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Biomedical subjects

H Nishida

Publications and source records attributed to H Nishida.

At least 397 records · Page 22Linked to original sources
PubMed1989

Carotid and aortic arch endarterectomy using hypothermic arrest with coronary bypass.

A 67-year-old man with symptomatic bilateral carotid artery obstructions and a large, friable atheromatous plaque of the transverse aortic arch required coronary artery bypass grafting for severe triple-vessel disease. An endarterectomy of the transverse arch and a left carotid endarterectomy were performed using deep hypothermic circulatory arrest concomitant with quadruple coronary artery bypass grafting. Recovery was uneventful. Hypothermic circulatory arrest provides adequate protection for this combined procedure and may eliminate cerebral embolization.

Aged↗
PubMed1989

Determination and regulation in the pigment cell lineage of the ascidian embryo.

The brain of the ascidian larva comprises two pigment cells, termed the ocellus melanocyte and the otolith melanocyte. Cell lineage analysis has shown that the two bilateral pigment lineage cells (a-line blastomeres) in the animal hemisphere give rise to these melanocytes in a complementary manner. The results of the present investigation suggest that the specification of the fate of pigment cells proceeds in two distinct steps. First, the determination of pigment lineage cells requires an inductive interaction from the vegetal blastomeres of the A-line. Cell dissociation experiments demonstrated that the inductive interaction is completed by the midgastrula stage. However, the two bilaterally positioned cells destined to become the pigment cells in the first step are still equipotent at this stage in that they can give rise to either the ocellus or otolith. Thus, they constitute what is termed an "equivalence group." In the second step, the individual fates of the two cells that compose the equivalence group are determined. Namely, one cell develops into an ocellus and the other cell develops into an otolith. Photoablation of one of the pigment precursor cells at various stages indicated that the second step of determination occurs at the midtailbud stage. It is suggested that the cue to choose one of the alternative developmental pathways may be positional information that exists along the anteroposterior axis. The second step of determination is thought to be mediated by a hierarchical interaction. In the absence of this interaction, melanocyte specification proceeds along the dominant pathway that results in the differentiation of an ocellus.

Animals↗
PubMed1989

Histopathological changes of human tumors following thermoradiotherapy.

Twenty human malignant tumors treated with thermoradiotherapy were examined histopathologically. Hyperthermia was administered regionally with a 13.56-MHz or 8-MHz RF heating device, once or twice a week after irradiation, 2 to 12 sessions in total. Fifteen tumors received a total radiation dose of 26 to 70 Gy in fractions of 1.8 Gy to 2.0 Gy a day, 5 days a week, whereas five tumors received a total dose of 20 to 60 Gy in fractions of 4 Gy each, twice a week. Microscopic examination of 4 of the 20 tumors revealed complete necrosis throughout the cross-section of the entire tumor. All the four tumors had received a total dose of over 60 Gy and a tumor center temperature of over 42 degrees C. In 10 tumors, more than 50% but less than 99% of the cross-section of the entire tumor had massive coagulation necrosis. The remaining six tumors showed relatively little change; the area of intratumor necrosis was less than 50%. The grade of tumor necrosis was dependent on both the temperatures of tumor center and periphery, and a total radiation dose. The small blood vessels and capillaries in the tumor parenchyma were markedly damaged in 16 of the 20 tumors, while the blood vessels in the tumor stroma were damaged in only 2 tumors. Condensation of the destroyed nucleus observed in 15 tumors was considered to be a typical change induced by thermoradiotherapy. Viable tumor cells remained in the tumor central area in only four tumors and around the blood vessels in only three tumors. However, in the tumor peripheral area, viable tumor cells were observed in 16 out of the 20 tumors. These results indicate that histopathological changes induced by thermoradiotherapy are greater in the tumor central area than in the tumor peripheral area, and provide strong rationale for utilizing full dose radiation therapy in combination with hyperthermia as opposed to lower doses for cancer therapy.

Adult↗
PubMed1989

The interrelated effects of n-6/n-3 and polyunsaturated/saturated ratios of dietary fats on the regulation of lipid metabolism in rats.

