Can diffusion-weighted imaging be used to differentiate brain abscess from other ring-enhancing brain lesions? A meta-analysis

AIM

To explore the role of diffusion-weighted imaging (DWI) in the discrimination of brain abscess from other ring-enhancing brain lesions through meta-analysis.

MATERIALS AND METHODS

The PUMBED, OVID, and China National Knowledge Infrastructure (CNKI) databases, from January 1995 to March 2013, were searched for studies evaluating the diagnostic performance of DWI in the discrimination of brain abscess lesions. Using the data collected, pooled sensitivities and specificities across studies were determined, positive and negative likelihood ratios (LR) were calculated, and summary receiver operating characteristic (SROC) curves were constructed.

RESULTS

A total of 11 studies fulfilled all of the inclusion criteria and were considered for the analysis. The pooled sensitivity values and pooled specificity values including 95% confidence intervals (CI) were 0.95 (0.87-0.98) and 0.94 (0.88-0.97). The pooled positive LR (95% CI) was 4.13(2.55-6.7); the pooled negative LR (95% CI) was 0.01 (0-1.7); and the area under the curve of the symmetric SROC was 0.98.

CONCLUSIONS

DWI has high sensitivity and specificity for the differentiation of brain abscess from other intracranial cystic mass lesions.

Bile deficiency induces changes in intestinal Cl(-) and HCO3 (-) secretions in mice

AIMS

Biliary tract obstruction is a common clinical lesion. However, the effect of biliary tract obstruction on intestinal secretion is poorly understood. In this study, we made an investigation on intestinal HCO3 (-) and Cl(-) secretions in an experimental model of murine biliary duct ligation.

METHODS

Murine intestinal mucosal HCO3 (-) and Cl(-) secretions were examined in vitro in Ussing chambers by pH-stat and short-circuit current (Isc ) techniques. The mRNA and protein expressions of the cystic fibrosis transmembrane conductance regulator (CFTR) and the Na(+) -K(+) -2Cl(-) cotransporter (NKCC1) were analysed by real-time PCR, western blot and immunohistochemistry.

RESULTS

Basal Cl(-) secretion and forskolin-stimulated duodenal and jejunal mucosal HCO3 (-) and Cl(-) secretions in mice with common biliary duct ligation were markedly elevated, compared with controls (P < 0.05 and P < 0.01). Further experiments showed that basal Cl(-) secretion and forskolin-stimulated duodenal and jejunal mucosal HCO3 (-) and Cl(-) secretions in mice with external bile drainage were also markedly elevated. CFTRinh -172 inhibited forskolin-stimulated HCO3 (-) and Cl(-) secretions. The mRNA and protein expression levels of CFTR and NKCC1 in the intestinal mucosa with both biliary duct ligation and external bile drainage were markedly higher than those in controls (P < 0.001). Bile acid administration restored the changes in function and expression of CFTR and NKCC1 in the intestinal mucosa.

CONCLUSION

Bile deficiency in the intestine up-regulates the expressions of intestinal mucosal CFTR and NKCC1 and enhances intestinal mucosal HCO3 (-) and Cl(-) secretion capacity, which contributes to the understanding of intestinal physiological function for patients with biliary duct obstruction.

Study on the treatment of the p15 gene combined with Bcr-abl-specific siRNA and STI571 for chronic myeloid leukemia

