The effect of anticonvulsant use on bone mineral density in non-ambulatory children with cerebral palsy

INTRODUCTION

Studies showed that use of anticonvulsants (antiepileptic drugs) might be associated with reduced bone mineral density. The primary objective of this study was to evaluate the effect of anticonvulsants on bone mineral density in non-ambulatory children with cerebral palsy. The secondary objective was to identify their risk factors for low bone mineral density.

METHODS

This case series with internal comparisons was conducted in a paediatric residential rehabilitation centre in Hong Kong. Overall, 32 patients were enrolled. The study group comprised 18 patients (6 males, 12 females) aged 5.0 to 19.5 years (mean ± standard deviation, 13.8 ± 4.7 years); all were prescribed anticonvulsant therapy for more than 2 years. The comparison group comprised 14 patients (6 males, 8 females) aged 7.0 to 19.1 years (mean, 16.4 ± 3.0 years) who were concomitant non-ambulatory residents with cerebral palsy and were not prescribed any anticonvulsant therapy prior to study recruitment. Patients underwent a physical examination, blood tests, nutritional assessment, and dual-energy X-ray absorptiometry scan of the total body less head. Z-scores were calculated.

RESULTS

There was no significant difference in Z-scores of total body less head between groups. Among children with low bone mineral density (Z-scores ≤-2.0) and normal bone mineral density, multivariate analysis revealed that higher weight-for-age Z-score (adjusted odds ratio=0.015) and presence of puberty (adjusted odds ratio=0.027) were independent factors for bone mineral density improvement. Hosmer-Lemeshow goodness of fit test (P=0.315) was not significant. Nagelkerke R(2) was 0.677, signifying a relatively well-fitting model.

CONCLUSION

There was no evidence that anticonvulsant therapy has any detrimental effect on bone mineral density in non-ambulatory children with cerebral palsy. A low weight-for-age Z-score was associated with low bone mineral density. Early nutritional intervention to optimise body weight may help to increase bone mineral density.

RFX1-dependent activation of SHP-1 induces autophagy by a novel obatoclax derivative in hepatocellular carcinoma cells

Obatoclax is a small molecule which targets the Bcl-2 family, and is to treat leukemia, lymphoma and lung carcinoma. Previously, an obatoclax analogue, SC-2001, was found to disrupt the protein-protein interactions of the Bcl-2 family and also repress Bcl-XL and Mcl-1 expression via STAT3 inactivation. Here, we report a novel mechanism of autophagy induction by SC-2001 in liver cancer cells. The findings indicate that SC-2001 induced the autophagy marker LC3-II in four hepatocellular carcinoma (HCC) cells. Autophagosomes induced by SC-2001-treated cells were confirmed by electron microscopy. SC-2001 activated SHP-1, dephosphorylated STAT3 and Mcl-1, and subsequently released free beclin 1. Overexpression of STAT3 and Mcl-1 in PLC5 cells attenuated the induction of SC-2001 on autophagy. Abolishment of SHP-1 by a specific inhibitor aboragated the autophagic effects induced by SC-2001. In addition, it was further revealed that RFX-1, a transcription factor of SHP-1, is a critical regulator in SC-2001-mediated autophagy. Downregulation of RFX-1 by si-RNA protected cells from SC-2001-induced autophagy. Importantly, Huh7 tumor-bearing nude mice treated with SC-2001 showed downregulation of Mcl-1 and p-STAT3 protein expression and upregulation of SHP-1, LC3II, and RFX-1 protein expression. In summary, our data suggest that SC-2001 induces autophagic cell death in a RFX1/SHP-1/STAT3/Mcl-1 signaling cascade.

The H3K9 methyltransferase G9a is a marker of aggressive ovarian cancer that promotes peritoneal metastasis

BACKGROUND

Ovarian cancer (OCa) peritoneal metastasis is the leading cause of cancer-related deaths in women with limited therapeutic options available for treating it and poor prognosis, as the underlying mechanism is not fully understood.

METHOD

The clinicopathological correlation of G9a expression was assessed in tumor specimens of ovarian cancer patients. Knockdown or overexpression of G9a in ovarian cancer cell lines was analysed with regard to its effect on adhesion, migration, invasion and anoikis-resistance. In vivo biological functions of G9a were tested by i.p. xenograft ovarian cancer models. Microarray and quantitative RT-PCR were used to analyze G9a-regulated downstream target genes.

RESULTS

We found that the expression of histone methyltransferase G9a was highly correlated with late stage, high grade, and serous-type OCa. Higher G9a expression predicted a shorter survival in ovarian cancer patients. Furthermore, G9a expression was higher in metastatic lesions compared with their corresponding ovarian primary tumors. Knockdown of G9a expression suppressed prometastatic cellular activities including adhesion, migration, invasion and anoikis-resistance of ovarian cancer cell lines, while G9a over-expression promoted these cellular properties. G9a depletion significantly attenuated the development of ascites and tumor nodules in a peritoneal dissemination model. Importantly, microarray and quantitative RT-PCR analysis revealed that G9a regulates a cohort of tumor suppressor genes including CDH1, DUSP5, SPRY4, and PPP1R15A in ovarian cancer. Expression of these genes was also inversely correlated with G9a expression in OCa specimens.

CONCLUSION

We propose that G9a contributes to multiple steps of ovarian cancer metastasis and represents a novel target to combat this deadly disease.

Activation of JNK contributes to evodiamine-induced apoptosis and G2/M arrest in human colorectal carcinoma cells: a structure-activity study of evodiamine

Evodiamine (EVO; 8,13,13b,14-tetrahydro-14-methylindolo[2′3′-3,4]pyrido[2,1-b]quinazolin-5-[7H]-one derived from the traditional herbal medicine Evodia rutaecarpa was reported to possess anticancer activity; however, the anticancer mechanism is still unclear. In this study, we investigated the anticancer effects of EVO on human colon COLO205 and HT-29 cells and their potential mechanisms. MTT and lactate dehydrogenase (LDH) release assays showed that the viability of COLOL205 and HT-29 cells was inhibited by EVO at various concentrations in accordance with increases in the percentage of apoptotic cells and cleavage of caspase-3 and poly(ADP ribose) polymerase (PARP) proteins. Disruption of the mitochondrial membrane potential by EVO was accompanied by increased Bax, caspase-9 protein cleavage, and cytochrome (Cyt) c protein translocation in COLO205 and HT-29 cells. Application of the antioxidant N-acetyl-L-cysteine (NAC) inhibited H₂O₂-induced reactive oxygen species (ROS) production and apoptosis, but did not affect EVO-induced apoptosis of COLO205 or HT-29 cells. Significant increases in the G₂/M ratio and cyclinB1/cdc25c protein expression by EVO were respectively identified in colon carcinoma cells via a flow cytometric analysis and Western blotting. Induction of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) protein phosphorylation was detected in EVO-treated cells, and the JNK inhibitor, SP600125, but not the ERK inhibitor, U0126, inhibited EVO-induced phosphorylated JNK protein expression, apoptosis, and G₂/M arrest of colon carcinoma cells. Data of the structure-activity analysis showed that EVO-related chemicals containing an alkyl group at position 14 were able to induce apoptosis, G₂/M arrest associated with increased DNA ladder formation, cleavage of caspase-3 and PARP, and elevated cycB1 and cdc25c protein expressions in COLO205 and HT-29 cells. Evidence supporting JNK activation leading to EVO-induced apoptosis and G₂/M arrest in colon carcinoma cells is provided, and alkylation at position 14 of EVO is a critical substitution for treatment of colonic cancer.

High-purity separation of cancer cells by optically induced dielectrophoresis

Detecting and concentrating cancer cells in peripheral blood is of great importance for cancer diagnosis and prognosis. Optically induced dielectrophoresis (ODEP) can achieve high resolution and low optical intensities, and the electrode pattern can be dynamically changed by varied light patterns. By changing the projected light pattern, it is demonstrated to separate high-purity gastric cancer cell lines. Traditionally, the purity of cancer cell isolation by negative selection is 0.9% to 10%; by positive selection it is 50% to 62%. An ODEP technology is proposed to enhance the purity of cancer cell isolation to about 77%.

