Dynamic overload control for distributed call processors using the neural network method

Overload control of call processors in telecom networks is used to protect the network of call processing computers from excessive load during traffic peaks, and involves techniques of predictive control with limited local information. Here we propose a neural-network algorithm, in which a group of neural controllers are trained using examples generated by a globally optimal control method. Simulations show that the neural controllers have better performance than local control algorithms in both the throughput and the response to traffic upsurges. Compared with the centralized control algorithm, the neural control significantly decreases the computational time for making decisions and can be implemented in real time.

Testosterone protects rat hearts against ischaemic insults by enhancing the effects of alpha(1)-adrenoceptor stimulation

BACKGROUND AND PURPOSE

Testosterone alleviates symptoms in patients with ischaemic heart disease. Androgen receptors are present in the heart, and testosterone upregulates gene expression of cardiac beta(1)-adrenoceptors. We hypothesize that testosterone may confer cardioprotection by interacting with adrenoceptors.

EXPERIMENTAL APPROACH

In isolated perfused hearts and ventricular myocytes from orchidectomized rats without or with testosterone (200 microg/100 g) replacement, we first determined the effect of ischaemia/reperfusion in the presence of noradrenaline (10(-7) M). Then we determined the contribution of interactions between testosterone and alpha(1)- or beta(1)-adrenoceptors in cardiac injury/protection (infarct size, release of lactate dehydrogenase, viability of myocytes, recovery of contractile function and incidence of arrhythmias) upon ischaemia/reperfusion by pharmacological manipulation using selective adrenoceptor agonists (alpha(1)-adrenoceptor agonist: phenylephrine 10(-6) M; non-selective beta-adrenoceptor agonist: isoprenaline 10(-7) M) and antagonists (alpha(1): prazosin or benoxathian 10(-6) M; beta(1): CGP 20712A 5 x 10(-7) M). We also determined the expression of alpha(1) and beta(1)-adrenoceptor in the hearts from rats with and without testosterone.

KEY RESULTS

Testosterone reduced injury induced by ischaemia/reperfusion and noradrenaline. This was achieved by enhancing the beneficial effect of alpha(1)-adrenoceptor stimulation, which was greater than the deleterious effect of beta(1)-adrenoceptor stimulation (also enhanced by testosterone). The effects of testosterone were abolished or attenuated by blockade of androgen receptors. Testosterone also enhanced the expression of alpha(1A) and beta(1)-adrenoceptor.

CONCLUSIONS AND IMPLICATIONS

Testosterone conferred cardioprotection by upregulating the cardiac alpha(1)-adrenoceptor and enhancing the effects of stimulation of this adrenoceptor. The effect of testosterone was at least partly mediated by androgen receptors.

The immunosuppressive and protective ability of glucose-regulated protein 78 for improvement of alloimmunity in beta cell transplantation

An insulinoma cell line, NIT-1, transfected with glucose-regulated protein 78 (GRP78) was established, namely NIT-GRP78, and used to study the immunosuppressive and protective ability of GRP78. In extended cytotoxic T lymphocyte (CTL) killing assay, NIT-1-primed lymphocytes were more cytotoxic in killing beta cells than NIT-GRP78-primed lymphocytes. Severe necrosis was observed only when the NIT-1-primed lymphocytes were cultured with NIT-1 beta cells, but not with NIT-GRP78 cells. In addition, an increase of interleukin (IL)-4 secretion from beta cell-primed splenocytes when GRP78 presence was observed in cytokine enzyme-linked immunosorbent assay (ELISA). Diabetic mice reached normoglycaemia promptly and gained weight after transplantation of either NIT-1 or NIT-GRP78 cells. However, the recipient mice transplanted with NIT-GRP78 cells lived much longer than those recipients transplanted with NIT-1 cells, which was due apparently to prolonged insulin production by the transplanted NIT-GRP78 cells. In fact, we observed a significant increase of insulin concentration after glucose stimulation of diabetic mice received NIT-GRP78 cells at day 7 post-transplantation. From the results we propose that GRP78 could have a dual function in both protecting NIT-1 cells from CTL-mediated lysis and stimulating a population of T helper 2 cells to down-regulate the immune response to the transplanted beta cells.

