bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Characteristics Analysis with Multi-Directional Coupling in a TBM Mainframe
Authors: Lin Laikuang , Xia Yimin , Li Zhengguang , Wu Caizhang , Cheng Yongliang , Tan Qing
Published: December 2019

The cutterhead of a full-face rock tunnel boring machine (TBM) is constantly subjected to varying impact and dynamic loads during tunneling processes, resulting in relatively large vibrations that could easily lead to fatigue cracking of the entire machine and affect the tunneling performance and efficiency. To explore the dynamic characteristics of the TBM mainframe, a TBM from a water-diversion project is investigated in this research. According to the TBM vibration transmission route, an equivalent dynamic model of the TBM mainframe is established using the lumped-mass method in which the relevant dynamic parameters are solved. Additionally, the dynamic response characteristics of the TBM mainframe are analyzed. The results indicate that the vibration levels in three directions are approximately the same, the multi-directional vibration of the cutterhead is more intense than that of other components, and the vibration and external excitation exhibit identical change trends. A set of vibration field tests is performed to analyze the in situ dynamic responses of the mainframe and verify the correctness of the dynamic model. The theoretical and measured acceleration values of the TBM mainframe have the same magnitude, which proves the validity of the dynamic model and its solution. The aforementioned results provide an important theoretical value and practical significance for the design and assessment of the TBM mainframe.
Effects of the proportion of high-risk patients and control strategies on the prevalence of methicillin-resistant Staphylococcus aureus in an intensive care unit
Authors: Chamchod Farida , Palittapongarnpim Prasit
Published: December 2019

Background

The presence of nosocomial pathogens in many intensive care units poses a threat to patients and public health worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen endemic in many hospital settings. Patients who are colonized with MRSA may develop an infection that can complicate their prior illness.

Methods

A mathematical model to describe transmission dynamics of MRSA among high-risk and low-risk patients in an intensive care unit (ICU) via hands of health care workers is developed. We aim to explore the effects of the proportion of high-risk patients, the admission proportions of colonized and infected patients, the probability of developing an MRSA infection, and control strategies on MRSA prevalence among patients.

Results

The increasing proportion of colonized and infected patients at admission, along with the higher proportion of high-risk patients in an ICU, may significantly increase MRSA prevalence. In addition, the prevalence becomes higher if patients in the high-risk group are more likely to develop an MRSA infection. Our results also suggest that additional infection prevention and control measures targeting high-risk patients may considerably help reduce MRSA prevalence as compared to those targeting low-risk patients.

Conclusions

The proportion of high-risk patients and the proportion of colonized and infected patients in the high-risk group at admission may play an important role on MRSA prevalence. Control strategies targeting high-risk patients may help reduce MRSA prevalence.
Mortality risk and causes of death in patients with non-cystic fibrosis bronchiectasis
Authors: Sin Sooim , Yun Seo Young , Kim Jee Min , Park Chang Min , Cho Jaeyoung , Choi Sun Mi , Lee Jinwoo , Park Young Sik , Lee Sang-Min , Yoo Chul-Gyu , Kim Young Whan , Han Sung Koo , Lee Chang-Hoon
Published: December 2019

Background

All-cause mortality risk and causes of death in bronchiectasis patients have not been fully investigated. The aim of this study was to compare the mortality risk and causes of death between individuals with bronchiectasis and those without bronchiectasis.

Methods

Patients with or without bronchiectasis determined based on chest computed tomography (CT) at one centre between 2005 and 2016 were enrolled. Among the patients without bronchiectasis, a control group was selected after applying additional exclusion criteria. We compared the mortality risk and causes of death between the bronchiectasis and control groups without lung disease. Subgroup analyses were also performed according to identification of Pseudomonas or non-tuberculous mycobacteria, airflow limitation, and smoking status.

Results

Of the total 217,702 patients who underwent chest CT, 18,134 bronchiectasis patients and 90,313 non-bronchiectasis patients were included. The all-cause mortality rate in the bronchiectasis group was 1608.8 per 100,000 person-years (95% confidence interval (CI), 1531.5–1690.0), which was higher than that in the control group (133.5 per 100,000 person-years; 95% CI, 124.1–143.8; P < 0.001). The bronchiectasis group had higher all-cause (adjusted hazard ratio (aHR), 1.26; 95% CI, 1.09–1.47), respiratory (aHR, 3.49; 95% CI, 2.21–5.51), and lung cancer-related (aHR, 3.48; 95% CI, 2.33–5.22) mortality risks than the control group. In subgroup analysis, patients with airflow limitation and ever smokers showed higher all-cause mortality risk among bronchiectasis patients. Therefore, we observed significant interrelation between bronchiectasis and smoking, concerning the risks of all-cause mortality (P for multiplicative interaction, 0.030, RERI, 0.432; 95% CI, 0.097–0.769) and lung cancer-related mortality (RERI, 8.68; 95% CI, 1.631–15.736).

Conclusion

Individuals with bronchiectasis had a higher risk of all-cause, respiratory, and lung cancer-related mortality compared to control group. The risk of all-cause mortality was more prominent in those with airflow limitation and in ever smokers.
The clinical impact of drug-induced hepatotoxicity on anti-tuberculosis therapy: a case control study
Authors: Song Jin Hwa , Yoon Seo-Young , Park Tae Yun , Heo Eun Young , Kim Deog Kyeom , Chung Hee Soon , Lee Jung-Kyu
Published: December 2019

Background

There are limited data available on whether drug-induced hepatotoxicity (DIH) affects the clinical outcomes of tuberculosis (TB) treatment. We explored the effects of DIH on the clinical course and outcomes of pulmonary TB.

