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Biomedical subjects

T Minami

Publications and source records attributed to T Minami.

At least 271 records · Page 15Linked to original sources

Thresholds for decrease in intracellular pH and increase in blood lactate during progressive exercise: 31P-MRS study.

The purpose of this study was to compare the intramuscular and the intravascular events in relation to energy metabolism during progressive arm exercise. Twelve healthy untrained Japanese males participated in this study as subjects. They performed wrist flexion in a ramp incremental load of 0.14 W/min until exhaustion. 31P-MR spectra were obtained from wrist flexor muscle before and throughout the exercise. Venous blood was also sampled from antecubital vein with one minute interval during the exercise, and a change in plasma lactate concentration (La) was observed. Intracellular pH (pH) was calculated from a chemical shift between phosphocreatine (PCr) and inorganic phosphate (Pi) of the 31P-MR spectra. Change in pH showed a threshold behavior during exercise. Threshold points at decline in pH (pHT), increase in Pi/PCr (PT), and increase in La (LT) were determined by piecewise linear regression analysis of minutes-by-minutes data. Mean values of pHT, PT and LT were 43.0, 42.5, and 24.8% of maximal work rate, respectively. LT was significantly smaller than pHT and PT. This result suggests that lactic acidosis has already existed when pH is kept at resting level, and pHT reflects the capacity of remaining intracellular biochemical homeostasis, which might be one of the physiological indices of muscle fatigue.

Adult↗

Effects of various inflammatory mediators on eustachian tube patency.

The effects of several inflammatory mediators on the patency of the Eustachian tube were evaluated in 15 mongrel dogs. Histamine, leukotriene C4(LTC4) and D4(LTD4), and platelet activating factor (PAF) were perfused through the Eustachian tube of anesthetized dogs at concentrations detected in human middle ear effusion of patients with otitis media. The patency of the Eustachian tube was then evaluated by perfusion pressure and opening pressure. Histamine at concentrations of more than 10(-5) M caused increased tubal resistance and opening pressure rapidly. LTC4 and LTD4 caused a rapid increase of tubal resistance and opening pressure at far lower concentrations, i.e. 10(-12) M. Doses of PAF over 10(-9) M may cause an increase in the opening pressure. These results indicate that various inflammatory mediators are capable of affecting the Eustachian tube function.

Animals↗

[A clinical trial of arterial infusion chemotherapy combined with calcium antagonist for liver metastases].

Calcium antagonists enhance the effect of some anticancer agents, but only limited administration is feasible because of their cardiovascular action. We noticed their inactivation in liver and investigated the possibility of combined intra-arterial chemotherapy. Both verapamil (0.5 mg/kg) and adriamycin were infused into hepatic artery in 8 patients with liver metastases. The serum concentration of verapamil in hepatic vein was 182 +/- 178 ng/ml at maximum. Blood pressures, heart rates and electrocardiograms were quite stable. Tumors became nearly necrotic after the therapy in three hepatectomized cases. A more appropriate dose, infusion method and prognosis should be studied in future.

Adult↗

[A case of stage IVb ovarian carcinoma successfully treated with intra-arterial infusion chemotherapy using implantable reservoir system].

A patient with liver metastasis from ovarian cancer was treated by intra-arterial infusion chemotherapy (well differentiated adenocarcinoma--CDDP 50 mg/body, ADR 30 mg/body, CPA 500 mg/body (iv)). After the chemotherapy, the metastatic tumor appeared remarkably smaller and could be resected successfully at the second reduction surgery. This patient is active 30 months after the first appearance and enjoying a favorable quality of life.

Adenocarcinoma, Papillary↗

[Mechanisms of hypoalgesia induced by intracisternal administration of PGD2 or PGE2].

Intracisternal administration of PGD2 (5 micrograms) and PGE2 (5 micrograms) induced hypoalgesia in conscious mice in acetic acid writhing test. The hypoalgesia caused by PGD2 was blocked by para-chlorophenylalanine, cyproheptadine or phenoxybenzamine. However, the suppression of writhing responses caused by PGE2 was not blocked at all by these drugs. These results indicate that the actions of PGD2 depend upon serotonin and norepinephrine systems.

Animals↗

Moebius syndrome with central hypoventilation and brainstem calcification: a case report.

