Study on the clinical and electrophysiological characteristics of nerve function in myasthenia gravis patients in Vietnam.

Background: In Vietnam, there is limited research on the role of nerve conduction in myasthenia gravis and its association with clinical features. Objective: This study aims to describe the electrophysiological features in patients with myasthenia gravis. Methods: This descriptive study was conducted from September 2019 to December 2021. The study included 33 myasthenia gravis patients who sought medical consultation or received inpatient treatment during this period. The Myasthenia Gravis Foundation of America classifies myasthenia gravis into five groups: I, IIa, IIb, IIIa, IIIb, IVa, IVb, and V. Notably, Group I involves pure ocular weakness, whereas Group a primarily impacts limb and axial muscles, and Group b mainly affects bulbar and respiratory muscles. Results: The study revealed that motor and sensory nerve conduction in the upper and lower limbs were within normal limits for the patient group under evaluation. Repetitive nerve stimulation testing at a frequency of 3 Hz showed positive results in 66.7% of myasthenia gravis patients. Myasthenia gravis patients displayed distinct clinical symptoms, with ptosis being the most common (87.9%). Myasthenia Gravis Foundation of America classification indicated the highest proportion in subgroup IIa (24.2%), with myasthenia gravis predominating in limb and axial muscles (Group a) observed in 51.5% of cases. Needle electromyography showed no abnormalities in myasthenia gravis patients. There was an association between acetylcholine receptor antibody titers and the results of the 3 Hz repetitive nerve stimulation test in myasthenia gravis patients, with a significance of p = 0.002. Conclusion: Nerve conduction studies should be performed in patients with suspected neuromuscular disorders to aid in differential diagnosis and definitive diagnosis of myasthenia gravis.

Feasibility of wearable monitors to detect heart rate variability in children with hand, foot and mouth disease.

Hand foot and mouth disease (HFMD) is caused by a variety of enteroviruses, and occurs in large outbreaks in which a small proportion of children deteriorate rapidly with cardiopulmonary failure. Determining which children are likely to deteriorate is difficult and health systems may become overloaded during outbreaks as many children require hospitalization for monitoring. Heart rate variability (HRV) may help distinguish those with more severe diseases but requires simple scalable methods to collect ECG data.We carried out a prospective observational study to examine the feasibility of using wearable devices to measure HRV in 142 children admitted with HFMD at a children's hospital in Vietnam. ECG data were collected in all children. HRV indices calculated were lower in those with enterovirus A71 associated HFMD compared to those with other viral pathogens.HRV analysis collected from wearable devices is feasible in a low and middle income country (LMIC) and may help classify disease severity in HFMD.

Emerging Enterovirus A71 Subgenogroup B5 Causing Severe Hand, Foot, and Mouth Disease, Vietnam, 2023.

We report on a 2023 outbreak of severe hand, foot, and mouth disease in southern Vietnam caused by an emerging lineage of enterovirus A71 subgenogroup B5. Affected children were significantly older than those reported during previous outbreaks. The virus should be closely monitored to assess its potential for global dispersal.

The effect of MnCO3 on the gain coefficient for the 4I13/2 → 4I15/2 transition of Er3+ ions and near-infrared emission bandwidth flatness of Er3+/Tm3+/Yb3+ co-doped barium zinc silicate glasses.

The roles of Mn2+ ions in the MnCO3 compound, leading to the formation of an Mn2+-Yb3+ dimer and affecting the gain coefficient for the 4I13/2 → 4I15/2 transition of Er3+ ions and near-infrared (NIR) emission bandwidth flatness of Er3+/Tm3+/Yb3+ co-doped in SiO2-ZnO-BaO (SZB) barium zinc silicate glasses, were investigated in this work. The composition of all elements from the original raw materials that exist in the host glasses was determined using energy-dispersive X-ray spectroscopy (EDS). Under the excitation of a 980 nm laser diode (LD), the NIR emission of Er3+/Tm3+/Yb3+-co-doped SZB glasses produced a bandwidth of about 430 nm covering the O, E, and C bands. The effects of Mn2+ ions and the Mn2+-Yb3+ dimer on the gain coefficient for the 4I13/2 → 4I15/2 transition of Er3+ ions and bandwidth flatness of NIR emission of Er3+/Tm3+-co-doped and Er3+/Tm3+/Yb3+-co-doped SZB glasses were also assigned. The optimal molar concentration of Mn2+ ions was determined such that the NIR bandwidth flatness of Er3+/Tm3+/Yb3+-co-doped SZB glasses was the flattest. In addition, the role of Mn2+ ions in reducing the gain coefficient for the 4I13/2 → 4I15/2 transition of Er3+ ions was also calculated and discussed.

