Acanthamoeba in Southeast Asia - Overview and Challenges

Acanthamoeba, one of free-living amoebae (FLA), remains a high risk of direct contact with this protozoan parasite which is ubiquitous in nature and man-made environment. This pathogenic FLA can cause sight-threatening amoebic keratitis (AK) and fatal granulomatous amoebic encephalitis (GAE) though these cases may not commonly be reported in our clinical settings. Acanthamoeba has been detected from different environmental sources namely; soil, water, hot-spring, swimming pool, air-conditioner, or contact lens storage cases. The identification of Acanthamoeba is based on morphological appearance and molecular techniques using PCR and DNA sequencing for clinico-epidemiological purposes. Recent treatments have long been ineffective against Acanthamoeba cyst, novel anti-Acanthamoeba agents have therefore been extensively investigated. There are efforts to utilize synthetic chemicals, lead compounds from medicinal plant extracts, and animal products to combat Acanthamoeba infection. Applied nanotechnology, an advanced technology, has shown to enhance the anti-Acanthamoeba activity in the encapsulated nanoparticles leading to new therapeutic options. This review attempts to provide an overview of the available data and studies on the occurrence of pathogenic Acanthamoeba among the Association of Southeast Asian Nations (ASEAN) members with the aim of identifying some potential contributing factors such as distribution, demographic profile of the patients, possible source of the parasite, mode of transmission and treatment. Further, this review attempts to provide future direction for prevention and control of the Acanthamoeba infection.

Synergistic effects of melphalan and Pinus kesiya Royle ex Gordon (Simaosong) extracts on apoptosis induction in human cancer cells

Background

This study aims to determine the synergistic effects of the chemotherapeutic drug melphalan and the phytoconstituents extracted from Pinus kesiya Royle ex Gordon (Simaosong) in human cancer cells.

Methods

P. kesiya twigs extracted from 50 % ethanol–water were evaluated alone (6–500 µg/mL) and in combination with melphalan (0.75–15 µg/mL). The cytotoxic effects of single extract or extract and melphalan combination were examined by a neutral red assay to investigate their antiproliferative and apoptosis induction effects in the U937 and HepG2 cell lines. Nuclei morphological change and DNA fragmentation were examined by DNA nuclei staining with 4´6-diamidino-2-phenylindole (DAPI) and agarose gel electrophoresis, respectively. The chemical constituents of the P. kesiya extract were assessed using gas chromatography–mass spectrometry (GC–MS) analysis. The synergistic effects of different IC₅₀ ratios of the P. kesiya extract and melphalan combination were analyzed in each cancer cell line. The dose reduction index (DRI) was calculated to determine the extent of concentration reduction in the combination treatment compared with the concentration of each single treatment.

Results

The IC₅₀ ratios for melphalan to P. kesiya extract that caused 75 % antiproliferation could be reduced after combination. This response was greater in the U937 cells than in the HepG2 cells (all P < 0.001). Melphalan and P. kesiya extract had a similar effect on apoptosis induction both singly and in combination. P. kesiya extract synergized the antiproliferation and apoptosis induction effects of melphalan.

Conclusions

Combining the P. kesiya extract with melphalan reduced toxicity while retaining the therapeutic efficacy of melphalan.

Induction of apoptosis in human hepatocellular carcinoma cells by extracts of Lannea coromandelica (Houtt.) Merr. and Diospyros castanea (Craib) Fletcher

Background

Herbal plants are a preferred source of anticancer agents. This study aims to screen the anticancer activity of a crude extract of twigs of (a) Bombax anceps Pierre var. anceps (BA); (b) Catunaregam tomentosa (Blume ex DC.) Tirveng. (CT); (c) Erythrophleum succirubrum Gagnep. (ES); (d) Lannea coromandelica (Houtt.) Merr. (LC); and (e) leaves and (f) twigs of Diospyros castanea (Craib) Fletcher (DC).

Methods

The 50 % ethanol–water extracts were prepared from each plant sample. In vitro anticancer effects of six extracts on the human hepatocellular carcinoma cell line (HepG2) in terms of cytotoxicity were investigated by neutral red assay, apoptosis induction by 4′,6-diamidino-2-phenylindole (DAPI) staining, and DNA fragmentation by agarose gel electrophoresis. Normal Vero cells were tested for comparison and to determine cancer selectivity. Gas chromatography–mass spectrometry analysis was performed to identify the compounds in the extracts.