The aim of this study was to investigate the effect of the p15 gene combined with Bcr-abl-specific siRNA and STI571 on the proliferation, cell cycle and apoptosis of K562 chronic myeloid leukemia cells. Using the gene sequence results, we amplified the p15 gene from normal peripheral blood by RT-PCR, and constructed a p15-pcDNA3.1 vector. The K562 cell line with G418 resistance was screened, synthesized and transfected for bcr-abl gene fusion point for 21-nt siRNA. In p15-pcDNA3.1-K562 cells, the growth rate was slower than that of the control K562 cells, G0/G1-phase was increased and S-phase was decreased significantly. In the siRNA group, bcr-abl fusion gene expression was significantly decreased in K562 cells accompanied by the downregulation of BCL-xL protein expression and G1-phase arrest. Cell survival rate was significantly decreased compared with the sole p15-K562 cell group and the sole RNA interference-K562 cell group. In the combination of p15-pcDNA3.1-K562 cells with STI571, the proportion of apoptosis was significantly increased and the cell survival rate was significantly decreased compared with the p15-K562 cell group and STI571-K562 cell group. siRNA at 30 pM combined with 0.5 μM STI571 promoted apoptosis compared with sole application. The p15 gene combined with siRNA had a synergistic effect on the inhibition of proliferation and the induction of apoptosis in K562 cells. Exogenous p15 protein expression combined with STI571 appeared to have a synergistic effect on proliferation inhibition and apoptosis induction in K562 cells. The combination of low-dose RNA interference with STI571 showed a synergistic effect in inducing apoptosis.

Association between PADI4 gene polymorphisms and anti-cyclic citrullinated peptide antibody positive rheumatoid arthritis in a large Chinese Han cohort

OBJECTIVES

The present study was undertaken to investigate the association of peptidyl-arginine-deiminase type IV gene (PADI4) single nucleotide polymorphisms (SNPs) with rheumatoid arthritis (RA) susceptibility, and to determine whether there is any impact of PADI4 polymorphisms on RA subsets or phenotypes in a large Chinese Han cohort.

METHODS

Two PADI4 SNPs (rs2240340 and rs1748033) were genotyped in 1216 Chinese Han RA patients and 1040 unaffected controls by TaqMan SNP Assays. Serum anti-CCP antibody and anti-PAD4 antibody levels were measured by ELISA. Bone destruction was scored by Sharp-van der Heijde scores (SHSs) of hands in 463 patients.

RESULTS

The two SNPs rs2240340 and rs1748033 of PADI4 showed strong association with RA susceptibility (OR=1.23, 95% CI 1.09-1.38, p=6.66×10⁻⁴; and OR=1.24, 95% CI 1.10-1.41, p=6.98×10⁻⁴, respectively). RA risk genotypes of PADI4 were specifically associated with anti-CCP positive RA (rs2240340: p=5.13×10⁻⁶; rs1748033: p=2.97×10⁻³, respectively). Furthermore, there was a trend association between PADI4 rs2240340 and radiographic severity, though it did not reach the statistic significance (p=0.088).

CONCLUSIONS

Our data provide strong evidence that PADI4 polymorphisms are risk factors contributed to RA susceptibility, especially for anti-CCP positive RA, and may confer higher risk of RA radiographic severity in Chinese Han population.

Serum anti-lipocalin 2 IgG is a novel biomarker in the diagnosis of systemic lupus erythematosus

BACKGROUND

Previous work suggests that lipocalin 2 is involved in the pathogenesis of systemic lupus erythematosus (SLE) and that this novel antigen could serve as a high-quality renal biomarker of acute kidney injury in SLE. However, serum lipocalin 2 antibody levels remain unclear. We have therefore undertaken this study to assess the level of serum IgG antibody against lipocalin 2 in different disease states and to evaluate the diagnostic value of this potential biomarker in SLE.

METHODS

Serum levels of anti-lipocalin IgG antibodies were measured by ELISA in 103 SLE patients, 93 rheumatoid arthritis (RA) patients, 29 primary Sjögren's syndrome (pSS) patients, 13 systemic sclerosis (SSc) patients, and 91 healthy controls. Diagnostic properties of anti-lipocalin IgG were determined by receiver-operating characteristic (ROC) curve analysis.