Molecular subtypes of Adenovirus-associated acute respiratory infection outbreak in children in Northern Vietnam and risk factors of more severe cases.

BACKGROUND: Under the pressure of Human Adenovirus (HAdV)-associated acute respiratory infection (ARI) outbreak in children in Northern Vietnam in the end of 2022, this study was initiated to identify the HAdV subtype(s) and examine the associated clinical features and risk factors of more severe cases. METHODS: This study evaluated pediatric patients with ARI which had tested positive for HAdV between October and November 2022 using a multiplex real-time PCR panel. Nasopharyngeal aspirates or nasal swab samples were used for sequencing to identify HAdV subtypes. Clinical data were collected retrospectively. RESULTS: Among 97 successfully sequenced samples, the predominant subtypes were HAdV-B3 (83%), HAdV-B7 (16%) and HAdV-C2 (1%). Lower respiratory manifestations were found in 25% of the patients of which 5% were diagnosed with severe pneumonia. There was no significant association between HAdV subtype and clinical features except higher white blood cell and neutrophil counts in those detected with HAdV-B3 (p<0.001). Co-detection of HAdV with ≥1 other respiratory viruses was found in 13/24(54%) of those with lower respiratory manifestations and 4/5(80%) of those with severe pneumonia (odds ratio (95% confidence interval) vs. those without = 10.74 (2.83, 48.17) and 19.44 (2.12, 492.73) respectively after adjusting for age, sex, birth delivery method, day of disease). CONCLUSION: HAdV-B3 and HAdV-B7 were predominant in the outbreak. Co-detection of HAdV together with other respiratory viruses was a strong risk factor for lower respiratory tract illnesses and severe pneumonia. The findings advocate the advantages of multi-factor microbial panels for the diagnosis and prognosis of ARI in children.

A giant thrombus in the right atrium of a patient with acute promyelocytic leukemia M3.

Acute promyelocytic leukemia is a special type of acute myeloid leukemia. Patients with this disease are at high risk of complications. Right atrial thrombosis is a rare but potentially serious complication. A 55-month-old girl with acute promyelocytic leukemia M3 was in her last phase of treatment. Radiologic examination revealed an echo structure in the right atrium that was still present after 6 weeks of anticoagulation treatment with enoxaparin. Cardiac surgery was performed to remove the mass, which was found to be a calcified thrombus. Although this is a rare occurrence, recognition of the possibility of a calcified thrombus may minimize misdiagnosis and allow surgical retrieval if the thrombus is sufficiently large.

Determination of the crystalline size of hexagonal La1-xSrxMnO3 (x = 0.3) nanoparticles from X-ray diffraction - a comparative study.

The electronic, magnetic, optical and elastic properties of nanomaterials are governed partially by the crystallite size and crystal defects. Here, the crystalline size of hexagonal La1-xSrxMnO3 (x = 0.3) nanoparticles was determined using various methods. Single-phase La0.7Sr0.3MnO3 nanopowders were produced after 10 h of milling in a commercial high-energy SPEX 8000D shaker mill, and then they were heated at 700 °C and 800 °C to study the effect of calcined temperature on the crystallization of nanoparticles. The modified Scherrer, Williamson-Hall, size-strain, and Halder-Wagner methods were used to determine the crystallite sizes and the elastic properties, such as intrinsic strain, stress, and energy density, from the X-ray diffraction peak broadening analysis. The obtained results were then compared with one another. The difference in crystallite sizes calculated from the different methods was due to the different techniques.

