[Quantitative analysis of risk assessment indicators for re-introduction of imported malaria in China]

OBJECTIVE

To quantitatively analyze the risk indicators of re-introduction of imported malaria in China and their weighting coefficients, so as to investigate the difference in the contribution of risk indicators included in the current risk assessment framework for re-introduction of imported malaria in China to the risk assessment of re-introduction of imported malaria.

METHODS

Publications pertaining to the risk assessment framework for re-introduction of imported malaria in China that reported the risk indicators and their weighting coefficients were retrieved in PubMed, Web of Science, CNKI, Wanfang Data, and VIP with terms of "malaria", "re-introduction/re-transmission/re-establishment", "risk assessment/risk evaluation/risk prediction" from the inception of the database through 3 August 2023, and literature search was performed in Google Scholar to ensure the comprehensiveness of the retrieval. Basic characteristics of included studies were extracted using pre-designed information extraction forms by two investigators, and data pertaining to risk indicators of re-introduction of imported malaria were cross-checked by these two investigators. The risk indicators included in the risk assessment framework for re-introduction of imported malaria in China and their weighting coefficients were visualized with the Nightingale's rose diagrams using the software R 4.2.1, and the importance of risk indictors was evaluated with the frequency of risk indicators included in the risk assessment framework and the ranking of weighting coefficients of risk indicators. In addition, the capability of risk indicators screened by different weighting methods was compared by calculating the ratio of the maximum to the minimum of the weighting coefficients of the risk indicators screened by different weighting methods.

RESULTS

A total of 2 138 publications were retrieved, and following removal of duplications and screening, a total of 8 publications were included in the final analysis. In these 8 studies, 8 risk assessment frameworks for re-introduction of imported malaria in China and 52 risk indicators of re-introduction of imported malaria were reported, in which number of imported malaria cases (n = 8) and species of malaria vectors were more frequently included in the risk assessment frameworks (n = 8), followed by species of imported malaria parasites (n = 6) and population density of local malaria vectors (n = 6), and species of local malaria vectors (n = 6), number of imported malaria cases (n = 5) and species of imported malaria parasites had the three highest weighting coefficients (n = 4). The weighting methods included expert scoring method, combination of expert scoring method and analytic hierarchy process, and combination of expert scoring method and entropy weight method in these 8 studies, and the ratios of the maximum to the minimum of the weighting coefficients of the risk indicators screened by the expert scoring method were 1.143 to 2.241, while the ratios of the maximum to the minimum of the weighting coefficients of the risk indicators screened by combination of the expert scoring method and analytic hierarchy process were 34.970 to 162.000.

CONCLUSIONS

Number of imported malaria cases, species of imported malaria parasites, species of local malaria vectors and population density of local malaria vectors are core indicators in the current risk assessment framework for re-introduction of imported malaria in China. Combination of the expert scoring method and analytic hierarchy process is superior to the expert scoring method alone for weighting the risk indicators.

[Risk predictive models of healthcare-seeking delay among imported malaria patients in Jiangsu Province based on the machine learning]

OBJECTIVE

To create risk predictive models of healthcare-seeking delay among imported malaria patients in Jiangsu Province based on machine learning algorithms, so as to provide insights into early identification of imported malaria cases in Jiangsu Province.

METHODS

Case investigation, first symptoms and time of initial diagnosis of imported malaria patients in Jiangsu Province in 2019 were captured from Infectious Disease Report Information Management System and Parasitic Disease Prevention and Control Information Management System of Chinese Center for Disease Control and Prevention. The risk predictive models of healthcare-seeking delay among imported malaria patients were created with the back propagation (BP) neural network model, logistic regression model, random forest model and Bayesian model using thirteen factors as independent variables, including occupation, species of malaria parasite, main clinical manifestations, presence of complications, severity of disease, age, duration of residing abroad, frequency of malaria parasite infections abroad, incubation period, level of institution at initial diagnosis, country of origin, number of individuals travelling with patients and way to go abroad, and time of healthcare-seeking delay as a dependent variable. Logistic regression model was visualized using a nomogram, and the nomogram was evaluated using calibration curves. In addition, the efficiency of the four models for prediction of risk of healthcare-seeking delay among imported malaria patients was evaluated using the area under curve (AUC) of receiver operating characteristic curve (ROC). The importance of each characteristic was quantified and attributed by using SHAP to examine the positive and negative effects of the value of each characteristic on the predictive efficiency.

