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Biomedical subjects

S Ozeki

Publications and source records attributed to S Ozeki.

At least 73 records · Page 4Linked to original sources
PubMed1994

Squamous cell carcinoma of the oral cavity consisting of band-like nests.

Four squamous cell carcinomas of the oral cavity shared common histological and clinical characteristics. The primary lesion was situated at the floor of the mouth or the tongue. The cancer cell nests were band-like. The border between nests and stroma was smooth and distinct, with the continuity of the basement membrane being well maintained. The response to preoperative chemoradiotherapy was relatively poor. Although the lesion was locally advanced, no cervical metastasis was detected. No recurrence has occurred after the operation.

Aged↗
PubMed1993

Depressor effect of intraventricular administration of calcium on spontaneously hypertensive rats.

The role of central Ca2+ in the regulation of blood pressure (BP) was investigated in conscious spontaneously hypertensive (SHR) and Wistar-Kyoto rats (WKY). Ten microliters of a high Ca2+ solution (Ca2+: 32.6 mM) administered intracerebroventricularly (i.c.v.) decreased the mean arterial pressure (MAP) for more than 20 min in SHR (n = 7, P < 0.005), while no change of MAP was observed in the WKY (n = 6). This depressor response to Ca2+ i.c.v. was dose-dependent at Ca2+ concentrations between 16.3 and 65.2 mM. We also investigated the effect of high Ca2+ i.c.v. in SHR after pretreatment with Ca2+ channel blockers, diltiazem (60 micrograms/10 microliters) or nisoldipine (4, 8, 16 and 32 micrograms/10 microliters), administered i.c.v., the autonomic ganglion blocker, hexamethonium (50 mg/kg), administered i.v. and alpha-methyl-p-tyrosine (100 and 400 micrograms/10 microliters) delivered i.c.v. Pretreatment with i.c.v. diltiazem (n = 8) or nisoldipine (n = 5 for 8 micrograms, n = 6 for 4, 16, 32 micrograms) abolished and/or blunted the decrease of MAP due to high Ca2+. Hexamethonium administered i.v. (n = 6) also canceled the depressor action of i.c.v. Ca2+. Pretreatment with 100 micrograms of i.c.v. alpha-methyl-p-tyrosine could not prevent the depressor action of i.c.v. Ca2+; however, 400 micrograms of alpha-methyl-p-tyrosine administered i.c.v. abolished the effect of i.c.v. Ca2+. Furthermore Ca2+ channel blockers administered i.c.v. in themselves increased MAP in SHR (P < 0.05). These results suggest that central Ca2+ is involved in the central regulation of BP in SHR. This effect may be mediated through changes in sympathetic activity.

Animals↗
PubMed1993

Mandibular reconstruction using hydroxylapatite granules, autogenous bone, and a cervical island skin flap.

Ten patients with gingival carcinoma who were treated by marginal mandibulectomy were reconstructed using hydroxylapatite granules, autogenous bone chips, and a cervical island skin flap. The cervical flap was used to produce a cover and partition, designed to prevent the displacement of the mixture of hydroxylapatite and bone. Reconstruction was successfully achieved in all patients. Loss of height of the reconstructed mandible over an average 18-month follow-up ranged from 8% to 22%. One patient has worn a full denture and five patients wear partial dentures.

Aged↗
PubMed1993

Augmented central pressor action of magnesium in SHR.

