Exploring the immunogenicity of Rv2201-519: A T-cell epitope-based antigen derived from Mycobacterium tuberculosis AsnB with implications for tuberculosis infection detection and vaccine development

Research dedicated to diagnostic reagents and vaccine development for tuberculosis (TB) is challenging due to the paucity of immunodominant antigens that can predict disease risk and exhibit protective potential. Therefore, it is crucial to identify T-cell epitope-based Mycobacterium tuberculosis (MTB) antigens characterized by specific and prominent recognition by the immune system. In this study, we constructed a T-cell epitope-rich tripeptide-splicing fragment (nucleotide positions 131-194, 334-377, and 579-643) of Rv2201 (also known as the 72 kDa AsnB)from the MTB genome, ultimately yielding the recombinant protein Rv2201-519 in Escherichia coli BL21 (DE3). Subsequently, we gauged the recombinant protein's ability to detect tuberculosis infection through ELISpot and assessed its immunostimulatory effect on mouse models using flow cytometry and ELISA. Our results indicated that Rv2201-519 possessed promising sensitivity; however, the sensitivity was lower than that of a commercial diagnostic kit containing ESAT-6, CFP-10, and Rv3615c (80.56 % vs. 94.44 %). The Rv2201-519 group exhibited a propensity for a CD4+ Th1 cell immune response in inoculated BALB/c mice that manifested as higher levels of antigen-specific IgG production (IgG2a/IgG1 > 1). In comparison to Ag85B, Rv2201-519 induced a more robust Th1-type cellular immune response as evidenced by a notable rise in the ratio of IFN-γ/IL-4 and IL-12 cytokine production and increased CD4+ T cell activation with a higher percentage of CD4+IFN-γ+ T cells. Rv2201-519 also induced a higher level of IL-6 compared with Ag85B, a higher percentage of CD8+ T cells specific for Rv2201-519, and a lower percentage of CD8+IL-4+ T cells. Collectively, the current evidence suggests that Rv2201-519 could potentially serve as an immunodominant protein for tuberculosis infection screening, laying the groundwork for further evaluation in recombinant Bacillus Calmette-Guérin (BCG) and subunit vaccines against MTB challenges in future studies.

A novel multistage antigens ERA005f confer protection against Mycobacterium tuberculosis by driving Th-1 and Th-17 type T cell immune responses

Introduction

Tuberculosis (TB) is a major threat to human health. In 2021, TB was the second leading cause of death after COVID-19 among infectious diseases. The Bacillus Calmette-Guérin vaccine (BCG), the only licensed TB vaccine, is ineffective against adult TB. Therefore, there is an urgent need to develop new effective vaccines.

Methods

In this study, we developed a novel multistage subunit vaccine (ERA005f) comprising various proteins expressed in metabolic states, based on three immunodominant antigens (ESAT-6, Rv2628, and Ag85B). We utilized the E. coli prokaryotic expression system to express ERA005f and subsequently purified the protein using nickel affinity chromatography and anion exchange. Immunogenicity and protective efficacy of ERA005f and ERA005m were evaluated in BALB/c mice.

Results

ERA005f was consistently expressed as an inclusion body in a prokaryotic expression system, and a highly pure form of the protein was successfully obtained. Both ERA005f and ERA005m significantly improved IgG titers in the serum. In addition, mice immunized with ERA005f and ERA005m generated higher titers of antigen-specific IgG2a than the other groups. Elispot results showed that, compared with other groups, ERA005f increased the numbers of IFN-γ-secreting and IL-4-secreting T cells, especially the number of IFN-γ-secreting T cells. Meanwhile, ERA005f induced a higher number of IFN-γ+ T lymphocytes than ERA005m did. In addition, ERA005f improved the expression of cytokines, including IFN-γ, IL-12p70, TNF-α, IL-17, and GM-CSF and so on. Importantly, both ERA005f and ERA005m significantly inhibited the growth of Mtb.

Conclusion

The novel multistage antigen ERA005f elicited a strong antigen-specific humoral response and Th-1 and Th-17 cell-mediated immunity in mice. Meanwhile, it can effectively inhibit H37Rv growth in vitro, and represents a correlate of protection in vivo, indicating that ERA005f may exhibit excellent protective efficacy against Mycobacterium tuberculosis H37Rv infection. Our study suggests that ERA005f has the potential to be a promising multistage tuberculosis vaccine candidate.

Immunogenicity and efficacy analyses of EPC002, ECA006, and EPCP009 protein subunit combinations as tuberculosis vaccine candidates

Tuberculosis (TB) is the leading cause of death from infectious diseases worldwide, and developing a new TB vaccine is a priority for TB control. Combining multiple immunodominant antigens to form a novel multicomponent vaccine with broad-spectrum antigens to induce protective immune responses is a trend in TB vaccine development. In this study, we used T-cell epitope-rich protein subunits to construct three antigenic combinations: EPC002, ECA006, and EPCP009. Fusion expression of purified protein EPC002f (CFP-10-linker-ESAT-6-linker-nPPE18), ECA006f (CFP-10-linker-ESAT-6-linker-Ag85B), and EPCP009f (CFP-10-linker-ESAT-6-linker-nPPE18-linker-nPstS1) and recombinant purified protein mixtures EPC002m (mix of CFP-10, ESAT-6, and nPPE18), ECA006m (mix of CFP-10, ESAT-6, and Ag85B), and EPCP009m (mix of CFP-10, ESAT-6, nPPE18, and nPstS1) were used as antigens, formulated with alum adjuvant, and the immunogenicity and efficacy were analyzed using immunity experiments with BALB/c mice. All protein-immunized groups elicited higher levels of humoral immunity, including IgG and IgG1. The IgG2a/IgG1 ratio of the EPCP009m-immunized group was the highest, followed by that of the EPCP009f-immunized group, which was significantly higher than the ratios of the other four groups. The multiplex microsphere-based cytokine immunoassay revealed that EPCP009f and EPCP009m induced the production of a wider range of cytokines than EPC002f, EPC002m, ECA006f, and ECA006m, which included Th1-type (IL-2, IFN-γ, TNF-α), Th2-type (IL-4, IL-6, IL-10), Th17-type (IL-17), and other proinflammatory cytokines (GM-CSF, IL-12). The enzyme-linked immunospot assays demonstrated that the EPCP009f- and EPCP009m-immunized groups had significantly higher amounts of IFN-γ than the other four groups. The in vitro mycobacterial growth inhibition assay demonstrated that EPCP009m inhibited Mycobacterium tuberculosis (Mtb) growth most strongly, followed by EPCP009f, which was significantly better than that of the other four vaccine candidates. These results indicated that EPCP009m containing four immunodominant antigens exhibited better immunogenicity and Mtb growth inhibition in vitro and may be a promising candidate vaccine for the control of TB.

