Evaluation of the antioxidant and pro-oxidant effects of tea catechin oxypolymers

Tea catechin oxypolymers (TCOP) were prepared by oxidizing tea catechin (TC, the content of EGCG was >85%) with H2O2. Their antioxidant and pro-oxidant effects were tested using a deoxyribose assay, a photoreduction of NBT assay, a lipoxygenase assay, a POV assay, and animal tests. The scavenging effects of TCOP to both the hydroxyl radical and superoxide radical were stronger than that of TC, and also they had no pro-oxidant effect; the rate constant for reactions of TC and TCOP for hydroxyl radical were 1.0 x 10(10) and (1.4-2.8) x 10(10) M(-1) x S(-1), respectively. TCOP can inhibit lipid peroxidation and lipoxygenase effectively, and it also can activate red cell SOD and reduce the MDA content in serum of mice very significantly. These results suggested that the antioxidant activity of TCOP was not less than or even more notable than that of TC.

Macrophages deficient in CTP:Phosphocholine cytidylyltransferase-alpha are viable under normal culture conditions but are highly susceptible to free cholesterol-induced death. Molecular genetic evidence that the induction of phosphatidylcholine biosynthesis in free cholesterol-loaded macrophages is an adaptive response

Macrophages in atherosclerotic lesions accumulate excess free cholesterol (FC) and phospholipid. Because excess FC is toxic to macrophages, these observations may have relevance to macrophage death and necrosis in atheromata. Previous work by us showed that at early stages of FC loading, when macrophages are still healthy, there is activation of the phosphatidylcholine (PC) biosynthetic enzyme, CTP:phosphocholine cytidylyltransferase (CT), and accumulation of PC mass. We hypothesized that this is an adaptive response, albeit transient, that prevents the FC:PC ratio from reaching a toxic level. To test this hypothesis directly, we created mice with macrophage-targeted disruption of the major CT gene, CTalpha, using the Cre-lox system. Surprisingly, the number of peritoneal macrophages harvested from CTalpha-deficient mice and their overall health under normal culture conditions appeared normal. Moreover, CT activity and PC biosynthesis and in vitro CT activity were decreased by 70-90% but were not absent. As a likely explanation of this residual activity, we showed that CTbeta2, a form of CT that arises from another gene, is induced in CTalpha-deficient macrophages. To test our hypothesis that increased PC biosynthesis is an adaptive response to FC loading, the viability of wild-type versus CTalpha-deficient macrophages under control and FC-loading conditions was compared. After 5 h of FC loading, death increased from 0.7% to only 2.0% in wild-type macrophages but from 0. 9% to 29.5% in CTalpha-deficient macrophages. These data offer the first molecular genetic evidence that activation of CTalpha and induction of PC biosynthesis in FC-loaded macrophages is an adaptive response. Furthermore, the data reveal that CTbeta2 in macrophages is induced in the absence of CTalpha and that a low level of residual CT activity, presumably due to CTbeta2, is enough to keep the cells viable in the peritoneum in vivo and under normal culture conditions.

[Improvement of pulse waveform detection with autoregressive model in blood oxygen saturation measurement]

Blood oxygen saturation is an important physiological parameter of human body. The accurate measurement of it is important to both physiological research and medical application. Dual-wavelength method is widely adopted in nonivasive detection of blood oxygen saturation. In this method, the calculation of blood oxygen saturation is based on the identification of pulse waveform and the extraction of peak characteristic values. But the pulse waveform obtained from this method merely has distinctive features such as the QRS complexes in ECG, so the ratio of correct detection of pulse waveform is always low. An autoregressive model of heart-beat intervals is developed. The output of the differential method is compared with that of the AR model so as to distinguish the false or missing detection. The ratio of correct detection is improved by the use of this method.

[The development and application of a minitype multifunctional bio-impactor]

This study was aimed to develop a device that can be used for gas percussion, rigid impact, cell injury and simple estimation of the condition of injury. The device has been developed with the use of aerodynamical principle, measuring technique for feeble signal, and integration of machine-electricity. The gas percussion, rigid impact, and cell injury can be produced by altering impact tip. It was examined in the experimental researches of eye, brain, lung and cell injury; the parameters of causing injury could be controlled and on-line tested by the computer. The neurological states of pre- and post-injury were evaluated with the device. The results of animal experiments showed that mild, moderate and severe injury models were produced by gas pressure respectively. The pressure was 400, 600, 700 kPa for rats brain gas percussion injury, 600, 800, 1000 kPa for rabbits' retinal contusion, 300, 450, 600 kPa for rats' lung rigid impact injury, and 100, 150, 200 kPa for cultured cells' injury. In conclusion, the device is simple and easy to use for making controllable injury models, in which different parts and levels of injuries on different minitype animals can be reproduced.

