscopy. RESULTS: Early complications such as splenic infarction and atrophy did not occur in any of the patients, but computed tomography revealed perigastric varices in 7 patients (70%) and submucosal varices in 2 patients (20%). Endoscopy showed gastric varices in 2 patients in whom submucosal gastric varices were identified on computed tomography. Gastrointestinal bleeding from gastric varices occurred in 1 patient. In 1 patient without gastric varices, a gastrorenal shunt was demonstrated on computed tomography. CONCLUSIONS: This study confirmed that gastric varices frequently occurred in patients who underwent spleen-preserving pancreatectomy with excision of the splenic artery and vein.

Esophageal and Gastric Varices↗
PubMed2005

First episodes of behavioral symptoms in Alzheimer's disease patients at age 90 and over, and early-onset Alzheimer's disease: comparison with senile dementia of Alzheimer's type.

We evaluated dementia symptoms to clarify the character of dementia with Alzheimer's disease (AD) observed in the oldest old patients and that of dementia with early-onset AD. Subjects were consecutive AD inpatients admitted for the first time at age of 90 years and over because of behavioral symptoms (demented nonagenarian group: D90G; n=18) and those with 24 consecutive inpatients with AD with early-onset (EOG). The Gottfries, Brane and Steen's scale and the Dementia Behavior Disturbance scale were used to evaluate the symptoms and troublesome behaviors. The scores of these scales in D90G and in EOG were compared with those of 26 sex distribution-, severity of dementia-, and disease duration-matched inpatients with AD with late-onset (LOG). Compared with LOG, wakefulness was more impaired and waking up at night was more frequent in D90G, while memory, orientation and inappropriate behaviors were more severe in EOG. These results suggest that the clinical features of dementia in EOG were quantitatively different from those of LOG. In contrast, the clinical feature of dementia of D90G were sleep-wake pattern disturbance and were qualitatively different from those of LOG.

Age of Onset↗
PubMed2004

Candidate cis-elements for human renin gene expression in the promoter region.

The regulation of renin gene expression, the rate-limiting enzyme of the system, is thought to be fundamental to the total system. Previously, we mapped six putative cis-elements in the promoter region of the human renin gene with nuclear proteins from human chorionic cells and human renal cortex by DNase I protection assay (footprint A-F). Each footprint contains Ets motif like site (A), HOXñPBX recognition sequence (B), unknown sequence as DNA binding consensus (C), CRE (D), COUP-TFII (ARP-1) motif like site (E), and AGE3 like site (F). Footprint D has been characterized by means of functional studies as the genuine human renin gene CRE interacting with CREB in cooperation with the site of footprint B. To obtain further clues to the specific expression in the promoter region, these putative cis-elements were conducted to a consensus-specific binding assay to compare renin-producing and non-renin-producing cells by EMSA and electromobility super-shift assay. Different sequence-specific DNA/protein binding was obtained among the different cell lines with footprint B site, with COUP-TFII (ARP-1) motif like site and possibly with footprint F site. The results implicate these putative cis-elements and each corresponding trans-factor in the specific expression of the human renin gene in the promoter region. Further functional characterization of these elements would provide important data for a better understanding of human renin gene expression.

Animals↗
PubMed2004

Palladium-catalysed cascade ring expansion reaction of cyclobutanols that have a propargylic moiety with nucleophiles.

Cascade ring rearrangement of four-membered ring systems containing various propargylic components by a palladium catalyst is described. The reactions of cyclobutanols that have a propargylic carbonate moiety with phenols as nucleophiles produce phenoxy-induced cyclopentanones in high yields. The reactions proceed in a regio- and diastereoselective manner to afford the substituted cyclopentanones with high selectivities. Imides also act as nucleophiles to produce the imidyl-induced products. Propargylic bromide successfully reacts with sodium alkoxides to produce the corresponding products in good yields.

Journal Article↗
PubMed2004

Novel methodologies for the synthesis of cyclic carbonates.

