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Biomedical subjects

E Watanabe

Publications and source records attributed to E Watanabe.

At least 19 recordsLinked to original sources
PubMed1992

cDNAs and deduced amino acid sequences of subunits in the binding component of mouse bactericidal factor, Ra-reactive factor: similarity to mannose-binding proteins.

The complement-dependent bactericidal factor, Ra-reactive factor, binds specifically to Ra polysaccharide, which is common to some strains of Gram-negative enterobacteria, and its is a complex of proteins composed of a polysaccharide-binding component and a component that is presumably responsible for the complement activation. The former component consists of two different 28-kDa polypeptides, P28a and P28b. We determined the partial amino acid sequences of P28a and P28b, and the results indicated that these polypeptides were similar to two species of mannose-binding protein, MBP-C and MBP-A (alternative names, liver and serum mannan-binding proteins, respectively), which have been isolated from rat liver and/or serum [Drickamer, K., Dordal, M. S., & Reynolds, L. (1986) J. Biol. Chem. 261, 6878-6887; Oka, S., Itoh, N., Kawasaki, T., & Yamashina, I. (1987) J. Biochem. 101, 135-144]. Thus, we cloned the respective cDNAs, using as probes synthetic oligonucleotides for which the sequences had been deduced from the amino acid sequences of P28a and P28b and of rat MBP cDNAs. The primary structures of P28a and P28b deduced from the cloned cDNAs are homologous to one another. They have three domains, a short NH2-terminal domain, a collagen-like domain, and a domain homologous to regions of some carbohydrate-binding proteins, as has been reported for rat MBPs. Southern and Northern blotting analyses using these cDNAs indicated that the P28a and P28b polypeptides are the products of two unique mouse genes which are expressed in hepatic cells.

Amino Acid Sequence↗
PubMed1992

ATPase activity of SopA, a protein essential for active partitioning of F plasmid.

The sopA, B, C genes of the F plasmid play an essential role in plasmid partitioning during cell division in Escherichia coli. In this paper, the products of the sopA and sopB genes were isolated and their biochemical activities studied. [alpha-32P]ATP was cross-linked to the SopA protein by UV irradiation; this cross-linking was observed only in the presence of magnesium ion, and was competitively inhibited in the presence of non-radioactive ATP, ADP and dATP, but not other NTPs or dNTPs. In contrast, no ATP binding activity was detected for the SopB protein. The SopA protein showed a modest magnesium ion-dependent ATPase activity and this activity was stimulated in the presence of DNA. The ATPase activity in the presence of DNA was further stimulated by addition of the SopB protein. However, the SopB protein alone failed to stimulate the ATPase activity.

Adenosine Triphosphatases↗
PubMed1992

Neosporosis in the aborted fetus and newborn calf.

Protozoal encephalitic lesions were found in four aborted fetuses and one dead newborn calf. The organism was identified as Neospora caninum by immunoperoxidase. The brain lesions were of two forms. One was observed in three fetuses of 5 months gestation and was characterized by multifocal necrosis. The other was found in a 7-month fetus and in a newborn calf, and showed severe infiltration with macrophages and plasma cells containing IgG. This association, between the age of fetus and inflammation, may reflect development of the immune system in bovine fetuses.

Abortion, Veterinary↗
PubMed1991

Biosensor system for continuous flow determination of enzyme activities. II. Simultaneous determination of plural enzyme activities.

A biosensor system for continuous flow determination of plural enzyme activities was prepared from the combination of two pyruvate sensors, a prereactor and a flow cell. This system was applied to the simultaneous determination of lactic dehydrogenase (LDH) and glutamic-pyruvic transaminase (GPT) activities in the same sample. These enzyme activities can be determined by measuring pyruvate produced by the enzyme reactions as follows. The amount of pyruvic acid can also be determined from the amount of oxygen consumed upon oxidation of pyruvic acid by pyruvate oxidase. (Formula: see text). Therefore, both of the detectors for the determination of lactic dehydrogenase and glutamic-pyruvic transaminase activities were prepared from the combination of a pyruvate oxidase membrane and an oxygen electrode. Pyruvate oxidase was covalently immobilized on a membrane prepared from cellulose triacetate. A linear relation was obtained between the output current and LDH or GPT activities in the range of 50 to 3,600 IU l-1 or 6 to 1,000 IU l-1, respectively. Each assay of these enzyme activities was completed within 15 min. The results obtained had a precision of ca. 4%. The sensor was stable for more than 25 days at 5 degrees C.

Alanine Transaminase↗
PubMed1991

Delayed hearing loss after surgery for acoustic neurinomas: clinical and electrophysiological observations.

In a series of 26 patients with medium-sized and large acoustic neurinomas and documented hearing before surgery, 7 patients had preservation of hearing initially after the procedure but then developed delayed hearing loss. The most prominent intraoperative electrophysiological finding in these cases was a gradual deterioration of brain stem auditory evoked potentials (BAEP), especially of Wave V. Four additional patients with a similar gradual intraoperative loss of BAEP and severe postoperative hearing deterioration received vasoactive treatment after surgery (low-molecular weight dextran). In all 4 patients, including 1 patient with documented total deafness after surgery, hearing was preserved. Initial preservation of cochlear nerve function after the removal of an acoustic neurinoma does not guarantee postoperative hearing. Intraoperative BAEP help to identify patients at risk for delayed postoperative hearing loss. The pathophysiological mechanism can be attributed to disturbances of the microcirculation in endoneurial vasa nervorum caused by the mechanical manipulation of the cochlear nerve.

