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Biomedical subjects

A Yamaguchi

Publications and source records attributed to A Yamaguchi.

At least 595 records · Page 33Linked to original sources
PubMed1989

[Operative indication for aortic valvuloplasty by rasping procedure from the point of histopathologic evaluation].

Rasping procedure is proposed by the author as one of the methods of aortic valvuloplasty and defined as shaving the surface of rheumato-degenerative aortic valve by using the electric rasp. Materials were the removed rheumato-degenerative aortic valves as specimen, and classified into 3 groups. The first group (type I) was valve lesion limited to valve free edge, second (type II) was mild thickening entirely, third (type III) was severe thickening with calcified degeneration. Rasping procedure was performed for the thickened portion of the valve specimen by the electric rasp. Morphologic examinations after rasping procedure were evaluated by histopathologic study. Histopathologically, there was hyaline degenerative connective tissue in superficial layer above the collagen fiber's layer in rheumato-degenerative thickened valve in type I. This hyaline degenerative connective tissue was considered to be fragile and pathologic in the tissue structure. Rasping procedure could remove this connective tissue layer. Type II, there was the similar finding to the type I from the free edge to the mid portion of the cusp. So, Rasping procedure was effective for type I and type II valve degeneration. On the contrary, the calcified lesion (type III), rasping procedure was not effective in valve coaptation and the pathological findings showed the fragmentation in the calcified layer. In the pathological comparison with the slicing procedure for type II by the surgical knife, there was a crack and cleft in the collagen fiber's layer in the case of slicing procedure. It can be concluded the results of histopathological study of the rasping procedure proved to be superior to the conventional aortic valvuloplasty (slicing method).

Aortic Valve↗
PubMed1989

[Postoperative intracranial pressure in severe cases with hypertensive intracerebral hematoma].

The relationship between the postoperative ICP and the size of hematoma on CT scan and the time of operation was studied to evaluate their influence on the therapeutic results in the severe cases with hypertensive intracerebral hematoma. Twenty one patients of putaminal hemorrhage with severe neurological deficit (semicoma) were studied. ICP was monitored continuously by the Subdural balloon method after craniotomy to remove the hematoma. The relationship between the postoperative ICP level (High ICP: above 40 mmHg, Moderate ICP: 40-20 mmHg, Low ICP: below 20 mmHg), the size of hematoma estimated from CTscan (Large: more than 80 ml, Medium: less than 80 ml), the time from onset to removing hematoma and the therapeutic results were evaluated. The outcome six months after onset was determined according to the Glasgow Outcome Scale. Of 6 cases with Medium hematoma operated on within 8 hours, Low ICP was found in 5 cases (83%) and Moderate ICP was in one case (17%). Of 6 cases with Medium hematoma operated on after 8 hours, High and Moderate ICP were found in 3 cases (50%), respectively. In the cases with Large hematoma, Low ICP was not observed, but High ICP was found in 4 of 7 cases operated on within 8 hours (57.1%) and the other three indicated Moderate ICP (42.9%). High ICP was found in two cases with Large hematoma operated on after 8 hours (100%). The outcome of High ICP cases was severe disability in 4 cases, vegetative state in one and dead in 4, and that of Moderate ICP cases was moderate disability in 3 cases and severe disability in 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Ca2+ influx and platelet membrane glycoproteins.

When aequorin-loaded platelets were stimulated with thrombin, the luminescence of aequorin showed two peaks. From experiments with 1 mM external Ca2+ or 1 mM EGTA, both one-half of the first peak and the entire second peak reflected the influx of Ca2+ from the external medium, and the remaining half of the first peak reflected the mobilization of Ca2+ from its storage site. A monoclonal antibody (TM83), that recognizes the GPIIb/IIIa complex which has binding sites for fibrinogen, and synthetic peptide GRGDSP are known to inhibit fibrinogen binding and platelet aggregation. Both of them eliminated the second peak of intracellular free calcium. Similar effects were observed during activation by collagen, but not by TPA. Also dihydrocytochalasin B inhibited the second peak of Ca2+ influx by thrombin, suggesting that the signal, which was caused by fibrinogen-binding to GPIIb/IIIa (aggregation) in thrombin-activated platelets, is transferred to the inner sites of GPIIb/IIIa complex and induces the cytoskeletal reorganization such as actin polymerization. This in turn, induces the secondary increase in [Ca2+] i of platelets. It is interesting that ticlopidine inhibited the Ca2+ influx through the GPIIb/IIIa complex. This result suggests the importance of such kinds of antiplatelet drugs to prevent thrombus formation.

