Effect of Sintering Temperature on Microstructure Characteristics of Porous NiTi Alloy Fabricated via Elemental Powder Sintering

To investigate the effect of the sintering temperature on the microstructure characteristics of porous NiTi alloys, two types of porous NiTi alloys with equal atomic ratios were fabricated via elemental powder sintering at 950 °C and 1000 °C. Afterwards, optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were collectively applied to investigate the pore characteristics and microstructure of the fabricated porous NiTi alloy. The results show that when the sintering temperature increases from 950 °C to 1000 °C, the average pore size increases from 36.00 μm to 181.65 μm, owing to the integration of these newly formed small pores into these pre-existing large-sized pores. The measured density increases from 2.556 g/cm3 to 3.030 g/cm3, while the porosity decreases from 60.4% to 51.8%. This is due to the occurrence of shrinkage after the sufficient diffusion of atoms. Furthermore, the characterization results confirm that a change in the sintering temperature would not change the phase types within a porous NiTi alloy; namely, the matrix consists primarily of B2 NiTi, with a significant amount of Ni4Ti3 precipitates and a small amount of Ni3Ti precipitates and Ti2Ni precipitates. However, as the sintering temperature increases, the number of Ni4Ti3 precipitates decreases significantly. The formation of a Ni4Ti3 phase in the present study is closely related to the enrichment of Ni content in the matrix owing to the diffusion rate difference between Ni atoms and Ti atoms and the absence of a transient liquid phase (TLP) during the sintering process owing to the relatively low sintering temperature (lower than the eutectic temperature). Moreover, the increasing sintering temperature speeds up the atom diffusion, which contributes to a reduction in the enrichment of Ni as well as the number of formed Ni4Ti3 precipitates.

Pediatric Crohn's disease diagnosis aid via genomic analysis and machine learning

Introduction

Determination of pediatric Crohn's disease (CD) remains a major diagnostic challenge. However, the rapidly emerging field of artificial intelligence has demonstrated promise in developing diagnostic models for intractable diseases.

Methods

We propose an artificial neural network model of 8 gene markers identified by 4 classification algorithms based on Gene Expression Omnibus database for diagnostic of pediatric CD.

Results

The model achieved over 85% accuracy and area under ROC curve value in both training set and testing set for diagnosing pediatric CD. Additionally, immune infiltration analysis was performed to address why these markers can be integrated to develop a diagnostic model.

Conclusion

This study supports further clinical facilitation of precise disease diagnosis by integrating genomics and machine learning algorithms in open-access database.

β-Boswellic Acid Suppresses Breast Precancerous Lesions via GLUT1 Targeting-Mediated Glycolysis Inhibition and AMPK Pathway Activation

Breast carcinoma is a multistep progressive disease. Precancerous prevention seems to be crucial. β-Boswellic acid (β-BA), the main component of the folk medicine Boswellia serrata (B. serrata), has been reported to be effective in various diseases including tumors. In this work, we demonstrated that β-BA could inhibit breast precancerous lesions in rat disease models. Consistently, β-BA could suppress proliferation and induce apoptosis on MCF-10AT without significantly influencing MCF-10A. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that β-BA may interfere with the metabolic pathway. Metabolism-related assays showed that β-BA suppressed glycolysis and reduced ATP production, which then activated the AMPK pathway and inhibited the mTOR pathway to limit MCF-10AT proliferation. Further molecular docking analysis suggested that GLUT1 might be the target of β-BA. Forced expression of GLUT1 could rescue the glycolysis suppression and survival limitation induced by β-BA on MCF-10AT. Taken together, β-BA could relieve precancerous lesions in vivo and in vitro through GLUT1 targeting-induced glycolysis suppression and AMPK/mTOR pathway alterations. Here, we offered a molecular basis for β-BA to be developed as a promising drug candidate for the prevention of breast precancerous lesions.

A dose-response meta-analysis to evaluate the relationship between high-density lipoprotein cholesterol and all-cause and cardiovascular disease mortality

PURPOSE

Previous studies have not fully described the relationship between high-density lipoprotein cholesterol (HDL-C) and death risks from all cause and cardiovascular disease (CVD). This study quantitatively evaluates HDL-C-mortality associations.

METHODS

Embase and PubMed databases were searched for relevant articles published up to 1 June 2019. Random-effects models were used to pool relative risks (RRs) and 95% confidence intervals (CIs). We used restricted cubic splines to model the dose-response association.

RESULTS

We identified 32 prospective cohort studies including 369,904 participants and 33,473 total deaths (9426 CVD deaths). Compared to the lowest HDL-C levels, all cause and CVD mortality risks were reduced by 18% (RR 0.82; 95% CI, 0.73-0.93) and 36% (0.64, 0.46-0.89), respectively, for the highest HDL-C levels. All cause and CVD mortality risks were reduced by 15% (0.85, 0.79-0.92) and 23% (0.77, 0.69-0.87), respectively, with each 1 mmol/L increment of HDL-C. We found evidence of nonlinear and negative dose-response associations of HDL-C with all cause and CVD mortality (P_nonlinearity < 0.001), and the lowest death risks from all cause and CVD were observed at approximately 1.34 and 1.55 mmol/L, respectively.

CONCLUSION

HDL-C is inversely associated with all cause and CVD mortality risks under approximately 2.05 and 2.33 mmol/L, respectively. Optimal doses require investigation via clinical practice or high-quality research.

[Efficacy of intravenous thrombolysis for acute severe cerebral infarction and risk factors of poor prognosis: a randomized controlled trial in 152 cases]

OBJECTIVE

To investigate the clinical efficacy and safety of intravenous thrombolysis in patients with acute severe cerebral infarction and analyze the risk factors of poor prognosis after thrombolysis.

METHODS

This randomized controlled trial was conducted among 152 patients with acute severe cerebral infarction, with the onset time all within 4.5 h. The patients were randomized into control group (76 cases) and observation group (76 cases) and received treatment with routine therapy (antiplatelet aggregation, statins, neuroprotection and drugs that stimulate blood flow) and intravenous thrombolytic therapy with alteplase in addition to the routine therapy, respectively. The NIHSS scores were recorded at 24 h, 1 week and 1 month after the treatment. The mRS scores at 3 months and the incidence of symptomatic intracranial hemorrhage at one week after the treatment were compared between the two groups. According to mRS scores at 3 months, the patients in the observation group were divided into good prognosis group (30 patients) and poor prognosis group (46 patients), and the risk factors for poor prognosis were analyzed using univariate and multivariate Logistic regression analysis.

