Biomedical subjects
Publications and source records attributed to Y Nan.
[reaction: see text] A highly effective cocatalysis system (PdI2-thiourea and CBr4) was developed for carbonylative cyclization of both electron-rich and electron-deficient o-hydroxylarylacetylenes to the corresponding methyl benzo[b]furan-3-carboxylates.
The change in the numbers of synapse is of importance in various kinds of physiological and pathological processes. The numerical density is the structural parameter measuring up the numbers of the particles in the space. A new stereological technique, the disector technique, has been described to count the number of particles in a given volume of tissue. It is a technique for counting the number of arbitrary particles in 3-dimensional space using adjacent parallel sections at known distance apart. In this article also discussed is the software for computer assisted count of the synaptic numerical density based on the physical director technique with Visual Basic 4.0.
OBJECTIVES: To observe the relation between serum transforming growth factor beta 1(TGF beta 1) and level of PCIII, LN, HA, proliferation of hepatic fibrotic tissue. METHODS: Serum TGF beta 1 was detected by ELISA in 58 patients with chronic hepatitis B(CHB) and 18 patients with liver cirrhosis(LC). 20 healthy persons served as normal control(NC). Liver puncture was performed in 29 patients with CHB. Diagnosis of pathological histology and quantitative analysis of collagenous and reticular fibers were made. RESULTS: (1)Serum TGF beta 1 levels in CHB and LC were notably higher than in NC (P < 0.01) and increased successively in mild, moderate and severe degrees of CHB and LC(P < 0.01/0.05). (2)Serum TGF beta 1 was correlated with serum levels of PCIII, LN, HA(P < 0.01/0.05)positively. The quantity of hepatic collagenous and reticular fibers went up in mild, moderate and severe degrees of CHB(P < 0.01/0.05). Meanwhile serum TGF beta 1 rose at the same degree. CONCLUSION: Serum TGF beta 1 levels increase in CHB and LC. With hepatic pathological change worsening, serum TGF beta 1 and the quantity of hepatic collagenous and reticular fibers increased to the same degree. This suggests that TGF beta 1 is a crucial factor in accelerating liver fibrosis and plays a decisive role in liver fibrosis.
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The in vivo and functional effects of several 7-arylidene and 7-heteroarylidene morphinan-6-ones were determined at the mu-, delta-, and kappa-opioid receptors using the guinea pig brain membranes, guinea pig ileum (GPI), and mouse vas deferens (MVD). In vivo effects included the antagonism by these compounds given subcutaneously on the antinociceptive actions of intracerebroventricularly injected [D-Pen2, D-Pen5]enkephalin (DPDPE) and [D-Ala2, Glu4]deltorphin II (deltorphin II), the highly selective putative delta 1- and delta 2-opioid receptor agonists. Finally, the partition coefficients of these compounds were estimated (CLOGP) and determined experimentally at pH 7.4 in the 1-octanol/water system. Compared with E-7-benzylidenenaltrexone (BNTX), most compounds except for E-7-(4-chlorobenzylidene)naltrexone, were more potent at delta-opioid receptors than at the mu-opioid receptor, whereas, in comparison to the kappa-opioid receptor, the activities of the E-7-arylidene or E-7-heteroarylidene naltrexone derivatives at the delta-receptor were in the following order, where the 7-substituents were: 4-fluorobenzylidene- > benzylidene > 3-pyridylmethylene- > 4-pyridylmethylene- > 1-methyl-2-imidazolylmethylene > 4-chlorobenzylidene. In the MVD preparation, the potencies at the delta-opioid receptor, in comparison to BNTX, were in the following order, where the 7-substituents were: benzylidene = 1-methyl-2-imidazolylmethylene- > 4-fluorobenzylidene- = 3-pyridylmethylene- = 4-pyridylmethylene-. All compounds antagonized delta 1, and delta 2-opioid receptor agonist-induced analgesia. The antagonist potencies at the delta 1-opioid receptor were in the following order, where the 7-substituents were: benzylidene- > 4-chlorobenzylidene- > 4-fluorobenzylidene- > 3-pyridylmethylene- > 1-methyl-2-imidazolymethylene- approximately 4-pyridylmethylene-, whereas at the delta 2-opioid receptor, the order was benzylidene- > 4-chlorobenzylidene- > 4-fluorobenzylidene- > 3-pyridylmethylene- > 1-methyl-2-imidazolymethylene- > 4-pyridylmethylene. In general, all compounds exhibited greater potency at the delta 2- than delta 1-opioid receptor. The computed partition coefficients were, as expected, greater than the apparent log P values, which were determined experimentally. Generally, the lipophilicity values in decreasing order were: 4-chlorobenzylidene- > 4-fluorobenzylidene- > benzylidene > 3-pyridylmethylene- = 4-pyridylmethylene- > 1-methyl-2-imidazolylmethylene-. In general, the benzylidene and 4-pyridylmethylene derivatives, which have medium lipophilicities, were equally effective at the delta 1- and delta 2-receptors; the 3-pyridylmethylene and 1-methyl-2-imidazolylmethylene derivatives had lower lipophilicities and were more selective for the delta 2- than delta 1-receptor; the 4-chlorobenzylidene and 4-fluorobenzylidene derivatives were more lipophilic and had intermediate activity. The plot of pED50 values for the in vivo tests for the delta 1- and delta 2-receptors showed that the two receptors are not independent with respect to this series of compounds.
