Implant site: a determinant of completeness of arterial prosthesis healing in the dog and possibly in humans

This paper compares the healing of supported knitted Dacron prostheses implanted in the descending thoracic aorta and in the subcutaneous carotid-femoral positions in each of 10 dogs. The descending thoracic aorta prostheses were 6 cm long and the carotid-femoral prostheses averaged 76 cm in length. The healing of four porous clinical axillofemoral grafts is compared to that of the experimental carotid-femoral grafts. There was little similarity between the healing observed in the descending thoracic aortic and subcutaneous positions; the descending thoracic aorta grafts healed rapidly and completely by eight weeks, with thrombus-free flow surfaces covered with confluent endothelial cells. However, the inner wall of the carotid-femoral grafts remained largely unhealed at one year, with endothelialization largely confined to a limited pannus ingrowth across the anastomoses. This indicates that the implant site in the dog is a primary determinant of the rapidity and completeness of healing. The clinical axillofemoral grafts explanted after 20 months to six and one-half years exhibited healing characteristics that were similar to those seen in the carotid-femoral position in the dog. These findings suggest that valid comparisons of interspecies healing require data obtained from similar implant locations. They present a challenge to the previously held concepts of major interspecies differences in speed and extent of tissue ingrowth based on data obtained from noncomparable implant sites.

Genetic disruption of host interferon-gamma drastically enhances the metastasis of pancreatic adenocarcinoma through impaired expression of inducible nitric oxide synthase

Synergistic induction of the inducible nitric oxide synthase (NOS II) gene requires a combination of interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS). In this study, we determined whether the induction of IFN-gamma was required for NOS II-mediated antitumor activity in vivo. Highly metastatic H7 murine pancreatic adenocarcinoma cells were implanted into the subcutis, footpad, and pancreas of syngeneic IFN-gamma(+/+) and IFN-gamma(-/-) mice. These cells grew and produced metastases and ascites in IFN-gamma(+/+) mice. In sharp contrast, the same tumor cells grew much more aggressively, metastasized more extensively, and produced a larger amount of malignant ascites in IFN-gamma(-/-) mice. Also, induction of IFN-gamma correlated with NOS II gene expression and NO production in IFN-gamma(+/+) injected with the tumor cells but not in IFN-gamma(-/-) mice or IFN-gamma(+/+) mice without tumor challenge. In vitro, only LPS plus IFN-gamma induced a high level of NO production and cytotoxicity against H7 cells. These data suggested that the tumor cells stimulated IFN-gamma secretion from host cells, which in turn stimulated NO production by host cells and suppressed tumor growth and metastasis.

Inflammation-associated extracellular β-glucuronidase alters cellular responses to the chemical carcinogen benzo[a]pyrene

Neutrophils infiltrate tissues during inflammation, and when activated, they release β-glucuronidase. Since inflammation is associated with carcinogenesis, we investigated how extracellular β-glucuronidase changed the in vitro cellular response to the chemical carcinogen benzo(a)pyrene (B[a]P). For this we exposed human liver (HepG2) and lung (A549) cells to B[a]P in the presence or absence of β-glucuronidase. β-Glucuronidase reduced B[a]P-induced expression of CYP1A1 and CYP1B1 at 6 h after exposure, which did not depend on β-glucuronidase activity, because the inhibitor D-saccharic acid 1,4-lactone monohydrate did not antagonize the effect of β-glucuronidase. On the other hand, the inhibitory effect of β-glucuronidase on CYP expression was dependent on signalling via the insulin-like growth factor receptor (IGF2R, a known receptor for β-glucuronidase), because co-incubation with the IGF2R inhibitor mannose-6-phosphate completely abolished the effect of β-glucuronidase. Extracellular β-glucuronidase also reduced the formation of several B[a]P metabolites and B[a]P-DNA adducts. Interestingly, at 24 h of exposure, β-glucuronidase significantly enhanced CYP expression, probably because β-glucuronidase de-glucuronidated B[a]P metabolites, which continued to trigger the aryl hydrocarbon receptor (Ah receptor) and induced expression of CYP1A1 (in both cell lines) and CYP1B1 (in A549 only). Consequently, significantly higher concentrations of B[a]P metabolites and DNA adducts were found in β-glucuronidase-treated cells at 24 h. DNA adduct levels peaked at 48 h in cells that were exposed to B[a]P and treated with β-glucuronidase. Overall, these data show that β-glucuronidase alters the cellular response to B[a]P and ultimately enhances B[a]P-induced DNA adduct levels.

