Structure-based discovery of SIAIS001 as an oral bioavailability ALK degrader constructed from Alectinib

Fusion proteins of the anaplastic lymphoma kinase (ALK) are promising therapeutic targets for cancer and other human diseases, especially for non-small cell lung cancer (NSCLC) and anaplastic large-cell lymphomas (ALCLs). We described herein a structure-based design, synthesis, and evaluation of ALK PROTACs (proteolysis-targeting chimeras) based on Alectinib as the warhead. We firstly screened CRBN ligands as the E3 ligase moiety, then obtained a series of potent ALK degraders based on different CRBN ligands, exemplified by SIAIS091 and SIAIS001 with lenalidomide/thalidomide-based linkers. Both of them induced effective ALK degradation at low nanomolar concentrations in cells, and showed much better growth inhibition effects than Alectinib. SIAIS091 or SIAIS001 also promoted cell cycle arrest in G1/S phase. Finally, SIAIS001 exhibited good oral bioavailability in Pharmacokinetics study.

Geniposide prevents H2 O2 -induced oxidative damage in melanocytes by activating the PI3K-Akt signalling pathway

BACKGROUND

Oxidative stress is one possible pathogenic event in vitiligo that induces melanocyte destruction. Geniposide exerts certain antioxidant effects on various cells by activating the phosphoinositol 3-kinase (PI3K)-Akt signalling pathway. However, researchers have not clearly determined whether geniposide protects human melanocytes from oxidative stress or identified the underlying mechanism of such protection.

AIM

To determine whether geniposide protects melanocytes from H₂ O₂ -induced oxidative damage and to explore the role of the PI3K-Akt signalling pathway in this protective effect.

METHODS

The antioxidant effects of geniposide on human melanocytes were examined by measuring cell viability, apoptosis rates, reactive oxygen species (ROS) production and activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). We examined expression of Akt, phosphorylated Akt (p-Akt), Bcl-2, Bax, and cleaved caspase 3 and cleaved caspase 9 proteins to determine the involvement of the PI3K-Akt pathway.

RESULTS

Pretreatment with geniposide 5, 25, 125 or 625 μmol/L increased cell viability and decreased the apoptosis rate of H₂ O₂ -treated melanocytes. In addition, geniposide enhanced the antioxidant activity of SOD and CAT, and decreased intracellular ROS accumulation. Furthermore, geniposide increased the levels of p-Akt and regulated the expression of downstream proteins in the PI3K-Akt pathway, such as Bcl-2, Bax, and cleaved caspase 3 and 9, in H₂ O₂ -treated melanocytes. Notably, these effects were largely blocked by treatment with LY294002 prior to H₂ O₂ treatment.

CONCLUSIONS

Based on these results, geniposide protects human melanocytes from H₂ O₂ -induced oxidative damage, and the PI3K-Akt signalling pathway is involved in its antioxidant effect.

Regulation of stem cell fate using nanostructure-mediated physical signals

One of the major issues in tissue engineering is regulation of stem cell differentiation toward specific lineages. Unlike biological and chemical signals, physical signals with adjustable properties can be applied to stem cells in a timely and localized manner, thus making them a hot topic for research in the fields of biomaterials, tissue engineering, and cell biology. According to the signals sensed by cells, physical signals used for regulating stem cell fate can be classified into six categories: mechanical, light, thermal, electrical, acoustic, and magnetic. In most cases, external macroscopic physical fields cannot be used to modulate stem cell fate, as only the localized physical signals accepted by the surface receptors can regulate stem cell differentiation via nanoscale fibrin polysaccharide fibers. However, surface receptors related to certain kinds of physical signals are still unknown. Recently, significant progress has been made in the development of functional materials for energy conversion. Consequently, localized physical fields can be produced by absorbing energy from an external physical field and subsequently releasing another type of localized energy through functional nanostructures. Based on the above concepts, we propose a methodology that can be utilized for stem cell engineering and for the regulation of stem cell fate via nanostructure-mediated physical signals. In this review, the combined effect of various approaches and mechanisms of physical signals provides a perspective on stem cell fate promotion by nanostructure-mediated physical signals. We expect that this review will aid the development of remote-controlled and wireless platforms to physically guide stem cell differentiation both in vitro and in vivo, using optimized stimulation parameters and mechanistic investigations while driving the progress of research in the fields of materials science, cell biology, and clinical research.

