Malaria is one of the serious global health problem, causing widespread sufferings and deaths in various parts of the world. With the large number of cases diagnosed over the year, early detection and accurate diagnosis which facilitates prompt treatment is an essential requirement to control malaria. For centuries now, manual microscopic examination of blood slide remains the gold standard for malaria diagnosis. However, low contrast of the malaria and variable smears quality are some factors that may influence the accuracy of interpretation by microbiologists. In order to reduce this problem, this paper aims to investigate the performance of the proposed contrast enhancement techniques namely, modified global and modified linear contrast stretching as well as the conventional global and linear contrast stretching that have been applied on malaria images of P. vivax species. The results show that the proposed modified global and modified linear contrast stretching techniques have successfully increased the contrast of the parasites and the infected red blood cells compared to the conventional global and linear contrast stretching. Hence, the resultant images would become useful to microbiologists for identification of various stages and species of malaria.
This study describes the chemical speciation of Pb, Zn, Cu, Cr, As, and Sn in soil of former tin mining catchment. Total five sites were selected for sampling and subsequent subsamples were collected from each site in order to create a composite sample for analysis. Samples were analysed by the sequential extraction procedure using optical emission spectrometry (ICP OES). Small amounts of Cu, Cr, and As retrieved from the exchangeable phase, the ready available for biogeochemical cycles in the ecosystem. Low quantities of Cu and As could be taken up by plants in these kind of acidic soils. Zn not detected in the bioavailable forms while Pb is only present in negligible amounts in very few samples. The absence of mobile forms of Pb eliminates the toxic risk both in the trophic chain and its migration downwards the soil profile. The results also indicate that most of the metals have high abundance in residual fraction indicating lithogenic origin and low bioavailability of the metals in the studied soil. The average potential mobility for the metals giving the following order: Sn > Cu > Zn > Pb > Cr > As.
Enterovirus 71 (EV71) is one of the viruses that cause hand, foot and mouth disease. Its viral capsid protein 1 (VP1), which contains many neutralization epitopes, is an ideal target for vaccine development. Recently, we reported the induction of a strong immune response in rabbits to a truncated VP1 fragment (Nt-VP1t) displayed on a recombinant Newcastle disease virus (NDV) capsid protein. Protective efficacy of this vaccine, however, can only be tested in mice, since all EV71 animal models thus far were developed in mouse systems. In this study, we evaluated the type of immune responses against the protein developed by adult BALB/c mice. Nt-VP1t protein induced high levels of VP1 IgG antibody production in mice. Purified VP1 antigen stimulated activation, proliferation and differentiation of splenocytes harvested from these mice. They also produced significant levels of IFN-γ, a Th1-related cytokine. Taken together, Nt-VP1t protein is a potent immunogen in adult mice and our findings provide the data needed for testing of its protective efficacy in mouse models of EV71 infections.
Nucleotide sequence comparison of the L gene of the Malaysian neurotropic-viscerotropic velogenic NDV strain AF2240 with other NDV strains revealed a single nucleotide insertion at position 3870. This mutation is compensated by a nucleotide deletion downstream at position 3958 which results in two forms of the L proteins containing a 30-amino acid substitution in Domain V. This compensatory mutation does not correlate with the pathogenicity of the viral strains but it may affect the viral replication as Domain V is believed to play an important role in the replication of paramyxoviruses.
Human respiratory syncytial virus is the most common cause of bronchiolitis and other respiratory infections in infants and the elderly worldwide. We have developed two new oral vaccines using Salmonella typhi TY21a to carry and express the immunogenic epitopes of RSV fusion (F) and attachment (G) glycoproteins on its surface, separately. To evaluate the efficacy of the designed vaccines, BALB/c mice were orally immunized and then infected with RSV. Immune response analyses showed that cellmediated, mucosal and humoral immunity in the vaccinated mice were significantly enhanced compared to the control group. Both vaccines generated a balanced Th1/Th2 immune response which is crucial for efficiency of vaccines against RSV. Furthermore, histopathological examination proved that these vaccines were safe as they did not cause any Th2-associated adverse effects in the lungs of RSV-infected mice. The findings of this research suggest that Salmonella-F and Salmonella-G vaccine candidates may have strong potential to prevent RSV infection.