Polymorphisms and drug resistance analysis of HIV-1 CRF01_AE strains circulating in Fujian Province, China

BACKGROUND

The database of genotypic drug resistance mutations in HIV-1 subtype B circulating in developed industrial countries has been well established; however, little is known regarding the prevalence of genotypic resistance patterns in patients harboring non-subtype-B HIV-1 variants in most Asian countries.

OBJECTIVE

To characterize the polymorphisms and emergence of drug-resistance mutations, resistance to antiretroviral drugs in naïve and pretreated patients infected with HIV-1 CRF01_AE isolates in Fujian province, China.

METHODS

HIV-1 pol amplicons from 52 pre- and 14 post-treatment samples were obtained by reverse transcription-polymerase chain reaction (RT-PCR) and sequencing. All of the 14 antiretroviral-treated patients were under a fixed regimen of stavudine (d4T), lamivudine (3TC) and nevirapine (NVP), and they had been on treatment for a mean of 6 months (SD, 4 months). The sequence data were analyzed using the Bioedit software, and the data regarding drug resistance mutations were obtained using the Stanford software ( http://hivdb.stanford.edu ).

RESULTS

In comparison with the consensus sequence of B strains, the most common protease polymorphisms in HIV-1 CRF01_AE strains prevailing in Fujian Province, China, were I13V (76.9%), E35D (76.9%), M36I (100%), R41K (98.1%), H69K (90.4%), and L89M (96.2%). Protease mutations between CRF01_AE strains and B' variants prevailing in China were observed. The proportion of substitutions L63P, A71T/V, V77I and I93L in subtype B' sequences was considerably higher than in CRF01_AE viruses, while the proportion of L10I, M36I and K20R/I substitutions in subtype B' sequences was relatively lower than in CRF01_AE strains. A high level of resistance to nucleoside reverse transcriptase inhibitors (NRTIs) (28.6%, 4/14) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) (35.7%, 5/14) was found in treatment-experienced patients. High-level resistance to nevirapine (NVP) and lamivudine (3TC) was found in the stavudine/lamivudine/nevirapine (d4T/3TC/NVP) treatment regimen. The overall drug resistance rate was 42.9% (6/14), the resistance rates to two and to all three drugs under treatment were 14.3% (2/14) and 7.1% (1/14), respectively.

CONCLUSION

This study is the first report on polymorphisms and emergence of drug-resistance mutations in HIV-1 subtype CRF01_AE prevailing in China. These findings provide useful information on global HIV genetic variability and non-B drug resistance.

Splice variants of the CYP27b1 gene and the regulation of 1,25-dihydroxyvitamin D3 production

The cytochrome P450 25-hydroxyvitamin D3-1alpha-hydroxylase (CYP27b1) plays a pivotal role in vitamin D physiology by catalyzing synthesis of active 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. In common with other P450s, CYP27b1 is known to exhibit alternative splicing. Here we have cloned and sequenced several novel intron 2-containing, noncoding splice variant mRNAs for CYP27b1 in 1,25(OH)2D3-producing HKC-8 human proximal tubule and THP-1 monocytic cells. Regulation of 1,25(OH)2D3 synthesis in these cell lines by calciotropic and noncalciotropic factors was associated with altered expression of the CYP27b1 splice variants. To assess the functional significance of this, HKC-8 cells were transfected with short hairpin RNA (shRNA) to inhibit mRNAs containing sequences from intron 2. This resulted in a significant increase in the expression of CYP27b1 protein and synthesis of 1,25(OH)2D3 by HKC-8 cells compared with control cells for two different intron 2-containing shRNAs (both P<0.001). shRNA to intron 2 had no significant effect on the levels of wild-type CYP27b1 mRNA, suggesting a posttranscriptional mechanism of action. By contrast, shRNA to wild-type CYP27b1 suppressed transcription and activity of the enzyme by 70 and 31%, respectively (both P<0.01). These data indicate that noncoding splice variants of CYP27b1 are functionally active and may play a significant role in the regulation of 1,25(OH)2D3 synthesis during normal physiology.