RESULTS

A total of 244 imported malaria patients were enrolled, including 100 cases (40.98%) with the duration from onset of first symptoms to time of initial diagnosis that exceeded 24 hours. Logistic regression analysis identified a history of malaria parasite infection [odds ratio (OR) = 3.075, 95% confidential interval (CI): (1.597, 5.923)], long incubation period [OR = 1.010, 95% CI: (1.001, 1.018)] and seeking healthcare in provincial or municipal medical facilities [OR = 12.550, 95% CI: (1.158, 135.963)] as risk factors for delay in seeking healthcare among imported malaria cases. BP neural network modeling showed that duration of residing abroad, incubation period and age posed great impacts on delay in healthcare-seek among imported malaria patients. Random forest modeling showed that the top five factors with the greatest impact on healthcare-seeking delay included main clinical manifestations, the way to go abroad, incubation period, duration of residing abroad and age among imported malaria patients, and Bayesian modeling revealed that the top five factors affecting healthcare-seeking delay among imported malaria patients included level of institutions at initial diagnosis, age, country of origin, history of malaria parasite infection and individuals travelling with imported malaria patients. ROC curve analysis showed higher overall performance of the BP neural network model and the logistic regression model for prediction of the risk of healthcare-seeking delay among imported malaria patients (Z = 2.700 to 4.641, all P values < 0.01), with no statistically significant difference in the AUC among four models (Z = 1.209, P > 0.05). The sensitivity (71.00%) and Youden index (43.92%) of the logistic regression model was higher than those of the BP neural network (63.00% and 36.61%, respectively), and the specificity of the BP neural network model (73.61%) was higher than that of the logistic regression model (72.92%).

CONCLUSIONS

Imported malaria cases with long duration of residing abroad, a history of malaria parasite infection, long incubation period, advanced age and seeking healthcare in provincial or municipal medical institutions have a high likelihood of delay in healthcare-seeking in Jiangsu Province. The models created based on the logistic regression and BP neural network show a high efficiency for prediction of the risk of healthcare-seeking among imported malaria patients in Jiangsu Province, which may provide insights into health management of imported malaria patients.

Dissolved organic matter (DOM) quality drives biogeographic patterns of soil bacterial communities and their association networks in semi-arid regions

It is of great interest to elucidate the biogeographic patterns of soil microorganisms and their driving forces, which is fundamental to predicting alterations in microbial-mediated functions arising from environment changes. Although dissolved organic matter (DOM) represents an important resource for soil microorganisms, knowledge of how its quality affects microbial biogeography is limited. Here, we characterized soil bacterial communities and DOM quality in 45 soil samples collected from a 1500-km sampling transect through semi-arid regions in northern China which are currently suffering great pressure from climate change, using Illumina Miseq sequencing and fluorescence spectroscopy, respectively. We found that DOM quality (i.e. the source of DOM and the humification degree of DOM) had profound shaping influence on the biogeographic patterns exhibited by bacterial diversity, community composition and association networks. Specifically, the composition of bacteria community closely associated with DOM quality. Plant-derived DOM sustained higher bacterial diversity relative to microbial-derived DOM. Meanwhile, bacterial diversity linearly increased with increasing humification degree of DOM. Additionally, plant-derived DOM was observed to foster more complex bacterial association networks with less competition. Together, our work contributes to the factors underlying biogeographic patterns not only of bacterial diversity, community composition but also of their association networks and reports previously undocumented important role of DOM quality in shaping these patterns.

Spatial Patterns of Soil Fungal Communities Are Driven by Dissolved Organic Matter (DOM) Quality in Semi-Arid Regions

Soil fungi are ecologically important as decomposers, pathogens, and symbionts in nature. Understanding their biogeographic patterns and driving forces is pivotal to predict alterations arising from environmental changes in ecosystem. Dissolved organic matter (DOM) is an essential resource for soil fungi; however, the role of its quality in structuring fungal community patterns remains elusive. Here using Illumina MiSeq sequencing, we characterized total fungi and their functional groups in 45 soil samples collected from a 1500-km sampling transect through semi-arid regions in northern China, which are currently suffering great pressure from climate change. Total fungi and their functional groups were all observed to exhibit significant biogeographic patterns which were primarily driven by environmental variables. DOM quality was the best and consistent predictor of diversity of both total fungi and functional groups. Specifically, plant-derived DOM was associated with greater diversity relative to microbe-dominated origins. In addition, fungal diversity linearly increased with increases in degree of humification in DOM. Similarly, among all measured environmental variables, DOM quality had the strongest effects on the community composition of total fungi and functional groups. Together, our work contributes to the factors underlying fungal biogeographic patterns and adds detail to the importance of DOM quality in structuring fungal communities.

Deciphering the archaeal communities in tree rhizosphere of the Qinghai-Tibetan plateau

BACKGROUND

The Qinghai-Tibetan Plateau represents one of the most important component of the terrestrial ecosystem and a particularly vulnerable region, which harbouring complex and diverse microbiota. The knowledge about their underground microorganisms have largely been studied, but the characteristics of rhizosphere microbiota, particularly archaeal communities remains unclear.

RESULTS

High-throughput Illumina sequencing was used to investigate the rhizosphere archaeal communities of two native alpine trees (Picea crassifolia and Populus szechuanica) living on the Qinghai-Tibetan Plateau. The archaeal community structure in rhizospheres significantly differed from that in bulk soil. Thaumarchaeota was the dominant archaeal phylum in all soils tested (92.46-98.01%), while its relative abundance in rhizospheres were significantly higher than that in bulk soil. Ammonium nitrogen, soil organic matter, available phosphorus and pH were significantly correlated with the archaeal community structure, and the deterministic processes dominated the assembly of archaeal communities across all soils. In addition, the network structures of the archaeal community in the rhizosphere were less complex than they were in the bulk soil, and an unclassified archaeal group (Unclassified_k_norank) was identified as the keystone species in all archaeal networks.

