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Biomedical subjects

T Mizuta

Publications and source records attributed to T Mizuta.

At least 55 records · Page 3Linked to original sources
PubMed1995

Multichannel detection of magnetic compound action fields with stimulation of the index and little fingers.

Magnetic compound action fields (CAFs) over the right arm were measured from 63 sensor positions with two 7-channel SQUID gradiometer systems following electrical stimulation of the index and little fingers as well as the ring finger separately. The wave forms of the CAFs were primarily biphasic, corresponding to the depolarization and repolarization currents of the stimulated nerves. Maximum amplitudes of the CAFs were 60-140 fT for the index finger stimulation and 40-90 fT for the little finger stimulation. The field mapping of the CAFs revealed a propagating quadrupolar pattern with different distributions for the index and little fingers. The results agree with the anatomical location of the median and ulnar nerves for the index and little finger stimulation respectively. The isofield maps, due to ring finger stimulation, showed complex patterns as a result of simultaneous activation of the median and ulnar nerves. By comparing the amplitudes of the maxima of the CAFs due to index finger stimulation with those after median nerve stimulation at the wrist, the numerical ratios of the constituent digital nerve fibers for the index finger within the median nerve at the wrist were estimated. The ratios of 0.14-0.41 (mean 0.27), determined with measurement of the CAFs, are fairly consistent with those calculated from the reported histological data.

Adult↗
PubMed1995

Amino acids and peptides. XXVI. Laminin-related peptide poly(ethylene glycol) hybrids and their inhibitory effect on experimental metastasis.

Laminin-related peptide poly(ethylene glycol) hybrid, Tyr-Ile-Gly-Ser-Arg-aminopoly(ethylene glycol) was prepared by the solution method and carboxylated poly(ethylene glycol)-Tyr-Ile-Gly-Ser-Arg was prepared by the solid phase method. Their inhibitory effects on experimental tumor metastasis were examined in mice. The inhibitory effect of Tyr-Ile-Gly-Ser-Arg was significantly potentiated by hybrid formation with poly(ethylene glycol) either at amino- or carboxyl terminals of the peptide. Of the hybrids, Tyr-Ile-Gly-Ser-Arg-amino(polyethylene glycol) #6000 hybrid exhibited about 10 times more potent anti-metastatic effect than the peptide itself. The inhibitory effect of a mixture of the carboxylated poly(ethylene glycol) hybrid and Arg-Gly-Asp-aminopoly(ethylene glycol) hybrid also exhibited an inhibitory effect.

Amino Acid Sequence↗
PubMed1995

Localized myxedema, associated with increased serum hyaluronic acid, and response to steroid pulse therapy.

A 66-year-old man presented with Graves' disease and widespread localized myxedema. Extensive lesions were present on the legs, feet, hands, and face. TSH receptor antibody (TBII) was markedly positive and the serum hyaluronic acid level was very high. Intravenous steroid pulse therapy was followed by oral therapy with gradual tapering. This regimen markedly improved the skin lesions and resulted in a decrease of the serum hyaluronic acid level. The findings suggest that steroid pulse therapy is effective for the treatment of extensive localized myxedema. In addition, the serum hyaluronic acid level may be a useful parameter for the follow-up of patients with this condition.

Administration, Oral↗
PubMed1995

Acute or chronic exercise alters angiotensin II-induced contraction of rat aorta.

Chronic exercise substantially shifted the dose-response curve for angiotensin II (ANG II)-induced contractions to the right with increases in the EC50 value in both endothelium-intact and endothelium-denuded aortae. An acute endurance exercise also caused a 3-fold increase in the EC50 value in both endothelium-intact and endothelium-denuded aortae from sedentary control rats. Whereas, no substantial increase in the EC50 value was observed in trained rats after an acute endurance exercise. Thus, chronic exercise attenuates ANG II receptor-mediated contraction of rat aortae. An acute exercise also caused the reduced responses to ANG II in sedentary control rats but not in chronically exercise-trained rats.

Angiotensin II↗
PubMed1995

[The role of thoracotomy for malignant mediastinal tumors (MMT)-- survey of consecutive 223 patients].

To elucidate the role of surgery for MMT, 214 patients during past 34 years were historically divided into the early (1960-1971, n = 80), intermediate (1972-1981, n = 79) and late series (1982-1993, n = 64). The thoracotomy rate for MMT, the rate of thoracotomy after preoperative diagnosis was done, and the number of postoperative survivors were significantly higher in the late series, compared with the early series. The intermediate series located between the early and late series. Nine patients in the late series undergoing chemo-radiation therapies obtained a good result after complete resection of the residual tissue. We conclude that surgical treatment of MMT should be based on accurate preoperative diagnosis and a distinct role for multidisciplinary treatment, especially regarding malignant thymoma, malignant lymphoma and malignant germ cell tumor.

Adolescent↗
PubMed1995

Serum anti-Helicobacter pylori antibodies and gastritis.