Cyclic carbonates are valuable compounds that have applications in a variety of chemical fields. Methodologies for the synthesis of cyclic carbonates are well investigated in recent years, and the most successful and popular procedure is the utilization of CO(2). This paper presents recent progress in the synthesis of cyclic carbonates by a CO(2)-fixation process, which involves novel palladium-catalyzed CO(2)-recycling reactions.

Journal Article↗
PubMed2004

Palladium-catalyzed ring expansion reaction of (Z)-1-(1,3-butadienyl)cyclobutanols with aryl iodides. stereospecific synthesis of (Z)-2-(3-aryl-1-propenyl)cyclopentanones.

[reaction: see text] A novel type of cascade ring expansion process has been developed by the palladium-catalyzed reaction of (Z)-1-(1,3-butadienyl)cyclobutanols with aryl iodides. The reaction proceeds in a stereospecific manner to produce (Z)-2-(3-aryl-1-propenyl)cyclopentanones. It has also been found that regioselective alpha-arylation of alkenyl cyclopentanones proceeds to afford the alpha-arylated cyclopentanones.

Butanols↗
PubMed2004

Diagnostic use of serum deoxyribonuclease I activity as a novel early-phase marker in acute myocardial infarction.

BACKGROUND: The delayed release of serum cardiac markers such as creatine kinase isoenzyme MB and equivocal early electrocardiographic changes have hampered a diagnosis of acute myocardial infarction (AMI) in the early phase after its onset. Therefore, a reliable serum biochemical marker for the diagnosis of AMI in the very early phase is desirable. METHODS AND RESULTS: Serum samples were collected from the patients with AMI, unstable angina pectoris, stable angina pectoris, and other diseases. Levels of serum deoxyribonuclease I (DNase I) activity in the patients were determined. An abrupt elevation of serum DNase I activity was observed within approximately 3 hours of the onset of symptoms in patients with AMI, with significantly higher activity levels (21.7+/-5.10 U/L) in this group compared with the other groups with unstable angina pectoris (10.4+/-4.41 U/L), angina pectoris (10.8+/-3.70 U/L), and other diseases (9.22+/-4.16 U/L). Levels of the DNase I activity in serum then exhibited a marked time-dependent decline within 12 hours and had returned to basal levels within 24 hours. CONCLUSIONS: We suggest that serum DNase I activity could be used as a new diagnostic marker for the early detection of AMI.

Adult↗
PubMed2004

Palladium-catalyzed carbon dioxide elimination-fixation reaction of 4-methoxycarbonyloxy-2-buten-1-ols.

A new type of palladium-catalyzed CO(2) recycling reaction using allylic carbonates is described. Reaction of trans-4-methoxycarbonyloxy-2-buten-1-ols in the presence of a palladium catalyst produces cyclic carbonates having a vinyl group via a CO(2) elimination-fixation process. A variety of allylic carbonates participate in the reaction giving cyclic carbonates with high efficiencies. Stereoselective construction of trans-cyclic carbonates is achieved by using nonsymmetric substrates. An enantiospecific reaction proceeds to give chiral cyclic carbonate when a chiral methyl-substituted substrate is subjected to the reaction conditions.

Journal Article↗
PubMed2004

Localization of islet-cell hyperplasia: value of pre- and intraoperative arterial stimulation and venous sampling.

Arterial stimulation and venous sampling was effective in the localization of Beta-cell hyperplasia of the pancreas in the islets of Langerhans in an 84-year-old woman. The patient presented with repeated episodes of unconsciousness and hypoglycemia. She was first suspected of having insulinoma, but diagnostic imaging failed to reveal any tumors. Arterial stimulation and venous sampling (ASVS) and percutaneous transhepatic portal venous sampling (PTPS) were performed to localize the tumor. By ASVS, increases in immuno reactive insulin (IRI) were noted in renal vein blood samples (because a splenorenal shunt was present) after splenic arterial stimulation and venous sampling, and PTPS revealed a stepup in IRI from splenic venous blood samples. Preoperative diagnosis suggested Beta-cell hyperplasia in the pancreas tail. Intraoperative ultrasound failed to find a tumor. Intraoperative ASVS showed the site of increase IRI as the pancreas tail, so distal pancreatectomy and splenectomy were performed. However, hypoglycemia was observed constantly after this operation. Relaparotomy, causing additional resection, was conducted to confirm the precise location and to remove the residual Beta-cell hyperplasia of the pancreas. At the second resection, the existing part of Beta-cell hyperplasia was confirmed through intraoperative ASVS, and additional resection of the pancreas body and neck was performed. At this time, complete removal of the residual Beta-cell hyperplasia was confirmed through ASVS. The hypoglycemia and impaired consciousness disappeared after the operation, and the patient's blood sugar level was maintained at a normal level. Pathological findings revealed islets of Langerhans hyperplasia extending to 1 cm in the pancreas tail region. We conclude that pre- and intraoperative ASVS is a useful test for Beta-cell hyperplasia, which is difficult to diagnose through ordinary imaging techniques.