Results

The six crude extracts had different cytotoxicities and were classified into three groups based on their IC₅₀ value and selectivity index (SI). DC (twig) crude extract had both a high cytotoxicity and SI toward HepG2 cells comparable to melphalan (P = 0.023). The crude extracts of DC (leaves), LC (twig), and BA (twig) had moderate cytotoxicity and a lower SI. Although all crude plant extracts induced apoptosis in more than 50 % of the DAPI-positive apoptotic HepG2 cells, only DC (twig) and LC (twig) showed laddering in the DNA fragmentation assay. 2-Palmitoylglycerol was the major compound common to both. Pyrogallol and lupeol were the major compounds in DC (twig) crude extract. Hexadecanoic acid and octadecenoic acid were the major compounds in LC (twig) crude extract, which had high toxicity but low selectivity.

Conclusion

Ethanolic extracts from DC and LC twigs induced apoptosis in the HepG2 cell line. Pyrogallol and lupeol in DC (twig) might be responsible for the cytotoxicity toward the HepG2 cancer cells.

Apoptosis-inducing effects of jujube (Zǎo) seed extracts on human Jurkat leukemia T cells

BACKGROUND

Jujube (Zǎo) seeds exhibited anticancer effects and used in Chinese medicine for many years. This study aims to investigate the apoptosis-inducing effects of seed extracts from eight different cultivated species ('Apple', 'Bombay', 'Jumbo', 'Kaew', 'Nomsod', 'Rianthong', 'Samros', and 'Taiwan') on human Jurkat leukemia T cells.

METHODS

We evaluated the effects of seed extracts from eight jujube cultivated species on human Jurkat leukemia T cells. The crude seed extracts were prepared sequentially by using water, 95 % ethanol, dichloromethane, ethyl acetate, chloroform or hexane. The antiproliferative effects of the jujube seed extracts relative to that of melphalan were evaluated by neutral red assays. Apoptotic cell death induced by the ethanolic extracts at 1 × IC50 and 2 × IC50 concentrations was demonstrated by DAPI staining, gel electrophoresis, flow cytometry with Annexin V/propidium iodide staining, and caspase-3, -8, and -9 enzyme activities.

RESULTS

Ethanolic extracts of 'Taiwan', 'Jumbo', 'Nomsod', 'Rianthong', 'Samros', and 'Bombay', significantly inhibited the proliferation of Jurkat cells compared with untreated cells (all P < 0.001), while the extracts of 'Kaew' and 'Apple' were inactive. The six active extracts preferentially induced apoptotic cell death in a concentration-dependent manner with DNA fragmentation (2 × IC50). Increased caspase-3 activity was detected after treatment with the six extracts. The 'Taiwan', 'Nomsod', 'Jumbo', and 'Rianthong' extracts (2 × IC50) induced both the extrinsic and intrinsic apoptosis pathways by increasing caspase-8 and caspase-9 activity, respectively. Alkaloids (Dragendorff's method) and reducing sugars (Fehling's test) were mainly identified in the apoptosis-inducing extracts.

CONCLUSIONS

The tested of six active extracts ('Taiwan', 'Jumbo', 'Nomsod', 'Rianthong', 'Samros' and 'Bombay') contained alkaloids or reducing sugars, and induced caspase-dependent apoptosis in human Jurkat leukemia T cells.

Epidemiology of hepatitis C virus genotypes in northeastern Thai blood samples

BACKGROUND

Hepatitis C virus (HCV) infection is an important cause of liver cancer in Thailand. The highest prevalence of anti-HCV positive among Thai blood donors is found in the northeastern region. The present analysis of the genotype distribution among anti-HCV positive northeastern-Thai blood donors was conducted to provide a base for the epidemiological pattern of HCV infection in this region.

MATERIALS AND METHODS

A total of 112 HCV seropositive healthy blood donors were randomly selected and tested for the presence of HCV-RNA by RT-PCR. HCV-RNA positive samples were genotyped by direct sequencing at core region genomes and confirmed by phylogenetic analysis.

RESULTS

HCV viremia was found in 94.6% (106/112) of HCV seropositive blood donors. There were 3 major genotypes distributed among this population. HCV genotype 3a was the most prevalent (71.7%) followed by genotypes 1a (7.5%), 1b (7.5%), 6i (3.8%), 6f (2.8%) and 6n (1.9%).

CONCLUSIONS

HCV genotype 3a in asymptomatic infections in northeastern Thailand is significantly higher than other previous reports. Subgenotype 6 prevalence is less than in neighboring countries and distribution patterns differ. The findings are relevant as predictors for using interferon therapy in this population.

