176
|
Akaboshi M, Kawai K, Maki H, Akuta K, Ujeno Y, Miyahara T. The number of platinum atoms binding to DNA, RNA and protein molecules of HeLa cells treated with cisplatin at its mean lethal concentration. Jpn J Cancer Res 1992; 83:522-6. [PMID: 1618702 PMCID: PMC5918865 DOI: 10.1111/j.1349-7006.1992.tb01959.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
HeLa S-3 cells were treated with 195mPt-radiolabeled cis-diamminedichloroplatinum(II) (CDDP) under various conditions, and the relationship between lethal effect and the number of Pt atoms binding to DNA, RNA and proteins was examined. The mean lethal concentrations for the cells treated with CDDP at 37 degrees C for 1, 2 and 3 h were 2.8, 2.0 and 1.1 microgram/ml, respectively. By using identically treated cells, the number of Pt atoms combined with DNA, RNA and protein molecules were determined after fractionation of the cells using the method of Schneider. In this way, the D0 values given as the drug concentration were substituted for the number of Pt atoms combined with each fraction, then the target volumes expressed as the reciprocals of D0 values were calculated for each fraction. The results provide strong support for the idea that DNA is the primary target for cell killing by CDDP, and the target volumes were 5.17 x 10(4), 5.71 x 10(4) and 1.03 x 10(5) nucleotides for 1, 2 and 3 h treated cells, respectively.
Collapse
|
177
|
Abstract
The authors report on their clinical experience with two new videoendoscopes developed in cooperation with Olympus Co. One of them is an instantaneous image method videoendoscope (EVIS 100), the other produces sequential images (EVIS 200). EVIS 100 is as compact as a fiberscope; EVIS 200 has the special advantages of electronic magnification, the use of infrared rays and image display of hemoglobin concentration in the tissue. In clinical application in 245 patients examined with EVIS 100 and 30 cases with EVIS 200, both instruments were found to be satisfactory in terms of daily use; EVIS 200 could be applied in further endoscopic research. In our opinion videoendoscopes will replace conventional fiberscopes in the future.
Collapse
|
178
|
Miyahara T, Kawaguchi A, Nogao S, Niwa H. [The influence of proton-pump inhibitors on the healing process of peptic ulcers--electronic endoscopic study]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 1992; 50:98-103. [PMID: 1347335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
It is highly important to analyze the of protonpump inhibitors on the healing process of peptic ulcers endoscopically since the use of proton-pump inhibitors is restricted in their period of usage. It is however, too early to evaluate proton-pump inhibitors as equal to or comparable to the many H2 blockers which have been tested basically and clinically. From the view-point of the number of clinical cases too, it is too early to conclude that the protonpump inhibitors are superior to previous H2 blockers. Most of the ear electronic endoscopic studies are highly conducted with the stereo-type electronic endoscopes except that on the regenerative epitheliums. The pictorial management of the regenerative epitheliums and intramucosal blood volume are not discussed in this paper, but results are expected to in the near future.
Collapse
|
179
|
Imamura M, Shimada Y, Kanda Y, Fukumoto M, Yanagibashi K, Miyahara T, Tobe T. Usefulness of preoperative low dose cisplatin treatment for advanced esophageal cancer. Surg Today 1992; 22:409-15. [PMID: 1421861 DOI: 10.1007/bf00308789] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In order to decrease the perioperative complications by preoperative cisplatin chemotherapy, the preoperative single administration of cisplatin (30 mg/m2) was performed weekly from one to six times in 36 consecutive patients with esophageal cancer classified as higher than Stage II. The survival curve of 17 patients in Stage III was significantly better (P < 0.05) than that of patients who had been treated without preoperative cisplatin treatment. In 3 of the 12 patients who had locally invasive cancer, either the main tumors or the metastatic lymph nodes, which had invaded the trachea or the left main bronchus, sufficiently receded, so that a curative esophagectomy became possible; 2 of them have survived over 33 months while 1 died of pneumonia 33 months after surgery. The number of perioperative complications was minimal, and thus, we consider that the postoperative use of cisplatin and fluorouracil is indicated in patients in whom a histological response is noted in the resected specimens.
