Analysis of brain structural covariance network in Cushing disease

Background

Cushing disease (CD) is a rare clinical neuroendocrine disease. CD is characterized by abnormal hypercortisolism induced by a pituitary adenoma with the secretion of adrenocorticotropic hormone. Individuals with CD usually exhibit atrophy of gray matter volume. However, little is known about the alterations in topographical organization of individuals with CD. This study aimed to investigate the structural covariance networks of individuals with CD based on the gray matter volume using graph theory analysis.

Methods

High-resolution T1-weighted images of 61 individuals with CD and 53 healthy controls were obtained. Gray matter volume was estimated and the structural covariance network was analyzed using graph theory. Network properties such as hubs of all participants were calculated based on degree centrality.

Results

No significant differences were observed between individuals with CD and healthy controls in terms of age, gender, and education level. The small-world features were conserved in individuals with CD but were higher than those in healthy controls. The individuals with CD showed higher global efficiency and modularity, suggesting higher integration and segregation as compared to healthy controls. The hub nodes of the individuals with CD were Short insular gyri (G_insular_short_L), Anterior part of the cingulate gyrus and sulcus (G_and_S_cingul-Ant_R), and Superior frontal gyrus (G_front_sup_R).

Conclusions

Significant differences in the structural covariance network of patients with CD were found based on graph theory. These findings might help understanding the pathogenesis of individuals with CD and provide insight into the pathogenesis of this CD.

[Spatial autocorrelation and related factors of stroke mortality in Zhejiang Province based on spatial panel model in 2015-2020]

Objective: To explore the spatial autocorrelation and macro influencing factors of stroke mortality in Zhejiang Province in 2015-2020 and provide a scientific basis for stroke prevention and control strategy. Methods: The data on stroke death were obtained from Zhejiang Chronic Disease Surveillance System. The spatial distribution of stroke mortality was explored by mapping and spatial autocorrelation analysis. The spatial panel model analyzed the correlation between stroke mortality and socioeconomic and healthcare factors. Results: From 2015 to 2020, the average stroke mortality was 68.38/100 thousand. The standard mortality of stroke was high in the areas of east and low in the west, high in the south and low in the north. Moreover, positive spatial autocorrelation was observed (Moran's I=0.274-0.390, P<0.001). Standard mortality of stroke was negatively associated with per capita gross domestic product (GDP) (β=-0.370, P<0.001), per capita health expenditure (β=-0.116, P=0.021), number of beds per thousand population (β=-0.161, P=0.030). Standard mortality of ischemic stroke was negatively associated with per capita GDP (β=-0.310, P=0.002) and standard management rate of hypertension (β=-0.462, P=0.011). Standard mortality of hemorrhagic stroke was negatively associated with per capita GDP (β=-0.481, P<0.001), per capita health expenditure (β=-0.184, P=0.001), number of beds per thousand population (β=-0.288, P=0.001) and standard management rate of hypertension (β=-0.336, P=0.029). Conclusions: A positive spatial correlation existed between stroke mortality in Zhejiang Province in 2015-2020. We must focus more on preventing and controlling strokes in relatively backward economic areas. Moreover, to reduce the mortality of stroke, increasing the investment of government medical and health funds, optimizing the allocation of medical resources, and improving the standard management rate of hypertension are important measures.

Default mode network overshadow executive control network in coma emergence and awakening prediction of patients with sTBI

OBJECTIVE

We aimed to explore the pathogenesis of traumatic coma related to functional connectivity (FC) within the default mode network (DMN), within the executive control network (ECN) and between the DMN and ECN and to investigate its capacity for predicting awakening.

METHODS

We carried out resting-state functional magnetic resonance imaging (fMRI) examinations on 28 traumatic coma patients and 28 age-matched healthy controls. DMN and ECN nodes were split into regions of interest (ROIs), and node-to-node FC analysis was conducted on individual participants. To identify coma pathogenesis, we compared the pairwise FC differences between coma patients and healthy controls. Meanwhile, we divided the traumatic coma patients into different subgroups based on their clinical outcome scores at 6 months postinjury. Considering the awakening prediction, we calculated the area under the curve (AUC) to evaluate the predictive ability of changed FC pairs.

RESULTS

We found a massive pairwise FC alteration in the patients with traumatic coma compared to the healthy controls [45% (33/74) pairwise FC located in the DMN, 27% (20/74) pairwise FC located in the ECN, and 28% (21/74) pairwise FC located between the DMN and ECN]. Moreover, in the awake and coma groups, there were 67% (12/18) pairwise FC alterations located in the DMN and 33% (6/18) pairwise FC alterations located between the DMN and ECN. We also indicated that pairwise FC that showed a predictive value of 6-month awakening was mainly located in the DMN rather than in the ECN. Specifically, decreased FC between the right superior frontal gyrus and right parahippocampal gyrus (in the DMN) showed the highest predictive ability (AUC = 0.827).

CONCLUSION

In the acute phase of severe traumatic brain injury (sTBI), the DMN plays a more prominent role than the ECN and the DMN-ECN interaction in the emergence of traumatic coma and the prediction of 6-month awakening.

Disruption of Rich-Club Connectivity in Cushing Disease

OBJECTIVE

Cushing disease (CD) is a rare clinical disease in which brain structural and function are impaired as the result of excessive cortisol. However, little is known whether rich-club organization changes in patients with CD, as visualized on resting-state magnetic resonance imaging (fMRI), can reverse to normal conditions after transsphenoidal surgery (TSS). In this study, we aimed to investigate whether the functional connectivity of rich-club organization is affected and whether any abnormal changes may reverse after TSS.

METHODS

In this study, 38 patients with active CD, 33 with patients with CD in remission, and 41 age-, sex-, and education-matched healthy control participants underwent resting-state fMRI. Brain functional connectivity was constructed based on fMRI and rich club was calculated with graph theory approach. We constructed the functional brain networks for all participants and calculated rich-club connectivity based on fMRI.

RESULTS

We identified left precuneus, right precuneus, left middle cingulum, right middle cingulum, right inferior temporal, right middle temporal, right lingual, right postcentral, right middle occipital, and right precentral regions as rich club nodes. Compared with healthy control participants, rich-club connectivity was significantly lower in patients with active CD (P < 0.001). Moreover, abnormal rich-club connectivity improved to normal after TSS.