The effects of various n-6/n-3 (0.45-9.31) and polyunsaturated/saturated (P/S; 0.25-6.08) ratios of dietary fatty acids on various lipid parameters were studied in rats using a combination of palm oil, safflower oil, soybean oil and perilla oil. When the n-6/n-3 ratio was changed while maintaining a constant P/S ratio (1.2), the concentration of serum cholesterol tended to increase linearly with the increasing n-6/n-3 ratio, whereas liver cholesterol tended to decrease. Serum triglyceride level increased linearly up to a n-6/n-3 ratio of approximately 5, whereas liver triglyceride was not influenced. When the n-6/n-3 ratio was kept relatively constant (5.6-6.4), serum and liver cholesterol levels decreased up to a P/S ratio of approximately 2, whereas serum triglyceride tended to be low below this value. The ratio of arachidonate to linoleate in tissue phosphatidylcholine (PC) was also influenced by the n-6/n-3 and P/S ratios; it increased up to a n-6/n-3 ratio of approximately 4, whereas it decreased up to a P/S ratio of approximately 2. The percentage of eicosapentaenoic and docosahexaenoic acid (n-3) in tissue phosphatidylcholine was positively related to dietary n-3 fatty acid levels. Prostacyclin (PGI2) production by thoracic aorta reached a plateau at a n-6/n-3 ratio approximately 5, whereas it tended to decrease with an increasing P/S ratio. Platelet production of thromboxane A2 exhibited a parabola-like pattern with a peak value at a n-6/n-3 ratio of approximately 2, whereas it was independent of the P/S ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1989

Assessment of cardiopulmonary baroreflex function in hypertensive and normotensive subjects with or without hypertensive relatives.

1. To investigate whether cardiopulmonary baroreflex control contributes to the pathogenesis and progression of hypertension, we have evaluated the function of the cardiopulmonary baroreflex in 22 patients with essential hypertension and in 17 volunteers with normotension. The normotensive group consisted of 8 subjects with a family history of hypertension and nine with no family history. 2. Forearm vascular resistance (FVR) and central venous pressure (CVP) were measured under control conditions when -10 mmHg lower body negative pressure was applied; the cardiopulmonary slope (CPS = delta FVR/delta CVP) was calculated as an index of the cardiopulmonary baroreflex function. 3. CPS was significantly higher in hypertensives (6.0 +/- 3.93 [s.d.], P less than 0.01) and also tended to be higher in normotensives with a family history of hypertension (3.9 +/- 3.53, P less than 0.05), compared with normotensives without a family history of hypertension (1.7 +/- 0.88). 4. When the hypertensives were divided into two groups, depending on whether CPS was greater or less than 6.0 units, cardiac wall thickness (20 +/- 1.6 mm vs 23 +/- 3.2 mm, P less than 0.05) and the renal vascular resistance (20.9 +/- 6.52 units vs 28.9 +/- 7.32 units, P less than 0.05) were both significantly higher in the Low CPS group. 5. These findings suggest that cardiopulmonary baroreflex function was augmented even in normotensive subjects with hypertensive relatives, as compared with those without hypertensive subjects. Furthermore, cardiopulmonary baroreflex function was augmented in the early stages of hypertension and diminished further with increasing severity.

Adult↗
PubMed1989

[Studies of cell-mediated immunity in mesangial proliferative glomerulonephritis--IgA nephropathy and non-IgA nephropathy].

In order to clarify the abnormalities of cell-mediated immunity in patients with mesangial proliferative glomerulonephritis [IgA nephropathy (IgA N) and Non-IgA nephropathy (Non-IgA N)], lymphocyte subsets were analysed by using monoclonal antibodies with flow cytometric two-color analysis and interleukin-2 (IL-2) production from lymphocytes of the patients was measured by ELISA system. A markedly decreased percentage (11.6 +/- 10.5%) of CD4+ 45R+ cells was found in the patients with IgA N when the results were compared with the normal controls (20 +/- 6%) (P less than 0.01). No difference was found between patients with IgA N and the controls as to the percentage of CD4+ 45R-, CD8+, 11+ and CD8+ 11- cells, respectively. Patients with Non-IgA N also showed a significantly decreased percentage of CD4+ 45R+ cells (10.9 +/- 6.5%), while CD8+ 11+ cells was parallely lowered (7.4 +/- 5%) in compared with the controls (10 +/- 4%). The percentage of HLA-DR positive cells was found to be increased in the patients with both IgA N and Non-IgA N, although the antigen bearing cells were reduced after stimulation with Concanavalin-A (Con-A). No difference in IL-2 production from lymphocyte of both patients groups and the controls cultured with Con-A was found. These results suggested that a deficiency of suppressor inducer T cells played a part of the pathogenesis of IgA N and Non-IgA N.

