Tuberculin skin testing and QuantiFERON™-TB Gold Plus positivity among household contacts in Vietnam.

SETTING: TB infection (TBI) is diagnosed using the technique-dependent tuberculin skin test (TST) or costly, more accurate interferon-gamma release assays. The TST (⩾10 mm) threshold was indicated by previous research among household contacts in Vietnam, but routine implementation with a different tuberculin reagent showed unexpectedly low TST positivity. OBJECTIVE: TST (⩾5 mm and ⩾10 mm) results were compared to QuantiFERON™-TB Gold Plus (QFT) results in household contacts during community campaigns in 2020 and 2021. DESIGN: This was a cross-sectional multi-center implementation study. RESULTS: Among 1,330 household contacts in 2020, we found a TBI prevalence of 38.6% (QFT), similar to TST ⩾5 mm (37.4%) and higher than TST ⩾10 mm (13.1%). QFT+/TST+ was higher for TST ⩾5 mm (20.7%) than TST ⩾10 mm (9.4%). QFT was not discordant with TST ⩾5 mm (McNemar's test = 0.6, P = 0.5) but was discordant with TST ⩾10 mm (McNemar's test = 263.9, P < 0.01). Older age and Southern region increased odds for positive TST ⩾5 mm and QFT with weaker associations for TST ⩾10 mm. Agreement and discordance were similar in 2021 for 1,158 household contacts. CONCLUSION: Tuberculin reagents affect TST positivity rates. High TB burden countries should monitor reliability of TBI diagnosis, including tuberculin potency, cold chain, and TST technique to optimize eligibility for TB preventive treatment.

CONTEXTE: L'infection tuberculeuse (TBI) est diagnostiquée à l'aide du test cutané à la tuberculine (TST), qui dépend de la technique, ou de tests de libération de l'interféron-gamma, coûteux et plus précis. Des recherches antérieures ont indiqué que le TST (⩾10 mm) est généralement utilisé pour diagnostiquer la TB parmi les contacts familiaux au Vietnam ; la mise en œuvre de routine avec un réactif de tuberculine différent a montré une faible positivité inattendue du TST. OBJECTIF: Les résultats du TST (⩾5 mm et ⩾10 mm) ont été comparés aux résultats de QuantiFERON™-TB Gold Plus (QFT) chez les contacts familiaux au cours des campagnes communautaires de 2020 et 2021. MÉTHODE: Il s'agissait d'une étude transversale multicentrique de mise en œuvre. RÉSULTATS: Parmi 1 330 contacts familiaux en 2020, nous avons trouvé une prévalence de TBI de 38,6% (QFT), similaire au TST ⩾5 mm (37,4%) et plus élevée que le TST ⩾10 mm (13,1%). Le QFT+/TST+ était plus élevé pour le TST ⩾5 mm (20,7%) que pour le TST ⩾10 mm (9,4%). Le QFT n'était pas discordant avec le TST ≥5 mm (test de McNemar = 0,6 ; P = 0,5) mais était discordant avec le TST ⩾10 mm (test de McNemar = 263,9 ; P < 0,01). L'âge avancé et la région méridionale augmentaient les probabilités d'un TST positif ⩾5 mm et d'un QFT, avec des associations plus faibles pour un TST ⩾10 mm. La concordance et la discordance étaient similaires en 2021 pour 1 158 contacts familiaux. CONCLUSION: Les réactifs de tuberculine affectent les taux de positivité des TST. Les pays à forte charge de TB doivent surveiller la fiabilité du diagnostic de TBI, y compris la puissance de la tuberculine, la chaîne du froid et la technique du TST afin d'optimiser l'éligibilité au traitement préventif de la TB.

Species composition and level of infestation of cockroaches in three areas in Hanoi.

