Search PubMed⌕ Search

Biomedical subjects

H Otsuka

Publications and source records attributed to H Otsuka.

At least 109 records · Page 6Linked to original sources
PubMed1998

Construction of canine herpesvirus vector expressing foreign genes using a lacZ-TK gene cassette as a double selectional marker.

An improved method for constructing canine herpesvirus (CHV) recombinants expressing foreign genes by using the lacZ-TK gene cassette as a double selectional marker was developed. A recombinant CHV carrying the lacZ-TK gene at a targeted gene locus was constructed and used as a parental virus for generating new recombinants. The parental virus formed blue plaques and was sensitive to TK-specific drugs, while newly generated recombinants, in which the lacZ-TK gene was replaced with the desired foreign gene, become both resistant to the TK-specific drugs and formed white plaques. Recombinants were isolated by using the combination of drug selection and color selection. This improved method allows construction of recombinant CHV with great ease, because the drug selection can enrich the frequency of recombinant CHV from 0.01-0.1% to 10-80%. This method was employed to construct a recombinant CHV that expressed rabies virus (RV) glycoprotein (G protein).

Animals↗
PubMed1998

Multiple schwannomas in the peripheral nerves.

Multiple tumours of peripheral nerves are often seen in patients with neurofibromatosis of type 1 or 2. Multiple schwannomas may occur without other manifestations of neurofibromatosis. We have reviewed 12 patients with multiple schwannomas arising from peripheral lesions who did not fulfil the criteria for either type of neurofibromatosis. Four had spinal and one an intracranial lesion in addition to the peripheral tumours. Two patients had one and three café-au-lait spots, respectively, and another had a probable family history. The largest tumours were 45 to 250 mm in size. Three patients had been referred as having von Recklinghausen's disease. The large size of tumours, the difficulties of histological diagnosis on biopsy, and the confusion with neurofibromatosis can lead to overtreatment. Malignant change seldom, if ever, occurs in patients with multiple schwannomas.

Adult↗
PubMed1998

Local cerebral blood flow autoregulation following "asymptomatic" cerebral venous occlusion in the rat.

OBJECT: Maintenance of cerebral blood flow (CBF) autoregulation in the brain is of major importance for patient outcome in various clinical conditions. The authors assessed local autoregulation after "asymptomatic" cortical vein occlusion. METHODS: In Wistar rats, a single cortical vein was occluded photochemically by using rose bengal and fiberoptic illumination. In rats with bilateral carotid artery occlusion, mean arterial blood pressure (MABP) was lowered in 5-mm Hg increments down to 40 mm Hg by using hypobaric hypotension. Local CBF at each pressure level was assessed by performing laser Doppler (LD) scanning at 25 (5 x 5) locations within bilateral cranial windows. In this manner, the lower limit of autoregulation (LLA) was detected. The LLA was 60 mm Hg in both right and left hemispheres in Group A (five rats), in which the animals received illumination without rose bengal and had no venous occlusion. Of the 11 rats that underwent vein occlusion, three developed severe reductions in local CBF and/or a growing venous thrombus and were distinguished as Group C (symptomatic; three rats); from previous work we know that those animals are bound to experience venous infarction. The remaining rats formed Group B (asymptomatic; eight rats). In this group the LLA remained at 60 mm Hg in the left hemisphere without occlusion, whereas, in the right cortex with the occluded vein, the LLA was found to be 65 mm Hg. Below a carotid stump pressure of 25 mm Hg regional CBF in the affected hemisphere dropped more abruptly to a possibly ischemic range than that in the opposite normal hemisphere. CONCLUSIONS: The results of the present study suggest that cerebral venous circulation disorders are manifested via additional pathways, that is, from a partially impaired local autoregulation in the vicinity of the occluded vein, even under conditions in which the vein occlusion itself does not cause brain damage. Care should be taken in the control of blood pressure in patients with this pathological condition.

Analysis of Variance↗
PubMed1998

[Surgical management of pulmonary metastases].

The results of surgical resection for pulmonary metastases from colorectal, breast, and renal cell carcinomas, soft tissue sarcoma, and osteosarcoma are reviewed. The number of pulmonary metastases, the presence of hilar or mediastinal involvement, and extrapulmonary foci are discussed in terms of surgical treatment. The size of pulmonary tumors or tumor doubling time has no significant effect on survival, while the number of metastatic foci does. Although a slight survival advantage has been noted for patients without hepatic metastases from colorectal cancer before pulmonary metastases occur, the difference in survival rates among patients with and without hepatic metastases is not significant. The role of surgery is less clear in breast cancer patients, and therefore further prospective study is considered essential. Higher relapse rates have been reported in patients with soft tissue sarcoma and osteosarcoma, although patients with these metastases can achieve long-term survival after a second metastasectomy. VATS is not be recommended for metastatic cancer surgery, because intraoperative identification of metastatic foci is often difficult.