Stigmatization and shame: consequences of caring for HIV/AIDS patients in China

Using a representative sample of 478 doctors, nurses, and lab technicians working with people living with HIV/AIDS (PLWHA), a cross-sectional study was conducted to assess the impact of the AIDS epidemic on medical care systems and service providers in China. Correlation analyses showed significant association between internalized shame reported by service providers and their perception of being stigmatized due to working with PLWHA. Multivariate analyses revealed that the perceived level of institutional support for AIDS care was significantly related to the stigmatization and shame reported by the service providers. The study findings suggest that improved institutional support for AIDS care at the facility level and HIV-related stigma reduction intervention are crucial to maintain a high quality performance by the workforce in the health care system.

Identification of predictive markers to differentiate ixabepilone from paclitaxel activity in ER-negative breast cancer patients

2525

Background: Ixabepilone (BMS-247550) is a microtubule stabilizing agent with demonstrable therapeutic value in taxane- refractory breast cancer (BC) patients. Biomarkers to predict either ixabepilone or paclitaxel activity in BC patients have previously been reported. However, markers that differentiate response to the two agents have yet to be identified. This study sought to discover predictive markers that will enable patient selection to differentially enhance response to ixabepilone or paclitaxel in ER-negative (ER-) patients. Materials and Methodologies: Pre-treatment gene expression profiles were generated for 62 ER- patients treated with ixabepilone in clinical study CA163080, and 51 ER- patients treated with T/FAC (paclitaxel and fluorouracil-doxorubicin-cyclophosphamide) in clinical study MDA133. Biomarkers differentially predictive of complete pathological response in breast were identified through gene set enrichment analysis (GSEA) or classification by threshold gradient descent (TGD). Gene knockdown by siRNA was used to study some of these candidate markers. Results: Four candidate models that differentiate response to ixabepilone treatment and taxane-containing therapy were identified. Two of the models, found by GSEA, are based on expression levels for single microtubule-related genes: transforming, acidic coiled-coil containing protein 3 (TACC3) and chromosome condensation protein G (HCAP-G). The potential of HCAP-G as a differential marker was supported by siRNA studies. Two of the models, found by TGD, are based on expression levels for 26 and 20 genes. Areas under the ROC curves for the models applied to each study separately are given in the table . Conclusions: We have identified four predictive models that differentiate response in a clinical trial of ixabepilone from that in a trial of T/FAC. A clinical trial is under way to further evaluate their utility for differentiating response to ixabepilone- and taxane-containing regimens.

[Table: see text]

[Table: see text]

Identification of predictive and surrogate molecular markers for dasatinib in prostate cancer: Rationale for patient selection and efficacy monitoring

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Background: Dasatinib is a potent, multi-targeted kinase inhibitor that was recently approved for treatment of chronic myelogenous leukemia resistant to imatinib. To aid its clinical development in prostate cancer, we used a panel of prostate cancer cell lines to identify molecular markers that could be used to predict sensitivity to dasatinib and to monitor its activity. Methods: Baseline gene expression profiles of 16 cell lines were used to identify predictive biomarkers based on the correlation of gene expression with in vitro sensitivity of cells to dasatinib. Selected cell lines were treated with dasatinib to identify surrogate biomarkers based upon changes in gene expression following dasatinib treatment. Results: We identified 174 genes whose baseline expression levels were highly correlated with sensitivity or resistance to dasatinib. These include cell lineage markers cytokeratin 5 (CK5), androgen receptor (AR), and prostate specific antigen (PSA). Our results indicate that “basal type” cell lines (those with high expression of CK5 and low expression of AR and PSA) are sensitive to dasatinib. Dasatinib treatment studies further identified genes whose expression levels were significantly modulated by the drug. Ten genes, including urokinase-type plasminogen activator (uPA), were not only significantly correlated with sensitivity to dasatinib but also reduced in their expression upon drug treatment. In addition, the down-regulation of uPA was specific to dasatinib and the effect was not seen in taxol-treated cells. The extent of down-regulation was correlated with the sensitivity of cell lines to dasatinib. EphA2, a specific kinase target of dasatinib, was identified as a biomarker common to prostate and breast cancers. Finally, the expression of 5 genes including CK5, AR, PSA, uPA and EphA2 in prostate tumors was examined and the dasatinib sensitivity signature was validated using a published data set derived from a clinical population. Conclusions: Candidate markers correlated with dasatinib sensitivity were identified. A five-gene model consisting of predictive markers as well as potential surrogate markers has been formulated and will be evaluated in ongoing dasatinib prostate cancer trials.

