Time Reverse Transcription-polymerase Chain Reaction Research Articles

The Frequency of Intestinal Parasitic Infections in COVID-19 Patients: A Case-Control Study in Tehran, Capital of Iran.

The present study was done to evaluate the prevalence of intestinal parasitic infections (IPIs) in patients with COVID-19 in health care centers (Imam Reza and Golestan hospitals), Tehran, capital of Iran. By designing a matched case-control study, 200 fecal samples were collected for each of the COVID-19 patients and healthy individuals. Nasopharyngeal/oropharyngeal swab samples were collected from all participants for the diagnosis of COVID-19. RNA extraction was performed, and then real time reverse-transcription polymerase chain reaction (rRT-PCR) assay was applied to detect viral RNA. Considering the lung complications, 25%> lung complications was detected in 49 patients, 25-49% in 42 patients, and 50%≤ in 109 patients. Fecal samples were examined using different parasitological techniques. After nested-PCR, sequencing was applied to identify Cryptosporidium spp. and microsporidia spp. A relatively lower prevalence of IPIs was detected among control group (7.5%), than in COVID-19 patients (13%), though not significant (P=0.13). The most prevalent parasite among patients was Blastocystis sp. (6%). Also, 13.76% of IPIs were detected in inpatients with more than 50% lung complication. As well, a remarkably significant difference in IPIs was observed among diarrheic COVID-19 patients, in comparison with nondiarrheic patients (P < 0.00001). Moreover, the isolated sequences in the present study belonged to C. parvum subtype IIa and Enterocytozoon bieneusi genotypes D and Peru 8. In conclusion, more epidemiological and clinical research studies are needed to better understand the status and interaction of IPI in COVID-19 in Iran and other countries.

Comparison of Cepheid Xpert Xpress SARS-CoV-2 Assay with Standard RTPCR Test for Detection of COVID-19 Infection: A Retrospective Cohort Study

Introduction: Real time Reverse Transcription-Polymerase Chain Reaction (RT-PCR) test, the gold standard test for Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) detection, is a tedious process and requires proficient workforce. Accurate and fast test results may permit more efficient use of protective and isolation resources and allow rapid therapeutic interventions. Aim: To evaluate the analytical performance characteristics of the Cepheid Xpert Xpress SARS-CoV-2 test, a rapid, automated molecular test for SARS-CoV-2 with gold standard RT-PCR test. Materials and Methods: This retrospective cohort study was conducted in Virus Research and Diagnostic Laboratory (VRDL) in Department of Microbiology at GGS Medical College, Faridkot from January 2021-June 2021. A total of 100 nasopharyngeal samples, collected from clinically suspected Coronavirus Diseae2019 (COVID-19) cases admitted at GGSMC during 1st January30th June 2021 were tested both by Xpert assay and RT-PCR test simultaneously, taking RT-PCR as the gold standard test. The data was analysed by MedCalc® statistical software version 19.6.4., and sensitivity, specificity, predictive values, likelihood ratios and the agreement between the two tests were calculated. Results: The mean age of the study participants was 46 years. Of these, 55 were males and 45 were females. The overall sample sensitivity and specificity of the Xpert assay were both 100% and there was perfect agreement across specimens, if authors, set a cut-off Cycle threshold-value (Ct-value) at 40 cycles for Xpert. Of 100 samples, 32 were positive for SARSCoV-2 by either of the tests and 68 were negative. Xpert assay could detect 100% positive cases and RT-PCR test could detect 84.37% positive cases. Out of the 32 samples which were positive by Xpert assay, 5 (15.62%) samples had a Ctvalue greater than 40. Conclusion: The Xpert assay found to be useful as a point-ofcare test in acute scenario, where rapid and authentic diagnosis is essential, but do not have expertise and infrastructure to perform RT-PCR.

Effect of antipyretics on performance of influenza surveillance in Ghana.

