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The sensitive telomeric repeat amplification protocol (TRAP) permits telomerase detection in mammalian cell and tissue extracts with very low telomerase activity levels. Unfortunately, conventional TRAP assays require complex post-amplification procedures, such as polyacrylamide gel electrophoresis and densitometry, to measure telomerase products. Therefore, a real-time quantitative TRAP assay (RQ-TRAP) was optimized in the present study and evaluated in comparison with a commercially available quantitative TRAP kit and by monitoring telomerase activity in human hepatocyte cultures, human hepatoma cell lines and telomerase reconstitution experiments. The novel real-time telomerase detection method has many advantages. Other than sample extraction and real-time cycling, no additional time-consuming steps have to be performed for telomerase quantification; reliable and linear telomerase quantification is possible down to single-cell dilutions without the interference of primer-dimer artifacts, and the costs are less. Moreover, the precision is similar to other amplification-based telomerase quantification assays and the results are comparable to data obtained with two commercially available assays. The closed-tube system reduces the risk of carryover contamination and supports high throughput. In conclusion, RQ-TRAP provides a new tool for the rapid and reliable quantification of telomerase activity.

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Beta-ketothiolase (T2) deficiency is an inherited disease of isoleucine and ketone body metabolism caused by mutations in the ACAT1 gene. Between 2005 and 2016, a total of 41 patients with T2 deficiency were identified at a medical center in northern Vietnam, with an estimated incidence of one in 190,000 newborns. Most patients manifested ketoacidotic episodes of varying severity between 6 and 18 months of age. Remarkably, 28% of patients showed high blood glucose levels (up to 23.3 mmol/L). Ketoacidotic episodes recurred in 43% of patients. The age of onset, frequency of episodes, and identified genotype did not affect patient outcomes that were generally favorable, with the exception of seven cases (five died and two had neurological sequelae). Custom-tailored acute and follow-up management was critical for a positive clinical outcome. Two null mutations, c.622C>T (p.Arg208*) and c.1006-1G>C (p.Val336fs), accounted for 66% and 19% of all identified ACAT1 mutant alleles, respectively. Most patients showed characteristic biochemical abnormalities. A newborn screening program could be expected to have a high yield in Vietnam. Investigation findings of haplotypes linked to the most common ACAT1 mutation (c.622C>T) are consistent with an ancient common founder of mutation-bearing chromosomes belonging to the Kinh ethnic population. The direct management and long-term follow-up of a large number of T2-deficient patients enabled us to study the natural history of this rare disease.

Background Carbapenem-resistant Klebsiella pneumoniae are becoming increasingly common in hospital settings worldwide and are a source of increased morbidity, mortality and health care costs. The global epidemiology of carbapenem-resistant K. pneumoniae is characterized by different strains distributed geographically, with the strain ST258 being predominant in Europe and USA, and ST11 being most common in East Asia. ST15 is a less frequently occurring strain but has nevertheless been reported worldwide as a source of hospital outbreaks of carbapenem-resistant K. pneumoniae. Methods In this study, whole-genome sequencing and antimicrobial susceptibility testing was used to characterize 57 clinical isolates of carbapenem-resistant K. pneumoniae belonging to a strain of ST15, which were collected at a Vietnamese pediatric hospital from February throughout September 2015. Results Aside from the carbapenem resistance gene blaKPC-2, which was carried by all isolates, prevalence of resistance genes to other antibiotics including aminoglycosides, macrolides, quinolones, fosfomycin and trimethoprim, was also high. All isolates were multidrug-resistant. Susceptibility was highest to ceftazidime/avibactam (96%), gentamicin (91%) and tigecycline (82%). Notably, the colistin resistance rate was very high (42%). Single-nucleotide polymorphism analysis indicated that most isolates belonged to a single clone. Conclusions The diverse variety of antibiotic resistance genes and the high antibiotic resistance rates to last-resort antibiotics such as carbapenems and colistin, is indicative of a highly adaptable strain. This emphasizes the importance of implementation of infection controls measures, continued monitoring of antibiotic resistance and prudent use of antibiotics to prevent further selection of resistant strains and the emergence of pan-resistant clones.

Currently, different techniques to expand human hepatocytes in vitro are being investigated to generate enough cells for liver-directed cell therapies. However, based on observations in fibroblasts and other cell types, telomere attrition limits the proliferative capacity of normal somatic cells. Therefore, we explored whether telomere-dependent replicative aging restricts the in vitro proliferation of human hepatocytes. Subpopulations of cells isolated from a neonatal liver and characterized as hepatocyte derived by RT-PCR and flow cytometry started to proliferate 5-7 days after plating and were termed proliferating human hepatocytes (PHH). Following retroviral-mediated transduction of the catalytic telomerase subunit, telomerase reverse transcriptase (hTERT), telomerase activity increased from almost undetectable levels to levels as high as in HepG2 and other telomerase-positive cell lines. As expected, untransduced PHH progressively lost telomeric repeats and arrested after 30-35 cell divisions with telomeres of less than 5 kilo bases. In comparison, telomerasereconstituted PHH maintained elongated telomeres and continued to proliferate as shown by colorimetric assays and cell counts. In this study, telomere stabilization extended the proliferative capacity of in vitro proliferating human neonatal hepatocytes. Therefore, telomere attrition needs to be addressed when developing techniques to expand human hepatocytes.

This cross-sectional study investigated the prevalence, genotypes, and risk factors for human papillomavirus (HPV) infection in Hanoi, Vietnam. The study included 192 males (mean age, 32.9 years) with symptoms related to sexually transmitted infections (STI). Urinary, penile, and urethral samples were collected in April and May, 2014. HPV DNA was detected with PCR, performed with modified and/or original GP5(+)/GP6(+) primers. HPV genotypes were determined with a gene array assay. Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) DNA were detected with loop-mediated isothermal amplification. HPV DNA, NG, and CT were detected in 48 (25.0%), 23 (12.0%), and 41 (21.4%) patients, respectively. HPV DNA appeared in penile samples (21.0%, 39/186) more frequently than in urinary (3.1%, 6/191, P < 0.001) and urethral (9.4%, 18/192, P = 0.002) samples. Among patients with HPV, genotype prevalence was: HPV81 (22.9%),  HPV52 (18.8%), HPV18 (16.7%), and HPV16 (6.3%). Multiple-type and high risk-type HPV infections were determined in 33.3% and 64.6%, respectively. Multivariate analysis showed a significant association of HPV infection in urethra with younger sexual debut age. HPV52 was the most prevalent high-risk HPV genotype, whereas HPV16 was less common in the male Vietnamese patients with STI-related symptoms. Younger sexual-debut age was a risk factor for HPV infection in urethra.