Accretion of the cratonic mantle lithosphere via massive regional relamination.

Continental, orogenic, and oceanic lithospheric mantle embeds sizeable parcels of exotic cratonic lithospheric mantle (CLM) derived from distant, unrelated sources. This hints that CLM recycling into the mantle and its eventual upwelling and relamination at the base of younger plates contribute to the complex structure of the growing lithosphere. Here, we use numerical modeling to investigate the fate and survival of recycled CLM in the ambient mantle and test the viability of CLM relamination under Hadean to present-day mantle temperature conditions and its role in early lithosphere evolution. We show that the foundered CLM is partially mixed and homogenized in the ambient mantle; then, as thermal negative buoyancy vanishes, its long-lasting compositional buoyancy drives upwelling, relaminating unrelated growing lithospheric plates and contributing to differentiation under cratonic, orogenic, and oceanic regions. Parts of the CLM remain in the mantle as diffused depleted heterogeneities at multiple scales, which can survive for billions of years. Relamination is maximized for high depletion degrees and mantle temperatures compatible with the early Earth, leading to the upwelling and underplating of large volumes of foundered CLM, a process we name massive regional relamination (MRR). MRR explains the complex source, age, and depletion heterogeneities found in ancient cratonic lithospheric mantle, suggesting this may have been a key component of the construction of continents in the early Earth.

IL-6 Mutation Attenuates Liver Injury Caused by Aeromonas hydrophila Infection by Reducing Oxidative Stress in Zebrafish.

Interleukin-6 (IL-6), a pleiotropic cytokine, plays a crucial role in acute stress induced by bacterial infection and is strongly associated with reactive oxygen species (ROS) production. However, the role of IL-6 in the liver of fish after Aeromonas hydrophila infection remains unclear. Therefore, this study constructed a zebrafish (Danio rerio) il-6 knockout line by CRISPR/Cas9 to investigate the function of IL-6 in the liver post bacterial infection. After infection with A. hydrophila, pathological observation showed that il-6-/- zebrafish exhibited milder liver damage than wild-type (WT) zebrafish. Moreover, liver transcriptome sequencing revealed that 2432 genes were significantly up-regulated and 1706 genes were significantly down-regulated in il-6-/- fish compared with WT fish after A. hydrophila infection. Further, gene ontology (GO) analysis showed that differentially expressed genes (DEGs) were significantly enriched in redox-related terms, including oxidoreductase activity, copper ion transport, etc. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that DEGs were significantly enriched in pathways such as the PPAR signaling pathway, suggesting that il-6 mutation has a significant effect on redox processes in the liver after A. hydrophila infection. Additionally, il-6-/- zebrafish exhibited lower malondialdehyde (MDA) levels and higher superoxide dismutase (SOD) activities in the liver compared with WT zebrafish following A. hydrophila infection, indicating that IL-6 deficiency mitigates oxidative stress induced by A. hydrophila infection in the liver. These findings provide a basis for further studies on the role of IL-6 in regulating oxidative stress in response to bacterial infections.

Racial and Ethnic Differences and Clinical Outcomes of Patients With Coronavirus Disease 2019 (COVID-19) Presenting to the Emergency Department.

BACKGROUND: Since the introduction of remdesivir and dexamethasone for severe COVID-19 treatment, few large multi-hospital-system US studies have described clinical characteristics and outcomes of minority COVID-19 patients who present to the emergency department (ED). METHODS: This cohort study from the Cerner Real World Database (87 US health systems) from 1 December 2019 to 30 September 2020 included PCR-confirmed COVID-19 patients who self-identified as non-Hispanic Black (Black), Hispanic White (Hispanic), or non-Hispanic White (White). The main outcome was hospitalization among ED patients. Secondary outcomes included mechanical ventilation, intensive care unit care, and in-hospital mortality. Descriptive statistics and Poisson regression compared sociodemographics, comorbidities, receipt of remdesivir or dexamethasone, and outcomes by racial/ethnic groups and geographic region. RESULTS: 94 683 COVID-19 patients presented to the ED. Blacks comprised 26.7% and Hispanics 33.6%. Nearly half (45.1%) of ED patients presented to hospitals in the South. 31.4% (n = 29 687) were hospitalized. Lower proportions of Blacks were prescribed dexamethasone (29.4%; n = 7426) compared with Hispanics (40.9%; n = 13 021) and Whites (37.5%; n = 14 088). Hospitalization risks, compared with Whites, were similar in Blacks (RR: .94; 95% CI: .82-1.08; P = .4) and Hispanics (.99; .81-1.21; P = .91), but risk of in-hospital mortality was higher in Blacks (1.18; 1.06-1.31; P = .002) and Hispanics (1.28; 1.13-1.44; P < .001). CONCLUSIONS: Minority patients were overrepresented among COVID-19 ED patients, and while their risks of hospitalization were similar to Whites, in-hospital mortality risk was higher. Interventions targeting upstream social determinants of health are needed to reduce racial/ethnic disparities in COVID-19.