Vasoactive intestinal peptide mediation of development and functions of T lymphocytes

The first phase in investigating neural regulation of immunity has delineated anatomical connections, shared mediators and receptors for mediators with distinctive effects, and the immune functional consequences of altering relevant neural activities. Vasoactive intestinal peptide (VIP) and pituitary adenylyl cyclase-activating peptide (PACAP) are represented prominently in immune organs. They have potent novel effects on many aspects of immunity, are derived from and serve as autacoids in some sets of immune cells, and they participate in both physiological and pathological immune responses. The present phase of neuroimmune research has begun to elucidate the genetic determinants of expression and functions of neuromediators in immunity. Our evolving understanding of the novel mechanisms for adaptation and specificity in the VIP/PACAP neuroimmune network suggests the importance of immunoselective transcriptional control of expression of VIP/PACAP receptors in T cells, a dominant role for numerous cytokines, and the critical involvement of small subsets of VIP-/PACAP-responsive thymocytes and T cells.

The risk for systemic embolization associated with percutaneous balloon valvuloplasty in adults. A prospective comprehensive evaluation

STUDY OBJECTIVE

To prospectively investigate the evidence for embolic phenomena associated with percutaneous mitral and aortic valvuloplasty.

DESIGN

Prospective, consecutive case series before and after balloon valvuloplasty.

SETTING

Referral center hospital and cardiac catheterization laboratory.

PATIENTS

Consecutive sample of 32 patients having balloon valvuloplasty for critical symptomatic stenosis of the mitral or aortic valve. Twenty-six patients had aortic stenosis; 6 had mitral stenosis.

INTERVENTION

Computed tomography of the head, funduscopy, and electrocardiography were done in all patients before and after valvuloplasty. Cardiac isoenzymes were measured serially in 19 patients.

MEASUREMENTS AND MAIN RESULTS

Previous cerebral infarction was seen in nine patients, with three showing a new abnormality after aortic valvuloplasty. In one of these patients a funduscopic hemorrhage was detected by photography. Total creatinine kinase and MB fraction were elevated in 1 of 19 patients. Serial electrocardiograms were unchanged in all patients.

CONCLUSIONS

The incidence of cerebral neurologic events and myocardial injury are acceptably low after balloon valvuloplasty of calcific aortic and mitral stenosis. Both episodes of symptomatic cerebral infarction occurred in patients with apparent bicuspid aortic valvular stenosis, suggesting that calcific bicuspid aortic stenosis may be associated with more neurologic events after aortic valvuloplasty.

Congenital choledochal cysts in adults: twenty-five-year experience

BACKGROUND

Choledochal cyst is rare in western countries. The relatively high incidence of coexistent hepatobiliary disease increases the difficulty of the surgical management of choledochal cyst. Here we analyze the diagnosis and treatment of congenital bile duct cyst in 122 Chinese adults.

METHODS

The clinical data of 122 patients with congenital choledochal cysts admitted from 1981 to 2006 were analyzed.

RESULTS

Clinical symptoms in most cases were nonspecific, resulting in delayed diagnosis. Sixty-one patients (50%) had coexistent pancreatobiliary disease. Among the 122 patients, 119 patients underwent ultrasonic examination; ERCP/MRCP was performed in 63 cases and CT in 102 cases. Abnormal pancreatobiliary duct junction was found in 48 patients. Sixteen patients had malignant lesions in the bile duct, arising in 11 of them from incomplete choledochal cyst that underwent various operations including cystenterostomy or cystojejunostomy. There was significant difference between the patients who underwent incomplete cyst resection and complete cyst resection in malignancy rate of bile duct (Chi square test, P = 0.000; odds ratio, 7.800; 95% confidence interval, 2.450 to 24.836).

CONCLUSIONS

ERCP, CT and MRCP had proved their great values in the classification of the disease. Cyst excision with Roux-en-Y hepaticojejunostomy is recommended as the treatment of choice for patients with type I or type IV cysts. For type V cyst (Caroli's disease) with recurrent cholangitis, liver transplantation should be considered.

Identification of Immune-Related Gene Signature and Prediction of CeRNA Network in Active Ulcerative Colitis

Background

Ulcerative colitis (UC) is an inflammatory disease of the intestinal mucosa, and its incidence is steadily increasing worldwide. Intestinal immune dysfunction has been identified as a central event in UC pathogenesis. However, the underlying mechanisms that regulate dysfunctional immune cells and inflammatory phenotype remain to be fully elucidated.

