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Lung cancer is the most common cancer and the leading cause of cancer-related death worldwide. However, mechanisms of its progression remained unclear and new treatments against this disease are rapidly emerging. As a novel preclinical model, patient-derived organoid (PDO) can also be established from the patient's tumor tissue and cultured in the laboratory, which preserves the key biological characteristics of the original tumor. Compared to the patient-derived xenograft (PDX) model of lung cancer, the culture success rate is improved, and the time and cost of model establishment are largely reduced. PDO is also expected to provide a more individual model to predict the efficacy of anti-cancer treatment in vitro. This paper summarizes the current application of PDO in the translational research of lung cancer. [ABSTRACT FROM AUTHOR]

Intradural extramedullary (IDEM) ependymomas are very rare, and IDEM ependymomas with craniospinal disseminated metastasis are exceptionally rare; only 2 preoperative cases have been confirmed, and postoperative cases have not been reported. We present a case of a 21-year-old female with an IDEM ependymoma of the craniocervical junction who experienced head and neck pain for more than 1 month. Magnetic resonance imaging (MRI) of the cervical spine revealed a large IDEM cystic lesion located in the medulla oblongata and the upper cervical spinal cord. The patient underwent surgery without complications, and the tumor was completely removed. Histopathological examination revealed a diagnosis of aplastic ependymoma, World Health Organization (WHO) grade III. The patient failed to follow-up with radiotherapy for one month after discharge. Nearly three months after surgery, craniospinal disseminated metastasis was found in the patient; subsequently, chemoradiotherapy was administered to prolong the survival time of the patient. Unfortunately, the patient underwent radiotherapy and chemotherapy for only 7 days; then, the patient gave up treatment and died 5 months later. To the best of our knowledge, no other cases of craniocervical junction anaplastic ependymomas with craniospinal disseminated metastasis have been reported in the literature. Total resection does not completely prevent recurrence and metastasis, and MRI of the entire neuraxis and timely postoperative craniospinal radiotherapy are necessary for the treatment of this disease. [ABSTRACT FROM AUTHOR]

Objective. To compare the current treatment approach in elderly patients with poor-grade aneurysmal subarachnoid hemorrhage (SAH) and identify the independent predictors of the outcome after aggressive surgical treatment. Method. This prospective, multicenter cohort study included 104 poor-grade aneurysmal SAH elderly patients, 60 years or older, treated in our institution from October 2010 to March 2013. Patients were grouped according to three treatment arms. Neurological outcome was assessed using the Glasgow Outcome Scale (GOS) at baseline and at a 12-month follow-up. Univariate and multivariate analysis were performed using the following factors: sex, age, smoking history, breathing ability, alcohol consumption, cerebral hernia, aneurysm location, aneurysm diameter, WFNS grade, CT Fisher grade, treatment approach, and the timing of the aneurysm surgery. Results. At the 12-month follow-up, patients in the coiling group and clipping group had better prognosis than patients in the palliative treatment group. Univariate analysis confirmed that the treatment approach, WFNS grade, CT Fisher grade, and age are critical factors for neurological outcomes in poor-grade SAH. Multivariate analysis indicated that WFNS grade V, CT Fisher grades 3–5, and palliative treatment were independent predictors of poor prognoses. Conclusion. Aggressive surgical treatment improves the prognoses in poor-grade aneurysm elderly patients with SAH. Elderly Patients of WFNS grade IV and CT Fisher grades 1-2 are more likely to have a better outcome. [ABSTRACT FROM AUTHOR]