RESULTS

At 24 h, 1 week and 1 month after the treatment, the reduction of NIHSS scores was more significant in the observation group than in the control group (F=24.684, P < 0.001). At 3 months after the treatment, the mRS scores were significantly lower (t=4.396, P < 0.001) and the good prognosis rate was significantly higher (χ²=13.636, P < 0.001) in the observation group than those of the control group. Symptomatic intracranial hemorrhage occurred in 4 cases in the observation group and in 2 cases in the control group within 1 week after the treatment (χ²=0.694, P=0.405). The time from onset to thrombolysis (OR=0.173, P=0.035), prethrombolytic systolic pressure (OR=0.869, P=0.019) and baseline NIHSS score (OR=0.466, P=0.011) were identified as independent risk factors for poor prognosis after intravenous thrombolysis.

CONCLUSION

Intravenous thrombolysis is effective and safe for patients with acute severe cerebral infarction, and the time from onset to thrombolysis, prethrombolytic systolic pressure and baseline NIHSS score are independent risk factors for a poor prognosis after intravenous thrombolysis.

Accuracy of molecular diagnostic tests for drug-resistant tuberculosis detection in China: a systematic review

OBJECTIVE: To evaluate the accuracy of molecular diagnostics for the detection of drug-resistant tuberculosis (TB) in Chinese patients.METHOD: Seven databases were searched for eligible studies that evaluated the accuracy of molecular diagnostics against drug susceptibility testing (DST) for detecting drug resistance. A bivariate random-effects meta-analysis was conducted to pool sensitivity and specificity by the index test and drug resistance type.RESULTS: A total of 159 studies were included. Compared with DST (reference standard), Xpert^® could diagnose rifampicin (RMP) resistant TB accurately, with a pooled sensitivity and pooled specificity of 92% (95%CI 90-94) and 98% (95%CI 97-98), respectively. Line-probe assays (LPAs) also performed well for RMP resistance, with a pooled sensitivity of 91% (95%CI 88-93) and pooled specificity of 98% (95%CI 96-99), but not for isoniazid (INH) or second-line drugs due to lower sensitivity (<80%). The pooled sensitivity of GeneChip^® microarrays for RMP, INH and multidrug resistance was 89% (95%CI 86-91), 79% (95%CI 75-82) and 79% (95%CI 73-84), respectively, and the specificities were all >97%. Similarly, the MeltPro^® TB/STR assay had better sensitivity and specificity for first-line drugs, varying from 87% to 89% and 97% to 98%, respectively, than for second-line drugs.CONCLUSION: The Xpert assay, LPA, GeneChip assay, and MeltPro assay are credible methods with high accuracy for RMP resistance detection, but they may not be appropriate for other anti-tuberculosis drugs due to low sensitivity.

P6290Enhanced IL-6/pSTAT3/fibroblast signaling pathway contributes to spontaneous postoperative atrial fibrillation in a novel simulated cardiac surgery mouse model

Background

Cumulative evidences have shown that IL-6 in atrium might play an important role in the pathogenesis of postoperative AF (POAF) via activation of atrial fibrosis in patients undergoing CABG. However, whether atria produces IL-6 after the stimulation of CABG and its causal relationship with spontaneous POAF (sPOAF) and its specific pathways is still unclear.

Purpose

To test the hypothesis that atrium will produce IL-6 after CABG and causes sustained sPOAF (ssPOAF) through activating pSTAT3-mediated fibroblast proliferation.

Methods

To determine the causal relationship between IL-6 and sPOAF, IL-6−/− and wild type (WT) mice were both divided into three groups (10 mice/group): CABG group (NAI, mimic CABG), anti-inflammatory group (AI, mimic CABG with pericardial administration of methylprednisolone for 3 days via chest tube), and control group (anesthesia only). Mice were monitored for ssPOAF for 7 days using implanted telemetry device. Another two sets of mice, using the same models mentioned above, were euthanatized at 48th hours postoperatively. The atria of one set animals were excised and separated into pericardium (PC), pulmonary vein (PV), left atrium (LA), and right atrium (RA) and cultured for 4 hours. IL-6 levels in the supernatant were measured at 10 min and 4 hours of culture using ELISA test. The region producing the largest amount of IL-6 in the other set of animals was harvested for analyzing expressions of IL-6, pSTAT3/STAT3, connexin 43 and 40, fibroblast deposition, and collagen I and III. Path analysis was performed to determine the causal relationship of CABG induced IL-6 release, pSTAT3/fibroblast signaling, and the onset of ssPOAF.

Results

40% NAI-WT mice developed ssPOAF (Figure 1A) which was completely protected in IL-6−/− and AI groups. IL-6 was produced by all 4 atrial regions at 4hrs after CABG stimulation with the LA producing the highest amount. Western blotting (Figure 1B), RT-CPR, Masson staining, and immunofluorescence all showed a significantly upregulation of IL-6, pSTAT3/STAT3, fibroblasts, collagen I and III, and downregulation of Cx40 an 43 in NAI-WT mice, but not in IL-6−/− and AI mice. IL-6 was colocalized with vimentin to a large extent in cytoplasm (Figure 1C). IL-6 had strong positive correlation with pSTAT3/STAT3, collagen I and III (all r>0.700, P<0.001), moderate and weak negative correlation with Cx40 and 43 (r=−0.505, P<0.001; r=−0.307, P=0.048, respectively). Path analysis (Figure 1D) revealed that every 1 unit increase in IL-6 upregulated a 0.589 unit increase in ssPOAF, which was mediated by pSTAT3/collagen indirectly and collagen I/ collagen III directly.

Conclusion

Our study, for the first time, to the best of our knowledge, established a novel pathophysiological role of IL-6/pSTAT3/fibroblast signaling in the pathogenesis of ssPOAF and demonstrated that inhibition of atrial IL-6 might be a potential novel sPOAF prevention strategy.