A novel multi-component protein vaccine ECP001 containing a protein polypeptide antigen nPstS1 riching in T-cell epitopes showed good immunogenicity and protection in mice

Tuberculosis (TB) is an infectious disease that seriously affects human health. Until now, the only anti-TB vaccine approved for use is the live attenuated Mycobacterium bovis (M. bovis) vaccine - BCG vaccine, but its protective efficacy is relatively low and does not provide satisfactory protection against TB in adults. Therefore, there is an urgent need for more effective vaccines to reduce the global TB epidemic. In this study, ESAT-6, CFP-10, two antigens full-length and the T-cell epitope polypeptide antigen of PstS1, named nPstS1, were selected to form one multi-component protein antigens, named ECP001, which include two types, one is a mixed protein antigen named ECP001m, the other is a fusion expression protein antigen named ECP001f, as candidates for protein subunit vaccines. were prepared by constructing one novel subunit vaccine by mixing or fusing the three proteins and combining them with aluminum hydroxide adjuvant, and the immunogenicity and protective properties of the vaccine was evaluated in mice. The results showed that ECP001 stimulated mice to produce high titre levels of IgG, IgG1 and IgG2a antibodies; meanwhile, high levels of IFN-γ and a broad range of specific cytokines were secreted by mouse splenocytes; in addition, ECP001 inhibited the proliferation of Mycobacterium tuberculosis in vitro with a capacity comparable to that of BCG. It can be concluded that ECP001 is a novel effective multicomponent subunit vaccine candidate with potential as BCG Initial Immunisation-ECP001 Booster Immunisation or therapeutic vaccine for M. tuberculosis infection.

Development of an animal model for rosacea‑like skin lesions caused by Demodex

To develop an animal model of rosacea-like skin lesions caused by Demodex mites, a suspension of Demodex mites was injected into the skin of Japanese rabbits. The pathology of the skin lesion was assessed using H&E staining after 4 weeks of modeling. The skin lesions observed after 4 weeks were further treated with the recombinant bovine basic fibroblast growth factor (rbFGF) gel. Untreated lesions in the same rabbit were considered as the blank control. Erythema papules were observed in the model rabbit skin and could be observed most clearly in the 2nd week. Lumpy foreign bodies, telangiectasia and granuloma-like structure were observed in the model rabbit in the 1st, 2nd, and 3rd weeks, respectively. An organized granuloma-like structure was observed in the 4th week. The color of the skin lesions became lighter than that of the self-control after 4 weeks of rbFGF treatment. In conclusion, the model of Demodex-induced rosacea-like skin lesions can be developed through intradermal injection of suspension of Demodex mites into Japanese rabbits. The model can mimic the phenotype of skin lesions and histopathological manifestations in the Demodex mite-positive patient with rosacea.

Feasibility of an ultra-low dose contrast media protocol for coronary CT angiography

AIM

To evaluate the feasibility of an ultra-low volume contrast media (CM) protocol for coronary computed tomography angiography (CTA).

MATERIALS AND METHODS

In total, 214 patients receiving coronary CTA were enrolled prospectively and divided into group A (n=107) receiving a conventional dose of CM and group B (n=107) receiving an ultra-low dose. CT values of the right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (LCX) were measured and radiation doses recorded. The image quality was compared between the groups. Changes in renal function indices and proteinuria before, 24, and 72 hours after coronary CTA among those with chronic kidney disease (CKD) were also assessed.

RESULTS

There were significant differences in CT values and radiation doses between groups A and B. In group A, the average RCA, LAD, and LCX CT values were 412.5 ± 79.2, 423.5 ± 73.7, and 422.0 ± 88.1 HU, respectively. In group B, the average RCA, LAD, and LCX CT values were 275.2 ± 16.2, 277.8 ± 16.4, and 278.9 ± 16.5 HU, respectively. The radiation dose in the ultra-low protocol recipients (118.70 ± 18.52 mGy·cm) was significantly lower than that used in conventional coronary CTA (131.75 ± 20.96 mGy·cm). The image quality of group B was comparable to that of group A, satisfying the diagnostic requirement. In patients with mild CKD, there were no significant differences in renal functions after coronary CTA.

CONCLUSION

An ultra-low CM protocol was established for coronary CTA, providing comparable image quality and diagnostic yields but significantly lower radiation dose compared with a conventional protocol. This new protocol might be applicable to patients with mild CKD.

High Immunogenicity of a T-Cell Epitope-Rich Recombinant Protein Rv1566c-444 From Mycobacterium tuberculosis in Immunized BALB/c Mice, Despite Its Low Diagnostic Sensitivity

The discovery of immunodominant antigens is of great significance for the development of new especially sensitive diagnostic reagents and effective vaccines in controlling tuberculosis (TB). In the present study, we targeted the T-Cell epitope-rich fragment (nucleotide position 109-552) of Rv1566c from Mycobacterium tuberculosis (MTB) and got a recombinant protein Rv1566c-444 and the full-length protein Rv1566c with Escherichia coli expression system, then compared their performances for TB diagnosis and immunogenicity in a mouse model. The results showed that Rv1566c-444 had similar sensitivity with Rv1566c (44.44% Vs 30.56%) but lower sensitivity than ESAT-6&CFP-10&Rv3615c (44.4% Vs. 94.4%) contained in a commercial kit for distinguishing TB patients from healthy donors. In immunized BALB/c mice, Rv1566c-444 elicited stronger T-helper 1 (Th1) cellular immune response over Rv1566c with higher levels of Th1 cytokine IFN-γ and IFN-γ/IL-4 expression ratio by ELISA; more importantly, with a higher proliferation of CD4⁺ T cells and a higher proportion of CD4⁺ TNF-α⁺ T cells with flow cytometry. Rv1566c-444 also induced a higher level of IL-6 by ELISA and a higher proportion of Rv1566c-444-specific CD8⁺ T cells and a lower proportion of CD8⁺ IL-4⁺ T cells by flow cytometry compared with the Rv1566c group. Moreover, the Rv1566c-444 group showed a high IgG secretion level and the same type of CD4+ Th cell immune response (both IgG1/IgG2a >1) as its parental protein group. Our results showed the potential of the recombinant protein Rv1566c-444 enriched with T-Cell epitopes from Rv1566c as a host T cell response measuring biomarker for TB diagnosis and support further evaluation of Rv1566c-444 as vaccine antigen against MTB challenge in animal models in the form of protein mixture or fusion protein.

Construction and immunogenicity of a T cell epitope-based subunit vaccine candidate against Mycobacterium tuberculosis

Despite antibiotic treatment and Bacille Calmette-Guérin (BCG) vaccination, Mycobacterium tuberculosis remains a major public health burden in most developing countries. Therefore, developing an improved vaccine is high priority. In this study, we cloned the genes of the immunodominant antigen of M. tuberculosis viz. its 38-kDa antigen (Pst homolog) (Rv0934, PstS1), and its T cell epitopes (amino acid [aa]169-405 and [aa]802-1119), which we termed PstS1p. Prokaryotic expression showed that the two recombinant proteins were mainly in the form of inclusion bodies. We also evaluated the immunity and immunogenicity of PstS1 and PstS1p. Both PstS1 and its T cell epitopes elicited significantly higher antigen-specific immunoglobulin G (IgG) antibodies in mouse serum, indicating that they enhanced antibody response. They also elicited the T helper 1 (Th1)-type response and promoted CD4⁺ T cell proliferation. Compared to PstS1, PstS1p promoted stronger cell-mediated immune response. These data indicate that PstS1p is highly immunogenic in mice, and may be a promising candidate vaccine for controlling tuberculosis.

