New Methods for Time-resolved Fluorescence Spectroscopy Data Analysis Based on the Laguerre Expansion Technique

Objectives : A new deconvolution method for the analysis of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) data is introduced and applied for tissue diagnosis.

Method : The intrinsic TR-LIFS decays are expanded on a Laguerre basis, and the computed Laguerre expansion coefficients (LEC) are used to characterize the sample fluorescence emission. The method was applied for the diagnosis of atherosclerotic vulnerable plaques.

Results : At a first stage, using a rabbit atherosclerotic model, 73 TR-LIFS in-vivo measurements from the normal and atherosclerotic aorta segments of eight rabbits were taken. The Laguerre deconvolution technique was able to accurately deconvolve the TR-LIFS measurements. More interesting, the LEC reflected the changes in the arterial biochemical composition and provided discrimination of lesions rich in macrophages/foamcells with high sensitivity (> 85%) and specificity (> 95%). At a second stage, 348 TR-LIFS measurements were obtained from the explanted carotid arteries of 30 patients. Lesions with significant inflammatory cells (macrophages/foam-cells and lymphocytes) were detected with high sensitivity (> 80%) and specificity (> 90%), using LEC-based classifiers.

Conclusion : This study has demonstrated the potential of using TR-LIFS information by means of LEC for in- vivo tissue diagnosis, and specifically for detecting inflammation in atherosclerotic lesions, a key marker of plaque vulnerability.

Puerarin injection for unstable angina pectoris

BACKGROUND

Puerarin is extracted from the Chinese herb puerariae lobata. Many users of Chinese herbal medicine believe that puerarin has positive effects in the treatment of coronary heart disease (CHD). In recent years puerarin injection has been widely used to treat CHD and angina pectoris.

OBJECTIVES

To assess the benefits and harms of puerarin injection for unstable angina.

SEARCH STRATEGY

The following electronic databases were searched: The Cochrane Controlled Trials Register on The Cochrane Library (Issue 3, 2004), MEDLINE (1995 to 2004), EMBASE (1995 to 2004), CBM (1995 to 2004), Chinese Cochrane Centre Controlled Trials Register (to 2004), Current Controlled Trials (www.controlled-trials.com) and The National Research Register. We also hand searched 60 Chinese traditional medicine journals.

SELECTION CRITERIA

Randomised controlled trials undertaken on adults with unstable angina evaluating the following types of interventions: Puerarin injection compared to western drugs or placebo, or puerarin injection used with western drugs compared to western drugs alone.

DATA COLLECTION AND ANALYSIS

Data were extracted and analysed independently by two reviewers. Differences in data extraction and analysis were resolved by consensus, referring back to the original article. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

20 trials involving 1240 people were included. All trials identified were classified as having a high risk of bias because of poor reported methodology. The duration of treatment was 7-20 days and no information supplied suggested longer follow-ups were conducted for any trials. This limited the observation to participants who were not undertaking normal activities of daily living. The primary outcome (death) was not report in any trial. For all the secondary outcome measures, frequency of acute angina attacks, improvements in ECG, doses and incidence of nitroglycerine needed and levels of plasma endothelin, there was no evidence that puerarin had better or worse effects to other conventional treatments. There was strong evidence to suggest that puerarin injection plus western drugs was a better treatment option than western drugs alone.

AUTHORS' CONCLUSIONS

Puerarin injection may be effective in unstable angina when used in addition to conventional treatments. However, these finding should be interpreted with care because of the very low methodological quality of studies and potential publication bias. In the light of the findings, a more rigorously designed, randomised double-blind placebo-controlled trial is needed.

VSV-G pseudotyped, MuLV-based, semi-replication-competent retrovirus for cancer treatment

Low levels of gene delivery in vivo using replication-defective retroviral vectors have severely limited their application for clinical protocols. To overcome this problem, we describe here a semi-replication-competent retrovirus (s-RCR) in which the gag-pol and envelope (VSV-G, vesicular stomatitis virus G protein) genes were split into two vectors. This system offers potential advantages over both replication-defective vectors, in terms of efficiency of in vivo spread through a tumor, and all-in-one replication-competent vectors in terms of the payload of therapeutic genes that can be carried. We achieved a viral titer of s-RCR viruses approximately 70-fold higher than VSV-G pseudotyped, replication-defective vectors. In addition, s-RCR vectors induced tumor killing by the cytotoxicity of VSV-G during viral spread. Inclusion of the herpes simplex virus thymidine kinase (HSVtk30) gene into vectors significantly improved tumor killing activity followed by ganciclovir (GCV) treatment in vitro under conditions of low-level viral replication. However, at high levels of viral spread, VSV-G-mediated cytotoxicity predominated. Xenografts of human fibrosarcoma HT1080 cells, preinfected by semi-replicative green fluorescent protein vectors (semi-GFP), were completely non-tumorigenic in nude mice. Implantation of cells preinfected by semi-replicative TK30 vectors (semi-TK30) mixed with parental HT1080 cells at a ratio of 1:1 efficiently prevented tumor growth in mice treated by GCV. Direct intratumoral injection of HT1080 tumors growing in nude mice, or B16 murine melanoma in immunocompetent mice, with semi-TK30 viruses significantly prolonged survival. Injection of autologous cells (B16) producing semi-TK30 vector into B16 tumors prolonged survival only in mice treated with GCV but not with phosphate-buffered saline (PBS). In contrast, when xenogeneic cells (293T) producing semi-TK30 vectors were injected into B16 tumors, an optimal survival advantage was obtained in mice treated with PBS rather than GCV. These data indicate that complex interactions exist between direct cytotoxicity of VSV-G and HSVtk expression when placed in the context of additional immune parameters, which combine to determine the efficacy of the therapy. Taken together, our data suggest that s-RCR vectors have some potential advantages for development to deliver genes into tumors for cancer treatment but that a combination of factors will impact on the decision as to whether the s-RCR strategy is worth developing to full clinical trials.

