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Biomedical subjects

K Oishi

Publications and source records attributed to K Oishi.

At least 163 records · Page 9Linked to original sources
PubMed1994

Aortic root replacement with a composite graft: results of 69 operations in 66 patients.

Between December 1973 and December 1992, 66 patients underwent aortic root replacement at our hospital. The mean age of the patients was 42.5 years (range, 20 to 71 years); 44 patients were male and 22 were female. Of the 66 patients, 34 (51.5%) had clinical stigmata of Marfan's syndrome. The aortic pathology requiring aortic root replacement was annuloaortic ectasia in 59 patients, aortic dissection in 5, and progressive dilatation of the ascending aorta after aortic valve replacement in 2. Twelve of the 59 patients with annuloaortic ectasia also had aortic dissection. The operative techniques used were the Bentall technique in 36 operations, the Cabrol technique in 21, the aortic button technique in 3, and other miscellaneous techniques in 9. The hospital mortality rate for the primary operation was 10.6% (7 patients), and the late mortality rate was 20.3% (12 patients). Four of the late deaths were related to the graft valve prosthesis, and 6 were related to the progression of aneurysmal diseases on the remaining aorta. The survival rate was 71.0% at 10 years. Pseudoaneurysm at the suture lines was detected in 7 patients, 6 of whom had been treated with the Bentall technique, and 5 patients also had Marfan's syndrome. No patients having aortic root replacement with the Cabrol technique have required reoperation for pseudoaneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1994

Actin-severing and Ca(2+)-induced reversal of smooth muscle contraction that is independent of Ca2+.

1. Intracellular actin filament organization of gastric smooth muscle cells of the guinea pig in primary culture was examined with rhodamine-labelled phalloidin using a confocal laser fluorescence microscope. 2. The resting cells, both in the presence and absence of Ca2+, showed an even distribution of microfilamentous actin fibers. 3. The characteristic image of the stimulated cells with 10 microM acetylcholine in the presence of 1.8 mM Ca2+ was that the actin filaments were located only on the periphery of the cell. 4. The characteristic image of the cells stimulated as above, but in the absence of Ca2+, was that the actin filaments were unevenly distributed in the cell. 5. The characteristic image of the cells stimulated in the presence of 1 microM Ca2+, which inhibits the above contraction, was pultaceous with the actin filaments absent, indicating severing of actin filaments by a Ca(2+)-activated system, such as gelsolin.

Actins↗
PubMed1994

Fc epsilon RI-stimulated Ca(2+)-dependent secretion from rat basophilic leukemia (RBL-2H3) cells permeabilized with Staphylococcal alpha-toxin: Fc epsilon RI-operated signals are not mimicked by the actions of GTP gamma S.

1. RBL-2H3 cells permeabilized with alpha-toxin responded to dinitrophenol (30-40 mol/mol)-conjugated human serum albumin, as antigen, to secrete [14C]serotonin in the micromolar range of free Ca2+. 2. Calcium ion alone did not cause substantial secretion. 3. Guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) (100 microM) in combination with Ca2+ produced only negligible [14C]serotonin secretion. 4. GTP gamma S, in the presence of cytochalasin D, caused optimal secretion of [14C]serotonin in a Ca(2+)-dependent manner.

Adenine↗
PubMed1994

Cloning of cDNA for vitellogenin of Athalia rosae (Hymenoptera) and characterization of the vitellogenin gene expression.

Athalia rosae (Hymenoptera) was previously shown to have two vitellins (L-Vn and S-Vn) and the two corresponding vitellogenins (L-Vg and S-Vg). A cDNA expression library was constructed from poly(A)+ RNA prepared from adult female fat body cells, and was screened for the vitellogenins by using antisera against the L- and S-Vn, respectively. Examinations of cloned cDNAs show that the vitellogenin gene is transcribed as a single unit, with the 5'-terminal site coding for the S-Vg and the 3'-terminal site for the L-Vg. Nucleotide sequence at the 5'-end suggests the presence of a 16 amino acid-long signal peptide. Deduced amino acid sequence following the signal peptide shows a complete match with up to the 28 N-terminal amino acid sequence determined on S-Vn. The S-L Vg boundary with deduced amino acid sequence matching with 6 N-terminal amino acid sequence determined on L-Vn is also detected. Northern blot hybridization analysis shows that the vitellogenin gene is expressed in the female fat body as a single 6.5 kb mRNA but not in the ovary, and not in the male fat body. Western blot analysis detects a large precursor polypeptide, reacting with the anti-L-Vn and S-Vn antisera, in the adult female fat body.