Acknowledgement/Funding

The National Natural Science Foundation (No.81170170)

[~1H-NMR-based metabonomics analysis of the acute hepatotoxicity mechanism of Artemisia argyi essential oil]

This study based on~1H-NMR urine metabolomics technique combined with biochemical indicators to focus on studying the acute hepatotoxicity mechanism of Artemisia argyi essential oil( AAEO). In order to further explore the acute hepatotoxicity mechanism of AAEO,the researchers collected the urine nuclear magnetic data of rats in different periods of high and low doses of olive oil and AAEO group. Using the principal component analysis( PCA) and orthogonal partial least squares-discrimination analysis( OPLSDA) to analyze the endogenous small molecule metabolites in rat urine to study the effects of AAEO on the metabolic process of normal rats. The results showed there was a significant difference between the olive oil group and the AAEO group,the PCA scores chart demonstrated that there was no obvious separation tendency in the urine of olive oil group rats 0-6,6-12,12-24 h,and the metabolic components were distributed in aggregation pattern. The urinary metabolic trajectory of the rats in the AAEO group was conspicuously separated at 0-6,6-12,12-24 h. The experiments proved that the analysis of metabolites by~1H-NMR found that AAEO caused metabolic disorders in rats and produced acute hepatotoxicity. After metabolite differential comparison,it was speculated that the mechanism of acute hepatotoxicity may be involved in the tricarboxylic acid cycle and energy metabolism,while the citrate and oleanolic acid would be the potential biomarkers. This study discussed that the acute hepatotoxicity mechanism of AAEO was used to provide the experimental data for the clinical prescription of Artemisia argyi.

Higher plane of nutrition pre-weaning enhances Holstein calf mammary gland development through alterations in the parenchyma and fat pad transcriptome

Background

To reduce costs of rearing replacement heifers, researchers have focused on decreasing age at breeding and first calving. To increase returns upon initiation of lactation the focus has been on increasing mammary development prior to onset of first lactation. Enhanced plane of nutrition pre-weaning may benefit the entire replacement heifer operation by promoting mammary gland development and greater future production.

Methods

Twelve Holstein heifer calves (< 1 week old) were reared on 1 of 2 dietary treatments (n = 6/group) for 8 weeks: a control group fed a restricted milk replacer at 0.45 kg/d (R, 20% crude protein, 20% fat), or an accelerated group fed an enhanced milk replacer at 1.13 kg/d (EH, 28% crude protein, 25% fat). At weaning (8 weeks), calves were euthanized and sub-samples of mammary parenchyma (PAR) and mammary fat pad (MFP) were harvested upon removal from the body. Total RNA from both tissues was extracted and sequenced using the Illumina HiSeq2500 platform. The Dynamic Impact Approach (DIA) and Ingenuity Pathway Analysis (IPA) were used for pathway analysis and functions, gene networks, and cross-talk analyses of the two tissues.

Results

When comparing EH vs R 1561 genes (895 upregulated, 666 downregulated) and 970 genes (506 upregulated, 464 downregulated) were differentially expressed in PAR and MFP, respectively. DIA and IPA results highlight a greater proliferation and differentiation activity in both PAR and MFP, supported by an increased metabolic activity. When calves were fed EH, the PAR displayed transcriptional signs of greater overall organ development, with higher ductal growth and branching, together with a supportive blood vessel and nerve network. These activities were mediated by intracellular cascades, such as AKT, SHH, MAPK, and Wnt, probably activated by hormones, growth factors, and endogenous molecules. The analysis also revealed strong communication between MFP and PAR.

Conclusion

The transcriptomics and bioinformatics approach highlighted key mechanisms that mediate the mammary gland response to a higher plane of nutrition in the pre-weaning period.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5303-8) contains supplementary material, which is available to authorized users.

Concurrent use of capecitabine with radiation therapy and survival in breast cancer (BC) after neoadjuvant chemotherapy

PURPOSE

Capecitabine has been studied as a radiosensitizer, and our study seeks to examine the association of concurrent capecitabine/radiation therapy (RT) on event-free- (EFS) and overall survival (OS) in women with breast cancer (BC) with residual disease after neoadjuvant chemotherapy (NAC).

METHODS/PATIENTS

In a retrospective study of women with BC who received adriamycin/taxane-based NAC from 2004-2016, we identified 21 women administered concurrent capecitabine/RT. To assess differences in survival, we selected a clinical control cohort (n = 57) based on criteria used to select patients for capecitabine/RT. We also created a matched cohort (2:1), matching on tumor subtype, pathological stage and age (< 50 or 50+ years). Differences in EFS, using STEEP criteria, and OS, using all-cause mortality, between those who received capecitabine/RT and controls were assessed.

RESULTS

Of the 21 women who received capecitabine/RT, median age was 52 years. The majority were pathologic stage III (n = 15) and hormone receptor-positive/HER2-negative BC (n = 20). In those receiving capecitabine/RT, there were 9 events, compared with 14 events in clinical and 10 events in matched controls. Capecitabine/RT was associated with worse OS in clinical (HR 3.83 95% CI 1.12-13.11, p = 0.03) and matched controls (HR 3.71 95% CI 1.04-13.18, p = 0.04), after adjusting for clinical size, pathological stage and lymphovascular invasion. Capecitabine/RT was also associated with a trend towards worse EFS in clinical (HR 2.41 95% CI 0.86-6.74, p = 0.09) and matched controls (HR 2.68 95% CI 0.91-7.90, p = 0.07) after adjustment.

CONCLUSION

Concurrent capecitabine/RT after NAC is associated with worse survival and should be carefully considered in BC.

Canceling the Gravity Gradient Phase Shift in Atom Interferometry

Gravity gradients represent a major obstacle in high-precision measurements by atom interferometry. Controlling their effects to the required stability and accuracy imposes very stringent requirements on the relative positioning of freely falling atomic clouds, as in the case of precise tests of Einstein's equivalence principle. We demonstrate a new method to exactly compensate the effects introduced by gravity gradients in a Raman-pulse atom interferometer. By shifting the frequency of the Raman lasers during the central π pulse, it is possible to cancel the initial position- and velocity-dependent phase shift produced by gravity gradients. We apply this technique to simultaneous interferometers positioned along the vertical direction and demonstrate a new method for measuring local gravity gradients that does not require precise knowledge of the relative position between the atomic clouds. Based on this method, we also propose an improved scheme to determine the Newtonian gravitational constant G towards the 10 ppm relative uncertainty.

Effectiveness and safety of acupuncture combined with Madopar for Parkinson's disease: a systematic review with meta-analysis

OBJECTIVE

To evaluate the effectiveness and safety of acupuncture combined with Madopar for the treatment of Parkinson's disease (PD), compared to the use of Madopar alone.

METHODS

A systematic search was carried out for randomised controlled trials (RCTs) of acupuncture and Madopar for the treatment of PD published between April 1995 and April 2015. The primary outcome was total effectiveness rate and secondary outcomes included Unified Parkinson's Disease Rating Scale (UPDRS) scores. Data were pooled and analysed with RevMan 5.3. Results were expressed as relative ratio (RR) with 95% confidence interval (CIs).