Anticancer effect of the extracts from Polyalthia evecta against human hepatoma cell line (HepG2)

OBJECTIVE

To investigate the anticancer activity of Polyalthia evecta (P. evecta) (Pierre) Finet & Gagnep against human hepatoma cell line (HepG2).

METHODS

The anticancer activity was based on (a) the cytotoxicity against human hepatoma cells (HepG2) assessed using a neutral red assay and (b) apoptosis induction determined by evaluation of nuclei morphological changes after DAPI staining. Preliminary phytochemical analysis of the crude extract was assessed by HPLC analysis.

RESULTS

The 50% ethanol-water crude leaf extract of P. evecta (EW-L) showed greater potential anticancer activity with high cytotoxicity [IC50 = (62.8 ± 7.3)µg/mL] and higher selectivity in HepG2 cells than normal Vero cells [selective index (SI) = 7.9]. The SI of EW-L was higher than the positive control, melphalan (SI = 1.6) and the apoptotic cells (46.4 ± 2.6) % induced by EW-L was higher than the melphalan (41.6 ± 2.1)% (P<0.05). The HPLC chromatogram of the EW-L revealed the presence of various kinds of polyphenolics and flavonoids in it.

CONCLUSIONS

P. evecta is a potential plant with anticancer activity. The isolation of pure compounds and determination of the bioactivity of individual compounds will be further performed.

Melatonin potentiates cisplatin-induced apoptosis and cell cycle arrest in human lung adenocarcinoma cells

OBJECTIVES

Melatonin produces anti-cancer effects via several mechanisms, including by induction of apoptosis. In this way, it has been shown to be of use, in combination with chemotherapeutic drugs, for cancer treatment. The study described here has evaluated effects of melatonin on cytotoxicity, apoptosis and cell cycle arrest induced with the chemotherapeutic agent cisplatin, in human lung adenocarcinoma cisplatin-sensitive cell line (SK-LU-1), which previously had only limit data.

MATERIALS AND METHODS

Cells of the SK-LU-1 line were treated with melatonin alone at 1-5 mM concentration or cisplatin alone 10-200 μM, for 48 h in culture. Cytotoxicity was measured by MTT reduction assay. Apoptosis induction was detected by annexin V/PI staining using flow cytometric analysis and DAPI nuclear staining. Change in mitochondrial membrane potential (ΔΨm) was quantified using DiOC6(3) reagent and activities of caspases-3/7 were also investigated. DNA fractions were measured using propidium iodide (PI) staining.

RESULTS

Melatonin or cisplatin alone had 50% (IC50 ) cytotoxicity at 5 mM or 34 μM concentrations respectively. Combination of 1 or 2 mM melatonin and cisplatin significantly augmented cytotoxicity of cisplatin by reducing its IC50 to 11 and 4 μM, respectively. Consistently, combined treatment increased population of apoptotic cells by elevating mitochondrial membrane depolarization, activating caspases-3/7 and inducing cell cycle arrest in the S phase, compared to treatment with cisplatin alone.

CONCLUSION

These data demonstrate that melatonin enhanced cisplatin-induced cytotoxicity and apoptosis in SK-LU-1 lung cancer cells. SK-LU-1 cell population growth inhibition was mediated by cell cycle arrest in the S phase. These findings suggest that melatonin has the potential to be used for NSCLC treatment in combination with a chemotherapeutic agent such as cisplatin.

Synergistic anticancer effect of the extracts from Polyalthia evecta caused apoptosis in human hepatoma (HepG2) cells

OBJECTIVE

To evaluate the anticancer activity of the extract fraction of Polyalthia evecta (P. evecta) (Pierre) Finet & Gagnep and the synergistic anticancer effect of the extracts from P. evecta by using the ATR/FT-IR spectroscopy.

METHODS

The 50% ethanol-water crude leaf extract of P. evecta (EW-L) was prepared and was further fractionated to isolate various fractions. The anticancer activity was investigated from cytotoxicity against HepG2 using a neutral red assay and apoptosis induction by evaluation of nuclei morphological changes after DAPI staining. Synergistic anticancer effects of the extracts from P. evecta were performed using the ATR/FT-IR spectroscopy.

RESULTS

The result showed that the EW-L showed higher cytotoxicity and apoptosis induction in HepG2 cells than its fractionated extracts. The hexane extract exhibited higher cytotoxicity and apoptosis induction than the water extracts, but less than the EW-L. The combined water and hexane extracts apparently increased cytotoxicity and apoptosis induction. The %apoptotic cells induced by the extract mixture were increased about 2-fold compared to the single hexane extract.