A study on the species composition and the level of infestation of cockroaches was carried out from April 2013 to October 2014 in three localities of Hanoi, Vietnam, namely the Lan Ong-Old Town, Linh Dam condominium and Tan Da Resort. Out of the 187 units of premises examined, 44.9% of units were infested with cockroaches. A total of 576 cockroaches were trapped, of which six species were identified: Periplaneta americana (L.) was the most dominant species (72.1%), followed by Blattella germanica (L.) (14.8%), Pycnoscelus surinamensis (L.) (7.3%), Periplaneta australasiae (Fabricius) (2.9%), Periplaneta fuliginosa (Serville) (1.9%) and Supella longipalpa (Fabricius) (1.0%). Infestation was the highest in Lan Ong (74.0%), followed by Linh Dam (40.5%) and Tan Da (25.9%). Cockroaches were abundantly found in warehouses (100%), electrical distribution room (56.3%), and kitchens (46.7%).

Application of co-anaerobic digester's effluent for sustainable agriculture and aquaculture in the Mekong Delta, Vietnam.

This investigation studied the application of digester effluent from co-digestion of pig manure and spent mushroom substrate as a fertilizer for leaf mustard planting and as feed for Tilapia fish growing. The fish raising experiment was set up in 1 × 1 × 1 m hapa conditions (triplicate for each treatment) with the density of 10 individiual per hapa; the fish weight and length were measured every 10 days for 50 continuous days. The leaf mustard was planted in real conditions at farmer's garden with normal cultivation style, and the weight and length of the plant were measured four times during the growing period. The study result shows that the harvest yield of leaf mustard fertilized by the digester effluent was 5.4 times higher than that by an inorganic fertilizer (IF). In addition to its contribution to a higher yield, the digester effluent accelerated the flower formation and shortened cultivation duration. For Tilapia fish culture, the growing rate of fish in the treatments supplied with 50% digester effluent + 50% commercial food (CF) was not significantly different in comparison to the fish cultivation with 100% CF. The result strongly confirms that the digester effluent from a co-digestion biogas plant of pig dung and spent mushroom compost is possible to be used as an organic fertilizer well for not only vegetable planting but also fish culture.

Tuning the band structure, magnetic and transport properties of the zigzag graphene nanoribbons/hexagonal boron nitride heterostructures by transverse electric field.

The paper presents the results of ab initio study of the opportunities for tuning the band structure, magnetic and transport properties of zigzag graphene nanoribbon (8-ZGNR) on hexagonal boron nitride (h-BN(0001)) semiconductor heterostructure by transverse electric field (E(ext)). This study was performed within the framework of the density functional theory (DFT) using Grimme's (DFT-D2) scheme. We established the critical values of E(ext) for the 8-ZGNR/h-BN(0001) heterostructure, thereby providing for semiconductor-halfmetal transition in one of electron spin configurations. This study also showed that the degeneration in energy of the localized edge states is removed when E(ext) is applied. In ZGNR/h-BN (0001) heterostructure, value of the splitting energy was higher than one in ZGNRs without substrate. We determined the effect of low E(ext) applied to the 8-ZGNR/h-BN (0001) semiconductor heterostructure on the preserved local magnetic moment (LMM) (0.3µ(B)) of edge carbon atoms. The transport properties of the 8-ZGNR/h-BN(0001) semiconductor heterostructure can be controlled using E(ext). In particular, at a critical value of the positive potential, the electron mobility can increase to 7× 10(5) cm(2)/V s or remain at zero in the spin-up and spin-down electron subsystems, respectively. We established that magnetic moments (MMs), band gaps, and carrier mobility can be altered using E(ext). These abilities enable the use of 8-ZGNR/h-BN(0001) semiconductor heterostructure in spintronics.

Evolution and adaptation of H5N1 influenza virus in avian and human hosts in Indonesia and Vietnam.

Highly pathogenic avian influenza virus H5N1 is endemic in poultry in East and Southeast Asia with disease outbreaks recently spreading to parts of central Asia, Europe and Africa. Continued interspecies transmission to humans has been reported in Vietnam, Thailand, Cambodia, Indonesia and China, causing pandemic concern. Here, we genetically characterize 82 H5N1 viruses isolated from poultry throughout Indonesia and Vietnam and 11 human isolates from southern Vietnam together with sequence data available in public databases to address questions relevant to virus introduction, endemicity and evolution. Phylogenetic analysis shows that all viruses from Indonesia form a distinct sublineage of H5N1 genotype Z viruses suggesting this outbreak likely originated from a single introduction that spread throughout the country during the past two years. Continued virus activities in Indonesia were attributed to transmission via poultry movement within the country rather than through repeated introductions by bird migration. Within Indonesia and Vietnam, H5N1 viruses have evolved over time into geographically distinct groups within each country. Molecular analysis of the H5N1 genotype Z genome shows that only the M2 and PB1-F2 genes were under positive selection, suggesting that these genes might be involved in adaptation of this virus to new hosts following interspecies transmission. At the amino acid level 12 residues were under positive selection in those genotype Z viruses, in the HA and PB1-F2 proteins. Some of these residues were more frequently observed in human isolates than in avian isolates and are related to viral antigenicity and receptor binding. Our study provides insight into the ongoing evolution of H5N1 influenza viruses that are transmitting in diverse avian species and at the interface between avian and human hosts.