RESULTS

The level of serum anti-lipocalin IgG in patients with SLE was significantly higher than in patients with RA, pSS, SSc, or healthy controls (p < 0.05), effectively distinguishing SLE from other conditions with high sensitivity and specificity (49.5% and 90.7%, respectively). In ROC curve analysis, the area under the curve (AUC) is 0.783, with a 95% confidence interval (CI) extending from 0.729 to 0.839. Anti-lipocalin antibodies were present in 48.1% of anti-Sm-negative SLE patients, and also occurred in SLE patients lacking anti-dsDNA (52%) or anti-nucleosome antibodies (46.3%) antibodies. Finally, SLE patients with positive anti-lipocalin IgG possessed higher levels of IgA and CRP than the negative group (p < 0.05), clearly demonstrating a positive correlation between anti-lipocalin IgG and these laboratory parameters.

CONCLUSIONS

Anti-lipocalin 2 IgG is a promising biomarker for the diagnosis of SLE, particularly when obtained in conjunction with anti-Sm, anti-dsDNA, and anti-nucleosome antibody levels.

Evaluation of simultaneous 201Tl/99mTc dual-isotope cardiac SPECT imaging with model-based crosstalk compensation using canine studies

BACKGROUND

Simultaneous (201)Tl/(99m)Tc-sestamibi dual-isotope myocardial perfusion SPECT imaging can reduce imaging time and produce perfectly registered rest/stress images. However, crosstalk from (99m)Tc into (201)Tl images can significantly reduce (201)Tl image quality. We have developed a model-based compensation (MBC) method to compensate for this crosstalk. The method has previously been validated with phantom and simulation studies. In this study, we evaluated the MBC method using a canine model.

METHODS

Left anterior descending or left circumflex coronary artery stenoses were created in 50 adult mongrel dogs weighing 20-30 kg. The dogs were injected with 111 MBq (3 mCi) of (201)Tl at rest, and a SPECT study acquired. Stress was induced by administering adenosine to the dog, followed by injection of 740 MBq (20 mCi) of (99m)Tc-sestamibi at peak stress. A second SPECT study was performed with data acquired in both (201)Tl and (99m)Tc energy windows to provide simultaneous dual-isotope projection data. The images were reconstructed using the ordered-subsets expectation-maximization reconstruction algorithm with compensation for attenuation, scatter, and detector response. For simultaneously acquired (201)Tl data, we also applied the MBC method to compensate for crosstalk contamination from (99m)Tc.

RESULTS

Without compensation, (99m)Tc crosstalk increased the estimated (201)Tl activity concentration in the rest images and reduced defect contrast. After MBC, the (201)Tl images were in good agreement with the registered single-isotope images and ex vivo count data. The ischemic (IS) to non-ischemic (NIS) region (201)Tl activity concentration ratios were computed for single-isotope and dual-isotope studies. The correlation with ex vivo IS-NIS ratios was 0.815 after MBC, compared to the 0.495 from data without compensation. In addition, the regression line for the IS-NIS ratios with MBC was almost parallel to the line of identity with a slope of 0.93, compared to a slope of 0.45 without compensation.

CONCLUSIONS

These results demonstrate that model-based crosstalk compensation can provide substantial reduction of crosstalk effects in simultaneously acquired myocardial perfusion SPECT images in living biological systems.

Sequence variations at I260 and A1731 contribute to persistent currents in Drosophila sodium channels

Tetrodotoxin-sensitive persistent sodium currents, INaP, that activate at subthreshold voltages, have been detected in numerous vertebrate and invertebrate neurons. These currents are believed to be critical for regulating neuronal excitability. However, the molecular mechanism underlying INaP is controversial. In this study, we identified an INaP with a broad range of voltage dependence, from -60mV to 20mV, in a Drosophila sodium channel variant expressed in Xenopus oocytes. Mutational analysis revealed that two variant-specific amino acid changes, I260T in the S4-S5 linker of domain I (ILS4-S5) and A1731V in the voltage sensor S4 of domain IV (IVS4), contribute to the INaP. I260T is critical for the portion of INaP at hyperpolarized potentials. The T260-mediated INaP is likely the result of window currents flowing in the voltage range where the activation and inactivation curves overlap. A1731V is responsible for impaired inactivation and contributes to the portion of INaP at depolarized potentials. Furthermore, A1731V causes enhanced activity of two site-3 toxins which induce persistent currents by inhibiting the outward movement of IVS4, suggesting that A1731V inhibits the outward movement of IVS4. These results provided molecular evidence for the involvement of distinct mechanisms in the generation of INaP: T260 contributes to INaP via enhancement of the window current, whereas V1731 impairs fast inactivation probably by inhibiting the outward movement of IVS4.