The perforin-dependent immunological synapse allows T-cell activation-dependent tumor targeting by MLV vector particles

We have reported that retroviral particles adhered to the surface of antigen-specific T cells can be carried to metastases following adoptive transfer in vivo, a process we have called viral hitch hiking. Following antigen-driven T-cell accumulation at tumors, viral particles productively infect tumor cells via envelope/receptor dependent interactions ('hand on' of virus from the T cell to the tumor cell). We describe here a second envelope/receptor independent pathway of viral hand on from T cells, dependent on T-cell activation. We show that the endosomolytic property of perforin promotes release of viral particles from endosomes into which they are co-delivered along with cytotoxic granules from the activated T cell. Therefore, hand on of MLV particles lacking any envelope can be used for in vivo delivery of vectors, where targeting is at the extremely specific level of recognition of antigen by the T-cell receptor, thereby dispensing with the need to engineer viral envelopes. These data reveal a novel pathway by which MLV viral particles exploit a functional immunological synapse and present new opportunities both to improve the efficacy of adoptive T-cell transfer and to target vectors for systemic gene delivery.

Chinese medicinal herbs for acute bronchitis

BACKGROUND

Acute bronchitis is one of the most common diagnoses made by primary-care physicians. It is traditionally treated with antibiotics, (although the evidence for their effectiveness is weak and modest at best), and other even less effective treatments. Chinese medicinal herbs have been also used as treatment.

OBJECTIVES

This review aims to summarise the existing evidence on the comparative effectiveness and safety of Chinese medicinal herbs for treating uncomplicated acute bronchitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2005), which includes the Cochrane Acute Respiratory Infections Group's specialised register; The Chinese Cochrane Centre's Controlled Trials Register (up to December 2004); MEDLINE (1966 to March Week 1, 2005); EMBASE (1988 to December 2004); and the Chinese Biomedical Database (CBM) (1980 to December 2004).

SELECTION CRITERIA

Randomised controlled trials comparing Chinese medicinal herbs with placebo, antibiotics or other Western medicines for the treatment of uncomplicated acute bronchitis.

DATA COLLECTION AND ANALYSIS

At least two authors extracted data and assessed trial quality.

MAIN RESULTS

Four trials reported the time to improvement of cough, fever, and rales associated with bronchitis and showed that patients treated with Chinese herbs had a shorter duration of signs and symptoms. Two trials reported the proportion of patients with improved signs and symptoms at follow up and showed that Chinese herbs were beneficial in terms of relief of signs and symptoms. Thirteen trials analysed the data on physician global assessment of improvement at follow up. Nine of thirteen trials showed that Chinese herbs were superior to routine treatment and the other four trials showed a similar effect to routine treatment. In general, Chinese herbs appeared beneficial. Only one trial reported on adverse effects during treatment.

AUTHORS' CONCLUSIONS

There is insufficient quality data to recommend the routine use of Chinese herbs for acute bronchitis. The benefit found in this systematic review could be due to publication bias and study-design limitations of the individual studies. In addition, the safety of Chinese herbs is unknown due to the lack of toxicological evidence on these Chinese herbs, though adverse events are rarely reported. Chinese herbs should be used carefully.

Direct evidence for the absence of intercellular trafficking of VP22 fused to GFP or to the herpes simplex virus thymidine kinase

The treatment of solid tumors by retroviral delivery of the herpes simplex virus thymidine kinase (TK) followed by ganciclovir (GCV) treatment has so far shown only limited success in patients. One major drawback in this approach is the lack of efficient in vivo gene delivery to cancer cells. Although, the transduction of every single tumor cell is not a requirement since the bystander effect (BE) mediated by gap junctions allows the diffusion of the toxic GCV metabolites from TK-expressing cells toward untransduced cells. To render the TK/GCV approach more potent, and independent of the level of gap junctions, we have tested the efficiency of a TK mutant (TK30) fused to VP22, a herpes simplex protein that seems to be capable of intercellular trafficking. We failed to detect an increase in the BE with cells expressing VP22 fused to TK30 versus cells containing TK30 alone, and this result forced us to reinvestigate the trafficking properties of VP22. Using very sensitive Western blot and fluorescence assays, we were not able to detect the spread of VP22 fused either to TK30 or GFP. These results indicate that VP22 cannot be used as a cargo to translocate TK30 or GFP.

RD114-pseudotyped retroviral vectors kill cancer cells by syncytium formation and enhance the cytotoxic effect of the TK/GCV gene therapy strategy

BACKGROUND

Wild-type RD114 virus is capable of generating syncytia during its replication, and it is believed that cell-free viruses direct the fusion of neighboring cells. The RD114 envelope (Env) that mediates this fusion event is now widely used to pseudotype retroviral and lentiviral vectors in gene therapy. Indeed, vectors pseudotyped with RD114 Env are very efficient to transfer genes into human hematopoietic cells, and they are resistant to human complement inactivation. In this study, we have tested the potential of RD114-pseudotyped vectors produced from the FLYRD18 packaging cell line to induce syncytia.

METHODS

RD114-pseudotyped vectors produced from the FLYRD18 packaging cells were added on tumor cell lines, and the formation of syncytia was assessed by microscopy after cell fixation and methylene blue staining. The kinetics of syncytium formation was analyzed by time-lapse microscopy. Finally, the cytotoxic effect of RD114-pseudotyped vectors was measured by the MTT assay on tumor cells, and in combination with the TK/GCV strategy.