Ischemic stroke is a highly complex pathological process that is divided into acute, subacute and chronic phases. Paeonol is a biologically active natural product with a variety of pharmacological effects, including those on neuronal activity. However, the effects of paeonol on subacute/chronic ischemic stroke have remained to be elucidated. The present study was designed to investigate the effects of paeonol against subacute and chronic cerebral ischemic injury and to explore the possible underlying mechanisms. Male adult Sprague Dawley rats were randomly divided into a sham group (treated with saline), a model group [subjected to middle cerebral artery occlusion (MCAO) and treated with saline] and a paeonol‑treated group (MCAO + paeonol at 25 mg/kg). Behavioral impairment, infarct volume and ischemic/contralateral hemispheric ratios were assessed at 72 h and at 28 days after MCAO, respectively. Immunofluorescence was employed to determine the neuronal damage and glial responses after MCAO. Compared with the model group, paeonol treatment significantly attenuated behavioral impairment, ischemic infarct volume and moderate cerebral edema in the ischemic brain at 72 h, as well as brain atrophy at 28 days after reperfusion. Furthermore, paeonol treatment ameliorated neuronal damage in the ischemic core and boundary zone regions at 72 h after reperfusion and in the boundary zone at 28 days after reperfusion. In addition, paeonol treatment reduced the proliferation of astrocytes in the boundary zone, and inhibited microglial activation in the ischemic core and boundary zone regions at 72 h and 28 days after reperfusion. These results demonstrated the protective effects of paeonol against subacute/chronic cerebral ischemia, and the mechanism of action may include subacute/chronic microglial activation and astrocyte proliferation. [ABSTRACT FROM AUTHOR]

Macamides are bioactive and marker compounds of maca (Lepidium meyenii). Thirty-five commercial maca products were surveyed for macamide composition and content by HPLC-UV/MS. Significant variations of macamide content were found in these products (69-2738 μg/g). Analysis of the macamide biosynthetic pathway suggests that: (a) glucosinolate catabolism, (b) lipid hydrolysis, and (c) amide formation are key steps controlling macamide accumulation in the tissues during the postharvest drying process. Therefore, we further investigated the effects of sample forms, drying temperatures, and storage times on macamide accumulation. Our results show that (1) powdered maca provided the largest macamide accumulation followed by sliced hypocotyls, while whole roots displayed a significantly reduced amide-generating potential; (2) the ideal temperature for macamide formation is about 30°C; (3) macamide content increases continuously along with storage time; (4) exposure to air results in the percentage of unsaturated macamides decreasing. These findings provide useful insights which can be applied in the industrial manufacture of maca products with higher content of bioactive amides. [ABSTRACT FROM AUTHOR]

Background Poor-grade aneurysmal subarachnoid hemorrhage (aSAH) is associated with increased intracranial pressure, and these patients are unstable with a high risk of rebleeding. Computed tomography angiography (CTA) has been proposed as an examination tool for the rapid detection of ruptured aneurysms. We aimed to determine the safety and efficacy of CTA alone for surgical treatment of poor-grade aSAH compared with digital subtraction angiography (DSA). Methods We conducted a multicenter retrospective analysis of 144 patients with poor-grade aSAH who underwent surgical treatment for 2 different cohorts. Patients were grouped into CTA alone and DSA groups. Baseline characteristics, postoperative complications, and clinical outcomes at discharge and at last follow-up were compared between the 2 groups. Multivariate logistic regression models were used to assess the association between CTA alone and clinical outcomes after we adjusted for potential confounders. Results Of the 116 patients included, 42 (36.2%) patents received CTA alone and 74 patients (63.7%), including 12 patients with CTA and DSA and 62 patients with DSA alone, received DSA before surgical treatment. Patients with larger ruptured aneurysms ( P = 0.006), aneurysm sizes of larger than 5 mm ( P = 0.025), presence of single aneurysms ( P = 0.018), and presence of intraventricular hemorrhage ( P = 0.019) more often received CTA alone. All ruptured aneurysms were clipped successfully during surgery. There were no statistically significant differences in postoperative complications and clinical outcomes between the 2 groups. Conclusions Although CTA alone can be safely and effectively used in most patients requiring surgical treatment, additional DSA may be considered in patients with smaller ruptured aneurysms or in those with multiple aneurysms. [ABSTRACT FROM AUTHOR]

