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Biomedical subjects

Y Irie

Publications and source records attributed to Y Irie.

At least 55 records · Page 3Linked to original sources

[Aortic valve operations through an upper partial sternotomy].

The median sternotomy has been accepted as the most common approach to the heart, because this approach is easily opened and closed, and easy access to the entire heart is possible. Following the pioneering work by Cosgrove and colleagues of using a parasternal incision for aortic and mitral valve operations, several reports suggested that modified minimal access procedures are likely to be associated with reduced postoperative discomfort and faster recovery. Since July 1997, we have used an upper partial sternotomy and a limited skin incision for isolated aortic valve replacement (AVR) at our hospital. To demonstrate the benefits of this approach, we compared 14 AVR operations using our minimal access incision (group M) with 19 patients undergoing isolated AVR using a conventional sternotomy (group F). In the minimal access group of patients, a small skin incision was made from the second intercostal space to the fourth rib. The pectralis major and intercostal muscle was freed from the sternum, and then a transverse half sternotomy was made in the fourth intercostal space using a striker without injury to the right internal mammary artery. A median partial sternotomy from the supersternal notch to the level of the fourth intercostal space. Cardiopulmonary bypass was connected through the same access site to avoid cannulation of both groins. Conversion to median sternotomy was not necessary in any patient including reexploration for postoperative bleeding. There was no operative mortality, stroke, aortic dissection and perivalvular leaks due to technical factors. In group F, wound infection occurred in 1 patient. One patient in group M required reoperation to control postoperative bleeding. Although mean duration of operation, cardiopulmonary bypass, and cross clamp time in group M was not prolonged, the initiation of cardiopulmonary bypass and aortic crossclamp was delayed by difficulties of cannulations. The distance between the transverse sternotomy (lower edge of divided sternum) and the midpoint of aortic valve annulus was correlated with mean duration of cardiopulmonary bypass and cross clamp time. Our experience demonstrates that isolated AVR through an upper partial sternotomy allows the same quality operations as the full sternotomy, although more clinical experience is required to clarify the benefits of this approach. Excellent exposure of the aortic valve through a partial sternotomy may be attained, if an adequate approach can be selected by the position of aortic valve.

Aortic Valve↗

[Double chambered right ventricle in a 62-year-old female: a surgical case report].

A 62-year-old female was admitted with a chief complaint of transient syncope on exertion. Angiography in right ventricle revealed a defect caused by an anomalous muscle bundle and a pressure gradient of 151 mmHg was observed between the two chambers by cardiac catheterization. Resection of the anomalouse muscle bundle was undertaken using a lower median sternotomy starting at the 2nd intercostal space level and through the outflow tract right ventriculotomy. Patch plasty was also undertaken in the outflow tract. Post-operative course was uneventful and pressure gradient had disappeared at the post-operative catheterization. A rare case of DCRV in a 62-year-old patient with a pressure gradient of 151 mmHg in the right ventricle was reported.

Cardiac Surgical Procedures↗

Endothelial cell responses to chitin and its derivatives.

The effects of chitin and its derivatives on the proliferation of human umbilical vein endothelial cells (HUVECs) and on the production of cytokines were examined in vitro. Chitin and its derivatives had no effect on the proliferation of cultured HUVECs. N-Sulfonated 70% deacetylated chitin (S-DAC70) stimulated the production of interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha from HUVECs. Compared to S-DAC70, the other materials tested in the present study showed less effect in the stimulation of IL-8 and TNF-alpha production and had no effect in the stimulation of IL-1beta and IL-6 production. These results indicated that S-DAC70 affects HUVECs function but not proliferation.

Biocompatible Materials↗

Trapdoor thoracotomy as a surgical approach for aortic arch aneurysm.