Hypercholesterolemia causes endothelial dysfunction, an early feature of atherosclerosis, leading to increased production of adhesion molecules and cytokines. The aim of this study was to investigate the effects of three months of treatment with low dose atorvastatin on serum levels of adhesion molecules, interleukin-6 (IL-6) and highly sensitive C-reactive protein (hs-CRP) in patients with non-familial hypercholesterolemia. Fifty-five patients with non-familial hypercholesterolemia were randomized to treatment with atorvastatin 10 mg/day or placebo for 3 months. Soluble intercellular adhesion molecules-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, IL-6 and hs-CRP levels were measured to assess the inflammatory activity of the endothelium. There was a significant reduction in ICAM-1 at 2 weeks (p<0.0001) with further reduction at 3 months (p<0.0001). At 3 months, there were significant reductions in VCAM-1 (p<0.02), IL-6 (p<0.0001) and hs-CRP (p<0.01), but an increase in E-selectin levels (p<0.002). Treatment with statin was an independent determinant of change in ICAM-1 (p<0.05) and IL-6 levels (p<0.05) after correcting for anthropometric indices, blood pressure and lipid profile. Low-dose atorvastatin treatment leads to reduction in proinflammatory markers of endothelial function, suggesting an attenuation of endothelial activation and improvement in endothelial function, independent of lipid lowering. This may lead to a reduction in the progression of atherosclerosis.
ACE inhibitors are important therapeutic agents in controlling hypertension, correcting some of its pathophysiological derangement and improving its prognosis. While there are many such agents, there may be some important differences between them. This placebo run-in, double blind, crossover study, using 24-hour ambulatory blood pressure monitoring, compares the efficacy of perindopril 4-8 mg and enalapril 10-20 mg as once daily antihypertensive agents on 32 patients. For diastolic blood pressure (DBP), perindopril had a placebo-corrected peak (P) reduction of blood pressure (BP) of -6.4 +/- 1.3 mmHg vs its placebo-corrected trough (T) of -5.2 +/- 1.7 mmHg. Enalapril had a reduction in DBP of -8.5 +/- 1.3 mmHg (P) and -5.7 +/- 1.7 mmHg (T). For systolic blood pressure (SBP), perindopril had a reduction of -7.5 +/- 1.6 mmHg (P) vs -7.3 +/- 2.2 mmHg (T) compared to enalapril with -10.8 +/- 1.6 mmHg (P) vs -8.3 +/- 2.3 mmHg (T). Placebo-corrected trough-to-peak ratio (SBP/DBP) for perindopril was 0.97/0.81 vs 0.77/0.67 for enalapril. There was no difference noted in 24-hour mean BP, area under the curve or post-dose casual BP measurements. Both perindopril and enalapril were well tolerated and the two treatment groups had similar safety profiles. Perindopril thus had a predictable and sustained blood pressure effect giving a 24-hour cover for the patient without excessive peak effect or poor trough effect.
Nine Newcastle disease virus (NDV) isolates from Newcastle disease (ND) outbreaks in different regions of Iran were characterized at molecular level. Sequence analysis revealed that the isolates shared two pairs of arginine and a phenylalanine at the N-terminus of the fusion (F) protein cleavage site similarly to other velogenic isolates of NDV characterized earlier. Eight of the nine isolates had the same amino acid sequence as VOL95, a Russian NDV isolate from 1995. However, one isolate, MK13 showed 5 amino acid substitutions, of which 3 have been reported for other velogenic NDV isolates. These results suggest that the origin of the outbreaks of ND in different parts of Iran in 1995-1998 is VOL95.