The World Health Organization's case definition for influenza-like illness (ILI) includes a measured temperature of ≥38°C. We conducted this study to assess the effect of antipyretics on performance of ILI surveillance in Ghana. A cross-sectional study was conducted in two districts of Ghana from September 2013 to May 2014. We collected epidemiological data and respiratory specimens from an expanded ILI case definition, which included patients presenting to health facilities with measured temperature ≥38°C or reported fever (but afebrile at the time of evaluation), and cough, with onset in the last 10days. Specimens were tested for influenza viruses by real time reverse-transcription polymerase chain reaction. Of 321 participants who met our expanded ILI case definition, 236 presented with temperature of <38°C but reported subjective fever. Of these, 17% (39/236) were positive for influenza virus; Of those with fever ≤38°C who took antipyretics, 21%(16/77) were positive for influenza, compared with 14%(23/159) of those who did not take antipyretics. The addition of subjective fever to the standard ILI case definition captured approximately an additional 57% influenza cases but also required testing of approximately four times as many patients. However, including those without fever on presentation that had taken antipyretics found an additional 23% of Influenza cases and only two times as much testing. Depending on the goals of surveillance (monitoring virus circulation or determining disease burden) and available resources, a more sensitive case definition including subjective fever and history of use of antipyretics may be warranted.

A Comparative Study of Rapid SARS-Cov-2 Antigen Detection Assay against RT-PCR Assay for Diagnosis of COVID-19 in a Tertiary Hospital of Kathmandu

Background The Coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2) has spread worldwide since its first recorded case in the city of Wuhan, China, in December 2019. SARS-CoV-2 infection causes asymptomatic to sever pneumonia. Severe cases may develop acute respiratory disease syndrome (ARDS), with an average mortality rate of 6.9%. Real Time Reverse Transcriptase Polymerase Chain Reaction (rRT-PCR) assay is the current reference standard laboratory method for the diagnosis of SARS-CoV-2 infection. However, it takes around 6-8 hours to get the result and is time consuming. Therefore, rapid and accurate tests for SARS-CoV-2 screening are essential to expedite disease prevention and control. Lateral flow immunoassay using monoclonal anti SARS-CoV-2 antibodies which target for SARS-CoV-2 antigen can be complimentary screening test if their accuracy were comparable to that of the real time reverse transcription-polymerase chain reaction (RT-PCR) assay.&#x0D; Objective To find the sensitivity and specificity of a rapid antigen test kit in comparison to reverse transcription-polymerase chain reaction (RT-PCR).&#x0D; Method A cross-sectional hospital based study was carried out at Shree Birendra Army Hospital, Kathmandu for a period of four months.&#x0D; Result Our finding shows sensitivity and specificity of rapid diagnostic tests (RDT) Ag kit as 60.6% and 96.4% respectively. Positive and negative predictive value was 83.7% and 89.0%. Likewise, positive and negative likelihood ratio was 17.0 and 0.4. The overall accuracy of the antigen kit was 88.1% in comparison to reverse transcription-polymerase chain reaction (RT-PCR) as the gold standard.&#x0D; Conclusion Our study concluded the use of rapid antigen kit is mainly useful for screening purposes.

Antibody profile in post-vaccinated & SARS-CoV-2 infected individuals.

During the COVID-19 pandemic it was important to assess the antibody profile in individuals vaccinated with Covaxin (BBV152) and Covishield (ChAdOx1 nCoV-19) with both 28 and 84 days gaps between two doses, those infected with SARS-CoV-2 and post-COVID-19-infected individuals vaccinated with only one dose of either of the vaccines. The present study was aimed to assess these objectives. Fifty real time reverse transcription-polymerase chain reaction (qRT-PCR)-confirmed COVID-19-infected individuals, along with 90 COVID-19-naïve (BBV152 and ChAdOx1 nCov-19)-vaccinated individuals, were included in the study. Individuals who received a single dose of either vaccine with a confirmed past diagnosis of SARS-CoV-2 infection (n=15) were also included. Blood samples were collected strictly between the 4th and 5th wk after development of symptoms for SARS-CoV-2 infected individuals and after the first/second vaccination dose. Antibody profile assessment was done using whole-virus, spike-receptor binding domain (RBD) and nucleocapsid-specific ELISA kits along with neutralizing antibody kit. There was an overall 97.7 per cent seropositivity rate in vaccinated individuals, and a strong correlation (R2=0.8, P<0.001) between neutralizing and spike-RBD antibodies. Among individuals who received two standard doses of ChAdOx1 nCoV-19 vaccine, the spike antibody levels developed were of higher titre with a longer prime boost interval than in those with shorter intervals (P<0.01). Individuals vaccinated with two doses as well as only one dose post-SARS-CoV-2 infection had high neutralizing and spike-specific antibodies. High neutralizing and spike-specific antibodies were developed in individuals vaccinated only with one dose of either vaccine post-SARS-CoV-2 infection. With the main priority being vaccinating majority of the population in our country, single-dose administration to such individuals would be a sensible way to make the most of the limited supplies. Furthermore, neutralizing antibody levels observed in COVID-19-naïve vaccinees imply the need for booster vaccination.

