Prevalence of sulfadoxine–pyrimethamine resistance-associated mutations in dhfr and dhps genes of Plasmodium falciparum three years after SP withdrawal in Bahir Dar,Northwest Ethiopia

Ethiopia changed the first-line anti-malarial drug for uncomplicated Plasmodium falciparum malaria from sulfadoxine–pyrimethamine (SP) to Coartem^® in 2004 following nation-wide assessment of the efficacy of both drugs in 2003. This study was conducted to assess the prevalence of sulfadoxine–pyrimethamine resistance-associated mutations in dhfr and dhps genes of P. falciparum three years after SP withdrawal in Bahir Dar, Northwest Ethiopia. A total of 165 blood spot samples were collected from patients infected with P. falciparum in Bahir Dar Health Center in 2005 (n = 78) and 2008 (n = 87) using Whatman (3M) filter papers. The three dhfr codons (dhfr108, dhfr 51 and dhfr 59) and the two dhps codons (dhfr 437 and 540) which are believed to determine SP resistance were detected by using nested PCR-based dot blot-hybridization technique. In dhfr, only the dhfr59Arg mutant-type showed statistically significant reduction from 80.3% in 2005 to 56.4% in 2008 (p < 0.01) with a significant increase of the wild type dhfr59Cys haplotypes from 4.9% in 2005 to 29.5% in 2008 (p < 0.01). The double mutants dhfr108Asn/51Ile were detected at rate of 98.4% in 2005 and 98.7% in 2008. A significant decrease in the triple dhfr (108Asn/51Ile/59Arg) mutation was observed from 2005 (78.6%) to 2008(56.4%) (p < 0.01). The quadruple mutations of dhfr (108Asn/51Ile/59Arg)/dhps437Gly were significantly declined from 78.6% in 2005 to 53.8% in 2008 (p < 0.01) while quintuple mutations (dhfr (108Asn/51Ile/59Arg)/dhps437Gly/dhps540Glu) showed a reduction from 60.6% to 37.2% after three years (p < 0.01). In conclusion, the decline in the prevalence of dhfr/dhps combination mutations might indicate the re-emergence of sensitive parasites in the population following SP withdrawal. Therefore, further monitoring and assessment is important to determine the feasibility of re-introduction of SP alone or in combination as a more affordable and safer drug in the future in Ethiopia.     

Expression and cellular distribution of TLR4, MyD88, and NF-κB in diabetic renal tubulointerstitial fibrosis, in vitro and in vivo

Aim

Inflammation and extracellular matrix hyperplasia are crucial in the pathogenesis of tubulointerstitial fibrosis (TIF) involved in diabetic nephropathy (DN). Macrophage accumulation plays a major role, but whether immune factors contribute to DN pathogenesis is not well understood. This study aimed to investigate TLR4-MyD88-NF-κB-dependent pathway's involvement in TIF pathogenesis.

Methods

STZ-induced diabetic rats and rat renal tubular epithelial NRK-52E cells cultured under high glucose conditions were used as in vivo and in vitro models, respectively. Real-time RT-PCR, western blot, immunohistochemistry and immunofluorescence were performed to examine the mRNA and protein levels of TLR4, MyD88, NF-κB, MCP-1, and α-SMA.

Results

Compared with 5.5 mmol/L glucose, treatment of NRK-52E cells with 25 and 50 mmol/L d-glucose resulted in significantly increased TLR4 and MyD88 mRNA and protein levels (P < 0.05). TLR4 and MyD88 were detected in the cytoplasm of most NRK-52E cells cultured under high glucose. Pronounced damage in the renal tubulointerstitium was observed in diabetic rats (scores: 3.82 ± 0.65 vs. 0.38 ± 0.08, P < 0.01). Compared with the normal controls, a sharp upregulation of TLR4, MyD88, NF-κB p65, MCP-1, and α-SMA mRNA and protein levels was observed in diabetic rat kidneys (P < 0.05). In diabetic animals, TLR4 and MyD88 were strongly expressed in the cytoplasm, while NF-κB p65 was widely expressed in cytoplasm and nuclei of renal tubular epithelial cells.

Conclusion

The inflammatory reaction and epithelial-mesenchymal transformation observed in renal tubulointerstitium may be the result of overactivation of the TLR4-MyD88-NF-κB-dependent innate immunity under high glucose, and may be involved in DN occurrence and progression.     

