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1.
Dilara Islam Nattaya Ruamsap Ajchara Aksomboon Patchariya Khantapura Apichai Srijan Carl J. Mason 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2014,122(11):1102-1113
Campylobacter spp. is a leading cause of diarrheal disease among US troops deployed to Thailand for exercise. We investigated the importance of immunological analysis and immune responses against Campylobacter infection in US troops deployed to Thailand. Blood and fecal samples were collected from volunteered soldiers with diarrhea and from healthy controls. Stool culture was performed to identify the pathogens. Campylobacter‐specific antibodies, antibody secreting cells and cytokines were measured. Several bacterial protein fragments in the outer membrane extract of Campylobacter spp., were identified by an immunoblot analysis with plasma and fecal antibodies. Among all of the diarrheal cases, 35% were Campylobacter‐positive. Based on antibody titers in plasma and in fecal extract and antibody secreting cells: 6% of healthy controls, 32% of the Campylobacter culture‐negative diarrheal cases, and 85% of the Campylobacter culture‐positive diarrheal cases were positive for Campylobacter. Our results indicate that the measurement of Campylobacter‐specific antibodies in plasma and fecal extract samples is a good marker of exposure to Campylobacter, and this test may be a useful diagnostic tool for seroepidemiological studies. Elicited antibodies against several bacterial outer membrane protein fragments suggest that these protein fragments are vital in providing protective immunity against Campylobacter. 相似文献
2.
Dilara Islam Nattaya Ruamsap Patchariya Khantapura Ajchara Aksomboon Apichai Srijan Boonchai Wongstitwilairoong Ladaporn Bodhidatta Montip Gettayacamin Malabi M Venkatesan Carl J. Mason 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2014,122(6):463-475
Shigellosis is a worldwide disease, characterized by abdominal pain, fever, vomiting, and the passage of blood‐ and mucus‐streaked stools. Rhesus monkeys and other primates are the only animals that are naturally susceptible to shigellosis. A suitable animal model is required for the pre‐clinical evaluation of vaccines candidates. In this study, the minimal dose of Shigella dysenteriae1 1617 strain required to produce dysentery in four of five (80% attack rate) monkeys using an escalating dose range for three groups [2 × 108, 2 × 109 and 2 × 1010 colony forming unit (CFU)] was determined. In addition, the monkeys were re‐infected. The identified optimal challenge dose was 2 × 109 CFU; this dose elicited 60% protection in monkeys when they were re‐challenged with a one log higher dose (2 × 1010 CFU). The challenge dose, 2 × 1010 CFU, produced severe dysentery in all monkeys, with one monkey dying within 24 h, elicited 100% protection when re‐challenged with the same dose. All monkeys exhibited immune responses. This study concludes that the rhesus monkey model closely mimics the disease and immune response seen in humans and is a suitable animal model for the pre‐clinical evaluation of Shigella vaccine candidates. Prior infection with the 1617 strain can protect monkeys against subsequent re‐challenges with homologous strains. 相似文献
3.
Fucharoen G Sanchaisuriya K Sae-ung N Dangwibul S Fucharoen S 《Bulletin of the World Health Organization》2004,82(5):364-372
OBJECTIVE: To evaluate a simple screening strategy for thalassaemia and haemoglobin (Hb) E in a prevention and control programme for thalassaemia in rural communities with limited resources. METHODS: Blood samples from 301 Thai-Khmer participants were screened for thalassaemia and Hb E using a combined modified one-tube osmotic fragility (OF) test and a modified dichlorophenolindophenol (DCIP) precipitation test. Results were evaluated with standard haematological analyses including erythrocyte indices, Hb typing and quantification and polymerase chain reaction (PCR) analysis of alpha-globin and beta-globin genes. FINDINGS: Participants were divided into four groups according to the results of the combined tests. Altogether, 104 of 301 participants (34.6%) had negative results on both tests; 48 (15.9%) were positive on the OF test but not the DCIP test; 40 (13.3%) were negative on the OF test but positive on DCIP test; and 109 (36.2%) were positive on both tests. No carrier of clinically significant forms of thalassaemia (alpha(o)-thalassaemia, beta-thalassaemia) or Hb E was found among the group that had negative results for both tests. All participants with Hb E had positive DCIP tests. Carriers of alpha+-thalassaemia or Hb Constant Spring could generate either positive or negative OF test results but they all had negative DCIP tests. Using both tests as a preliminary screening for the three important groups of carriers gave a sensitivity of 100% and a specificity of 69.8%. The positive predictive value of the combined test was 77.2%. The negative predictive value was 100%. Further evaluation of the screening system by local staff at three community hospitals found a sensitivity of 98.1-100% and a specificity of 65.4-88.4% with positive predictive values of 75.0-86.9% and negative predictive values of 98.1-100%. CONCLUSION: A combined test using OF and DCIP could be used as an effective preliminary screening alternative to an electronic blood cell count for identifying carriers with alpha(o)-thalassaemia, beta-thalassaemia and Hb E. The strategy should prove useful for population screening in prevention and control programmes in rural communities in south-east Asia where laboratory facilities and economic resources are limited. 相似文献
4.
