Biomedical subjects

I Watanabe

Publications and source records attributed to I Watanabe.

At least 145 records · Page 8Linked to original sources

PubMed1997

Raynaud's phenomenon in vibration syndrome: the impact of cold feet on skin temperature and vasomotion of the hand after immersion in cold water.

Patients with vibration syndrome, suffering from Raynaud's phenomenon, are sensitive to cold. Rewarming time, after local cooling, is delayed. The present study evaluated whether rewarming of the hand after cooling is influenced by the temperature of the feet. In five Japanese patients (former forest workers) with vibration syndrome, suffering from Raynaud's phenomenon, and in five healthy controls, temperature changes of the hand after cooling were registered under the two test situations (on different days) with the feet immersed in water of 35 degrees C or 20 degrees C, respectively. In both patients and controls (in both groups, in four of five cases) rewarming of the hand after cooling was faster when the feet were immersed in cold water, compared with when the feet were immersed in warm water. In this test situation, the systemic thermoregulative counterreaction appears to be more important for rewarming of the hand after cooling than a possible synchronous passive reaction accompanying warming of the feet. A deliberate training of the systemic counterreaction may prove beneficial for patients with Raynaud's phenomenon.

Adult↗

PubMed1997

Effect of pressure difference on the quality of titanium casting.

In casting titanium using a two-compartment casting machine, Herø et al. (1993) reported that the pressure difference between the melting chamber and the mold chamber affected the soundness of the castings. This study tested the hypothesis that differences in pressure produce castings with various amounts of porosity and different mechanical properties values. Plastic dumbbell-shaped patterns were invested with an alumina-based, phosphate-bonded investment material. Both chambers of the casting machine were evacuated to 6 x 10(-2) torr; the argon pressure difference was then adjusted to either 50, 150, 300, or 450 torr. The porosity of the cast specimens was determined by x-ray radiography and quantitative image analysis. Tensile strength and elongation were measured by means of a universal testing machine at a strain rate of 1.7 x 10(-4)/s. The fractured surfaces were examined by SEM. Changes in Vickers hardness with depth from the cast surface were measured on polished cross-sections of the specimens. Raising the argon pressure difference to 300 and 450 torr caused a significant increase in internal porosity and a resultant decrease in the engineering tensile strength and elongation. The highest tensile strength (approximately 540 MPa), elongation (approximately 10%), bulk hardness (HV50g 209), and lowest porosity level (approximately 0.8%) occurred in the specimens cast at 150 torr. Turbulence of the metal during casting was thought to be responsible for the increase in porosity levels with the increase in argon pressure difference. By choosing an argon pressure difference (around 150 torr) suitable for this geometry, we could produce castings which have adequate mechanical properties and low porosity levels.

Analysis of Variance↗

PubMed1997

Structural requirements for potential Na/H exchange inhibitors obtained from quantitative structure-activity relationships of monocyclic and bicyclic aroylguanidines.

The quantitative structure-activity relationship (QSAR) of N-(3-amino-6-chloro-5-ethylisopropylaminopyrazine-4-carbonyl) guanidine (EIPA) 1ac and its derivatives as Na/H exchange inhibitors was analyzed using th steric parameters and an indicator variable. The results indicated that bicyclic aroylguanidines might have Na/H exchange inhibitory activity. Therefore, various bicyclic aroylguanidines were synthesized and tested for Na/H exchange inhibitory activity. The QSAR study of the bicyclic aroylguanidines showed that hydrophobic bicyclic rings seemed to be preferable for potent activity. The hydrophobicity of the aroyl ring moiety was thought to be particularly important. Thus, the QSAR of EIPA and its derivatives was re-analyzed using hydrophobicity and steric parameters. The results indicated that high hydrophobicity of the pseudo-ring moiety and a substituent of appropriate length at the position corresponding to the 5-position of the naphthalene ring enhance the activity. As expected from the results, 5-bromo-2-naphthoylguanidine 3b and 5-methoxy-2-naphthoylguanidine 3c exhibited strong activity. These findings will be helpful to design new, potent Na/H exchange inhibitors.

Animals↗

PubMed1997

Design, synthesis and quantitative structure-activity relationship study of N-(3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-7-carbonyl)guanidine derivatives as potent Na/H exchange inhibitors.

