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Biomedical subjects

S Ozeki

Publications and source records attributed to S Ozeki.

At least 91 records · Page 5Linked to original sources
PubMed1989

Salivary excretion of 5-fluorouracil (5-FU). IV. Dependency of saliva/plasma concentration ratio and salivary clearance on plasma concentration of 5-FU during constant-rate intravenous infusion in rats.

Salivary excretion profiles of 5-fluorouracil (5-FU) were investigated following simultaneous bolus intravenous injection of a loading dose and constant-rate intravenous infusion of a maintenance dose of at one of three dose levels in rats. By stimulating salivation with pilocarpine infused intravenously, mandibular (M) and parotid (Pr) saliva samples were periodically collected separately via cannulas inserted into the ducts. Simultaneously, salivary pH and salivary flow rate were determined. (1) There was a good correlation between plasma concentration and each of the saliva concentrations of 5-FU with regard to the pooled data of the three doses (p less than 0.01). (2) A gland type difference between M and Pr in the saliva/plasma concentration ratio (S/P ratio) of 5-FU was observed. This difference seemed to result from that in salivary pH. These findings were similar to the results following bolus intravenous administration of 5-FU in rats. (3) The fluctuations of the S/P ratio and salivary clearance of 5-FU were smaller than those following the bolus intravenous administration. (4) The S/P ratio and salivary clearance were larger at higher dose and higher plasma concentration of 5-FU. It was confirmed that non-linear kinetics might be involved in the salivary excretion of 5-FU in rats, and it was speculated that 5-FU excreted into primary saliva might be reabsorbed partly through some saturable process.

Animals↗
PubMed1989

Investigation on interaction of fractionated 3H-heparin with plasma proteins by gel filtration chromatography.

Interaction of fractionated 3H-heparin with plasma proteins was investigated by gel filtration chromatography. The peak of the elution profile for fractionated 3H-heparin in rat plasma was observed at the higher molecular weight fraction than that for fractionated 3H-heparin in buffer without any protein, suggesting the existence of fractionated 3H-heparin binding protein(s) in plasma. Then the interaction of fractionated 3H-heparin with such plasma proteins as albumin, antithrombin III, thrombin and alpha-globulin was investigated. The elution profile for fractionated 3H-heparin in albumin solution, antithrombin III solution and the solution containing antithrombin III and thrombin were different from that for fractionated 3H-heparin in plasma. The elution profile for fractionated 3H-heparin in alpha-globulin solution, of a concentration close to that in plasma, was comparable to that of fractionated 3H-heparin in plasma, though two peaks were found. The major peak corresponded to that of fractionated 3H-heparin in plasma, and the minor peak eluted at a higher molecular weight fraction. When alpha-globulin concentration was decreased, the major peak shifted to the lower molecular weight fraction, and the minor peak was diminished and then disappeared. Thus it was suggested that alpha-globulin is dominant for plasma protein binding of fractionated 3H-heparin.

Alpha-Globulins↗
PubMed1989

Inter-organ relation between salivary gland and kidney in lithium excretion. II. Salivary, renal and systemic clearances of lithium under continuous stimulation of salivation in water loaded dogs.

This study was undertaken to investigate the effects of water loading on lithium clearance in dogs under the continuous stimulation of salivation as well as to clarify the mechanism of the inter-organ relation between salivary gland and kidney in lithium excretion. Dogs were given intravenously 0.145 meq/kg of lithium chloride followed by the continuous stimulation of salivation with citric acid solution. Fifty ml of water was loaded orally 7 times at 1-h intervals. Parotid and mandibular-sublingual salivas were collected separately by means of permanent fistulae. (1) Plasma concentrations of lithium were not significantly different from either those in the experiment with continuous stimulation under no water loading or those in the control experiment without continuous stimulation. (2) Salivary clearance of lithium was markedly increased compared with that in the control experiment. The urinary flow rate, which was decreased under the continuous stimulation of salivation without water loading, was restored by the water loading. The renal clearance of lithium, which was also decreased under the continuous stimulation, remained at the reduced level under the condition of this study. Consequently, the systemic clearance of lithium did not change from that in the experiment under the continuous stimulation without water loading or that in the control experiment. (3) It was suggested that the salivary and renal excretion mechanisms of lithium might be similar to those of potassium, since a similar interrelation between salivary and renal clearances was observed for potassium. (4) It was suggested that the reduction in the renal clearance of lithium under the continuous stimulation of salivation was attributed to the sodium loss caused by the excessive salivation.

Animals↗
PubMed1988

Late occurring recurrence of oral cancer after combined treatment with bleomycin and radiotherapy.