Successful Application of a Galanin-Coated Scaffold for Periodontal Regeneration

The nervous system exerts finely tuned control over all aspects of the life of an organism, including pain, sensation, growth, and development. Recent developments in tissue regeneration research have increasingly turned to small molecule peptides to tailor and augment the biological response following tissue loss or injury. In the present study, we have introduced the small molecule peptide galanin (GAL) as a novel scaffold-coating agent for the healing and regeneration of craniofacial tissues. Using immunohistochemistry, we detected GAL and GAL receptors in healthy periodontal tissues and in the proximity of blood vessels, while exposure to our periodontal disease regimen resulted in a downregulation of GAL. In a 3-dimensional bioreactor culture, GAL coating of collagen scaffolds promoted cell proliferation and matrix synthesis. Following subcutaneous implantation, GAL-coated scaffolds were associated with mineralized bone-like tissue deposits, which reacted positively for alizarin red and von Kossa, and demonstrated increased expression and protein levels of RUNX2, OCN, OSX, and iBSP. In contrast, the GAL receptor antagonist galantide blocked the effect of GAL on Runx2 expression and inhibited mineralization in our subcutaneous implantation model. Moreover, GAL coating promoted periodontal regeneration and a rescue of the periodontal defect generated in our periodontitis model mice. Together, these data demonstrate the efficacy of the neuropeptide GAL as a coating material for tissue regeneration. They are also suggestive of a novel role for neurogenic signaling pathways in craniofacial and periodontal regeneration.

[Predictive value of combination of MRI tumor regression grade and apparent diffusion coefficient for pathological complete remission after neoadjuvant treatment of locally advanced rectal cancer]

Objective: Pelvic high-resolution magnetic resonance imaging (MRI) has now become a standard method for evaluating the efficacy of neoadjuvant treatment for locally advanced rectal cancer (LARC). However, this traditional morphological qualitative assessment method based on T2-weighted imaging (T2WI) is not effective in predicting pathological complete remission (pCR). The purpose of this study is to investigate whether combining the magnetic resonance tumor regression grade (mrTRG) with apparent diffusion coefficient (ADC) can improve diagnostic value for pCR after preoperative neoadjuvant chemoradiotherapy (nCRT) of LARC. Methods: This was a diagnostic study. Clinicopathological data of 134 LARC patients who received nCRT and radical surgery in the First Affiliated Hospital of Kunming Medical University from January 2017 to December 2019 were retrospectively analyzed. All the patients underwent MRI which included T2WI and DWI sequences before and 8 weeks after nCRT. Two radiologists independently drew ROIs on T2WI and DWI to estimate mrTRG stage and calculate the mean ADC value. Receiver operating characteristics (ROC) method was applied to evaluate the predict value of mrTRG combined with mean ADC value for pCR. Results: Of 134 LARC patients, 85 were male and 49 were female with median age of 58 (28-82) years. After nCRT, MRI suggested 21 patients (15.7%) had clinical complete remission (cCR), e.g. mrTRG stage 1-2. Postoperative pathology revealed 31 (23.1%) patients had pCR. The evaluations of mrTRG and ADC value by the two readers were highly consistent, and the intra-group correlation coefficients were 0.83 (95% CI: 0.703-0.881) and 0.96 (95% CI: 0.989-0.996), respectively. There was a negative correlation between mrTRG and pCR (r(s)=-0.505, P<0.01), and a positive correlation between mean ADC value and pCR (r(s)=0.693, P<0.01). The ROC curve showed that mrTRG alone had a medium predictive value for pCR, with an area under the curve (AUC) of 0.832 (95% CI: 0.743-0.921); the mean ADC value had a higher predictive value for pCR, with AUC of 0.906 (95% CI: 0.869-0.962). The predictive value of the combined model of mrTRG and ADC value for pCR was significantly better than that of mrTRG alone (P=0.015), and the AUC was 0.908 (95% CI: 0.849-0.968). Conclusion: Both mrTRG and mean ADC value can be non-invasive methods to predict the efficacy of nCRT for LARC. Combining the mean ADC value with mrTRG can result in better pCR prediction.

Chlamydia trachomatis glycogen synthase promotes MAPK-mediated proinflammatory cytokine production via TLR2/TLR4 in THP-1 cells

AIMS

To investigate the roles and mechanisms of C. trachomatis glycogen synthase (GlgA) in regulating the inflammatory response in THP-1 cells.

MAIN METHODS

In this work, after THP-1 cells were stimulated with GlgA, transcript and protein expression levels were measured by qRT-PCR and ELISA, respectively. Western blotting and immunofluorescence were used to determine the signaling pathway involved in the inflammatory mechanism.

KEY FINDINGS

GlgA elicited the expression of interleukin-8 (IL-8), interleukin-1beta (IL-1β) and tumor necrosis factor alpha (TNF-α) in THP-1 cells, and the blockade of TLR2 and TLR4 signaling abrogated the induction of IL-8, TNF-α and IL-1β expression. Similarly, IL-8, IL-1β and TNF-α secretion was reduced by transfection with a dominant negative plasmid (pDeNyhMyD88). Moreover, Western blotting and immunofluorescence experiments further validated that MAPKs and NF-кB signaling are involved in the transcription and translation of these cytokines. Treatment of the cells with ERK and JNK inhibitors dramatically attenuated the induction of IL-8, IL-1β and TNF-α.

SIGNIFICANCE

These results suggest that GlgA contributes to inflammation during C. trachomatis infection via the TLR2, TLR4 and MAPK/NF-кB pathways, which may enhance our understanding of the pathogenesis of C. trachomatis.

SETD1 and NF-κB Regulate Periodontal Inflammation through H3K4 Trimethylation

The inflammatory response to periodontal pathogens is dynamically controlled by the chromatin state on inflammatory gene promoters. In the present study, we have focused on the effect of the methyltransferase SETD1B on histone H3 lysine K4 (H3K4) histone trimethylation on inflammatory gene promoters. Experiments were based on 3 model systems: 1) an in vitro periodontal ligament (PDL) cell culture model for the study of SETD1 function as it relates to histone methylation and inflammatory gene expression using Porphyromonas gingivalis lipopolysaccharide (LPS) as a pathogen, 2) a subcutaneous implantation model to determine the relationship between SETD1 and nuclear factor κB (NF-κB) through its activation inhibitor BOT-64, and 3) a mouse periodontitis model to test whether the NF-κB activation inhibitor BOT-64 reverses the inflammatory tissue destruction associated with periodontal disease. In our PDL progenitor cell culture model, P. gingivalis LPS increased H3K4me3 histone methylation on IL-1β, IL-6, and MMP2 gene promoters, while SETD1B inhibition decreased H3K4me3 enrichment and inflammatory gene expression in LPS-treated PDL cells. LPS also increased SETD1 nuclear localization in a p65-dependent fashion and the nuclear translocation of p65 as mediated through SETD1, suggestive of a synergistic effect between SETD1 and p65 in the modulation of inflammation. Confirming the role of SETD1 in p65-mediated periodontal inflammation, BOT-64 reduced the number of SETD1-positive cells in inflamed periodontal tissues, restored periodontal tissue integrity, and enhanced osteogenesis in a periodontal inflammation model in vivo. Together, these results have established the histone lysine methyltransferase SETD1 as a key factor in the opening of the chromatin on inflammatory gene promoters through histone H3K4 trimethylation. Our studies also confirmed the role of BOT-64 as a potent molecular therapeutic for the restoration of periodontal health through the inhibition of NF-κB activity and the amelioration of SETD1-induced chromatin relaxation.