Two transition metal phosphonate coordination polymers: Treatment activity on recurrent oral ulcers by enhancing the immune response of macrophage

Two transition metal phosphonate coordination polymers [Cu(H2L)(4,4′-bipy)0.5] (1， H4L is 4-F-C6H4CH2N(CH2PO3H2)2, 4,4′-bipy is 4,4′-bipyridine) and [Zn2(L)(4,4′-bipy)1.5]·5H2O (2) have been produced through hydrothermal approaches, which were characterized structurally with single crystal X-ray diffraction (SCXRD), Fourier Transform infrared (FT-IR) spectroscopy, Thermogravimetric analysis (TGA) and elemental analysis (EA). For the treatment of the recurrent oral ulcers, their biological activity on recurrent oral ulcers was evaluated and the specific mechanism was also discussed. At first, this work detected the IL-18 (interleukin 18) and IL-1β (interleukin-1β) with enzyme linked immunosorbent assay (ELISA) detection. Besides, the activation for the signaling pathway of inflammatory was identified through real time reverse transcription-polymerase chain reaction (RT-PCR).

Identification and expression profiling of serine protease-related genes in Tenebrio molitor.

In insects, serine proteases and serine protease homologs (SPs/SPHs) are involved in a variety of physiological processes including digestion, development, and immunity. Here, we identified 112 SP and 88 SPH genes in the genome of the yellow mealworm, Tenebrio molitor. Based on the features of domain structure, they were divided into "S" group containing single Tryp-SPc or Tryp-SPHc domain, "C" group containing 1-4 CLIP domain (CLIPA-D) and "M" group containing the CBD, CUB, EGF, Fz, Gd, LDLa, PAN, SEA, SR, Sushi, and TSP domains, and have 115, 48, and 37 gene members, respectively. According to the active sites in the catalytic triad, the putative trypsin, chymotrypsin, or elastase-like enzyme specificity of the identified SPs/SPHs were predicted. Phylogenetic and genomic location analyses revealed that gene duplication exists in the large amount of SPs/SPHs. Gene expression profiling using RNA-seq data along with real time reverse transcription-polymerase chain reaction analysis showed that most SP/SPH genes display life stage specific expression patterns, indicating their important roles in development. Many SP/SPH genes are specifically or highly expressed in the gut, salivary gland, fat body, hemocyte, ovary, and testis, suggesting that they participate in digestion, immunity, and reproduction. The findings lay the foundation for further functional characterization of SPs/SPHs in T. molitor.

Digital RT-PCR Chip method for detection of SARS-CoV-2 virus

The “gold standard” method for detection of SARS-CoV-2 is the real time reverse transcription-polymerase chain reaction, but due to pre-analytical and technical limitations, biological samples with low viral load are not sometimes detected. For this purpose a digital RT-PCR method on-chip was developed for detection of the SARS-CoV-2 virus, using two TaqMan™ Assays for quantification of the N Protein (Nucleocapsid) and the S Protein (Spike), and the QuantStudio™ 3D Digital PCR instrument. The method was applied to assess the nasopharyngeal swabs of asymptomatic subjects recruited in the UNICORN Study. The digital RT-PCR method is characterized by a higher sensitivity than the RT-qPCR method, even if performed with the same TaqMan™, and could be a promising tool for SARS-CoV-2 viral load quantification.