CONCLUSIONS

The polar extract fraction is necessary for the anticancer activity of the non-polar extract fraction. The ATR/FT-IR spectra illustrates the physical interaction among the constituents in the extract mixture and reveals the presence of polyphenolic constituents in the EW-L, which might play a role for the synergistic anticancer effect.

Melatonin induces apoptosis through biomolecular changes, in SK-LU-1 human lung adenocarcinoma cells

OBJECTIVES

Anti-cancer effects of melatonin (N-acetyl-5-methoxytryptamine, an indole-amine), have been widely reported, however, little has been known, regarding its mechanism(s) of action in lung cancer. Thus, we investigated its induction of apoptosis through biomolecular changes (lipid, protein and nucleic acid/DNA) in the SK-LU-1 human lung cancer cell line.

MATERIALS AND METHODS

We used Fourier transform infrared (FTIR) microspectroscopy, and conventional methods, to confirm changes in lipid (annexin V/PI staining for membrane alteration), protein (caspase-3/7 protein activity) and DNA (DAPI staining for DNA fragmentation).

RESULTS

We observed from FTIR data that melatonin increased lipid content and reduced intensity of nucleic acid/DNA, confirmed by annexin V/PI and DAPI respectively. Secondary protein structure at 1656 cm(-1) (α-helix) was reduced and peak position of β-sheet structure (1637 cm(-1) ) was shifted to lower frequency. Alteration in apoptotic proteins was demonstrated via caspase-3/7 activity induction.

CONCLUSIONS

High melatonin concentration exerted anti-cancer effects by changing biomolecular structure of lipids, nucleic acids and proteins, supporting its enhancement of apoptotic induction.

Immunomodulatory effect of melatonin in SK-LU-1 human lung adenocarcinoma cells co-cultured with peripheral blood mononuclear cells

OBJECTIVES

The anti-cancer potential of melatonin has been examined using a variety of experimental approaches. Melatonin immunomodulatory action was evaluated against the lung cancer cell line SK-LU-1, in co-culture with human peripheral blood mononuclear cells (PBMC).

MATERIALS AND METHODS

Melatonin was tested on the cell line only after 24 h incubation (direct effect), and on the co-culture system of SK-LU-1 and PBMC to investigate any indirect effect. Apoptotic induction of the cancer cells was assessed using annexin V/PI staining with flow cytometric analysis for membrane alteration. Intracellular superoxide anion (O2 (•-) ) and hydrogen peroxide (H2 O2 ) for intracellular oxidative stress and glutathione (GSH) for intracellular anti-oxidation were measured with specific fluorescence probes. DNA fractions were measured employing propidium iodide (PI) fluorescence staining.

RESULTS

High doses of melatonin were directly toxic to SK-LU-1 cells, while PBMC-mediated indirect effect occurred after moderate doses (1 μm). Under co-culture conditions, increases in apoptotic cell death, increase in oxidative stress by reduction of GSH and cell cycle arrest in G0 /G1 in SK-LU-1 cells, were observed as the immunomodulatory effect of melatonin.

CONCLUSION

Melatonin had indirect effects on lung cancer cells by enhancement of immunomodulatory effects, but further studies of mechanism(s) involved are needed.

Antioxidant, antimelanogenic, and skin-protective effect of sesamol

Sesame contains high nutritional value and important bioactive lignans which are good for health-promoting effects including sesamol. Sesamol is found in trace amounts in sesame. The biological action from the trace amounts of sesamol found might indicate its efficacy. This paper presents a systematic study of the antimelanogenic and skin-protective effects (antioxidant) of sesamol and positive compounds. The results showed that sesamol had the most scavenging 2,2-Diphenyl-1-picrylhydrazyl hydrate (DPPH·) radical with an IC50 value < 14.48 µM. The antioxidant power (Ferric reducing antioxidant power value) of sesamol at a concentration of 0.1129 µM was 189.88 ± 17.56 µM FeSO4. Sesamol inhibited lipid peroxidation with an IC50 value of 6.15 ± 0.2 µM. Moreover, sesamol possessed a whitening effect by inhibition of mushroom tyrosinase at an IC50 value of 1.6 µM and an inhibition of cellular tyrosinase with 23.55 ± 8.25% inhibition at a concentration of 217.2 µM. Sesamol exhibited high antioxidant and anti-tyrosinase activity compared to the positive control, kojic acid and β-arbutin. Sesamol from edible sesame seed could therefore have an alternative cosmeceutical purpose.