Effects of the FABP4 gene on steroid hormone secretion in goose ovarian granulosa cells

1. To investigate the physiological role of FABP4 in the goose ovary, this study determined the effects of overexpressing and siRNA interfering FABP4 on progesterone (P₄) and oestradiol (E₂) production in granulosa cells. Measurements were made by ELISA, real-time qRT-PCR and western blotting. 2. The concentrations of P₄ and E₂ in the FABP4 overexpression granulosa cells were increased compared to the control group (P > 0.05 for P₄; P < 0.05 for E₂). Likewise, the mRNA and protein expression levels of CYP11A1 and CYP19A1 were significantly higher than in the control group (P < 0.05 or P < 0.001). Conversely, the concentrations of P₄ and E₂ in the FABP4 silencing granulosa cells were significantly decreased compared with the control group (P < 0.001). Likewise, the mRNA and protein expression levels of CYP11A1 and CYP19A1 were significantly lower than in the control group (P < 0.001, or P < 0.01). 3. The study indicated that the FABP4 gene may regulate steroid hormone secretion and the expression of the steroidogenic genes in geese ovarian granulosa cells. These results support the possibility that the FABP4 gene mediates ovarian steroid hormone biosynthesis function and reproduction in geese.

Histone Methylation: Achilles Heel and Powerful Mediator of Periodontal Homeostasis

The packaging of DNA around nucleosomes exerts dynamic control over eukaryotic gene expression either by granting access to the transcriptional machinery in an open chromatin state or by silencing transcription via chromatin compaction. Histone methylation modification affects chromatin through the addition of methyl groups to lysine or arginine residues of histones H3 and H4 by means of histone methyl transferases or histone demethylases. Changes in histone methylation state modulate periodontal gene expression and have profound effects on periodontal development, health, and therapy. At the onset of periodontal development, progenitor cell populations such as dental follicle cells are characterized by an open H3K4me3 chromatin mark on RUNX2, MSX2, and DLX5 gene promoters. During further development, periodontal progenitor differentiation undergoes a global switch from the H3K4me3 active methyl mark to the H3K27me3 repressive mark. When compared with dental pulp cells, periodontal neural crest lineage differentiation is characterized by repressive H3K9me3 and H3K27me3 marks on typical dentinogenesis-related genes. Inflammatory conditions as they occur during periodontal disease result in unique histone methylation signatures in affected cell populations, including repressive H3K9me3 and H3K27me3 histone marks on extracellular matrix gene promoters and active H3K4me3 marks on interleukin, defensin, and chemokine gene promoters, facilitating a rapid inflammatory response to microbial pathogens. The inflammation-induced repression of chromatin on extracellular matrix gene promoters presents a therapeutic opportunity for the application of histone methylation inhibitors capable of inhibiting suppressive trimethylation marks. Furthermore, inhibition of chromatin coregulators through interference with key inflammatory mediators such as NF-kB by means of methyltransferase inhibitors provides another avenue to halt the exacerbation of the inflammatory response in periodontal tissues. In conclusion, histone methylation dynamics play an intricate role in the fine-tuning of chromatin states during periodontal development and harbor yet-to-be-realized potential for the treatment of periodontal disease.

Identification of HeLa cell proteins that interact with Chlamydia trachomatis glycogen synthase using yeast two‑hybrid assays

Chlamydia trachomatis (C. trachomatis) is the leading cause of bacterial sexually transmitted diseases and infectious diseases that cause blindness. The pathophysiology of chlamydial infections is poorly understood, but secreted proteins have emerged as key virulence factors. C. trachomatis glycogen synthase (GlgA) is a chlamydial secretory protein, which localizes in the lumen of chlamydial inclusion bodies and the cytosol of host cells. In order to improve understanding of the roles of GlgA in chlamydial pathogenesis, four proteins that interact with GlgA, Homo sapiens CXXC finger protein 1, prohibitin (PHB), gelsolin-like actin-capping protein and apolipoprotein A-I binding protein were identified using yeast two-hybrid assays. The functions of these proteins are complex, and preliminary results suggested that PHB interacts with GlgA. However, further studies are required to determine the specific interactions of these proteins with GlgA. The findings of the present study may provide a direction and foundation for future studies focusing on the mechanism of GlgA in C. trachomatis infection.

Vaccination with MIP or Pgp3 induces cross-serovar protection against chlamydial genital tract infection in mice

Previously we reported that recombinant Chlamydia muridarum macrophage infectivity potentiator (MIP) provided partial protection against C. muridarum genital tract infection in mice. On the other hand, Chlamydia trachomatis plasmid encoded Pgp3could induce the protection against C. muridarum air way infection. This study aimed to evaluate the immunogenicity of MIP and Pgp3 from C. trachomatis serovar D and further investigate whether MIP and Pgp3 provide cross-serovar protection against C. muridarum genital tract infection in mice. Our results showed that vaccination by any regimen, including MIP alone, Pgp3 alone or MIP plus Pgp3, induced specific serum antibody production and Th1-dominant cellular responses in mice. Live chlamydial shedding from the vaginal and inflammatory pathologies in the oviduct markedly reduced. However, MIP + Pgp3 vaccination did not provide better protection than the single immunization. In conclusion, this study demonstrated that both MIP and Pgp3 can induce cross-serovar protective against chlamydial genital tract infection, and provided the guide for the development of optimal multisubunit vaccines against C. trachomatis infection.

Macropinocytosis activated by oncogenic Dbl enables specific targeted delivery of Tat/pDNA nano-complexes into ovarian cancer cells

BACKGROUND

Successful implementation of gene therapy heavily relies on efficiently delivering genetic materials and specific targeting into cells. Oncogene-driven endocytosis stimulates nutrient uptake and also develops an endocytosis-mediated defense against therapeutic agents. Cell-penetrating peptides, typically HIV-Tat, are well known for efficient delivery of nucleic acid drugs but lack targeting specificity. Various passive targeting strategies were pursued to enhance the tumor targeting efficiency; however, they are still limited by complicated cellular endocytosis routes and the heterogeneity of cancer types.

METHODS

Tat/pDNA complexes were noncovalently compacted and their physiochemical properties were determined. The siRNA pool and pLV-RNAi-GFP lentivirus were used to knock down dbl oncogene (originally isolated from diffuse B-cell lymphoma) expression, and its overexpression was performed by plasmid transient transfection. The cellular uptake of fluorescent ligands was quantified by confocal imaging and flow cytometry analysis. The transgene efficiency was determined by the Luciferase expression assay. Rho GTPase activation was checked by the GST-Rho GTPase-binding domain pull-down assay.

RESULTS

pGL3 plasmid DNA was noncovalently compacted with the Tat peptide into nano-size complexes at high N/P ratios. Macropinocytosis, a clathrin- and caveolin-independent endocytosis process, was shown to contribute to the uptake of middle-sized (∼600 nm) Tat/pGL3 complexes. Cell-type-specific variation in macropinocytosis was essentially controlled by the action of the Dbl oncogene. Onco-Dbl presentation constantly induced a high level of macropinocytosis activity in ovarian cancer cells. Onco-Dbl overexpression hyperstimulated macropinocytosis enhancement in cells mainly through actin cytoskeleton reorganization mediated by the PH domain and Rac1 activation. The Dbl-driven Rho GTPase signaling collectively determined the cell-type-specific macropinocytosis phenotype.

CONCLUSION

Such an aspect can be exploited to selectively confer targeted delivery of Tat/pDNA nano-complexes into ovarian cancer cells. Our work provides a novel alternative for targeted delivery of cell-penetrating peptide-based nucleic acid drugs into certain tumor types if specific endocytosis pathways are used.