Since 1991 ten patients, 9 male and 1 female, with aortic arch aneurysm underwent surgical therapy with trapdoor thoracotomy. The mean age was 67.4 +/- 9.1 (standard deviation) years at operation. In addition to the aortic arch repair, we also performed seven descending aortic replacements. We performed one partial arch replacement, one total arch replacement, and one aneurysmorrhaphy and wrapping of the aortic arch aneurysm. We experienced 1 case of paraplegia, no hospital death, and no long-term mortality.

Aged↗

Cryoglobulinaemia among maintenance haemodialysis patients and its relation to hepatitis C infection.

It has been shown that hepatitis C virus (HCV) infection is closely associated with mixed type cryoglobulinaemia. It is also known that HCV infection is rampant among chronic haemodialysis patients. We studied 531 renal failure patients on maintenance dialysis including 170 with positive HCV antibodies for cryoglobulinaemia, and its incidence was compared with controls which consisted of 242 chronic hepatitis C patients without renal failure and 183 healthy adults. Cryoglobulinaemia was present in 30.6% of dialysis patients with HCV infection, 10.8% of dialysis patients without HCV infection, 29.8% of patients with chronic hepatitis C without renal failure, and 0% of healthy adults. Among the 30 new renal failure patients who were started on dialysis within 6 months, four were positive for HCV antibodies, and one of them had cryoglobulinaemia; of the 26 HCV-negative patients, four (15%) were cryoglobulinaemic. The cryocrit values among dialysis patients were much lower than those of the control cases and other reports on non-dialysis cases. Patients with cryoglobulinaemia were generally younger compared with patients negative for this condition. There was no correlation between cryoglobulinaemia and past blood transfusion, underlying disease or length of dialysis. Cryoglobulinaemic patients seem to develop renal failure at relatively young ages and a considerable proportion of cryoglobulinaemic dialysis patients may have already had cryoglobulinaemia at the time of the start of haemodialysis. There was no indication that the presence of cryoglobulin in serum adversely affects the liver disease nor increases serum virus load in HCV-infected dialysis patients. Thus, it was concluded that although HCV infection has a certain role in the development of cryoglobulinaemia in dialysis patients, they develop cryoglobulinaemia less frequently and produce cryoglobulin to a lesser degree in the presence of HCV infection as compared with non-dialysis patients.

Adult↗

Acute hepatitis C among renal failure patients on chronic haemodialysis.

Hepatitis C virus (HCV) infection is common in haemodialysis units, yet little information is available about the clinical feature of acute hepatitis C among renal failure patients. The present study is based on 49 cases of acute hepatitis C seen at a haemodialysis centre where sporadic nosocomial infection was occurring up to June 1993. Liver function tests were done at 4 weekly intervals on all dialysis patients, anti-HCV antibodies were tested by the C-100 and second generation tests and serum HCV-RNA was determined by the branched DNA and Amplicore tests. Diagnosis of acute hepatitis C was made on the basis of an acute rise in alanine aminotransferase (ALT) and seroconversion to positive anti-HCV antibodies. Clinical presentation of acute hepatitis was generally mild with rare overt jaundice and the diagnosis was possible only from increased ALT, which was generally low. Spontaneous resolution of acute hepatitis within 8 months with clearance of viral RNA occurred in only four cases, 91.8% of patients developing chronic hepatitis. Biopsy in 12 cases with high ALT levels showed mild to moderate inflammatory activities. In conclusion, the clinical presentation of acute hepatitis C is generally mild in chronic haemodialysis patients, but spontaneous resolution is infrequent. A longer follow-up period is required for defining the long-term prognosis.

