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Biomedical subjects

T Murakami

Publications and source records attributed to T Murakami.

At least 343 records · Page 19Linked to original sources

[Recent donation and clinical results of homograft tissue].

Between August 1995 and July 1999, we have experienced 14 donors for allografts (mean age: 39.8 +/- 15.8, M/F = 10/4, mean warm ischemic time: 359 minutes). Donated tissues were included 12 aortic valves and 12 pulmonary valves, respectively. Since February 1994, clinical diagnoses of 14 patients included 7 congenital heart disease, 5 infective heart disease, 1 artificial graft infection, and 1 thrombosed valve. There was no graft-transmitted disease. In congenital heart disease, 3 patients (HLHS: 1, Truncus: 1, TOF + PA: 1) died (early mortality, 42%) and 1 with TGA had residual conduit stenosis. However, in infective heart disease, all patients survived without recurrent infection and did not need reoperation (early mortality, 0%). Our clinical results of homograft implantation for infective heart disease were excellent, but more careful consideration will be needed for congenital heart disease in neonates and/or patients with poor preoperative condition.

Adolescent↗

[Successful aortic root replacement for prosthetic valve endocarditis using the freestyle stentless bioprosthesis: report of two cases].

We report two cases of prosthetic valve endocarditis which were successfully treated with aortic root replacement using the freestyle stentless bioprosthesis. Prosthetic valve endocarditis occurred in two patients after aortic valve replacement and modified Bentall operation, respectively. The aortic annulus was severely damaged and left ventriculo-aortic discontinuity was found in both cases. We used the freestyle stentless bioprosthesis, which fits well to the destroyed aortic annulus with left ventriculo-aortic discontinuity, because of its flexibility. Postoperative echocardiography revealed excellent hemodynamic results in both cases. Although the long-term results obtained with the freestyle stentless bioprosthesis, such as resistance to bacterial infection, have not been reported, this prosthesis appears to be very useful for treatment of prosthetic valve endocarditis. We expect that this prosthesis might be a option for PVE as an alternative to a homograft.

Adult↗

[Progress in biochemical and genetic examinations in clinical laboratory of cardiovascular diseases].

For diagnosing cardiovascular emergencies, cardiologists mainly rely on physiological examinations. Biochemical laboratory examinations can facilitate emergency diagnosis and genetic diagnosis can facilitate a fundamental understanding of cardiovascular diseases. Recent progress in biochemical examinations for cardiovascular diseases includes measurement of troponin T, heart type fatty acid-binding protein, and LDL-cholesterol. Recent progress in genetic examinations includes analysis of mitochondrial DNA, obesity-related genes and single nucleotide polymorphisms. A safe and convenient system of collecting, transporting, and storing blood and other biological specimens, and the subsequent purification of genomic DNA from the stored specimens is available. Therefore, busy doctors and staff of clinical laboratory can plan subsequent DNA examinations without causing concern and pain. A recently reported human mutation of heterotrimeric G protein beta 3 subunit produces a gain-of-function G protein signaling abnormality. A common polymorphic base substitution, C825T, in the GNB3 gene is associated with an aberrantly spliced transcript lacking 123 nucleotides. A significant association of the T allele with essential hypertension or obesity has been suggested.

Cardiovascular Diseases↗

Relationship between chromosomal instability and intratumoral regional DNA ploidy heterogeneity in primary gastric cancers.

The purpose of this study was to elucidate the relationship between intratumoral regional heterogeneity in DNA ploidy and chromosomal instability (CIN) in primary gastric adenocarcinomas. In 45 sporadic gastric adenocarcinomas, we measured DNA ploidy and numerical aberrations for chromosomes 7, 11, 17, and 18 by laser scanning cytometry and fluorescence in situ hybridization, respectively, in small tissue specimens taken from 2 to 6 (on the average 4) different portions of the same tumor. A total of 231 specimens including 45 normal control specimens were examined. All 98 tumor specimens with DNA aneuploidy (DNA index > or = 1.2) showed large intercellular variations in chromosome copy number, indicating CIN. In contrast, 85 tumor specimens with (near) diploidy (1.0 < or = DNA index < 1.2) exhibited much small intercellular variations in chromosome copy number as compared with aneuploid specimens (P < 0.0001). The relationship between DNA ploidy and intercellular variation in chromosome copy number was true for tumors consisting of a mixture of (near) diploid and aneuploid subpopulations. These data indicate that DNA aneuploidy is associated with CIN but that (near) diploidy is not. Intratumoral regional DNA ploidy heterogeneity was conspicuous in 33 (92%) of 36 tumors with regions of DNA aneuploidy, and all aneuploid specimens showed great intercellular variation in chromosome copy number. Diploid regions were predominant in early stage cancers (intramucosal and submucosal cancers), and five of eight early cancers contained only diploid population. In contrast, all tumors without (near) diploid regions were advanced cancers. These observations suggest that CIN is a necessary prerequisite for developing intratumoral DNA ploidy heterogeneity with DNA aneuploidy.