Acute systemic inflammation up-regulates secretory sphingomyelinase in vivo: a possible link between inflammatory cytokines and atherogenesis

Inflammation plays a critical role in atherogenesis, yet the mediators linking inflammation to specific atherogenic processes remain to be elucidated. One such mediator may be secretory sphingomyelinase (S-SMase), a product of the acid sphingomyelinase gene. The secretion of S-SMase by cultured endothelial cells is induced by inflammatory cytokines, and in vivo data have implicated S-SMase in subendothelial lipoprotein aggregation, macrophage foam cell formation, and possibly other atherogenic processes. Thus, the goal of this study was to seek evidence for S-SMase regulation in vivo during a physiologically relevant inflammatory response. First, wild-type mice were injected with saline or lipopolysaccharide (LPS) as a model of acute systemic inflammation. Serum S-SMase activity 3 h postinjection was increased 2- to 2.5-fold by LPS (P < 0.01). To determine the role of IL-1 in the LPS response, we used IL-1 converting enzyme knockout mice, which exhibit deficient IL-1 bioactivity. The level of serum S-SMase activity in LPS-injected IL-1 converting enzyme knockout mice was approximately 35% less than that in identically treated wild-type mice (P < 0.01). In LPS-injected IL-1-receptor antagonist knockout mice, which have an enhanced response to IL-1, serum S-SMase activity was increased 1. 8-fold compared with LPS-injected wild-type mice (P < 0.01). Finally, when wild-type mice were injected directly with IL-1beta, tumor necrosis factor alpha, or both, serum S-SMase activity increased 1. 6-, 2.3-, and 2.9-fold, respectively (P < 0.01). These data show regulation of S-SMase activity in vivo and they raise the possibility that local stimulation of S-SMase may contribute to the effects of inflammatory cytokines in atherosclerosis.

Sex hormone-induced mammary carcinogenesis in the female Noble rats: expression of bcl-2 and bax in hormonal mammary carcinogenesis

We have established a Noble rat model to explore the mechanisms of hormonal mammary carcinogenesis, in which the role of androgen in promoting mammary carcinogenesis was highlighted. We have also established that stromal-epithelial interactions may be responsible for the promotional effects of testosterone in mammary carcinogenesis. Based on these understandings, in the present study we examined the expression of Bcl-2 and Bax in pre-malignant mammary glands from rats treated with different protocols of sex hormones for 7 weeks as well as sex hormone induced mammary tumours. We observed that Bcl-2 was strongly expressed in most of mammary tumour cells, whereas weak or negative in adjacent normal or hyperplastic ductal structures. On the contrary, Bax immunoreactivity was weak in mammary tumour cells while strongly expressed in adjacent normal or hyperplastic ductal structures. More importantly, the results from comparative study of 'pre-malignant' glands further showed that when animals were treated with 17beta-oestradiol, the mammary epithelial cells expressed high levels of Bcl-2. The results from rats treated with testosterone, either alone or in combination with oestrogen, give rise to high levels of Bax expression in 'pre-malignant' mammary glands. These observations indicate that in 'pre-malignant' mammary glands, treatment with testosterone, either alone or in combination with 17beta-oestradiol, may induce high apoptotic activities. However, in fully developed mammary tumours, the apoptotic activities apparently decrease in tumour cells. TUNEL assay provides further data to support this conclusion. Our study, thus, suggests that androgens may play a promoting role in mammary carcinogenesis by upregulation of Bax expression and induction of high apoptotic activities in 'pre-malignant' stage, which would provide a selective pressure favouring the expansion of the initiated cells.