Methods

Transcriptome profiling of intestinal mucosa biopsies were downloaded from the GEO database. Robust Rank Aggregation (RRA) analysis was performed to identify statistically changed genes and differentially expressed genes (DEGs). Gene Set Enrichment Analysis (GSEA), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to explore potential biological mechanisms. CIBERSORT was used to evaluate the proportion of 22 immune cells in biopsies. Weighted co-expression network analysis (WGCNA) was used to determine key module-related clinical traits. Protein-Protein Interaction (PPI) network and Cytoscape were performed to explore protein interaction network and screen hub genes. We used a validation cohort and colitis mouse model to validate hub genes. Several online websites were used to predict competing endogenous RNA (ceRNA) network.

Results

RRA integrated analysis revealed 1838 statistically changed genes from four training cohorts (adj. p-value < 0.05). GSEA showed that statistically changed genes were enriched in the innate immune system. CIBERSORT analysis uncovered an increase in activated dendritic cells (DCs) and M1 macrophages. The red module of WGCNA was considered the most critical module related to active UC. Based on the results of the PPI network and Cytoscape analyses, we identified six critical genes and transcription factor NF-κB. RT-PCR revealed that andrographolide (AGP) significantly inhibited the expression of hub genes. Finally, we identified XIST and three miRNAs (miR-9-5p, miR-129-5p, and miR-340-5p) as therapeutic targets.

Conclusions

Our integrated analysis identified four hub genes (CXCL1, IL1B, MMP1, and MMP10) regulated by NF-κB. We further revealed that AGP decreased the expression of hub genes by inhibiting NF-κB activation. Lastly, we predicted the involvement of ceRNA network in the regulation of NF-κB expression. Collectively, our results provide valuable information in understanding the molecular mechanisms of active UC. Furthermore, we predict the use of AGP and small RNA combination for the treatment of UC.

TRADES: Targeted RNA Demethylation by SunTag System

N6-methyladenosine (m6A) is rapidly being studied and uncovered to play a significant role in various biological processes as well as in RNA fate and functions, while the effects of defined m6A sites are rarely characterized for the lack of convenient tools. To provide an applicable method to remove m6A modification at specific loci, an m6A editing system called "targeted RNA demethylation by SunTag system (TRADES)" is engineered. In this system, the targeting element dCas13b is fused to ten copies of GCN4 peptides which can recruit multiple scFv-fusion RNA demethylase to demethylate the target m6A site. Owing to this design, TRADES is more flexible to the indistinct m6A sites for its wide editing window. By site-specific demethylation of messenger RNA (mRNA) SON A2699, the lifetime of SON RNA is successfully prolonged in HeLa cells. Meanwhile, TRADES negligibly influences the lifetime of other non-targeted transcripts. TRADES also can regulate the gene expression of target transcript in an m6A-dependent manner. Moreover, the interference occuring for HBV and HIV replications demonstrates that the TRADES system holds potential in viral life cycle regulation and clinical applications.

Lignans extracted from Vitex negundo possess cytotoxic activity by G2/M phase cell cycle arrest and apoptosis induction

Evn-50 is a lignan compounds mixture extracted from Vitex negundo, a widely used herb in traditional Chinese medicine. This study is aimed to define the spectrum of cytotoxic activity of EVn-50, and also to investigate mechanisms underlying the anticancer actions via assessing the influence on cell cycle using EVn-50, and the lignan compound VB1 purified from EVn-50. The cytotoxic effect of EVn-50 and VB1 was determined with SRB assay using a panel of cancer cell lines. Breast cancer cell line MDA-MB-435 and liver cancer cell line SMMC-7721 were selected for further evaluating the effect of EVn-50 or VB1 on cell cycle by flow cytometric analysis. Apoptosis exerted by EVn-50 or VB1 was measured by TUNEL assay and DAPI staining, and Western blot analysis was utilized to assess the influence on expression and phosphorylation of proteins which are closely related to cell cycle and apoptosis. EVn-50 possessed a broad spectrum of in vitro anticancer activity for those tested cancer cells, especially sensitive to MDA-MB-435, SKOV-3, BXPC-3, SMMC-7721, MCF-7, HO-8910, SGC-7901, BEL-7402, HCT-116, and 786-O, with the respective IC50 below 10 μg/ml. Treatment with EVn-50 or VB1 resulted in arresting the MDA-MB-435 and SMMC-7721 cells at G2/M phase, which was further supported by observations of increased phosphorylation of Histone 3 at Ser10, phosphorylation of Cdk1 at Tyr15, expression of cyclin B1, and decreased expression of Cdc25c. Moreover, we found that exposure of MDA-MB-435 cells to EVn-50 or VB1 caused obvious apoptosis of MDA-MB-435 cells. Our data show that EVn-50, lignan compounds extracted from Vitex negundo, possesses a broad spectrum cytotoxic effect via arresting cancer cells at G2/M phase cell cycle and subsequently inducing apoptosis.

