[Zeng-Ding phenomenon: further demonstration and studies on its predictive value in epidemic of measles and scarlet fever]

OBJECTIVE

To demonstrate further the existence of Zeng-Ding phenomenon in disease epidemic and to explore the relationship between it and the time series in different kinds of diseases.

METHODS

Incidence data of notifiable communicable diseases during 1975 to 1996 were collected. Time series of measles and scarlet fever incidence during 1975 to 1995, 1980 to 1995, 1985 to 1995 and 1990 to 1995 were established. Correlation analysis was conducted between monthly cumulative percentage and predictive ratio of increase to decrease in incidence rate at the best cut-off point. Prediction was studied based on the constructed extrapolation model.

RESULTS

Correlation analysis showed that 98.3% (232/236) of the coefficients of correlation were negative (R < 0), indicating further the existence of Zeng-Ding phenomenon in disease epidemic. There was significant difference in coefficients of correlation between the four time series, which accounted for 63.8%, 54.2%, 44.1% and 35.0%, respectively; and for 73.3%, 56.7%, 36.7% and 36.7%, respectively, in measles, and for 53.6%, 51.8%, 51.7% and 33.3%, respectively, in scarlet fever. It showed that Zeng-Ding phenomenon correlated with the time series and the kinds of diseases. Prediction from extrapolation model showed that there was significant difference in predictive agreement between two time series of 1975 to 1995 (65.5%) and 1985 to 1995 (37.0%) with chi 2 of 4.54 and P < 0.05, indicating a trend that predictive agreement increased with prolonging of time series, and a trend that predictive agreement for scarlet fever increased with decreasing of coefficients of correlation.

CONCLUSION

Predictive value of the incidence data can be evaluated by their source and length of time series.

Alteration of ganglioside composition by stable transfection with antisense vectors against GD3-synthase gene expression

Gangliosides are ubiquitous components of mammalian cells. Their expression is frequently altered in many tumor types. We previously showed that alteration of the ganglioside composition often resulted in changes in cellular morphology and differentiation of cultured cells. In this study, we targeted sialyltransferase gene expression by the antisense knockdown experiment, and the results showed that inhibition of the expression of gangliosides GD3 and O-acetylated GD3 (OAc-GD3) in the neuroblastoma F-11 cells greatly reduced the tumor growth in nude mice. The sense and antisense vectors containing either a 5' end fragment or the entire sequence of the cDNA coding for GD3-synthase were prepared and used in separate experiments to transfect the F-11 cells which express high levels of gangliosides GD3 and OAc-GD3. Single clones were isolated and expanded. Both the activity of the GD3-synthase and the concentrations of GD3 and OAc-GD3 in the antisense-transfected cells were dramatically decreased as a result of transfection with the antisense expression vectors. Further characterization of the antisense-transfected cells showed reduced rates of cell growth and neurite formation and changes in cellular morphology. When the cells were inoculated in athymic nude mice, the tumor growth rate was remarkably suppressed although the tumor incidence was not affected by the altered ganglioside composition. These results indicate that the tumor-associated ganglioside(s) is(are) involved in regulation of tumor growth, probably through the stimulation of angiogenesis of the tumor.

[Effects of nutritional intervention on several chronic diseases in communities]

Eighty seven subjects with abnormal blood glucose, blood pressure and serum triglycerides and cholesterol were selected. They are living in the urban area of Chengdu. Nutritional intervention measures included making suggestions on recipe, nutrition education and consultation etc. The following parameters were observed: 1. fasting blood glucose and postprandial blood glucose at 2 h after meal; 2. serum triglycerides and cholesterol; 3. blood pressure and body weight, and 4. symptom score. Data were analyzed by paired t-test, correlation and stepwise regression analysis. The results showed that above parameters were significantly improved by the end of the study. It can be considered that reasonable diet is a simple and effective measure to control these chronic diseases in communities.

Molecular cloning and expression of mouse brain sialidase

Sialidase (EC 3.2.1.18) catalyzes the release of sialic acid from sialo-oligosaccharides, gangliosides, or sialo-glycoproteins. In this investigation, we cloned a novel cDNA for mouse brain sialidase and expressed the cDNA in COS-7 cells. This 1,699 bp cDNA codes for a 41.6 kDa protein consisting of 372 deduced amino acid residues. In COS-7 cells transiently transfected with the cDNA, a 250-fold increase was observed in specific activity toward 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid. Similarity searches of the nonredundant GenBank peptide sequence database by the PSI-BLAST program identified rat, hamster, human, and bacterial sialidases homologous to this mouse brain sialidase. Amino acid sequence identities to rat and hamster sialidases (84% and 77%, respectively) suggest that this form of sialidase is conserved in rodents. Sequence identities to human and mouse lysosomal sialidases (30% and 28%, respectively) indicate that the mouse brain sialidase is distinct from the lysosomal enzyme. Mouse brain sialidase has two amino acid sequence motifs common to bacterial sialidases: the 'F/YRIP' motif and the 'Asp-box' motif. The 'F/YRIP' motif is present near the N terminus while two 'Asp-box' motifs are present downstream.