Adult↗
PubMed1991

[Magnetoencephalographic studies on spike foci using a 37-channel biomagnetometer system].

We report the results of a clinical trial of Magnetoencephalography (MEG) on spike foci in patients with epilepsy, which was performed from December 1990 to June 1991 at The University of Tokyo Hospital. Fifty patients with focal epilepsy; 26 primary epilepsy, 24 secondary epilepsy (7 brain tumor, 4 arteriovenous malformation, 4 encephalitis, 3 porencephaly, 2 arachnoid cyst, 1 brain abscess, 1 hemimegaloencephaly, 1 Lance-Adams syndrome, 1 hygroma), and ten normal subjects were enrolled in this study. MEG data were recorded using a 37-channel biomagnetometer system SMI-1001 (BTi Magnes, Biomagnetic Technologies, Inc., San Diego). A simultaneous 19-channel EEG recording with linked-ear reference was also obtained. The overall study was completed safely and none of the normal subjects showed abnormal paroxysmal MEG activity. Two patients showed interictal EEG spikes which would not have been noticed without first noting the presence of corresponding prominent MEG spikes. On the whole, the MEG signal seemed to have a wider frequency bandwidth than EEG. In most cases, the source localization predicted by MEG corresponded well with the EEG findings. The relative accuracy of MEG spike source localization was estimated to be within a cubic centimeter from the cases which showed tightly clustered localization of individual spikes. High-pass filtering reduced interference by superimposed slow wave activity, thereby improving the localization of spike sources. These results demonstrate that 37-channel biomagnetometer system could be a useful tool for analyzing epileptic spike sources.

Adolescent↗
PubMed1991

[The reduction in the local anesthetic dose required for a caudal epidural block in infants and children using a Teflon cannula].

We investigated the spread of mepivacaine mixed with a radio-opaque substance in caudal epidural anesthesia for hernioplasty in 37 patients aged from 3 months to 5 years. All patients were placed in the left lateral position. Conventional caudal epidural anesthesia was performed on one group of patients (Group C) using a 23 gauge needle (25 mm in length). This new method was also performed on another group (Group N) using a 23 gauge Teflon cannula (63 mm in length), which was introduced as close to the S1 segment as possible. The volume for 9 segmental anesthesia (7.0 +/- 2.3 ml) was determined by following Takino's formula: Volume (ml.segmental-1) = 0.067 x [body weight (kg)] + 0.06. The amount was injected from the S1 in Group N patients, and the cephalad spread of the anesthetic reached Th12.8 +/- 0.8 on left side, and L1.1 +/- 0.7 on right side. When the volume for 13 segmental anesthesia (11.5 +/- 2.8 ml) was injected in Group C patients, the cephalad spread of the anesthetic reached Th12.6 +/- 1.2 on the left side, and Th12.5 +/- 1.1 on the right side. In conclusion, we detected no significant difference between Group C and Group N in the cephalad spread of the anesthetic. The required dose of local anesthetic for caudal epidural anesthesia using the Teflon cannula was about two-third the volume of that used for the conventional local anesthetic method.

Anesthesia, Caudal↗
PubMed1990

Cell attachment to and neurite outgrowth on tissue sections of developing, mature and lesioned brain: the role of inhibitory factor(s) in the CNS white matter.

Chick neocortical cells were cultured on cryostat tissue sections of the brain. Cells preferentially attached to the gray matter of adult rat central nervous system (CNS) tissues. In contrast, they attached to any part of the brain when cultured on developing rat or mature frog brain tissues. Transection of fiber bundles at the superior cerebellar peduncle decussation of adult rat, which reportedly causes regeneration of cerebellofugal axons, made nearby white matter permissive to cell attachment. Superimposition of the gray matter of one section onto the white matter of another, converted the former into a nonpermissive substrate for cell attachment, evidence suggesting that preferential cell attachment to the gray matter of adult rat CNS is due to inhibitory factor(s) localized in the white matter. This inhibitory factor appears to be absent in frog brain and developing rat brain. These results taken together suggest possible involvement of this factor in the regulation of axonal elongation in vivo.

Animals↗
PubMed1979

Common leukemia-associated antigen of DBA/2 mouse leukemia detected by tumor rejection and complement-dependent cytotoxicity assays.

A cytotoxic antibody for L1210 leukemia cells was found in the (C57BL/6 x DBA/2)F1 (BDF1) mice immunized with L1210 leukemia cells infected with ts mutant of HVJ (HVJ-pi) and challenged several times with uninfected L1210 leukemia cells. These immune mice fell into two categories; high and low responders regarding the titer of cytotoxic antibody produced. The antigen defined by this cytotoxic antibody was present on leukemia cells originating in DBA/2 mice but not on leukemia induced by passage-A Gross virus or spontaneous mammary tumors. This serological cross-reactivity among L1210, P388, and L5178Y leukemia cells has been substantially confirmed by the observation of cross protection against challenge with DBA/2 leukemia cells in immune BDF1 mice. These findings strongly suggested the presence of a common DBA/2 leukemia-associated antigen different from known cell-surface antigens of murine leukemia. The results obtained in the present work also demonstrated the great efficacy of non-cytopathic, viable HVJ-pi-injected tumor cells as an immunogen for inducing tumor immunity.

Animals↗