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Biomedical subjects

K Hayashi

Publications and source records attributed to K Hayashi.

At least 253 records · Page 14Linked to original sources
PubMed2001

Yokonolide A, a new inhibitor of auxin signal transduction, from Streptomyces diastatochromogenes B59.

Bio-probes that inhibit the action of auxin are useful tools for the study of auxin signaling. To screen for specific inhibitors of auxin signaling, we used an Arabidopsis transgenic line harboring the auxin-inducible promoter derived from PS-IAA4/5 and the reporter gene, GUS (beta-glucuronidase). In this transgenic plant, the exogenous auxin specifically enhanced the expression of the GUS reporter gene. A novel 22-membered spiroketal-macrolide, yokonolide A (1), and related previously known compound, A82548A (2), were isolated from Streptomyces diastatochromogenes B59 as inhibitors of auxin inducible gene expression. The absolute structure of I was determined by detailed spectral analyses and chemical derivatization. 1 and 2 completely inhibited the auxin-induced transcription of the reporter gene at 5 and 1 microm, respectively. In contrast, 1 and 2 did not affect the translation of GUS reporter transcripts. In addition, 1 and 2 did not inhibit the gibberellin-induced alpha-amylase expression at 100 microM in barley aleurone cells. These results suggest that 1 and 2 specifically inhibit auxin signaling leading to auxin-mediated gene expression.

Anti-Bacterial Agents↗
PubMed2001

[Immunohistochemical analysis of protein gene product 9.5, a new marker for parietal epithelial cells of Bowman's capsules, in anti-glomerular basement membrane(GBM) antibody induced glomerulonephritis of WKY rats].

Protein gene product 9.5(PGP 9.5) is expressed specifically in neuroendocrine cells and considered to be one of the neuroendocrine markers. Recently, we reported that PGP 9.5 is localized in the parietal epithelial cells(PECs) of Bowman's capsules as well as in neural tissues. In the present study, immunohistochemical analysis of PGP 9.5 as a specific marker of the PECs of Bowman's capsules, synaptopodin as a podocyte-specific marker, and ED-1 as a specific marker of monocytes/macrophages was performed in the cellular crescents in anti-GBM antibody induced glomerulonephritis of WKY rats using serial renal sections. In the acute phase of anti-GBM antibody induced glomerulonephritis, and the expression of PGP 9.5 and ED-1 was observed diffusely in proliferating cells of cellular crescents. However, in most part of cellular crescents, PGP 9.5 positive areas did not overlap with the ED-1 positive areas. Synaptopodin was constantly detected along the glomerular tufts compressed by the crescents. In the chronic phase of this disease, PGP 9.5 was observed in the cells covering the surface of fibrous crescents or scattered within fibrocellular crescents. Synaptopodin was partially detected in such cells. It appears that cellular crescents are composed mainly of proliferating PECs and macrophages in rat anti-GBM antibody-induced glomerulonephritis.

Animals↗
PubMed2001

[CT-guided needle biopsy of the lung: factors affecting risk of complications].

PURPOSE: To analyze factors influencing the risk of complications associated with CT-guided percutaneous needle biopsy for lung lesions. MATERIALS AND METHODS: Sixty patients, aged 24-85 years (37 men and 23 women), underwent CT-guided needle biopsy. A definite diagnosis was made in 49 of 60 cases (81.7%), including 38 of 43 malignant lesions (88.4%) and 11 of 17 benign lesions (64.7%). Complications associated with biopsy were observed in 35 patients (58.3%). Major complications included pneumothorax (n = 26) and pulmonary hemorrhage (n = 20). Chest tube placement was needed in 5 (19.2%) of 26 pneumothorax cases (8.3% of all biopsies). RESULTS: The high frequency of pneumothorax (43.3%) in this series had several contributing factors, including the presence of pulmonary emphysema, lesion size, and traversal of aerated lung. Chest tube replacement was necessary more frequently in patients with pulmonary emphysema. The number of pleural passes, location of lesions, and size of needles were not correlated with the incidence of pneumothorax. CONCLUSION: The presence of pulmonary emphysema, lesion size, and traversal of aerated lung are the predominant risk factors for pneumothorax in patients with CT-guided lung biopsy.

Adult↗
PubMed2001

[Study of factors that influence the use of ambulances in Japanese prefectures].