Breast Neoplasms↗
PubMed1998

Application of a 3D display system for biplane cerebral angiography.

To improve the total safety for the biplane cerebral angiographic examination, we have developed a new three dimensional (3D) display system. By applying this system, shortening the examination time and reducing the risk of infection and embolization were achieved. We added just one graphic-workstation for 3D reconstruction to an ordinary biplane digital-cine-angiography system. This system can process the images of angiogram extempore in a short time and display the run of arterial vessels to the examiner. Biplane images were taken from the digital-cine-angiography system into the workstation through a video display. Three dimensional positions were calculated and displayed on a CRT monitor. It took from 15 to 45 seconds for the calculation. This system could display instantly the run of arterial vessels from any angle by using the computer mouse. Our system doesn't disturb the examination, but helps us to understand the run of the arterial vessels. This system was useful in cases where the arteries wound their way around or over-lapped each other.

Algorithms↗
PubMed1998

Plasma lipoprotein profiles change significantly during cardiac catheterization.

Most patients in acute myocardial infarction (AMI) undergo emergent coronary angiography (CAG). However, when to analyze lipoprotein profiles in AMI is not clear. To determine whether lipoprotein profiles change during catheterization, we measured serum lipid and apolipoprotein concentrations in 65 patients (51 men and 14 women) before and after catheterization. Heparin was injected at 50 units/kg for CAG and 200 units/kg for percutaneous transluminal coronary angioplasty (PTCA). We found that cholesterol and triglyceride decreased by 9.4% (P < 0.001) and 53.1% (P < 0.001), respectively, after catheterization. Apolipoproteins also decreased significantly. Variables decreased two to five times more after PTCA than after CAG. Lipoprotein lipase mass was higher after PTCA (267.8 +/- 135.3 micrograms/L) than after CAG (93.3 +/- 48.4 micrograms/L; P < 0.05). In conclusion, lipoprotein profiles change during catheterization. We recommend avoiding analysis of lipoprotein profiles after emergent CAG in AMI.

Adult↗
PubMed1998

Effects of volatile anesthetics on respiratory activity and chemosensitivity in the isolated brainstem-spinal cord of the newborn rat.

To elucidate the various actions of volatile anesthetics on respiratory activity and chemosensitivity, we have studied the activities of the respiration-related structures in the medulla of the in vitro brainstem-spinal cord preparation of the newborn rat. Halothane decreased respiratory burst frequency (fR), inspiratory duration (Ti), integrated ventral C4 root activity (integral of C4) and respiratory minute activity (RMA) in a concentration-dependent fashion. Bicuculline counteracted the depressive effect of halothane on fR, integral of C4, and RMA. Inspiratory neuronal activity recorded at the rostral ventrolateral medulla (RVL) corresponded to these changes. Activities of Pre-Inspiratory (Pre-I) neurons and expiratory neurons in the RVL were also inhibited by halothane. The C4 activity did not always correspond to Pre-I neurons' discharge. In this comparative study of three volatile anesthetics, the inhibitory effect on fR appeared to be greater with enflurane than with halothane or isoflurane. The reversal effects of bicuculline on decreases in fR, integral of C4, and RMA also seemed to be greater with enflurane than with halothane or isoflurane. Hypercapnia (pH 7.0) induced a significant increase in fR and RMA, and a significant decrease in Ti. Although halothane inhibited overall activities, chemo-responsiveness to hypercapnia changed similarly even during halothane application. Hypocapnia (pH 7.8) significantly decreased fR, and increased integral of C4 and Ti. Hypocapnia during halothane application also induced a significant decrease in fR and RMA. These results suggest that the modification of GABAA receptor-mediated neurotransmission is in part responsible for the respiratory depression by volatile anesthetics, affecting especially fR, integral of C4, and RMA. Low respiratory rate by enflurane is associated with GABAergic modification. Prolongation of Ti by enflurane, seen clinically, does not seem to be either central or GABAergic. These findings demonstrate the responsiveness to CO2 and the respiratory compensation mechanism via respiratory frequency in the isolated preparation. It is, furthermore, indicated that halothane preserves the central chemosensitivity while its concentration is high enough to reduce the respiratory activities.

Anesthetics, Inhalation↗
PubMed1997

Protective effect of a prostaglandin I2 analog, TEI-7165, on ischemic neuronal damage in gerbils.