Griseofulvin-induced aneuploidy and meiotic delay in male mouse germ cells: detected by using conventional cytogenetics and three-color FISH

Griseofulvin (GF) was tested in male mouse germ cells for the induction of meiotic delay and aneuploidy. Starved mice were orally treated with 500, 1000 and 2000 mg/kg of GF in corn oil and testes were sampled 22 h later for meiotic delay analysis and chromosome counting in spermatocytes at the second meiotic metaphase (MMII). A dose-related increase in meiotic delay by dose-dependently arresting spermatocytes in first meiotic metaphase (MMI) or/and prolonging interkinesis was observed. Hyperhaploid MMII cells were not significantly increased. Sperm were sampled from the Caudae epididymes 22 days after GF-treatment of the males for three-color fluorescence in situ hybridization (FISH). The frequencies of diploidies were 0.01-0.02% in sperm of the solvent control animals and increased dose-dependently to 0.03%, 0.068% and 0.091%, respectively, for 500, 1000 and 2000 mg/kg of GF. The frequencies of disomic sperm were increased significantly above the controls in all GF-treated groups but showed no dose response. The data for individual classes of disomic sperm indicated that MII was more sensitive than MI to GF-induced non-disjunction in male mice. A comparison of the present data from male mice and literature data from female mice suggests that mouse oocytes are more sensitive than mouse spermatocytes to GF-induced meiotic delay and aneuploidy.

Factor VIII inhibitors: von Willebrand factor makes a difference in vitro and in vivo

BACKGROUND

The important association between von Willebrand factor (VWF) and factor VIII (FVIII) has been investigated for decades, but the effect of VWF on the reactivity of FVIII inhibitory antibodies, referred to as inhibitors, is still controversial.

OBJECTIVE

To investigate the interaction among VWF, FVIII and FVIII inhibitory antibodies.

METHODS

Three sources of inhibitors were used for in vitro studies, including the plasma from immunized VWF(null) FVIII(null) mice, purified plasma IgG from human inhibitor patients, or human monoclonal antibody from inhibitor patients' B-cell clones. Inhibitors were incubated with recombinant human FVIII (rhFVIII) either with or without VWF. The remaining FVIII activity was determined by chromogenic assay and inhibitor titers were determined. For in vivo studies, inhibitors and rhFVIII were infused into FVIII(null) or VWF(null) FVIII(null) mice followed by a tail clip survival test.

RESULTS

VWF has a dose-dependent protective effect on FVIII, limiting inhibitor inactivation of FVIII in both mouse and human samples. A preformed complex of VWF with FVIII provides more effective protection from inhibitors than competitive binding of antibodies and VWF to FVIII. The protective effect of VWF against FVIII inactivation by inhibitors was further confirmed in vivo by infusing inhibitors and FVIII into FVIII(null) or VWF(null) FVIII(null) mice followed by a tail clip survival test.

CONCLUSION

Our results demonstrate that VWF exerts a protective effect, reducing inhibitor inactivation of FVIII, both in vitro and in vivo.

