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Biomedical subjects

S Adachi

Publications and source records attributed to S Adachi.

At least 253 records · Page 14Linked to original sources
PubMed1993

[Surgical results in atherosclerotic distal aortic arch aneurysm].

Results of surgical treatment of atherosclerotic aneurysm of the distal aortic arch, reported to date, are not satisfactory. We recently analyzed the surgical results in 119 patients with this condition who were treated at our department. There were 104 males and 15 females, ranging in age from 38 to 81 years (mean: 66 years). The arch was reconstructed by total replacement in 29 cases, partial replacement in 49 cases, patch reconstruction in 34 cases and extra-anatomic bypass in 7 cases. The lesion was approached by median sternotomy in 75 cases, median sternotomy+left thoracotomy in 9 cases and left thoracotomy in 35 cases. In cases where median sternotomy was used, selective cerebral perfusion was generally employed as an auxiliary procedure. After surgery, cerebral complications were observed in 19 cases (16.0%). In 15 of these 19 cases, postoperative cerebral damage was attributed to atheromatous emboli. Twenty-six patients (21.8%) died in the hospital. Major causes of death included respiratory insufficiency, multiple organ failure and low cardiac output syndrome. To improve surgical results for this type of aneurysm, the operative procedure needs to be modified so that these postoperative complications are prevented. Especially it is essential to prevent intraoperative embolisms of brain and coronary arteries, and a reconstruction by total arch replacement with median sternotomy has improved recent surgical results.

Adult↗
PubMed1993

[A case of constrictive pericarditis following graft replacement of the descending aorta under left ventricular bypass using a centrifugal pump].

We experienced a case of constrictive pericarditis following replacement of the descending aorta. It has been pointed out that constrictive pericarditis can be developed following LV bypass using centrifugal pump due to the cardiotomy. But no actual case has reported so far. The case was a 61-year-old man for whom graft replacement of the descending aorta through left thoracotomy was performed. Fever and heart failure was elicited 3 weeks after the operation, and he was diagnosed as constrictive pericarditis by chest CT and echocardiography. The reoperation was performed 39 days after the graft replacement. Anterior wall of the both ventricle and postero-lateral wall of the left ventricle were strongly adhered to the pericardium. The adhesion was entirely dissected and the thickened pericardium was resected. The post-operative course was uneventful and the patient was discharged 42 days after the reoperation.

Aorta, Thoracic↗
PubMed1993

[The effect of oxytocin stimulation on PGE2, 6keto PGF1 alpha production in human myometrial monolayer culture].

In order to clarify the mechanism by which oxytocin induces the generation of prostaglandin (PG) in human myometrial smooth muscle cell, we determined the concentration of PGE2 and 6ketoPGF1 alpha in the culture supernatant of human myometrial monolayer cells stimulated by oxytocin. PGE2 and 6ketoPGF1 alpha demonstrated a biphasic increasing curve when oxytocin was added. The first increase, phase 1, was a transient phenomenon with a peak at 20 seconds whereas the second increase, phase 2, was a continuous phenomenon starting at 120 seconds. Moreover, phase 1 was significantly inhibited by the DG lipase inhibitor, RHC80267. Phase 2 was significantly inhibited by the PLA2 inhibitor, Mepacrine. Phase 1 and 2 were dose dependent in the range 10(-10) to 10(-6) M. PG production at rest during which 6ketoPGF1 alpha was higher than PGE2, was reversed by oxytocin stimulation. These results suggest that oxytocin stimulation would actuate biphasic PG production, and this mechanism would probably regulate the myometrial construction in labor-pain initiation.

Calcium↗
PubMed1993

[Study of cell populations of bronchoalveolar lavage fluid in patients with pneumonia due to Chlamydia psittaci and Mycoplasma pneumoniae].

We have performed bronchoalveolar lavage (BAL) examination in 27 cases; 5 with Chlamydial pneumonia, 7 with Mycoplasmal pneumonia and 15 in the control group (5 non-smokers, 10 smokers), and the following results were obtained. 1. In Chlamydial pneumonia and Mycoplasmal pneumonia, the cell population of alveolar macrophages in BALF decreased (p < 0.01) and that of lymphocytes increased compared with control group (p < 0.01). 2. In all cases of Mycoplasmal pneumonia without peripheral eosinophilia, the cell population of eosinophils in BALF increased compared with cases of Chlamydial pneumonia (p < 0.05). These results indicate that lymphocytes played the main role in the immune host defense in Chlamydial pneumonia, whereas infiltration of lymphocytes and eosinophils into the pneumonic lesion occurred in Mycoplasma pneumoniae infection.