Dietary patterns and risk factors of diabetes mellitus among urban indigenous women in Fiji.

The dietary patterns of indigenous Fijians are changing rapidly. Dietary relationships in regard to the prevalence of diabetes are poorly studied in Fiji. A survey was conducted to show the relationship of dietary patterns and other lifestyle factors for the development of diabetes among urban indigenous women in Fiji. A sample of 200 Fijian women aged 30-39 who agreed to participate were interviewed by the use of semiquantitative food frequency, 3 day-24 h recall study. Physical activity and ceremonial dietary customs were also taken into consideration. Anthropometry included measurements of height, weight, waist and hip. Total percentage bodyfat measurements and glycosuria tests were also conducted. The results showed high rates of obesity manifested in high percentage bodyfat, high body mass index (BMI) and high waist and hip ratio (WHR). The mean 24 h dietary intake exhibited a moderate intake of protein, high intake of fat and a low intake of carbohydrate. The carbohydrate reduction was a result from the decline in consumption of traditional staples. Consumption of cereals and related products favored the high intake of butter and margarine and also encouraged the use of cooking oil in frying varieties of flour products. The daily intake of anti-oxidant vitamins of beta-carotene and vitamin E were low, however there was a high intake of vitamin C. The food frequency study revealed cassava, bread and sugar were consumed daily as the main carbohydrate foods. Fish and meat were the most frequently consumed protein foods. The main beverage was sweet tea with whole-cream milk. Butter, margarine, coconut cream, cheap lamb flaps and cooking oil provided the main sources of fat. Levels of physical activity included high sedentary lifestyles with a high rate of subjects being overweight and obese. Ceremonial dietary customs showed a high consumption of meat and fish. Fruits were rarely consumed. Glycosuria existed among the age group under study. The impact of dietary transition, coupled with dietary excesses and physical inactivity, seem to be potential risk factors of diabetes among the indigenous women in the urban area.

Blood pressure, serum cholesterol concentration and their related factors in urban and rural elderly of Ho Chi Minh City.

In Vietnam, information about blood pressure, serum lipids and their factors is limited. To obtain some of this information, a cross sectional nutrition survey was carried out in an urban and rural area of Ho Chi Minh City with 217 participants aged 60-69 y (148 females and 69 males). Anthropometry and blood pressure were measured. For three consecutive weekdays, 24 h dietary recalls were performed. Single 24 h urine was collected for sodium and potassium analysis. A fasting blood sample was taken and biochemical parameters were measured. Results indicate a high percentage of hypertension in urban (female: 35.5%, male: 43.8%) and rural areas (female: 22.2%, male: 35.1%). Blood pressure was correlated with body mass index (BMI) and 24 h urinary sodium-to-potassium (Na/K) ratio. A high prevalence of serum total cholesterol (TC) above 220 mg/dL (female: 55.3%, male: 31.3%) and overweight (female: 34.2%, male: 25.0%) were observed in urban residents. By contrast, 5.6% and 24.3% of rural females and males respectively had TC below 150 mg/dL and both genders had the same prevalence of underweight (32.4%). TC was positively correlated with body weight, BMI, dietary protein and dietary lipids. Overweight might be a major risk factor for hypertension in our urban elderly. A high Na/K intake ratio might be a risk factor for hypertension in both areas. The high prevalence of elevated TC in the urban area might to be related to the high lipid intake, and the high prevalence of low TC in the rural area might to be related to the low lipid intake.