Acute Disease↗

A single stranded DNA-binding protein, ssCRE-BP/Pur alpha, in rat lung and its increase in allergic airway inflammation.

ssCRE-BP/Pur alpha is a single stranded DNA-binding protein and may be involved in gene replication and transcription and in the development of morphine dependence. We found a ssCRE-BP/Pur alpha (45 kDa) in rat lung that was larger than those (40 kDa) identified in rat and mouse brains and mouse lung. Immunohistochemistry showed that ssCRE-BP/Pur alpha is primarily distributed in the lung epithelium. As allergic inflammation induces various gene expressions, we investigated the changes of Pur alpha during airway inflammation. Ovalbumin-sensitized rats were used for inducing allergic airway inflammation. The expression and DNA-binding activity of 45-kDa ssCRE-BP/Pur alpha were significantly increased in the sensitized rat lungs 24 hr after antigen challenge, but not in those of rats nonsensitized or sensitized with ovalbumin and challenged with saline. Immunohistochemistry and in situ hybridization demonstrated that the vascular endothelial cells and numerous infiltrated eosinophils around the airways were stained with anti-Pur alpha antibody. These data suggest that rat lung and the eosinophils contain a 45-kDa ssCRE-BP/Pur alpha that is increased when airway inflammation occurs.

Animals↗

[A case report of mitral valve replacement using a parasternal incision (minimally invasive cardiac surgery) with pleuritis tuberculosa and after esophagus operation].

A 68-year-old man underwent mitral valve replacement because of mitral regurgitation (prolaps of anterior mitral leaflet) using parasternal incision (Delos M. Cosgrove, minimally invasive surgery). He had been treated as pulmonary tuberculosis previously and had undergone esophagus operation using stomach role reconstruction beneath the sternum four years before the mitral valve procedure. We could not select median-sternotomy as an approach due to stomach role beneath the sternum, nor left posterolateral thoracotomy because of the heavy left-side pleural adhesion. Cardio-pulmonary bypass cannulations were performed through the same incision, because severe atherosclerosis was found at the distal arteries of the abdominal aorta.

Aged↗

[Re-do surgery with minimally invasive cardiac surgery (MICS): mitral valve replacement 6 years after open mitral commissurotomy].

A 60-year-old man, who had undergone open mitral commissurotomy 6 years ago, underwent re-do surgery (mitral valve replacement) with minimally invasive cardiac surgery (MICS), using lower partial sternotomy to the height of the right side second intercostal space. Cannulation of the heart was carried out placing a cannula directly into the superior vena cava and a second cannula in the inferior vena cava via the right atrium. Arterial return was through the ascending aorta. Cardioplegia was administered directly into the ascending aorta with intermittent perfusion. Valve replacement was performed by opening directly right side left atrium.

Cardiac Surgical Procedures↗

[Thoracoabdominal aortic repair without using assisted bypass].

A 41-year-old man, who had undergone descending aortic repair following rupture of the DeBakey type III aortic dissection, underwent thoracoabdominal aneurysm repair 1 year after the first surgery. The operation was performed by partial-clamping and single crossclamping without using assisted bypass or shunt, in order to minimize bleeding ensuing the re-thoracotomy and dissection between lung and the graft.

Adult↗

Analysis of the T beta gamma-binding domain of MEKA/phosducin.

MEKA/phosducin, a 33 kDa phosphoprotein in the photoreceptor cell, associates with transducin beta gamma (T beta gamma) with its N-terminal domain (N-terminal 105 amino acids of MEKA), and translocates T beta gamma from the photoreceptor disc membrane to the soluble fraction. The present study further localized the T beta gamma-binding domain to aa 17-105 of MEKA, and showed that the activity of MEKA to translocate T beta gamma depends on the domain. A series of deletion mutant MEKA proteins were prepared to investigate the domain of MEKA which binds to and translocates T beta gamma. Both binding and translocation activities were not impaired by the deletion of the N-terminal 16 amino acids of MEKA, but completely abolished by further deletion to 42Val. Although anti-MEKA serum inhibited the T beta gamma-MEKA association, the antiserum absorbed with a recombinant peptide corresponding to aa 17-105 of MEKA did not, confirming that aa 17-105 of MEKA directly interacts with T beta gamma.

