Seroprevalence of SARS-CoV-2 infection in pediatric patients in a tertiary care hospital setting.

Globally, cases of children's coronavirus disease 2019 (COVID-19) have been reported since the pandemic started. Most children have an asymptomatic or mild infection. Therefore, the incidence rate of COVID-19 in children might have been underestimated.

External quality assessment scheme for HbA1c assays in Thailand: A 5-year experience.

Background: Thailand National External Quality Assessment Scheme (NEQAS) for HbA1c was established to evaluate the quality of HbA1c assays in Thailand in 2016.

Methods: HbA1c results from participating laboratories were compared to the target value assigned by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference system.

Results: The pass rates of participating laboratories during 2016-2020 were72-88%.

SARS-CoV-2 RT-PCR positivity of individuals subsequent to completing quarantine upon entry into a country during a transmission-free period.

Background: During the current coronavirus disease 2019 (COVID-19) pandemic, many countries require travellers to undergo a reverse transcription-polymerase chain reaction (RT-PCR) testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) before travelling across borders. However, in persons having recovered from COVID-19, RT-PCR positivity can persist for an extended period.

Materials And Methods: We describe three cases who sought fit-to-fly certificates in Thailand during the period free of local transmission but were tested positive for RT-PCR for SARS-CoV-2.

SARS-CoV-2 neutralizing antibodies decline over one year and patients with severe COVID-19 pneumonia display a unique cytokine profile.

Objectives: As coronavirus disease 2019 (COVID-19) rages on worldwide, there is an urgent need to characterize immune correlates of protection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and to identify immune determinants of COVID-19 severity.

Methods: This study examined the longitudinal profiles of neutralizing antibody (NAb) titers in hospitalized COVID-19 patients clinically diagnosed with mild symptoms, pneumonia, or severe pneumonia, up to 12 months after illness onset, using live-virus neutralization. Multiplex, correlation, and network analyses were used to characterize serum-derived inflammatory cytokine profiles in all severity groups.

Application of QuantiFERON ELISA for Detection of Interferon-Gamma Autoantibodies in Adult-Onset Immunodeficiency Syndrome.

Objective: Patients who develop interferon-gamma autoantibodies (IFN-ɤ autoAbs) in adult-onset immunodeficiency (AOID) syndrome are more likely to develop opportunistic and recurrent intracellular infections. The assay to detect IFN-ɤ autoAbs is essential for the diagnosis and therapeutic monitoring of AOID syndrome. Therefore, this study applied the QuantiFERON assay for the detection of IFN-ɤ autoAbs.

Rh blood phenotyping (D, E, e, C, c) microarrays using multichannel surface plasmon resonance imaging.

The application of Surface Plasmon Resonance Imaging (SPRi) for the detection of transmembrane antigen of the Rhesus (Rh) blood group system is demonstrated. Clinically significant Rh blood group system antigens, including D, C, E, c, and e, can be simultaneously identified via solid phase immobilization assay, which offers significant time savings and assay simplification. Red blood cells (RBCs) flowed through the micro-channel, where a suitable condition for Rh blood group detection was an RBC dilution of 1:10 with a stop-flow condition.

Surface plasmon resonance imaging for ABH antigen detection on red blood cells and in saliva: secretor status-related ABO subgroup identification.

Low antigenic expression of ABO subgroup system on red blood cell (RBC) is cause of discrepancy between forward and reverse blood typing in the standard agglutination technique. Neutralization agglutination is employed for verification of the detection of ABH substances in saliva. However, the neutralization technique is complicated, time-consuming and requires expertise.

Colorimetric Detection by Gold Nanoparticle DNA Probes for Miltenberger Series (GP.Mur, GP.Hop, and GP.Bun) Identification.

Background: Miltenberger (Mi) series are the collective glycophorin hybrids in the MNS blood group system. Mi series are composed of several subtypes, for examples, GP.Mur, GP.

Comparison of Double RBC Collection by Blood Cell Separators.

Background: The problem of red blood cell (RBC) shortage occurs because of the expanding demand for blood utilization and the dfficulties in donor recruitment and retention. Resources can be maximized by using current technology to collect two units of RBC from the same donor during a single collection session.

Objective: To evaluate the performance, collection efficiency (CE), production cost, and donor satisfactions of two commercially available blood cell separators (BCS) for double dose red cell (DDRC) collection.

Miltenberger blood group typing by real-time polymerase chain reaction (qPCR) melting curve analysis in Thai population.

Objectives: To develop reliable and convenient methods for Miltenberger (Mi(a) ) blood group typing.

Aim: To apply real-time polymerase chain reaction (qPCR) melting curve analysis to Mi(a) blood group typing.

Background: The Mi(a) blood group is the collective set of glycophorin hybrids in the MNS blood group system.

Microfluidic PMMA-based microarray sensor chip with imaging analysis for ABO and RhD blood group typing.

Background And Objectives: Solid phase microarrays have been described for use in blood typing; red blood cells (RBCs) captured on immobilized antibodies were detected using surface plasmon resonance or fluorescence. We present antibody microarray on Poly (methylmethacrylate) (PMMA) surface coupled with microfluidic system for ABO and RhD blood typing. After immobilized by antigen-antibody interaction, the RBCs were detected by image recognition.

Evaluation of agglutination strength by a flow-induced cell movement assay based surface plasmon resonance (SPR) technique.

