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Biomedical subjects

T Ohta

Publications and source records attributed to T Ohta.

At least 847 records · Page 47Linked to original sources
PubMed1993

Endoscopic observation of the syrinx in Chiari malformation--case report.

The cervical syrinx cavity in a 27-year-old male with Chiari 1 malformation was inspected with a flexible small-caliber endoscope during syringo-subarachnoid shunting. A cleft was observed in the midline on the ventral wall of the cavity, from which blood vessels emerged and ran along the wall. Several strands accompanying the blood vessels passed from one wall to another. The endoscope was also used to evaluate whether any obstacles to the passage of a shunt tube were present in the subarachnoid space. Endoscopic observation of the syrinx cavity is helpful in performing the shunt operation.

Adult↗
PubMed1993

Modification of genotoxicity by naturally occurring flavorings and their derivatives.

The number of studies in the research field of antimutagenesis is increasing. The aims of many of these studies are preventing genetic hazards from environmental mutagens and elucidating the process of mutagenesis. Some naturally occurring flavorings such as vanillin, cinnamaldehyde, and coumarin have been reported to inhibit mutagenesis induced by mutagens in bacterial and mammalian cells. These flavorings are considered to act as antimutagens by modifying DNA replication and/or DNA repair systems after cellular DNA was damaged by mutagens. A factor that suppresses mutagenicity in a given situation, however, sometimes exerts enhancing effects when the endpoints investigated or the test conditions used are varied. This makes the evaluation of antimutagenic factors complicated. Different modifying effects of the above-mentioned flavorings observed in various test systems for genotoxicity are discussed, based on their proposed mechanisms.

Animals↗
PubMed1993

[Relation of habitual exercise to basal metabolic rate and energy expenditure during exercise in older people].

The relation between habitual exercise and the basal metabolic rate, energy expenditure during exercise (lactic threshold and maximal oxygen uptake) was examined in 291 older people. Metabolic rate was highest in old players of gatebowl (a form of croquet) (male; 23.3 +/- 2.3, female; 22.7 +/- 3.0 kcal/kg/day), higher in old untrained people (male; 21.9 +/- 2.5, female; 20.8 +/- 2.4 kcal/kg/day), and lower in old people in a home for the aged (male; 20.6 +/- 3.5, female; 20.8 +/- 3.7 kcal/kg/day). Energy expenditure while walking at a speed of less than 100 m/min was similar in trained and untrained old people aged 60-69 years. However, lactic threshold was higher in trained (30.2 +/- 4.8 ml/kg/min) than in untrained (20.9 +/- 2.8 ml/kg/min) females aged 60-69 years. Maximal oxygen uptake was higher in trained (male; 50.4 +/- 4.1, female; 36.6 +/- 3.9) than in untrained (male; 30.9 +/- 3.7, female; 26.8 +/- 2.8) old people aged 60-69 years. It was suggested that a higher basal metabolic rate, lactic threshold and maximal oxygen uptake resulted in higher daily physical activity and larger daily energy consumption in trained old people.

Aged↗
PubMed1993

A new brain retractor. Technical note.

A new brain retractor is presented that can be applied easily and safely from any direction. It is particularly useful in the evacuation of intracerebral hematomas.

Brain↗
PubMed1993

Ring chromosome 15 involving deletion of the insulin-like growth factor 1 receptor gene in a patient with features of Silver-Russell syndrome.

An 11-year-old girl with de novo r(15) (p12q26.3) with a clinical diagnosis of Silver-Russell syndrome (SRS) is presented. She had prenatal and postnatal growth deficiency with a severe short stature, peculiar facies characterized by a triangular face, a pinched nose with anteverted nostrils and down-turned corners of the mouth, bilateral clinodactyly of the fifth fingers, café-au-lait nevi, mental retardation, and a high level of serum follicular stimulating hormone. Southern blot analysis and chromosome fluorescence in situ hybridization revealed a deletion of the insulin-like growth factor 1 receptor gene (IGF1R) in the patient, the result indicating that IGF1R is assigned to 15q26.3. The deleted segment in our patient and comparisons with those of other reported cases of 15q-suggest that one of the putative SRS loci is at 15q26.3.