Methods

In this retrospective cohort study, we included patients with culture-proven pulmonary TB treated in a tertiary hospital from 2013 to 2016. DIH was defined as proposed by the official American Thoracic Society statement. We compared the clinical outcomes of DIH and non-DIH patients.

Results

Between January 1, 2013 and December 31, 2016, a total of 168 TB patients were included, and 20 (11.9%) were diagnosed with DIH. These patients were significantly older, had a higher Charlson Comorbidity Index score, exhibited more chronic liver disease, included more chronic alcoholics, and had a lower body mass index than non-DIH patients. We found no significant differences between DIH and non-DIH patients in the 2-month sputum culture conversion rate, the time to sputum culture conversion, treatment outcomes, or total treatment duration. However, the ratio of treatment interruption time to total treatment duration and the proportion of hepatotonic users were significantly higher among DIH patients.

Conclusion

DIH development during TB treatment does not significantly affect the clinical outcomes of pulmonary TB. However, treatment interruption caused by DIH may increase the risks of future relapse and acquired resistance. Further study is needed.
Comparative analyses of long non-coding RNA profiles in vivo in cystic fibrosis lung airway and parenchyma tissues
Authors: Kumar Parameet , Sen Chaitali , Peters Kathryn , Frizzell Raymond A. , Biswas Roopa
Published: December 2019

Background

Recent advances in the functional analyses of endogenous non-coding RNA (ncRNA) molecules, including long non-coding RNAs (LncRNAs), have provided a new perspective on the crucial roles of RNA in gene regulation. Consequently, LncRNA deregulation is a key factor in various diseases, including pulmonary disorders like Cystic Fibrosis (CF). CF is the most common life limiting recessive disease in the U.S., and is due to mutations in the CFTR gene. CF mutations, of which the most common is F508del-CFTR, prevents correct folding, trafficking and function of the mutant CFTR protein and is further manifested by the hyper-expression of pro-inflammatory cytokines and chemokines into the airway lumen leading to bronchiectasis and culminating in lung destruction.

Methods

Here we report a distinct LncRNA signature and corresponding mRNAs that distinguishes CF lung (airway and parenchyma) tissues from matched non-CF controls (n = 4 each group), generated by microarray specific for LncRNAs which includes corresponding mRNA expressions. In silico analyses of the cellular processes that are impacted by these LncRNAs was performed using Gene Ontology (GO). A selected subset of LncRNAs were validated by quantitative real-time PCR.

Results

We have identified 636 LncRNAs differentially expressed in CF airway epithelium and 1974 in CF lung parenchyma compared to matched non-CF controls (fold change ≥2, p < 0.05), majority of which (> 50%) are intergenic. Interestingly, 15 of these differentially expressed LncRNAs and 9 coding mRNAs are common to airway and parenchyma tissues. GO analyses indicates that signaling pathways and cell membrane functions are significantly affected by the alteration in LncRNA expressions in CF lung tissues. Seven of the differentially expressed LncRNAs, exhibit similar expression trends in CFBE41o- compared to control cells.

Conclusion

Understanding the mechanisms by which these LncRNAs regulate CF disease phenotype will help develop novel therapeutic targets for CF and related pulmonary diseases, such as COPD and Asthma.
Efficient Cas9-based genome editing of Rhodobacter sphaeroides for metabolic engineering
Authors: Mougiakos Ioannis , Orsi Enrico , Ghiffary Mohammad Rifqi , Post Wilbert , de Maria Alberto , Adiego-Perez Belén , Kengen Servé W. M. , Weusthuis Ruud A. , van der Oost John
Published: December 2019

Background

Rhodobacter sphaeroidesis a metabolically versatile bacterium that serves as a model for analysis of photosynthesis, hydrogen production and terpene biosynthesis. The elimination of by-products formation, such as poly-β-hydroxybutyrate (PHB), has been an important metabolic engineering target forR. sphaeroides. However, the lack of efficient markerless genome editing tools forR. sphaeroidesis a bottleneck for fundamental studies and biotechnological exploitation. The Cas9 RNA-guided DNA-endonuclease from the type II CRISPR-Cas system ofStreptococcus pyogenes(SpCas9) has been extensively employed for the development of genome engineering tools for prokaryotes and eukaryotes, but not forR. sphaeroides.

Results

Here we describe the development of a highly efficient SpCas9-based genomic DNA targeting system forR. sphaeroides, which we combine with plasmid-borne homologous recombination (HR) templates developing a Cas9-based markerless and time-effective genome editing tool. We further employ the tool for knocking-out the uracil phosphoribosyltransferase (upp)genefrom the genome ofR. sphaeroides,as well as knocking it back in while altering its start codon. These proof-of-principle processes resulted in editing efficiencies of up to 100% for the knock-out yet less than 15% for the knock-in. We subsequently employed the developed genome editing tool for the consecutive deletion of the two predicted acetoacetyl-CoA reductase genesphaBandphbBin the genome ofR. sphaeroides. The culturing of the constructed knock-out strains under PHB producing conditions showed that PHB biosynthesis is supported only by PhaB, while the growth of theR. sphaeroidesΔphbBstrains under the same conditions is only slightly affected.

