Radiomics in Brain Tumor: Image Assessment, Quantitative Feature Descriptors, and Machine-Learning Approaches

Radiomics describes a broad set of computational methods that extract quantitative features from radiographic images. The resulting features can be used to inform imaging diagnosis, prognosis, and therapy response in oncology. However, major challenges remain for methodologic developments to optimize feature extraction and provide rapid information flow in clinical settings. Equally important, to be clinically useful, predictive radiomic properties must be clearly linked to meaningful biologic characteristics and qualitative imaging properties familiar to radiologists. Here we use a cross-disciplinary approach to highlight studies in radiomics. We review brain tumor radiologic studies (eg, imaging interpretation) through computational models (eg, computer vision and machine learning) that provide novel clinical insights. We outline current quantitative image feature extraction and prediction strategies with different levels of available clinical classes for supporting clinical decision-making. We further discuss machine-learning challenges and data opportunities to advance radiomic studies.

Anatomic considerations of pedicle screw placement in the thoracic spine. Roy-Camille technique versus open-lamina technique

STUDY DESIGN

In this cadaveric study, the outcomes of two techniques for pedicle screw placement in the thoracic spine were compared.

OBJECTIVES

To assess the Roy-Camille technique, and to determine whether pedicle screw placement, aided by partial laminectomy, could decrease the incidence of pedicle violations.

SUMMARY OF BACKGROUND DATA

Pedicle screw fixation in the thoracic spine remains technically challenging. The Roy-Camille method may be one of the leading techniques of thoracic pedicle screw placement. However, there are few studies evaluating this technique and determining methods to decrease the incidence of thoracic pedicle penetration with screw insertion.

METHODS

Ten cadaveric thoracic spines from T1 to T10 were used for pedicle screw placement. Two techniques of transpedicular screw placement were used, the Roy-Camille technique (screw placed on the right side; used in 95 screw placements) and the open-lamina technique screw placement with combined partial laminectomy (screw placed on the left side; used in 94 screw placements). After screw placement, all specimens were evaluated visually to determine violation of the pedicle.

RESULTS

The screw placement with the Roy-Camille technique had a higher percentage of pedicle violation (54.7%) than did that with the open-lamina technique (15.9%). No Grade III violation was seen in the screw placement with the open-lamina technique.

CONCLUSIONS

The Roy-Camille technique was associated with a high incidence of pedicle violation, whereas screw placement with a partial laminectomy significantly reduced the incidence of pedicle violation. Pedicle screw fixation in the thoracic spine remains a technical challenge and should not be used routinely. Screw placement with the open-lamina technique is recommended if pedicle screw fixation is strongly indicated in the thoracic spine.

Whole exome sequencing as a diagnostic adjunct to clinical testing in fetuses with structural abnormalities

OBJECTIVES

To evaluate the diagnostic yield of prenatal whole exome sequencing (WES) for monogenic disorders in fetuses with structural malformations and normal results on cytogenetic testing, and to describe information on pathogenic variants that is provided by WES.

METHODS

Karyotyping, chromosomal microarray analysis (CMA) and WES were performed sequentially on stored samples from a cohort of 3949 pregnancies with fetal structural abnormalities detected on ultrasound and/or magnetic resonance imaging, referred between January 2011 and December 2015. Diagnostic rates of the three techniques were investigated overall, for phenotypic subgroups and for proband-only vs fetus-mother-father samples. Information on pathogenic variants was identified by WES.

RESULTS

Overall, 18.2% (720/3949) of fetuses had an abnormal karyotype. Pathogenic copy number variants were detected on CMA in 8.2% (138/1680) of fetuses that had a normal karyotype result. WES performed on a subgroup of 196 fetuses with normal CMA and karyotype results revealed the putative genetic variants responsible for the abnormal phenotypes in 47 cases (24%). The molecular diagnosis rates for fetus-mother-father and proband-only samples were 26.5% (13/49) and 23.1% (34/147), respectively. Variants of uncertain significance were detected in 12.8% (25/196) of fetuses, of which 22 were identified in the fetal proband-only group (15%; 22/147) and three in the fetus-mother-father group (6.1%; 3/49). The incidental finding rate was 6.1% (12/196).