Inhibition of the Na/H exchanger is a promising approach for treating ischemia-reperfusion injury, but no clinical agent is yet available. Recently, we established the structural requirements for potent inhibitors of the Na/H exchanger. In the present work, we designed N-(3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-7-carbonyl)guanidine 3a as a new lead compound for potent inhibitors with good water-solubility, based on the previous information. During the structural optimization, care was taken to keep the hydrophobicity (clogP) in the range of about 1.5-2.0, which is considered optimum for good bioavailability. Various derivatives of 3a were synthesized and the quantitative structure-activity relationship (QSAR) was studied. The QSAR result indicated that the lengths of the substituents at the 2- and the 4-positions of the 2H-benzo[1,4]oxazine ring are parabolically related to activity. The most potent compounds were (R) and/or (S)-N-(2-ethyl-4-isopropyl(or ethyl)-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-7-carbonyl)guanidines 3q-t with IC50 values of 0.036-0.073 microM. The water-solubility of the hydrochlorides and methanesulfonates is 3-5 mg/ml, which is sufficient for therapeutic use.

Animals↗

PubMed1997

Syntheses and antifungal activity of dl-griseofulvin and its congeners. III.

Several congeners (1b-g), with novel substituents on the benzene ring of griseofulvin, were prepared by the application of a synthetic method developed by us. Antifungal activity of these congeners decreased in order of dl-griseofulvin (1a) = 1d > 1b, c >> 1e-f (inactive). The relationship between the antifungal activity and the position or kind of substituents on the benzene ring of griseofulvin is discussed.

Antifungal Agents↗

PubMed1997

Relationship between preinfarction angina and time interval to reperfusion with thrombolytic therapy in acute myocardial infarction.

This study was conducted in an attempt to clarify whether preinfarction angina has an ischemic preconditioning effect. The subjects of this study were Killip class I patients who had suffered a first acute myocardial infarction (MI) as a result of total occlusion of the proximal left anterior descending coronary artery without development of collateral vessels and multivessel coronary artery disease. All subjects achieved successful reperfusion [thrombolysis in myocardial infarction (TIMI) flow grade 3] through intracoronary thrombolysis with single-chain urokinase-type plasminogen activator (SCU-PA). Subsequently, they received the same drug therapy and remained free of reocclusion. The patients were divided into those who experienced a new onset of prodromal angina within 24 h before the onset of acute MI [PA(+) group] and those who had a sudden onset of acute MI without the preceding angina [PA(-) group]. They were further divided according to the time interval from the onset of acute MI to reperfusion (within 1 h, 1-2 h, 2-3 h, 3-4 h, and 4-7 h). In addition, the left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume index (LVEDVI), and the amount of creatine kinase (CK) released (sigma CK) were compared in these 2 groups at reperfusion time. The results of this study showed that sigma CK was significantly lower in the PA(+) group than in the PA(-) group (1,850 mIU vs 3,583 mIU) when reperfusion was induced within 1 h after the onset of acute MI. When reperfusion was induced 1-2 h after the onset of acute MI, sigma CK tended to be lower in the PA(+) group than in the PA(-) group (3,677 mIU vs 5,261 mIU). Once the time to reperfusion exceeded 2 h, there was no significant difference in sigma CK between these 2 groups. On the other hand, there were no significant differences in LVEF and LVEDVI between these 2 groups at any reperfusion time. In conclusion, preinfarction angina had a preconditioning effect (reduction in sigma CK), but this effect was lost once the time interval from the onset of acute MI to reperfusion exceeded 2 h.

Adult↗

PubMed1997

Catheter ablation of canine ventricular myocardium. The use of repetitive short time constant capacitive shocks to increase lesion volume.

Arching and barotrauma, seen with high energy DC catheter ablation, are responsible for diffuse cardiac damage and coronary sinus rupture. In six anesthetized dogs, we investigated the effects of an increasing number of short time-constant capacitive shocks on the volume of myocardial damage. Each dog received capacitive shocks of 2 J/kg at 3 sites in the left ventricle. One shock was delivered in 2 dogs, 2 shocks were delivered in 2 dogs and 3 shocks were delivered in 2 dogs. Shock delivery was not accompanied by hemodynamic collapse, sustained ventricular tachycardia or ventricular fibrillation. The dogs were sacrificed at 60 minutes. Mean (SEM) lesion volumes were 195 (39) mm3, 480 (41) mm3, and 595 (110) mm3, respectively. Despite variability in individual volume of damage, there was a significant increase in lesion volume with an increasing number of shocks. There was no evidence of perforation or tamponade. Increasing myocardial damage can be produced using repetitive capacitive shocks. Delivery of 2 shocks produces clinically useful lesions without the adverse effects associated with single high energy shocks. Repetitive capacitive shocks offer a method of increasing lesion volume without increasing energy and thereby without compromising safety.