Down-regulation of the expression of O-acetyl-GD3 by the O-acetylesterase cDNA in hamster melanoma cells: effects on cellular proliferation, differentiation, and melanogenesis

The composition of the gangliosides of hamster melanoma cells is closely related to their cellular growth and degree of differentiation, with slow-growing, highly differentiated melanotic melanoma MI cells expressing GM3 and fast-growing, undifferentiated amelanotic Ab melanoma cells having a preponderance of GD3 and O-acetyl-GD3. To study the putative function of O-acetyl-GD3, we established stably transfected AbC-1 amelanotic hamster melanoma cells with O-acetylesterase gene from influenza C virus to hydrolyze the O-acetyl group from O-acetyl-GD3. The content of O-acetyl-GD3 in the transfected cells expressing O-acetylesterase gene was reduced by >90%. These O-acetyl-GD3-depleted cells differed from the parental ones in their cellular morphology, growth behavior, and melanogenesis activity. The absence of O-acetyl-GD3 in the transfected cells was accompanied by increased thick dendrite formation with an enlarged cell body, which is in striking contrast to the control cells, which were rounded and flattened, with few processes. Their growth was significantly slower than that of the control cells. They also demonstrated significantly lower tyrosinase activity and melanogenic potential. We suggest that the enhanced expression of melanoma-associated O-acetyl-GD3 ganglioside may stimulate cellular growth and suppress certain differentiated phenotypes such as dendrite formation but not melanogenesis.

[Studies on decomposed crop residues by FTIR differential analysis]

The decomposing process of corn leaf residues (CLR) was studied by FTIR differential analysis, and the differential spectra were compared with normal spectra. The result showed that the purification process to remove inorganic matters from decomposed CLR could be omitted when differential analysis is used, and the differential spectra were clear and distinct. As far as the studies of decomposed crop residues, the FTIR differential analysis was a convenient and forthright method.

Regulation of the actin cytoskeleton organization in yeast by a novel serine/threonine kinase Prk1p

Normal actin cytoskeleton organization in budding yeast requires the function of the Pan1p/ End3p complex. Mutations in PAN1 and END3 cause defects in the organization of actin cytoskeleton and endocytosis. By screening for mutations that can suppress the temperature sensitivity of a pan1 mutant (pan1-4), a novel serine/threonine kinase Prk1p is now identified as a new factor regulating the actin cytoskeleton organization in yeast. The suppression of pan1-4 by prk1 requires the presence of mutant Pan1p. Although viable, the prk1 mutant is unable to maintain an asymmetric distribution of the actin cytoskeleton at 37 degreesC. Consistent with its role in the regulation of actin cytoskeleton, Prk1p localizes to the regions of cell growth and coincides with the polarized actin patches. Overexpression of the PRK1 gene in wild-type cells leads to lethality and actin cytoskeleton abnormalities similar to those exhibited by the pan1 and end3 mutants. In vitro phosphorylation assays demonstrate that Prk1p is able to phosphorylate regions of Pan1p containing the LxxQxTG repeats, including the region responsible for binding to End3p. Based on these findings, we propose that the Prk1 protein kinase regulates the actin cytoskeleton organization by modulating the activities of some actin cytoskeleton-related proteins such as Pan1p/End3p.

A breast and melanoma-shared tumor antigen: T cell responses to antigenic peptides translated from different open reading frames

Infusion of TIL586 along with IL-2 into the autologous patient with metastatic melanoma resulted in the objective regression of tumor. Here, we report that screening a cDNA library from the 586mel cell line using CTL clones derived from TIL586 resulted in the isolation of a gene, CAG-3 (cancer Ag gene 3). Sequence analysis revealed that CAG-3 encodes an open reading frame identical to NY-ESO-1, which was recently reported to be recognized by autologous serum from a patient with esophageal cancer. Thus, NY-ESO-1 appears to be an immune target for both Ab- and T cell-mediated responses. Significantly, NY-ESO-1-specific CTL clones were capable of recognizing two HLA-A31-positive fresh and cultured breast tumors. To our knowledge, this represents the first direct demonstration that tumor-specific CTL clones can recognize both breast and melanoma tumor cells. A 10-mer antigenic peptide ESO10-53 (ASGPGGGAPR) was identified from the normal open reading frame of NY-ESO-1 based on its ability to sensitize HLA-A31-positive target cells for cytokine release and specific lysis. Interestingly, two additional CTL clones that were sensitized with NY-ESO-1 recognized two overlapping antigenic peptides derived from an alternative open reading frame of the same gene. These findings indicate that CTLs simultaneously responded to two different gene products translated from the normal and alternative reading frames of the same gene. Understanding of this mechanism by which the alternative reading frame is translated may have important implications in tumor immunology.

