Hypothermic treatment for neonatal asphyxia in low-resource settings using phase-changing material-An easy to use and low-cost method

AIM

To evaluate whether phase-changing material can be used for therapeutic hypothermia of asphyxiated newborns in low-resource settings.

METHODS

Prospective interventional study of asphyxiated term infants fulfilling criteria for hypothermia treatment at Vietnam National Children's Hospital from September 2014 to September 2016. Hypothermia was induced within 6 hours after birth and maintained for 72 hours by a phase-changing material mattress with melting point of 32°C. Rectal temperature was continuously measured, and deviations from target temperature range 33.5-34.5°C were recorded.

RESULTS

In total 52 infants (mean gestational age 39.3 ± 1.1 weeks) included and cooled, the median temperature at initiation of cooling was 35.3 (IQR 34.5-35.9)°C. The median time to reach target temperature was 2.5 (IQR 2-3) hours. The mean temperature during the cooling phase was 33.95 ± 0.2°C. Throughout the cooling phase, the target temperature range (33.5-34.5°C) was maintained more than 80% of the time. Rate of rewarming was 0.5 ± 0.14°C/hour.

CONCLUSION

Phase-changing material can be used as an effective cooling method. Though not a servo-controlled system, it is easy to induce hypothermia, maintain target temperature and rewarm infants in a slow and controlled manner without need for frequent changes and minimum risk of skin injury.

A rapid smartphone-based lactate dehydrogenase test for neonatal diagnostics at the point of care

There is a growing recognition of the importance of point-of-care tests (POCTs) for detecting critical neonatal illnesses to reduce the mortality rate in newborns, especially in low-income countries, which account for 98 percent of reported neonatal deaths. Lactate dehydrogenase (LDH) is a marker of cellular damage as a result of hypoxia-ischemia in affected organs. Here, we describe and test a POC LDH test direct from whole blood to provide early indication of serious illness in the neonate. The sample-in-result-out POC platform is specifically designed to meet the needs at resource-limited settings. Plasma is separated from whole blood on filter paper with dried-down reagents for colorimetric reaction, combined with software for analysis using a smartphone. The method was clinically tested in newborns in two different settings. In a clinical cohort of newborns of Stockholm (n = 62) and Hanoi (n = 26), the value of R using Pearson's correlation test was 0.91 (p < 0.01) and the R² = 0.83 between the two methods. The mean LDH (±SD) for the reference method vs. the POC-LDH was 551 (±280) U/L and 552 (±249) U/L respectively, indicating the clinical value of LDH values measured in minutes with the POC was comparable with standardized laboratory analyses.

Synthesis and antibacterial properties of a novel magnetic nanocomposite prepared from spent pickling liquors and polyguanidine

Magnetic nanoparticles have received much interest for their application in wastewater treatment because of their easy retrieval and reuse. However, the methods used to synthesise high saturation magnetization magnetic nanoparticles require expensive and pure precursors. In the current study, we explore the potential for using spent pickling liquor, a wastewater solution from steel factories, as the iron precursor for preparing iron oxide nanoparticles. Here, magnetic Fe₃O₄ nanoparticles were synthesized via the oxidation–precipitation of spent pickling liquors using a saturated solution of calcium hydroxide at room temperature. The Fe₃O₄ nanoparticles were then modified with antibacterial polyguanidine to form a nanocomposite. It was found that monodisperse magnetic Fe₃O₄ nanoparticles with a size in the range 20–30 nm and a high saturation magnetization value of 73.9 emu g⁻¹ were synthesised. The Fe₃O₄ nanoparticles were successfully encapsulated with polyguanidine to form an Fe₃O₄/polyguanidine nanocomposite. FT-IR and TGA analysis results indicated the presence of the polymer on the Fe₃O₄ surface and the polymer content in the nanocomposite was about 15% (w/w). The Fe₃O₄/polyguanidine nanocomposite exhibited strong antibacterial activity against Escherichia coli (E. coli), demonstrating its potential for use in disinfecting wastewater.

An Fe₃O₄/polyguanidine nanocomposite with strong antibacterial activity was prepared from Fe₃O₄ nanoparticles, using spent pickling liquors as the iron source, which were then encapsulated with polyguanidine.