Animals↗

PubMed1997

[A long-term follow-up of patients with Meniere's disease--comparative study of unilateral and bilateral Mènière's disease].

A retrospective study was carried out on 46 patients with Meniere's disease (MD). Twenty of them were followed up for 20-40 years (long-term follow-up cases), and 26 of them for 5-12 years (middle-term follow-up cases). Thirteen of the patients suffered from fluctuating sensorineural hearing loss in one ear (unilateral MD), and 33 of them suffered from it in both ears (bilateral MD). Comparing the results of repeated audio-vestibular examinations of patients with unilateral MD with those of patients with bilateral MD revealed the following differences between them: 1) The range of fluctuation of the hearing level of the patients with unilateral MD was greater than that of the patients with bilateral MD. 2) Most patients with unilateral MD showed three audiometric configurations, but most patients with bilateral MD showed two audiometric configurations during the first 5 years of the follow-up period. 3) The patients with unilateral MD showed unilateral weakness on the caloric test more often than the patients with bilateral MD. But other clinical features in the patients with unilateral MD and those with bilateral MD were similar. We confirmed that there was an increase in bilaterality with time, but it is impossible to speculate whether the patients with unilateral MD will also suffer it in the contralateral ear or not. Therefore, it is possible that in all patients who have suffered from unilateral MD for a long time the disease may become bilateral in the future. Clinical observation of patients with MD as long as possible is the only way to clarify the relationship between unilateral and bilateral MD. It is stressed that to gain the patient's confidence is not only the basis of long-term follow-up of the patient, but also of effective treatment of MD.

Aged↗

PubMed1997

[Possible ectopic cerebral tissue in the middle ear--a case report].

A 58-year-old woman suffered from chronic otitis media with possible ectopic cerebral tissue on the aditus ad antrum and the epitympanum. This 6 x 2 mm ectopic brain mass was removed carefully after discontinuity between this mass and intracranial cerebral tissue was detected. By histopathological examination, this possible ectopic cerebral mass was found to include mucous glands of middle ear mucosa. An exposed area of the dura mater 2 mm in diameter was found at the tagmen of the mastoid cavity and the aditus ad antrum, but there was neither perforation of the dura nor cerebrospinal fluid leakage from my part of the dura. This patient has not experienced any trouble during the one year post-operative course, and she obtained about a 15 dB hearing improvement in the ten months after surgery when compared with her preoperative status.

Brain↗

PubMed1997

Field emission SEM, conventional TEM and HVTEM study of submandibular gland in prenatal and postnatal aging mouse.

The development of acinar and ductal cells of the mouse submandibular gland was studied using field emission SEM, conventional TEM and HVTEM methods. The specimens, at 15 and 18 days of gestation and 1, 3, 7, 14, 21, 30, 90 and 180 postnatal days were fixed in 2.5% glutaraldehyde solution in 0.1 M sodium phosphate buffer (pH 7.3). At 15 and 18 days of gestation, the structure of mouse submandibular gland contains acinar and ductal cells in proliferation. The cytoplasmic organelles such as mitochondria, granular endoplasmic reticulum and Golgi apparatuses are scattered in the cytoplasm. At 18 prenatal days only several acinar cells present immature secretory granules in the apical portion. In this stage the acinar and ductal cells are enveloped by bundles of fine collagen fibrils disposed in several directions. There are also numerous capillaries located closely to the acinar cell membranes. In the aging stages of 1, 3, 7, 14, 21, and 30 postnatal days, the histo-differentiation of acinar, intercalated and ductal cell components are observed. At newborn day one the cytoplasmic organelles start to place themselves around the nucleus. Several immature secretory granules are observed at day one, however, they increase in the aging days. At postnatal day 30, the cytoplasms of acinar and ductal cells are filled with a large number of secretory granules of different sizes. The stacks of granular endoplasmic reticulum and Golgi apparatus and some vesicles and free ribosomes are noted. The intercellular membranes are attached by desmosomes and cytoplasmic interdigitations. The luminal surface shows several small projections of microvilli. An electron-dense line of basement membranes followed by fine collagen fibrils are recognized. Delicate capillaries are found in the outer surface of acinar cells. At postnatal day 90 and 180 the acinar, intercalated and striated ductal cells reveal numerous secretory granules in the apical portion. The acinar cells showed basal nuclei and the parallel arrangement of granular endoplasmic reticulum. The mitochondria are located at the base of ductal cells showing a typical pattern of cristae. In these stages the intercellular digitations of cytoplasmic protrusions and desmosomes are also noted. The cytoplasm of myoepithelial cells are seen along the cell membranes. The spongy-like structures constituting the basement membrane are followed by bundles of fine collagen fibers.