Transgenic animals with inducible, targeted gene expression in brain

Several inducible gene expression systems have been developed in vitro in recent years to overcome limitations with traditional transgenic mice. One of these, the tetracycline-regulated system, has been used successfully in vivo. Nevertheless, concerns remain about the ability of this system to direct high levels of transgene expression in vivo and to enable such expression to be turned on and off effectively. We report here the generation, using a modified tetracycline-regulated system under the control of the neuron-specific enolase promoter, of several lines of mice that direct transgene expression to specific brain regions, including the striatum, cerebellum, CA1 region of the hippocampus, or deep layers of cerebral neocortex. Transgene expression in these mice can be turned off completely with low doses of doxycycline (a tetracycline derivative) and driven to very high levels in the absence of doxycycline. We demonstrate this tissue-specific, inducible expression for three transgenes: those that encode luciferase (a reporter protein) or DeltaFosB or the cAMP-response element binding protein (CREB) (two transcription factors). The various lines of transgenic mice demonstrate an inducible system that generates high levels of transgene expression in specific brain regions and represent novel and powerful tools with which to study the functioning of these (or potentially any other) genes in the brain.

Development of a retrovirus-based complementary DNA expression system for the cloning of tumor antigens

A new retroviral system has been developed for the generation of a cDNA library and the functional cloning of tumor antigens. These retroviral vectors contain a cytomegalovirus promoter in the 5' long terminal repeat, an extended packaging signal for rapid production of high-titer retroviral particles, and many convenient cloning sites for cDNA library construction. The vesicular stomatitis virus G protein has been used to generate pseudotype retroviral particles to enable efficient viral infection. Using this system, viral titers in the range of 10(6) colony-forming units/ml could be generated routinely, and a high transduction efficiency in human primary cells, including fibroblasts, was achieved. In addition, a new procedure has been devised for screening a retrovirus-based cDNA library without a functional selection. The utility of this system was demonstrated by constructing a retrovirus-based cDNA library and re-isolating the NY-ESO-1 tumor antigen from a cDNA library using an antigen-specific CTL. This approach can facilitate the identification of novel tumor antigens recognized by T cells without knowledge of MHC class I restriction elements and is generally applicable for the isolation of any gene as long as a biological assay is available.

[Study on the relative absorption of food carbohydrate in healthy adults]

The absorption of food carbohydrate was determined with breath hydrogen test (BHT) in healthy adults. When the absorption of lactulose was assumed as 0, the absorption of food carbohydrates were as follows: 100% for rice with ground lean pork; 98% for rice; 85% for bread; 58% for corn and 30% for red potato. The absorption of food carbohydrate was positively related to the oral-colon transit time (OCTT, r = 0.8790) and the peak hydrogen time (PHT, r = 0.6745), and was negatively related to the peak hydrogen value (PHV, r = -0.6468) and to the hydrogen producing percentage (H2 > 1.8 mg/m3, r = -0.8679). The breath hydrogen test can be used in estimating the absorption of food carbohydrate in human body because this method is safe, non-invasive, reproducible and accurate.

Isolation and functional analysis of the promoter of the rat CMP-NeuAc:GM3 alpha2,8 sialyltransferase gene 1

A 2.1-kb 5'-flanking fragment of the rat CMP-NeuAc:GM3 alpha2,8 sialyltransferase (GD3-synthase) gene was cloned by the genomic walking procedure. The promoter activity of the fragment was assessed in F-11 cells by transient transfection and the locations for the basal and maximal promoter activities were defined. Primer extension analysis identified a transcription start site approximately 98 bp upstream of the ATG start codon. DNA sequence analysis of the promoter revealed a number of consensus binding sites for known transcription factors such as SP1, AP1, NFkappaB, C/EBP and TFIID, and a repeat GC-GT sequence motif seen for the formation of Z-type DNA. Both TATA and CCAAT boxes were not found in the promoter. Our results from deletion constructs suggested that both positive and negative cis-acting regulatory regions were present in this TATA-less promoter of the rat GD3-synthase gene.

Infectious disease surveillance in China

A national system of infectious disease surveillance was established in 1959 in China. Now it consists of three subunits, namely, national disease reporting system (NDRS), nationwide disease surveillance points (DSPs), and surveillance network for specific infectious diseases. There are 35 notifiable infectious diseases, which are divided into Classes A, B, and C. The functions of the surveillance include explaining the natural history of infectious diseases, describing the distribution of case occurrence, triggering disease-control effort, monitoring epidemic of infectious diseases during natural disasters, predicting and controlling epidemics and providing the base of policy adjustment.