Collapse
|
180
|
Imamura M, Shimada Y, Kanda T, Miyahara T, Hashimoto M, Tobe T, Arai T, Hatano Y. Hemodynamic changes after resection of thoracic duct for en bloc resection of esophageal cancer. Surg Today 1992; 22:226-32. [PMID: 1392326 DOI: 10.1007/bf00308827] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
An en bloc resection of esophageal cancer is one of the most radical forms of esophagectomy, and includes the resection of the thoracic duct, but a relatively high hospital mortality rate has been reported. There is very little knowledge on the pathophysiological changes after resection of the thoracic duct. We examined 24 patients who underwent en bloc resection. Some patients developed severe tachycardia or shock postoperatively which subsided after a massive infusion of plasma. Analysis of the fluid balance revealed that much more fluid was necessary during surgery and the postoperative 24 h than in patients treated by a standard esophagectomy. Postoperative lymphangiography or CT revealed abnormal collateral lymphatics around the kidneys or in the pelvic cavity. This suggests the development of the lymphaticovenous shunts, which differed depending on the anatomy of each patient. One patient with chronic hepatitis developed uncontrollable ascites. These are important findings which can hopefully reduce the high rate of hospital death after this operation.
Collapse
|
181
|
Miyahara T, Takata M, Mori-Uchi S, Miyata M, Nagai M, Sugure A, Matsusista M, Kozuka H, Kuze S. Stimulative effects of cadmium on bone resorption in neonatal parietal bone resorption. Toxicology 1992; 73:93-9. [PMID: 1589882 DOI: 10.1016/0300-483x(92)90173-c] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Effects of cadmium on bone resorption were investigated using neonatal mouse parietal bone culture system. Cadmium at 0.5 microM and above stimulated hydroxyproline release as well as 45Ca release. As cadmium-stimulated bone resorption was inhibited by calcitonin, bone resorption induced by cadmium is osteoclast-mediated bone resorption. CI-1, collagenase inhibitor, depressed cadmium-stimulated bone resorption in a dose-dependent manner. Osteoblasts are also involved in cadmium-induced bone resorption. Indomethacin-inhibited cadmium-stimulated bone resorption and cadmium-treated bones released prostaglandin E2 to a greater extent than untreated bones. Cadmium-stimulated bone resorption was shown to be dependent on the production of prostaglandin E2. 3-Isobutyl-1-methylxanthine potentiated cadmium-stimulated bone resorption and verapamil depressed it. It is possible that an increase in levels of cAMP and calcium ion in bone cells is involved in cadmium-induced bone resorption. From these results, cadmium was found to stimulate osteoclast-mediated bone resorption which is dependent on prostaglandin E2. Second messengers in cadmium-induced bone resorption may be cAMP and calcium ion.
Collapse
|
182
|
Miyahara T. [Modulation of soleus H-reflex by teeth clenching]. KOKUBYO GAKKAI ZASSHI. THE JOURNAL OF THE STOMATOLOGICAL SOCIETY, JAPAN 1991; 58:670-86. [PMID: 1795137 DOI: 10.5357/koubyou.58.670] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Modulation of the human soleus H-reflex (Sol. H-R) was studied during voluntary teeth clenching in 11 healthy adult volunteers, to investigate the possible correlation of motor functions between the jaw and body. The following results were obtained: (1) Sol. H-R was facilitated during the maximum voluntary teeth clenching more than during the maximum voluntary efforts in the other parts of the body, i.e., Jendrassik maneuver and clenching of both hands. (2) The amount of the Sol. H-R facilitation increased with the masseter EMG activity. (3) Facilitation of the Sol. H-R in association with teeth clenching started ca 60ms before the onset of the masseter EMG activity, reached its peak ca. 100ms after the onset and thereafter decreased to a certain plateau level in accordance with the masseter EMG activity level. (4) During the inhibition of the masseter EMG reflexively evoked by electrical stimulation of the lower lip, the amount of the facilitation of the Sol. H-R during teeth clenching decreased compared with that without lip stimulation, though the facilitation was still retained. It was concluded that: 1) The excitability of the Sol. H-R is remarkably elevated during teeth clenching. 2) There is a positive correlation between the amount of the facilitation of the Sol. H-R and the teeth clenching force level. 3) The facilitation is due to both the descending influence from the higher brain and the afferent inputs from the oral structures. It is assumed that the oral motor activity exerts a strong influence on the bodily motor function in general.
