Decoupling the dynamic mechanism revealed by FGFR2 mutation-induced population shift

The fibroblast growth factor receptor 2 (FGFR2) is a key component in cellular signaling networks, and its dysfunctional activation has been implicated in various diseases including cancer and developmental disorders. Mutations at the activation loop (A-loop) have been suggested to trigger an increased basal kinase activity. However, the molecular mechanism underlying this highly dynamic process has not been fully understood due to the limitation of static structural information. Here, we conducted multiple, large-scale Gaussian accelerated molecular dynamics simulations of five (K659E, K659N, K659M, K659Q, and K659T) FGFR2 mutants at the A-loop, and comprehensively analyzed the dynamic molecular basis of FGFR2 activation. The results quantified the population shift of each system, revealing that all mutants had a higher proportion of active-like states. Using Markov state models, we extracted the representative structure of different conformational states and identified key residues related to the increased kinase activity. Furthermore, community network analysis showed enhanced information connections in the mutants, highlighting the long-range allosteric communication between the A-loop and the hinge region. Our findings may provide insights into the dynamic mechanism for FGFR2 dysfunctional activation and allosteric drug discovery.Communicated by Ramaswamy H. Sarma.

[Acute macular neuroretinopathy: a case report]

A 16-year-old female patient experienced a rapid decline in bilateral visual acuity accompanied by central scotomas for 5 days following coronavirus disease 2019 infection. Ocular examination revealed findings consistent with acute macular neuroretinopathy. Structural en face imaging using optical coherence tomography demonstrated a wedge-shaped lesion with low reflectivity directed towards the fovea in both eyes. B-scan images revealed localized hyperreflective bands involving the outer nuclear layer and photoreceptor layer, with discontinuity of the ellipsoid zone. Based on clinical presentation and examination findings, a diagnosis of bilateral acute macular neuroretinopathy was established.

Chinese patent medicines combined with hormone replacement therapy for premature ovarian failure: A Bayesian network meta-analysis

Objective

The objective of this study was to compare the efficacy differences between Chinese patent medicines combined with hormone replacement therapy (HRT) in the treatment of premature ovarian failure (POF) by the Bayesian network meta-analysis (NMA) method.

Methods

Randomized controlled trials (RCTs) reporting Chinese patent medicine combined with HRT for POF included Medline (via PubMed), Embase, Cochrane Library, China National Knowledge Infrastructure Database (CNKI), Wanfang Database (Wanfang), VIP Database (VIP), and China Biology Medicine Database (CBM) from the inception of the databases to July 2022. Two researchers independently screened the articles, extracted data, and evaluated the quality. The literature that met the inclusion criteria was screened out, the quality and risk of bias of the included studies were assessed according to the Cochrane 5.1 manual and RevMan 5.4, and NMA was performed using Stata 15.0 and R software.

Results

Sixty-four RCTs involving 5,675 individuals containing 12 oral Chinese patent medicines combined with HRT were enrolled into the current NMA. The results showed that when compared with patients using only HRT, the total clinical response rate is greater in patients using HRT combined with one of these 12 oral Chinese patent medicines. Among them, Zuogui pills + HRT [odds ratio (OR) = 3.92; 95% credible interval (CrI) = 0.86, 23.84; SUCRA = 73.76%] is most likely to be the best intervention, and the suboptimal intervention is Guishen pills + HRT (OR = 3.22, 95% CrI = 1.16, 9.44, SUCRA = 70.60%).

Conclusion

Chinese patent medicines combined with HRT were more effective than HRT alone in the treatment of POF. Zuogui pills are good at decreasing follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and more effective in the improvement of total clinical response rate; Xuefu Zhuyu capsule is also good at decreasing FSH. Ziheche capsule is an expert in improving estradiol level; Kuntai capsule shows the lowest incidence of adverse reactions. However, the quality of the literature included in this study is relatively low, so it may affect the results of the study. Therefore, higher quality and multi-center trial would be necessary for supporting these results.

Systematic review registration

[www.crd.york.ac.uk/prospero], identifier [CRD42022350587].