[Demonstration on Z-D phenomenon in the occurrence of infectious diseases]

A systematic analysis, including retrospective test by means of correlation analysis and extrapolation test was carried out to demonstrate a new hypothesis named Z-D phenomenon which states that the skew of a seasonal case distribution curve of an infectious disease may appear to be the omen of its epidemic trend in the following year. A total number of 353 data sets belong to 17 notifiable infectious diseases in 29 provinces and the whole nation were chosen. Data from retrospective test showed that 91.2% (322/353) of the correlation coefficients of between the skew of the seasonal distribution curve of the previous year and the morbidity variation of its following year were negative. The extrapolation test showed that 68.1% (203/295) of the data sets accorded with the actually epidemic situation at the level of r < -0.5. The results proved the existence of Z-D phenomenon may serve as an indicator for the purpose of forecasting. Using this systematic analysis, we found that Z-D phenomenon was more expressive in viral hepatitis, pertussis, epidemic cerebrospinal meningitis and scarlet fever than in other diseases.

[Preparation and property investigations of nanosized titanium oxide microcrystals]

A naosized TiO2 powder was successfully prepared by the hydrolysis of titanium isopropoxide through sol-gel process. The microstructure of TiO2 powder was investigated by transmission electron microscopy and X-ray diffraction. Both anatase and rutile phases were found in TiO2 powder annealed for 1 hour at 600 degrees C. The characteristics of X-ray photoelectron spectra and infrared spectra could be affected by the size and aggregation state of the microsrystalc constituting the TiO2 powder.

[Spectroscopic study of Langmuir-Blodgett films of octa-4-(hexadecoxy) lanthanium bisphthalocyanine]

The surface pressure/molecular area isotherms ( pi approximately A ) of lanthanium bisphthalocyanine were investigated, showing an edge-on molecular orientation of the macrocycle rings on the water subphase. Langmuir-Blodgett films of this compound were prepared and characterized using IR, UV-vis absorption spectroscopy.

Cloning of the cDNA coding for rat brain CMP-NeuAc:GD3 alpha2-8 sialyltransferase

The cDNA coding for GT3-synthase has been cloned from a rat fetal brain cDNA library. The complete nucleotide sequence and the deduced amino acid sequence of the rat GT3-synthase cDNA were highly homologous to those of the mouse GT3-synthase. Quantitative RT-PCR showed that, as a key enzyme for the synthesis of 'c'-series gangliosides, the expression of GT3-synthase was developmentally regulated in embryonic rat brains.

[A study of therapeutic efficacy of Koukangning gargle in the treatment of oral mucositis]

A study of therapeutic efficacy was carried out in 118 patients with oral mucositis (recurrent oral aphthous ulceration, erosive lichen planus, herptic stomatitis and infectious oral mucosal hematoma) at random. As a topical medication, Koukangning gargle was applied to 59 patients of the experimental group, 29 patients of the control group 1 applied Dobell's solution to rinse their mouths, and 30 patients of the control group 2 applied Koutai solution. A satisfactory result was observed in the experimental group, its effectiveness and effective rates rose more than those of control group 1 at both treatments for 3 days and 6 days. Between the two groups, there were markedly significant difference (P < 0.005, P < 0.01, P < 0.005, P < 0.005). Koukangning gargle was nontoxic and no side-effects in the clinical tests. Its efficacy was no significant difference compared with the control group 2. Experimental study demonstrates that it possesses anti-inflamation effect and excellent antibiotic effect, therefore it is a new gargle for rinse mouth combined traditional Chinese medicine with Western medicine.

Induction of proto-oncogenes during 3-deazaadenosine-stimulated differentiation of 3T3-L1 fibroblasts to adipocytes: mimicry of insulin action

3-Deazaadenosine (DZA) mimicked the molecular action of insulin in the induction of 3T3-L1 fibroblasts to differentiate into adipocytes. The molecular effects of DZA were compared with insulin, which served as a positive control, on the expression of proto-oncogenes during the initial stage of differentiation of 3T3-L1 fibroblasts. Treatment of confluent 3T3-L1 fibroblasts with DZA or insulin produced a rapid but-transient expression of mRNA for proto-oncogenes c-fos and c-jun within 30-60 min. The mRNA of c-myc increased for 2 h and then decreased 4 h after treatment. Electrophoretic mobility shift assays showed a heightened increase in the appearance of transcription factors AP-1 and AP-2. The increase was detectable as early as 1 h after the treatment with either DZA or insulin and was maintained for 6 h. 3T3-L1 cells stably transfected with the promotor of c-fos linked to a CAT reporter gene showed an increase in CAT activity in response to DZA in a time- and dose-dependent manner. In cells stably transfected with antisense c-fos, neither DZA nor insulin was able to induce a differentiation response. The early transcription of c-fos, c-jun, and c-myc proto-oncogenes and the increased expression of transcription factors AP-1 and AP-2, induced by DZA and insulin, appear to be crucial events in the differentiation of the 3T3-L1 fibroblasts to adipocytes.