Prevailing Plasmodium falciparum dihydrofolate reductase 108-asparagine in Hodeidah,Yemen: A questionable sulfadoxine–pyrimethamine partner within the artemisinin-based combination therapy

Given that the evolution and spread of resistance to sulfadoxine–pyrimethamine (SP) have been documented at a quick pace worldwide, the present study investigated the mutant Plasmodium falciparum dihydrofolate reductase 108-asparagine (dhfr 108N) as a key marker of resistance to the combination among parasite isolates from Hodeidah. The association of parasitologic indices with the dhfr 108N mutant allele was also studied. Ninety patients with microscopically confirmed P. falciparum infection from Hodeidah were included in the present study. Polymerase chain reaction-restriction fragment length polymorphism approach was adopted for the molecular detection of this marker. The dhfr 108N was detected among about 61% of P. falciparum isolates, in its pure and mixed-type forms, from Hodeidah. Age, gender and residence of patients were not significant predictors for the presence of the mutant allele among parasite isolates. In contrast, a history of malaria and antimalarial drug intake in the year preceding the study as well as frequent antimalarial drug intake were significantly associated with this mutant allele. The high frequency of dhfr 108N among parasites isolates makes the role of SP questionable as a partner with outstanding effectiveness within the ACT, at least, in the near future. SP plus artesunate should be monitored for its antimalarial efficacy at regular intervals, preferably through the molecular detection of resistance-associated mutations.     

Is Fc gamma receptor IIA (FcγRIIA) polymorphism associated with clinical malaria and Plasmodium falciparum specific antibody levels in children from Burkina Faso?

In the present study, the influences of FcγRIIA polymorphism on susceptibility to malaria and antibody responses to Plasmodium falciparum antigens were analyzed in children.     

Evaluation of serum tumour markers concentrations in patients with homozygous β-thalassaemia in relation to demographical,clinical and biochemical parameters

Increased life expectancy in patients with homozygous β-thalassaemia consequently increases the risk for neoplastic diseases. This study was conducted to assess the levels of five common tumour markers in thalassaemic patients and to investigate possible correlations to demographical, clinical and laboratory data. Eighty-five patients (44 female and 41 male) with homozygous β-thalassaemia (mean age = 27.92 ± 12.5), on regular blood transfusions and adequate chelation treatment, and 60 sex and age- matched healthy controls were enrolled in the study. Blood samples for the determination of carcinoma antigen (CA) 15.3, CA 125, CA 19.9, carcinoembryonic antigen (CEA) and α-fetoprotein (a-FP) were collected from every subject. Results showed that 69% of the thalassaemic patients had abnormal levels of CA 15.3, whereas only sporadic cases had increased levels of CA 125 and CA 19.9. On the contrary, all controls had normal levels of CA 15.3, CA 19.9 and CA 125. CEA and a-FP were within reference ranges both in the thalassaemic and in the control group. Levels of CA 15.3 were significantly lower in patients aged less than 20 years compared to older patients. Male patients had significantly increased levels of CA 15.3 compared to female patients. Relatively recent studies show an increased expression of CA 15.3 on progenitor cells of the erythroid lineage and increased amounts of circulating progenitor cells even in well-transfused thalassaemic patients. However, it seems that there are also other factors contributing to this phenomenon. In conclusion, our results indicate that CA 15.3 seems to be an unreliable marker of occult malignancy in patients with β-thalassaemia. However, more studies are needed to support these preliminary results.     

CYPIA1, GSTs and mEH polymorphisms and susceptibility to esophageal carcinoma： Study of population from a high- incidence area in north China

AIM: To characterize cytochrome P4501A1 (CYPIA1), glutathione S-transferases (GSTs) and microsomal epoxide hydrolase (mEH) polymorphisms in Chinese esophageal cancer patients. METHODS: Multiplex polymerase chain reaction (PCR) and PCR based restriction fragment length polymorphisms (PCRRFLP) were used to detect polymorphism changes of CYP,GSTs and mEH on esophageal cancerous and precancerous lesions as well as in case control group. All the examination samples were obtained from Linzhou (formerly Linxian), Henan Province, the highest incidence area for esophageal. RESULTS: The frequency of CYP1A1 3‘‘ polymorphism in case control group (26/38, 68 %) was significantly higher than in esophageal squamous cell carcinoma~roup (ESCC) (29/62, 47 %) (P&lt;0.05). A significant difference in the incidence of mEH slow allele variant was observed between case control group (15/38, 39 %) and esophageal dysplasiagroup (22/32, 69 %) or ESCC group (39/62, 63 %) (P&lt;0.05). However, no significant difference was observed among different groups in the polymorphisms of CYPIA1 exon 7, GSTM1, GSTT1, GSTP1 and mEH fast allele. CONCLUSION: The present results suggest that CYPIA1 3‘‘ polymorphism may be one of the promising protectivef actors and its wild gene type may be an indicator for higher susceptibility to esophageal cancer, mEH slow allele variant,associated with the progression of esophageal precancerous lesions, may conthbute to the high susceptibility to esophageal carcinoma.     

