High performance liquid chromatographic determination of phenolic acids in fruits and vegetables

A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% methanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds of foods studied. The average concentrations of chlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.

Diversity and specificity in cestodes of the genus Moniezia: genetic evidence

Electrophoretic study of two species of Moniezia cestodes, M. expansa and M. benedeni, sampled in African (Senegal) domesticated ruminants, revealed a complex of species and a degree of specificity more pronounced than that previously described. The status of the different species is validated by the probable occurrence of within species cross-mating. A European origin is suggested for M. expansa due to identical isoenzyme patterns in cestodes from France, whereas some atypical individuals may be derived from wild African ruminants.

A strategy for isolating differentiation-inducing complementary DNAs from human esophageal cancer cell line treated with retinoic acid

Treatment of the human esophageal cancer cell line EC8712 with retinoic acid (RA) stopped the cell growth significantly and gave rise to terminal differentiation of the cells characterized by increased expression of involucrin gene. Two cDNA libraries were constructed from the parental and RA-treated cells respectively. Repeated subtractive hybridization of single-stranded plasmid DNA prepared from pooled colonies of cDNA library of the parental cells with cDNA probe generated from the RA-treated cells exhausted sequences common to both libraries of the cell. The unhybridized cDNA probe represented, therefore, the genes activated after RA-treatment. By using these enriched cDNAs as probe to screen the cDNA library constructed from the RA-treated cells thirty-nine positive colonies were obtained, of which two were specifically due to RA-induction. One of these two cDNA clones, designated as pRA538, has undergone further analysis and shown differentiation-inducing effect on parental cancer cells. A novel strategy for cloning genes involved in terminal differentiation of cancer cells is developed.

Reliability and validity of the Chinese versions of the Scales for Assessment of Positive and Negative Symptoms

This 4-center study assesses the reliability and validity of the Chinese versions of the Scale for Assessment of Positive Symptoms and the Scale for Assessment of Negative Symptoms. Interrater reliability, short-term test-retest reliability, and internal consistency were excellent; intraclass correlation coefficients and Cronbach alphas for the overall scores were all over 0.8. The strong correlation of the scales with an independently assessed parallel measure (the Chinese version of the Brief Psychiatric Rating Scale) and the separate positive and negative factors found with principal components analysis confirm the construct validity of the instruments. These findings demonstrate the importance of culturally sensitive revision and rigorous psychometric evaluation of Western instruments prior to their use in non-Western cultures.

Favored patterns in spontaneous spike trains

By using the modified detection method, favored patterns can be detected in a total of 44 spontaneous spike trains. Among these the 'periodical burst' discharge of one sympathetic preganglionic neuron and the 'fast-slow' alternative discharge of some hypothalamic neurons have visible characteristics, hence we use them to test the reliability of our method by comparing the detected patterns with the non-sequential interval histograms and oscillograms of the spike trains. The comparisons show that our method is reliable. The spike trains of nucleus raphe magnus (NRM) and the locus coeruleus (LC) have no visible characteristics; from these the following results have been observed: (1) all spike trains have one or more favored patterns; (2) some spike trains from neurons in the same nucleus have common fragments of favored patterns; (3) the favored patterns in spike trains recorded from different nuclei are different from each other; (4) some favored patterns in spike trains of the NRM neurons remain unchanged from beginning to end in 35-min records and their repetitions are relatively stable; and (5) microinjection of normal saline or normal serum into the LC has no significant influence on the occurrence of favored patterns in 35-min records of spike trains of the LC neurons. The above results indicate that the favored patterns in spike trains are objective and regular phenomena with relative stability. It seems likely that favored pattern may be used (as an index of the neuronal activity) in combination with the microinjection technique, etc., for various studies including studies on neural coding.

[Effects of panaxadiol and panaxatriol saponins on action potentials of normal and xanthine-xanthine oxidase damaged cultured myocardial cells]

Wistar rat myocardial cells were cultured. PDS 20-80 micrograms.ml-1; PTS 1.25-20 micrograms.ml-1 dose-dependently decreased their action potential parameters, indicating the possibility of being concerned in the blockage of Ca channel. After the free radical damage was induced by xanthine 0.42 mmol.L-1--xanthine oxidase 5.3 nmol.L-1 (X-XO). All the action potential parameters of the cardiac cells decreased without exception. Both PDA and PTS antagonized the electrical appearance of membrane damage induced by X-XO, suggesting that both PDS and PTS protect the myocardial cells from oxidative damage.

