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T Masuzawa

Publications and source records attributed to T Masuzawa.

At least 91 records · Page 5Linked to original sources
PubMed1996

Impact of systemic depulsation on tissue perfusion and sympathetic nerve activity.

BACKGROUND: We postulated that pathophysiologic processes under nonpulsatile circulation are related to the behavior of the sympathetic nerve activity that regulates tissue perfusion. METHODS: Pulsatile and nonpulsatile pumps were installed in parallel in the left heart bypass circuit of anesthetized goats (n = 9) so that pulsatile circulation could be converted to nonpulsatile circulation instantly. At 5 minutes before and after systemic depulsation, we measured hemodynamic indices, renal nerve activity, and regional blood flow of the brain, heart, and renal cortex. RESULTS: Renal nerve activity was significantly elevated after systemic depulsation (15.6 +/- 9.3 versus 19.4 +/- 9.8 microV), when mean aortic pressure remained almost constant. The renal cortical flow was significantly reduced after depulsation (3.61 +/- 1.23 versus 2.93 +/- 1.19 mL.min-1.g-1), whereas no significant difference was found in the regional blood flow of the brain or the heart. CONCLUSIONS: The significant reduction of renal cortical blood flow after systemic depulsation is associated with a significant increase in renal nerve activity. Our results suggest that increased renal nerve activity plays an important role in the reduction of renal function after systemic depulsation.

Animals↗
PubMed1996

Presence of common antigenic epitope in outer surface protein (Osp) A and OspB of Japanese isolates identified as Borrelia garinii.

Japanese Borrelia strains FujiP2, AP83, NT24, NT29 and HT2 which had a 31-kilodalton protein non-reactive with monoclonal antibody (MAb) H5332 to outer surface protein A (OspA) were identified as B. garinii by the DNA hybridization method. MAb P3134 raised to strain NT24 reacted with OspA and the OspB-ranging protein of these isolates and cross-reacted with the OspB-ranging protein of some other isolates. Since the reactive protein was extracted by the Triton X-114 phase partitioning method, the MAb recognized the common epitope present in OspA and OspB. To our knowledge, this is the first report of an MAb reactive to both OspA and OspB.

Antibodies, Bacterial↗
PubMed1996

Comparison of OspA serotypes for Borrelia burgdorferi sensu lato from Japan, Europe and North America.

UNLABELLED: Sixty-one Borrelia burgdorferi sensu lato strains from various sources (ticks, human, and wild animals) in Japan and two strains from ticks in Far Eastern Russia were classified on the basis of reactivity with 16 monoclonal antibodies (mAb) to outer surface protein A (OspA) and by DNA-DNA hybridization assay. Eleven OspA serotypes (J1 to J11) were recognized among the Japanese and the Far East Russian isolates (serotypes J1 to J9 were identified as B. garinii, serotype J10 was identified as B. afzelii, and serotype J11 corresponded to B. japonica), whereas 7 OspA serotypes for North American and European isolates previously reported (Bettina Wilske et al, J. Clin. Microbiol. 31:340-350,1993) were not observed except for OspA serotype 2 which showed identical reactivity with OspA serotype J10. This finding provides helpful information for understanding the geographical distribution of Lyme disease borrelia and the development of vaccine and diagnostic tests. IN CONCLUSION: 1.B. burgdorferi sensu stricto has not been observed in Japan, 2. Japanese B. afzelii isolates are closely related to those from Europe, 3. B. garinii isolates from Japan are highly heterogeneous and apparently different from European B. garinii isolates.

Animals↗
PubMed1996

Reservoir competence of the vole, Clethrionomys rufocanus bedfordiae, for Borrelia garinii or Borrelia afzelii.

In autumn of 1994 and spring of 1995, we examined Borrelia infection among Microtinae voles, Clethrionomys rufocanus bedfordiae, in Hokkaido, Japan. In BSK culturing of the earlobe tissues of 45 C. rufocanus bedfordiae captured, twelve rodents were positive for Borrelia. Eight isolates were used for the polymerase chain reaction (PCR) and the restriction fragment length polymorphism (RFLP) analysis. According to the results, these isolates were classified into B. garinii or B. afzelii. It is considered that a common vole, C. rufocanus bedfordiae, plays a significant role in the transmission and maintenance of B. garinii and B. afzelii, similar to the role of Apodemus speciosus mice.