This study attempted to determine whether central magnesium (Mg) influences the regulation of blood pressure (BP). An intracerebroventricular (icv) injection of a high Mg2+ solution (190.0 mEq/L, 10 microL), made by adding MgC12 to artificial cerebrospinal fluid, increased the mean BP in both conscious spontaneously hypertensive rats (SHR; n = 17, p < 0.001) and Wistar Kyoto rats (WKY; n = 8, p < 0.005). Spontaneously hypertensive rats showed a greater pressor response than WKY (+11.7 +/- 0.9 mm Hg versus +3.5 +/- 1.1 mm Hg, p < 0.001). This pressor response to Mg2+ given icv was dose-dependent in the range of Mg2+ concentration between 47.5 and 190.0 mEq/L in SHR. A high Mg2+ solution (190.0 mEq/L), made by adding MgSO4 given icv, also increased the mean BP in SHR (n = 7, p < 0.001) and WKY (n = 6, p < 0.01), whereas the high osmolarity solution (340 mOsm/kg H2O) given icv did not change the mean BP in either SHR or WKY. Also administered was a high Mg2+ solution icv after either hexamethonium bromide (Hx; 50 mg/kg intravenously) or arginine vasopressin antagonist (aAVP, (CH2)5Tyr(Me)AVP, 30 micrograms/kg i.v.). The pressor response to the high Mg2+ solution was abolished by arginine vasopressin antagonist both in SHR and WKY, although it was not canceled by Hx. A high Mg2+ solution administered icv caused a 3.5-fold increase in plasma arginine vasopressin concentration in SHR (n = 5, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Renin-secreting renal tumor. A case report].

We reported a case of juxtaglomerular cell tumor, which excessively produced renin, resulting in secondary hypertension. A 25-year-old woman complained of headache and nausea. Hypertension and elevation of plasma renin activity were found by physical and laboratory examination. US and CT showed a space occupying lesion at upper pole of the right kidney. Angiography showed a hypovascular area at the corresponding area of the right kidney. Renin-secreting renal tumor of the right kidney was diagnosed and right nephrectomy was performed. Postoperatively, blood pressure and plasma renin activity became normalized and symptoms ameliorated. The juxtaglomerular cell tumor was pathologically confirmed and localization renin in the tumor cells was shown by immunohistochemical study. Forty one cases of juxtaglomerular cell tumor have been reported, since Robertson reported the first case. We discussed the clinical and pathological characteristics of the disease in this report.

Adult↗
PubMed1993

Comparison of early glottic and supraglottic carcinoma treated with conventional fractionation of radiotherapy.

There were a few reports to compare the treatment results of glottic and supraglottic carcinoma. We investigated the difference of glottic and supraglottic carcinoma. From 1967 through 1985, 338 cases with early glottic (T1: 210, T2: 52) and supraglottic carcinoma (T1: 34, T2: 42) were treated with the conventional fractionation of radiation and evaluated the tumor response during radiation at the Department of Radiology, Osaka University Hospital. The ten-year actuarial survival rates of T1, T2 glottic and T1 and T2 supraglottic carcinoma were 63%, 64%, 58% and 46%, the corresponding ten-year cause-specific survival rates 92%, 89%, 88% and 78%, and the corresponding ten-year local control rates 76%, 67%, 69% and 59%, respectively. Tumor clearance rates of T1 and T2 glottic and T1 and T2 supraglottic carcinoma at 40 Gy were 68%, 40%, 35% and 24%, respectively. The local control rate of the tumor which disappeared at 40 Gy was 84%, that persisted at 40 Gy and disappeared at 60 Gy 69%, and that persisted at 60 Gy 33%. The local control rate and the tumor clearance rate of T1 glottic carcinoma were the highest among early laryngeal carcinoma, and those of T2 glottic carcinoma were the same as those of T1 supraglottic cases. The local control rate, the cause-specific survival rate, and the actuarial survival rate of T2 supraglottic were significantly lower than other cases.

Actuarial Analysis↗
PubMed1992

Contribution of the central interaction between calcium and sodium to hemodynamic regulation in spontaneously hypertensive rats.

