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Biomedical subjects

S Okuda

Publications and source records attributed to S Okuda.

At least 145 records · Page 8Linked to original sources

Effects of anti-hyperlipidaemic agent or dietary protein restriction on progressive renal deterioration in adriamycin-induced nephropathy in rats.

Hyperlipidaemia is strongly suggested to contribute to the pathogenesis of glomerular sclerosis. This study intends to clarify the effects of either a lipid lowering agent, lovastatin (LO) or protein restriction (PR) on adriamycin (ADR)-induced progressive glomerular sclerosis in rats. During the study period both serum cholesterol and triglyceride were significantly reduced in ADR-injected rats with either lovastatin administration (ADR-LO) or protein restriction (ADR-PR) compared to those without such treatment (ADR-NP). At week 22, urinary protein excretion, serum creatinine, blood urea nitrogen, glomerular sclerosis and tubulointestinal alterations, which were marked in ADR-NP, were ameliorated in both ADR-LO and ADR-PR rats. ADR-LO resulted in a body weight similar to that in ADR-NP while ADR-PR induced a marked weight loss. An antihyperlipidaemic agent, such as lovastatin, seems to be a useful tool for the prevention of renal deterioration.

Animals↗

[A case of tuberculous meningitis with abnormal contrast enhancement of choroid plexus on CT and MRI].

A 55-year-old man first noted a swelling on his back in September 1990, when CT scan of his chest suggested a pleural fistula and a cold abscess. In the following month, he became pyrexial and felt nauseated with headache. Subsequently he was transferred to our hospital. Results of neurological examination were abnormal only in that he had neck stiffness and bilateral nystagmus with drowsiness. Cerebrospinal fluid (CSF) showed turbid yellowish fluid with an opening pressure of 360 mmH2O, a protein content of 173 mg/dl, a glucose level of 19 mg/dl, and a white blood cell count of 3,024/ml (75% polymorphs, 25% lymphocytes). Tryptophane test was positive. No bacteria, fungi or acid-fast bacilli were seen on direct smear. Adenosine deaminase activity in CSF was 13.9 IU/l. Antibiotics, antituberculous drugs, corticosteroids and glycerol were administered. The clinical course in the hospital was satisfactory for the next two months, but a contrast enhanced CT scan showed prominent enhancement in the left choroid plexus, and MRI revealed another mass in the subarachnoidal space under the right frontal lobe. An open biopsy was done on the massive lesion in the frontal lobe. Macroscopically, this lesion was an encapsulated granulomatous one. On the other hand, there were groups of epitheloid cells with micronecrosis in their centers microscopically. These findings were compatible with tuberculoma, in spite of the absence of acid-fast bacilli or caseous necrosis. Medication was intensively continued: a follow-up CT showed gradual reduction of the choroid plexus lesion and shrinkage of the left lateral ventricle.

Choroid Plexus↗

Possibility of hepatic resection in patients on maintenance hemodialysis.

A review of seven hepatic resections in six patients undergoing maintenance hemodialysis is presented. These cases consisted of hepatocellular carcinoma in four, and cholangiocellular carcinoma, myelolipoma and focal nodular hyperplasia in one each. The last preoperative hemodialysis was undertaken within 24 h prior to the operation with heparin. Intraoperatively, infused solutions containing no potassium, along with strict attention to preventing overhydration, allowed us to manage the patients without hemodialysis on the day of the operation. No specific intra-operative complications related to hemodialysis were noted. Postoperative hemodialysis was performed on the first or second day after operation, using nafamstat mesilate, a synthetic protease-inhibiting agent. The morbidity rate in the hemodialyzed patients was 85.7% (6/7), which was significantly higher than that in the non-hemodialyzed patients who underwent hepatic resections in our hospital. Fluid collection in the pleural and/or peritoneal cavities was frequent and difficult to control, but transient. Our experience suggests that hepatic resection is an acceptable procedure for hemodialyzed patients, when used in conjunction with careful perioperative management.

Adenoma, Bile Duct↗

Cytologic examination of pure pancreatic juice in the diagnosis of pancreatic carcinoma. The endoscopic retrograde intraductal catheter aspiration cytologic technique.