HRCT CHEST EVALUATION OF SEQUELAE OF COVID-19 PNEUMONIA

Since December 2019, many unexplained cases of pneumonia have been reported, as a result of exposure in Wuhan city, Hubei province, China. The pathogen identied was coronavirus and the disease was named COVID-19 by World Health Organization (WHO). Based on the epidemiological surveys done, dry cough, fever and fatigue were the main clinical manifestations reported.(Huang et al., 2020; X. Liu et al., 2020) Few patients had symptoms such as runny nose, nasal obstruction, myalgia, sore throat, and diarrhoea. Seriously ill patients rapidly progressed to ARDS. The COVID-19 outbreak has been declared public health emergency of international concern by the WHO. A specic viral nucleic acid assay, real time reverse transcription-polymerase chain reaction (RT-PCR) was developed to diagnose COVID-19. However, published literature on COVID-19 pneumonia showed some patients with initial negative RT-PCR results. According to current literature, HRCT thorax may show abnormalities earlier than even RT-PCR(Zhou et al., 2020). Therefore, high resolution CT had been included as one of the main tools particularly for screening and in the evaluation of the severity of disease (Salameh et al., 2020) Although most of the patients showed complete resolution from illness, some of the them were likely to have some kind of long-term lung damage. Radiological ndings have proven to be helpful in estimating the course of the disease and they can be used to evaluate long-term consequences of the disease. CT had been recommended as an important tool for screening and also for evaluation of severity of the illness.(Dai et al., 2020; Shah et al., 2021) AIM: Ÿ Aim of the study was to determine the sequelae of COVID-19 pneumonia in positive patients 4 – 8 weeks after RT-PCR negative report. OBJECTIVE: Ÿ To describe the HRCT chest ndings of sequelae of COVID-19 pneumonia- GGO, brosis, bronchovascular bundle distortion and small pleural effusion. Ÿ To explore the relevant factors affecting the sequelae - initial clinical symptoms of onset, risk factors, age, and gender and laboratory examinations. Ÿ To determine the cumulative percentage of complete radiological resolution - using CT severity score

Pooled surveillance testing for asymptomatic SARS-CoV-2 infections at a Veterinary Teaching Hospital College, University of Minnesota, December 2020-April 2021.

To evaluate the use of asymptomatic surveillance, we implemented a surveillance program for asymptomatic SARS-CoV-2 infection in a voluntary sample of individuals at the College of Veterinary Medicine at the University of Minnesota. Self-collected anterior nasal samples were tested using real time reverse transcription-polymerase chain reaction (RT-PCR), in a 5:1 pooled testing strategy, twice weekly for 18 weeks. Positive pools were deconvoluted into individual tests, revealing an observed prevalence of 0.07% (3/4,525). Pooled testing allowed for large scale testing with an estimated cost savings of 79.3% and modeling demonstrated this testing strategy prevented up to 2 workplace transmission events, averting up to 4 clinical cases. At the study endpoint, antibody testing revealed 80.7% of participants had detectable vaccine antibody levels while 9.6% of participants had detectable antibodies to natural infection.

STUDY OF TWO YEARS EPIDEMIOLOGICAL TREND OF SWINE FLU (H1N1) CASES BY CROSS SECTIONAL ANALYSIS IN TERTIARY CARE TEACHING HOSPITAL OF WESTERN INDIA

BACKGROUND &amp; OBJECTIVE: To study region-wise monthly incidence, alteration in seasonal trend and geographical distribution of Swine Flu (H1N1) cases in district of western India for two years. After Ethics Committee approval, a cross-sectionalMATERIAL AND METHOD: study was carried out with analysis of two years' demographic prole, geographical distribution and seasonal variation of real time Reverse Transcription–Polymerase Chain Reaction (RT-PCR) - H1N1 positive cases. Annual change in pattern of positive cases was analyzed by independent sample student's t - test (P &lt; 0.05). Out of 3,524 Seasonal Flu cases investigated by Inuenza A (H1N1) RT-PCR, total 1,600RESULT: Seasonal Flu–positive cases were analyzed. On looking at Age-wise distribution of patients, during rst year, maximum number of Seasonal Flu positive cases was from age group of 1 to 10 years, while during next year, maximum number of cases was from age group of 51 to 60 years. During rst year of epidemic, incidence of 836.12 cases per 1,00,000 population per year was detected with peak during winter as compared to 121.49 cases per 1,00,000 population per year with peak during monsoon in second year of epidemic. DuringINTERPRETATION &amp; CONCLUSION: Epidemic of Seasonal Flu, Swine Flu (H1N1) positive cases got reduced annually, and seasonal pattern of H1N1 positive cases changed with peak during monsoon as compared to conventional winter peak. Overall change in seasonal trend, pediatric age distribution suggests need of in depth analysis of development of herd immunity, and risk factors involved for monsoon peak with alarming precaution by epidemic preparedness.

Molecular characterisation of hemagglutinin and neuraminidase genes of the first highly pathogenic Avian Influenza H5N1 2.3.2.1c virus isolated from Sabah, Malaysia.