Rat strain-specific actions of 17beta-estradiol in the mammary gland: correlation between estrogen-induced lobuloalveolar hyperplasia and susceptibility to estrogen-induced mammary cancers

The genetically related ACI and Copenhagen (COP) rat strains display diametrically opposed susceptibilities to mammary cancer development when treated chronically with 17beta-estradiol (E2). Here, we compare the actions of E2 on cell proliferation and lobuloalveolar development in the mammary glands of female ACI and COP rats. After 12 wk of E2 treatment, the mammary glands of ACI rats exhibited a significantly greater proliferative response to E2, compared with COP rats, as evidenced by quantification of S phase fraction and development of lobuloalveolar hyperplasia. Focal regions of atypical epithelial hyperplasia were observed in ACI, but not COP, rats. These strain differences were not because of differences in circulating E2, progesterone or, prolactin. Two-thirds of the induced mammary cancers in ACI rats exhibited aneuploidy. The E2-induced mammary cancers regressed when hormone treatment was discontinued, indicating that they were estrogen-dependent. Progesterone receptor was expressed by the great majority of epithelial cells within the E2-induced atypical hyperplastic foci and the mammary carcinomas, suggesting a link between these lesions. These data demonstrate a correlation between E2 action in the induction of mammary cell proliferation and atypical epithelial hyperplasia and genetically conferred susceptibility to E2-induced mammary cancers.

[Cost-effectiveness analysis of Beijing Fangshan cardiovascular prevention program in 1992 - 1997]

OBJECTIVE

To determine whether a community-based cardiovascular disease (CVD) intervention program, undertaken over six years, was cost-effective.

METHODS

Based on Beijing Fangshan Cardiovascular Disease Comprehensive Prevention Program, the cost for intervention and expenditure saved from caring for CVD in the communities with intervention from 1992 to 1997 were calculated, and cost-effectiveness analysis was performed using disability-adjusted life years (DALYs) gained as an indicator of effectiveness.

RESULTS

The cost for one DALY gained reduced gradually from 1992 to 1997, with an average ratio of cost to effectiveness of four to one (4:1). It cost annually 1,586.00, 1,380.20, -2,350.80, -905.30, -1,495.60 and -1,766.70 RMB yuan for one life-year saved, from 1992 to 1997 respectively, in a gradually decreasing trend with the increase in length of intervention. After intervention for two years, ratio of cost to effectiveness has become negative since 1994, which meant a positive benefit from intervention. Sensitivity analysis showed that ratio of cost to effectiveness was little sensitive to the changes in discount rate, weight of age and increase in cost of hospitalization for stroke and coronary heart disease, which reflected its reliability.

CONCLUSION

Community-based comprehensive intervention for CVD in rural population is cost-effective.

Sex hormone-induced mammary carcinogenesis in female Noble rats: expression of TGF-beta1 and its receptors, TGF-alpha, and EGF-R in mammary carcinogenesis

We have established a Noble rat model to explore the mechanisms of hormonal mammary carcinogenesis, in which the role of androgen in promoting mammary carcinogenesis was highlighted. We have also established that stromal-epithelial interactions may be responsible for the promotional effects of testosterone in mammary carcinogenesis. Based on these understandings, in the present study we examined the expression of transforming growth factor beta-1 (TGF-beta1) and its receptors (TGF-beta RI, TGF-beta RII), transforming growth factor alpha (TGF-alpha), and epidermal growth factor receptor (EGF-R) in 'pre-malignant' mammary glands treated with different protocols of sex hormones, as well as in mammary cancers. We observed that TGF-beta1 was strongly expressed in most mammary tumors, whereas TGF-beta RI and TGF-beta RII were negative in most mammary tumor cells. The results from comparative study of 'pre-malignant' glands further showed that when the animals were treated with testosterone, either alone or in combination with 17beta-estradiol, the mammary gland epithelial cells expressed high levels of TGF-beta1. This over-expression of TGF-beta1 can be blocked by flutamide, indicating that testosterone may be responsible for the expression of TGF-beta1 in mammary glands. TGF-beta RI and TGF-beta RII were also expressed strongly in testosterone-treated mammary epithelial cells and only weakly detectable in 17beta-estradiol treated and control mammary epithelial cells. Furthermore, TGF-beta RI and TGF-beta RII were also expressed in stromal cells, both in mammary tumors and in hormone-treated mammary glands. These observations indicate that the mechanism of testosterone in mammary carcinogenesis may be through its regulation of expression of TGF-beta1 and its receptors. On the other hand, TGF-alpha was also expressed in all 39 mammary cancers, while only 81% of the cancers were EGF-R positive. TGF-alpha was also strongly expressed in stromal cells in all three experimental groups, but only moderately expressed in epithelial cells when treated with a combination of testosterone and 17beta-estradiol. By contrast, EGF-R was strongly expressed in epithelial cells in the three experimental groups but negative in stromal cells. Flutamide or tamoxifen was unable to block the expression of TGF-alpha induced by the combined sex hormone treatment. However, they were effective in blocking the expression of TGF-alpha when the animals were treated with testosterone or 17beta-estradiol alone, respectively. These results suggest that both testosterone and 17beta-estradiol may be required for the over-expression of TGF-alpha in the mammary carcinogenesis induced by sex hormones. To our knowledge, this is the first experimental study to explore the regulation of TGF-beta1, TGF-alpha, and their receptors by testosterone and 17beta-estradiol in mammary carcinogenesis.