RESULTS

Finally, 11 RCTs with 831 subjects were included. Meta-analyses showed that acupuncture combined with Madopar for the treatment of PD can significantly improve the clinical effectiveness compared with Madopar alone (RR=1.28, 95% CI 1.18 to 1.38, P<0.001). It was also found that acupuncture combined with Madopar significantly improved the UPDRS II (SMD=-1.00, 95% CI -1.71 to -0.29, P=0.006) and UPDRS I-IV total summed scores (SMD=-1.15, 95% CI -1.63 to -0.67, P<0.001) but not UPDRS I (SMD=-0.37, 95% CI -0.77 to 0.02, P=0.06), UPDRS III (SMD=-0.93, 95% CI -2.28 to 0.41, P=0.17) or UPDRS IV (SMD=-0.78, 95% CI -2.24 to 0.68, P=0.30) scores. Accordingly, acupuncture combined with Madopar appeared to have a positive effect on activities of daily life and the general condition of patients with PD, but was not better than Madopar alone for the treatment of mental activity, behaviour, mood and motor disability. In the safety evaluation, it was found that acupuncture combined with Madopar was associated with significantly fewer adverse effects including gastrointestinal reactions (RR=0.38, 95% CI 0.23 to 0.65, P<0.001), on-off phenomena (RR=0.27, 95% CI 0.11 to 0.66, P=0.004) and mental disorders (RR=0.24, 95% CI 0.06 to 0.92, P=0.04) but did not significantly reduce dyskinesia (RR=0.64, 95% CI 0.35 to 1.16, P=0.14).

CONCLUSION

Acupuncture combined with Madopar appears, to some extent, to improve clinical effectiveness and safety in the treatment of PD, compared with Madopar alone. This conclusion must be considered cautiously, given the quality of most of the studies included was low. Therefore, more high-quality, multicentre, prospective, RCTs with large sample sizes are needed to further clarify the effect of acupuncture combined with Madopar for PD.

Molecular network-based analysis of the mechanism of liver injury induced by volatile oils from Artemisiae argyi folium

Background

Volatile oils from Artemisiae argyi folium (VOAAF) is reported with hepatotoxicity, but the underlying mechanism is still unclear.

Methods

In the present study this molecular mechanism was explored with the Ingenuity Pathway Analysis (IPA). The chemical components of the VOAAF were searched in the database, and their target proteins were all identified in the PubChem, while drug-induced liver injury (DILI) genes were searched in the PubMed gene databases. The molecular network of protein targets for VOAAF and DILI genes was built with the IPA. The canonical pathways between the 2 networks were compared to decipher the molecular mechanisms of the liver injury induced by VOAAF.

Results

There were 159 target proteins for VOAAF and 338 genes related to DILI identified, which were further analyzed in the IPA. The canonical pathway comparison showed that VOAAF and DILI both worked on aryl hydrocarbon receptor (AHR), lipopolysaccharide (LPS)/interleukin 1 (IL-1) mediated inhibition of retinoid X receptor (RXR) function, pregnane X receptor (PXR)/RXR activation, xenobiotic metabolism, peroxisome proliferator-activated receptor (PPAR), hepatic cholestasis, farnesoid X receptor (FXR)/RXR activation, and glucocorticoid receptor.

Conclusion

VOAAF-induced liver injury may be involved in many pathways in which the AHR signaling and LPS/IL-1 mediated inhibition of RXR function pathways could be the most vital.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12906-017-1997-4) contains supplementary material, which is available to authorized users.

RNA interference unveils the importance of Pseudotrichonympha grassii cellobiohydrolase, a protozoan exoglucanase, in termite cellulose degradation

Based on prior work, a cellulase from glycosyl hydrolase family 7 (GHF7) was identified and found to be expressed at a high level in Coptotermes formosanus. To determine the function of GHF7 family members in vivo, we used RNA interference (RNAi) to functionally analyse the exoglucanase gene Pseudotrichonympha grassii cellobiohydrolase gene (PgCBH), which was highly expressed in Pseudotrichonympha grassii, a flagellate found in the hindgut of C. formosanus. In this study, the expression level of PgCBH was down-regulated by RNAi, causing the death of P. grassii, but no effect was observed for other flagellates found in C. formosanus. RNAi also resulted in significantly reduced exoglucanase activity, and no effect was observed for endoglucanase and β-glucosidase activities. This result demonstrated that the PgCBH gene plays a role in the protist lignocellulolytic process and is also important for host survival. PgCBH can be used as a target gene and has potential as a bioinsecticide for use against termites.

SeGSTo, a novel glutathione S-transferase from the beet armyworm (Spodoptera exigua), involved in detoxification and oxidative stress

Members of the glutathione S-transferase superfamily can protect organisms against oxidative stress. In this study, we characterized an omega glutathione S-transferase from Spodoptera exigua (SeGSTo). The SeGSTo gene contains an open reading frame (ORF) of 744 nucleotides encoding a 248-amino acid polypeptide. The predicted molecular mass and isoelectric point of SeGSTo are 29007 Da and 7.74, respectively. Multiple amino acid sequence alignment analysis shows that the SeGSTo sequence is closely related to the class 4 GSTo of Bombyx mori BmGSTo4 (77 % protein sequence similarity). Homologous modeling and molecular docking reveal that Cys35 may play an essential role in the catalytic process. Additionally, the phylogenetic tree indicates that SeGSTo belongs to the omega group of the GST superfamily. During S. exigua development, SeGSTo is expressed in the midgut of the fifth instar larval stage, but not in the epidermis or fat body. Identification of recombinant SeGSTo via SDS-PAGE and Western blot shows that its molecular mass is 30 kDa. The recombinant SeGSTo was able to protect super-coiled DNA from damage in a metal-catalyzed oxidation (MCO) system and catalyze the 1-chloro-2,4-dinitrobenzene (CDNB), but not 1,2-dichloro-4-nitrobenzene (DCNB), 4-nitrophenethyl bromide (4-NPB), or 4-nitrobenzyl chloride (4-NBC). The optimal reaction pH and temperature were 8 and 50 °C, respectively, in the catalysis of CDNB by recombinant SeGSTo. The mRNA expression of SeGSTo was up-regulated by various oxidative stresses, such as CdCl2, CuSO4, and isoprocarb, and the catalytic activity of recombinant SeGSTo was noticeably inhibited by heavy metals (Cu(2+) and Cd(2+)) and various pesticides. Taken together, these results indicate that SeGSTo plays an important role in the antioxidation and detoxification of pesticides.