Highly Pathogenic Avian Influenza (HPAI) is a highly contagious disease in poultry. The outbreaks can lead to flock mortality up to 100% in two to three days. In July 2018, high mortality in a commercial layer farm in Kauluan village, Sabah was reported. Samples were sent to Veterinary Research Institute Ipoh for diagnosis. Virus isolation and molecular detection is carried out simultaneously. The causative agent was then identified as AI H5N1 virus by real time reverse transcription-polymerase chain reaction (RT-PCR). The virus was then subjected for further nucleotide sequencing of full length hemagglutinin (HA) and neuraminidase (NA) gene. The PQRERRRKR/GLF motif at the HA cleavage site indicated that the isolate was of HPAI virus. Phylogenetic analysis of the HA gene showed that the isolate was belonged to the clade 2.3.2.1c virus. In the HA gene, besides the S133A substitution, the virus possesses conserved amino acid at most of the avian receptor binding sites including the glutamine (Q) and glycine (G) at position 222 and 224 respectively, indicating that the virus retains the avian-type receptor binding preference. As such, the zoonotic potential of the virus was relatively low. On the other hand, though the N154D and T156A substitution were detected in the same gene, the pandemic potential of this Sabah 2.3.2.1c virus is low in the absence of the Q222L, G224S, H103Y, N220K and T315I. A typical 20 amino acid deletion with loss of four corresponding glycosylation sites in the NA stalk region was visible. Though three NA resistance markers were detected, the virus was predicted to be sensitive to NA inhibitor. This is the first HPAI H5N1 outbreak in Sabah. The introduction of this virus into East Malaysia for the first time raised an alert alarm of the future epidemic potential. Strict farm biosecurity, continuous surveillance programme in poultry, wild birds, migratory birds; molecular epidemiology as well as risk assessment for the virus with pandemic potential are needed in dealing with emergence of new influenza virus in the country.

MO1039: 1-Year Follow-Up Data of Arterial Abnormalities Identified in Kidneys Transplanted into Children During the First Covid-19 Pandemic Wave

BACKGROUND AND AIMSGraft artery stenosis can have a significant short- and long-term negative impact on kidney graft function. We previously reported an unusual number of graft-arterial anomalies following kidney transplantation (KTx) in children during the first coronavirus disease (COVID-19) pandemic wave (Berteloot et al.) [1]. We report herein the 1-year follow-up of these patients.METHODIn this retrospective study, we included all children who received a KTx at our centre from February to July 2020. We compared their outcome to that of paediatric recipients who were transplanted at our centre from 2015 to 2019 and presented an allograft vascular complication (‘Historic’ group) by querying our local data warehouse.RESULTSAmong the 9 children who received a KTx at our centre between February and July 2020 [8 boys, median age 10 years (3–17)], 8 presented Doppler features suggesting arterial stenosis, with an unusual extensive pattern (Figure 1) after a median delay of 13 days (8–113). For comparison, persistent spectral Doppler arterial anomalies were observed in only 5% of children following KTx at our centre over the previous 5-year period and were all focal anastomotic stenoses. In addition, five children had lymphoceles, which required surgical management as compared to only one patient in the 5 previous years (1%).  We retrospectively diagnosed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-20 infection in 6/8 children with arterial stenosis on serologies performed at D0, including one boy with a history of positive real time reverse transcription-polymerase chain reaction (RT-PCR) 120 days before KTx. None of the patients had reported any symptom suggestive of COVID-19. The remaining two patients had received a graft from an asymptomatic deceased adolescent donor with a positive serology at D0. These data led us to suspect immune post-viral graft vasculitis, triggered by SARS-CoV-2.At 1-year post-transplantation, the outcome was favourable in the 8 isolated KTx recipients. A total of 4/8 children had normal blood pressure and 4 had controlled high blood pressure on mono or bi-therapy. Doppler anomalies had resolved in 5/8 and persisted in 3/8 with a trend for improvement of peak systolic velocities and no severe consequences on kidney function and histology. Indeed, the median glomerular filtration rate (GFR) was 91 mL/min/1.73 m² (65–129), with unspecific and mild lesions on 4/8 protocol kidney biopsies (IFTA 1 or Cpt 1). One liver-kidney graft recipient had persistent hypertension and diffuse irregular inflammatory parietal thickening of the whole vascular graft associated with a parietal thrombus upstream of the birth of the two hepatic arteries (Figure 2); treated with anti-aggregation and prednisone 10 mg/d.CONCLUSIONOur case series suggests a risk of post-viral kidney graft vasculitis in children with recent SARS-CoV-2 infection in the recipient or donor. Pre-transplant vaccination against COVID-19 is mandatory in children > 5 years and their kidney donor candidates at our centre. We also strongly recommend vaccination of all people aged > 5 years in the household.FIGURE 1:Angio-CT scan of a KTx recipient showing an atypical extensive stenosis, with a diffuse, thin and irregular appearance of the graft artery.FIGURE 2:Angio-CT scan of the liver-kidney graft recipient showing an atypical diffuse irregular inflammatory parietal thickening of the whole vascular graft associated with a parietal thrombus upstream of the birth of the two hepatic arteries.