[Shandong hilly rural natural population cohort study: method and baseline characteristics of survey subjects]

Objective: To understand the study method and the baseline characteristics of the survey subjects of Shandong hilly rural natural population cohort study, and provide reference for the research of the prevalence and risk factors of common chronic and non-communicable diseases. Methods: Baseline survey, including questionnaire survey, physical examination, biochemical index examination and blood and saliva collection, was conducted in local residents aged 20-79 years in Kongcun and Xiaozhi townships of Pingyin county, Shandong province, from 2017 to 2019. Shandong hilly rural natural population cohort was established and main baseline characteristics of the study subjects were statistically analyzed. Results: A total of 10 296 study subjects aged 54.45 years were included in the study, in whom 40.6% were males. Among the study subjects, 88.3% had education level of junior high school or below, 62.1% were famers, and 90.7% were married. Smokers accounted for 45.6% of men and 0.9% of women, and drinkers accounted for 65.8% of men and 3.0% of women, respectively. The self-reported rates of hypertension, diabetes, coronary heart disease, stroke and tumors were 19.8%, 3.2%, 2.8%, 2.7% and 1.2%, respectively. Conclusion: The Shandong hilly rural cohort natural population study provided important evidence for assessing the risk for common chronic and non-communicable diseases and disease prevention and control in hilly rural areas.

Propofol ameliorates acute postoperative fatigue and promotes glucagon-regulated hepatic gluconeogenesis by activating CREB/PGC-1α and accelerating fatty acids beta-oxidation

Postoperative fatigue (POF) is the most common and long-lasting complication after surgery, which brings heavy burden to individuals and society. Recently, hastening postoperative recovery receives increasing attention, but unfortunately, the mechanisms underlying POF remain unclear. Propofol is a wildly used general anesthetic in clinic, and inspired by the rapid antidepressant effects induced by ketamine at non-anesthetic dose, the present study was undertaken to investigate the anti-fatigue effects and underlying mechanisms of propofol at a non-anesthetic dose in 70% hepatectomy induced POF model in rats. We first showed here that single administration of propofol at 0.1 mg/kg ameliorated acute POF in hepatectomy induced POF rats. Based on metabonomics analysis, we hypothesized that propofol exerted anti-fatigue activity in POF rats by facilitating free fatty acid (FFA) oxidation and gluconeogenesis. We further confirmed that propofol restored the deficit in FFA oxidation and gluconeogenesis in POF rats, as evidenced by the elevated FFA utilization, acetyl coenzyme A content, pyruvic acid content, phosphoenolpyruvic acid content, hepatic glucose output and glycogen storage. Moreover, propofol stimulated glucagon secretion and up-regulated expression of cAMP-response element binding protein (CREB), phosphorylated CREB, peroxlsome prolifeator-activated receptor-γ coactivator-1α (PGC-1α), phosphoenolpyruvate carboxykinade1 and carnitine palmitoltransferase 1A. In summary, our study suggests for the first time that propofol ameliorates acute POF by promoting glucagon-regulated gluconeogenesis via CREB/PGC-1α signaling and accelerating FFA beta-oxidation.

Magnitude and temporal trend of acne vulgaris burden in 204 countries and territories from 1990 to 2019: A analysis from the Global Burden of Disease Study 2019

BACKGROUND

Acne vulgaris is widespread across the world. Mapping the latest magnitudes and temporal trends of acne vulgaris provides the essential foundation for targeted public policies at the national, regional, and global levels.

METHODS

Complying with the framework of the Global Burden of Disease 2019 Study, the incidence, prevalence and disability-adjusted life years (DALYs) on acne vulgaris were retrieved in 204 countries and regions from 1990 to 2019. The average annual percentage change was calculated to depict the temporal trends in age-standardized rates (ASRs) of acne vulgaris burden by region, sex, and age.