Moebius syndrome (MS) is described in an infant with central hypoventilation and brainstem calcification. The patient had limb defects and bilateral paralysis of the 6th, 7th, 9th, 10th, and 12th cranial nerves. Mechanical ventilation was continued from birth because of shallow spontaneous respiration. Computed tomography revealed brainstem atrophy and four small calcifications restricted to the dorsal portion of the pons and medulla. Prenatal brainstem injury such as ischaemia may have caused MS and central hypoventilation.

Abducens Nerve↗

Gastropericardial and gastrobrachiocephalic vein fistulae caused by penetrating ulcers in a gastric pedicle following esophageal cancer resection: a case report.

The gastric pedicle is commonly used for reconstruction following resection of esophageal cancer. However, we recently experienced a case in which two gastric tube ulcers occurred three months postoperatively; one penetrating into the pericardial cavity and the other into the left brachiocephalic vein. To our knowledge, no other such a case has ever been reported and we therefore report and discuss its etiology and management.

Aged↗

Esophageal reconstruction using microvascular anastomosis to the thoracoacromial artery and cephalic vein.

For reconstruction of the pharynx and cervical esophagus following pharyngolaryngoesophagectomy, free gut transfer revascularized to such cervical vessels as the cervical transverse artery and external jugular vein is commonly performed. However, for reconstruction of the esophagus in the cervicothoracic junction or anterior to the chest wall, using the cervical vessels has more disadvantages than using the vessels in the chest wall. Thus, we developed a method of using the throracoacromial artery and cephalic vein for vascular anastomoses of a free jejunal graft and report herein our results in six cases. Three of these cases underwent reconstruction for an esophageal defect anterior to the chest wall, while the other three underwent reconstruction of the thoracic esophagus using a colonic pedicle graft. Satisfactory results were obtained in five of the six cases. Therefore, we recommend the use of the thoracoacromial artery and cephalic vein in vascular anastomoses during a free gut transfer or colonic pedicle graft for reconstruction of the esophagus anterior to the chest wall.

Anastomosis, Surgical↗

Upper esophagectomy with pharyngolaryngectomy for esophageal carcinoma at the cervicothoracic junction.

The choice remains controversial as to which surgical procedure should be selected for carcinomas situated in the esophagus at the cervicothoracic junction involving the trachea. After mediastinal tracheostomy associated with pharyngolaryngoesophagectomy and thoracic esophagectomy, numerous reports have previously described severe postoperative complications, such as tracheal necrosis and rupture of the great vessels in the neck. To prevent such complications, we have developed the procedure called "upper esophagectomy" followed by a free jejunal graft and mediastinal tracheostomy through either manuburectomy or upper median sternotomy. We have established that this procedure maintains the vascular networks between the trachea and the esophagus, avoids an occurrence of tracheal necrosis or great vessel bleeding postoperatively, and obtains an improved prognosis in the surgical treatment of esophageal carcinoma at the cervicothoracic junction.

Aged↗

Dynamics of faecal egg counts in rabbits experimentally infected with Strongyloides papillosus.

An experiment using rabbits was carried out to determine basic data to maintain the calf strain of Strongyloides papillosus (SPL). Rabbits treated with four different numbers of doses of dexamethasone were exposed to 50,000 or about 100,000 infective larvae of SPL (Himeji strain, 1988). As a result, faecal egg output was valid in individual rabbits, regardless of dexamethasone administration. Eggs appeared in the faeces 9 or 10 days after exposure, and increased to as much as 20,000-573,000 eggs per gram (EPG). Thirteen of 18 rabbits died (72%) 12-29 days after infection. Five surviving rabbits discharged eggs in their faeces for more than 1 month; however, the EPG value of these cases on the last day was comparatively low.

Animals↗

Prognostic value of early somatosensory evoked potentials for adverse outcome in full-term infants with birth asphyxia.

SEPs were examined during the first weeks of life in 34 infants with mild to severe birth asphyxia, in an attempt to provide a more accurate prediction of neurodevelopmental outcome. Normal, delayed and absent responses were compared with the infant's acute clinical condition, imaging findings using different imaging techniques and neurodevelopmental outcome. All infants with normal SEPs were normal at follow-up. All but two of the infants with a delayed or absent response died or suffered from severe neurological sequelae. A delayed or absent N1 latency carried a risk for death or severe handicap of 71 and 100%, respectively, compared with 25 and 89% for moderate or severe encephalopathy on neurological assessment, and 29 and 85% for moderate or severe changes seen using different imaging techniques. SEPs may provide useful additional information when assessing the infant with birth asphyxia.