Isolation, characterization and expression of the complementary DNA for human tumor necrosis factor (TNF-alpha)

A cDNA for human TNF-alpha (615bp) was isolated by means of polymerase chain reaction (PCR) using first strand cDNA from PMA-induced HL-60 cells as template. The result from sequencing the 615 bp cDNA fragment indicated that it corresponded to the entire sequence of mature human TNF coding region. Direct expression of mature human TNF was achieved using a plasmid pHT-1 constructed by ligation of the cDNA and a synthetic DNA. The IPTG-induced bacterial product (hTNF) showed cytotoxicity to mouse L-929 cells. The TNF activity was further identified by neutralization of a specific monoclonal antibody against human TNF-alpha. Approximately 80,000 units of activity were detected per ml of culture at A600 = 2.

Observations of fragile sites in patients with lymphoma and leukemia

Chromosomal fragile sites analyses were performed in peripheral lymphocytes of 37 patients with lymphoma and 16 patients with leukemia, and also of 50 healthy individuals as controls. The results were: 1) The rates of chromosomal aberration and frequency of expression of fragile sites in patients with lymphoma and leukemia were significantly higher than those of normal controls. 2) There was a statistical association between 21 of 44 fragile sites and specific cancer breakpoints in patients with lymphoma and this was also the case with 19 of 30 fragile sites and specific cancer breakpoints in patients with leukemia. 3) Concordance between fragile sites and location of oncogenes in the diseases was established. The possible important role of fragile sites in the pathogenesis of lymphoma and leukemia is discussed.

Transfer of foreign genes by electroporation and their expression in mammalian cells

Expression of foreign genes transferred into mammalian cells by electroporation has been studied. The pX1TK gene, pSV2Neo gene and pUCEJ oncogene have been introduced into MLTK- cells and NIH/3T3 cells, respectively. Stable transformation transient expression of TK gene by MLTK- cells as well as stable and malignant transformation of NIH/3T3 cells have been obtained. Transient expression frequency is about 80% and stable transformation frequency is about 10(-4). Integration of foreign genes into the cellular genome was verified with molecular hybridization. Tumor development was observed after inoculation of transformed cells into nude mice.

Comparison of morphology, pathogenicity and drug response among three isolates of Schistosoma japonicum in the mainland of China

Geographic differences among isolates of Schistosoma japonicum from Anhui Province (A) in the east, Guangxi Autonomous Region (G) in the south and Yunnan Province (Y) in the southwest of mainland of China were studied. C57BL mice were used to compare these isolates. Morphologically, both male and female worms of isolate Y were shorter than those of isolates A and G, and the ovary of female worm of isolate G was the smallest. In isolate A, the percentage of male worms bearing 7 testes was 87%, while 64% of isolate Y and 75% of isolate G were with 7 testes. As to the volume of hepatic egg granuloma which was used as a parameter of pathogenicity in our experiment, that of isolate G was the smallest. The sensitivity to praziquantel of isolates was estimated by parasite reduction rate at ED50 (230 mg/kg) level. It was found that isolate Y's response was significantly higher than that of isolates A and G, and the latter two were similar in drug response. The results indicate significant differences among the three isolates studied.

G-banded chromosome analyses of mucosal epithelium adjacent to esophageal cancer (EC)--some consistent chromosomal changes

G-banded chromosomes of primary cultures taken from mucosal epithelium adjacent to esophageal cancer (EC) were first analyzed. Consistent chromosomal changes, i.e. marker chromosomes, appeared in 2 of seven specimens of esophageal epithelium. Some of the marker chromosomes are very similar to those found in EC8501 cell line. These results imply that the cytogenetic analyses of the mucosal epithelium adjacent to EC may detect the numerical and structural chromosome aberrations occurring at the very beginning of carcinogenesis of esophageal epithelium.

SPECT Compton-scattering correction by analysis of energy spectra

The hypothesis that energy spectra at individual spatial locations in single photon emission computed tomographic projection images can be analyzed to separate the Compton-scattered component from the unscattered component is tested indirectly. An axially symmetric phantom consisting of a cylinder with a sphere is imaged with either the cylinder or the sphere containing 99mTc. An iterative peak-erosion algorithm and a fitting algorithm are given and employed to analyze the acquired spectra. Adequate separation into an unscattered component and a Compton-scattered component is judged on the basis of filtered-backprojection reconstruction of corrected projections. In the reconstructions, attenuation correction is based on the known geometry and the total attenuation cross section for water. An independent test of the accuracy of separation is not made. For both algorithms, reconstructed slices for the cold-sphere, hot-surround phantom have the correct shape as confirmed by simulation results that take into account the measured dependence of system resolution on depth. For the inverse phantom, a hot sphere in a cold surround, quantitative results with the fitting algorithm are accurate but with a particular number of iterations of the erosion algorithm are less good. (A greater number of iterations would improve the 26% error with the algorithm, however.) These preliminary results encourage us to believe that a method for correcting for Compton-scattering in a wide variety of objects can be found, thus helping to achieve quantitative SPECT.