Co-expression of vascular endothelial growth factor (VEGF) and its receptors (flk-1 and flt-1) in hormone-induced mammary cancer in the Noble rat

Vascular endothelial growth factor (VEGF) is recognized to play a predominant role in breast cancer prognosis. The action of VEGF is mediated by two high-affinity receptors with ligand-stimulated tyrosine kinase activity: VEGFR-1/flt-1 and VEGFR-2/flk-1, which are expressed mainly in vascular endothelial cells. To the best of our knowledge, no previous studies on the expression of these receptors in breast cancer cells has been made. We have established a new animal model for breast cancer, using a combination of 17beta-oestradiol and testosterone as 'carcinogens'. Taking advantage of the animal model, we have demonstrated that mammary cancer cells expressed not only high levels of VEGF but also, surprisingly, its receptors (fit-1 and flk-1) in mammary cancer cells. Intense reactivities to VEGF, flt-1 and flk-1 were observed in mammary cancer cells, especially in invasive mammary carcinoma. Western blot analysis confirmed the increase in flk-1 and flt-1 proteins in induced mammary cancers. Based on these observations, we hypothesize that in mammary cancer, VEGF regulates, in addition to endothelial proliferation and angiogenesis, also growth of cancer cells by an autocrine mechanism mediated through its receptors. To further verify this hypothesis, we investigated the correlation between cellular proliferation and the expression of VEGF, flt-1 and flk-1. Using double-labelling immunocytochemistry, we have shown a correlation between high VEGF activity and Ki-67 expression. The Ki-67 indices in the areas of strong and weak VEGF reactivities were 58.3% and 3.7% respectively. Similarly, there was also a correlation of strong flk-1 and Ki-67 reactivity. The Ki-67 indices for areas of strong and weak flk-1 reactivities were 53.9% and 3.1% respectively. On the other hand, there was a reverse correlation between fit-1 and Ki-67 activities. These results indicate that overexpression of VEGF and flk-1 is correlated with high Ki-67 index. The data, therefore, suggest that VEGF may act as an autocrine growth factor for mammary cancer cells in vivo and this autocrine regulatory role may be mediated through flk-1. The present study is the first report showing that VEGF may act as a growth stimulator for mammary cancer cells.

[The study of amino acid constituents on fungus garden of Odontotermes formosanus]

The qualitative and quantitative analysis of twenty free amino acids for fungus garden of Odontotermes formosanus and its aqueous extracts were studied by auto-amino acid analytic instrument.

[Analysis of ethereal extracts from Odondotermes formosanus and fungus garden]

Nine, twelve compounds were isolated and identifacted from ethereal extracts of Odotntotermes formosanus (insect body) and its fungus garden respectively, by GC-MS analysis.

Sex hormone-induced mammary carcinogenesis in female noble rats: the role of androgens