[Role of inflammation and apoptosis in right ventricular dysfunction induced by injurious mechanical ventilation in rats].

To investigate whether myocardial inflammation and apoptosis are involved in right ventricular dysfunction (RVD) induced by injurious mechanical ventilation with high tidal volume (VT) in rats. Total 30 adult male SD rats were randomly divided into the control group (CON group), the low VT ventilation group (LVT group) and the injurious mechanical ventilation group (HVT group), with 10 rats in each group. The CON group was maintained spontaneous breathing, the LVT group and HVT group were ventilated with different VT 6 mL/kg and 20 mL/kg for 4 hours, respectively. The right jugular vein and the left carotid artery were catheterized and connected with the PowerLab biological signal acquisition and analysis system to record heart rate (HR), mean arterial pressure (MAP), right ventricular systolic pressure (RVSP), the maximum rate of rising of right ventricular pressure (+dp/dt max). Echocardiography was performed to measure left ventricular end-diastolic diameter (LVEDd), right ventricular end-diastolic diameter (RVEDd), tricuspid annulus plane systolic migration (TAPSE) and myocardial performance index (MPI). The rats were sacrified by cervical dislocation. Specimens of right ventricle tissues were taken for hematoxylin-eosin (HE) staining, and morphological changes of right ventricle tissues were observed under light microscope. Real time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to detect the mRNA and protein expressions of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), caspase-3, apoptosis-related proteins Bax and Bcl-2. HR, MAP, +dp/dt max gradually decreased, while RVSP gradually increased in different group with the increase of VT ventilation. There was no significant difference between the CON group and LVT group. However, there was a statistically significant difference with respect to these index in HVT group as compared to CON group and LVT group [HR (bpm): 397.6±5.7 vs. 433.0±4.8, 441.6±7.8; MAP (mmHg, 1 mmHg ≈ 0.133 kPa): 102.0±2.4 vs. 108.5±2.2, 110.6±2.1; +dp/dt max (mmHg/s): 2 357.65±62.80 vs. 2 661.27±55.62, 2 679.43±75.13; RVSP (mmHg): 28.8±1.0 vs. 22.6±10.8, 21.9±0.4; all P < 0.05]. Echocardiography findings showed that RVEDd/LVEDd and MPI gradually increased, TAPSE gradually decreased in different group with the increase of VT ventilation. There was no significant difference between the LVT group and CON group. However, there was a statistically significant difference with respect to these indexes in HVT group as compared to the CON group and LVT group [RVEDd/LVEDd: 0.36±0.02 vs. 0.26±0.01, 0.23±0.02; MPI: 1.23±0.03 vs. 0.84±0.04, 0.86±0.03; TAPSE (mm): 1.65±0.03 vs. 1.88±0.02, 1.91±0.04; all P < 0.05]. Histopathological observation of the right ventricle tissue showed that myocardial cells of the rats in the CON group were orderly arranged and uniformed in size. In the LVT group, there was a small amount of inflammatory cell infiltration in the myocardial interstitium, while in the HVT group, the myocardial cell arrangement was obviously disordered, the structure was obviously damaged, and more inflammatory cell infiltration was found. RT-PCR and Western blotting analysis showed that the mRNA and protein expressions of IL-6, TNF-α, caspase-3 and Bax in HVT group were significantly higher than those in the LVT group and CON group [mRNA expression (2-ΔΔCt): IL-6 were 1.97±0.07 vs. 1.09±0.02, 1.02±0.03, TNF-α were 1.69±0.10 vs. 1.10±0.03, 1.05±0.04, caspase-3 were 1.82±0.09 vs. 1.08±0.02, 1.06±0.03, Bax were 2.19±0.14 vs. 1.07±0.03, 1.04±0.03; protein expression (gray value): IL-6 were 0.64±0.02 vs. 0.38±0.03, 0.31±0.04, TNF-α were 0.50±0.04 vs. 0.16±0.01, 0.15±0.01, caspase-3 were 0.58±0.02 vs. 0.29±0.01, 0.25±0.02, Bax were 0.50±0.03 vs. 0.21±0.01, 0.26±0.02; all P < 0.05], and the mRNA and protein expressions of Bcl-2 in the HVT group were lower than those in the LVT group and CON group [mRNA expression (2-ΔΔCt): 1.23±0.05 vs. 1.43±0.05, 1.50±0.08; protein expression (gray value): 0.42±0.02 vs. 0.62±0.03, 0.65±0.03, all P < 0.05]. Myocardial inflammation and apoptosis may be involved in RVD induced by injurious mechanical ventilation.