Comparison of the effect of monopolar and bipolar cauterization on skeletonized, dissected internal thoracic arteries

The internal thoracic artery is preferable to the saphenous vein for use as a conduit for coronary artery bypass. More extensive use is possible if this artery is mobilized in a skeletonized form to provide greater length. Internal thoracic arteries are usually mobilized with cauterization. This study compared the effectiveness and effects on neighboring areas of division of the branches of the canine internal thoracic artery with bipolar cauterization and monopolar cauterization. Branch closure was significantly more secure in the bipolar cauterization group, with bleeding in 25 (9%) of 279 branches of 15 internal thoracic arteries treated with monopolar cauterization, in contrast to bleeding in 4 (1.3%) of 306 branches in the 15 internal thoracic arteries treated with bipolar cauterization, which were paired with the group treated with monopolar cauterization. The group of internal thoracic arteries treated with monopolar cauterization had a significantly higher prevalence of leakage when luminal pressure was increased from 120 to 160 mm Hg. Scanning electron microscopy demonstrated partial loss of endothelial cells on the flow surface of internal thoracic arteries treated with bipolar cauterization, compared with almost complete loss of endothelial cells around the orificial areas after monopolar cauterization. Secondary bipolar cauterization treatment caused only slightly more damage than primary treatment, but secondary monopolar cauterization was much more severe and extensive than primary treatment. These data suggest that bipolar cauterization is preferable to monopolar cauterization for skeletonized dissection of the internal thoracic artery.

The important role of von Willebrand factor in platelet-derived FVIII gene therapy for murine hemophilia A in the presence of inhibitory antibodies

BACKGROUND

Our previous studies have demonstrated that targeting FVIII expression to platelets results in FVIII storage together with von Willebrand factor (VWF) in platelet α-granules and that platelet-derived FVIII (2bF8) corrects the murine hemophilia A phenotype even in the presence of high-titer anti-FVIII inhibitory antibodies (inhibitors).

OBJECTIVE

To explore how VWF has an impact on platelet gene therapy for hemophilia A with inhibitors.

METHODS

2bF8 transgenic mice in the FVIII(-/-) background (2bF8(tg+/-) F8(-/-) ) with varying VWF phenotypes were used in this study. Animals were analyzed by VWF ELISA, FVIII activity assay, Bethesda assay and tail clip survival test.

RESULTS

Only 18% of 2bF8(tg+/-) F8(-/-) VWF(-/-) animals, in which VWF was deficient, survived the tail clip challenge with inhibitor titers of 3-8000 BU mL(-1) . In contrast, 82% of 2bF8(tg+/-) F8(-/-) VWF(+/+) mice, which had normal VWF levels, survived tail clipping with inhibitor titers of 10-50,000 BU mL(-1) . All 2bF8(tg+/-) F8(-/-) VWF(-/-) mice without inhibitors survived tail clipping and no VWF(-/-) F8(-/-) mice survived this challenge. Because VWF is synthesized by endothelial cells and megakaryocytes and is distributed in both plasma and platelets in peripheral blood, we further investigated the effect of each compartment of VWF on platelet-FVIII gene therapy for hemophilia A with inhibitors. In the presence of inhibitors, 42% of animals survived tail clipping in the group with plasma-VWF and 50% survived in the platelet-VWF group.

CONCLUSION

VWF is essential for platelet gene therapy for hemophilia A with inhibitors. Both platelet-VWF and plasma-VWF are required for optimal platelet-derived FVIII gene therapy for hemophilia A in the presence of inhibitors.

In vitro activity of isoimperatorin, alone and in combination, against Mycobacterium tuberculosis

Previous studies have shown that isoimperatorin (IO), a furanocoumarin isolated from several medicinal plants, has antimycobacterial activity against Mycobacterium tuberculosis strain H37Rv (ATCC 27294). This study demonstrated that IO has antimycobacterial activity against 2 drug-sensitive and 6 drug-resistant isolates, with minimum inhibitory concentrations (MICs) of 50-100 μg ml(-1) and 100-200 μg ml(-1), respectively. IO exhibited synergistic antimycobacterial effects with rifampin (RMP), isoniazid (INH) and ethambutol (EMB) against 6 drug-resistant strains, with fractional inhibitory concentration index (FICI) values of 0·133-0·472, 0·123-0·475 and 0·124-0·25, respectively. The IO/RMP, IO/INH and IO/EMB combination treatments had synergistic effects or no interaction in the 2 drug-sensitive strains and the standard strain ATCC 27294. The synergism of combined drugs against drug-resistant strains was better than drug-sensitive strains. No antagonism was observed in with the aforementioned combinations against all strains tested. IO exhibited relatively low cytotoxicity to Vero cells. Our results indicate that IO may serve as promising a template for future antimycobacterial drug development.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report on the in vitro synergistic antimycobacterial effects of isoimperatorin (IO) in combination with three first-line drugs: rifampin (RMP), isoniazid (INH) and ethambutol (EMB). The results indicated that the antimycobacterial activity of IO was modest; however, IO was a useful and effective agent against Myco. tuberculosis when it was combined with first-line antimycobacterial drugs and is worthy of further development as a lead compound for the development of novel antimycobacterial therapeutic agents.