CONCLUSIONS

WES is a promising method for the identification of genetic variants that cause structural abnormalities in fetuses with normal results on karyotyping and CMA. This enhanced diagnostic yield has the potential to improve the clinical management of pregnancies and to inform better the reproductive decisions of affected families. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

The transmembrane domains of ectoapyrase (CD39) affect its enzymatic activity and quaternary structure

Mammalian ectoapyrase (CD39) is an integral membrane protein with two transmembrane domains and a large extracellular region. The enzymatic activity of ectoapyrase is inhibited by most detergents used for membrane protein solubilization. In contrast, the enzymatic activities of soluble E-type ATPases, including potato tuber (Solanum tuberosum) apyrase and parasite ecto-ATPase, are not affected by detergents. Here we show that ectoapyrase is a tetramer and that detergents that reduce the activity of the enzyme promote dissociation of the tetramer to monomers. We expressed a secreted form of the ectoapyrase in COS-7 cells by fusing the signal peptide of murine CD4 with the extracellular domain of the ectoapyrase. The soluble ectoapyrase is catalytically active and its activity is not affected by detergents. Mutants of the ectoapyrase with only the NH2- or the COOH-terminal transmembrane domain are membrane-bound, and their activity is no longer affected by detergents. The enzymatic activity of all of the mutant proteins is less than that of the native enzyme. These results suggest that the proper contacts between the transmembrane domains of the monomers in the tetramer are necessary for full enzymatic activity.

SCN5A is expressed in human jejunal circular smooth muscle cells

Tetrodotoxin-resistant Na+currents are expressed in a variety of muscle cells including human jejunal circular smooth muscle (HJCSM) cells. The aim of this study was to determine the molecular identity of the pore-forming alpha-subunit of the HJCSM Na+ channel. Degenerate primers identified a cDNA fragment of 1.5 kb with 99% nucleotide homology with human cardiac SCN5A. The identified clone was also amplified from single smooth muscle cells by reverse transcriptase-polymerase chain reaction (RT-PCR). Northern blot analysis showed expression of full-length SCN5A. Laser capture microdissection was used to obtain highly purified populations of HJCSM cells. RT-PCR on the harvested cells showed that SCN5A was present in circular but not in longitudinal muscle. A similar result was obtained using a pan-Na+ channel antibody. The full-length sequence for SCN5A was obtained by combining standard polymerase chain reaction with 5' and 3' rapid amplification of cDNA end techniques. The intestinal SCN5A was nearly identical to the cardiac SCN5A. The data indicate that SCN5A is more widely distributed than previously thought and encodes the pore-forming alpha-subunit of the tetrodotoxin-resistant Na+ current in HJCSM cells.

Detection of fetal copy number variants by non-invasive prenatal testing for common aneuploidies

OBJECTIVE

To evaluate the clinical performance of non-invasive prenatal testing (NIPT) in detecting fetal copy number variants (CNVs).

METHODS

NIPT of cell-free fetal DNA was performed retrospectively, using stored maternal plasma, at an average gestational age of 21.1 weeks in 117 pregnant women who had previously undergone invasive prenatal testing for chromosome microarray analysis (CMA). Among the fetal samples tested by CMA, 18 had positive results (CNVs > 1 megabase (Mb)) and 99 had negative results (CNVs < 1 Mb or without CNVs detected). The results of NIPT and CMA were then compared.

RESULTS

In the 11 CMA-positive samples with CNVs > 5 Mb, the detection rate of CNVs was 90.9%; the one case missed by NIPT had a fetal fraction of 4.7%. For the other seven CMA-positive samples with CNVs < 5 Mb, the detection rate was 14.3%; only one case with a 2.82-Mb duplication was detected, with a fetal fraction of 26.7%. For 35.7% (5/14) of CNVs detected by both NIPT and CMA, the differences in fragment length were within ± 1 Mb. In this study, the overall sensitivity and specificity of NIPT for detecting CNVs > 1 Mb were 61.1% and 95.0%, respectively, with a false-positive rate of 5.0%.