Two new photoactive metal-organic compounds for degradation of methylene blue and treatment in ophthalmic local anesthesia.

Two new metal-organic compounds, namely [Cu(CrO4)(4,4'-bipy)(H2O)]·n(H2O) (1) together with [Mn(Cr2O7)(bpp)2]n (2) (4,4'-bipy is 4,4'-bipyridine and bpp is 1,3-bis(4-pyridyl)propane), were hydrothermally generated, which were characterized structurally through a series of characterization techniques. Moreover, compounds 1 and 2 have 2.95eV and 3.02eV of narrow optical band gap values, and possess outstanding photocatalytic effects for the methylene blue degradation under irradiation of visible light. The application of above compounds in the ophthalmic local anesthesia was examined and the specific mechanism was tested. First of all, the acetylcholine content in the synaptic cleft was measured with enzyme linked immunosorbent assay (ELISA) assay after treated with the CPs. The acetylcholine receptor relative expression on nerve cells was subsequently measured via real time reverse transcription-polymerase chain reaction (RT-PCR) under the treatment of compounds. In the end, the complexes' toxicity was evaluated by Cell Counting Kit-8 (CCK-8) detection.

Carboxymethyl carrageenan immobilized on 3D-printed polycaprolactone scaffold for the adsorption of calcium phosphate/strontium phosphate adapted to bone regeneration

Three dimensional (3D) substrates based on natural and synthetic polymers enhance the osteogenic and mechanical properties of the bone tissue engineering scaffolds. Here, a novel bioactive composite scaffolds from polycaprolactone /kappa-carrageenan were developed for bone regeneration applications. 3D PCL scaffolds were fabricated by 3D printing method followed by coating with carboxymethyl kappa-carrageenan. This organic film was used to create calcium and strontium phosphate layers via a modified alternate soaking process in CaCl 2 /SrCl 2 and Na2HPO4 solutions in which calcium ions were replaced by strontium, with different amounts of strontium in the solutions. Various characterization techniques were executed to analyze the effects of strontium ion on the scaffold properties. The morphological results demonstrated the highly porous with interconnected pores and uniform pore sizes scaffolds. It was indicated that the highest crystallinity and compressive strength were obtained when 100% CaCl2 was replaced by SrCl2 in the solution (P-C-Sr). Incorporation of Sr onto the structure increased the degradation rate of the scaffolds. Mesenchymal stem cells (MSCs) culture on the scaffolds showed that Sr effectively improved attachment and viability of the MSCs and accelerated osteogenic differentiation as revealed by Alkaline phosphatase activity, calcium content and Real Time-Reverse transcription polymerase chain reaction assays.

Application value of a new Zn(II)-coordination polymer in enteral nutrition rehabilitation by enhancing intestinal villi transport function

In the present study, a novel coordination polymer (CP) based on Zn(II), that is [Zn3(H3TTHA)(μ3-O)(μ3-OH)(μ2-H2O)2(H2O)]·2H2O (1), has been generated in success with a reaction between 1,3,5-triazine-2,4,6-triamine hexaacetic acid (H3TTHA), flexible triazine polycarboxylic acid ligand and Zn(NO3)2·6H2O. Its application value on the enteral nutrition rehabilitation was assessed and the specific mechanism was also analyzed. Firstly, the recombinant Sodium/Glucose Cotransporter 1 (SGLT1) and Glucose Carrier Protein SGLT1 relative expression on the small intestinal villi epithelial cells was determined via carrying out real time reverse transcription-polymerase chain reaction (RT-PCR). In addition to this, the recovery of gastrointestinal function was determined after compound treatment.