CONCLUSIONS

Overall, the structure, assembly and co-occurrence patterns of archaeal communities are significantly affected by the presence of roots of alpine trees living on the Qinghai-Tibetan Plateau. This study provides new insights into our understanding of archaeal communities in vulnerable ecosystems.

Microplastics from mulching film is a distinct habitat for bacteria in farmland soil

Microplastics, as an emerging pollutant of global importance, have been well documented in aquatic ecosystems. However, little is known about the effects of microplastics on agroecosystems, particularly for soil microbial communities. Herein, microplastics collected from cotton fields in Xinjiang, China, were analysed with a scanning electron microscope (SEM) and high-throughput sequencing to investigate the attached bacterial communities. Microplastic surfaces, especially pits and flakes, were colonized by various microorganisms, suggesting active hydrolysis of plastic debris. The bacterial communities colonizing microplastics were significantly different in structure from those in the surrounding soil, plant litter and macroplastics. In addition, statistical analysis of differentially abundant OTUs showed that microplastics serve as a "special microbial accumulator" in farmland soil, enriching some taxa that degrade polyethylene, such as Actinobacteria, Bacteroidetes and Proteobacteria. Co-occurrence network analysis revealed that the biotic interactions between microorganisms on microplastics are as complex as those in soil, and Acidobacteria, Chloroflexi, Gemmatimonadetes, and Bacteroidetes are considered keystone species in bacterial communities. Collectively, the findings imply that microplastics acted as a distinct habitat for bacteria in farmland soil, which increases our understanding of microplastic pollution.

Potential metal-binding ability of proteins in the extracellular slime of Laccaria bicolor exposed to excessive Cu and Cd

Ectomycorrhizal fungi can enhance the tolerance of plants to heavy metal stress by reducing the accumulation of heavy metals in the aerial parts of the plants. Extracellular chelation is a major mechanism of heavy metal tolerance in ectomycorrhizal fungi in which extracellular slime plays a fundamental role. The objectives of this study were to investigate the potential metal-binding ability and the protein composition of extracellular slime. The extracellular slime of Laccaria bicolor (L. bicolor) cultivated under Cd²⁺ and Cu²⁺ stress was separated using various ultrasonic pre-treatments. The protein content, composition, and metal content of the extracellular slime were measured. The results showed that the protein content in the extracellular slime significantly increased under both Cd²⁺ and Cu²⁺ stress. The SDS-PAGE profile showed that Cd²⁺ and Cu²⁺ stress induced the expression of several new proteins. Heavy metal quantification revealed that the Cd content fixed in the extracellular slime accounted for 22-28% of the metal fixed by the fungal mycelia. Meanwhile, no Cu was detected in the fungal extracellular slime, implying that the extracellular slime may not be effective for the fixation of essential metallic elements such as Cu. Taken together, these results provided evidence that L. bicolor was able to ameliorate the intracellular Cd content by stimulating extracellular slime exudation and altering the composition of the proteins therein. Nevertheless, this blocking strategy may be effective only for the non-essential element Cd and was ineffective for the physiological element Cu.

Urbanization altered regional soil organic matter quantity and quality: Insight from excitation emission matrix (EEM) and parallel factor analysis (PARAFAC)

Soil organic matter (SOM) play an important role in soil ecology and global carbon dynamic. As one of the most sever and irreversible land use change, urbanization could alter the regional carbon storage and composition pattern. However how urbanization influence on SOM is still unclear. In this study, we collected soil samples from highly urbanized area of Beijing, China and explore the quantity and quality variations of SOM by using fluorescence spectroscopy in combine with parallel factor analysis (PARAFAC). The results shown that the soil physic-chemical properties were shaped by urbanization. Comparing to nature soil, moisture content, total organic carbon and total nitrogen in urban and rural soil significantly decreased. The fluorescence spectrum demonstrated that SOM quality was also altered by urbanization induced environmental changes. Five fluorescent compounds in SOM was identified by PARAFAC model and three of them was assigned to humic-like substances. The fluorescence intensity of humic-like substances in nature land was significantly higher than of rural and urban land, meanwhile microbial related substance accumulated in urban land in comparison with rural and nature land. The multivariate analyses further reveal the relationship between soil physic-chemical properties and SOM composition. These results suggest that urbanization could not only decrease the SOM quantity but also change the SOM composition. The SOM loss caused by urbanization was mainly consist of humic-like substance loss. Besides urbanization also stimulate the accumulation of microbial related substance in SOM which highlight the importance of microorganism is SOM dynamic.