Collapse
|
183
|
Kitajima M, Nakamura K, Fujitsuka M, Shinno H, Katoh H, Miyahara T. Electronic structure in the valence band of molybdenum being bombarded with argon ions. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 44:8338-8341. [PMID: 9998776 DOI: 10.1103/physrevb.44.8338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
184
|
Sato T, Simatsu T, Miyahara T, Miyazaki T. Magnetooptic Effect of Fe-Ni, Ni-Co and Fe-Co Binary Alloy Films. ACTA ACUST UNITED AC 1991. [DOI: 10.1109/tjmj.1991.4565269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
185
|
Mori MA, Kobayashi M, Yumoto Y, Nakafuku K, Miyahara T, Kozuka H. Metabolism of mephentermine in male guinea pigs and male mice. Xenobiotica 1991; 21:1301-9. [PMID: 1796607 DOI: 10.3109/00498259109043205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. Urinary metabolites of mephentermine (MP), after i.p. administration of MP to male Hartley guinea pigs and mice, were identified by g.l.c.-electron impact (EI) mass spectrometry. Excretion of urinary radioactivity, and metabolites of 3H-MP, after i.p. administration, were determined by preparative t.l.c.-liquid scintillation counting. 2. About 27% of the radioactivity administered was excreted in the 24 h urine of guinea pigs, and 36% dose was excreted in 5 days. In mice, about 47% of the radioactivity was excreted in the 24 h urine, and 52% in 5 days. 3. Excretion rates of metabolites detected in the 24 h urine of guinea pigs were phentermine (Ph, 7.8%), a conjugate of N-hydroxyphentermine (N-hydroxy-Ph, 3.6%), p-hydroxyphentermine (p-hydroxy-Ph, 1.0%) and its conjugate (2.9%), and other metabolites (conjugates of MP and Ph, N-hydroxymephentermine (N-hydroxy-MP) and its conjugate, p-hydroxymephentermine (p-hydroxy-MP) and its conjugate, and N-hydroxy-Ph; less than 1.0%). The rates of excretion for mice were Ph (11.7%), conjugates of p-hydroxy-MP (3.1%), Ph (2.7%) and p-hydroxy-Ph (1.6%), and N-hydroxy-Ph (1.2%) and other metabolites (conjugates of MP and N-hydroxy-Ph, N-hydroxy-MP and its conjugate, p-hydroxy-Ph, and p-hydroxy-MP; less than 1.0%). 4. These results indicate that MP administered to mice is metabolized mainly to Ph and p-hydroxy-MP by N-demethylation and p-hydroxylation of the parent compound, and in guinea pigs the primary metabolic reaction of MP is N-demethylation producing Ph.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
186
|
Ishibashi A, Yamaji K, Hayashi Y, Miyahara T, Niwa H. Large bullous eruption in patients with ulcerative colitis. J Dermatol 1991; 18:549-51. [PMID: 1686267 DOI: 10.1111/j.1346-8138.1991.tb03132.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Oligocentric large bullous eruptions in two patients with ulcerative colitis were reported. Such bullae were similar to those seen in drug-induced coma, and those described as drug eruption due to high dose frusemide. However, neither narcotic drugs nor frusemide had been given in either case. The bullae were cured after the administration of corticosteroid and/or salazosulfapyridine with a course paralleling that of the ulcerative colitis. Thus the bullae seem to be a cutaneous manifestation of ulcerative colitis.
Collapse
|
187
|
Miyahara T, Nemoto M, Tukamoto S, Yamada H, Kozuka H, Kuze S, Sudo H, Yamamoto S. Induction of metallothionein and stimulation of calcification by dexamethasone in cultured clonal osteogenic cells, MC3T3-E1. Toxicol Lett 1991; 57:257-67. [PMID: 1882387 DOI: 10.1016/0378-4274(91)90200-p] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To clarify the effects of dexamethasone (Dex) on metallothionein (MT) synthesis and calcification in osteoblastic cells, a clonal osteogenic cell line (MC3T3-E1) was used in the present study. Under culture conditions designed not to cause calcification, MT synthesis of cells at 3 days after inoculation increased with increasing concentration of Dex (2.5-50 nM) for a 24-h culture period. Cells at 6 or 9 days after inoculation also synthesized MT by a 24-h exposure to Dex. These show that undifferentiated osteoblasts have the ability to synthesize MT by Dex. Under culture conditions designed to cause calcification, cells at 6 days after inoculation were cultured with 50 nM Dex in the presence of 7 mM beta-glycerophosphate (beta-GP) for 7 days. Ca content of Dex-treated cells was about 7.5 times as high as that of untreated cells. Dex-treated cells showed a high activity of alkaline phosphatase (ALP). The Zn content of the MT fraction in Dex-treated cells was about 8 times as high as that of untreated cells. These results show that Dex has the ability to induce MT synthesis in osteoblastic cells and to cause a high calcification which is due at least partly to an enhanced activity of ALP.