Adolescent↗
PubMed1993

Tissue-type plasminogen activator (t-PA) lysis of aortic and mitral valve thrombosis.

Valve thrombosis is one of the most serious complications after prosthetic valve replacement. We report the use of tissue-type plasminogen activator (t-PA) in the treatment of a patient with thrombosed aortic and mitral valves. Thrombolysis resulted in immediate hemodynamic improvement and resolution of congestive heart failure, thereby avoiding surgical intervention. Based on our experience, thrombolysis with t-PA is an effective alternative in the treatment of thrombosed prosthetic valves.

Adult↗
PubMed1993

[The effect of oxytocin on production of free fatty acid in primary human uterine myometrial cell culture].

Oxytocin(OT) is considered to have several activities besides strongly inducing myometrial contraction by activating phosphatidilinositol-specific phospholipase C(PI-PLC). These include reconstructing the phospholipid constituents of the cell membrane and activating a variety of fatty acid producing systems. On the other hand, pregnancy-related steroid hormones which are produced by the fetus, placenta and mother are considered to be closely involved in the maintenance of pregnancy and the initiation of labor. In the present study with cultured myometrial cells, we examined what effect these steroid hormones might exert on the intramyometrial production of fatty acid by OT. Our results confirmed bi-phasic production of arachidonic acid(AA), linoleic acid(LA), palmitic acid(PA), and stearic acid(SA) by OT. Phase 1 was an increasing but transient phenomenon having its peak at 30 sec. It is considered to be derived from phosphatidylinositol bis-phosphate. Phase 2 was a persistent and increasing phenomenon which was initiated after 120 sec. It is considered to be mediated by Ca-dependent phospholipase. We also studied the effect of steroid hormones on the production of fatty acid. For AA, LA, and PA, we confirmed that dehydroepiandrosterone sulfate(DHAS) shortened the time taken in reaching the peak of Phase 1 to half of that of the control, and progesterone(P) extended the time 2-3 fold. These findings suggest that DHAS, P and F might modify the human myometrial construction mechanism as a factor which regulates the quantity and velocity of fatty acid production.

Arachidonic Acid↗
PubMed1993

[A case report of sarcoid reactions with hepatocellular carcinoma and two early gastric carcinomas].

Non-caseating epithelioid-cell granulomas named "sarcoid reactions" may occur rarely in regional lymph nodes of a malignant tumor. In this article, sarcoid reactions in a patient with hepatocellular carcinoma and two early gastric carcinomas are reported. A 78-year-old woman followed with a Hbs antigen positive liver cirrhosis from 1980 was admitted to our hospital to receive the operation for two early gastric carcinomas and hepatocellular carcinoma. Subsegmentectomy of the liver and subtotal gastrectomy were performed. Histologic examination of dissected lymph nodes revealed sarcoid reactions. There have been no reports regarding the association between sarcoid reactions and hepatocellular carcinoma combining early gastric carcinoma.

Aged↗
PubMed1993

[Effects of steroid hormones on change in [Ca2+]i following oxytocin stimulation in cultured human myometrial cells, and on myometrial oxytocin receptor].

