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Biomedical subjects

T Kitamura

Publications and source records attributed to T Kitamura.

At least 739 records · Page 41Linked to original sources
PubMed1984

Modeling technique of prosthetic heart valves.

This paper demonstrates a modeling technique of prosthetic heart valves. In the modeling, a pumping cycle is divided into four phases, in which the state of the valve and flow is different. The pressure-flow relation across the valve is formulated separately in each phase. This technique is developed to build a mathematical model used in the real time estimation of the hemodynamic state under artificial heart pumping. The model built by this technique is simple enough for saving the computational time in the real time estimation. The model is described by the first-order ordinary differential equation with 12 parameters. These parameters can be uniquely determined beforehand from in-vitro experimental data. It is shown that the model can adapt, with sufficient accuracy, to a change in the practical pumping condition and the viscosity of the fluid in their practical range, and is also demonstrated that the estimated backflow volume by model agrees closely with the actual one.

Heart Valve Prosthesis↗
PubMed1984

Infectivity titration of hemorrhagic fever with renal syndrome virus: use of immune adherence hemagglutination for detection of virus growth.

Serial dilutions of hemorrhagic fever with renal syndrome viruses were inoculated into Vero-E6 cells in microplates. After 2 weeks of incubation, infected cells were disrupted by freezing and thawing, and virus antigens were detected by immune adherence hemagglutination. The infectivity titers of the virus as determined by this method were in close agreement with those obtained by the immunofluorescent antigen endpoint method. Then, a neutralization method was established. Japanese hemorrhagic fever with renal syndrome isolates, strains SR-11 and TR-352, were found to be distinct from Hantaan virus, strain 76-118, by the neutralization test.

Animals↗
PubMed1984

Controlled study on time reproduction of depressive patients.

23 depressive inpatients and the same number of matched nonpsychiatric controls were examined three times: following admission, and 14 and 28 days thereafter. Hamilton's Rating Scale for Depression and the Time Reproduction Test were administered. Time reproduction was found not to be different between patients and normal controls and within patients. Nor was a significant correlation found with any clinical symptoms.

Adult↗
PubMed1984

Abnormal reflex vasoconstriction to cold stimulation in forearm of patients with variant angina.

The responses of the blood vessels of the forearm to cold pressor test and mental stress were examined in patients with variant angina and in control subjects. In response to cold pressor test, blood pressure, heart rate and forearm vascular resistance increased with statistical significance in both groups. Percentage changes in blood pressure and heart rate were not significantly different in patients and control subjects. Percentage change in forearm vascular resistance in patients with variant angina (120 +/- 101%) was significantly greater (p less than 0.05) than that in control subjects (47 +/- 26%). In response to mental stress, percentage change in forearm vascular resistance was -20 +/- 19% in patients with variant angina and -24 +/- 18% in control subjects and there was no significant difference in the two groups. We conclude that, in some patients with variant angina, not only the coronary artery but the forearm vessels show the abnormal reflex vasoconstriction and it may be postulated that it represents the generalized abnormality of vascular smooth muscle or of their neural control which exists in some patients with variant angina.

Adult↗
PubMed1984

Transfusion-mediated spread of the human T-cell leukemia virus in chronic hemodialysis patients in a heavily endemic area, Nagasaki.

The incidence of anti-adult T-cell leukemia-associated antigens (ATLA) was surveyed in 134 patients under chronic hemodialysis in the Nagasaki area, as well as 4708 blood donors resident in the same area as controls: 23 patients (17%) and 201 donors (4.3%) were positive for anti-ATLA antibody. All seropositive patients were found to have had a positive history of blood transfusions. Seroconversions were confirmed in 9 cases, all of them after initiation of transfusions. In total, 216 units of blood were transfused in 7 seroconverted patients, and this is consistent with the estimated rate of anti-ATLA antibody-positive donor blood supplied by the Red Cross Nagasaki Blood Center (5%).