Abnormalities, Multiple↗
PubMed1993

Direct evidence of plastid DNA and mitochondrial DNA in sperm cells in relation to biparental inheritance of organelle DNA in Pelargonium zonale by fluorescence/electron microscopy.

The fate of plastid DNA and mitochondrial DNA was followed during spermatogenesis in thin sections of the pollen grains in Pelargonium zonale by epifluorescence microscopy, after staining with 4'-6-diamidino-2-phenylindole (DAPI), by the combination of fluorescence and electron microscopic images by color image processor, and by immunogold electron microscopy. DAPI-stained thin sections showed that there are two different types of fluorescent spots due to organelle DNA in the cytoplasm of generative cells and sperm cells: spherical spots that emit strong fluorescence (SF spots) and a ring-shaped group of tiny spots that emit a pale fluorescence (RG spots). The RG spots correspond to peanut-shaped refractive dense bodies under a phase-contrast microscope. Combination of the fluorescence and electron microscopic images by a color image processor showed that SF spots are not emitted from peanut-shaped electron-dense bodies but are from small spherical granules with cristae-like lamellae. Immunogold electron microscopy using ultrathin sectioning showed that the small spherical granules are mitochondria with typical cristae and that the peanut-shaped electron-dense bodies are plastids. The results clearly indicate that mitochondria and plastids with DNA molecules are present in the cytoplasm of sperm cells. The presence of these plastid DNA molecules may be responsible for the biparental inheritance of plastids. In addition, mitochondrial DNA may also show biparental inheritance.

DNA, Mitochondrial↗
PubMed1993

[Effect of training fitness on obesity, hypertension, hyperlipidemia and disorders in glucose metabolism].

Effects of physical training on obesity, hypertension, hyperlipidemia and disorders of glucose metabolism were investigated in 359 males, 30-59 years of age. Body mass index (BMI), systolic and diastolic blood pressure (SBP and DBP), high density lipoprotein cholesterol (HDL-C), total cholesterol (TC) and fructosamine (FA) were measured before and after the 2 month period of physical training at intensities of about 50% of maximal O2 uptake. Results are summarized as follows; 1. Means of BMI, SBP, DBP, TC and FA after the training were significantly lower than before the training. Mean of HDL-C was significantly higher than before the training. 2. In subjects with high BMI (n = 124), high SBP (n = 129) and high DBP (n = 128), means of BMI, SBP and DBP decreased with increase of training time per week. In subjects with low HDL-C (n = 104), high TC (n = 135) and high FA (n = 66), changes in means of TC, HDL-C and FA after the training did not show a relationship to training time per week. 3. Differences observed for measured values before and after the training of 2-3 hours per week were 0.4 kg/m2 in BMI, 15 mmHg in SBP and 10 mmHg in DBP, suggesting that training of 2-3 hours per week was effective in intervention of obesity and hypertension.

Adult↗
PubMed1993

[The characteristic flow of the superior vena cava in cardiac tamponade: a case report].

A case of cardiac tamponade showing the characteristic flow pattern in the superior vena cava is reported. An 80-year-old man was admitted to our hospital complaining of anorexia and general fatigue. We observed a paradoxical pulse of 25 mmHg, dilatation of the jugular vein, and marked cardiomegaly on chest radiography. A two-dimensional echocardiogram demonstrated a massive pericardial effusion and collapse of the right atrial and right ventricular walls. On the basis of his echocardiograms and clinical signs, we diagnosed his condition as cardiac tamponade. Pulsed Doppler echocardiograms showed two-peaked flow in the superior vena cava in systole. To assess the diagnostic significance of this characteristic flow pattern, the superior vena cava flow was recorded simultaneously with the intrapericardial pressure and the right atrial pressure. The intrapericardial pressure was higher than the right atrial pressure in early systole. After pericardial drainage, these pressures became reversed and the two-peaked flow disappeared. The two-peaked flow is attributed to collapse of the right atrial wall caused by the higher intrapericardial pressure than the right atrial pressure. The superior vena cava flow represents the right heart filling dynamics in cardiac tamponade.