It is considered that steroid hormones, the concentrations of which vary during pregnancy, play an important role in the initiation of delivery. In the present study, we measured intracellular Ca2+ ([Ca2+]i) change following oxytocin stimulation in cultured human myometrial cells with fura-2, a fluorescent Ca2+ indicator. We also studied the effect of the steroid hormones on changes in [Ca2+]i due to oxytocin stimulation. When the [Ca2+]i change due to 10(-6) M oxytocin reached 100%, the addition of 10(-6) M DHAS (dehydroepiandrosterone sulfate) just before the stimulation raised the [Ca2+]i level to 207%, whereas that of 10(-6) M progesterone dropped to 64%. Moreover DHAS accelerated the speed of increase until the maximum response of [Ca2+]i, while progesterone decelerated it. In another study, human myometrial plasma membrane was solubilized in 7.5mM CHAPSO solution and applied to a binding study. Oxytocin receptors of two different molecular weights, namely 350kD(OTR-1) and 39kD(OTR-2), were extracted from solubilized plasma membrane by employing a gel filtration column. Binding assays were performed for OTR-1 and OTR-2 in the presence of DHAS and progesterone (10(-5) M). The results showed that DHAS enhanced the binding affinity of the receptors, whereas progesterone reduced the maximum binding capacity. It is therefore considered that the steroid hormones added just before oxytocin stimulation might act on receptor levels and modify intracellular Ca2+ response over short periods.

Calcium↗
PubMed1993

[The effect of steroid hormone on oxytocin receptor expression in primary human uterine myometrial cell culture].

In the present study, we have examined the steroid hormone effect on oxytocin receptor (OTR) expression in human myometrial monolayer culture. The myometrial cells were cultured for 24-72 hours in serum-free media with various concentrations of steroid hormones. The plasma membrane of the cultured cells was then collected. The 125I-oxytocin(OT) was employed for a binding assay and the mean binding and dissociation constant were evaluated by Scatchard analysis. 1. The OT binding values in the presence of estradiol free, 10(-8) M, and 10(-7) M at 72 hours were 19.85, 28.12, and 36.20pM/mg protein, respectively. 2. The OT binding values in the presence of estradiol (10(-7) M) at 24, 48, and 72 hours were 17.85, 23.72, and 36.20pM/mg protein, respectively. 3. Dehydroepiandrosterone sulfate (10(-5) M) exerted almost no effect on the OTR expression by estradiol (10(-7) M). Cortisol (10(-5) M) decreased the amount of OTR expressed by estradiol. 4. The changes in OTR expression caused by estradiol (10(-7) M) were inhibited according to the concentration by progesterone. The concentration of progesterone at which OT binding was reduced 50% was 2.7 x 10(-6) M (E/P ratio = 0.037). These results suggested that estradiol increased the amount of OTR discovered in human myometrial cells in a time and concentration dependent manner, while progesterone inhibited the changes in OTR expression by estradiol in a concentration dependent manner. Thus, it was indicated that the changes in the E/P ratio during pregnancy which regulate the OTR expression control the myometrial contraction.

Cell Membrane↗
PubMed1993

Clinical utility of Gd-DTPA-enhanced magnetic resonance imaging in lung cancer.

Magnetic resonance (MR) imaging has both advantages and disadvantages in its application in lung cancer staging. Because of its ability to provide superior contrast resolution and to display structures in many planes, MR imaging is better than computed tomography (CT) for the detection of mediastinal and chest wall invasion. MR imaging also is more sensitive than CT for detection of hilar and mediastinal lymph node enlargement. Multiplanar T1- and T2-weighted images are optimal for differentiating lymph nodes from large vessels without the need for contrast enhancement; in these cases administration of Gd-DTPA provides no more information than plain MR images. MR studies should be used for examining patients with suspected mediastinal or chest wall invasion and those who have equivocal hilar or mediastinal adenopathy. The shortening effect of Gd-DTPA on the T1 value results in a high signal. This effect is dependent upon both the perfusion and diffusion of the contrast agent and the amount of extracellular fluid. The distribution of Gd-DTPA is similar to that of iodinated water-soluble contrast media. Gd-DTPA examination should be tailored to provide information regarding blood flow, vascularity, and permeability, none of which is easily appreciated on CT or plain MR images. Applications for which Gd-DTPA enhancement may be helpful include differentiating between malignant and benign pulmonary masses, differentiating between hilar lung cancer and peripheral postobstructive atlectasis or pneumonia, determining therapeutic effect after radiation therapy, and differentiating between recurrent or residual tumor and radiation pneumonitis.

Diagnosis, Differential↗
PubMed1993

Interstitial lung disease in rheumatoid arthritis: assessment with high-resolution computed tomography.