Aged↗
PubMed2004

A duodenum-preserving and bile duct-preserving total pancreatic head resection with associated pancreatic duct-to-duct anastomosis.

A duodenum-preserving pancreatic head resection technique was first reported in 1980, but the indications have been limited to benign pancreatic disease as it involves a subtotal pancreatic head resection. In 1988 we detailed a duodenum-preserving total pancreatic head resection (DPTPHR) technique. This procedure involved a total pancreatic head resection and as such expanded the indications for this approach to include tumorigenic masses. The original method involved closure of the proximal pancreatic duct and an anastomosis of the pancreatic duct of the distal pancreas to a newly created small hole in the duodenum (we termed this a "pancreatoduodenostomy"). Our current technique involves a duct-to-duct anastomosis of the proximal pancreatic duct and the distal pancreas to better preserve anatomic structure. DPTPHR was performed in 26 patients from 1988 to 2002, including 12 cases of DPTPHR with pancreatoduodenostomy and 14 cases of DPTPHR with pancreatic duct-to-duct anastomosis. No differences were observed between the two methods with respect to operative time or blood loss during surgery. Postoperatively, there was one case of cholecystitis and one case of pancreatitis in a patient who underwent a pancreatoduodenostomy; both of these patients were treated conservatively with curative intent. No complications were observed in the group undergoing duct-to-duct anastomosis. The advantage of duct-to-duct anastomosis is that the pancreatic head is totally resected, thus allowing removal of neoplastic disease such as an intraductal papillary mucinous tumor and also therapy for chronic pancreatitis. A key benefit of this procedure is that sphincter function of the duodenal papilla is preserved permitting drainage of pancreatic/bile juice into the duodenum, preserving a more physiologic state than is the case after a pancreatoduodenostomy.

Anastomosis, Surgical↗
PubMed2004

Differential diagnosis of hepatic nodules using delayed parenchymal phase imaging of levovist contrast ultrasound: comparative study with SPIO-MRI.

T2-weighted fast spin echo images and T2*-weighted gradient-echo images of superparamagnetic iron oxide magnetic resonance imaging (SPIO-MRI) have been reported to reflect the number and function of macrophages in reticuloendothelial organs and be useful to differentiate malignant tumors from benign nodules of liver. We tried to prove that contrast-enhanced ultrasound can diagnose hepatocellular carcinoma (HCC) by comparing the findings of SPIO-MRI and the findings of the liver parenchyma on the delayed parenchymal phase of ultrasound imaging using the intravenous contrast agent Levovist, not through the evaluation of vascular imaging. Forty-six patients (52 nodules) with histopathological diagnosis of hepatic tumors were studied. They consisted of 11 non-malignant nodules (six regenerative nodules and five dysplastic nodules) and 41 HCC. All the patients were examined by Levovist contrast-enhanced ultrasonography and SPIO-MRI. The delayed liver parenchymal images of contrast-enhanced ultrasound using the intravenous contrast agent Levovist were similar to those observed on SPIO-MRI. The similarity of both findings suggests that delayed phase imaging by Levovist is closely related to the number and function of Kupffer cells in liver tumors. The diagnostic accuracy of contrast-enhanced ultrasound for HCC was high (90.4%) demonstrating that it is as reliable as SPIO-MRI.