Aged↗
PubMed1993

[Mutagen extraction from bile of patients with inflammatory biliary pathology: Ames test using blue rayon].

Gallbladder carcinoma is frequent in Chile. The aim of this study was to report the mutagenicity of whole human bile, using the Ames/Salmonella microsome assay with Salmonella typhimurium TA98. The bile of 19 patients, aged 23 to 64 years old, subjected to cholecystectomy was examined, and mutagen activity was found in 13 (72%). Mutagens were extracted using blue rayon and three dilutions for the eluted material from blue rayon were used (50, 100 and 200 ul). The best result was obtained using 200 ul. In some cases, the amount of revertive colonies was very high (over 5 times the control value). We propose that the bile from these patients possibly contains mutagenic substances with frame shift mutagenic activity and that these substances may be related to gallbladder carcinoma. Our results have addressed the importance of bile studies to elucidate the pathogenesis of gallbladder carcinoma.

Adult↗
PubMed1993

[Transcatheter embolization of ascending aorto-pulmonary fistula combined with coronary arteriovenous fistula].

We encountered a patient with a coronary arteriovenous fistula accompanied by an ascending aortopulmonary fistula, a rare malformation. The patient was a 42-year-old female complaining of exertional dyspnea and chest pain at rest. She noticed dyspnea while going up and down the stairs, and chest pain at rest at the age of about 40 years. While she was being treated for hypertension, a cardiac murmur was detected. She was admitted to our hospital for close examination. Coronary angiography (CAG) showed a coronary arteriovenous fistula that branches from the left anterior descending branch and forms an aneurysm, running to the trunk of the pulmonary artery. On March 28, 1989, ligation of the fistula was performed. Postoperative CAG demonstrated an ascending aorto-pulmonary fistula that flowed to an aneurysm adjacent to the pulmonary artery. On November 29, transcatheter embolization was performed. She was discharged 7 days after embolization without complications. She is now being treated on an outpatient basis, and the symptoms in her chest have disappeared. Transcatheter embolization used in this patient may also be applicable in the treatment for coronary arteriovenous fistulae.

Adult↗
PubMed1993

[Concomitant arterial infusion chemotherapy with tamoxifen therapy for hepatic metastases from pancreatic adenocarcinoma--a preliminary report].

The prognosis for hepatic metastasis from pancreatic adenocarcinoma is generally poor. Estrogen receptors have recently been demonstrated in pancreatic adenocarcinoma, and it has been suggested that tamoxifen increases patient survival. We have tried tamoxifen therapy combined with intermittent intraarterial infusion chemotherapy using mainly 5-FU for 4 patients with hepatic metastasis from pancreatic adenocarcinoma. Clinical evaluation of initial response was available for these 4 patients. Although the number of the patients in this study was small, we obtained a response rate of 50%; CR in one case, PR in one case. No patients showed progressive disease (PD). Median survival period was 4.6 months; 3 of 4 patients died with carcinomatous peritonitis at 2.5 to 6 months from the initiation of the therapy. No severe complication was observed. It is believed that this new concomitant therapy is effective in controlling hepatic metastasis from pancreatic adenocarcinoma. But additional therapy for carcinomatous peritonitis, which often develops after achieving hepatic control, is necessary to achieve long-term survival benefit.

Adenocarcinoma↗
PubMed1993

Preliminary crystallographic studies on hammerhead ribozymes.

Crystallization of hammerhead ribozymes was tried by the hanging drop vapor diffusion method. The crystals grown up to 0.5 x 0.05 x 0.05 mm3 in size gave diffraction patterns with about 5 A resolution using synchrotron radiation. The crystal was determined to be trigonal with space group P3(1) or P3(2) and cell parameters a = b = 49.6 A and c = 53.3 A.

Base Sequence↗