Socioeconomic status and children with intellectual disability in China

BACKGROUND

Intellectual disability (ID) accounts for 70% of all disabilities among children in China's Second National Sampling Survey on Disability. Although studies have shown a relationship between social class and ID in children, none have investigated the association of socioeconomic variables in Chinese children with mild or severe ID.

METHODS

Data for children aged 0-6 years with and without ID were abstracted from the Second National Sampling Survey on Disability in China, conducted in 2006. Crude odds ratios showed the effect of sociodemographic factors on mild and severe ID. Adjusted odds ratios (OR(a) ) (95% confidence intervals) estimated the independent effects of these factors.

RESULTS

For both mild and severe ID, risk of having ID increased with male sex, birth to a woman aged 35 years and older, lower maternal education, mother's older age at delivery, lower income and rural residence. After age, gender and parent disability were controlled, mothers aged 35 years and older were more likely to have a child with ID: mild ID, OR(a) 1.47 (1.15-1.88); severe ID, OR(a) 1.32 (1.00-1.73). There was an approximate increasing monotonic risk of severe ID with increasing socioeconomic disadvantage: lowest income, OR(a) 3.00 (2.19-4.12); low income, OR(a) 2.28 (1.63-3.19); lower middle income, OR(a) 1.72 (1.27-2.33); middle income, OR(a) 1.73 (1.28-2.36).

CONCLUSIONS

There is a significant relationship between sociodemographic factors and ID. Similar patterns were found for both mild and severe ID. Recommendations are given for preventing ID in Chinese children.

GABAergic excitotoxicity injury of the immature hippocampal pyramidal neurons' exposure to isoflurane

BACKGROUND

Certain anesthetics exhibit neurotoxicity in the brains of immature but not mature animals. γ-Aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the adult brain, is excitatory on immature neurons via its action at the GABAA receptor, depolarizing the membrane potential and inducing a cytosolic Ca2+ increase ([Ca2+]i), because of a reversed transmembrane chloride gradient. Recent experimental data from several rodent studies have demonstrated that exposure to isoflurane during an initial phase causes neuronal excitotoxicity and apoptosis. GABAA receptor-mediated synaptic voltage-dependent calcium channels' (VDCCs) overactivation and Ca2+ influx are involved in these neural changes.

METHODS

We monitored [Ca2+]i using Fluo-4 AM fluorescence imaging. Using whole-cell patch clamp techniques, IVDCC (voltage-dependent calcium channel currents) were recorded from primary cultures of rat hippocampal neurons (5-day culture) exposed to isoflurane. To further investigate the neurotoxicity of high cytosolic-free calcium after isoflurane in a dose- and time-dependent manner, the possibility of increased caspase-3 levels was evaluated by Western blot and quantitative real-time polymerase chain reaction. Statistical significance was assessed using the Student t test or 1-way analysis of variance followed by the Tukey post hoc test.

RESULTS

Under control conditions, isoflurane enhanced the GABA-induced [Ca2+]i increase in a dose-dependent manner. Dantrolene and nicardipine markedly inhibited this enhancement mediated by isoflurane. Moreover, in Ca2+-free media, pretreatment with isoflurane did not show any influence on the caffeine-induced increase of [Ca2+]i. Similarly, using whole-cell recording, isoflurane increased the peak amplitude of IVDCC in the cultured neurons from rat hippocampus by depolarization pulses. Isoflurane (0.25, 0.5, 0.75, and 1 minimum alveolar concentration [MAC]) potentiated IVDCC peak current amplitude by 109.11%±9.03%, 120.56%±11.46%, 141.33%±13.87%, and 146.78%±15.87%, respectively. To analyze variation in protein levels, the effect of treatments with isoflurane on caspase-3 activity was dose- and time-dependent, reaching a maximal caspase-3 activity after exposure to 1 MAC for 6 hours (P<0.001). However, in the mRNA levels, hippocampal caspase-3 mRNA levels began to be significantly increased in isoflurane-treated developing rat hippocampal neurons after 6 hours of exposure to 0.25 MAC isoflurane (P<0.001).