Two new flavonoids, bismilachinone ( 11 ) and smilachinin ( 14 ), were isolated from the leaves of Smilax china L. together with 14 known compounds. Their structures were elucidated using spectroscopic methods. The PTP1B, α-glucosidase, and DPP-IV inhibitory activities of compounds 1 – 16 were evaluated at the molecular level. Among them, compounds 4 , 7 , and 10 showed moderate DPP-IV inhibitory activities with IC 50 values of 20.81, 33.12, and 32.93 μM, respectively. Compounds 3 , 4 , 6 , 11 , 12 , and 16 showed strong PTP1B inhibitory activities, with respective IC 50 values of 7.62, 10.80, 0.92, 2.68, 9.77, and 24.17 μM compared with the IC 50 value for the positive control (ursolic acid: IC 50 = 1.21 μM). Compounds 2 – 7 , 11 , 12 , 15 , and 16 showed potent α -glucosidase inhibitory activities, with respective IC 50 values of 8.70, 81.66, 35.11, 35.92, 7.99, 26.28, 11.28, 62.68, 44.32, and 70.12 μM. The positive control, acarbose, displayed an IC 50 value of 175.84 μM. In the kinetic study for the PTP1B enzyme, compounds 6 , 11 , and 12 displayed competitive inhibition with K i values of 3.20, 8.56, and 5.86 μM, respectively. Compounds 3 , 4 , and 16 showed noncompetitive inhibition with K i values of 18.75, 5.95, and 22.86 μM, respectively. Molecular docking study for the competitive inhibitors ( 6 , 11 , and 12 ) radically corroborates the binding affinities and inhibition of PTP1B enzymes. These results indicated that the leaves of Smilax china L. may contain compounds with anti-diabetic activity. [ABSTRACT FROM AUTHOR]

Background: Solitary cysticercus granuloma (SCG) is the commonest form of neurocysticercosis in the Indian subcontinent and in travelers. Several different treatment options exist for SCG. We conducted a Bayesian network meta-analysis of randomized clinical trials (RCTs) to identify the best treatment option to prevent seizure recurrence and promote lesion resolution for patients with SCG. Methods and Principal Findings: PubMed, EMBASE and the Cochrane Library databases (up to June 1, 2015) were searched for RCTs that compared any anthelmintics or corticosteroids, alone or in combination, with placebo or head to head and reported on seizure recurrence and lesion resolution in patients with SCG. A total of 14 RCTs (1277 patients) were included in the quantitative analysis focusing on four different treatment options. A Bayesian network model computing odds ratios (OR) with 95% credible intervals (CrI) and probability of being best (Pbest) was used to compare all interventions simultaneously. Albendazole and corticosteroids combination therapy was the only regimen that significantly decreased the risk of seizure recurrence compared with conservative treatment (OR 0.32, 95% CrI 0.10–0.93, Pbest 73.3%). Albendazole and corticosteroids alone or in combination were all efficacious in hastening granuloma resolution, but the combined therapy remained the best option based on probability analysis (OR 3.05, 95% CrI 1.24–7.95, Pbest 53.9%). The superiority of the combination therapy changed little in RCTs with different follow-up durations and in sensitivity analyses. The limitations of this study include high risk of bias and short follow-up duration in most studies. Conclusions: Dual therapy of albendazole and corticosteroids was the most efficacious regimen that could prevent seizure recurrence and promote lesion resolution in a follow-up period of around one year. It should be recommended for the management of SCG until more high-quality evidence is available. [ABSTRACT FROM AUTHOR]

A novel sesquiterpene-based Psidium meroterpenoid, possessing an unusual coupling pattern, and two new monoterpene-based meroterpenoids with unprecedented skeletons were isolated from the leaves of Psidium guajava. Their structures and absolute configurations were elucidated by spectroscopic, X-ray diffraction, and computational methods. The plausible biosynthetic pathway of these meroterpenoids as well as their cytotoxicities toward HepG2 and HepG2/ADM cells were also discussed. [ABSTRACT FROM AUTHOR]

Nitrooleic acid (OA-NO2) is an endogenous lipid product which has novel signaling properties, particularly the activation of peroxisome proliferator-activated receptors. The current study aimed to evaluate the protective effects of OA-NO2 against cisplatin-induced kidney injury in mice. Mice were pretreated with OA-NO2 for 48 h before cisplatin administration, and the cisplatin-caused nephrotoxicity was evaluated. After the cisplatin treatment (72 h), the vehicle-treated mice displayed renal dysfunction, as evidenced by the elevated plasma urea and creatinine, which was consistent with the histological damage, such as tubular necrosis, dilation, protein cast, and desquamation of epithelial cells. In contrast, the severity of the renal dysfunction and histological change were reduced in the OA-NO2 pretreated mice. The renal COX-2 and mPGES-1 mRNAs and their respective proteins expression, together with the renal PGE2 amounts, were induced by the cisplatin treatment, but their initiation was reduced by OA-NO2. Moreover, the circulating TNF-α, renal TNF-α, IL-1β, MCP-1, ICAM-1, and VACAM-1 mRNA levels were higher in the cisplatin-treated mice, compared with the controls, but they were attenuated in the OA-NO2 pretreatment group. In summary, the pretreatment with OA-NO2 remarkably ameliorated the cisplatin-induced kidney injury in mice, possibly via the inhibition of the inflammatory response, associated with the COX-2/mPGES-1/PGE2 cascade. [ABSTRACT FROM AUTHOR]