Animals↗
PubMed1996

Borrelia burgdorferi sensu lato in an endemic environment: wild sika deer (Cervus nippon yesoensis) with infected ticks and antibodies.

Ticks and blood samples were collected from wild sika deer (Cervus nippon yesoensis) during a hunting season (August to October) of 1991 at a selected location in Hokkaido, Japan. Ixodes persulcatus (adult and nymph) and I. ovatus (adult) were the common ticks on sika deer. Spirochetes were detected in the midgut of the ticks by the indirect peroxidase-conjugated antibody staining method and by dark-field microscopy after cultivation. By the reactive pattern of monoclonal antibodies, isolates were considered to belong to Borrelia garinii or B. japonica. In an antibody test, the percentage of seropositive deer was 69.0%. Most of the adult sika deer were positive for antibodies to the spirochetes. There are significant age-dependency in antibody level and seropositive rate. The surveillance of deer should be valuable in monitoring the transmission risk of B. burgdorferi sensu lato in nature.

Age Factors↗
PubMed1996

Immunochemical characteristics and localization on cells of protective antigen (PAg) prepared from Leptospira interrogans serovar lai.

Immuno-electron microscopic methods revealed that the protective antigen (PAg) of Leptospira interrogans serovar lai exists on the outer envelope sheathing the leptospiral cell body. PAg lost its protective activity after treatment by hydrolysis with 2 M formic acid at 100 C for 2 hr, or oxidation with periodate at 4 C for 40 hr. The antigenic oligosaccharide fraction was further purified from the hydrolyzed PAg by immunoaffinity column coupled with protective monoclonal antibody, LW2, and by gel filtration of HPLC. The antigenic oligosaccharide fraction contained two unknown sugars and 4-O-methylmannose (molar ratio 3:5:1). These findings suggested that these sugars are components of an antigenic determinant contributing to the protective immunity against serovar lai infection.

Antigens, Bacterial↗
PubMed1996

Influence of ventricular fibrillation on sympathetic nerve activity under biventricular bypass circulation.

Autonomic nerves play an important role in circulatory control. The characteristics of sympathetic nerve activity (SNA) during artificial circulation, however, are not well understood. In this study, we examined the influence of natural heart beating on the renal SNA (RSNA) using pulsatile 100% biventricular assistance and electrically induced ventricular fibrillation in anesthetized goats, whose heart rate and size are similar to the human heart's. Following induction of the ventricular fibrillation, the pulse-synchronous discharges in the RSNA did not change their periodicity and quantity significantly. It was concluded that the beating of the heart had little influence on the RSNA and was presumably not essential for maintaining nervous control of circulation as long as the circulation was maintained by an artificial heart.

Animals↗
PubMed1996

A volume-controlled liquid ventilator with pressure-limit mode: imperative expiratory control.

Liquid ventilation with perfluorocarbon (PFC) has been considered to offer advantages over gas ventilation to respiratory distress syndrome patients. We developed a volume-controlled liquid ventilator with pressure-limit mode; inspiration is performed mechanically with an actuator under the preset limit of the intratracheal pressure (Paw); expiration is performed by gravity assistance. Oxygenation and CO2 removal of PFC are done with a membrane oxygenator. An endotracheal tube with a Paw monitor line was placed in 5 rabbits weighing 2.7 +/- 0.6 kg, and liquid ventilation was conducted with the condition that the upper and lower limits of Paw were 20 and -20 mm Hg, respectively. The best arterial pH and gas tension were examined. The averaged arterial pH and gas tension were examined. The averaged arterial pH. Pao2, Paco2, and Sao2 were 7.45 mm Hg, 369 mm Hg, 46.2 mm Hg, and 100% at the best values, respectively. Ventilatory conditions at the best values were as follows: ventilation rates, tidal volume peak Paw, average Paw, and trough Paw were 5-15 (11 +/- 4) times/min, 13.3-17.3 (15.6 +/- 1.4) ml/kg, 5-18 (12 +/- 5) mm Hg, -7-4 (-1 +/- 4) mm Hg, and -20(-)-6 (-13 +/- 5) mm Hg, respectively. Pressure-limit control of the system worked well, but in the initial 3 animals, fluorothrax, that is the leakage of PFC into thoracic cavity, was recognized at the Paw from 20 to 25 mm Hg after the upper pressure limit was raised to 25 mm Hg to improve Paco2. The fluorothrax seemed to be caused by excess end-expiratory residual volume. An expiratory control mechanism appears to be imperative for further improvement of our liquid ventilator.

