[Effect of irradiation on the shelf-life of aquatic products].

The effect of irradiation at doses of 0-10 kGy on the shelf-life of aquatic products was determined. The results showed that irradiation could not prolong the shelf-life of aquatic products kept at 25 degrees C. While the aquatic products were kept at refrigerator (4 degrees C), the irradiation could prolong the shelf-life and effectively reduce the total aerobic plate count.

[Immunological study on the antitumor effects of fungus polysaccharides compounds].

Fungus polysaccharides compounds (FPC) are the mixture of procyanidins oligomers, glycyrrhetinicacid and polysaccharides of hericium erinaceus, lentinus edodes and poria cocos. The antitumor effects of FPC and its immunity regulating effects as an immunostimulant on the mice burdened with sarcoma 180 (S-180) were studied. FPC (100, 200 and 400 mg/kg BW) was gavaged to mice for 31 days.

[Establishment of monoclonal antibodies against aflatoxin M1].

The monoclonal antibodies against aflatoxin M1 were established. Spleen cells from Balb/c mice immunized with AFM1-oxime-BSA conjugate were fused with murine Sp2/0 myeloma cells. Three hybridoma cell lines secretine monoclonal antibodies against AFM1 were established after the fusion cells subcloned for 3-4 cycles.

[Quantitative determination of 3-nitropropionic acid by HPLC].

A reversed-phase liquid chromatographic method to determine the concentration of 3-nitropropionic acid (3-NPA) in the culture medium with Aspergillus oryzae was developed. The culture medium samples were extracted with ethyl acetate. The analytic column was Hypersil C18 and the mobile phase was CH3CN/KH2PO4(0.

[Inhibition of Lactobacillus species on the germination of Aspergillus flavus spore].

Actively growing Lactobacillus plantarum CGMCC 1.1856 cells totally inhibited the germination of mold spores. Cell-free supernatant broth from the fermentation of Lactobacillus plantarum could not destroy the viability of mold spore.

[A simple method for screening of highly inhibitory Lactic acid bacteria on Aspergillus flavus growth].

A simple and rapid method for screening of Lactic acid bacteria with high inhibitory power is developed. The methodology employed was the agar-diffusion assay, which was standardized for medium composition, and incubation conditions. The assay was composed of two layers of medium, MRS agar at the bottom of plate, PDA at the top of MRS agar.

[Study on the hypotensive effect of manascus].

The hypotensive effect of manascus was studied by using three well established rat models with hypertension: spontaneously hypertensive rat (SHR), renalvascular hypertensive rat (RHR, 2K1C) and DOCA-salt hypertensive rat. Manascus of 0.0, 0.

[Toxicity of microcystin and its bioaccumulation effect].

Microcystins are cyclic heptapeptide hepatotoxins from certain cyanobacteria. It can inhibit hepatic protein phosphatase 1 and 2A activities, break the balance between protein phosphorylation and phosphorylysis, causing liver damage even necrocytosis. Furthermore, it is a strong tumor promoter.

[Biological synthesis and application of bacteriocins].

Bacteriocins produced by lactic acid bacteria are a heterogeneous group of peptide inhibitors. Most of bacteriocins have relatively narrow inhibitory spectra. A few of them have wider inhibitory spectra, being active against a wide range of gram-positive bacteria.

[Anti-oxidative effects of proanthocyanidins in mice induced by D-galactose].

The anti-oxidative effect of proanthocyanidins(PC) was evaluated in D-galactose-induced murine model. Male KUNMING mice were divided into different groups at random. The mice were induced by subcutaneous injection of D-galactose on the back of mice daily for 60 days and simultaneously PC and VE were administered to the mice by oral feeding.

[Development of a peristaltic inhibition model in mice].

Diphenoxylate was administered to mice at the dose of 5 mg/kg BW for the development of peristaltic inhibition model for formulating the examination procedure of health foods. An ink solution containing 5% charcoal was then administered 30 minutes later. The length of ink progradation of the small intestine of mice was calculated 25 minutes after the administration of ink.

Treatment of melasma with Pycnogenol.

Melasma (or chloasma) is a common disorder of cutaneous hyperpigmentation predominantly affecting sun-exposed areas in women. The pathogenesis of melasma is not fully understood and treatments are frequently disappointing and often associated with side effects. Pycnogenol is a standardized extract of the bark of the French maritime pine (Pinus pinaster), a well-known, potent antioxidant.

[Investigation on the contamination of Listeria monocytogenes in seven kinds of foods].

An examination on 3746 samples of 7 kinds of foods from 12 provinces of China for the detection of Listeria monocytogenes (LM) was carried out in 1996-1997. The detected rates of LM in commercial cold drinks, raw meat, sterilized milk products, cooked meat products, raw milk and aquatic products were 1.39%, 1.