Increasing aridity affects soil archaeal communities by mediating soil niches in semi-arid regions

Soil archaea plays a vital role in the functioning of dryland ecosystems, which are expected to expand and get drier in the future as a result of climate change. However, compared with bacteria and fungi, the impacts of increasing aridity on archaea in these ecosystems remain largely unknown. Here, soil samples were collected along a typical aridity gradient in semi-arid regions in Inner Mongolia, China, to investigate whether and how the increasing aridity affects archaeal communities. The results showed that archaeal richness linearly decreased with increasing aridity. After partialling out the effects of soil properties based on partial least squares regression, the significant aridity-richness relationship vanished. The composition of archaeal communities was distributed according to the aridity gradient. These variations were largely driven by the changes in the relative abundance of Thaumarchaeota, Euryarchaeota and unclassified phyla. Niche-based processes were predominant in structuring the observed archaeal aridity-related pattern. The structural equation models further showed that aridity indirectly reduced archaeal richness through improving soil electrical conductivity (EC) and structured community composition by changing soil total nitrogen (TN). These results suggested that soil salinization and N-losses might be important mechanisms underlying the increasing aridity-induced alterations in archaeal communities, and highlighted the importance of soil niches in mediating the indirect impacts of increasing aridity on archaea.

[Retrospective clinical analyses of otogenic intracranial infections]

Objective: To investigate the clinical characteristics and treatment options for otogenic intracranial infections. Method: Clinical records of all the patients of otogenic intracranial infections admitted to the First Affiliated Hospital of Zhejiang University from 2008 to 2016 were retrospectively analyzed. Their clinical presentations, radiological findings, culture results, and medical and surgical therapy modalities, as well as treatment outcomes were studied. Results: Sixteen cases were identified. The majority of the otogenic patients had a history of cholesteatoma, other rare events included congenital cerebrospinal fluid otorhinorrhea, Gorham-Stout disease and after radiation therapy for nasopharyngeal carcinoma. Meningitis, cerebral venous thrombosis and brain abscess were the primary intracranial infection. Eight patients had received modified radical mastoidectomy at least one time. Results of routine culture for cerebrospinal and pus samples had high negative rate. All patients received initial empirical broadspectrum intravenous antibiotics therapy. Four cases of brain abscesses were drained or excised at the same time for otologic surgery. The mortality rate was 6.25% (1 case). Conclusions: Cholesteatoma is still the most commonly primary disease of otogenic intracranial complications. Diagnosis and treatment of otogenic intracranial infections require multidisciplinary cooperation. Surgical intervention for primary ear lesions and intracranial abscess is still the main option in the treatment of otogenic intracranial infections.

Characterization of the In Vivo and In Vitro Metabolites of Linarin in Rat Biosamples and Intestinal Flora Using Ultra-High Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Tandem Mass Spectrometry

Linarin, a flavone glycoside, is considered to be a promising natural product due to its diverse pharmacological activities, including analgesic, antipyretic, anti-inflammatory and hepatoprotective activities. In this research, the metabolites of linarin in rat intestinal flora and biosamples were characterized using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS/MS). Three ring cleavage metabolites (4-hydroxybenzoic acid, 4-hydroxy benzaldehyde and phloroglucinol) were detected after linarin was incubated with rat intestinal flora. A total of 17 metabolites, including one ring cleavage metabolite (phloroglucinol), were identified in rat biosamples after oral administration of linarin. These results indicate that linarin was able to undergo ring fission metabolism in intestinal flora and that hydrolysis, demethylation, glucuronidation, sulfation, glycosylation, methylation and ring cleavage were the major metabolic pathways. This study provides scientific support for the understanding of the metabolism of linarin and contributes to the further development of linarin as a drug candidate.

Metabolic profiles of corydaline in rats by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

1. Corydaline, an isoquinoline alkaloid obtained from the rhizomes of Corydalis yanhusuo, exhibits anti-acetylcholinesterase, anti-angiogenic, anti-allergic and gastric-emptying activities. In this study, a rapid and reliable ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) method was developed and employed for the comprehensive study of the metabolites of corydaline in rats. 2. Altogether, 43 metabolites were identified in the plasma (11), bile (9), urine (34) and feces (21) of rats after oral administration of corydaline at a dose of 4.5mg/kg. 3. It was demonstrated that demethylation, hydroxylation, sulfation and glucuronidation were the major metabolic transformation pathways. Among these, two metabolites were identified as tetrahydropalmatine and isocorybulbine, and 33 phase I and phase II products were inferred to be new metabolites arising from the in vivo metabolism of corydaline. 4. Importantly, this research provides scientific and reliable support for full understanding of the metabolic profiles of corydaline and the results could help to elucidate its safety and efficacy.

Comparisons of external fixator combined with limited internal fixation and open reduction and internal fixation for Sanders type 2 calcaneal fractures: Finite element analysis and clinical outcome

OBJECTIVES

The aim of this study was to compare the biomechanical stability and clinical outcome of external fixator combined with limited internal fixation (EFLIF) and open reduction and internal fixation (ORIF) in treating Sanders type 2 calcaneal fractures.

METHODS

Two types of fixation systems were selected for finite element analysis and a dual cohort study. Two fixation systems were simulated to fix the fracture in a finite element model. The relative displacement and stress distribution were analysed and compared. A total of 71 consecutive patients with closed Sanders type 2 calcaneal fractures were enrolled and divided into two groups according to the treatment to which they chose: the EFLIF group and the ORIF group. The radiological and clinical outcomes were evaluated and compared.