Adolescent↗
PubMed1989

[Surgery of aortic disease with coronary heart disease].

From 1978 through 1989, 1200 patients underwent attempted coronary surgery. Seventy-six CABG-patients were recognized aorto-vascular disease. Thirty-one CABG-patients were operated with vascular surgery. Operative mortality of CABG was 0% (0/76). Operative mortality of vascular surgery was 3.2% (1/31). Total operative mortality was 1.1% (1/91).

Aortic Aneurysm↗
PubMed1989

[Aortic wall injury and thrombogenesis in catheterization: experimental study].

Arterial and venous catheterization is a very useful procedure in the diagnosis of heart diseases. However, some complications with thrombogenesis have been reported. Two kinds of Mikaelson-type non-heparin-coated angiographic catheters (with 6.5 Fr. and 80 cm length) were used for the experiments. One was of polyurethane (PUC) and the other of polyethelene (PEC). Eight experimental dogs were used for each group. The catheter was inserted into the ascending aorta through the femoral artery. No antithrombogenic drugs were given to the animal. One hour later, sodium heparin (100 U/kg) was administered intravenously. The animal was sacrificed by acute exanguination. The aorta was opened longitudinally. The position of the thrombi on the aortic wall was macroscopically observed and the weight of the thrombi attached to the catheters were measured. A piece of the aorta at each level was excised for light and scanning electron microscopic observations. Mural thrombi of various lengths still remained on the aortic wall of every dog after the removal of the catheters. Microscopic observation revealed that the mural thrombus was formed on the aortic wall, where the endothelial cells had peeled off and the internal elastic membrane was partially destroyed. SEM observation also showed that fibrin network on the aortic wall where the endotherial cells were peeled off. Microscopic observation of aortic wall also revealed intimal tears, inner elastic membrane injury and bleeding in the elastic membrane. This damage could worsen leading to dissection of the aorta, thrombosis of the abdominal organs. The injury is considered due to mechanical irriation by the catheter.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[A dermaerosion case dealing with a leakage of a chemically irrigable solution (NaOCI solution)].

This paper is a report regarding a dermaerosion case dealing with a leakage of a chemically irrigable solution in a 3 year old boy. We are continuing to observe the dermal changes during as he grows. Also, we carried out a pathological experiment on a rabbit and a patch test of the derm of seven people. The following conclusions were obtained. 1. We observed the dermaerosion of an epithelium repair after a complete elapse of one year. The dermaerosion of the corium could not be repaired but changed the color of the derma of the patient who recovered after a lapse of 2 years and 8 months. 2. We recognized in the rabbit experiment that a 12% H2O2 solution damaged the corium of the rabbit over a period of 24 hours. The 12% H2O2 solution was four times higher, for we normally used a 3% H2O2 solution. 3. When we used a 10% NaOCl solution (which we usually use in the widening of the root canal) for 20 minutes on the derma of the rabbit, the derma damaged the epithelium but over a period of 40 minutes the solution we used on the derma of the rabbit damaged the corium. 4. When we used a NaOCl and H2O2 solution the reaction on the skin of the rabbit is weaker than when only one solution was used. 5. We used 0.5% NaOCl and 0.3% H2O2 solutions for the biceps of 2 atopic diseased people and 5 normal people for 48 hours, with no change noticed in their biceps. 6. The results may be summarized as follows.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Mitral insufficiency due to ruptured chordae tendineae--clinical features, early and late results of valve replacement and repair].

