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Biomedical subjects

T Chinzei

Publications and source records attributed to T Chinzei.

At least 55 records · Page 3Linked to original sources
PubMed1988

[An autopsy case of a gastric cancer associated with elevated AFP, CEA and CA19-9].

A 48-year-old male developed gastric cancer (Borrmann III) with lung and liver metastases. Laboratory examination revealed a markedly elevated AFP (24, 241 ng/ml), CEA (9739.8 ng/ml), and CA-19-9 (726U/ml). Nevertheless, he underwent a subtotal gastrectomy for the hemostasis of a bleeding malignant lesion. Histological examination showed a moderately differentiated adenocarcinoma. A PAP for an AFP and a CEA disclosed positive staining. In addition, An autopsy revealed metastases to the liver and lungs with a positive result of PAP for AFP and CEA. Further, CA19-9 also was confirmed weakly in these same tissues, histochemically. Therefore this gastric cancer was considered an AFP, CEA, and CA19-9-producing tumor. Gastric cancer with 3 elevated tumor markers in the same patient is rare and its mechanism may elucidate the origin of gastric cancer and the resulting differentiation in the foregut.

Adenocarcinoma↗
PubMed1988

[A case of hypercalcemia with ovarian carcinoma].

A 45-year-old female manifested lower abdominal fullness and symptoms of hypercalcemia with nausea, vomiting, and thirst. Physical examination showed a right ovarian mass and laboratory data demonstrated hypercalcemia (14.6 mg/dl). The radiographic findings confirmed a right ovarian tumor without any evidence of bone metastasis. Tests revealed that her PTH, nephrogenic urinary cyclic AMP, and 1-25 (OH)2 Vitamin D were not high but that her prostaglandin E2 (PGE2) was elevated. After correction of her calcium elevation with infusion and prednisolone, right oophorectomy with tumor excision was performed. A histological examination of the tumor revealed a mucinous cysto-adenocarcinoma. The postoperative course has been uneventful, with normal calcium and PGE2 values. This case illustrates that hypercalcemia associated with an ovarian carcinoma (Malignancy-associated hypercalcemia) can be mediated by the patient's PGE2 in part.

Combined Modality Therapy↗
PubMed1987

Research and development on total artificial heart in University of Tokyo.

The research and development on the total artificial heart (TAH) in the University of Tokyo can be divided chronologically into the three stages, i.e., the first stage (1959-1970); trial and error stage to find appropriate hardwares, the second stage (1970-1985); software stage to find how to control pneumatic TAH and to manage the animals, and the third stage (1985- ); final goal to develop implantable TAH for animal and human. This paper reviews the process of research and development in each stage.

Animals↗
PubMed1987

[A case of metastatic malignant melanoma mimicking pancreatic pseudocyst].

A 74-year-old male was admitted to our hospital complaining of an abdominal mass. Abdominal US and ERCP disclosed a cyst in the pancreas, communicating with a crater in the stomach. Spontaneous rupture of a pancreatic pseudocyst into the stomach was considered. Laparotomy demonstrated an irregular black pancreatic cyst, and histological examination showed atypical spindle shaped cells with brown to black pigmentation, compatible with malignant melanoma. Autopsy confirmed the diagnosis of malignant melanoma involving the pancreas, stomach and other organs. Efforts to elucidate the primary site were unsuccessful, Metastatic melanoma without a primary site is well known and has been reported to occur in from 2.4% to 8.7% of all cases. This case suggests that malignant melanoma must be considered in cases of tumors with various symptoms and multiple metastases without a definite primary site.

Aged↗
PubMedDate not supplied

In vitro and in vivo evaluation of a jellyfish valve for practical use.

A practical model (Model-1) of a jellyfish valve was developed, which was composed of a valve seat and a flexible membrane. The valve seat has 12 spokes to hold the membrane, and is made of solution-cast polyurethane coated with segmented polyurethane or Cardiothane. The flexible membrane is 200 microns thick, and made of segmented polyurethane or Cardiothane by a casting method. The valves were built into a sac type blood pump. In mock circulation tests, this jellyfish valve revealed performance superior to Bjork-Shiley (B-S) valves. No stagnation point was observed in the flow visualization study, and durability testing is ongoing beyond 7.5 months. The valves were used in animal artificial heart experiments for up to 112 days with good performance. No thrombi were formed on the valve membrane or around the spokes. Although a ring thrombus was observed behind the valve, it would be prevented by perfect adhesion of the valve seat to the blood pump. The plasma free hemoglobin level was less than 2 mg/dl during these experiments. These results suggest that a jellyfish valve (Model-1) is useful in ventricular assist devices, and in short-term bridge use of a total artificial heart.

Animals↗
PubMedDate not supplied

Use of a total right heart bypass model for analyses of abnormal hemodynamics in total artificial heart animals, and the function and regulatory mechanisms of a natural heart.