Collapse
|
188
|
Kawai T, Honda T, Tokuyama Y, Taneno A, Oishi S, Okamura H, Nonaka F, Sakai E, Miyahara T, Eto M. Reproduction of turbinate atrophy in pigs by intranasal consecutive-day inoculation with suspensions of a toxigenic serotype D strain of Pasteurella multocida. J Vet Med Sci 1991; 53:507-9. [PMID: 1832039 DOI: 10.1292/jvms.53.507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
|
189
|
Ishida H, Takei N, Funato E, Miyahara T, Nukaga H, Yokoi M, Sato T, Hisa T, Yoshimasu H, Sakurabayashi S. [Spontaneous rupture of the spleen in a case of infectious mononucleosis]. NIHON SHOKAKIBYO GAKKAI ZASSHI = THE JAPANESE JOURNAL OF GASTRO-ENTEROLOGY 1991; 88:1275-9. [PMID: 1880961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
190
|
Kaji T, Takata M, Miyahara T, Kozuka H, Koizumi F. Interaction between cadmium and copper on ossification of embryonic chick bone in tissue culture. Toxicol Lett 1991; 55:255-62. [PMID: 2003268 DOI: 10.1016/0378-4274(91)90005-q] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To investigate the interaction between cadmium and copper in ossification, femurs from 9-day-old chick embryos were cultured for 6 days in the presence of 2 microM cadmium and/or 1 microM copper. It was found that cadmium + copper treatment caused interactively severe damage to osteogenic mesenchymal cells in the periosteum and a severe degenerative change in osteoblasts around the trabecula, resulting in severe impairment of ossification in the diaphysis. Cadmium content was increased by copper; however, copper content was unaffected by cadmium in the diaphysis. It was therefore considered that the copper-induced increase in cadmium content was a primary factor in the interactive toxic effect of the cadmium + copper treatment in ossification.
Collapse
|
191
|
Ito T, Miura Y, Kadokawa T, Hori S, Shimada J, Miyahara T. Effects of enoxacin and its combination with 4-biphenylacetate, an active metabolite of fenbufen, on population spikes in rat hippocampal slices. PHARMACOLOGY & TOXICOLOGY 1991; 68:220-5. [PMID: 2057453 DOI: 10.1111/j.1600-0773.1991.tb01227.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effects of enoxacin, a new quinolone antibacterial agent, and its combination with 4-biphenylacetate (BPA), an active metabolite of the non-steroidal antiinflammatory agent fenbufen, were examined on population spikes induced by electrical stimulation of the stratum radiatum in the CA1 pyramidal cell layer in rat hippocampal slices. Enoxacin (10(-4) M) and bicuculline (10(-6) M) increased the amplitude of the population spikes and anew elicited the second spikes (latency: 10 msec.), while BPA (10(-5) M) decreased the amplitude of the population spikes. However, the combination of enoxacin (10(-6), 10(-5) M) with BPA (10(-5) M) elicited the second spikes or epileptiform bursts with an increase of the population spike amplitude. The dose-response relationships showed that the effect of enoxacin was 100 times potentiated in the presence of BPA (10(-5) M). The second spikes induced by enoxacin (10(-4) M) were suppressed by muscimol (10(-6) M) and baclofen (10(-6) M), but not by clorazepate (5 x 10(-5) M) and pentobarbital (5 x 10(-5) M). The second spikes induced by bicuculline (10(-6) M) were suppressed by these four drugs. The second spikes by the combination of enoxacin (10(-6) M) with BPA (10(-5) M) were suppressed by muscimol (5 x 10(-6) M), but not by clorazepate (5 x 10(-5) M). These results suggest that the combination of enoxacin with BPA exerts a drug interaction to elicit the second spikes or epileptiform bursts with its mode of action different from that of bicuculline.