Clitocybe nuda Activates Dendritic Cells and Acts as a DNA Vaccine Adjuvant

This work represents the first evaluation of the effects of water extract of C. nuda (WE-CN), an edible mushroom, on murine bone marrow-derived dendritic cells (BMDCs) and the potential pathway through which the effects are mediated. Our experimental results show that WE-CN could induce phenotypic maturation of DCs, as shown by the increased expression of MHC and costimulatory molecules. In addition, it also induced the proinflammatory cytokines expression on DCs and enhanced both the proliferation and IFN- γ secretion of allogenic T cells. Therefore, since WE-CN did not induce maturation of DCs generated from mice with mutated TLR-4 or TLR-2, suggesting that TLR4 and TLR2 might function as membrane receptors for WE-CN. Moreover, the mechanism of action of WE-CN may be mediated by increased phosphorylation of ERK, p38, and JNK mitogen-activated protein kinase (MAPK) and increased NF- κ B p65 activity, which are important signaling molecules downstream of TLR-4 and TLR-2. Finally, coimmunization of mice with WE-CN and a HER-2/neu DNA vaccine induced a HER-2/neu-specific Th1 response that resulted in significant inhibition of HER-2/neu overexpressing mouse bladder tumor (MBT-2) growth. These data suggest that WE-CN induces DC maturation through TLR-4 and/or TLR-2 and that WE-CN can be used as an adjuvant in cancer vaccine immunotherapy.

Differential proteomic analysis of cancer stem cell properties in hepatocellular carcinomas by isobaric tag labeling and mass spectrometry

Malignant tumors are relatively resistant to treatment due to their heterogeneous nature, drug resistance, and tendency for metastasis. Recent studies suggest that a subpopulation of cancer cells is responsible for the malignant outcomes. These cells are considered as cancer stem cells (CSC). Although a number of molecules have been identified in different cancer cells as markers for cancer stem cells, no promising markers are currently available for hepatocellular carcinoma cells. In this study, two clones of Hep3B cell lines were functionally characterized as control or CSC-like cells, based on properties including spheroid formation, drug resistance, and tumor initiation. Furthermore, their protein expression profiles were investigated by isobaric tags for relative and absolute quantitation (iTRAQ), and a total of 1,127 proteins were identified and quantified from the combined fractions; 50 proteins exhibited at least 2-fold differences between these two clones. These 50 proteins were analyzed by GeneGo and were found to be associated with liver neoplasms, hepatocellular carcinoma (HCC), and liver diseases. They were also components of metabolic pathways, immune responses, and cytoskeleton remodeling. Among these proteins, the expressions of S100P, S100A14, and vimentin were verified in several HCC cell lines, and their expressions were correlated with tumorigenicity in HCC cell lines. The functional significance of vimentin and S100A14 were also investigated and verified.

Selecting tyrosine kinase inhibitors for gastrointestinal stromal tumor with secondary KIT activation-loop domain mutations

Advanced gastrointestinal stromal tumors (GIST), a KIT oncogene-driven tumor, on imatinib mesylate (IM) treatment may develop secondary KIT mutations to confer IM-resistant phenotype. Second-line sunitinib malate (SU) therapy is largely ineffective for IM-resistant GISTs with secondary exon 17 (activation-loop domain) mutations. We established an in vitro cell-based platform consisting of a series of COS-1 cells expressing KIT cDNA constructs encoding common primary±secondary mutations observed in GISTs, to compare the activity of several commercially available tyrosine kinase inhibitors on inhibiting the phosphorylation of mutant KIT proteins at their clinically achievable plasma steady-state concentration (Css). The inhibitory efficacies on KIT exon 11/17 mutants were further validated by growth inhibition assay on GIST48 cells, and underlying molecular-structure mechanisms were investigated by molecular modeling. Our results showed that SU more effectively inhibited mutant KIT with secondary exon 13 or 14 mutations than those with secondary exon 17 mutations, as clinically indicated. On contrary, at individual Css, nilotinib and sorafenib more profoundly inhibited the phosphorylation of KIT with secondary exon 17 mutations and the growth of GIST48 cells than IM, SU, and dasatinib. Molecular modeling analysis showed fragment deletion of exon 11 and point mutation on exon 17 would lead to a shift of KIT conformational equilibrium toward active form, for which nilotinib and sorafenib bound more stably than IM and SU. In current preclinical study, nilotinib and sorafenib are more active in IM-resistant GISTs with secondary exon 17 mutation than SU that deserve further clinical investigation.

The role of COX-2/PGE2 in gossypol-induced apoptosis of colorectal carcinoma cells

Our previous study showed that gossypol (GOS) exhibits potent cytotoxic effects via apoptosis induction against human colorectal carcinoma cells; however, the role of cyclooxygenase (COX)-2/prostaglandin (PG)E(2) on GOS-induced apoptosis is still unknown. In the present study, 12-O-tetradecanoylphorbol-13-acetate (TPA) addition significantly inhibited GOS-induced apoptosis in human colorectal carcinoma HT-29 cells in accordance with inducing COX-2 protein/PGE(2) production. TPA inhibition of GOS-induced apoptosis was blocked by adding protein kinase (PK)C inhibitors including staurosporine (ST), GF109203X (GF), and H7, characterized by the occurrence of cleaved caspase 3 proteins and a decrease in COX-2 protein/PGE(2) production in HT-29 cells. The addition of COX activity inhibitors, including NS398 (NS), aspirin (AS), diclofenac (DI), and indomethacin (IN), suppressed TPA protection of GOS-induced apoptosis with decreased PGE(2) production in HT-29 cells. Application of PGE(2), but not it analogs PGD(2), PGJ(2), or PGF(2α), protected HT-29 cells from GOS-induced DNA ladders, and the E-prostanoid (EP(1)) receptor agonist, 17PT-PGE(2), mimicked the protection induced by PGE(2), whereas the selective EP(2) receptor agonist, butaprostol (BUT), the EP(3) receptor agonist, sulprostol (SUL), and the EP(4) receptor agonist, PGE(1) alcohol (PGE(1)), showed no significant effects on GOS-induced apoptosis in HT-29 cells. PGE(2) 's protection against GOS-induced apoptosis was reversed by adding the selective EP(1) receptor antagonist, SC-19220. Furthermore, GOS had an effective apoptotic effect on COLO205 colorectal carcinoma cells which expressed undetectable level of endogenous COX-2 protein than HT-29 cells, and the decreased COX-2 protein level via COX-2 siRNA or addition of COX-2 activity inhibitor NS significantly elevated GOS-induced cell death in HT-29 cells. COLO205-T cells were established through sustained TPA incubation of COLO205 cells, and COLO205-T cells showed a lower sensitivity to GOS-induced cell death with increased COX-2 (not Bcl-2 and Mcl-1) protein than parental COLO-205 cells. A decrease in COX-2 protein expression in COLO205-T cells by COX-2 siRNA transfection or enhanced GOS-induced cell death according to MTT assay and DNA integrity assay. The notion of COX-2/PGE(2) activation against GOS-induced apoptosis in colon carcinoma cells was demonstrated, and the combination of GOS and COX-2 inhibitors to treat colon carcinoma possesses clinical potential worthy of further investigation.

Abstract B26: Drug-Diagnostic co-development to target FLT3-ITD mutations in chemo-resistant acute myeloid leukemia cells

FMS-like tyrosine kinase-3 (FLT3) overexpression is the common phenomenon in acute myeloid leukemia (AML). There are two major types of FLT3 mutations: internal tandem duplication (ITD) and the activation-loop point mutation at 835th amino residue. Although these FLT3/ITD and the 835th point mutation only account for only 20–25% and 5–10% in AML patients, they have worse prognosis and are often resistant to conventional chemotherapy. Several drugs including CEP-701, MLN-518, and PKC-412 have been developed to target FLT3 tyrosine kinase activity in AML and have been evaluated in clinical trials and showed different efficacy towards these mutations. Therefore, identification of these mutations at the time of diagnosis during drug development, in the case of our drug candidate, BELK01260, will provide a better prognostic prediction, might guide the treatment selection and follow-up strategies. In the study, we developed a sensitive molecular assay with our drug candidate well-suited for this therapeutic need to detect FLT3 mutations and proposed to be used for future clinical application. 100 AML samples with at least 20 samples with known FLT3 mutations are collected and evaluated. The standardize procedure has met the requirement of clinical pathology laboratory with reasonable cost, and both the sensitivity and specificity of this technology achieve 99.9% compared with commonly used methods.