Detection of heterozygous c.1708C>T and c.1978C>G thyroid peroxidase (TPO) mutations in Iraqi patients with toxic and nontoxic goiter

Sixty-three Arabic patients (16 males and 47 females) with thyroid toxic and nontoxic goiter who attended the endocrinologist in Nuclear Medicine Hospital and Al Yarmok Nuclear Medicine Department in Baghdad, Iraq were examined for thyroid peroxidase (TPO) gene mutations. A total of ten heterozygous mutations have been identified in the human TPO gene associated with thyroid toxic and nontoxic goiter. These mutations involved transition or transversion of cysteine either by thymine or guanine at the position 1708 of the exon 10 (c.1708C>T) and the position 1978 of the exon 11 (c.1978C>G). From a total of ten detected mutations, two c.1978C>G mutations were detected in nontoxic goiter patients and eight (two c.1708C>T and six c.1978C>G mutations) were detected in toxic goiter. In conclusion, this study identified ten TPO mutations associated with toxic and nontoxic goiter that have not been yet reported in Iraq, and most of them are detected among females (90 %) and adults age between 30 and 50 years old (80 %).

Evaluation of the anticancer potential of six herbs against a hepatoma cell line

Background

Six herbs in the Plant Genetics Conservation Project that have been used as complementary medicines were chosen on the basis of their medicinal value, namely Terminalia mucronata, Diospyros winitii, Bridelia insulana, Artabotrys harmandii, Terminallia triptera, and Croton oblongifolius. This study aims to evaluate the potential anticancer activity of 50% ethanol-water extracts of these six herbs.

Methods

Fifty percent ethanol-water crude extracts of the six herbs were prepared. The cytotoxicity of the herbal extracts relative to that of melphalan was evaluated using a hepatoma cell line (HepG2), and examined by neutral red assays and apoptosis induction by gel electrophoresis and flow cytometry after 24 h.

Results

A significant difference was found between the cytotoxicity of the 50% ethanol-water crude extracts and melphalan (P = 0.000). The 50% ethanol-water crude extracts of all six herbs exhibited cytotoxicity against HepG2 cells, with IC₅₀ values ranging from 100 to 500 μg/mL. The extract of T. triptera showed the highest cytotoxicity with an IC₅₀ of 148.7 ± 12.3 μg/mL, while melphalan had an IC₅₀ of 39.79 ± 7.62 μg/mL. The 50% ethanol-water crude extracts of D. winitii and T. triptera, but not A. harmandii, produced a DNA ladder. The 50% ethanol-water crude extracts of D. winitii, T. triptera, and A. harmandii induced apoptosis detected by flow cytometry.

Conclusion

The 50% ethanol-water crude extracts of D. winitii, T. triptera, and A. harmandii showed anticancer activity in vitro.

FTIR microspectroscopy discriminates anticancer action on human leukemic cells by extracts of Pinus kesiya; Cratoxylum formosum ssp. pruniflorum and melphalan

Apoptosis is the principal molecular goal of chemotherapeutics for effective anticancer action. We studied the effect of 50% ethanolic-water extracts of Pinus kesiya, Cratoxylum formosum ssp. pruniflorum and melphalan on cytotoxicity and apoptosis induction for human leukemic U937 cells, and explored the mode of action using FTIR microspectroscopy. The number of viable U937 cells in vitro was decreased in a concentration-dependent manner by all tested compounds, although potency differed between the U937 and Vero cells. Melphalan and the extract of C. formosum exhibited relatively lower IC(50) values (15.0 ± 1.0 and 82.7 ± 3.2 μg/mL respectively) and higher selectivity (selective index>3) than the extract of P. kesiya (299.0 ± 5.2 μg/mL; selective index<3) on the U937 cells. All three compounds significantly induced apoptosis through the late stage - seen by the indicative DNA ladder - with the most effective being melphalan, then the P. kesiya and C. formosum extracts. FTIR microspectroscopy revealed that all three compounds raised the intensity of the β-pleated sheet - higher than that of the untreated U937 cells - corresponding to a shift in the α-helix band associated with an alteration in the secondary structure of the protein band, confirming induction of apoptosis via pro-apoptotic proteins. The differences in intensity of the FTIR bands associated with lipids, proteins and nucleic acids were responsible for discrimination of the anticancer mode of action of each of the three compounds. The FTIR data suggest that the two plant extracts possessed anticancer activity with a different mode of action than melphalan.

