Application of Statistical Analysis and Machine Learning to Identify Infants' Abnormal Suckling Behavior.

OBJECTIVE: Identify infants with abnormal suckling behavior from simple non-nutritive suckling devices. BACKGROUND: While it is well known breastfeeding is beneficial to the health of both mothers and infants, breastfeeding ceases in 75 percent of mother-child dyads by 6 months. The current standard of care lacks objective measurements to screen infant suckling abnormalities within the first few days of life, a critical time to establish milk supply and successful breastfeeding practices. MATERIALS AND METHODS: A non-nutritive suckling vacuum measurement system, previously developed by the authors, is used to gather data from 91 healthy full-term infants under thirty days old. Non-nutritive suckling was recorded for a duration of sixty seconds. We establish normative data for the mean suck vacuum, maximum suck vacuum, suckling frequency, burst duration, sucks per burst, and vacuum signal shape. We then apply computational methods (Mahalanobis distance, KNN) to detect anomalies in the data to identify infants with abnormal suckling. We finally provide case studies of healthy newborn infants and infants diagnosed with ankyloglossia. RESULTS: In a series of case evaluations, we demonstrate the ability to detect abnormal suckling behavior using statistical analysis and machine learning. We evaluate cases of ankyloglossia to determine how oral dysfunction and surgical interventions affect non-nutritive suckling measurements. CONCLUSIONS: Statistical analysis (Mahalanobis Distance) and machine learning [K nearest neighbor (KNN)] can be viable approaches to rapidly interpret infant suckling measurements. Particularly in practices using the digital suck assessment with a gloved finger, it can provide a more objective, early stage screening method to identify abnormal infant suckling vacuum. This approach for identifying those at risk for breastfeeding complications is crucial to complement complex emerging clinical evaluation technology. CLINICAL IMPACT: By analyzing non-nutritive suckling using computational methods, we demonstrate the ability to detect abnormal and normal behavior in infant suckling that can inform breastfeeding intervention pathways in clinic.Clinical and Translational Impact Statement: The work serves to shed light on the lack of consensus for determining appropriate intervention pathways for infant oral dysfunction. We demonstrate using statistical analysis and machine learning that normal and abnormal infant suckling can be identified and used in determining if surgical intervention is a necessary solution to resolve infant feeding difficulties.

In Situ Simultaneous Detection of Surface Protein and microRNA in Clustered Extracellular Vesicles from Cancer Cell Lines Using Flow Cytometry.

Extracellular vesicles (EVs) are becoming increasingly important in liquid biopsy for cancer because they contain multiple biomarkers, including proteins and RNAs, and circulate throughout the body. Cancer cell-derived EVs are highly heterogeneous, and multiplexed biomarker detection techniques are required to improve the accuracy of diagnosis. In addition, in situ EV biomarker detection increases the efficiency of the detection process because EVs are difficult to handle. In this study, in situ simultaneous detection of EV surface proteins, programmed cell death-ligand 1 (PD-L1), and internal miRNA-21 (miR-21) analyzed by conventional flow cytometry was developed for a breast cancer liquid biopsy. However, the majority of EVs were not recognized by flow cytometry for biomarker detection because the size of EVs was below the detectable size range of the flow cytometer. To solve this problem, the formation of EV clusters was induced by 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE)-polyethylene glycol-DSPE during biomarker detection. Consequently, both PD-L1 and miR-21 detection signals from cancer cell-derived EVs were drastically increased, making them distinguishable from normal cell-derived EVs. The in situ simultaneous cancer biomarker detection from EV clusters analyzed by flow cytometry contributes to an increase in the sensitivity and accuracy of the EV-based liquid biopsy for cancer.

Diagnostic Value of DAPK Methylation for Nasopharyngeal Carcinoma: Meta-Analysis.