PURPOSE: The objective of this study was to clarify the factors that influence the rate of patient-carriage by ambulances in Japanese Prefectures. METHOD: The study was conducted using data on cases of patients with mild conditions carried by ambulances in Japanese prefectures in 1993, concentrating the factors that influence the rate of usage. The cases were analyzed focusing on three major types of medical emergencies (accounting for 93.4% of the total): sudden illnesses, traffic accidents and general injuries. SPSS for Windows was used for statistical analysis. RESULTS AND DISCUSSION: Data analysis by age group and type of medical emergency showed a positive correlation (r > 0.7) for the rate of cases with mild conditions carried by ambulances in all age groups (early childhood, adolescence, adult and senior) and the three major types of medical emergencies. Particularly, a strong correlation (r > 0.9) was observed with regard to patients suffering from sudden illnesses and general injuries. Multiple regression analysis showed that the rate for patients with mild cases carried by ambulances was higher in prefectures where; (1) there were more cases of administrative litigation related to individuals' rights, and (2) there were many nuclear families that tended to lack the capacity for family care. In addition, it also became evident that the rate for patients with mild injuries from traffic accidents was higher in prefectures where; (1) the rate for male-driver license holders for small- and medium-size cars was higher, and (2) the ratio of numbers of vehicles to total roadway area was higher. CONCLUSIONS: The findings suggest that factors unrelated to medical emergencies have a major influence on use of ambulance. Reevaluation of policy in order to promote appropriate utilization is necessary.

Accidents, Traffic↗
PubMed2001

[Evaluation of value of coronary artery bypass grafting without cardiopulmonary bypass for emergency or subemergency case].

From August 1999 through September 2000, emergency (operation within 24 hours after hospitalization) or subemergency (within 48 hours) coronary artery bypass grafting without cardiopulmonary bypass (OPCAB) was performed in 16 patients (EM group) with a mean age 71.9 years old (range: 47-85). The patients were divided into 3 groups of which were acute myocardial infarction (AMI) group, chronic heart failure (CHF) group and unstable angina (u-AP) group, and compared preoperative hemodynamics, the number of graft, target arteries, bypass patency and hospitalization period after surgery with 26 patients performed the elective OPCAB in the same duration (EL group). All patients in EM group were used intra-aortic balloon pumping (IABP) assist before operation. In EL group, 16 patients (61.5%) were required IABP (p < 0.05). Ejection fraction and cardiac index in CHF group were significantly lower than those of EL group (47.8 +/- 1.1 vs. 63.3 +/- 2.4, 2.8 +/- 0.2 vs. 1.9 +/- 0.2: p < 0.05). Pulmonary capillary wedge pressure in AMI group and CHF group was significantly higher than that of EL group (16.7 +/- 5.9, 20.8 +/- 5.4 vs. 7.2 +/- 0.8: p < 0.01). There was a significant difference in the mean number of bypass in EM group compared with that of EL group (1.8 +/- 0.2 vs. 2.7 +/- 0.2: p < 0.05). In AMI group and CHF group, the grafting rate to the major vessel in the anterior wall was occupied in more than 70% of all bypasses per patient, however that was less than 50% in EL group. The arterial graft was actively used for revascularization. The hospitalization period in AMI group and CHF group was longer than that in u-AP group and EL group (28.5 +/- 9.8, 38.8 +/- 7.4 vs. 15.7 +/- 1.5, 13.0 +/- 0.7: p < 0.01). There was no difference in bypass patency between EM group and EL group (96.6 vs. 97.2). During the follow-up period, any death and complications were not recognized in both groups. These results suggested that OPCAB would be one of the valuable procedures in the emergent coronary artery bypass grafting.

Adult↗
PubMed2001

[A case of primary racemose hemangioma of bronchial artery with recurrent hemoptysis].

A 42-year old man was admitted to our hospital because of hemoptysis. Bronchial arteriography revealed a tortuous and dilated left bronchial artery with a shunt formation between the bronchial and pulmonary arteries. Bronchial artery embolization using a sponge was performed three times to treat the hemoptysis, but all attempts failed. The patient therefore underwent left lower lobectomy, after which no hemoptysis was observed. Histopathologically, the resected tissue showed no inflammatory change. Interestingly, abnormal vessels resembling arteriovenous malformations were also found. Although the embolization therapy was effective in several reported cases, we concluded that surgery was required for this patient with persistent hemoptysis because of the development of collaterals and a bronchial-pulmonary artery shunt.

Adult↗
PubMed2001

[The effect of immunization with herpes simplex virus glycoprotein D fused with interluekin-2 against murine herpetic keratitis].