Breast cancer is the most common cancer and the second most frequent cause of cancer death in women. Despite extensive research, the precise mechanisms of breast carcinogenesis remain unclear. We have shown that in female rats, treatment with a combination of oestrogen and testosterone can induce a high incidence of mammary cancer. The dosage of testosterone affects only the latency period of mammary cancer, not the final incidence. Based on these observations, we hypothesize that oestrogen and androgens may act in concert on the mammary gland to induce mammary carcinogenesis, with oestrogen serving as the predominant initiator whereas the androgen acts as a major promoter. In the present study, we report the changes in morphology of the mammary gland with special emphasis on the perialveolar or interlobular stroma after treatment with various sex hormone protocols. Our data showed that after treatment with testosterone, either alone or in combination with 17beta-oestradiol, there was overexpression of the androgen receptor in alveolar or ductal epithelial cells. Concurrent with strong expression of the androgen receptor in epithelium, there was also an increase in the amount of perialveolar and interlobular connective tissue, a decrease in surrounding adipose tissue and an increase in proliferation rate of fibroblast-like cells in the stroma. All these changes were blocked by simultaneous implantation of flutamide, indicating that androgens play a crucial role in the process despite the absence of androgen receptors in stromal cells. We further measured the mammary gland density (MGD), in order to determine the ratio of fatty to non-fatty tissue. The data showed that MGD values were significantly higher in animals treated with testosterone alone or in combination with 17beta-oestradiol than in those treated with 17beta-oestradiol alone or in controls. Furthermore, treatment with different doses of testosterone resulted in an increase in MGD in a dose-dependent manner. These findings highlight the effect of androgens on the stroma, probably through a paracrine action of epithelial cells. The stroma may, in turn, promote mammary carcinogenesis in a reciprocal fashion.

Dual chamber pacing for neurally mediated syncope with a prominent cardioinhibitory component

The role of cardiac pacing for treatment of recurrent neurally mediated syncope (NMS) remains controversial. We hypothesized that dual chamber pacing in NMS patients with a prominent cardioinhibitory component may be beneficial. Twelve patients (mean age = 37.8+/-17 years, range 15-78 years, 7 men and 5 women) with a mean of 4+/-2.2 episodes of syncope underwent tilt table evaluation. Patients were passively tilted to 70 degrees head-up position for 20 minutes and then returned to the supine position. Isoproterenol was then infused at 1-2 microg/min to increase heart rate by > or = 25% and tilt was repeated. Patients lost consciousness after 16+/-6 minutes of tilt; nine patients had syncope in the baseline state and three during isoproterenol infusion. All patients had at least 5 seconds of asystole with a mean of 9.5+/-4 seconds (range 5-20 s). A dual chamber permanent pacemaker with a special feature allowing heart rate acceleration in response to bradycardia was implanted in all patients. During a mean follow-up of 18.6+/-4.2 months, 11 (92%) of these patients were free of syncope and had negative tilt table test. One (8%) patient had two episodes of syncope. We conclude that dual chamber pacing may be beneficial in patients with NMS with a prominent cardioinhibitory component.

Induction of high incidence of mammary tumour in female Noble rats with a combination of 17beta-oestradiol and testosterone

Breast cancer is the most common cancer and the second most frequent cause of cancer death in women. Despite extensive research, the precise mechanisms of breast carcinogenesis remain unclear. One of the reasons for this is due, at least in part, to a lack of a suitable animal model which can closely mimic the breast carcinogenesis in normal situations without using chemical carcinogens. We have developed an animal model of mammary gland carcinogenesis using a combination of oestradiol and testosterone, and succeeded in inducing a high percentage of female Noble rats to develop mammary cancer in a relatively short time (approximately 6 months). The results showed that androgens might work as a promoter to shorten the latency time of mammary gland carcinogenesis. Histopathological examination revealed that hyperplasia and dysplasia were first observed 2 months after treatment, in situ carcinoma after 3 months, and fully developed carcinoma of various forms including cribriform, papillary and camedo types were observed from 5 to 6 months after hormone implantation. Animals implanted with oestrogen or testosterone alone also developed mammary cancers, though with a lower overall incidence than the two hormones combined. They ranged from well differentiated to poorly differentiated forms with predominantly infiltrating ductal carcinoma. We have also observed a case of secondary cancer in the uterus. In addition to the high incidence of carcinoma, there was also a peculiar unexplained ipsilateral correlation between the site of hormonal implantation and the location of tumours, and the highest incidence of carcinogenesis was found to be in thoracic mammary gland. The study showed that both oestrogens and androgens are important in mammary cancer development. The animal model would prove to be a useful model for analysis of the mechanism(s) of hormonal carcinogenesis.

Principles of enzyme thermistor systems: applications to biomedical and other measurements

This chapter presents an overview of thermistor-based calorimetric measurements. Bioanalytical applications are emphasized from both the chemical and biomedical points of view. The introductory section elucidates the principles involved in the thermometric measurements. The following section describes in detail the evolution of the various versions of enzyme-thermistor devices. Special emphasis is laid on the description of modern "mini" and "miniaturized" versions of enzyme thermistors. Hybrid devices are also introduced in this section. In the sections on applications, the clinical/biomedical areas are dealt with separately, followed by other applications. Mention is also made of miscellaneous applications. A special section is devoted to future developments, wherein novel concepts of telemedicine and home diagnostics are highlighted. The role of communication and information technology in telemedicine is also mentioned. In the concluding sections, an attempt is made to incorporate the most recent references on specific topics based on enzyme-thermistor systems.