High-intensity focused ultrasound combined with dilatation and curettage for Cesarean scar pregnancy

We describe a new technique for the management of Cesarean scar pregnancy (CSP), high-intensity focused ultrasound (HIFU) combined with dilatation and curettage (D&C), in four patients managed at our university hospital. All four had elevated serum human chorionic gonadotropin (hCG) levels and large lesions with strong peripheral color Doppler signals, indicating possible risk of profuse bleeding, and all four women wished to preserve their fertility. HIFU was performed under local anesthesia. Success of the treatment in all four cases was indicated by complete primary evacuation of the CSP and return of serum hCG to normal levels (serum hCG < 20 mIU/mL). However, one patient in whom there was a large scar defect and placental implantation underwent laparotomy to remove the trophoblastic tissue and repair the defect, although the hCG level had already returned to normal levels. HIFU, by utilizing ultrasound energy to heat tissue at a focal point, is able to stop embryonic cardiac activity and leads to a rapid reduction in serum hCG levels. Subsequent D&C under hysteroscopic guidance enables complete removal of products of conception following the HIFU procedure.

[Prevalence and temporal trend of known diabetes mellitus: results of the German Health Interview and Examination Survey for Adults (DEGS1)]

The first wave of the "German Health Interview and Examination Survey for Adults" (DEGS1, 2008-2011) allows for up-to-date, representative prevalence estimates of known diabetes amongst the 18- to 79-year-old resident population of Germany. Temporal trends can be shown by comparing the survey findings with those of the "German National Health Interview and Examination Survey 1998" (GNHIES98). The definition of known diabetes was based on self-reports in physician-administered interviews that asked respondents if they had ever been diagnosed with diabetes by a doctor or were on anti-diabetic medication. Overall, diabetes had been diagnosed in 7.2 % of the adults (7.4 % of the women; 7.0 % of the men). The prevalence increased substantially with advancing age and was higher in persons of low than of high socioeconomic status. Prevalence varied depending on the type of health insurance held and was highest amongst those insured with AOK health insurance funds. In comparison with GNHIES98, there was a 38 % increase in prevalence, of which approximately one third is to be attributed to demographic ageing. In the context of other nationwide studies, the results indicate a figure of at least 4.6 million 18- to 79-year-olds having been diagnosed with diabetes at some point. Planned analyses of undiagnosed diabetes will contribute to the interpretation of the observed increase in the prevalence of known diabetes. An English full-text version of this article is available at SpringerLink as supplemental.

[Prevalence of dyslipidemia among adults in Germany: results of the German Health Interview and Examination Survey for Adults (DEGS 1)]

Interview and laboratory data from the first wave of the German health interview and examination survey for adults (DEGS1) from 2008 to 2011 were used to provide current estimates of the prevalence of dyslipidemia which are representative of the population in Germany 18 to 79 years of age. A total of 56.6 % of men and 60.5 % of women 18 to 79 years have elevated serum total cholesterol concentrations in excess of the currently recommended threshold of 190 mg/dL; 17.9 % of men and 20.3 % of women have highly elevated total cholesterol concentrations ≥ 240 mg/dL. A total of 19.3 % of men and 3.6 % of women have high density lipoprotein cholesterol concentrations below 40 mg/dL. The overall prevalence of dyslipidemia (total cholesterol ≥ 190 mg/dL or medical diagnosis of dyslipidemia) is 64.5 % for men and 65.7 % for women. Of these, more than half of both men and women have previously undiagnosed dyslipidemia. Among persons with known dyslipidemia, 30.8% take lipid-lowering medication. Dyslipidemia is widely prevalent among adults in Germany. More in-depth analyses will examine time trends in the prevalence of dyslipidemia in Germany and in an international comparison. An English full-text version of this article is available at SpringerLink as supplemental.