PURPOSE: To evaluate the effect of vaccination with fusion protein(gD-IL-2) consisting of herpes simplex type1(HSV-1) glycoprotein D(gD) and human interleukin-2(IL-2), and the effect of plasmid DNA vaccine encoding gD-IL-2 against murine herpetic keratitis. METHODS: Plasmid containing gD-IL-2(pHDL-neol) was constructed, and gD-IL-2 peptide was purified. BALB/c mice were injected twice hypodermally or subconjunctivally with 1 microgram/0.1 ml of gD-IL-2 peptide, or twice subconjunctivally with 90 micrograms/0.05 ml of gD-IL-2 plasmid DNA. Neutralizing antibody titer and delayed-type hypersensitivity (DTH) against HSV-1 were measured. Immunized mice were challenged with CHR3 strain of HSV-1 via the cornea. The clinical picture of epithelial and stromal keratitis was scored. RESULTS: Stromal keratitis was inhibited in gD-IL-2 peptide- or gD-IL-2 DNA-immunized mice, but epithelial keratitis was not. It was confirmed that plasmid gD-IL-2 elicited significant serum virus neutralizing titer and DTH response. CONCLUSION: Vaccination with gD-IL-2 was effective against herpetic keratitis.

Animals↗
PubMed2001

[A case of cerebral arteriovenous malformation complicated with intracerebral hemorrhage after endovascular embolization].

We reported a case of cerebral arteriovenous malformation (AVM), complicated with intracerebral hemorrhage (ICH), after endovascular embolization. A 51-year-old male suffered from intraventricular hemorrhage due to a rupture of an intranidal aneurysm on October 4, 1999. The first embolization procedure for the aneurysm and a part of the nidus was performed with 2-hydroxyethyl methacrylate-methyl methacrylate (HEMA-MMA) and Liquid coil on day 21 after admission. On day 28, a second embolization was carried out for the residual nidus. Although most of the nidus was obliterated, the patient became comatose 10 hours after the second embolization. Computed tomography revealed a massive ICH in the right parietal lobe, and he underwent emergency evacuation of the hematoma. During the surgery, HEMA-MMA was seen in a draining vein. This caused venous stasis. Although the patient gradually improved postoperatively, he became comatose again because of a recurrence of ICH on day 36. Evacuation of the hematoma and removal of the nidus were performed again. The operative specimen showed AVM embolized by HEMA-MMA with non-specific inflammation and partial inflammatory degeneration of the vascular wall. Hemodynamic change such as venous stasis or elevated pressure of the feeding artery seemed to be the cause of the hemorrhage. Multi-staged embolization with longer intervals and intraoperative flow control were regarded as crucial for avoiding delayed hemorrhage.

Aneurysm, Ruptured↗
PubMed2001

[High-dose therapy and peripheral blood stem cell transplantation for patients with aggressive non-Hodgkin's lymphoma remaining in initial remission: results of a feasibility study].

High-dose therapy with peripheral blood stem cell transplantation (HDT/PBSCT) was performed as one aspect of front-line therapy in patients with poor-risk aggressive non-Hodgkin's lymphoma (high-intermediate/high risk) according to the age-adjusted international prognostic index (aaIPI). Twenty-nine patients were enrolled in this study between November 1994 and March 1999. CHOP + etoposide (CHOP-E) was used as an initial chemotherapy and as a chemotherapy agent for the purpose of cell harvesting. Peripheral blood stem cells were harvested from 17 patients, and HDT with CEC (carboplatin, etoposide, cyclophosphamide)/PBSCT was performed in 11 patients. Eighteen patients dropped out, including five for whom CHOP-E therapy was ineffective and 5 who did not give consent for cell harvesting or HDT/PBSCT. CHOP-E therapy produced complete remission (CR) in 15 out of 26 patients (58%) after discounting the 3 who were ineligible among the 29 who were initially enrolled. The median observation period after PBSCT in the 11 patients who underwent HDT/PBSCT was 25 months (3 to 50 months), and the 3-year disease-free survival rate was 73%. No serious complications associated with the transplantation were observed. We were able to confirm the feasibility and safety of HDT/PBSCT as one form of front-line therapy for aggressive non-Hodgkin's lymphoma in patients under 60 years of age.

Adolescent↗
PubMed2001

[A case of spinal dural AVF treated by endovascular embolization].

Here we report a case of spinal dural arteriovenous fistula(AVF) treated by endovascular embolization. A 58-year-old female presented with progressive intermittent claudication and numbness of the lower extremities. MRI showed swelling of the spinal cord with intramedullary high signal intensity on T2-weighted image and intramedullary enhancement, suggested spinal cord myelopathy. Myelography demonstrated the dilated serpentine vessels in the subarachnoid space and focal filling defect. Angiography showed spinal dural AVF fed by bilateral lateral sacral artery. The draining vein was posterior spinal vein. Endovascular embolization using liquid material was performed under general anesthesia. The injection of glue included the distal feeding artery, the shunt itself and the initial part of draining vein. A complete cure was achieved, with a normal postoperative angiogram. MRI returned to normal with complete disappearance of T2 high signal, cord enlargement and enhancement by contrast medium. It was suggested that venous congestion induced the transient spinal ischemia, manifested as intermittent claudication. Endovascular embolization using liquid material was safe and quite effective for spinal dural AVF.