No significant financial relationships to disclose.

Oxygen adsorption by carbon nanotubes and its application in radiotherapy

The ability to deliver large molecules, for example nucleic acids, to cells using carbon nanotubes has been reviewed. Potential applications of functionalised nanotubes to deliver oxygen to cancer cells to enhance the effects of radiotherapy are considered.

The telemedicine and teleconsultation system application in clinical medicine

Telemedicine and teleconsultation are the application and development of the telecommunication networks. Health experts can solve problems by using the electronic and communication technologies without distance limitation. In this study, we try to develop the telemedicine and teleconsultation system between local site and consulting expert site. Two applications of this system in clinical medicine are discussed. The system at each site has a workstation including a cable modem or ADSL connection, a monitor, a web camera, speakers, a microphone for communication, and NetMeeting application software. The first application in this study is to develop a school-based intervention program by using this system for high-risk school-age children in one of the earthquake-struck areas. The preliminary result of this study is that the telemedicine and teleconsultation system is more effective than traditional consultation and supervision. Moreover, we can apply this system in training local volunteers, educators, and welfare workers. Meanwhile, we can save lots of cost and time since we don't need to travel between the local site and the expert site. In the end of this study, the second application of this system in SARS case treatment was also discussed.

Congenital neuromuscular disease with uniform type 1 fiber and RYR1 mutation

BACKGROUND

Congenital neuromuscular disease with uniform type 1 fiber (CNMDU1) is a rare form of congenital myopathy, which is pathologically diagnosed by the presence of more than 99% of type 1 fiber, with no specific structural changes. Its pathogenic mechanism is still unknown. We recently reported that almost all patients with central core disease (CCD) with ryanodine receptor 1 gene (RYR1) mutations in the C-terminal domain had type 1 fibers, nearly exclusively, in addition to typical central cores.

OBJECTIVE

To investigate whether CNMDU1 is associated with RYR1 mutation.

METHODS

We studied 10 unrelated Japanese patients who were diagnosed to have CNMDU1 based on clinical features and muscle pathology showing more than 99% type 1 muscle fibers. We extracted genomic DNA from frozen muscles and directly sequenced all 106 exons and their flanking intron-exon boundaries of RYR1.

RESULTS

Four of 10 patients had a heterozygous mutation, three missense and one deletion, all in the C-terminal domain of RYR1. Two missense mutations were previously reported in CCD patients. Clinically, patients with mutations in RYR1 showed milder phenotype compared with those without mutations.

CONCLUSION

Congenital neuromuscular disease with uniform type 1 fiber (CNMDU1) in 40% of patients is associated with mutations in the C-terminal domain of RYR1, suggesting that CNMDU1 is allelic to central core disease at least in some patients.

The clinical anatomy of the triangle of Petit

INTRODUCTION

Hernias through the triangle of Petit (TP) are uncommon. The anatomy of the TP is known to be variable, yet quantitative data are scant.

MATERIALS AND METHODS

The triangle was observed in 80 adult cadavers and its dimensions and surface area were measured.

RESULTS

On the basis of surface area we classified the triangles into four types. Type I or small TP, with a surface area of <8 cm2, accounted for 43.7% of our specimens. Type II (26.2%) were intermediate in size, with a surface areas of 8-12 cm2. Type III (12.5%) were large triangles with surface areas >12 cm2. Finally, Type IV (17.5%) were not triangles. In these, the latissimus dorsi was covered by the external abdominal oblique muscle.

CONCLUSIONS

We hope these data will help prediction of which patients are at greater risk of herniation through the TP.

Gene and protein expression of protease-activated receptor 2 in structural and inflammatory cells in the nasal mucosa in seasonal allergic rhinitis

BACKGROUND

Protease-activated receptor 2 (PAR 2) has been shown to be responsible for trypsin and mast cell tryptase-induced airway inflammation. Here, the present study aimed to explore the expression of PAR 2 in the nasal mucosa of seasonal allergic rhinitis (SAR).