The contribution of the central interaction between calcium and sodium to hemodynamic regulation was assessed in spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) rats. The effect of a high calcium solution (Ca2+, 130 mg/dl, 10 microliters) infused into the cerebral ventricle (i.c.v.) on hemodynamic responses induced by a high sodium solution (Na+, 1,000 mEq/1, 10 microliters) i.c.v. and the mechanism by which high Ca2+ affects the hemodynamic responses induced by high Na+ i.c.v. were studied. High Na+ i.c.v. induced a pressor response with tachycardia in the SHRs, but induced a pressor response with reflex bradycardia in the WKYs. Prior treatment with high Ca2+ i.c.v. attenuated the pressor response induced by high Na+ i.c.v. (+55.6 +/- 4.4 to +33.1 +/- 3.2 mmHg, P < 0.01) and restored reflex bradycardia (+86.4 +/- 7.7 to -26.7 +/- 7.6 bpm, P < 0.01) in SHRs. Whereas prior treatment with high Ca2+ i.c.v. attenuated the pressor response (+35.7 +/- 2.0 to +22.2 +/- 4.0 mmHg, P < 0.05), it did not alter the degree of reflex bradycardia (-81.7 +/- 7.1 to -69.2 +/- 120 bpm, n.s.) in WKYs. Ganglionic blockade attenuated the pressor response (+56.9 +/- 3.5 to +42.9 +/- 2.3 mmHg, P < 0.05) and restored reflex bradycardia (+82.1 +/- 10.3 to -65.9 +/- 11.0 bpm, P < 0.01) in SHRs, whereas, inhibition of arginine vasopressin attenuated the pressor response without modification of the tachycardic response.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Uptake of fractionated [3H]heparin by rat parenchymal hepatocytes in primary culture: effects of alpha-globulin, temperature, and pH.

The mechanism of uptake of fractionated [3H]heparin in conjunction with the effect of alpha-globulin (the major binding protein of heparin) was investigated in primary cultures of rat parenchymal hepatocytes. The uptake clearances were estimated from the initial linear phase, up to 1 min, of the uptake-versus-time profile. The uptake clearance for fractionated [3H]heparin was 11.0 mL/min/g of liver at 7.5 nM fractionated [3H]heparin in the absence of alpha-globulin. This value decreased with increasing concentration of alpha-globulin in the incubation solution, a fact suggesting that the rate of uptake of alpha-globulin-bound, fractionated [3H]heparin is lower than that of unbound [3H]heparin, as generally assumed for hepatic drug elimination. However, the uptake clearance in the presence of alpha-globulin at 8 mg/mL, where free, fractionated [3H]heparin was supposed to be negligible according to the results of our in vitro study, was approximately 12% of that in the absence of alpha-globulin. These results suggest that alpha-globulin-bound, fractionated [3H]heparin also contributes to the uptake of fractionated [3H]heparin. This effect on uptake could be explained by the protein-mediated transport concept rather than the traditional assumption that protein-bound drugs are not transported. The uptake clearance was reduced significantly by reducing the incubation temperature from 37 to 4 degrees C. However, neither the pH of the incubation solution (6.4-8.4) nor several inhibitors of active transport had any clear effects on the uptake clearance.

Alpha-Globulins↗
PubMed1992

Cervical island skin flap for intraoral repair following cancer surgery.

Seventy three patients with oral cancer were operated on using the cervical island skin flap of Farr et al. (1969). Primary sites of the lesions were the tongue, floor of the mouth and lower gingiva. Most of the patients received total doses of 22.5 Gy of radiation and 110 mg bleomycin as a preoperative treatment. Among the 73 patients, complete necrosis of the skin island was observed in 3 cases. There was half necrosis in 4 cases, one quarter necrosis in 6 cases and marginal necrosis in 17 cases. The flaps in 43 patients completely survived. Results were better in the operations undertaken in the last 4 years in which a superficial layer of deep cervical fascia on the sternocleidomastoid muscle was included in the flap.

Adult↗
PubMed1992

Macromolecule-macromolecule interaction in drug distribution. II. Effect of alpha-globulin on saturable uptake of fractionated [3H]heparin by rat parenchymal hepatocytes in primary culture.