RESULTS

The relative displacement of the EFLIF was less than that of the plate (0.1363 mm to 0.1808 mm). The highest von Mises stress value on the plate was 33% higher than that on the EFLIF. A normal restoration of the Böhler angle was achieved in both groups. No significant difference was found in the clinical outcome on the American Orthopedic Foot and Ankle Society Ankle Hindfoot Scale, or on the Visual Analogue Scale between the two groups (p > 0.05). Wound complications were more common in those who were treated with ORIF (p = 0.028).

CONCLUSIONS

Both EFLIF and ORIF systems were tested to 160 N without failure, showing the new construct to be mechanically safe to use. Both EFLIF and ORIF could be effective in treating Sanders type 2 calcaneal fractures. The EFLIF may be superior to ORIF in achieving biomechanical stability and less blood loss, shorter surgical time and hospital stay, and fewer wound complications.Cite this article: M. Pan, L. Chai, F. Xue, L. Ding, G. Tang, B. Lv. Comparisons of external fixator combined with limited internal fixation and open reduction and internal fixation for Sanders type 2 calcaneal fractures: Finite element analysis and clinical outcome. Bone Joint Res 2017;6:433-438. DOI: 10.1302/2046-3758.67.2000640.

Identification of metabolites of palmatine in rats after oral administration using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Palmatine (PAL), a protopalmatine alkaloid, is an active constituent in a number of medicinal plants. In order to obtain a comprehensive and systematic metabolic profile of PAL, we investigated its metabolites in plasma, liver tissue, bile, urine, and feces samples after intragastrical administration to Sprague-Dawley rats with a dose of 100 mg/kg/day.

METHODS

In this study, a rapid and sensitive method by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS), and Metabolynx™ software with the mass defect filter (MDF) technique was developed for screening and identification of the metabolites. The structural elucidation of the metabolites was performed by comparing their molecular weights and fragment ions with those of the parent drug.

RESULTS

As a result, a total of 58 metabolites were identified in rat biological samples including 46 metabolites in urine, 18 metabolites in plasma, 34 metabolites in bile, 26 metabolites in liver tissue, and 10 metabolites in feces. Among them, six major metabolites were fully confirmed using reference standards and others were identified by retention time, accurate mass and fragment ions.

CONCLUSIONS

These results indicated that phase I reactions (demethylation and hydroxylation) and phase II reaction (glucuronidation and sulfation) were the main metabolic pathways of PAL in vivo. This research enhances our understanding of metabolism of PAL in rats, and provides useful information on the action mechanism of PAL. Copyright © 2017 John Wiley & Sons, Ltd.

Two sulfonate metabolites of physalin A in rats

1. Physalin A is a bioactive withanolide isolated from the natural plant Physalis alkekengi var. franchetii (Solanaceae), a common traditional Chinese herbal medicine. This study aims to investigate the metabolites of physalin A in vivo. 2. Two metabolites (M1 and M2) were characterized as sulfonate metabolites in the feces obtained from rats treated with physalin A orally at a dose of 15 mg/kg/day for 3 days, by application of a UPLC-Q/TOF-MS method. Furthermore, formation of the two sulfonate metabolites was verified by chemical synthesis and NMR, including ¹H NMR, ¹³C NMR and two-dimensional NMR. The structures of M1 and M2 were identified to be 3α-sulfo-2,25β,27-trihydrophysalin A and 3α,27-disulfo-2,25α-dihydrophysalin A, respectively. 3. In summary, this study indicated that physalin A could be biotransformed to sulfonate metabolites with strong polarity, which contributed to the elimination of physalin A. A rare metabolic pathway has been revealed in this study.

Oxidative damage of naphthenic acids on the Eisenia fetida earthworm

Naphthenic acids (NAs) have been gaining recognition in recent years as potentially harmful environmental contaminants. Few studies have focused on the potential ecotoxicity of NAs to terrestrial environment. In this study, the responses of antioxidant system and lipid peroxidation and DNA damage were investigated after exposing Eisenia fetida to soil contaminated with NAs. The results indicated that NAs induced a significant increase (p < 0.05) in superoxide dismutase and catalase enzyme activities. The glutathione peroxidase enzyme activities were significantly inhibited (p < 0.05) in the medium and high dose treatments. An increase in malondialidehyde indicated that NAs could cause cellular lipid peroxidation in the tested earthworms. The percentage of DNA in the tail of comet assay of coelomocytes as an indication of DNA damage increased after treatment with different doses of NAs, and a dose-dependent DNA damage of coelomocytes was found. In conclusion, oxidative stress caused by NAs exposure induces physiological responses and genotoxicity on earthworms. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1337-1343, 2016.