CONCLUSIONS

Our results show rich-club organization was disrupted in patients with active CD with excessive cortisol production. TSS can reverse abnormal rich-club connectivity. Rich club may be a new indicator to investigate the outcomes of TSS and to increase our understanding of the effect of excessive cortisol on brain functional connectivity in patients with CD.

Bone marrow mesenchymal stem cells transplantation alleviates brain injury after intracerebral hemorrhage in mice through the Hippo signaling pathway

Intracerebral hemorrhage (ICH) is a common acute nervous system disease with high mortality and severe disability. Mesenchymal stem cells (MSCs) have been reported to promote neurogenesis and to alleviate side effects in areas of brain injury areas. The Hippo pathway regulates diverse cellular processes, including cell survival, proliferation, differentiation, and organ size. Here, we found that transplantation of bone marrow MSCs (BM-MSCs) into the brains of mice could alleviate ICH-mediated injury and protect astrocytes from apoptosis by regulating mammalian sterile 20-like kinase (MST)1 and Yes-associated protein (YAP). Knocking down of MST1 by si-RNA triggered YAP nuclear translocation. We further demonstrated that astrocytes undergo astroglial-mesenchymal phenotype switching and become capable of proliferating after BM-MSC transplantation via the Hippo signaling pathway. Together, our identification of the Hippo pathway in mediating the beneficial effects of BM-MSCs may provide a novel therapeutic target in the treatment and management of ICH.

[Management of Fournier gangrene in perineal region by negative-pressure wound therapy combined with delayed repair]

Objective: To explore the effects of negative pressure wound therapy (NPWT) combined with delayed repair on Fournier gangrene in perineal region. Methods: During July 2010 to September 2018, 16 patients with Fournier gangrene in perineal region were admitted to our center, with 13 males and 3 females, aged 30 to 76 years. In the first stage, the necrotic tissue of the wound was completely removed according to the scope of the lesion, and NPWT was applied. After the operation, general anti-infection and nutritional support were performed. In the second stage, the local flaps, free flaps, or skin grafts were chosen to repair the wounds according to the specific condition of wounds. The average length of stay and pathological diagnosis were recorded, and the survival and follow-up of skin grafts and flaps were recorded. Results: All the 16 patients were cured and discharged, with an average of 29.6 days in hospital. The pathological diagnosis of biopsies were necrotizing inflammation. The wound of 1 patient was healed directly after only NPWT, the skin grafts of 5 patients, local flaps of 9 patients, and anterolateral thigh island flap of 1 patient who had NPWT combined with delayed repair survived well. Sixteen patients were followed up for 1 to 2 years after discharge, and no recurrence of Fournier gangrene was found. Among them, 5 patients with wounds involved perineum and scrotum had good appearance and function of scrotum and mons pubis. Conclusions: NPWT combined with delayed plastic repair have great effects on Fournier gangrene.

[Investigation of epidemic status of clonorchiasis sinensis in western regions of Jilin Province]

OBJECTIVE

To understand the epidemic status of clonorchiasis sinensis in western region of Jilin Province, so as to provide the evidence for formulating the planning and strategy of prevention and control of the disease.

METHODS

In 2017, the areas where the residents had the customs of eating Sashimi were selected as the research areas in the western region of Jilin Province, and according to the cluster sampling, 25 villages in 25 towns (each village per town) of 5 counties in the region were selected as the investigation points. The basic information of crowd was collected by a questionnaire investigation. The Kato-Katz method was used for etiological examinations. The results were analyzed statistically.

RESULTS

A total of 4 980 people in the 25 villages were investigated, and 1 220 people were infected with Clonorchis sinensis. The average infection rate was 24.50%. There was a significant difference among different counties (cities, districts) in the infection rate of C. sinensis (P < 0.01), and the infection rate in Daan City was the highest (53.82%). In addition, there were significant differences between/among the gender, nation, age, educational level, and occupation in the infection rate (all P values < 0.01). The infection rate of the male was higher than that of the female, the rate of Han was higher than that of other ethnic groups, the rate of the high age group was higher than that of the low age group, the rate of the college degree group was higher than that of the other educational level groups, the rate of the cadre was higher than that of the other occupation groups, and the rate of the group who had vermifuge before the investigation was lower than that of the group who did not have vermifuge.

CONCLUSIONS

The western region of Jilin Province is still the highincidence area of clonorchiasis sinensis. Therefore, the comprehensive control and prevention measures, such as giving vermifuge and health education, should be strengthened in key population and areas in the future.

[Evaluation on the effect of salt reduction intervention among fourth-grade primary school students and their parents in Shandong Province]

In order to evaluate the intervention effect of the school-based salt reduction model, 28 primary schools were selected in Shandong Province in September 2014 and randomly divided into intervention group (1 361 students, 1 306 parents) and control group (1 364 students,1 340 parents). A series of "small hands and big hands" salt reduction intervention activities were conducted in intervention group for 8 months. After the intervention, the total awareness rate of salt reduction knowledge, the total holding rate of related beliefs and the total reporting rate of related behaviors were 70.65%, 80.30% and 67.03% among students, and 85.66%, 93.77% and 87.93% among parents, in the intervention group, which were higher than those in the control group (37.12%, 66.52% and 50.07% among students; 55.11%, 87.52% and 57.96% among parents) (all P values <0.05). The school-based salt reduction model is effective and feasible.

The stability of Cu clusters and their adsorption for CH4 and CH3 by first principle calculations

Two-dimensional (2D) and three-dimensional (3D) Cu _n clusters (n indicates the atom number) and their adsorption behaviors for both methane (CH₄) and methyl (CH₃) are studied in this work using the density functional theory method, where n ranges from 6 to 20. In these small clusters, it is found that the CH₄ molecule is always adsorbed on the top site with the adsorption energy between -0.05 eV and -0.21 eV. Considering methane dehydrogenation, stronger adsorption for CH₄ is required, so 2D clusters with n = 7, 14, 15, and 16 and 3D clusters with n = 6, 10, 12, and 17 are found to have relatively stronger adsorption. However, for the adsorption of CH₃, there is an obvious even-odd oscillation change in the size of 3D clusters, while it is not clear in 2D clusters since one cannot find an even-odd change as n > 14. The weaker adsorption for CH₃ occurs on 3D clusters when n is even except 6 and also on 2D clusters when n = 6, 7, 10, and 12 with higher carbon poisoning resistance. Based on these calculated results, some Cu clusters which show good potential ability for methane dehydrogenation are provided, especially when n = 10 and 12 for 3D structures, and n = 7 for the 2D ones.