Amino Acid Sequence↗
PubMed1994

Surgical treatment for acute aortic dissection and coexistent degenerative aortic aneurysm. Report of three cases.

Acute aortic dissection occurring in an aorta previously afflicted with degenerative, atherosclerotic is unusual. We report three cases with acute aortic dissection (DeBakey type III-b) occurring in an aorta which had a preexistent degenerative aortic aneurysm. Two of the three patients had acute aortic dissection originating from the distal end of the degenerative aneurysm, and the remaining one had the acute aortic dissection and degenerative aneurysm at different segments of the aorta. Since the risk of rupture is likely to be much higher in the patients with coexistence of acute aortic dissection and degenerative aortic aneurysm, compared with patients with DeBakey type III acute aortic dissection alone, we believe that a prompt and aggressive surgical approach is essential to prevent rupture, and that digital subtraction angiography (DSA) is more helpful in making a correct diagnosis and in helping to decide surgical procedures and supportive methods than other noninvasive diagnostic procedures.

Acute Disease↗
PubMed1994

False aneurysm of the ascending aorta with fistula to the right atrium. Noninvasive diagnosis by computed tomographic scan and two-dimensional echocardiography with successful repair.

A 57-year-old Japanese man presented with symptoms of congestive heart failure 9 years after aortic valve replacement. On auscultation, a continuous murmur was heard at the left lower sternal border. Chest radiograph showed moderate cardiomegaly and a widened upper mediastinum. Computed tomographic scans showed a dilated ascending aorta, in which there was no intimal flap, and also showed a large mass which compressed the right atrium. Two-dimensional Doppler echocardiography revealed abnormal continuous blood flow directed from the dilated ascending aorta to the right atrium and no periprosthetic leak. At operation, a false aneurysm of the ascending aorta which originated from the aortotomy suture line and a fistula from the aorta to the right atrium were confirmed. The fistula was closed with pledgeted sutures, and the ascending aorta was replaced with a collagen-coated double woven velour dacron graft. The patient recovered uneventfully. Computed tomographic scan and two-dimensional echocardiography are complementary techniques for reliable non-invasive assessment of the complexity of an aortic aneurysm.

Aneurysm, False↗
PubMed1994

Surgical treatment of aneurysms of the aortic arch using a simplified selective cerebral perfusion technique.

Between April 1989 and October 1993, 35 patients underwent aortic arch reconstruction for aneurysms using cardiopulmonary bypass (CPB) with selective cerebral perfusion (SCP). Of the 35 patients, the initial 19 (Group P) consecutively received simplified SCP (partial brachiocephalic perfusion; PBP), and the next 16 (Group S) were consecutively treated with standard SCP. For cerebral protection, blood was supplied to the right axillary artery in Group P, and to the right axillary and the left common carotid arteries in Group S. The aneurysms was aortic dissection in 24 patients, and was secondary to arteriosclerosis in the remaining 11. Partial replacement of the aortic arch together with the ascending aorta was the most commonly performed procedure in both groups. The cardiopulmonary bypass time and the cardiac arrest time were not significantly different between the two groups. The overall cerebral perfusion time was significantly longer in Group S (100 min) than in Group P (65 min); however, when 2 patients with an accidental prolongation of the cerebral perfusion time in Group S were excluded, there was no significant difference in the cerebral perfusion time between the two groups. Early death occurred in 3 patients (15.8%) in Group P, and 2 patients (12.5%) in Group S, however, there were no deaths related to the selective cerebral perfusion technique, and there were no late deaths in either group. Cerebral complications were seen in 1 patient in each group (6.3% vs. 6.7%, not significant). These results suggest that the simplified SCP (PBP) under hypothermic CPB provides as satisfactory cerebral protection as standard SCP, so long as the patency of the circle of Willis is confirmed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

ERM family members as molecular linkers between the cell surface glycoprotein CD44 and actin-based cytoskeletons.