Collapse
|
192
|
Matsunami T, Yokota M, Iwase M, Watanabe M, Miyahara T, Koide M, Saito H, Takeuchi J. Dynamic exercise-induced elevation in plasma levels of atrial natriuretic peptide in patients with effort angina pectoris. Am Heart J 1990; 120:1298-305. [PMID: 2147350 DOI: 10.1016/0002-8703(90)90239-t] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We investigated the relationship between plasma atrial natriuretic polypeptide (ANP) levels and hemodynamic indices during dynamic exercise testing in 15 patients with effort angina pectoris. Patients exercised on an angina-limited, supine, multistage bicycle ergometer, and plasma ANP levels and hemodynamic indices were measured at rest, at peak exercise, and 6 minutes after exercise. Plasma ANP levels increased significantly at peak exercise. Pulmonary artery wedge pressure (PAWP) and coronary sinus blood flow (CSBF) were significantly correlated with plasma ANP levels before and at peak exercise (PAWP: r = 0.69, p less than 0.001; CSBF; r = 0.45, p less than 0.05). In six of eight patients whose PAWP exceeded 20 mm Hg at peak exercise, plasma ANP levels were increased at 6 minutes after exercise, whereas PAWP had decreased relative to the values obtained at peak exercise. Plasma ANP concentrations at 6 minutes after exercise were not correlated with PAWP at the same time. However, PAWP at peak exercise was correlated with the plasma ANP levels at 6 minutes after exercise (r = 0.80, p less than 0.001). These results suggest that in patients with effort angina pectoris left ventricular dysfunction resulting from exercise-induced myocardial ischemia may increase preload excessively and may contribute to the excess secretion of ANP after dynamic exercise.
Collapse
|
193
|
Watanabe M, Yokota M, Miyahara T, Saito F, Matsunami T, Kodama Y, Saito H, Takeuchi J. Clinical significance of simple heart rate-adjusted ST segment depression in supine leg exercise in the diagnosis of coronary artery disease. Am Heart J 1990; 120:1102-10. [PMID: 2239662 DOI: 10.1016/0002-8703(90)90123-f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To evaluate the clinical significance of simple heart rate-adjusted ST segment depression (delta ST/delta HR) in the diagnosis of coronary artery disease, 42 patients with stable exertional angina underwent supine leg exercise testing and cardiac catheterization. During exercise, heart rate, a multilead electrocardiogram, and pulmonary artery wedge pressure were recorded. The sensitivity and accuracy of the delta ST/delta HR criteria (greater than or equal to 3.0 microV/beat/min) were significantly greater than the conventional analysis of ST segment depression criteria (greater than or equal to 0.2 mV) for detecting three-vessel coronary artery disease at a matched specificity of 72% (100% versus 46%, 81% versus 64%, p less than 0.01). A significant linear correlation was found between maximum pulmonary artery wedge pressure increments during exercise (delta PAWP) or Gensini score and the delta ST/delta HR (delta PAWP: r = 0.51, p less than 0.001; Gensini score: r = 0.47, p less than 0.001). There were no statistically significant differences in the delta PAWP or Gensini score between patients with three-vessel disease who had delta ST/delta HR greater than or equal to 3.0 microV/beat/min and those with one- or two-vessel disease who had delta ST/delta HR greater than or equal to 3.0 microV/beat/min (delta PAWP: 18.1 +/- 2.0 versus 21.9 +/- 3.3, p = NS; Gensini score: 68.5 +/- 6.6 versus 66.3 +/- 11.3, p = NS). These findings demonstrate that delta ST/delta HR is more useful than a conventional analysis of ST segment depression for identifying not only anatomically severe coronary artery disease but also functionally severe coronary artery disease.