Effects of Maillard reaction products on the oxidative cleavage and polymerization of protein under ascorbic acid-transition metal system.

This study investigated the effects of Maillard reaction products (MRPs) on the oxidative cleavage and polymerization of BSA (bovine serum albumin) in an aqueous system. In L-ascorbic acid (AsA) and Cu(II) or Fe(III) reaction system, 50-60% of BSA was cleaved under physiological conditions (37 degrees C, pH 7.2). The oxidative cleavage induced by AsA-Cu(II) system was suppressed to the extent of 32-86% by model melanoidins or brown pigments from amino acids and foodstuffs. In the AsA-Fe(III) system, the oxidative cleavage was inhibited to the extent of 45-93% by melanoidins and brown pigments. However, this cleavage was promoted by amino acid Amadori rearrangement products and brown pigment from soy paste. Therefore, MRPs show both suppression and promotion activity on oxidative cleavage of BSA in the system of AsA and a transition metal. The quantity of Amadori rearrangement moiety (ARM) in melanoidins from Lysine and brown pigments molecules from foods was also measured. From these data, it was estimated that the suppression and/or promotion of oxidative cleavage of BSA did not only depend on the quantity of ARM, but also depended on the chemical structure of ARM in melanoidins or brown pigments.

The importance of quality control of sputum smear microscopy: the effect of reading errors on treatment decisions and outcomes.

SETTING: Ho Chi Minh City, Vietnam. OBJECTIVE: To evaluate the impact of slide reading errors at peripheral level on case-finding and treatment decisions. DESIGN: Over a 6-month period in 1997, information on date, type of slide, results of other slides from the patient, and treatment status was collected for all slides from district TB centers detected as having reading errors during smear microscopy quality control re-readings. RESULTS: Reading errors were detected in 117 slides: 115 (98.3%) were incorrectly read as negative, and 75 (65.2%) of these errors occurred in case-finding slides. In the 75 falsely negative case-finding slides, re-reading resulted in initiation of treatment in 38 patients (50.7%). The remaining 37 (49.3%) had only one positive slide and were told to return for follow-up after 6 months; the two (5.4%) who did return were both diagnosed with active TB. Detection of errors in the 40 false-negative follow-up slides resulted in treatment changes in four patients (10%). CONCLUSIONS: Quality control plays a critical role in helping to ensure the timely diagnosis and treatment of new TB cases and appropriate management of patients currently on treatment. The usefulness of quality control could be enhanced by focusing greater efforts on case-finding slides initially read as negative.

Quality control of smear microscopy for acid-fast bacilli: the case for blinded re-reading.

SETTING: Quality control of sputum smear microscopy, which is essential for ensuring correct tuberculosis (TB) diagnosis, is often performed through the unblinded rereading of all positive slides and a sample of negative slides. OBJECTIVE: To assess misclassification error introduced by knowledge of prior results. METHODS: The Southern Vietnam Regional TB Laboratory prepared three gold-standard sets of 750 slides: an unblinded set, an unblinded set in which 13% of negative slides were replaced by weakly positive slides purposefully mislabelled as negative, and a blinded set. Six provincial technicians who normally perform district quality control each reread 125 slides from each set. RESULTS: In the three sets only one negative slide was misread as positive. In the unblinded set (referent), 2.9% (9/311) positive slides were misread as negative, compared with 18.7% (57/305) in the blinded set (prevalence ratio [PR] = 6.5; 95% confidence interval [CI] 3.3-12.8; P < 0.001), and 11.3% (33/293) in the unblinded set with mislabelled slides (PR = 3.9; 95%CI 1.9-8.0; P < 0.001). CONCLUSIONS: False-negative error was more common than false-positive error. Knowledge of prior reading influences re-reading. Blinded re-reading of systematically selected slides would appear preferable, although this method requires high levels of proficiency among quality control technicians.

Effect of long-term alcohol administration on bone metabolism in rats.

