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Biomedical subjects

A Sekiguchi

Publications and source records attributed to A Sekiguchi.

At least 19 recordsLinked to original sources
PubMed2006

Type I IFN-mediated enhancement of anti-leukemic cytotoxicity of gammadelta T cells expanded from peripheral blood cells by stimulation with zoledronate.

BACKGROUND: In order to establish efficient gammadelta T-cell based tumor immunotherapy, we explored a method to enhance the cytotoxicity of gammadelta T cells against leukemia cells by stimulating gammadelta T cells with type I IFN. METHODS: Gammadelta T cells were expanded from normal PBMC by culturing with zoledronate and a low concentration of IL-2 for 2 weeks. For the activation of gammadelta T cells, gammadelta T cells were cultured with type I IFN (HLBI, IFN-alpha2b and IFN-beta) for 1-3 days. The cytotoxicity of HLBI-activated gammadelta T cells against leukemia cell lines and fresh leukemia cells was evaluated by 51Cr-release assay. RESULTS: Gammadelta T cells, which were expanded and purified with magnetic beads using an anti-gammadelta TCR MAb, were demonstrated to be cytotoxic against leukemia cell lines of both lymphoid and myeloid origin and fresh myeloid leukemia cells. By culturing expanded gammadelta T cells with type I IFN, the expression of the activation marker CD69 was increased and the cytometric bead array showed an elevated production of IFN-gamma by gammadelta T cells. In addition, the cytotoxicity of gammadelta T cells against leukemia cells was definitely enhanced by culturing gammadelta T cells with HLBI. DISCUSSION: The present study has demonstrated that type I IFN could enhance the anti-leukemic cytotoxicity of expanded gammadelta T cells, which implies that in vitro bisphosphonate (such as zoledronate)-expanded and type I IFN-activated gammadelta T cells could be applied to immunotherapy for hematologic malignancies such as leukemia and lymphoma.

Antigens, CD↗
PubMed2004

Prevalence of periodontal bacterial infection in non-obese Japanese type 2 diabetic patients: relationship with C-reactive protein and albuminuria.

The aim of the present study was to investigate the relationship between periodontal bacteria infection ( Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedius) and C-reactive protein (CRP) and albuminuria in non-obese Japanese type 2 diabetic patients. One hundred and thirty-four non-obese Japanese type 2 diabetic patients without evidence of current acute illness including clinically significant acute infectious disease were enrolled into the study. The degree of periodontal bacterial infection was evaluated using IgG titer against Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, or Prevotella intermedius. The bacterial sonic extracts were used as antigens. High-sensitivity CRP (hCRP), glucose, glycosylated hemoglobin (HbA (1c)), and lipids were also measured after an overnight fast. Urinary albumin excretion rate as a ratio of urinary albumin and urinary creatinine was assessed in a morning spot urine sample using a commercial enzymatic immunoassay. The prevalence of Porphyromonas gingivalis infection was 52.2 % and that of Actinobacillus actinomycetemcomitans and Prevotella intermedius was 7.5 and 14.2 %, respectively. IgG titer against Porphyromonas gingivalis significantly correlated with CRP (r = 0.225, p < 0.001) and albuminuria (r = 0.185, p < 0.05), while IgG titer against Actinobacillus actinomycetemcomitans or Prevotella intermedius was not associated with either parameter. These results suggest that among periodontal bacteria, Porphyromonas gingivalis infection is associated with atherosclerosis in non-obese Japanese type 2 diabetic patients.

Actinobacillus Infections↗
PubMed2001

Successful surgical management of a tracheopulmonary artery fistula caused by an intratracheal expandable metal stent.

We describe a boy who underwent slide tracheoplasty and relocation of the left pulmonary artery at 3 months of age to treat pulmonary artery sling with congenital tracheal stenosis. Persisting tracheal stenosis required that he have a Palmaz stent inserted on postoperative day 77. He developed massive hemoptysis after the fourth attempt to expand the stent balloon and immediate computed tomography showed a tracheopulmonary artery fistula. Using cardiopulmonary bypass, we conducted emergency surgery to successfully manage the fistula. He currently depends on mechanical ventilation.

Arterio-Arterial Fistula↗
PubMed2001

Direct closure of ostium primum defect in the repair of atrioventricular septal defect.