Viral hepatitis B, C infection and genotype distribution among cholangiocarcinoma patients in northeast Thailand

The prevalence of HBV and HCV infection among 295 cholangiocarcinoma (CCA) patients in northeast Thailand was analyzed. Hepatitis B surface antigen (HBsAg) was detected in 8.8% (26/295 cases) and antibodies to HCV (anti-HCV) in 2.7% (8/295 cases) of CCA cases. Screening for HBV DNA was performed in 15 of 26 HBV seropositive cases and genotypes could be determined in all 15. HBV genotypes C and B were detected in 73.3% (11/15 cases) and 26.7% (4/15 cases), respectively. HCV RNA was detected in 87.5% (7/8 cases) of anti-HCV positive cases. Specifically, 57.1% (4/7 cases) were HCV genotype 1a and 42.9% (3/7 cases) were HCV genotype 3a. The prevalence of infection and genotype distribution of both HCV and HBV among CCA in northeast Thailand is comparable to that in the general population, suggesting that HCV and HBV infections are, if at all, not serious risk factors for CCA.

Cytotoxic and apoptotic effects of six herbal plants against the human hepatocarcinoma (HepG2) cell line

Background

Six plants from Thailand were evaluated for their cytotoxicity and apoptosis induction in human hepatocarcinoma (HepG2) as compared to normal African green monkey kidney epithelial cell lines.

Methods

Ethanol-water crude extracts of the six plants were tested with neutral red assay for their cytotoxicity after 24 hours of exposure to the cells. Apoptotic induction was tested in the HepG2 cells with diamidino-2-phenylindole staining. DNA fragmentation, indicative of apoptosis, was analyzed with agarose gel electrophoresis. Alkylation, indicative of DNA damage, was also evaluated in vitro by 4-(4'-nitrobenzyl) pyridine assay.

Results

The extract of Pinus kesiya showed the highest selectivity (selectivity index = 9.6) and potent cytotoxicity in the HepG2 cell line, with an IC₅₀ value of 52.0 ± 5.8 μg/ml (mean ± standard deviation). Extract of Catimbium speciosum exerted cytotoxicity with an IC₅₀ value of 55.7 ± 8.1 μg/ml. Crude extracts from Glochidion daltonii, Cladogynos orientalis, Acorus tatarinowii and Amomum villosum exhibited cytotoxicity with IC₅₀ values ranging 100-500 μg/ml. All crude extracts showed different alkylating abilities in vitro. Extracts of P. kesiya, C. speciosum and C. orientalis caused nuclei morphological changes and DNA laddering.

Conclusion

The extracts of C. speciosum, C. orientalis and P. kesiya induced apoptosis. Among the three plants, P. kesiya possessed the most robust anticancer activity, with specific selectivity against HepG2 cells.

Abstract 2344: Soluble MICA in cervical cancer is in a deglycosylated form: Implication for soluble MICA detection

Background: Major histocompatibility complex class I chain related A (MICA/PERB11.1) molecules are expressed as transmembrane proteins. They are ligands recognized by the natural killer cell receptor group (NKG)2D, an activating receptor on NK cells, gamma delta T cells and activated CD8 T cells. Up-regulated MICA expression was reported in many tumors. Shedding of MICA from tumor cells as soluble MICA (sMICA) is a mechanism for immune evasion. MICA proteins could be presented in various sizes from 43 to 75 kDa depending on degree of glycosylation. Eight potential N-glycosylation sites in a MICA molecule were reported. This study aimed to investigate the size of sMICA in sera of cervical cancer patients and women blood donors by western blot technique.

Methods: The sMICA*009 plasmid DNA was transfected to COS7 cells for recombinant sMICA protein production in culture supernatant. The recombinant sMICA protein was harvested and validated with mouse monoclonal anti-MICA antibody (WW6B7) by indirect ELISA and immunobloting. Molecular weight of deglycosylated recombinant sMICA protein treated with N-glycosidase F enzyme and sMICA in cervical cancer and healthy sera was determined.

Results: The recombinant sMICA and serum sMICA showed 62 kDa and 45 kDa in molecular weight, respectively. The molecular weight of recombinant sMICA treated with N-glycosidase F enzyme was reduced to 45 kDa which equal to serum sMICA indicating that sMICA in sera of patients and blood donor controls was in a deglycosylated form.

Conclusion: Recombinant sMICA produced in COS7 had a molecular weight of 62 kDa. In contrast, sMICA in sera was in a deglycosylated form and had a molecular weight of 45 kDa equal to in vitro deglycosylation with N-glycosidase F enzyme of produced recombinant sMICA. The mechanism and kinetic of deglycosylation of sMICA in sera await further investigation. It would be interesting to see whether this form of sMICA would affect sMICA detection in sera.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2344.