RESULTS

We have found that these vectors were able to mediate cell-to-cell fusion of human tumor cell lines. A few hours after addition of the vector, cells started to aggregate to form syncytia that eventually evolved toward cell death 48 h postinfection. RD114-pseudotyped vectors were very efficient at killing human cancer cells, and they were also able to enhance dramatically the cytotoxic effect of the TK/GCV strategy.

CONCLUSIONS

These findings indicate that RD114-pseudotyped vectors used alone, or in combination with a suicide gene therapy approach, have great potential for the treatment of cancer.

Correlation between serum level of neuron-specific enolase and long-term functional outcome after acute cerebral infarction: prospective study

OBJECTIVE

To determine the value of measuring serum levels of neuron-specific enolase in predicting extent of disease and short- and long-term functional outcome after acute cerebral infarction.

DESIGN

Prospective study.

SETTING

Neurology departments at two university teaching hospitals, Shanghai.

PATIENTS

Thirty-eight patients who presented for acute cerebral infarction between October 1998 and October 2000 were divided into two groups: those whose infarction extended to the cerebral cortex in the carotid artery region (cortical group) and those with an infarction in the subcortical carotid artery region (subcortical group).

MAIN OUTCOME MEASURES

Using a solid-phase enzyme immunoassay, we measured serum levels of neuron-specific enolase on admission and on days 2, 3, and 15. Infarct volume was measured by computed tomography on day 5. The Activities of Daily Living scale was used to assess the clinical outcome at 1-, 3-, and 6-month follow-up after onset.

RESULTS

Mean (standard deviation) serum neuron-specific enolase levels were significantly higher among patients with acute cerebral infarction than among controls (18.48 [16.61] ng/mL versus 9.00 [2.70] ng/mL; P<0.001). The neuron-specific enolase level was also higher in the cortical group than in the subcortical group (33.54 [29.71] ng/mL versus 15.97 [5.91] ng/mL; P<0.01). Levels peaked after 2.11 (0.86) days and correlated positively with the infarct volume (r=0.81; P<0.01) and negatively with clinical outcome at 1 month (r= -0.37; P<0.05), 3 months (r= -0.45; P<0.01), and 6 months (r= -0.65; P<0.001), as assessed on the Activities of Daily Living scale.

CONCLUSION

Serum neuron-specific enolase levels after cerebral infarction may be a useful marker to predict infarct volume and short- or long-term functional outcome.

[Morphological observation on Blastocystis hominis]

AIM

To observe the morphology of Blastocystis hominis.

METHODS

The morphology of Blastocystis hominis found in the fecal specimens from school children and diarrheal cases was examined by using normal saline smear, iodine stain and iron-hematoxylin staining method in Ali, Xizang Autonomous Region and Xinjiang Autonomous Region.

RESULTS

The morphology of Blastocystis hominis was found to include four types, namely vacuolized, granular, amoeboid and binary fission.

CONCLUSION

The vacuole type was the most often seen and accounted for 84% of all 4 types. Blastocystis hominis infection was often found to be associated with Entamoeba coli and other intestinal protozoa, leading to diarrhea in these patients.

The effects of cigarette smoke extract on the endothelial production of soluble intercellular adhesion molecule-1 are mediated through macrophages, possibly by inducing TNF-alpha release

Cigarette smoke (CS) is a major risk factor for many human diseases, although the underlying mechanisms are not clearly understood. This study was undertaken to investigate the effect of a water-soluble CS extract (CSE) on soluble intercellular adhesion molecule-1 (sICAM-1) production by human umbilical vein endothelial cells (HUVEC) mediated through ANA-1 macrophages. First, macrophages were incubated with or without CSE, and the supernatants collected at different time points were used to measure the levels of tumor necrosis factor-alpha (TNF-alpha) and sICAM-1 by enzyme-linked immunosorbent assay (ELISA); and second, HUVEC were cultured with CSE, a vehicle, or ANA-1 supernatants (collected at different time points) and the sICAM-1 levels in the supernatants were measured by ELISA at 24 h. The results showed that: i) CSE showed no effect on the production of sICAM-1 by HUVEC; ii) sICAM-1, in unstimulated or CSE-stimulated ANA-1 supernatants collected at different time points, was under the detectable level; iii) CSE-stimulated ANA-1 supernatants collected at 3 or 6 h showed no effect on sICAM-1 production in HUVEC, while those collected at 12 and 24 h significantly increased sICAM-1 production (p < 0.02 and p < 0.005, respectively); iv) no significant difference in TNF-alpha levels was detected between unstimulated and CSE-stimulated macrophage supernatants collected at 3 and 6 h, however, higher levels of TNF-alpha were found in CSE-stimulated supernatants collected at 12 and 24 h (p < 0.05 and p < 0.002, respectively); and v) a significant correlation (r = 0.9693, p < 0.001) was found between the levels of TNF-alpha in CSE-stimulated ANA-1 supernatants and those of related sICAM-1 production in HUVEC. These findings indicate that CSE indirectly increases the production of sICAM-1 in HUVEC by activating macrophages, which possibly induces the release of TNF-alpha from them, which in turn enhances the production of sICAM-1 from HUVEC.

Testosterone and estradiol modulate TNF-alpha-induced expression of adhesion molecules in endothelial cells

Cytokine-activated endothelial expression of adhesion molecules plays an important role in immune responses. In the present study, we investigated the influences of testosterone and 17 beta-estradiol on tumor necrosis factor-alpha (TNF-alpha)-induced expression of adhesion molecules in human umbilical vein endothelial cells (HUVEC). HUVEC were incubated with TNF-alpha, testosterone or 17 beta-estradiol separately, or in a combination of TNF-alpha plus testosterone or 17 beta-estradiol. The expression of E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) was evaluated at 3, 6, 12 and 24 h following exposure by flow cytometric analysis. The results showed that although testosterone or 17 beta-estradiol did not affect the expression of these adhesion molecules in unstimulated HUVEC, both of them transiently increased the expression of E-selectin and VCAM-1 in TNF-alpha stimulated HUVEC. Neither testosterone nor 17 beta-estradiol affected the expression of ICAM-1 induced by TNF-alpha. It is concluded that both testosterone and 17 beta-estradiol increase TNF-alpha-induced expression of E-selectin and VCAM-1 in endothelial cells and these facts might indicate a mechanism by which gonadal hormones can indirectly enhance immune responses.