Conclusions

In this study, we combine the SpCas9 targeting activity with the native homologous recombination (HR) mechanism ofR. sphaeroidesfor the development of a genome editing tool. We further employ the developed tool for the elucidation of the PHB production pathway ofR. sphaeroides.We anticipate that the presented work will accelerate molecular research withR. sphaeroides.
Triple blockade of EGFR, MEK and PD-L1 has antitumor activity in colorectal cancer models with constitutive activation of MAPK signaling and PD-L1 overexpression
Authors: Napolitano S. , Matrone N. , Muddassir A. L. , Martini G. , Sorokin A. , De Falco V. , Giunta E. F. , Ciardiello D. , Martinelli E. , Belli V. , Furia M. , Kopetz S. , Morgillo F. , Ciardiello F. , Troiani T.
Published: December 2019

Background

Molecular mechanisms driving acquired resistance to anti-EGFR therapies in metastatic colorectal cancer (mCRC) are complex but generally involve the activation of the downstream RAS-RAF-MEK-MAPK pathway. Nevertheless, even if inhibition of EGFR and MEK could be a strategy for overcoming anti-EGFR resistance, its use is limited by the development of MEK inhibitor (MEKi) resistance.

Methods

We have generated in vitro and in vivo different CRC models in order to underline the mechanisms of MEKi resistance.

Results

The three different in vitro MEKi resistant models, two generated by human CRC cells quadruple wild type for KRAS, NRAS, BRAF, PI3KCA genes (SW48-MR and LIM1215-MR) and one by human CRC cells harboring KRAS mutation (HCT116-MR) showed features related to the gene signature of colorectal cancer CMS4 with up-regulation of immune pathway as confirmed by microarray and western blot analysis. In particular, the MEKi phenotype was associated with the loss of epithelial features and acquisition of mesenchymal markers and morphology. The change in morphology was accompanied by up-regulation of PD-L1 expression and activation of EGFR and its downstream pathway, independently to RAS mutation status. To extend these in vitro findings, we have obtained mouse colon cancer MC38- and CT26-MEKi resistant syngeneic models (MC38-MR and CT26-MR). Combined treatment with MEKi, EGFR inhibitor (EGFRi) and PD-L1 inhibitor (PD-L1i) resulted in a marked inhibition of tumor growth in both models.

Conclusions

These results suggest a strategy to potentially improve the efficacy of MEK inhibition by co-treatment with EGFR and PD-L1 inhibitors via modulation of host immune responses.
Patients with pathogenic variants for breast cancer other than BRCA1 and BRCA2: qualitative interviews about health care experiences
Authors: Clift Kristin E. , Macklin Sarah K. , Hines Stephanie L.
Published: December 2019

Background

Genetic testing for hereditary cancer syndromes has been revolutionized by next-generation sequencing, which allows for simultaneous review of numerous genes. Multigene panels are regularly offered to patients because of their scope and decreased cost and turnaround time. However, many genes included on larger panels have not been studied as extensively as BRCA1 and BRCA2 (BRCA1/2), and their clinical effects are often not as well established.

Methods

We identified patients who received positive test results for pathogenic variants of breast cancer genes from January 2012 through May 2018. We mailed a survey and conducted qualitative interviews to explore the personal and health care experiences of patients with pathogenic variants of BRCA1/2 and patients with “other” (ie, non-BRCA1/2 or PALB2; PTEN; ATM; TP53; NBM, RAD51C; MSH6) variants. We compared the experiences of these patients.

Results

Fifty-nine out of 128 individuals responded to the survey (46%). Thirty-two patients had BRCA1/2 variants, and 27 had other variants. (49 women and 10 men; median [range] age, 63 [34–87] years). We interviewed 21 patients (17 women and 4 men; median [range] age, 59.6 [34–82] years). Of the interview participants, ten patients had BRCA1/2 variants, and 11 had non-BRCA1/2 variants. Patients reported receiving poor information about their genetic test results, and they often educated their physicians about their results. Some patients believed that they had been ignored or “brushed off” by health care professionals because non-BRCA1/2 genes are less understood outside the genetics research community. Patients with BRCA1/2 variants had similar problems with health care providers, despite increased awareness and established guidelines about BRCA1/2.

Conclusions

Research is required to understand the clinical significance and proper management of diseases attributable to newly characterized hereditary cancer genes. Additional evaluation of patient and provider education should be at the forefront of efforts to improve patient care.
Functional electrical stimulation-assisted cycle ergometry in the critically ill: protocol for a randomized controlled trial
Authors: Waldauf Petr , Gojda Jan , Urban Tomáš , Hrušková Natália , Blahutová Barbora , Hejnová Marie , Jiroutková Kateřina , Fric Michal , Jánský Pavel , Kukulová Jana , Stephens Francis , Řasová Kamila , Duška František
Published: December 2019

Background

Intensive care unit (ICU)-acquired weakness is the most important cause of failed functional outcome in survivors of critical care. Most damage occurs during the first week when patients are not cooperative enough with conventional rehabilitation. Functional electrical stimulation-assisted cycle ergometry (FES-CE) applied within 48 h of ICU admission may improve muscle function and long-term outcome.

