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.     

Genetic structure of Aedes aegypti populations in Chiang Mai (Thailand) and relation with dengue transmission

We analysed the population genetic structure and differentiation regarding vector competence for a dengue virus of 15 Aedes aegypti samples collected from Chiang Mai in northern Thailand. Based on polymorphism of 10 isoenzyme loci, genetic differentiation was confirmed among samples collected in different subdistricts (high FST values and P < 0.05). Based on infection rate for a dengue 2 virus, susceptibilities were similar in mosquitoes collected in San Nuea subdistrict and in Choeng Doi subdistrict, and were heterogeneous in populations sampled in other subdistricts. These findings are discussed and related to insecticide treatments.     

A dosimetric comparison of two-phase adaptive intensity-modulated radiotherapy for locally advanced nasopharyngeal cancer

The purpose of this investigation was to evaluate the potential dosimetric benefits of a two-phase adaptive intensity-modulated radiotherapy (IMRT) protocol for patients with locally advanced nasopharyngeal cancer (NPC). A total of 17 patients with locally advanced NPC treated with IMRT had a second computed tomography (CT) scan after 17 fractions in order to apply and continue the treatment with an adapted plan after 20 fractions. To simulate the situation without adaptation, a hybrid plan was generated by applying the optimization parameters of the original treatment plan to the anatomy of the second CT scan. The dose–volume histograms (DVHs) and dose statistics of the hybrid plan and the adapted plan were compared. The mean volume of the ipsilateral and contralateral parotid gland decreased by 6.1 cm³ (30.5%) and 5.4 cm³ (24.3%), respectively. Compared with the hybrid plan, the adapted plan provided a higher dose to the target volumes with better homogeneity, and a lower dose to the organs at risk (OARs). The Dmin of all planning target volumes (PTVs) increased. The Dmax of the spinal cord and brainstem were lower in 94% of the patients (1.6–5.9 Gy, P < 0.001 and 2.1–9.9 Gy, P < 0.001, respectively). The D_mean of the contralateral parotid decreased in 70% of the patients (range, 0.2–4.4 Gy). We could not find a relationship between dose variability and weight loss. Our two-phase adaptive IMRT protocol improves dosimetric results in terms of target volumes and OARs in patients with locally advanced NPC.     

Additional Drug Resistance of Multidrug-Resistant Tuberculosis in Patients in 9 Countries

Data from a large multicenter observational study of patients with multidrug-resistant tuberculosis (MDR TB) were analyzed to simulate the possible use of 2 new approaches to treatment of MDR TB: a short (9-month) regimen and a bedaquiline-containing regimen. Of 1,254 patients, 952 (75.9%) had no resistance to fluoroquinolones and second-line injectable drugs and thus would qualify as candidates for the 9-month regimen; 302 (24.1%) patients with resistance to a fluoroquinolone or second-line injectable drug would qualify as candidates for a bedaquiline-containing regimen in accordance with published guidelines. Among candidates for the 9-month regimen, standardized drug-susceptibility tests demonstrated susceptibility to a median of 5 (interquartile range 5–6) drugs. Among candidates for bedaquiline, drug-susceptibility tests demonstrated susceptibility to a median of 3 (interquartile range 2–4) drugs; 26% retained susceptibility to <2 drugs. These data may assist national TB programs in planning to implement new drugs and drug regimens.     

Cardiovascular effects of 14-deoxy-11,12-didehydroandrographolide and Andrographis paniculata extracts

Andrographis paniculata has been widely used as a traditional medicine for the treatment of common cold, diarrhea and hypertension. The three major active diterpenoids are andrographolide (AP1), 14-deoxy-11,12-didehydroandrographolide (AP3) and neoandrographolide (AP4). It has been reported that AP3 has hypotensive and vasorelaxation effects. However, there is only limited information on the cardiovascular effects of the other diterpenoids and crude extracts containing different levels of AP3. Therefore, the present study investigated the effects of these diterpenoids, AP1, AP3, and AP4, isolated from A. paniculata, and different aqueous plant extracts on blood pressure, vascular and chronotropic responses by using conscious rats and their isolated aortas and right atria as the test models. Among the three major diterpenoids, AP3 was the most potent compound for inducing vasorelaxation and decreasing heart rate. In addition, Extract B (high level of AP3) had greater hypotensive effect in conscious rats than Extract A (low level of AP3). Verapamil, a Ca2+ channel blocker, also had a hypotensive effect less than that of Extract C containing a high level of AP3. At the doses and durations of Extract A and B which produced hypotension, the responses of the Extract A-treated aorta to norepinephrine, and the vascular muscarinic responses to acetylcholine of both extracts were decreased. However, repeated doses of both extracts did not alter cardiac beta-adrenoceptor and muscarinic responses of extract-treated rats to NE and ACh, respectively. The results of this study suggest that vascular smooth muscle is the major site of these hypotensive effects of both AP3 and A. paniculata extracts. Furthermore, the consumption of A. paniculata products containing high levels of AP3 may be responsible for causing hypotension in some patients taking this herbal drug.     