Tumor-specific transcriptional targeting of suicide gene therapy

Transcriptional targeting of gene expression has been plagued by the weakness of tissue-specific promoters. Thus, to increase promoter strength while maintaining tissue specificity, we constructed a recombinant adenovirus containing a binary promoter system with a tumor-specific promoter (CEA; carcinoembryonic antigen) driving a transcription transactivator, which then activates a minimal promoter to express a suicide gene (HSV-tk; herpes simplex virus thymidine kinase). This ADV/binary-tk induced equal or greater cell killing in a CEA-specific manner in vitro compared with the CEA-independent killing of a vector with a constitutive viral promoter driving HSV-tk (ADV/RSV-tk). To monitor adenovirus-mediated HSV-tk gene expression in vivo, we employed noninvasive nuclear imaging using a radioiodinated nucleoside analog ([((1)31)I]-FIAU) serving as a substrate for HSV-tk. [((1)31)I]-FIAU-derived radioactivity accumulated after intratumoral injection of ADV/binary-tk only in the area of CEA-positive tumors with significantly less spread to the adjacent liver tissue than after administration of the universally expressed ADV/RSV-tk. Both viruses exhibited similar antitumor efficacy upon injection of liver metastases. Importantly, in vivo dose escalation studies demonstrated significantly reduced toxicity after intravenous administration of ADV/binary-tk versus ADV/RSV-tk. In summary, the increased therapeutic index of this novel, amplified CEA-driven suicide gene therapy vector is a proof of principle for the powerful enhancement of a weak tissue-specific promoter for effective tumor restricted gene expression.

The DRASIC cation channel contributes to the detection of cutaneous touch and acid stimuli in mice

Cation channels in the DEG/ENaC family are proposed to detect cutaneous stimuli in mammals. We localized one such channel, DRASIC, in several different specialized sensory nerve endings of skin, suggesting it might participate in mechanosensation and/or acid-evoked nociception. Disrupting the mouse DRASIC gene altered sensory transduction in specific and distinct ways. Loss of DRASIC increased the sensitivity of mechanoreceptors detecting light touch, but it reduced the sensitivity of a mechanoreceptor responding to noxious pinch and decreased the response of acid- and noxious heat-sensitive nociceptors. The data suggest that DRASIC subunits participate in heteromultimeric channel complexes in sensory neurons. Moreover, in different cellular contexts, DRASIC may respond to mechanical stimuli or to low pH to mediate normal touch and pain sensation.

Multiple fibroblast growth factors support growth of the ureteric bud but have different effects on branching morphogenesis

Together with glial-derived neurotrophic factor (GDNF), soluble factors present in a metanephric mesenchyme (MM) cell conditioned medium (BSN-CM) are necessary to induce branching morphogenesis of the isolated ureteric bud (UB) in vitro (Proc. Natl. Acad. Sci. USA 96 (1999) 7330). Several lines of evidence are presented here in support of a modulating role for fibroblast growth factors (FGFs) in this process. RT-PCR revealed the expression of two FGF receptors, FGFR1(IIIc) and FGFR2(IIIb), in isolated embryonic day 13 rat UBs, which by indirect immunofluorescence displayed a uniform distribution. Rat kidney organ culture experiments in the presence of a soluble FGFR2(IIIb) chimera or a neutralizing antibody to FGF7 suggested an important contribution of FGFs other than FGF7 to the branching program. Several FGFs, including FGF1, FGF2, FGF7 and FGF10, in combination with GDNF and BSN-CM were found to affect growth and branching of the isolated UB, albeit with very different effects. FGF1 and FGF7 were at extreme ends of the spectrum, with FGF10 (more FGF1-like) and FGF2 (more FGF7-like) falling in between. FGF1 induced the formation of elongated UB branching stalks with distinct proliferative ampullary tips, whereas FGF7 induced amorphous buds displaying nonselective proliferation with little distinction between stalks and ampullae. Electron microscopic examination demonstrated that FGF1 treatment induced cytoskeletal organization, intercellular junctions and lumens along the stalk portion of the developing tubules, while the ampullary regions contained 'less differentiated' cells with an abundant secretory apparatus. In contrast, FGF7-induced UBs displayed this 'less differentiated' morphology regardless of position on the structure and were virtually indistinguishable from FGF1-induced ampullae. Consistent with this, GeneChip array analysis (employing a novel nanogram-scale assay consisting of two rounds of amplification and in vitro transcription for analyzing small quantities of RNA) revealed that FGF7-induced UBs expressed more markers of cell proliferation than FGF1, which caused the UB to express cytoskeletal proteins, extracellular matrix proteins, and at least one integrin, some of which may be important in UB branch elongation. Thus, while the various FGFs examined all support UB growth, FGF1 and FGF10 appear to be more important for branching and branch elongation, and may thus play a role in determination of nephron number and patterning in the developing kidney. These in vitro data may help to explain results from knockout and transgenic studies and suggest how different FGFs may, together with GDNF and other factor(s) secreted by MM cells, regulate branching morphogenesis of the UB by their relative effects on its growth, branching and branch elongation and differentiation, thereby affecting patterning in the developing kidney.