Animals↗

PubMed1997

[A case of advanced breast cancer receiving combination therapy with 5'-DFUR and MPA with remarkable results].

A 75-year-old woman was admitted to our hospital with advanced breast cancer (T4bN3M0, Stage IIIb). She received chemoendocrine therapy of 5'-DFUR 800 mg/day and MPA 800 mg/ day for 2 months. The main tumor and metastatic lymph nodes were remarkably reduced and became resectable. Histological examination revealed necrotic change of the tumor tissues. This combination therapy proved very useful for advanced breast cancer.

Aged↗

PubMed1997

[Correlations between cell proliferating activity and apoptosis in the colorectal cancer and apoptosis in the mucosa adjacent to colorectal cancer].

To investigate the growth and progression of colorectal cancer, cell production versus cell loss in colorectal cancer was examined using the proliferating cell nuclear antigen (PCNA) positivity rate and apoptotic index (AI). Cell loss was then examined using AI in the mucosa adjacent to colorectal cancer. The higher the PCNA positivity rate, the higher the apoptotic index in colorectal cancer. These results suggested that changes in cell production and cell loss may be closely correlated and play a role in the growth and progression of colorectal cancer. In patients with advanced colorectal cancer, the mucous composition of the adjacent mucosa was classified as sialomucin-predominant. Apoptosis at the proliferating zone in the mucosa adjacent to colorectal cancer (one or two glandular ducts) was also examined using the TUNEL method. This suggests that the mucosa adjacent to cancer is involved in apoptosis.

Apoptosis↗

PubMed1997

Time series analysis of the course of Menière's disease.

Subjective symptoms of Menière's disease (vertiginous attacks, nonparoxysmal dizziness, tinnitus, hearing loss, headache, stiff neck, nausea etc.) were graded respectively according to severity (0-3 or 0-5) and were recorded daily by affected patients. These recordings, from 20 cases of Menière's disease, were collected and analysed by an original program of time series analysis including autocorrelation, cross-correlation, daily sum of inner ear related factors and general factors, and their moving average. Cluster occurrence of dizzy spells in the active stage and a marked cross-correlation between inner ear factors and general factors were found to constitute a characteristic pattern in Menière's disease in relation to its pathophysiology. Time series analysis was also useful for clinical decision-making, such as evaluation of the effect of treatment, and estimation of prognosis.

Anti-Inflammatory Agents↗

PubMed1997

[Combination use of second generation cephem and isepamicin for the treatment of post-surgical infection of the lower digestive tract].

Effects of combination use of a second generation cephem and an aminoglycoside antibiotic isepamicin (ISP), for the treatment of post-surgical infections of the lower digestive tract were examined from a laboratory and clinical perspective. Thirty-three out of total 35 cases were included in the analysis of the test, while the other 2 cases did not meet the criteria for analysis. ISP was administered in combination with one of the second generation cephems among cefotiam (CTM), cefmetazole (CMZ), or cefuroxime (CXM) for 26 cases of wound infection and 7 cases of peritonitis. The overall efficacy rate was 88%; 92% in wound infection and 71% in peritonitis individually. There was no significant difference in efficacy among different groups. Bacteriological study showed the combination use of any one of the second generation cephems and ISP was very effective in all 14 cases of infections with a single species of bacterium, the efficacy rate was 100%. It was also effective in 9 out of 10 cases with mixed infections of 2 species of bacteria (90%), but effectiveness was diminished in only 6 out of 9 cases with mixed infections of 3 species (67%). Sixty-nine strains were isolated from the 35 cases, more than half of which (44 strains) were Gram-negative; 14 strains of E. coli (20%), 13 strains of E. faecalis (13%) and 6 strains of P. aeruginosa (9%). The MIC50 and MIC90 were, respectively, 1.56 micrograms/ml and 100 micrograms/ml for ISP, 6.25 micrograms/ml and 100 micrograms/ml for CTM, 12.5 micrograms/ml and 100 micrograms/ml for CMZ, and 25 micrograms/ml and 100 micrograms/ml for CXM. The MICs in any combination uses decreased synergistically according to ISP concentration. Adverse events were observed in 3 out of 35 cases, but they were not severe. The results indicated that the combination use of a second generation cephem and ISP was useful and should be one of the choices for the treatment of post-operative infections of the lower digestive tract.

