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Biomedical subjects

T Horiuchi

Publications and source records attributed to T Horiuchi.

At least 541 records · Page 30Linked to original sources

Oxygen--insensitive nitrofuran reductases in Salmonella typhimurium TA100.

The present study demonstrated by DEAE-cellulose column chromatography that oxygen-insensitive nitrofuran reductases in Salmonella typhimurium TA100 consisted of at least two reductases, NADPH- and NAD(P)H-linked enzymes. The NADPH- and NADH-linked activities of the latter enzyme seemed to originate from a single enzyme, because both activities were similarly inactivated by heat and urea treatments, and also inhibited by dicumarol. On the other hand, the NADPH-linked enzyme was less sensitive to heat, urea and dicumarol. Furthermore, the study showed that the NAD(P)H-linked enzyme was a flavoenzyme which could be inactivated by dialysis against 1 M potassium bromide and reactivated by FMN.

Apoenzymes↗

Left ventricular-right atrial communication with an aneurysm of the atrioventricular membranous septum. A case report.

A 40-year-old man with combination of left ventricular-right atrial communication and aneurysm of the atrioventricular membranous septum is presented. A supravalvular type defect, 14 X 15 mm in size, was closed with a Teflon patch. An oval shaped aneurysm of the atrioventricular membranous septum, 20 X 17 mm in size was also noted, but was left untouched. To our knowledge, this is the first reported case with this combination in Japan.

Adult↗

Reconstruction of the right ventricle with diaphragm driven right ventricular wall device.

For the treatment of congenital cardiac anomalies associated with hypoplastic right ventricle such as tricuspid atresia, various methods have been used in clinical and experimental studies. Though these methods were effective, there remained still some problems such as postoperative right heart failure or restriction of indications for the cases associated with high pulmonary vascular resistance. In order to solve these problems, diaphragm driven right ventricular wall device (RVWD) was newly developed. The device is composed of hard outer housing and soft diaphragm made of polyurethane and actuated pneumatically triggered to R wave of ECG or left ventricular pressure. Characteristics of RVWD were checked using a mock circulation to find optimal driving condition for animal experiments. Acute experiments were carried out using 15 mongrel dogs. Right ventricular free wall was excised as wide as possible under hypothermic inflow occlusion and RVWD was sutured to the edges of right ventriculotomy. Hemodynamics were investigated with and without driving of RVWD for 6 to 24 hr. RVWD was able to maintain hemodynamics efficiently during immediate postoperative period. After body temperature and cardiac function returned to normal, systemic circulation could be maintained without driving of RVWD. From the results of this study, possibly of surgical correction of hypoplastic right ventricle using RVWD was presumed.

Animals↗

Histologic findings of ductus arteriosus and pulmonary vascular disease in interrupted aortic arch.

There are still a number of unsolved problems concerning the total correction of interruption of the aortic arch. Here we report a histopathological investigation of the patent ductus arterious and pulmonary vascular disease using autopsy material of a patient with Celoria type B interruption of the aortic arch who died postoperatively. The so-called ductus arteriosus between the pulmonary arterial trunk and the descending aorta was lacking in elastic fibers and smooth muscle cells at the media showing discontinuous, transverse fibrous tissue. The vessel walls were weak and normal development was apparently impossible. Consequently, it was concluded that in the reconstruction of the aortic arch in such cases with PDDT, it is advisable not to use the patent ductus arteriosus. In this case, hypertrophy of the media of small pulmonary arteries was marked, but pulmonary vascular intimal lesions were mild. With regard to the pathogenesis, it is thought that there was sufficient thickening of the media of the pulmonary arterial system in response to the pulmonary hypertension present from birth, and it prevented the progression of the intimal lesions by accommodating to the intraarterial pressure.

Aorta↗

Long-term follow-up of patients who have undergone valve replacements for acquired valvular disease: a clinical and hemodynamic study.

Thirty-three cases, comprizing 5 of mitral regurgitation (MR), 11 of mitral stenosis (MS), 11 of aortic regurgitation (AR) and 6 of AR and mitral steno-regurgitation (MSR), underwent both preoperative and postoperative heart catheterization in association with a muscle exercise test. Comparisons were made between preoperative and postoperative clinical symptoms, hemodynamics and cardiac functions. The following results were obtained: 1) Improvements in clinical symptoms and hemodynamics at rest were observed in all but two patients. 2) Abnormalities in hemodynamics were obtained after the muscle exercise test, even in cases exhibiting normal hemodynamics at rest. 3) An increase in pulmonary artery mean pressure was noted in MR and MS groups after the muscle exercise test. 4) The cardiac function index values in both the MR and MS groups showed lower levels than those in both the AR and AR + MSR groups. 5) The presence of atrial fibrillation and extent of myocardial fibrosis were related to improvements in postoperative cardiac functions.

Adult↗

Survey on antibody against egg drop syndrome-1976 virus among chicken flocks in Japan.

