Inducible nitric oxide synthase 2 promoter polymorphism and malaria disease severity in children in Southern Ghana

No Association Between Interleukin 6 and Inducible Nitric Oxide Synthase Polymorphisms and Dengue Infection: A Case-Control Study

BACKGROUND

Dengue is a life-threatening disease. The factors that lead to severe cases are not completely understood. The host immune system is involved in the response to infections and plays an important role in dengue infection. IL-6 and iNOS are components of the immune system and genetic polymorphisms in these genes may be involved in dengue virus infection. The study aimed to investigate the association of genetic polymorphisms in the IL6 and iNOS genes and dengue.

METHODS

We performed a case-control study using 60 dengue-infected individuals and 119 healthy controls. Polymorphisms in the IL6 (T15A) and iNOS (-1173CT) genes were amplified by Real-Time PCR. Statistical analyses were performed using BioEstat 5.0.

RESULTS

We identified that the frequency of T/A genotype of IL6 was higher in dengue fever patients and C/T genotype of iNOS was higher in dengue hemorrhagic fever patients, however, no association was found between these polymorphisms and dengue.

CONCLUSION

Polymorphisms in iNOS and IL6 were not associated with dengue infection.

Potential Benefits of Lycopene Consumption: Rationale for Using It as an Adjuvant Treatment for Malaria Patients and in Several Diseases

Malaria is a disease that affects thousands of people around the world every year. Its pathogenesis is associated with the production of reactive oxygen and nitrogen species (RONS) and lower levels of micronutrients and antioxidants. Patients under drug treatment have high levels of oxidative stress biomarkers in the body tissues, which limits the use of these drugs. Therefore, several studies have suggested that RONS inhibition may represent an adjuvant therapeutic strategy in the treatment of these patients by increasing the antioxidant capacity of the host. In this sense, supplementation with antioxidant compounds such as zinc, selenium, and vitamins A, C, and E has been suggested as part of the treatment. Among dietary antioxidants, lycopene is the most powerful antioxidant among the main carotenoids. This review aimed to describe the main mechanisms inducing oxidative stress during malaria, highlighting the production of RONS as a defense mechanism against the infection induced by the ischemia-reperfusion syndrome, the metabolism of the parasite, and the metabolism of antimalarial drugs. Furthermore, the effects of lycopene on several diseases in which oxidative stress is implicated as a cause are outlined, providing information about its mechanism of action, and providing an evidence-based justification for its supplementation in malaria.

Oxidative Stress in Malaria: Potential Benefits of Antioxidant Therapy

Malaria is an infectious disease and a serious public health problem in the world, with 3.3 billion people in endemic areas in 100 countries and about 200 million new cases each year, resulting in almost 1 million deaths in 2018. Although studies look for strategies to eradicate malaria, it is necessary to know more about its pathophysiology to understand the underlying mechanisms involved, particularly the redox balance, to guarantee success in combating this disease. In this review, we addressed the involvement of oxidative stress in malaria and the potential benefits of antioxidant supplementation as an adjuvant antimalarial therapy.

Association of TNF-Alpha, MBL2, NOS2, and G6PD with Malaria Outcomes in People in Southern Ghana

Background

One major issue that has set back the gains of the numerous malaria control interventions that national malaria control programs have implemented is asymptomatic malaria. Certain host genetic factors are known to influence symptomatic malaria; however, not much is known about how host genetics influences the acquisition of asymptomatic malaria.

Methods

Genomic DNA was extracted from whole blood collected from 60 symptomatic and 149 nonfebrile (asymptomatic, N = 109, and uninfected, N = 40) volunteers aged between 2 and 69 years from a high (Obom) and a low (Asutsuare) malaria transmission setting in Southern Ghana. Restriction fragment length polymorphism (RFLP) was used to determine polymorphisms at the MBL2 54, TNF-α 308, NOS2 954, and G6PD 202/376 gene loci.

Results

Polymorphisms at the MBL2 54 and TNF-α 308 loci were significantly different amongst the three categories of volunteers in both Asutsuare (p = 0.006) and Obom (p=0.05). In Asutsuare, a low malaria transmission area, the allele G has significantly higher odds (3.15) of supporting asymptomatic malaria as against symptomatic malaria. There were significantly higher odds of TNF-α genotype GA being associated with symptomatic malaria as against asymptomatic malaria in both sites, Obom (p=0.027) and Asutsuare (p=0.027). The allele B of the G6PD gene was more prevalent in symptomatic rather than asymptomatic parasite-infected individuals in both Obom (p=0.001) and Asutsuare (p=0.003).

Conclusion

Individuals in Southern Ghana carrying the TNF-α 308 GA genotype are more likely to exhibit symptoms of malaria when infected with the malaria parasite as opposed to harboring an asymptomatic infection. Also, the B allele of the G6PD gene is likely to prevent a P. falciparum-infected person from exhibiting symptoms and thereby promote asymptomatic parasite carriage.

Association of NOS2A gene polymorphisms with susceptibility to bovine tuberculosis in Chinese Holstein cattle

Bovine tuberculosis (bTB) is a global zoonotic disease that has detrimental economic impacts worldwide. The NOS2A gene plays a key role in immunological control of many infectious diseases. However, research on the association between NOS2A polymorphisms and bTB infection in Holstein cattle reared on the Yunnan-Guizhou plateau of China is scarce. This study investigated a possible linkage between NOS2A polymorphisms and risk of developing bTB in Chinese Holstein cattle. The NOS2A gene was genotyped in 144 bTB-infected Holstein cows and 139 healthy controls were genotyped through nucleotide sequencing. Ten single-nucleotide polymorphisms (SNPs) were detected, six of which were associated with susceptibility/resistance patterns of bTB. Furthermore, the C/T genotypes of 671 and 2793, and T/T genotype of E22 (+15) were significantly associated with susceptibility risk; the G/A genotype of 2857, T/T genotype of E9 (+65), and C/C genotype of E9 (+114) probably increased resistance to bTB. In addition, the haplotypes of NOS2A-2 and NOS2A-9 were risk factors for bTB susceptibility, while the NOS2A-5 and NOS2A-8 haplotypes were contributing protective variants against tuberculosis. There is a significant association between variation in SNPs of NOS2A and tuberculosis susceptibility/resistance pattern. These findings suggest that substitution of genetic selection would be helpful for eradicating bTB. However, further investigation is required to study the underlying mechanism through which NOS2A polymorphisms affect bTB infection.