BACKGROUND: Methylation of DAPK has been reported to play a key role in the initiation and progression of nasopharyngeal cancer. However, there are differences between the studies on it. This meta-analysis was performed to evaluate the diagnostic value of DAPK promoter methylation for NPC. METHOD: The study method involves the systematic research of eligible studies based on criteria. The frequency, odds ratios (OR), sensitivity as well as specificity with the corresponding 95% confidence intervals (CIs) were used to assess the effect sizes. RESULTS: A total of 13 studies, including 1048 NPC samples and 446 non-cancerous samples, were used for the meta-analysis. The overall frequencies of DAPK methylation were 56.94% and 9.28% in NPC samples and non-cancerous samples, respectively. The association between DAPK methylation and risk of NPC was also confirmed by calculating the OR value which was 13.13 (95%CI = 54.24-40.72) based on a random-effect model (Q = 64.74; p < 0.0001; I2 = 81.47% with 95%CI for I2 = 69.39-88.78). Additionally, the study results suggest that testing for DAPK methylation in tissue samples or brushing may provide a promising method for diagnosing NPC. CONCLUSION: This is the first meta-analysis that provided scientific evidence that methylation of the DAPK gene could serve as a potential biomarker for diagnosis, prognosis, and early screening of NPC patients.

Simultaneous real-time PCR detection of nine prevalent sexually transmitted infections using a predesigned double-quenched TaqMan probe panel.

Sexually transmitted diseases are major causes of infertility, ectopic pregnancy, and premature birth. Here, we developed a new multiplex real-time polymerase chain reaction (PCR) assay for the simultaneous detection of nine major sexually transmitted infections (STIs) found in Vietnamese women, including Chlamydia trachomatis, Neisseria gonorrhoeae, Gardnerella vaginalis, Trichomonas vaginalis, Candida albicans, Mycoplasma hominis, Mycoplasma genitalium, and human alphaherpesviruses 1 and 2. A panel containing three tubes × three pathogens/tube was predesigned based on double-quenched TaqMan probes to increase detection sensitivity. There was no cross-reactivity among the nine STIs and other non-targeted microorganisms. Depending on each pathogen, the agreement with commercial kits, sensitivity, specificity, repeatability and reproducibility coefficient of variation (CV), and limit of detection of the developed real-time PCR assay were 99.0%-100%, 92.9%-100%, 100%, <3%, and 8-58 copies/reaction, respectively. One assay cost only 2.34 USD. Application of the assay for the detection of the nine STIs in 535 vaginal swab samples collected from women in Vietnam yielded 532 positive cases (99.44%). Among the positive samples, 37.76% had one pathogen, with G. vaginalis (33.83%) as the most prevalent; 46.36% had two pathogens, with G. vaginalis + C. albicans as the most prevalent combination (38.13%); and 11.78%, 2.99%, and 0.56% had three, four, and five pathogens, respectively. In conclusion, the developed assay represents a sensitive and cost-effective molecular diagnostic tool for the detection of major STIs in Vietnam and is a model for the development of panel detections of common STIs in other countries.

Non-Nutritive Suckling System for Real-Time Characterization of Intraoral Vacuum Profile in Full Term Neonates.

Infant breastfeeding diagnostics remain subjective due to the absence of instrumentation to objectively measure and understand infant oral motor skills and suckling characteristics. Qualitative diagnostic exams, such as the digital suck assessment which relies upon a clinician's gloved finger inserted into the infant's mouth, produce a diversity of diagnoses and intervention pathways due to their subjective nature. In this paper, we report on the design of a non-nutritive suckling (NNS) system which quantifies and analyzes quantitative intraoral vacuum and sucking patterns of full-term neonates in real time. In our study, we evaluate thirty neonate suckling profiles to demonstrate the technical and clinical feasibility of the system. We successfully extract the mean suck vacuum, maximum suck vacuum, frequency, burst duration, number of sucks per burst, number of sucks per minute, and number of bursts per minute. In addition, we highlight the discovery of three intraoral vacuum profile shapes that are found to be correlated to different levels of suckling characteristics. These results establish a framework for future studies to evaluate oromotor dysfunction that affect the appearance of these signals based on established normal profiles. Ultimately, with the ability to easily and quickly capture intraoral vacuum data, clinicians can more accurately perform suckling assessments to provide timely intervention and assist mothers and infants towards successful breastfeeding outcomes.