Dovitinib induces apoptosis and overcomes sorafenib resistance in hepatocellular carcinoma through SHP-1-mediated inhibition of STAT3

The multiple kinase inhibitor dovitinib is currently under clinical investigation for hepatocellular carcinoma (HCC). Here, we investigated the mechanistic basis for the effects of dovitinib in HCCs. Dovitinib showed significant antitumor activity in HCC cell lines PLC5, Hep3B, Sk-Hep1, and Huh-7. Dovitinib downregulated phospho-STAT3 (p-STAT3) at tyrosine 705 and subsequently reduced the levels of expression of STAT3-related proteins Mcl-1, survivin, and cyclin D1 in a time-dependent manner. Ectopic expression of STAT3 abolished the apoptotic effect of dovitinib, indicating that STAT3 is indispensable in mediating the effect of dovitinib in HCC. SHP-1 inhibitor reversed downregulation of p-STAT3 and apoptosis induced by dovitinib, and silencing of SHP-1 by RNA interference abolished the effects of dovitinib on p-STAT3, indicating that SHP-1, a protein tyrosine phosphatase, mediates the effects of dovitinib. Notably, dovitinib increased SHP-1 activity in HCC cells. Incubation of dovitinib with pure SHP-1 protein enhanced its phosphatase activity, indicating that dovitinib upregulates the activity of SHP-1 via direct interactions. In addition, dovitinib induced apoptosis in two sorafenib-resistant cell lines through inhibition of STAT3, and sorafenib-resistant cells showed significant activation of STAT3, suggesting that targeting STAT3 may be a useful approach to overcome drug resistance in HCC. Finally, in vivo, dovitinib significantly suppressed growth of both Huh-7 and PLC5 xenograft tumors and downregulated p-STAT3 by increasing SHP-1 activity. In conclusion, dovitinib induces significant apoptosis in HCC cells and sorafenib-resistant cells via SHP-1-mediated inhibition of STAT3.

The association between Internet addiction and psychiatric disorder: a review of the literature

Internet addiction is a newly emergent disorder. It has been found to be associated with a variety of psychiatric disorders. Information about such coexisting psychiatric disorders is essential to understand the mechanism of Internet addiction. In this review, we have recruited articles mentioning coexisting psychiatric disorders of Internet addiction from the PubMed database as at November 3, 2009. We describe the updated results for such disorders of Internet addiction, which include substance use disorder, attention-deficit hyperactivity disorder, depression, hostility, and social anxiety disorder. We also provide discussion for possible mechanisms accounting for the coexistence of psychiatric disorders and Internet addiction. The review might suggest that combined psychiatric disorders mentioned above should be evaluated and treated to prevent their deteriorating effect on the prognosis of Internet addiction. On the other hand, Internet addiction should be paid more attention to when treating people with these coexisting psychiatric disorders of Internet addiction. Additionally, we also suggest future necessary research directions that could provide further important information for the understanding of this issue.

GaN epitaxial layers prepared on nano-patterned Si(001) substrate

We report the growth of GaN epitaxial layer on Si(001) substrate with nano-patterns prepared by dry etching facility used in integrated circuit (IC) industry. It was found that the GaN epitaxial layer prepared on nano-patterned Si(001) substrate exhibits both cubic and hexagonal phases. It was also found that threading dislocation observed from GaN prepared on nano-patterned Si(001) substrate was significantly smaller than that prepared on conventional unpatterned Si(111) substrate. Furthermore, it was found that we can reduce the tensile stress in GaN epitaxial layer by about 78% using the nano-patterned Si(001) substrate.

Reciprocal activation of macrophages and breast carcinoma cells by nitric oxide and colony-stimulating factor-1

Induction of inducible nitric oxide synthase (iNOS) gene expression, nitric oxide (NO) production and migration of RAW264.7 macrophages by coculture with breast cancer MDA-MB-231 cells or the addition of conditioned medium derived from MDA-MB-231 cells (MDA-CM) was identified. Increased iNOS/NO induction and migration of macrophages by MDA-CM were significantly blocked by adding the c-Jun-N-terminal protein kinase (JNK) inhibitor, SP600125, the nuclear factor-kappa B (NF-κB) inhibitor, BAY117082 and pyrrolidine dithiocarbamic acid and a dominant-negative JNK. The addition of an NO donor, Diethylenetriamine-NONOate, significantly activated expressions of MMP-9 and VEGF-A genes in breast carcinoma MDA-MD-231 cells and invasion of MDA-MB-231 cells in coculture with RAW264.7 macrophages as determined using Transwell systems, but that was inhibited by adding SP600125, BAY117082 and the nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester. Induction of heme oxygenase-1 in macrophages reduced MDA-CM-induced iNOS/NO, JNK and NF-κB activations in accordance with inhibiting VEGF-A and MMP-9 gene expressions by MDA-MB-231 cells via Transwell assays. Furthermore, VEGF, sRANKL, TNF-α, IL-1α, TGF-β, CSF-1 and MCP-1 were applied, and CSF-1 showed the most potent stimulation of iNOS/NO production and migration of macrophages. MCF-7 cells with lower CSF-1 expression than MDA-MB-231 cells showed a poor stimulatory effect on iNOS/NO production and migration of macrophages. Neutralization of CSF-1 in MDA-CM using CSF-1 antibody inhibited MDA-CM-induced iNOS protein expression and migration of macrophages, and CSF-1-induced iNOS protein and migration was blocked by adding JNK inhibitor SP and NF-κB inhibitor BAY. The reciprocal activation of breast cancer and macrophages via NO-CSF-1 is first elucidated herein.

Abstract LB-160: ITRI-260, a promising candidate for treatment of acute myeloid leukemia

Acute myeloid leukemia (AML) is a highly malignant hematopoietic tumor characterized by an abnormal proliferation of myeloid progenitor cells, decreased rate of self-destruction and an arrest in cell differentiation. The internal tandem duplication mutations of FMS-like tyrosine kinase-3 (FLT3/ITD mutations) are common in AML and linked to poor prognosis. ITRI-260 generated from designed by computer-assisted rationale drug design and in silico prioritized approaches, was proved to be a potent cell growth inhibitor against FLT3/ITD mutated AML cells through FLT3 and c-Kit inhibition. The in vivo efficacy of ITRI-260 via oral route was demonstrated in MV4-11 xenograft mice model. Besides, two more orthotopic murine models were used to assess the in vivo therapeutic efficacy of ITRI-260. The first one is MV4-11 cell orthotopically engraft into NOD/SCID mice bone marrow and the second one is primary AML cells from AML patient engraft into NOD/SCID mice bone marrow. The results show that ITII-260 can decrease FLT3/ITD mutant leukemia blasts in peripheral blood and bone marrow in both animal models. Finally, ITRI-260 prolongs the survival in both bone marrow engraft mice models. These findings strongly suggest clinical benefits of ITRI-260 in patients with FLT3/ITD AML. Currently we are planning the bridged projects to push ITRI-260 toward IND status.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-160.

Abstract 728: Development of pharmacophore-based RET inhibitors for thyroid cancer therapy

The new therapeutic option is pivotal due to the restricted efficacy of current treatments (surgery, radioactive iodine treatment, and chemotherapy) in progressive thyroid carcinomas. Gain-of-function mutations of the receptor tyrosine kinase RET have been identified as driving oncogenic events in subsets of papillary and medullary thyroid cancers (PTC and MTC), but targeted therapy for RET-driven cancers is currently clinically unavailable. Some mulit-kinase inhibitors, such as sunitinib and vandetanib, which have shown efficacy against other neoplastic diseases, are being evaluated in clinical trials for thyroid cancer therapy. However, the anti-VEGFR activities of these mulit-kinase inhibitors have been considered to lead cardiotoxicity in some patients. Moreover, Ret mutation-associated resistance have been reported by some RET inhibitors in preclinical data. The “in silico model” was applied to design the specific RET target compounds through mapping the pharmacophore of RET ATP-binding pocket. Some novel scaffold compounds which fit the pharmacophore model were selected form ITRI library, and their anti-RET activities were evaluated by kinase assay. The in vitro anti-cell proliferation activities of the compounds to the TT cells (MTC specific cells) were demonstrated by MTT assay. From the screening of ITRI library, ITRI-305 showed the impressive anti-RET (IC50 ∼ 90 nM) and anti-cell proliferation (IC50 at low micro molar) activities and the activities are compatible to those of sunitinib and vandetanib. ITRI-305 also shows good solubility and favorable oral PK profiles. The xenograft study of TT cells with ITRI-305 is proceeding. In conclusion, a novel scaffold RET inhibitor, ITRI-305, with less potent VEGFR activity (anti-VEFGR IC50 ∼ 1 μM) is developed to overcome the cardiotoxicity and resistance problems which is caused by conventional RET inhibitors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 728.