RESULTS

Globally, 117.4 [95% uncertainty interval (UI): 103.0, 133.7] million incident cases of acne vulgaris, 231.2 million (95% UI: 208.2, 255.5) prevalent cases and 5.0 (95% UI: 3.0, 7.9) million DALYs were estimated in 2019, with about 47% increase compared with 1990. Moreover, the overall ASRs of acne vulgaris increased by around 0.55% annually over the past three decades. We observed huge disparities in ASRs of acne vulgaris with its changing trends in sex, location, and age. The ASR of acne vulgaris among women was around 1.3 times that of men, but the gender difference was narrowed for the pronounced increase among men. The ASRs of acne vulgaris were higher in high-income regions, but the increasing trend was more pronounced in other regions.

CONCLUSION

The burden rate of acne vulgaris continues to increase in almost all countries. Understanding the specific characteristics of acne vulgaris burden is essential to formulate more effective and targeted interventions for controlling acne burden.

Conformational Selection Mechanism Provides Structural Insights into the Optimization of APC-Asef Inhibitors

Metastasis is the major cause of death in colorectal cancer and it has been proven that inhibiting an interaction between adenomatous polyposis coli (APC) and Rho guanine nucleotide exchange factor 4 (Asef) efficaciously restrain metastasis. However, current inhibitors cannot achieve a satisfying effect in vivo and need to be optimized. In the present study, we applied molecular dynamics (MD) simulations and extensive analyses to apo and holo APC systems in order to reveal the inhibitor mechanism in detail and provide insights into optimization. MD simulations suggested that apo APC takes on a broad array of conformations and inhibitors stabilize conformation selectively. Representative structures in trajectories show specific APC-ligand interactions, explaining the different binding process. The stability and dynamic properties of systems elucidate the inherent factors of the conformation selection mechanism. Binding free energy analysis quantitatively confirms key interface residues and guide optimization. This study elucidates the conformation selection mechanism in APC-Asef inhibition and provides insights into peptide-based drug design.

Tojapride Reverses Esophageal Epithelial Inflammatory Responses on Reflux Esophagitis Model Rats

OBJECTIVE

To investigate the mechanism of Tojapride, a Chinese herbal formula extract, on strengthening the barrier function of esophageal epithelium in rats with reflux esophagitis (RE).

METHODS

Ten out of 85 SD rats were randomly selected as the sham group (n10), and 75 rats were developed a reflux esophagitis model (RE) by the esophageal and duodenal side-to-side anastomosis. Fifty successful modeling rats were divided into different medicated groups through a random number table including the model, low-, medium-, and high-dose of Tojapride as well as omeprazole groups (n10). Three doses of Tojapride [5.73, 11.46, 22.92 g/(kg•d)] and omeprazole [4.17 mg/(kg•d)] were administrated intragastrically twice daily for 3 weeks. And the rats in the sham and model groups were administered 10 mL/kg distilled water. Gastric fluid was collected and the supernatant was kept to measure for volume, pH value and acidity. Esophageal tissues were isolated to monitor the morphological changes through hematoxylin-eosin (HE) staining, and esophageal epithelial ultrastructure was observed by transmission electron microscopy. The expressions of nuclear factor kappa-light-chain-enhancer of activated B cells p65 (NF-KBp65), κB kinase beta (IKKß), occludin, and zonula occludens-1 (ZO-1) in the esophageal tissues were measured by immunohistochemistry and Western blot, respectively.

RESULTS

The gastric pH value in the model group was significantly lower than the sham group (P<0.05). Compared with the model group, gastric pH value in the omeprazole and medium-dose of Tojapride groups were significantly higher (P<0.05). A large area of ulceration was found on the esophageal mucosa from the model rats, while varying degrees of congestion and partially visible erosion was observed in the remaining groups. Remarkable increase in cell gap width and decrease in desmosome count was seen in RE rats and the effect was reversed by Tojapride treatment. Compared with the sham group, the IKKß levels were significantly higher in the model group (P<0.05). However, the IKKß levels were down-regulated after treatment by all doses of Tojapride (P<0.01 or P<0.05). The occluding and ZO-1 levels decreased in the model group compared with the sham group (Ps0.01 or Ps0.05), while both indices were significantly up-regulated in the Tojapride-treated groups (P<0.01 or P<0.05).