Amino Acid Sequence↗

Characterization of a nuclear factor that enhances DNA binding activity of SSCRE-BP/PUR alpha, a single-stranded DNA binding protein.

Pur alpha has been identified as a single-stranded DNA binding protein that specifically binds to the purine-rich strand present in the DNA replication initiation zone of the human c-myc gene. We have previously demonstrated that chronic morphine treatment decreases the DNA binding activity of ssCRE-BP (single-stranded cyclic AMP response element-binding protein), which has been shown to be identical to pur alpha by cDNA cloning, and is abundant in the brain. In this report we identified an activator of ssCRE-BP/pur alpha in the brain and characterized it. Although purified ssCRE-BP/pur alpha or its GST-fusion protein exhibited very low DNA binding activities, they were markedly enhanced by including nuclear extract in the binding assay. The enhanced binding activity is trypsin-sensitive, heat-stable and has a molecular weight of approximately 66 kDa. Casein could substitute for the activator and increased the DNA binding activity of ssCRE-BP/pur alpha by one order. A series of deletion mutants were prepared in order to determine the DNA binding and activator interacting domains, and both of them were found to reside in AA 50-215 of ssCRE-BP/pur alpha. These data suggest that the DNA binding activity of ssCRE-BP/pur alpha is augmented by a nuclear protein, which may modulate the ssCRE-BP/pur alpha activity to develop morphine dependence and tolerance.

Animals↗

Antibiotic MICs and short time-killing against Helicobacter pylori: therapeutic potential of kanamycin.

We compared the susceptibility of Helicobacter pylori to several antibiotics, expressed as MICs and as bactericidal effectiveness in short (3 h) time-killing studies. Of the antimicrobial agent tests, clarithromycin and amoxycillin had the lowest MIC50, 0.063 and 0.125 mg/L respectively, for 24 strains of H. pylori. Minocycline, levofloxacin and lansoprazole followed, with MIC50s of 0.5, 1, and 2 mg/L, respectively. Three-hour time-killing studies using a standard strain demonstrated a different pattern. At 4 x MIC, kanamycin, metronidazole and clarithromycin produced 4.4, 2.6 and 2.1 log decreases in viability, whereas the remaining seven antibiotics (including amoxycillin) were less bactericidal. Amoxycillin's lack of bactericidal activity during brief incubations was confirmed by examining several different clinically isolated H. pylori strains. Clarithromycin's effect, on the other hand, was strain- and concentration-dependent. Kanamycin was the most potent antibiotic in short time-killing studies, with concentrations of 1 x MIC and 4 x MIC producing a reduction of more than 2 and 4 log respectively in all ten strains. Our data suggest that the MIC of antimicrobial agents against H. pylori does not necessarily predict their activity in short time-killing studies. Furthermore, our short time-kill data suggest kanamycin as a potential therapeutic choice for H. pylori infection, even though this agent's MIC would suggest limited activity.

Amoxicillin↗

GB virus-C infection among chronic haemodialysis patients: clinical implications.