CONCLUSIONS

Our results demonstrate that NIPT for common aneuploidies can detect fetal CNVs > 5 Mb with high sensitivity, provided that fetal fraction is high enough, without increasing sequencing depth. The detection power of NIPT is determined mostly by fetal fraction and CNV size. A positive NIPT screening result for CNVs must be interpreted with caution and validated by additional diagnostic study.

SeO(2) induces apoptosis with down-regulation of Bcl-2 and up-regulation of P53 expression in both immortal human hepatic cell line and hepatoma cell line

An immortal human hepatic cell line HL-7702 and human hepatoma cell line SMMC-7721 were treated with 3-30 microM SeO(2). SeO(2) at 30 microM markedly inhibited cell proliferation and viability, and prompted apoptosis of both normal hepatic and hepatoma cells after 48h treatment. SeO(2) could also down-regulate the Bcl-2 level, greatly in HL-7702 and slightly in SMMC-7721 cells, but up-regulate wild type P53 level a little in HL-7702 and significantly in SMMC-7721 cells. The Bcl-2/P53 value was closely correlated with the apoptotic rate as well as SeO(2) concentrations.

Autoantigens of the nuclear pore complex

The nuclear envelope (NE) is one of many intracellular targets of the autoimmune response in patients with autoimmune liver disease, systemic lupus erythematosus, and related conditions. In eukaryotic organisms the NE consists of five interconnected regions: an outer nuclear membrane (ONM) that is continuous with the endoplasmic reticulum, an intermembrane or perinuclear space, an inner nuclear membrane (INM) with a unique set of integral membrane proteins, the underlying nuclear lamina, and the pore domains that are regions where the ONM and INM come together. The pore domains are sites of regulated continuity between the cytoplasm and nucleus that are occupied by supramolecular structures, termed nuclear pore complexes (NPCs). Human autoantibodies identified to date bind to specific components in three of the five NE compartments. Autoantigen targets include the lamins A, B, and C of the nuclear lamina, gp210, p62 complex proteins, Nup153, and Tpr within the NPC, and LBR, MAN1, LAP1, and LAP2 that are integral proteins of the INM. Autoantibodies to these NE targets have been shown to be correlated with various autoimmune diseases such as primary biliary cirrhosis, other autoimmune liver diseases and systemic rheumatic diseases. Now that the proteome of the NE is more clearly defined, other autoantibodies to components in this cell compartment are likely to be defined.

Randomised controlled trial: comparison of colloid or crystalloid for partial exchange transfusion for treatment of neonatal polycythaemia

AIM

To compare the efficacy of using isotonic saline (crystalloid) or 5% albumin (colloid) as replacement fluid in partial exchange transfusion (PET) for the treatment of neonatal polycythaemia.

METHODS

One hundred and two polycythaemic full term infants were randomly allocated to receive PET with either isotonic saline or 5% albumin. The criteria for PET were: (a) venous haematocrit > or = 0.7; or (b) venous haematocrit 0.65-0.69 with symptoms or signs attributable to polycythaemia.

RESULTS

PET with either saline (n = 53) or 5% albumin (n = 50) resulted in a significant and sustained decline in haematocrit up to 24 hours after PET. Although the immediate haemodilution effect of isotonic saline was statistically smaller than that of 5% albumin (decline in haematocrit 19.3% vs 22.8% of pre-PET value), the difference was too small to be of any clinical significance, and the haematocrit at 4 or 24 hours after PET did not differ significantly between the two groups. PET with either replacement fluid was not associated with any complication. The serum sodium and potassium concentrations were not significantly affected by the PET in either group.