Chemical composition, anti-inflammatory and cytotoxic activity of essential oils from two Luvunga species (L. scandens and L. hongiaoensis) from Vietnam.

New essential oils (EOs) extracted from different parts of two Luvunga species (L. scandens and L. hongiaoensis) from Vietnam were investigated for their chemical composition, anti-inflammatory and cytotoxic activity. Sixty-nine total compounds were identified in the EOs by GC/MS. The major constituent of the leaf, fruit, and root EOs from L. scandens was ß-caryophyllene (71.5%, 63.0%, and 31.5% respectively). The main compounds in L. hongiaoensis EOs were ß-elemene (34.3% in leaf oil) and caryophyllene oxide (21.2% in root oil, 19.4% in stem oil). The EO from L. scandens fruits significantly inhibited nitric oxide production on LPS-induced RAW264.7 cells (IC50 = 37.95 ± 2.76 µg/mL). The EOs from L. hongiaoensis roots and L. scandens leaves and fruits exhibited cytotoxic activity against MCF-7, SK-LU-1, and HepG2 (IC50 from 49.74 ± 3.36 to 97.82 ± 8.61 µg/mL). This is the first report on L. hongiaoensis EOs and significantly complements the composition and bioactivity of L. scandens EOs.

Prostatic stromal sarcoma: A case report and literature review.

Stromal sarcoma of the prostate is extremely rare. In this article, we report the case of a 43-year-old male admitted to the local hospital due to dysuria. Although the pathological findings from transurethral prostatic resection showed low-grade stromal sarcoma, the surgical specimen after radical prostatectomy revealed high-grade sarcoma with hypercellularity, marked atypical spindle cells, and high mitotic activity. This case study and literature analysis aim to emphasize its rarity and raise awareness about clinical and pathological diagnosis.

The High Re-Ulceration Rate in Lower Extremity Amputation Intervention in Type 2 Diabetic Vietnamese Patients After 24-Month Follow-Up at Cho Ray Hospital, Vietnam.

Diabetic foot ulcers (DFU) are a prevalent and severe disease with vascular and/or neurological complications, and if not diagnosed and treated promptly, it may rapidly deteriorate. Despite amputation or nonamputation treatment, there is still a high rate of re-ulceration. Previous studies have shown that the recurrence rate varies from 43% to 59% after 2 years. Currently, there is still a high rate of lower extremity amputation intervention, particularly above-the-ankle amputation, at Cho Ray Hospital in Vietnam, reaching 50%. The effectiveness of this intervention in the long term based on re-ulceration has not been evaluated in Vietnamese diabetic patients (DPs). This study aims to describe the long-term outcomes of amputation intervention in Type 2 DPs after 24 months and identify factors related to DFU recurrence in order to improve DFU management in low-middle-income countries like Vietnam. From January to June 2022, archived clinical and direct visit or phone follow-up data were collected and analyzed from diabetic foot ulcer patients with low extremity amputation who were treated at Cho Ray hospital from 2018 to 2020. The high re-ulceration rate in the 24th month was 29.8% (17/57), and the factor related to this outcome was "late diagnosis and care" (32.4 days vs 26.9 days with P = .03). Other potential factors (higher rates but no significant statistical difference with P > .05) included failure of HbA1c control greater than 9% (82.5% vs 67.5%), the severity of foot ulcers with TEXAS 3B (82% vs 60%), the number of years having diabetes (8.7 years vs 6.7 years), loss of monofilament sensation (82.5% vs 70.6%), and a history of diabetic foot ulcer (17.6% vs 10%). The re-ulceration after 24 months might depend on various clinical factors. Therefore, early diagnosis and care for diabetic foot ulcers could help reduce amputation rates and the risk of re-ulceration.

Spatiotemporal Evolution of SARS-CoV-2 Alpha and Delta Variants during Large Nationwide Outbreak of COVID-19, Vietnam, 2021.

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions.