We investigated the relationship between the severity of Helicobacter pylori-associated gastritis and serum anti-H. pylori antibodies. A total of 158 consecutive patients underwent upper gastroduodenal endoscopy. At the time of endoscopy, three biopsy specimens were taken from the antrum and the body of the stomach for culture of H. pylori, CLO test, and histology. Specimens with a negative rapid urease test and no organisms found by culture were judged to be H. pylori-negative. The GAP test used for the antibody measurement is a kit designed to measure serum IgG, IgA, and IgM antibodies. The severity of gastritis was classified according to the Sydney System. The sensitivity and specificity of the IgG antibody measurement kit was 98.3 and 71.4%, respectively. The sensitivity and specificity of the IgM antibody measurement kit was 14.3 and 60.8%, respectively. The sensitivity and specificity of the IgA antibody measurement kit was 45.1 and 100%, respectively. Serum anti-H. pylori IgG antibody titers were correlated significantly with the severity of inflammation in both the antrum and body. Significant associations were found between serum anti-H. pylori IgG and IgA antibody titers and the development of atrophic gastritis. These results suggest that measurement of serum anti-H. pylori antibody titers is useful in the diagnosis of H. pylori infection and severity of gastritis.

Antibodies, Anti-Idiotypic↗
PubMed1994

Visualization of a moving quadrupole with magnetic measurements of peripheral nerve action fields.

Magnetic compound action fields (CAFs) over the right arm were measured from 63 sensor positions with two 7-channel SQUID gradiometer systems following electrical stimulation of the median nerve at the wrist. The field mapping of the CAFs revealed a propagating quadrupolar pattern with the leading depolarization and trailing repolarization fronts. The average distribution of the CAFs in the longitudinal direction was 9.0 cm in length for the depolarization field and 7.3 cm for the repolarization field in good agreement with a theoretical prediction based on the duration (3 msec) of the CAFs and the conduction velocity of the nerve (50 m/sec). The distance between the maxima of the depolarization front and the minima of the repolarization front was 6.3 cm. This spatial separation of the leading and trailing dipole locations suggests in part mutual cancellation of the fields with opposite polarity at or near the depolarized segment of nerve fibers.

Adult↗
PubMed1994

Human laminin M chain: epitope analysis of its monoclonal antibodies by immunoscreening of cDNA clones and tissue expression.

We have produced four monoclonal antibodies (mAbs) against human placenta laminin purified by immunoaffinity chromatography. Three clones, 2D9, 3DM, and 4F1, recognized 320 kDa (M) chain of the laminin and the other one, 3DB, recognized B2 chain. One cDNA clone (HLM-1, 3.5 kb) was immunoscreened from human placenta cDNA library using 2D9, and three further overlapping cDNA clones (HLM-2, HLM-3, and HLM-4) covering 2.0 kb were isolated. Nucleotide sequencing and fusion protein analysis demonstrated that the amino acid sequence deduced from HLM-1 coincided with that of the G-domain of human merosin chain, and HLM-2, HLM-3, and HLM-4 encoded the long-arm and EGF-like domain of M chain. The binding regions of 2D9 and 3DM to M chain were defined as homologous repeating sequences of G2-G3 region of G-domain and the carboxy-terminal region of the long-arm, respectively. The extents of identity of amino acid sequences of the long-arm and EGF-like domains between human M chain and A chain were about 37% and 52%, respectively, which were lower than between mouse and human A chains. Northern blot analysis revealed that M chain mRNA, 8.6 kb, was highly expressed in heart and placenta, but less highly expressed in skeletal muscle, brain, and lung. Immunostaining showed selective distributions of M chain in nerve fibers in the dermis and mesangial matrix of the kidney, and B2 chain in subepidermal and kidney glomerular basement membranes.

Amino Acid Sequence↗
PubMed1994

Amino acids and peptides. XXI. Laminin-related peptide analogs including poly(ethylene glycol) hybrids and their inhibitory effect on experimental metastasis.

Laminin-related peptides, Tyr-Ile-Gly-Ser-Arg analogs, were prepared and their inhibitory effects on experimental metastasis were examined. Of the amino acids in the Tyr-Ile-Gly-Ser-Arg sequence, L-Arg was very important and Ile was not essential for the inhibitory effect. To obtain a potent inhibitor of metastasis, hybrids of Tyr-Ile-Gly-Ser-Arg-Gly and 2 types of poly(ethylene glycol) were prepared. The inhibitory effects of the hybrids were more potent than that of Tyr-Ile-Gly-Ser-Arg-Gly.

Amino Acid Sequence↗
PubMed1994

[Successful reconstruction of a skull base fracture with frontal lobe contusion by omental transplantation for recurrent posttraumatic tension pneumocephalus: a case report].

In July 1983, 26 year-old male was admitted to our neurosurgical clinic after severe head injury caused by a car accident. Recovery of consciousness was delayed for months due to bilateral frontal lobe contusions with anterior skull base fractures on both sides. He was first discharged 6 months after surgery for ventriculo-peritoneal shunting. He was readmitted to our department due to an episode of urinary incontinence with gait disturbance 11 months after the accident. CT film of the head revealed the presence of an air shadow at the left frontal base. Utilizing lyophyllized dura mater, the first cranial surgery for closure of cerebrospinal fluid leakage was carried out in July, 1984. Pneumocephalus with meningitis recurred again five years later. Repeated conventional surgery failed including a transsphenoidal and transfrontal sinus approach to treat the recurrent pneumocephalus. In order to close the defect in the skull base, and to obliterate the dead space in the left frontal lobe, vital tissue transplantation was planned. On May 23, 1990, seven years after the accident, the skull base defect was repaired by suturing fascia taken from the temporal muscle. Then the patient's vascularized omentum was utilized as an autograft by micro-surgical technique. A superficial temporal artery and vein, and superficial sylvian vein were used to vascularize the omentum. The patient has been totally free of pneumocephalus for more than three and half years following the radical surgery. Clinical omental transplantation using microsurgical technique for vascularization of cerebral circulation as well as plastic surgery has been reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