Among 11 patients with oral cancer that disappeared after combined treatment with bleomycin and radiotherapy without surgery, one had an early recurrence and three had recurrences after 2 years or more. These late occurring recurrences were microcancers on mucous membranes that were thought to have been cured. Two of the three patients whose tumors recurred and another patient were found to have epithelial dysplasia at 1 year and 2 months, 4 years and 2 months, and 1 year and 3 months later, respectively. Among 59 patients who underwent surgery after the combined treatment, no viable cancer cells were found in the resected specimens of 20 patients, but moderate or severe epithelial dysplasia was noted in ten of the 20 patients. The present findings imply that patients in whom an apparent cure has been brought about by conservative treatment may harbor latent malignancy.

Adult↗
PubMed1988

Effect of perfused rat mandibular-gland pHI on the ratio of procainamide concentration in saliva to that in venous effluent.

The saliva to venous-effluent concentration ratio (S/E ratio) for procainamide (PA) was determined and compared with the ratio calculated by using the intracellular pH value of glandular cells. Exposed mandibular gland was perfused in situ with Krebs-Ringer bicarbonate buffer containing PA (10-100 micrograms/ml) and acetylcholine (ACh, 0.1 to 10 microM) or pilocarpine (10 microM). These perfusion conditions maintained almost normal physiological function of the mandibular gland throughout the perfusion period of 60 min, since the salivary Na+ and K+ concentrations were kept at almost constant levels, comparable with those reported in vivo, and the salivary flow, pH and protein level were also stabilized. Under fixed stimulation conditions with 1 microM ACh or 10 microM pilocarpine, the perfusate PA concentration ranging from 20 to 100 micrograms/ml did not affect the S/E ratio (approximately 0.3). There was a negative correlation between the S/E ratio and salivary pH when stimulated with 0.1 to 10 microM ACh. However, Matin's equation [S. B. Matin et al., Clin. Pharmac. Ther. 16, 1052 (1974)] employing venous effluent and salivary pH values did not explain fully these observed ratios. In contrast, Borzelleca's model [J. F. Borzelleca and J. W. Putney, J. Pharmac. exp. Ther. 174, 527 (1970)] for salivary drug transport using intracellular pH of the mandibular gland cells predicted S/E ratios relatively close to the observed values when the gland was perfused at pH 7.4 or 8.0.

Acetylcholine↗
PubMed1988

Familial occurrence of oral cancer: report of cases.

Four cases of familial occurrence of oral cancer are described and the postulated causes and predisposing factors of oral cancer are reviewed. None of these factors could satisfactorily explain the unusual familial occurrence observed in the cases presented.

Adult↗
PubMed1988

Cervical lymph node metastasis in carcinoma of the tongue. Correlation between clinical and histopathological findings and metastasis.

The factors relating to lymph node metastasis occurring in association with carcinoma of the tongue have been investigated clinically and histopathologically by many authors. Nevertheless, accuracy in predicting lymph node metastasis has not yet been attained. The present study describes the results of analysis performed in an attempt to predict lymph node metastasis of carcinoma of the tongue. Ninety-eight patients with squamous cell carcinoma of the tongue who were treated at our institution were investigated. Among the 98 patients, lymph node metastases were histologically proven after neck dissection in 40 patients. For statistical analysis in the present study, the quantification theory Type II of Hayashi (1954) was employed for discriminatory analysis. According to this discriminatory analysis, the correlations between the clinical (age, tumour size, N-category) and histopathological (degree of keratinization, mitoses, structure, mode of invasion) findings and metastasis were assessed on the basis of the partial correlation coefficients; these coefficients for each finding were not greatly different from each other and 74 out of 98 patients (76%) could be differentiated between patients with metastasis and without metastasis accurately. The prediction of lymph node metastasis by such discriminatory analysis had significant validity.

Adult↗
PubMed1988

Salivary excretion of 5-fluorouracil. II. Fluctuation of saliva/plasma concentration ratio and salivary clearance during a constant rate intravenous infusion in beagle dogs.