By fixing the function of one ventricle, a total right heart bypass model can clarify the function and regulatory mechanism of the natural heart, and the etiology of abnormal hemodynamics in TAH animals such as increased CVP blood pressure and hepatic congestion. The pulmonary artery of a right heart bypass in a goat was clamped proximally; the pulmonary circulation was thus supplied entirely by the artificial heart and the systemic circulation by the natural heart. This model enabled studies of long-term effects of an artificial right heart on systemic circulation at a right heart output of 80-100 ml/kg/min; the response of the natural left heart to changes in output of the right heart; and the response of the natural left heart and artificial right heart to treadmill exercise. It was found that only slight increase in CVP or no increase in blood pressure was observed during the experiment (112 days); a rapid increase in output of the RAH resulted in an increase in left atrial pressure, stroke volume and output of the left ventricle, and a decrease in its heart rate at rest; and significant increase in both artificial right heart and natural left heart output and heart rates were observed during treadmill exercise, despite the marked decrease in left atrial pressure. The above results suggest that the increase in CVP and blood pressure in total artificial heart animals are not due to factors involving the artificial right heart, and that although left ventricular function acts in accordance with Starling's law at rest, this is no longer true during treadmill exercise.

Animals↗
PubMedDate not supplied

Development of a new circulatory assist method with the combined effects of intra-aortic balloon pumping and counter pulsation. First report.

Current circulatory assist methods, such as intra-aortic balloon pumping (IABP), are not always adequate to save acute circulatory failure patients. Therefore, a stronger, percutaneously accessible method is required. We found that the combination of IABP and CP generated a profound circulatory assist effect, and we have consequently developed a new assist system in this study. A sac type blood pump with a volume of 20 ml and a single port without a valve, was developed for CP. In the mock circulatory test, a 20 ml stroke volume was obtained using a cannula with a 5 mm diameter under the following driving conditions: air pressure = 200/-100 mmHg; S/D = 50%; pulse rate = 100 bpm. In vivo experiments were performed using four mongrel dogs with body weights of 12-20 kg. A cannula for CP was inserted via the brachial artery or subclavian artery into the aortic root. The pump flow (PF), coronary artery flow (CF), renal arterial flow (RF), and aortic pressure (AP) were measured, and the combined effects of IABP and CP were compared with their individual effects. In the most effective case, a marked increase in diastolic AP (60%), cardiac output (40%), and CF (100%) was obtained by the combination of IABP and CP, which produced a remarkable effect compared with the single use of IABP and CP. There was no negative effect on RF by this assist method. As this new circulatory support system has many circulatory assist effects, and is percutaneously accessible, it will be available for clinical use.

Animals↗
PubMedDate not supplied

Fabrication of a jellyfish valve for use in an artificial heart.

For a valve to be fabricated seamlessly into an artificial heart (AH) blood pump, a jellyfish valve has been developed, in which a thin membrane is fixed at the center of a valve seat having several spokes to protect against prolapse of the membrane. The valve is superior in performances to a Björk-Shiley valve, and reveals good blood compatibility. The valve would be very useful not only for AH animal study, but for future clinical use in infants to adults. Several institutions are already trying the valve. In this paper, the fabrication of the jellyfish valve is introduced, and in vitro and in vivo results summarized. A computer aided design (CAD) system was developed to cut a male wax mold of the valve seat. The input parameters to the CAD are diameter, height, thickness of rim, number of spokes, width and thickness of spokes, etc. Jellyfish valves with diameters of 4 to 27 mm have already been fabricated for many types of AHs and assist pumps.

Animals↗
PubMedDate not supplied

Changes with respect to time in the in vivo adsorption of plasma proteins onto artificial heart blood pumps.

The distribution of adsorbed plasma proteins (albumin, IgG, and fibrinogen) on 10 artificial heart blood pumps coated with 2 segmented polyurethanes was evaluated quantitatively after long-term in vivo experiments with goats to determine how the adsorption of plasma proteins on the pumps was affected by the kinds of biomaterials used, and by the pumping duration. The adsorbed plasma proteins on the materials were determined quantitatively using the iodine-125 conjugated antibody method. Microscopically, the adsorbed plasma proteins were marked by the gold colloid conjugated antibody method, and analyzed using a field emission scanning electron microscope. The macroscopic results showed that: 1) the adsorbed plasma proteins on KP-13 were more evenly and finely distributed than those on Cardiothane; 2) with KP-13, the adsorption of IgG and albumin at the center of the pumps was significantly less than in the peripheral areas, and the adsorbed IgG and albumin decreased significantly as the pumping duration increased; 3) in contrast, the adsorbed fibrinogen increased significantly with time; and 4) with Cardiothane, the tendencies for adsorbed IgG and albumin to decrease, and for adsorbed fibrinogen to increase, were less significant than with KP-13. Microscopically, the gold colloids marking plasma proteins were found to not cover the whole of the surface, but were found scattered randomly or in clusters, with no relationship observed between the distributions of the three plasma proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorption↗