Neurokinin-1 receptor blocker CP-99 994 improved emesis induced by cisplatin via regulating the activity of gastric distention responsive neurons in the dorsal motor nucleus of vagus and enhancing gastric motility in rats

BACKGROUND

Nowadays, chemotherapy induced nausea and vomiting (CINV) is still common in patients with cancer. It was reported that substance P mediated CINV via neurokinin-1 (NK₁ ) receptor and antagonists of NK₁ receptor has been proved useful for treating CINV but the mechanism are not fully understood. This study aimed to examine the role of NK₁ receptor blocker, CP-99 994, when administrated into dorsal motor nucleus of vagus (DMNV), on the cisplatin-induced emesis in rats and the possible mechanism.

METHODS

Rats' kaolin intake, food intake, and bodyweight were recorded every day; gastric contraction activity was recorded in conscious rats through a force transducer implanted into the stomach; gastric emptying was monitored using the phenol red method; single unit extracellular firing in the DMNV were recorded.

KEY RESULTS

DMNV microinjection of CP-99 994 reduced the changes of increased kaolin consumption and suppressed food intake in cisplatin-treated rats; enhanced the gastric contraction activity dose-dependently in control and cisplatin-treated rats but enhanced gastric emptying only in cisplatin-treated rats; reduced the firing rate of gastric distention inhibited (GD-I) neurons but increased the firing rate of GD excited (GD-E) neurons in the DMNV. The effects of CP-99 994 on gastric motility and neuronal activity were stronger in cisplatin-treated rats than those of control rats.

CONCLUSIONS AND INFERENCES

Our results suggested that CP-99 994 could improve emesis induced by cisplatin by regulating gastric motility and gastric related neuronal activity in the DMNV.

Effects of processing techniques on oxidative stability of

This paper investigated the effects of Prunus pedunculatus (P. pedunculatus) seed pre-treatment, including microwaving (M), roasting (R), steaming (S) and roasting plus steaming (RS) on crude oil quality in terms of yield, color change, fatty acid composition, and oxidative stability. The results showed an increase in monounsaturated fatty acid content and oxidative stability of the oils obtained from different processing treatments compared to the oil obtained from raw seeds (RW) without processing. The oils, obtained from pretreated seeds, had higher conjugated diene (CD) and 2-thiobarbituric acid (2-TBA) values, compared to that obtained from RW when stored in a Schaal oven at 65 °C for 168 h. However, polyphenol and tocopherol contents decreased in all oil samples, processed or unprocessed. The effect of pre-treating the seeds was more prominent in the oil sample obtained through the RS technique, and showed higher oxidative stability than the other processed oils and the oil from RW.

MicroRNAs and Periodontal Homeostasis

MicroRNAs (miRNAs) are a group of small RNAs that control gene expression in all aspects of eukaryotic life, primarily through RNA silencing mechanisms. The purpose of the present review is to introduce key miRNAs involved in periodontal homeostasis, summarize the mechanisms by which they affect downstream genes and tissues, and provide an introduction into the therapeutic potential of periodontal miRNAs. In general, miRNAs function synergistically to fine-tune the regulation of biological processes and to remove expression noise rather than by causing drastic changes in expression levels. In the periodontium, miRNAs play key roles in development and periodontal homeostasis and during the loss of periodontal tissue integrity as a result of periodontal disease. As part of the anabolic phase of periodontal homeostasis and periodontal development, miRNAs direct periodontal fibroblasts toward alveolar bone lineage differentiation and new bone formation through WNT, bone morphogenetic protein, and Notch signaling pathways. miRNAs contribute equally to the catabolic aspect of periodontal homeostasis as they affect osteoclastogenesis and osteoclast function, either by directly promoting osteoclast activity or by inhibiting osteoclast signaling intermediaries or through negative feedback loops. Their small size and ability to target multiple regulatory networks of related sets of genes have predisposed miRNAs to become ideal candidates for drug delivery and tissue regeneration. To address the immense therapeutic potential of miRNAs and their antagomirs, an ever growing number of delivery approaches toward clinical applications have been developed, including nanoparticle carriers and secondary structure interference inhibitor systems. However, only a fraction of the miRNAs involved in periodontal health and disease are known today. It is anticipated that continued research will lead to a more comprehensive understanding of the periodontal miRNA world, and a systematic effort toward harnessing the enormous therapeutic potential of these small molecules will greatly benefit the future of periodontal patient care.

BMIT facility at the Canadian Light Source: Advances in X-ray phase-sensitive imaging

The BioMedical Imaging and Therapy (BMIT) facility [1,2] located at the Canadian Light Source, provides synchrotron-specific imaging and radiation therapy capabilities. There are two separate beamlines used for experiments: the bending magnet (05B1-1) and the insertion device (05ID-2) beamline. The bending magnet beamline provides access to monochromatic beam spanning a spectral range of 15-40keV, and the beam is 240mm wide in the POE-2 experimental hutch. Users can also perform experiments with polychromatic (pink) beam. The insertion device beamline was officially opened for general user program in 2015. The source for the ID beamline is a multi-pole, superconducting 4.3T wiggler. The high field gives a critical energy over 20keV. The optics hutches prepare a beam that is 220mm wide in the last experimental hutch SOE-1. The monochromatic spectral range spans 25-150+keV. Several different X-ray detectors are available for both beamlines, with resolutions ranging from 2μm to 200μm. BMIT provides a number of imaging techniques including standard absorption X-ray imaging, K-edge subtraction imaging (KES), in-line phase contrast imaging (also known as propagation based imaging, PBI) and Diffraction Enhanced Imaging/Analyzer Based Imaging (DEI/ABI), all in either projection or CT mode. PBI and DEI/ABI are particularly important tools for BMIT users since these techniques enable visualization of soft tissue and allow for low dose imaging.

Relationship between the expression of Notch1 and EZH2 and the prognosis of breast invasive ductal carcinoma

We determined whether the coexpression of Notch1 and EZH2 influences the progression and prognosis of breast invasive ductal carcinoma. Using the χ(2) test, a significant difference was found between high and low expression of Notch1 in terms of lymph node, hormone receptor, and p53 expression (P < 0.05). Moreover, a significant difference was found between high and low expression of EZH2 in terms of tumor size, histologic grade, hormone receptor, and expression of Ki67 (P < 0.05). Using Pearson correlation analysis, we found a significant positive correlation between Notch1 and EZH2 expression in the tissue samples of breast invasive ductal carcinoma (P = 0.038). High Notch1 and EZH2 expression was associated with poor progression-free survival compared with low expression (PNotch1 = 0.000, 40.3 vs 48.9 months; PEZH2 = 0.000, 40.2 vs 49.9 months). Moreover, we found that high Notch1 and EZH2 expression was associated with poor overall survival compared with low expression (PNotch1 = 0.000, 51.2 vs 56.2 months; PEZH2 = 0.002, 51.7 vs 56.4 months). In conclusion, Notch1 and EZH2 coexpression contributes to the progression and prognosis of breast invasive ductal carcinoma.

