Bibliometric and visual analysis of intestinal flora and immunity

BACKGROUND

The gut microbiota and its stability have important relationships with immunity. However, bibliometric analysis in this field is underdeveloped. This study aims to visualize publications related to the gut microbiota and immunity to identify research frontiers and hotspots, providing references and guidance for further research.

METHODS

Gut microbiota and immunity data were retrieved from the Web of Science Core Collection database, and Microsoft Excel, Scimago Graphica and VOSviewer software were used to analyze publication output trends, the most productive countries/regions, journals, authors, co-cited references, and keywords.

RESULTS

This study analyzed 16,611 publications, including 10,865 articles and 5746 reviews, and found a continuous increase in publications related to gut microbiota and immunity since 2013. We identified 62,872 authors contributing to this field from 2144 journals and 9965 organizations/institutions in 145 countries/regions. The top publisher with the highest output is University of California System with 525 papers. Among these journals, the top 3 most prolific journals are Frontiers in Immunology, Frontiers in Microbiology, and PLOS ONE. The literature with the highest citation frequency is published in Science and has been cited 3006 times by Patrick M. Smith and others.Gut microbiota research hotspots include gut microbiota inflammation, immune response, inflammatory bowel diseases (IBDs), and microbiota tumors. The gut microbiota and its microbial homeostasis play critical roles in immune reactions, inflammation, and even tumors and IBDs.Current research on gut microbiota and immunity is a popular field. Previous studies have shown that the gut microbiota and its microbial species have important effects on maintaining human health, immune function, inflammation, tumorigenesis, and IBDs. Understanding the roles of microbial communities and specific bacterial species as well as their interactions with humans has led to numerous discoveries that provide unique opportunities for exploring human health and future research.

CONCLUSION

This study used bibliometric and visualization analysis to identify the development trends and hotspots of publications related to the gut microbiota and immunity. The findings of this study provide valuable insights into the emerging trends and future directions in this field.

Effect of Liuzijue exercise in different periods on circadian rhythm of blood pressure in patients with essential hypertension: A randomized trial

BACKGROUND

Exercising at different times of the day is a widely employed strategy for treating essential hypertension, aimed at enhancing the circadian rhythm of blood pressure. This study aimed to investigate the effects of Liuzijue exercise in the morning and afternoon on the circadian rhythm of blood pressure in patients with essential hypertension.

METHODS

This clinical randomized trial recruited 36 patients. They were randomly divided into 3 groups: morning exercise, afternoon exercise, and waiting treatment group. Randomization was performed at a ratio of 1:1:1, ensuring an equal distribution of participants among the 3 groups. Based on maintaining routine work and rest and continuing the original drug treatment, the exercise performed Liuzijue exercise for 12 weeks. The exercise time was 9:00 to 10:00 in the morning exercise group and 14:00 to 15:00 in the afternoon exercise group. The waiting treatment group did not perform any form of fitness exercise. The subjects in the 3 groups were monitored by 24-hour ambulatory blood pressure on the day before and after the first day.

RESULTS

After the 12-week Liuzijue exercise intervention, mean systolic blood pressure during the night significantly decreased in the morning exercise group (P < .01). In contrast, the waiting group experienced substantial increases in 24-hour mean systolic blood pressure (24hSBP), 24-hour mean diastolic blood pressure (24hDBP), mean systolic blood pressure during the daytime (dSBP), and mean diastolic blood pressure during the daytime (dDBP) (P < .01). Further analysis showed that the morning exercise group had significantly lower 24hSBP, 24hDBP, dSBP, dDBP, and mean systolic blood pressure during the night than the waiting group (P < .05). Additionally, the morning exercise group had lower 24hSBP and dSBP levels than the afternoon exercise group (P < .05). In contrast, the afternoon exercise group had lower 24hDBP and dDBP than the waiting treatment group (P < .05).

CONCLUSIONS

The 12-week Liuzijue exercise in the morning regimen demonstrated superior efficacy in reducing 24-hour ambulatory blood pressure levels among patients with essential hypertension. Moreover, it facilitates the transition of non-dipper blood pressure patterns to dippers, thereby rectifying aberrant circadian rhythms.