Ultraviolet lasing in Zn-rich ZnO microspheres fabricated by laser ablation

Zinc (Zn) surface plasmons (SPs) have been widely reported for their impressive performance in improving the optical properties of semiconductors. Zn is an effective metal with SPs response in the ultraviolet region, but the disadvantage of strong metal activity limits the application mentioned above. Here, in order to ensure the stability of metal Zn, ZnO/Zn microspheres were synthesized by an one-step laser ablation method to distribute Zn nanoparticles simultaneously on both inner and outer surfaces of ZnO microspheres. Lasing performance enhancement and a lower threshold were obtained in the composite which originates from the coupling between Zn SPs and the excitation light source. Accompanied by the lasing emission measurements, the coupling mechanism was explained through time-resolved photoluminescence spectroscopy (TRPL) for the samples by rapid annealing in situ. This work displays the results of lasing enhancement and the physical process of Zn SPs resonance in the ZnO/Zn microsphere.

[The effects of levosimendan on the cardiac function and prognosis in elderly patients with septic shock and myocardial contractility impairment]

Objective: To investigate the effect of levosimendan on cardiac function and prognosis in elderly patients with septic myocardial contractility impairment. Methods: A prospective, randomized, controlled study was conducted. The elderly patients with septic myocardial contractility impairment who were admitted to Intensive Care Unit in Zhejiang Hospital were consecutively enrolled from January 2017 to September 2017. The key inclusive criterion was left ventricular ejection fraction (LVEF) ≤50% after fluid resuscitation. A total of 30 patients were randomly assigned to levosimendan group (n=15) and dobutamine group (n=15). Based onconventional treatment, intravenous dobutamine (5 μg per kilogram of body weight per minute) or levosimendan (0.2 μg per kilogram of body weight per minute)were continuously administrated for 24 hours in two groups. At 0 h,24 h,48 h, 72 h after injection, the following parameters or values were recorded including serum lactic acid (Lac), and echocardiographic parameters such as LVEF, stroke volume (SV). The time of mechanical ventilation, length of stay in ICU and 28-day mortality were compared in two groups. Results: Compared with dobutamine group, blood Lac at 24 h [(1.97±1.10)mmol/L vs. (2.73±2.06) mmol/L, P=0.002] decreased significantlyin levosimendan group. LVEF and SV were significantly higher in levosimendan group at 24 h [LVEF:(47.93±5.01)% vs.(45.60±5.47)%, P=0.004;SV:(47.73±14.01) ml vs. (44.80±16.89) ml, P=0.035;respectively], 48 h [LVEF:(51.07±5.05)% vs.(46.73±6.34)%, P=0.004;SV: (49.87±14.15) ml vs. (45.07±16.94) ml, P=0.005;respectively] and 72 h [LVEF:(53.20±5.92)% vs. (47.70±6.71)%, P=0.002;SV:(51.27±14.98) ml vs. (45.73±17.34) ml, P=0.010]. The time of mechanical ventilation, length of stay in ICU and 28-day mortality were comparable between two groups (P>0.05). Conclusions: Levosimendan improves cardiac systolic function and tissue perfusion in elderly patients with septic myocardial contractility impairment. However, cardiac diastolic function, liver and kidney function are not further improved by levosimendan compare with dubutamine. Time of mechanical ventilation, length of stay in ICU and 28-day mortality in two groups are similar.

Zinc alpha2 glycoprotein protects against obesity-induced hepatic steatosis

BACKGROUND/AIM

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis, impaired insulin sensitivity, and chronic low-grade inflammation. Our previous studies indicated that zinc alpha2 glycoprotein (ZAG) alleviates palmitate (PA)-induced intracellular lipid accumulation in hepatocytes. This study is to further characterize the roles of ZAG on the development of hepatic steatosis, insulin resistance (IR), and inflammation.

METHODS

ZAG protein levels in the livers of NAFLD patients, high-fat diet (HFD)-induced or genetically (ob/ob) induced obese mice, and in PA-treated hepatocytes were determined by western blotting. C57BL/6J mice injected with an adenovirus expressing ZAG were fed HFD for indicated time to induce hepatic steatosis, IR, and inflammation, and then biomedical, histological, and metabolic analyses were conducted to identify pathologic alterations in these mice. The molecular mechanisms underlying ZAG-regulated hepatic steatosis were further explored and verified in mice and hepatocytes.

RESULTS

ZAG expression was decreased in NAFLD patient liver biopsy samples, obese mice livers, and PA-treated hepatocytes. Simultaneously, ZAG overexpression alleviated intracellular lipid accumulation via upregulating adiponectin and lipolytic genes (FXR, PPARα, etc.) while downregulating lipogenic genes (SREBP-1c, LXR, etc.) in obese mice as well as in cultured hepatocytes. ZAG improved insulin sensitivity and glucose tolerance via activation of IRS/AKT signaling. Moreover, ZAG significantly inhibited NF-ĸB/JNK signaling and thus resulting in suppression of obesity-associated inflammatory response in hepatocytes.

CONCLUSIONS

Our results revealed that ZAG could protect against NAFLD by ameliorating hepatic steatosis, IR, and inflammation.

Extra green light induced ZnO ultraviolet lasing enhancement assisted by Au surface plasmons

We observed the dramatic enhancement of the intrinsic spontaneous and stimulated emission as well as the ensuing suppression of defect-related green emission in Au-decorated ZnO microrods. A series of spectral experiments and theoretical analysis demonstrated an electron transfer assisted process by surface plasmon (SP) resonant coupling between the Au nanoparticles and ZnO. The mechanism indicates an approach to enhance the UV emission of ZnO through an extra excitation of visible light similar to that for the defect emission of ZnO. Based on the coupling mechanism, the externally enhanced ultraviolet lasing was further improved from 1.5 to 2.8-fold by adjusting the pumping power of the green light intensity in the Au/ZnO hybrid cavity. This research not only further confirms the SPR-assisted electron transfer process but also offers an approach to improve the intrinsic UV emission even for heavily-defected ZnO through visible light excitation via a nonlinear process.

