Performance of the OptiMAL test for malaria diagnosis among suspected malaria patients at the rural health centers

The OptiMAL test detects both Plasmodium falciparum and P. vivax malaria infections. In this study, we evaluated the performance of the OptiMAL test at the Basic Health Units (BHUs) and the District Health Quarter (DHQ) Center in rural villages of Punjab, Pakistan that provide minimal health services. Two sets of blood specimens obtained from 930 suspected malaria patients attending these BHUs were tested at BHUs and the DHQ Center by microscopy and the OptiMAL test. At the BHUs, 231 (25%) of the patients were positive by microscopy and 278 (30%) patients tested positive by the OptiMAL test. At the DHQ Center, microscopic analysis of a second set of specimens from the same patients confirmed the malaria infection in 386 (42%) patients and the OptiMAL test result was positive in 300 (32%) patients. To determine the performance of OptiMAL test at the BHUs and the DHQ Center, all data were compared with microscopy results obtained at the DHQ Center. The OptiMAL test results for P. falciparum at the BHUs were comparable to those of the OptiMAL test at the DHQ Center. However, the sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of the OptiMAL test were considerably lower for P. vivax infections than for P. falciparum infections, irrespective of whether the test was performed at the BHUs or at the DHQ Center (P. falciparum: sensitivity = 78-85%, PPV = 89-97%, NPV = 96-98%; P. vivax: sensitivity = 61-76%, PPV = 88-95%, NPV = 90-93%). The OptiMAL test also detected a number of false-positive and false-negative results at both the BHUs and the DHQ Center. The false-positive results ranged from 1% to 2%; however, the number of false-negative results was much higher (BHUs: P. falciparum = 22%, P. vivax = 39%; DHQ Center: P. falciparum = 15%, P. vivax = 24%). In conclusion, these results, when combined with other advantages of the OptiMAL test, suggest that this test can be used by relatively inexperienced persons to diagnose malaria infection in rural areas where facilities for microscopy are not available.     

Molecular characterization of hepatitis E virus ORF1 gene supports a papain-like cysteine protease (PCP)-domain activity

Hepatitis E Virus (HEV) ORF1 encodes the nonstructural polyprotein wherein a role of PCP-domain in ORF1 proteolysis and/or RNA replication still remains contested. A series of ORF1 mutants of HEV-SAR₅₅ replicon were constructed and tested for viability in S10-3 cells. Six of PCP-‘cysteine’ (C457A, C459A, C471A, C472A, C481A and C483A) and three ‘histidine’ (H443L, H497L and H590L) mutants were lethal. Further, a highly conserved ‘glycine-triad’ (G815-G816-G817) in downstream X-domain, homologous to rubella virus protease-substrate (G1299-G1300-G1301) was identified where two of X-mutants (G816V and G817V) turned lethal. However, all ORF1 sequential nucleotide-mutants conserving the amino acids were viable, which clearly showed post-translational regulation of HEV replication by PCP- and X-domains. Moreover, while vector-expressed ORF1-fusion polyprotein yielded a ∼191 kDa band in vitro, it produced ∼78 and ∼35 kDa fragments ex vivo. Collectively, the indispensability and functional effects of ‘PCP-catalytic’ and ‘X-substrate’ residues on HEV replication strongly supported a viral protease.     

HLA class II DQA and DQB epitopes: Recognition of the likely binding sites of HLA-DQ alloantibodies eluted from recombinant HLA-DQ single antigen cell lines

Donor-specific antibodies (DSA) in sera of sensitized transplant patients are often produced against the specific epitopes on mismatched HLA antigens. In this study, we selected sera from 30 kidney transplant patients with DSA and AMR to define DQ epitopes. Using adsorption and elution assays, we identified 18 antibody reaction patterns to define 6 new epitopes and to confirm 12 previously defined epitopes. In one patient case, one mismatched antigen produced 3 different antibodies and, in another, antibodies were produced against the alpha and beta chains of the same antigen. For some sera, a single epitope can explain reactions for 27 of the 29 DQ beads in the single antigen panel.     

Evolution of β-catenin-independent Wnt–GSK3–mTOR signalling in regulation of energy metabolism in isoproterenol-induced cardiotoxicity model

Inflammation Research - Isoproterenol (ISO) is widely used agent to study the effects of interventions which could prevent or attenuate the development of myocardial infarction. The sequence of...