It is known that patients on chronic haemodialysis are frequently infected with hepatitis C virus (HCV). It has recently been found that GB virus-C (GBV-C) and hepatitis G virus frequently coinfect patients with HCV. This study aimed at elucidating the clinical implications of GBV-C infection among haemodialysis patients who have and do not have HCV infection. GBV-C RNA was detected in sera of randomly selected 98 anti-HCV-positive and 85 -negative patients on dialysis by reverse transcription-polymerase chain reaction using two sets of amplification primers made from the reported sequences of the non-structural protein 3 and 5' untranslated regions. In these patients, liver function tests were carried out at regular intervals. There were six patients who were coinfected with HCV and GBV-C and three who had only GBV-C RNA. All had a history of past blood transfusion. The onset of mild hepatitis was identified in three HCV-negative patients; elevation of alanine aminotransferase (ALT) following blood transfusion was very mild but recognizable, and aspartate aminotransferase (AST) was higher than ALT. In two of six coinfected patients, the onset of liver disease was recognized with a peak ALT of 72 and 90 IU/L, respectively. Two of these six were Amplicore (HCV-RNA) negative and asymptomatic, two had low-grade HCV viraemia and two moderate-grade HCV viraemia. Of the 98 anti-HCV-positive cases, 41 were thought to have had nosocomial infection of HCV or non-A, non-B virus; none of them had GBV-C. GBV-C RNA was negative in nine patients who had chronic non-A-E hepatitis. GBV-C infection was detected in 6.1% of anti-HCV-positive and in 3.5% of -negative dialysis patients. All had blood transfusion in the past, and there was no evidence of patient-to-patient spread of GBV-C in hospital. The liver disease was very mild and self-limited in GBV-C infection alone. The natural history of coinfected patients may be similar to that of those with chronic HCV infection, but the liver disease appears to be milder.

Aged↗

Adsorption of hepatitis C virus particles onto the dialyzer membrane.

It was recently found that the blood level of hepatitis C virus (HCV) RNA is significantly reduced after each dialysis procedure in patients on chronic hemodialysis. This study was designed to elucidate the mechanism for this phenomenon. In two patients with high serum levels of HCV RNA, the filtrate through the dialyzer (TF-alpha, Teijin Co., Tokyo, Japan) was analyzed for viral RNA using the polymerase chain reaction. At the end of dialysis, the filter was washed with saline, and during the saline washing, aliquots were taken for quantification of RNA by the branched DNA method. The HCV core antigen was quantified as a measure of viral particles, and hemoglobin was also measured for correcting for blood contamination. After the clearance of the blood, the filter was washed with guanidinium isothiocyanate, and the recovery of RNA was measured. The filtrate did not contain detectable RNA. The saline washing of the filter after dialysis contained a significant amount of RNA. Washing with guanidinium isothiocyanate of the thoroughly saline washed filter also recovered a significant amount of RNA. During saline washing, the recovery of RNA in the washing was much delayed behind that of hemoglobin, suggesting the adsorption of the former onto the filter membrane. There was a discordant recovery of RNA and HCV core antigen in the washing, the recovery of the former being delayed behind that of the latter. These results indicate that viral particles are adsorbed onto the inner surface of the filter membrane during dialysis. Some of these adsorbed viral particles are perhaps destroyed by hydraulic pressure applied to blood for dialysis.

Adsorption↗

[The comparison of tepid and moderate hypothermic cardiopulmonary bypass in cardiac surgery].

Normothermic cardiopulmonary bypass (CPB) is being increasingly used at some institutions. Patients undergoing normothermic CPB have a higher systemic oxygen demand and may be at higher risk for ischemic injury. This study was designed to confirm the clinical efficacy and safety of tepid hypothermic CPB. Thirty-six patients undergoing open heart surgery between June 1993 and August 1994 were divided into two groups: tepid (n = 18, 32 degrees C) and moderate (n = 18, 26 degrees C) hypothermic CPB. There were no significant differences in preoperative and perioperative patients characteristics between the two groups. The mean aortic cross-clamp time did not differ between two groups, but the mean CPB time was significantly shorter in tepid hypothermic patients. Serum lactate after CPB and lactate/pyrvate ratio during CPB in tepid hypothermic patients were significantly lower than in moderate hypothermic patients. The mixed venous oxygen saturation in tepid hypothermic patients was significantly lower however, it was maintained at levels more than 70% during CPB. This study suggests that tepid hypothermic CPB is a safe and effective alternative to moderate hypothermic CPB for patients undergoing open heart surgery. Previous reports have documented that patients undergoing normothermic CPB are at greater risk for cerebral desaturation. We should evaluate cerebral venous oxygen saturation during tepid hypothermic CPB before the induction of normothermic CPB.

Cardiac Surgical Procedures↗