Dietary supplementation with nanoparticle CMCS-20a enhances the resistance to GCRV infection in grass carp (Ctenopharyngodon idella).

Combination of antimicrobial proteins and nanomaterials provides a platform for the development of immunopotentiators. Oral administration of immunopotentiators can significantly enhance the immunity of organisms, which provides ideas for disease prevention. In this study, we confirmed that nanoparticles CMCS-20a can efficiently prevent grass carp reovirus (GCRV) infection. Firstly, we verified that CiCXCL20a is involved in the immune responses post GCRV challenge in vivo and alleviates the cell death post GCRV challenge in CIK cells. Then, we prepared nanoparticles CMCS-20a using carboxymethyl chitosan (CMCS) loaded with grass carp (Ctenopharyngodon idella) CXCL20a (CiCXCL20a). Meanwhile, we confirmed nanoparticles CMCS-20a can alleviate the degradation in intestine. Subsequently, we added it to the feed by low temperature vacuum drying method and high temperature spray drying method, respectively. Grass carp were oral administration for 28 days and challenged by GCRV. Low temperature vacuum drying group (LD-CMCS-20a) significantly improve grass carp survival rate, but not high temperature spray drying group (HD-CMCS-20a). To reveal the mechanisms, we investigated the serum biochemical indexes, intestinal mucus barrier, immune gene regulation and tissue damage. The complement component 3 content, lysozyme and total superoxide dismutase activities are highest in LD-CMCS-20a group. LD-CMCS-20a effectively attenuates the damage of GCRV to the number of intestinal villous goblet cells and mucin thickness. LD-CMCS-20a effectively regulates mRNA expressions of immune genes (IFN1, Mx2, Gig1 and IgM) in spleen and head kidney tissues. In addition, LD-CMCS-20a obviously alleviate tissue lesions and viral load in spleen. These results indicated that the nanoparticles CMCS-20a can enhance the disease resistance of fish by improving their immunity, which provides a new perspective for fish to prevent viral infections.

In Silico and In Vitro Antimalarial Screening and Validation Targeting Plasmodium falciparum Plasmepsin V.

Malaria chemotherapy is greatly threatened by the recent emergence and spread of resistance in the Plasmodium falciparum parasite against artemisinins and their partner drugs. Therefore, it is an urgent priority to develop new antimalarials. Plasmepsin V (PMV) is regarded as a superior drug target for its essential role in protein export. In this study, we performed virtual screening based on homology modeling of PMV structure, molecular docking and pharmacophore model analysis against a library with 1,535,478 compounds, which yielded 233 hits. Their antimalarial activities were assessed amongst four non-peptidomimetic compounds that demonstrated the promising inhibition of parasite growth, with mean IC50 values of 6.67 µM, 5.10 µM, 12.55 µM and 8.31 µM. No significant affection to the viability of L929 cells was detected in these candidates. These four compounds displayed strong binding activities with the PfPMV model through H-bond, hydrophobic, halogen bond or π-π interactions in molecular docking, with binding scores under -9.0 kcal/mol. The experimental validation of molecule-protein interaction identified the binding of four compounds with multiple plasmepsins; however, only compound 47 showed interaction with plasmepsin V, which exhibited the potential to be developed as an active PfPMV inhibitor.