Exploration of chalcones as 3-chymotrypsin-like protease (3CLpro) inhibitors of SARS-CoV-2 using computational approaches.

The main protease 3CLpro is one of the potential targets against coronavirus. Inhibiting this enzyme leads to the interruption of viral replication. Chalcone and its derivatives were reported to possess the ability to bind to 3CLpro protease in the binding pocket. This study explored an in-house database of 269 chalcones as 3CLpro inhibitors using in silico screening models, including molecular docking, molecular dynamics simulation, binding free energy calculation, and ADME prediction. C264 and C235 stand out as the two most potential structures. The top hit compound C264 was with the Jamda score of -2.8329 and the MM/GBSA binding energy mean value of -28.23 ± 3.53 kcal/mol, which was lower than the reference ligand. Despite the lower mean binding energy (-22.07 ± 3.39 kcal/mol), in-depth analysis of binding interaction suggested C235 could be another potential candidate. Further, in vitro and in vivo experiments are required to confirm the inhibitory ability. Supplementary Information: The online version contains supplementary material available at 10.1007/s11224-022-02000-3.

Fast and Sensitive Real-Time PCR Detection of Major Antiviral-Drug Resistance Mutations in Chronic Hepatitis B Patients by Use of a Predesigned Panel of Locked-Nucleic-Acid TaqMan Probes.

We developed a novel real-time PCR assay that simultaneously evaluates 11 major nucleos(t)ide antiviral (NA) drug resistance mutations (mt) in chronic hepatitis B patients (CHB), including L180M, M204I/V, and V207M (lamivudine [LMV] resistance), N/H238A/T (adefovir [ADF] resistance), which are circulating in Vietnam; and T184G/L, S202I, and M250V (entecavir [ETV] resistance) and A194T (tenofovir resistance), which have been recently reported in several studies across the globe. We detected drug-resistant mt in hepatitis B virus (HBV) samples using our predesigned panel of allele-specific locked-nucleic acid (LNA) probes. Our assay had a high sensitivity of 5% in a low-HBV DNA population of ≥5 × 103 IU/ml and was validated in a cohort of 130 treatment-naive children and 98 NA-experienced adults with CHB. Single-point mt for LMV and ADF resistance were detected in 57.7% and 54.1% of the child and adult samples, respectively, with rtV207M (children, 42.3%; adults, 36.7%) and rtN238T/A (children, 15.4%; adults, 16.3%) being the most frequent mt in these populations. Multiple-point mt, including rtL180M-rtM204V- rtN238A and rtL180M-rtM204I, were identified in only two children, resulting in LMV-ADF resistance and reduced ETV susceptibility. In conclusion, this assay accurately identified the mt profile of children (98.4%) and adults (91.2%) with CHB, which is comparable to established methods. This fast and sensitive screening method can be used for the detection of major NA-resistant mt circulating in developing countries, as well as providing a model for the development of similar mt-detection assays, especially for use in nonhospitalized patients who need their results within half a day, before starting treatment.

Respiratory microbes detected in hospitalized adults with acute respiratory infections: associations between influenza A(H1N1)pdm09 virus and intensive care unit admission or fatal outcome in Vietnam (2015-2017).

