A lipid-polypeptide conjugate (lipo-polypeptide) was obtained by the ring-opening polycondensation of N-epsilon-Z-L-lysine N-carboxyanhydride (NCA) using 3-aminopropyl dioctadecylamine as initiator and subsequent deprotection. Maltose lactone was coupled with the lipo-polypeptide to give novel amphiphiles which carried many maltoamide residues as pendent groups. The sugar group-carrying amphiphiles incorporated in phospholipid liposomes were recognized by a lectin from Canavalia ensiformis (Con A), which was proven by the increase in turbidity of the liposome suspension after mixing with the lectin. The recognition was largely affected by the degree of polymerization of lysine residues and the surface density of the amphiphile in the liposomes. The association constant (K(ass)) of Con A with maltoamide residues on the liposome was much larger than those for small molecular weight sugars due to the "cluster effect".

Carbohydrates↗

PubMedDate not supplied

Galactose-containing amphiphiles prepared with a lipophilic radical initiator.

Novel amphiphiles which contain galactose residues (degree of polymerization (DP) = 6.2, 10, and 15) were prepared by telomerization of 2-[(methacryloyloxy)ethyl]-beta-D-galactopyranoside using a lipophilic radical initiator. The galactose-carrying amphiphile incorporated in a liposome was recognized by a lectin from Ricinus communis (RCA120), which was proven by the increase in turbidity of the liposome suspension after mixing with the lectin. The recognition was largely affected by the degree of polymerization and the surface density of the amphiphile. The amphiphile would be useful as a component of the drug delivery system to hepatocytes.

Drug Carriers↗

PubMedDate not supplied

Galactose-containing amphiphiles prepared with a lipophilic radical initiator: association processes between liposomes triggered by enzymatic reaction.

A galactose-containing monomer (2-(methacryloyloxy)ethyl beta-D-galactopyranoside, MEGal) was polymerized by using a lipophilic radical initiator. The amphiphile obtained formed a liposome by mixing with bis(trans,trans-2,4-dioctadecadienoyl)phosphatidylcholine (DDPC), and the liposome obtained was physically stabilized by the polymerization of DDPC by UV irradiation. The enzymatic treatment of the galactose-containing liposomes with galactose oxidase resulted in the formation of aldehyde groups on the liposome surface. By the subsequent mixing of the liposome suspension with the amino group-containing liposome suspension, a rapid increase in turbidity was observed due to the formation of Schiff bases between the aldehyde groups and the amino groups at the interface of the liposomes. The rate of turbidity change strongly depended on the degree of polymerization of MEGal, the surface densities of galactose and amino groups on the liposome, the distance from the liposome surface to amino end groups, and the flexibility and deformability of the liposomes.

1,2-Dipalmitoylphosphatidylcholine↗

PubMedDate not supplied

Catalytic properties of galactose oxidase to liposome-forming amphiphiles which have many pendent galactose residues.

A galactose-carrying vinyl monomer [2-(methacryloyloxy)ethyl beta-D-galactopyranoside, MEGal] was polymerized by using a lipophilic radical initiator. The amphiphiles obtained (DODA-PMEGal) formed stable liposomes by mixing with phospholipids, and the galactose residues on the liposome surface were effectively recognized and oxidized by galactose oxidase. The affinity (estimated by the 1/Km value) of galactose oxidase for the galactose residues on the liposomes was higher than those for free galactose and MEGal and dependent on the length of galactose-carrying polymer chains on the liposome surface and the fluidity of the membranes, whereas not significantly influenced by the surface density of galactose residues on the liposomes. The affinity of galactose oxidase for the galactose-carrying linear polymers, which were prepared by using an ordinary azo-type radical initiator and a chain-transfer reagent, was also higher than those for free galactose and MEGal and dependent on the degree of polymerization of MEGal. The affinity was, however, relatively much smaller than those for DODA-PMEGals incorporated in liposomes.

Amides↗

PubMedDate not supplied

Recognition of novel amphiphiles with many pendent mannose residues by Con A.

Novel amphiphiles which carry many mannose residues as side chains were prepared by telomerization of N-methacryloylaminopropyl D-mannopyranoside (alpha:beta = 20:1), N-methacryloylaminohexyl D-mannopyranoside (alpha:beta = 20:1), or 3-(2-methacryloylaminoethylthio)propyl D-mannopyranoside (alpha:beta = 4:1) using a lipophilic radical initiator. The mannose-carrying amphiphiles incorporated in liposomes were recognized by a lectin from Canavalia ensiformis (Con A), which was proven by the increase in turbidity of the liposome suspension after mixing with Con A. The interaction between sugar residues on the liposome surface and the lectin was largely affected by the degree of polymerization (DP) and the surface density of the amphiphile in the liposomes. The distance between the sugar residues and the polymer main chain did not affect the specific recognition by the lectin significantly in the liposome system, whereas it appreciably affected the recognition in the water-soluble polymer system. The association constants (Ka) of the amphiphiles (DP approximately 18) with Con A (0.3-2.2 x 10(6) M-1 at 25 degrees C) were much larger than that of alpha-methyl D-mannopyranoside (8.2 x 10(3) M-1) due to the "cluster effect ". The positive entropy change (20-52 J/mol K) for the binding of Con A to mannose residues on the liposome surface showed that the recognition in the liposome system was largely promoted by the release of water molecules from both the sugar residues on the liposome surface and the binding site of Con A.