Torquetenovirus infection among northeastern Thai blood donors

Semi-nested polymerase chain reaction technique was used to detect Torquetenovirus (TTV) DNA in 234 healthy blood donors in northeast Thailand. The incidence of TTV was 28% in 101 healthy blood donors negative for HBsAg and anti-HCV antibody, 25% in 71 HBsAg carriers and 29% among 62 with anti-HCV antibody. No association of TTV infection was found with gender, age, and HBV or HCV infection.

Anti-HIV antibody titer: an alternative supplementary test for diagnosis of HIV-1 infection

The diagnosis of HIV infection is based on screening of HIV antibodies and confirmed by a more specific supplementary test. The most common confirmation test is Western blot, which is expensive, time consuming and subject to technical skill. The present study was carried out to evaluate whether the anti-HIV-1 antibody titer is valid as a supplementary test for diagnosis of HIV-1 infection. Anti-HIV-1 antibody titers of 2,414 anti-HIV-1 positive sera determined by the particle agglutination (PA) method were analysed in comparison with the Western blot analysis. The Western blot negative result was found in 11 of 2,414 (0.46%) anti-HIV-1 positive sera, these sera also gave negative anti-HIV by ELISA. The PA titers of these sera were found in the range of 16 to 64. Seventeen samples (0.70%) with anti-HIV-1 in the titer range of 16 to 256 showed indeterminate Western blot analysis. The rest, 2,386 of these 2,414 sera (98.84%), were shown to be positive by Western blot. However, all of the 2,356 sera with antibody titers > or = 512 (97.6%) demonstrated positive Western blot results. Five cases among the 17 (29.4%) indeterminate sera were examples of early seroconversion of HIV infection, which were confirmed in follow up specimens. The results suggest that only the samples with antibody titers < 512 are required to be confirmed for HIV infection by Western blot. It is possible that early seroconversion may be inferred from anti-HIV titers. Therefore, in order to reduce time and cost, the PA anti-HIV titer can be used as an alternative supplementary test for diagnosis of HIV-1 infection in most positive screened anti-HIV samples. Western blot is needed for testing in only a few cases.

Seroepidemiology of HTLV-I infection in northeast Thailand: a four year surveillance

The human T-lymphotropic virus type I (HTLV-I) can be transmitted through blood transfusion, sexual contact, perinataly and by breast feeding. We carried out a four years seroepidemiology surveillance study of HTLV-I infection among northeast Thai population by screening for antibodies to HTLV-I (anti-HTLV-I) in 1992, 1993, 1995 and 1997. A total of 8,323 blood samples were collected from 6,228 blood donors, 832 pregnancies, 219 multitransfused patients, 53 HIV positive intravenous drug users and 1,000 northeast-Thai workers at different periods of time. The serum samples were tested for anti-HTLV-I by particle agglutination (PA) technique and confirmed by Western blot. One sample from a multitransfused patient collected in 1992 and one sample from a blood donor collected in 1995 demonstrated positive anti-HTLV-I screening by PA but negative by Western blot. This finding indicates that at present HTLV-I is not a public health problem in the northeast of Thailand but surveillance should be continually conducted.

DNA typing of the HLA-A, -B and -C genes: possible MHC class I haplotypes in the northeastern-Thais

The phenotype and gene frequencies of HLA class I were studied in the Northeastern Thai population. Blood samples were collected from 100 unrelated healthy northeastern-Thais. HLA-A, -B and -Cw alleles were determined using the polymerase chain reaction- amplification refractory mutation system (PCR-ARMS). 12 HLA-A, 20 HLA-B and 14 HLA-Cw alleles were found. Linkage disequilibrium analysis indicated the existence of 7 HLA-A-B and 19 HLA-B-Cw haplotypes. A*0207-Cw*01-B*4601 was the most common possible haplotype in this population. These results provide regional basic information for further studies in anthropology, organ transplantation and MHC disease associations in the northeastern-Thais.