RETRACTED: Two new luminescent coordination polymers: Therapeutic effects on angina pectoris

Via tuning the central metal ions from Zn(II) to Cd(II), two new coordination polymers was acquired in success, namely {(H 3 O)[Zn 4 (bptc) 3 (3-bpmh)]} n ·6n(H 2 O) ( 1 ) and [Cd 3 (bptc)(3-bpmh)(H 2 O) 3 ] n ·4n(H 2 O) ( 2 ) (H 3 bptc = biphenyl-3,4′,5-tricarboxylic acid, 3-bpmh = N,N-bis-pyridin-3-ylmethylene-hydrazine), under hydrothermal conditions. The luminescent properties investigations showed that 1 – 2 emit intense luminescence with different maximum emission peaks. Their therapeutic and nursing protective effects on angina pectoris were assessed and we also discussed the corresponding mechanism simultaneously. The content of Interleukin-6 (IL-6) and soluble vascular cell adhesive molecule (SVCAM-1) released by endothelial cells (EC) was discovered through enzyme linked immunosorbent assay (ELISA) detection kit. Besides, the activation of Notch signaling pathway was also evaluated by the real time reverse transcription-polymerase chain reaction (RT-PCR). Influence of compounds on the peripheral blood white blood cell (WBC) numbers was measured with flow cytometry. We utilized optical coherence tomography (OCT) to measure the thickness of the fibrous cap of atherosclerotic plaque in patients with angina pectoris.

RETRACTED: Therapeutic effect of two Co(II) coordination polymers by inhibiting tumor cell proliferation and invasion on pancreatic cancer

In this work, through utilizing the mixed-ligand synthesis method, two coordination polymers (CPs) based on Co(II), namely, {[Co(μ-ppda)(μ-pbmeix)]·H 2 O} n ( 2 ) and [Co(μ-opda)(μ-pbmeix) 0.5 ] n ( 1 ), have been triumphantly formed from 1,4-bis(2-methylimidazol-1-ylmethyl)benzene (pbmeix), a semi-rigid ligand with Co(II) nitrate salts and distinct carboxylic acid co-ligands (o/ppda = 1,2-/1,4-phenylenediacetate). For treatment of pancreatic cancer, the as-generated compounds’ inhibitory activity against the viability of cancer cell was determined by the Cell Counting Kit-8 (CCK-8) assay. The above compounds’ suppression effect against the cells invasion and migration ability was investigated by the trans-well detection. The real time reverse transcription-polymerase chain reaction (RT-PCR) subsequently was employed to test the VEGF signaling pathway activation. Eventually, the cancer cells apoptosis levels after treating with above compound were assessed via detecting the BCL-2 protein expression level. Furthermore, results from molecular docking simulation indicate that complex 1 not only exhibits relatively lower affinity energy, but also forms more binding interactions in comparison to complex 2 when binding to a given target protein. Complex 1 was much superior to complex 2 on treating pancreatic cancer via suppressing the cancer cell invasion, migration and viability ability.

An international, interlaboratory ring trial confirms the feasibility of an extraction-less "direct" RT-qPCR method for reliable detection of SARS-CoV-2 RNA in clinical samples.

Reverse transcription–quantitative polymerase chain reaction (RT-qPCR) is used worldwide to test and trace the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). “Extraction-less” or “direct” real time–reverse transcription polymerase chain reaction (RT-PCR) is a transparent and accessible qualitative method for SARS-CoV-2 detection from nasopharyngeal or oral pharyngeal samples with the potential to generate actionable data more quickly, at a lower cost, and with fewer experimental resources than full RT-qPCR. This study engaged 10 global testing sites, including laboratories currently experiencing testing limitations due to reagent or equipment shortages, in an international interlaboratory ring trial. Participating laboratories were provided a common protocol, common reagents, aliquots of identical pooled clinical samples, and purified nucleic acids and used their existing in-house equipment. We observed 100% concordance across laboratories in the correct identification of all positive and negative samples, with highly similar cycle threshold values. The test also performed well when applied to locally collected patient nasopharyngeal samples, provided the viral transport media did not contain charcoal or guanidine, both of which appeared to potently inhibit the RT-PCR reaction. Our results suggest that direct RT-PCR assay methods can be clearly translated across sites utilizing readily available equipment and expertise and are thus a feasible option for more efficient COVID-19 coronavirus disease testing as demanded by the continuing pandemic.