A Systematic Review of Scope and Quality of Health Economic Evaluation Studies in Vietnam

Introduction

The application of health economic evaluation (HEE) evidence can play an important role in strategic planning and policy making. This study aimed to assess the scope and quality of existing research, with the goal of elucidating implications for improving the use of HEE evidence in Vietnam.

Methods

A comprehensive search strategy was developed to search medical online databases (Medline, Google Scholar, and Vietnam Medical Databases) to select all types of HEE studies except cost-only analyses. Two researchers assessed the quality of selected studies using the Quality of Health Economic Studies (QHES) instrument.

Results

We selected 26 studies, including 6 published in Vietnam. The majority of these studies focused on infectious diseases (14 studies), with HIV being the most common topic (5 studies). Most papers were cost-effectiveness studies that measured health outcomes using DALY units. Using QHES, we found that the overall quality of HEE studies published internationally was much higher (mean score 88.7+13.3) than that of those published in Vietnam (mean score 67.3+22.9). Lack of costing perspectives, reliable data sources and sensitivity analysis were the main shortcomings of the reviewed studies.

Conclusion

This review indicates that HEE studies published in Vietnam are limited in scope and number, as well as by several important technical errors or omissions. It is necessary to formalize the process of health economic research in Vietnam and to institutionalize the links between researchers and policy-makers. Additionally, the quality of HEE should be enhanced through education about research techniques, and the implementation of standard HEE guidelines.     

Isolation and characterization of novel microsatellite markers and their application for diversity assessment in cultivated groundnut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis>)

Background  

Cultivated peanut or groundnut (Arachis hypogaea L.) is the fourth most important oilseed crop in the world, grown mainly in tropical, subtropical and warm temperate climates. Due to its origin through a single and recent polyploidization event, followed by successive selection during breeding efforts, cultivated groundnut has a limited genetic background. In such species, microsatellite or simple sequence repeat (SSR) markers are very informative and useful for breeding applications. The low level of polymorphism in cultivated germplasm, however, warrants a need of larger number of polymorphic microsatellite markers for cultivated groundnut.     

Enhanced Toxic Metal Accumulation in Engineered Bacterial Cells Expressing Arabidopsis thaliana Phytochelatin Synthase

Phytochelatins (PCs) are metal-binding cysteine-rich peptides, enzymatically synthesized in plants and yeasts from glutathione in response to heavy metal stress by PC synthase (EC 2.3.2.15). In an attempt to increase the ability of bacterial cells to accumulate heavy metals, the Arabidopsis thaliana gene encoding PC synthase (AtPCS) was expressed in Escherichia coli. A marked accumulation of PCs was observed in vivo together with a decrease in the glutathione cellular content. When bacterial cells expressing AtPCS were placed in the presence of heavy metals such as cadmium or the metalloid arsenic, cellular metal contents were increased 20- and 50-fold, respectively. We discuss the possibility of using genes of the PC biosynthetic pathway to design bacterial strains or higher plants with increased abilities to accumulate toxic metals, and also arsenic, for use in bioremediation and/or phytoremediation processes.     

Genetic relationships among Vietnamese local pigs investigated using genome‐wide SNP markers

Vietnam is one of the most important countries for pig domestication, and a total of 26 local breeds have been reported. In the present study, genetic relationships among the various pig breeds were investigated using 90 samples collected from local pigs (15 breeds) in 15 distantly separated, distinct areas of the country and six samples from Landrace pigs in Hanoi as an out‐group of a common Western breed. All samples were genotyped using the Illumina Porcine SNP60 v2 Genotyping BeadChip. We used 15 160–15 217 SNPs that showed a high degree of polymorphism in the Vietnamese breeds for identifying genetic relationships among the Vietnamese breeds. Principal components analysis showed that most pigs indigenous to Vietnam formed clusters correlated with their original geographic locations. Some Vietnamese breeds formed a cluster that was genetically related to the Western breed Landrace, suggesting the possibility of crossbreeding. These findings will be useful for the conservation and management of Vietnamese local pig breeds.     