METHODS

Study subjects were recruited for the study by medical history, physical examination and laboratory screening tests. Using immunohistochemistry, laser-assisted cell picking and subsequently real-time PCR, nasal mucosa biopsies of SAR patients were investigated for PAR 2 gene and protein expression in complex tissues of the nasal mucosa.

RESULTS

Gene and protein expression of PAR 2 was firstly detected in nasal mucosa of SAR patients. The relative gene expression level of PAR 2 was significantly increased in complex tissues of the nasal mucosa of SAR (6.21+/-4.02 vs. controls: 1.38+/-0.86, P=0.004). Moreover, PAR 2 mRNA expression in epithelial cells (SAR: 4.78+/-4.64 vs. controls: 0.84+/-0.61, P=0.003) but not in mucus (SAR: 1.51+/-1.15 vs. controls: 1.35+/-1.02, P=0.78) and endothelial cells (SAR: 1.20+/-0.57 vs. controls: 1.73+/-1.30, P=0.5) was found to be significantly changed in the nasal mucosa in SAR. Using double immunohistochemistry the present study demonstrated that the total numbers of mast cells (P=0.0003) and eosinophils (P=0.03) and the numbers of eosinophils expressing PAR 2 (P=0.006) were significantly elevated in the nasal mucosa of SAR compared with the controls.

CONCLUSION

The abundant presence and distribution of gene and protein expression of PAR 2 in different cell types in the nasal mucosa under normal situation, the increased expression of PAR 2 in epithelial cells and the increased number of eosinophils with PAR 2 suggest that PAR 2 may contribute to the pathogenesis of allergic diseases such as SAR.

NK Cells Lyse T Regulatory Cells in Human Infection with An Intracellular Pathogen (B167)

Previously we found that regulatory T cells (CD4+CD25+Foxp3+ cells, Tregs) expand in response to M.tuberculosis (M. TB) through mechanism that depend on prostaglandin E2 production. In the current study, we determined the role of NK cells in regulating Tregs expansion in human M. TB infection. M. TB whole cell lysate (TB lysate) resulted in regulatory T cell expansion (15.33±1.02% vs 1.5±0.22%, P&lt;0.001). Addition of monokine-activated NK cells (IL-12, IL-15 and IL-18) markedly inhibited Treg expansion (6.2±1.2% vs 15±1.5%, P&lt;0.001) but freshly isolated NK cells had no effect. NK cells activated with TB lysate-stimulated monocytes also reduced Tregs expansion (13.2±0.3% to 3.4±1.4%, P&lt;0.001) confirming the physiological relevance of this effect. Reduced Tregs expansion was not due to inhibition of PGE2 production or because of IFN γ. Monokine activated NK cells lysed TB lysate-expanded Tregs, but not freashly isolated Tregs (% specific lysis of 21±3% vs 1±1% P&lt;0.001), nor T regs depleted T cells. Anti-NKG2D and anti-NKp46 reduced the % specific lysis of expanded Tregs from 22±3% to 7±3% and 8±3%, respectively (P&lt;0.001) but abs to CD16, DNAM-1, and 2B4 had no effect. NKG2D ligand, ULBP1 expression was markedly upregulated on expanded T regs, compared to T regs depleted cells ( 31±5% vs 2.1 ±0.4%, P=0.002) and freshly isolated Tregs (4.6±1.1%). Anti -ULBP1 significantly inhibited the NK mediated lysis of expanded Tregs (specific lysis of 27±4% vs 9±2%, P&lt;0.001) but abs to ULBP2, ULBP3 and MICA/B had no effect. These finding suggest that NK cells reduce the frequency of M.TB-expanded T regs by direct lysis.