Collapse
|
194
|
Koide T, Shidara T, Fukutani H, Fujimori A, Miyahara T, Kato H, Otani S, Ishizawa Y. Optical study of the stoichiometry-dependent electronic structure of TiCx, VCx, and NbCx. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 42:4979-4995. [PMID: 9996057 DOI: 10.1103/physrevb.42.4979] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
195
|
Miyahara T, Kozuka H, Nemoto S, Tsukamoto S. [Induction of Cd and Zn-thionein in a clonal osteogenic cell, MC3T3-E1]. [NIHON KOSHU EISEI ZASSHI] JAPANESE JOURNAL OF PUBLIC HEALTH 1990; 37:782-9. [PMID: 2132395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Clone MC3T3-E1 cells at various differentiation stages were exposed to 0.44-13.3 microM Cd or 50-175 microM Zn in culture medium. After a 2-h culture period, the amount of Zn accumulated in the cells was shown to be larger than that for Cd, but the production of Zn-thionein was much less compared with that of Cd-thionein. After a 24-h incubation period, the synthesis of Zn-thionein increased markedly at levels of 150 microM Zn or greater, Cd induced metallothionein (MT) synthesis in a dose-dependent manner at 0.44 microM Cd or greater. Since calcified cells differentiated into osteoblastic cells also produced MT, osteoblasts were confirmed to have an ability to induce MT synthesis. Initiation of production of Cd-or Zn-thionein in the cells occurred at an accumulation of about 0.4 nmol Cd and 2.5 nmol Zn/mg cytosol protein. The ratios of thionein-binding Cd/Cd accumulated in the cytosol and thionein-binding Zn/Zn accumulated in the cytosol were 0.11 mol/mol and 0.067 mol/mol, respectively. These results show that the concentration of accumulated Zn necessary for initiating production of MT is about six times that of Cd and one molecule of Cd induces thionein about 1.6 times as effectively as one molecule of Zn does.
Collapse
|
196
|
Shimada J, Saito A, Shiba K, Kaji M, Hori S, Yoshida M, Miyahara T. [Effects of antacids on absorption, excretion and metabolism of cefteram pivoxil]. THE JAPANESE JOURNAL OF ANTIBIOTICS 1990; 43:1353-70. [PMID: 2178195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Effects of various antacids (sodium bicarbonate, aluminium hydroxide gel) and an H2-blocker (cimetidine) on the absorption and excretion of a new cephem drug for oral use, cefteram pivoxil (CFTM-PI), were studied in healthy adult volunteers. 1. No significant differences were found in serum levels of CFTM and CFTM-A (an inactive isomer of cefteram (CFTM)) or their urinary excretion levels (concentration, recovery rate) between the group given CFTM-PI in combination with sodium bicarbonate and that given CFTM-PI alone. 2. There were no significant differences in serum levels of CFTM and CFTM-A or their urinary excretion levels (concentration, recovery rate) between the group given CFTM-PI in combination with aluminium hydroxide gel and that given CFTM-PI alone. 3. In contrast, serum levels of CFTM and its urinary recovery rate were significantly less in the group given the drug in combination with cimetidine than in that given a single administration 2-3.5 hours and 2-4 hours after administration, respectively. Clinical considerations remain.
Collapse
|
197
|
Kamihara S, Yokota M, Inagaki H, Iwase M, Matsunami T, Yoshida J, Miyahara T, Koide M, Hayashi H. Prediction of left ventricular function during supine bicycle ergometer exercise in angina-free patients with old myocardial infarction. Clin Cardiol 1990; 13:480-4. [PMID: 2364582 DOI: 10.1002/clc.4960130710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We investigated whether or not left ventricular function during dynamic exercise in angina-free patients with old myocardial infarction could be estimated using resting left ventricular function and noninvasive parameters determined during exercise. We studied 70 patients with old myocardial infarction by measuring hemodynamic parameters during supine multistage bicycle ergometer exercise. Coronary arteriography and left ventriculography were performed: then the left ventricular ejection fraction and left ventricular end-diastolic volume were measured. The parametric changes (delta) between rest and peak exercise were determined. Significant positive correlations were observed between cardiac index (CI) at rest and at peak exercise (r = 0.62, p less than 0.001), as well as between pulmonary artery wedge pressure (PAWP) at rest and at peak exercise (r = 0.72, p less than 0.001). Multiple regression analysis indicated that CI and PAWP at peak exercise as dependent variables were best described by the equations: CI at peak exercise = 1.074 [CIrest] +0.031 [delta HR] + 0.004 [ExD] + 0.018 [LVEF] - 1.560 (r = 0.79, p less than 0.001), PAWP at peak exercise = 0.994 [PAWPrest] - 0.181 [LVEF] + 0.203 [delta DBP] -0.076 [delta HR] -21.488 (r = 0.80, p less than 0.001). These data suggested that CI and PAWP during dynamic exercise in angina-free patients with old myocardial infarction could be predicted using noninvasive parameters, such as increments of blood pressure and heart rate as well as exercise duration, together with data on resting left ventricular function, such as resting CI, resting PAWP, and resting left ventricular ejection fraction (LVEF).