CONCLUSIONS

Both isotonic saline and 5% albumin are effective when used as replacement fluid in PET for the treatment of neonatal polycythaemia. Isotonic saline, which is cheaper and free of infection, should be the replacement fluid of choice.

Species dependent expression of intestinal smooth muscle mechanosensitive sodium channels

A mechanosensitive Na(+) current carried by Na(v)1.5 is present in human intestinal circular smooth muscle and contributes to regulation of intestinal motor function. Expression of this channel in different species is unknown. Our aim was to determine if Na(+) currents and message for the alpha subunit of the Na(+) channel (SCN5A) are found in circular smooth muscle cells of human, dog, pig, mouse and guinea pig jejunum. Currents were recorded using patch clamp techniques. Message for SCN5A was investigated using laser capture microdissection and reverse transcription polymerase chain reaction (RT-PCR). Na(+) currents were identified consistently in human and dog smooth muscle cells; however, Na(+) current was not found in pig (0/20) or guinea pig smooth muscle cells (0/21) and found only one mouse cell (1/21). SCN5A mRNA was found in circular muscle of human, dog, and mouse, but not in pig or guinea pig, and not in mouse longitudinal or mucosal layers. In summary, SCN5A message is expressed in, and Na(+) current recorded from, circular muscle layer of human and dog but not from pig and guinea pig. These data show that there are species differences in expression of the SCN5A-encoded Na(v)1.5 channel, suggesting species-specific differences in the electrophysiological response to mechanical and depolarizing stimuli.

A subset of centrosomal proteins are arranged in a tubular conformation that is reproduced during centrosome duplication

The centrosome plays a fundamental role in organizing the interphase cytoskeleton and the mitotic spindle, and its protein complexity is modulated to support these functions. The centrosome must also duplicate itself once during each cell cycle, thus ensuring the formation of a bipolar spindle and its continuity through successive cell divisions. In this study, we have used a battery of antibodies directed against centrosomal components to study the general organization of the centrosome during the cell cycle and during the centrosome duplication process. We demonstrate that a subset of centrosomal proteins are arranged together to form a tubular pattern within the centrosome. The tubular conformation defined by these proteins has a polarity and is closed at one end. The centriole complement of the centrosome is normally placed near this end. We show that the "wall" of the tube is enriched in proteins such as CDC2, ninein, and pericentrin as well as gamma-tubulin. In addition, a subset of gamma-tubulin is localized to the "lumen" of the tube. We also demonstrate, for the first time, that antibody staining can be used to detect centrosome duplication allowing the identification of duplication intermediates. We show that one product of centrosome duplication is the replication of the tubular structure found within the centrosome. The position of the centriole duplexes prior to and during centrosome duplication is documented and a model of the morphogenesis of the centrosome during the duplication process is proposed.

The nuclear pore complex protein Tpr is a common autoantigen in sera that demonstrate nuclear envelope staining by indirect immunofluorescence

We studied the autoantigen targets of 75 human sera that had antibodies to the nuclear envelope (NE) as identified by indirect immunofluorescence (IIF) on HEp-2 cells. Several different IIF staining patterns could be identified when antibodies to different components of the nuclear membrane (NM) and nuclear pore complexes (NuPC) were identified: a smooth membrane pattern characteristic of antibodies to nuclear lamins, a punctate pattern typical of antibodies to the nuclear pore complex and more complex patterns that included antibodies to nuclear and cytoplasmic organelles. Western immunoblotting of isolated nuclear and NE proteins and immunoprecipitation of radiolabelled recombinant proteins prepared by using the full-length cDNAs of the Translocated promoter region (Tpr), gp210 and p62 were used to identify specific autoantibody targets. Fifty-two of the 75 (70%) sera bound to Tpr, 25 (33%) bound to lamins A, B or C, 15 (20%) reacted with gp210 and none reacted with p62. Sixteen (21%) did not react with any of the NE components tested in our assays. The clinical features of 37 patients with anti-NE showed that there were 34 females and three males with an age range of 16-88 years (mean 59 years). The most frequent clinical diagnosis (9/37 = 24%) was autoimmune liver disease (ALD; two with primary biliary cirrhosis), followed by seven (19%) with systemic lupus erythematosus (SLE), four (11%) with a motor and/or sensory neuropathy, three (8%) with anti-phospholipid syndrome (APS), two with systemic sclerosis (SSc), two with Sjögren's syndrome (SjS), and others with a variety of diagnoses. This report indicates that Tpr, a component of the NuPC, is a common target of human autoantibodies that react with the NE.