The effects of age at cochlear implantation and hearing aid trial on auditory performance of Chinese infants

CONCLUSION

Most of the infants demonstrated rapid improvement in the three different auditory skills within the first year after switch-on. Infants undergoing hearing aid trial and habilitation demonstrated a significant positive effect on the development of auditory skills in comparison with infants without trial and habilitation.

OBJECTIVE

This paper aims to evaluate the auditory performance of infants of different age at cochlear implantation, emphasize the importance of the hearing aid trial and habilitation before implant, and provide baseline data of auditory development.

METHODS

In all, 259 infants with prelingually profound hearing loss participated in this study. The Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) was used to assess auditory skills in infants at different intervals.

RESULTS

The mean scores for the auditory skills improved significantly over time. The mean scores of three skills for each group at each interval were significantly different. The mean scores of the auditory skills were significantly superior for infants undergoing hearing aid trial and habilitation in comparison with those of infants without hearing aid trial and habilitation.

Activities of different cysteine proteases of Paragonimus westermani in cleaving human IgG

Cleaving host immunoglobulins is a well known mechanism of evading host immune reactions exploited by helminth parasites. Secreted cysteine proteases of helminth are a part of enzymes cleaving host IgG. Paragonimus westermani produces at least six different species of the cysteine protease in its developmental stages. This study was undertaken to evaluate comparatively the activities against human IgG by the different enzymes. When the metacercariae, which secrete 27 and 28 kDa cysteine proteases, were incubated in human IgG solution, IgG was degraded at its hinge region. Further incubation resulted complete hydrolysis. From 4-week and 7-week old juveniles and 16-week old adults of P. westermani, five different enzymes at 15, 17, 27, 28 and 53 kDa have been purified, if the enzyme with the same molecular mass is regarded to be identical. In cleaving human IgG, each cysteine protease exhibited decreasing activities with age.

HMGA2 plays an important role in Cr (VI)-induced autophagy

Cr (VI) is mutagenic and carcinogenic, but the mechanism is unclear. In this study, the involvement of high mobility group A2 (HMGA2) in Cr (VI)-induced autophagy was investigated. Cr (VI) treatment induced formation of autophagosomes, increased expression of LC3II, Atg12-Atg5, Atg4, Atg10, HMGA1 and HMGA2 proteins, and decreased the expression of p62 in A549 cells. Silencing of HMGA2 gene by siRNA blocked Cr (VI)-induced formation of autophagosomes, expression of LC3II, Atg12-Atg5, Atg10 and reduction of p62. Overexpression of HMGA2 in HEK 293 and HeLa cells could induce the expression of LC3II, Atg12-Atg5 and Atg10, and decrease the expression of p62. Although the protein level of Atg12-Atg5 conjugation changed after Cr (VI) treatment, silencing of HMGA2 and overexpression of HMGA2, both the proteins and mRNA levels of Atg12 and Atg5 were not changed significantly. ChIP assay demonstrated that HMGA2 protein directly bound to the promoter sequence of Atg10 gene, which modulated the conjugation of Atg12-Atg5. Interestingly, 3-MA markedly prevented Cr (VI)-induced cell growth of A549 cells. Our further in vivo study confirmed that the expression of HMGA1, HMGA2, LC3II, Atg12-Atg5, Atg4, Atg5, Atg7, Atg10, Atg12, Beclin 1 were increased and p62 was reduced in lung tissues of Cr (VI)-treated BALB/c mice. Combining, our data demonstrated that HMGA2 plays an important role in Cr (VI)-induced autophagy and the mechanism underlies Atg12-Atg5 conjugation modulated by HMGA2-dependent transcriptional regulation of Atg10. This suggests that HMGA2 might be an important biomarker in Cr (VI)-induced autophagy, cell-growth or other toxicities.

Lossy (15:1) JPEG compression of digital coronary angiograms does not limit detection of subtle morphological features

BACKGROUND

Development of the "all-digital" cardiac catheterization laboratory has been slowed by substantial computer archival and transfer requirements. Lossy data compression reduces this burden but creates irreversible changes in images, potentially impairing detection of clinically important angiographic features.