BACKGROUND: Although cytologic examination of pure pancreatic juice obtained with a duodenofiberscope has been useful for the diagnosis of pancreatic carcinoma, the rate of false-negative results is reported to be high. To eliminate these false-negative results, the authors developed a new technique, endoscopic retrograde intraductal catheter aspiration cytology, especially for an accurate cytologic diagnosis of carcinoma of the body or tail of the pancreas. METHODS: The accuracy of conventional cytologic examination of pure pancreatic juice was assessed in 25 patients with pancreatic carcinoma, 29 patients with pancreatitis, and 52 control subjects. Pure pancreatic juice was collected from the pancreatic duct by endoscopic cannulation using a videoimaging duodenoscope after intravenous administration of secretin. The new endoscopic retrograde intraductal catheter aspiration technique was used in four patients with carcinoma of the body or tail of the pancreas and five patients with localized pancreatitis in whom a correct diagnosis was not made by previous cytologic examination of pure pancreatic juice. RESULTS: Positive cytologic findings were obtained in 76% of the patients with pancreatic carcinoma. Positive cytologic results were more frequent in patients with carcinoma of the head of the pancreas than in those with carcinoma of the body or tail. By the new technique, positive cytologic results were obtained in all of the patients with pancreatic carcinoma. This technique caused no severe complications. CONCLUSIONS: This procedure of endoscopic retrograde intraductal catheter aspiration cytology seems useful for diagnosis of pancreatic carcinoma.

Catheterization↗

Measurement of glycated albumin by the nitroblue tetrazolium colorimetric method.

A method has been developed for the measurement of glycated albumin (albumin-fructosamine) by the nitroblue tetrazolium (NBT) colorimetric method. In this method, polyethylene glycol was added to the serum and then the mixture was centrifuged to separate globulin proteins from albumin proteins. This made it possible to measure the glycated albumin in the supernatant by the NBT colorimetric method, without the interference of globulin proteins. This measurement method correlated with the measurement of glycated albumin using boronate affinity chromatography with an r value of 0.942 (P < 0.001). Our method using polyethylene glycol permits easy measurement of albumin fructosamine and is therefore useful as an index of diabetic control and for diabetic screening.

Chromatography, Affinity↗

Early depressed adenocarcinomas of the large intestine.

From January 1987 to December 1990, five cases of early depressed cancer of the large intestine were seen. Endoscopically, almost all of these tumors were located in the proximal colon and looked like a reddish depression (similar to the sucker of an octopus). Histologically, all of these cancers were well differentiated and tended to reach deeper layers at an early stage. Four (80%) of these cancers were not associated with adenoma and were thought to have arisen de novo.

Adenocarcinoma↗

Enhancement by thyroxine of experimental carcinogenesis induced in rat colon by azoxymethane.

The effect of thyroxine (T4) on the incidence, number and histology of colon tumors induced by azoxymethane (AOM), and on the labeling index of colon mucosa were investigated in Wistar rats. Rats were given AOM by injection once a week for 10 weeks, together with T4 in depot form until the end of the experiment. Administration of T4 resulted in a significant increase in the incidence of colon tumors in week 35. However, it did not influence the histological appearance of the colon tumors or the histological types and depths of involvement of colon adenocarcinomas. Furthermore, it caused a significant increase in the labeling index of the colon during, but not after, AOM treatment. Our findings indicate that T4 enhances the development of colon tumors, which may be related to its effect in increasing proliferation of epithelial cells in the colon mucosa during administration of the carcinogen.

Adenocarcinoma↗

Enhancement by vaso-active intestinal peptide of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats.

The effects of vaso-active intestinal peptide (VIP) on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were investigated in Wistar rats given VIP every other day for 27 weeks after oral administration of MNNG for 25 weeks. In week 52, administration of VIP caused a significant increase in the incidence of gastric cancers, but did not influence their histological appearance. VIP significantly increased the labeling indices of the antral mucosa. Our findings indicate that VIP enhances gastric carcinogenesis, and that this effect may be related to its effect in increasing cell proliferation of the antral epithelial cells.

Animals↗

A prospective trial of early detection of pancreatic cancer by ultrasonographic examination combined with measurement of serum elastase 1.