CONCLUSIONS

Tojapride could improve the pathological conditions of esophageal epithelium in RE rats. The underlying mechanisms may involve in down-regulating the IKKß expression and elevating ZO-1 and occludin expression, thereby alleviating the inflammation of the esophagus and strengthening the barrier function of the esophageal epithelium.

Possible mechanisms of lycopene amelioration of learning and memory impairment in rats with vascular dementia

Oxidative stress is involved in the pathogenesis of vascular dementia. Studies have shown that lycopene can significantly inhibit oxidative stress; therefore, we hypothesized that lycopene can reduce the level of oxidative stress in vascular dementia. A vascular dementia model was established by permanent bilateral ligation of common carotid arteries. The dosage groups were treated with lycopene (50, 100 and 200 mg/kg) every other day for 2 months. Rats without bilateral carotid artery ligation were prepared as a sham group. To test the ability of learning and memory, the Morris water maze was used to detect the average escape latency and the change of search strategy. Hematoxylin-eosin staining was used to observe changes of hippocampal neurons. The levels of oxidative stress factors, superoxide dismutase and malondialdehyde, were measured in the hippocampus by biochemical detection. The levels of reactive oxygen species in the hippocampus were observed by dihydroethidium staining. The distribution and expression of oxidative stress related protein, neuron-restrictive silencer factor, in hippocampal neurons were detected by immunofluorescence histochemistry and western blot assays. After 2 months of drug administration, (1) in the model group, the average escape latency was longer than that of the sham group, and the proportion of straight and tend tactics was lower than that of the sham group, and the hippocampal neurons were irregularly arranged and the cytoplasm was hyperchromatic. (2) The levels of reactive oxygen species and malondialdehyde in the hippocampus of the model group rats were increased, and the activity of superoxide dismutase was decreased. (3) Lycopene (50, 100 and 200 mg/kg) intervention improved the above changes, and the lycopene 100 mg/kg group showed the most significant improvement effect. (4) Neuron-restrictive silencer factor expression in the hippocampus was lower in the sham group and the lycopene 100 mg/kg group than in the model group. (5) The above data indicate that lycopene 100 mg/kg could protect against the learning-memory ability impairment of vascular dementia rats. The protective mechanism was achieved by inhibiting oxidative stress in the hippocampus. The experiment was approved by the Animal Ethics Committee of Fujian Medical University, China (approval No. 2014-025) in June 2014.

Chang'an II Decoction ( II )-Containing Serum Ameliorates Tumor Necrosis Factor-α-Induced Intestinal Epithelial Barrier Dysfunction via MLCK-MLC Signaling Pathway in Rats

OBJECTIVE

To investigate the effect of Chang'an II Decoction ( II ))-containing serum on intestinal epithelial barrier dysfunction in rats.

METHODS

Tumor necrosis factor (TNF)-α-induced injury of Caco-2 monolayers were established as an inflammatory model of human intestinal epithelium. Caco-2 monolayers were treated with blank serum and Chang'an II Decoction-containing serum that obtained from the rats which were treated with distilled water and Chang'an II Decoction intragastrically at doses of 0.49, 0.98, 1.96 g/(kg·d) for 1 week, respectively. After preparation of containing serum, cells were divided into the normal group, the model group, the Chang'an II-H, M, and L groups (treated with 30 ng/mL TNF-α and medium plus 10% high, middle-, and low-doses Chang'an II serum, respectively). Epithelial barrier function was assessed by transepithelial electrical resistance (TER) and permeability of fluorescein isothiocyanate (FITC)-labeled dextran. Transmission electron microscopy was used to observe the ultrastructure of tight junctions (TJs). Immunofluorescence of zonula occludens-1 (ZO-1), claudin-1 and nuclear transcription factor-kappa p65 (NF-κ Bp65) were measured to determine the protein distribution. The mRNA expression of myosin light chain kinase (MLCK) was measured by real-time polymerase chain reaction. The expression levels of MLCK, myosin light chain (MLC) and p-MLC were determined by Western blot.