[Prevalence, awareness, treatment and control of hypertension in adults in Shandong province, 2013]

Objective: To understand the prevalence, awareness, treatment and control of hypertension in adults in Shandong province in 2013. Methods: Adults aged ≥18 were selected through multistage clustering sampling in 19 counties and districts in Shandong province. Design-based methods were adopted to analyze the prevalence, awareness, treatment and control of hypertension among local residents. Results: A total of 11 270 adults aged 18-69 years were surveyed, the prevalence of hypertension was 27.9% (31.4% in males, 24.3% in females) in Shandong province. The awareness rate of hypertension was 37.4% (34.7% in males, 41.0% in females), and the treatment rate of hypertension was 26.6% (23.4% in males, 30.7% in females). The treatment control rate of hypertension was 26.7% (28.3% in males, 25.1% in females) and the control rate of hypertension was 7.1% (6.6% in males, 7.7% in females). Conclusions: The prevalence of hypertension was high, but the awareness rate of hypertension, the treatment rate and the control rate of hypertension were low in adults in Shandong province. It is necessary to strengthen the health education about hypertension in young population, the prevention and control of hypertension in old population and those with low education level, the standardized management of hypertension cases and the reduction of risk factors for hypertension.

Chronic inflammation triggered by the NLRP3 inflammasome in myeloid cells promotes growth plate dysplasia by mesenchymal cells

Skeletal complications are common features of neonatal-onset multisystem inflammatory disease (NOMID), a disorder caused by NLRP3-activating mutations. NOMID mice in which NLRP3 is activated globally exhibit several characteristics of the human disease, including systemic inflammation and cartilage dysplasia, but the mechanisms of skeletal manifestations remain unknown. In this study, we find that activation of NLRP3 in myeloid cells, but not mesenchymal cells triggers chronic inflammation, which ultimately, causes growth plate and epiphyseal dysplasia in mice. These responses are IL-1 signaling-dependent, but independent of PARP1, which also functions downstream of NLRP3 and regulates skeletal homeostasis. Mechanistically, inflammation causes severe anemia and hypoxia in the bone environment, yet down-regulates the HIF-1α pathway in chondrocytes, thereby promoting the demise of these cells. Thus, activation of NLRP3 in hematopoietic cells initiates IL-1β-driven paracrine cascades, which promote abnormal growth plate development in NOMID mice.

ETV2/ER71 regulates hematopoietic regeneration by promoting hematopoietic stem cell proliferation

Xu et al. show that Etv2 is required for hematopoietic stem and progenitor cell (HSPC) proliferation and expansion after bone marrow transplantation and hematopoietic injury. c-Kit functions downstream of Etv2 in mediating HSPC proliferation and expansion.

Recent studies have established that hematopoietic stem cells (HSCs) are quiescent in homeostatic conditions but undergo extensive cell cycle and expansion upon bone marrow (BM) transplantation or hematopoietic injury. The molecular basis for HSC activation and expansion is not completely understood. In this study, we found that key developmentally critical genes controlling hematopoietic stem and progenitor cell (HSPC) generation were up-regulated in HSPCs upon hematopoietic injury. In particular, we found that the ETS transcription factor Ets variant 2 (Etv2; also known as Er71) was up-regulated by reactive oxygen species in HSPCs and was necessary in a cell-autonomous manner for HSPC expansion and regeneration after BM transplantation and hematopoietic injury. We found c-Kit to be downstream of ETV2. As such, lentiviral c-Kit expression rescued Etv2-deficient HSPC proliferation defects in vitro and in short-term BM transplantation in vivo. These findings demonstrate that Etv2 is an important regulator of hematopoietic regeneration.

Lasing mode regulation and single-mode realization in ZnO whispering gallery microcavities by the Vernier effect

The wide direct bandgap and strong exciton binding energy of ZnO have inspired examinations of ultraviolet lasing over the previous decades. However, regulation of the lasing mode, especially the realization of single mode lasing, is still a challenge. In this study, a ZnO comb-like structure with an array of microrods was selected to design coupled whispering-gallery-mode cavities, wherein the naturally varied air-gap between the adjacent microrods created a flexible condition for optical field coupling without any complicated micromanipulation. Spectral behaviour of lasing and coupling interaction between coupled ZnO microrods were systematically investigated. By regulating the nano-scale inter-space of dual coupled microrods, stable single-mode lasing with a higher Q factor and lower threshold was obtained successfully based on the Vernier effect. The formation conditions and the mechanism of single-mode lasing derived from the coupled ZnO microrods were discussed in detail. It also demonstrated an approach to construct high quality single-mode lasing by tuning the diameters of the coupled ZnO microrods.

Beta-naphthoflavone (DB06732) mediates estrogen receptor-positive breast cancer cell cycle arrest through AhR-dependent regulation of PI3K/AKT and MAPK/ERK signaling

Beta-naphthoflavone (BNF, DB06732) is an agonist of aryl hydrocarbon receptor (AhR) and a putative chemotherapeutic agent that has antitumor activity against mammary carcinomas in vivo. However, the mechanism by which BNF exerts this antitumor effect remains unclear. Thus, we explored mechanisms of BNF's antitumor effects in human breast cancer cells. This study showed that BNF suppressed cell proliferation and induced cell cycle arrest in the G0/G1 phase with downregulation of cyclin D1/D3 and CDK4 and upregulation of p21(Cip1/Waf1), leading to a senescence-like phenotype in estrogen receptor (ER)-positive MCF-7 cells, but not in ER-negative MDA-MB-231 cells. In addition, BNF inhibited PI3K/AKT signaling, and the PI3K inhibitor, LY294,002, exhibited the same inhibitory effects on cyclinD1/D3, CDK4 and the cell cycle as BNF. Interestingly, BNF activated mitogen-activated protein kinase-extracellular signal-regulated kinase (MAPK-ERK) signaling, and more notably, MEK inhibitor PD98059 significantly blocked the BNF-induced cell cycle arrest and upregulation of p21(Cip1/Waf1). Furthermore, specific ERα and AhR siRNA studies indicate that ERα is required in BNF-induced p21(Cip1/Waf1) expression, and BNF-mediated cell cycle arrest and modulation of AKT and ERK signaling is AhR-dependent. Taken together, AhR-dependent inhibition of the PI3K/AKT pathway, activation of MAPK/ERK and modulation of ERα is a novel mechanism underlying BNF-mediated antitumor effects in breast cancer, which may represent a promising strategy to be exploited in future clinical trials.