MicroRNA-138 Inhibits Periodontal Progenitor Differentiation under Inflammatory Conditions

Inflammatory conditions as they occur during periodontal disease often result in decreased alveolar bone levels and a loss of connective tissue homeostasis. Here we have focused on the effect of microRNA-138 (miR-138) as a potential regulator of periodontal stem cells as they affect homeostasis during inflammatory conditions. Our data indicate that miR-138 was significantly upregulated in our periodontal disease animal model. Interaction of miR-138 with a predicted targeting site on the osteocalcin (OC) promoter resulted in a 3.7-fold reduction of luciferase activity in promoter assays compared with controls; and miR-138 overexpression in periodontal progenitors significantly inhibited OC (3.4-fold), Runx2 (2.8-fold), and collagen I (2.6-fold). Moreover, treatment with inflammatory modulators such as interleukin (IL)-6 and lipopolysaccharide (LPS) resulted in a significant 2.2-fold (IL-6) or 1.9-fold (LPS) increase in miR-138 expression, while OC and Runx2 expression was significantly decreased as a result of treatment with each inflammatory mediator. Further defining the role of miR-138 in the OC-mediated control of mineralization, we demonstrated that the LPS-induced downregulation of OC expression was partially reversed after miR-138 knockdown. LPS, miR-138 mimic, and OC small interfering RNA inhibited osteoblast differentiation marker alkaline phosphatase activity, while miR-138 inhibitor and OC protein addition enhanced alkaline phosphatase activity. Supporting the role of OC as an essential modulator of osteoblast differentiation, knockdown of miR-138 or addition of OC protein partially rescued alkaline phosphatase activity in periodontal ligament (PDL) cells subjected to LPS treatment. Our data establish miR-138 inhibitor as a potential therapeutic agent for the prevention of the bone loss associated with advanced periodontal disease.

Efficacy and safety of short-term administration of recombinant human atrial natriuretic peptide (rhANP) for congestive heart failure: a phase II, multicentre randomized controlled dose-finding study

WHAT IS KNOWN AND OBJECTIVE

Although the long-term infusion of ANP has proved effective to treat heart failure, no published randomized controlled study has been reported to confirm the efficacy of the short-term ANP infusion in congestive heart failure (CHF) patients. This study was designed to assess the efficacy and safety of short-term infusion of recombinant human atrial natriuretic peptide (rhANP) in CHF patients.

METHODS

A total of 48 patients with CHF were enrolled and randomized into four groups, treated with standard therapy or rhANP (0·05, 0·1 or 0·2 μg/kg/min) for 1-hour infusion in addition to standard therapy. The hemodynamics were assessed for 12 h by Swan-Ganz catheter.

RESULTS AND DISCUSSION

The effect of the 0·05 μg/kg/min rhANP dose group on CO was modest and transient. The 0·2 μg/kg/min rhANP dose group tended to be associated with better effect on SV, CO and dyspnoea improvement, but modest effect on PCWP and more adverse events probably attributed to the study drug. However, the 0·1 μg/kg/min rhANP infusion was well tolerated and effective both on PCWP decrease (maximum:-9·46 ± 5·81 mmHg compared with baseline (P = 0·0002) and -6·75 mmHg compared with standard therapy, the 95% confidential interval [-13·43, -0·06 mmHg] at 1 h) and CO increase (maximum: 1·02 ± 1·43 L/min [P = 0·0308] at 1 h).

WHAT IS NEW AND CONCLUSION

In this small-sample study, 1-hour infusion of rhANP produced beneficial hemodynamic effects in CHF patients compared with standard therapy, and it was well tolerated. 0·1 μg/kg/min may be the optimum dose for short-term rhANP infusion to treat CHF for the further large sample trial before clinical application.

Expression and function of enamel-related gene products in calvarial development

Enamel-related gene products (ERPs) are detected in non-enamel tissues such as bone. We hypothesized that, if functional, ERP expression corresponds with distinct events during osteoblast differentiation and affects bone development and mineralization. In mouse calvariae and MC3T3 cells, expression profiles of enamel-related gene products (ERPs) correlated with key events in post-natal calvarial development and MC3T3 cell mineralization. Developing skulls from both Amel- and Ambn-deficient animals were approximately 15% shorter when compared with those of wild-type controls, and their sutures remained patent for a longer period of time. Analysis of Amel- and Ambn-deficient calvariae and calvarial osteoblast cultures revealed a dramatic reduction in mineralized nodules, a significant reduction in Runx2, Sp7, Ibsp, and Msx2 expression, and a reduction in Alx4 in Amel-deficient calvariae vs. an increase in Alx4 in Ambn-deficient calvariae. Analysis of these data indicates that ERP expression follows defined developmental profiles and affects osteoblast differentiation, mineralization, and calvarial bone development. We propose that, in parallel to their role in the developing enamel matrix, ERPs have retained an evolutionary conserved function related to the biomineralization of bones.

The role of invariant NKT cells in liver transplant tolerance in rats

OBJECTIVE

The aim of this study was to investigate the role of invariant natural killer T (iNKT) cells in liver transplant tolerance in rats.

METHODS

Animals were randomly divided into 3 groups. The α-galactosylceramide (α-GalCer) group underwent injection through the caudal vein; the saline group received the same dose of saline and the control group received no treatment. Ten rats in each group were examined for survival the others were humanely killed on the seventh day posttransplantation. Liver tissues were used to assess histopathologic changes. Real-time polymerase chain reaction (PCR) was performed to determine the relative expressions of messanger RNAs of Th1/Th2-related cytokine (mRNAs) in the liver allograft. The serum levels of related cytokines were determined using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Allograft survival was significantly higher among the α-galactosylceramide α-GalCer group than the saline or control groups. The histopathology showed mild changes in the α-galactosylceramide α-GalCer compared with the other 2 groups. Real-time PCR showed the relative expression of Th1-related cytokine interferen (IFN)-γ mRNA to be significantly lower in the α-galactosylceramide α-GalCer compared with the other 2 groups, while the Th2-related cytokine interleukin (IL)-10 mRNA was much higher. The ELISA results confirmed these differential expressions.

CONCLUSION

The iNKT cells may play a pivotal role in liver transplant tolerance due to their regulatory functions on the Th1/Th2 imbalance. iNKT cells should be considered to be significant targets because of their attractive specificity and induction of liver allograft tolerance.

Inhibition of the Signal Transducers and Activators of Transcription (STAT) 3 Signalling Pathway by AG490 in Laryngeal Carcinoma Cells

Signal transducers and activators of transcription (STAT) are important in the development of laryngeal carcinomas and are potential novel molecular targets for therapy to improve survival of patients with this cancer. This study was designed to investigate the influence of the janus activated kinase (JAK)/STAT inhibitor AG490 on proliferation and apoptosis of Hep-2 human laryngeal cancer cells and whether there was any inhibition by AG490 of the JAK/STAT3 signalling pathway. AG490 inhibited cell proliferation in dose-and time-dependent manners and induced apoptosis in Hep-2 cells, with the number of apoptotic cells increasing with time. AG490 inhibited G1 to S cell cycle transition and induced G1 cell cycle arrest as well as significantly down-regulating STAT3, phosphorylated STAT3 and survivin in Hep-2 cells. This study showed that AG490 significantly inhibited proliferation and induced apoptosis of laryngeal carcinoma cells through down-regulation of STAT3 and survivin, suggesting a potential target for laryngeal carcinoma treatment.