TTC-909 (Clinprost), a chemically stable PGI2 analog, isocarbacyclin methyl ester (TEI-9090 or Clinprost) incorporated in lipid microspheres, when administered intravenously after brain ischemia, prevents ischemic neuronal damage possibly by modulating cerebral blood flow and platelet aggregation. However, the possibility exists that TEI-7165, which is the free acid form and a central metabolite of TEI-9090, has direct neurotrophic action in vivo, since TEI-7165 has been shown to block neuronal voltage-dependent Ca2+ channels in vitro, and a novel prostacyclin receptor showing high affinity with TEI-7165 has been detected in a variety of brain regions including the hippocampus. In the present study, we infused TEI-7165 for 7 days into the lateral ventricle of gerbils starting 2 h before or just after 3-min forebrain ischemia. TEI-7165 infusion prevented significantly the ischemia-induced shortening of response latency time as revealed by a step-down passive avoidance task. Subsequent light and electron microscopic examinations showed that pyramidal neurons in the hippocampal CA1 region, as well as synapses within the strata moleculare, radiatum and oriens of the region, were significantly more numerous in gerbils infused with TEI-7165 than in those receiving vehicle infusion. TEI-7165 infusion did not affect hippocampal blood flow or temperature. These findings, together with the previously depicted accumulation of centrally administered [3H]TEI-7165 around hippocampal neurons, suggest that TEI-7165 has a direct neuroprotective action in brain ischemia.

Animals↗
PubMed1997

Periosteal chondrosarcoma invading the medullary cavity.

We present a case of periosteal chondrosarcoma of the femur, in which a tumor invaded the medullary cavity and the lesion was clearly demonstrated only on MRI. To the best of our knowledge, there have been no previous reports of an intramedullary lesion caused by periosteal chondrosarcoma demonstrated on MRI.

Adult↗
PubMed1997

Analysis of canine herpesvirus gB, gC and gD expressed by a recombinant vaccinia virus.

The genes encoding the canine herpesvirus (CHV) glycoprotein B (gB), gC and gD homologues have been reported already. However, products of these genes have not been identified yet. Previously, we have identified three CHV glycoproteins, gp 145/112, gp80 and gp47 using a panel of monoclonal antibodies (MAbs). To determine which CHV glycoprotein corresponds to gB, gC or gD, the putative genes of gB, gC, and gD of CHV were inserted into the thymidine kinase gene of vaccinia virus LC16mO strain under the control of the early-late promoter for the vaccinia virus 7.5-kilodalton polypeptide. We demonstrated here that gp145/112, gp80 and gp47 were the translation products of the CHV gB, gC and gD genes, respectively. The antigenic authenticity of recombinant gB, gC and gD were confirmed by a panel of MAbs specific for each glycoprotein produced in CHV-infected cells. Immunization of mice with these recombinants produced high titers of neutralizing antibodies against CHV. These results suggest that recombinant vaccinia viruses expressing CHV gB, gC and gD may be useful to develop a vaccine to control CHV infection.

Animals↗
PubMed1997

Megastigmane glycosides from Salvia nemorosa.

From the aerial parts of Salvia nemorosa, three new megastigmane glycosides, salvionosides A-C, were isolated, along with the known compounds, (6S,9R)- and (6S,9R)-roseosides, (6R,9R)- and (6R,9S)-3-oxo-alpha-ionol glucosides and blumeol C glucoside. The structures of the new compounds were elucidated on the basis of spectral and chemical evidence.

Carbohydrates↗
PubMed1997

Multiple intramedullary spinal sarcoidosis: case report.

BACKGROUND: According to past reported cases, spinal intramedullary sarcoidosis has the radiologic characteristics of a single enhanced lesion with cord swelling. However, it is difficult to make a diagnosis using only radiologic examinations. Including our case, 20 cases have been reported of intramedullary spinal sarcoidosis. Only six cases were diagnosed as primary spinal sarcoidosis. We present a rare case of multiple spinal intramedullary sarcoidosis without cord swelling. CASE DESCRIPTION: This 63 year-old man was afflicted with progressive paraparesis and numbness of the lower extremities. Magnetic resonance imaging showed intramedullary lesions without cord swelling. The patient underwent biopsy for diagnosis and the specimen showed a noncaseating granuloma mainly composed of epitheloid cells. Postoperative corticosteroid therapy was effective and the lesion disappeared 1 month after the operation. CONCLUSIONS: Biopsy is a less invasive method and is useful for early diagnosis. Early diagnosis is important for spinal sarcoidosis so that high-dose corticosteroid therapy can be commenced while the lesion still has a good chance of being successfully treated.

Humans↗
PubMed1997

Antiviral activity of 5,6,7-trimethoxyflavone and its potentiation of the antiherpes activity of acyclovir.