Repressor for the sn-glycerol 3-phosphate regulon of Escherichia coli K-12: primary structure and identification of the DNA-binding domain

The nucleotide sequence of the glpEGR operon of Escherichia coli was determined. The translational reading frame at the beginning, middle, and end of each gene was verified. The glpE gene encodes an acidic, cytoplasmic protein of 108 amino acids with a molecular weight of 12,082. The glpG gene encodes a basic, cytoplasmic membrane-associated protein of 276 amino acids with a molecular weight of 31,278. The functions of GlpE and GlpG are unknown. The glpR gene encodes the repressor for the glycerol 3-phosphate regulon, a protein predicted to contain 252 amino acids with a calculated molecular weight of 28,048. The amino acid sequence of the glp repressor was similar to several repressors of carbohydrate catabolic systems, including those of the glucitol (GutR), fucose (FucR), and deoxyribonucleoside (DeoR) systems of E. coli, as well as those of the lactose (LacR) and inositol (IolR) systems of gram-positive bacteria and agrocinopine (AccR) system of Agrobacterium tumefaciens. These repressors constitute a family of related proteins, all of which contain approximately 250 amino acids, possess a helix-turn-helix DNA-binding motif near the amino terminus, and bind a sugar phosphate molecule as the inducing signal. The DNA recognition helix of the glp repressor and the nucleotide sequence of the glp operator were very similar to those of the deo system. The presumptive recognition helix of the glp repressor was changed by site-directed mutagenesis to match that of the deo repressor or, in a separate construct, to abolish DNA binding. Neither altered form of the glp repressor recognized the glp or deo operator, either in vivo or in vitro. However, both altered forms of the glp repressor were negatively dominant to the wild-type glp repressor, indicating that the inability to bind DNA with high affinity was due to alteration of the DNA-binding domain, not to an inability to oligomerize or instability of the altered repressors. For the first time, analysis of repressors with altered DNA-binding domains has verified the assignment of the helix-turn-helix motif of the transcriptional regulators in the deoR family.

Endogenous TGF-beta activity is modified during cellular aging: effects on metalloproteinase and TIMP-1 expression

In culture, nontransformed human diploid fibroblasts divide a limited number of times, resulting in a nonproliferating senescent cell culture which exhibits an altered pattern of gene expression. Previously we reported that an early event in the process of replicative senescence was an increase in the synthesis of two connective tissue degrading metalloproteinases, collagenase and stromelysin, and a decrease in the synthesis of the physiological inhibitor of those enzymes, tissue inhibitor of metalloproteinases-1 (TIMP-1). The cytokine TGF-beta1 is known to regulate the expression of each of these three genes and to be synthesized and secreted by cultured human fibroblasts. This suggested the hypothesis that the age-specific modulation of collagenase, stromelysin, and TIMP-1 expression is the result of a change in TGF-beta1 activity during replicative senescence. To test this hypothesis, the responses of early, mid, and late passage (presenescent) fibroblast cell cultures to a TGF-beta neutralizing antibody were evaluated. In early passage cell cultures, exposure to TGF-beta neutralizing antibody resulted in a significant increase in the expression of collagenase and stromelysin and decreased TIMP-1 expression. The antibody did not affect expression of either of those genes by late passage cell cultures, although late passage cultures did respond to added TGF-beta1. Quantification of the levels of active TGF-beta, using a growth inhibition assay, indicates that the level of active TGF-beta1 is decreased during replicative senescence, supporting the conclusion that the modulation of collagenase, stromelysin, and TIMP-1 expression results from diminished TGF-beta activity.

Molecular cloning of cDNA for rat brain GD3-synthase

The complete nucleotide sequence of the cDNA coding for rat GD3-synthase was determined for the first time using PCR and the rapid amplification of cDNA ends (RACE) procedures. The deduced amino acid sequence consists of 359 residues. The protein contains a potential transmembrane domain with a short N-terminus and such highly conserved regions as the sialylmotifs. An antisense oligonucleotide derived from the rat GD3-synthase cDNA was applied to the cultures of rat cerebellar neurons and results showed a decrease in the synthesis of ganglioside GD3, indicating that the expression of GD3-synthase was modulated by the antisense sequence.