BACKGROUND: Acute respiratory tract infection (ARI) is a leading cause of hospitalization, morbidity, and mortality worldwide. Respiratory microbes that were simultaneously detected in the respiratory tracts of hospitalized adult ARI patients were investigated. Associations between influenza A(H1N1)pdm09 virus (H1N1pdm) detection and intensive care unit (ICU) admission or fatal outcome were determined. METHODS: This prospective observational study was conducted between September 2015 and June 2017 at Bach Mai Hospital, Hanoi, Vietnam. Inclusion criteria were hospitalized patients aged ≥15 years; one or more of symptoms including shortness of breath, sore throat, runny nose, headache, and muscle pain/arthralgia in addition to cough and fever > 37.5 °C; and ≤ 10 days from the onset of symptoms. Twenty-two viruses, 11 bacteria, and one fungus in airway specimens were examined using a commercial multiplex real-time PCR assay. Associations between H1N1pdm detection and ICU admission or fatal outcome were investigated by univariate and multivariate logistic regression analyses. RESULTS: The total of 269 patients (57.6% male; median age, 51 years) included 69 ICU patients. One or more microbes were detected in the airways of 214 patients (79.6%). Single and multiple microbes were detected in 41.3 and 38.3% of patients, respectively. Influenza A(H3N2) virus was the most frequently detected (35 cases; 13.0%), followed by H1N1pdm (29 cases; 10.8%). Hematological disease was associated with ICU admission (p < 0.001) and fatal outcomes (p < 0.001) using the corrected significance level (p = 0.0033). Sex, age, duration from onset to sampling, or number of detected microbes were not significantly associated with ICU admission or fatal outcomes. H1N1pdm detection was associated with ICU admission (odds ratio [OR] 3.911; 95% confidence interval [CI] 1.671-9.154) and fatal outcome (OR 5.496; 95% CI 1.814-16.653) after adjusting for the confounding factors of comorbidities, bacteria/Pneumocystis jirovecii co-detection, and age. CONCLUSIONS: H1N1pdm was associated with severe morbidity and death in adult patients hospitalized with respiratory symptoms. The diagnosis of subtype of influenza virus may be epidemiologically important.

Next-Generation Sequencing Analysis of the Within-Host Genetic Diversity of Influenza A(H1N1)pdm09 Viruses in the Upper and Lower Respiratory Tracts of Patients with Severe Influenza.

The influenza A(H1N1)pdm09 virus emerged in April 2009 with an unusual incidence of severe disease and mortality, and currently circulates as a seasonal influenza virus. Previous studies using consensus viral genome sequencing data have overlooked the viral genomic and phenotypic diversity. Next-generation sequencing (NGS) may instead be used to characterize viral populations in an unbiased manner and to measure within-host genetic diversity. In this study, we used NGS analysis to investigate the within-host genetic diversity of influenza A(H1N1)pdm09 virus in the upper and lower respiratory samples from nine patients who were admitted to the intensive care unit (ICU). A total of 47 amino acid substitution positions were found to differ between the upper and lower respiratory tract samples from all patients. However, the D222G/N substitution in hemagglutinin (HA) protein was the only amino acid substitution common to multiple patients. Furthermore, the substitution was detected only in the six samples from the lower respiratory tract. Therefore, it is important to investigate influenza A(H1N1)pdm09 virus populations using multiple paired samples from the upper and lower respiratory tract to avoid overlooking potentially important substitutions, especially in patients with severe disease.IMPORTANCE The D222G/N substitution in the hemagglutinin (HA) protein of influenza A(H1N1)pdm09 virus has been reported to be associated with disease severity and mortality in numerous previous studies. In the present study, 75% of lower respiratory samples contained heterogeneous influenza populations that carried different amino acids at position 222 of the HA protein, whereas all upper respiratory samples only contained the wild-type 222D. These results suggest the influenza A(H1N1)pdm09 virus has diversified inside the host owing to differences in tissue specificity. In this study, the within-host genetic diversity of influenza A(H1N1)pdm09 virus was investigated for the first time using next-generation sequencing analysis of the viral whole-genome in samples extracted from the upper and lower respiratory tracts of patients with severe disease.

Nosocomial Coronavirus Disease Outbreak Containment, Hanoi, Vietnam, March-April 2020.