Neural crest lineage segregation: a blueprint for periodontal regeneration

During the recent decade, the periodontal attachment apparatus has become one of the premier areas of the body for the development of novel tissue-engineering strategies. In the present review, we describe a developmental biology approach to characterize current concepts in periodontal regeneration and to discuss strategies for future applications in periodontal therapies. To decipher the developmental make-up of the periodontal region, we have followed the path of the migratory neural crest, since it gives rise to periodontal progenitor tissues, which in turn are subjected to the influence of diverse craniofacial extracellular matrices and peptide growth factors. Based on this developmental perspective, we have conducted a systematic analysis of the factors, progenitor cells, and matrices used in current periodontal tissue-engineering approaches. We propose that the developmental history of a tissue is a highly instructive design template for the discovery of novel bioengineering tools and approaches.

Visual assessment of jaundice in term and late preterm infants

OBJECTIVE

To determine the accuracy of predischarge visual assessment of jaundice for estimating bilirubin concentration and predicting risk of significant neonatal hyperbilirubinaemia.

DESIGN

Prospective cohort study.

SETTING

Well Baby Nursery at the Hospital of the University of Pennsylvania.

PATIENTS

522 term and late preterm newborns.

INTERVENTIONS

Nurses used a 5-point scale to grade the maximum cephalocaudal extent of jaundice prior to discharge.

MAIN OUTCOME MEASURES

(1) Correlation between jaundice grade and bilirubin concentration. (2) Predictive accuracy of jaundice grade for identifying infants who developed significant hyperbilirubinaemia, defined as a bilirubin level that at any time after birth exceeded or was within 1 mg/dl (17 micromol/l) of the American Academy of Pediatrics-recommended hour-specific phototherapy treatment threshold.

RESULTS

Nurses' assessment of jaundice extent was only moderately correlated with bilirubin concentration and was similar in black and non-black infants (Spearman's rho = 0.45 and 0.55, respectively (p = 0.13)). The correlation was particularly weak among infants <38 weeks' gestational age (rho = 0.29) compared with infants > or = 38 weeks' gestation (rho = 0.53, p = 0.05). Jaundice extent had poor overall accuracy for predicting risk of significant hyperbilirubinaemia (c-statistic = 0.65) but complete absence of jaundice had high sensitivity (95%) and excellent negative predictive value (99%) for ruling out the development of significant hyperbilirubinaemia.

CONCLUSIONS

Clinicians should not use extent of cephalocaudal jaundice progression to estimate bilirubin levels during the birth hospitalisation, especially in late preterm infants. However, the complete absence of jaundice can be used to predict with very high accuracy which infants will not develop significant hyperbilirubinaemia.

Relationship between TH1/TH2 cytokines and immune tolerance in liver transplantation in rats

OBJECTIVE

To explore the relationship between Th1/Th2 cytokine expressions and immune tolerance in rat liver transplantation.

METHODS

Recipients were divided into three groups (each group = 12 rats). The allograft group underwent orthotopic liver transplantation from male Wistar-to-Sprague-Dawley (SD) rats. The isograft group of SD-to-SD liver transplantation was complemented with a control group of normal male SD rats that had sham operations. We evaluated the 2-week survival rates histological changes, as well as serum and mRNA expression levels of Th1/Th2 cytokines: interferon-gamma (IFN-gamma) and interleukin-10 (IL-10).

RESULTS

The 1-week survival in the isograft and allograft groups were 100% and 41.67%, respectively. The 2-week survival rates were 75% and 8.33% (P < .05). Light microscopic inspection revealed severe acute rejection in the allograft but not the isograft group in the first week postoperation. This observation was verified by the cellular morphology under transmission electron microscopy. Serum IFN-gamma (Th1 cytokine) levels (pg/mL) determined by enzyme-linked immunosorbent assay in the allograft, isograft, and control groups were 386.67 +/- 14.36, 159.83 +/- 16.53, and 87.83 +/- 8.67, respectively; for IL-10 (Th2 cytokine), they were 126.33 +/- 13.10, 288.33 +/- 17.10, and 70.50 +/- 7.23, respectively (P < .05, allograft vs isograft). The semiquantitative reverse-transcriptase polymerase chain reaction assay showed that expression of IFN-gamma and IL-10 mRNA was similar to that of serum levels. IFN-gamma mRNA was more highly expressed in the allograft group and IL-10 mRNA, in the isograft group (P < .05).

CONCLUSIONS

The dynamic equilibrium of Th1/Th2 cytokines is critically involved in immune tolerance. The deviation of Th1 to Th2 may be one mechanism of immune tolerance.

GPR54 polymorphisms in Chinese girls with central precocious puberty

AIMS

The GPR54 gene has been proved to be important in the process of puberty onset, yet no association study has been performed to evaluate the effect of polymorphisms in the gene on central precocious puberty (CPP). This study was designed to scan for polymorphisms in the GPR54 gene and to investigate the relationships between the genotypes of GPR54 and the disease.

METHODS

272 Chinese Han girls diagnosed to be CPP patients were recruited as the case group and 288 unrelated normal Chinese Han girls as the control group. The whole GPR54 gene was directly sequenced in randomly selected case samples, and the polymorphisms identified were genotyped by ligase detection reaction in both groups. Distributions of the polymorphisms and haplotypes were calculated for statistical evaluation.

RESULTS

Totally 6 polymorphisms were found in sequencing, one of which is a nonsynonymous mutation, while genotyping declared that another SNP located in the promoter region was statistically related to the disease (p = 0.037).

CONCLUSION

One polymorphism in GPR54 gene might be correlated with some cases of CPP, likely by changes in expression of the receptor, but the moderate p value and the lack of functional data make it hard to confirm the correlation. Further studies on the polymorphisms are needed for the exact mechanism.

Expression and characterization of a Rana pipiens amelogenin protein

Amelogenin, the major protein of developing enamel matrix, controls enamel crystal growth via unique supermolecular features. While much has been contributed to our understanding of mammalian amelogenin function, little is known about how amelogenin and its unique physico-chemical features have evolved among vertebrates. Here we report, for the first time, amphibian amelogenin recombinant protein expression and characterization in Rana pipiens. In order to characterize R. pipiens amelogenin, the newly discovered amelogenin coding sequence was amplified, subcloned, and expressed in Eshcerichia coli. Our newly generated R. pipiens amelogenin-specific antisera resolved a major 19-kDa band on western blots of frog tooth extracts and revealed an enamel organ tissue-specific localization pattern using immunohistochemistry. Using mass spectroscopy, a single major compound with a molecular weight of 21.6 kDa was detected, which corresponded to the amino acid sequence-based molecular weight prediction of the His fusion recombinant protein. Dynamic light scattering studies resolved 41-nm radius subunits compared with 14-nm radius subunits from mouse recombinant amelogenin controls. Transmission electron microscopy revealed defined spherical subunits in R. pipiens matrix self-assembly in contrast with a homogeneous 'stippled' matrix in mouse amelogenin matrix self-assembly. Our data suggest that R. pipiens amelogenin is distinguished from mammalian amelogenins by a number of unique physico-chemical properties which may be related to specific modes of crystal formation in frog enamel.

Identifying newborns at risk of significant hyperbilirubinaemia: a comparison of two recommended approaches

AIMS

To compare the predictive performance of clinical risk factor assessment and pre-discharge bilirubin measurement as screening tools for identifying infants at risk of developing significant neonatal hyperbilirubinaemia (post-discharge total serum bilirubin (TSB) >95th centile).