[The significance of Titin antibody in diagnosing myasthenia gravis with thymoma]

OBJECTIVE

To investigate the clinical significance of Titin antibody (Titin-ab) in diagnosing myasthenia gravis with thymoma (MGT).

METHODS

Titin-ab and acetylcholine receptor antibody (AChR-ab) in the sera of 73 MGT patients with different thymic pathological patterns and 58 MG patients without thymoma (NTMG) were detected by ELISA.

RESULTS

The positive rate of Titin-ab in MGT group was 76.7%, significantly higher than those of NTMG group, other neurologic diseases group and healthy control group (P < 0.01). The sensitivity of Titin-ab in diagnosis of MGT was significantly lower than that of CT scan or MR of thymus (P < 0.05), but the specificity of Titin-ab in diagnosis of MGT was significantly higher than that of CT scan or MR of thymus (P < 0.05). The positive rate of Titin-ab was mainly related to the thymic pathology and was the highest in the thymic epithelial thymoma (TET) subgroup (95.1%). There was no significant correlation between the positive rate of Titin-ab and the Masaoka's stage of thymoma (P > 0.05). The titer of Titin-ab was highly correlated to the titer of AChR-ab in MGT group (r = 0.496, P < 0.01), but not in MGH group (r = 0.385, P > 0.05).

CONCLUSION

Detection of Titin-ab is a rather sensitive, specific, handy method in diagnosis of MGT (especially TET). It may play an important role in the pathogenesis of MGT.

[The effect of fluid shear stress on the proliferation of rat primary osteoblast-like cells in vitro]

OBJECTIVE

To inquire into the cellular mechanism by which mechanical stress regulates bone remodeling and make an attempt at establishing the most suitable physiological stress to stimulate bone formation.

METHODS

The isolated rat primary osteoblast-like cells were exposed to fluid shear stress 2, 4, 8, 12, 14, 17 and 19 dyn/cm2 for 60 min respectively in the flow chamber. The ability of proliferation of cells was studied by flow cytometry.

RESULTS

After exposed to fluid shear stress, the cells rearranged and the cells' axes were elongated following the flow direction. The proliferation indexes (PI) of the cells went up with the gradual increase of shear stress. When fluid stress reached 12 dyn/cm2, the PI of cells increased significantly (P < 0.05), compared with the control. But the PI of cells began to decrease when the fluid stress continued to increase, and when fluid stress reached 14 dyn/cm2, the PI of cells decreased significantly (P < 0.01), compared with the control.

CONCLUSION

The mechanism by which mechanical stress regulates bone remodeling is related to the proliferation of the osteoblast cells stimulated by stress-induced fluid flow. Low shear stress has no marked influence on the proliferation of cells. Medium shear stress (12 dyn/cm2) can stimulate cells significantly. Major shear stress (14 dyn/cm2) can inhibit cells significantly.

Estrogen inhibits lipopolysaccharide-induced tumor necrosis factor-alpha release from murine macrophages

During their reproductive years, female have a lower risk for atherosclerosis as compared with age-matched males, although the mechanisms behind this are not clearly understood. Cytokines, including TNF-alpha play an important role in the pathogenesis of atherosclerosis. We therefore evaluated whether or not there was any difference between 17 beta-estradiol and testosterone in modulating TNF-alpha release from murine bone marrow-derived macrophages (BMM) in vitro. Cells were incubated with or without physiological concentrations (10(-10)-10(-8) M) of 17 beta-estradiol or testosterone for 48 h, followed by an additional 6 h in the absence or presence of lipopolysaccharide (LPS; 10 micrograms/ml). The amount of TNF-alpha released into the culture medium was determined with radioimmunoassay. We found that 17 beta-estradiol or testosterone alone did not affect TNF-alpha release from BMM as compared to untreated controls. Preincubation with 17 beta-estradiol significantly inhibited LPS-induced TNF-alpha release by 18.15% (p < 0.05). 25.28% (p < 0.05) and 40.83% (p < 0.01) for 10(-10), 10(-9) and 10(-8) M of 17 beta-estradiol, respectively, as compared to LPS alone. In contrast, testosterone tested for 3 concentrations did not significantly effect TNF-alpha release induced by LPS. The results indicate that 17 beta-estradiol, but not testosterone, inhibits TNF-alpha release from LPS-stimulated macrophages, which may be one of the mechanisms by which estrogen protects against atherosclerosis.

[Effects of fluid shear stress on PGE2 synthesis of primary osteoblast-like cells in rats]

OBJECTIVE

The purpose of this study is to study the function of PGE2 during the signal transduction in which fluid shear stress regulates the proliferation and differentiation of osteoblast-like cells.

METHODS

The isolated rat primary osteoblast-like cells were exposed to fluid shear stress 0.12 mN/cm2 for 5, 10, 15, 30, 60 and 120 minutes respectively in a flow chamber. The release of PGE2 was examined.

RESULTS

After exposure to fluid shear stress, the PGE2 synthesis of rat primary osteoblast-like cells increased significantly (P < 0.01) when compared with the control. After 10 minutes, the release of PGE2 began to increase significantly (P < 0.01) and the effect was maximal after 60 minutes (P < 0.01).

CONCLUSION

PGE2 pathway may be one of the signal-transduction pathways which can transduce the fluid shear stress into osteoblast-like cells and then stimulate the bone remodeling.