Selection and evaluation of potential reference genes for gene expression analysis in the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae) using reverse-transcription quantitative PCR

The brown planthopper (BPH), Nilaparvata lugens (Hemiptera, Delphacidae), is one of the most important rice pests. Abundant genetic studies on BPH have been conducted using reverse-transcription quantitative real-time PCR (qRT-PCR). Using qRT-PCR, the expression levels of target genes are calculated on the basis of endogenous controls. These genes need to be appropriately selected by experimentally assessing whether they are stably expressed under different conditions. However, such studies on potential reference genes in N. lugens are lacking. In this paper, we presented a systematic exploration of eight candidate reference genes in N. lugens, namely, actin 1 (ACT), muscle actin (MACT), ribosomal protein S11 (RPS11), ribosomal protein S15e (RPS15), alpha 2-tubulin (TUB), elongation factor 1 delta (EF), 18S ribosomal RNA (18S), and arginine kinase (AK) and used four alternative methods (BestKeeper, geNorm, NormFinder, and the delta Ct method) to evaluate the suitability of these genes as endogenous controls. We examined their expression levels among different experimental factors (developmental stage, body part, geographic population, temperature variation, pesticide exposure, diet change, and starvation) following the MIQE (Minimum Information for publication of Quantitative real time PCR Experiments) guidelines. Based on the results of RefFinder, which integrates four currently available major software programs to compare and rank the tested candidate reference genes, RPS15, RPS11, and TUB were found to be the most suitable reference genes in different developmental stages, body parts, and geographic populations, respectively. RPS15 was the most suitable gene under different temperature and diet conditions, while RPS11 was the most suitable gene under different pesticide exposure and starvation conditions. This work sheds light on establishing a standardized qRT-PCR procedure in N. lugens, and serves as a starting point for screening for reference genes for expression studies of related insects.

Selection and evaluation of reference genes for expression analysis using qRT-PCR in the beet armyworm Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae)

Quantitative real-time PCR (qRT-PCR) is a reliable and reproducible technique for measuring and evaluating changes in gene expression. The most common method for analyzing qRT-PCR data is to normalize mRNA levels of target genes to internal reference genes. Evaluating and selecting stable reference genes on a case-by-case basis is critical. The present study aimed to facilitate gene expression studies by identifying the most suitable reference genes for normalization of mRNA expression in qRT-PCR analysis of the beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae). For this purpose, three software tools (geNorm, NormFinder and BestKeeper) were used to investigate 10 candidate reference genes in nine developmental stages and five different tissues (epidermis, head, midgut, fat body and hemolymph) in three larval physiological stages (molting, feeding and wandering stages) of, S. exigua. With the exception of 18S ribosomal RNA (18S), all other candidate genes evaluated, β-actin1(ACT1), β-actin2 (ACT2), elongation factor1(EF1), elongation factor 2 (EF2), Glyceralde hyde-3-phosphate dehydrogenase (GAPDH), ribosomal protein L10 (L10), ribosomal protein L17A (L17A), superoxide dismutase (SOD), α-tubulin (TUB),proved to be acceptable reference genes. However, their suitability partly differed between physiological stages and different tissues. L10, EF2 and L17A ranked highest in all tissue sample sets. SOD, ACT2, GAPDH, EF1 and ACT1 were stably expressed in all developmental stage sample sets; ACT2, ACT1 and L10 for larvae sample sets; GAPDH, ACT1 and ACT2 for pupae and adults; SOD and L17A for males; and EF2 and SOD for females. The expression stability of genes varied in different conditions. The findings provided here demonstrated, with a few exceptions, the suitability of most of the 10 reference genes tested in tissues and life developmental stages. Overall, this study emphasizes the importance of validating reference genes for qRT-PCR analysis in S. exigua.

The cardiovascular effects of glucagon-like peptide-1 receptor agonists: a trial sequential analysis of randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Glucagon-like peptide-1 (GLP-1) receptor agonists are a new class of antidiabetic drugs. Their wider use for the treatment of patients with type 2 diabetes mellitus has led to concerns about its cardiovascular effects. However, the robustness of data leading to those concerns is unclear. The purpose of this study is to systematically assess the robustness of the available evidence on the adverse cardiovascular effects of GLP-1 receptor agonists in patients with type 2 diabetes.

METHODS

The Cochrane library, MEDLINE, EMBASE and www.clinicaltrials.gov were searched from inception through to 25 January 2013. Randomized controlled trials (RCTs) were selected if they compared GLP-1 receptor agonists with placebo or other drugs with a duration ≥12 weeks. Mantel-Haenszel odds ratio (MH-OR) of cardiovascular events with 95% confidence interval (CI) was estimated using a random effects model. Trial sequential analysis based on required information size with an assumption of plausible reductions in relative risk in the low-bias trials, 5% risk of a type I error and 20% risk of a type II error was used to explore the robustness of available evidence.

RESULTS

Fifty-eight trials were included in the analysis (10 466 patients receiving GLP-1 receptor agonists and 7138 patients receiving comparators, respectively). Overall, the OR for cardiovascular events with GLP-1 receptor agonists was 0·52 (95% CI: 0·27-0·99) compared with placebo and 0·84 (95% CI: 0·52-1·36) with active controls. Trial sequential analyses showed that the actual accumulated sample size was only 11% (7445 of 65 212) and 13% (10 157 of 79 198) of the required information size for placebo-controlled trials and active-controlled trials, respectively. These results indicate that there is still insufficient evidence on cardiovascular events.

WHAT IS NEW AND CONCLUSION

GLP-1 receptor agonists do not seem to show any increased risk of cardiovascular events However, the available data from RCTs remain insufficient to confirm an absence of detrimental effect. More long-term trials and population-based studies are required to provide the necessary reassurance on the cardiovascular safety of GLP-1 receptor agonists.