RESULTS

Chang'an II Decoction-containing serum significantly attenuated the TER and paracellular permeability induced by TNF-α. It alleviated TNF-α-induced morphological alterations in TJ proteins. The increases in MLCK mRNA and MLCK, MLC and p-MLC protein expressions induced by TNF-α were significantly inhibited in the Chang'an II-H group. Additionally, Chang'an II Decoction significantly attenuated translocation of NF-κ Bp65 into the nucleus.

CONCLUSION

High-dose Chang'an II-containing serum attenuates TNF-α-induced intestinal barrier dysfunction. The underlying mechanism may be involved in inhibiting the MLCK-MLC phosphorylation signaling pathway mediated by NF-κ Bp65.

A coliform-targeted metagenomic method facilitating human exposure estimates to Escherichia coli-borne antibiotic resistance genes

Antimicrobial resistance and the spread of antibiotic resistance genes (ARGs) pose a threat to human health. Community-acquired infections resistant to treatment with first-line antibiotics are increasing, and there are few studies investigating environmental exposures and transmission. Our objective is to develop a novel targeted metagenomic method to quantify the abundance and diversity of ARGs in a faecal indicator bacterium, and to estimate human exposure to resistant bacteria in a natural environment. Sequence data from Escherichia coli metagenomes from 13 bathing waters in England were analysed using the ARGs Online Analysis Pipeline to estimate the abundance and diversity of resistance determinants borne by this indicator bacterium. These data were averaged over the 13 sites and used along with data on the levels of E. coli in English bathing waters in 2016 and estimates of the volume of water that water users typically ingest in an average session of their chosen activityto quantify the numbers of ARGs that water users ingest. Escherichia coli in coastal bathing waters were found to harbour on average 1.24 ARGs per cell. Approximately 2.5 million water sports sessions occurred in England in 2016 that resulted in water users ingesting at least 100 E. coli-borne ARGs.

Berberine hydrochloride counteracts enhanced IL-8 expression induced by SN 38 in AGS cells

IL-8 over-expression could enhance cancer metastasis. In present study, berberine hydrochloride (BER) triggered proliferative inhibition and G2/M arrest in AGS cells, down-regulated protein expression of cyclin B1, Bcl-2, up-regulated expression of p21, p53 and cleaved caspase 3, but showed no effect on protein expression of CHOP, Bip, and caspase 4. BER could down-regulate the enhanced IL-8 expression through down-regulating ERK1/2 and p38 MAPK over-activation induced by SN 38. The increased IL-8 mediated adhesive ability of AGS cells to HUVECs induced by SN 38, could be reduced by BER. Thus, BER could reduce the side-effect of SN 38 in clinic.

Efficacy and safety of Xiangsha Liujunzi granules for functional dyspepsia: A multi-center randomized double-blind placebo-controlled clinical study

AIM

To assess the efficacy and safety of a Chinese herbal medicine (CHM), Xiangsha Liujunzi granules, in the treatment of patients with functional dyspepsia (FD).

METHODS

We performed a randomized, double-blind, placebo-controlled trial with patients from three centers. Two hundred and sixteen subjects diagnosed with FD according to ROME III criteria and confirmed by upper gastrointestinal endoscopy and spleen-deficiency and Qi-stagnation syndrome were selected to receive Xiangsha Liujunzi granules or placebo for 4 wk in a 2:1 ratio by blocked randomization. The subjects also received follow-up after the 4-wk intervention. Herbal or placebo granules were dissolved in 300 mL of water. Participants in both groups were administered 130 mL (45 °C) three times a day. Participants were evaluated prior to and following 4 wk of the intervention in terms of changes in the postprandial discomfort severity scale (PDSS) score, clinical global impression (CGI) scale score, hospital anxiety and depression scale (HADS) score, traditional Chinese medicine symptoms score (SS), scores of various domains of the 36-item short form health survey (SF-36), gastric emptying (GE) and any observed adverse effects.