Increasing Incidence of Advanced Non-cardia Gastric Cancers Among Younger Hispanics in the USA.

BACKGROUND: Recent findings indicate a shift in the epidemiology of non-cardia gastric cancer in the USA. In particular, an uprising trend in incidence rates among non-Hispanic whites aged < 50 years. AIM: To examine secular trends in the incidence of non-cardia gastric cancer among adults aged < 50 years in the USA by race/ethnicity and stage at diagnosis. METHODS: Age-adjusted incidence rates and trends in adults aged < 50 years and ≥ 50 years were calculated using data from all 50 states in the National Program of Cancer Registries and the SEER program. We used joinpoint regression to compute average annual percent change (AAPC) in cancer incidence rates. RESULTS: Overall, we found an increasing trend of non-cardia gastric cancer among non-Hispanic whites aged < 50 years between 2001 and 2014 (AAPC = 1.24, 95% CI 0.49, 1.99). However, among non-Hispanic whites aged < 50 years, the rates of localized disease increased (AAPC = 5.28, 95% CI 3.94, 6.64), whereas the rates of distant stage non-cardia gastric cancer remained unchanged (AAPC = 0.68, 95% CI - 0.63, 2.00). Conversely, we found a significant increase in rates of distant stage non-cardia gastric cancer among Hispanics aged < 50 years (AAPC = 1.78, 95% CI 0.66, 2.91). Non-cardia gastric cancer incidence rates decreased over the study period among non-Hispanic whites and Hispanics aged ≥ 50 years. CONCLUSION: Given the rapid growth of the young Hispanic population in the USA, preventative strategies for non-cardia gastric cancer cannot neglect this population.

Dialysis facility referral and start of evaluation for kidney transplantation among patients treated with dialysis in the Southeastern United States.

Variability in transplant access exists, but barriers to referral and evaluation are underexplored due to lack of national surveillance data. We examined referral for kidney transplantation evaluation and start of the evaluation among 34 857 incident, adult (18-79 years) end-stage kidney disease patients from 690 dialysis facilities in the United States Renal Data System from January 1, 2012 through August 31, 2016, followed through February 2018 and linked data to referral and evaluation data from nine transplant centers in Georgia, North Carolina, and South Carolina. Multivariable-adjusted competing risk analysis examined each outcome. The median within-facility cumulative percentage of patients referred for kidney transplantation within 1 year of dialysis at the 690 dialysis facilities in Network 6 was 33.7% (interquartile range [IQR]: 25.3%-43.1%). Only 48.3% of referred patients started the transplant evaluation within 6 months of referral. In multivariable analyses, factors associated with referral vs evaluation start among those referred at any time differed. For example, black, non-Hispanic patients had a higher rate of referral (hazard ratio [HR]: 1.22; 95% confidence interval [CI]: 1.18-1.27), but lower evaluation start among those referred (HR: 0.93; 95% CI: 0.88-0.98), vs white non-Hispanic patients. Barriers to transplant varied by step, and national surveillance data should be collected on early transplant steps to improve transplant access.

Association Between Dialysis Facility Ownership and Access to Kidney Transplantation.