Animals↗
PubMed1996

[A case of Lyme borreliosis which was suspected to be caused by Borrelia japonica infection in Shizuoka, Japan].

We report a case of Lyme borreliosis (Lyme disease) found in Shizuoka City, Japan which was suspected to be caused by Borrelia japonica infection. A 8-year-old female was bitten on her head by a tick at a camping ground, near Tamagawa, Shizuoka. The tick was removed by the patient and was discarded before species identification. After one week, lymph node swelling with tenderness developed on her left neck. She consulted a local pediatrician and was suspected to have upper respiratory infection. As oral antibiotic, cefaclor was not effective, the patient was referred to us. The patient's serum showed positive reaction with Lyme Borreliosis ELISA kit (Dakopatts, Denmark) using Borrelia burgdorferi flagellum as antigen. The serum also gave positive results with home-made ELISA to B. japonica strain IKA2, which was isolated from I. ovatus, but not with other borrelial strain isolated in the United States, Europe, and from I. persulcatus and wild rodent in Japan. In western blotting, the serum reacted with flagellin and outer surface protein A (OspA) of B. japonica. We diagnosed her as Lyme disease and got a successful result with oral penicillin, sultamicillin. From a result of our field tick survey, we have not collected I. persulcatus around the area where the patient had a tick bite. These findings indicated that Lyme disease was caused by B. japonica infection with I. ovatus bite.

Antibodies, Bacterial↗
PubMed1996

Prevalence of Lyme disease spirochetes in Ixodes persulcatus and wild rodents in far eastern Russia.

Borrelia spirochetes were isolated from the adult ixodid tick (Ixodes persulcatus) in three areas of far eastern Russia, namely, Khabarovsk, Vladivostok, and Yuzhno-Sakhalinsk. Borrelia infective rates of ticks in those areas were 24.5, 41.4, and 25.1%, respectively (total rate was 26.6%). Spirochetes were also isolated from the tissues of small mammals captured at Khabarovsk (infective rate was 20.8%). Samples were classified by rRNA gene restriction fragment length polymorphism (RFLP) analysis. The isolated spirochetes from ticks were classified mainly RFLP ribotype group IV (B. garinii), followed by groups II (B. garinii), III (B. afzelii), and V (B. garinii), showing that B. garinii is a dominant species among them. Both B. garinii and B. afzelii were also found in rodents, and multiple infections with those two species were observed in some rodents. B. burgdorferi sensu stricto (group I) was not isolated from either ticks or rodents.

Animals↗
PubMed1996

Sympathetic nerve activities in pulsatile and nonpulsatile systemic circulation in anesthetized goats.

To investigate the effects of pulsatile and nonpulsatile systemic circulation on the sympathetic nerve activity, using a left heart bypass technique, we converted systemic circulation between the pulsatile and the nonpulsatile mode in anesthetized goats and analyzed differences in periodicity and quantity of renal nerve activity (RNA). After pulsatile systemic circulation was converted to the nonpulsatile mode, the mean RNA was significantly increased from 10.7 +/- 3.6 to 13.1 +/- 3.4 microV and periodic discharges of RNA, which corresponded to pulse-related rhythm during pulsatile circulation, became obscure, whereas an 8-12 cycle/s rhythm, which was distinguished and accounted for 30 +/- 9% of total intervals during pulsatile circulation, became dominant (48 +/- 11%). These results clarified a significant increase in mean RNA after depulsation of the systemic circulation and indicated that the cardiac-related rhythm in RNA could be produced by periodic inputs from arterial baroceptors alone, whereas the 8-12 cycle/s rhythm that was present regardless of the type of circulation was the fundamental rhythm originating from the vasomotor center.

Animals↗
PubMed1996

Protective activity of rabbit polyclonal anti-idiotype antibody against Leptospira interrogans infection in hamsters.