METHODS AND RESULTS

Fifty image sequences from 31 interventional procedures were viewed both in the original (uncompressed) state and after 15:1 lossy Joint Photographic Expert's Group (JPEG) compression. Experienced angiographers identified dissections, suspected thrombi, and coronary stents, and their results were compared with those from a consensus panel that served as a "gold standard." The panel and the individual observers reviewed the same image sequences 4 months after the first session to determine intraobserver variability. Intraobserver agreement for original images was not significantly different from that for compressed images (89.8% versus 89.5% for 600 pairs of observations in each group). Agreement of individual observers with the consensus panel was not significantly different for original images from that for compressed images (87.6% versus 87.3%; CIs for the difference, -4.0%, 4.0%). Subgroup analysis for each observer and for each detection task (dissection, suspected thrombus, and stent) revealed no significant difference in agreement.

CONCLUSIONS

The identification of dissections, thrombi, and coronary stents is not substantially impaired by the application of 15:1 lossy JPEG compression to digital coronary angiograms. These data suggest that digital angiographic images compressed in this manner are acceptable for clinical decision-making.

Cthrc1 overexpression is an independent prognostic marker in gastric cancer

Collagen triple helix repeat containing 1 (CTHRC1) was identified as a novel gene expressed in the adventitia and neointima on arterial injury and was found to be overexpressed in several malignant tumors, such as breast cancer and malignant melanoma. However, the expression of Cthrc1 and its role in gastric cancer progression remain unknown. We investigated the expression of the Cthrc1 protein by immunohistochemistry in 30 normal tissues from the control subjects and 166 gastric carcinomas and analyzed its correlation with various clinicopathological features, including patient outcome. Cthrc1 immunoreactivity was overexpressed in gastric carcinoma cases compared with normal tissues (P < .001). High Cthrc1 expression was found in 108 (65.06%) of these 166 carcinomas and was positively correlated with the American Joint Committee on Cancer stage classification, depth of gastric wall invasion, lymph node metastasis, lymphovascular space involvement, and recurrence but not with age, tumor site, and carcinoembryonic antigen level. Patients with high Cthrc1 expression had significantly poorer overall survival and disease-free survival compared with patients with low expression of Cthrc1 (P = .001 and P = .002, respectively). Multivariate analysis showed that high Cthrc1 expression was an independent prognostic factor for both overall survival and disease-free survival of patients with gastric carcinoma (both P = .005). These results showed that high Cthrc1 expression was associated with progression and prognosis of gastric carcinoma.

Variation in anisotropy and diffusivity along the medulla oblongata and the whole spinal cord in adolescent idiopathic scoliosis: a pilot study using diffusion tensor imaging

BACKGROUND AND PURPOSE

Disturbed somatosensory evoked potentials have been demonstrated in patients with adolescent idiopathic scoliosis (but this functional delay was found to originate above the C5-6 level, while the lower cord level was unaffected). Together with MR imaging observation of tonsillar ectopia and a relatively tethered cord, we hypothesized that there is disturbed mean diffusivity integrity along the spinal cord. In this study, advanced DTI was used to evaluate whether there was underlying decreased WM integrity within the brain stem and spinal cord in adolescent idiopathic scoliosis and any relationship to cerebellar tonsillar ectopia. Clinical impact on balance testing was also correlated.

MATERIALS AND METHODS

Thirteen girls with adolescent idiopathic scoliosis with right thoracic curves were compared with 13 age-matched healthy girls. DTI of the brain and whole spinal cord was performed. ROIs were manually defined for the medulla oblongata and along each intervertebral segment of the cord. Mean values of fractional anisotropy and mean diffusivity were computed at the defined regions. Between-group comparisons were performed by 1-way ANOVA.

RESULTS

Significantly decreased fractional anisotropy values and increased mean diffusivity values were found at the medulla oblongata and C1-2, C2-3, C3-4, and C4-5 segments in patients with adolescent idiopathic scoliosis compared with healthy subjects. No significant difference was found in the lower cord levels. Significant correlation was found between the tonsillar level and fractional anisotropy value at the C4-5 level in patients with adolescent idiopathic scoliosis only.

CONCLUSIONS

The findings from this study are in agreement with previous findings showing abnormal somatosensory evoked potential readings occurring only above the C5-6 level in patients with adolescent idiopathic scoliosis; these findings might partially explain the pathophysiology of the neural pathway involved.