The ERM family members, ezrin, radixin, and moesin, localizing just beneath the plasma membranes, are thought to be involved in the actin filament/plasma membrane association. To identify the integral membrane protein directly associated with ERM family members, we performed immunoprecipitation studies using antimoesin mAb and cultured baby hamster kidney (BHK) cells metabolically labeled with [35S]methionine or surface-labeled with biotin. The results indicated that moesin is directly associated with a 140-kD integral membrane protein. Using BHK cells as antigens, we obtained a mAb that recognized the 140-kD membrane protein. We next cloned a cDNA encoding the 140-kD membrane protein and identified it as CD44, a broadly distributed cell surface glycoprotein. Immunoprecipitation with various anti-CD44 mAbs showed that ezrin and radixin, as well as moesin, are associated with CD44, not only in BHK cells, but also in mouse L fibroblasts. Furthermore, immunofluorescence microscopy revealed that in both BHK and L cells, the Triton X-100-insoluble CD44 is precisely colocalized with ERM family members. We concluded that ERM family members work as molecular linkers between the cytoplasmic domain of CD44 and actin-based cytoskeletons.

Actins↗
PubMed1994

Transurethral microwave thermotherapy for benign prostatic hyperplasia: patient characteristics in good and poor responders.

Transurethral microwave thermotherapy (TUMT) has been shown to produce a clinical benefit in patients with symptomatic benign prostatic hyperplasia. In order to identify the features of the ideal candidate, a retrospective analysis was conducted in 32 patients who were followed for 2 mo or more. Good responders (GR) were defined as having their Siroky peak flow rate (PFR) standard deviation (SD) increase by < 0.5 or a decrease in the International Prostatic Symptom Score (I-PSS) of > 10 (22 patients). Poor responders (PR) were defined as having their PFR SD increase by < or = 0.5 and their I-PSS decrease by < or = 10 (10 patients). The prostate volume, pre-TUMT I-PSS and intravesical opening pressure were significantly greater in the GR group, while there were no significant differences between the 2 groups for the other baseline patient characteristics: age, prostate length, PFR, PFR SD, post-voiding residual volume and quality of life. Concerning the operational parameters, significantly more total energy was delivered to the prostate in the GR group (mean 131 kJ) than in the PR group (mean 101 kJ). Moreover, the 7 patients with anti-androgen therapy pre-TUMT received less total energy and 5 of the 7 were poor responders. These results suggest that patients with apparent obstructive symptoms and with moderate enlargement of prostate could benefit more from this less invasive therapy. Clinical response seems to be dose-dependent and patients with a history of recent anti-androgen treatment may have a less favorable response.(ABSTRACT TRUNCATED AT 250 WORDS)

Allylestrenol↗
PubMed1994

Role of interleukin-8 (IL-8) and an inhibitory effect of erythromycin on IL-8 release in the airways of patients with chronic airway diseases.

To evaluate of the role of interleukin-8 (IL-8), a chemotactic cytokine, in the continuous neutrophil accumulation in the airways of patients with chronic airway disease (CAD) and persistent Pseudomonas aeruginosa infection, we investigated the cell population, IL-8 levels, IL-1 beta levels, tumor necrosis factor (TNF) activities, and neutrophil elastase (NE) activities of bronchoalveolar lavage (BAL) fluids in 17 CAD patients (with P. aeruginosa infections [CAD+PA], n = 9; without any bacterial infections [CAD-PA], n = 8) and 8 normal volunteers. We found significant elevations of neutrophil numbers, IL-8/albumin ratios, and NE/albumin ratios in BAL fluids from CAD patients, in the following rank order: CAD+PA > CAD-PA > normal volunteers. IL-1 beta/albumin ratios were elevated only in CAD+PA, while no TNF bioactivity was detected in BAL fluids. The neutrophil numbers correlated significantly with the IL-8/albumin ratios and NE/albumin ratios in the BAL fluids of CAD patients. When anti-human IL-8 immunoglobulin G was used for neutralizing neutrophil chemotactic factor (NCF) activities in BAL fluids, the mean reduction rate of NCF activities in CAD+PA patients was significantly higher than that in CAD-PA patients. We also evaluated the effects of low-dose, long-term erythromycin therapy in BAL fluids from three CAD+PA and two CAD-PA patients. Treatment with erythromycin caused significant reductions of neutrophil numbers, IL-8/albumin ratios, and NE/albumin ratios in BAL fluids from these patients. To elucidate the mechanism of erythromycin therapy, we also examined whether erythromycin suppressed IL-8 production by human alveolar macrophages and neutrophils in vitro. We demonstrated a moderate inhibitory effect of erythromycin on IL-8 production in Pseudomonas-stimulated neutrophils but not in alveolar macrophages. Our data support the view that persistent P. aeruginosa infection enhances IL-8 production and IL-8-derived NCF activity, causing neutrophil accumulation in the airways and the progressive lung injuries observed in patients with CAD. The clinical efficacy of erythromycin therapy for CAD patients might be partly mediated through a reduced IL-8 production, diminishing neutrophil accumulation and NE release in the airways.