Wnt1 and SFRP1 as potential prognostic factors and therapeutic targets in cutaneous squamous cell carcinoma

The Wnt signaling pathway plays a key role in insurgence and progression of many different forms of cancer. Some crucial components of the Wnt pathway have been proposed to be novel targets for cancer therapy. To date, the Wnt signaling pathway has not been studied in cutaneous squamous cell carcinoma (CSCC). This study was designed to investigate the expression of Wnt1 and SFRP1 from the Wnt pathway in CSCC. Tissue samples were obtained from 35 patients with CSCC and 30 controls admitted to the Xinjiang Uygur Autonomous Region People's Hospital at Urumchi City, China. Gene and protein expressions of Wnt1 and SFRP1 were quantified by immunohistochemistry and western blotting. Wnt1 expression was significantly higher (P < 0.05) in CSCC samples than in normal skin cells of the control subjects; in contrast, SFRP1 expression was significantly lower in CSCC tissues than that in tissues of control subjects (P < 0.05). Moreover, Wnt1 expression (P < 0.05) was found to be correlated with histopathological differentiation in CSCC, and negatively correlated with SFRP1 expression in CSCC (rs = -0.473, P = 0.015). Therefore, we concluded that Wnt1 and SFRP1 play important roles in the development of CSCC and could be potent markers for diagnosis, prevention, and therapy of CSCC.

Prognostic value of circulating tumor cells in metastatic breast cancer: a systemic review and meta-analysis

OBJECTIVE

Metastatic breast cancer (MBC) remains the main cause of cancer-related death, and the clinical significance and prognostic role of circulating tumor cells (CTCs) in metastatic breast cancer are still controversial. Here, we conducted a meta-analysis to clarify the correlation between CTCs and the clinicopathological features and prognosis of MBC.

METHODS

We performed a comprehensive search of Pubmed and the ISI Web of Science through December 2014. Only articles that focused on MBC patients and detected CTCs using the CellSearch system were included. The associations between CTCs and survival rate and clinicopathological parameters, including molecular pattern, metastatic region and treatment response, were evaluated.

RESULTS

This meta-analysis included 24 studies (3701 MBC patients), 13 prospective studies and 11 retrospective studies. We found that CTCs were more frequently detected with HER2 + primary tumors (pooled RR = 0.73, 95 % CI = 0.63-0.84). Additionally, higher CTC numbers indicated a worse treatment response (RR = 0.56, 95 % CI = 0.40-0.79), poorer PFS (RR = 0.64, 95 % CI = 0.56-0.73) and poorer OS (RR = 0.69, 95 % CI = 0.64-0.75) in MBC patients.

CONCLUSION

Based on these results, we propose that HER2 positivity could be a significant risk factor for the presence of CTCs. Additionally, CTCs have a significant prognostic value for MBC patients. Therefore, CTCs should be continually monitored to guide the treatment of MBC patients, especially those with HER2 + primary tumors.

Transcriptional responses of earthworm (Eisenia fetida) exposed to naphthenic acids in soil

In this study, earthworms (Eisenia fetida) were exposed to commercial NAs contaminated soil, and changes in the levels of reactive oxygen species (ROS) and gene expressions of their defense system were monitored. The effects on the gene expression involved in reproduction and carcinogenesis were also evaluated. Significant increases in ROS levels was observed in NAs exposure groups, and the superoxide dismutase (SOD) and catalase (CAT) genes were both up-regulated at low and medium exposure doses, which implied NAs might exert toxicity by oxidative stress. The transcription of CRT and HSP70 coincided with oxidative stress, which implied both chaperones perform important functions in the protection against oxidative toxicity. The upregulation of TCTP gene indicated a potential adverse effect of NAs to terrestrial organisms through induction of carcinogenesis, and the downregulation of ANN gene indicated that NAs might potentially result in deleterious reproduction effects.

Quantitative FRET measurement using emission-spectral unmixing with independent excitation crosstalk correction

Quantification of fluorescence resonance energy transfer (FRET) needs at least two external samples, an acceptor-only reference and a linked FRET reference, to calibrate fluorescence signal. Furthermore, all measurements for references and FRET samples must be performed under the same instrumental conditions. Based on a novel notion to predetermine the molar extinction coefficient ratio (RC ) of acceptor-to-donor for the correction of acceptor excitation crosstalk, we present here a robust and independent emission-spectral unmixing FRET methodology, Iem-spFRET, which can simultaneously measure the E and RC of FRET sample without any external references, such that Iem-spFRET circumvents the rigorous restriction of keeping the same imaging conditions for all FRET experiments and thus can be used for the direct measurement of FRET sample. We validate Iem-spFRET by measuring the absolute E and RC values of standard constructs with different acceptor-to-donor stoichiometry expressed in living cells. Our results demonstrate that Iem-spFRET is a simple and powerful tool for real-time monitoring the dynamic intermolecular interaction within single living cells.

Genetic polymorphism studies in periodontitis and Fcγ receptors

Periodontitis is a complex chronic subgingival plaque-induced inflammatory disease influenced by multiple factors, including genetics, behavior and the environment. Many genetic association studies have been conducted in periodontology. One of the most extensively investigated gene families is the Fcγ receptor gene family, which plays a key role in regulating host immune responses to bacteria. Unlike other genetic polymorphisms reported in periodontology, most Fcγ receptor polymorphisms reported not only have established biological functions but are reported to associate with other autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. There are, however, few recent reviews summarizing the association of this gene family with periodontitis. This article critically reviews the current understanding of genetic polymorphism studies in periodontitis, then summarizes the research status of Fcγ receptor polymorphisms and periodontitis and also of other genes involved in the regulatory network of Fcγ receptors, with special reference to their anticipated biological roles. Moreover, some possible future research directions in the related area are discussed.