Interstitial lung disease (ILD) is a frequent manifestation of rheumatoid arthritis (RA), and it has a close bearing on the prognosis of RA patients. Computed tomography (CT) has been shown to be excellent for the diagnosis of diffuse lung disease. In this study chest radiographs and high-resolution CT (HRCT) scans were obtained in 91 patients with RA to evaluate their ILD precisely. By HRCT 43 patients could be diagnosed as having interstitial pneumonitis (IP), and 5 could be diagnosed as having bronchiolitis. The remaining 43 patients were normal by HRCT. Chest radiographic findings were consistent with the HRCT findings in approximately 50% of patients with IP. HRCT was superior to chest radiographs for the detection of early interstitial changes. The histogram of HRCT values might be a useful adjunct to HRCT diagnosis by adding some degree of objectivity. HRCT is useful for the diagnosis of ILD in patients with RA.

Adult↗
PubMed1993

Multiple primary lung cancers: radiographic and bronchoscopic diagnosis.

The article reports a review of 1140 cases of primary lung cancer diagnosed between 1974 and 1987 (13-year period) to examine the clinicopathologic features of multiple primary lung cancer. The following criteria were used: There were no malignant tumors in other organs; the tumors were separate or located in different lobes; the tumors were of different histologic types; if the histologic types were similar, there was no carcinoma in the common lymphatics of any tumors and no extrapulmonary metastases at the time of diagnosis. The following results were obtained. The incidence was 1.2% (14 of 1140 cases); 11 patients were heavy smokers; the most common histologic type was squamous cell carcinoma, and the combination of two squamous cell carcinomas was most common; 12 cases were bilateral, and 11 cases were synchronous; 19 tumors were diagnosed by bronchoscopic biopsy; 9 patients with bilateral tumors received chemotherapy and radiation therapy.

Aged↗
PubMed1993

[Etoposide/cis-platinum (CDDP) combined chemotherapy for ovarian cancer: evaluation of optimum schedule for CDDP administration in chronic continuous exposure of ovarian cancer cells to low-dose etoposide in vitro].

Combined chemotherapy with etoposide and cis-platinum (CDDP) is considered a second line regimen for refractory cases of ovarian cancer. In addition to the time-dependent cytocidal kinetic of etoposide, much attention has been paid to low-dose continuous administration of etoposide. In this study, ovarian cancer cells (SHIN-3) were continuously exposed to low-dose etoposide in vitro to determine the optimum schedule for CDDP administration. Etoposide concentrations of 1-3 micrograms/ml were used; per os administration of etoposide at 25 mg x 2/day has been shown to produce a continuous plasma concentration of etoposide of around 1 microgram/ml. The results were as follows: 1) The IC50 of CDDP after 72 hours of exposure was 8.0 micrograms/ml and that of etoposide after 114 hours was 3.0 micrograms/ml. 2) After 100 hours of exposure to 1 microgram/ml of etoposide, cell cyclic phase analysis showed cells predominantly in G2/M phase arrest. 3) After 24-hour administration of CDDP, it was more than 24 hours before a cytocidal effect was observed. 4) During continuous exposure of SHIN-3 to etoposide (1 microgram/ml) for 6 days, CDDP was added on the 1st, 3rd, and 5th days. The largest ratio of growth inhibition with combined treatment to that with CDDP alone was attained on the 5th day. We conclude that, in combination regimens using low-dose continuous etoposide, CDDP should be added after etoposide administration is begun.

Administration, Oral↗
PubMed1993

[A case of ceftazidime-induced pneumonitis].

We report a case of ceftazidime-induced pneumonitis. A 76-year-old man had been treated with cefotiam for acute pneumonia; however, he developed a high fever. On November 8, 1991, cefotiam was changed to ceftazidime and S-sulfonated human immunoglobulin. The patient showed good improvement. Four days after commencement of ceftazidime therapy, he developed chills, rigors, and high fever, with interstitial infiltrates in the right lung of his chest X-ray. On physical examination, small bubbling and crepitant rales were heard at the right lung. Once ceftazidime therapy was discontinued, he showed rapid resolution of symptoms and marked regression of the pulmonary infiltrates in the right lung of his chest X-ray. In view of the above, ceftazidime-induced pneumonitis was considered to be the diagnosis in this case. To our knowledge, there has been no previous case report of pulmonary hypersensitivity to ceftazidime. Clinicians should be alerted to the possibility of the occurrence of such a complication in patients being treated with ceftazidime.