Methods

An assessor-blinded, pragmatic, single-centre randomized controlled trial will be performed. Adults (n = 150) mechanically ventilated for < 48 h from four ICUs who are estimated to need > 7 days of critical care will be randomized (1:1) to receive either standard of care or FES-CE-based intensified rehabilitation, which will continue until ICU discharge. Primary outcome: quality of life measured by 36-Item Short Form Health Survey score at 6 months. Secondary outcomes: functional performance at ICU discharge, muscle mass (vastus ultrasound, N-balance) and function (Medical Research Council score, insulin sensitivity). In a subgroup (n = 30) we will assess insulin sensitivity and perform skeletal muscle biopsies to look at mitochondrial function, fibre typing and regulatory protein expression.

Trial registration

ClinicalTrials.gov, NCT02864745. Registered on 12 August 2016.
Breastfeeding success with the use of the inverted syringe technique for management of inverted nipples in lactating women: a study protocol for a randomized controlled trial
Authors: Nabulsi Mona , Ghanem Rayan , Abou-Jaoude Marlie , Khalil Ali
Published: December 2019

Background

Breastfeeding provides ideal infant nutrition, conferring several health benefits to children and their mothers. Women with inverted nipples, however, face difficulties that force them to prematurely terminate breastfeeding. Whereas available conservative measures for the correction of inverted nipples are of limited success, the use of an inverted syringe may be effective in achieving high rates of infant latching and exclusive breastfeeding. This technique, however, has not been investigated in a clinical trial.

Methods/design

This open-label randomized controlled trial aims to investigate whether, in women with inverted nipples, the use of an inverted syringe increases the rate of exclusive breastfeeding at one month compared to standard care. One-hundred healthy women with grade 1 or 2 inverted nipples will be recruited as of 37 weeks of gestation. They will be randomly allocated to standard care (control group) or to an intervention group. The intervention consists of using an inverted syringe to evert the nipple before every breastfeed, starting with the first feed after delivery. The primary outcome measure is the rate of exclusive breastfeeding at 1 month. Secondary outcome measures include exclusive breastfeeding rates at 3 and 6 months, nipple eversion rate, successful latching rate, rates of any breastfeeding at 1, 3, and 6 months, breastfeeding-associated complications, maternal satisfaction with breastfeeding, maternal quality of life, and adverse events. Descriptive and regression analysis will be conducted under the intention to treat basis.

Discussion

The use of the inverted syringe to evert inverted nipples is a simple, inexpensive, and safe technique that can be performed by mothers with inverted nipples. Findings of this trial, if positive, will provide much needed evidence for a safe, affordable, readily available, and simple intervention to treat inverted nipples, and improve breastfeeding practice among affected women.

Trial registration

ClinicalTrials.gov, NCT03529630. Registered May 8, 2018.
Sports participation related to injuries and illnesses among ambulatory youth with chronic diseases: results of the health in adapted youth sports study
Authors:   on behalf of the HAYS study group, Lankhorst Kristel , de Groot Janke , Takken Tim , Backx Frank
Published: December 2019

Background

Although sports participation leads to important health enhancement for youth with chronic diseases or physical disabilities (CDPD), it may pose an increased risk for injury or illness. This study investigated the incidence, type, severity and risks to (sports-related) injuries and illnesses among ambulatory youth with CDPD.

Methods

Over a 12-month period, every 2 weeks, the characteristics of injuries and illnesses were registered by an online questionnaire and phone-based interview. Physical activity level was measured with the Activ8 during 1 week. Complete data was available of 103 youngsters with CDPD (61 boys, 42 girls), with a mean age of 14.4 (SD = 2.7) years. The personal characteristics, the injury and illness rates per 1000 h of PA were investigated per group of organized sports participation per week (0, 1 or ≥ 2 times p/wk).

Results

Almost half of the youngsters sustained one or more injuries (46%) or illnesses (42%) during 1 year. The injury rate per 1000 h of PA between 0, 1 and ≥ 2 times per week of sports participation was 0.84, 1.88, 133 respectively and the illness rate were 1.87, 1.88 and 1.18 respectively. Differences between the rates were not statically significant. Most reported health problems had no subsequent restriction (49%) or other minor consequences (21%) in school, physical education or sports participation. Most reported health problems were contusions (41%) at the lower extremity (74%) and flu plus fever (58%).

Conclusions

Participation in sports ≥2 times per week does not pose a significant increased risk in the incidence of injury or illness per 1000 h of PA in youth with CDPD compared to their peers who participate less frequent (once weekly) and compared to non-sports participants. Athletes who participate in sports at least twice weekly get injured mostly during their sporting activities, while peers who do participate in sports once a week or not at all, get injured during less intense physical activities during physical eduction lessons, ADL or non-organized sports and play in leisure time. The social impact of injuries or illnesses was limited.
Mesenchymal stem cell-derived exosomal microRNA-133b suppresses glioma progression via Wnt/β-catenin signaling pathway by targeting EZH2
Authors: Xu Haiyang , Zhao Guifang , Zhang Yu , Jiang Hong , Wang Weiyao , Zhao Donghai , Hong Jin , Yu Hongquan , Qi Ling
Published: December 2019

Background

Mesenchymal stem cells (MSCs) play a significant role in cancer initiation and metastasis, sometimes by releasing exosomes that mediate cell communication by delivering microRNAs (miRNAs). This study aimed to investigate the effects of exosomal miR-133b derived from MSCs on glioma cell behaviors.