[G-banded chromosome analysis of bone marrow and peripheral blood cells from small cell lung cancer (SCLC) patients]

Detailed G-banded chromosome analysis was carried out on the bone marrow and/or PHA-stimulated peripheral blood cells from 17 SCLC patients (14 males and 3 females), who were diagnosed cytologically or pathologically or both. Twelve of them had no prior treatment and 16 had a heavy smoking history. High chromosome aberration rates were found in the bone marrow (31% for average structural aberration rate and 63% for numerical aberration rate) and peripheral blood cells (37% for average structural aberration rate and 49% for numerical aberration rate). The smoking index, as a whole, was positively correlated to the structural chromosome aberration rate, indicating that smoking is one of the most important environmental factors in causing chromosome aberrations. But some patients gave a high aberration rate dis-proportional to their smoking index, suggesting that genetically determined susceptibility to smoking or even other factors also play an important role. The structural chromosome aberrations in the bone marrow and peripheral blood cells were mainly clustered on chromosome 3 and chromosomes 1, 9 and 11, respectively. The aberration types were manifold and complicated. No consistent or specific aberration as del 3p14-23 for SCLC was found in this study.

The studies of malignant transformation of human epithelial cells induced by diethyl-nitrosamine (NDEA) in vitro

This is the first report on the diethylnitrosamine-induced malignant transformation of human epithelial cells derived from fetal kidney. The transformed cells have prolonged life span and aneuploid karyotypes. They also form anchorage independent colonies in soft agar. With additional one or two NDEA treatments, these cells could elicit poorly differentiated carcinomas in immunosuppressed new-born rats. This experiment indicates that the human fetal kidney cells seem to be a good material for studying the mechanisms of carcinogenesis of human epithelial cell.

Malignant transformation of human fetal lung fibroblasts induced by nitrosamine compounds in vitro

This report, for the first time, demonstrates that diethyl-nitrosamine (NDEA) and a new nitrosamine compound-N-1-methylacetonyl-N-3-methylbutyl-nitrosamine (MAMBNA), which are suspicious carcinogens of esophageal cancer (EC) in Linxian, Henan Province, are able to cause the malignant transformation (altered morphology, extended life span, anchorage independent growth, invasiveness, tumorigenicity, etc.) of normal diploid fibroblasts derived from human fetal lung. Besides, the preselection for clonogenic cells, which seem to be more readily to be transformed, in soft agar before carcinogen treatment, could be considered as one of the useful ways in establishment of a model system of malignant transformation of human fibroblasts in vitro.

Studies on mechanism of entry of EB virus into non-B lymphocytes. Establishment of an EB virus-producing human-tupaia hybrid cell line TuH18

With the use of the EB virus-producing lymphoblastoid cell line H18, an attempt was made to infect the monolayer cell culture of nasopharyngeal tissue from the normal tupaia, and an EB virus-producing, human-tupaia hybrid cell line was established. The mechanism of entry of EB virus into cells other than B lymphocytes is discussed in this paper.

Malignant transformation of baby hamster lung fibroblasts induced in vitro by a new nitrosamine compound

A new nitrosamine compound, N-1-methylacetonyl-N-3-methylbutyl-nitrosamine (MAMB-NA), isolated from corn bread inoculated with moulds commonly occurring in Linxian County, a high incidence area for esophageal cancer in North China was tested for its potential carcinogenicity in vitro. Baby hamster lung fibroblasts (BHL) were treated with MAMBNA in tissue culture medium containing liver microsome preparation of Aroclor 1254 treated rat. Cell transformation was assessed by morphological changes, loss of density-dependent inhibition and unlimited growth in vitro, chromosome changes, colony formation on soft agar, growth at low serum concentration, Con A agglutinability and tumor formation after heterotransplantation into immunosuppressed newborn rats. Like the known carcinogens N-methyl-N'-nitro-N-nitroso-guanidine and diethylnitrosamine, MAMBNA was able to cause malignant transformation of cells cultured in vitro.