We report on the public health response generated by an outbreak of coronavirus disease (COVID-19) that occurred during March 2020 at Bach Mai Hospital (BMH) in Hanoi, northern Vietnam's largest hospital complex. On March 18, a total of 3 distinct clusters of COVID-19 cases were identified at BMH. Diagnosis of the initial 3 COVID-19 cases led to contact tracing, symptom screening, and testing of 495 persons and limited quarantine of affected institutes or departments. When 27 staff members in the catering company tested positive for SARS-CoV-2, the entire BMH staff (7,664 persons) was put under quarantine. Contact tracing in the community resulted in an additional 52,239 persons being quarantined. After 3 weeks, the hospital outbreak was contained; no further spread occurred in the hospital. Rapid screening of cases, extensive testing, prompt quarantine, contact tracing, and social distancing contributed to prevent community transmission in Hanoi and northern Vietnam.

A Compact Optical Pressure Measurement System for Acquiring Intraocular Pressure and Ocular Pulse.

Frequent and accurate monitoring of intraocular pressure is an important aspect of glaucoma management and is central to timely therapeutic intervention and treatment optimization. Intraocular pressure is known to fluctuate not only throughout the day, but also as a function of the heart rate. This pulsatory pressure change behavior is known as the ocular pulse. In this study, we report on the measurement of the ocular pulse profile using a miniaturized intraocular pressure sensor implanted in the eye of a New Zealand White rabbit. The pressure sensor is based on the principle of interferometry and does not require an internal power source. The ocular pulse variation has been measured up to 5 Hz with an accuracy of +/- 0.15 mmHg using both a DSLR reader and a handheld smartphone reader.

COLD-PCR Method for Early Detection of Antiviral Drug-Resistance Mutations in Treatment-Naive Children with Chronic Hepatitis B.

We investigated Nucleos(t)ide-analogue (NA)-resistance mutations (mt) in 142 treatment-naive children with Chronic Hepatitis B (CHB), using a sensitive co-amplification at lower denaturation temperature (COLD)-PCR with Sanger DNA sequencing. An NA resistance-associated mt in the hepatitis B virus (HBV) reverse transcriptase (RT) was found in 66.2% of the patients, with nonclassical mt contributing the most (64.8%). Significantly higher frequencies of Lamivudine (LMV) and Adefovir dipivoxil (ADF) resistance-associated mt were found in genotypes B and C, respectively (ORLMV/ADF: 1495.000; 95% CI: 89.800-24,889.032; p < 0.001). Single-point mt associated to LMV and ADF resistance were detected in 59.9% of the tested children with rtV207M (38.0%) and rtN238T (9.9%) being the most frequent. Multiple-point mt were found only in 8 cases (5.6%): 6 children carried double mt (rtV207M + rtL229V; rtV207M + rtI233V; rtV207I + rtV207M × 2 cases; rtV207M + rtS213T; rtN238A + rtS256G) relating to LMV or/and ADF resistance and 3 children carried triple mt (rtL180M + rtM204I + rtN238T; rtV207M + rtS213T + rtS256G) or quadruple mt (rtL180M + rtM204V + rtV207I/M) for LMV-ADF resistance and Entecavir-reduced susceptibility. Our data indicate that significantly higher frequencies of LMV and ADF-associated mutations were found in treatment-naïve children infected with HBV genotypes B and C, respectively. The developed COLD-PCR method and obtained data may contribute to the development of suitable treatments for children with CHB.

A Wireless Handheld Pressure Measurement System for In Vivo Monitoring of Intraocular Pressure in Rabbits.

Intraocular pressure (IOP) is the leading modifiable risk factor for preventing vision loss in glaucoma patients. Direct and frequent IOP measurements are highly desirable to assess adequacy of treatment and prevent further vision loss. In this study, we report on successful in vivo measurements of intraocular pressure in rabbits using an optical IOP measurement system. The sensor was implanted during cataract surgery in two New Zealand white (NZW) rabbits and tested in vivo for ten weeks. Prior to implantation, the sensors were characterized in vitro in the physiologically relevant pressure range of 0-60 mmHg. A portable wireless handheld reader consisting of an internal beam splitter, a monochromatic light source, and a digital single-lens reflex (DSLR) camera was also designed and implemented to capture interference patterns from the sensor. The sensitivity and accuracy of the sensor was 30 nm/mmHg and ±0.2 mmHg, respectively. Ten weeks post-implantation, the two NZW rabbits continued to respond well to the implant with no observable inflammation, signs of infection, or biofouling. All IOP measurements were obtained using the portable DSLR handheld reader. Successful in vivo studies demonstrate biocompatibility of the IOP sensor and prove feasibility of the IOP measurement system. The system has the potential to be used in both clinical and patient point-of-care (home) settings to frequently and accurately measure pressure.