Altered gene expression profiles in the lungs of benzo[a]pyrene-exposed mice in the presence of lipopolysaccharide-induced pulmonary inflammation

Patients with inflammatory lung diseases are often additionally exposed to polycyclic aromatic hydrocarbons like B[a]P and B[a]P-induced alterations in gene expression in these patients may contribute to the development of lung cancer. Mice were intra-nasally treated with lipopolysaccharide (LPS, 20μg/mouse) to induce pulmonary inflammation and subsequently exposed to B[a]P (0.5mg/mouse) by intratracheal instillation. Gene expression changes were analyzed in mouse lungs by RNA microarrays. Analysis of genes that are known to be involved in the cellular response to B[a]P indicated that LPS significantly inhibited gene expression of various enzymes linked to B[a]P metabolism, which was confirmed by phenotypic analyses of enzyme activity. Ultimately, these changes resulted in higher levels of B[a]P-DNA adducts in the lungs of mice exposed to B[a]P with prior LPS treatment compared to the lungs of mice exposed to B[a]P alone. Using principle component analysis (PCA), we found that of all the genes that were significantly altered in their expression, those that were able to separate the different exposure conditions were predominantly related to immune-response. Moreover, an overall analysis of differentially expressed genes indicated that cell-cell adhesion and cell-cell communication was inhibited in lungs of mice that received both B[a]P and LPS. Our results indicate that pulmonary inflammation increased the genotoxicity of B[a]P via inhibition of both phase I and II metabolism. Therefore, inflammation could be a critical contributor to B[a]P-induced carcinogenesis in humans.

A novel monoclonal antibody against human CD80 and its immune protection in a mouse lupus-like disease

Blockade of the interactions between CD28/CTLA-4 and their ligands, CD80 (B7, B7.1)/CD86 (B70, B7.2), is an attractive means to induce antigen-specific peripheral tolerance in autoimmune disease and organ transplantation. In this study, we generated and characterized a monoclonal antibody (Clone 4E5) against human CD80. 4E5 could recognize both human and mouse CD80 and suppress mixed lymphocyte reaction in vitro. To investigate their potency for clinical use, we further administrated 4E5 to a mouse lupus-like disease model (C57BL/J6) induced by Pristane. 4E5 could inhibit the immune response and attenuate the severity of lupus-like disease. The data showed 4E5 function and suggested that blockade of CD80/CD28 co-stimulatory signal pathway with 4E5 is a promising strategy to decelerate the progression of lupus-like disease and other autoimmune diseases.

Characterization and application of two novel monoclonal antibodies against human OX40: costimulation of T cells and expression on tumor as well as normal gland tissues

OX40, a membrane-bound molecule of the tumor-necrosis-factor-receptor superfamily, is a critical costimulatory receptor during the immune response. Here, we newly generated two specific mouse antihuman OX40 monoclonal antibodies (mAbs) (2G2 and 1F7), whose specificities are quite different from the available OX40 mAb (ACT35) by competition assay. It was also found that both mAbs could enhance the proliferation, activation and differentiation of T lymphocytes primed by anti-CD3 mAb. These results evidenced that both were functional antihuman OX40 mAbs. Furthermore, stained by 2G2 and 1F7, FCM and immunohistochemistry detected the constitutive expression of OX40 on tumor cell lines from epithelium, breast cancer and glioma tissues. Meanwhile, the non-tumor tissues (thyroid gland, stomach gland) were also found OX40 expression. These results suggested that OX40 is not only expressed in activated T cells, but also in some tumors as well as normal gland tissues. Such expression pattern indicated that OX40 may be a valuable surface antigen in unveiling its expression and function outside the immune system. Briefly, these novel antibodies may contribute to the evaluation of the mechanism of tumor metastasis and eventually shed light on further study of tumor immunotherapy and autoimmune diseases.