Adenocarcinoma↗

[Thromboembolic and bleeding complications in patients treated with oral anticoagulant therapy after mechanical heart valve prostheses implantation].

Thromboembolic and bleeding events are major cause of morbidity and mortality in patients with mechanical heart valves. Ninety-three patients had been received anticoagulant (warfarin with bucolome 300 mg) for mechanical prosthetic valves, and the regulation of anticoagulation was performed within a prothrombin time international normalized ratio (PT-INR) about 2.0 of normal. The mean duration of follow-up was 64.1 months, and the total duration of follow-up was 496.8 patient-years (py). The valve related complications occurred in 10 cases (2.0 per 100 py). Anticoagulant related hemorrhagic events occurred in 7 cases, and valve thrombosis in 3 cases. All three cases of valve thrombosis were in cases with Björk-Shiley valve at the mitral position. An artificial valve in mitral position increased the valve related risk compared with the aortic position (3.1%/py vs 0.0%/py). Bileaflet valve showed a lower incidence of thromboembolism than tilting disc valve (2.3%/py vs 0.0%/py). The risk of valve related complication varied with the type and the position of the prosthesis, it is desirable that the intensity of anticoagulation would be changed according to the prosthetic valve type and its position. These results suggest that the intensity of anticoagulation is optimal when the PT-INR is 1.8-2.0 for patients with bileaflet valve in the mitral position, and is 1.6-1.8 in the aortic position. Tilting disc valve needs more intensity of anticoagulation, and needs additional antiplatelet agent in the mitral position.

Anticoagulants↗

[Transcatheter arterial embolization for advanced hepatocellular carcinoma--indications and limitations].

Many patients with advanced hepatocellular carcinoma (HCC) in stage IV have no surgical indications. Transcatheter methods such as transcatheter arterial embolization (TAE) and hepatic arterial infusion chemotherapy play a main role of the treatment for advanced HCC. Conventional TAE (from proper hepatic artery) is performed for patients without liver dysfunction. Patients with severe liver dysfunction could not in the past be treated with TAE, but lately it has become possible to treat them with the method of segmental TAE or subsegmental TAE due to the development of a microcatheter and advances in equipment. Although technical progress is remarkable, there are no fixed guidelines for advanced HCC. Suitable methods for individuals need to be discussed.

Antibiotics, Antineoplastic↗

[A case of lung tumorlets with pulmonary carcinoid].

It has been postulated that differential pathological diagnosis of lung tumorlet from pulmonary carcinoid is very important to decide the therapeutic strategy, because both of them are pathologically consisted of similar type of cells originated from same cells. At the present, although lung tumorlet is considered to be a hyperplastic lesion of Kultschitzky cells which is located in the epithelial cell of the bronchial mucosa by stimuli such as hypoxia and inflammation, but it occasionally recognized in the normal lung and the concept that it is a subtype of carcnoid is also undeniable. In this paper, a case of lung tumorlet with minute pulmonary carcinoid suggesting a subtype of carcinoid operated upon in our department is presented. Although simple pulmonary resection is a method of choice for pulmonary carcinoid, but it is still controversial as to therapeutic strategy for the lung tumorlet, because it is a benign entity and not tumorous lesion. However pulmonary resection with a close subsequent followed-up study must be a best method of choice for the case with lung tumorlet includes a minute lesion of carcinoid seen in this particular case.