The average total intake of sodium was 6.11 g in a Chinese urban diet and 6.49 g in the rural sample in China. Discretionary use of salt provided 53% of the total sodium intake in the urban and 63% in the rural diet. Sodium intakes derived from processed foods, soy sauce and monosodium glutamate were 17%, 16% and 6% respectively in the urban diet, and 4%, 16%, 2% respectively in the rural diet. The mean intake of potassium was 1.95 g in the urban and 1.83 g in the rural diet. Cereals and vegetables were the major sources of dietary potassium. The intakes of total sodium, salt and soy sauce decreased as educational level increased. Similar results were found in white-collar workers and blue-collar workers or farmers. Nevertheless, an inverse association between blood pressure and education was found. The results suggest that reduction in sodium intake, especially cooking salt, and increased potassium intake are needed for nutritional control of hypertension in population-based interventions aimed at all social classes.
OBJECTIVES: To assess food pattern and nutrition profile aiming at planning population-based nutrition intervention for chronic diseases control. DESIGN: A randomized survey. SETTING: The survey was carried out in Tianjin, one of the three largest cities in China. SUBJECTS: 3683 subjects aged 15-64 years old were selected by a random stratified multilevel cluster sampling. INTERVENTION: The diet was assessed by food weighing plus consecutive individual 3 day food records. RESULTS: Distinct differences in dietary pattern and nutrient intakes were found between subjects living in urban and rural areas. The diet of urban people was richer in fat and high quality protein compared with the diet of rural people. Low intakes of vitamin A, calcium, riboflavin, and zinc were found in both areas, the situation being worse in the rural areas. The sodium intake and sodium:potassium ratio was very high in both areas. Cholesterol intake was much higher among the urban people. CONCLUSION: The study suggests that integrated nutrition intervention is needed to prevent insufficient intake of some nutrients and control dietary risk factors related to chronic diseases.
OBJECTIVE: To examine the associations between blood pressure and sodium, potassium, calcium and magnesium in a cross-sectional study by 24-h urine collections and food weighing with 3-day food records in 328 males and 335 females in Tianjin, People's Republic of China. RESULTS: A very high sodium intake and sodium:potassium ratio was confirmed in the study population. After adjusting for confounding variables, both dietary and urinary sodium and sodium:potassium ratio were significantly and positively correlated with blood pressure. Although a negative correlation was found between potassium and blood pressure, the association was significant only between urinary potassium and systolic blood pressure in females and in both sexes combined. No significant associations were found between blood pressure and either intake of or urinary excretion of calcium and magnesium. The dietary intake correlated highly with urinary excretion of electrolytes. In both sexes a strong positive association was found between blood pressure and age, and between blood pressure and body mass index. Higher blood pressure was shown in subjects with higher sodium and alcohol intake, higher body mass index and lower potassium intake. CONCLUSION: The present results indicate that factors contributing to high blood pressure in Tianjin, People's Republic of China, are related to age, body mass index, high sodium intake and sodium:potassium ratio.
OBJECTIVE: To identify commonly consumed processed foods with high sodium (Na) content and sodium to potassium (Na:K) ratio for the purpose of using this information in a community-based nutrition education programme. DESIGN: Calculations of Na and K intake were based on the data of a dietary survey carried out in Tianjin in 1992. All processed foods were randomly sampled based on manufacturers and market survey. SETTING: The survey was conducted in the urban area in Tianjin, China. PARTICIPANTS: 2317 subjects aged 15-64 years old were included in the dietary survey. The response rate was 95%. MAIN RESULTS: The mean sodium intake was 6517 mg in men and 5708 mg in women. 38% of the total Na intake came from processed foods and condiments in both of the urban men and women in Tianjin. 122 processed foods with sales volumes were identified. Most of the processed foods had high Na content and high Na:K ratio, especially Na-rich condiments, salted vegetables, fried dough cake and sausages. The Na content of most processed foods in Tianjin was higher than the mean value reported in the Chinese Food Composition Table. CONCLUSION: Processed foods contribute an important part of dietary Na in the urban diet in Tianjin. It is necessary to initiate nutrition intervention activities aiming at regulations on the Na content of processed foods and to advise the people to reduce consumption of salty foods.