The accuracy of ultrasonographic examination combined with measurement of elastase 1 levels for early detection of pancreatic cancer was evaluated prospectively. Abdominal ultrasonographic examination and measurement of serum elastase 1 levels were done within 2 weeks after the initial visit to the clinic in a total of 2098 patients older than 35 years of age with symptoms suggesting pancreatic disease. Those in which one or both of these examinations had abnormal results underwent additional tests such as endoscopic retrograde cholangiopancreatography and computed tomography. Of those with pancreatosonograms with abnormal results with or without abnormally high serum elastase 1 levels, 19 patients eventually were found to have pancreatic cancer. No patients with pancreatic cancer, a normal level of serum elastase 1, and a pancreatosonogram with normal results were found, but follow-up studies revealed one pancreatic cancer in 189 patients after technically unsatisfactory ultrasonographic examination. In 9 (45%) of the 20 cases detected in this study, the pancreatic cancers were resectable, and two (10%) were less than 2.0 cm in longest diameter. These findings indicate that this combined examination is useful for early detection of pancreatic cancer. However, no pancreatic cancer was found in patients with abnormally high serum elastase 1 levels without a pancreatosonogram with abnormal results. Moreover, a combination of ultrasonographic examination and measurement of the elastase 1 level did not raise the diagnostic accuracy over that of ultrasonographic examination alone. These findings indicate that ultrasonographic examination alone is useful in screening for early pancreatic cancer.

Adult↗

Attenuating effect of ornithine decarboxylase inhibitor (1,3-diaminopropane) on bombesin enhancement of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine.

The effects of combined administration of bombesin and the ornithine decarboxylase (ODC) inhibitor 1,3-diaminopropane (DAP) on the incidence and number of gastric tumors induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), the ODC activity of the gastric wall and the labelling index of the gastric mucosa were investigated in inbred Wistar rats. Rats were given drinking water containing MNNG (50 micrograms/ml) for 25 weeks and then drinking water containing DAP (2.5 g/l) and/or injections of 40 micrograms/kg body weight of bombesin in depot form every other day. Administration of bombesin alone resulted in significant increases in the incidence of gastric cancers, the ODC activity of the antral portion of the gastric wall and the labelling index of the antral mucosa. Administration of DAP with bombesin significantly reduced enhancement by the latter of gastric carcinogenesis, ODC activity of the antral portion of the gastric wall and the labelling index of the antral mucosa. Our results suggest that ODC inhibition attenuated the enhancement of gastric carcinogenesis by bombesin, and that this enhancement by bombesin was mediated by polyamine biosynthesis.

Adenocarcinoma↗

Intrahepatic venous and portal venous aneurysms examined by color Doppler flow imaging.

Thirteen cases with liver cystic lesions, which were suspected to communicate with intrahepatic vessels on the basis of ordinary sonography, were examined by color Doppler flow imaging. By this method, blood flow within the cystic lesion was detected in 5 of these cases, and the communication to the intrahepatic vessel confirmed. Information about the hemodynamics of aneurysms was obtained. Two of these lesions were diagnosed as an aneurysmal porta-hepatic venous fistula, another 2 as a portal venous aneurysm, and the remaining 1 as a hepatic venous aneurysm.

Aneurysm↗

Enhancement of dopaminergic agonist bromocriptine of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of the dopamine agonist 2-bromo-alpha-ergocryptine methanesulfonate (bromocriptine) on the incidence, number and histology of gastric cancer induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were investigated in Wistar rats. Rats were given 1 or 2 mg kg-1 body weight of bromocriptine subcutaneously every other day in depot form after 25 weeks of oral treatment with MNNG. Prolonged administration of bromocriptine at both dosages every other day resulted in a significant increase in the incidence and number of gastric cancers of the glandular stomach by week 52. Bromocriptine treatment did not influence the histological type of gastric cancer, but caused a significant increase in the labelling index of epithelial cells of the antrum. These findings indicate that the dopamine agonist bromocriptine promotes gastric carcinogenesis, and that this effect may be related to its effect in increasing proliferation of epithelial cells in the antral mucosa.

Adenocarcinoma↗

Effect of treatment with cisapride alone or in combination with domperidone on gastric emptying and gastrointestinal symptoms in dyspeptic patients.