Periodontal ligament stem cells ( PDLSCs) are considered as potential mesenchymal stem cell sources for future clinical applications in periodontal regeneration therapy. Simvastation, widely used for lowering serum cholesterol, is known to have a bone stimulatory effect. However, it is not clear whether simvastation affects the differentiation of PDLSCs. This study examined the effects of simvastatin on human PDLSCs in vitro and in vivo. Using the limiting dilution technique, human PDLSCs were isolated and expanded. PDLSCs were cultured with simvastatin (0.01-10 μ m), and the proliferation was measured. The osteogenic differentiation was characterized by alkaline phosphatase ( ALP) activity and Alizarin Red-S staining for calcium deposition. The gene expression levels of osteogenic markers were evaluated by RT- PCR. In addition, PDLSCs were transplanted into nude mice with ceramic bovine bone powders as carriers to observe the capacity of mineralized tissue formation in vivo. Simvastatin at concentrations <1 μ m did not suppress the proliferation of PDLSCs. After the administration of 0.1 μ m simvastatin, the expression of ALP, bone sialoprotein, and bone morphogenetic protein-2 genes were significantly upregulated, and the ALP activity and mineralized nodule formation were significantly higher in the simvastatin-treated cells than the control cells. In addition, the in vivo transplantation results showed that simvastatin treatment promoted the degree of mineralized tissue formation. Collectively, simvastatin has positive effects on osteogenic differentiation of human PDLSCs in vitro and in vivo. This suggests that simvastatin might be a useful osteogenic induction agent for periodontal bone regeneration. [ABSTRACT FROM AUTHOR]

A series of thiazolo[5,4- d ]pyrimidine derivatives were designed through the atom replacement strategy based on biologically validated scaffolds and then evaluated for their antiproliferative activities on cancer cell lines. The structure-activity relationship studies were conducted, leading to the identification of compound 22 , which exhibited good antiproliferative activity against HGC-27 with an IC 50 value of 1.22 μM and low toxicity against GES-1 cells. Mechanistic studies showed that compound 22 inhibited the colony formation and migration of HGC-27 as well as induced apoptosis. The western blot experiments proved that compound 22 up-regulated expression of Bax, down-regulated expression levels of Bcl-2 and cleaved caspased-3/9. These findings indicate that compound 22 may serve as a template for designing new agents for the treatment of human gastric cancers. The atom replacement strategy could be viable strategy for designing new anticancer drugs and may find its applications in drug design. [ABSTRACT FROM AUTHOR]

Highlights: [•] The role of miR-29 in vitro in HSC [•] The role of miR-29 in HCV-infected patients [•] The role of miR-29 in vivo in mice from liver fibrosis [ABSTRACT FROM AUTHOR]

To study the characterization and hepatoprotective activity of polysaccharide from maca ( Lepidium meyenii ), the main polysaccharide from maca (MP-1) was obtained by DEAE-52 cellulose column. The average molecular weight of MP-1 was 1067.3 kDa and the polysaccharide purity was 91.63%. In order to assess the antioxidant activities of MP-1, four kinds of methods were used, including scavenging hydroxyl radical, DPPH, superoxide anion radical, and FRAP, and the results indicated high antioxidant activities. Furthermore, hepatoprotective activity of MP-1 was studied both in vitro and vivo . In vitro , the alcohol induced Hep-G2 cells model was established to evaluate the protective effect of MP-1, which demonstrated MP-1 can alleviate alcohol damage in Hep-G2 cells. In vivo , the Institute　of　Cancer　Researcch (ICR) mice were used to evaluate hepatoprotecive effects of MP-1 on alcoholic liver disease (ALD). Supplement with MP-1 supressed the triglyceride level both in serum and in hepatic tissue. In addition, MP-1 ameliorated serous transaminases increase induced by alcohol, including aspartate transaminase, alanine aminotransferase, and γ-glutamyl transpeptidase. Moreover, MP-1 also dramatically increased the superoxide dismutase, glutathione peroxidase, and glutathione s-transferase levels in alcoholic mice. Meantime, histopathologic results MP-1 lighten inflammation induced by alcohol. These results indicate that MP-1 possesses hepatoprotective activity against hepatic injury induced by alcohol. [ABSTRACT FROM AUTHOR]