Eutectic condensation and nucleation in vapor-liquid-solid grown ZnO nanorod arrays on Si substrate

It is very important to understand the growth mechanism of ZnO nanostructures for control of the morphologies and further design of optoelectronic devices. In this paper, the eutectic condensation of Zn vapor and catalyst Au, nucleation and epitaxy of ZnO nanorods were intuitionally observed in chemical vapor deposition process by controlling the temperature and atmosphere. The vertically aligned ZnO nanorod arrays were fabricated on Au-coated Si substrate. A Zn-riched buffer layer was found on Si substrate. Under the atmosphere nearly without O2, it was clearly observed that the nano-sized sprouts appeared on the buffer layer and Au-Zn condensed bigger and bigger with increase of temperature. When the O2 was introduced, the as-grown nanorods almost kept the same size and density with those sprouts grown at the same temperature without O2. The morphologies and composition analysis provided direct evidence for a bottom-catalyzed vapor-liquid-solid mechanism of ZnO nanorod arrays on the lattice-mismatched substrate.

Aryl hydrocarbon receptor activation attenuates Per1 gene induction and influences circadian clock resetting

Light-stimulated adjustment of the circadian clock is an important adaptive physiological response that allows maintenance of behavioral synchrony with solar time. Our previous studies indicate that the aryl hydrocarbon receptor (AhR) agonist 2,3,7,8- tetrachlorodibenzo-p-dioxin attenuates light-induced phase resetting in early night. However, the mechanism of inhibition remains unclear. In this study, we showed that another potent AhR agonist-β-naphthoflavone (BNF)-significantly decreased light-induced phase shifts in wild-type (WT) mice, whereas AhR knockout mice had an enhanced response to light that was unaffected by BNF. Mechanistically, BNF blocked light induction of the Per1 transcript in suprachiasmatic nucleus and liver in WT mice, and BNF blocked forskolin (FSK)-induced Per1 transcripts in Hepa-1c1c7 (c7) cells. An E-box decoy did not affect BNF inhibition of FSK-induced Per1 transcripts in c7 cells. cAMP-response element (CRE)-dependent induction of Per1 promoter activity in response to FSK in combination with phorbol 12-tetradecanoate 13-acetate was suppressed in cells that expressed high levels of AhR (c7) compared with cells lacking functional AhR activity (c12). In addition, the inhibitory effect of BNF on FSK-induced Per1 was dependent on phosphorylation of JNK. Together, these results suggest that AhR activation inhibits light-induced phase resetting through the activation of JNK, negative regulation of CREs in the Per1 promoter, and suppression of Per1.

Conjugated linoleic acid synthesis-related protein proteasome subunit α 5 (PSMA5) is increased by vaccenic acid treatment in goat mammary tissue

This study was conducted to identify proteins associated with the endogenous synthesis of conjugated linoleic acid (CLA) from trans-vaccenic acid (TVA; trans-11 C18:1, a precursor for CLA endogenous synthesis) in mammary tissues. Six lactating goats were divided into 2 groups. One group was given an intravenous bolus injection of TVA (150mg) twice daily over 4 d; the other group received saline injections. Treatment with TVA increased the concentration of cis-9,trans-11 CLA and TVA in goat milk. Additionally, TVA treatment increased the expression of stearoyl-CoA desaturase (SCD) in mammary tissue. Using 2-dimensional gel electrophoresis and electrospray ionization quadrupole time-of-flight mass spectrometry, 3 proteins affected by infusions of TVA were identified. Proteasome (prosome, macropain) subunit α type 5 (PSMA5) was upregulated, whereas peroxiredoxin-1 and translationally controlled tumor protein 1 were downregulated in TVA-treated animals compared with the vehicle-injected controls. Only the effect of TVA on PSMA5 could be confirmed by Western blot analysis. To further explore the regulation of PSMA5 in mammary epithelial cells when TVA is converted into CLA, we used a differentiated bovine mammary epithelial cell line treated with TVA for 6h. Changes in cis-9,trans-11 CLA concentrations and mRNA expression patterns of both SCD and PSMA5 were monitored. The concentration of cis-9,trans-11 CLA increased after TVA treatment. The mRNA expression level of PSMA5 was significantly elevated to 6h, but SCD mRNA expression only increased in 2h after TVA treatment. These results indicate that PSMA5 is highly expressed in goat mammary tissue and bovine mammary epithelial cells when TVA is converted into CLA. Our data suggest that PSMA5 protein is associated with CLA biosynthesis in mammary tissue.

Fabrication and characterization of n-ZnO nanonails array/p(+)-GaN heterojunction diode

A novel heterojunctional structure of n-ZnO nanonails array/p(+)-GaN light-emitting diode was fabricated by Chemical Vapor Deposition method. A broad electroluminescence spectrum shows two peaks centered at 435 nm and 478 nm at room temperature, respectively. By comparing the photoluminescence and electroluminescence spectra, together with analyzing the energy band structure of heterojunction light emitting diode, it suggested that the electroluminescence peak located at 435 nm originates from Mg acceptor level of p(+)-GaN layer, whereas the electroluminescence peak located at 478 nm originates from the defects of n-ZnO nanonails array.

Aryl hydrocarbon receptor deficiency enhances insulin sensitivity and reduces PPAR-α pathway activity in mice

BACKGROUND

Numerous man-made pollutants activate the aryl hydrocarbon receptor (AhR) and are risk factors for type 2 diabetes. AhR signaling also affects molecular clock genes to influence glucose metabolism.

OBJECTIVE

We investigated mechanisms by which AhR activation affects glucose metabolism.

METHODS

Glucose tolerance, insulin resistance, and expression of peroxisome proliferator-activated receptor-α (PPAR-α) and genes affecting glucose metabolism or fatty acid oxidation and clock gene rhythms were investigated in wild-type (WT) and AhR-deficient [knockout (KO)] mice. AhR agonists and small interfering RNA (siRNA) were used to examine the effect of AhR on PPAR-α expression and glycolysis in the liver cell line Hepa-1c1c7 (c7) and its c12 and c4 derivatives. Brain, muscle ARNT-like protein 1 (Bmal1) siRNA and Ahr or Bmal1 expression plasmids were used to analyze the effect of BMAL1 on PPAR-α expression in c7 cells.