OBJECTIVES: To describe the distribution of serum lipids and examine the relationship between serum lipids and dietary and non-dietary factors. DESIGN: A randomised survey. SETTING: The survey was carried out in Tianjin, China. SUBJECTS: Altogether 680 subjects were screened. Forty-nine of those were excluded but 314 men and 317 women remained. INTERVENTION: The serum lipids were measured by enzymatic methods. The diet was assessed by food weighing plus consecutive individual 3-day food records. RESULTS: The mean cholesterol concentrations were 4.08 and 3.94 mmol/l in men and women respectively. The mean high-density lipoprotein cholesterol (HDL-C) levels were 1.24 and 1.35 mmol/l, and the mean triglyceride levels were 1.48 and 1.20 mmol/l. The energy intake derived from fat was approximately 29% (6.9% from saturated fat) and the polyunsaturates:saturates ratio of the diet was 1.3 in both sexes. Multiple regression analyses showed that no association was discovered between serum lipids and dietary variables. Age and body mass index (BMI) were strong and independent predictors of serum lipids in both sexes. BMI was positively related to serum total cholesterol, triglyceride and low-density lipoprotein cholesterol (LDL-C), and inversely related to HDL-C. Education was a predictor only in men. Men with a higher education had more coronary heart disease risk factors than men with lower education attainment. CONCLUSION: The Chinese have favourable serum lipid profiles and dietary fat pattern. No relationship was found between lipids and dietary variables, which warrants further studies because these relationships have not been investigated previously in any Chinese population.
The effects of BRB-I-28, SAZ-VII-22 and SAZ-VII-23, a novel class of antiarrhythmic agents and other 3,7-diheterobicyclo[3.3.1]nonane (DHBCN) derivatives on guinea pig myocardial Na+,K(+)-ATPase and Mg(2+)-activated ATPase activities were investigated in comparison with those of tedisamil, lidocaine and ouabain. BRB-I-28, SAZ-VII-22, SAZ-VII-23, tedisamil and their derivatives produced concentration-dependent inhibition on both Na+,K(+)-ATPase and Mg(2+)-activated ATPase. Ouabain had no effect on the Mg(2+)-activated ATPase activity and GLG-IV-44 had no significant inhibition on Na+,K(+)-ATPase. Molar refractivity, retention time in reverse-phase HPLC, and partition coefficients were determined and the influence of these three parameters on the inhibitory effects of DHBCN on ATPase was examined. It seems that inhibitory effects of DHBCN derivatives on Na+,K(+)-ATPase and Mg(2+)-activated ATPase increase with an increase in lipophilicity, while hydrophilic groups of the drugs may not be important for interaction between drugs and ATPases. The effects of BRB-I-28 on contractile force development in rabbit atrial and papillary muscles were studied. At paced rates of 0.5 and 1.0 Hz in atrial muscle, BRB-I-28 produced an apparent positive inotropic effect in isolated rabbit atrial muscle, which is consistent with its inhibitory effects on Na+,K(+)-ATPase and Mg(2+)-ATPase activities. Inhibitory effects on myocardial Na+,K(+)-ATPase and Mg(2+)-activated ATPase activities may be the basis of some electrophysiological effects of antiarrhythmic properties of BRB-I-28, SAZ-VII-22, SAZ-VII-23, and tedisamil.
This paper takes as index the content of free acids and total acids, the action of pepsin in the stomachs of hungry mice, impelling functions and intestines of hungry mice and makes a comparison of the raw products with the processed products of medicated leaven. It is suggested that bran-perched or burnt perched leaven is better for invigorating the function of the spleen and promoting digestion.
The only recognized gene for the metabolism of p-hydroxybenzoate in Pseudomonads (pobA) has been isolated from Pseudomonas aeruginosa to provide the DNA for mutagenesis studies of the protein product, p-hydroxybenzoate hydroxylase. Since pobA is induced by p-hydroxybenzoate to produce large amounts of enzyme, its regulation in P. aeruginosa is significant. The nucleotide sequence of pobA is presented with the derived amino acid (aa) sequence, which has only two substitutions compared to the amino acid sequence obtained from the enzyme from P. fluorescens. The derived amino acid sequence predicts that the enzyme is a single polypeptide of 394 aa residues and contains one molecule of FAD. The complete structure of the protein from P. aeruginosa can be derived by analogy from the published structure of the protein from P. fluorescens. Transcription mapping was used to determine that there is one site for the initiation of mRNA synthesis in P. aeruginosa. The presence of a putative operator in the sequence suggests primary regulation by a repressor protein which binds p-hydroxybenzoate. The ribosome-binding site permits translation of the gene in Escherichia coli at levels comparable to its production in P. aeruginosa, but it produces no detectable product in E. coli under the influence of its own promoter sequence. The promoter does not conform to the common consensus sequence of E. coli promoters. The results have identified an apparent novel promoter for P. aeruginosa, which may reflect the presence of a sigma factor required for pobA induction. Repression of expression by glucose suggests a binding site in the sequence for catabolite repression.