Journal Article↗
PubMed2004

17beta-estradiol up-regulates prostacyclin production in cultured human uterine myometrial cells via augmentation of both cyclooxygenase-1 and prostacyclin synthase expression.

OBJECTIVE: To investigate whether 17beta-estradiol elevates prostacyclin (PGI(2)) production in human myometrial cells in the middle of gestation. METHODS: The concentration of 6-keto-PGF(1alpha), a stable metabolite of PGI(2), in the culture medium was assessed using enzyme-linked immunosorbent assay (ELISA). Western blot analysis and quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) using TaqMan (Applied Biosystems, Foster City, CA) technology were performed to evaluate the expression of cytosolic phopholipase A(2) (cPLA(2)), cyclooxygenase-1 (COX-1), COX-2, and prostacyclin synthase (PGIS) in cultured human myometrial cells prepared from second trimester pregnant women (n = 3) after stimulation with 17beta-estradiol. RESULTS: Treatment with 17beta-estradiol (4-400 nM) dose-dependently elevated PGI(2) secretion from cultured human myometrial cells. Western blot analysis detected cPLA(2) and COX-1 and PGIS protein expression in the cultured human myometrial cells; however, COX-2 protein expression was below the detection sensitivity. Stimulation with 40-nM 17beta-estradiol significantly up-regulated protein and mRNA expression of both COX-1 and PGIS. CONCLUSION: 17beta-Estradiol from placenta may contribute to the augmentation of PGI(2) production in the human myometrium in the middle of gestation via up-regulation of both COX-1 and PGIS expression.

6-Ketoprostaglandin F1 alpha↗
PubMed2004

Tricuspid valve repair with papillary muscle shortening for severe tricuspid regurgitation in children.

We describe tricuspid valve repair using papillary muscle shortening for severe tricuspid regurgitation due to leaflet prolapse in children combined with De Vega annuloplasty. The papillary muscle was shortened until the prolapsed leaflet was at the same height as the other nonprolapsed leaflets. Although echocardiographic tricuspid regurgitation tends to increase over time, it rarely requires long-term intervention.

Abnormalities, Multiple↗
PubMed2004

Efficacy of a criterion-driven transfusion protocol in patients having pediatric cardiac surgery.

OBJECTIVES: Low-hematocrit bypass is one technique used to prevent allogeneic transfusion during cardiopulmonary bypass. The purpose of this study is to determine the efficacy of a criterion-driven transfusion protocol and the effect of low-hematocrit bypass with moderate hypothermia in pediatric cardiac surgery. METHODS: Seventy-five children who underwent cardiopulmonary bypass with low-hematocrit bypass for repair of congenital heart disease were studied. Criteria for red blood cell transfusion included anemia with a hematocrit level of less than 15% during bypass and 20% after bypass. During cardiopulmonary bypass, venous oxygen saturation, hematocrit values, and regional cerebral oxygenation were continuously monitored. Arterial lactate levels were measured postoperatively. RESULTS: All patients had an uncomplicated perioperative course, and no perioperative death occurred. Twenty-two patients (29.3%) received a transfusion, and 53 (70.7%) patients did not. The hematocrit levels before and after modified ultrafiltration in the transfused group (21.6 +/- 5.5%, 26.6 +/- 6.5%) were significantly higher than those in the nontransfused group (18.9 +/- 3.7%, 23.1 +/- 4.1%) (P <.05). There was no significant difference between the group's arterial lactate levels immediately after admission to the intensive care unit and 1 day after the operation. The arterial lactate levels 6 hours after the admission to the intensive care unit for the nontransfused patients were higher than with the transfused patients (4.3 +/- 3.0 versus 2.5 +/- 1.5 mmol/L, (P <.05). For arterial lactate level, the relation with patients' weight had the highest correlation (R = 0.678, P <.0001). CONCLUSIONS: A criterion-driven transfusion program can be effective, and low-hematocrit bypass with a hematocrit value below 20% may affect lactate production or clearance from the body.

Adolescent↗