Research trends and hotpots on the relationship between high salt and hypertension: A bibliometric and visualized analysis

INTRODUCTION

A high salt diet is a significant risk factor for hypertension, and scholarly investigations into this relationship have garnered considerable attention worldwide. However, bibliometric analyses in this field remain underdeveloped. This study aimed to conduct a bibliometric and visual analysis of research progress on the link between high salt and hypertension from 2011 to 2022 with the goal of identifying future research trends and providing valuable insights for this field.

METHODS

High salt and hypertension data were obtained from the Web of Science Core Collection database. Microsoft Excel, Scimago Graphica, CiteSpace, and VOSviewer software were employed to analyze publication output trends, the most productive countries or regions, journals, authors, co-cited references, and keywords.

RESULTS

After screening, 1470 papers met the inclusion criteria. Relevant publications increased annually by 3.66% from 2011 to 2022. The United States led in research productivity, with The Journal of Hypertension publishing the most papers, and David L. Mattson as the most prolific author. Oxidative stress has emerged as a prominent research topic, and extensive investigations have been conducted on related mechanisms. "Oxidative stress," "gut microbiota," and "kidney injury" are recent hotspots that are expected to remain so, and this study carefully characterizes the mechanism of high salt-induced hypertension based on these hotspots.

CONCLUSION

This study utilized bibliometric and visualization analysis to identify the development trends and hotspots of publications related to high salt and hypertension. The findings of this study offer valuable insights into the forefront of emerging trends and future directions in this field.

Trends in research on dietary behavior and cardiovascular disease from 2002 to 2022: a bibliometric analysis

Background

Dietary behaviors and cardiovascular disease are two major health issues that have attracted a lot of attention from researchers worldwide. In this study, we aimed to provide a comprehensive analysis of the publication trends, authorship patterns, institutional affiliations, country/region contributions, journal outlets, highly cited documents, and keyword clusters in the field of dietary behaviors and cardiovascular disease research over the past two decades.

Methods

We conducted a systematic literature review of peer-reviewed articles published from 2002 to 2022 in the Web of Science Core Collection database. We extracted and analyzed data on the annual publication volume, authorship patterns, institutional affiliations, country/region contributions, journal outlets, highly cited documents, and keyword clusters using bibliometric methods and visualization tools.

Results

Our study analyzed 3,904 articles, including 702 reviews and 3,202 research articles. The results revealed a continuous increase in the number of publications in this field over the past two decades. The top 10 authors, institutions, and countries/regions with the highest publication output were identified, indicating the leading contributors to this field. Moreover, the most frequently cited documents and highly clustered keywords were identified, providing insights into the research themes and topics in this field.

Conclusion

Our study provides a comprehensive analysis of the publication trends, authorship patterns, institutional affiliations, country/region contributions, journal outlets, highly cited documents, and keyword clusters in the field of dietary behaviors and cardiovascular disease research over the past two decades. The findings provide valuable information for researchers, policymakers, and stakeholders to understand the research landscape, identify research gaps, and develop future research directions in this field.

Network Pharmacology Prediction and Metabolomics Validation of the Mechanism of Fructus Phyllanthi against Hyperlipidemia

Hyperlipidemia has become a leading risk factor for cardiovascular diseases and liver injury worldwide. Fructus Phyllanthi (FP) is an effective drug against hyperlipidemia in Traditional Chinese Medicine (TCM) and Indian Medicine theories, however the potential mechanism requires further exploration. The present research aims to reveal the mechanism of FP against hyperlipidemia based on an integrated strategy combining network pharmacology prediction with metabolomics validation. A high-fat diet (HFD)-induced mice model was established by evaluating the plasma lipid levels, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). Network pharmacology was applied to find out the active ingredients of FP and potential targets against hyperlipidemia. Metabolomics of plasma and liver were performed to identify differential metabolites and their corresponding pathways among the normal group, model group, and intervention group. The relationship between network pharmacology and metabolomics was further constructed to obtain a comprehensive view of the process of FP against hyperlipidemia. The obtained key target proteins were verified by molecular docking. These results reflected that FP improved the plasma lipid levels and liver injury of hyperlipidemia induced by a HFD. Gallic acid, quercetin, and beta-sitosterol in FP were demonstrated as the key active compounds. A total of 16 and six potential differential metabolites in plasma and liver, respectively, were found to be involved in the therapeutic effects of FP against hyperlipidemia by metabolomics. Further, integration analysis indicated that the intervention effects were associated with CYP1A1, AChE, and MGAM, as well as the adjustment of L-kynurenine, corticosterone, acetylcholine, and raffinose, mainly involving tryptophan metabolism pathway. Molecular docking ensured that the above ingredients acting on hyperlipidemia-related protein targets played a key role in lowering lipids. In summary, this research provided a new possibility for preventing and treating hyperlipidemia.