Methods

Microarray-based analysis identified the differentially expressed genes (DEGs) in glioma. The expression patterns of EZH2 and miR-133b along with interaction between them were clarified in glioma. The expression of miR-133b and EZH2 in glioma cells was altered to examine their functions on cell activities. Furthermore, glioma cells were co-cultured with MSC-derived exosomes treated with miR-133b mimic or inhibitor, and EZH2-over-expressing vectors or shRNA against EZH2 to characterize their effect on proliferation, invasion, and migration of glioma cells in vitro. In vivo assays were also performed to validate the in vitro findings.

Results

miR-133b was downregulated while EZH2 was upregulated in glioma tissues and cells. miR-133b was found to target and negatively regulate EZH2 expression. Moreover, EZH2 silencing resulted in inhibited glioma cell proliferation, invasion, and migration. Additionally, MSC-derived exosomes containing miR-133b repressed glioma cell proliferation, invasion, and migration by inhibiting EZH2 and the Wnt/β-catenin signaling pathway. Furthermore, in vivo experiments confirmed the tumor-suppressive effects of MSC-derived exosomal miR-133b on glioma development.

Conclusion

Collectively, the obtained results suggested that MSC-derived exosomes carrying miR-133b could attenuate glioma development via disrupting the Wnt/β-catenin signaling pathway by inhibiting EZH2, which provides a potential treatment biomarker for glioma.
The combinatory effect of sinusoidal electromagnetic field and VEGF promotes osteogenesis and angiogenesis of mesenchymal stem cell-laden PCL/HA implants in a rat subcritical cranial defect
Authors: Chen Jingyuan , Tu Chang , Tang Xiangyu , Li Hao , Yan Jiyuan , Ma Yongzhuang , Wu Hua , Liu Chaoxu
Published: December 2019

Background

Restoration of massive bone defects remains a huge challenge for orthopedic surgeons. Insufficient vascularization and slow bone regeneration limited the application of tissue engineering in bone defect. The effect of electromagnetic field (EMF) on bone defect has been reported for many years. However, sinusoidal EMF (SEMF) combined with tissue engineering in bone regeneration remains poorly investigated.

Methods

In the present study, we investigated the effect of SEMF and vascular endothelial growth factor (VEGF) on osteogenic and vasculogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs). Furthermore, pretreated rBMSC- laden polycaprolactone-hydroxyapatite (PCL/HA) scaffold was constructed and implanted into the subcritical cranial defect of rats. The bone formation and vascularization were evaluated 4 and 12 weeks after implantation.

Results

It was shown that SEMF and VEGF could enhance the protein and mRNA expression levels of osteoblast- and endothelial cell-related markers, respectively. The combinatory effect of SEMF and VEGF slightly promoted the angiogenic differentiation of rBMSCs. The proteins of Wnt1, low-density lipoprotein receptor-related protein 6 (LRP-6), and β-catenin increased in all inducted groups, especially in SEMF + VEGF group. The results indicated that Wnt/β-catenin pathway might participate in the osteogenic and angiogenic differentiation of rBMSCs. Histological evaluation and reconstructed 3D graphs revealed that tissue-engineered constructs significantly promoted the new bone formation and angiogenesis compared to other groups.

Conclusion

The combinatory effect of SEMF and VEGF raised an efficient approach to enhance the osteogenesis and vascularization of tissue-engineered constructs, which provided a useful guide for regeneration of bone defects.
Allogeneic mesenchymal stem cells for treatment of severe burn injury
Authors: Jeschke Marc G. , Rehou Sarah , McCann Matthew R. , Shahrokhi Shahriar
Published: December 2019

The most important determinant of survival post-burn injury is wound healing. For decades, allogeneic mesenchymal stem cells (MSCs) have been suggested as a potential treatment for severe burn injuries. This report describes a patient with a severe burn injury whose wounds did not heal with over 18 months of conventional burn care. When treated with allogeneic MSCs, wound healing accelerated with no adverse treatment complications. Wound sites showed no evidence of keloids or hypertrophic formation during a 6-year follow-up period. This therapeutic use of allogeneic MSCs for large non-healing burn wounds was deemed safe and effective and has great treatment potential.
Relative safety of various spermatogenic stem cell purification methods for application in spermatogenic stem cell transplantation
Authors: Tian Jia , Ma Ke , Pei Cheng-bin , Zhang Shao-hua , Li Xue , Zhou Yue , Yan Bei , Wang Hong-yan , Ma Liang-hong
Published: December 2019

Background

Spermatogonial stem cell (SSC) transplantation technology as a promising option for male fertility preservation has received increasing attention, along with efficient SSC purification technology as a necessary technical support; however, the safety of such application in patients with tumors remains controversial.

Methods

In this study, we used a green fluorescent protein mouse xenograft model of B cell acute lymphocytic leukemia. We isolated and purified SSCs from the testicular tissue of model mice using density gradient centrifugation, immune cell magnetic bead separation, and flow cytometry. The purified SSCs were transplanted into convoluted seminiferous tubules of the nude mice and C57BL/6 male mice subjected to busulfan. The development and proliferation of SSCs in the recipient testis were periodically tested, along with whether B cell acute lymphocytic leukemia was induced following SSC implantation. The genetic characteristics of the offspring obtained from natural mating were also observed.