Urinary catecholamine excretion, cardiovascular variability, and outcomes in tetanus.

Severe tetanus is characterized by muscle spasm and cardiovascular system disturbance. The pathophysiology of muscle spasm is relatively well understood and involves inhibition of central inhibitory synapses by tetanus toxin. That of cardiovascular disturbance is less clear, but is believed to relate to disinhibition of the autonomic nervous system. The clinical syndrome of autonomic nervous system dysfunction (ANSD) seen in severe tetanus is characterized principally by changes in heart rate and blood pressure which have been linked to increased circulating catecholamines. Previous studies have described varying relationships between catecholamines and signs of ANSD in tetanus, but are limited by confounders and assays used. In this study, we aimed to perform detailed characterization of the relationship between catecholamines (adrenaline and noradrenaline), cardiovascular parameters (heart rate and blood pressure) and clinical outcomes (ANSD, mechanical ventilation required, and length of intensive care unit stay) in adults with tetanus, as well as examine whether intrathecal antitoxin administration affected subsequent catecholamine excretion. Noradrenaline and adrenaline were measured by ELISA from 24-h urine collections taken on day 5 of hospitalization in 272 patients enrolled in a 2 × 2 factorial-blinded randomized controlled trial in a Vietnamese hospital. Catecholamine results measured from 263 patients were available for analysis. After adjustment for potential confounders (i.e., age, sex, intervention treatment, and medications), there were indications of non-linear relationships between urinary catecholamines and heart rate. Adrenaline and noradrenaline were associated with subsequent development of ANSD, and length of ICU stay.

Seroprotection against tetanus in southern Vietnam.

BACKGROUND: Ongoing tetanus cases and sporadic outbreaks of vaccine-preventable diseases associated with routine vaccination programmes remain problems in many low and middle-income countries, including Vietnam. With no human-to-human transmission or natural immunity, tetanus antibody levels indicate both individual risk of tetanus and gaps in vaccination programmes. METHODS: To investigate gaps in immunity to tetanus in Vietnam, a country with a historically high level of tetanus vaccination coverage, tetanus antibodies were measure by ELISA from samples selected from a long-term serum bank, established for the purposes of general-population seroepidemiological investigations in southern Vietnam. Samples were selected from 10 provinces, focussing on age-groups targeted by national vaccination programmes for infants and pregnant women (Expanded Programme on Immunization, EPI, and Maternal and Neonatal Tetanus, MNT). RESULTS: Antibodies were measured from a total of 3864 samples. Highest tetanus antibody concentrations occurred in children under 4 years old, over 90 % of whom had protective levels. Approximately 70 % of children aged 7-12 years had protective antibody concentrations although there was variation among provinces. For infants and children, there were no significant differences in tetanus protection between males and females, but for adults aged 20-35 years, in five of the ten provinces surveyed, protection against tetanus was higher in females (p < 0.05) who are eligible for booster doses under the MNT programme. In seven of ten provinces, antibody concentrations were inversely related to age (p < 0.01) and protection of older individuals was generally low. CONCLUSION: Widespread immunity to tetanus toxoid is seen in infants and young children consistent with the high coverage rates reported for diptheria tetanus toxoid and pertussis (DTP) in Vietnam. However, the lower antibody concentrations seen in older children and men suggest reduced immunity to tetanus in populations not targeted by EPI and MNT programmes.

Monkeypox Virus Infection in 2 Female Travelers Returning to Vietnam from Dubai, United Arab Emirates, 2022.

Mpox was diagnosed in 2 women returning to Vietnam from the United Arab Emirates. The monkeypox viruses belonged to an emerging sublineage, A.2.1, distinct from B.1, which is responsible for the ongoing multicountry outbreak. Women could contribute to mpox transmission, and enhanced genomic surveillance is needed to clarify pathogen evolution.

Kinetics of Neutralizing Antibodies against Omicron Variant in Vietnamese Healthcare Workers after Primary Immunization with ChAdOx1-S and Booster Immunization with BNT162b2.