To evaluate the early and late results of mitral valve replacement and reconstruction for mitral insufficiency due to ruptured chordae tendineae respectively, 74 consecutive cases were analyzed. Fifty-five (74.3%) of the patients were men, and the mean age was 48 +/- 12 years old (range 16 to 76). The causes of the mitral disease were idiopathic in 50 (67.6%), rheumatic in 7 (9.4%) and infective endocarditis in 11 (14.9%) patients. In idiopathic 50 cases, 24 had mitral valve prolapse and 16 had both mitral valve prolapse and hypertension. Forty-one (55.4%) of the patients were in NYHA functional class III or IV preoperatively. Thirty (40.5%) cases underwent surgery within one year after their initial symptoms of heart failure onsets including six emergency operation cases due to uncontrollable acute lung edema. Chordae to anterior mitral leaflet were ruptured in 31 (a5, m16, p10)[41%] patients, to the posterior mitral leaflet in 45 (a4, m23, p18)[59%], and to both leaflets in one patient. Mitral valve replacement was performed in 68 patients (91.9%) and 6 patients (8.1%) underwent mitral valve repairs. Twenty cases underwent associated procedures that included tricuspid valve annuloplasty in 8, aortic valve replacement in 5 and myocardial revascularization in 4 cases. There were two operative deaths (2.4%); both occurred after replacement, left ventricular rupture in one and DIC in one. Mean follow-up period was 4.5 years (range 1 to 17) in 67 cases. There were four late deaths; all occurred after replacement. However five patients sustained mild mitral insufficiency after mitral valve repair including one that became worse of regurgitation three years after isolated Kay's annuloplasty, there were no cases that had needed reoperation and no late death after reconstruction. Left ventricular function and pulmonary arterial pressure were almost normalized in more than 90% cases postoperatively. Our data indicated that mitral valve reconstruction (McGoon's plus Kay's method as standardized maneuver) was the procedure of choice for selected patients with mitral insufficiency owing to ruptured chordae tendineae to the posterior mitral leaflet, including more limited patients with ruptured chordae to the anterior mitral leaflet.

Adolescent↗
PubMed1989

[Selection of candidates for a ventricular assist device as a bridge to heart transplantation].

This study was undertaken to see how many people could receive the ventricular assist device (VAD) as a bridge to heart transplantation and to get selection criteria of the recipient. From January 1984 to December 1987, 9916 patients were admitted to our institute and 399 cases of them were dead. All dead cases were examined in terms of age, heart disease, other organ function, infection, and so on. There were 42 possible candidates for VAD, 31 men and 11 women. The average age was 50 years with a range from 22 to 63 years. Ten cases (23.8%) of them had the indication for VAD bridge to transplantation. The criteria for transplantable patients included the following three categories: I) Cardiogenic shock: Irreversible left or double ventricular failure with or without life-threatening dysrhythmia during IABP therapy--4 cases. II) End-stage valvular heart disease; Operation under VAD stand-by--2 cases. III) Postoperative refractory ventricular pump failure: Failure to wean from assist circulation after IABP trial or sustained ventricular failure under IABP support--4 cases. It was indicated that continuous precise evaluation of the deteriorating hemodynamics and the intensive care for major organ functions (renal, pulmonary, neurologic, hepatic, coagulation, etc.) were important to select the candidate for VAD bridge to heart transplantation.

Adult↗
PubMed1989

[Successful repair of tetralogy of Fallot with severe right ventricular dysfunction using veno-arterial bypass in an adult].

A 35-year-old male with tetralogy of Fallot, who had undergone left Blalock-Taussig shunt at ten year old, developed severe dysfunction of right ventricle with decreased right ventricular ejection fraction of 25% and frequent premature ventricular contractions of right ventricular origin. Following intracardiac procedure, the venoarterial assist circulation was successfully employed for 9 hours, until his hemodynamic conditions were improved. This experience reemphasized the importance of right ventricular protection and mechanical circulatory assist in the surgical treatment of Fallot's tetralogy in older children and adults who developed severe right ventricular dysfunction as a natural history of this disease.

Adult↗