RESULTS

Compared with the placebo group, patients in the CHM group showed significant improvements in the scores of PDSS, HADS, SS, SF-36 and CGI scale (P < 0.05 or P < 0.01). They also showed the amelioration in the GE rates of the proximal stomach and distal stomach (P < 0.05 or P < 0.01).

CONCLUSION

Xiangsha Liujunzi granules offered significant symptomatic improvement in patients with FD.

Effect of Pixu 1 recipe on isocitrate dehydrogenase expression in liver tissue of functional dyspepsia rats with spleen deficiency

AIM

To investigate the expression of isocitrate dehydrogenase (IDH) protein and mRNA in liver tissue of functional dyspepsia (FD) rats with spleen deficiency after intervention with Pixu 1 recipe.

METHODS

Seventy 10-day-old male SD rat pups were randomly divided into a normal control group (n = 10), an FD model group (n = 10), and an FD with spleen deficiency model group (n = 50). The normal control group was gavaged with 0.2 mL of 2% sucrose, and the FD model group and FD with spleen deficiency model group were gavaged with 0.2 mL of 0.1% iodacetamide in 2.0% sucrose, for 6 d. From the postnatal age of 43 d, the FD with spleen deficiency model group was given modified multiple platform method (MMPM), 14 h every day, for 14 d. The FD with spleen deficiency model group was then randomly divided into an FD with spleen deficiency model group (n = 10), a western medicine group (n = 10), a low-dose Chinese herbs group (n = 10), a medium-dose Chinese herbs group (n = 10), and a high-dose Chinese herbs group (n = 10), which were gavaged with 1 mL/100 g•d of distilled water, 0.3125 mg/100 g•d of domperidone, 0.1275 g/100 g•d of Pixu 1 recipe, 0.255 g/100 g•d of Pixu 1 recipe, and 0.51 g/100 g•d of Pixu 1 recipe, for 14 d, respectively. IDH protein and mRNA expression in liver tissues was detected by Western blot, immunohistochemistry and RT-PCR.

RESULTS

Compared with the FD with spleen deficiency model group, IDH protein expression detected by immunohistochemistry was significantly higher in the normal group, FD model group, domperidone group, low-, medium-, and high-dose Pixu 1 recipe groups (P < 0.05 or P < 0.01); IDH protein expression detected by Western blot was significantly higher in the normal group, domperidone group, high-dose Pixu 1 recipe group and FD model group (P < 0.05 or P < 0.01); IDH mRNA expression detected by RT-PCR was significantly higher in the normal group, FD model group, domperidone group, high-dose Pixu 1 recipe group (P < 0.01).

CONCLUSION

FD rats with spleen deficiency have reduced energy metabolism, and Pixu 1 recipe improves spleen deficiency probably by increasing the expression of IDH protein and mRNA in FD rats with spleen deficiency.

G protein coupled signal transduction mechanisms in malfunction of smooth muscle relaxation and contraction in functional dyspepsia

Functional dyspepsia (FD) is a heterogeneous disease associated with gastrointestinal dysmotility, and it relates to malfunction of smooth muscle relaxation and contraction that is mainly mediated by G protein coupled signal transduction mechanisms involving phosphatidyl inositol (PI) signal transduction pathway, cyclic nucleus signal transduction pathway and small G protein signal transduction pathway. By discussing different components and signal pathways of G protein coupled signal transduction system and their associations with malfunction of smooth muscle relaxation and contraction in FD, this review aims to provide a new thought about the treatment of FD through the regulation of gastrointestinal motility from a microcosmic perspective.