CONCLUSIONS

Isoflurane-mediated enhancement of GABA-triggered [Ca2+]i release results from membrane depolarization with subsequent activation of VDCCs and further Ca2+-induced Ca2+ release from the ryanodine-sensitizing Ca2+ store. An increase in [Ca2+]i, caused by activation of the GABAA receptor and opening of VDCCs, is necessary for isoflurane-induced calcium overload of immature rat hippocampal neurons, which may be involved in the mechanism of an isoflurane-induced neurotoxic effect in the developing rodent brain.

Diazoxide decreases ischemia-reperfusion injury in a rat model of lung transplantation

BACKGROUND

Ischemia-reperfusion injury (IRI) is a significant factor contributing to primary graft failure in lung transplantation. Given a pivotal role of mitochondria in IRI-related molecular events, the effects of diazoxide, a selective opener of mitochondrial adenosine-5'-triphosphate (ATP)-sensitive potassium channels (mitoK(ATP)), on IRI were investigated in a rat model of lung transplantation.

METHODS

The 108 rats were randomly assigned to 5 groups; a sham-operated, 2 control, and 2 experimental groups that received either diazoxide alone or a combination of diazoxide with 5-hydroxydecanoate sodium salt. Lung injuries were assessed by multiple parameters at 2 hours or 24 hours after reperfusion, including oxygenation index, wet/dry weight ratio of transplanted lungs, lung morphology, as well as measurements of myeloperoxidase, malondialdehyde, total antioxidant capacity, tumor necrosis factor-α, and interleukin-6.

RESULTS

Compared with the sham group, the 2 control groups revealed significant changes among most parameters of lung injury measured at either 2 hours or 24 hours after reperfusion. The extent of the changes was dramatically reduced by the administration of diazoxide. Importantly, the protective effect of diazoxide was almost completely reversed by co-administration of 5-hydroxydecanoate sodium salt, a selective blocker of mitoK(ATP).

CONCLUSIONS

These data provide evidence for substantial protective effects of diazoxide in an in vivo rat lung IRI model. Pharmacological modulation of mitoK(ATP) may be a potential strategy to reduce IRI-induced primary graft failure in lung transplantation.

ZD6474, a small molecule tyrosine kinase inhibitor, potentiates the anti-tumor and anti-metastasis effects of radiation for human nasopharyngeal carcinoma

PURPOSE

To investigate the capacity for ZD6474, a small molecule tyrosine kinase inhibitor, to enhance anti-tumor and anti-metastasis effects of radiation on human nasopharyngeal carcinoma (NPC).

EXPERIMENTAL DESIGN

NPC cell lines and xenograft models were evaluated following treatment with ZD6474 and radiation alone and in combination compared with untreated control mice.

RESULTS

Treatment with ZD6474 enhanced the anti-proliferative effect of radiation on NPC cell lines as detected by cell proliferation and apoptosis assays. ZD6474 also induced a significant increase in the radiosensitivity of NPC cells, with radiation enhancement ratios (RERs) ranging from 1.2 to 1.6. Despite the cytotoxicity exhibited by NPC cells following radiotherapy, the invasion and migration of NPC cells was found to be unaffected. In contrast, treatment with ZD6474 strongly inhibited the invasion and migration of NPC cells. When the administration of radiation and ZD6474 was investigated in vitro, the ability of ZD6474 to inhibit activation of the pro-survival signaling pathways induced by radiation was demonstrated. In vivo, ZD6474 significantly enhanced the anti-metastasis effects of radiation, while treatment with radiation and ZD6474 was found to be well tolerated and resulted in a strong inhibition of tumor growth.

CONCLUSIONS

Our results suggest the combination of radiation and ZD6474 represents a promising strategy for the treatment of human NPC.