Genetic polymorphisms of interleukin-1β (?511C/T) and interleukin-1 receptor antagonist (86-bpVNTR) in susceptibility to knee osteoarthritis in a Chinese Han population

Osteoarthritis (OA) is a multifactorial disorder in which genetic factors act as important contributors to its onset and progression. Associations between genetic polymorphisms of the interleukin-1 (IL-1) gene cluster and OA susceptibility have been studied continuously in different ethnic groups, yielding controversial results. This study investigated the association of interleukin-1β (−511C/T) and interleukin-1 receptor antagonist (86-bp VNTR) polymorphisms with knee OA susceptibility in a Chinese Han population. A case–control association study was conducted. The two polymorphisms were genotyped in 453 patients who had primary symptomatic knee OA with radiographic confirmation and in 487 matched controls. Allelic and genotypic frequencies and haplotype distribution were compared between OA and control subjects. For either of the two loci, no significant difference was detected in genotype or allele distribution between knee OA and control groups (all P > 0.05). The haplotype distribution of the two loci showed no difference between the two groups, either. Furthermore, no association between the genotype of the −511 and VNTR polymorphisms and the clinical variables, age, sex, body mass index and Kellgren/Lawrence score was observed in OA patients. The genetic polymorphisms of interleukin-1β and interleukin-1 receptor antagonist are not risk factors for OA etiology in Han Chinese. H. Ni and D. Shi contributed equally to this work.     

A review of the response to HIV/AIDS in Trinidad and Tobago: 1983–2010

Abstract

This paper examines the character of the response to HIV/AIDS in Trinidad and Tobago and assesses the impact of the response on reducing the spread of the epidemic. The launch of the National HIV/AIDS Strategic Plan in 2004 signalled the intent of the government to take the response to HIV/AIDS to a different level. This is seen by the sheer increase in the volume of resources allocated to the response from the levels of the 1980s and 1990s. The expectation was that there would be increased cohesiveness, which would allow for targeted interventions to be more effective. Though in 2009, there was a slight increase in the HIV prevalence rate to 1.5%, this was due mainly to improvements in access to antiretrovirals and same-day testing as well as improvements in data collection and analysis. The annual number of new infections fell from a high of 1709 in 2003 to 1154 in 2010. Additionally, great strides have been made in the prevention of mother-to-child transmission programme with some regions reporting 100% coverage of antenatal attendees. The study indicates that the country has responded relatively well in the areas of Strategic Planning, Care and Support, and Prevention and there has been involvement by both the public and private sector (NGOs in particular), in the response. However, there are gaps in the provision of social services and the implementing legislation to protect the rights of persons living with HIV/AIDS. Of note is the fact that a successful response to the HIV/AIDS epidemic is one that embraces all social groups, all spheres of activity and all areas of the country.     

Impact of IL28B polymorphisms on response to peginterferon and ribavirin in HIV–hepatitis C virus-coinfected patients with prior nonresponse or relapse

IL28B polymorphisms predict treatment response in chronic hepatitis C. However, no information exists in prior treatment failures. A total of 62 HIV/hepatitis C virus (HCV) patients who completed retreatment with peginterferon-α/ribavirin were examined, of whom 25 (40%) had been cured. Predictors of response [odds ratio, OR (95% confidence interval, CI)] were HCV genotypes 2/3 [16.1 (2.7-90.9)], prior relapse [9.6 (1.5-62.4)] and ribavirin plasma trough concentrations at week 4 [4.9 (1.3-18.4)]. IL28B-CC only predicted response in prior nonresponders carrying HCV genotypes 1/4 [25.1 (1.9-337)].     

Common polymorphisms of the peroxisome proliferator-activated receptor-γ (Pro12Ala) and peroxisome proliferator-activated receptor-γ coactivator-1 (Gly482Ser) and the response to pioglitazone in Chinese patients with type 2 diabetes mellitus

