[The progress in management of esophagogastric variceal bleeding in cirrhotic portal hypertension].

Esophagogastric variceal bleeding (EVB) is the most dangerous complication of cirrhotic portal hypertension.With the continuous emergence of research findings on EVB, multiple disciplinary team, including internal medicine department, surgery department, intervention therapy department, radiology department, has become a new mode for the prevention and treatment of EVB. This article first reviewed the classification of esophageal varices and gastric varices, and then reviewed the recent research findings of EVB from three aspects: primary prophylaxis, active variceal bleeding treatment, and secondary prophylaxis.The aim was to provide new ideas for the individualized prevention and treatment of EVB.

Association between renin-angiotensin system gene polymorphism and recurrent wheezing in Chinese children: a 4-year follow-up study.

This study aimed to clarify the association between angiotensin-converting enzyme (ACE) gene polymorphisms and infant wheezing, and to determine whether an association may contribute to early prediction of persistent wheezing and asthma. The study cohort comprised 149 patients with asthma, 169 patients with wheezing but no clinical diagnosis of asthma and 165 healthy control subjects. The insertion/deletion (I/D) polymorphism of the ACE gene was determined by polymerase chain reaction. Total serum immunoglobulin E was determined for the wheezy group and a 4-year follow-up study was carried out to observe wheezing relapse. Significant differences were found between patients and controls in allele frequency and genotype distribution. The DD genotype was more frequent in patients in the wheezing and asthma groups than in the control subjects. Patients with the DD genotype had a higher frequency of relapse than patients expressing the ID or II genotypes. It is concluded that the DD genotype of ACE is a risk factor for recurrent wheezing in early childhood.

The partition of glycosaminoglycan-quaternary ammonium complexes, II. The effects of polymer molecular weight and sulfation.

Previous results have shown the possibility for obtaining high-resolution separations of glycosaminoglycans by partition in butanol/aqueous two-phase systems containing quaternary ammonium salts. In this paper, the effects on partition behavior of both polymer molecular weight and sulfation were examined. Two series of fractionated chondroitin sulfate polymers were isolated in which the molecular weight and sulfation varied systematically. In the molecular weight series the six samples, spanned the range from 3200 +/- 300 to 19 700 +/- 500 and each sample carried 0.8 sulfate groups per uronic acid residue. In the sulfation series, each sample had an essentially constant molecular weight of 13 000, but the sulfation varied from 0.58 to 0.88 sulfate groups per uronic acid. The C50 of each of these samples was determined in the 1-butanol/aqueous NaCl phase system containing 1% hexadecylpyridinium chloride. In the series wherein the molecular weight varied, the C50 increased with molecular weight up to 12 000 where a limiting value was reached. In the series wherein the sulfation varied, a linear relationship was found between the C50 and the square of the number of anionic substituents per disaccharide. These results show that fractionation by partition techniques will be sensitive to the anionic nature of the polymer, but for the common connective tissue glycosaminoglycan, there will be no fractionation according to molecular weight.

The partition of glycosaminoglycan-quaternary ammonium complexes. I. The effect of phase composition.

The complexes formed between quaternary ammonium cations and polyanionic glycosaminoglycans can be partitioned between partially miscible aqueous inorganic salt and alcohol phases. Small changes in salt concentration can completely shift the complex from one phase to the other. The effect of the phase composition variables: the type of inorganic salt, the type of quaternary ammonium salt, and the alcohol used, were systematically investigated. The sharp transition from solubility in the upper non-aqueous phase to solubility in the lower, aqueous phase was found to be strongly affected by the type of inorganic salt. This transition occurred at higher salt concentrations when NaCl, KCl, or LiCl were used than when CaCl2 or MgCl2 were used. Differences in behavior among glycosaminoglycans were larger for NaCl than for CaCl2. The complex is stabilized to dissociation by salt by increasing hydrophobicity of the non-aqueous phase. However, aggregation of the complex into an insoluble form is also favored by an increasingly hydrophobic environment. The most consistent partition was observed with 1- and 2-butanol. The partition isotherm of chondroitin 4-sulfate was investigated at constant salt concentration. It was found that the partition coefficient varies with the concentration of chondroitin 4-sulfate, although the magnitude of this effect could be diminished by increasing the quaternary ammonium salt concentration.

[Base composition of DNA from fluoride resistant strains of streptococcus mutans and streptococcus sobrinus].

OBJECTIVES: To evaluate the genotype change of fluoride-resistant strains of S.mutans and S.sobrinus. METHODS: High potential liquid chromatography was used to measure the base composition of DNA from F-resistant strains of S.mutans and S.sobrinus and their parent strains. RESULTS: The data showed that the DNA G+C mol% of F-resistant and F-sensitive S.mutans were quite different, the difference was over 5%. The four F-resistant strains were 54.45, 44.86, 54.41, 55, 390, whereas the corresponding four parent strains were 35.38, 37.4, 43.35, 46.62, respectively. CONCLUSION: The genotypes of F-resistant strains of S.mutans and S.sobrinus have been changed and may comprise several gene mutations.

Acidogenicity and acidurance of fluoride-resistant Streptococcus sobrinus in vitro.

OBJECTIVE: To induce fluoride-resistant mutants of Streptococcus sobrinus in vitro and to study the acidogenic and acid tolerance of fluoride-resistant strains. METHODS: Fluoride-resistant mutants 6715-FR and S1-FR were obtained by subculturing S. sobrinus 6715 and freshly isolated S. sobrinus SSMU-S1 to media TSA or TSB, which contained different concentrations of fluoride. The lactic production and growth of fluoride-resistant strains and their respective parent strains were measured by gas chromatography and ultra-violet visible spectrophotometer. RESULTS: The stable fluoride-resistant mutants of S. sobrinus had been induced successfully in vitro. The acid production of 6715-FR or S1-FR was significantly greater than their parent strains in the presence of 0.5 or 5.0 mM fluoride. In the absence of fluoride, there were 2 situations: The lactic production of F-resistant S. sobrinus was less than or equal to its parent strains when initial pH value was above 5.0 while the result was the opposite when pH value was below 5.0. The F-resistant strains and the parent strains of S. sobrinus could reduce the suspension pH to identical values in the absence of fluoride, and the F-resistant strains were more aciduric in the presence of fluoride. CONCLUSIONS: The F-resistant strains of S. sobrinus had higher acidogenic and aciduric ability than the wild-type strains, and were expected to have stronger cariogenic potential at plaque fluoride levels.

[Binding ability of fluoride-resistant strains of S. mutans and S. sobrinus in vitro].

OBJECTIVE: To investigate the binding ability of S.mutans and S.sobrinus after their fluoride-resistant mutation. METHODS: The binding amount and binding percentage of S.mutans, S.sobrinus and their F-resistant strains to saliva-coated hydroxyapatite(SHA)were measured and compared by(3)H-labeled binding assay. RESULTS: The binding percentages of F-resistant and their parent strains had few difference(P>0.05) whereas the binding percentage of S.sobrinus was significantly lower than S.mutans (P<0.01). CONCLUSION: The data showed that the binding ability to SHA between F-resistant and F-sensitive S.mutans had no significant difference which indicated that the emerge of F-resistant strains could not reduce the cariogenicity of S.mutans and S.sobrinus.