Peripheral T-cell lymphoma: review and updates of current management strategies

The classification of T-cell and natural-killer- (NK-) cell lymphomas has been updated in the 4th edition of the World Health Organization (WHO) classification of tumors of the haematopoietic and lymphoid tissue published in 2008. Based on recent epidemiological studies, NK-cell lymphomas occur almost exclusively in Asia and South America, although T-cell lymphomas appear to occur in the East as commonly as in the West. Due to the low prevalence of this disease, diagnosis and optimal treatment of patients have not been studied prospectively in large randomized trials. Nevertheless, there has been development in the understanding of T-cell lymphomas and how they should be managed; FDG-PET emerges as an increasingly important tool in diagnosis, gene-expression signatures may aid with prognostication in the future, and novel therapies are currently being studied to improve outcomes in T-cell lymphomas. More work, however, needs to be done, and international collaboration will be pertinent to deriving meaningful results from future clinical studies.

Abstract 1824: Sun exposure and the risk of malignant lymphoma in an Asian population: The Singapore Lymphoma Study

INTRODUCTION

Recent epidemiological studies have reported an inverse association between sun exposure and Non-Hodgkin lymphoma (NHL) which may be related to vitamin D or other factors, but these studies have been conducted almost exclusively in the Western countries, and in temperate locations.

METHODS

The Singapore Lymphoma Study is a hospital-based, case-control study conducted in Singapore between Feb 2005 and Dec 2008. Singapore residents (men and women, ethnic Chinese/Malays/Indians) aged 18 to 90 formed the study population. Detailed information on outdoor activities under sun (for recreational or occupational purposes) during childhood and in adulthood, skin colour and sun sensitivity, and other information on other possible risk factors were collected in personal interviews.

A total of 543 incident malignant lymphomas including 74 Hodgkin's lymphoma (HL), 403 B-cell and 61 T and NK-cell NHL and 5 others, and 830 controls were recruited. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis, adjusted for age, gender, ethnicity, and housing types as surrogate for social economic status.

RESULTS

Skin colour and sun sensitivity did not show any association with risk of malignant lymphoma, after adjusting for ethnicity. We observed a reduced overall risk of NHL (but not HL) among subjects who reported spending time outdoors regularly, especially on weekends/rest days.

A lower risk of NHL was associated with recreational sun exposure in childhood non-school days (OR 0.7, 95% CI 0.5-0.9) and in adulthood weekends/rest days (OR 0.8, 95%CI 0.6-1.0), and the observed association was significant in females when stratified by gender. In addition, occupational sun exposure in males was inversely associated with the risk of NHL (OR 0.7, 95%CI 0.5-1.0). Cumulative working time outside under sun appeared unrelated to NHL overall. The associations were more consistently observed in B-cell NHL subtypes (OR 0.6, 95%CI 0.5-0.8), in diffuse large B-cell lymphoma (OR 0.6, 95%CI 0.5-0.9) and mucosal-associated lymphoid tissue lymphoma (OR 0.5, 95%CI 0.2-1.0), than in T-cell NHL.

CONCLUSION As the first case-control lymphoma study in Asia, our data are consistent with an inverse association between intermittent sun exposure and NHL in this study population.

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 1824.

Rapid vinculin exchange dynamics at focal adhesions in primary osteoblasts following shear flow stimulation

The adaptor protein vinculin plays a key position in the formation of focal adhesions and regulates cell attachment. To study the turnover of vinculin in bone-derived cells, we expressed green fluorescent protein-tagged vinculin in primary bovine osteoblasts and examined the appearance of focal adhesions in cells exposed to laminar shear flow. Already 20 sec after application of shear stress fluorescently labelled focal adhesions became visible as small flashing dots at the periphery of cells. The number of newly formed focal adhesions per individual cell increased continuously over approximately 300 sec and then remained relatively stable. The assembly of focal adhesions in shear stress-stimulated osteoblasts was accompanied by a transient rise in intracellular calcium levels. The mean assembly time of an individual focal adhesion plaque was 32.2+/-2.2 sec and the mean disassembly time was 60.5+/-6.0 sec. The recruitment of vinculin to nascent focal adhesions was in the same range as the recovery half-life of GFP-vinculin at stable focal adhesions (13.0+/-2.0 sec). These data show that accumulation of GFP-vinculin in newly formed focal adhesions and its exchange from pre-existing, mature plaques are both rapid processes that occur in mechanically stimulated osteoblasts within less than one minute.