Results

In testicular leukemia model mice, a large number of BALL cells infiltrated into the seminiferous tubule, spermatogenic cells, and sperm cells in the testis tissue decreased. After spermatogonial stem cell transplantation, the transplanted SSCs purified by immunomagnetic beads and flow cytometry methods colonized and proliferated extensively in the basement of the seminiferous tubules of mice; a large number of spermatogenic cells and sperm were found in recipient testicular tissue after 12 weeks of SSC transplantation. In leukemia detection in nude mice after transplantation in the three SSC purification groups, a large number of BALL cells could be detected in the blood of recipient mice 2–3 weeks after transplantation in the density gradient centrifugation group, but not in the blood of the flow cytometry sorting group and the immunomagnetic bead group after 16 weeks of observation.

Conclusions

In this study, we confirmed that immunomagnetic beads and flow cytometry methods of purifying SSCs from the testicular tissue of the testicular leukemia mouse model could be safely applied to the SSC transplantation technology without concomitant tumor implantation. The results thus provide a theoretical basis for the application of tumor SSC cryopreservation for fertility preservation in patients with tumors.
The superiority of conditioned medium derived from rapidly expanded mesenchymal stem cells for neural repair
Authors: Chen Ya-Tzu , Tsai May-Jywan , Hsieh Nini , Lo Ming-Jei , Lee Meng-Jen , Cheng Henrich , Huang Wen-Cheng
Published: December 2019

Abstracts

Background

Spinal cord injury (SCI) is a complex and severe neurological condition. Mesenchymal stem cells (MSCs) and their secreted factors show promising potential for regenerative medicine. Many studies have investigated MSC expansion efficacy of all kinds of culture medium formulations, such as growth factor-supplemented or xeno-free medium. However, very few studies have focused on the potential of human MSC (hMSC) culture medium formulations for injured spinal cord repair. In this study, we investigated the effect of hMSC-conditioned medium supplemented with bFGF, EGF, and patient plasma, namely, neural regeneration laboratory medium (NRLM), on SCI in vitro and in vivo.

Methods

Commercial and patient bone marrow hMSCs were obtained for cultivation in standard medium and NRLM separately. Several characteristics, including CD marker expression, differentiation, and growth curves, were compared between MSCs cultured in standard medium and NRLM. Additionally, we investigated the effect of the conditioned medium (referred to as NRLM-CM) on neural repair, including inflammation inhibition, neurite regeneration, and spinal cord injury (SCI), and used a coculture system to detect the neural repair function of NRLM-MSCs.

Results

Compared to standard culture medium, NRLM-CM had superior in inflammation reduction and neurite regeneration effects in vitro and improved functional restoration in SCI rats in vivo. In comparison with standard culture medium MSCs, NRLM-MSCs proliferated faster regardless of the age of the donor. NRLM-MSCs also showed increased adipose differentiative potential and reduced CD90 expression. Both types of hMSC CM effectively enhanced injured neurite outgrowth and protected against H2O2toxicity in spinal cord neuron cultures. Cytokine arrays performed in hMSC-CM further revealed the presence of at least 120 proteins. Among these proteins, 6 demonstrated significantly increased expression in NRLM-CM: adiponectin (Acrp30), angiogenin (ANG), HGF, NAP-2, uPAR, and IGFBP2.

Conclusions

The NRLM culture system provides rapid expansion effects and functional hMSCs. The superiority of the derived conditioned medium on neural repair shows potential for future clinical applications.
Modeling appendicular skeletal cartilage development with modified high-density micromass cultures of adult human bone marrow-derived mesenchymal progenitor cells
Authors: Pirosa Alessandro , Clark Karen L. , Tan Jian , Yu Shuting , Yang Yuanheng , Tuan Rocky S. , Alexander Peter G.
Published: December 2019

Background

Animal cell-based systems have been critical tools in understanding tissue development and physiology, but they are less successful in more practical tasks, such as predicting human toxicity to pharmacological or environmental factors, in which the congruence between in vitro and clinical outcomes lies on average between 50 and 60%. Emblematic of this problem is the high-density micromass culture of embryonic limb bud mesenchymal cells, derived from chick, mouse, or rat. While estimated predictive value of this model system in toxicological studies is relatively high, important failures prevent its use by international regulatory agencies for toxicity testing and policy development. A likely underlying reason for the poor predictive capacity of animal-based culture models is the small but significant physiological differences between species. This deficiency has inspired investigators to develop more organotypic, 3-dimensional culture system using human cells to model normal tissue development and physiology and assess pharmacological and environmental toxicity.

Methods

We have developed a modified, miniaturized micromass culture model using adult human bone marrow-derived mesenchymal progenitor cells (hBM-MPCs) that is amenable to moderate throughput and high content analysis to study chondrogenesis. The number of cells per culture was reduced, and a methacrylated gelatin (gelMA) overlay was incorporated to normalize the morphology of the cultures.

Results

These modified human cell-based micromass cultures demonstrated robust chondrogenesis, indicated by increased Alcian blue staining and immunodetectable production of collagen type II and aggrecan, and stage-specific chondrogenic gene expression. In addition, in cultures of hBM-MPCs transduced with a lentiviral collagen type II promoter-driven GFP reporter construct, levels of GFP reporter activity correlated well with changes in endogenous collagen type II transcript levels, indicating the feasibility of non-invasive monitoring of chondrogenesis.