A flow-induced cell movement assay combined with a surface plasmon resonance (SPR) technique was developed to quantify the agglutination strength, derived from the standard tube-agglutination test. Red blood cells (RBCs), based on the ABO blood group system, were specifically captured by anti-A and/or anti-B antibodies immobilized on a sensor surface. The agglutination strength corresponds to the amount of antigen-antibody interactions or the strength of RBC adhesion.

ABO blood-typing using an antibody array technique based on surface plasmon resonance imaging.

In this study, readily available antibodies that are used in standard agglutination tests were evaluated for their use in ABO blood typing by a surface plasmon resonance imaging (SPR imaging) technique. Five groups of antibodies, including mixed clones of anti-A, anti-B, and anti-AB, and single clones of anti-A and anti-B, were used to construct the five-line detection arrays using a multichannel flow cell in the SPR imager. The red blood cell (RBC) samples were applied to a multichannel flow cell that was orthogonal to the detection line arrays for blood group typing.

HemoglobinA1c level in healthy Thai adults: reference interval and fasting plasma glucose.

Aim: To establish reference interval of HbA1c IFCC in Thai.

Materials And Methods: 699 whole blood samples were used. Samples had fasting plasma glucose >or=126 mg/dl (7.

Fecal alpha1--antitrypsin in healthy and intestinal-disorder Thai children.

Objective: Determine the normal FA1-AT level in random wet stool of Thai children using RID and NPL, and to study the correlation between RID and NPL methods for measurement of FA1-AT.

Material And Method: Random stool samples were collected from healthy children and intestinal-disorders patients. Alpha1-antitrypsin (FA1-AT) in wet stool samples was measured by nephelometry (NPL) and radial-immunodiffusion (RID) methods.

Mycoplasma pneumoniae and Chlamydophila pneumoniae in children with community-acquired pneumonia in Thailand.

Background: The prevalence of community-acquired pneumonia (CAP) caused by atypical pathogens in Thai children is unknown.

Objective: To examine the prevalence of Mycoplasma pneumoniae and Chlamydophila pneumoniae infections in paediatric patients (aged 2-15 years) with CAP in three academic hospitals using standardised laboratory techniques. The characteristics of atypical pneumonia were also compared with other causes of CAP.

Quorum sensing regulates dpsA and the oxidative stress response in Burkholderia pseudomallei.

Burkholderia pseudomallei is the causative agent of melioidosis, a fatal human tropical disease. The non-specific DNA-binding protein DpsA plays a key role in protecting B. pseudomallei from oxidative stress mediated, for example, by organic hydroperoxides.

Prevalence and clinical features of mycoplasma pneumoniae in Thai children.

Objective: To determine the prevalence and clinical features of mycoplasma pneumoniae in Thai children with community acquired pneumonia (CAP).

Material And Method: Diagnosis of current infection was based on > or = 4 fold rise in antibody sera or persistently high antibody titers together with the presence of mycoplasma DNA in respiratory secretion. The clinical features were compared between children who tested positive for M pneumoniae, and those whose results were negative.

Prevalence and clinical presentations of atypical pathogens infection in community acquired pneumonia in Thailand.

Objectives: To determine the prevalence of atypical pneumonia and clinical presentations in patients with community acquired pneumonia (CAP).

Material And Method: A prospective multi-centered study was performed in patients aged > or = 2 years with the diagnosis of CAP who were treated at seven governmental hospitals in Bangkok from December 2001 to November 2002. The diagnosis of current infection was based on > or = 4 fold rise in antibody sera or persistently high antibody titers together with the presence of DNA of M.

Functional genetic analysis reveals a 2-Alkyl-4-quinolone signaling system in the human pathogen Burkholderia pseudomallei and related bacteria.

Pseudomonas aeruginosa synthesizes diverse 2-alkyl-4(1H)-quinolones (AHQs), including the signaling molecule 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS), via the pqsABCDE locus. By examining the genome databases, homologs of the pqs genes were identified in other bacteria. However, apart from P.

Identification of a novel 74-kiloDalton immunodominant antigen of Pythium insidiosum recognized by sera from human patients with pythiosis.

The oomycetous, fungus-like, aquatic organism Pythium insidiosum is the etiologic agent of pythiosis, a life-threatening infectious disease of humans and animals that has been increasingly reported from tropical, subtropical, and temperate countries. Human pythiosis is endemic in Thailand, and most patients present with arteritis, leading to limb amputation and/or death, or cornea ulcer, leading to enucleation. Diagnosis of pythiosis is time-consuming and difficult.

Raising rheumatoid factor cutoff helps distinguish rheumatoid arthritis.

The presence of rheumatoid factor (RF) is one of the clinical criteria for the diagnosis of rheumatoid arthritis (RA). The cutoff point of RF assays is usually based on a reference level obtained from normal subjects in the same population as the patients. We evaluated 63 rheumatoid arthritis (RA), 25 other arthritis patients and 110 blood donors.

Ocular pythiosis: is it under-diagnosed?

Purpose: To increase awareness of ocular pythiosis by presenting a typical case and summarizing clinical data of 11 ocular pythiosis cases in Ramathibodi Hospital.

Design: Interventional case report.

Methods: A 48-year-old healthy woman with a history of 3-week painful corneal ulcer of left eye was treated with enucleation.

Role of the stationary growth phase sigma factor RpoS of Burkholderia pseudomallei in response to physiological stress conditions.

The Burkholderia pseudomallei rpoS gene was identified, and an rpoS null mutant was constructed. The mutant was shown to have an increased sensitivity to carbon starvation and oxidative stress. By using rpoS-lacZ fusions, transcription of rpoS was shown to be growth phase regulated, reaching a peak upon entry into stationary phase.