RESULTS

KO mice displayed enhanced insulin sensitivity and improved glucose tolerance, accompanied by decreased PPAR-α and key gluconeogenic and fatty acid oxidation enzymes. AhR agonists increased PPAR-α expression in c7 cells. Both Ahr and Bmal1 siRNA reduced PPAR-α and metabolism genes. Moreover, rhythms of BMAL1 and blood glucose were altered in KO mice.

CONCLUSIONS

These results indicate a link between AhR signaling, circadian rhythms, and glucose metabolism. Furthermore, hepatic activation of the PPAR-α pathway provides a mechanism underlying AhR-mediated insulin resistance.

Disruption of CLOCK-BMAL1 transcriptional activity is responsible for aryl hydrocarbon receptor-mediated regulation of Period1 gene

The aryl hydrocarbon receptor (AhR) is a period-aryl hydrocarbon receptor nuclear transporter-simple minded domain transcription factor that shares structural similarity with circadian clock genes and readily interacts with components of the molecular clock. Activation of AhR by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) alters behavioral circadian rhythms and represses the Period1 (Per1) gene in murine hematopoietic stem and progenitor cells. Per1 expression is driven by circadian locomotor activity cycles kaput-brain muscle ARNT-like (CLOCK-BMAL1)-dependent activation of Eboxes in the Per1 promoter. We hypothesized that the effects of AhR activation on the circadian clock are mediated by disruption of CLOCK-BMAL1 function and subsequent Per1 gene suppression. Effects of AhR activation on rhythmic Per1 transcripts were examined in livers of mice after treatment with the AhR agonist, TCDD; the molecular mechanisms of Per1 repression by AhR were determined in hepatoma cells using TCDD and beta-napthoflavone as AhR activators. This study reports, for the first time, that AhR activation by TCDD alters the Per1 rhythm in the mouse liver and that Per1 gene suppression depends upon the presence of AhR. Furthermore, AhR interaction with BMAL1 attenuates CLOCK-BMAL1 activity and decreases CLOCK binding at Ebox1 and Ebox3 in the Per1 promoter. Taken together, these data suggest that AhR activation represses Per1 through disrupting CLOCK-BMAL1 activity, producing dysregulation of rhythmic Per1 gene expression. These data define alteration of the Per1 rhythm as novel signaling events downstream of AhR activation. Downregulation of Per1 could contribute to metabolic disease, cancer, and other detrimental effects resulting from exposure to certain environmental pollutants.

Polybrominated diphenyl ethers in leaves and soil from typical electronic waste polluted area in South China

Polybrominated diphenyl ethers (PBDEs) in leaves and soil from typical e-waste polluted area in South China were investigated. The concentrations (ng/g dry weight) of PBDE congeners and summation operatorPBDE of five leaf samples were much lower than those in soil sample. The general patterns of summation di-BDEs to summation hepta-BDEs percentage distribution in leaf samples were similar to those of the soil sample, except the percentage of BDE209 which were lower than in soil. The percentages of summation di-BDEs to summation hepta-BDEs in soil were in the range of those in leaf samples. The results showed that the contamination of PBDEs in the leaf samples had good correlation with the soil around them.

Nestin expression in different tumours and its relevance to malignant grade

BACKGROUND

Nestin, an intermediate filament (IF) protein, is expressed in proliferating progenitor cells of developmental and regenerating tissues, and is identified as a neuroepithelial precursor cell marker. Recently, nestin was detected in some neoplasms such as glioma, ependymoma, melanoma, rhabdomyosarcoma, gastrointestinal stromal tumour (GIST), and testicular stromal tumour. Moreover, the expression intensity of nestin exhibited significant correlation with the malignant grade of glioma.

AIMS

To detect the expression of nestin in different tumours and to analyse the relationship between the expression of nestin and the malignant grade of the tumours.

METHODS

Formalin-fixed and paraffin-embedded surgical samples of neoplastic tissues were obtained from the Department of Pathology of Sun Yat-sen University. Histological analysis and immunohistochemical staining for nestin were performed. Histoscores were analysed by semi-quantitative evaluation.

RESULTS

Nestin was expressed predominantly in the cytoplasm of angiosarcoma, pancreatic adenocarcinoma and GIST samples, and some tumour cells expressed in the nucleus. There was a statistically significant difference between the histoscore of nestin in high malignant GIST (2.2366 (0.6920)) and that in low malignant GIST (1.3783 (0.4268)) (p = 0.003); and also between that in high malignant angiosarcoma (1.9188 (0.2069)) and that in low malignant angiosarcoma (0.6474 (0.3273)) (p = 0.000). Cavernous angioma did not express nestin. The histoscore of nestin in high malignant pancreatic adenocarcinoma (7/14) was 1.1767 (0.4676), and that in low malignant pancreatic adenocarcinoma (3/8) was 0.6577 (0.0056) (no significant difference, p = 0.112).

CONCLUSIONS

Results suggest that the expression of nestin may play an important role in the development of some neoplasms such as GIST and angiosarcoma.

Growth mechanism of tubular ZnO formed in aqueous solution

Tubular ZnO microstructural arrays were fabricated by a hydrothermal decomposition method. The dependence of the morphologies on the growth time and temperature was investigated in detail. An experiment was carried out to determine the mechanism of tubular ZnO formation. Our results showed that ZnO microtubes originated from an ageing process from ZnO microrods at a lower temperature (compared to the temperature when hydrothermal deposition of ZnO microrods was dominant) due to the preferential chemical dissolution of the metastable Zn-rich (0001) polar surfaces. A growth model was proposed based on the coexistence of hydrothermal deposition and dissolution of ZnO in the fabrication process.

Apoptosis and hormonal milieu in ductal system of normal prostate and benign prostatic hyperplasia

AIM

To study the apoptotic rate (AR) and the androgen and estrogen milieu in the proximal and distal ductal systems of prostate, in order to help exploring the effects of these factors on prostatic growth and the pathogenesis of benign prostatic hypertrophy (BPH).

METHODS

The proximal and distal ends of the ductal system were incised from 20 normal prostate as well as the hypertrophic prostate tissue from 20 patients with BPH. The AR was determined by the DNA end-labeling method and dihydrotestosterone (DHT) and estrodiol (E2), by radioimmunoassay.