Large-scale analysis of factors influencing nonalcoholic fatty liver disease and its relationship with liver enzymes

Serum liver enzyme levels are often used effectively for the evaluation of nonalcoholic fatty liver disease (NAFLD). We aimed to investigate the associations between serum liver enzyme levels and risks for NAFLD in over 8000 cases in a large-scale analysis. A cross-sectional survey with multiple stages and random samplings was performed from May 2007 to May 2009 on 8102 workers at Tongji University. A questionnaire was given, assessments of physical measurements, plasma glucose, lipid profiles, and liver enzymes were made, and real-time liver ultrasounds conducted. The prevalence of NAFLD in Tongji University was 22.2%. It was higher in males than in females (P = 0.0023). The body mass index, waist-to-hip ratio, serum total triglycerides, serum total cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT) values were all higher in the NAFLD group than in the control group. For moderate and severe NAFLD patients, the ALT, AST and GGT values were significantly increased, high density lipoprotein cholesterol was decreased, and drinking much, heavy entertainment and less exercise were more prevalent (P < 0.001). There were strong correlations between serum liver enzyme levels and NAFLD (P < 0.001), with GGT being a more sensitive marker for NAFLD than ALT or AST. ALT and GGT were independent predictors for NAFLD, and GGT was a better predictor than ALT for NAFLD.

Accelerated healing of Dacron grafts seeded by preclotting with autologous bone marrow blood

> Studies have suggested that bone marrow-derived cells in the circulation may have the capacity and potential to endothelialize and heal vascular graft surfaces. We have investigated whether accelerated endothelialization could be achieved for Dacron grafts seeded by preclotting with bone marrow blood (BMB). Five 8 mm x 6 cm Dacron grafts seeded and preclotted with BMB and four controls preclotted with peripheral blood were implanted in the descending thoracic aorta (DTA) of mongrel dogs for 2 and 4 weeks. Two additional BMB DTA grafts were studied for 3 months. Five pairs of BMB and control grafts (4 mm x 6 cm) were bilaterally implanted into the carotids of dogs for 1 week and five pairs for 4 weeks. All grafts remained patent. BMB seeding/preclotting was a simple, effective method to accelerate early graft endothelialization without increasing thrombogenicity. Further studies are needed before clinical application can be recommended.

Innovative estimation of survival using log-normal survival modelling on ACCENT database

Background:

The ACCENT database, with individual patient data for 20 898 patients from 18 colon cancer clinical trials, was used to support Food and Drug Administration (FDA) approval of 3-year disease-free survival as a surrogate for 5-year overall survival. We hypothesised substantive differences in survival estimation with log-normal modelling rather than standard Kaplan–Meier or Cox approaches.

Methods:

Time to relapse, disease-free survival, and overall survival were estimated using Kaplan–Meier, Cox, and log-normal approaches for male subjects aged 60–65 years, with stage III colon cancer, treated with 5-fluorouracil-based chemotherapy regimens (with 5FU), or with surgery alone (without 5FU).

Results:

Absolute differences between Cox and log-normal estimates with (without) 5FU varied by end point. The log-normal model had 5.8 (6.3)% higher estimated 3-year time to relapse than the Cox model; 4.8 (5.1)% higher 3-year disease-free survival; and 3.2 (2.2)% higher 5-year overall survival. Model checking indicated greater data support for the log-normal than the Cox model, with Cox and Kaplan–Meier estimates being more similar. All three model types indicate consistent evidence of treatment benefit on both 3-year disease-free survival and 5-year overall survival; patients allocated to 5FU had 5.0–6.7% higher 3-year disease-free survival and 5.3–6.8% higher 5-year overall survival.

