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Biomedical subjects

M Nemoto

Publications and source records attributed to M Nemoto.

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

[Complete eradication by endoscopic injection sclerotherapy reduces the recurrence of esophageal varices].

Endoscopic intravariceal injection sclerotherapy (EIS) using sclerosant mixed with contrast medium was done in 100 patients without hepatocellular carcinoma. They were followed longer than 12 months (mean; 58 +/- 29 months) after EIS. The recurrence rate of esophageal varices in cases with complete eradication (n = 79) and cases with incomplete eradication of (n = 21) was 8.9% and 85.7%, respectively (p < 0.01). In 21 cases, complete eradication was achieved by intravariceal injection and additional therapy using paravariceal injection was not performed. The recurrence rate of this group was only 4.8%. Endoscopic varicealography during injection sclerotherapy were evaluated in 91 cases. At final session of EIS, narrowing of diameter (less than 1 mm) and irregularity of vessel walls were observed in small vessels (devastated vessels). Appearance rate of devastated vessel in 75 cases with completely eradicated esophageal varices was 65.3%. In contrast, among 16 cases with incomplete eradication of varices, devastated vessels were seen only in 6.3% (p < 0.01). It is concluded that the important point in preventing the recurrence of esophageal varices after EIS was the complete eradication of esophageal varices by intravariceal injection sclerotherapy resulting in the eradication of the routes to esophageal varices from port-splenic venous system. For the sake of accomplishment of this treatment, appearance of devastated vessel is very useful.

Adult↗
PubMed1994

[Deterioration of liver function following endoscopic injection sclerotherapy of esophageal varices--significance of the new liver function test "intravariceal injection (I.I.) index"].

Changes of liver functions associated with endoscopic injection sclerotherapy (EIS) were investigated in 143 patients with remarkable esophageal varices. The index used for evaluating hepatic reserve was the ratio between the increase of total bilirubin and the increase of LDH after EIS [I.I. index = (delta T.Bil./delta LDH) x 100] in cases treated by intravariceal injection of 5% ethanolamine oleate. I.I. index value caused by hemolysis was stable and always below 0.2, while the elevation of I.I. index above 0.2 was regarded as the reflection of the deterioration of liver function. After the entire sessions of EIS, the changes of liver function tests before and after EIS were estimated in 104 cases using 3 factors as follows; (1) delta T.Bil.; increase of total bilirubin more than 0.5 mg/dl (2) delta PT; decrease of prothrombin time more than 5% (3) delta ICG R15; increase of ICG R15 more than 5%. I.I. index of group I (without any changes of 3 factors mentioned above; n = 66) was 0.22 +/- 0.16, approximately within normal range. However, in group II (with 1 factor; n = 29), group III (with 2 factors; n = 5), group IV (with all factors; n = 4), I.I. index was elevated according to the severity of their liver dysfunction. The cases whose I.I. index value increased gradually during the course of EIS, were apt to deteriorate the liver functions and therefore, should be carefully observed. Also, I.I. index seems to reflect the prognosis of the patients treated by EIS for some extent, since the survival period of the cases treated by EIS were correlative with the value of I.I. index (r = -0.542, p < 0.01), and I.I. index of 32 cases who survived for longer than 5 years after EIS was almost normal (0.22 +/- 0.15).

Adult↗
PubMed1993

[Studies of WBN/Kob rat, 18th report: effect of 1 alpha-OH-D3 on diabetic osteopenia].

We examined the effect of 1 alpha-OH-D3 on diabetic osteopenia in spontaneously-developed diabetic WBN/Kob rats. Diabetic male WBN/Kob rats aged 12 to 15 months were randomly divided into 1 alpha-OH-D3-treated group (n = 6) and control group (n = 5). 1 alpha-OH-D3 was administered 3 times a week at an oral dose of 0.1 microgram/kg and triglyceride was administered in the control group during the observation period of 12 weeks. Although plasma Ca level decreased significantly in the vehicle-treated group, there was no significant change in plasma Ca level in the 1 alpha-OH-D3-treated group. Urinary Ca excretion significantly increased in the 1 alpha-OH-D3-treated group compared with that in the vehicle-treated group. As for plasma vitamin D metabolites levels after the 12 week-treatment, although there was no significant difference in plasma 25-OH-D and 24,25(OH)2D levels, plasma 1,25(OH)2D level was significantly increased in the 1 alpha-OH-D3-treated group compared with that in the vehicle-treated group. There was no significant difference in plasma bone-Gla protein level between 1 alpha-OH-D3-treated and vehicle-treated groups. As for bone mineral content (BMC) in the femur measured by a dual energy absorptiometer, BMC was significantly increased in the 1 alpha-OH-D3-treated group compared with than in the vehicle-treated group. In conclusion, 1 alpha-OH-D3 ameliorated diabetic osteopenia in WBN/Kob rats through the normalization of vitamin D metabolism.