Piccolo mediates EGFR signaling and acts as a prognostic biomarker in esophageal squamous cell carcinoma

The presynaptic cytomatrix protein Piccolo, encoded by PCLO, is frequently mutated and amplified in esophageal squamous cell carcinoma (ESCC), but its exact roles in ESCC remain unclear. Here we report that Piccolo expression correlates significantly with clinical stage, patient survival and tumor embolus. Functional studies demonstrate that PCLO knockdown remarkably attenuates ESCC malignancy in vitro and in vivo, and ectopic EGFR expression partially compensates for Piccolo loss. PCLO knockdown promotes ubiquitination and degradation of EGFR, which is associated with the negative regulatory effect of Piccolo on E3 ligase Siah1. An anti-Piccolo monoclonal antibody inhibited tumor proliferation in a mouse model of ESCC. These results demonstrate that Piccolo contributes to tumor aggressiveness in ESCC, likely by stabilizing EGFR and promoting EGFR-dependent signaling. Our results further suggest that Piccolo may represent a novel prognostic biomarker and therapeutic target for patients with ESCC.

Treatment of tibia avulsion fracture of posterior cruciate ligament with high-strength suture fixation under arthroscopy

Aim

To evaluate the outcome of arthroscopy treatment using high-strength line in the treatment of tibial avulsion fracture of posterior cruciate ligament.

Methods

Both the avulsed bone block and the tibia bone bed were refreshed. The procedure was completed with the assistance of PCL director drill guide. The reduction and fixation using high-strength line were used to fix the avulsed bone by from posterior middle portal. Rehabilitation began early postoperatively.

Results

From January 2010 to June 2012, a total of 18 arthroscopically treated cases of PCL tibial avulsion fracture were retrospectively evaluated. Reduction of the avulsion fragment was obtained in all cases. 16 cases were followed up for 7–30 months (average 13.6), and 2 cases were out of follow-up. In the 16 followed patients, flexion and extension were back to normal within 6 weeks, and return to normal walk in 12 weeks. The bone healing was good without any vascular or nerve complications. All the patients regained the preinjury activity level. The mean score (and standard deviation) increased from 38.9 ± 4.9 points to 95.2 ± 3.8 points with the system of Lysholm, from 57.1 ± 10.3 points to 94.3 ± 4.4 points with the system of IKDC. Post-test displacement of KT3000 declined from 3.6 ± 0.39 to 1.1 ± 0.27 mm.

Conclusion

Arthroscopic vertical fixation by high-strength line is a simple, safe, reliable, and micro-invasive treatment to PCL tibial avulsion fracture. It is a kind of real all arthroscopic technique, and good for early postoperative rehabilitation. The total stability of the knee could be gained, and the second operation to remove the internal fixation is avoided.

Integrating centrosome structure with protein composition and function in animal cells

The centrosome found in animal cells is a complex and dynamic organelle that functions as the major microtubule organizing center. Structural studies over the past several decades have defined the primary structural features of the centrosome but recent studies are now beginning to reveal structural detail previously unknown. Concurrent with these studies has been an explosion in the identification of the proteins that reside within the centrosome. Our growing understanding of how protein composition integrates with centrosome structure and hence with function is the focus of this review.