To research the preliminary characterizations, antioxidant and hepatoprotective activity of polysaccharides from Cistanche deserticola (CDPs), three polysaccharide fractions, CDP-A, CDP-B and CDP-C, were obtained by successively membrane filtration (microfiltration, ultrafiltration and nanofiltration). Molecular weights, monosaccharide compositions, purities and IR spectra of the three fractions were analyzed. Results showed that CDP-C contained higher proportion of galacturonic acid (GalUA) than CDP-B and CDP-A. Antioxidant activities were also analyzed and the results revealed that CDP-C possessed the highest activity. Thus, hepatoprotective activity of CDP-C was studied further. In vitro research, CDP-C promoted viability of HepG2 cells. In vivo research, CDP-C ameliorated the alterations induced by alcohol, including serological indexes (alanine transaminase, acid phosphatase, γ-glutamyl transpeptidase and triglyceride) and hepatic indicators (superoxide dismutase, malondialdehyde, glutathione S-transferase and triglyceride) in model animals. The prominent microvesicular steatosis and mild necrosis in hepatic histopathology of model animals were also attenuated by CDP-C administration. These findings indicated that CDP-C possessed hepatoprotective activity against chronic hepatic injury induced by alcohol. The underlying mechanism might be that CDP-C can reduce the contents of MDA and TG, and modulate the activities of the relative enzyme. This property might associate with GalUA in CDP-C. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Tauroursodeoxycholic acid (TUDCA), one of the main ingredients from bear gall which hold “Clearing heat and detoxification, Removing liver fire for improving eyesight” functions, is formed by the conjugation of ursodeoxycholic acid (UDCA) with taurine. However, the limited information of TUDCA on protecting diabetic retinopathy (DR) has been known. The present study was conducted to evaluate the protection of TUDCA on high glucose-induced human retinal microvascular endothelial cells (HRMECs) dysfunction and streptozotocin (STZ)-induced diabetic retinopathy (DR) rats and the possible mechanism underlying was also explored. Materials and methods The proliferation of high glucose-induced HRMECs was determined by MTT assay. DR rats’ model was established by an administration of high-glucose-fat diet and an intraperitoneal injection of STZ (30 mg/kg). The cell supernatant and rats’ serum were collected for the assays of NO content by ELISA kits. Retinas were stained with hematoxylin and eosin (HE) to observe pathological changes. Immunohistochemical assay was applied to examine the protein expression of ICAM-1, NOS, NF-κB p65 and VEGF in rat retinas. Furthermore, western blot analysis was carried out to examine the protein expression of ICAM-1, NOS, NF-κB p65 and VEGF in high glucose-induced HRMECs. Results After treating with TUDCA, high glucose-induced HRMECs proliferation could be significantly inhibited. TUDCA (5.0 μM, 25.0 μM and 125.0 μM) could decrease NO content in high glucose-induced HRMECs. Furthermore, TUDCA (500 mg/kg/d and 250 mg/kg/d) also decrease NO content in serum of DR rats. Additionally, both immunocytochemistry analysis and western blot analysis showed that the over-expression of ICAM-1, NOS, NF-κB p65 and VEGF were significantly decreased by TUDCA. Conclusion The data indicated that TUDCA could ameliorate DR by decreasing NO content and down-regulating the protein expression of ICAM-1, NOS, NF-κB p65 and VEGF. Thus, our experimental results suggested that TUDCA might be a potential drug for the prevention and treatment of DR. [ABSTRACT FROM AUTHOR]