Perceptions of caring in China: patient and nurse questionnaire survey

BACKGROUND

The concept of caring is important to both patients and nurses. If patients and nurses perceive caring behaviours differently, patients may not have their needs met or will be dissatisfied with the nursing.

AIM

This study conducted in mainland China compared the perceptions of nurses and patients concerning nurses' caring behaviours.

METHODS

From November 2011 to June 2012, 680 patients and 540 of their nurses in five hospitals in southern, central and eastern China were invited to complete a descriptive comparative survey with four subcategories, the Caring Behaviors Inventory-24. Respondents scored each of the 24 items on the survey from 1 (low) to 6 (high). Of those invited, 595 patients (87.50%) and 445 (82.41%) nurses completed the survey.

RESULTS

The mean item score on the Caring Behaviors Inventory-24 was 4.32 and 4.96 for patients and nurses, respectively. The subcategory with the highest mean score for both groups was knowledge and skills (4.73, 5.25), and the lowest for both groups was positive connectedness (3.98, 4.51). Nurses' scores were significantly higher than those of patients for all four subcategories (P < 0.001).

CONCLUSIONS

The gap between the two groups indicates that nurses need to improve their understanding and response to patients' actual and perceived needs and expectations. In China, patients require more support from nurses of their psychological needs.

STUDY LIMITATIONS

Participants came from a limited number of hospitals in three cities. A larger sample from different hospitals in mainland China could have increased the power of the study.

Proline-rich tyrosine kinase 2 and its phosphorylated form pY881 are novel prognostic markers for non-small-cell lung cancer progression and patients' overall survival

BACKGROUND

Our previous study revealed that proline-rich tyrosine kinase 2 (Pyk2) is implicated in both anchorage-independent growth and anoikis resistance in lung cancer cells. This study aims to explore the expression and clinical significance of Pyk2 and its phosphorylated forms in non-small-cell lung cancer (NSCLC).

METHODS

The mRNA and protein levels of Pyk2 or cancer stem cell markers (ALDH1a1, ABCG2 and Bmi-1) were either examined by reverse transcription-PCR or western blotting. An immunohistochemistry (IHC) assay was conducted to analyse the expression of Pyk2 and its phosphorylated forms in 128 NSCLC cases.

RESULTS

The levels of Pyk2 mRNA, total protein, and its phosphorylated form pY881 were higher in lung cancer lesions than in the paired noncancerous tissues. The IHC analysis showed the levels of the Pyk2 and Pyk2[pY881] proteins were highly expressed in 70 (54.7%) and 77 (60.2%) cases, respectively. Both Pyk2 and Pyk2[pY881] were independent prognostic factors for NSCLC patients. The gain and loss study of Pyk2 function revealed that Pyk2 could upregulate the expression of ALDH1a1, ABCG2 and Bmi-1 and enhance the ability of colony formation in soft agar assay in A549 and H460 cells.

CONCLUSION

Both Pyk2 and phosphorylated Pyk2[pY881] are potential prognostic factors and therapeutic targets for NSCLC.

Intra-articular nuclear factor-κB blockade ameliorates collagen-induced arthritis in mice by eliciting regulatory T cells and macrophages