Asphyxia Neonatorum↗

The late waves of brainstem auditory evoked potentials in children with cerebrovascular diseases.

We examined brainstem auditory evoked potentials (BAEPs) in 28 children with cerebrovascular diseases and 38 normal control subjects and investigated the neuroanatomic correlations of the late waves (VI and VII) of the BAEPs. The patients included 19 patients with moyamoya disease and 9 with other cerebrovascular accidents. Wave VI was more consistently seen (only missing in 2 cases, 5%-2 ears, 3%) than wave VII (missing in 26 cases, 68%-40 ears, 53%) in the control group. Absent, depressed or prolonged wave VI correlated well with cerebral lesions involving internal capsule and basal ganglia, while wave VII had a less significant correlation with any cerebral lesions in children with cerebrovascular diseases.

Adolescent↗

Oral passive immunization against dental caries in rats by use of hen egg yolk antibodies specific for cell-associated glucosyltransferase of Streptococcus mutans.

The effect of polyclonal egg yolk immunoglobulin G antibodies (yIgG) raised against whole cells, cell-free (CF) glucosyltransferase (GTase), or cell-associated (CA) GTase of serotype c Streptococcus mutans was examined in terms of in vitro inhibition of virulence-related factors of S. mutans and protection of S. mutans-infected rats against the development of dental caries. Hens (18 weeks old) were immunized with formalin-treated whole cells, purified CF-GTase, or CA-GTase together with Freund's complete adjuvant. In addition, yIgG to surface protein antigen was used in some in vitro experiments for comparison with other antibodies. yIgG was purified by ammonium sulfate precipitation followed by DEAE-Sephacel column chromatography or fractional precipitation with ethanol. Purified yIgG was found to be a 220-kDa protein, which was dissociated into heavy and light chains upon addition of 2-mercaptoethanol. yIgG to whole cells and surface protein antigen gave a heavy aggregation of S. mutans organisms, while yIgG to CF- and CA-GTase specifically inhibited the enzymatic activity of the respective GTase. yIgG to CA-GTase and whole cells was found to clearly suppress the adherence of S. mutans cells to a glass surface. Specific-pathogen-free Sprague-Dawley rats that had been infected heavily and repeatedly with S. mutans and fed diet no. 2000 developed severe dental caries, while rats fed diet 2000 containing greater than or equal to 0.1% yIgG to CA-GTase showed a statistically significant reduction in dental plaque accumulation and caries development. Administration of yIgG to CF-GTase and whole cells failed to protect against caries. These results clearly suggest that yIgG to S. mutants CA-GTase specifically inhibited a virulence factor of this organism, i.e., insoluble glucan-synthesizing CA-GTase, resulting in a significant reduction in the development of dental caries.

Administration, Oral↗

Trehalulose does not induce dental caries in rats infected with mutans streptococci.

The effects of trehalulose, a structural isomer of sucrose, and a syrup (TP syrup) rich in trehalulose and palatinose on caries development were examined in specific pathogen-free Sprague-Dawley rats. Streptococcus mutans MT8148R and Streptococcus sobrinus 6715 fermented the syrup which resulted in acid production, while both strains were found not to utilize trehalulose. Furthermore, trehalulose did not serve as a substrate for glucosyltransferases of these mutans streptococci to synthesize water-insoluble glucan, and it inhibited the sucrose-dependent adherence of mutans streptococci to a glass surface. Although trehalulose induced no significant dental caries in specific pathogen-free rats infected with either MT8148R or 6715, TP syrup was found to induce significant but low dental caries. Furthermore, replacement of the dietary sucrose content with trehalulose resulted in a significant reduction of caries development in rats infected with strain 6715.

Animals↗

Analysis of protein compositions and surface protein epitopes of Anaplasma centrale and Anaplasma marginale.

Protein composition was compared and epitopes were analyzed among the isolates of Anaplasma centrale and A. marginale by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting using bovine antisera and monoclonal antibodies, and enzyme-linked immunosorbent assay. Common and unique proteins were found among the isolates. All isolates tested had a major surface protein with an apparent molecular weight of 38 to 40 kilodalton which had slight molecular size variations between species. This protein was also a dominant immunogen to the host. At least two species-common epitopes, one of which might contain carbohydrate(s), were present on the major surface protein. One species-specific epitope was identified on the major surface protein of A. marginale isolates.

Anaplasma↗