Epidemiologic and clinical characteristics of Kawasaki disease in Shaanxi Province, China, 1993-1997

The objective of this paper is to describe the epidemiological and clinical characteristics of Kawasaki disease (KD) in Shaanxi Province, China during the 5-year period from January 1993 to December 1997. A province-wide epidemiological survey on KD was made by the China-Japan Kawasaki Disease Study Group. The questionnaire form and the diagnostic criteria of KD, which were prepared by the Japan Kawasaki Disease Research Committee and translated into Chinese, were sent to the departments of pediatrics of all the hospitals with 100 beds or more in Shaanxi province. All the KD patients who were diagnosed during the observation period from 1993 to 1997 were asked to take part in this survey. The databases of reported KD in this survey were analysed at the Department of Pediatrics of the Shaanxi Provincial People's Hospital, Xi'an, China. All the patients that satisfied the diagnostic criteria were included in the report. A total of 105 (70 per cent) hospitals responded and 376 cases of KD were confirmed. More cases were reported in 1993 and 1994. Of the total patients reported, 69 per cent were children under 3 years old with a male to female ratio of 1.6:1. The proportion of patients with cardiac sequelae was 19 per cent with a male to female ratio of 3:1. There were four fatal cases with a fatality rate of 1 per cent. It is concluded that KD is common in China. Continuous surveillance is necessary to maintain high awareness of KD so as to find possible risk factors and their association with the disease.

[Study on the mode of inheritance for familial polycystic ovary syndrome]

OBJECTIVE

To investigate the mode of inheritance of polycystic ovary syndrome(PCOS).

METHODS

The first female relatives with irregular cycle and the first male relatives with premature balding in each nuclear family were designated the affected. Their prevalence rates in families were respectively calculated. Analyses of segregation ratio were carried out among 139 nuclear families with PCOS by the methods of simple segregation and complex segregation of genetic epidemiology, respectively.

RESULTS

The prevalence rates of irregular cycle among mothers and sisters with PCOS were 37.4% and 33.1% respectively, and the prevalence rates of premature balding among fathers and brothers of patients were 19.4% and 6.5%, respectively. The simple segregation analysis indicated that the segregation ratio of PCOS trait in siblings was 0.3023, the complex segregation analysis indicated that it fitted in with the inheritance model of co-dominant disorder with full penetrance and sporadic cases. The frequency of homozygote of disease gene in population was 0.046.

CONCLUSION

PCOS presents the mode of co-dominant inheritance with complete penetrance.

The mammalian sodium channel BNC1 is required for normal touch sensation

Of the vertebrate senses, touch is the least understood at the molecular level The ion channels that form the core of the mechanosensory complex and confer touch sensitivity remain unknown. However, the similarity of the brain sodium channel 1 (BNC1) to nematode proteins involved in mechanotransduction indicated that it might be a part of such a mechanosensor. Here we show that disrupting the mouse BNC1 gene markedly reduces the sensitivity of a specific component of mechanosensation: low-threshold rapidly adapting mechanoreceptors. In rodent hairy skin these mechanoreceptors are excited by hair movement. Consistent with this function, we found BNC1 in the lanceolate nerve endings that lie adjacent to and surround the hair follicle. Although BNC1 has been proposed to have a role in pH sensing, the acid-evoked current in cultured sensory neurons and the response of acid-stimulated nociceptors were normal in BNC1 null mice. These data identify the BNC1 channel as essential for the normal detection of light touch and indicate that BNC1 may be a central component of a mechanosensory complex.

Pain as a mutual experience for patients, nurses and families: a perspective from Shanghai, China

The author of this article visited China for the purpose of helping the faculty of the School of Nursing learn research skills by participating in research--a kind of learn by doing. Both investigators had conducted quantitative studies in the US--one with children and one with adults--that were adapted for use in China. Seeking to also include a qualitative study, the investigators explored several possible research areas. Because pain is a universal phenomena, it was chosen as the subject for the study using the qualitative methodology reported in the first part of this article.

[A clinical and epidemiological study of 86 cases on abused children]

OBJECTIVE

To study the clinical and epidemiological manifestations on abused children, in order to find ways of prevention.

METHODS

Retrospective study was carried out clinically and epidemiologically on 86 cases abused children from 1998.1 - 1999.12.

RESULTS

The sex ratio (male:female) in the abused children was 0.76:1. Most cases were 3 - 16 years olds. Abuse incidences were most commonly occurred in spring and winter, accounted for 32.56% and 33.72% respectively. Most abuses happened physically (45.34%), predominantly involved skin (30.23%) and parenchyma (11.27%). Mental abuse accounted for 24.41%. 14 cases resulted in death (16.27%). 55 (64%) of the abusers were illiterate or with poor education.

CONCLUSION

The abused sites mostly involved skin and parenchyma, but also caused harm to children's mental health, even causing deaths. Most abused children were female and abusers had lower cultural background. Thus, we need to provide a sounding board, to work on child abuse preventin.

Characterization of phi 13, a bacteriophage related to phi 6 and containing three dsRNA genomic segments

The three dsRNA genomic segments of bacteriophage Phi 13 were copied as cDNA and the nucleotide sequences were determined. The organization of the genome is similar to that of Phi 6, and there is significant similarity in the amino acid sequences of the proteins of the polymerase complex and one of the membrane proteins, P6. There is little or no similarity in the nucleotide sequences. Several features of the viral proteins differ markedly from those of Phi 6. Although both phages are covered by a lipid-containing membrane, the protein compositions are different. The host attachment protein consists of two peptides rather than one and the phage attaches directly to the LPS of the host rather than to a Type IV pilus. Despite the differences in the structure of the membranes, the two viruses can successfully exchange the genes for host attachment proteins and thereby change their host specificities.