Nuclear factor (NF)-κB is a transcription factor implicated in the pathogenesis of autoimmune disorders such as rheumatoid arthritis (RA). Here we have examined the effect of intra-articular administration of the IKK inhibitor, NEMO-binding domain peptide (NBD), on the severity of collagen-induced arthritis (CIA). NBD peptides were injected intra-articularly into the knee joints of DBA/1J mice after the onset of disease. Collagen-injected mice given a scrambled peptide served as controls. Arthritis severity was determined by visual examination of paws. Intra-articular NBD injection reduced the arthritis score and ameliorated morphological signs of bone destruction compared to the controls. Serum levels of type-II collagen-specific immunoglobulin (Ig)G2a antibodies were lower in NBD-treated mice versus the control mice, whereas the levels of type-II collagen-specific IgG1 antibodies were increased by NBD treatment. NBD treatment diminished the proinflammatory cytokines interleukin (IL)-17 and interferon (IFN)-γ in serum, but increased the regulatory cytokine IL-10. NBD-treated CIA mice exhibited significantly higher percentages and numbers of forkhead box protein 3 (FoxP3(+)) CD4(+) CD25(+) regulatory T cells than controls. Immunofluorescence analysis of NBD-treated mice revealed that FoxP3 and Ym1, a marker of alternatively activated macrophages, were juxtaposed to each other within draining inguinal lymph nodes. Intra-articular administration of NBD peptide is effective as an experimental therapy in a murine model of RA. Nevertheless, the intra-articular treatment modality is still associated with systemic effects on the immune system.

Gαq gene promoter polymorphisms and rheumatoid arthritis in the Han Chinese population are not associated

Mice that lose Gαq from their immune system can spontaneously develop inflammatory arthritis. Gαq expression in the peripheral blood lymphocytes of rheumatoid arthritis (RA) patients is significantly decreased in comparison to that in healthy individuals, and reduced Gαq expression is closely correlated with RA disease activity. These indicate that Gαq plays critical roles in the pathogenesis of RA. To address whether single nucleotide polymorphism in the promoter region of the Gαq gene (GNAQ) influenced Gαq expression in RA patients and was a genetic risk factor for RA, we sequenced the promoter region of GNAQ in a Han Chinese population. A common dinucleotide polymorphism at position -695/-694, an exchange of 2 adjacent nucleotides (GC>TT), was revealed in 118 RA patients and 101 healthy adults. The proportions of genotypes observed for -695/-694 in the RA group were GC/GC (65.25%), GC/TT (33.05%), and TT/TT (1.70%), and those in the control group were GC/GC (62.38%), GC/TT (33.66%), and TT/TT (3.96%). No significant difference in the allele and genotype frequencies between RA patients and healthy controls for dinucleotide polymorphism was found in the Han Chinese population, neither in the whole data set nor in stratified subsets, i.e., rheumatoid factors, anti-cyclic citrullinated peptide antibody, and Gαq expression status (P > 0.05). We conclude that the GNAQ promoter polymorphism is not a genetic risk factor for RA in the Han Chinese population, and that decreased Gαq expression in peripheral blood lymphocytes of RA might potentially be due to other causes.

Membrane association and destabilization by Aggregatibacter actinomycetemcomitans leukotoxin requires changes in secondary structures

Aggregatibacter actinomycetemcomitans is a common inhabitant of the upper aerodigestive tract of humans and non-human primates and is associated with disseminated infections, including lung and brain abscesses, pediatric infective endocarditis, and localized aggressive periodontitis. Aggregatibacter actinomycetemcomitans secretes a repeats-in-toxin protein, leukotoxin, which exclusively kills lymphocyte function-associated antigen-1-bearing cells. The toxin's pathological mechanism is not fully understood; however, experimental evidence indicates that it involves the association with and subsequent destabilization of the target cell's plasma membrane. We have long hypothesized that leukotoxin secondary structure is strongly correlated with membrane association and destabilization. In this study, we tested this hypothesis by analysing lipid-induced changes in leukotoxin conformation. Upon incubation of leukotoxin with lipids that favor leukotoxin-membrane association, we observed an increase in leukotoxin α-helical content that was not observed with lipids that favor membrane destabilization. The change in leukotoxin conformation after incubation with these lipids suggests that membrane binding and membrane destabilization have distinct secondary structural requirements, suggesting that they are independent events. These studies provide insight into the mechanism of cell damage that leads to disease progression by A. actinomycetemcomitans.