Insulin-stimulated production of nitric oxide is inhibited by wortmannin. Direct measurement in vascular endothelial cells

Hypertension is associated with insulin-resistant states such as diabetes and obesity. Nitric oxide (NO) contributes to regulation of blood pressure. To gain insight into potential mechanisms linking hypertension with insulin resistance we directly measured and characterized NO production from human umbilical vein endothelial cells (HUVEC) in response to insulin using an amperometric NO-selective electrode. Insulin stimulation of HUVEC resulted in rapid, dose-dependent production of NO with a maximal response of approximately 100 nM NO (200,000 cells in 2 ml media; ED50 approximately 500 nM insulin). Although HUVEC have many more IGF-1 receptors than insulin receptors (approximately 400,000, and approximately 40,000 per cell respectively), a maximally stimulating dose of IGF-1 generated a smaller response than insulin (40 nM NO; ED50 approximately 100 nM IGF-1). Stimulation of HUVEC with PDGF did not result in measurable NO production. The effects of insulin and IGF-1 were completely blocked by inhibitors of either tyrosine kinase (genestein) or nitric oxide synthase (L-NAME). Wortmannin (an inhibitor of phosphatidylinositol 3-kinase [PI 3-kinase]) inhibited insulin-stimulated production of NO by approximately 50%. Since PI 3-kinase activity is required for insulin-stimulated glucose transport, our data suggest that NO is a novel effector of insulin signaling pathways that are also involved with glucose metabolism.

Association of a 14-3-3 protein with CMP-NeuAc:GM1 alpha 2,3-sialyltransferase

CMP-NeuAc:GM1 alpha 2,3-sialyltransferase (ST-IV) was purified to homogeneity from rat brain. Microsequencing of the tryptic peptides derived from the purified enzyme revealed two amino acid sequences homologous to the 14-3-3 proteins. A polyclonal antibody was raised against purified ST-IV. A 33 kDa protein was co-immunoprecipitated from rat brain extracts with the anti-(ST-IV) antibody as detected by Western blot analysis. This protein was identified as a subtype of 14-3-3 family by an anti-(14-3-3) antibody. Screening of a rat brain lambda gt11 library using the anti-(ST-IV) antibody resulted in the identification of a cDNA clone coding for the subtype of 14-3-3 protein. These results indicate an association of the 14-3-3 protein with the sialyltransferase. Since the 14-3-3 protein has PKC inhibitor activities and the activity of sialyltransferases is, at least in part, regulated by PKC, the association of the 14-3-3 protein with ST-IV may indicate a role for this protein in the post-translational regulation of the sialyltransferase activity through the processes of phosphorylation and dephosphorylation.

Differential regulation of collagenase and stromelysin mRNA in late passage cultures of human fibroblasts

Nontransformed human fibroblast cell cultures have been extensively studied as an in vitro model for cellular senescence. Recently there has been considerable interest in using the human fibroblast in the identification of genes relevant to the process of replicative senescence. We demonstrated that in comparison with early passage cultures the expression of collagenase and stromelysin mRNAs and proteins was increased > 8 x in late passage cultures of human fibroblasts and, in addition, expression of Il-1 alpha, a cytokine that regulates collagenase and stromelysin expression, was also significantly increased in late passage cell cultures. These findings suggested the hypothesis that constitutive Il-1 alpha expression in late passage cells may coordinately regulate the age-associated increase in the expression of collagenase and stromelysin. To test this hypothesis we examined the effects of long-term Il-1 alpha treatment, serum starvation, and cycloheximide inhibition on collagenase and stromelysin mRNA levels in early and late passage human fibroblast cell cultures. Here we report that in late passage cell cultures, collagenase and stromelysin mRNAs respond differentially to Il-1 alpha, serum starvation, and cycloheximide addition. Continuous exposure to Il-1 alpha reduced the half-life of stromelysin mRNA but had little effect on the half-life of collagenase mRNA. In contrast to stromelysin, the collagenase mRNA level is dependent on serum factors. Collagenase is induced during recovery from cycloheximide inhibition, but stromelysin expression is not affected. These results establish that collagenase and stromelysin mRNAs are differentially regulated in both early and late passage human fibroblasts and suggest that the mechanisms responsible for the age-associated increase in the two mRNAs are different. In addition, these studies support the conclusion that continuous long-term exposure to Il-1 alpha, a condition that is characteristic of late passage cells, is not the factor responsible for the high levels of collagenase expression, but may be critical for stromelysin expression.

Regulation of glycolipid synthesis in HL-60 cells by antisense oligodeoxynucleotides to glycosyltransferase sequences: effect on cellular differentiation

Treatment of the human promyelocytic leukemia cell line HL-60 with antisense oligodeoxynucleotides to UDP-N-acetylgalactosamine:beta-1,4-N-acetylgalactosaminyl-transferase (GM2-synthase; EC 2.4.1.92) and CMP-sialic acid:alpha-2,8-sialyltransferase (GD3-synthase; EC 2.4.99.8) sequences effectively down-regulated the synthesis of more complex gangliosides in the ganglioside synthetic pathways after GM3, resulting in a remarkable increase in endogenous GM3 with concomitant decreases in more complex gangliosides. The treated cells underwent monocytic differentiation as judged by morphological changes, adherent ability, and nitroblue tetrazolium staining. These data provide evidence that the increased endogenous ganglioside GM3 may play an important role in regulating cellular differentiation and that the antisense DNA technique proves to be a powerful tool in manipulating glycolipid synthesis in the cell.