Repair of oligodeoxyribonucleotides by O(6)-alkylguanine-DNA alkyltransferase

Activity of the DNA repair protein O(6)-alkylguanine-DNA alkyltransferase (AGT) is an important source of tumor cell resistance to alkylating agents. AGT inhibitors may prove useful in enhancing chemotherapy. AGT is inactivated by reacting stoichiometrically with O(6)-benzylguanine (b(6)G), which is currently in clinical trials for this purpose. Short oligodeoxyribonucleotides containing a central b(6)G are more potent inactivators of AGT than b(6)G. We examined whether human AGT could react with oligodeoxyribonucleotides containing multiple b(6)G residues. The single-stranded 7-mer 5'-d[T(b(6)G)(5)G]-3' was an excellent AGT substrate with all five b(6)G adducts repaired although one adduct was repaired much more slowly. The highly b(6)G-resistant Y158H and P140K AGT mutants were also inactivated by 5'-d[T(b(6)G)(5)G]-3'. Studies with 7-mers containing a single b(6)G adduct showed that 5'-d[TGGGG(b(6)G)G]-3' was more poorly repaired by wild-type AGT than 5'-d[T(b(6)G)GGGGG]-3' and 5'-d[TGG(b(6)G)GGG]-3' and was even less repairable by mutants Y158H and P140K. This positional effect was unaffected by interchanging the terminal 5'- or 3'-nucleotides and was also observed with single-stranded 16-mer oligodeoxyribonucleotides containing O(6)-methylguanine, where a minimum of four nucleotides 3' to the lesion was required for the most efficient repair. Annealing with the reverse complementary strands to produce double-stranded substrates increased the ability of AGT to repair adducts at all positions except at positions 2 and 15. Our results suggest that AGT recognizes the polarity of single-stranded DNA, with the best substrates having an adduct adjacent to the 5'-terminal residue. These findings will aid in designing novel AGT inhibitors that incorporate O(6)-alkylguanine adducts in oligodeoxyribonucleotide contexts.     

Growth-rate-related and hydroxysterol-induced changes in membrane fluidity of cultured hepatoma cells: correlation with 3-hydroxy-3-methyl glutaryl CoA reductase activity

Creatine kinase (CK) activity in plasma obtained non-invasively from adult healthy, Sprague-Dawley, male rats was found to be 528 +/- 270 U/L (N = 17), a value which was 7 times that obtained in human specimens. Agarose gel electrophoresis revealed that the only detectable CK isoenzyme present was CK-BB, in contrast to the human serum isoenzyme which was CK-MM. Furthermore, it was found that the rat CK-BB could be detected using an RIA technique designed to quantitate human CK-BB occasionally present in blood after brain injury (rat CK-BB = 84.5 +/- 55.2 micrograms/L, N = 17, human CK-BB: Not detectable). It was thus possible to calculate the CK-BB specific activity (SA) in rat plasma using total CK assay and RIA (rat CK-BB SA = 6.25 +/- 3.87 U/micrograms, N = 17). When six rats (156 +/- 23 g) were treated with lead acetate in the drinking water (26 mM) for 3 weeks, the CK-BB SA rose to 18 +/- 5.8 U/micrograms (P less than .02). At this point the electrophoresis pattern of the CK-BB showed a transient change from a single band to a doublet. The dose was then increased to 52 mM for 6 weeks, during which time the CK-BB SA declined steadily to 1.6 +/- 0.6, a level significantly less than that of the untreated animals (p less than .02). The results suggest that chronic lead treatment evokes a biphasic response in CK-BB SA with the initial release of enzyme of high SA from tissues. Further treatment apparently results in an inactivation of the enzyme within lead sensitive tissues.     

The Effects of Heat Activation on Bacillus Spore Germination,with Nutrients or under High Pressure,with or without Various Germination Proteins

Nutrient germination of spores of Bacillus species occurs through germinant receptors (GRs) in spores'' inner membrane (IM) in a process stimulated by sublethal heat activation. Bacillus subtilis spores maximum germination rates via different GRs required different 75°C heat activation times: 15 min for l-valine germination via the GerA GR and 4 h for germination with the l-asparagine–glucose–fructose–K⁺ mixture via the GerB and GerK GRs, with GerK requiring the most heat activation. In some cases, optimal heat activation decreased nutrient concentrations for half-maximal germination rates. Germination of spores via various GRs by high pressure (HP) of 150 MPa exhibited heat activation requirements similar to those of nutrient germination, and the loss of the GerD protein, required for optimal GR function, did not eliminate heat activation requirements for maximal germination rates. These results are consistent with heat activation acting primarily on GRs. However, (i) heat activation had no effects on GR or GerD protein conformation, as probed by biotinylation by an external reagent; (ii) spores prepared at low and high temperatures that affect spores'' IM properties exhibited large differences in heat activation requirements for nutrient germination; and (iii) spore germination by 550 MPa of HP was also affected by heat activation, but the effects were relatively GR independent. The last results are consistent with heat activation affecting spores'' IM and only indirectly affecting GRs. The 150- and 550-MPa HP germinations of Bacillus amyloliquefaciens spores, a potential surrogate for Clostridium botulinum spores in HP treatments of foods, were also stimulated by heat activation.