Transport of Sr2+ and SrEDTA2- in partially-saturated and heterogeneous sediments

Strontium-90 has migrated deep into the unsaturated subsurface beneath leaking storage tanks in the Waste Management Areas (WMA) at the U.S. Department of Energy's (DOE) Hanford Reservation. Faster than expected transport of contaminants in the vadose zone is typically attributed to either physical hydrologic processes such as development of preferential flow pathways, or to geochemical processes such as the formation of stable, anionic complexes with organic chelates, e.g., ethylenediaminetetraacetic acid (EDTA). The goal of this paper is to determine whether hydrological processes in the Hanford sediments can influence the geochemistry of the system and hence control transport of Sr(2+) and SrEDTA(2-). The study used batch isotherms, saturated packed column experiments, and an unsaturated transport experiment in an undisturbed core. Isotherms and repacked column experiments suggested that the SrEDTA(2-) complex was unstable in the presence of Hanford sediments, resulting in dissociation and transport of Sr(2+) as a divalent cation. A decrease in sorption with increasing solid:solution ratio for Sr(2+) and SrEDTA(2-) suggested mineral dissolution resulted in competition for sorption sites and the formation of stable aqueous complexes. This was confirmed by detection of MgEDTA(2-), MnEDTA(2-), PbEDTA(2-), and unidentified Sr and Ca complexes. Displacement of Sr(2+) through a partially-saturated undisturbed core resulted in less retardation and more irreversible sorption than was observed in the saturated repacked columns, and model results suggested a significant reservoir (49%) of immobile water was present during transport through the heterogeneous layered sediments. The undisturbed core was subsequently disassembled along distinct bedding planes and subjected to sequential extractions. Strontium was unequally distributed between carbonates (49%), ion exchange sites (37%), and the oxide (14%) fraction. An inverse relationship between mass wetness and Sr suggested that sandy sediments of low water content constituted the immobile flow regime. Our results suggested that the sequestration of Sr(2+) in partially-saturated, heterogeneous sediments was most likely due to the formation of immobile water in drier regions having low hydraulic conductivities.

An economic analysis of biomass gasification and power generation in China

With vast territory and abundant biomass resources China appears to have suitable conditions to develop biomass utilization technologies. As an important decentralized power technology, biomass gasification and power generation (BGPG) has a potential market in making use of biomass wastes. In spite of the relatively high cost for controlling secondary pollution by wastewater, BGPG is economically feasible and can give a financial return owing to the low price of biomass wastes and insufficient power supply at present in some regions of China. In this work, experimental data from 1 MW-scale circulating fluidized bed (CFB) BGPG plants constructed recently in China were analyzed; and it was found that the unit capital cost of BGPG is only 60-70% of coal power station and its operation cost is much lower than that of conventional power plants. However, due to the relatively low efficiency of small-scale plant, the current BGPG technology will lose its economic attraction when its capacity is smaller than 160 kW or the price of biomass is higher than 200 Yuan RMB/ton. The development of medium-scale BGPG plants, with capacity ranging from 1000 to 5000 kW, is recommended; as is the demonstration of BGPG technology in suitable enterprises (e.g. rice mill and timber mill) in developing countries where large amounts of biomass wastes are available so that biomass collection and transportation can be avoided and the operation cost can be lowered.

Analysis of loss of heterozygosity on chromosomes 10q, 11, and 16 in medulloblastomas

OBJECT

The loss of genetic material from specific chromosome loci is a common feature in the oncogenesis of tumors and is often indicative of the presence of important tumor suppressor genes at these loci. Recent molecular genetic analyses have demonstrated frequent loss of chromosomes 10q, 11, and 16 in medulloblastomas. The aim of this study was to localize the targeted deletion regions on the three aforementioned chromosomes in medulloblastomas.

METHODS

Loss of heterozygosity (LOH) was examined on chromosomes 10q, 11, and 16 in a series of 22 primary and two recurrent medulloblastomas by using polymerase chain reaction-based microsatellite analysis. The DNA extracted from the tumors and corresponding normal blood samples were amplified independently in the presence of radioactively labeled microsatellite primers, resolved by denaturing gel electrophoresis and processed for autoradiography. The DNA obtained from control blood samples that displayed allelic heterozygosity at a given microsatellite locus were considered informative. Loss of heterozygosity was inferred when the allelic signal intensity of the tumor sample was reduced by at least 40%, relative to that of the constitutional control. The LOH analysis demonstrated that deletions of chromosomes 10q, 11p, and 16q are recurrent genetic events in the development of medulloblastomas. Three subchromosomal regions of loss have been identified and are localized to the deleted in malignant brain tumors 1 [DMBT1] gene site on chromosomes 10q25, 11p13-11p15.1, and 16q24.1-24.3.