A survey on antibody against egg drop syndrome-1976 virus was carried out with 4,518 sera collected from 667 flocks over a period from 1971 to 1981 in Japan. Antibody-positive sera were initially detected in 1976, and the number of positive sera increased suddenly in 1979, and a total of 270 sera from 23 flocks were positive. The positive flocks consisted of 20 broiler parent flocks belonging to 9 farms and 3 layer flocks belonging to 2 farms. It seemed from the results of this survey that the prevalence of the virus might have been limited in Japan.

Adenoviridae↗

Cloning of mutator genes and identification of their products.

To elucidate molecular mechanisms leading to the increment of mutation frequency by mutator genes, we have cloned the dnaQ and uvrD genes of Escherichia coli and identified their gene products. By in vitro recombination hybrid plasmids capable of complementing a dnaQ mutation were constructed. The dnaQ+ plasmids consist of a full-length pBR322 DNA and a 1.5-kilobase DNA fragment derived from the E. coli chromosome. Specific labeling of plasmid-encoded proteins by the maxicell method revealed that the 1.5-kilobase insert codes for two proteins, one with a molecular weight of 25,000 and the other with a weight of 21,000. Because insertion of the gamma delta sequence into the dnaQ gene of the plasmid resulted in disappearance of the 25,000-dalton protein, it was concluded that that protein is the dnaQ gene product. The 21,000-dalton protein was identified as RNase H. The uvrD (uvrE, recL, mutU, and pdeB) gene has been cloned with phage lambda as vector. The increased sensitivity to ultraviolet light, high mutability and conditional lethality of uvrD- strains and their derivatives were all suppressed by lysogenization of the mutant cells with lambda uvrD+. In addition to the uvrD gene, lambda uvrD+ carried the corA gene that controls transport of Mg2+, Mn2+, and Co2+ through the cell membrane. By analyzing proteins produced by the transducing phages, the uvrD and corA gene products were identified as a 75,000-dalton protein and a 37,000-dalton protein, respectively.

Bacterial Proteins↗

[Transthoracic catheterization under monitoring by ultrasono-cardiotomography and its clinical usefulness].

When serious postoperative complications such as mechanical malfunction of the implanted valve occur in patients with multiple valvular replacements, it is very urgent to evaluate the function of the valve and heart and to establish an accurate diagnosis as to the damaged prosthetic valve, while giving intensive life-saving bed-side care. Under such circumstances, transvascular heart catheterization necessary for obtaining hemodynamic data or for angiocardiography can not be applied because it is almost impossible for a catheter to pass through a prosthetic valve without potential danger. Then, the present authors have introduced a method of cardiac catheterization by a direct transthoracic route during which cardiac structures are monitored by ultrasono-cardiotomography. This method is called "transthoracic catheterization monitored by ultrasono-cardiotomography," and was applied to cases of double (aortic and mitral) valve replacements. The immobile adhesive area in the vicinity the right ventricular wall is detected from the longitudinal or horizontal cross-section pictures, through which a polyethylene catheter with stylet was introduced from the subxiphoid region and was advanced toward the left ventricle. After introduction of the catheter into the right ventricle, the catheter tip was advanced to the midportion of the ventricular septum, which was selected to avoid the penetration of the tricuspid valve and coronary arteries. Then, the catheter was passed into the left ventricle on the ultrasonic scanning plane along the direction of the short axis of the heart. After placing the catheter into the left ventricle, a small amount of contrast material was injected to confirm the precise positioning of the catheter tip in the left ventricle. Thus, the hemodynamic measurement and angiocardiograpy were performed easily. By utilizing contrast cardiotomography, valvular function was evaluated easily without any side effects as in case of angiocardiography. Furthermore, ultrasono-cardiotomography was sensitive in detecting cardiac tamponade if appeared during direct heart catheterization, making immediate treatment possible. Thus, transthoracic catheterization monitored by ultrasono-cardiotomography was useful for the evaluation of the function of the prosthetic valve, especially in cases with double valve prostheses.

Adult↗

Hematopathological changes in dead and moribund chicks induced by chicken anemia agent.

Fifty day-old chicks were inoculated wit the Gifu-1 strain of chicken anemia agents. They began to show anemia and a drop in body weight 10 days postinoculation. Thirty-five of them died over a period of 12 to 23 days, mostly between 14 and 18 days postinoculation. Hematocrit value and red and white blood cell counts were markedly reduced in moribund birds. Polychromatic erythrocytes and granulocytes dropped in incidence in the peripheral blood accompanied with a fall in hematocrit value, and gained again with recovery from anemia. Macroscopically, dead and moribund birds revealed yellow bone marrow, marked atrophy of the thymus and bursa of Fabricius, discoloration and swelling of the liver, spleen and kidneys. In some cases, there were partially well-defined necrotic foci in the liver, round heart, fresh hemorrhages in the proventricular mucosa, erosion on the gizzard mucosa, and subcutaneous edema. Microscopically, marked hypoplasia or aplasia of hematopoietic cells in the bone marrow and severe depletion of lymphocytes in lymphoid organs, such as the thymus, bursa of Fabricius, spleen, and cecal tonsils, were commonly seen in affected birds. The changes described above suggested that the anemia induced by chicken anemia agent might closely be related to the bone marrow function.

Anemia↗