Conclusions

The modified hBM-MPC micromass culture system described here represents a reproducible and controlled model for analyzing mechanisms of human skeletal development that may later be applied to pharmacological and environmental toxicity studies.
Genetically modified mesenchymal stem cell therapy for acute respiratory distress syndrome
Authors: Han Jibin , Liu Yuxiang , Liu Hong , Li Yuanyuan
Published: December 2019

Acute respiratory distress syndrome (ARDS) is a devastating hypoxemic respiratory failure, characterized by disruption of the alveolar-capillary membrane barrier. Current management for ARDS remains supportive, including lung-protective ventilation and a conservative fluid strategy. Mesenchymal stem cells (MSCs) have emerged as a potentially attractive candidate for the management of ARDS through facilitating lung tissue regeneration and repair by releasing paracrine soluble factors. Over the last decade, a variety of strategies have emerged to optimize MSC-based therapy. Among these, the strategy using genetically modified MSCs has received increased attention recently due to its distinct advantage, in conferring incremental migratory capacity and, enhancing the anti-inflammatory, immunomodulatory, angiogenic, and antifibrotic effects of these cells in numerous preclinical ARDS models, which may in turn provide additional benefits in the management of ARDS. Here, we provide an overview of recent studies testing the efficacy of genetically modified MSCs using preclinical models of ARDS.
Development of a high-throughput screen to identify small molecule enhancers of sarcospan for the treatment of Duchenne muscular dystrophy
Authors: Shu Cynthia , Kaxon-Rupp Ariana N. , Collado Judd R. , Damoiseaux Robert , Crosbie Rachelle H.
Published: December 2019

Background

Duchenne muscular dystrophy (DMD) is caused by loss of sarcolemma connection to the extracellular matrix. Transgenic overexpression of the transmembrane protein sarcospan (SSPN) in the DMDmdxmouse model significantly reduces disease pathology by restoring membrane adhesion. Identifying SSPN-based therapies has the potential to benefit patients with DMD and other forms of muscular dystrophies caused by deficits in muscle cell adhesion.

Methods

Standard cloning methods were used to generate C2C12 myoblasts stably transfected with a fluorescence reporter for human SSPN promoter activity. Assay development and screening were performed in a core facility using liquid handlers and imaging systems specialized for use with a 384-well microplate format. Drug-treated cells were analyzed for target gene expression using quantitative PCR and target protein expression using immunoblotting.

Results

We investigated the gene expression profiles of SSPN and its associated proteins during myoblast differentiation into myotubes, revealing an increase in expression after 3 days of differentiation. We created C2C12 muscle cells expressing an EGFP reporter for SSPN promoter activity and observed a comparable increase in reporter levels during differentiation. Assay conditions for high-throughput screening were optimized for a 384-well microplate format and a high-content imager for the visualization of reporter levels. We conducted a screen of 3200 compounds and identified seven hits, which include an overrepresentation of L-type calcium channel antagonists, suggesting that SSPN gene activity is sensitive to calcium. Further validation of a select hit revealed that the calcium channel inhibitor felodipine increased SSPN transcript and protein levels in both wild-type and dystrophin-deficient myotubes, without increasing differentiation.

Conclusions

We developed a stable muscle cell line containing the promoter region of the human SSPN protein fused to a fluorescent reporter. Using the reporter cells, we created and validated a scalable, cell-based assay that is able to identify compounds that increase SSPN promoter reporter, transcript, and protein levels in wild-type and dystrophin-deficient muscle cells.
Changes in cerebral glucose metabolism caused by morphologic features of prodromal idiopathic normal pressure hydrocephalus
Authors: Miyazaki Koichi , Hanaoka Kohei , Kaida Hayato , Chiba Yasutaka , Ishii Kazunari
Published: December 2019

Background

Decreased cerebral glucose metabolism has been reported in idiopathic normal pressure hydrocephalus (iNPH). However, the timing of appearance in the preclinical stage of iNPH remains unknown. Herein, we evaluated the changes in regional cerebral glucose metabolism with respect to the characteristic morphologic features of iNPH.

Methods

We performed a cross-sectional study in > 2000 elderly patients who received a whole body 18F-fluorodeoxyglucose-positron emission tomography/computed tomography scanning and recruited subjects with clinical and preclinical iNPH. We included 12 subjects with iNPH, 32 subjects with asymptomatic ventriculomegaly with features of iNPH on magnetic resonance imaging (AVIM), and 33 subjects with preclinical morphologic features of DESH (PMD). We previously reported that iNPH develops in the order of PMD (asymptomatic subjects with incomplete DESH), AVIM (asymptomatic subjects with DESH), and iNPH (symptomatic subjects with DESH). We measured the median regional standardized uptake value ratio (SUVR) on 18F-fluorodeoxyglucose-positron emission tomography/computed tomography images between the three groups and compared them with background-matched normal controls in the frontal lobes, temporal lobes, medial parietal lobes, striata, and thalami.

Results

In the frontal and temporal lobes, the SUVR distributions of the PMD, AVIM, and PMD groups were significantly lower than for each NC (p < 0.05 for all). In the medial parietal lobes, the SUVR distributions were significantly higher in PMD and AVIM groups (p < 0.05 for all). In the thalami and striata, the SUVR distributions were significantly lower in the iNPH group (p < 0.05 for all).