Administration, Oral↗
PubMed1993

Unruptured aneurysms associated with ischaemic cerebrovascular diseases. Surgical indication.

Out of 3435 patients with ischaemic cerebrovascular disease 2540 cases were investigated using cerebral angiography. In 127 of them (5%) aneurysms were found, but without clinical evidence of subarachnoid haemorrhage (SAH). 45 cases were operated upon and 82 were treated conservatively. Five of these 82 cases (6%) suffered from SAH 3 months to 10 years (mean interval 5.6 years) after the angiographic diagnosis. Four of these 5 patients with SAH died. Among the 45 surgical cases follow-up was uneventful in 29 (64%). The other 16 cases postoperatively showed neurological deterioration (36%), which was transient in 6 but with only minor improvement in 10. Of these 10 cases 2 died from cerebral infarction related to intra-operative temporary vascular occlusion respectively myocardial infarction. Thus surgical mortality was 4% and permanent morbidity 18%. Causes of postoperative neurological deterioration were partly related to general arteriosclerotic changes and special fragility of the ischaemic brain, and partly to operative technique (excessive brain retraction, damage to cortical veins, occlusion of major vessels or damage to perforators, temporary artery occlusion). Apparently in cases with ischaemic cerebrovascular diseases operative procedures, which in other cases as a rule are well tolerated, may produce harmful effects. Therefore, in these cases, the indication for operative treatment of so far silent aneurysms should be restricted to patients who are in good general condition with longer life expectancy as far as the vascular disease is concerned, and without major neurological deficit. Furthermore, the operative technique should be especially gentle and atraumatic.

Adult↗
PubMed1993

The protective effect of taurine on the biomembrane against damage produced by oxygen radicals.

The effect of taurine in protecting biomembrane against oxygen radicals was investigated using canine erythrocytes. 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH), a water-soluble azo-compound, was used as the oxygen-radical generator. Taurine suppressed erythrocyte hemolysis more effectively than alpha-alanine, used for comparison. To clarify the relationship to the lipid peroxidation, the amount of lipid peroxide was measured using liposomes prepared with egg yolk lecithin. However, the peroxidation was not suppressed by taurine. When intact erythrocytes were subjected to hemolysis by hyposmotic solutions, taurine suppressed the osmotic hemolysis more effectively than alpha-alanine. These results suggest that taurine does not have an antioxidative effect like vitamin E, but interacts with the biomembrane, and helps to protect it against damage caused by AAPH.

Amidines↗
PubMed1993

Stable positively charged liposome during long-term storage.

The effect of taurine, as an isotonic solute, and of benzalkonium chloride (BZC), as a positive membrane component, on the long-term stability of liposomal suspensions was investigated by measuring surface potential. The surface potential, which introduced electrostatic repulsion to liposomes against aggregation, increased dose-dependently with the addition of BZC, which gave a positive charge. However, a further addition of BZC caused unexpected aggregation during storage, so the optimum addition of BZC was defined. On the other hand, taurine, which forms a zwitter ion in an aqueous solution, did not reduce the surface potential, suggesting that taurine is of possible utility as an isotonic solute. As the result of stability testing, the liposomal system using taurine and BZC was stable against aggregation during 6 months at 40 degrees C. We were successful in developing a stable, positively charged liposomal system during long-term storage, and our liposomal system is believed to be of wide utility as a drug carrier for therapeutic drugs applied topically to negatively charged mucosal tissues. We applied the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to estimate the colloidal stability of liposomes. As a result of stability testing, positively charged liposomes had a good correlation between maximum total repulsive energy (VT(max)/kT) between two liposome particles and colloidal stability, suggesting that the VT(max)/kT value is useful for estimating stability and for designing liposomal preparations containing some ionic substances.