Recent advances of tanshinone in regulating autophagy for medicinal research

Initially described as an ancient and highly conserved catabolic biofunction, autophagy plays a significant role in disease pathogenesis and progression. As the bioactive ingredient of Salvia miltiorrhiza, tanshinone has recently shown profound effects in alleviating and treating various diseases by regulating autophagy. However, compared to the remarkable achievements in the known pharmacological effects of this traditional Chinese medicine, there is a lack of a concise and comprehensive review deciphering the mechanism by which tanshinone regulates autophagy for medicinal research. In this context, we concisely review the advances of tanshinone in regulating autophagy for medicinal research, including human cancer, the nervous system, and cardiovascular diseases. The pharmacological effects of tanshinone targeting autophagy involve the regulation of autophagy-related proteins, such as Beclin-1, LC3-II, P62, ULK1, Bax, ATG3, ATG5, ATG7, ATG9, and ATG12; the regulation of the PI3K/Akt/mTOR, MEK/ERK/mTOR, Beclin-1-related, and AMPK-related signaling pathways; the accumulation of reactive oxygen species (ROS); and the activation of AMPK. Notably, we found that tanshinone played a dual role in human cancers in an autophagic manner, which may provide a new avenue for potential clinical application. In brief, these findings on autophagic tanshinone and its derivatives provide a new clue for expediting medicinal research related to tanshinone compounds and autophagy.

[Soft tissue reconstruction strategy for sacral tumor resection]

Objective: To investigate the clinical strategy and effect of soft tissue reconstruction after sacral tumor resection in different planes. Methods: The data of 27 consecutive patients who underwent primary or secondary sacral tumor resection and soft tissue reconstruction from June 2012 to June 2021 at Dongnan Hospital of Xiamen University (the 909th Hospital) were retrospectively analyzed. There were 11 males and 16 females, aged (M(IQR)) (46.2±23.6) years (range: 16 to 72 years). Sacrospinous muscle, gluteus maximus and vertical rectus abdominis muscle flap were selected for soft tissue reconstruction according to the tumor site and the size of tissue defect. the postoperative follow-up was performed. The operative methods, intraoperative conditions, complications and disease outcomes were summarized. Results: Among the 27 patients with sacral tumor, the tumor plane was located in S₁ in 8 cases, S₂ in 5 cases and S₃ or below in 14 cases. There were 12 patients with tumor volume≤400 cm³ and 15 patients with tumor volume>400 cm³. Operation time was 100(90) minutes (range: 70 to 610 minutes), intraoperative blood loss was 800(1 600) ml (range: 400 to 6 500 ml). Soft tissue reconstruction was performed by transabdominal rectus abdominis transfer repair in 2 cases, extraperitoneal rectus abdominis transfer repair in 1 case, gluteus maximus transfer repair in 5 cases, gluteus maximus advancement repair in 13 cases, and sacrospinous muscle transfer repair in 6 cases. Postoperative complications occurred in 6 cases, including 1 case of incision infection, 4 cases of skin border necrosis, and 1 case of delayed infection due to fracture of internal fixator 3 years after operation, all of them were cured. The follow-up time was (35±21) months. Among the patients, 6 patients had recurrence, 2 patients with Ewing sarcoma died of lung metastasis 1 year after operation, 4 patients with metastatic cancer died of primary disease, and the remaining patients survived without disease. Conclusion: Choosing different soft tissue reconstruction strategies according to sacral tumor location and tissue defect size can effectively fill the dead space after sacral tumor resection, reduce postoperative complications and improve the prognosis of patients.

