Discovery of novel halogenated 8-hydroxyquinoline-based anti-MRSA agents: In vitro and QSAR studies

Methicillin-resistant Staphylococcus aureus (MRSA) infection has been considered to be one of global health problems due to limited classes of effective antimicrobial drugs. Herein, 8-hydroxyquinoline (8HQ) and its derivatives ( 1-7 ) were investigated for their anti-MRSA and antioxidant activities. Cloxyquin ( 2 ), a halogenated 8HQ, exerted the highest antimicrobial activity (MIC₅₀ ≤ 5.57 μM) with high safety index, whereas an amino-derivative 7 showed the strongest antioxidant activity. Additionally, quantitative structure-activity relationship (QSAR) study demonstrated that mass, polarizability, topological charge, and van der Waals volume are essential properties governing the anti-MRSA activity. Taken together, cloxyquin was highlighted as a promising compound for further development as a novel anti-MRSA agent. QSAR findings would also benefit for further rational design of novel 8HQ-based compounds to combat the MRSA resistance.     

How can clinicians ensure the diagnosis of meningitic angiostrongyliasis?

Meningitic angiostrongyliasis (MA), caused by Angiostrongylus cantonensis, is often diagnosed by clinical criteria alone, because the confirmative serologic tests are not always available in the rural endemic areas. In this study, we evaluated the relationship between various clinical parameters of MA and the sero-positivity to sort out the predictive parameters to ensure the diagnosis. We enrolled consecutive adults in whom MA had been clinically diagnosed, who had serologic results for A. cantonensis, and negative serologic results for Gnathostoma spinigerum. There were 75 eligible patients; 26 (34.7%) and 49 (65.3%) patients who had negative and positive serologic tests for A. cantonensis, respectively. Baseline characteristics and laboratory results were comparable between sero-positive and -negative groups. Only the cerebrospinal fluid (CSF) eosinophil counts of 40% or higher was significantly predictive for positive serologic test with the adjusted odds ratio of 4.970 (95% confidence interval of 1.337-18.477). In diagnostic facilities in the endemic areas with the limited availability of serologic tests, clinicians can ensure the diagnosis of MA by using CSF eosinophil level.     

Forensic entomology cases in Thailand: a review of cases from 2000 to 2006

This paper presents and discusses 30 cases of cadavers that had been transferred for forensic entomology investigations to the Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, northern Thailand, from 2000 to 2006. Variable death scenes were determined, including forested area and suburban and urban outdoor and indoor environments. The fly specimens found in the corpses obtained were the most commonly of the blow fly of family Calliphoridae, and consisted of Chrysomya megacephala (F.), Chrysomya rufifacies (Macquart) Chrysomya villeneuvi Patton, Chrysomya nigripes Aubertin, Chrysomya bezziana Villeneuve, Chrysomya chani Kurahashi, Lucilia cuprina (Wiedemann), Hemipyrellia ligurriens (Wiedemann), and two unknown species. Flies of the family Muscidae [Hydrotaea spinigera Stein, Synthesiomyia nudiseta (Wulp)], Piophilidae [Piophila casei (L.)], Phoridae [Megaselia scalaris (Loew)], Sarcophagidae [Parasarcophaga ruficornis (F.) and three unknown species], and Stratiomyiidae (Sargus sp.) were also collected from these human remains. Larvae and adults of the beetle, Dermestes maculatus DeGeer (Coleoptera: Dermestidae), were also found in some cases. Chrysomya megacephala and C. rufifacies were the most common species found in the ecologically varied death scene habitats associated with both urban and forested areas, while C. nigripes was commonly discovered in forested places. S. nudiseta was collected only from corpses found in an indoor death scene.     

Fracture strength of all-ceramic lithium disilicate and porcelain-fused-to-metal bridges for molar replacement after dynamic loading

The replacement of missing posterior teeth using all-ceramic bridges remains a challenge. This study compares the fracture resistance of all-ceramic 3-unit bridges for the replacement of first molars to conventional porcelain-fused-to-metal bridges. Human premolars and molars were used to create two test groups and one control group of 16 specimens each. To simulate clinical parameters, the specimens were exposed to cyclic fatigue loading in an artificial mouth with simultaneous thermocycling. All samples were thereafter exposed to fracture strength testing. Porcelain-fused-to-metal bridges showed significantly higher fracture strengths than all-ceramic bridges. However, the fracture strength of the all-ceramic bridges was higher than peak physiological chewing forces.     