Screening of SLE sera using purified recombinant Sm-D1 protein from a baculovirus expression system

The Sm-D1 polypeptide is a major target of autoantibodies diagnostic for systemic lupus erythematosus (SLE). The cDNA encoding the human antigen was expressed as a full-length, nonfusion protein using a eukaryotic baculovirus expression system. This recombinant version of Sm-D1 (rSm-D1) was purified to apparent homogeneity by a combination of differential extraction steps and FPLC chromatography. A direct antibody-binding ELISA was developed using the purified antigen. There was 96% correlation between the rSm-D1 and bona fide Sm-D1 from either HeLa cells or rabbit thymus when tested against Sm-positive patient sera by ELISA. The baculovirus-expressed Sm-D1 is reactive not only with patient anti-Sm sera, but also with anti-Sm monoclonal antibodies. Our results suggest that this rSm-D1 mimics the bona fide sources, providing a valuable addition to the roster of antigens available for SLE screening, epitope mapping and overall structure study.

Dentine hypersensitivity - Australian dentists' perspective

BACKGROUND

Dentine hypersensitivity is a frequent clinical presentation though inadequately comprehended by dentists. The objective of this study was to describe Australian dentists' perception on the occurrence, predisposing factors, triggers, diagnosis and management of dentine hypersensitivity.

METHODS

Eight hundred dentists were randomly selected using the Australian Dental Association membership list and invited to participate in a questionnaire-based survey.

RESULTS

Out of 295 responding dentists, 284 private practitioners were included in the final analysis. Most dentists perceived that the occurrence of dentine hypersensitivity was <20% and commonest among 30-49 year olds. According to them, abrasion and gingival recession were the main predisposing factors whilst cold stimuli were the commonest trigger. A differential diagnosis-based approach was adopted by a majority to diagnose dentine hypersensitivity although routine screening was resorted to by a few. Most dentists were aware of the current mechanisms underlying dentine hypersensitivity whereas the majority perceived that ongoing predisposing factors was the main reason for dentine tubules to remain exposed. The commonest management strategy employed by most dentists was to prescribe desensitizing agents for home use.

CONCLUSIONS

Australian dentists' perception of dentine hypersensitivity is generally consistent with the current scientific consensus on this subject.

Artificial neural network to assist psychiatric diagnosis

BACKGROUND

Artificial Neural Network (ANN), as a potential powerful classifier, was explored to assist psychiatric diagnosis of the Composite International Diagnostic Interview (CIDI).

METHOD

Both Back-Propagation (BP) and Kohonen networks were developed to fit psychiatric diagnosis and programmed (using 60 cases) to classify neurosis, schizophrenia and normal people. The programmed networks were cross-tested using another 222 cases. All subjects were randomly selected from two mental hospitals in Beijing.

RESULTS

Compared to ICD-10 diagnosis by psychiatrists, the overall kappa of BP network was 0.94 and that of Kohonen was 0.88 (both P < 0.01). In classifying patients who were difficult to diagnose, the kappa of BP was 0.69 (P < 0.01). ANN-assisted CIDI was compared with expert system assisted CIDI (kappa = 0.72-0.76); ANN was more powerful than a traditional expert system.

CONCLUSION

ANN might be used to improve psychiatric diagnosis.

Mapping and characterization of the functional domains of the nucleolar protein RNA helicase II/Gu

RNA helicase II/Gu (RH-II/Gu) is a nucleolar RNA helicase of the DEAD-box superfamily. In this study, the functional domains of RH-II/Gu molecule were mapped by fusing the protein or its deletion mutants with a green fluorescence protein and subsequently transfecting or microinjecting the recombinant constructs into HeLa cells. In addition to the identification of a nuclear localization signal (NLS) in the N-terminus and a nucleolar targeting signal in the central helicase domain, a hidden NLS and a nucleolar targeting signal were found in the C-terminal arginine/glycine-rich domain. RH-II/Gu colocalized with fibrillarin, a component of the dense fibrillar region of the nucleolus. Overexpression of the entire RH-II/Gu protein or specific domains of the protein in HeLa cells did not interfere with the normal distribution of fibrillarin. However, when the helicase domain was truncated, the distribution pattern of fibrillarin was distorted. Microinjection of the wild-type RH-II/Gu cDNA into the nucleus of HeLa cells did not disrupt normal cell growth. However, when cells were injected with mutant DNA, only a small percentage of HeLa cells progressed through the cell cycle. Analysis of centrosomes in transfected cells demonstrated that most of the mutant-expressing cells were arrested early in the cell cycle. The results suggest that each of the structural domains of RH-II/Gu is necessary for cell growth and cell cycle progression.