[Pathogenic gene analysis of Listeria isolated from foods].

In 1996-1997, Listeria in foods from 12 provinces of China were detected by using the national standard examination method GB 4789.30-94 (routine traditional methods). Twenty four strains Listeria monocytogenes and 141 strains Listeria were identified by biochemical procedures and animal toxicity experiment.

[Study of fungus polysaccharides compounds (FPC) in inducing the apoptosis of liver cancer cell Bel-7402].

To observe the influence of fungus polysaccharides compounds (FPC) in inducing human liver cancer cell Bel-7402 apoptosis in cell cultivating in vitro, the authors analyzed tumor inhibitive gene P53 expression in Bel-7402 apoptosis by applying double immuno-marker. The result showed that the multilevel of FPC could all apparently induce Bel-7402 apoptosis. With the enhancement of FPC concentration, the authors observed chromatin condensation in some phases companying with the characteristic apoptosis.

[Determination of taurine in food by high performance liquid chromatography].

Taurine in food was separated by HPLC as its phthalaldehyde-ethanethiol derivative on mu-Bondapak C18 reverse column and measured at 330 nm. The determination was not interfered by sulphosalicylic acid, excess dervatizing reagents and 20 kinds of amino acids. The stability of the taurine dervatives was discussed in this paper.

[A rapid simple and reliable method for sequencing the targeted gene of shuttle vector pSP189].

The authors established a simple, rapid and effective procedures for sequencing the targeted a-gene SupF TRNA of shuttle vector pSP189, which is very important and useful in molecular mechanism research of mutagens. In this method, double-stranded plasmid DNA as template, prepared single-stranded DNA with alkali denaturation, applied r-32P-ATP for labelling 5'-end of primer, were used. A satisfactory result was achieved.

[Study on the contamination level and the tolerable limit of mould and yeast in yoghurt].

The results show that 67.33% of yoghurt samples collected from factories, supermarkets and retailers are contaminated by mould and yeast. The main problem of yoghurt product is yeast contamination (56.

[Molecular mechanism of mutagenesis induced by aflatoxin B1 using a shuttle vector pSP189/mammalian cell system].

AFB1 is one of the most potent carcinogenic mycotoxins, naturally occurred in foods. We applied a new SV40-based shuttle vector pSP189 and African Green kidney cells (VeroE6 cell line), which constitute shuttle vector/mammalian cell system to detect mutagenesis induced by AFB1 and to study the effects of AFB1 on the mutation site, type and sequence specificity of DNA molecular level through sequence analysis of pSP189 target gene SupF TRNA. The results indicated that through various time treatment of AFB1 and rat liver microsome, the mutants were obtained by transformation of E.

Regulated hypothermia in the hypothyroid rat induced by administration of propylthiouracil.

Propylthiouracil (PTU), an antithyroidal drug that reduces serum L-thyroxine (T4) and 3,5,3'-triiodothyronine (T3), is presumed to lower core temperature (T0) by impairing metabolic thermogenesis. However, it is not understood why PTU-treated animals cannot use behavioral and other thermoeffectors to maintain normal Tc. Male rats were administered PTU in drinking water (0.

[Evaluation on the method to test the sex-improve function and its key points].

The mating-test with normal mouse is one of the methods built to test wheather the type of sexual function improvement food could improve the sexual function. Through controlling the influence factor of the experiment such as the most suitabke mating time, the weights of mating mice, the mating temperature and the mating cage, and through making the female mice in different sexual response circle to be in the same, we got quite good results. The authors' study affirms the availability and dependability of the sexual function experiment method set by the authors' intitute.

[A monoclonal antibody-based indirect competitive inhibition enzyme-linked immunosorbent assay for detecting tetrodotoxin in puffer fish].

The homogenized tissue samples of puffer fish were extracted with boiling 0.1% acetic acid solution for 2 times, then the combined filtrate was defatted with ether ethyl for 2 times and the water phase were diluted with 0.05 mol/L PBS for ELISA determination (adjusted pH to 6.

Monitoring of organochlorine pesticide residues--the GEMS/Food program in China.

This paper covers the monitoring activities of organochlorine (OCS) pesticide residues in the GEMS/Food program, which China took part in for the first time in 1992. The levels of HCH and DDT were determined in 355 samples of eight main varieties of food, taken from five provinces and cities. The results show that the positive rate of HCH is 69%, of which 99.

A dietary survey of the Chinese population in urban and rural areas of Tianjin.

Objectives: A survey was carried out to assess the food pattern and of nutrient intakes of 15-64 year old Chinese in Tianjin.

Design: The survey was randomised and the diet assessed by weighing household food items and by individual food records over 3 consecutive days.

Setting: The survey was carried out in Tianjin; the third largest city in China (population about 8 million).