A disulfide constrained random heptapeptide library displayed on filamentous bacteriophage M13 was applied to select specific ligands that interact with Newcastle disease virus (NDV). A fusion phage carrying the amino acid sequence TLTTKLY was selected from the panning procedure. An antibody competition assay showed that the selected phage was capable of competing with the polyclonal antibodies raised against NDV for binding sites on the virus. Determination of the binding affinity of this phage with NDV by an equilibrium binding assay in solution revealed two different dissociation constants, suggesting that there could be two distinct binding sites for the phage on NDV. Synthetic peptides with the sequence CTLTTKLYC, either in linear or cyclic conformations inhibited the binding of phage bearing the same sequence to NDV. These peptides also inhibited the hemolytic activity of the virus as well as its propagation in embryonated chicken eggs.
The PreS domain of hepatitis B virus (HBV) is believed to be involved in virion assembly and attachment to a hepatocyte receptor during infection. In order to study the functions of this region, we fused it to the g3p protein of bacteriophage M13 that allows the fusion protein to be displayed at the tip of the filament. The fusion protein was detected by the anti-E tag antibody on a Western blot. The polypeptide in a soluble form was produced by transfecting a non-suppressor E. coli host cell with the recombinant phagemid. The soluble protein was detected in cytoplasm, in the periplasmic space and also in the medium. The functional display of the PreS domain would provide an alternative means to study its interactions with the nuleocapsid and hepatocytes.
A biotin-avidin-linked immunosorbent assay was developed to detect Aspergillus antigens in sera of immunocompromised patients. The assay was based on a double antibody sandwich ELISA using polyclonal antibodies raised against water-soluble antigens of Aspergillus fumigatus. Aspergillus antigens were positive in sera of 9 of 16 (56%) patients who were studied prospectively and in 13 of 73 (19%) patients studied retrospectively. The 9 prospectively studied patients who were antigen positive were febrile neutropenic hematological malignancy patients who exhibited a high risk of acquiring invasive aspergillosis.
Laboratories intending to adopt cycle sequencing of PCR products in their routine analysis often face a confusing range of methods and kits. Through the study of mitochondrial cytochrome b, we have shown that clean and highly reproducible sequences could be obtained by using a combination of existing simple and economical methods in the preparation of DNA templates, PCR, purification of PCR products and sequencing. Our protocol is useful in itself or as a standard in typing other PCR-amplified DNA at the population level.
Destructive thyroiditis commonly occurs during the postpartum period, with a prevalence rate of 5% to 16%, and is mainly due to postpartum autoimmune thyroiditis (PPT) and, very rarely, to subacute thyroiditis. The thyroiditis is similar to Hashimoto's thyroiditis and is generally painless in nature, although cases with painful thyroiditis have been described. We report a case of painful destructive thyroiditis occurring during the postpartum period, which was clinically and biochemically indistinguishable from the variant of painful PPT or subacute thyroiditis. Fine needle aspiration cytology showed multi-nucleated giant cells diagnostic of subacute thyroiditis.
A total of 143 microsatellites were isolated from Mystus nemurus using a 5' anchored polymerase chain reaction technique or the random amplified hybridization microsatellite method, the first set of microsatellite markers developed for the Southeast Asian river catfish. Twenty polymorphic microsatellite loci were used as markers for population characterization of M. nemurus from six different geographical locations in Malaysia (Perak, Kedah, Johor, UPM, Sarawak and Terengganu). The number of alleles per locus ranged from 2 to 11 with 6.3 as the average number of alleles per locus. Characterization of the populations showed relatively high levels of genetic variation compared with previous studies using allozyme markers. The highest genetic similarity was found between Perak and Kedah, while the highest genetic distance was found between Terengganu and Kedah. The majority of clustering was in accordance with geographical locations and the histories of the populations. Microsatellite analysis indicated that the Sarawak population might be genetically closer to the Peninsular Malaysian populations than has been previously shown by other molecular marker studies.