Objective To identify whether age, sex, and lesion location are associated with initial presentation in patients with brain arteriovenous malformations (AVMs). Methods Collected data of 3299 consecutive patients with AVM treated at Beijing Tiantan Hosptial from January 1980 to January 2015 were analyzed. The variables assessed were age at diagnosis, sex, AVM location, and mode of initial presentation. Results Initial presentation was AVM hemorrhage in 57.9%, seizure in 20.9%, chronic headache in 14.9%, focal neurologic deficit in 5.2%, and incidental in 1.2%. Younger age and female sex were associated with initial hemorrhage (all P < 0.05). Hemorrhage was more likely to occur in patients with AVMs in the basal ganglia, the corpus callosum, the ventricles, the cerebellum, and the brainstem (all P < 0.05). Male sex was associated with initial seizure ( P < 0.05). Initial seizure was more likely to occur in patients with AVMs in the frontal, temporal, parietal, frontotemporal, and frontoparietal lobe (all P < 0.05). Compared with frontal AVMs, temporal AVMs were more likely to present with hemorrhage ( P < 0.05) and less likely to present with seizure ( P < 0.05). AVMs involving the occipital lobe were more likely to present with chronic headaches ( P < 0.05). Conclusions Initial AVM presentation varied with patient age, sex, and AVM locations. Younger age, female sex, and deep and infratentorial locations may be associated with initial hemorrhage. Male sex and frontal, temporal, and parietal AVM locations may be predictors of initial seizure. Chronic headache was more likely to occur in patients with AVMs involving the occipital lobe. [ABSTRACT FROM AUTHOR]

Objective We reviewed our prospective study of patients with occipital arteriovenous malformations (AVMs) to assess whether the display of optic radiation diffusion tensor imaging (DTI) during neuronavigation-guided surgery can reduce the severity of postoperative visual field deficits (VFDs) and to evaluate the factors associated with visual field preservation. Methods Forty-six consecutive patients with occipital AVMs were randomized in our study. DTI of the optic radiation was displayed during neuronavigation surgery in 24 patients. The other 22 patients were treated surgically without neuronavigation. Modified Rankin Scale (mRS) scores and visual fields were evaluated preoperatively, immediately after surgery, and at the last follow-up. Results The patients' baseline characteristics and AVM features were statistically similar between the 2 surgical groups. The postoperative obliteration rate was 100%. The postoperative mRS scores did not differ between the 2 groups ( P > 0.05). Preexisting VFDs were more common ( P = 0.00004) in patients who bled than in those with unruptured AVMs. The application of DTI-incorporated neuronavigation reduced the frequency and severity of postoperative VFDs ( P = 0.013 and 0.001, respectively). Visual fields were more likely to be preserved in patients with an AVM >5 mm from the optic radiation ( P = 0.025). Conclusions A history of hemorrhage is an independent risk factor for VFDs associated with occipital AVMs. Although not showing superiority in postoperative mRS, functional MRI navigation-guided surgery may help to radically resect occipital AVMs and preserve patient visual fields. A 5-mm distance from the optic radiation may be a suitable safety margin for visual field preservation. [ABSTRACT FROM AUTHOR]

The emergence of extensively drug-resistant tuberculosis (XDR-TB) in China is a great threat to TB control. To determine the molecular characterisation of XDR-TB isolates from China and the correlations between specific drug resistance-associated mutations and different genotype strains, 58 XDR-TB isolates were sequenced in eight drug loci, including katG , inhA , oxyR–ahpC intergenic region, rpoB , eis , rrs , gyrA and gyrB , and were genotyped using spoligotyping and analysis of the noise transfer function region. Compared with the phenotypic data, the sensitivities and specificities for DNA sequencing were 87.9% and 100.0% for isoniazid (INH), 91.4% and 98.3% for rifampicin (RIF), 60.4% and 100.0% for kanamycin (KAN) and 81.0% and 100.0% for ofloxacin (OFX), respectively. A combination of eight drug loci predicted XDR-TB phenotypes with 53.4% sensitivity (31/58 isolates) and 100.0% specificity. The most frequent mutations among these XDR-TB isolates were katG 315 and inhA -15 (for INH), 531, 526 and 516 in rpoB (for RIF), rrs 1401 and eis –10 (for KAN) and 94, 90 and 91 in gyrA (for OFX). Also, among these XDR-TB isolates, 44 (75.9%) were identified as Beijing genotype strain, of which 31 (70.5%) belonged to the modern Beijing sublineage. inhA -8, rpoB 526 and rpoB 531 mutations demonstrated significant statistical associations with ancient and modern Beijing family sublineage ( P < 0.05). However, Beijing and non-Beijing genotypes showed no association with specific resistance-conferring mutations. These results will be helpful in designing new molecular biology-based techniques to diagnose XDR-TB in China. [ABSTRACT FROM AUTHOR]