BACKGROUND: Patch closure is generally performed for atrial septation of an atrioventricular septal defect. We recently developed a new surgical technique for repairing atrioventricular septal defects that avoids the use of any patch material for closing the atrial septal defect. We report our experience with this procedure. METHODS: Seven patients (complete type: 5, partial type: 2) underwent this new operation. The diameters of the atrial septal defects were measured by transesophageal echocardiography. The preoperative electrocardiograms were compared with those taken after the operations. RESULTS: Diameters of the atrial defects ranged from 3 to 10 mm. Electrocardiograms before and after the operations did not change. No significant atrioventricular valve regurgitation and no residual shunts were detected by postoperative echocardiography. CONCLUSIONS: This method simplifies the repair of atrioventricular septal defects. In the short-term results, no arrhythmia and no valve regurgitation was seen.

Blood Vessel Prosthesis Implantation↗
PubMed2001

Quantitative analysis of hypertrophy in cardiac chambers in cyanotic tetralogy of Fallot.

Although early total corrective repair for cyanotic tetralogy of Fallot is now safely performed at many institutions, long-term complications after surgical repair have been demonstrated. Therefore, the optimal procedure and timing for surgical treatment remain controxersial. In the present study, we conducted a quantitative analysis of the hypertrophy of all four chambers of 87 autopsied hearts of cyanotic tetralogy of Fallot and 71 normal control hearts utilizing the myocardial mass index, and evaluated the progression of lesions with advancing age. In cyanotic tetralogy of Fallot, hypertrophy of the right ventricle progresses immediately after birth, with that of the right atrium developing soon after. The left side of the heart is normal or slightly atrophied which could be corrected by sufficient palliative intervention or total corrective repair. The growth curves of both ventricles were parallel to those of normal hearts for the period studied. Pulmonary atresia, palliative operation, and total corrective repair have been shown to have some influence on the morphological characteristics of hearts of cyanotic tetralogy of Fallot.

Child, Preschool↗
PubMed2000

Severity of hyperemesis gravidarum correlates with serum levels of reverse T3.

To investigate the possible physiological relevance of extra-thyroidal production of reverse T3 (rT3) in hyperemesis gravidarum, measurements of serum rT3, free T3 (FT3), free T4, (FT4), and nonesterified fatty acids (NEFA) were correlated with weight loss of hyperemetic women. All the thyroid hormones, NEFAs and weight loss were significantly higher in hyperemesis gravidarum than in control subjects, and also higher than in those with milder symptoms of morning sickness (p < 0.05). Elevations of FT3, FT4 and NEFAs correlated with the extent of weight loss, the latter taken as the index of the severity of hyperemesis gravidarum (p < 0.05). Only rT3 correlated with both weight loss and the rate of lipolysis, as reflected by elevations of NEFAs (p < 0.05). The data are consistent with a shift from T3 to rT3 as products of 5'-monodeiodination of thyroxine in hyperemesis gravidarum. Because reverse T3 is physiologically inactive a control mechanism may be postulated wherein T3 production is minimized, thereby reducing weight loss and lipolysis in patients with hyperemesis gravidarum.

Fatty Acids, Nonesterified↗
PubMed2000

[Modified extended septoplasty for left ventricular outflow tract obstruction after repair of double-outlet right ventricle report of a case].

A three-year-old boy with residual VSD and LVOTO after repair of double outlet right ventricle underwent modified extended septoplasty successfully. Preoperative left ventriculography showed a residual VSD and LVOTO. The peak systolic pressure gradient between the left ventricle and aorta was 38 mmHg. Operation aimd not only at relief of the obstruction, but also at streamlining of the LVOT by removal of protrusions. We modified the extended septoplasty reported by Belli et al in 1996. The postoperative course was uneventful and patient was discharged at 15 postoperative day. The most recent echocargiogram revealed no residual LVOTO.

Cardiac Surgical Procedures↗
PubMed1999

Long-term results of the fenestrated Fontan operation. Progress of patients with patent fenestrations.

The fenestrated Fontan operation was introduced as a modification of the "completed" Fontan operation for patients with high risk factors, and low operative mortality has frequently been reported. However, use of the umbrella device is now restricted, and this procedure should be performed without subsequent closure. In this paper, we review our clinical experience with this procedure and discuss ongoing problems. Sixteen patients (4 tricuspid atresia and 12 other cardiac anomalies including 5 cases of univentricular heart) underwent the fenestrated Fontan operation (7 atriopulmonary and 9 total cavopulmonary connection). All of them have some risk factors for a completed Fontan operation. There were three early deaths of the 16. Two experienced an anticipated thromboembolic accident, one of which involved the pulmonary aspect while the other involved the arterial aspect. Patients who survived the operation have progressed well and have a clinical status of New York Heart Association class I, with the exception of one late death due to congestive heart failure. There have been no thromboembolic accidents in this group during the late follow-up period. Spontaneous closures of the fenestrations were noted in two patients. The late mean Qp/Qs value in patients with patent fenestrations was 0.80 +/- 0.1, SaO2 was 88.8 +/- 5.6%, and right atrial pressure was 9.7 +/- 3.8 mmHg. No major problems have been encountered in patients with a patent fenestration over extended periods. A modified Fontan operation to fit a permanently open fenestration may be considered as a final surgical option for certain high-risk patients.