Carcinoid Tumor↗

[Pneumocystis carinii pneumonia associated with acquired immunodeficiency syndrome followed by KL-6, surfactant protein-D and beta-D-glucan in serum].

A 40-year-old man was admitted to our hospital with acute respiratory failure. The patient was given a diagnosis of Pneumocystis carinii pneumonia (PCP) associated with acquired immunodeficiency syndrome (AIDS). After treatment with trimethoprim-sulfamethoxazole and corticosteroid, the respiratory failure was improved and the abnormal shadows disappeared. The serum beta-D-glucan level, significantly elevated (76.0 pg/ml) on admission, returned to the normal range within two weeks. Serum KL-6 (max. 7580 U/ml) and surfactant protein-D (SP-D) (max. 235 ng/ml), which are produced by type II pneumocytes, increased after elevation of the beta-D-glucan level and decreased gradually following successful treatment. These findings suggest that beta-D-glucan may be a serological marker for PCP infection and KL-6 may be a serological marker for lung injury in PCP with AIDS.

AIDS-Related Opportunistic Infections↗

[Respiratory failure due to diaphragmatic dysfunction in Charcot-Marie-Tooth disease: a case report].

A 56-year-woman with type 2 respiratory failure due to diaphragmatic dysfunction in Charcot-Marie-Tooth disease (CMT) is reported. The patient, who had a 50-year history of CMT, was referred to our hospital because of nocturnal dyspnea. Arterial blood gas analysis on admission showed marked hypoxia with hypercapnia, and physical examination revealed thoracoabdominal paradoxus in the supine position. Chest radiography revealed elevation of both sides of the diaphragm. The vital capacity and arterial blood gas pressure in the sitting position were markedly higher than those in the supine position. Electrical phrenic nerve stimulation failed to produce any convincing muscle action potential in the diaphragm. These findings suggested that her respiratory failure was induced by both diaphragmatic dysfunction caused by bilateral phrenic nerve palsy due to CMT. Treatment of this patient was started at home with a pressure support ventilator, resulting in satisfactory clinical improvement. In general, respiratory muscle impairment is a rare phenomenon in a patient with CMT. However when a patient with CMT complains of dyspnea or if unexpected heart failure develops, it is important to keep in mind that CMT may be associated with phrenic nerve palsy.

Charcot-Marie-Tooth Disease↗

Transesophageal echocardiography for detection of mitral regurgitation due to papillary muscle rupture or dysfunction associated with acute myocardial infarction: a report of five cases.

Severe mitral regurgitation was associated with cardiogenic shock in five (0.8%) of 623 patients with acute myocardial infarction who were urgently admitted to the authors' hospitals between 1994 and 1996. The infarct was located in the inferior wall in four patients and in the inferoposterior wall in one patient. Severe mitral valve regurgitation occurred concurrently with cardiogenic shock between one and six days after the onset of myocardial infarction. A mitral regurgitant murmur was not audible in four of five patients. Similarly, mitral regurgitant Doppler signals were not detected in four patients by transthoracic echocardiographic examination, while transesophageal echocardiographic examination detected mitral regurgitant signals clearly in all patients. Thus, when cardiogenic shock is unexpectedly associated with inferior or inferoposterior wall acute myocardial infarction, severe mitral regurgitation should be suspected, even when a mitral regurgitant murmur is not audible. Furthermore, mitral regurgitant flow signals may not always be detected by transthoracic echocardiography. Thus, examination for mitral regurgitation by transesophageal echocardiography should be considered.

Aged↗

[Novel extracorporeal granulocyte apheresis column inhibits myocardial reperfusion injury: future clinical applications].

