Acid Phosphatase as a Marker in Malaria

The serum acid phosphatase (ACP) activity and Hemoglobin (Hb) levels were measured in malaria patients and nonmalarial fever patients. The results were compared with normal healthy control subjects. ACP was significantly increased (P < 0.001) in all the malaria patients. ACP was significantly higher in Plasmodium falcifarum malaria and mixed malaria when compared to Plasmodium vivax malaria. Hb levels were significantly decreased in all the malaria patients which indicates that malaria parasite uses host erythrocyte Hb as a major nutrient source. There is negative correlation(r = −0.478) between ACP and Hb in malaria patients, which is highly significant. These results suggest that the measurement of ACP could be used as a marker for malaria.     

Evaluation of Students' Conceptual Understanding of Malaria

In this study, a two‐tier diagnostic test for understanding malaria was developed and administered to 314 Bruneian students in Year 12 and in a nursing diploma course. The validity, reliability, difficulty level, discriminant indices, and reading ability of the test were examined and found to be acceptable in terms of measuring students' understanding and identifying alternative conceptions with respect to malaria. Results showed that students' understanding of malaria was high for content, low for reasons, and limited and superficial for both content and reasons. The instrument revealed several common alternative conceptual understandings students' hold about malaria. The MalariaTT2 instrument developed could be used in classroom lessons for challenging alternative conceptions and enhancing conceptions of malaria.     

Extracellular Methemoglobin Mediated Early ROS Spike Triggers Osmotic Fragility and RBC Destruction: An Insight into the Enhanced Hemolysis During Malaria

Malaria infection is known to cause severe hemolysis due to production of abnormal RBCs and enhanced RBC destruction through apoptosis. Infected RBC lysis exposes uninfected RBC to the large amount of pro-oxidant molecules such as methemoglobin. Methemoglobin (MetHb) exposure dose dependently makes RBCs susceptible to osmotic stress and causes hemolysis. MetHb mediated oxidative stress in RBC correlated well with osmotic fragility and hemolysis. Interestingly, a reactive oxygen species (ROS) spike at 15 min was responsible for the observed effects on RBC cells. Two natural antioxidants N-acetyl cysteine and mannitol protected the RBC from MetHb-mediated defects, which clearly indicated involvement of oxidative stress in the process. MetHb due to its pseudo-peroxidase activity produces ROS in the external microenvironment. Therefore, classical peroxidase inhibitors were tested to probe peroxidase activity mediated ROS production with defects in RBCs. Clotrimazole (CLT), which irreversibly inactivates the MetHb (CLT-MetHb) and abolishes peroxidase activity, did not produce significant ROS outside RBC and was inefficient to cause osmotic fragility and hemolysis. Hence, initiating a chain reaction, MetHb released from ruptured RBC produces significant ROS in the external microenvironment to make RBC membrane leaky and enhanced hemolysis. Together data presented in the current work explored the role of MetHb in accelerated humorless during malaria which could be responsible for severe outcomes of pathological disorders.     

Plasma proteins and proteinuria in gestational malaria

The plasma concentrations of total protein, albumin, immunoglobulins IgG, IgA and IgM and urinary protein were assayed in 250 pregnant Nigerian women with malaria and compared with 250 healthy pregnant women which served as controls. The mean values of plasma total proteins, albumin, IgG and IgA were significantly lowered (P<0.05) while a slight increase in IgM was observed in the malaria patients. Urinary proteins value of 23.10±0.50 mg/dl was obtained for the pregnant women with malaria, this was significantly higher (P<0.05) than that of the controls with the corresponding value of 15.32±0.09 mg/dl. This study has therefore demonstrated elevations of the urinary and decrease in plasma proteins in gestational malaria. These findings suggest that the protein profile should be considered in the diagnosis and treatment of malaria.     