Importance: For-profit (vs nonprofit) dialysis facilities have historically had lower kidney transplantation rates, but it is unknown if the pattern holds for living donor and deceased donor kidney transplantation, varies by facility ownership, or has persisted over time in a nationally representative population. Objective: To determine the association between dialysis facility ownership and placement on the deceased donor kidney transplantation waiting list, receipt of a living donor kidney transplant, or receipt of a deceased donor kidney transplant. Design, Setting, and Participants: Retrospective cohort study that included 1 478 564 patients treated at 6511 US dialysis facilities. Adult patients with incident end-stage kidney disease from the US Renal Data System (2000-2016) were linked with facility ownership (Dialysis Facility Compare) and characteristics (Dialysis Facility Report). Exposures: The primary exposure was dialysis facility ownership, which was categorized as nonprofit small chains, nonprofit independent facilities, for-profit large chains (>1000 facilities), for-profit small chains (<1000 facilities), and for-profit independent facilities. Main Outcomes and Measures: Access to kidney transplantation was defined as time from initiation of dialysis to placement on the deceased donor kidney transplantation waiting list, receipt of a living donor kidney transplant, or receipt of a deceased donor kidney transplant. Cumulative incidence differences and multivariable Cox models assessed the association between dialysis facility ownership and each outcome. Results: Among 1 478 564 patients, the median age was 66 years (interquartile range, 55-76 years), with 55.3% male, and 28.1% non-Hispanic black patients. Eighty-seven percent of patients received care at a for-profit dialysis facility. A total of 109 030 patients (7.4%) received care at 435 nonprofit small chain facilities; 78 287 (5.3%) at 324 nonprofit independent facilities; 483 988 (32.7%) at 2239 facilities of large for-profit chain 1; 482 689 (32.6%) at 2082 facilities of large for-profit chain 2; 225 890 (15.3%) at 997 for-profit small chain facilities; and 98 680 (6.7%) at 434 for-profit independent facilities. During the study period, 121 680 patients (8.2%) were placed on the deceased donor waiting list, 23 762 (1.6%) received a living donor kidney transplant, and 49 290 (3.3%) received a deceased donor kidney transplant. For-profit facilities had lower 5-year cumulative incidence differences for each outcome vs nonprofit facilities (deceased donor waiting list: -13.2% [95% CI, -13.4% to -13.0%]; receipt of a living donor kidney transplant: -2.3% [95% CI, -2.4% to -2.3%]; and receipt of a deceased donor kidney transplant: -4.3% [95% CI, -4.4% to -4.2%]). Adjusted Cox analyses showed lower relative rates for each outcome among patients treated at all for-profit vs all nonprofit dialysis facilities: deceased donor waiting list (hazard ratio [HR], 0.36 [95% CI, 0.35 to 0.36]); receipt of a living donor kidney transplant (HR, 0.52 [95% CI, 0.51 to 0.54]); and receipt of a deceased donor kidney transplant (HR, 0.44 [95% CI, 0.44 to 0.45]). Conclusions and Relevance: Among US patients with end-stage kidney disease, receiving dialysis at for-profit facilities compared with nonprofit facilities was associated with a lower likelihood of accessing kidney transplantation. Further research is needed to understand the mechanisms behind this association.

Helicobacter pylori Infection Is Associated With Reduced Risk of Barrett's Esophagus: An Analysis of the Barrett's and Esophageal Adenocarcinoma Consortium.

OBJECTIVES: Epidemiological studies of Helicobacter pylori infection and risk of Barrett's esophagus (BE) have reported conflicting results. We examined the association between H. pylori infection and BE and sought to determine whether the association is mediated by gastroesophageal reflux disease (GERD) and to identify potential effect modifiers. METHODS: We used individual level data from 1308 patients with BE (cases), 1388 population-based controls, and 1775 GERD controls in the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON). We estimated study-specific odds ratios (ORs) and 95% CIs using multivariable logistic regression models and obtained summary risk estimates using a random-effects meta-analytic approach. We examined potential effect modification by waist-to-hip ratio (WHR), body mass index (BMI), and smoking status by conducting stratified analyses. RESULTS: For comparisons with population-based controls, H. pylori infection was inversely associated with the risk of BE (adjusted OR = 0.44, 95% CI = 0.36-0.55), with no evidence of between-study heterogeneity (I2 = 0%). A stronger inverse association between H. pylori and BE was observed among individuals with the CagA-positive strain (P for interaction = 0.017). We found no evidence of interaction between WHR, BMI, smoking status, and H. pylori infection on the risk of BE. There was no association between H. pylori infection and BE for comparisons with GERD controls (OR = 0.96, 95% CI = 0.67-1.37; I2 = 48%). CONCLUSIONS: This study provides the strongest evidence yet that H. pylori infection is strongly inversely associated with BE. This effect is probably mediated by a decrease in GERD in infected patients, since the protective effect disappears in patients with GERD symptoms.

Telomere length and risk of developing gastric adenocarcinoma: The Singapore Chinese Health Study.