Adenovirus mediated gene transfer of vascular smooth muscle cells and endothelial cells in vitro

Introducing foreign gene(s) into vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) is the pre-requirement of gene therapy for cardiovascular diseases. We have explored the use of adenoviral vectors (Adv-CMV/LacZ) to transfer LacZ gene into cultured VSMCs and ECs. Our results demonstrated that adenoviral vectors transferred foreign gene into VSMCs and ECs high-efficiently with dose-dependent response pattern. The frequencies of transfection reached 100% at the viral titer of 10(9) pfu/ml. Comparing the sensitivities of VSMCs and ECs to adenoviral vectors, we found that ECs were more sensitive than VSMCs, of which the frequencies of transfection in ECs reached 80% while in VSMCs only 40% for 8 hrs after transfection. In addition, the transfection of ECs and VSMCs with adenoviral vectors was partly blocked by monoclonal antibodies to Fiber and Core protein of the adenoviral capsid, but not by monoclonal antibody to Hexon protein. It is suggested transfection of ECs and VSMCs with adenovirus vectors is mediated by Fiber or Core protein of adenoviral capsid proteins.

Enhanced adeno-associated virus vector expression by adenovirus protein-cationic liposome complex. A novel and high efficient way to introduce foreign DNA into endothelial cells

Adeno-associated virus vector (AAV), a non-pathogenic integrating vector, can integrate on chromosome 19 in humans. But its gene transfer efficiency is quite low. In this study we combined adenovirus (Adv-5) capsid protein or the Fiber protein of Adv with liposome, termed adenosome (adenovirus protein-cationic liposome complex). This complex can bring AAV/CMV-LacZ to the endothelial cells, and improve the efficiency of gene transfer. It may be a novel, specific, stable and safe gene delivery system and will be widely used in human gene therapy.

Breastfeeding practices in Chengdu, Sichuan, China

Barriers to increased breastfeeding rates in Chengdu, Sichuan were investigated in 1992 and 1993. Responses of focus groups showed that ignorance about breastfeeding and belief that the mother's milk was inadequate, and lack of support from their families, places of employment, and the health system acted as barriers to the women's breastfeeding their infants up to the age of four to six months. Subsequently, 363 mothers of 4- to 12-month-old Chengdu infants were surveyed. Although most mothers in both studies said breastmilk was the best food for their infant up to age of four to six months, only about half of the mothers breastfed for longer than one month. Both studies showed that infants who roomed with their mothers after birth were more likely to have been put to their mother's breast earlier, fed colostrum, breastfed somewhat longer, and exclusively breastfed for a somewhat longer period, although their mothers' infant feeding knowledge did not differ. The researchers conclude that Chengdu health workers should teach parents and parents-to-be more about breastfeeding, and that rooming-in be expanded in Chengdu hospitals.

[An epidemiological study on the characteristics of smoking behaviors among 910 young workers in Shangqiu City, Henan Province]

This paper dealt with an epidemiological investigation on the smoking behaviors of the young people in Shangqiu city, Henan province. The period of their working history was less than 5 years and their ages younger than 30 years. The interviewees were chosen from the hospitals, middle or professional schools, and large factories in the city. There were 587 males and 339 females included in this sample. Everyone was asked to complete the self-administered questionnaire in the workplace. The total number of sample was 926. The rate of respondence was 98.3%. Of the 926 questionnaires, 910 (98.3%) were identified as qualified. The investigation showed that the overall smoking rate was 32.1%, with male 64.2% and female 1.5%, respectively. The smoking rate of male was approaching the highest rate of adult males in our country, much higher than that of adolescents in school. The rates were parallelly increasing with years of working. About 50% of the young smokers began to be habitual since started their job, especially from the first four years of work. More than 80 percent of the smoking young workers were mild or light smokers, and did not smoke in "Ban Smoking Place". However, the most popular places for smoking were the place where there is a sign at their workplaces. They smoke most often with their colleagues and friends.