Adult↗

PubMed1996

Balneotherapy and platelet glutathione metabolism in type II diabetic patients.

Effects of balneotherapy on platelet glutathione metabolism were investigated in 12 type II (non-insulin-dependent) diabetic patients. Levels of the reduced form of glutathione (GSH) on admission were well correlated with those of fasting plasma glucose (FPG; r = 0.692, P < 0.02). After 4 weeks of balneotherapy, the mean level of GSH showed no changes; however, in well-controlled patients (FPG < 150 mg/dl), the level increased (P < 0.01) and in poorly controlled patients (FPG > 150 mg/dl), the value decreased (P < 0.05). There was a negative correlation between glutathione peroxidase (GPX) activities and the levels of FPG (r = -0.430, P < 0.05). After balneotherapy, the activity increased in 5 patients, decreased in 3 patients and showed no changes (alteration within +/- 3%) in all the other patients. From these findings in diabetic patients we concluded: (1) platelet GSH synthesis appeared to be induced in response to oxidative stress; (2) lowered GPX activities indicated that the antioxidative defense system was impaired; and (3) platelet glutathione metabolism was partially improved by 4 weeks balneotherapy, an effect thought to be dependent on the control status of plasma glucose levels. It is suggested that balneotherapy is beneficial for patients whose platelet antioxidative defense system is damaged, such as those with diabetes mellitus and coronary heart disease.

Antioxidants↗

PubMed1996

Trace element accumulation in Baikal seal (Phoca sibirica) from the Lake Baikal.

Trace element concentrations (Fe, Mn, Zn, Cu, Pb, Ni, Cd, Co and Hg) were determined in 60 Baikal seals and in fishes collected from Lake Baikal in 1992. Low levels of Hg and Cd were found in Baikal seals in comparison with those of marine mammals and it was due to their low concentrations in dietary fish. These results suggest that pollution by Hg and Cd was low in Lake Baikal and these toxic elements were unlikely to be the causative factors for mass mortality of Baikal seal in 1987-1988. Significant correlation of Hg concentration between hair and internal tissues suggested the use of hair for Hg monitoring in pinnipeds. Among essential elements, higher Fe and lower Cu levels were specifically found in the liver of Baikal seal. The noticeable accumulation of essential elements might be related to the unique and specific environment of Lake Baikal.

Journal Article↗

PubMed1996

A case report of occult thyroglossal duct carcinoma.

A 50-year-old male had an occult thyroglossal duct carcinoma in the thyroglossal duct remnant attached to the upper pole of a thyroglossal duct cyst which was noticed due to extravasation of the cyst. After the patient had been struck into the thyroid cartilage with the tip of a bamboo sword while practicing Japanese fencing. The authors emphasize again that the important matter in the treatment of thyroglossal duct cysts is the removal of the whole thyroglossal duct remnant with the central portion of the hyoid bone according to Sistrunk's method in order to prevent not only recurrence of the thyroglossal duct cyst but also not to overlook any microcarcinoma.

Carcinoma↗

PubMed1996

Diverse effects of tumor necrosis factor-alpha on three subclones from human myelomonocytic leukemia cell line ME-1 exhibiting different differentiation stages.

The effects of tumor necrosis factor-alpha (TNF-alpha) were examined in three subclone cells from human myelomonocytic leukemia cell line ME-1. These three subclone cells exhibit different differentiation stages of the myelomonocytic lineage. TNF-alpha exerted a growth-suppressive effect on the least mature subclone cells, ME-F2 cells. On the other hand, TNF-alpha induced the most mature ME-F1 cells and intermediate ME-F3 cells to differentiate along the monocytic pathway. TNF-alpha also enhanced interferon-gamma (IFN-gamma)-induced complement C2 production by ME-F1 and ME-F3 cells but did not affect production by differentiated ME-F1 and ME-F3 cells. These results suggest that the diversity of the effects of TNF on subclone cells from ME-1 depends on the stage of cell differentiation.

Cell Differentiation↗