Abstract 3356: A controversial study on well reported liver cancer stem cell marker

Recent studies suggest that the presence of cancer stem cells (CSC) could be linked with patients’ survival. The ability of cancers to grow indefinitely has fueled the idea that cancer and stem cells may have common underlying mechanisms. It has been suggested that tumors are initiated from cancer stem cells (CSCs) with proliferation potential drives the growth of cancer. CSCs are resistant to chemotherapy and radiation. However, the suggested cancer stem cell markers in human hepatocellular carcinoma cells are variable and confused. In this study, we profiled some of the most reported CSC markers, including CD133, epithelial cell adhesion molecule (EpCAM), aldehyde dehydrogenase (ALDH), CD90, CD24, c-kit, global-H and stemness genes in eight human hepatocellular carcinoma cell lines. Through specific marker expressed cell sorting by FACs aria or magnetic beads, the CSC associated drug resistance and tumorigenicity were further evaluated. However, there is no obvious difference among parental group, marker-positive group and marker-negative group in these CSC characteristics evaluated. It seems no good correlation between reported markers in liver cancer stem cells. Therefore, presence of markers alone should be taken with caution as single prognostic parameters. Through harsh culture condition, spheroid cell grew and had been isolated, which perform CSC-like properties. Moreover, forced activation of an ESC-like gene expression program can reprogram HCC cells into CSC-like cells and achieve pathologic self-renewal. The ability to create induced cancer stem cells (iCSC) may provide opportunities to better define the biology of cancer stem cells in order to trace or eliminate them in human patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3356.

Biochemical and molecular characterization of tyrosine hydroxylase deficiency in Hong Kong Chinese

Tyrosine hydroxylase deficiency is a rare neurotransmitter disorder affecting the rate-limiting step in catecholamine biosynthesis. There are about 40 cases reported worldwide. Here, we report the biochemical and molecular findings of eight unrelated Chinese patients with tyrosine hydroxylase deficiency. We have identified eight novel mutations with 5 missense, 2 nonsense and 1 splicing mutations in the TH gene, namely p.R153X, p.R169X, p.G294R, p.G315S, p.A385V, p.I394T, p.G408R, and c.1163+5G>C. The mutations of the TH gene in Chinese are heterogeneous.

Comparison of oesophagogastroduodenoscopy findings and diagnostic value in neurologically impaired children and 'normal' children

OBJECTIVES

To review the oesophagogastroduodenoscopy findings in children with severe neurological impairment and 'normal' children, over a 7-year period from 2000 to 2007.

DESIGN

Retrospective study.

SETTING

Paediatric Unit of Caritas Medical Centre, Hong Kong.

MAIN OUTCOME MEASURES

The frequencies of Helicobacter pylori status, peptic ulceration, and oesophagitis were compared. The diagnostic value of oesophagogastroduodenoscopy in these two groups of children was also examined.

PATIENTS

Patient data were retrieved from the Hospital Authority Clinical Management system, excluding those under surgical care. The children were divided into two groups: 'normal' and neurologically impaired. Their demographic data, indications for oesophagogastroduodenoscopy, endoscopy diagnoses, and Helicobacter pylori status were compared, as was the diagnostic value of oesophagogastroduodenoscopy.

RESULTS

From 2000 to 2007, 223 oesophagogastroduodenoscopies were performed in 176 patients aged 3 to 22 years; 134 were performed in 'normal' children (median age, 14; range, 3-22 years) and 89 in neurologically impaired children (median age, 12; range, 3-20 years). The three most common indications in 'normal' children were: epigastric pain (60%), gastro-intestinal bleeding (13%), and vomiting (7%). In neurologically impaired children, they were gastro-intestinal bleeding (51%), assessment for percutaneous endoscopic gastrostomy (27%), and follow-up for previous lesions (9%). Among 'normal' children, 14 had duodenal ulcers (associated with Helicobacter pylori in 13), but no patients had gastric ulcers or oesophagitis. Among neurologically impaired children, one had a Helicobacter pylori-negative duodenal ulcer, and four had gastric ulcers (three were Helicobacter pylori-positive). Twenty-four neurologically impaired children had oesophagitis. Neurologically impaired children had significantly more oesophagitis and gastric ulcers (P<0.001 and P=0.004, respectively) but less duodenal ulcers (P=0.024). In 111 children who had gastric biopsies, the Helicobacter pylori infection rate was 35% (31% in 'normal' children and 43% in the neurologically impaired). The diagnostic value was 37% in 'normal' children and 81% in the neurologically impaired (P<0.001). The overall diagnostic value of oesophagogastroduodenoscopy was 50%.

CONCLUSION

The clinical presentation and endoscopic findings in 'normal' and neurologically impaired children were discrepant. Oesophagogastroduodenoscopy appeared to confer greater diagnostic value in neurologically impaired than 'normal' children. Diagnostic values in our unit were comparable to reports from western studies.

Gossypol reduction of tumor growth through ROS-dependent mitochondria pathway in human colorectal carcinoma cells

Among 13 different cell lines, gossypol (GOS) showed the most potent cytotoxic effect against human colorectal carcinoma cells including HT29, COLO205, COLO320HSR and COLO320DM cells according to an MTT assay. The cytotoxic effect of GOS was mediated by its induction of apoptosis as characterized by the occurrence of DNA ladders, apoptotic bodies and chromosome condensation in both COLO205 and HT29 cells. Activation of caspase 3, 6, 8 and 9, but not caspase 1, accompanied by the appearance of cleaved fragments of PARP (85 kDa), and caspase 3 (p17/p15), was identified in GOS-treated cells. Decreases in Bcl-xL and phosphorylated Bad proteins were found in GOS-treated cells. GOS induction of ROS production was detected by in vitro plasmid digestion, and an increase in the intracellular peroxide level was observed in GOS-treated COLO205 cells by the DCHF-DA assay. Antioxidants including N-acetyl-L-cysteine (NAC), catalase (CAT), tempol (TEM) and melatonin (MEL), but not allopurinol (ALL), pyrrolidine dithiocarbamate (PDTC) or diphenylene iodonium (DPI), significantly inhibited GOS-induced Reactive oxygen species (ROS) production through blocking the occurrence of apoptosis. GOS induced mitochondrial dysfunction characterized by a loss of the mitochondria membrane potential via DiOC6 staining, and the release of cytochrome c (Cyt c) and apoptosis-inducing factor (AIF) from mitochondria to the cytoplasm was observed. Removing mitochondria by ethidium bromide (EtBr) treatment significantly reduced the apoptotic effect of GOS in COLO205 cells. Furthermore, an intraperitoneal injection of GOS or gossypol acetic acid (GAA) significantly reduced the growth of colorectal carcinoma induced by a subcutaneous injection of COLO205 cells in nude mice. Results of the present study provide the first evidences demonstrating the in vitro and in vivo antitumor effects of GOS via an ROS-dependent mitochondrial apoptosis in colorectal carcinoma.

Risk factors of long bone fracture in non-ambulatory cerebral palsy children

OBJECTIVES

To identify the risk factors for long bone fractures in non-ambulatory cerebral palsy children. DESIGN. Case-control study.

SETTING

A residential rehabilitation centre in Hong Kong.

PATIENTS

The fracture group comprised 19 (13 male, 6 female) cerebral palsy children aged 4 years 5 months to 18 years 11 months (mean, 10 years; standard deviation, 3 years 9 months), who had their first long bone fracture during the period June 1992 to May 2001 inclusive. The control group was composed of 90 (46 male, 44 female) concomitant cerebral palsy residents aged 6 years 1 month to 16 years 11 months (mean, 9 years 11 months; standard deviation, 2 years 4 months) with no history of long bone fracture.

MAIN OUTCOME MEASURES

Presence of features considered relevant to the risk of fracture, namely: anthropometry, feeding practice, orthopaedic surgery and duration of postoperative immobilisation, extremity contracture, anti-epileptic medications, and general health status in the 12 months prior to the fracture.