Characterization of the anti-AChE potential and alkaloids in Rhizoma Coptidis from different Coptis species combined with spectrum-effect relationship and molecular docking

Coptis species are the main source of Rhizoma Coptidis (RC) drugs, which have always been used to treat Alzheimer's disease in the clinical experience of ancient China. However, many species of this genus have been largely underutilized until now. With this fact, this research has been designed to investigate for the first time the anti-acetylcholinesterase (AChE) property of different extracts for RC drugs from four Coptis species (C. chinensis, C. deltoidea, C. teeta and C. omeiensis) and to quantify the main alkaloids. Petroleum ether, ethyl acetate and n-butanol fractions of RC drugs were sequentially collected using an accelerated solvent extraction technique. Spectrum-effect relationship and molecular docking were applied to analyse the relationships between alkaloids and AChE inhibitory activity. The N-butanol extract was proven to be the main active fraction, and C. teeta may be the best source of RC drugs for Alzheimer's disease treatment, with significantly lower IC 20, IC 50 and IC 80 values for AChE inhibition. The UPLC/QqQ-MS quantitative analysis showed that the accumulations of 10 alkaloids in RC drugs from different sources greatly varied. Three data processing methods (Random forest, Boruta and Pearson correlation) comprehensively analysed the spectrum-effect relationship and revealed that columbamine, berberine and palmatine were the most important AChE inhibitors that could be used as quality markers to select RC drugs for Alzheimer's disease treatment. In addition, the dominant compounds were successfully docked against AChE to verify the binding affinity and interactions with the active site. The present study can contribute to the reasonable development and utilization of RC drugs from different sources, especially to provide certain evidence for their application in the treatment of Alzheimer's disease.

[Macrophage migration inhibitory factor meditates MPP+/MPTP-induced NLRP3 inflammasome activation in microglia cells]

OBJECTIVE

To explore the mechanisms of macrophage migration inhibitory factor (MIF)/nucleus factor-κB (NF-κB) in mediating 1-methyl-4-phenylpyridinium iodide (MPP +)/1-Methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced activation of Nod-like receptor protein 3 (NLRP3) inflammasome in microglials and the its effects on neurons.

METHODS

Murine microglial cell line Bv-2 was infected with a lentivirus carrying MIF shRNA for MIF knockdown and then treated with MPP+. The total protein levels of NLRP3, caspase-1, p65 and p65 in the cell nuclei and cytoplasm were detected. ELISA was used to detect the levels of IL-1β and IL-18 in the culture supernatant, which served as the conditioned culture medium for MN9D cells, whose TH expression level was detected using Western blotting. The effect of stereotactic injection of an adeno-associated virus (AAV) carrying MIF shRNA on behaviors was assessed in a C57BL/6 mouse model of Parkinson disease (PD) induced by intraperitoneal MPTP injection. TH and Iba-1 immunohistochemistry was used to evaluate the number of substantia nigra neurons and the activation of microglia cells, and the protein expressions of MIF, NLRP3 and TH in the substantia nigra were detected with Western blotting.

RESULTS

MPP+ significantly increased NLRP3 and MIF expressions in Bv-2 cells (P < 0.05). MIF knockdown in Bv-2 cells significantly lowered NLRP3 and caspase-1 protein expressions and IL-1β and IL-18 levels in the culture supernatant (P < 0.05) without affecting total protein level of p65. Bv-2 cells with MIF knockdown showed significantly lowered p65 protein expression in the nuclei but increased p65 expression in the cytoplasm (P < 0.05). The conditioned medium derived from Bv-2 cells with MIF knockdown, as compared with that from than MPP +-treated Bv-2 cells, significantly increased TH expression in MN9D cells (P=0.01). Compared with those in MPTP group, the mice receiving injections of AAV-MIF-shRNA had higher scores in pole test and open field test with lower scores in traction test, and showed increased TH-positive neurons, decreased Iba-1 microglia cell activation, reduced expressions of MIF and NLRP3, and increased expression of TH in he substantia nigra (all P < 0.05).

CONCLUSION

Inhibition of MIF can reduce the expression of NLRP3 inflammasomes and inflammatory factor caused by MPP+ in microglia cells to relieve the damage of dopaminergic neurons and alleviate microglia cell activation, thus offering protection against neuroinflammation in Parkinson's disease.