Model-based small area estimation at two scales using Moran's spatial filtering.

In spatial epidemiology and public health studies, including covariates in small area estimation of spatial binary data remains a challenge. In this paper, Moran's spatial filtering is proposed to model two-scale spatial binary data. Two models are developed: the first uses deterministic estimation of the sample size at small areal level; the second generates a random sample size using the multinomial distribution. The models were applied to estimate the underweight among children at Vietnamese district level using sampling survey data at provincial level. The results show that the first model outperformed the second model regarding its accuracy and simplicity. Eigenvector maps improve model parameter estimation, and allow for the effects of spatial spillover and covariates. Prediction at the district level indicates that many underweight children came from the mountainous areas in 2014. The study concludes that the proposed models serve as alternatives to small area estimation of spatial binary data.

A spatial-temporal statistical analysis of health seasonality: explaining HFMD infections within a children population along the Vietnamese south central coast.

BACKGROUND: Various neglected tropical diseases show spatially changing seasonality at small areas. This phenomenon has received little scientific attention so far. Our study contributes to advancing the understanding of its drivers. This study focuses on the effects of the seasonality of increasing social contacts on the incidence proportions at multiple district level of the childhood hand-foot-mouth disease in Da Nang city, Viet Nam from 2012 to 2016. METHODS: We decomposed the nonstationary time series of the incidence proportions for the nine spatial-temporal (S-T) strata in the study area, where S indicates the spatial and T the temporal stratum. The long-term trends and the seasonality are presented by the Fourier series. To study the effects of the monthly average ambient temperature and the period of preschooling, we developed a spatial-temporal autoregressive model. RESULTS: Seasonality of childhood hand-foot-mouth disease incidence proportions shows two peaks in all spatial strata annually: large peaks synchronously in April and small ones asynchronously during the preschooling period. The peaks of the average temperature are asynchronous with the seasonal peaks of the childhood hand-foot-mouth disease incidence proportions in the period between January and May, with the negative values of the regression coefficients for all spatial strata, respectively: [Formula: see text]. The increasingly cumulative preschooling period and the seasonal component of the incidence proportions are negatively correlated in the period between August and December, with the negative values of the regression coefficients for all temporal strata, respectively: [Formula: see text]. CONCLUSIONS: The study shows that social contact amongst children under five years of age is the important driving factor of the dynamics of the childhood hand-foot-mouth disease outbreaks in the study area. The preschooling season when children's contact with each other increases stimulates the geographical variation of the seasonality of childhood hand-foot-mouth disease infections at small areas in the study area.

Basophil-derived tumor necrosis factor can enhance survival in a sepsis model in mice.

Basophils are evolutionarily conserved in vertebrates, despite their small numbers and short life span, suggesting that they have beneficial roles in maintaining health. However, these roles are not fully defined. Here we demonstrate that basophil-deficient mice exhibit reduced bacterial clearance and increased morbidity and mortality in the cecal ligation and puncture (CLP) model of sepsis. Among the several proinflammatory mediators that we measured, tumor necrosis factor (TNF) was the only cytokine that was significantly reduced in basophil-deficient mice after CLP. In accordance with that observation, we found that mice with genetic ablation of Tnf in basophils exhibited reduced systemic concentrations of TNF during endotoxemia. Moreover, after CLP, mice whose basophils could not produce TNF, exhibited reduced neutrophil and macrophage TNF production and effector functions, reduced bacterial clearance, and increased mortality. Taken together, our results show that basophils can enhance the innate immune response to bacterial infection and help prevent sepsis.