Benzalkonium Compounds↗
PubMed1993

Reactivity of taurine with aldehydes and its physiological role.

Chemical reactions of the amino group of taurine with aldehyde were investigated. Glucose, acetaldehyde, and malondialdehyde (MDA) were used as aldehydes. After taurine was reacted with the aldehydes, the amounts of remaining taurine and aldehydes were measured, and thereby the reactivity was evaluated. The amino acids such as glycine, alpha-alanine, and beta-alanine were compared because of their structural resemblance to each other. Taurine showed a high reactivity with each one of the aldehydes tested. It is known that protein is altered through reactions of the amino group with various aldehydes. Low density lipoprotein (LDL) was used as a model protein, and the inhibiting effect of taurine against the modification of LDL by MDA was examined. Our results indicate that taurine inhibited the production of LDL modified by MDA. It was shown that the inhibiting effects correlated with the reactivity of MDA with the amino acids. Further, the taurine-glucose reaction product showed an antioxidative effect on the peroxidation of liposomes made of yolk phosphatidylcholine as a biomembrane model. The results suggest the possibility of an inhibiting effect of taurine against the modification of protein, as well as an antioxidative effect through the reactions of taurine with aldehydes in vivo.

Aldehydes↗
PubMed1993

Quantitative evaluation of the effectiveness of taurine in protecting the ocular surface against oxidant.

Quantitative evaluation of the effectiveness of taurine against ocular surface damage caused by hypochlorous acid (HOCl) was investigated using albino rabbits. The activity of lactate dehydrogenase (LDH) released from ocular tissues into meniscus tears at eye irritation was used as an index of ocular surface damage. Instead of collecting meniscus tears directly with a glass micropipette, a new sampling method, where 150 microliters of saline was instilled into the cul-de-sac of rabbit eyes and collected all of the diluted tears within 10 s, was developed. The LDH activity after serial instillations of HOCl increased dose-dependently with increasing HOCl concentration. After serial instillation of taurine, HOCl was instilled in the same way. Pre-application of taurine effectively suppressed (p < 0.01, n = 11) the HOCl-induced LDH release as compared to saline, suggesting that the residual taurine in ocular surface tissues was still effective in protecting the tissues against HOCl by scavenging HOCl. LDH activity at 30 in after post-application of taurine was significantly lower (p < 0.01, n = 10) than that in the case of saline. This result indicates that taurine is effective in protecting the ocular surface after it has been attacked by HOCl. LDH activity in meniscus tears became a good index of quantitatively estimating ocular surface damage due to HOCl by devising the new sampling method. By using this method, we were able to prove objectively and quantitatively that taurine is effective in protecting the ocular surface against HOCl. It was suggested that taurine is clinically useful in the treatment of ocular surface damage caused by oxidants, such as HOCl.

Animals↗
PubMed1992

Interaction between polyethylene films and bromhexine HCl in solid dosage form. IV. Prevention of the sorption by addition of magnesium aluminum silicate.

The effects of magnesium aluminum silicate (MAS) addition on the sorption of bromhexine HCl to polyethylene film in tablets were studied. The addition of MAS prevented the sorption of bromhexine HCl to polyethylene film. In order to investigate the mechanism, the interaction between bromhexine HCl and MAS was studied by the powder X-ray diffraction method. It was observed that bromhexine HCl was preferentially adsorbed to the surface of MAS rather than to polyethylene film. The adsorption was accelerated at high temperature and reduced pressure conditions. The sorption of bromhexine base and bromhexine HCl to packaging material were compared using tablet dosage forms. The sorption of bromhexine base to polyethylene film was greater than that of bromhexine HCl.

Aluminum Compounds↗
PubMed1992

Interaction between polyethylene films and bromhexine HCl in solid dosage form. V. Effect of packaging materials on the sorption of bromhexine HCl.

A prevention method of the sorption of bromhexine HCl to plastic materials used in packaging was investigated. Four kinds of plastic packaging materials were used: Polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP) and polyacrylonitrile (PAN). Three polyethylenes having different densities were used. No effect of PE density on the sorption of bromhexine HCl from granules was observed. The effects of different kinds of plastics on the sorption of bromhexine HCl from solution and granules were studied. The sorption of bromhexine HCl to PAN, which had a high relative dielectric constant, was the most depressed among the four plastics. The sorption of meclizine HCl to PAN from the solution was also lowest, the same as bromhexine HCl.