Photophysical processes of a copolymer containing naphthalene and carbazole rings

The photophysical processes of copolymer formed by copolymerization of beta-naphthyl-methacrylate (NMA) with vinylcarbazole (VCZ) were studied. The results show that when the solution of copolymer (NMA-VCZ) in THF is located in a low concentration range (about 10(-8) mol/l), the fluorescence emission is in good agreement with that of NMA monomer and the excimer is formed with gradual increase in concentration of copolymer (NMA-VCZ). The fluorescence of copolymer (NMA-VCZ) can be efficiently quenched both by electron donors and acceptors where the quenching effects follow the Stern-Volmer equation. The dimolecular exciplex between copolymer (NMA-VCZ) and N,N-dimethylaniline (DMA) is formed and the triple exciplex is also observed in the same system.

A role for Timeless in epithelial morphogenesis during kidney development

Central to the process of epithelial organogenesis is branching morphogenesis into tubules and ducts. In the kidney, this can be modeled by a very simple system consisting of isolated ureteric bud (UB) cells, which undergo branching morphogenesis in response to soluble factors present in the conditioned medium of a metanephric mesenchyme cell line. By employing a targeted screen to identify transcription factors involved early in the morphogenetic program leading to UB branching, we identified the mammalian ortholog of Timeless (mTim) as a potential immediate early gene (IEG) important in this process. In the embryo, mTim was found to be expressed in patterns very suggestive of a role in epithelial organogenesis with high levels of expression in the developing lung, liver, and kidney, as well as neuroepithelium. In the embryonic kidney, the expression of mTim was maximal in regions of active UB branching, and a shift from the large isoform of mTim to a smaller isoform occurred as the kidney developed. Selective down-regulation of mTim resulted in profound inhibition of embryonic kidney growth and UB morphogenesis in organ culture. A direct effect on the branching UB was supported by the observation that down-regulation of mTim in the isolated UB (cultured in the absence of mesenchyme) resulted in marked inhibition of morphogenesis, suggesting a key role for Tim in the epithelial cell morphogenetic pathway leading to the formation of branching tubules.

Enhanced ganciclovir killing and bystander effect of human tumor cells transduced with a retroviral vector carrying a herpes simplex virus thymidine kinase gene mutant

Gene transfer of the herpes simplex virus thymidine kinase (TK) gene associated with ganciclovir (GCV) treatment can lead to death of TK-expressing cells, and of neighboring TK- cells because of the bystander effect. Thus, a small proportion of TK+ cells in a tumor can lead to its complete regression after GCV treatment. However, a lack of efficacy of gene transfer into tumors associated with low GCV sensitivity and poor bystander effect of human cancer cells currently limit the clinical use of this suicide gene therapy approach. To increase the potency of suicide gene therapy, we have tested the GCV sensitivity and the bystander effect of TK mutants that have been previously described. After retroviral transduction of the TK mutants into human tumor cells of various origins, we have found a strong killing effect of GCV with cells expressing the mutants TK30 or TKF161C. The GCV sensitivity of several human tumor cell types expressing TK30 was 9- to 500-fold higher than cells containing wild-type TK. Furthermore, TK30-expressing cells were able to kill bystander cells much more efficiently than TK-expressing cells. Thus, TK30 mutant is a promising candidate for suicide gene therapy clinical trials.

Carbachol blocks beta-amyloid fragment 31-35-induced apoptosis in cultured cortical neurons

We reported previously that many neurodegenerative changes characteristic of apoptosis could be induced by a short fragment of beta-amyloid protein, A(beta31-35), in cultured newborn mice cortical neurons, and that these changes were accompanied with alterations in expression of some genes. This study was designed to examine whether the apoptotic processes and related gene modulations in this model could be affected by coadministration of carbachol by electrophoretic analysis for DNA ladder formation and by RT-PCR assays for genomic modulation. The results showed that (1) simultaneous incubation with carbachol dose- and time-dependently blocked the specific DNA ladder formation induced by exposure to A(beta31-35) and (2) the A(beta31-35)-induced downregulation of bcl-2 and upregulations of bax, p53, and c-fos genes were reversed or ameliorated by the coadministration of carbachol. It is proposed that A(beta31-35)-induced apoptosis can be prevented by carbachol through mechanisms that modulate the expression of related genes.

[Epidemiological and clinical characteristics of Kawasaki disease in Shanxi province]

OBJECTIVE

The objective of this paper is to describe the epidemiological and clinical characteristics of Kawasaki disease (KD) in Shanxi province, China during a 5 year - period from January 1993 to December 1997.

METHODS

A province - wide epidemiological survey on Kawasaki disease (KD) was carried ont by the China - Japan Kawasaki disease study group. The questionnaire form and the diagnostic criteria of KD which was prepared by the Japan Kawasaki disease research committee and translated into Chinese were sent of the departments of pediatrics of all the hospitals with 100 or more beds in Shanxi province. All the KD patients who were diagnosed during the observation period from 1993 to 1997 were asked to report to this survey. The database of reported KD in this survey was analyzed at the Department of pediatrics of the Shanxi provincial people's hospital, Xian, China. All the patients that satisfied the diagnostic criteria were included.

RESULTS

A total of 105 (70%) hospitals responded and 376 cases of KD were confirmed. More cases were reported in 1993 and 1994. Of the total patients reported, 69% were children under 3 years old with male to female ratio of 1.6:1. The proportion of patients with cardiac sequelae was 19% with male to female ratio: 3:1. There were 4 fatal cases with a fatality rate of 1%.

CONCLUSIONS

Since KD is common in China continuous surveillance is necessary to maintain high awareness of KD so as to identify possible risk factors and its association with other disease.