Hypermethylation of DcR1 Gene-based Biomarker in Non-invasive Cancer Screening of Vietnamese Cervical Cancer Patients.

BACKGROUND: The infection of human papillomavirus (HPV) has been considered as the common cause of cervical cancer, which is the leading cause of cancer death in women, in Vietnam. Recently, hypermethylation at tumor suppressor genes (TSGs) has been also demonstrated to be an early epigenetic event and cofactor in human cancer, including cancer of cervix. This study evaluated the frequency of DcR1 gene promoter hyper-methylation status as well as whether did or not an association between patterns of DNA hypermethylation and high-risk HPV infection, led to risk of cervical cancer. METHODS: Methylation-Specific-PCR (MSP) was performed to analyze hypermethylation status from 109 liquid-based Papanicolaou test samples, archived and admitted from the Medic Medical Center and Au Lac Clinic Laboratory, Vietnam, from 2011-2014, a kind of non-invasive samples identified whether HPV/or non-HPV, high-risk/low-risk HPV infection. RESULTS: DcR1 promoter was differentially methylated in 50% cases of high-risk HPV genotype 16 and 18 infected samples. In contrast, a low frequency of hypermethylated DcR1 promoter was found in low risk HPV genotype infected sample (16.0%), and non-HPV infected sample (14.6%). A trend toward positive association was found between hypermethylation of DcR1 gene and HPV exposure was observed (P=0.0005). Moreover, the odds ratio (OR) and relative risk (RR) were found in statistical significant value (OR=5.63 (95%CI = 2.25 - 14.07, P<0.01), RR=3.31 (95%CI = 1.75 - 6.26, P<0.01)). CONCLUSION: The hypermethylation of DcR1 gene promoter is a significant characteristic of high-risk HPV infected samples in Vietnamese cervical patients. The OR and RR values showed that the strong correlation between DcR1 hypermethylation and high-risk HPV infection, in which increased the risk of cervical cancer. The combination of DcR1 hypermethylation and HPV detection based biomarker could be used in noninvasive samples obtained from high-risk cancer patients, offer significant practical advantages.

Sensitivity and specificity of two dried blood spot methods for HIV-1 viral load monitoring among patients in Hanoi, Vietnam.

The use of dried blood spot (DBS) specimens for HIV viral load (VL) monitoring is recommended to support the roll-out of routine VL monitoring in low and middle income countries (LMICs). To better understand the use of DBS for VL monitoring, we evaluated two DBS testing methods, Roche TaqMan® Free Virus Evolution protocol (DBS-FVE) and Roche TaqMan® SPEX protocol (DBS-SPEX)) in patients receiving ART at an HIV clinic in Hanoi, Vietnam. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each DBS testing method at the thresholds of 1000 and 5000 copies/ml compared to plasma VL. At a threshold of 1000 copies/ml, sensitivity, specificity, PPV and NPV of the DBS-SPEX method were 98.8% (95% CI: 93.3%-100%), 74.3% (95% CI: 70.8%-77.5%), 31.5% (95% CI: 25.8%-37.6%), and 99.8% (95% CI: 98.9%-100%), respectively. Increasing the VL threshold value to 5000 copies/ml improved specificity (97.9% CI: 96.6%-98.9%) and PPV (83.9% CI: 74.5%-90.9%). Using the DBS-FVE method, at the threshold of 1000 copies/ml and with a correction factor of +0.3 log copies/ml, sensitivity was 95.1% (87.8%-98.6%) and specificity was 98.8% (97.7%-99.5%). Sensitivity decreased at the threshold of 5000 copies/ml (65.8%, 95% CI: 54.3%-76.1%). With a correction factor of +0.7 log copies/ml, the sensitivity was 96.3% (89.6%-99.2%) and specificity was 98.2% (96.9%-99.1%) at the threshold of 1000 copies/ml. We found that the Roche DBS-FVE method, with a +0.7 log copies/ml correction factor, performed well with sensitivity and specificity greater than 96% at a VL threshold of 1000 copies/m. These findings add to the growing body of evidence supporting the use of DBS VL testing for ART monitoring. Future research should evaluate the association between VL results by DBS and clinical outcome measures such as HIV drug resistance, morbidity, and mortality.