Attawut Chaibunruang Hataichanok Srivorakun Supan Fucharoen Goonnapa Fucharoen Nattaya Sae-ung Kanokwan Sanchaisuriya 《Blood cells, molecules & diseases》2010,44(3):140-145
Hemoglobin (Hb) Lepore is a variant consisting of two α-globin and two δβ-globin chains. In heterozygote, it is associated with clinical findings of thalassemia minor but interactions with other hemoglobinopathies can lead to various clinical phenotypes. Using a combination of Hb-HPLC, Hb-capillary electrophoresis and DNA analyses, we have identified 14 patients with Hb Lepore–Hollandia including eight heterozygotes, two double heterozygotes with α+-thalassemia, two compound heterozygotes with Hb E (initially diagnosed as Hb E-β-thalassemia) and two previously undescribed conditions of double heterozygote for Hb Lepore/Hb Constant Spring and Hb Lepore/α0-thalassemia, both associated with higher levels of Hb F and lower levels of Hb Lepore. Hematological and molecular features of these patients are presented along with those observed in four other Thai individuals encountered with heterozygous Hb Lepore–Washington–Boston. Haplotype analysis of the β-globin gene cluster showed that all Hb Lepore–Hollandia genes were associated with a single haplotype not described previously in other populations, (? + ? + + ? +) whereas the four Hb Lepore–Washington–Boston genes were associated with haplotypes (+ ? ? ? ? + ?/+) (N = 1) and (+ ? ? ? ? ? +) (N = 3), data indicating multiple origins of these two variants. Hb Lepore may not be uncommon in the Thai and other Asian populations and both hematological and molecular studies are required for accurate diagnosis. To facilitate rapid epidemiological, diagnostic screening and differentiation of the two Hb Lepore defects, a simple assay based on multiplex PCR has been developed. 相似文献
5.
Alpha(0)-thalassemia is the most severe form of alpha-thalassemia commonly encountered in Asians. To provide relevant information for effective prevention and control of this disorder, we have examined the molecular basis and hematological features of alpha(0)-thalassemia-related disorders in northeast Thailand. A multiplex polymerase chain reaction for simultaneous detection of the southeast Asian (SEA) and the THAI alpha(0)-thalassemia determinants was developed and used for screening of 1,541 Thai individuals who were positive at the preliminary screening in an ongoing thalassemia control program. Alpha(0)-thalassemia deletions were detected in 397 (25.8%) cases, 396 with the SEA deletion and 1 with the THAI deletion. While the latter was found in association with the Hb Constant Spring in a patient with severe Hb H disease, the former was encountered in as many as 12 thalassemia genotypes whose hematological features were comparatively presented. The results obtained should prove useful in carrier screening and prenatal diagnosis programs of this common genetic disorder in the region. 相似文献
6.
Prachya S Wiyakrutta S Sriubolmas N Ngamrojanavanich N Mahidol C Ruchirawat S Kittakoop P 《Planta medica》2007,73(13):1418-1420
Mycoepoxydiene ( 1) and derivatives, deacetylmycoepoxydiene ( 2) and 2,3-dihydromycoepoxydiene ( 3), were isolated from a broth extract of the endophytic fungus, phomopsis sp., which was isolated from a Thai medicinal plant, Hydnocarpus anthelminthicus. Compounds 1 and 2 exhibited potent cytotoxic activity, while a dihydro derivative 3 was inactive. The present work suggests that the alpha,beta-unsaturated lactone moiety in mycoepoxydienes might be responsible for the cytotoxicity. 相似文献
7.