The purpose of this study was to investigate the effects of different degrees of alcohol ingestion on bone strength and mineral density. Three different groups of growing female rats were administered different doses of an alcohol-water solution for a period of 6 months. These three groups were divided into: 1) the control group, which was only given water; 2) the moderate group, which was given 5% ethanol solution for only 2 h per day; and 3) the excess group, which was given only 5% ethanol solution for 163 days. This ethanol consumption induced no detrimental effect on biochemical parameters including liver function. The moderate group showed significantly higher (p < 0.05) levels of proximal metaphysis as compared to the control group, while there was no difference between the excess group and the control group. Similarly, in comparison to the control group, the moderate group exhibited a significant increase (p < 0.001) in bone mechanical strength, while the excess group showed either the same or decreased bone stiffness. These results indicate that alcohol intake has both beneficial and hindering effects on the skeleton, depending on the concentration and frequency of ethanol intake.

Emergence and scattering of multiple neurofibromatosis (NF1)-related sequences during hominoid evolution suggest a process of pericentromeric interchromosomal transposition.

Type 1 neurofibromatosis (NF1) gene encodes for a member of the GTPase activating protein family and is considered to be a tumor suppressor gene. Its very high rate of de novo mutation in humans led us to study a specific feature of this gene: the presence of numerous NF1-related sequences. According to our results, the human genome contains at least 11 NF1-related sequences, nine of which are scattered near centromeric sequences of seven different chromosomes. These NF1-related sequences, whose extent is quite varied according to loci, are unprocessed copies of the NF1 gene, and bear numerous mutations. A phylogenetic analysis of the six largest sequences indicates that they are all derived from a common ancestor, which would have appeared 22-33 million years ago, and was subsequently duplicated several times during hominoid evolution. The most recent duplication and interchromosomal transposition occurred in the last million years suggesting that the process could still be ongoing. Intriguing similarities between the evolution of alpha-satellite DNA and NF1-related sequences suggest the involvement of a common genetic mechanism for the generation and pericentric spreading of these NF1 partial copies.

Chromosomal mapping and expression of the human cyr61 gene in tumour cells from the nervous system.

AIMS: To characterise the human cyr61 gene (cyr61H) and determine its chromosomal locality. To compare expression of cyr61H in human tumour cell lines with that of two other structurally related genes, novH (nephroblastoma overexpressed gene) and CTGF (connective tissue growth factor), that are likely to play a role in the control of cell proliferation and differentiation. METHODS: To isolate the human cyr61 gene, placental genomic and HeLa cDNA libraries were screened with murine cyr61 cDNA. The nucleotide sequence of the complete cyr61H cDNA was established. Both Southern blotting of a panel of somatic cell hybrids and in situ hybridisation on chromosomes were performed to map the cyr61H gene. Expression of cyr61H, novH, CTGF, and novH was analysed by northern blotting in both human neuroblastomas and glioblastoma cell lines. RESULTS: Genomic and cDNA clones encompassing the cyr61H gene were isolated and characterised. Comparison of mouse and human cyr61 sequences indicated that their genomic organisation is highly conserved. Alignment of coding sequences highlighted the conservation of cyr61 regions that might be critical for its biological function. The data showed that the cyr61H gene is assigned to chromosome 1p22.3 and that different levels of cyr61H, CTGF, and novH mRNA have been detected in several human tumour cell lines derived from the nervous system. CONCLUSIONS: The human cyr61 gene belongs to an emerging family of genes including CTGF/fisp12 and nov. The murine cyr61 encodes an extracellular cysteine rich protein that exhibits chemotactic activity, promotes attachment and spreading of cells, and potentiates the mitogenic effect of growth factors. Assignment of the cyr61H gene to chromosome 1p22.3 will allow studies to determine whether human pathologies derived from the nervous system or from other tissues are associated with chromosomal abnormalities involving this region. Although the coding regions of cyr61H, CTGF, and novH are highly homologous, a growing body of evidence suggests that expression of these genes is regulated differentially, and that a balance between expression of these genes might represent a key element in determining the stage of differentiation and/or the malignant potential of tumour cells.

Dual localization of the human gene encoding hnRNP I/PTB protein to chromosomes 19p13.3 and 14q23.