Collapse
|
198
|
Imamura M, Hattori Y, Nishida O, Honda T, Shimada Y, Miyahara T, Wagata T, Baba N, Tobe T. Unresponsiveness of insulinoma cells to secretin: significance of the secretin test in patients with insulinoma. Pancreas 1990; 5:467-73. [PMID: 2166285 DOI: 10.1097/00006676-199007000-00015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
It is well known that B cells in the pancreas release insulin when stimulated by secretin, but there have been few reports on the response of insulinoma cells to secretin. In five patients with insulinoma, changes in serum immunoreactive insulin (IRI) concentration were measured after the intravenous injection of secretin into the peripheral vein before and after extirpation of the insulinoma. The extirpated insulinomas were cultured and tested for their response to secretin. The rise in serum IRI in response to secretin in patients with insulinoma was significantly slower and smaller than in normal volunteers. After removal of the insulinoma, the response to secretin became prompt and increased with time. Cultured insulinoma cells did not release insulin when stimulated by secretin. Therefore, it is concluded that the response of insulinoma cells to secretin is quite different from that of normal beta cells, and that the function of beta cells in the insulinoma-bearing pancreas is suppressed by the autonomous hypersecretion of insulin by the insulinoma. The extent of the decrease in function of the beta cells in patients with insulinoma can be estimated by the intravenous secretin test. Thus, the secretin test is sometimes useful in the differentiation of hypoglycemia due to insulinoma from that due to beta cell hyperplasia or alimentary hyperinsulinemia.
Collapse
|
199
|
Miyahara T, Yokota M, Iwase M, Watanabe M, Matsunami T, Koide M, Saito H, Takeuchi J. Mechanism of abnormal postexercise systolic blood pressure response and its diagnostic value in patients with coronary artery disease. Am Heart J 1990; 120:40-9. [PMID: 2360516 DOI: 10.1016/0002-8703(90)90158-t] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To define the factors that affect an abnormal postexercise systolic blood pressure (SBP) response and to verify the diagnostic value of that response in patients with coronary artery disease (CAD), we studied 33 normal subjects, eight patients with hypertension who had no CAD, and 42 patients with documented CAD who underwent supine leg exercise testing. SBP recovery ratios were derived by dividing the values obtained 1 and 3 minutes after exercise by the peak value. The upper normal limit of the SBP ratio was defined by two standard deviations from the mean for 33 normal subjects. The specificity of this criterion for identifying patients with CAD was 97% and the sensitivity was 60%. None of the eight patients with hypertension showed an abnormal postexercise SBP response. At peak exercise the pulmonary artery wedge pressure was significantly greater in the patients with CAD having an abnormal response. In multiple regression analysis the exercise pulmonary artery wedge pressure, the exercise SBP, and the systemic vascular resistance after exercise were determining factors for an abnormal SBP response. Three-vessel disease was more common in patients with an abnormal response. Results of this study indicate that an abnormal postexercise SBP response appears to be determined by (1) the extent of exercise-induced impairment of left ventricular function and (2) peripheral vascular tone during recovery. This study also suggests that this criterion can increase the specificity of supine exercise testing in patients with CAD including those with hypertension and might provide a marker for the severity of impaired left ventricular function by exercise in CAD.
Collapse
|
200
|
Mori MA, Uy-Yu N, Sakai K, Inoue M, Miyahara T, Kozuka H. Isolation of urinary p-hydroxylated metabolites of mephentermine and phentermine in male Wistar rats. Xenobiotica 1990; 20:653-6. [PMID: 2238700 DOI: 10.3109/00498259009046881] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1. p-Hydroxymephentermine (p-hydroxy-MP) and p-hydroxyphentermine (p-hydroxy-Ph) were isolated as hydrochlorides from urine of male Wistar rats repeatedly dosed with mephentermine (MP). In addition, p-hydroxy-Ph was isolated as the hydrochloride from urine of the rats dosed with phentermine (Ph). 2. These results substantiate previous indications that p-hydroxylation of MP and Ph was a primary metabolic reaction in the rat.
Collapse
|