Expression of 72-kDa gelatinase and TIMP-2 in early and late passage human fibroblasts

The expression and regulation of 72-kDa gelatinase and TIMP-2 were examined in cultures of early and late passage human fibroblasts. In contrast to collagenase expression, which was low in early passage cells and highly expressed in late passage fibroblasts, 72-kDa gelatinase mRNA expression was enhanced only slightly in late passage cultures and 72-kDa gelatinase protein expression was similar in early and late passage cultures. In contrast to published reports of decreased TIMP-1 expression, TIMP-2 mRNA and protein were increased in late passage cells. Exposure to Il-1 alpha increased the steady-state level of 72-kDa gelatinase mRNA by 3x in early passage cells but had no effect on late passage cells. Although Il-1 alpha had no significant effect on TIMP-2 mRNA or on expression of 72-kDa gelatinase, in either early or late passage cells, Il-1 alpha increased the level of a TIMP-2-72-kDa gelatinase complex. Using monoclonal antibodies to TIMP-2 and to 72-kDa gelatinase we detected two forms of TIMP-2. One form was complexed to 72-kDa gelatinase and migrated with an apparent molecular weight of 72 kDa and the other migrated at the expected molecular weight of 21 kDa. Autoradiography in conjunction with Western analysis confirmed that in the late passage cell medium the newly synthesized 72-kDa gelatinase-TIMP-2 complex was increased even though the expression of 72-kDa gelatinase did not change. The present results establish that the regulation of 72-kDa gelatinase and TIMP-2 in early and late passage cultures of human fibroblasts are different from collagenase and TIMP-1 regulation. Further, they establish that in late passage cultures the activity of 72-kDa gelatinase may be regulated through the formation of a denaturation-resistant complex.

[Study and improvement of Reed-Frost model]

The purpose of this paper is to modify the Reed-Frost theory of epidemics with the underlying assumptions of the model including the occurrence of inapparent infections, and their influence on the course of the epidemic. With this model two epidemics were computed: (1) the Aycock outbreak of measles in a New England boy-boarding school in 1934; (2) the outbreak of chickenpox in a Shanghai kindergarten in 1950. The calculated and observed results were well in agreement. A substantial improvement in fitness was shown as measured by chi-square tests. As presented, the model offers a reasonably good explanation on the occurrence of inapparent infections and its effect on the pattern of the disease.

Early post-operative ankle pressure indices help predict late patency rates after femoro-distal vein bypass grafting

A prospective graft surveillance programme included 115 femorodistal autogenous vein bypass grafts that were patent when studied by measurements of ankle/brachial pressure indices (ABIs) at 3-5 weeks after operation. The grafts were followed for up to 3 years to determine whether early ABIs helped to predict subsequent failures, defined as graft thrombosis or graft or anastomotic stenosis causing diameter reduction greater than 75% treated by surgery or balloon dilatation. Receiving operating characteristics curves showed that resting ABIs predicted failure better than post-exercise ABIs or the differences between the two, and that an early resting ABI less than 0.85 was the optimal value to predict failure. Primary patency rates at 2 years were 88% for resting ABI greater than or equal to 0.85 and 36% for resting ABI less than 0.85 (p less than 0.0005). Most stenoses occurred in the grafts and not at anastomoses. Arteriographic grading of crural artery outflow was not significantly different for successful or failed grafts or for grafts with resting ABI greater than or equal to 0.85 or less than 0.85. The observation that late graft failure was 3-4 times more likely if the early post-operative ABI was low suggests that most graft failures result from faults relating to the operation.

Effectiveness of a worksite nutrition education activity in a factory in China

To evaluate the effectiveness of a worksite nutrition education activity in China, a two-group pretest-posttest nutrition education lesson was designed and carried out in two divisions (N = 240 in each division) of a steel tube factory in Chengdu, Sichuan. Special features of the program were nutrition education materials developed from both (a) the results of a pretest survey of the employees, and (b) focus group discussions conducted with factory hospital and workteam staff; a colloquial style; a slogan; and an illustrated handout depicting the new Chinese Dietary Guidelines and a proposed Food Guide. Analysis of variance, chi-square, and t-tests showed both significant increases (p < 0.05) in nutrition knowledge and attitude scores and significant improvements in dietary practices in the group receiving the education. It is concluded that the method is a useful and practical model for designing and developing worksite nutrition education in China.

[The use of Bayes' theorem in controlling the coming epidemic peak of epidemic meningitis in the 1980s]

To control the coming epidemic peak of epidemic cerebrospinal meningitis (ECM) in the 1980s in the regions with 100 million population in China, the mathematical models based upon Bayes' theorem (BT) were established and used respectively in provincial, regional and county's level. Reports of ECM from each ten-day's period or each month during the meningitis season were analysed to create forecast models. Records of ECM vaccinating rate in previous years were fully taken into account to modify the theoretical values. Calibration, split-sample, random-sample selection, as well as actual forecast tests, were used to check the efficiency of the models. The distribution of meningitis vaccine was planned according to the final predictive results. The incidence rates of ECM of above regions decreased obviously faster than other areas in China. Attributing the application of BT forecast research, it was estimated only in Henan province 79795 ECM cases; 4388 deaths and 21 million Yuan economic damage were avoided during the 4 years period, from 1985 to 1988.