Biodiversity of aquatic organisms in the Mekong Delta, Vietnam.

Background: The Mekong River is the 10th largest river in the world. It is recognised as the most productive river in Southeast Asia and economically essential to the region, with an estimated 60-65 million people living in the lower Mekong Basin. The Mekong Delta within Vietnam is considered a highly vulnerable ecosystem under threat from increasing anthropogenic pressure, such as dam construction and, as a consequence, the Delta is sinking and altering the natural hydrological cycle. Dams also lead to eutrophication and pollution of downstream water from regulated water flux and water stagnation. Another threat is climate change coupled with the lower rainfall, which could lead to an increased risk of drought in the Mekong Delta Basin. Thus, these project data represent an important baseline reference. The ecological health of the Mekong Delta's environment, as indicated by the quality and availability of its water and biological resources, largely determines the economic and social development of the region, which produces about half of the agriculture and aquaculture products of Vietnam. New information: This paper reports quantitative data on the biodiversity of six groups of aquatic organisms: bottom and pelagic fish, macrozoobenthos, microorganisms, phyto- and zooplankton in the Mekong Delta within Vietnam, as well as data on the physicochemical parameters of water and bottom sediments. The data were collected during 2018-2022 as part of the Ecolan E-3.4 programme within the framework of the research plan of the Joint Russian-Vietnamese Tropical Research and Technological Center. All presented datasets are published for the first time.

Groundwater in Southern Vietnam: Understanding geochemical processes to better preserve the critical water resource.

A thorough understanding of groundwater geochemical characteristics and dominant hydro(bio)geochemical processes in the aquifers is valuable for sustainable groundwater protection. With this respect, this study provides a comprehensive assessment of hydrogeochemical characteristics of groundwater in sedimentary aquifers of the Southern region of Vietnam. The dataset comprised 291 water samples collected in rainy and dry seasons from 155 wells, and their chemical compositions of dissolved ions (Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, SO42-, NO3-, NH4+, Fe, total dissolved solids) and pH. We calculated the groundwater quality index to determine the suitability of groundwater for drinking purposes. Accordingly, about 47% of groundwater samples range from poor to unsuitable quality for drinking purposes, in which total dissolved solid (TDS) and high iron concentrations are primary factors. We also examined hydrogeochemical characteristics by multivariate statistical analyses (Hierarchical Cluster Analysis and Principal Component Analysis). The results demonstrated four groups of water: fresh groundwater (TDS < 1 g/L) in the highland (Group 1), lowland fresh-to-saline groundwater (2a), lowland saline groundwater (2b), and lowland saline/acidic groundwater (2c). Although the highland area is currently not impacted by salinization, the contamination by nitrate and chloride associated with a dense urban population and agricultural practices is deteriorating its fresh groundwater resources. On the other hand, the lowland area of Southern Vietnam is highly vulnerable to seawater intrusion (groups 2b and 2c). Only 34% out of 191 samples collected in the lowland area of southern Vietnam remained fresh. In this light, this study depicted the specific geographical location for various groundwater groups in Southern Vietnam. This finding is significant to assist water scientists and decision-makers in implementing targetted groundwater management measures as prevention and protection strategies should be tailored to groundwater geochemical characteristics and the dominant hydro(bio)geochemical processes.

Molecular Identification and Evaluation of the Genetic Diversity of Dendrobium Species Collected in Southern Vietnam.