Clicky hip alone is not a true risk factor for developmental dysplasia of the hip

AIMS

A clicky hip is a common referral for clinical and sonographic screening for developmental dysplasia of the hip (DDH). There is controversy regarding whether it represents a true risk factor for pathological DDH. Therefore a 20-year prospective, longitudinal, observational study was undertaken to assess the relationship between the presence of a neonatal clicky hip and pathological DDH.

PATIENTS AND METHODS

A total of 362 infants from 1997 to 2016 were referred with clicky hips to our 'one-stop' paediatric hip screening clinic. Hips were assessed clinically for instability and by ultrasound imaging using a simplified Graf/Harcke classification. Dislocated or dislocatable hips were classified as Graf Type IV hips.

RESULTS

The mean age at presentation was 13.8 weeks (12.8 to 14.7). In all 351 out of 362 children (97.0%) had Graf Type I hips (normal) that required no treatment. Nine children (2.5%) had Graf Type II hips but all resolved to Graf Type I hips on follow-up scans. One child (0.3%) had Graf Type III hip dysplasia and one child (0.3%) had an irreducible hip dislocation. The two pathological hips were associated with unilateral limited hip abduction. Mean referrals increased from 12.9 to 23.3 each year (p = 0.002) from the first decade of the study to the second, driven by increasing primary care referrals (5.5 versus 16.7 per year, p < 0.001).

CONCLUSION

Most clicky hips required no treatment other than reassurance to parents. Clicky hips with a normal hip examination should be considered a variant of normal childhood and not a risk factor for DDH. However, an abnormal hip examination including unilateral limited hip abduction should prompt urgent further investigations. Cite this article: Bone Joint J 2017;99-B:1533-6.

SU-E-J-108: Quantitative Analysis of Longitudinal Cognitive Impairment Due to Radiation Therapy Based on Automatic Segmentation of Hippocampus and Subcortical Structure

PURPOSE

In this study, we developed a quantitative analysis tool based on patient's longitudinal MR images to 1) measure the radiation dose received by each subcortical structure, 2) follow the change of volume and shape of each structure longitudinally. This tool provides a systematic approach to study the radiation therapy (and subsequent chemotherapy) associated with cognitive impairments.

METHODS

MRI scans of one patient taken before and after radiation therapy are demonstrated in this study. 3D Conformal radiation therapy was performed on RapidArc™. An open source MRI analysis tool, FMRIB's Integrated Registration and Segmentation Tool (FIRST), was used for segmentation. The images are registered to a standard template with expert-defined labeling for all sub-cortical structures, and the labeling of each structure is mapped back to the individual MRI space for segmentation. After the segmentation, the radiation dose map was coregistered to the MRI space to calculate the dose received by each structure.

RESULTS

For the structure that is contained within the radiation zone, we can calculate the total dose based on the volumetric distribution of radiation dose. For the structure that is outside the radiation field, we can calculate the distance from the radiation zone. We have demonstrated in this work that the analysis can be done for all segmented sub-cortical structures. The change of volume before and after radiation treatment can be analyzed, and the results can be correlated with the change of cognitive performance over time.

CONCLUSIONS

We presented an automated tool for efficient, quantitative and user-independent measurements of radiation dose in subcortical structures. The obtained results can be correlated with the cognitive test score and the clinical outcome to evaluate radiation and the subsequent chemotherapy induced changes in brain structures and functions.

SU-D-211-04: Sector Intensity Modulated (SIM) Gamma Knife Stereotactic Radiosurgery

PURPOSE

The latest Gamma Knife (GK) system, Perfexion, consists of 192 Co-60 sources divided into eight sectors. Treatment delivery includes multiple shots placed at different positions. For every shot, each sector can be either blocked or open with four different aperture sizes. However, the beam-on time is designed to be fixed. We proposed an innovative concept, Sector Intensity Modulated (SIM) Gamma Knife by dynamically varying the beam-on time for each individual sector to improve stereotactic radiosurgery planning quality.

