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Biomedical subjects

T Hata

Publications and source records attributed to T Hata.

At least 19 recordsLinked to original sources
PubMed2006

[Surgical technique of aortic valve replacement for small aortic annulus in elderly patients].

Recent reports have shown that aortic valve replacement in elderly patients over 65 years with atherosclerotic aortic stenosis and a small aortic annulus is possible by using a small sized bioprosthesis (Carpentier-Edwards pericardial valve). Here we present out surgical technique. Firstly, the native calcified aortic valve was removed completely to gain total exposure of the surrounding aortic root and sinus of Valsalva like Bentall procedure. Secondly, a small sized bioprosthesis was implanted with intermittent noneverting mattress 2-0 sutures with spaghetti and small polytetrafluoroethylene (PTFE) felt. Aortic annulus is the dilated by inserting Hegar dilator sizing from 25 to 27 mm. Therefore, aortic valve replacement for small aortic annulus in intra- or supra-annular position should be easily accomplished. Good surgical results and hemodynamic state were achieved in 25 consecutive cases using this technique.

Aged↗
PubMed2006

[Usefulness of ultrasonically activated scalpel for pulmonary resection in video-assisted thoracoscopic surgery].

We evaluated the reliability and efficacy of the ultrasonically activated scalpel (Harmonic Scalpel) for pulmonary resection in video-assisted thoracoscopic surgery (VATS). Fifty-six cases of primary or metastatic lung cancer with history of lobectomy or segmentectomy from July 2003 to June 2006 were investigated. The ultrasonically activated scalpel was used to separate aborted lobulation and segment in the surgery. The outcome of the operation using the ultrasonically activated scalpel revealed the mean operation time of 224.5 minutes and mean blood loss volume of 116.7 ml. The chest drainage catheter was removed at the postoperative day 3.4 and hospitalization lasted 10.4 days on average. By means of statistical analysis, no significant differences were noted when compared with the cases using surgical stapler to separate the lobules or segments of the lungs. Histopathological results showed destruction of alveolar structures and denaturation of cells at the cut surface of the resected lung through the use of the ultrasonically activated scalpel. This method resulted in good lung expansion and preservation of the residual lung volume. Furthermore, it prevented postoperative air leakage by appropriate treatment to the cut surfaces of the residual lung. Indeed, the method appears to be useful in the separation of lung tissues in severe aborted lobulation and segmentectomy by VATS.

Aged↗
PubMed2005

Macrognathia secondary to dialysis-related renal osteodystrophy treated successfully by parathyroidectomy.

Renal osteodystrophy (ROD) is one of the most common complications affecting patients with chronic renal failure both before and after the initiation of maintenance dialysis, but macrognathia secondary to ROD is rare. Usually, enlarged jaws due to ROD do not return to their normal contours after the treatment of hyperparathyroidism. To the authors' knowledge, this article describes the second case of macrognathia secondary to dialysis-related ROD treated successfully by parathyroidectomy. Immunohistochemical study of the maxilla confirmed that parathyroidectomy could stop maladaptive parathyroid hormone stimulation, which leads not only to the formation of osteoblastic progenitors that become fibroblast-like cells but also to osteoclast formation.

Chronic Kidney Disease-Mineral and Bone Disorder↗
PubMed2004

Transferrin microheterogeneity in fetal blood.

OBJECTIVES: To investigate the distribution of microheterogeneous subfractions of transferrin in fetal blood and the influence of highly sialylated transferrins on fetal growth. STUDY METHOD: Serum transferrin concentrations were determined by a standard turbidimetric assay. Microheterogeneous transferrin subfractions were assessed by crossed immunoisoelectric focusing. RESULTS: In normal term infants, total serum transferrin concentrations and percent distribution of highly sialylated transferrins (> or = 5-sialo-transferrins) were markedly lower; the percent distributions of hyposialylated transferrins (0- and 1-sialo-transferrins) were apparently higher than those in non-pregnant and pregnant women. There was no significant positive correlation between the serum concentrations of total transferrin or highly sialylated transferrins in infants' blood and birth weights (r = 0.187, p = 0.582; r = 0.374, p = 0.257, respectively). CONCLUSION: The transferrin microheterogeneity pattern shifted towards reduced glycosylation and sialylation in addition to a decrease in total transferrin concentration in fetal blood compared to that of non-pregnant and pregnant women. The concentrations of serum total transferrin and the highly sialylated transferrins in fetal blood, if higher than a certain level, did not seem to have any influence on normal fetal growth.