Avirutnan P Punyadee N Noisakran S Komoltri C Thiemmeca S Auethavornanan K Jairungsri A Kanlaya R Tangthawornchaikul N Puttikhunt C Pattanakitsakul SN Yenchitsomanus PT Mongkolsapaya J Kasinrerk W Sittisombut N Husmann M Blettner M Vasanawathana S Bhakdi S Malasit P 《The Journal of infectious diseases》2006,193(8):1078-1088
BACKGROUND: Vascular leakage and shock are the major causes of death in patients with dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Thirty years ago, complement activation was proposed to be a key underlying event, but the cause of complement activation has remained unknown. METHODS: The major nonstructural dengue virus (DV) protein NS1 was tested for its capacity to activate human complement in its membrane-associated and soluble forms. Plasma samples from 163 patients with DV infection and from 19 patients with other febrile illnesses were prospectively analyzed for viral load and for levels of NS1 and complement-activation products. Blood and pleural fluids from 9 patients with DSS were also analyzed. RESULTS: Soluble NS1 activated complement to completion, and activation was enhanced by polyclonal and monoclonal antibodies against NS1. Complement was also activated by cell-associated NS1 in the presence of specific antibodies. Plasma levels of NS1 and terminal SC5b-9 complexes correlated with disease severity. Large amounts of NS1, complement anaphylatoxin C5a, and the terminal complement complex SC5b-9 were present in pleural fluids from patients with DSS. CONCLUSIONS: Complement activation mediated by NS1 leads to local and systemic generation of anaphylatoxins and SC5b-9, which may contribute to the pathogenesis of the vascular leakage that occurs in patients with DHF/DSS. 相似文献
8.
Phenethyl isothiocyanate is a chemopreventive phytochemical present in cruciferous vegetables where it exists as the glucosinolate
gluconasturtiin. It is a mechanism-based inhibitor of both rat and human cytochrome P450 enzymes. The principal objective
of the present study was to ascertain whether phenethyl isocyanate, formed by the cytochrome P450-mediated oxidative desulphuration
of phenethyl isothiocyanate, is the metabolite responsible for the mechanism-based inhibition. Phenethyl isothiocyanate, following
incubation with Aroclor 1254-induced rat liver microsomes in the presence of NADPH, markedly suppressed the CYP1A-mediated
O-deethylation of ethoxyresorufin; extent of inhibition was directly related to the pre-incubation time and was antagonised
by reduced glutathione. When human liver microsomes were used, the inhibitory effect of phenethyl isothiocyanate, which was
once again related to the pre-incubation time, was even more pronounced. When the ability of phenethyl isothiocyanate and
phenethyl isocyanate to directly inhibit the O-deethylation of ethoxyresorufin in rat microsomes was compared, the latter compound was only moderately more effective. In
human microsomes, both compounds were equipotent. In phenobarbital-induced lung microsomes, phenethyl isothiocyanate was a
direct and potent inhibitor of the O-depentylation of pentoxyresorufin; pre-incubation of the isothiocyanate had no impact. Human precision-cut liver slices were
more effective than rat slices in metabolising phenethyl isothiocyanate. Pre-treatment of rats, however, with phenobarbitone
significantly enhanced the metabolism of isothiocyanate. It may be inferred from the present studies that: (a) phenethyl isocyanate
is not the metabolite of phenethyl isothiocyanate responsible for its mechanism-based inhibition, and (b) CYP2B is an important
catalyst of the metabolism of phenethyl isothiocyanate. 相似文献
9.
Isothiocyanates are small molecules characterized by high chemical reactivity that allows them to interact readily with cellular constituents eliciting a plethora of biological activities. They are present exclusively in cruciferous vegetables, as glucosinolates, the intake of which has been associated with cancer chemoprevention. When the physical structure of these vegetables is disturbed, e.g. during mastication, the enzyme myrosinase is released and converts the glucosinolates to isothiocyanates (R–N=C=S), where R can be aliphatic or aromatic. Although sulforaphane, an aliphatic isothiocyanate, has received most attention worldwide, the most extensively studied aromatic isothiocyanate is phenethyl isothiocyanate (PEITC), and there are substantial differences in biological activity between the two sub-classes. In animal cancer models, PEITC effectively antagonized the carcinogenicity of chemicals, especially nitrosocompounds. A principal mechanism of their action is to protect the integrity of DNA by decreasing the levels of the genotoxic metabolites of chemical carcinogens. Extensive studies established that PEITC modulates the metabolism of the tobacco-specific carcinogenic nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) by inhibiting its cytochrome P450-mediated bioactivation. Moreover, PEITC is a potent inducer of detoxification enzymes such as quinone reductase, glutathione S-transferase and glucuronosyl transferase. PEITC is rapidly absorbed and is characterized by a large bioavailability; Cmax concentrations achieved in plasma after dietary intake are sufficient to modulate carcinogen metabolism. PEITC is primarily metabolized by glutathione conjugation and is excreted in the urine and bile as the mercapturate. The ability of PEITC to perturb carcinogen metabolism through modulation of cytochrome P450 and phase II detoxification enzymes is comprehensively and critically reviewed. 相似文献
10.