A method for serological diagnosis of Nipah virus (NiV) is described. DNA encoding truncated G protein of NiV was cloned into the pFastBac HT vector, and the fusion protein to His-tag was expressed in insect cells by recombinant baculovirus. The resulting His-G recombinant fusion protein was purified by affinity chromatography and used as the coating antigen for serological testing by indirect enzyme-linked immunosorbant assay (ELISA). When tested against a panel of swine serum samples, the recombinant G protein-based ELISA successfully discriminated all 40 samples previously determined to be serum neutralizing test (SNT) positive from 11 SNT negatives samples. The data show that the recombinant G protein exhibits the antigenic epitopes and conformation necessary for specific antigen-antibody recognition. The main advantage of the recombinant G protein-based NiV ELISA compared to an ELISA using whole virus antigen is the use of a single antigenic protein instead of inactivated whole virus which is required to be prepared under high risk and cost. This test is suitable for routine diagnosis of NiV and also for epidemiological surveys as it allows highly reliable testing of a large number of sera rapidly.
The structure and distribution of organelles within developing goat oocytes at various stages of incubation were studied. In oocytes with 5 or more layers of cumulus cells, at 0 h of incubation, the zona pellucida had developed although zonation was not evident. Lipid bodies were present but no mitochondria were observed. At 20 h, the zona pellucida had differentiated into thicker and thinner regions. Clusters of membrane-bound electron-transparent bodies were present in the perivitelline space. The mitochondria were fully developed, distributed evenly and usually in close proximity with dilated endoplasmic reticula. Cortical granules were distributed at the periphery. At 40 h of incubation, a number of mitochondria was hooded. In oocytes of 2 to 4 layers of cumulus cells at 0 h, the zona pellucida was penetrated by cumulus cell processes, and the mitochondria were not well developed. However, in 20-h incubated oocytes, fully developed mitochondria, many of which were hooded, could be observed. Clusters of membrane-bound electron-transparent bodies were also observed, while cortical granules were at the periphery. In cumulus-free oocytes, zonation within the zona pellucida was indistinct. Very few vesicles and lipid bodies were observed. At 20 h, mitochondria were sparsely distributed and were not well developed and lacked cristae. At 40 h, the zona pellucida was less compact, and the membrane-bound electron-transparent bodies were less numerous compared with those of the other groups. Endoplasmic reticula were not dilated, and cortical granules were few and had no definite pattern of distribution.
A case control study to determine the association of dietary fibre and cancer among Malaysians. It was conducted among 100 newly-diagnosed cancer patients admitted to the Radiotherapy and Oncology Ward, Hospital Kuala Lumpur. A total of 100 controls matched with the cases for age, sex and ethnic origin were selected from the Outpatient Health Clinic in Sentul. The subjects were interviewed to obtain information on their habitual dietary intakes and lifestyles. Family history of cancer, smoking habits, and alcohol consumption were found to be significant risk factors for cancer (p<0.05 for all parameters). The mean intake of total energy was higher among men with nasopharyngeal cancer and women with gastrointestinal cancer as compared to their controls (p<0.05 for both parameters). The percentage of energy contribution from fat was higher among cases (35%) than controls (32.1%). The mean dietary fibre intake among cases (10.86 ± 8.90 g/d) was apparently lower than the controls (13.22 ± 5.99 g/d), with significant differences noted for breast cancer and also nasopharyngeal cancer. Women with low fibre intake (<10g/d) had a 2.2 times higher risk of getting breast cancer. There is a need to educate the public to adhere to a wholesome diet, in particular to increase the consumption of high-fibre food for disease prevention.
Study site: Radiotherapy and Oncology Ward, Hospital Kuala Lumpur and Outpatient Health Clinic in Sentu
To assess the knowledge, attitudes and experience of a group of Malaysian dental health care providers regarding child physical abuse (CPA) cases in terms of frequency of occurrence, diagnosis, risk factors and reporting.