Female↗
PubMed2004

[Esophageal leiomyoma enucleated under the thoracoscopy; report of a case].

We report a case of a 40-year-old male with a posterior mediastinal mass that was 8 cm in size and located behind the trachea. The thoracoscopic surgery was performed. The tumor was located from the level of left brachiocephalic vein to the carina. The mediastinal pleura over the tumor was longitudinally opened by cautery-scissors. The azygos vein lying over the tumor was divided by means of an endoscopic stapler. The muscular layer of the esophagus was also longitudinally opened. The tumor was enucleated. Then, the dissected proper muscle layer of the esophagus was suture-closed. The postoperative course was uneventful. On the first postoperative day Gastrografin was swallowed, showing the absence of leaks. The patient was discharged on the fourth postoperative day. The advantages of the thoracoscopic surgery are as follows: rapid, full recovery of the patient; decreased postoperative pain; short postoperative hospital stay. Esophageal leiomyoma in selected patient was suitable for thoracoscopic enucleation.

Adult↗
PubMed2002

Neuronal hyperexcitability in stroke-like episodes of MELAS syndrome.

BACKGROUND: The pathogenesis of stroke-like episodes in patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) remains unknown. METHODS: Fourteen stroke-like episodes in six patients with MELAS were studied using clinical, neuroradiologic, and electrophysiologic approaches. In two patients postmortem examination was done. RESULTS: Headache and epileptic seizure were the most common presenting symptoms. In 13 of 14 episodes the cerebral cortex was primarily involved with variable subcortical edema particularly in the temporal, occipital, and parietal cortex. Repeated MRI performed in two episodes revealed progressive spread of the cortical lesion to the surrounding cortex for a few weeks after the onset of symptoms. In 6 of 11 episodes T1-weighted hyperintense cortical signal compatible with cortical laminar necrosis was seen during subacute stage of the episode. Fat-suppression MRI confirmed intracortical gyral hemorrhage in one episode. Petechial gyral microhemorrhages were also pathologically confirmed in the autopsy of another patient. In 9 of 11 episodes focal epileptiform discharges on EEG were noted in the acute brain lesion. In seven of nine episodes focal cortical hyperperfusion was seen in SPECT studies. CONCLUSION: The stroke-like episodes in MELAS may reflect neuronal hyperexcitability, which increases energy demand and creates energy imbalance between energy requirement and adequate availability of adenosine triphosphate due to oxidative phosphorylation defect particularly in the susceptible neuronal population, causing cortical necrosis. The episodic nature of stroke-like episodes is unexplained.

Adult↗
PubMed2002

Comparison of three-dimensional, two-dimensional and color Doppler ultrasound in predicting the presence of a nuchal cord at birth.

OBJECTIVES: To compare the use of two-dimensional, color Doppler and three-dimensional ultrasound for predicting the presence of a nuchal cord at birth. METHODS: Eighty-five singleton pregnancies without nuchal cord and 35 with nuchal cord (30 with a single coil of cord, four with a double coil, and one in which the cord was coiled around the neck three times) were studied within 1 week before delivery using transabdominal three-dimensional sonography. Two-dimensional and color Doppler ultrasound were also conducted for comparison. RESULTS: Two-dimensional, color Doppler and three-dimensional sonography identified in utero 24 (69%), 29 (83%) and 25 (71%), respectively, of the cases of nuchal cord found at birth. There were no significant differences in overall diagnostic indices of each diagnostic modality for detecting nuchal cord. However, the ability to view the nuchal cord (subjective assessment of the ease of visualization of nuchal cord) was better with three-dimensional sonography than with two-dimensional or color Doppler ultrasound. CONCLUSIONS: Three-dimensional surface imaging does not provide more useful diagnostic information compared with two-dimensional and color Doppler ultrasound for detecting nuchal cord in utero.

Female↗
PubMed2002

Distribution of brain oedema in the contralateral hemisphere after cerebral infarction: repeated MRI measurement in the rat.