RESULTS

Of the 19 fracture episodes, 18 occurred in the femur and one in the tibia/fibula. Multivariate analysis revealed that weight for age Z scores (adjusted odds ratio=0.41, 95% confidence interval, 0.19-0.86) and recent postoperative immobilisation (weeks) [adjusted odds ratio=1.35, 95% confidence interval, 0.97-1.89] were independent predictors for fracture occurrence.

CONCLUSION

Early intervention targeting these risk factors may reduce the fracture risk in non-ambulatory cerebral palsy children.

Myricetin inhibits matrix metalloproteinase 2 protein expression and enzyme activity in colorectal carcinoma cells

Colorectal carcinoma is a leading cause of human mortality due to its high metastatic ability. Because the activation of matrix metalloproteinases (MMP) is a key factor in the metastatic process, agents with the ability to inhibit MMP activity have potential in the treatment of colorectal carcinoma. In the present study, among 36 flavonoids examined, myricetin was found to be the most potent inhibitor of MMP-2 enzyme activity in COLO 205 cells (IC50 = 7.82 micromol/L). Myricetin inhibition of MMP-2 enzyme activity was also found in the human colorectal carcinoma cell lines COLO 320HSR, COLO 320DM, HT 29, and COLO 205-X (IC50 = 11.18, 11.56, 13.25, and 23.51 micromol/L, respectively). In contrast, no inhibitory effect of MMP-2 protein expression or enzyme activity was observed in myricitrin (myricetin-3-rhamnoside)-treated cells. In 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated COLO 205 cells, an increase in MMP-2 protein expression and enzyme activity, as well as of protein kinase C (PKC) alpha protein translocation, extracellular signal-regulated kinase (ERK) 1/2 protein phosphorylation, and c-Jun protein expression was observed. ERK inhibitor (PD98059) and PKC inhibitors (GF-109203X and H-7), but not p38 inhibitor (SB203580) or c-jun-NH2-kinase inhibitor (SP600125), significantly inhibited TPA-induced MMP-2 protein expression, with reduced ERK phosphorylation and c-Jun protein expression. Addition of myricetin but not myricitrin suppressed TPA-induced MMP-2 protein expression in COLO 205 cells by blocking the TPA-induced events, including translocation of PKCalpha from cytosol to membrane, phosphorylation of ERK1/2 protein, and induction of c-Jun protein expression. Addition of PD98059 or GF-109203X significantly enhanced the inhibitory effect of myricetin on MMP-2 enzyme activity induced by TPA. Furthermore, myricetin, but not myricitrin, suppressed TPA-induced invasion of COLO 205 cells in an in vitro invasion assay using Engelbreth-Holm-Swarm sarcoma tumor extract Matrigel-coated Transwells. Results of the present study indicate that myricetin significantly blocked both endogenous and TPA-induced MMP-2 enzyme activity by inhibiting its protein expression and enzyme activity. The blockade involved suppression of PKC translocation, ERK phosphorylation, and c-Jun protein expression.

Myricetin inhibits matrix metalloproteinase 2 protein expression and enzyme activity in colorectal carcinoma cells

Colorectal carcinoma is a leading cause of human mortality due to its high metastatic ability. Because the activation of matrix metalloproteinases (MMP) is a key factor in the metastatic process, agents with the ability to inhibit MMP activity have potential in the treatment of colorectal carcinoma. In the present study, among 36 flavonoids examined, myricetin was found to be the most potent inhibitor of MMP-2 enzyme activity in COLO 205 cells (IC50 = 7.82 μmol/L). Myricetin inhibition of MMP-2 enzyme activity was also found in the human colorectal carcinoma cell lines COLO 320HSR, COLO 320DM, HT 29, and COLO 205-X (IC50 = 11.18, 11.56, 13.25, and 23.51 μmol/L, respectively). In contrast, no inhibitory effect of MMP-2 protein expression or enzyme activity was observed in myricitrin (myricetin-3-rhamnoside)-treated cells. In 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated COLO 205 cells, an increase in MMP-2 protein expression and enzyme activity, as well as of protein kinase C (PKC) α protein translocation, extracellular signal-regulated kinase (ERK) 1/2 protein phosphorylation, and c-Jun protein expression was observed. ERK inhibitor (PD98059) and PKC inhibitors (GF-109203X and H-7), but not p38 inhibitor (SB203580) or c-jun-NH2-kinase inhibitor (SP600125), significantly inhibited TPA-induced MMP-2 protein expression, with reduced ERK phosphorylation and c-Jun protein expression. Addition of myricetin but not myricitrin suppressed TPA-induced MMP-2 protein expression in COLO 205 cells by blocking the TPA-induced events, including translocation of PKCα from cytosol to membrane, phosphorylation of ERK1/2 protein, and induction of c-Jun protein expression. Addition of PD98059 or GF-109203X significantly enhanced the inhibitory effect of myricetin on MMP-2 enzyme activity induced by TPA. Furthermore, myricetin, but not myricitrin, suppressed TPA-induced invasion of COLO 205 cells in an in vitro invasion assay using Engelbreth-Holm-Swarm sarcoma tumor extract Matrigel–coated Transwells. Results of the present study indicate that myricetin significantly blocked both endogenous and TPA-induced MMP-2 enzyme activity by inhibiting its protein expression and enzyme activity. The blockade involved suppression of PKC translocation, ERK phosphorylation, and c-Jun protein expression.

Correlation of colposcopic anogenital findings and overall assessment of child sexual abuse: prospective study

OBJECTIVE

To examine the relationship between colposcopic anogenital findings and overall assessment of sexual abuse.

DESIGN

Prospective study.

SETTING

Regional hospital, Hong Kong.

PATIENTS

Seventy-seven children (mean age, 6.5 years; range, 6 months-16 years) referred consecutively for sexual abuse evaluation between July 1999 and June 2002 were included.

MAIN OUTCOME MEASURES

Colposcopic anogenital findings (categorised as normal, non-specific, concerning for abuse, or clearly abnormal) were correlated with the overall assessment of likelihood of abuse (classified as no evidence of abuse, possible abuse, probable abuse, or definite abuse). The sensitivity and specificity of clearly abnormal findings in detecting definite abuse were computed, and the diagnostic impact of colposcopy findings were expressed as likelihood ratios.

RESULTS

Anogenital findings were normal in 45% of patients, non-specific in 29%, concerning for abuse in 13%, and clearly abnormal in 13%. Seven of the 16 confirmed cases of sexual abuse had normal or non-specific findings. Overall assessment showed that 46% of all patients had no evidence of abuse, 20% had cases of possible abuse, 13% had cases of probable abuse, and 21% had cases of definite abuse. The sensitivity and specificity of abnormal anogenital findings in detecting definite abuse were 56.3% and 98.4%, respectively. Colposcopy showed a fair correlation with the overall assessment of abuse (weighted kappa, 0.245). The diagnostic impact of normal, non-specific, concerning, and clearly abnormal findings in terms of likelihood ratios were 0.23, 1.12, 0.00, and 34.30, respectively.

CONCLUSIONS

Anogenital findings are often normal or non-specific in sexual abuse. In general, colposcopy examination findings do not directly reflect the final diagnosis. A category-4 finding on colposcopy is very helpful in confirming definite abuse, whereas other findings do not rule out the diagnosis.

Randomised control trial of tongue acupuncture versus sham acupuncture in improving functional outcome in cerebral palsy

BACKGROUND

Traditional Chinese medicine (TCM) has been used historically in the treatment of cerebral palsy (CP). We investigated the efficacy of acupuncture in improving the motor function of children with CP.

METHODS

A randomised control trial was conducted to assess the effect of tongue acupuncture (TAC) in 33 CP children. The subjects were randomised to treatment (n = 22) with TAC or control (n = 11). Clinical outcome was evaluated using the gross motor function measure (GMFM) and the pediatric evaluation of disability inventory (PEDI).

RESULTS

The increase in mean GMFM score was significantly greater in the treatment than in the control group (p = 0.042).

CONCLUSION

An improvement in motor function of CP subjects is seen following a short course of acupuncture.