A cDNA probe representative of the human hnRNP I/PTB gene was used to perform fluorescence in situ hybridization (FISH) on metaphases of human chromosomes. A new localization was found on band 19p13.3 in addition to the previously reported localization to band 14q23. Identical results were obtained when FISH analysis was repeated with probes covering different parts of the hnRNP I cDNA clone. This supported the notion that most, if not all, of the sequences of the different parts of this clone are present on both chromosomes. Moreover, Southern blot analysis of DNAs from interspecies somatic hybrids containing chromosomes 19 and 14 revealed that the whole hnRNP I cDNA probe generated very similar patterns in each hybrid DNA. These data suggest that two closely related copies of the hnRNP I gene exist in the human genome.

Assignment of the NTRK4 (trkE) gene to chromosome 6p21.

Reverse transcriptase-polymerase chain reactions using foetal brain RNA with reverse and forward primers of the first, second and third NTRK4 region allowed us to obtain three amplified NTRK4 fragments. The specificity of amplified fragments was checked by digestion with restriction endonucleases AvrII, HindIII and PspII for the first, second and third regions, respectively. Each restriction site was specific for each amplified fragment. The fragment of the NTRK4 first region was also sequenced and the sequence determined was identical to the human NTRK4 sequence. The three amplified fragments were cloned in pBS. For the Southern technique, plasmid pBS-NTRK4a (with an insert of 1052 bp) detected a human 9-kb HindIII sequence which was localised unambiguously on chromosome 6. For fluorescence in situ hybridisation, the three plasmids, pBS-NTRK4a, pBS-NTRK4b (insert 924 bp) and pBS-NTRK4c (insert 1114 bp) were pooled and used as a probe. This NTRK4 probe was localised on 6p21. Of 50 metaphases analysed, 49 contained twin spot signals on both sister chromatids.

Desmutagenicity of soybean after heating.

The mutagenicity and desmutagenicity of extracts of soybeans heated at 225 +/- 5 degrees C were investigated by the Ames test. The soybeans were refluxed in water, methanol, or diethylether for 2 h. The aqueous and methanol extracts (2-4 mg/plate) of the heated soybeans exhibited strong desmutagenic activity of 43-92% against heterocyclic amines (Trp-P-1. Glu-P-2, IQ, MeIQx. PhIP), while no mutagenicity was observed. The desmutagenicity of the heated soybean extracts remained even after denaturation by 0.1 N HCl in vitro and absorption by the rat small intestine. The desmutagenic mechanism for heated soybeans was evaluated, and it was verified that the soybean extract exhibited its desmutagenicity by blocking the mutagenicity of activated Trp-P-1, and not by inhibiting the S9 enzyme system.

MDM2 amplification in a primary alveolar rhabdomyosarcoma displaying a t(2;13)(q35;q14).

This report describes a case of rhabdomyosarcoma associated with a 2;13 translocation and multiple double minute chromosomes. The origin of the amplified DNA was identified using comparative genomic hybridization, which pinpointed a unique spot at 12q13-->q14. Band 12q13 has been shown to contain several genes that are occasionally amplified in other sarcomas. Fluorescene in situ hybridization to tumor metaphases with probes specific for this region indicated that the double minutes contained the MDM2 gene but not the CDK4 gene. MDM2 amplification was further quantified by Southern hybridization, which showed a mean value of 25 copies per haploid genome. This is the first example of MDM2 amplification in a rhabdomyosarcoma.

The MUC5AC gene: RFLP analysis with the Jer58 probe.

We have recently obtained evidence that the locus corresponding to three groups of partial tracheobronchial cDNAs (A = Jer47, B = Jer57, C = Jer58) which mapped to chromosome 11p15 and was given the symbol MUC5 corresponds to two distinct genes which we have provisionally called MUC5B and MUC5AC. Here we describe the detection, using the Jer58 probe, which contains a 24-bp tandem repeat, of polymorphism in the MUC5AC gene with seven different restriction enzymes.

A Tsp509I variant in exon 13 of the neurofibromatosis type 1 (NF1) gene allows the identification of both alleles at the mRNA level.

We describe here a new sequence variant occurring in the coding region of the neurofibromatosis (NF1) gene (exon 13). This exonic polymorphism can be directly investigated by simple restriction enzyme digestion of RT-PCR (reverse transcription-polymerase chain reaction) products, making it a powerful tool for examining allele-specific mRNA expression levels.