Acrylic Resins↗
PubMed1991

Induction of metallothionein and stimulation of calcification by dexamethasone in cultured clonal osteogenic cells, MC3T3-E1.

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.

Alkaline Phosphatase↗
PubMed1991

[Problems of surgical treatment for multiple intracranial aneurysms].

A series of 105 patients presenting with multiple aneurysms and subarachnoid hemorrhage (SAH) were operated on for ruptured and unruptured aneurysms between 1976 and 1984. Clinical factors other than the severity of SAH affecting the outcomes included: 1) Misdiagnosis of the location of a ruptured aneurysm among multiple aneurysms resulted in poor outcomes because of multiple surgical approaches or rebleeding during the acute period. 2) Combinations of aneurysmal locations requiring multiple surgical approaches, such as interhemispheric and transsylvian, during the acute stage caused worse outcomes than with multi-stage surgeries. If an unruptured aneurysm could not be reached during the initial exposure, multi-stage surgery was safe if the ruptured aneurysm had been clipped during the acute period. 3) Complications occurring during unruptured aneurysm surgery. The patient's age, the location and size of the unruptured aneurysms were significant factors in the clinical prognosis. Surgery for unruptured aneurysm caused 1.8% morbidity in patients between 28 and 55 years, but 18.0% morbidity in patients over 56 years of age. Surgery for internal carotid artery aneurysms resulted in 14.8% overall morbidity. Surgery for middle cerebral and anterior cerebral artery aneurysms caused below 5% morbidity. Postoperative morbidity in patients with aneurysms less than 5 mm in diameter was 1.3%, and with aneurysms measuring 10 mm or more, 20%. The optimum treatment for multiple aneurysms with SAH should be based on all factors of the patient's condition, including the unruptured aneurysms.

Age Factors↗
PubMed1990

[Interaction between polyethylene films and brombexine HCl in solid dosage form. II. Effects of moisture property on the sorption of the drug].

The interaction between bromhexine HCl and polyethylene containers was studied in solutions and in tablet packaging systems. Various bromhexine HCl aqueous solutions of different pHs were stored in polyethylene containers at 25 degrees C. The remaining amount of bromhexine HCl was determined by high performance liquid chromatography. It was observed that the transition of bromhexine HCl to polyethylene was inhibited by the addition of some surfactants into the solution, and by lowering the solution pH. In the solid dosage forms, influences of the additives were also studied. It was observed that the decrease of the content of bromhexine HCl in the solid dosage form was inhibited by the addition of acids (citric acid, tartaric acid) and surfactant (sodium dodecyl sulfate) and accelerated by the addition of sodium bicarbonate, similarly to those in solutions. The results indicated that the transition to polyethylene films was influenced by the molecular state of bromhexine HCl.

Adsorption↗
PubMed1990

Characteristics of aztreonam as a substrate, inhibitor and inducer for beta-lactamases.

Aztreonam was investigated as to its characteristics as a substrate, inhibitor and inducer for the well-defined beta-lactamases of Gram-negative bacteria, and its antibacterial efficacy as to bacterial cells producing eight types of beta-lactamases was also evaluated. Aztreonam was hydrolyzed at measurable rates by class A beta-lactamases, a TEM-2 type penicillinase and the Proteus vulgaris cephalosporinase with a broad substrate range. However, the affinity of aztreonam for the class A enzymes was low, this property being well reflected by its high antibacterial activity toward producers of class A beta-lactamases. Aztreonam was extremely stable as to the typical class C cephalosporinase of Citrobacter freundii, and acted as a competitive and progressive inhibitor for the beta-lactamase. While the MICs of aztreonam in the cases of the constitutive producers of class C beta-lactamases were evidently affected by enzyme production. An experiment involving aztreonam as a inhibitor in combination with a hydrolyzable beta-lactam gave ambiguous results, however, a strong synergistic effect was found in combination with mecillinam. Using Pseudomonas aeruginosa, aztreonam was confirmed to be a poor inducer of beta-lactamases.

Amdinocillin↗