CONCLUSIONS

These results indicate that DMBT1 is closely associated with the oncogenesis of medulloblastomas and highlight regions of loss on chromosomes 11p and 16q for further fine mapping and cloning of candidate tumor suppressor genes that are important for the genesis of medulloblastoma.

Detection of multiple gene amplifications in glioblastoma multiforme using array-based comparative genomic hybridization

We have used a new method of genomic microarray to investigate amplification of oncogenes throughout the genome of glioblastoma multiforme (GBM). Array-based comparative genomic hybridization (array CGH) allows for simultaneous examination of 58 oncogenes/amplicons that are commonly amplified in various human cancers. Amplification of multiple oncogenes in human cancers can be rapidly determined in a single experiment. Tumor DNA and normal control DNA were labeled by nick translation with green- and red-tagged nucleotides, respectively. Instead of hybridizing to normal metaphase chromosomes in conventional comparative genomic hybridization (CGH), the probes of the mixed fluorescent labeled DNA were applied to genomic array templates comprised of P1, PAC, and BAC clones of 58 target oncogenes. The baseline for measuring deviations was established by performing a series of independent array CGH using test and reference DNA made from normal individuals. In the present study, we examined fourteen GBMs (seven cell lines and seven tumours) with CGH and array CGH to reveal the particular oncogenes associated with this cancer. High-level amplifications were identified on the oncogenes/amplicons CDK4, GLI, MYCN, MYC, MDM2, and PDGFRA. The highest frequencies of gains were detected on PIK3CA (64.3%), EGFR (57.1%), CSE1L (57.1%), NRAS (50%), MYCN (42.9%), FGR (35.7%), ESR (35.7%), PGY1 (35.7%), and D17S167 (35.7%). These genes are suggested to be involved in the GBM tumorigenesis.

[Role of pp60c-src in mitogen-activated protein kinase activation of vascular smooth muscle cells]

The effect of pp60c-src on mitogen-activated protein kinase (MAPK) activation induced by angiotensin II (Ang II) in vascular smooth muscle cells (VSMCs) was observed to explore the signal transduction process of VSMCs proliferation mediated by Ang II. Following transfection of the synthetic antisense c-src oligodeoxynucleotides (ODNs) wrapped in lipofectin into cultured rat VSMCs, pp60c-src content markedly decreased, pp60c-src kinase activity was only 14.4% of control, while MAPK activity was not significantly changed (P>0.05). When these transfected VSMCs were further stimulated by Ang II, the increase in MAPK activity was only 1.6% of control. These data suggest that pp60c-src is needed for MAPK activation in VSMCs stimulated by Ang II, and pp60c-src may be an important signaling molecule in abnormal proliferation of VSMCs.

Detection of chromosomal imbalances in central neurocytomas by using comparative genomic hybridization

OBJECT

Central neurocytomas are rare neuronal tumors commonly found in the intraventricular regions. Little is known about the tumorigenesis of these neoplasms. The aim of this study was to provide an overview of genetic imbalances in central neurocytomas.

METHODS

In this study, comparative genomic hybridization was used to identify DNA sequence copy number changes (losses and gains) in a series of 10 central neurocytomas. Tumor DNA and normal reference DNA were differentially labeled and allowed to cohybridize to normal metaphase chromosomes. After hybridization and fluorescent staining of the bound DNA, regions of gain or of loss of DNA sequences were detected as changes in the tumor/normal fluorescence intensity ratio along the target metaphase chromosomes. A gain of DNA sequence was detected in chromosomes 2p, 10q, and 18q. A protooncogene, Bcl2, which maps to 18q21, was evaluated by immunohistochemical analysis to determine its role in the formation of central neurocytomas.

CONCLUSIONS

In this study the authors identified recurrent genetic changes on chromosomes 2p, 10q, and 18q in central neurocytomas and highlighted chromosomal regions for additional mapping and cloning of candidate genes that are important in the development of central neurocytomas.