We prepared an anti-idiotype (Id) antibody against leptospirosis. Serum from rabbit immunized with monoclonal antibody (MAb) LW2, which reacted to the main protective antigen prepared from Leptospira interrogans serovar lai, inhibited agglutination of the organism by MAb LW2. The immune rabbit serum was applied to a column coupled with normal mouse IgG as a ligand (first column), and the unbound fraction eluted was applied to a column coupled with MAb LW2 as a ligand (second column). The bound fraction (anti-Id antibody) eluted from the second column inhibited the binding of MAb LW2 to sonicated leptospiral cells in ELISA. Mice produced antibodies against Leptospira by intraperitoneal immunization with the anti-Id antibody at doses of 2 mu g/mouse or more. Hamsters were protected by immunization with the anti-Id antibody at doses of 2 and 20 mu g/hamster from the lethal infection of Leptospira. This is the first report concerning the use of an anti-Id antibody against leptospirosis.

Agglutination↗
PubMed1996

Characterization of Borrelia spp. isolated from the tick, Ixodes tanuki and small rodents in Japan.

Spirochetes were isolated from the tick, Ixodes tanuki, as well as wood mice (Apodemus speciosus) and voles (Clethrionomys rufocanus and Eothenomys smithii), caught in Fukui, Tokushima, and Hokkaido, Japan, from 1991 to 1993. Spirochetes were characterized on the basis of protein profiles, reactivities with monoclonal antibodies (mAbs), Outer surface protein A gene (ospA) and Outer surface protein B gene (ospB) amplification analysis, rRNA gene and flagellin gene restriction fragment length polymorphism (RFLP) analysis, and DNA homology values. Protein profiles of all isolates were homologous and reacted with mAb to OspA, OspB, OspC, flagellin, and heat shock protein 60. The primer reactivity to ospA and ospB were different from those of Borrelia burgdorferi sensu stricto, B. afzelii, B. japonica, and B. garinii. Based on the DNA/DNA homology value and RFLP analysis of rRNA and flagellin gene, these Borrelia sp. isolates are a new group of B. burgdorferi sensu lato. The isolates from ticks and the host rodents were identical in these assays. We propose that these Borrelia sp. are adapted to I. tanuki and are maintained in these field rodents.

Animals↗
PubMed1996

Development of a centrifugal pump with improved antithrombogenicity and hemolytic property for chronic circulatory support.

A centrifugal pump with a unique structure has been developed for chronic support. The pump is driven by a magnetic coupling and has no rotating shaft, no seal around the rotating part, and a balancing hole at the center of the impeller and the thrust bearing. The pump was improved in stepwise fashion to realize good antithrombogenicity and low hemolysis. The first pump, the National Cardiovascular Center (NCVC)-0, had an impeller with 4 rectangular and curved vanes; 6 triangularly shaped curved vanes were employed in the second model, the NCVC-1, to reduce trauma to the blood. In the third design, the NCVC-2, the central hole was enlarged, and the thrust bearing shoulder was rounded so that blood washing was enhanced around the impeller; stream lines also were smoothed for improved antithrombogenicity. The hemolytic property of the device was evaluated in vitro with heparinized fresh goat blood; hemolysis indexes of the NCVC-0, -1, and -2 were 0.05, 0.01, and 0.006 g per 100 L, respectively. Antithrombogenicity of the pumps was examined in animal experiments as a left heart bypass device in goals weighing 52-75 kg. Six NCVC-0 pumps were driven for 14 to 33 (22.0 +/- 7.6) days in goats receiving the antiplatelet drug cilostazol orally. Four NCVC-1 pumps ran for 1 to 80 (28.5 +/- 30.6) days with the same drug regimen in 2 cases and with no anticoagulation therapy in 2 cases. After 3 preliminary 1-week tests of NCVC-2 pumps in animals, the pump was installed in 3 goats; 2 pumps were still running on the 182nd and 58th pumping day. Intracorporeal implantation also was attempted successfully. The results indicate that this pump has promising features for chronic support although longer term and additional evaluations are necessary.

Animals↗
PubMed1996

Tandem operation of a turbo blood pump (BP-80--type centrifugal pump) to reduce hemolysis.