BACKGROUND: Extreme telomere length has been previously reported to be associated with increased risk of gastric cancer. However, evidence from prospective studies on a relative large sample size with long-term follow-up to further corroborate previous study findings is meager. METHODS: The association between peripheral blood leukocyte telomere length and risk of gastric adenocarcinoma was prospectively examined in a cohort of 26,540 middle-aged or older Chinese nested in the Singapore Chinese Health Study. Telomere length was determined using a validated qPCR-based method. The Cox proportional regression method was used to estimate hazard ratio (HR) and its 95% confidence interval (CI) of gastric adenocarcinoma associated with telomere length after adjustment for potential confounders. Restricted cubic spline analysis was applied to assess the nonlinear relationship between telomere length and gastric cancer risk. RESULTS: A U-shaped association was found between telomere length and risk of gastric adenocarcinoma (P nonlinearity = 0.020). Compared with the second quintile of telomere length, a statistically significant higher risk of gastric adenocarcinoma was associated with either the lowest quintile (HR = 1.63, 95% CI, 1.07-2.47) or the highest quintile (HR = 1.55, 95% CI, 0.97-2.47) of telomere length. This U-shaped relationship was more apparent in men and younger individuals. CONCLUSIONS: This is the first prospective study demonstrating a higher risk of gastric cancer to be associated with either extremely short or extremely long telomere length. Short and long telomere length may function differently in the early and late stages of gastric carcinogenesis.

Epidemiology of Comorbid Conditions Among Adults 50 Years and Older With Traumatic Brain Injury.

OBJECTIVES: Aging individuals with traumatic brain injury (TBI) experience multiple comorbidities that can affect recovery from injury. The objective of this study was to describe the most commonly co-occurring comorbid conditions among adults 50 years and older with TBI. SETTING: Level I Trauma centers. PARTICIPANTS: Adults 50 years and older with moderate/severe TBI enrolled in the TBI-Model Systems (TBI-MS) from 2007 to 2014 (n = 2134). DESIGN: A TBI-MS prospective cohort study. MAIN MEASURES: International Classification of Disease-9th Revision codes collapsed into 45 comorbidity categories. Comorbidity prevalence estimates and trend analyses were conducted by age strata (50-54, 55-64, 65-74, 75-84, ≥85 years). A dimension reduction method, Treelet Transform, classified clusters of comorbidities that tended to co-occur. RESULTS: The 3 most commonly occurring comorbid categories were hypertensive disease (52.6/100 persons), other diseases of the respiratory system (51.8/100 persons), and fluid component imbalances (43.7/100 persons). Treelet Transform classified 3 clusters of comorbid codes, broadly classified as (1) acute medical diseases/infections, (2) chronic conditions, and (3) substance abuse disorders. CONCLUSION: This study provides valuable insight into comorbid conditions that co-occur among adults 50 years and older with TBI and provides a foundation for future studies to explore how specific comorbidities affect TBI recovery.

Composite protective lifestyle factors and risk of developing gastric adenocarcinoma: the Singapore Chinese Health Study.

BACKGROUND: Incidence of gastric cancer is the highest in Eastern Asia. Multiple modifiable lifestyle factors have been identified as risk factors for gastric cancer. However, their aggregated effect on the risk of gastric cancer has not been examined among populations with high prevalence of Helicobacter pylori. METHODS: A study was conducted to examine the association between multiple lifestyle factors together and the risk of developing gastric adenocarcinoma in the Singapore Chinese Health Study, a prospective cohort of 63 257 men and women between 45 and 74 years enroled during 1993-1998. Composite score of cigarette smoking, alcohol consumption, obesity, dietary pattern, and sodium intake at baseline was assessed with hazard ratio (HR) and 95% confidence interval (CI) of gastric adenocarcinoma using Cox regression method. RESULTS: Higher healthy composite lifestyle scores were significantly associated with reduced risk of gastric adenocarcinoma in a dose-dependent manner. Hazard ratios (95% CIs) for total, cardia, and non-cardia gastric adenocarcinoma for the highest (score 5) vs lowest composite score (score 0/1/2) were 0.42 (0.31-0.57), 0.22 (0.10-0.47), and 0.55 (0.39-0.78), respectively (all Ptrend<0.001). These lifestyles together accounted for 48% of total gastric adenocarcinoma cases in the study population. The inverse association was observed in both genders, and remained after exclusion of first 5 years of follow-up. CONCLUSIONS: The inverse association between the aggregated healthy lifestyle factors and the risk of gastric adenocarcinoma is in dose-dependent manner in this highly H. pylori-exposed population. These lifestyle factors together may account for up to half of disease burden in this study population.