Developmental regulation and antifungal activity of a growth-blocking peptide from the beet armyworm Spodoptera exigua

Insect cytokine growth-blocking peptides (GBPs) are involved in growth regulation and the innate immune response. However, the microbial binding and antimicrobial activities of GBPs remain unclear. Here, we investigate the developmental role and antifungal activity of a GBP from the beet armyworm Spodoptera exigua (SeGBP). Sequence analysis predicted that mature SeGBP consists of 24 amino acid residues, including 2 cysteine residues. During S. exigua development, SeGBP is constitutively expressed in the fat body during the larval and adult stages but not in pupae. SeGBP expression is up-regulated by 20-hydroxyecdysone and down-regulated by juvenile hormone analog. Recombinant SeGBP purified from baculovirus-infected insect cells retards the growth of S. exigua larvae. Additionally, SeGBP expression is acutely induced in the fat body after injection with Escherichia coli, Bacillus thuringiensis, or Beauveria bassiana. Recombinant SeGBP can bind to B. bassiana but not to E. coli or B. thuringiensis. Consistent with these findings, SeGBP shows antifungal activity against B. bassiana. Therefore, these results provide insight into the role of SeGBP during the innate immune response following microbial infection, and furthermore, they suggest a novel function for SeGBP as a direct antifungal agent against entomopathogenic fungi, such as B. bassiana.

A spider (Araneus ventricosus) chymotrypsin inhibitor that acts as an elastase inhibitor and a microbial serine protease inhibitor

Spider-derived Kunitz-type serine protease inhibitors have been shown to exhibit plasmin and elastase inhibition activity and potassium channel blocking activity, but thus far, no additional roles for spider-derived chymotrypsin inhibitors have been elucidated. In this study, a spider (Araneus ventricosus) chymotrypsin inhibitor (AvCI) that acts as an elastase inhibitor and a microbial serine protease inhibitor was identified. AvCI is a 70-amino acid mature peptide that displays eight conserved cysteine residues and a P1 lysine residue. Recombinant AvCI expressed in baculovirus-infected insect cells demonstrated inhibitory activity against chymotrypsin (Ki 49.85 nM), but not trypsin, which defines a role for AvCI as a spider-derived chymotrypsin inhibitor. AvCI also exhibited inhibitory activity against microbial serine proteases such as subtilisin A (Ki 20.51 nM) and proteinase K (Ki 65.42 nM). Furthermore, AvCI exhibited no detectable inhibitory effects on factor Xa, thrombin, tissue plasminogen activator, or plasmin; however, AvCI strongly inhibited human neutrophil elastase (Ki 8.74 nM) and porcine pancreatic elastase (Ki 11.32 nM), indicating that AvCI acts as an anti-elastolytic factor. These findings constitute molecular evidence that AvCI acts as an inhibitor against chymotrypsin, microbial serine proteases, and elastases. This paper provides a novel view of the functions of a spider-derived chymotrypsin inhibitor.

Progressive elevation of ap-1 activity during preneoplastic-to-neoplastic progression as modeled in mouse jb6 cell variants

The JB6 mouse epidermal cell system has been used extensively as an in vitro model for the study of tumor promotion and progression. The present study was directed to assessing the role of basal AP-1 activity in JB6 variants which represent preneoplastic to neoplastic progression and to addressing whether AP-1 activity is required for maintenance of the tumor phenotype. Constitutively higher AP-1 activity was found in tumorigenic JB6 RT101 cells than in later or earlier preneoplastic P+ or P- cells. Levels of c-jun mRNA and protein correlated with progression stage. Enhancement of AP-1 activity by TPA increased the formation of anchorage independent colonies by tumorigenic RT101 cells. Inhibition of AP-1 activity by retinoic acid or fluocinolone acetonide inhibited expression of tumor phenotype as measured by AI growth. These data together with our previous results suggest that in the JB6 model (i) basal levels of Jun and AP-1 appear to be important for preneoplastic-to-neoplastic progression; (ii) induced AP-1 appears to be required for further progression by tumor cells; (iii) constitutively elevated AP-I activity may be important for the expression of transformed phenotype; (iv) inhibition of AP-1 activity by RA or FA is not a general suppression of transcription but is gene-specific; and (v) even though both inhibition of AP-1 activity and activation of RARE-dependent or GRE-dependent gene transcription correlate with inhibition of AI growth in RT101 cells by RA or FA, transactivation of RARE or GRE might better correlate with the inhibition of AI growth than the inhibition of AP-1 activity in RT101 cells.

Frequency of glycated hemoglobin monitoring was inversely associated with glycemic control of patients with Type 2 diabetes mellitus

BACKGROUND

The frequency of monitoring glycated hemoglobin (HbA(1c)) and its impact on glycemic control of Chinese Type 2 diabetes mellitus (T2DM) patients have not been well understood.

AIM

To explore the current status of the glycemic control, the frequency of HbA(1c) monitoring, and their relationship in T2DM outpatients in urban China.

SUBJECTS AND METHODS

A cross-sectional study was carried out in 15 hospitals purposely sampled from 4 cities of China. T2DM outpatients were consecutively recruited, and underwent a face-to-face interview in outpatient consulting rooms using a self-developed structured questionnaire to collect information. All consented patients were invited to have a free HbA(1c) test.

RESULTS

Among 1511 subjects, the average level of HbA(1c) was 8.1±1.6% with the ideal percents of 13.6% and 24.8% (HbA(1c)<6.5% and <7.0%, respectively). Less than 1/3 (339/1157) had received 2 or more HbA(1c) tests per yr, and they had a significantly lower average of HbA(1c) than those having only 1 or no test per yr (F=5.012, p=0.007). After adjustment for possible confounders including age, gender, and city, there was a significantly inverse association with adjusted odds ratios of 2.56 [95% confidence interval (CI): 1.71, 3.86] and 1.67 (95% CI: 1.11, 2.50), respectively, between the frequency of monitoring HbA(1c) (null, once vs ≥2 times per yr) and worse glycemic control (HbA(1c)≥7.0%).

CONCLUSIONS

Glycemic control of T2DM outpatients was poor in urban China. Frequency of HbA(1c) monitoring is seriously insufficient in majority of patients. Lower frequency of HbA(1c) monitoring is significantly associated with poor glycemic control.

Application of an ELISA-elution assay to dissociate digoxin-antibody complexes in immunoaffinity chromatography

In this study, we used a modified enzyme-linked immunosorbent assay (ELISA)-elution technique as a screening tool to select specific elution conditions. We examined 12 different elution conditions for the removal of antibodies from a complex on an ELISA plate; 0.2 mol/l glycine-HCl (pH 2.5), 1.0 mol/l acetic acid (pH 2.5), 25% methanol (pH 2.5) and 3 mol/l NaSCN showed a higher elution efficiency. We conducted affinity chromatography with these four conditions for the purification of anti-digoxin antibodies from hyperimmune sera with a digoxin-specific column using omega-aminoalkyl derivatives of Sepharose 4B, whose elution efficiency was similar to that of ELISA. We also monitored the relative specific activities during elution from the digoxin-specific column. The optimum, general-purpose dissociation reagent for this immunoaffinity system was identified as 25% methanol (pH 2.5) with an elution efficiency and relative specific activity of 88.40% and 62.25%, respectively. The high purity of the purified antibodies was demonstrated with sodium dodecyl sulphate-polyacrylamide gel electrophoresis.