STAT5 interaction with the T cell receptor complex and stimulation of T cell proliferation

The role of STAT (signal transducer and activator of transcription) proteins in T cell receptor (TCR) signaling was analyzed. STAT5 became immediately and transiently phosphorylated on tyrosine 694 in response to TCR stimulation. Expression of the protein tyrosine kinase Lck, a key signaling protein in the TCR complex, activated DNA binding of transfected STAT5A and STAT5B to specific STAT inducible elements. The role of Lck in STAT5 activation was confirmed in a Lck-deficient T cell line in which the activation of STAT5 by TCR stimulation was abolished. Expression of Lck induced specific interaction of STAT5 with the subunits of the TCR, indicating that STAT5 may be directly involved in TCR signaling. Stimulation of T cell clones and primary T cell lines also induced the association of STAT5 with the TCR complex. Inhibition of STAT5 function by expression of a dominant negative mutant STAT5 reduced antigen-stimulated proliferation of T cells. Thus, TCR stimulation appears to directly activate STAT5, which may participate in the regulation of gene transcription and T cell proliferation during immunological responses.

[Gas chromatography-infrared spectroscopy(GC-IR) analysis of the oxidation products of cyclohexene]

Gas chromatography-infrared spectroscopy technique integrates the excellent resolution ability of GC with the structural information of IR. Based on the GC and IR spectra, the complicated products of a reaction can be analyzed quantitatively and qualitatively. From the analysis of the products, the reaction process and its mechanism can be elucidated. In this work, analysis by GC-IR of the oxidation products of cyclohexene catalyzed by zeolite TS-1 in H2O2 was performed. The products are 2-cyclohexenone, 2-cyclohexen-1-ol and 2,3-epoxy-1-cyclohexanone. 2,3-Epoxy-1-cyclohexanone is an unexpected product. It must be a further oxidation product of 2-cyclohexenone. From the analysis, the reaction mechanisms were presumed.

Interaction between alpha 5 beta 1 integrin and secreted fibronectin is involved in macrophage differentiation of human HL-60 myeloid leukemia cells

We examined the role of fibronectin (FN) and FN-binding integrins in macrophage differentiation. Increased FN and alpha5beta1 integrin gene expression was observed in phorbol 12-myristate 13-acetate PMA-treated HL-60 cells and PMA- or macrophage-CSF-treated blood monocytes before the manifestation of macrophage markers. After treatment of HL-60 cells and monocytes, newly synthesized FN was released and deposited on the dishes. An HL-60 cell variant, HL-525, which is deficient in the protein kinase Cbeta (PKC-beta) and resistant to PMA-induced differentiation, failed to express FN after PMA treatment. Transfecting HL-525 cells with a PKC-beta expression plasmid restored PMA-induced FN gene expression and macrophage differentiation. Untreated HL-525 cells (which have a high level of the alpha5beta1 integrin) incubated on FN differentiated into macrophages. The percentage of cells having a macrophage phenotype induced by PMA in HL-60 cells, by FN in HL-525 cells, or by either PMA or macrophage-CSF in monocytes was reduced in the presence of mAbs to FN and alpha5beta1 integrin. The integrin-signaling nonreceptor tyrosine kinase, p72Syk, was activated in PMA-treated HL-60 and FN-treated HL-525 cells. We suggest that macrophage differentiation involves the activation of PKC-beta and expression of extracellular matrix proteins such as FN and the corresponding integrins, alpha5beta1 integrin in particular. The stimulated cells, through the integrins, attach to substrates by binding to the deposited FN. This attachment, in turn, may through integrin signaling activate nonreceptor tyrosine kinases, including p72Syk, and later lead to expression of other genes involved in evoking the macrophage phenotype.