RESULTS

There was no significant difference in DHT and E2 density between the proximal and distal ends of the ductal systems in normal prostate. E2 appeared to be higher in BPH than in normal prostatic tissues, but the difference was statistically insignificant. In normal prostatic tissue, the AR was significantly higher in the distal than in the proximal ends of the ductal system (P < 0.05), while the AR of the proximal ends was significantly higher (P < 0.01) than that in the BPH tissue. No significant correlation was noted between the DHT and E2 density and the AR both in the normal prostate and BPH tissues.

CONCLUSION

The paper is the first time describing a difference in AR in different regions of the ductal system of normal prostate, while the hormonal milieu is similar, indicating a functional inhomogeneity of these regions. A low AR in the proximal duct, where BPH originates, and an even lower AR in the BPH tissue, suggesting the participation of apoptosis in the BPH pathogenesis.

[Analyse of the site of lesion in auditory neuropathy]

OBJECTIVE

To analyze the clinic signs, the site of lesion and terminology of a kind of hearing loss which is characterized by speech hearing loss.

METHOD

The data of 11 patients were collected and analyzed including the clinic symptoms, pure tone audiometry, acoustic impedance audiometry, auditory brainstem response (ABR), electrocochleogram(ECochG), distortion product otoacoustic emission (DPOAE), CT/MRI.

RESULT

All these cases had following contradictory phenomena: Pure tone audiograms were low-frequency hearing loss; ABRs were absent or seriously abnormal, and ABR response threshold was worse than pure tone threshold and click subjective threshold; ECochG could be recorded in some patients; The stapes muscle reflex was absent; DPOAEs were normal or near normal, the average amplitude of low-frequency was higher than normal hearing group, but the average amplitude of high frequency was lower than normal hearing group; The imaging examination did not show any abnormality.

CONCLUSION

All data of this group show that the sites of lesion in most patients may be in lower brainstem, but the sites of lesion in some patients may be in the spiral ganglion of cochlea. The research of this disease should be continued.

Anticancer effect of Howiinol A and its mechanism of action

Howiinol A (GHM-10) is a kind of phenylethylene pyrone compounds isolated from Goniothalamus howii. By using the techniques of cell growth curve determination, MTT test, soft agar colony assay and experimental therapy of transplantable tumors in mice, it is found that GHM-10 exerts potent inhibitory effect on cancer cells but its influence on normal cells is relatively slight; the sensitivity of a drug-resistant cell line, KB/VCR 2000, to GHM-10 is similar to its parent cell line KB. Remarkable therapeutic effect can be seen in mice bearing H22 hepatoma and Lewis lung cancer and in mice with ascetic sarcoma 180 when GHM-10 is orally or intraperitoneally administered. The IC50s of L1210 cells treated with GHM-10 for 1 and 24 h are 6.85 and 3.32 micrograms.ml-1 respectively. The ratio of IC50 1 h and IC50 24 h is only 2.06, indicating that the action of GHM-10 is conformed to a cell cycle non-specific cytotoxic agent. By using trypan blue exclusive test and morphological examination, it is demonstrated that the main effect of GHM-10 is to inhibit the cell proliferation. Flow cytometery technique is used to analyze the cell cycle of L1210 cells. The results show that to some extent, GHM-10 blocks the cell cycle transition from G1 phase to S phase. By using [3H] labeled precursor incorporation technique, it is shown that GHM-10 significantly suppresses the biosynthesis of DNA, RNA and protein in L1210 cells, and the DNA synthesis is mostly affected. At 1 h after the cells were treated with GHM-10, these inhibitory effects have already been irreversible, suggesting that GHM-10 may cause structural damage on DNA molecules. However, GHM-10 is unable to intercalate into DNA molecules or to destroy its structure directly. By using single cell gel electrophoresis and alkaline elution technology, it is confirmed that GHM-10 causes DNA molecule damage and single strand breakage in L1210 cells. Further studies show that GHM-10 markedly inhibits DNA dehelix induced by DNA topoisomerase II both inside and outside the cells, indicating that GHM-10 is acting as an inhibitor of DNA topoisomerase II.

[Effect of HH07A, A derivative of hainanensine, on DNA polymerase I]

The effect of HH07A on DNA polymerase I in a cell free system was studied. The results showed that HH07A strongly inhibited the DNA synthesis catalyzed by DNA polymerase I in a dose dependent manner. Further results indicated that the DNA synthesis decreased significantly after DNA polymerase I was preincubated with HH07A. However, no change was found when DNA template was preincubated with HH07A. These results suggest that the inhibitory action of HH07A appeared to be on the enzyme molecules rather than on the DNA template.

[Studies on the anticancer effect of HH07A, a derivative of hainanensine]

The effect of HH07A on the growth of tumor cells in vitro was investigated using the techniques of cell growth curve determination and soft-agar colony-forming assay. The result showed that HH07A inhibited the growth of L1210 cells and HL-60 cells at a concentration of 1.5 micrograms.ml-1 and 4.0 micrograms.ml-1, respectively. Among the cells tested, L1210 cells were shown to be the most sensitive, followed by KB cells and HL-60 cells (with IC50 of 2.29, 4.13 and 4.36 micrograms.ml-1, respectively). Normal mouse granulocyte-macrophage progenitor cells (GM-CFC) were less sensitive to the drug (with IC50 of 11.15 micrograms.ml-1) as compared with the tumor cells. As they were exposed to HH07A 3.5 micrograms.ml-1 for 5 days, HL-60 cells did not show NBT reductive ability. Intraperitoneal injection of HH07A exerted inhibitory effect on the ascitic tumors of L1210 and S180 in mice. Oral or ip administration of HH07A also showed some effect on S180 solid tumors in mice.

Preparation and performance of cross-linked agar encapsulated activated charcoal (CAAC-III)

A technique is described to encapsulate activated charcoal for hemoperfusion to be used in an artificial liver support. Spherical activated charcoal was coated with agar and shaped in organic solvent, as well as cross-linked by epichlorohydrin (40-50 degrees C). The product withstood autoclaving at 121 degrees C for 0.5 hours, and had a good adsorption ability for compounds with molecular weight ranging from 113-5200. The adsorption kinetic showed pore diffusion limitation to compounds of small molecular weight, and film diffusion limitation to compounds of large molecular weight. Microparticles of charcoal release were greatly reduced, and within the permissible range according to the requirements in the U.S. Pharmacopeia (1985).