Inhibitory effects on HIV-1 protease of constituents from the wood of Xanthoceras sorbifolia

From a methanolic extract of the wood of Xanthoceras sorbifolia, two new compounds, 29-hydroxy-3-oxotirucalla-7,24-dien-21-oic acid (3, xanthocerasic acid) and epigallocatechin-(4beta-->8, 2beta-->O-7)-epicatechin (6), were isolated, together with 11 known compounds. Of the isolated compounds, 3-oxotirucalla-7, 24-dien-21-oic acid (2), oleanolic acid (4), and 6 were found to be inhibitory substances against human immunodeficiency virus (HIV-1) protease, with their 50% inhibitory concentrations (IC(50)) being 20, 10, and 70 microg/mL, respectively. Condensed tannins of high molecular weights with epicatechin and epiafzelechin as the main extender units were found to be the most active principles of this plant (IC(50) values ca. 6.0 microg/mL).

[Comparative studies on the absorption properties of charge transfer complexes of C60 with three organic amines]

Comparative studies on the absorption properties of charge transfer complexes of C60 with N,N-dimethylaniline, diethylamine and triethylamine in toluene, CCl4 and cyclohexane were carried out, respectively. It was found that interactions of C60 with various amines in different solvent media are all in the order: cyclohexane > CCl4 > toluene, while these interactions are different in the same solvent. Both of the molar extinction coefficients and apparent constants of CTC were determined. Meanwhile, the influences of temperature on CT interactions of C60 with various amines in different solvent media were also studied.

Isolation of additional bacteriophages with genomes of segmented double-stranded RNA

Eight different bacteriophages were isolated from leaves of Pisum sativum, Phaseolus vulgaris, Lycopersicon esculentum, Daucus carota sativum, Raphanus sativum, and Ocimum basilicum. All contain three segments of double-stranded RNA and have genomic-segment sizes that are similar but not identical to those of previously described bacteriophage phi6. All appear to have lipid-containing membranes. The base sequences of some of the viruses are very similar but not identical to those of phi6. Three of the viruses have little or no base sequence identity to phi6. Two of the viruses, phi8 and phi12, contain proteins with a size distribution very different from that of phi6 and do not package genomic segments of phi6. Whereas phi6 attaches to host cells by means of a pilus, several of the new isolates attach directly to the outer membrane. Although the normal hosts of these viruses seem to be pseudomonads, those viruses that attach directly to the outer membrane can establish carrier states in Escherichia coli or Salmonella typhimurium. One of the isolates, phi8, can form plaques on heptoseless strains of S. typhimurium.

[Study on the ternary complex of CPFX, copper (II) and DNA by the method of fluorescence]

Using the method of fluorescence spectrometry, the formation of binary complexes of CPFX-Cu(II) and CPFX-eucaryote DNA, and ternary complexes of CPFX-Cu(II)-eucaryote DNA was studied. The results show that the fluorescent intensity of CPFX can be quenched in the presence of Cu(II ) or DNA in CPFX system. In the presence of Cu (II), the fuorescence quenching action of DNA on CPFX was enhanced strongly. Based on the fluorescent intensity, the formation constants of CPFX-Cu (II) and CPFX-DNA in either the presence or absence were calculated,and the mechanism of interaction among CPFX,Cu(II) and DNA was presented.

Construction and characterization of a recombinant adenoviral vector expressing human interleukin-12

Interleukin-12 (IL-12) is a 70-kDa heterodimeric cytokine composed of a 35-kDa subunit (p35) and a 40-kDa subunit (p40). We have demonstrated previously that intratumoral delivery of a recombinant adenoviral vector expressing the mouse IL-12 gene significantly prolongs the survival time of mice with metastatic colon carcinoma in the liver. We now report the molecular cloning of cDNA for both subunits of human IL-12 (hIL-12) in a recombinant adenoviral vector in which the p40 and p35 subunits are linked and coexpressed using the encephalomyocarditis virus internal ribosome entry site. The recombinant adenoviral vector was used to transduce human tumor cell lines, and the presence of hIL-12 in the conditioned media was illustrated by enzyme-linked immunosorbent assay. The biological activity of hIL-12 in the conditioned media was also demonstrated in vitro through its ability to induce interferon-gamma production from peripheral blood mononuclear cells (PBMCs), to stimulate PBMC proliferation, and to enhance natural killer activity from normal human PBMCs to lyse natural killer-sensitive K562 target cells. The results of these studies support the application of this recombinant adenoviral vector construct as an efficient gene delivery vehicle in phase I/II clinical studies of hIL-12 gene therapy for cancer.

Branching morphogenesis independent of mesenchymal-epithelial contact in the developing kidney

Whether mesenchymal-epithelial interactions leading to branching morphogenesis in developing epithelial tissues such as the kidney require direct cell-cell contact or are due to soluble mediators elaborated by the inducing tissue has been the subject of much debate. Here we demonstrate that ureteric bud (UB) epithelium, from which the kidney collecting system and upper urinary tract are derived, can undergo impressive three-dimensional branching morphogenesis when cultured in the appropriate extracellular matrix context in the absence of direct contact with mesenchymal tissue, indicating that the program for branching morphogenesis is inherent to the UB. Both a soluble factor in BSN cell-conditioned medium (BSN-CM) derived from an immortalized cell line thought to originate in the early metanephric mesenchyme and glial cell line-derived neurotrophic factor (GDNF) were required for early and later events in branching morphogenesis. In the absence of BSN-CM, the isolated UB did not survive; a similar result was obtained in the presence of neutralizing antibodies against glial cell line-derived neurotrophic factor. Preliminary analysis of key activity present in BSN-CM indicates that it is a heat-sensitive, heparin-binding factor with a probable molecular mass greater than 100 kDa. When the in vitro cultured UB was recombined with freshly isolated metanephric mesenchyme, nephric units were induced in the mesenchyme, and the UB branches underwent elongation. Our data suggest that, although UB branching morphogenesis per se does not require direct mesenchymal contact, such contact may play a key role in regulating branch elongation and establishing the pattern of branching. The results also suggest an approach to in vitro engineering of nephron.