Salivary excretion of 5-fluorouracil (5-FU) was investigated during constant rate intravenous infusion (0.306 mg/kg/min) in three male beagle dogs. Parotid (Pr) and mandibular-sublingual (MS) saliva were collected separately by stimulating salivation with 10% citric acid. After the start of 5-FU infusion, plasma and salivary 5-FU concentration increased rapidly to approach their steady state levels. There was a significant correlation between each saliva and plasma 5-FU concentration (p less than 0.01). The saliva/plasma drug concentration ratio (S/P ratio) and salivary pH were significantly higher in Pr than in MS saliva (p less than 0.001), similar to the results following bolus intravenous administration of 5-FU in beagle dogs. Both S/P ratio and salivary clearance increased with time before steady state. Thereafter, these values approached almost constant levels and their fluctuations became smaller than those following the bolus intravenous administration. These results showing S/P ratio and salivary clearance of 5-FU were affected by the plasma drug concentration, suggested the possibility that non-linear pharmacokinetics may be involved in the salivary excretion of 5-FU.

Animals↗
PubMed1988

Inter-organ relation between salivary gland and kidney in lithium excretion. I. Effects of continuous stimulation of salivation on salivary, renal and systemic clearances of lithium in dog.

The effects of continuous stimulation of salivation on salivary, renal and systemic clearances of lithium were investigated following bolus intravenous administration of lithium chloride (0.145 meq/kg) in three beagle dogs. The salivation was frequently stimulated with citric acid solution, then parotid saliva and mandibular-sublingual saliva were collected separately by means of permanent fistulae. Although the continuous stimulation of salivation markedly increased the salivary clearance of lithium, no significant change was observed in plasma concentrations or systemic clearance of lithium. This was because the decrement in the renal clearance of lithium canceled out the effect of increased salivary clearance. It is suggested that the reabsorption of lithium in the renal tubule was enhanced under the continuous stimulation of salivation, and this seemed to be caused by loss of water or sodium through the salivary glands.

Animals↗
PubMed1988

[Pulmonary tuberculosis in patients with oral cancer].

During an 11 year period, from 1976 to 1986, 33 (10.1%) out of 328 patients with oral cancer treated at our clinic had either a scarred pulmonary tuberculosis (TB) or active TB. Four of these 33 patients developed active TB. In two of these cases TB occurred before the therapy of oral cancer commenced and in the other two, after the operation for oral cancer. In one of the 4 cases, a recrudescence of the TB was suspected. Five cases that were suspected of having TB on analysis of their chest X-rays were administered prophylactic anti-tuberculous chemotherapy, after which no recrudescence or onset of TB.

Adult↗
PubMed1987

Mandibular and parotid salivary excretion of procainamide and N-acetylprocainamide after intravenous administration of procainamide to rats.

Flow rate, protein level and pH of mandibular and parotid saliva samples in rats were almost stabilized 2 h after induction of salivation with pilocarpine (9.0 mg h-1 kg-1). Salivary excretion profiles of procainamide, 50 mg kg-1 i.v., and its metabolite N-acetylprocainamide (NAPA) were then investigated. Plasma and salivary procainamide levels declined bi-exponentially with time almost in parallel. Salivary procainamide levels (Y) from both types of gland were correlated with the plasma level (X) over a wide concentration range [Y = 0.108X + 1.96 (r = 0.795) for mandibular and Y = 0.917X (r = 0.974) for parotid glands]. The mean saliva to plasma concentration ratio (S/P ratio) was significantly higher in parotid (0.974 +/- 0.243) than in mandibular (0.284 +/- 0.119) saliva samples. Similar correlations and S/P ratios were observed for NAPA. Procainamide and NAPA mean S/P ratios for saliva from both glands were fairly consistent with the calculated value according to the pH-partition hypothesis.

Acecainide↗
PubMed1986

Role of mandibular striated duct in salivary excretion of urea in dogs.

The role of mandibular striated duct in salivary excretion of endogenous urea was studied by a technique of retrograde ductal injection of HgCl2 and a stop flow analysis. (1) It was verified in this study that treatment with HgCl2 markedly inhibited Na+ reabsorption in the striated duct so that water reabsorption driven by the Na+ reabsorption would be inhibited substantially. (2) The saliva/plasma concentration ratios (S/P ratios) of urea in HgCl2-treated saliva (about 0.71) were significantly higher than those in untreated saliva (about 0.37). (3) The excretion rate of urea in HgCl2-treated saliva (about 0.02 mg/min/kg) was also significantly higher than those in untreated saliva (about 0.01 mg/min/kg) despite the same flow rate for both saliva samples. Furthermore, (4) The S/P ratios of urea in the second (0.25-0.50 ml) poststop-flow saliva (about 0.65) were significantly higher than those in prestop-flow saliva (about 0.35). These results suggest a possibility that salivary urea is reabsorbed in the dog mandibular striated duct and that the enhancement of the S/P ratio as well as the salivary level of urea by the pre-treatment with HgCl2 may be due to the inhibition of urea reabsorption.

Animals↗