Central Nervous System Vascular Malformations↗
PubMed2001

[Therapeutic strategy for progressive renal disease].

Renal disease constitutes an important determinant of cardiovascular disease. Although the mechanisms for the progression of renal impairment remain fully undetermined, available evidence indicate that renal glomerular hypertension is responsible in part for the development of renal injury. In renal disease, afferent arteriolar tone is reported to be reduced, while the augmented intrarenal angiotensin II serves to act as an efferent arteriolar constrictor, both of which result in an increase in glomerular capillary pressure. Angiotensin converting enzyme inhibitors (ACE-I) are established as the agent possessing both antihypertensive and renoprotective actions, which exert vasodilator action on efferent arterioles. Calcium antagonists are also reported to have salutary effect on renal disease, although their beneficial action varies depending on the antagonists used and the underlying disease. The use of calcium antagonists, however, is mandatory particularly under the circumstance where renal failure moderately to severely progresses and the ACE-I cannot be used.

Angiotensin Receptor Antagonists↗
PubMed2001

[Efficacy of weekly docetaxel therapy for advanced or recurrent breast cancer].

To evaluate the safety and efficacy of weekly docetaxel (weekly TXT) in cases of advanced or recurrent breast cancer, 31 patients were enrolled in this pilot study of weekly TXT given at 25 mg/m2/w. Each cycle consisted of 3 weeks of therapy followed by a 1-week treatment break in an outpatient setting. Patients received a median of 15 infusions with a median cumulative dose of 680 mg. The median time to treatment failure was 8 months. The overall response rate was 32.3%, and 22.6% of patients had stable disease for at least 6 months. The response rate was consistent regardless of prior chemotherapy with anthracycline. There was no grade 3 or 4 toxicity, and the regimen was generally well tolerated. Although 37.5% of patients had grade 1 or 2 nail change, myelosuppression, fatigue, nausea, vomiting and fluid retention were mild. Weekly TXT seems to be an effective and feasible treatment for advanced or recurrent breast cancer patients.

Adult↗
PubMed2001

Japan-specific subtype of hepatitis C virus genotype 1b, J subtype, has relatively low pathogenicity.

The prognostic implication of viral genotype 1b for hepatitis C virus (HCV) infection has been controversial, possibly due to the pathogenetic heterogeneity of genotype 1b. We analyzed two newly delineated subtypes of HCV genotype 1b subtypes with respect to progression of liver disease. Patients with chronic HCV 1b infection (113 total, including 18 with chronic persistent hepatitis, 60 with chronic active hepatitis, 19 with cirrhosis, and 16 with hepatocellular carcinoma with cirrhosis) were studied to elucidate the factors associated with progression of liver disease. Factors evaluated included sex, age at diagnosis, blood transfusion history, and HCV genotype 1b subtype (W subtype or J subtype). W subtype was identified more often in association with chronic active hepatitis than with chronic persistent hepatitis (P = 0.0089), and more often in patients with cirrhosis than in those without (P = 0.0044). The age-, sex-, and transfusion history-adjusted odds ratios with respect to histological activity and presence of cirrhosis for W subtype compared to J subtype were 6.966 (1.856 to 26.145) and 6.397 (1.506 to 27.179), respectively. Age at diagnosis was the most important risk factor for predicting development of cirrhosis and carcinoma. In conclusion, the W subtype of HCV 1b is associated closely with histologically active disease and development of cirrhosis, whereas the Japan-specific J subtype has relatively low pathogenicity. HCV genotype 1b, therefore, is heterogeneous in its pathogenicity.

Adult↗
PubMed2001

[On line display of the reconstructed pressure waves of the radial artery from the monitored output pressure waves at the same site].

The input-output relationship of transducer and catheter system is described by linear, second-order differential equation with three coefficients: inductance (L), resistance (R), and capacitance (C). Once the natural frequency (fo) and the damping ratio (beta) of the monitoring system have been measured, three coefficients of the differential equation are uniquely obtained. We measured the frequency response of the monitoring system, which we usually use in our hospital, to obtain fo and beta, and reconstructed the original input arterial pressure wave from output signal on the display using the simple time-domain approach. The analysis of this linear, second-order differential equation, is applicable in on-line bedside monitoring, because the calculation of this equation is simpler than that using Fourier's translation. The pressure waves of the radial artery both monitored (output) and restored (input) were depicted on the same display at the same time. We can evaluate the changes in systemic circulation from the changes in the wave shapes of arterial blood pressure.

Blood Pressure↗