OBJECTIVES: Leukocyte infiltration is very important in myocardial ischemia/reperfusion injury. A new extracorporeal circulation therapy using a granulocyte-apheresis column (G-1) has recently been proved to be effective and safe in patients with rheumatoid arthritis and with ulcerative colitis. This study investigated whether this therapy would reduce myocardial ischemia/reperfusion injury. METHODS: Rabbits were subjected to 30 min ischemia followed by 180 min reperfusion with no treatment (control group: n = 12); or treated with extracorporeal blood circulation (2 ml/min) passing through the G-1 (G-1 group: n = 12), or sham column (sham group: n = 12). Infarct size was determined by tetrazolium staining and expressed as a percentage of the area at risk. RESULTS: Infarct size in the G-1 group (15.9 +/- 3.4%) was significantly (p < 0.01) smaller than in the control (34.7 +/- 3.9%) and sham (35.2 +/- 4.1%) groups. Granulocyte emigration into the ischemic myocardium assessed by histopathological score was significantly (p < 0.01) less in the G-1 group (0.58 +/- 0.17) than in the sham group (1.42 +/- 0.26). There was a significant (r = 0.78, p < 0.0001) positive correlation between this score and infarct size. Flow cytometry showed alterations in the adhesion molecule expression on granulocytes during the passage through the G-1, but not sham, columns as a low L-selectin and high Mac-1 form, which is associated with the inability to home to the inflamed site. CONCLUSIONS: Extracorporeal circulation with the G-1 column, a newly-developed clinically applicable therapy, appears to reduce infarct size at least in part by limiting the emigration capacity of granulocytes into the ischemic myocardium.

Animals↗

[Vertebral arterial dissection with subarachnoid hemorrhage after ischemic onset].

A case is reported of the vertebral arterial dissection presenting initially with cerebellar infarction, and which subsequently occurred with subarachnoid hemorrhage 14 days later. A 75-year old male was admitted because of vertigo and ataxia. MR T2-weighted imaging showed a hyperintensity areas on the left cerebellar hemisphere and MR angiography showed multiple stenotic lesions in the left vertebral artery. We diagnosed his illness as dissection of the left vertebral artery and antiplatelet therapy and the blood pressure control were carried out. Fourteen days after the onset, the patient complained of sudden onset of headache and subarachnoid hemorrhage was confirmed on CT scan. Proximal clip occlusion of the left vertebral artery and OA-PICA anastomosis was carried out immediately. The patient was discharged with slight truncal ataxia. We evaluated the features of this vertebral arterial dissection presenting with subarachnoid hemorrhage after ischemic stroke with reference to another reported cases.

Aged↗

Clinicocytopathological and immunohistochemical study of adenoma malignum of the uterine cervix.

Adenoma malignum is a rare type of very highly differentiated adenocarcinoma of the uterine cervix, and is quite difficult to diagnose because there are few findings definitely suggesting malignancy on cytologic or histologic examination. We recently encountered four patients with adenoma malignum and reviewed their clinicocytopathological and immunohistochemical findings. The most characteristic symptom was a watery discharge and an enlarged cervix was palpable, while multiple cystic lesions (MCL) were observed by transvaginal and abdominal ultrasonography, CT or MRI. On cytodiagnosis, the cervical gland cells formed large sheets or showed a palisading arrangement. Slightly enlarged nuclei and yellowish-orange staining of the cytoplasmic mucus were the characteristic findings. On histological examination, many cervical glands of different sizes were present and extended deep into the muscle layer, while branching or papillary growth into the lumen was also observed. On immunohistochemical study, HIK1083, a monoclonal antibody for gastric gland mucous cell mucin, was found to be positive in 3 of 4 cases, and this was fairly useful in the diagnosis of adenoma malignum.

Adenocarcinoma↗

Roles of chemokines and chemokine receptors in HIV-1 infection.

Human immunodeficiency virus type 1 (HIV-1) uses a coreceptor together with CD4 to enter CD4+ target cells. The chemokine receptors CXCR4 and CCR5 have been found to be the major coreceptors for T-cell line-tropic and macrophage-tropic HIV-1 strains, respectively, although many other chemokine and orphan receptors have also been identified as potential coreceptors for HIV-1. Genetic analyses has revealed the importance of chemokine and chemokine receptor genes in disease progression. The discovery of coreceptors provides a more defined scheme for virus entry in which the HIV-1 envelope glycoprotein sequentially binds CD4 and coreceptor, leading to a membrane fusion reaction between the viral envelope and the plasma membrane of the target cell. It also provides the basis for HIV-1 cell tropism. The identification of HIV coreceptors provides new opportunities for the development of anti-HIV therapy. Many coreceptor-based therapeutic approaches have been developed, some of which are currently in clinical trials.

Anti-HIV Agents↗