The uptake of fractionated [3H]heparin was investigated in rat parenchymal hepatocytes in primary culture. The initial uptake of fractionated [3H]heparin was found to be saturable with the maximum uptake velocity (Vmax) of 10.1 +/- 1.46 pmol/min/mg protein and the Michaelis constant (Km) of 284 +/- 47.9 nM. The effect of alpha-globulin, the major protein binding to fractionated [3H]heparin, on the saturable uptake profile of fractionated [3H]heparin was also investigated. The uptake clearance was reduced, depending on the concentration of fractionated [3H]heparin, by the addition of 1 mg/ml alpha-globulin. We assumed that fractionated 3H-heparin bound to alpha-globulin was not available for uptake and that the reduction in the uptake clearance was solely attributable to the saturable binding of fractionated [3H]heparin to alpha-globulin. The uptake clearance versus concentration profile was analyzed to obtain the dissociation constant (Kd) of 31.8 nM and the capacity (n) of 0.047 for the binding of fractionated [3H]heparin to alpha-globulin. The saturable binding of fractionated [3H]heparin to alpha-globulin was supported by in vitro binding experiments using gel chromatography, in which bound fractionated [3H]heparin decreased with the concentration of fractionated [3H]heparin in the presence of alpha-globulin. In conclusion, the present study demonstrated the saturable uptake of fractionated [3H]heparin by rat parenchymal hepatocytes and the saturable binding of fractionated [3H]heparin to alpha-globulin. The saturable uptake may suggest the involvement of a specific transport system such as receptor-mediated endocytosis.

Alpha-Globulins↗
PubMed1992

[Solitary infected renal cyst: a case report].

A 48-year-old man was admitted to our hospital because of high fever and left flank pain. Laboratory findings revealed a high white blood cell count, high C-reactive protein level, and severe pyuria. Sonographic examination revealed an enlargement of the cyst at the upper pole of the left kidney that had already been detected. Percutaneous drainage was performed for the cyst and 60 ml of purulent fluid was obtained. Bacterial culture of the fluid was positive for Propionibacterium acnes and gamma-Streptococcus. The drainage and administration of povidone-iodine was continued for 7 days. The size of the cyst was reduced with disappearance of symptoms.

C-Reactive Protein↗
PubMed1991

The kinetics of chain exchange in two-chain coiled coils: alpha alpha- and beta beta-tropomyosin.

Measurements are presented on the time course of chain exchange among two-chain alpha-helical coiled coils of rabbit tropomyosin. All experiments are in a regime (temperature, protein concentration) in which coiled-coil dimers are the predominant species. Self-exchange in alpha alpha-tropomyosin was investigated by mixing alpha alpha species with alpha* alpha*, the asterisk designating an alpha-chain whose lone sulfhydryl (C190) has been blocked by carboxyamidomethylation. The overall process alpha alpha + alpha* alpha* in equilibrium with 2 alpha alpha* is followed by measurement of the fraction (h) of alpha alpha* species as a function of time. Similarly, self-exchange in beta beta-tropomyosin is examined by measurements of the overall process: beta beta + beta* beta* in equilibrium with 2 beta beta*, in which beta* signifies a beta-chain blocked at both sulfhydryls (C36 and C190). The observed time course for both chains is well fit by the first-order equation: h (t) = h (infinity) (1-e-k1t), with h (infinity) congruent to 0.5. This long-time limit is as expected for self-exchange, and agrees with experiments that attain equilibrium after slow cooling of thermally dissociated and unfolded chains. The simplest consonant mechanism is chain exchange by rate-limiting dissociation of dimers followed by random reassociation. Kinetic analysis shows k1 to be the rate constant for the chain dissociation step, a quantity not previously measured for any coiled coil. This rate constant for beta beta species is about an order of magnitude greater than for alpha alpha. In both, the activation enthalpy and entropy are very large, suggesting that activation to an extensively (greater than 50%) unfolded species necessarily precedes dissociation. Experiments are also reported for overall processes: alpha alpha + beta* beta* in equilibrium with 2 alpha beta* and alpha* alpha* + beta beta in equilibrium with 2 alpha* beta. Results are independent of which chain is blocked. Again h (infinity) congruent to 0.5, in agreement with equilibrium experiments, and the time course is first order. The rate constants and activation parameters are intermediate between those for self-exchange.

Animals↗
PubMed1991

A novel lipopolysaccharide-binding hemagglutinin isolated from hemocytes of the solitary ascidian, Halocynthia roretzi: it can agglutinate bacteria.