Reproductive factors, hormone use and gastric cancer risk: The Singapore Chinese Health Study.

Gastric cancer incidence varies greatly worldwide, but is consistently twice as high in men than in women. The hormone-related factors hypothesized to be associated with lower risk of gastric cancer in women have not been fully explored in populations with a high background risk of gastric cancer. The Singapore Chinese Health Study (SCHS) is a prospective cohort study in which 34,022 of the participants enrolled between 1993 and 1998 were women between 45 and 74 years of age. Information on reproductive histories, hormone replacement therapy (HRT) and oral contraceptive (OC) use was collected through in-person interviews at baseline. As of December 31, 2013, 269 incident gastric cancer cases were identified. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to evaluate gastric cancer risk associations. Older age at natural menopause (≥55 versus <45 years: HR = 0.50, 95% CI: 0.25-0.99), type of menopause (other versus natural: HR = 0.48, 95% CI: 0.27-0.87) and greater years of menstrual cycling (fourth versus first quartile: HR = 0.67, 95% CI: 0.46-0.96) were associated with a decreased risk of gastric cancer. Ever use of OCs and HRT was also associated with reduced risk of gastric cancer; the multivariable-adjusted HRs (95% CIs) were 0.40 (0.17-0.90) for use of HRT >3 years and 0.67 (0.47-0.94) for ever use of OCs, compared with never use. Reproductive factors associated with a longer window of fertility and the use of exogenous hormones were shown to reduce gastric cancer development in a cohort of Chinese women with a high background risk of gastric cancer.

Incidence and prognosis of gastroesophageal cancer in rural, urban, and metropolitan areas of the United States.

BACKGROUND: The objective of this study was assess differences in the incidence, late-stage diagnosis, and prognosis of squamous cell carcinoma of the esophagus (SCCE), adenocarcinoma of the esophagus (AE), and adenocarcinoma of the gastric cardia (AGC) in metropolitan, urban, and rural areas in the United States. METHODS: The authors identified 29,527 patients with SCCE, AE, or AGC who were reported to the Surveillance, Epidemiology, and End Results Program between 2004 and 2009. Incidence estimates for each malignancy were compared across metropolitan, urban, and rural areas. Multivariable logistic regression models were applied to evaluate the association between residential setting and late (distant-stage) diagnosis, and the results were reported as adjusted odds ratios and 95% confidence intervals (CIs). Cox proportional hazard models were used to examine the association between residential setting and cause-specific survival. RESULTS: When residential setting was analyzed using metropolitan population centers as the reference category, the incidence of AE was higher in urban areas (rate ratio [RR], 1.13; 95% CI, 1.06-1.20) and rural areas (RR, 1.15; 95% CI, 1.05-1.25), whereas the incidence of SCCE was lower in rural areas (RR, 0.80; 95% CI, 0.70-0.91). Rural patients were less likely to be diagnosed with stage IV AE compared with patients residing in metropolitan areas (odds ratio, 0.79; 95% CI, 0.65-0.97). No differences in prognosis were observed when patients from large metropolitan centers were compared with their rural counterparts. CONCLUSIONS: The current findings indicated that preconceptions regarding disparities in the time of diagnosis and survival between patients from metropolitan and rural areas in the United States are either unwarranted or out of date, at least with respect to gastroesophageal cancers.

Chronic Mucocutaneous Candidiasis: A Case Report.