The effects on gastric emptying and gastrointestinal symptoms of treatment with cisapride alone and in combination with domperidone were investigated in 25 patients with chronic idiopathic dyspepsia. In a double-blind study, 9 patients were randomly assigned to receive cisapride 2.5 mg three times daily, and 8 patients to receive placebo. After 7 days of treatment, gastric emptying was significantly accelerated and the score of gastrointestinal symptoms was significantly reduced in patients treated with cisapride. Placebo treatment had no significant effect. A randomized, double-blind crossover study of 8 patients compared the effects of combined treatment with cisapride 2.5 mg plus domperidone 10 mg three times daily for 7 days against the effects of cisapride plus placebo. Administration of cisapride plus domperidone gave significantly higher gastric emptying and lower gastrointestinal symptoms than cisapride plus placebo.

Chronic Disease↗

Synthesis of fibronectin by isolated glomeruli from nephrectomized hypertensive rats.

The accumulation of extracellular matrix (ECM) is an important feature of most forms of progressive glomerular diseases. In order to examine the relationship between ECM synthesis and glomerulosclerosis, we evaluated fibronectin synthesis by glomeruli with the immunoprecipitation of conditioned media from isolated glomeruli in 5/6 nephrectomized spontaneously hypertensive rats (5/6N-SHR). There was no difference in blood pressure between 5/6N-SHR and control SHR throughout the experiment. Two weeks after the nephrectomy, most of the glomeruli were intact and no difference in the synthesis of fibronectin was observed between either groups. Twenty weeks after the nephrectomy, marked glomerulosclerosis associated with an increase in urinary protein was revealed in 5/6N-SHR but no glomerular lesions in control SHR. The synthesis of fibronectin by isolated glomeruli increased in 5/6N-SHR compared to control SHR. The administration of enalapril or hydralazine + reserpine + hydrochlorothiazide markedly attenuated the glomerular sclerosis and urinary protein excretion to a comparable degree, although the later therapy reduced blood pressure more effectively. These antihypertensive therapies also suppressed fibronectin synthesis in the 5/6N-SHR group at week 20. In conclusion, increased synthesis of glomerular fibronectin appeared to contribute to the glomerulosclerosis caused by subtotal nephrectomy and hypertension.

Animals↗

Enhancement by methionine- and leucine-enkephalin of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of the opioid receptor agonists methionine-enkephalin (Met-ENK) and leucine-enkephalin (Leu-ENK) on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine were investigated in Wistar rats. After 25 weeks of oral treatment with the carcinogen, the rats received subcutaneous injections of Met-ENK (20 micrograms/kg) or Leu-ENK (20 micrograms/kg) once every 2 days. The prolonged administrations of Met-ENK and Leu-ENK significantly increased the incidence of gastric cancers in week 52. Treatments with these opioid receptor agonists significantly increased the labeling index of the antral mucosa. These findings indicate that opioids enhance gastric carcinogenesis and suggest that their effects may be related to their influence on increasing proliferation of the antral epithelial cells.

Animals↗

[Newly developed MRSA medium].

We have developed a new selective medium, tentatively named MR(SA)2, for rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) from clinical specimens. MR(SA)2 medium contained modified Müller-Hinton agar supplemented with 75 g of NaCl, 10 g of mannit, 20 mg of bromcresol purple, 20 g of egg-yolk, 4 mg of oxacillin, and 12.5 mg of ceftisoxime per 1,000 ml. There were no differences between the growth of MRSA strains on this medium at 30 C and that of 37 C. This medium can detect the egg-yolk reaction instead of the coagulase reaction. By single streaking of a test material on the surfaces of MR(SA)2 agar, MRSAs can easily be distinguished from methicillin-resistant coagulase-negative staphylococci (MR-CNS), other bacteria and fungi from their colony morphologies in a quantitative manner. A few MRSA strains would not form colonies on this medium because of their susceptibilities to ceftisoxime, but this may not inpede its use, since most MRSA strains isolated from clinical materials showed resistance to ceftisoxime. From the above results, the MR(SA)2 medium may be suitable for rapid detection of MRSA and MR-CNS.

Ceftizoxime↗