Blood Platelets↗
PubMed1989

[Coronary artery stenosis following aortic valve replacement--a case report].

A case with severe left main trunk (LMT) stenosis nine months after aortic valve replacement was presented. The patient, 57-year-old female, underwent aortic valve replacement with a tilting disk valve (Omnicarbon 21 A). Her postoperative course was uneventful, but angina pectoris developed after nine months. Coronary angiography was performed and revealed 99% LMT stenosis. Operation was performed with OTCA to LMT and with a saphenous vein graft to left anterior descending artery. Coronary artery stenosis following aortic valve replacement may be dangerous and it must be treated as soon as the diagnosis is established.

Aortic Valve↗
PubMed1989

[Surgical treatment of Taussig-Bing malformation in an adult--a case report].

With the development of pediatric cardiac surgery, the surgical treatment of Taussig-Bing malformation has been common in frequency and a majority of these cases are reported. However, because the patient's condition is so critical in the early stage of life, the importance of adequate initial operation is emphasized, and this area is restricted to the operative cases of child patient. In this clinical study, the operation for 41-year-old adult patient with Taussing-Bing malformation was successfully performed using the Kawashima's procedure, and we would like to report the detailed operative procedure as well as its clinical courses. This patient was female of 41 years of age and at surgery, this case was found to be the Taussig-Bing malformation associated with pulmonic stenosis, and the operation for intracardiac repair was carried out using intracardiac conduit (5 x 4 cm) and also extracardiac conduit (5 x 3 cm). It is reported that there are many operative procedure available in child patients but we believe that Kawashima's procedure is probably the best choice of operation for adult patients because of its simplicity.

Adult↗
PubMed1989

[Immunohistochemical localization of laminin and its relation to the grade of histological malignancy in oral cancer].

The immunohistochemical localization of Laminin has been investigated with a monoclonal antibody in biopsy specimens from 27 patients with an invasive squamous cell carcinoma of the oral cavity. In normal mucosa, laminin was found distributed in a linear pattern in the epithelial-stromal junction, around the blood vessels, the nerve fibres, and the skeletal muscle bundles. In the cancerous tissues a variety in the linear staining around the cancer cell nests was seen. Extreme attenuation or complete loss of the linear staining of laminin was demonstrated in 8/27 specimens, and these tumors histologically showed a high grade of malignancy with H.E. staining.

Basement Membrane↗
PubMed1989

[Monoclonal antibody NCC-ST-439 in gastric cancer tissue].

An immunohistochemical study revealed that NCC-ST-439 positive tumor were detected in 33% of the 244 gastric carcinomas. The incidence of NCC-ST-439 immunoactivity in well differentiated adenocarcinomas (papillary and tubular adenocarcinoma) was significantly higher than in poorly differentiated adenocarcinomas (including signet-ring cell and mucinous adenocarcinoma). Moreover, NCC-ST-439 immunoreactive tumors showed more frequent vessel invasion and higher DNA content than non-reactive tumors. The recurrence rates of NCC-ST-439 immunoreactive tumors in the liver and lymph nodes were significantly higher than those of non-reactive tumors. Patients with NCC-ST-439 immunoreactive carcinoma had much worse prognosis than those with NCC-ST-439 non-reactive carcinoma. These results suggest that NCC-ST-439 antigen produced by tumor cells plays an important role in the invasive growth and vessel invasion and also serves as a biological marker of malignancy in patients with gastric cancer.

Adenocarcinoma↗
PubMed1989

[Clinical evaluations of surgical treatment of infective endocarditis].