Adult↗
PubMed1994

[Desensitization of the m3-muscarinic acetylcholine-receptor in the smooth muscle and the intracellular signal transduction].

Desensitization of the m3-muscarinic acetylcholine-receptor in the smooth muscle of the digestive tract is discussed together with the changes in intracellular signal transduction. Isolated single cells that show an all-or-none contractile response to acetylcholine were desensitized by treatment with 0.1 mM acetylcholine for 10 min, resulting in an increase in the threshold concentration of acetylcholine for contraction, but without changing any of the binding characteristics. Permeabilized cells showed that the desensitization is via uncoupling between the receptor and G-protein. Secretory cells (rat basophil leukemia-2H3 cells) transfected with human m3-receptor showed desensitization when treated with 0.1 mM carbachol for 30 min. The coupling between the receptor and G-protein was not impaired, but some unknown Ca(2+)-independent mechanism may be involved. Smooth muscle tissue was tested for its time-course of desensitization, and a novel transient resensitization was found at 1 min of incubation with 0.1 mM carbachol. This resensitization, and the desensitization prior to it, were accompanied with changes in binding affinity. However, the affinity was not changed, in parallel with desensitization afterwards, but the positive feedback loop of Ca(2+)-influx caused by alkalization via receptor-stimulation was suppressed. After a 30-min treatment, a Ca(2+)-independent mechanism caused the uncoupling and affinity decrease. Treatment for 3 hr increased the number of binding sites without recovery of the response. The desensitizing process is very diverse to achieve selectivity, but its purpose is in unity.

Animals↗
PubMed1994

[A case of sarcoidosis with middle lobe atelectasis].

We report a case of sarcoidosis complicated by middle lobe atelectasis. A chest radiograph and a chest CT film on admission revealed middle lobe atelectasis and mediastinal lymphadenopathy. Bronchofiberscopic findings showed slit-like stenosis and reddish, edematous mucosal change of the middle lobe orifice. On admission, the serum angiotensin-converting enzyme (ACE) level was within the normal range. However, the ACE level had increased beyond the normal range by 2 months later, histological examination of a specimen from a transbronchial lung biopsy (TBLB) of the middle lobe revealed noncaseating epithelioid cell granulomas. We diagnosed sarcoidosis because of the histological findings from the TBLB and serum ACE elevation. Treatment with predonisolone resulted in remarkable alleviation of middle lobe atelectasis and mediastinal lymphadenopathy. Cases of sarcoidosis with middle lobe atelectasis are rare in Japan.

Bronchoscopy↗
PubMed1994

Long-term results of valve replacement with the St. Jude Medical valve.

Between 1980 and 1992, 908 patients underwent single aortic (n = 178), single mitral (n = 577), or double aortic and mitral (n = 153) valve replacement with the St. Jude Medical valve at our hospital. There were 392 male patients and 516 female patients whose ages ranged from 1.2 to 74 years (mean, 52 years). The early mortality rate was 5.0% (45 patients). A 94% complete follow-up was accomplished for 863 patients who were discharged from the hospital (4682.3 patient-years). Sixty-nine of these patients died, for a late mortality rate of 8.0%. Fifty-two patients, including four patients (0.3%/100 patient-years) had anticoagulant-related hemorrhage, 4(0.1%/100 patient-years) had prosthetic valve endocarditis, 11 (0.2%/100 patient-years) had nonstructural valve dysfunction, and 16 (0.3%/100 patient-years) underwent reoperation. There were no structural valve failures in this series. The total number of valve-related deaths was 22. Of those patients who survived, 98% were in New York Heart Association functional class I or II at the date of the last follow-up. The probabilities of freedom from thromboembolism and anticoagulant-related hemorrhage at 10 years were 94% +/- 2% and 97% +/- 2% in aortic valve replacement, 89% +/- 2% and 98% +/- 4% in mitral valve replacement, and 89% +/- 6% and 92% +/- 6% in double valve replacement, respectively. Significant hemolysis related to the St. Jude Medical valve occurred in 8 of the 577 patients who received mitral valve replacement in our early experience, and modifying the valve orientation appeared to play an important role in reducing hemolysis. The event-free rate, including all complications and late deaths, at 10 years was 75% +/- 7%, 74% +/- 3%, and 81% +/- 6% in aortic valve replacement, mitral valve replacement, and double valve replacement, respectively. On the basis of these results, the St. Jude Medical valve seems to be an excellent mechanical valve in terms of durability and low thrombogenicity and remains our prosthetic valve of choice when valve replacement with a mechanical valve is indicated.