METHODS

The anatomic structures and dose matrices from each sector for every shot were obtained from the GK workstation. The beam-on time for each sector was decomposed with various discrete levels and brute-force algorithm was used to get the optimal solution. The resulting SIM plan was then re-entered into the GK workstation. Six indices were used to benchmark the plan quality: Coverage, Conformality, Gradient, Maximum Dose(s) to critical structure(s), Volume receiving over 8 and 12 Gy. All the SIM plans in comparison with the original plans were further reviewed by an experienced oncologist.

RESULTS

The simulations were tested on various pituitary adenoma cases. Results consistently showed that SIM yielded better plans with all quantitative indices improved compared to original plan. It provides better conformality, quicker drop off of the isodose line outside the tumor, lower doses to the critical structures as optical- nerve/chiasm while maintaining at least 99% coverage of the tumor. Results were more favorable according to oncologist's view. In particular, up to 20% or 0.6 cc volume decrease in healthy tissue receiving 8 Gy was observed. This may translate into clinically observable reduction in acute/late toxicities.

CONCLUSIONS

Our preliminary results show that Sector Intensity Modulated Gamma Knife offers superior treatment plans compared to the originally delivered plans. Further works as adding dynamic shot location and dynamic shot shaping will be discussed.

WITHDRAWN: MyD88 is required for the recruitment of eosinophils and neutrophils but dispensable for host protective immune responses during Fasciola hepatica infection

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Clinical characteristics and biomarkers of breast cancer associated with choline concentration measured by 1H MRS

This study investigated the association between the total choline (tCho) concentration and the clinical characteristics and biomarker status of breast cancer. Sixty-two patients with breast cancer, 1.5  cm or larger in size on MR images, were studied. The tCho concentration was correlated with the MRI features, contrast enhancement kinetics, clinical variables and biomarkers. Pairwise two-tailed Spearman's nonparametric test was used for statistical analysis. The tCho concentration was higher in high-grade than moderate-/low-grade tumors (p = 0.04) and in tumors with higher K(trans) and k(ep) (p < 0.001 for both). The association of tCho concentration with age (p = 0.05) and triple negative biomarker (p = 0.09) approached significance. tCho was not detected in 17 patients, including 15 with invasive ductal cancer and two with infiltrating lobular cancer. Fifteen of the 17 patients had moderate- to low-grade cancers, and 11 had human epidermal growth factor-2-negative cancer, suggesting that these two factors might lead to false-negative choline. Higher tCho concentration in high-grade tumors and tumors with higher K(trans) and k(ep) indicates that choline is associated with cell proliferation and tumor angiogenesis. The higher choline level in younger women may be caused by their more aggressive tumor type. The results presented here may aid in the better interpretation of (1)H MRS for the diagnosis of breast lesions.

Sequence analysis of the first internal transcribed spacer of rDNA supports the existence of the intermediate Fasciola between F. hepatica and F. gigantica in mainland China

In the present study, a polymerase chain reaction-linked single-strand conformation polymorphism (PCR-SSCP) approach combined with DNA sequencing was used to characterise samples of Fasciola spp. from different host species and geographical locations in mainland China. The first internal transcribed spacer (ITS-1) of ribosomal DNA (rDNA) was amplified by PCR from individual Fasciola and analysed by SSCP. SSCP analyses displayed three different banding profiles that allowed the identification of all Fasciola samples examined into three groups: Fasciola hepatica, F. gigantica and the "intermediate" Fasciola. Then, the ITS-1 rDNA was sequenced from representative Fasciola samples, and analysis of the complete ITS-1 sequences supported the identification of all Fasciola samples by SSCP approach. The length of the ITS-1 sequences was 422 bp for all Fasciola samples sequenced. Although there was no variation in length or composition of the ITS-1 sequences among multiple specimens within each of the taxa, F. hepatica and F. gigantica differed by 1.2% in their ITS-1 sequences, whereas the "intermediate" Fasciola was unique, in which two different ITS-1 sequences exist in the rDNA array within a single Fasciola worm. One of the sequences is identical to that of F. hepatica, and the other is identical to that of F. gigantica. This study demonstrated that PCR-SSCP analysis of the ITS-1 rDNA followed by selective sequencing provides a reliable approach for the accurate identification of Fasciola spp., and also supports the existence of the "intermediate" Fasciola between F. hepatica and F. gigantica in mainland China.