METHODS

Retrospective cohort study of term and near term infants born in an urban community teaching hospital in Pennsylvania (1993-97). A clinical risk factor scoring system was developed and its predictive performance compared to a pre-discharge TSB expressed as a risk zone on a bilirubin nomogram. Main outcome measures were prediction model discrimination, range of predicted probabilities, and sensitivity, specificity, positive and negative predictive values, and likelihood ratios for various positivity criteria.

RESULTS

The clinical risk factor scoring system developed included birth weight, gestational age <38 weeks, oxytocin use during delivery, vacuum extraction, breast feeding, and combination breast and bottle feeding. The pre-discharge bilirubin risk zone had better discrimination (c = 0.83; 95% CI 0.80 to 0.86) than the clinical risk factor score (c = 0.71; 95% CI 0.66 to 0.76) and predicted risk of significant hyperbilirubinaemia as high as 59% compared with a maximum of 44% for the clinical risk factor score. Neither the risk score nor the pre-discharge TSB risk zone predicted the outcome with > or =0.98 sensitivity without significantly compromising specificity (0.13 and 0.21, respectively). Multi-level clinical risk factor scores and TSB risk zones produced likelihood ratios of 0.15-3.25 and 0.05-9.43, respectively.

CONCLUSIONS

The pre-discharge bilirubin expressed as a risk zone on an hour specific bilirubin nomogram is more accurate and generates wider risk stratification than a clinical risk factor score.

Exercise pre-conditioning reduces brain damage in ischemic rats that may be associated with regional angiogenesis and cellular overexpression of neurotrophin

There is increasing evidence that physical activity is associated with a decreased stroke risk. The purpose of this study was to determine if exercise could also reduce brain damage in rats subjected to transient middle cerebral artery (MCA) occlusion, and if the reduced brain injury is associated with angiogenesis as well as cellular expression of the nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in regions supplied by the MCA. Adult male Sprague Dawley rats (n=36) exercised 30 min each day for 3 weeks on a treadmill on which repetitive locomotor movement was required. Then, stroke was induced by a 2-h MCA occlusion using an intraluminal filament, followed by 48 h of reperfusion. In addition to the two exercised groups of animals with or without MCA occlusion, there were two other groups of animals, with or without MCA occlusion, housed for the same duration and used as non-exercised controls. Brain damage in ischemic rats was evaluated by neurologic deficits and infarct volume. Exercise preconditioned and non-exercised brains were processed for immunocytochemistry to quantify the number of microvessels or NGF- and BDNF-labeled cells. Pre-ischemic motor activity significantly (P<0.01) reduced neurologic deficits and infarct volume in the frontoparietal cortex and dorsolateral striatum. Cellular expressions of NGF and BDNF were significantly (P<0.01) increased in cortex (neuron) and striatum (glia) of rats under the exercise condition. Significant (P<0.01) increases in microvessel density were found in striatum. Physical activity reduced stroke damage. The reduced brain damage may be attributable to angiogenesis and neurotrophin overexpression in brain regions supplied by the MCA following exercise.

Motor balance and coordination training enhances functional outcome in rat with transient middle cerebral artery occlusion

The goal of this study was to determine if relatively complex motor training on Rota-rod involving balance and coordination plays an essential role in improving motor function in ischemic rats, as compared with simple locomotor exercise on treadmill. Adult male Sprague-Dawley rats with (n=40) or without (n=40) ischemia were trained under each of three conditions: (1) motor balance and coordination training on Rota-rod; (2) simple exercise on treadmill; and (3) non-trained controls. Motor function was evaluated by a series of tests (foot fault placing, parallel bar crossing, rope and ladder climbing) before and at 14 or 28 days after training procedures in both ischemic and normal animals. Infarct volume in ischemic animals was determined with Nissl staining. Compared with both treadmill exercised and non-trained animals, Rota-rod-trained animals with or without ischemia significantly (P<0.01) improved motor performance of all tasks except for foot fault placing after 14 days of training, with normal rats having better performance. Animals trained for up to 28 days on the treadmill did not show significantly improved function. With regard to foot fault placing task, performance on foot placing was improved in ischemic rats across the three measurements at 0, 14 and 28 days regardless of training condition, while the normal group reached their best performance at the beginning of measurement. No significant differences in infarct volume were found in rats trained either with Rota-rod (47+/-4%; mean+/-S.E.), treadmill (45+/-5%) or non-exercised control (45+/-3%). In addition, no obvious difference could be detected in the location of the damage which included the dorso-lateral portion of the neostriatum and the frontoparietal cortex, the main regions supplied by the middle cerebral artery. The data suggest that complex motor training rather than simple exercise effectively improves functional outcome.

Analysis of polymorphisms affecting immune complex handling in systemic lupus erythematosus

OBJECTIVES

Systemic lupus erythematosus (SLE) is a polygenic disorder of dysregulated inflammation. Numerous specific candidate genes have been identified and most relate to the handling of immune complexes or antigen presentation. This is consistent with the classic finding of immune complex deposition in affected end organs. We wished to examine combinatorial effects of polymorphic variants of genes involved in immune complex clearance in susceptibility to lupus.

METHODS

This study examined the occurrence of polymorphisms in genes which encode proteins known to be involved in immune complex handling and clearance. Each polymorphic variant of a complement protein (C2, mannose binding protein and C4), complement receptor (CR1) or Fc receptor (FcgammaRIIA and FcgammaRIIIA) gene is known to affect function adversely. One hundred and sixty SLE patients and 212 control subjects were genotyped using polymerase chain reaction methods.

RESULTS

We found an increasing association of SLE with increasing numbers of gene defects. Combinations of severe defects in FcgammaRIIA and FcgammaRIIIA were particularly deleterious for both African American and Caucasian patients, even though only one defective variant was individually statistically significantly associated with SLE.

CONCLUSIONS

The results of the study suggest that genes may interact in ways that either synergize or modify the effect of a single genetic effect and imply that association studies must be interpreted within the genetic background of the populations.

CP27 affects viability, proliferation, attachment and gene expression in embryonic fibroblasts

CP27 is a gene that has been cloned from an E11 early embryonic library and has been suggested to mediate early organogenesis (Diekwisch et al., 1999, Gene 235, 19). We have hypothesized that CP27 exhibits its effects on organogenesis by affecting individual cell function. Based on the CP27 expression pattern we have selected the CP27 expressing embryonic fibroblast cell line BALB/c 3T3 to determine the effects of CP27 on cell function. CP27 loss of function strategies were performed by adding 5, 12.5 or 25 micro g/ml anti-CP27 antibody to cultured BALB/c 3T3 cells and comparing the results to controls in which identical concentrations of rabbit serum were added to the culture medium. Other controls included an antibody against another extracellular matrix protein amelogenin (negative control) and anti-CP27 antibodies directed against other areas of the CP27 molecule (positive control). Following cell culture, cell viability, apoptosis, cell proliferation, cell shape, cellular attachment and fibronectin matrix production were assayed using MTT colourimetric assay, BrdU staining, morphometry, immunostaining and western blot analysis. Block of CP27 function using an antibody strategy resulted in the following significant changes: (i) reduced viability, (ii) increased number of apoptotic cells, (iii) reduced proliferation, (iv) alterations in cell shape, (v) loss of attachment, and (vi) reduction in fibronectin matrix production. There was also a redistribution in fibronectin matrix organization demonstrated by immunohistochemistry. We conclude that CP27 plays an important role in the maintance of normal cell function and that CP27 block leads to significant changes in cellular behaviour.