Ultrastructure of spiracles of <Emphasis Type="BoldItalic">Musca domestica</Emphasis> and <Emphasis Type="BoldItalic">Hydrotaea chalcogaster</Emphasis> (Diptera: Muscidae)

Spiracles are major respiratory openings in the exoskeleton of insects. Oxygen, a necessary gas for cell activity, must pass through the spiracle to enter the respiratory system. In this study, we investigated the fine structure of spiracles of adult females of Musca domestica L. and Hydrotaea chalcogaster (Wiedemann), both medically important fly species in many parts of the world, by utilizing scanning electron microscopy. The mesothoracic spiracle of M. domestica is large and elongate-oval in shape, with its anterior end being gradually tapered. The outer surface is densely covered with slender setae of variable distribution and orientation. The metathoracic spiracle is semicircular or D-shaped, with its rim possessing long, fine, inwardly curved setae. A net-like valve or sieve plate, which has a smooth rim with swollen surface, is located within the atrium of this species. The abdominal spiracles are circular with a symmetrically swollen peritreme surrounding the opening. The inner filtering apparatus is composed of many spiral tubes, each possessing many small spines. As for H. chalcogaster, the tapering mesothoracic spiracle is covered with long setae arranged consistently inward from the peritreme, giving it a “combed” appearance. The metathoracic spiracle is similarly arranged but triangularly rounded in shape, with the anterior and posterior rims possessing long fine setae. The net-like valve within the atrium has a smooth, swollen rim, whereas the inner edge of the atrium bears short, slender setae where it meets with the peritreme of the spiracle. The abdominal spiracles of this species look similar to that of M. domestica, with the exception of the filtering apparatus that bears only a few small spines. The function of these spiracles is discussed.     

Morphology of puparia of Megaselia scalaris (Diptera: Phoridae), a fly species of medical and forensic importance

Megaselia scalaris (Loew), a scuttle fly, is a fly species of medical and forensic importance. For use in forensic investigation, fly specimens found to associate with human corpses have to be identified at species level. Herein, we present the morphology of the puparia of the above fly species using scanning electron microscopy. The characteristic of the intersegmental spines along the dorsal and lateral segments and sculpture of the pupal respiratory horn of this puparia may be useful in future studies, to distinguish it from other closely related species.     

Gemcitabine plus cisplatin (GC): a salvage regimen for advanced breast cancer patients who have failed anthracycline and/or taxane therapy

BACKGROUND: In clinical studies of both heavily and minimally pretreated patients with advanced breast cancer, the combination of Gemcitabine plus cisplatin (GC), given in a variety of schedules and doses, has demonstrated moderate safety and efficacy in both heavily and minimally pretreated advanced breast cancer with response rate from 29-63% (median 46%). METHODS: We evaluated the activity and toxicity of another GC regimen (gemcitabine 1,000 mg/m(2) days 1, 8 plus cisplatin 75 mg/m(2) day 1 every 3 weeks) in 30 breast cancer patients who failed chemotherapy with anthracycline and/or taxanes as adjuvant or neoadjuvant, or primary therapy. RESULTS: We obtained overall response in 15 of 29 evaluable patients (52%), with responses occurring in all subgroups of disease (unresectable locally advanced, locoregional recurrence, and distant metastasis). Toxicity was primarily hematologic, with grade 3/4 neutropenia and thrombocytopenia in 37% and 17% of patients, respectively. The only grade 3/4 non-hematologic toxicity was grade 3 nausea/vomiting in 12% of patients. CONCLUSION: Our data suggest that gemcitabine plus cisplatin appears to be effective and has an acceptable toxicity profile in anthracycline and/or taxane pretreated patients with advanced breast cancer.     

Calcification of intraocular hydrogel lens: evidence of dystrophic calcification

PURPOSE: To report and describe the surface calcification of three cases of implanted intraocular hydrogel lens. Methods: Three surgically extracted hydrogel intraocular lenses were studied by light and transmission electron microscopy as well as by energy dispersion X-ray microanalysis. RESULTS: The lens surfaces were covered by granular deposits of calcium phosphate, clearly delineated by von Kossa and alizarin stains for calcium. Transmission electron microscopy showed the deposits to be located within the superficial lens material to a depth of 7 microm and to be associated with what appear to be traces of cellular material including basement membrane and plasmalemma. To the authors' knowledge there has been only one other transmission electron microscopic study. Energy dispersion X-ray microanalysis showed the deposits to contain calcium and phosphorous in all cases. CONCLUSIONS: This study confirms and extends the previous reports of five cases of calcification of hydrogel intraocular lenses. The exact mechanism of calcification remains obscure but evidence suggesting cell-mediated dystrophic calcification of the lens surface is presented. Further study is required to monitor the incidence and development of this phenomenon.     

泰国高中生对青少年怀孕、人工流产及医疗服务设施态度的调查

目的:了解高中生对青少年怀孕、人工流产及医疗服务设施的态度,分析个人因素、家庭因素及环境因素对他们所持态度的影响。方法:采用自行设计量表,于2003年初在泰国某中学对270名高中生进行抽样调查。结果:大多数被调查者对青少年怀孕持消极态度(52.6%),对青少年人工流产和医疗服务设施持积极态度(56.7%和56.3%)。每月所得花费、亲戚给予相关教育及同伴给予安全性行为信息影响他们对青少年怀孕的态度;年龄、年级高低、父母职业、父母亲戚或卫生人员给予相关教育、同伴给予安全性行为信息影响他们对青少年人工流产的态度;年级高低、每月所得花费、父母教育程度、父母亲戚或卫生人员给予相关教育影响他们对医疗服务设施的态度。结论:个人家庭以及环境因素均可影响泰国高中生对青少年怀孕、人工流产及医疗服务设施态度。