Dentatorubral-pallidoluysian atrophy in two Chinese families in Hong Kong

We report on two Hong Kong Chinese families with dentatorubral-pallidoluysian atrophy. Two children in one family presented with progressive myoclonic epilepsy syndrome, and two children in the other family presented with ataxochoreo-athetoid symptoms. Early-onset childhood dentatorubral-pallidoluysian atrophy involved mental retardation, whereas myoclonic epilepsy was the predominant complaint in later-onset childhood version of the disease. Aspiration pneumonia was common in the late stage of disease. Dentatorubral-pallidoluysian atrophy is an autosomal dominant condition attributed to CAG trinucleotide repeats in the dentatorubral-pallidoluysian atrophy gene. The four children in this series had 63 to 79 CAG repeats. The expanded allele was inherited from the father in both families. One father had 54 CAG repeats and was asymptomatic; the other had 66 repeats and had an unsteady gait. Because the radiological, electroencephalographic, and electrophysiological findings were non-specific, we suggest that DRPLA gene testing should be performed in any child presenting with a variable combination of myoclonic epilepsy, mental retardation or developmental regression, and ataxochoreo-athetosis.

3-OH flavone inhibition of epidermal growth factor-induced proliferaton through blocking prostaglandin E2 production

Epidermal growth factor (EGF) has been shown to induce proliferation in cells, however, the role of prostaglandin E(2) (PGE(2)) plays in EGF-induced proliferation in still unclear. EGF and PGE(2) showed proliferation responses in epidermoid carcinoma cell A431 by MTT and [(3)H] thymidine incorporation assay. Activation of the EGF receptor and extracellular signal-regulated protein kinases (ERK1/2), but not p38 and JNK, appeared 10 min after EGF treatment, whereas total amounts of ERK1/2, p38 and JNK remained unchanged in A431 cells, accompanied by induction of COX-2 and PGE(2) production. PD98059, a specific ERK1/2 inhibitor, inhibited EGF-induced proliferation with concomitant decreases in ERK1/2 phosphorylation and COX-2/PGE(2) induction. Non-steroid anti-inflammatory drugs (NSAIDs) such as aspirin and diclofenac, a COX activity inhibitor, inhibited EGF-induced proliferation by blocking PGE(2) production. The addition of PGE(2) reversed the inhibitory effects of PD98059, aspirin, and diclofenac on EGF-induced proliferation. This suggests that COX-2/PGE(2) activation involves in EGF-induced proliferation and locates at the downstream of ERK1/2 activation. Furthermore, the natural product, 3-OH flavone, showed the most-potent inhibitory activity on EGF-induced proliferation among 9 structurally-related compounds, and suppression of EGF receptor phosphorylation, ERK1/2 phosphorylation, and COX-2/PGE(2) production by 3-OH flavone was identified. PGE(2) addition attenuates the inhibitory activity of 3-OH flavone on EGF-induced proliferation by MTT assay and colony formation by soft agar assay. Additionally, 3-OH flavone also showed more-specific inhibition on EGF- than on fetal bovine serum (FBS)-induced proliferation in A431 cells. Results of our present study provide evidence to demonstrate that PGE(2) is an important downstream molecule in EGF-induced proliferation, and 3-OH flavone, which inhibits PGE(2) production by blocking MAPK cascade, might reserve potential for development as an anti-cancer drug.

Nitric oxide and prostaglandin E2 participate in lipopolysaccharide/interferon-gamma-induced heme oxygenase 1 and prevent RAW264.7 macrophages from UV-irradiation-induced cell death

Induction of heme oxygenase (HO)-1 during inflammation has been demonstrated in many cell types, but the contribution of inflammatory molecules nitric oxide (NO) and prostaglandin E(2) (PGE(2)) has remained unresolved. Here we show that NO donors including sodium nitroprusside (SNP) and spermine nonoate (SP-NO), and PGE(2) significantly stimulate HO-1 expression in RAW264.7 macrophages, associated with alternative induction on NO and PGE(2) in medium, respectively. NO donors also show the inductive effect on cyclo-oxygenase 2 protein and PGE(2) production. In the presence of lipopolysaccharide and interferon-gamma (LPS/IFN-gamma), HO-1 protein was induced slightly but significantly, and SNP, SP-NO, and PGE(2) enhanced HO-1 protein induced by LPS/IFN-gamma. L-Arginine analogs N-nitro-L-arginine methyl ester (L-NAME) and N-nitro-L-arginine (NLA) significantly block HO-1 protein induced by LPS/IFN-gamma associated with a decrease in NO (not PGE(2)) production. And, NSAIDs aspirin and diclofenase dose dependently inhibited LPS/IFN-gamma-induced HO-1 protein accompanied by suppression of PGE(2) (not NO) production. PD98059 (a specific inhibitor of MEKK), but not SB203580 (a specific inhibitor of p38 kinase), attenuated PGE(2) (not SP-NO) induced HO-1 protein. Under UVC (100 J/m(2)) and UVB (50 J/m(2)) irradiation, PGE(2) or SP-NO treatment prevents cells from UVC or UVB-induced cell death, and HO-1 inhibitor tin protoporphyrin (SnPP) reverses the preventive effects of PGE(2) and SP-NO. The protective activity induced by PGE(2) on UVC or UVB irradiation-induced cell death was blocked by MAPK inhibitor PD98059 (not SB203580). These results demonstrated that inflammatory molecules NO and PGE(2) were potent inducers of HO-1 gene, and protected cells from UV-irradiation-induced cell death through HO-1 induction.

Emodin induces apoptosis in human promyeloleukemic HL-60 cells accompanied by activation of caspase 3 cascade but independent of reactive oxygen species production

Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is an active constituent of Rheum palmatum, and showed inhibitory activity on lipopolysaccharide-induced NO production in our previous study. However, the apoptosis-inducing activity of emodin has remained undefined. Among three structurally related anthraquinones, including emodin, physcion, and chrysophanol, emodin showed the most potent cytotoxic effects on HL-60 cells, accompanied by the dose- and time-dependent appearance of characteristics of apoptosis including an increase in DNA ladder intensity, morphological changes, appearance of apoptotic bodies, and an increase in hypodiploid cells. Emodin at apoptosis-inducing concentrations causes rapid and transient induction of caspase 3/CPP32 activity, but not caspase 1 activity, according to cleavage of caspase 3 substrates poly(ADP-ribose) polymerase and D4-GDI proteins, the appearance of cleaved caspase 3 fragments being detected in emodin- but not physcion- or chrysophanol-treated HL-60 cells. A decrease in the anti-apoptotic protein, Mcl-1, was detected in emodin-treated HL-60 cells, whereas other Bcl-2 family proteins including Bax, Bcl-2, Bcl-XL, and Bad remained unchanged. The caspase 3 inhibitor, Ac-DEVD-CHO, but not the caspase 1 inhibitor, Ac-YVAD-CHO, attenuated emodin-induced DNA ladders, associated with the blockage of PARP and D4-GDI cleavage. Free radical scavenging agents including NAC, catalase, SOD, ALL, DPI, L-NAME and PDTC showed no preventive effect on emodin-induced apoptotic responses, whereas NAC, CAT and PDTC prevented HL-60 cells from ROS (H(2)O(2))-induced apoptosis through inhibition of caspase 3 cascades. Induction of catalase, but not SOD, activity was detected in emodin-treated HL-60 cells by in gel activity assays, and H(2)O(2)-induced intracellular peroxide level was significantly reduced by prior treatment of emodin in HL-60 cells. Our experiments provide evidence that emodin is an effective apoptosis inducer in HL-60 cells through activation of the caspase 3 cascade, but that it is independent of ROS production.