SNPs of Fc-gamma receptor genes and chronic periodontitis

Genetic polymorphisms of host defense genes might increase risk for periodontitis. This case-control study investigated whether 102 single-nucleotide polymorphisms (SNPs) in Fc gamma receptor (FCGR) genes are associated with chronic periodontitis. Cases were 190 Hong Kong Chinese patients with severe chronic periodontitis, and there were 169 periodontitis-free individuals as controls. Genotype CC and allele C of rs445509 (p < 0.0001, OR = 0.30) of FCGR3A were significantly more prevalent among control individuals than among cases, after adjustment for age, sex, and smoking. Smoking was significantly associated with chronic periodontitis (p = 0.003, OR = 3.35). Within the limitations of this study, SNP rs445509 of FCGR3A seem to be negatively associated, while smoking was positively associated, with severe chronic periodontitis among Hong Kong Chinese.

Single nucleotide polymorphisms of complement component 5 and periodontitis

BACKGROUND AND OBJECTIVE

Polymorphisms of host defence genes might increase one's risks for periodontitis. This study investigated whether tagging single nucleotide polymorphisms (SNPs) of the gene encoding complement component 5 (C5) are associated with periodontitis in a Hong Kong Chinese population.

MATERIAL AND METHODS

Eleven tagging SNPs of 229 patients with at least moderate periodontitis and 207 control subjects without periodontitis were genotyped using an i-plexGOLD MassARRAY mass-spectrometry system.

RESULTS

Genotype AG of SNP rs17611 was more prevalent in the group of periodontitis patients than in the controls (54.6% vs. 41.7%, p = 0.007). The haplotype CGCA of the haplotype block consisting of rs1035029, rs17611, rs25681 and rs992670 was significantly associated with periodontitis in a dominant model (p = 0.001). The SNP rs17611 showed high linkage disequilibrium with rs1035029, rs25681 and rs992670. Smoking was also significantly associated with periodontitis (p = 0.006).

CONCLUSION

The tagging SNP rs17611 of the C5 gene and smoking may be associated with periodontitis among the Hong Kong Chinese population.

Co-grafts of fetal ventral mesencephalon and fibroblasts expressing sonic hedgehog: effect on survival and function of dopamine grafts

Fibroblasts derived from the Rat2 parental cell line were genetically modified to express the cell-associated form of Sonic hedgehog (Shh) and then co-grafted along with E14 fetal ventral mesencephalon (VM) tissue into the denervated striatum of F344 rats; fetal VM grafts alone or co-grafts using the nonexpressing Rat2 fibroblasts served as controls. Seven weeks after grafting, co-grafts of fetal VM and fibroblasts expressing Shh (Rat2/Shh) contained significantly more tyrosine hydroxylase-positive (TH+) neurons than either the fetal VM grafts or co-grafts of fetal VM plus nonexpressing fibroblasts (Rat2). Despite a significantly higher yield of grafted TH+ neurons in the fetal VM + Rat2/Shh co-grafts than in either of the other two control groups, amphetamine-induced rotational behavior scores were not significantly different between any of the three treatment groups. The number of TH+ neurons in the Rat2 (nonexpressing) co-grafts was significantly lower than the other two treatment groups. The results from this study suggest that fibroblasts expressing Shh may improve the number of co-grafted dopamine neurons, but do not improve the functional capacity of the graft in terms of improving amphetamine-induced rotational behavior.

SALL1 expression in the human pituitary-adrenal/gonadal axis

SALL1 was originally identified on the basis of its DNA sequence homology to the region-specific homeotic gene Sal, in Drosophila melanogaster, which acts as a downstream target of hedgehog/tumor growth factor-beta-like decapentaplegic signals. The SALL1 gene has been associated with the Townes-Brocks Syndrome (TBS), a disorder characterized by multiorgan dysgenesis including renal and genital malformations. In this study, SALL1 message production was evaluated in association with the tissue localization of the protein product of SALL1, p140. SALL1 protein expression was observed in various adult and fetal tissues which elaborate reproductive endocrine hormones. The p140 was localized in specific microanatomic sites of the pituitary, adrenal cortex and the placenta. In the human pituitary, SALL1 protein expression was limited to the adenohypophysis, where it colocalized to those cells producing GH and the gonadotropins, LH and FSH. SALL1 expression was also found in most of the fetal and adult adrenal cortex in addition to the trophoblastic cells of the placenta. This pattern of expression complements prior studies demonstrating p140 in testicular fetal Leydig cells, adult Leydig and Sertoli cells, and granulosa cells of the ovary. The SALL1 protein was also shown here to be highly expressed in trophoblast tumors, which overproduce sex hormones. The expression patterns of SALL1 at multiple levels of the reproductive endocrine axis and the phenotypic effects associated with TBS suggest that SALL1 may have an important role in the interaction of the pituitary-adrenal/gonadal axis during reproduction.