When operating turbo blood pumps in tandem, the strength of shear stress is reduced, but the exposure duration of the stress is increased. The purpose of this experiment was to compare the degree of contribution of these two factors on hemolysis as well as to evaluate the effectiveness of the tandem operation of turbo blood pumps. Tandem operation of two Bio-pumps (BP-80; Medtronics Bio-medicus, Inc., Eden Prairie, Minnesota, U.S.A.) were compared with single operation of a BP-80 in in vitro hemolysis tests in three different driving conditions, that is, pumping heads of 200, 350, and 500 mm Hg under a pump flow rate of 5 L/min. The Allen's hemolytic indexes of the tandem operation at pumping heads of 200, 350, and 500 mm Hg were 0.014, 0.020, and 0.080 mg/dl, respectively. The hemolytic indexes of the single operation at pumping heads of 200, 35, and 500 mm Hg were 0.014, 0.056, and 0.12 mg/dl, respectively. These results indicate that tandem operation is a useful method of reducing hemolysis with the BP-80 under high pumping heads and that the effect on hemolysis of exposure to higher shear stresses may be more serious than that of longer durations of exposure to shear stress in turbo blood pumps.

Animals↗
PubMed1996

[Hypoplasia of the left internal carotid artery associated with anterior communicating aneurysm, intercarotid anastomosis and left rete carotidis].

Hypoplasia of the internal carotid artery with cerebral aneurysm is extremely rare. The authors report a case of hypoplasia of the left internal carotid artery associated with anterior communicating aneurysm, intercarotid anastomosis and left rete carotidis. A 45-year-old man was admitted to Minamata Municipal Hospital because of severe headache and disturbance of consciousness. CT scan showed subarachnoid hemorrhage with intracerebral hematoma. Right carotid angiogram showed the anterior communicating aneurysm arising from the right A1-A2 corner and intercarotid anastomosis on the cavernous portion. The distal part from the C4 portion of the left internal carotid artery was revealed through these anastomotic vessels. Left carotid angiogram showed hypoplasia of the left internal carotid artery and unusual tortuous collateral vessels arising from the left internal maxillary artery, ascending pharyngeal artery and its branches to the left internal carotid artery. These collateral vessels are called "rete carotidis" or "rete mirabile caroticum." Both the intercarotid anastomosis and rete carotidis are unusual anastomotic vessels and are considered not to appear during normal development of the cranial circulation in humans. CT scan with skull base bone target image showed hypoplasia of the left carotid canal. In this case, the change in cranial circulation due to hypoplasia of the internal carotid artery was considered one of the main factors in the development of these unusual anastomotic vessels and cerebral aneurysm.

Carotid Arteries↗
PubMed1996

[A case of alveolar soft-part sarcoma with cerebral metastases].

A case of alveolar soft-part sarcoma with multiple cerebral metastases in addition to multiple lung and bone metastases is reported. This is a rare tumor which thus far has only been recognized as a malignant soft tissue tumor with great uncertainty. A 24-year-old man with a chief complaint of left frontal headache was admitted to our unit on September 26, 1994. A tumor of the right forearm had been surgically removed 9 years previously, and surgery had been followed by two courses of chemotherapy with vincristine, cyclophosphamide and actinomycin-D and subsequent irradiation for bone metastasis. The chemotherapy, however, did not have any clear effect. Neurological examination at the time revealed only bilateral papilledema, but CT and MRI scan of the brain showed a round mass in the left occipital lobe with homogeneous enhancement and another small mass was detected in the right occipital lobe. A cerebral angiogram showed a vascular tumor. The preoperative diagnosis was multiple cerebral metastases of alveolar soft part sarcoma. Left occipital craniotomy was performed on October 12, 1994, and the tumor was completely removed by lobectomy. Specimens of the tumor showed typical histological features of alveolar soft-part sarcoma. Whole-brain radiotherapy was administered postoperatively, and the patient is well neurologically without right homonymous hemianopsia. The clinical features of alveolar soft-part sarcoma are discussed. Only a few cases have been reported in the literature, but the most frequent site of the primary lesion has been the lower extremities, and cerebral metastasis has not been rare. All efforts should be focused on discovering this tumor in the early stage because surgical removal can yield good results, and radiotherapy is thought to be effective in terms of patient "quality of life".

Adult↗