Conclusions

Changes in brain glucose metabolism in the cortices are observed in preclinical iNPH, while metabolic decline in the basal ganglia is only detected in clinical iNPH.
Mapping evidence on access to healthcare information by women of reproductive age in low-and-middle-income countries: scoping review protocol
Authors: Shatilwe Joyce T. , Mashamba-Thompson Tivani P.
Published: December 2019

Background

Research shows that there are inadequate interventions in resource-limited settings that could enable women of reproductive age to access and use health services in those settings. The main objective of this scoping review is to map the evidence on access to healthcare information by women of reproductive age in LMICs.

Method and analysis

The primary search will include Google Scholar, Science Direct, PubMed, EBSCOhost (Academic search complete, CINAHL with full text, MEDLINE with full text, MEDLINE), Emerald, Embase, CDSR, PsycINFO, published and peer review journals, organisational projects, conference papers, reference list, grey literature sources, as well as reports related to this objective will be included in the study. Identified keywords will be used to search articles from the studies. The articles and abstracts will be screened by two independent reviewers (JS and TPMT). Inclusion and exclusion criteria will be considered to guide the screening. A thematic content analysis will be used to present the narrative account of the reviews, using NVivo computer software (version 11).

Discussions

The scoping review will focus on women of reproductive age in LMICs. We anticipate finding relevant literature on the interventions aimed at accessing health care services in LMICs. The study findings will help reveal research gaps to guide future research.

Scoping review registration

Not registered with PROSPERO (not needed).

Protocol and registration

This scoping review was not registered.
Prevalence of lifetime substances use among students in Ethiopia: a systematic review and meta-analysis
Authors: Roba Hirbo Shore , Beyene Addisu Shunu , Irenso Asnake Ararsa , Gebremichael Berhe
Published: December 2019

Background

The use of substances is a growing concern in Ethiopia, and their impacts on younger generation have been a concern of different professionals. Even though students are at high-risk of substance abuse, there is lack of comprehensive evidence for policy decision on substance use among students. Therefore, the aim of this systematic review and meta-analysis was to estimate the prevalence of common substances among students in Ethiopia.

Method

A comprehensive literature searches were done from biomedical databases: PubMed/Medline, African Journal Online, HINARI, Science Direct, and Google Scholar for article published until Dcember 31, 2017, and Addis Ababa Uiversity’s electronic library search of unpublished thesis and dissertations. Two authors autonomously selected studies, extracted data, and evaluated quality of studies. The prevalence of lifetime substances use was estimated using the random effects model.QandI2statistics were computed to measure the extents of heterogeneity.

Results

A total 676 study articles were identified from electronic databases, and 28 of them were included in meta-analysis. The analysis revealed that the lifetime prevalence of any substance use was 52.5% (95% CI 42.4–62.4%), khat 24.7% (95% CI 21.8–27.7%), alcohol 46.2% (95% CI 40.3–52.2%), and smoking cigarette 14.7% (95% CI 11.3–18.5%). Significant heterogeneity was observed but there was no significant publication bias. The lifetime prevalence of khat, alcohol, and cigarette smoking among high school vs university students was 22.5% (95% CI 15.2–30.7%) vs 25.1% (95% CI 21.9–28.5%), 41.4% (95% CI 22.1–62.1%) vs 47.8% (95% CI 39.9–55.7%), and 21.5% (95% CI 12.6–32.1%) vs 12.9% (95% CI 10.1–16.0%), respectively.

Conclusion

This meta-analysis highlighted the extent of lifetime prevalence of any substance, khat, alcohol, and cigarettes smoking among students in Ethiopia. Significant percent of high school students have exposed to substances. Policy makers should devise and implement strictly binding regulation to curb widespread of substances around educational institution premises at national level. Priority should be given to intervention strategies that help delay first use of substance to prevent problems later in life. Besides, the problem warrants regular national-level educational institutions based studies focusing on the magnitude, trajectory, and consequences of substance use among students.

Systematic review registration: PROSPEROCRD42018082635
Assessing ecotoxicological effects of 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, and 2,3,4,7,8-PeCDF in soil using Allivibrio fischeri
Authors: Lee Sung Jong , Ha Hong Joo , Jho Eun Hea
Published: December 2019

The toxic effect of dioxins and dioxin-like compounds have largely been studied using in vivo techniques; however, in vivo studies can be limited when rapid screening is required. Microtox® can be used as a rapid ecotoxicity assessment tool for dioxins in the environment, but studies on the assessment of dioxins and dioxin-like compounds using bioluminescent bacteria Allivibrio fischeri are limited. This study investigated the potential of using A. fischeri for assessing different dioxins and dioxin-like compounds, and the toxic effects of soils contaminated with dioxins and dioxin-like compounds were tested using different fractions of dioxins in soil to determine the appropriate way of assessing the toxic effects of contaminated soils. The results show that A. fischeri can potentially be used as a test species for rapidly evaluating toxic effects of dioxins and dioxin-like compounds in the environment. With the soil used in this study, the toxic effects of the water extracts (i.e., mobile fraction of dioxins) and the soil slurries (i.e., bioavailable fraction of dioxins) were similar to that of the controls. This suggests that the toxicity assessment of the organic extracts (i.e., total amount of dioxins) can be inappropriate in a managerial perspective, as the mobile or bioavailable fraction of contaminants in soils is often more of concern than the total amount of contaminants present in soils. Overall, when A. fischeri are to be used for a rapid toxicity assessment of dioxins-contaminated soils, different fractions of dioxins need to be assessed for better management of the contaminated soils.