Drug-metabolising enzyme polymorphisms and predisposition to anti-tuberculosis drug-induced liver injury: a meta-analysis

BACKGROUND

Although some case-control studies have investigated the association between drug-metabolising enzyme (DME) gene polymorphisms and susceptibility to anti-tuberculosis drug-induced liver injury (ATLI), their results are conflicting, mainly due to limited power.

OBJECTIVE

To review the literature systematically, by means of a meta-analytical review, to evaluate the putative association and provide a quantitative summary estimate on the association with ATLI.

DESIGN

We searched the databases of MEDLINE, PubMed, EMBASE and CBMdisc from 1966 to May 2007 using 'DME', 'hepatotoxicity', 'genetic polymorphism', 'genetic susceptibility' in combination with 'antitubercular agents', performed a manual search of citations from relevant original studies and review articles, and corresponded with authors.

RESULTS

Nine eligible articles were included in this meta-analysis, including five on N-acetyltransferase 2 (NAT2), four on cytochrome P450 2E1 (CYP2E1) and two on glutathione S-transferase (GST) studies, separately. The overall ORs of ATLI risk associated with NAT2 homozygous variant genotype (mt/mt), CYP2E1 homozygous wild genotype (*1A/*1A), GSTM1 homozygous null genotype (null/null) and GSTT1 homozygous null genotype (null/null) were respectively 1.93 (95%CI 0.81-4.62), 2.22 (95%CI 1.06-4.66), 2.62 (95%CI 1.45-4.75) and 1.18 (95%CI 0.61-2.29). In addition, the OR for Asian ATLI associated with the NAT2 homozygous variant (mt/mt) and the combined genotype (w/w + w/mt) was 2.52 (95%CI 1.49-4.26).

CONCLUSIONS

NAT2 mt/mt, CYP2E1*1A/*1A and GSTM1 null/null were observed to increase the risk of ATLI in tuberculosis patients. Our results support the hypothesis that NAT2 mt, CYP2E1*1A and GSTM1 null have a modest effect on genetic susceptibility to ATLI, but no significant evidence for GSTT1 null/null.

Fine mapping of E(kp)-1, a locus associated with silkworm (Bombyx mori) proleg development

The silkworm homeotic mutant E(kp) has a pair of rudimentary abdominal legs, called prolegs, in its A2 segment. This phenotype is caused by a single dominant mutation at the E(kp)-1 locus, which was previously mapped to chromosome 6. To explore the possible association of Hox genes with proleg development in the silkworm, a map-based cloning strategy was used to isolate the E(kp)-1 locus. Five E(kp)-1-linked simple sequence repeat markers on chromosome 6 were used to generate a low-resolution map with a total genetic distance of 39.5 cM. Four additional cleaved amplified polymorphic sequence markers were developed based on the initial map. The closest marker to E(kp)-1 was at a genetic distance of 2.7 cM. A high-resolution genetic map was constructed using nine BC1 segregating populations consisting of 2396 individuals. Recombination suppression was observed in the vicinity of E(kp)-1. Four molecular markers were tightly linked to E(kp)-1, and three were clustered with it. These markers were used to screen a BAC library. A single bacterial artificial chromosome (BAC) clone spanning the E(kp)-1 locus was identified, and E(kp)-1 was delimited to a region less than 220 kb long that included the Hox gene abdominal-A and a non-coding locus, iab-4. These results provide essential information for the isolation of this locus, which may shed light on the mechanism of proleg development in the silkworm and possibly in Lepidoptera.

Subthalamic nucleus stimulation for primary dystonia and tardive dystonia

With the renaissance of stereotactic pallidotomy for Parkinson's disease in 1990s, pallidotomy has become increasingly used as an effective treatment for various manifestations of medically refractory dystonia. More recently, deep brain stimulation of globus pallidus internus (GPi) has been replacing pallidotomy. Although GPi DBS has great promise for treating dystonia, there are some disadvantages. We introduce our experiences in subthalamic nucleus (STN) DBS for primary dystonia and tardive dystonia in this chapter. We propose that STN DBS has the following advantages over GPi DBS: (1) symptomatic improvement is seen immediately after stimulation, allowing us to quickly select the most suitable stimulation parameters; (2) the stimulation parameters for the STN are lower than those used for the GPi, resulting in longer battery life; and (3) STN DBS results in better symptomatic control than GPi DBS in dystonia patients when our STN data is compared to that obtained by others with using the GPi as the target. We suggest that STN DBS may be the most appropriate surgical technique for dystonia.

Decrease in density of INa is in the common final pathway to heart block in murine hearts overexpressing calcineurin

Overexpression of calcineurin in transgenic mouse heart results in massive cardiac hypertrophy followed by sudden death. Sudden deaths are caused by abrupt transitions from sinus rhythm to heart block (asystole) in calcineurin-overexpressing (CN) mice. Preliminary studies showed decreased maximum change in potential over time (d V/d tmax) of phase 0 of the action potential. Accordingly, the hypothesis was tested that decreased activity of the sodium channel contributes to heart block. Profound decreases in activity of sodium currents ( INa) paralleled the changes in action potential characteristics. Progressive age-dependent decreases were observed such that at 42–50 days of life little sodium channel function existed. However, this was not paralleled by decreased protein expression as assessed by immunocytochemistry or by Western blot. Since calcineurin can interact with the ryanodine receptor, we assessed whether chronic in vitro treatment with BAPTA-AM, thapsigargin, and ryanodine could rescue the decrease of INa. All of these treatments rescued INa to levels indistinguishable from wild type. The nonspecific PKC inhibitor bisindolylmaleimide I also rescued the decrease of INa. To assess whether decreased sodium channel activity contributes to sudden death in vivo, the response to encainide (20 mg/kg) was assessed: 6 of 10 young CN mice died because of asystole, whereas 0 of 10 wild-type mice died ( P < 0.01). Moreover, encainide produced exaggerated prolongation of the QRS width in sinus beats before the heart block. Catecholamine tone appears necessary to support life in older CN mice because propranolol (1 mg/kg) triggered asystolic death in five of six CN mice. We conclude that decrease in sodium channel activity is in the common final pathway to asystole in CN mice.