Adolescent↗
PubMed1999

Alteration of mosaic methylation of the repeat unit of the human ribosomal RNA genes in lung cancer.

We have investigated the methylation status of the repeat unit of the human ribosomal RNA genes in lung cancer. Using a Southern blot analysis approach we have determined that the non-transcribed region of these genes was generally heavily methylated, while the transcribed region was not methylated in either tumor or normal DNA. Our study also revealed that, in one tumor, the boundary of mosaic methylation of the repeat unit was not distinct. In the same tumor, both the non-transcribed ribosomal spacer region and the L1 interspersed repeat sequences became partially demethylated. In tumor cells, the methylation status of DNA can be altered, but the methylation of subtelomeric repeats was found to be maintained. These results suggest that the mosaic methylation of the repeat unit is not necessarily maintained in tumor DNA, while subtelomeric repeats escape tumor-specific wave of demethylation.

Blotting, Southern↗
PubMed1999

Tight interaction between densely methylated DNA fragments and the methyl-CpG binding domain of the rat MeCP2 protein attached to a solid support.

In a previous report we have found that a number of short DNA fragments methylated at CpG sequences bound more tightly to a methyl-CpG binding column than DNA fragments having a larger number of methyl-CpG sequences. The column consists of a polypeptide comprising the DNA binding domain of the rat MeCP2 protein attached to a solid support. In the present study, we have investigated the features of short DNA fragments which bind tightly to a methyl-CpG binding column. Tight binding was observed when the DNA fragment had a high density of methyl-CpG sequences. Many of these fragments, derived from human genomic DNA, contained Alu repeated sequences supporting the previous observation that the highly-abundant Alu sequences are highly methylated. Our results suggest that methyl-CpG density is an important factor in the interaction between DNA fragments and the DNA binding domain of MeCP2 attached to a solid support.

Animals↗
PubMed1999

[A case of large congenital right ventricular outflow aneurysm].

A rare case of large congenital right ventricular outflow aneurysm is reported. A 5-year-old girl had been diagnosed as having atrial septal defect and pulmonary valvular stenosis. A large cavity in front of right ventricular outflow was noticed by her follow-up echocardiography. The non-contracting cavity was confirmed as an aneurysm originating from right ventricular outflow tract by angiocardiogram. Surgical resection was performed successfully with concomitant atrial septal defect closure and pulmonary valvular commissurotomy. Histological examination revealed that the wall of the ventricular outflow aneurysm consisted of dense fibrous tissue, contained no myocardium, and the cavity was lined with endocardium. It is reported that rupture of congenital ventricular aneurysm may occur even if there is no symptom. Surgical resection will be recommended especially when increasing in size is diagnosed.

Cardiac Surgical Procedures↗
PubMed1997

A Free Cyclotrigermenium Cation with a 2pi-Electron System

The reaction of tetrakis(tri-tert-butylsilyl)cyclotrigermene with trityl tetraphenylborate in benzene produces tris(tri-tert-butylsilyl)cyclotrigermenium tetraphenylborate [(tert-Bu3SiGe)3+BPh4-], which can be isolated as a yellow solid that is stable in the absence of air. The crystal structure of the cyclotrigermenium ion reveals a free germyl cation with a 2pi-electron system. The three germanium atoms form an equilateral triangle similar to the carbon analog, the cyclopropenium ion.

Journal Article↗
PubMed1997

[A case report of a fenestrated Fontan operation after bivalvation of the common atrioventricular valve in right isomerism].

The patient is a boy of five years old with asplenia, dextrocardia, right aortic arch, bilateral superior vena cavae, single atrium, common atrioventricular orifice, double outlet right ventricle and pulmonary stenosis. He underwent operations of right Blalock-Taussig shunt and right superior vena cava ligation when he was eight months old and at the age of three years old, bidirectional Glenn procedure and bivalvation of the common atrioventricular valve (CAVV) as he, then, suffered from severe regurgitation of the CAVV. The regurgitation improved from grade 3 to 1 and his recovery allowed the fenestrated Fontan operation at the age of four years and nine months. Bivalvation is an effective means for the mitigation of regurgitation of CAVV and paves the way for application of Fontan-type operation.

Child, Preschool↗