Evaluation of p16INK4α Hypermethylation from Liquid-based Pap Test Samples in Vietnamese Population.

BACKGROUND: Human papillomavirus (HPV) infection has been considered as main cause of cervical cancer. Recently, aberrant DNA methylation at tumor suppressor genes (TSGs), leading to inactivation, has also been an early epigenetic event and cofactor in cervical carcinogenesis. This study was performed to evaluate an association between the hypermethylation of p16INK4α gene's promoter and HPV exposure in non-invasive samples (liquid-based papanicolaous samples) in Vietnamese population. METHODS: 109 liquid-based papanicolaous test samples were archived and admitted from the Medic Medical Center and Au Lac Clinic Laboratory, Vietnam, from 2011-2014. Methylation-Specific-PCR (MSP) was performed to analyze methylation status from the liquid-based papanicolaous test samples identified whether HPV/or non-HPV, high-risk/low-risk HPV infection. RESULTS: An upward trend was observed concerning the p16INK4α hypermethylation frequency in high-risk HPV infection, counting for 55.6%, and the low methylation frequency in low-risk and non-HPV infected samples, counting for 22.9%, 8.0%, respectively. The significant correlation between candidate p16INK4α hypermethylation and HPV exposure was observed (P<0.0001). Moreover, the odds ratio (OR) and relative risk (RR) were found in statistical significant value. (OR=5.76, 95%CI: 2.36 - 14.04, P<0.01; RR=3.11, 95%CI: 1.75-5.53, P<0.01). CONCLUSION: Presence of p16INK4α hypermethylation was the specific characteristic of high-risk HPV infected samples in Vietnamese population. The OR and RR values showed that the strong correlation between p16INK4α hypermethylation and high-risk HPV infection, in which increased the risk of cervical cancer. The combination of p16INK4α hyper-methylation and HPV detection based biomarker could be used in non-invasive samples obtained from high-risk cancer patients, offer significant practical advantages.

Proteome analysis of mast cell releasates reveals a role for chymase in the regulation of coagulation factor XIIIA levels via proteolytic degradation.

BACKGROUND: Mast cells are significantly involved in IgE-mediated allergic reactions; however, their roles in health and disease are incompletely understood. OBJECTIVE: We aimed to define the proteome contained in mast cell releasates on activation to better understand the factors secreted by mast cells that are relevant to the contribution of mast cells in diseases. METHODS: Bone marrow-derived cultured mast cells (BMCMCs) and peritoneal cell-derived mast cells were used as "surrogates" for mucosal and connective tissue mast cells, respectively, and their releasate proteomes were analyzed by mass spectrometry. RESULTS: Our studies showed that BMCMCs and peritoneal cell-derived mast cells produced substantially different releasates following IgE-mediated activation. Moreover, we observed that the transglutaminase coagulation factor XIIIA (FXIIIA) was one of the most abundant proteins contained in the BMCMC releasates. Mast cell-deficient mice exhibited increased FXIIIA plasma and activity levels as well as reduced bleeding times, indicating that mast cells are more efficient in their ability to downregulate FXIIIA than in contributing to its amounts and functions in homeostatic conditions. We found that human chymase and mouse mast cell protease-4 (the mouse homologue of human chymase) had the ability to reduce FXIIIA levels and function via proteolytic degradation. Moreover, we found that chymase deficiency led to increased FXIIIA amounts and activity, as well as reduced bleeding times in homeostatic conditions and during sepsis. CONCLUSIONS: Our study indicates that the mast cell protease content can shape its releasate proteome. Moreover, we found that chymase plays an important role in the regulation of FXIIIA via proteolytic degradation.