The appearance of local cerebral dysfunction at remote regions from the focus in the acute stage of stroke (diaschisis) is well known, but its mechanism has not been established. We have analysed serial MR images of the infarcted brain of rats to evaluate the distribution of oedema. Forty-seven Sprague-Dawley rats were anaesthetized with halothane, and the right middle cerebral artery (MCA) was permanently occluded via the intraluminal approach using a nylon 2-0 suture. At 3, 6, 9 and 24 hours after the occlusion, coronal T(2)-weighted MR images were taken and the signal intensity (SI) was computed at each region of the brain. After occlusion of the right MCA, SI increased diachronically up to 24 hours on the occluded side of the cortex (52.9+/-3.2 to 104.8+/-22.4) and striatum, which are within the perfusion territory of the MCA. SI increment was also observed at the hippocampus, alveus hippocampi and pyriform lobe, which are not within the territory of the MCA, and at some regions of the contralateral side (52.5+/-4.8 to 69.4+/-14.8 at the cortex). These changes were prominent in ischaemia-vulnerable portions, mild in the cortex, and minimal in the striatum. This contralateral side SI increment indicates remote oedema, which corresponds to diaschisis. We suggest that the mechanism of this remote contralateral oedema is the movement of extravasated protein from the lesion.

Animals↗
PubMed2002

[Ventricular free wall re-rupture after surgical treatment of ventricular free wall rupture due to acute myocardial infarction; report of a case].

An in-hospital 72-year-old male with complaint of anterior chest pain was presented with shock. Pericardial effusion was confirmed by echocardiography, and therefore, he was brought to the operating room immediately with diagnosis of ventricular free wall rupture. The repair was performed using fibrin glue, fibrin sheet, and pericardial patch. His post-operative course was uneventful until massive bleeding came through the chest tube on the 5th day from the initial surgery. The emergency sternotomy was made again for hemostasis. In the re-operation, an approximately 20 mm laceration along the proximal circumflex artery was found and this was successfully repaired with 2 pledgetted horizontal mattress sutures. It is important and necessary to treat a postoperative patient taking care of re-rupture.

Aged↗
PubMed2001

Crystallization and preliminary X-ray crystallographic studies on a Fab fragment of the mouse anti-human Fas monoclonal antibody HFE7A.

The Fas-Fas ligand system is involved in apoptosis. The mouse anti-human Fas monoclonal antibody HFE7A (m-HFE7A) has a potential use in human therapy against autoimmune diseases such as rheumatoid arthritis. Information on the three-dimensional structure is essential for antibody humanization. Crystals of an antigen-binding fragment (Fab) of m-HFE7A were obtained by the hanging-drop vapour-diffusion method using sodium citrate as a precipitant and 2-methyl-2,4-pentanediol as an additive. Fast optimization to produce single crystals suitable for X-ray analysis was achieved by the streak-seeding technique. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 43.4, b = 74.0, c = 133.8 A. The crystals diffract at least to 2.5 A resolution.

Animals↗
PubMed2001

Total tetra knockout of GP138 multigene family implicated in cell interactions in Dictyostelium discoideum.

The cellular slime mold Dictyostelium discoideum reproduces sexually under submerged and dark conditions. A cell surface glycoprotein gp138 has been identified as a target molecule for cell fusion-blocking antibodies, and is considered to be indispensable for the sexual cell fusion in this organism. Currently, four isoforms of gp138, DdFRP1alpha, DdFRP1beta, DdFRP2, and DdFRP3, are known. Genes encoding the latter three isoforms, GP138C, GP138A, and GP138B, have been isolated, comprising a GP138 multigene family. Here we isolated the fourth GP138 gene, GP138D, encoding DdFRP1alpha. These GP138 genes were found to cluster in a tandem array on chromosome 5, being bordered by two GP138-like sequences highly homologous to them but truncated. To clarify functional relationships among the GP138 family members, the entire GP138 region was deleted by a single knockout. Northern hybridization and western immuno-blotting analyses confirmed complete losses of GP138 mRNA and DdFRPs in the knockout strains, indicating that there are no more GP138 genes. Unexpectedly, however, the GP138-null mutants were fully potent for both sexual cell fusion and subsequent development. In addition, the original fusion-blocking antibodies detected a cell surface protein of close electrophoretic mobility to gp138 in the knockouts, suggesting the possibility that the actual target molecule of the fusion-blocking antibodies was not DdFRPs but this unidentified component. Since GP138-null mutants exhibited no obvious defects either in growth or asexual development, the real function of the GP138 family is unknown. Nevertheless, the expression levels of other developmental genes such as acaA, csaA, cotA-C, and spiA appeared to be altered in the GP138-null mutants. Therefore, it seems to have a non-critical but some role(s) during asexual development.

Amino Acid Sequence↗