Prevalence of cervical infection with HPV type 16 and 18 in Vietnam: implications for vaccine campaign

Background

The Expanded Program on Immunization currently considers offering Human Papilomavirus vaccine on a routine basis in Vietnam. However, as the current available vaccine can prevent only two types HPV 16 and 18, before implementing a large-scale vaccine campaign we need information about the prevalence of infection with only HPV 16 and 18 in Viet Nam. This study was done in 5 large cities in Vietnam to estimate the prevalence of HPV 16 and/or 18 infections and to explore the distribution of other high risk types of HPV among married women in these provinces.

Methods

The study employed a cross-sectional design with multistage sampling. The sample size included 4500 married women in two rounds (aged ranged from 18-69 years old, median age: 40 year old). Participant were randomly selected, interviewed and given gynaecological examinations. HPV infection status (by real-time PCR kit using TaqMan probe) and HPV genotyping test (by Reverse dot blot) were done for all participants.

Results

The prevalence of cervical infection with HPV type 16 and/or 18 among married women in this study ranged from 3.1% to 7.4%. Many positive HPV cases (ranged from 24.5% to 56.8%) were infected with other type of high risk HPV which can lead to cervical cancer and cannot prevented by currently available vaccines. In addition to HPV 16 and/or 18, most common types of high risk HPV were types 58, 52, 35 and 45. Awareness about HPV and HPV vaccines was still low in the study samples.

Discussion

While it is relevant to implement an HPV vaccine campaign in Viet Nam, it is important to note that one can be infected with multiple types of HPV. Vaccination does not protected against all type of high risk HPV types. Future vaccine campaigns should openly disclose this information to women receiving vaccines.

Conclusion

High prevalence of infection with HPV high risk types was observed in this study. As HPV infection has a high correlation with cervical cancer, this study emphasizes the need for both primary prevention of cervical cancer with HPV vaccines as well as secondary prevention with screening.

Cervical human papilloma virus infection among the general female population in Vietnam: a situation analysis

Human papilloma virus (HPV) is the necessary cause of cervical cancer. This survey used a sample of 1,500 married women aged 15-69 to examine the prevalence of HPV infection and HPV specific types in Vietnam as well as risk factors of HPV infection. Results indicated that the prevalence of HPV infection in Hanoi and HCM was 6.13 and 8.27. The proportion of multiple HPV infection was also higher in HCM than in Hanoi (35.5% vs. 17.4%). Risk factors having significant associations with general HPV infection were early age at first sexual intercourse, number of life time sexual partners and period of use of oral contraceptives. Future implementation of HPV vaccine campaigns in Vietnam should consider the fact that HPV type 58 is common among both Hanoi and HCM populations, which none of the currently available vaccines target.

Evaluation of Trichoderma spp. for biocontrol of tomato sudden caused by Pythium aphanidermatum following flooding in tropical hot season

Tomato sudden death is a major problem in tomato production in tropical lowland areas. The plant wilts and dies following artificial or natural flooding for 48-72 hrs in the summer season. Occurrence of this disease is related to aggressiveness of Pythium aphanidermatum on tomato at high soil temperature (>30 degrees C). Several methods such as using biological control agents, fungicides and other cultural practices were applied in attempts to control tomato sudden death. Three Trichoderma harzianum and two Trichoderma virens isolates were evaluated for biocontrol of the disease in the greenhouse and in the field T. harzianum and T. virens isolates were separately used to treat the seed, potting medium and also incorporated into the soil before transplanting. Field soil was naturally infested with P. aphanidermatum, while greenhouse soil was inoculated with the pathogen 10 days after transplanting. All treatments were flooded for 48 hrs at 32 degrees C soil temperature. Results from this study show that most tested T. harzianum and T. virens isolates have little promise for control of tomato sudden death following flooding. The percentage of tomato plants that wilted after growing in soil treated with either T. harzianum or T. virens and P. aphanidermatum was not significantly different when compared to the soil treated with P. aphanidermatum alone. No wilted plants were observed in the control (non treated soil).