Flavanones structure-related inhibition on TPA-induced tumor promotion through suppression of extracellular signal-regulated protein kinases: involvement of prostaglandin E2 in anti-promotive process

Biological functions of flavanones have been studied extensively, however, the structure-related activities of flavanones on 12-o-tetradecanoylphorbol 13-acetate (TPA)-induced promotive effects are still unclear. In this study, flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone showed the most significant dose-dependent inhibition on TPA-induced proliferative effects among eight tested flavanones in NIH3T3 cells. TPA-induced mitogen activated protein kinases (MAPK) phosphorylation, ornithine decarboxylase (ODC), c-Jun, and cyclooxygenase 2 (COX-2) protein expressions in a time-dependent manner, and the maximal inductive time point is at 1 h for MAPK phosphorylation and 6 h for others. Flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone showed the dose-dependent inhibition on TPA-stimulated MAPK phosphorylation, COX-2, ODC, c-Jun protein expressions. Induction of, prostaglandin E(2) (PGE(2)) production was detected in TPA-treated NIH3T3 cells, and flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone inhibited significantly PGE(2) production induced by TPA. Addition of PGE(2) reverses the inhibitory activities of flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone on TPA-induced proliferation. And, PD98059, a specific inhibitor of ERKs, inhibited TPA-induced MAPK phosphorylation, accompanied by decreasing COX-2, c-Jun, and ODC protein expression, and showed dose-dependent inhibition on TPA-induced proliferation in cells. These results demonstrated that PGE(2) is an important mediator in TPA-induced proliferation, and MAPK phosphorylation was located at the upstream of COX-2, c-Jun, and ODC gene expressions in TPA-induced responses. Furthermore, flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone (100 microM) suppressed TPA-induced colony formation associated with blocking MAPK phosphorylation, ODC, c-Jun, and COX-2 proteins expression. And, 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay showed that flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone did not perform potent anti-radical activities among these eight tested compounds. In conclusion, this study provided molecular evidences to demonstrate that flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone were potent inhibitors on TPA-induced responses without notable cytotoxicity through suppression of PGE(2) production; and anti-radical activity of flavanones was not correlated with preventing the occurrence of tumor promotion. We proposed that blocking TPA-induced intracellular signaling responses might be involved in the anti-promotive mechanism of flavanones.

In vitro and in vivo inhibitory activities of rutin, wogonin, and quercetin on lipopolysaccharide-induced nitric oxide and prostaglandin E(2) production

Flavonoids are widely distributed in plants, but their biological functions are still unclear. In the present study, in vitro and in vivo experiments were performed to demonstrate the inhibitory activities of rutin, wogonin, and quercetin on lipopolysaccharide-induced nitric oxide (NO) and prostaglandin E(2) production in RAW 264.7 macrophages, primary peritoneal macrophages, and Balb/c mice, respectively. In vitro results showed that wogonin and quercetin dose-dependently suppressed lipopolysaccharide-induced NO production in RAW 264.7 macrophages and primary peritoneal macrophages without a notable cytotoxic effect on either cell types associated with a decrease in inducible nitric oxide synthase (iNOS) protein expression in both cells. Rutin, at 80 microM only, had a slight but obvious inhibitory effect on lipopolysaccharide-induced NO production in primary peritoneal macrophages. Both wogonin and quercetin attenuated lipopolysaccharide-induced prostaglandin E(2) production in vitro. Intravenous injection of lipopolysaccharide (10 mg/kg, i.v.) resulted in a time-dependent induction of NO production in serum, and pretreatment with the L-arginine analog N-nitro-L-arginine methyl ester (L-NAME) blocked this induction. Intravenous pretreatment of Balb/c mice with rutin, wogonin or quercetin for 1 h followed by lipopolysaccharide treatment significantly inhibited lipopolysaccharide-induced NO production, but no inhibition of prostaglandin E(2) production was found. A decrease in iNOS protein, but not cyclooxygenase-2 protein, was detected in liver and lung specimens of lipopolysaccharide-treated Balb/c mice in the presence of rutin, wogonin or quercetin. In conclusion, data obtained both in vitro and in vivo suggest that wogonin and quercetin exert inhibitory activity on lipopolysaccharide-induced NO production through suppression of iNOS expression.

Paediatric stroke: case series

Five cases of paediatric stroke are reported. Two patients presented with idiopathic stroke, another following vertebral artery dissection, one secondary to Moyamoya disease, and one patient with the syndrome of mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes. The presentation, investigation, and management of paediatric stroke are discussed.

Wogonin and fisetin induction of apoptosis through activation of caspase 3 cascade and alternative expression of p21 protein in hepatocellular carcinoma cells SK-HEP-1

Wogonin and fisetin are flavonoids, which are widely distributed in plants. Our recent study demonstrated that, among seven structurally related flavonoids, wogonin and fisetin showed the most potent apoptosis-inducing activities in human promyeloleukemic cells HL-60. In the present investigation, we performed molecular studies to assess the apoptotic effects of wogonin and fisetin on hepatocellular carcinoma cells SK-HEP-1. Both wogonin and fisetin showed dose-dependent cytotoxic effects on SK-HEP-1 cells, accompanied by DNA fragmentation. Microscopic observation under Giemsa staining showed that wogonin and fisetin, at the dose of 80 microM, induced cellular swelling and the appearance of apoptotic bodies, characteristics of apoptosis, in SK-HEP-1 cells. Furthermore, flow cytometry analysis showed an increase of hypodiploid cells in wogonin- and fisetin-treated SK-HEP-1 cells. These data demonstrated that wogonin and fisetin were effective inducers of apoptosis in SK-HEP-1 cells. Treatment with an apoptosis-inducing concentration of wogonin or fisetin caused induction of caspase 3/CPP32 activity, but not of caspase 1 activity. In addition, a caspase 3 inhibitor, Ac-DEVD-CHO, but not the caspase 1 inhibitor Ac-YVAD-CHO, reversed the cytotoxic effects of wogonin and fisetin on SK-HEP-1 cells. Further, cleavage of caspase 3 substrates including poly(ADP-ribose) polymerase (PARP) and D4-GDI protein, and decrease of pro-caspase 3 protein were detected in wogonin- and fisetin-treated SK-HEP-1 cells. Increase of p53 protein was associated with wogonin- and fisetin-induced apoptosis; however, a p53-controlled gene, p21(Waf/Cip-1), was only induced in wogonin- (not fisetin-) treated SK-HEP-1 cells. Serum starvation elevated p21(Waf/Cip-1) protein expression, and enhanced the apoptotic induction activity of wogonin (not fiseitn) in SK-HEP-1 cells. Our study has provided molecular evidence to demonstrate that wogonin and fisetin had effective cytotoxic effects through apoptosis induction in hepatocellular carcinoma cells SK-HEP-1; activation of caspase 3 cascade, induction of p53 protein and alternative expression of p21(Waf/Cip-1) protein were involved.

Clinical efficacy of proton pump inhibitor therapy in neurologically impaired children with gastroesophageal reflux: prospective study

OBJECTIVE

To study the effects of proton pump inhibitors in reducing vomiting, gastrointestinal bleeding, and chest infections in institutionalised neurologically impaired children with gastroesophageal reflux.

DESIGN

Prospective study.

SETTING

A regional hospital, Hong Kong.

PATIENTS

Neurologically impaired children with refractory gastroesophageal reflux.

MAIN OUTCOME MEASURES

Episodes of vomiting, gastrointestinal bleeding, and pneumonia in the baseline and proton pump inhibitor treatment periods.

RESULTS

Nine children received proton pump inhibitor therapy for a median duration of 81 days. Mean reflux index was 9.3% (standard deviation, 5%). Dosage of omeprazole used was 1.0-2.3 mg/kg/d. Vomiting was reduced significantly with proton pump inhibitor treatment (median vomiting index [baseline]=0.4, median vomiting index [proton pump inhibitors]=0.2; P<0.05). No significant decrease in gastrointestinal bleeding or chest infection was observed.

CONCLUSION

Proton pump inhibitors significantly reduced vomiting episodes in neurologically impaired children with gastroesophageal reflux.

Topiramate-induced metabolic acidosis: report of two cases

Two children who presented with symptomatic metabolic acidosis after being put on topiramate (TPM) are reported. The first patient was an 11-year-old male with refractory complex partial epilepsy who was put on TPM for 13 months. He developed hyperventilation 1 week after increasing the dose to 300 mg/day. Arterial blood gas revealed hyperchloraemic metabolic acidosis with partial respiratory compensation: pH 7.36, PCO2 27.2 mmHg, bicarbonate 14.9 mEq/L, base excess -8.9 mmol/L. Hyperventilation and acidosis resolved after administration of sodium bicarbonate and reduction of the dose of TPM. The second patient was a female who developed increasing irritability at age 16 months and 21 months, each time associated with introduction of TPM and resolved promptly upon withdrawal of the drug. Venous blood gas taken during the second episode revealed pH 7.34, PCO2 37.4 mmHg, bicarbonate 20.4 mEq/L, base excess -4.2 mmol/L. The predominant mechanism of TPM-induced hyperventilation involves inhibition of carbonic anhydrase at the proximal renal tubule, resulting in impaired proximal bicarbonate reabsorption. The occurrence of hyperpnoea or mental status change in any patient who is on TPM should prompt an urgent blood gas sampling, with correction of the acid-base disturbances accordingly.