[Influence of radix Astragali on noise-caused changes in hepatic glycogen content in the rat]

It has been found that in rats exposed to a noise of 2kHz (mai frequency) and 103 dB(A) (potency) for 60 minutes, the hepatic glycogen content (HGC) is significantly higher than that of the control group unexposed to the noise (P less than 0.05), whereas in those treated with a prior ip Radix Astragali plus noise the HGC appears apparently lower than that of the noise group (P less than 0.05), very close to the control group (P greater than 0.2). This indicates that Radix Astragali might have some antinoise effect.

[Cytocidal action of homoharringtonine on L1210 cells in vitro]

The proliferation of L 1210 cells ceased rapidly after they were exposed to homoharringtonine (HH) 1 microgram/ml during exponential growth phase. However, 25.3% of the cells were still able to form colonies in soft agar if HH was removed after 24 h of incubation (the colony-forming efficiency for control cells was 62.5%). The clonogenic cells survived from the treatment were still sensitive to HH-continuous exposure. The IC50 of the treated and control cells were 15 and 20 ng/ml, respectively. Yet, the sensitivity of the treated cells to cytarabine decreased enormously. For instance, the survival rate of HH-treated cells remained at 100% level after they were exposed to cytarabine 4-8 micrograms/ml for 1 h, but only 40% control cells survived from the same treatment. When cells were continuously exposed to HH 0.4 micrograms/ml, the colony-forming efficiency decreased exponentially as a function of exposure time. The T1/2 of the clonogenic cells was about 18 h. The DNA contents in L 1210 cells was measured with a flow-cytometer. The results showed that the cell-cycle progress in all cells was interrupted by HH, regardless which phase they belonged to. So the cells seemed to be in a "frozen" state and the histogram unchanged.

Residual deficiencies in hemopoietic precursor cell populations after repeated irradiation of mice with x-rays or neutrons: dose-response relationships

Persistent reductions in the femoral content of hemopoietic colony-forming cells (CFU-S and GM-CFC) were observed after four doses of irradiation, delivered with three weeks between doses. In general, the reductions were dose dependent, and similar reductions were produced by single doses and repeated doses using the same total dose. After the lowest doses investigated, 4 X 0.75 Gy 300-kVp x-rays or 4 X 0.38 Gy 14.7-MeV neutrons, the recovered levels remained at 60%-80% of control for at least one year after irradiation. The relative biological effectiveness (RBE) of neutrons is about 2 for these long-term hemopoietic deficiencies.

A comparison of low and high dose-rate radiation for recipient mice in spleen-colony studies

Over the last 15 years, endogenous spleen-colony formation in our mice, following lethal irradiation, has increased to an unacceptable level. It has been found necessary, therefore, to introduce a new method of preparing recipient mice for spleen-colony studies. Irradiation with low dose-rate 60Cobalt gamma rays has been compared with high dose-rate linear accelerator electrons, and their effects on endogenous spleen colony formation compared with earlier X and gamma ray dose-response data. It was found that a large dose (13.5 Gy) of gamma rays results in fewer endogenous colonies than 8.5 Gy of electrons, yet because of its low dose rate (14.1 X 10(-3) Gy/min) it has a marked sparing of the intestinal tissue as measured by the intestinal microcolony technique. This in turn permits better survival and, therefore, a 'healthier' animal for spleen-colony work. Exogenous colony formation is also lower in the low dose-rate, gamma-irradiated recipients and this is shown to be due to a reduced spleen-seeding efficiency. It is concluded that very low dose-rate radiation is preferable for haemopoietic ablation, that a mouse colony requires constant monitoring for changes of endogenous spleen-colony formation and that the spleen-seeding efficiency of CFU-s depends on the irradiation technique used--there is no absolute value for a given strain of mouse.

A cellular analysis of residual hemopoietic deficiencies in mice after 4 repeated doses of 4.5 Gray X rays

A sub-optimal plateau in numbers of femoral stem-cells (CFU-S) in mice after 4 doses of 4.5 Gray X rays (each separated by 21 days), was shown to persist at 20-30% of control up to 1 year after the last dose, when about 50% of the mice had survived. The concentration of white cells in the blood was maintained persistently at about 70% of control, whereas the concentration of red cells was normal up to 4 months and then it declined to about 75% of control at 10 months after irradiation. Concentrations of some committed progenitor cells in the marrow (GM-CFC and ERC), which are capable of amplification cell divisions, were intermediate between the concentrations of marrow stem cells and mature blood cells in both the granuloid and the erythroid cell lineages, respectively. Hence increased amplification was a mechanism operating for a prolonged period in the production of numbers of mature cells. The numbers were subnormal, however, and this corresponded to only 1 extra amplification division on average. There was a slow decline after 6 months in the numbers of CFU-S, BFU-E and GM-CFC, and in the hematocrit, with reference to age-matched controls. The decline was due partly to a prevention of the natural increase in cell numbers in the marrow with the age of the mice, which was also seen with the femoral content of a stromal progenitor cell (CFU-F). A defect in the repeatedly-irradiated CFU-S population was detected as a persistent inability to produce colonies containing the same number of daughter CFU-S as contained in colonies derived from unirradiated marrow and assayed at the same time.

The response of stromal progenitor cells in mouse marrow to graded repeated doses of X rays or neutrons

After four repeated doses of 1.5 Gy X rays to mice (3-week intervals), the number of colonies containing fibroblasts that could be grown in vitro from femoral marrow recovered to control numbers by 80 days. After four higher doses, recovery was incomplete, and after four doses of 4.5 Gy, the number was half of the control level up to 1 year after irradiation. After four doses of 14.7 MeV neutrons, no threshold was detected for this late effect, and the RBE was about 2 at 4.5 Gy X rays and about 6 at 1.5 Gy X rays. The RBE for the acute effect on the stromal progenitor cells was also about 2 at 4.5 Gy X rays. The stromal progenitor cells could not be spared relative to hemopoietic stem cells (CFU-S) after neutrons, in contrast to the sparing observed after low-dose fractions of X rays. Experiments with local X irradiations of the leg, and with subcutaneous transplants of femora, revealed no significant recovery of stromal progenitor cells due to migration. However, recovery in situ could be enhanced slightly by marrow grafts i.v.