Adult↗
PubMed1984

Clinical implications of anti-HTLV antibody titer, abnormal lymphocytes in HTLV carriers and HTLV genome negative adult T-cell leukemia-lymphoma.

Abnormally large lymphocytes with Pelger-like nuclear lobulation have been found in peripheral blood of smoldering adult T-cell leukemia-lymphoma (ATL) patients. They are also found in quite low percentage in peripheral blood of healthy HTLV carriers. Therefore, it has become difficult to discriminate smoldering ATL having only abnormal lymphocytes from a healthy human T-cell leukemia virus (HTLV) carrier only by morphology and serology. We found that patients with smoldering ATL with visceral organ involvement such as skin or lung lesions had much higher titer (about 1 : 1,000) of anti-HTLV antibodies than those with other subtypes of ATL (about 1 : 250); the difference was highly significant (p less than 0.001). In addition, the period of survival of patients with smoldering ATL having antibody with high titer was much longer than that of patients with other subtypes of ATL, suggesting the role of a host immune response. Four cases of HTLV-negative ATL were found to have the same chromosomal abnormality as that has been seen in HTLV-positive typical ATL; the situation was quite similar to Burkitt's lymphoma. Since it has been considered that HTLV does not include oncogenes, a common oncogenic mechanism, ATL specific cellular oncogenes, might exist: they might be activated by HTLV or a mechanism other than a virus.

Antibodies, Viral↗
PubMed1984

[AFP producing stomach cancer--a study of transplanted tumor in nude mice].

AFP producing cancer of the stomach was divided into 2 groups; Group A demonstrated a marked elevation of serum AFP levels before gastrectomy and was positive for AFP by PAP staining; group B showed delayed elevation of AFP levels at recurrence or in the terminal stage. Experimentally, we could establish three cell lines from group A and two lines from group B from transplanted tumor in nude mice. Tumor growth, changes of serum AFP levels and PAP staining investigated in each group. Group A and B were not only thought to exhibit different biological behavior, but also different mechanisms in AFP production. Group A cells may have the ability to secrete high levels of AFP; this may be a property of these tumor cells. On the other hand, group B tumor cells initially have little ability to secrete AFP. However, they may transform into AFP producing cells as a phenomenon of cell differentiation.

Aged↗
PubMed1984

[Multiple primary cancers in patients with malignant lymphoma].

This study of 502 patients with malignant lymphoma revealed the following: In all, 18 cases (3.6%) of histologically confirmed multiple primary cancers were found. Eleven cases of second malignancies were observed after diagnosis of malignant lymphoma, whereas 7 cases of malignant lymphoma occurred after other malignancies. The expected number of second malignancies in 502 patients with malignant lymphoma was calculated as 4.94 by the person-years approach. The observed number (11) was significantly higher than the expected (p less than 0.01). There was, however, no case of second malignancy considered to be related to the previous radiotherapy.

Adenocarcinoma↗
PubMed1984

[Sonographic diagnosis of biliary tumor].

Biliary tract is the most suitable for sonographic diagnosis. That is caused by the biliary structure composing of bile and ductal system. Therefore, sonographic diagnosis of biliary tumor also is not so difficult. Careful observation of total biliary wall is necessary for diagnosis of the resectable small tumor. On the other hand, sonographic detection of advanced large tumor is easy. In the case of large tumor, the diagnosis of benign or malignant also is easy, but that of originating organ is rather difficult. However, in the case of small nodule or papillary tumor of biliary system, the detection of that is fairly difficult and the diagnosis of benign or malignant is more difficult. In the case of obstructing jaundice also, the ascertain of the end of dilated biliary duct is easy, and the detection of the tumor is not so difficult, but the diagnosis of benign or malignant is difficult. Therefore if the small nodule or papillary tumor in the biliary system was detected by the sonographic diagnosis, the following decision should be taken, suitably and promptly, that is the selection of the next one or more out of following many diagnostic modalities. There are ERCP, PTC, PTCD, angiography, sonographic guided biopsy or puncture, or laparatomy and so on.

Bile Duct Neoplasms↗