Conclusion:

Substantive absolute differences between estimates of 3-year disease-free survival and 5-year overall survival with log-normal and Cox models were large enough to be clinically relevant, and warrant further consideration.

Characterization and functional study of five novel monoclonal antibodies against human OX40L highlight reverse signalling: enhancement of IgG production of B cells and promotion of maturation of DCs

OX40 ligand (OX40L), a molecule originally identified as human gp34, is an important co-stimulatory molecule during immune response. In this study, we report on five functional mouse anti-human OX40L monoclonal antibodies named as 9H10, 4C12, 8D10, 4H4 and 1G1, characterized by means of flow cytometry, Western blot and competition assay. These monoclonal antibodies bound to distinct OX40L epitopes on activated B cells and dendritic cells (DCs) and two of them could suppress the proliferation of T lymphocytes co-stimulated by mature DCs. Furthermore, we demonstrated that our monoclonal antibodies, such as 9H10 and 4C12, could trigger OX40L reverse signal that enhanced IgG production of B cells and promoted maturation of DCs as evidenced by the upexpression of CD80, CD86, CD83 and CXCR4 and monoclonal antibody 9H10 could also promote anti-CD40 monoclonal-antibody-stimulated DCs in order to induce T cells to secrete more interleukin-2 and interferon-gamma, which suggested that OX40L signals could strengthen the effect of CD40 signals on promoting Th1 differentiation.

Evaluation of the change of outcomes over a 10-year period in patients with stage III colon cancer: pooled analysis of 6501 patients treated with fluorouracil, leucovorin, and oxaliplatin in the ACCENT database

BACKGROUND

Since 2004, adjuvant 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX or FLOX) have been the standard of care for patients with resected colon cancer. Herein we examine the change of outcomes over a 10-year period in patients with stage III colon cancer who received this regimen.

PATIENTS AND METHODS

Individual patient data from the ACCENT database was used to compare the outcomes in older (1998-2003) and newer (2004-2009) treatment eras for patients with stage III colon cancer who received adjuvant FOLFOX or FLOX. The outcomes were compared between the two groups by the multivariate Cox proportional-hazards model adjusting for age, sex, performance score, T stage, N stage, tumor sidedness, and histological grade.

RESULTS

A total of 6501 patients with stage III colon cancer who received adjuvant FOLFOX or FLOX in six randomized trials were included in the analysis. Patients enrolled in the new era group experienced statistically significant improvement in time to recurrence [3-year rate, 76.1% versus 73.0%; adjusted hazard ratio (HRadj) = 0.83 (95% CI, 0.74-0.92), P = 0.0008], disease-free survival (DFS) [3-year rate, 74.7% versus 72.3%; HRadj = 0.88 (0.79-0.98), P = 0.024], survival after recurrence (SAR) [median time, 27.0 versus 17.7 months; HRadj = 0.65 (0.57-0.74), P < 0.0001], and overall survival (OS) [5-year rate, 80.9% versus 75.7%; HRadj = 0.78 (0.69-0.88), P < 0.0001]. The improved outcomes remained in patients diagnosed at 45 years of age or older, low-risk patients (T1-3 and N1), left colon, mismatch repair proficient (pMMR), BRAF, and KRAS wild-type tumors.

CONCLUSION

Improved outcomes were observed in patients with stage III colon cancer enrolled in clinical trials who received adjuvant FOLFOX/FLOX therapy in 2004 or later compared with patients in the older era. Prolonged SAR calls for revalidation of 3-year DFS as the surrogate endpoint of OS in adjuvant clinical trials and reevaluation of optimal follow-up of OS to confirm the trial findings based on the DFS endpoints.

CLINICAL TRIALS NUMBERS

NCT00079274; NCT00096278; NCT00004931; NCT00275210; NCT00265811; NCT00112918.