A hemagglutinin was isolated from hemocytes of the ascidian, Halocynthia roretzi, by a procedure including extraction and ion-exchange chromatography on CM-cellulose. The molecular weight of the hemagglutinin was estimated to be 120,000 by gel filtration. It was resistant to acid treatment but sensitive to alkali or heat treatment. The hemagglutinating activity was inhibited by heparin, chondroitin sulfate, and lipopolysaccharide (LPS), but not by mono- and disaccharides such as N-acetyl-galactosamine, galactose, and melibiose. The hemagglutinin showed binding ability to heparin and LPS, as demonstrated by heparin-Sepharose chromatography and centrifugation experiments, respectively. It was also found that the hemagglutinin can bind to various bacteria such as Escherichia coli, Bacillus subtilis, Vibrio anguillarum, Pseudomonas perfectomarinus, Achromobacter aquamarinus, and Alteromonas putrefaciens, and can agglutinate all of them.

Animals↗
PubMed1991

Guide groove for pinning subcondylar fractures.

For pinning subcondylar fractures, a guide groove cut on the lateral surface of the mandibular ramus is a useful method of directing a Kirschner wire into the correct position. An extended groove correctly guides the pin in difficult cases.

Bone Nails↗
PubMed1990

Macromolecule-macromolecule interaction in drug distribution: effect of alpha-globulin concentration on the hepatic uptake of fractionated 3H-heparin by perfused rat liver.

The effect of alpha-globulin, the dominant binding protein for fractionated 3H-heparin, on the hepatic uptake of 3H-heparin was studied by liver perfusion experiments in rats. Fractionated 3H-heparin concentration in the recirculated perfusate decline one-exponentially with time for each of six initial concentration levels of alpha-globulin. The hepatic uptake clearance of fractionated 3H-heparin was 0.154 ml/min/g liver in the absence of alpha-globulin, and it decreased with increasing alpha-globulin concentrations. This result indicates that the hepatic uptake rate of alpha-globulin-bound fractionated 3H-heparin is lower than that of unbound fractionated 3H-heparin. On the other hand, it was indicated that almost all fractionated 3H-heparin binds to alpha-globulin at 8 mg/ml of alpha-globulin in in vitro study. However, the hepatic uptake clearance of the heparin at the concentration was of a certain value that could not be ignored. It was suggested that alpha-globulin-bound fractionated 3H-heparin also contributed to the hepatic uptake of fractionated 3H-heparin. Therefore, a protein-mediated transport system, which has been reported for some low molecular weight drugs, may also exist in the hepatic uptake of such a high molecular weight compound as fractionated 3H-heparin.

Alpha-Globulins↗
PubMed1990

Inter-organ relation between salivary gland and kidney in lithium excretion. III. Enhanced salivary and systemic clearance of Li+ by oral administration of NaCl in dogs.

Effects of oral administration of NaCl on salivary and systemic clearance of Li+ were investigated following bolus intravenous administration of LiCl in male beagle dogs. Fifty ml of NaCl solution (100 meq/l) was administered orally 7 times at 1 h intervals. Gustatory stimulation of salivation was continued for 390 min using citric acid solution. Saliva was collected by means of permanent fistulae for parotid and mandibular-sublingual glands. Salivary clearance of Li+ was markedly increased by continuous stimulation of salivation, and was enhanced further after oral administration of NaCl solution. Renal clearance of Li+ showed a decreasing tendency under continuous salivation compared with the condition without gustatory stimulation; however, this decreasing tendency disappeared after oral administration of NaCl solution. Consequently, systemic clearance of Li+ was increased due to the contribution of increased salivary clearance. Enhancement of salivary Li+ clearance after administration of NaCl suggests the salivary excretion mechanism of Li+ may include a reabsorption process, like its renal excretion. Administration of NaCl solution had similar effects on salivary and systemic clearances of K+ to those on Li+ clearances, and a significant correlation was observed between Li+ and K+ clearances of both salivary gland and kidney.

Animals↗