We studied the development and persistence of neutralizing antibodies against SARS-CoV-2 ancestral strain, and Delta and Omicron (BA.1 and BA.2) variants in Vietnamese healthcare workers (HCWs) up to 15 weeks after booster vaccination. We included 47 HCWs, including group 1 (G1, N = 21) and group 2 (G2; N = 26) without and with breakthrough Delta variant infection before booster immunization, respectively). The study participants had completed primary immunization with ChAdOx1-S and booster vaccination with BNT162b2. Neutralizing antibodies were measured using a surrogate virus neutralization assay. Of the 21 study participants in G1, neutralizing antibodies against ancestral strain, Delta variant, BA.1, and BA.2 were (almost) abolished at month 8 after the second dose, but all had detectable neutralizing antibodies to the study viruses at week 2 post booster dose. Of the 26 study participants in G2, neutralizing antibody levels to BA.1 and BA.2 were significantly higher than those to the corresponding viruses measured at week 2 post breakthrough infection and before the booster dose. At week 15 post booster vaccination, neutralizing antibodies to BA.1 and BA.2 dropped significantly, with more profound changes observed in those without breakthrough Delta variant infection. Booster vaccination enhanced neutralizing activities against ancestral strain and Delta variant compared with those induced by primary vaccination. These responses were maintained at high levels for at least 15 weeks. Our findings emphasize the importance of the first booster dose in producing cross-neutralizing antibodies against Omicron variant. A second booster to maintain long-term vaccine effectiveness against the currently circulating variants merits further research.

Passengers' self-protective intentions while using ride-hailing services during the COVID-19 pandemic.

In the transport context, there has been limited research examining passengers' health-protective behaviour while travelling during a health-related crisis such as COVID-19. This study develops a conceptual model aiming to explore determinants associated with passengers' self-protective intentions using the context of ride-hailing services in Vietnam. Ride-hailing services are popular in countries where public transport is underdeveloped. The conceptual model is based on perceived risk and self-efficacy as the main predictor of self-protective intentions when using ride-hailing services. In addition, the proposed conceptual model explores the direct and indirect impact of subjective knowledge and the perceived effectiveness of preventive measures on self-protective intentions. The proposed conceptual model was tested on a large sample of ride-hailing users in Vietnam (n = 527). The structural equation modelling (SEM) analysis results indicate that self-efficacy has the highest total impact on self-protective behaviour, followed by subject knowledge and perceived effectiveness of preventive measures. Self-efficacy also plays a fully mediating role in the linkage between the perceived effectiveness of preventive measures implemented by ride-hailing organisations and the intention to engage in self-protective behaviour. The results of this study expand the current understanding of ride-hailing passengers' health-protective behaviour and contribute to the transport and public health literature.

HPAI-resistant Ri chickens exhibit elevated antiviral immune-related gene expression

Background@#Highly pathogenic avian influenza viruses (HPAIVs) is an extremely contagious and high mortality rates in chickens resulting in substantial economic impact on the poultry sector. Therefore, it is necessary to elucidate the pathogenic mechanism of HPAIV for infection control. @*Objective@#Gene set enrichment analysis (GSEA) can effectively avoid the limitations of subjective screening for differential gene expression. Therefore, we performed GSEA to compare HPAI-infected resistant and susceptible Ri chicken lines. @*Methods@#The Ri chickens Mx(A)/BF2(B21) were chosen as resistant, and the chickens Mx(G)/ BF2(B13) were selected as susceptible by genotyping the Mx and BF2 genes. The tracheal tissues of HPAIV H5N1 infected chickens were collected for RNA sequencing followed by GSEA analysis to define gene subsets to elucidate the sequencing results. @*Results@#We identified four differentially expressed pathways, which were immune-related pathways with a total of 78 genes. The expression levels of cytokines (IL-1β, IL-6, IL-12), chemokines (CCL4 and CCL5), type interferons and their receptors (IFN-β, IFNAR1, IFNAR2, and IFNGR1), Jak-STAT signaling pathway genes (STAT1, STAT2, and JAK1), MHC class I and II and their co-stimulatory molecules (CD80, CD86, CD40, DMB2, BLB2, and B2M), and interferon stimulated genes (EIF2AK2 and EIF2AK1) in resistant chickens were higher than those in susceptible chickens. @*Conclusions@#Resistant Ri chickens exhibit a stronger antiviral response to HPAIV H5N1 compared with susceptible chickens. Our findings provide insights into the immune responses of genetically disparate chickens against HPAIV.