Chronic mucocutaneous candidiasis (CMC) is a rare infectious skin disease. This study reported a case of CMC in a child with clinical manifestations of oral mucosal leukoplakia and erythema and crust-like thick scabs on the skin of the face and upper limbs. Microscopic fungal examination revealed a large amount of pseudohyphae, and the fungal culture indicated Candida albicans. A drug sensitivity test indicated that it was sensitive to itraconazole and nystatin. Laboratory tests did not show significant immunodeficiency or endocrine abnormalities, and gene sequencing did not identify DNA gene mutations in the coiled-coil domain (CCD) or the DNA-binding domain (DBD) of signal transducer and activator of transcription 1 (STAT1). The skin lesions subsided after oral administration of itraconazole but relapsed 6 months later, and hypoparathyroidism occurred 1 year later. Patients with repeated superficial fungal infection should be alert to the possibility of CMC. CMC has numerous complications and a poor prognosis that requires the attention of clinicians. In this case, STAT1 mutation was not found, and parathyroid dysfunction was rare, providing reference for clinical diagnosis and treatment of CMC.

A fluorescence-based assay for Trichomonas vaginalis drug screening.

BACKGROUND: The emergence and spread of drug resistance in Trichomonas vaginalis parasites has become an important concern in trichomoniasis treatment. Fast and reliable growth assessment is critical for validating in vitro drug susceptibility and high-throughput screening of newly developed drugs. METHODS: Modified media without yeast extract were evaluated for their ability to support the growth of T. vaginalis parasites. The potential of the nucleic acid-binding dye SYBR Green I for detecting T. vaginalis drug resistance was characterized, and seeding parasite concentration and incubation time were optimized. The fluorescence assay based on SYBR Green I was further validated in four T. vaginalis isolates with different susceptibilities to the antibiotics metronidazole, tinidazole, ornidazole and secnidazole, and compared with the traditional method that detects minimum lethal concentrations (MLCs). RESULTS: A modified medium consisting of RPMI 1640 and Tryptone Plus as replacements for yeast extract and tryptone, respectively, in traditional trypticase-yeast extract-maltose (TYM) medium exhibited similar performance as TYM medium in maintaining T. vaginalis growth, while it showed much lower background fluorescent signals. The T. vaginalis SYBR Green I-based fluorescence (TSF) drug assay was found to have to satisfy one of two conditions to demonstrate the 50% inhibitory concentration of metronidazole for the sensitive isolate TV-334: (i) a seeding density of 3 × 104 parasites/ml and an incubation time of 48 h; or (ii) a seeding density of 1 × 104 parasites/ml and an incubation time of 72 h. Subsequent validation experiments revealed that the 48-h incubation/3 × 104 parasites/ml seeding density condition had a greater sensitivity to detect drug resistance than the 72-h condition. The TSF assay also exhibited high efficiency in identifying parasite drug resistance, as evidenced by its strong correlation with the standard MLC assay results (P = 0.003). CONCLUSIONS: This study presents a robust TSF assay that has the potential to facilitate high-throughput, automated in vitro anti-trichomoniasis susceptibility testing for drug resistance monitoring and drug development. In comparison to the standard MLC method, this assay offers the advantages of reduced labor and elimination of subjective examination.

Long noncoding RNA HAND2-AS1: A crucial regulator of malignancy.

Long non-coding RNAs (LncRNAs) are single-stranded RNAs over 200 nucleotides in length that have no protein-coding function and have long been considered non-functional by-products of transcription. Recent studies have shown that dysregulation of lncRNAs may be involved in the malignant biological behavior of tumors. Targeted regulation of lncRNAs has become a research focus of anti-tumor treatment. LncRNAs heart and neural crest derivatives expressed 2 antisense RNA 1 (HAND2-AS1) was down-regulated in various tumors and can be used as a critical tumor regulator to modulate tumor cells proliferation, apoptosis, metastasis, invasion, metabolism and drug resistance. Additionally, aberrantly expressed HAND2-AS1 was closely related to the clinical pathological characteristics of cancer patients and serve as a promising tumor diagnostic and prognostic biomarker. This article aims to review the roles of HAND2-AS1 in tumorigenesis and development, as well as the underlying molecular mechanisms and clinical significance.