A naturally occurring flavone, 5,6,7-trimethoxyflavone (TMF), isolated from the plant Callicarpa japonica, was subjected to antiviral assays. The compound exhibited relatively high inhibitory effects on herpes simplex virus type 1 (HSV-1), human cytomegalovirus and poliovirus. The anti-HSV-1 action was not due to the inhibition of virus adsorption, entry and viral protein synthesis, but might involve, at least in part, a virucidal activity, which results in a suppression of viral binding to host cells at an early replication stage. TMF and acylovir were synergic in their anti-HSV activities at levels below the 50% inhibitory concentrations for antiviral activity.

Acyclovir↗
PubMed1997

Identification and characterization of bovine herpesvirus-1 glycoproteins E and I.

To identify the products of the bovine herpesvirus-1 (BHV-1) gE and gI genes, we constructed baculovirus recombinants containing the putative gE or gI genes. These recombinant viruses synthesized BHV-1 gE and gI with apparent molecular masses of 84 and 41 kDa, respectively. Polyclonal antibodies against these recombinant gE or gI proteins were produced and by using these antibodies, we showed the presence of gE and gI with apparent molecular masses of 94 and 45 kDa, respectively, in purified BHV-1 virions. We also demonstrated that like their herpes simplex virus-1 and pseudorabies virus counterparts BHV-1 gE and gI form a complex. A gI- BHV-1 mutant failed to express gI but gE was found in the virions. On the other hand, neither gE nor gI was found in the virions of a gE- BHV-1 mutant. In the gE- BHV-1 mutant, gI was produced but released into the medium without being integrated in the virions.

Animals↗
PubMed1997

Synthesis biological evaluation of alkyl, alkoxy, alkylthio, or amino-substituted 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones.

2,3-Dihydro-1,5-benzothiazepin-4(5H)-ones substituted with an alkyl, alkoxy, alkylthio, hydroxy, or amino group on the fused benzene ring of the 1,5-benzothiazepine skeleton were synthesized and their vasodilating, antihypertensive, and platelet aggregation-inhibitory activities were investigated. (-)-cis-3-Acetoxy-5-[2-(di-methylamino) ethyl]-2,3-dihydro-8-methyl-2-(4-methylphenyl)-1,5-benzothiazepin- 4(5H)-one ((-)-13e) was selected for further studies as a potent inhibitor of platelet aggregation.

Alkylation↗
PubMed1997

[Ruptured traumatic aneurysms of the peripheral anterior cerebral artery: study of delayed hemorrhage after closed head injury].

We report three cases of ruptured traumatic aneurysms of the peripheral anterior cerebral artery after closed head injury. These cases were all young men with closed head injury due to traffic accidents. Consciousness level on admission was coma in all three cases. Case 1 was a 19-year-old man with interhemispheric hematoma on initial CT, then 7 days later his consciousness cleared. However, 14 days later he suddenly lapsed into a deep coma with a severe frontal hemorrhage. Case 2 was a 13-year-old boy. Plain skull films demonstrated a frontal depressed fracture, but CT scan showed no bleeding. Four days later his consciousness cleared but 11 days after trauma, he lapsed into a deep coma with a frontal hemorrhage. Case 3 was a 22-year-old man. Initial CT showed a slight ventricular hemorrhage. Fourteen days later, his consciousness had almost cleared, but then he lapsed into a deep coma with a large frontal hemorrhage 11 weeks after the trauma. These patients all died within a few days after intracranial bleeding. All patients underwent cerebral angiography but none of them showed filling defect. Autopsy was performed and ruptured aneurysms were found on the distal anterior cerebral artery that had no relation to the branch of bifurcation. Histological examination demonstrated a lack of elastic lamina and media in all of these three cases, so each of them was a victim of so-called false aneurysm. Twenty reported cases of ruptured traumatic aneurysms of the peripheral cerebral artery with delayed hemorrhage after closed head injury were reviewed. Factors in the traumatic aneurysm showed no relation to the duration of disturbed consciousness. Within one month, delayed hemorrhage due to ruptured traumatic aneurysm occurred. None of the delayed hemorrhages involved subarachnoid hemorrhage. Subdural hematoma was seen in the distal middle cerebral artery and frontal hemorrhage was found in the distal anterior cerebral artery. We consider that frontal hemorrhage is a predictive finding for the type of delayed hemorrhage due to traumatic aneurysm in the distal anterior cerebral artery.

Accidents, Traffic↗
PubMed1997

[Transverse relaxation time of metabolites by proton MRS: one of the parameters concerned with quantification].

We examined the transverse relaxation time of metabolites observed by proton MRS at 6 different points of TE(18, 30, 60, 90, 135, and 270ms). The double exponential curve was better fitted to the 6 points than the single exponential curve for calculating the T2 values of the three major metabolites. We considered that these metabolites would have a long T2 component and short T2 component, and the correct T2 value is difficult to obtain under the limitations of measurement time available in clinical applications.

Adult↗