Are Broadly Neutralizing Antibodies against HIV-1 Unusual? (47.32)

To date, AIDS vaccines cannot induce broadly(b)-neutralizing (Nt) antibodies (Abs) against HIV-1. It has been suggested that HIV’s Nt epitopes mimic “self” epitopes, and that bNt Abs are rare because they develop from autoreactive B cell clones that are normally deleted or made anergic by self antigens (Agns); such Abs are thought to have long CDR-H3 loops (H3s). Thus, self-tolerance must be broken to accumulate self-reactive naïve B cells whose Abs recognize Nt, HIV-1 epitopes. It has been reported that most of the bNt monoclonal (M)Abs have very long H3s, and that most react with self molecules (e.g., cardiolipin, CL). Alternatively, bNt Abs may arise out of “normal” Ab responses, with HIV Agns selecting bNt Abs with long H3s, and/or long H3s may develop via processes driven by persistent Agn.

We have begun to test these models by several approaches. Using autoAgn ELISAs and microarrays, bNt MAbs were shown not to be unusually self-reactive, compared to genuine autoreactive MAbs or autoimmune sera; also, bNt sera did not react significantly with CL. Finally, sequence analysis of ~700 human MAbs indicated that the bNt MAbs are no different than non-Nt MAbs against HIV-1 or other chronic viruses, or autoimmune anti-protein MAbs; but they are very different from autoimmune MAbs against non-protein autoAgns. Taken together, our results support the conclusion that HIV-bNt Abs are not unusual in their reactivity or structures.

Difference of NPY and its receptor gene expressions between obesity and obesity-resistant rats in response to high-fat diet

AIM

To investigate the effect of high-fat diet on expressions of hypothalamic neuropeptide Y (NPY) and Y1, Y2, Y5 receptors and the mechanism relative to the susceptibility of obesity.

METHODS

Thirty-six female SD rats were randomly divided into high-fat diet group (HF, n=27) and chow food group (CF, n=9), and given either HF or CF diet for 13 weeks. Then the HF diet group was subdivided into dietary induced obesi-ty (DIO) and dietary induced obesity resistant (DIO-R) rat according to the final body weight. Body weight, caloric intake, energy efficiency, visceral fat pads were measured and compared. The levels of plasma and hypothalamic NPY were determined by Radioimmunoassay. Real-time Polymerase Chain Reaction (PCR) was used to measure the gene expression of NPY and its receptors in hypothalamus.

RESULTS

Body weight, caloric intake, energy efficiency and visceral fat pads in DIO rats were higher significantly than those in CF or DIO-R rats (p<0.01). No difference in plasma NPY level was detected among the three groups (p>0.05); the hypothalamic NPY level was significantly higher in DIO group than in CF or DIO-R group (p<0.01). Gene expression levels of NPY and Y1, Y2, Y5 receptors were higher significantly in DIO group than in CF or DIO-R group (p<0.01), while no significant difference was found between DIO-R and CF rats (p>0.05), except that Y2 receptor was lower in DIO-R rats (p<0.01).

CONCLUSIONS

SD rat fed with a HF diet showed different susceptibility to obesity, and up-regulated hypothalamic NPY and Y1, Y2, Y5 receptor gene expressions were closely associated with being predisposed to obesity and overeating of DIO rats.

Left ventricular hypertrophy in patients with renal artery stenosis

Left ventricular hypertrophy (LVH) has been shown to be 3 times more prevalent in patients with renal artery stenosis (RAS) compared to essential hypertension, but factors that predict LVH in this population are not known. We identified 66 patients with unilateral renal artery stenosis and an interpretable electrocardiogram (ECG). LVH by either Cornell voltage-duration product or Sokolow-Lyon voltage criteria was present in 18 of the 66 patients (27%). The mean intra-aortic blood pressure was 100 +/- 14 mm Hg in patients with LVH, and 104 +/- 23 mm Hg in those without LVH (P = 0.37). The average stenosis by quantitative computerized angiography was 68 +/- 17% in patients with LVH, and 64 +/- 13% in those without LVH (P = 0.34). The mean translesional pressure gradient was 11 +/- 15 mm Hg in patients with LVH, and 13 +/- 20 mm Hg in those without LVH (P = 0.60). Using linear regression models, there was no correlation between intra-aortic blood pressure, percentage of stenosis, or translesional pressure gradient and either Cornell voltage-duration product or Sokolow-Lyon voltage criteria. In summary, LVH using ECG criteria was present in 27% of patients with unilateral RAS but was not associated with blood pressure at the time of the procedure or severity of renal artery stenosis.