Phylogenetic relationships and divergence dates of softshell turtles (Testudines: Trionychidae) inferred from complete mitochondrial genomes

The softshell turtles (Trionychidae) are one of the most widely distributed reptile groups in the world, and fossils have been found on all continents except Antarctica. The phylogenetic relationships among members of this group have been previously studied; however, disagreements regarding its taxonomy, its phylogeography and divergence times are still poorly understood as well. Here, we present a comprehensive mitogenomic study of softshell turtles. We sequenced the complete mitochondrial genomes of 10 softshell turtles, in addition to the GenBank sequence of Dogania subplana, Lissemys punctata, Trionyx triunguis, which cover all extant genera within Trionychidae except for Cyclanorbis and Cycloderma. These data were combined with other mitogenomes of turtles for phylogenetic analyses. Divergence time calibration and ancestral reconstruction were calculated using BEAST and RASP software, respectively. Our phylogenetic analyses indicate that Trionychidae is the sister taxon of Carettochelyidae, and support the monophyly of Trionychinae and Cyclanorbinae, which is consistent with morphological data and molecular analysis. Our phylogenetic analyses have established a sister taxon relationship between the Asian Rafetus and the Asian Palea + Pelodiscus + Dogania + Nilssonia + Amyda, whereas a previous study grouped the Asian Rafetus with the American Apalone. The results of divergence time estimates and area ancestral reconstruction show that extant Trionychidae originated in Asia at around 108 million years ago (MA), and radiations mainly occurred during two warm periods, namely Late Cretaceous-Early Eocene and Oligocene. By combining the estimated divergence time and the reconstructed ancestral area of softshell turtles, we determined that the dispersal of softshell turtles out of Asia may have taken three routes. Furthermore, the times of dispersal seem to be in agreement with the time of the India-Asia collision and opening of the Bering Strait, which provide evidence for the accuracy of our estimation of divergence time. Overall, the mitogenomes of this group were used to explore the origin and dispersal route of Trionychidae and have provided new insights on the evolution of this group.

Protein restriction and succedent realimentation affecting ileal morphology, ileal microbial composition and metabolites in weaned piglets

Dietary protein restriction is one of the effective ways to reduce post-weaning diarrhoea and intestinal fermentation in piglets, but it may also reduce growth performance. The compensatory growth induced by subsequent protein realimentation may solve the issue. However, little research has been done on the impact of protein realimentation on the gut. In this study, the effects of protein restriction and realimentation on ileal morphology, ileal microbial composition and metabolites in weaned piglets were investigated. Thirty-six 28-day-old weaned piglets with an average body weight of 6.47 ± 0.04 kg were randomly divided into a control group and a treatment group. The CP level in the diet of the control group was 18.83% for the entire experimental period. The piglets in the treatment group were fed 13.05% CP between days 0 and 14 and restored to a diet of 18.83% CP for days 14 to 28. On day 14 and 28, six pigs from each group were sacrificed and sampled. It was found that the abundance of Lactobacillus and Salmonella in the ileal digesta was significantly lower in the treatment group than the control group on day 14, whereas the abundance of Clostridium sensu stricto 1, Streptococcus, Halomonas and Pseudomonas significantly increased in the ileal digesta of the treatment group on day 14 compared with the control group. In addition, reduced concentrations of lactic acid, total short-chain fatty acids (total SCFAs), total branched chain fatty acids, ammonia and impaired ileal morphology and mucosal barrier were observed in the treatment group on day 14. However, diarrhoea levels decreased in the treatment group throughout the experiment. During the succedent protein realimentation stage, the treatment group demonstrated compensatory growth. Compared with the control group, the treatment group showed increased abundance of Lactobacillus and reduced abundance of Salmonella, Halomonas and Pseudomonas in the ileum on day 28. The concentrations of lactic acid and total SCFAs increased significantly, whereas the concentration of ammonia remained at a lower level in the treatment group on day 28 compared with the control group. Overall, protein realimentation could improve ileal morphology and barrier functions and promote ileal digestive and absorptive functions. In conclusion, ileal microbial composition and metabolites could change according to dietary protein restriction and realimentation and eventually influence ileal morphology and barrier functions.