[Adverse drug reaction and rational use of levofloxacin: a prospective study]

OBJECTIVE

To study the rate of adverse drug reaction(ADR) and the rational use of levofloxacin among in-patients.

METHOD

All in-patients treated with levofloxacin were prospectively observed in 7 hospitals of Beijing.

RESULTS

One hundred and five ADR cases were found in 2,661 patients injected with levofloxacin. The ADR rate was 3.9% while 4.8% of them were classified as severe cases. All severe ADR cases had a nature of double infections. The ADR occurrence was related to older age, irrational drug use, combined medicine and allergic history. The rate of levofloxacin irrational use was 19.9%, especially in the elderly population, due to too long or too short course of treatments.

CONCLUSION

Levofloxacin is viewed as a safe injection in clinical practice, however, combined medicine and elderly patients should be paid more attention when on administration of this medication. The irrational use of levofloxacin was recognized as one of the main reasons causing the increase of ADR.

Bid is cleaved by calpain to an active fragment in vitro and during myocardial ischemia/reperfusion

Reperfusion after myocardial ischemia is associated with a rapid influx of calcium, leading to activation of various enzymes including calpain. Isolated perfused adult rabbit hearts subjected to global ischemia and reperfusion were studied. Calpain or a calpain-like activity was activated within 15 min after reperfusion, and preconditioning suppressed calpain activation. In contrast, caspase activation was not detected although cytochrome c was released after ischemia and reperfusion. The pro-apoptotic BH3-only Bcl-2 family member, Bid, was cleaved during ischemia/reperfusion in the adult rabbit heart. Recombinant Bid was cleaved by calpain to a fragment that was able to mediate cytochrome c release. The calpain cleavage site was mapped to a region within Bid that is extremely susceptible to proteolysis. These findings suggest that there is cross-talk between apoptotic and necrotic pathways in myocardial ischemia/reperfusion injury.

Ultrasound detection of blunt splenic injury

The purpose of this study was to determine the sensitivity of emergency ultrasound (US) for the detection of blunt splenic injury (BSI), and to describe sonographic parenchymal patterns. Over 3 years, 2138 emergency US were performed, and 162 patients had BSI. CT was performed for 76 patients, and there were 86 laparotomies. Seventy patients (43%) had concomitant intraabdominal injuries. Ultrasound detected free fluid in 109 patients (67%), and parenchymal injury in 31 patients (19%). There were 48 false negative US (30%). Sonographic patterns included a diffuse heterogeneous appearance, hyperechoic and hypoechoic perisplenic crescents, and discrete hypoechoic or hyperechoic areas within the spleen. Overall sensitivity of US for detection of BSI was 69%, but was 86% for grade III or higher injuries. Ultrasound is most sensitive for the detection of grade III or higher BSI based on the presence of haemoperitoneum. Ultrasound may also identify BSI on the basis of parenchymal abnormality, with a diffuse heterogeneous pattern most commonly encountered. Sonographic evaluation for both free fluid and parenchymal injury improves sensitivity of US.

[The relationship of low density lipoprotein receptor gene polymorphism and hyperlipidemia]

OBJECTIVE

To study the relationship of low density lipoprotein receptor gene polymorphism and hyperlipidemia in the population with essential hypertension.

METHODS

People with different lipid levels including 107 hyperlipidemia, 104 at margin level and 108 normal were recruited in the study. Their polymorphisms of LDL-R gene were analyzed using PCR-RFLP.

RESULTS

There were three kinds of genotype: (+/+), (+/-), (-/-). In male, the frequencies of the (+/-) in three study groups were shown as follows: 41.18% in hyperlipidemia, 46.15% in margin level, 19.05% in normal lipid. The frequency of (+) allele was significantly higher in hyperlipidemia than that in normal lipid (24.51%, 25.00% and 11.11%, respectively). In women, the differences were not statistically significant. The nonconditional univariate and multivariate logistic regression analysis demonstrated that (+) allele of Ava II polymorphism of LDL-R was a genetic marker of male's hypercholesterolemia.

CONCLUSIONS

The frequency of (+/-) hyperlipidemia in males was higher than that in normal lipid group and the (+) allele in male hyperlipidemia was significantly more frequent seen than that in normal lipid group. These results suggested that polymorphisms of LDL-Rgene might play an independent role of risk factor for hyperlipidemia.

Single subject research designs for disability research

PURPOSE

The objective of this article is to offer an overview of single subject designs and provide clinicians with information regarding the components of single subject designs and how they can be used in clinical and other rehabilitation environments.

METHOD/RESULT

Three basic designs in single subject research are presented, with corresponding examples illustrating each design. A review of visual and statistical analysis techniques commonly used in single subject designs is provided, and the advantages and limitations of each are noted.

CONCLUSION

Single subject designs are ideally suited for research in the rehabilitation practice environment. If properly applied, these designs can help establish the efficacy of rehabilitation practice and contribute to rehabilitation science.

Radio-frequency electrocautery ablation of mammary tissue in swine

PURPOSE

To establish the size, configuration, and histopathologic features of acute, subacute, and chronic radio-frequency (RF) electrocautery of mammary tissue in swine.

MATERIALS AND METHODS

Eighteen RF treatments were performed in the mammary tissue of three domestic swine under ultrasonographic (US) guidance. Histopathologic examination was performed immediately after (acute animal); 2 weeks after (subacute animal); and 4 weeks after (chronic animal) treatment.

RESULTS

In the acute animal, lesions were firm nodules on palpation and had a distinct line of demarcation between necrotic and viable mammary tissue (mean lesion volume, 14.24 cm(3); largest volume, 29.06 cm(3)). In the subacute animal, there was diffuse coagulation necrosis with neutrophilic infiltrates at the periphery (mean lesion volume, 6.46 cm(3); largest volume, 9.47 cm(3)), and two treatment areas had a secondary bacterial infection. In the chronic animal, lesions were still palpable and firm (mean lesion volume, 11.67 cm(3); largest volume, 25.5 cm(3)), and five of six treatment sites had an area of gray to white fibrotic tissue that blended with the surrounding tissue. However, one site had a pale yellow area of central necrosis surrounded by a fibrotic area. In both the subacute and chronic animals, two and one treatment site, respectively, had minimal areas of skin necrosis.

CONCLUSION

RF ablation of breast tissue is feasible in this animal model. Problems included minimal skin erythema, residual firm treatment regions at 4 weeks, slightly variable margins of coagulation necrosis, and occasional bacterial infection.