Adolescent↗
PubMed1994

[Surgical treatment for postinfarction ventricular septal perforation].

Between August 1981 and August 1992, operation for ventricular septal perforation (VSP) after acute myocardial infarction (AMI) was performed in 12 patients and the results were studied. During this period, medical treatment was attempted as a standard therapy for more than two weeks after AMI, followed by operation. However, only four patients received elective operation two weeks after the onset of AMI. Regarding the relationship between the preoperative circulatory status and timing of surgery, elective operative could not be performed in seven patients showing a pulmonary to systemic flow ratio (Qp/Qs) of more than 3.0, while four out of five patients with a ratio of less than 3.0 received operation more than two weeks after the onset of AMI. Two patients with severe right heart failure after the repair of VSP died on table without weaning from the pump. Ten operative survivors were weaned from the pump without any difficulty of hemostasis and intraaortic balloon pumping was removed after operation. However, three patients died of multiple organ failure which had been deteriorating before operation. Postoperative activity improved to New York Heart Association Functional Class I or II in six survivors for the late follow-up period. In the case of high Qp/Qs due to VSP, early operation is recommended to prevent multiple organ failure.

Aged↗
PubMed1994

[Unresolved questions in hormonal therapy for prostate cancer].

Although there still are unresolved questions in hormonal therapy for prostatic cancer patients, it has long been considered one of the major therapeutic modalities after the report by Dr. Huggins in 1941. The unresolved questions are: "Can hormonal therapy for prostatic cancer prolong the survival of the patients?" "Can hormonal therapy improve the quality of life of prostatic cancer patients?" "Is complete androgen blockade superior to androgen reduction therapy?" "Is pre-operative hormonal therapy more beneficial than post-operative hormonal therapy?" and "How do we handle relapsed prostatic cancer?" We, urologists, unanimously recognize the beneficial effects of hormonal therapy in most prostatic cancer patients, even in a rather short span. Furthermore, other therapeutic modalities, except radical prostatectomy or radical radiation, can not eradicate cancer cells from patients. We can not treat prostatic cancer patients leading to better outcomes without hormonal therapy. Thus, hormonal therapy is chosen in most of the prostatic cancer patients as a first line therapy. Each type of hormonal therapy for prostatic cancer has specific characteristics, with advantages and disadvantages. We must choose the best hormonal therapy in terms of cost-benefit and quality of life during the therapy.

Androgen Antagonists↗
PubMed1994

[Intractable bacterial infection--review].

The factors involved in the mechanism of intractable bacterial infections are systemic, local and iatrogenic compromised conditions which mean the deficiency of host defence. From our results, especially on diffuse panbronchiolitis with Pseudomonas aeruginosa, we have learned about the harmful effects of destroyed neutrophils accumulated in bronchial and bronchiolar trees. Although low doses of erythromycin therapy is effective for intractable DPB. There are many evidences on the mechanisms for this treatment reported by Japanese researchers. We also reported our data of IL-8 level in BALF after this treatment. Bacterial factors of intractable processes are also important.

Bronchi↗
PubMed1994

Stereotactic fine needle aspiration of mammographic lesions.

Stereotactic fine needle aspiration biopsy (FNAB) is being offered at many centers across the United States in lieu of open surgical biopsy for nonpalpable mammographic lesions. To determine how accurate this procedure is in a community hospital, the authors performed stereotactic FNAB of 62 nonpalpable mammographic lesions using Siemens upright stereotactic equipment. FNAB was immediately followed by hook wire localization and open biopsy. Ten lesions were histologically malignant. Seven of these had been identified cytologically as atypical, suspicious or malignant. Three carcinomas were undetected by FNAB, for a sensitivity rate of 70 percent. There were no false-positive FNAB diagnoses. Three different radiologists performed the FNAB and localizations. Our results were insufficiently sensitive to be able to offer stereotactic FNAB to patients in lieu of open surgical biopsy. We are currently planning to evaluate the dedicated stereotactic prone biopsy equipment to compare the results of needle core biopsies with subsequent hook wire localization and open biopsy.

Biopsy, Needle↗