Longitudinal evaluation of markers of inflammation in HIV-positive and HIV-negative Rwandan women

OBJECTIVES

African women are disproportionately affected by HIV infection and may experience non-AIDS-related complications associated with inflammation. High-sensitivity C-reactive protein (hsCRP), d-dimer and transthyretin have been examined as inflammatory markers elsewhere, but it is unclear how they change over time in HIV-negative or HIV-positive African women with or without antiretroviral therapy (ART) initiation.

METHODS

We examined hsCRP, d-dimer and transthyretin levels at baseline and at follow-up of ≥2 years in 185 HIV-negative and 510 HIV-positive Rwandan women who were ART naïve at study entry. Generalized estimating equations for each marker were used to investigate the association with HIV infection/CD4 count, ART and follow-up time.

RESULTS

Compared with HIV-negative women, HIV-positive women had higher hsCRP and d-dimer and lower transthyretin concentrations, with greater differences at lower CD4 counts. After adjusting for CD4 count and other factors, ART was not significantly associated with log hsCRP (P = 0.36) at follow-up, but was independently associated with lower log d-dimer (P = 0.03) and higher transthyretin (P = 0.0008) concentrations. At ≥ 2 years of follow-up, hsCRP had not significantly changed in any group but log d-dimer had decreased significantly in all groups. Transthyretin declined significantly over time in HIV-negative women and HIV-positive non-ART initiators, but increased significantly in HIV-positive ART initiators.

CONCLUSIONS

HIV infection and advanced immune suppression were associated with higher hsCRP and d-dimer and lower transthyretin concentrations. ART (independently of CD4 changes) was significantly associated with decreases in d-dimer and increases in transthyretin, but, in contrast to other studies, was not associated with decreases in hsCRP. We found no change in hsCRP over time in any group.

Atomic force microscopy measurements reveal multiple bonds between Helicobacter pylori blood group antigen binding adhesin and Lewis b ligand

The strength of binding between the Helicobacter pylori blood group antigen-binding adhesin (BabA) and its cognate glycan receptor, the Lewis b blood group antigen (Le(b)), was measured by means of atomic force microscopy. High-resolution measurements of rupture forces between single receptor-ligand pairs were performed between the purified BabA and immobilized Le(b) structures on self-assembled monolayers. Dynamic force spectroscopy revealed two similar but statistically different bond populations. These findings suggest that the BabA may form different adhesive attachments to the gastric mucosa in ways that enhance the efficiency and stability of bacterial adhesion.

Effect of interleukin (IL)-8 on benzo[a]pyrene metabolism and DNA damage in human lung epithelial cells

It has been well established that inflammation and concurrent mutagenic exposures drive the carcinogenic process in a synergistic way. To elucidate the role of the inflammatory cytokine IL-8 in this process, we studied its effect on the activation and deactivation of the chemical mutagen benzo[a]pyrene B[a]P in the immortalized pulmonary BEAS-2B cell line. After 24h incubation with B[a]P in the presence or absence of IL-8, the B[a]P induced cytochrome P450 1A1 and 1B1 (CYP1A1 and CYP1B1) gene expression and CYP1A1 enzyme activity was significantly higher in the presence of the cytokine. Consistent with these findings, we observed higher concentration of the metabolite B[a]P-7,8-diol under concurrent IL-8 treatment conditions. Interestingly, we also found higher concentrations of unmetabolized B[a]P. To explain this, we examined the downstream effects of IL-8 on NADPH oxidases (NOXes). IL-8 lowered the intracellular NADPH level, but this effect could not explain the changes in B[a]P metabolism. IL-8 also significantly depleted intracellular glutathione (GSH), which also resulted in enhanced levels of unmetabolized B[a]P, but increased concentrations of the metabolite B[a]P-7,8-diol. No differences in B[a]P-DNA adducts level were found between B[a]P and B[a]P combined with IL-8, and this might be due to a 3-fold increase in nucleotide excision repair (NER) after IL-8 treatment. These findings suggest that IL-8 increased the formation of B[a]P-7,8-diol despite an overall delayed B[a]P metabolism via depletion of GSH, but DNA damage levels were unaffected due to an increase in NER capacity.