We investigated the effects of the common polymorphisms in the peroxisome proliferator-activated receptor-γ (PPAR-γ; Pro12Ala) and in PPAR-γ coactivator-1(PGC-1; Gly482Ser) genes on the response to pioglitazone in Chinese with type 2 diabetes mellitus. A total of 250 patients with type 2 diabetes mellitus were treated with pioglitazone (30 mg/d) for 24 weeks without a change in previous medications. All patients were genotyped for the PPAR-γ Pro12Ala and PGC-1 Gly482Ser polymorphisms. The Ala12Ala and Pro12Ala genotypes (26.0% vs 13.5%, P = .025) and Ala allele (15.6% vs 7.3%, P = .008) were significantly more frequent in pioglitazone responders than in nonresponders. The distribution of PGC-1 genotypes and alleles was not significantly different between responders and nonresponders. The decrease in fasting glucose (50.4 ± 52.2 vs 43.3 ± 51.7 mg/dL, P < .001) and hemoglobin A_1c (0.57% ± 1.44% vs 0.35% ± 1.10%, P = .004) levels was significantly greater in subjects with the Ala12 carriers (Pro12Ala and Ala12Ala) than in those without the allele (Pro12Pro). Baseline fasting glucose and triglyceride levels were related to the response of pioglitazone. Only the PPAR-γ Pro12Ala polymorphism was found to be associated with the response of pioglitazone by multiple logistic regression analysis. The PPAR-γ Pro12Ala gene polymorphism is associated with the response to pioglitazone in Chinese patients with type 2 diabetes mellitus. These findings may be helpful for targeted treatment of diabetes by identifying patients who are likely to respond to pioglitazone.     

Sustained elevation of interleukin-33 in sera and synovial fluids from patients with rheumatoid arthritis non-responsive to anti-tumor necrosis factor: possible association with persistent IL-1β signaling and a poor clinical response

Although TNF inhibitors have dramatically improved the outcome of patients with rheumatoid arthritis, 30–40% of patients do not respond well to them and treatment needs to be changed. In an effort to discriminate good and poor responders, we focused on the change in serum and synovial fluid levels of interleukin (IL-) 33 before and after treatment with TNF inhibitors. They were also measured in synovial fluids from 17 TNF inhibitor-na?ve patients, and fibroblast-like synoviocytes (FLS) in-culture from 6 patients and correlated with various pro-inflammatory cytokines. Serum levels of IL-33 at 6?months after treatment decreased significantly in responders, while they did not change in non-responders. Synovial fluid levels of IL-33 in 6 patients under treatment with TNF inhibitors stayed high in 3 who were refractory and slightly elevated in 2 moderate responders, while they were undetectable in one patient under remission. Among inflammatory cytokines measured in 17 synovial fluids from TNF inhibitor-na?ve patients, levels of IL-33 showed a significant positive correlation only to those of IL-1β. IL-1β increased IL-33 expression markedly in FLS in vitro, compared to TNF-α. IL-1β might be inducing RA inflammation through producing pro-inflammatory IL-33 in TNF inhibitor-hypo-responders. Sustained elevation of serum and/or synovial levels of IL-33 may account for a poor response to TNF inhibitors, although how TNF inhibitors affect the level of IL-33 remains to be elucidated.     

Report and policy brief from the 4th Africa Conference on Social Aspects of HIV/AIDS Research: Innovations in access to prevention,treatment and care in HIV/AIDS,Kisumu, Kenya, 29 April–3 May 2007

About 520 delegates from all over Africa and 21 countries attended the conference. This report and policy brief summarises the key findings and suggested policy options that emerged from rapporteur reports of conference proceedings including the following themes: (1) Orphans and vulnerable children, (2) Treatment, (3) Prevention, (4) Gender and male involvement, (5) Male circumcision, (6) People living with HIV/AIDS, (7) Food and nutrition, (8) Socioeconomics, and (9) Politics/policy. Two (11.8%) of the 17 OVC projects from the three countries were classified as best practice interventions. Of the 83 abstracts that were accepted at the conference, only 7 (8.4%) were dealing with antiretroviral therapy (ART). There has been tremendous effort by various organisations to provide information about prevention of HIV/AIDS. Information received by adolescents has been effective in increasing their knowledge, but without positive sexual behaviour change.The conference noted the contribution of gender discrimination and violence to the HIV epidemic and the different risks that men and women face in relation to the epidemic. Social scientists need to study the deep cultural meanings attached to male circumcision among different ethnic groups to be able to guide the debate on the latest biomedical findings on the protective effect of circumcision against HIV. Palliative care and support is crucial for coping among people living with HIV/AIDS (PLWHA) in order to deal with medical and psychological issues. Results from several countries have helped researchers to explore alternative ways of examining poverty in the context of HIV and AIDS. Policy frameworks which are likely to succeed in combating HIV/AIDS need to be updated to cover issues of access, testing, disclosure and stigma. In general, the conference was successful in identifying innovations in access to prevention, treatment and care in HIV/AIDS.