Paraneoplastic limbic encephalitis masquerading as chronic behavioural disturbance in an adolescent girl

AIM

To describe an unusual but treatable cause of behavioural disturbance in adolescence.

METHODS

The case is reported of a 15-y-old girl presenting with acute confusion, memory problems and psychotic symptoms following an 18-mo history of change in personality, school failure and running away from home. A review of the literature is also presented.

RESULTS

Microbiology, toxicology, computed tomography and magnetic resonance imaging did not show any pathology of the central nervous system. Bilateral ovarian immature teratomas were eventually diagnosed and removed. The rapid improvement in the patient's mental and cognitive functions after corticosteroid treatment and the abnormality shown on the single photon emission computed tomography suggested a diagnosis of paraneoplastic limbic encephalitis.

CONCLUSION

Paediatricians and neurologists should be aware of this rare disease entity among the more common conditions of behavioural problems and substance abuse in adolescents.

Effect and mechanism of andrographolide on the recovery of Pseudomonas aeruginosa susceptibility to several antibiotics

Effectiveness and mechanism of action of andrographolide on the recovery of Pseudomonas aeruginosa susceptibility to antibiotics was investigated. In the presence of andrographolide, the Mueller-Hinton broth dilution method measured minimal inhibitory concentrations (MIC) of ceftazidine, cefpirome, chloramphenicol, L-ofloxacin, kanamycin, imipenem and meropenem. Real-time fluorescence quantitative polymerase chain reaction was used to determine mexB mRNA expressions in P. aeruginosa PAO1 strain and MexAB-OprM overexpressing strain. Relative mexB mRNA expression was detected in both strains incubated for 3 and 9 h. When andrographolide-treated groups were compared with controls, the MIC of ceftazidine, cefpirome, L-ofloxacin and meropenem for both strains decreased, and the relative mexB mRNA expression was significantly lower, although between andrographolide groups there were no significant differences. Compared with the inactivated quorum-sensing system, relative amounts of mexB mRNA in the PAO1 strain and MexAB-OprM overexpressing strain in the activated quorum-sensing system increased 10- and 30-fold, respectively. Andrographolide recovered P. aeruginosa susceptibility to antibiotics and reduced the MexAB-OprM efflux pump expression level.

Imatinib inhibits CSF1R that stimulates proliferation of rheumatoid arthritis fibroblast-like synoviocytes

In this study, we aimed to explore the effects of imatinib on the proliferation of rheumatoid arthritis synovial cell (RA-FLS) and inflammatory responses by regulating CSF1R. Differential genes were screened via microarray analysis, followed by being analysed through the weighted co-expression network (WGCNA) network, that included module and cluster analysis. The relationship between imatinib and genes was visualized using the Search Tool for the Retrieval of Interacting Genes (STITCH) database. Expressions of mRNA and protein were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively. Cell viability was examined via clone formation assay, while cell cycle and apoptosis were analysed through flow cytometry analysis. The hub gene CSF1R was ultimately determined by microarray analysis and WGCNA analysis. Colony-stimulating-factor receptor-1 (SF1R) was highly expressed in rheumatoid arthritis tissues and cells, and CSF1R over-expression could promote inflammatory responses. Moreover, CSF1R could promote RA-FLS proliferation, inhibit apoptosis and accelerate the cell cycle. The targeting relationship between imatinib and CSF1R was also validated in this study. Imatinib attenuated RA-FLS inflammation in a concentration-dependent manner. Meanwhile, imatinib could inhibit RA-FLS proliferation and promote apoptosis, ultimately reducing the damage of RA-FLS. Over-expression of CSF1R accelerated the cell cycle and proliferation of RA-FLS, while inhibiting cell apoptosis. Conversely, imatinib could significantly restrain the cell cycle and viability of RA-FLS and accelerated apoptosis via suppression of CSF1R expression. Further, histological and serological assay investigated and proved the proinflammatory effects of CSF1R in RA rabbits.