Amines↗

PubMedDate not supplied

Association between variants of mast cell chymase gene and serum IgE levels in eczema.

851 school children aged at 12-13 years including 145 with eczema were tested for genetic association to a mast cell chymase (MCC) genetic variant. MCC genotypes showed a strong association with eczema, but not with asthma and rhinitis. This association is strongest in eczematous children with lower serum total IgE levels. Independent of IgE responsiveness when total serum IgE of less than 500 IU/ml, MCC variants may play an important role in inflammatory skin disorders.

Adolescent↗

PubMedDate not supplied

Studies of cochlear blood flow in guinea pigs with endolymphatic hydrops.

Laser Doppler flowmetry was used to assess cochlear blood flow (CoBF) in guinea pigs with experimental endolymphatic hydrops following intravenous infusion of 5 types of drugs: 50% glycerol, 70% isosorbide, 20% mannitol, 7% sodium bicarbonate, and 1% diphenidol. The magnitude of the CoBF changes following infusion tended to be smaller in the hydropic ears than in the normal control ears. A significant reduction in CoBF changes was observed in hydropic ears infused with isosorbide and sodium bicarbonate. These results suggest that the cochlear microvascular sensitivity to various stimuli such as drug infusion is reduced in hydropic ears. This may result from atrophy of the stria vascularis which is often observed in the hydropic ears of guinea pigs. Thus it seems likely that the same reaction occurs in the inner ear of patients with Ménière's disease in whom atrophy of the stria vascularis is also presumed to exist in conjunction with extensive endolymphatic hydrops. Therefore, it seems probable that the function of the microvasculature of the stria vascularis is impaired in the inner ear of patients with Ménière's disease, resulting in the slow progressive deterioration of the inner ear with time.

Animals↗

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Intraoperative mitomycin C in endolymphatic sac surgery for Ménière's disease: A pilot study.

The long-term results of endolymphatic sac (ES) shunt surgery in Ménière's disease have been reported to be unsatisfactory compared to the short-term results, probably because of fibrosis and/or reclosure of the incised ES. To solve this problem, we tried to apply mitomycin C (MMC) intraoperatively to the incised ES as used in trabeculectomy for glaucoma. MMC has an antiproliferative effect as well as an antineoplastic effect. Thus, it is expected that MMC would have a benefit to prevent rapid fibrosis and/or reclosure of the ES. MMC did not show any ototoxicity in our animal study and we started a clinical trial after being approved by the Ethics Committee for Human Research at our university. Fourteen patients with Ménière's disease underwent ES mastoid shunt surgery with intraoperative application of MMC and they were followed up more than 6 months. No patients experienced vertigo, although some complained of slight dizziness. Five patients out of 14 showed remarkable hearing improvement by more than 10 dB, accompanied with decrease of tinnitus.

Adult↗

PubMedDate not supplied

Clinical outcome of laryngotracheal separation for intractable aspiration pneumonia.

OBJECTIVES: To confirm that laryngotracheal separation (LTS) is a satisfactory treatment for patients with intractable aspiration pneumonia, even though it does not require tracheoesophageal anastomosis. STUDY DESIGN: Retrospective. METHODS: Nine patients with intractable aspiration pneumonia underwent LTS at our institution from 1996 to 1999. Two patients underwent postoperative barium swallow radiography. RESULTS: Neither halitosis nor stimulation of the cough reflex occurred due to pooled secretions in the blind pouch of the proximal tracheal segment. Barium swallow radiography confirmed that the secretions drained within 40 min by swallowing or a change in patient position. CONCLUSION: LTS is a satisfactory solution to the problem of chronic aspiration. Neither pooled secretions in the proximal tracheal segment nor fistula formation were significant postoperative problems.

Adolescent↗

PubMedDate not supplied

Multiple symmetrical lipomatosis: no longer just a Mediterranean disease?

Multiple symmetrical lipomatosis is a rare condition, of which the etiology remains unclear. Most reported cases have been from the Mediterranean countries, and it is generally thought of as a disorder characteristic of that region. However, there have been 11 cases reported in Japan since 1978, suggesting that this condition is no longer confined to Mediterranean countries.

Adult↗

PubMedDate not supplied

Comparison of effectiveness of maneuvers and medication in the treatment of benign paroxysmal positional vertigo.

In this paper, the treatment by medication together with two maneuvers-the particle repositioning maneuver (PRM) reported by Parnes and Price-Jones and the liberatory maneuver (LM) reported by Semont et al.-were compared with treatment by medication alone. Fourteen of 15 cases (93.3%) treated with the PRM and 11 of 14 cases (78.6%) treated with the LM showed improvement after 2 weeks. These results were better than that obtained by medication alone, in which 8 of 26 cases (30.8%) showed improvement after 2 weeks. The most important benefit of these maneuvers seemed to be the speedier recovery than with medication alone, as there was no significant difference in the late success rate after 3 months between the maneuvers and medication alone.

Adult↗

PubMedDate not supplied

Experimental study on Meniere's disease.

Experimental hydrops caused by underabsorption of endolymphatic fluid is a model of remissional stage of Meniere's disease. In this study, another type of model, ie, hydrops caused by overproduction of endolymphatic fluid, was accomplished by applying various pressures into scala media through a micropipette via stria vascularis. This type of hydrops could be a model of attacks of Meniere's disease. By using two types of the model, effects of glycerol administration and of opening the endolymphatic sac were discussed.

Animals↗