This paper shows the clinical evaluations of surgical and medical treatment of infective endocarditis (IE). IE occurred in 33 cases (10.1%) among 372 cases of valve replacement. Of all the 33 patients, IE was consisted of native valve endocarditis (NVE) and prosthetic valve endocarditis (PVE). IE was evaluated as for the microorganism, complication, operative indication and operative mortality. At first, all of NVE underwent surgical treatment, active phase endocarditis 4 and healed endocarditis 14. Microorganism was streptococcus aureus in an overwhelming majority. Operative indications was congestive heart failure in almost all cases, next to vegetation and infection resistant to medical treatment. Operative mortality was 5.6% (1 out of 18 cases), which case was in the septic shock and cerebral bleeding prior to the surgical treatment. The others was satisfactory condition postoperatively. Next of PVE, PVE happened in 15 cases, in which there were 5 cases of bioprosthetic PVE and 10 cases of mechanical valve PVE. Microorganism for PVE was staphylococcus epidermidis in the major part (60%). Mortality in PVE was 53.3% (8 out of 15), but mechanical valve PVE was worse in prognosis than bioprosthetic PVE. Cerebral complications occurred in 3 cases of mechanical valve PVE, on the other hand there was no cerebral complication in bioprosthetic PVE. As for the hemodynamic change in PVE, mechanical valve PVE had the tendency to take the prompt or sudden deterioration of hemodynamics caused by endocarditis surrounding the suture ring, especially in mitral position, on the contrary hemodynamic deterioration was gradually proceeded in bioprosthetic PVE. UCG made much of the diagnosis of PVE, especially in mechanical valve PVE, in which cases endocarditis was recognized only surrounding the suture ring. PVE takes the miserable outcome in many cases, so carefully observation is necessary in order not to lose the timing of the surgical treatment.

Adult↗
PubMed1989

[Time-related degeneration of Carpentier-Edwards bioprosthesis in mitral position].

Carpentier-Edwards bioprostheses have been shown to provide a low incidence of valve-related complications, especially thromboembolism, but the durability has caused the serious concern. This report suggests that Carpentier-Edwards prostheses have been gradually degenerative, and stenotic degeneration and the year after operation are well correlative. In Osaka National Hospital, Carpentier-Edwards prostheses were implanted in 89 patients in mitral position from 1973 to 1981. Of all the patients, 50 patients were undertaken to single valve replacement in mitral position and could be followed up in our department. For a total of 50 patients, materials are 30 patients who could be detected by clinical findings, pulsed Doppler echocardiography, cardiac catheterization and soft X-ray evaluation in explanted prostheses at reoperation. Follow-up duration was ranged 4.2 to 12.1 years with a mean duration of 7.94 years. The age ranged from 32 to 71 years of age. The initial diagnosis of the time-related degeneration was the appearance of newly acoustic rumbiling murmur. Furthermore, regurgitant murmur, arrythmia (atrial fibrillation) and cardiac enlargement were followed in addition to rumbling murmur. The assess of the transmitral flow such as pressure half time and peak pressure gradient by pulsed Doppler echocardiography was the easy way to evaluated the time-related degeneration. Time-related stenotic change by pulsed Doppler was expressed as a linearized curve. At 6 years and below valve function seemed not to be impaired but stenotic dominant degeneration with the cusp tear was prominent beyond 7 years. Cardiac catheterization data could make sure of the pulsed Doppler findings by assessing mitral valve gradient and mitral valve area.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Microassay for screening newborns for galactosemia with use of a fluorometric microplate reader.

We describe a microassay for measuring galactose (Gal) and galactose 1-phosphate (Gal-1-P) in dried blood spots. After a coupled enzyme reaction involving galactose dehydrogenase (GADH, EC 1.1.1.48) and alkaline phosphatase (AP, EC 3.1.3.1) in a microplate well, NADH fluorescence is measured by a highly sensitive fluorometric microplate reader, capable of rapid measurement of fluorescence (2 min per 96 samples). Within- and between-run CVs for measurements of Gal at 90 mg/L with Gal-1-P at 130 mg/L were both less than 5% (n = 8), and analytical recoveries for Gal at 90 mg/L and Gal-1-P at 130 mg/L were 98% and 92%, respectively. Five hundred dried blood-spot samples can be assayed within 2 h, with full calculation of results by an on-line microcomputer. This rapid and reliable assay system is very useful for the routine screening of newborns for galactosemia.

Female↗