Septic arthritis in hemophilia with central venous catheter: a case report

A case is reported of septic arthritis in a child with human immunodeficiency virus-negative hemophilia A associated with a Staphylococcus aureus catheter-associated septicemia. The infection occurred in relation to the use of a totally implantable central venous catheter. The organism was eventually eradicated with antibiotics injected via the catheter. With increasing use of such catheters in the hemophilic population, clinicians should be alerted to the possibility of septic arthritis for prompt diagnosis and treatment.

High incidence of juvenile Graves' disease in Hong Kong

OBJECTIVE

Childhood Graves' disease has been reported to be rare and epidemiological data on its incidence are limited. In our Paediatric Endocrine Clinic, Graves' disease was the most common thyroid disorder seen. There is no previous epidemiological study on Graves' disease in Chinese children. This study was performed to determine the incidence of childhood Graves' disease in Hong Kong Chinese.

DESIGN AND PATIENTS

We established a registry of childhood Graves' disease in 1990 at our centre, which has a catchment population of 1,010,000 with 240,000 under 15 years of age. Graves' disease was diagnosed on clinical features, diffuse thyroid gland enlargement, elevated free thyroxine or triiodothyronine levels with suppressed TSH level. All confirmed cases were recorded prospectively. Population data were obtained from the Statistics Department of the Hong Kong Government.

RESULTS

Forty-six Chinese children under 15 years of age had a confirmed diagnosis of Graves' disease during the study period from January 1990 to December 1994. The overall incidence was 3.8/100,000/year with a 95% confidence interval of 1.8-7.3/100,000/year. Incidence was low in children under 4 years. The highest incidence was in girls between 10 and 14 years of age at 15.5/100,000/year. The cumulative incidence for boys and girls of developing Graves' disease during the first 15 years was 11 and 104 per 100,000 respectively.

CONCLUSIONS

Our data demonstrate a very high incidence of Graves' disease in Hong Kong Chinese children, with an overall incidence about 5 times that reported in Danish children. A female predominance was found in all three age groups (0-4, 5-9 and 10-14 years) and was particularly striking in the adolescent girls.

Simian varicella virus gene 61 encodes a viral transactivator but is non-essential for in vitro replication

Simian varicella virus (SVV) is closely related to varicella-zoster virus (VZV), the causative agent of chickenpox and shingles. The SVV and VZV gene 61 polypeptides are homologs of the HSV-1 ICP0, a viral transactivator which appears to play a role in viral latency and reactivation. In this study, the molecular properties of the SVV 61 were characterized. The SVV open reading frame (ORF) 61 encodes a 54.1-kDa polypeptide with 37% amino acid identity to the VZV 61. Homology to the HSV-1 ICP-0 is limited to a conserved RING finger motif at the amino terminus of the protein. A nuclear localization sequence (nls) at the carboxy-terminus directs the SVV 61 to the cell nucleus, while a SVV 61nls(-) mutant is confined to the cell cytoplasm. The SVV 61 transactivates its own promoter as well as SVV immediate early (IE, ORF 62), early (ORFs 28 and 29), and late (ORF 68) gene promoters in transfected Vero cells. The RING finger and nls motifs are required for efficient SVV 61 transactivation. The SVV 61 has no effect on the ability of the major SVV transactivator (IE62) to induce SVV promoters. Generation and propagation of a SVV gene 61 deletion mutant demonstrated that the SVV 61 is non-essential for in vitro replication. SVV gene 61 is expressed in liver, lung, and neural ganglia of infected monkeys during acute simian varicella.