Atypical presentation of dopa-responsive dystonia: generalized hypotonia and proximal weakness

Dopa-responsive dystonia (DRD) is an autosomal dominant disorder typically presenting as dystonia with diurnal variability. Described is an 8-year-old boy who had had waddling gait, generalized hypotonia, and proximal weakness since early childhood. He responded well to low-dose L-dopa. He had a point mutation of the GTP cyclohydrolase I gene. The patient's father and sister had the same mutation but did not have proximal weakness. GTP cyclohydrolase I deficiency can present with hypotonia and weakness.

Ictal 99mTc ECD SPECT in paroxysmal kinesigenic choreoathetosis

Paroxysmal kinesigenic choreoathetosis is a rare neurologic disorder characterized by sudden attacks of brief involuntary dyskinetic movement that are precipitated by voluntary movement. A 14-year-old male who presented with frequent brief attacks of hemidystonia triggered by sudden movement is reported. Investigations, including video electroencephalogram and magnetic resonance imaging of brain, were normal. There was excellent and sustained response to carbamazepine. Ictal single-photon emission computed tomography using ^99mTc ethyl cysteinate dimer revealed increased perfusion of the contralateral basal ganglia, which is associated with onset of choreoathetosis attacks. Our findings provide evidence that hyperactivity of the basal ganglia is associated with the dyskinetic attacks in paroxysmal kinesigenic choreoathetosis.

Valproic acid and thrombocytopenia: cross-sectional study

OBJECTIVE

To investigate the relationship between platelet count and serum valproic acid level, age, duration of valproic acid therapy, and polytherapy, and to determine the clinical significance of thrombocytopenia associated with high-dosage valproic acid therapy.

DESIGN

Cross-sectional study.

SETTING

Residential unit for neurologically impaired children and paediatric out-patient clinic, Hong Kong.

PATIENTS

Ninety-six neurologically impaired children who were treated with valproic acid between 1 July 1991 to 3 June 1999. The comparison group consisted of 48 children receiving antiepileptic drugs other than valproic acid.

INTERVENTION

Low- or high-dosage valproic acid, using the threshold value of 40 mg/kg/d.

MAIN OUTCOME MEASURES

Platelet count and liver function, duration of valproic acid treatment, dosage, and trough serum valproic acid concentration.

RESULTS

Seventeen (17.7%) patients in the treatment group developed thrombocytopenia, compared with two (4.2%) in the comparison group (P<0.05). The platelet count was negatively correlated to serum valproic acid level and age, and positively correlated to polytherapy. The duration of valproic acid treatment was not a confounding factor in the age-related decrease in platelet count. Children with a trough level of >450 micromol/L or a daily dose of >40 mg/kg were more likely to develop thrombocytopenia. Thrombocytopenia was mild in most cases.

CONCLUSIONS

A trough valproic acid level of >450 micromol/L or a daily dose of >40 mg/kg should alert the clinician to the risk of developing thrombocytopenia. The risk is further increased for older children. The platelet count should be monitored for patients receiving a high concentration of valproic acid who are also receiving drugs that would affect homeostasis, or who are undergoing surgical procedures.

Classic late infantile neuronal ceroid lipofuscinosis in a Chinese patient

Neuronal ceroid lipofuscinoses are a group of rare neurodegenerative disorders that are characterised by an accumulation of autofluorescent lipopigments in neurons and extraneuronal tissues. We report on a 4-year-old boy who presented with an acute onset of seizures followed by rapid psychomotor deterioration, ataxia, and visual failure. Photic stimulation at 1 to 3 Hz elicited discrete spike and wave discharges in the electroencephalogram, which were diminished at a higher frequency of stimulation. The electroretinogram was extinct. Magnetic resonance imaging of the brain showed generalised cerebral and cerebellar atrophy. Electron microscopic examination of lymphocytes and samples of muscle and skin revealed characteristic curvilinear inclusion bodies. To our knowledge, this is the first case of late infantile neuronal ceroid lipofuscinosis to be reported in a Hong Kong Chinese patient.

De novo mutation in the mitochondrial tRNALeu(UUR) gene (A3243G) with rapid segregation resulting in MELAS in the offspring

A 14-year-old Chinese boy with a normal perinatal and early developmental history presented at 5 years of age with migraine, intractable epilepsy, ataxia, supraventricular tachycardia, paralytic ileus and progressive mental deterioration. Computerized tomography revealed multiple cerebral infarcts in the parieto-occipital region without basal ganglial calcification. Magnetic resonance imaging showed increased signal intensity in T2 weighted images in the same regions. A cerebral digital subtraction angiogram was normal. Venous lactate, pyruvate, lactate to pyruvate ratio and cerebrospinal fluid lactate were elevated. Muscle biopsy did not reveal any ragged red fibres; dinucleotide-tetrazolium reductase activity was normal. Mitochondrial DNA analysis detected an adenine to guanine mutation at nucleotide position 3243 of tRNALeu(UUR). All four tissues analysed demonstrated heteroplasmy: leucocyte 56%, hair follicle 70%; buccal cell 64%; muscle 54%. The mother and brother of the proband, both asymptomatic, were also found to have a heteroplasmic A3243G mutation in the leucocytes, hair follicle and buccal cells. Other members of the maternal lineage, including the maternal grandmother, did not have the mutation. This report describes a patient with mitochondrial encephalopathy, lactic acidosis, stroke-like episodes, who presented with multisystem involvement. The absence of ragged red fibres in muscle biopsy did not preclude the diagnosis. Mutational analysis of mitochondrial DNA conveniently confirmed the diagnosis of the disorder. A de novo mutation is demonstrated in this family.

Circadian phase-shifted rats show normal acquisition but impaired long-term retention of place information in the water task

It is thought that circadian rhythms may influence learning and memory processes. However, research supporting this view does not dissociate a mnemonic impairment from other performance deficits. Furthermore, published reports do not specify the type of memory system influenced by the circadian system. The present study assessed the effects of phase shifting on acquisition and expression of place navigation in the water maze, a task sensitive to hippocampal dysfunction. The results showed that phase-shifting circadian rhythms in rats impaired the expression of place information on a retention test but not initial acquisition or encoding of place information. These results suggest that disruption of circadian rhythms may impair consolidation of previously encoded hippocampal place information.

Baseline metal concentration in the Asian periwinkle Littorina brevicula employed as a biomonitor to assess metal pollution in Korean coastal water

Concentrations of Al, Fe, Mn, Cu, Zn, V, Ni, Co, Cr, Cd and Pb in the Asian periwinkle Littorina brevicula were determined from 39 sampling locations along the whole Korean coast. Metal concentrations in the periwinkle varied highly with sampling stations, but the variations could be well explained by the body size after eliminating the data exceeding the 'High' criteria. Among the stations exceeding the 'High' criteria corresponding to mean plus one standard deviation of the logarithms of the individual site mean, some stations exhibited values higher than expected from the relationship between metal body burden and body size, indicating that these locations were polluted with metals. However, several 'High' stations followed the trends of the curve, suggesting that they resulted from the effect of their small body size, not from environmental contamination. Periwinkles of similar body sizes exhibited same range of metal concentrations in their body, independent of geographical position.

Coupled Influence of Colloidal and Hydrodynamic Interactions on the RSA Dynamic Blocking Function for Particle Deposition onto Packed Spherical Collectors

The influence of electrostatic double-layer and hydrodynamic interactions on random sequential adsorption (RSA) of colloidal particles onto packed spherical collectors was investigated using inverse analysis of colloid breakthrough data obtained from well-controlled particle deposition experiments. Deposition experiments were carried out using monodisperse aqueous suspensions of positively charged latex colloids and packed columns of negatively charged uniform glass beads for different combinations of ionic strength, particle size, and approach velocity. From the experimental particle breakthrough data, the initial particle deposition rates and the virial coefficients of the dynamic blocking function based on RSA mechanics were determined. The magnitudes of the virial coefficients were observed to increase from the hard sphere values with increasing flow rates and decreasing ionic strengths of the background electrolyte. Particle size also plays a significant role in governing the deposition dynamics. The deviation from the hard sphere RSA behavior becomes more prominent for larger particles. Copyright 2000 Academic Press.