Cloning and characterization of two promoters for the human HSAL2 gene and their transcriptional repression by the Wilms tumor suppressor gene product

HSAL2 is a member of a gene family that encodes a group of putative developmental transcription factors. The HSAL gene complex was originally identified on the basis of DNA sequence homology to a region-specific homeotic gene (SAL) in Drosophila. This study reveals a novel, functional 5' exon for HSAL2 and demonstrates that two distinct HSAL2 gene transcripts arise from two overlapping transcription units, resulting in proteins that differ by 25 amino acids. By utilizing functional luciferase reporter assays, two distinct promoters for HSAL2, P1 for the proximal promoter (upstream of exon 1) and P2 for the distal promoter (upstream of exon 1A), were identified. Evaluation of mRNA prevalence and tissue specificity, with particular focus on adult tissues, revealed that production of mRNA from P1 was selective and relatively rare. Production of mRNA from P2 was demonstrably higher and was expressed by a greater number of tissues. In contradistinction, HSAL2 expression directed by P2 was undetectable in some malignant populations as opposed to their normal human counterparts, suggesting a potential role as a tumor suppressor gene. Consensus-binding sites were identified for several transcriptional factors, with multiple sites for WT-1, and Hox-1.3 present within both the P1 and P2 regions. In transient transfection assays, transcription from both HSAL2 P1 and P2 was strikingly repressed by the WT-1 tumor suppressor protein. These findings suggest that an intracellular WT-1/HSAL2 pathway may play a role in development and hematopoiesis.

Overexpression of the HER-2/neu oncogene in pancreatic adenocarcinoma

Novel systemic treatments are needed in pancreatic cancer. The authors sought to establish the frequency of overexpression of the HER-2/neu oncogene in patients with pancreatic adenocarcinoma to determine the potential role of trastuzumab (Herceptin) as a therapeutic agent in this disease. Tumor specimens from patients with pancreatic adenocarcinoma were analyzed by staining for p185HER2 protein using the DAKO immunohistochemical assay. Patients with and without HER-2/neu overexpression by immunohistochemistry were compared with respect to clinical and pathologic characteristics. HER-2/neu gene amplification was also evaluated by fluorescence in situ hybridization (FISH). Thirty-two of 154 patients (21%) had pancreatic adenocarcinoma that demonstrated HER-2/neu overexpression by immunohistochemistry. At initial diagnosis, 16% of resectable cancers, 17% of locally advanced cancers, and 26% of metastatic cancers were determined to have HER-2/neu overexpression. Three of 11 (27%) patients with HER-2/neu overexpression by immunohistochemistry had gene amplification by FISH. HER-2/neu overexpression occurs in a subset of pancreatic cancer. Evaluation of the efficacy of trastuzumab for patients with pancreatic cancer who overexpress HER-2/neu appears indicated.

Hsal 1 is related to kidney and gonad development and is expressed in Wilms tumor

Townes-Brocks syndrome (TBS) is a human genetic disorder with features including urogenital, limb, anal and cardiac malformations associated with mutations of the TBS gene, Hsal 1. To begin to understand the role of the Hsal 1 protein (p140) in both normal development and disease pathogenesis, both message and protein expression were evaluated in specific tissues associated with TBS. DNA sequence information for Hsal 1 predicts that this homeotic, Drosophila homologue (Sal) encodes a zinc-finger protein consistent with a transcription factor. mRNA for Hsal 1 was highly expressed in fetal kidney and brain, with detectable production in thymus and heart. p140 was found in fetal ureteric bud, fetal and postnatal renal tubular epithelium, and renal blastema. In the 14-week fetal testis, the Hsal 1 protein was specifically expressed in the testosterone producing Leydig cells while in adult gonads Hsal 1 was also found in both Leydig and Sertoli cells, spermatogonia of the testis, and granulosa cells of the ovary. Evaluation of Wilms tumor revealed consistently high expression of the gene product in the epithelial and blastemal components. These spatial and temporal patterns of expression for Hsal 1, and the phenotypic effects associated with TBS, suggest that Hsal 1 plays an important role in the development and functional maintenance of the kidney and gonads. Furthermore, the Hsal 1 gene product may play a part in the pathogenesis of specific neoplasms occurring in these organs in addition to its specific role in Townes-Brocks syndrome.

Monitoring of bio-oxidation process of ferrous ion by using piezoelectric impedance analysis

A new method of monitoring the bio-oxidation process of ferrous ion in the presence of Thiobacillus ferroxidans was proposed by piezoelectric impedance analysis. The time courses of the responses of impedance parameters for a quartz crystal in a culture system were simultaneously obtained and discussed. It was found that the frequency shift response originates mainly from the adsorption of bacterial metabolites on the surface of gold electrode. Experiments also examined the effect of culture temperature on the bio-oxidation process. Combined with the growth situation of the bacterium, an impedance response model reflecting the process was established. By fitting Delta f vs. time curves toward the proposed model, we obtained and discussed the bacterial growth parameters. The results showed that the proposed method could provide real time and multidimensional information to monitoring of the bio-oxidation process.