Discovery of a Brigatinib Degrader SIAIS164018 with Destroying Metastasis-Related Oncoproteins and a Reshuffling Kinome Profile

Proteolysis-targeting chimera (PROTAC) is an attractive technology in drug discovery. Canonically, targets act as a basic starting point in the most previous PROTAC design. Here, we designed degraders considering from the view of clinical benefits. With this novel design, Brigatinib was turned into a degrader SIAIS164018 and endowed with unique features. First, SIAIS164018 could degrade not only ALK fusion proteins in activating or G1202R-mutated form but also mutant EGFR with L858R + T790M, which are two most important targets in non-small-cell lung cancer. Second, SIAIS164018 strongly inhibited cell migration and invasion of Calu-1 and MDA-MB-231. Third and surprisingly, SIAIS164018 degrades several important oncoproteins involved in metastasis such as FAK, PYK2, and PTK6. Interestingly, SIAIS164018 reshuffled the kinome ranking profile when compared to Brigatinib. Finally, SIAIS164018 is orally bioavailable and well tolerated in vivo. SIAIS164018 is an enlightening degrader for us to excavate the charm of protein degradation.

Incidence of mitral valve prolapse in one hundred clinically stable newborn baby girls: an echocardiographic study

Clinical and echocardiographic examinations were performed on 100 clinically stable, newborn baby girls. Mitral valve prolapse was noted on the echocardiograms of seven babies. Three subjects had systolic clicks, two of whom had systolic murmurs following the click. The four other babies who had echocardiographic evidence of mitral valve prolapse had no abnormal auscultatory signs. Of the 93 babies without evidence of mitral prolapse, 91 had normal echocardiograms and auscultatory features; one was noted to have a murmur consistent with a ventricular septal defect, and another had an eccentric aortic valve on the echocardiogram which was suggestive of a bicuspid aortic valve. Serial studies on our group of subjects will yield useful information regarding the natural history of mitral valve prolapse.

Distribution of insertion- and deletion-associated genetic polymorphisms among four Mycobacterium tuberculosis phospholipase C genes and associations with extrathoracic tuberculosis: a population-based study

The Mycobacterium tuberculosis genome contains four phospholipase C (PLC)-encoding genes, designated plcA, plcB, plcC, and plcD, respectively. Each of the four genes contributes to the overall PLC activity of M. tuberculosis. PLC is hypothesized to contribute to M. tuberculosis virulence. Infection of M. tuberculosis strains carrying a truncated plcD gene is associated with the occurrence of extrathoracic tuberculosis. However, whether the other three plc genes are also associated with extrathoracic tuberculosis remains to be assessed. We investigated the insertion- and deletion-associated genetic diversity in all four plc genes among 682 epidemiologically and clinically well-characterized M. tuberculosis clinical isolates using PCR, DNA sequencing, and Southern hybridization. Two hundred sixty-six (39%) of the 682 isolates had an interruption in at least one of the four plc genes, most often associated with an IS6110 insertion. The plcD gene interruption was the most common: it was observed in 233 (34%) of the isolates, compared to 4.7%, 4.1%, and 5.9% for plcA, plcB, and plcC gene interruption, respectively. The association between the plc gene genotypes and disease presentation was adjusted for clustering using generalized estimating equations for both bivariate and multivariate analyses. After controlling for the genotypes of the plcABC genes and the host-related risk factors, interruption in the plcD gene remained significantly associated with extrathoracic tuberculosis (odds ratio, 3.27; 95% confidence interval, 1.32 to 8.14). The data suggest that the plcD gene might play a more important role in the pathogenesis of thoracic TB than it does in the pathogenesis of extrathoracic TB.

Application of optical imaging to study of extrapulmonary spread by tuberculosis

The incidence of extrapulmonary tuberculosis is increasing, possibly due to the high frequency of co-infection with HIV. Extrapulmonary infections complicate diagnosis, have higher mortality rates and are more difficult to treat. Insight into the mechanisms involved in extrapulmonary spread of tuberculosis is critical to improving management. We set out to better understand extrapulmonary spread kinetics in mice and guinea pigs as well as the effects of infectious dose. We found that extrapulmonary spread occurs at a discrete time point when infected by low-dose aerosol, but at high-dose aerosol it occurs within the first 24h. The ability to follow tuberculosis in real-time during infection would allow us to better address the mechanisms involved. We found that mycobacteria can be optically imaged after pulmonary infection in the mouse lung, suggesting that this technology could be applied to study of extrapulmonary spread of tuberculosis.