Aged↗
PubMed1992

BALB/3T3 fibroblast-conditioned medium attracts cultured mast cells derived from W/W but not from mi/mi mutant mice, both of which are deficient in mast cells.

Proliferation of murine mast cells is induced by both T-cell-derived and fibroblast-derived growth factors. Because the most potent T-cell-derived mast cell growth factor, interleukin-3, promotes the migration of mast cells, we investigated whether fibroblast-derived growth factors had the chemoattractive activity as well. Conditioned medium (CM) of BALB/3T3 fibroblasts induced the migration of cultured mast cells (CMC) derived from normal (+/+) mice. BALB/3T3-CM contained the mast cell growth factor (MGF)/stem cell factor (SCF)/kit ligand (KL), which is the ligand for the receptor encoded by the W (c-kit) gene. CMC derived from the spleen of W/W mice lack the extracellular domain of the W (c-kit) receptor, and W/W CMC did not proliferate in response to BALB/3T3-CM. However, W/W CMC did migrate normally toward BALB/3T3-CM and, moreover, the antibody to the extracellular domain of the W (c-kit) receptor did not inhibit the chemoattractive activity of +/+ CMC toward BALB/3T3-CM. These results indicated that MGF/SCF/KL itself did not represent the major chemoattractive activity. On the other hand, BALB/3T3-CM induced neither proliferation nor migration of CMC derived from mi/mi mice. Both W/W and mi/mi mice are deficient in mast cells, but the present results suggest that the mechanism of the abnormality is different between W/W and mi/mi mice.

Animals↗
PubMed1992

[Utility of helical CT for the secondary mass screening of lung cancer].

From December 1991 to 1992, helical CT scan was performed in 55 patients with having abnormal shadow in the chest X-ray on the secondary screening for lung cancer. In all patients with suspected pulmonary lesions at first screening, helical CT scan was performed with 10 mm slice thickness for 300 mm. The moving speed of the patients table is 20 mm/l rot./1.5 sec for 300 mm in a single breath-hold. Helical CT allowed shortening of examination time and providing both better data continuity and resolution than conventional CT. In conclusion, helical CT can be useful for secondary screening of lung cancer but it was considered that there are some problems such as method of final pathological diagnosis and treatment for small nodular lesion.

Female↗
PubMed1992

Modification of the distal histidyl imidazole in myoglobin to N-tetrazole-substituted imidazole and its effects on the heme environmental structure and ligand binding properties.

The mechanism of N-tetrazole ring formation at the distal histidyl imidazole of sperm whale myoglobin (Mb) has been studied by nitrogen-15 (15N) NMR spectroscopy by utilizing 15N-labeled cyanogen bromide (BrCN) and azide ion (N3-). The 15N-NMR spectrum of BrC15N-modified Mb + N3- afforded two hyperfine-shifted 15N resonances, both of which are identical with the resonance positions of two of the three 15N resonances for BrCN-modified Mb + 15NN2-. This unusual spectral feature is due to the formation of the N-tetrazole ring attached to the distal histidyl imidazole and the scrambling of the labeled nitrogen originated from N3- or BrCN over the tetrazole ring upon coordination to the ferric heme iron. The ferric iron-bound N-tetrazole ring comes off upon reduction to the ferrous state, and the stable CO complex of tetrazole-modified Mb (tetrazole-Mb) is formed. Electronic absorption and 1H-NMR spectra of deoxy and carbonmonoxy forms of tetrazole-Mb are slightly altered from those of native Mb by the modification, while the most significant effect is exerted on the C-O stretching frequency of iron-bound CO. The C-O stretching band for tetrazole-MbCO is observed at 1966 cm-1 in contrast to 1945 cm-1 for native MbCO, suggesting that the geometry of iron-bound CO in tetrazole-Mb is relatively upright which is characteristic of the "open" conformer. This result corresponds to the 15-fold increase of the CO association rate constant by the N-tetrazole modification of the distal His. The oxy form of tetrazole-Mb is readily autoxidized to its ferric state, indicating that hydrogen bonding between the distal His and iron-bound oxygen is essential for stable O2 binding to the heme iron.

Animals↗