[Survey on breakfast-eating behavior among residents in Beijing, Guangzhou and Shanghai]

A survey of breakfast-eating behavior among residents in Beijing, Guangzhou and Shanghai was carried out in 1994-1995. The results showed that the breakfast-eating rates in three cities were 74.8%-90.5%. Subjects aged below 35 years skipped breakfast more often. "Time limiting" in the morning became the main cause of breakfast-skipping. Nearly half of subjects in three cities got their breakfast out of home. Moreover, compared with two years ago, the present rates of eating outside increased at various levels in three cities. Steamed bun, bread and congee were main foods consumed at breakfast. In addition, 39% to 56% of subjects often drank milk. Through this survey, the authors got an all-round understanding on breakfast-eating rates, eating outside rates and variety of food consumed of residents in 3 cities. This survey will also provide a background for nutrition intervention and education in the future.

Fibronectin-mediated cell adhesion is required for induction of 92-kDa type IV collagenase/gelatinase (MMP-9) gene expression during macrophage differentiation. The signaling role of protein kinase C-beta

Induction of the 92-kDa gelatinase (MMP-9) gene expression is associated with macrophage differentiation. In this study, we explored the regulatory mechanisms underlying this differentiation-associated MMP-9 gene expression in human HL-60 myeloid leukemia cells and human peripheral blood monocytes. Phorbol 12-myristate 13-acetate (PMA) markedly induced MMP-9 gene expression in HL-60 cells; the induction closely paralleled the timing and extent of PMA-induced cell adhesion and spreading, a hallmark of macrophage differentiation. Similarly, treatment with PMA or macrophage-colony stimulating factor stimulated adherence and spreading of blood monocytes with a concurrent 7- or 5-fold increase in MMP-9 production, respectively. In protein kinase C (PKC)-beta-deficient HL-60 variant cells (HL-525), PMA failed to induce cell adhesion and MMP-9 gene expression. Transfecting HL-525 cells with a PKC-beta expression plasmid restored PKC-beta levels and PMA inducibility of cell adhesion and spreading as well as MMP-9 gene expression. Induction of cell adhesion and MMP-9 gene expression in HL-60 cells and blood monocytes was strongly inhibited by neutralizing monoclonal antibodies to fibronectin (FN) and its receptor alpha5 beta1 integrin. HL-525 cells, which constitutively display high levels of surface alpha5 beta1 integrin, adhered and spread on immobilized FN with concomitant induction of MMP-9 gene expression. Cytochalasins B and D were each a potent inhibitor of MMP-9 production. Our results suggest that alpha5 beta1 integrin-mediated interaction of immature hematopoietic cells with FN plays a critical role in modulating matrix-degrading activities during macrophage differentiation.

Autocrine regulation of macrophage differentiation and 92-kDa gelatinase production by tumor necrosis factor-alpha via alpha5 beta1 integrin in HL-60 cells

Tumor necrosis factor-alpha (TNF-alpha) gene is one of the early response genes induced by phorbol 12-myristate 13-acetate (PMA) in human HL-60 myeloid leukemia cells. In the present study, we examined the role of the TNF-alpha autocrine loop in PMA-induced macrophage differentiation and gene expression of 92- and 72-kDa gelatinases (MMP-9 and MMP-2). In HL-60 cells, PMA inhibited cell proliferation and induced cell adhesion and spreading, expression of surface maturation marker OKM1 and phagocytic activity, as well as the expression of both gelatinases, which all characterize the macrophage phenotype. In contrast, TNF-alpha alone was only effective in inhibiting cell proliferation. Blocking the endogenous TNF-alpha activity with neutralizing anti-TNF-alpha antibodies abolished all these PMA-induced events with the exception of MMP-2 gene expression. Since fibronectin (FN)-mediated cell adhesion and spreading are prerequisite for both macrophage differentiation and MMP-9 gene expression in HL-60 cells, we hypothesized that TNF-alpha might be involved in modulating the expression of either the FN or its integrin receptor genes. Whereas PMA substantially enhanced the steady state mRNA and protein levels of both FN and alpha5 beta1 integrins, TNF-alpha alone had little effect on the expression of these genes. However, anti-TNF-alpha antibodies blocked PMA-induced augmentation of both alpha5 and beta1 integrin gene expression without affecting the expression of the FN gene. Our results suggest that TNF-alpha may regulate macrophage differentiation and critical matrix-degrading activities of myeloid progenitor cells in an autocrine manner by augmenting surface levels of the alpha5 beta1 integrin, thus promoting interactions with the extracellular matrix, a key event for maturation and migration of these cells during inflammation.