Dendrobium has been widely used not only as ornamental plants but also as food and medicines. The identification and evaluation of the genetic diversity of Dendrobium species support the conservation of genetic resources of endemic Dendrobium species. Uniquely identifying Dendrobium species used as medicines helps avoid misuse of medicinal herbs. However, it is challenging to identify Dendrobium species morphologically during their immature stage. Based on the DNA barcoding method, it is now possible to efficiently identify species in a shorter time. In this study, the genetic diversity of 76 Dendrobium samples from Southern Vietnam was investigated based on the ITS (Internal transcribed spacer), ITS2, matK (Maturase_K), rbcL (ribulose-bisphosphate carboxylase large subunit) and trnH-psbA (the internal space of the gene coding histidine transfer RNA (trnH) and gene coding protein D1, a polypeptide of the photosystem I reaction center (psaB)) regions. The ITS region was found to have the best identification potential. Nineteen out of 24 Dendrobium species were identified based on phylogenetic tree and Indel information of this region. Among these, seven identified species were used as medicinal herbs. The results of this research contributed to the conservation, propagation, and hybridization of indigenous Dendrobium species in Southern Vietnam.

Further Molecular Analysis of G6PD Deficiency Variants in Southern Vietnam and a Novel Variant Designated as G6PD Ho Chi Minh (173 A>G; 58 Asp>Gly): Frequency Distributions of Variants Compared with Those in Other Southeast Asian Countries.

We conducted a survey of glucose-6-phosphate dehydrogenase (G6PD) deficiency among newborn babies at Tu Du Hospital, Ho Chi Minh, southern Vietnam. A total of 90 deficient babies were detected, including 85 in the Kinh ethnic group, 4 Chinese, and 1 in the K'Ho minority group. In the Kinh ethnic group, G6PD variants such as G6PD Viangchan (n=32), Kaiping (n=11), Canton (n=8), Chinese-5 (n=7), Union (n=5) and Quing Yuan (n=4) were detected. A variant with silent mutations at 1311 C>T and IVS11 nt 93 T>C was also detected in 17 cases. A novel mutation (173 A>G) in exon 4 with a predicted amino acid change of 58 Asp>Gly was also found in a Kinh newborn girl and her father, and it was designated as G6PD Ho Chi Minh. These findings demonstrated that the Kinh ethnic group in southern Vietnam has 8 different G6PD variants, indicating that the members of this group have many ancestors in terms of G6PD variants from Southeast Asia, China, and Oceania. We compared the frequency distribution of G6PD variants in the Kinh population with those of other Southeast Asian populations, and the Kinh population's distribution was quite similar to that in the Thai population, but differed from it by the absence of G6PD Mahidol.

Current status and actual need for pediatric liver transplantation in Southern Vietnam.

Liver transplantation (LT) has considerably improved the outcome of patients with end-stage liver disease, especially in children. The first pediatric LT in Vietnam was performed in 2004. To assess the current need for pediatric LT in Southern Vietnam, a total of 280 patients with chronic liver disease followed at Children's Hospital 2 (Ho Chi Minh City), the only pediatric LT center in this region, were evaluated from January 2009 to June 2014. Sixty-seven patients satisfied criteria for LT but only one transplant surgery occurred since 2009. Parental consent for LT was obtained only in 28.4% of patients. The main reasons for the small number of LTs were financial costs, far distance from home, lifelong follow-up and treatment, and shortage of organ donors. We conclude that the current need for pediatric LT in Southern Vietnam is high. Efforts should be made to develop the liver transplant program in this developing country.

Trading legitimacy: everyday corruption and its consequences for medical regulation in southern Vietnam.

Government regulation of health professionals is believed to ensure the efficacy and expertise of practitioners for and on behalf of patients. Certification and licensing are two common means to do so, legalizing a physician to practice medicine. However, ethnography from Ho Chi Minh City (HCMC) suggests that in corrupt socioeconomic environments, certification and licensing can alternatively produce a trade in legitimacy. Drawing on participant observations during 15 months of fieldwork with 25 medical acupuncturists in private practice in HCMC, southern Vietnam, and their patients, I argue that everyday practices of corruption and the importance of personal networks meant that legality, efficacy, and expertise separated. Certificates and licenses did not unproblematically validate expertise and efficacy. Consequently, compliance and enforcement of regulations as solutions to inadequate medical care may not achieve the effects intended.