Determination of immunoreactivity of<Emphasis Type="Italic">Plasmodium falciparum</Emphasis> antigens,serum dilutions and biomaterials

Immunoreactivity properties of serum dilutions andPlasmodium falciparum malaria antigens were measured and compared by ELISA technique using different ELISA plates to evaluate the role of antigens and serum dilutions for optimum binding. Also effort has been made to see the effect of reaction surface and material i.e. ELISA plates for binding capacity. Serological properties were estimated by ELISA methods for detection of malaria and determination of immunological characteristics. Three Pf antigens (PfAg) i.e. ring infected erythrocyte surface antigen: AR-1 (RESA), histidine-rich protein 2 antigen (HRP-2) and glycophospholipid antigen (grown and developed Pf antigen from PSJ-M strain): GPL1 have been used for serological testing of human blood samples by Enzyme Link Immunosorbant Assay (ELISA). 1∶100, 1∶1000 and 1∶10000 dilutions of Pf positive and negative serum (50 samples in each group) and 1∶1000 dilution of Pf antigens were used to measure immunoreactive properties by ELISA method. Result of PfAg-serum immunoreactivity study showed that GPL1 has the highest degree of immuno binding reactivity compared to other Pf antigens. HRP-2 and RESA antigens showed no significant difference to each other. Study also found that Costar and Fastec ELISA plates have a better Ag−Ab binding capability compared to immulon and Falcon plates at all dilutions of serum. Serum dilution of 1∶100 showed best binding and reactivity with Pf antigens followed by 1∶1000 and 1∶10000 showed lowest reactivity.     

Use of antigen prepared from in vitro culture ofPlasmodium falciparum for the detection of antibodies in sera from patients exposed toPlasmodium vivax

The blood stage parasites fromin vitro cultures ofPlasmodium falciparum were employed for the detection of malaria antibodies in patient sera havingP. vivax infections employing indirect fluorescent antibody (IFA) test. The antibody titres obtained for theP. vivax infected sera ranged from 1∶128 to 1∶1024. Control slides smeared with non-immune sera did not show any fluorescence. On the basis of the results of the present study it maybe concluded that antigen prepared fromin vitro cultures ofP. falciparum cross-reacts withP. vivax antibodies.     

Studies on biochemical changes with special reference to oxidant and antioxidants in malaria patients

Oxidative stress plays an important role in the development of malarial anemia. The present study was undertaken to study the role of oxidant and antioxidants in the patients ofPlasmodium falciparum malaria (n=25),Plasmodium vivax malaria (n=25) as against the normal control subjects (n=25). The parameters included are the hematological [hemoglobin, erythrocyte adenosine deaminase (ADA) activity, ADP-induced platelet aggregation] and serum total lipid peroxide as an index of oxidative stress and antioxidants [erythrocytic superoxide dismutase (SOD) activity, serum vitamin E] & serum iron. Significant alterations in all above parameters were noted in both groups of malaria patients as compared to control subjects. Maximum significant alterations in hematological parameters were noticed inP. falciparum infection as compared toP. vivax malaria (p<0.001). Substantial rise in serum total lipid peroxides and a significant reduction in antioxidants such as serum vitamin E and serum iron were noted inP. falciparum malaria as compared toP. vivax malaria (p<0.001), whereas maximum decline in erythrocytic SOD activity was observed inP. vivax infection as compared toP. falciparum malaria (p<0.05). Follow-up examination revealed the restoration of the levels of all biochemical parameters to the normal level after 20 days of antimalarial therapy. The study specified severity ofP. falciparum malaria and also functional duality of oxidant.     

Comparative study on lipid peroxidation and antioxidant vitamins E and C inFalciparum andVivax malaria

Reactive oxygen species are thought to be involved in the pathogenesis of Malaria. To assess the extent of oxidative stress, a study was conducted in patients withPlasmodium falciparum malaria andPlasmodium Vivax malaria. Plasma Thiobarbituric acid reactive substances (TBARS) were measured to assess the degree of lipid peroxidation. Antioxidant status was measured by estimating the levels of Vitamins E and C. Results were compared with age and sex matched control subjects. This study suggests that plasma TBARS levels were significantly increased in malaria patients. The patients withP. falciparum infection showed significantly increased levels of lipid peroxides when compared toP. vivax malaria. The antioxidant Vitamins E and C were decreased significantly in malaria patients in both the groups. Maximum decline in Vitamin C was observed inP. vivax malaria. Therefore it is been hypothesized that antioxidant Vitamins E and C could provide protection against the oxidative stress induced by malaria.