Corononema vulgare sp. n. and Hofmaenneria coralis sp. n. (Nematoda, Monhysterida) from coral reefs off the coast of Vietnam.

Two new nematode species of the order Monhysterida, found in coral reefs on the coast of Vietnam, are described and illustrated. Corononema vulgare sp. n. morphology is similar to C. thai Nicholas & Stewart, 1995 but differs from it by the shorter outer labial setae, shorter tail in males, and a different shape of the guiding lateral bodies in the spicular apparatus of males. Hofmaenneria coralis sp. n. morphology is close to H. niddensis Gerlach & Meyl, 1957 and H. optata Alekseev, 1983. The new species differs from the first species by having thinner body, a shorter and less slender tail, and shorter spicules. The new species differs from H. optata in having a longer body, shorter pharynx, shorter tail, and longer outer labial setae.

Influence of structure phase transition on the thermoelectric properties of Cu2Se1-x Te x liquid-like compounds.

Copper chalcogenide Cu2(Se,Te) compounds are well known as typical p-type thermoelectric materials with a figure of merit (ZT) that can be optimized by the ratio of Se : Te. Here, by using the mechanical alloying and solid-state reaction methods, Te was substituted into Se sites within Cu2Se as the formula Cu2Se1-x Te x (x = 0.1, 0.2, 0.25, and 0.3). The observed changes in structural phase, grain morphologies, and grain size were recorded by XRD and FE-SEM imaging with the appearance of the secondary phase of Cu2Te, with a Te content of x = 0.25. The layered structure morphology was observed more clearly at the high Te content. The electrical conductivity was greatly increased with enriched Te content while the maximum Seebeck coefficient was obtained in the Cu2Se0.75Te0.25 sample. Accordingly, a power factor value of up to 9.84 µW cm-1 K-2 at 773 K was achieved. The appearance of a Cu2Te phase with a Te content of 0.25 created a structural phase transition which results in a ZT value of 1.35 at 773 K in the Cu2Se0.75Te0.25 sample.

Community-acquired pneumonia-causing bacteria and antibiotic resistance rate among Vietnamese patients: A cross-sectional study.

Due to the overuse of antibiotics in treatment and regional variation in disease factors, community-acquired pneumonia (CAP) has a relatively high morbidity and mortality rate. This study determined the prevalence of bacteria that cause CAP and the rate of antibiotic resistance. From April 2018 to May 2019, a cross-sectional study was conducted on 254 CAP patients at hospitals and medical centers in the province of Vinh Long. Based on interviews and medical records, SPSS 18.0 was used to analyze the data. CAP-causing bacteria, antibiotic susceptibility, and extended-spectrum ß-lactamase production of bacteria were determined by performing Identification and Antibiotic Susceptibility Testing on sputum specimens using the VITEK 2 Automated instrument. With a total of 254 patients, the age of 60s accounted for the highest prevalence. Streptococcus pneumonia was the leading factor, accounting for 12.6%, followed by Klebsiella pneumonia and Pseudomonas aeruginosa at 12.2% and 8.3%, respectively. The Enterobacteriaceae group was the highest at 36.5%, followed by other gram-negative bacteria (34%) and gram-positive bacteria (29.5%). Amoxicillin/clavulanic acid ranked the highest in antibiotic resistance, accounting for 31.4% of Enterobacteriaceae and 91.7% of non-Enterobacteriaceae. S. pneumonia resisted erythromycin at a high prevalence (84.4%), followed by clindamycin (71.9%) and tetracycline (78.1%). The age of 60s was the leading group in community pneumonia and had increased resistance to amoxicillin/clavulanic acid and cefuroxime.