Comparative study of the effects of several chemical and physical treatments on the activity of protease resistance and infectivity of scrapie strain 263K

To study the influences of chemical and physical factors on the protease resistant activity in vitro and the infectivity in vivo of scrapie strain 263K, PrPSc from the hamsters infected intracerebrally with scrapie strain 263K were treated with several commonly used disinfection methods, including sodium hydroxide (NaOH), sodium hypochlorite (NaOCl), heating or autoclaving at 80, 100, 121 and 134 degrees C in the solutions with or without 3% sodium dodecyl sulphate (SDS). The protease resistance of PrPSc was analysed by a proteinase K (PK) digesting Western blot and the infectivity of PrPSc was analysed by intracerebral (i.c.) inoculation into experimental hamsters. The results showed that PrPSc signals were removed in the preparations treated with NaOH higher than 0.05 mol/l, NaOCl higher than 0.1%, autoclaved over 121 degrees C, or heated over 80 degrees C in the presence of 3% SDS. Animal challenges revealed that mixing with 2 mol/l NaOH or 2% NaOCl, autoclaving at 134 degrees C, as well as heating at 100 degrees C or autoclaving at 121 degrees C in the solutions with 3% SDS completely blocks the transmission of scrapie 263K in this experimental situation. It is obvious that the removal of PK resistance of PrPSc happened at relatively lower concentration chemicals or lower temperature, while elimination of the infectivity needs more vigorous conditions. Our data provide the useful evidences for several commonly used methods to inactivate TSEs agent and suggest that it is inappropriate to use PrPSc as a surrogate for TSEs infectivity in inactivation experiments.

MAP kinase activation in cells exposed to a 60 Hz electromagnetic field

This research provides evidence that mitogen-activated protein kinase or extracellular signal-regulated kinase (MAPK/ERK) is activated in HL-60 human leukemia cells, MCF-7 human breast cancer cells, and rat fibroblast 3Y1 cells exposed to a 60 Hertz (Hz), 1 Gauss (G) electromagnetic field (EMF). The effects of EMF exposure were compared to those observed using 12-O-tetradecanoylphorbal-13-acetate (TPA) treatment. The level of MAPK activation in cells exposed to EMF was approximately equivalent to that in cells treated with 0.1-0.5 ng/ml of TPA. A role for protein kinase C (PKC) in the process leading to MAPK activation in EMF exposed cells is also suggested by the results. MAPK activation is negated by an inhibitor to PKCalpha, but not PKCdelta inhibitors, in cells subjected to EMF exposure or TPA treatment. Thus, similarities between the effects of EMF exposure and TPA treatment are supported by this investigation. This provides a possible method for revealing other participants in EMF-cell interaction, since the TPA induction pathway is well documented.

Treatment field shape verification using elliptic Fourier transform

An automated field shape correlation technique based on elliptic Fourier transform (EFT) is developed to verify the radiation treatment field in digital portal images. In this method, the edge of the treatment field is initially extracted from the portal image and is then approximated by a polygon. The polygon is further represented with elliptic Fourier coefficients. The invariants to shift, rotation, and scale are computed from the elliptic Fourier coefficients to characterize the genuine shape feature and are used to match the reference treatment field. Invariants calculated from both test and reference field shapes are compared to determine the similarity between two treatment fields. The proposed procedure uses the first approved field shape as the reference for automated comparison with subsequent portal images. This technique not only verifies the shape of each portal field but also provides information about relative shift, rotation, and scale. A set of generic shapes is simulated to test the robustness of the algorithm and to determine the parameters used in the decision procedure. Experimental results on the simulated shapes show that this method can detect shape distortions of 2% in area and the standard deviations are 0 for shifting, 0.24 degrees for rotation, and 0.0031 for scaling. Preliminary tests on clinical portal images indicated that this technique is potentially useful for automated real-time portal verification.

[Advances of research on speech signal processing strategy in cochlear implant]

Cochlear implant is a new technology to restore hearing ability to totally deaf people. First of all, this paper presents its principle and system design. Then, the advances of research on its speech signal processing strategy is reviewed in detail. Finally, on the basis of preliminary results, further promising development in cochlear implant is proposed.