Comparison of microplate hybridization with gel electrophoresis and dot blot hybridization for the rapid detection of Mycobacterium tuberculosis PCR products

A microplate ELISA hybridization assay has been developed for the detection of the IS6110 PCR products of M. tuberculosis from sputum specimens. In this study, its efficacy was evaluated by comparison with agarose gel electrophoresis (AGE) and dot blot hybridization (DBH), with culture results as the 'gold standard'. The assay was used with 190 sputum samples: the PCR results detected by ELISA and AGE showed close agreement, with sensitivity, specificity and accuracy of 90%, 100% and 96% respectively. The same values for DBH were 92%, 98% and 96% respectively. The validities of these methods were not statistically significantly different (p>0.05). The agreement rates of PCR product detection by AGE comparing with DBH and ELISA were 0.964 and 0.964 respectively, while that of DBH and ELISA was 1.0 by Kappa analysis. The overall agreement was not statistically significantly different (p>0.05). Use of DBH or ELISA hybridization increased the sensitivity of detection by AGE 10-fold from 10 pg to 1 pg of purified DNA per reaction; ie from about 30 to about 3 organisms. The amount of PCR product detected by ELISA was only one half of that detected by the other methods; the total assay time of ELISA following the PCR was 4 hours. In conclusion, the microplate hybridization assay may replace AGE and DBH for the detection of the PCR products of M. tuberculosis because of its sensitivity, specificity and accuracy. Additional advantages of the microplate assay over AGE and DBH include rapidity, ease of use, greater safety, cost effectiveness and greater objectivity in the reading of results; the technique is suitable for use in epidemiological studies for the analysis of a large number of samples.     

The system of care for the elderly in Thailand: capitalizing from an integrated community-based health system through reform

Thailand is facing a dramatic challenge of how to ensure good health and quality of life for its rapidly increasing number of elderly citizens. The modern health services system established a century ago has a larger proportion of public providers, but only 35-40% share public spending on health. The health services administration, its infrastructure and health policies underwent a number of reforms resulting in a system that emphasizes community-based comprehensive health services with a multi-sectoral approach to health. There has been remarkable concern over the health and well-being of the elderly for the last two decades, leading to the introduction of specific policies and programs, both in health and social sectors. The health service infrastructure has better coverage compared to social services, with a varying degree of integration between the two depending partly on existing resources and management in each locality. Among many other social services, there are homes for the elderly and income support for the poor elderly. However, health services and institutions for the elderly are not being created separately, but rather by adding new services and programs to the existing comprehensive and integrated system of service delivery. The changing political and socio-economic environment provides a great opportunity to make the health and social services more responsive to the needs of the elderly, now and in the future. Decentralization and the universal health insurance policy of the new government with an emphasis on strong primary care providers will give a great push forward to the presently community-oriented nature of the extensive health service infrastructure.     

HIV/AIDS care and treatment in three provinces in northern Thailand before the national scale-up of highly-active antiretroviral therapy

In 2003, Thailand launched a program to place 50,000 persons on highly active antiretroviral therapy (HAART) by the end of 2004, following a series of efforts since the early 1990s to develop comprehensive HIV/AIDS care services. To evaluate existing services and needs in advance of the national HAART scale-up, in 2002 we surveyed 31 hospitals and 389 community health centers in three northern Thai provinces, and interviewed 1,015 HIV-infected patients attending outpatient clinics. All hospitals offered voluntary HIV counseling and testing, 84% provided primary prophylaxis for Pneumocystis carinii pneumonia, 58% for tuberculosis, 39% for cryptococcal meningitis, and 87% had some experience providing antiretroviral therapy. Community health centers provided more limited service coverage. Of patients interviewed, 63% had been diagnosed with symptomatic HIV disease, and of these, 32% reported ever receiving antiretroviral therapy; 51 % of all patients had received a CD4 T-lymphocyte count. Thailand's current national HAART scale-up is being performed in a setting of well-developed hospital-based services introduced over the course of the epidemic.     

Screening HIV-infected women for cervical cancer in Thailand: findings from a demonstration project

OBJECTIVES: Although cervical cancer is an AIDS-defining illness, few HIV-infected women are routinely screened for cervical cancer in Thailand. We screened HIV-infected women for cervical cancer as a component of HIV care and assessed high-risk human papillomavirus (HPV) and cervical cancer prevalence. METHODS: From July 2003 through February 2004, HIV-infected women attending either an infectious disease clinic or a sexually transmitted infection (STI) clinic in Bangkok were tested for high-risk HPV types by Hybrid Capture 2 and screened for cervical cancer by Pap test; those with abnormal cervical cytology were referred for diagnosis and treatment. RESULTS: Two hundred ten HIV-infected women at an infectious disease clinic (n = 150) and an STI clinic (n = 60) received cervical cancer screening. The high-risk HPV prevalence was 38.6% and the prevalence of abnormal cervical cytology was 20.4%. Abnormal cervical cytology and high-risk HPV detection were associated (P < 0.001). We received pathology reports for 23 (53.5%) of 43 women, including all those with a Pap test showing high-grade squamous intraepithelial lesions; the cervical cancer prevalence was 1.9% (4 of 210; 95% confidence interval, 0.5-4.8%). CONCLUSION: The estimated prevalence of high-risk HPV and cervical cancer among HIV-infected women in Thailand was high. This emphasizes the need to integrate cervical cancer screening into HIV care.