Association of HCV and Treponema pallidum infection in HIV infected northeastern Thai male blood donors

The study was performed to determine the association of seroprevalence of hepatitis C virus (HCV) and Treponema pallidum (T. pallidum) infection among HIV infected first time male blood donors (HIV group) in comparison with the HIV seronegative blood donors (control group) in the Northeast of Thailand (NET). Serum samples were collected from 10,321 first blood donation voluntary male donors. All samples were screened for anti-HIV and anti-HCV by particle agglutination test, and syphilis antibody by RPR. The anti-HIV positive sera were repeated by EIA and confirmed by western blot. The reactive anti-HCV samples were confirmed by EIA whereas reactive syphilis antibody samples were confirmed by TPPA. Fisher's exact test was used for statistical analysis. The prevalence of anti-HIV in first time male donors was 0.70 per cent (72/10,321). The age of HIV group and 10,018 male control group ranged from 17-50 years old. The prevalence of HIV among 21-40 years old age group was significantly higher than the 17-20 years old (p = 0.00003). The 17-20 years old HIV group showed significantly higher sero-prevalence of TPPA (p = 0.003). The 21-30 years old HIV group gave significantly higher sero-prevalence of anti-HCV (p = 0.0008) and TPPA (p = 0.045), but the seroprevalence of anti-HCV and TPPA among the 31-50 year old group were nonsignificantly different (p > 0.05). The concurrence of anti-HCV and TPPA in HIV groups was not found. This result indicated that HIV infection among NET voluntary male blood donors was significantly associated with T. pallidum infection in young adults and the HCV infection in mature adults.

Reducing the risk of HIV transmission through blood transfusion by donor self-deferral

A cross sectional study was conducted to evaluate the validity of implementing a blood donor self-deferral form for reducing the risk of HIV transmission through blood transfusion. The self-deferral form which was given to all blood donors, included questions about HIV risk factors in the three month period prior to blood donation. Donors were asked to declare confidentially whether their blood was safe for transfusion or not. Blood was collected and examined for HIV antigen, anti-HIV antibodies, HBsAg and syphilis antibodies. All of the serological markers detected among high risk donors and general donors were compared and analysed by Yates corrected X2 test and one-tailed Fisher's exact test with a significance level of 0.05. There were 401 self-deferred high risk donors and 15,523 general donors. The HIV antigen was found as a single marker in only one male high risk individual. The prevalence of anti-HIV antibodies, HBsAg and syphilis antibodies among the general donors was 0.61%, 5.29% and 1.17%, respectively. The anti-HIV, HBsAg and syphilis antibodies in the high risk donors were 1.99%, 7.98% and 1.25%, respectively. In comparison with the general donors, the high risk donors demonstrated statistically significant higher prevalence rates of HIV antigen (p < 0.05), anti-HIV (p < 0.005) and HBsAg (p < 0.05). In conclusion, donor self-deferral is valid for reducing the risk of HIV transmission through blood transfusion and its implementation should be encouraged when recruiting blood donors.

Frequency of human platelet antigens among blood donors in northeastern Thailand

BACKGROUND

Platelet transfusions have been widely used in Thailand, but little is known about the phenotyping of human platelet antigens.

STUDY DESIGN AND METHODS

Whole blood was collected from 483 blood donors for preparation of platelets. An improved mixed passive hemagglutination assay was used for this study.

RESULTS

Frequencies demonstrated were 100 percent for HPA-1a (PlA1), 15.94 percent for HPA-2b (Siba), 60.25 percent for HPA-3a (Baka), 98.76 percent for HPA-4a (Yukb), 1.86 percent for HPA-4b (Yuka), 5.38 percent for HPA-5b (Br(a)), and 97.72 percent for Naka.

CONCLUSION

HPA-1a was found in 100 percent of Thais, which is the same frequency as in other Asian populations but somewhat different from that in whites (97.9%). Therefore, HPA-1a will not cause neonatal alloimmune thrombocytopenia or post-transfusion purpura in Thais. According to the frequencies of HPA-2b, HPA-3a, HPA-4a, HPA-4b, HPA-5b, and Naka antigens, they may induce neonatal alloimmune thrombocytopenia, posttransfusion purpura, and platelet refractoriness in Thais.

Different cell volume with high target cell population between liver disease and homozygous hemoglobin E

Blood samples with increased percentage of target cells were collected from liver disease, thalassemia, homozygous hemoglobin E (E/E), and nonidentified cases. Normal cases who had no history of liver disease and normal hemoglobin typing were also included in the study for control. Patients with liver disease had increased target cell percentage with normal MCV, whereas, the other three groups had increased target cell percentage and reduced MCV. The difference was more obvious when compared with liver disease and homozygous Hb E cases. These two groups had comparable target cell percentage (14.36 +/- 4.77 in liver disease, and 14.22 +/- 1.59 in homozygous Hb E) and comparable degree of anemia (Hb level in liver disease = 11.19 +/- 0.39, and 11.30 +/- 0.16 in homozygous Hb E) but they showed a statistical significance (p less than 0.0001) between MCV (79.66 +/- 2.18 fL in liver disease, and 60.40 +/- 0.75 fL in homozygous Hb E).