CcpA regulates biofilm formation and competence in Streptococcus gordonii

Streptococcus gordonii is an important member of the oral biofilm community. As an oral commensal streptococcus, S. gordonii is considered beneficial in promoting biofilm homeostasis. CcpA is known as the central regulator of carbon catabolite repression in Gram-positive bacteria and is also involved in the control of virulence gene expression. To further establish the role of CcpA as central regulator in S. gordonii, the effect of CcpA on biofilm formation and natural competence of S. gordonii was investigated. These phenotypic traits have been suggested to be important to oral streptococci in coping with environmental stress. Here we demonstrate that a CcpA mutant was severely impaired in its biofilm-forming ability, showed a defect in extracellular polysaccharide production and reduced competence. The data suggest that CcpA is involved in the regulation of biofilm formation and competence development in S. gordonii.

The insulin resistance Grb14 adaptor protein promotes thyroid cancer ret signaling and progression

The growth factor receptor-bound protein (Grb) 14 is an adapter molecule of the Grb7/10/14 family with characteristic BPS domains serving to avidly bind tyrosine kinases. Grb14 inhibits insulin receptor (IR) catalytic activity through interaction with the BPS domain and impedes peptide substrate binding. Members of this Grb family have also been shown to interact with other kinases through their SH2 domain. Here we examined the functional role of Grb14 in thyroid cancer using loss- and gain-of-function approaches. Stable knockdown of Grb14 in thyroid cancer cells facilitated insulin receptor signaling. In contrast, RET phosphorylation was diminished in concert with reduced activation of Akt and STAT3. Loss of Grb14 also resulted in diminished cell proliferation and invasion both in vitro and in mouse flank xenografts. In complementary studies, forced expression of Grb14 interrupted insulin receptor signaling but facilitated RET activation, STAT3, and Akt phosphorylation. Consistent with these findings Grb14 over-expression enhanced cell invasion and resulted in striking metastases in an orthotopic thyroid cancer mouse xenograft model. Primary human thyroid cancer microarrays revealed a positive correlation between Grb14 expression and invasive behavior. Our findings uncover a new role for Grb14 in finely tuning receptor signaling and modulating thyroid cancer progression.

First Report of Stem Blight of Eleocharis dulcis Caused by Phoma bellidis in China

Eleocharis dulcis is a perennial herbaceous plant in the family Cyperaceae, which is native to China and India where it grows well in moist-to-wet soils. It is commonly used as a fruit or a vegetable. From August 2009 to December 2010, symptoms were observed on E. dulcis stems in Tuanfeng County, Hubei, China, with the crop area affected estimated to be more than 1,300 ha per year. Corm yield was reduced by 20% on average with as much as 60% yield losses in some fields. Lesions were initially small, red-brown, and oval or circular that enlarged to produce apical necrosis and extending until the stems withered, usually within 2 months. To obtain isolates, diseased tissue was disinfested for 1 min in 0.1% mercuric chloride solution, rinsed with sterilized water, and plated on potato dextrose agar. Isolates with similar morphological characteristics were consistently recovered. Three isolates, CTF-3, CTF-10, and CTF-11, were used to further evaluate characteristics of the pathogen. After 7 days, white colonies were 76 to 80 mm across on oatmeal agar (OA) with sparse aerial hyphae and a slight salmon color in the conidial masses. Pycnidia produced on OA were globose to subglobose, usually with one slightly ostiolar papilla, olivaceous to olivaceous black, and 93 to 245 μm in diameter. Conidia were hyaline, unicellular, ellipsoidal, mostly with two polar guttules, and 3.6 to 6.2 × 2.0 to 3.3 μm. Chlamydospores were absent. Growth of the isolates on malt extract agar (MEA) was slower than on OA, and the colony diameters at 7 days were 60 to 65 mm. The reactions with 1M NaOH were both positive on OA and MEA where the cultures initially changed to yellow green and gradually turned to red. The pathogen was identified as Phoma bellidis Neerg. based on descriptions in Boerema et al. (2). Pathogenicity tests were performed with the three isolates in the laboratory by spraying conidial suspensions (1 × 10⁶ conidia/ml) containing 0.1% Tween 20 until runoff (30 ml per plant) onto stem surfaces of 50-day-old, 60 cm tall plants. For each isolate, there were 50 stems from five replicate plants that had multiple stems per plant. Control plants were treated with sterilized water containing 0.1% Tween 20 only. Plants were incubated with a 16-h photoperiod at 28°C and 90% relative humidity in an artificial climate chamber. Five days after inoculation, typical red-brown spots were observed on all inoculated stems but no symptoms were seen on water-treated control plants. Koch's postulates were fulfilled by reisolation of P. bellidis from diseased stems. The pathogenicity tests were repeated twice more with the same results. P. bellidis has only been reported previously on Bellis spp. from England, Denmark, Italy, the Netherlands, and Switzerland (1,2). Furthermore, there are only a few fungal diseases known to be associated with E. dulcis, and none so far that involve species of Phoma (3,4). To our knowledge, this is the first report of P. bellidis infecting E. dulcis worldwide. References: (1) M. M. Aveskamp et al. Stud. Mycol. 65:27, 2010. (2) G. H. Boerema et al. Phoma Identification Manual: Differentiation of Specific and Infra-Specific Taxa in Culture. CABI Publishing, Wallingford, UK, 2004. (3) P. L. Lentz. Am. Midl. Nat. 67:184, 1962. (4) L. Pan et al. J. Changjiang Vegetables (in Chinese) 14:10, 2010.

Lymphatic sparing versus lymphatic non-sparing laparoscopic varicocelectomy in children and adolescents: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to explore the true efficacy and potential advantages of lymphatic sparing laparoscopic varicocelectomy (LSV) over lymphatic non-sparing laparoscopic varicocelectomy (LNSV) in children and adolescents.

METHODS

A search was made for studies published up until 31 August 2010 using the terms "lymphatic sparing varicocelectomy", "laparoscopy", "adolescent" and "children" in the Medline, Embase, Ovid, Web of Science, and Cochrane databases. Randomized controlled trials (RCTs) and observational clinical studies (OCSs) comparing LSV and LNSV were included. A systematic review and meta-analysis was performed using odds ratios (ORs) for dichotomous variables.

RESULTS

Out of 127 studies, 2 RCTs and 4 OCSs were eligible for inclusion, comprising 489 cases of LSV and 307 cases of LNSV. The hydrocele rates after LSV were significantly lower than after LNSV (OR = 0.19; 95% confidence interval [CI] = 0.10 to 0.36; p < 0.00001). However, no significant difference was observed between LSV and LNSV with regard to recurrence (OR = 0.65; 95% CI = 0.32-1.33; p = 0.24) or catch-up growth (OR = 2.14; 95% CI =0.97-4.72; p = 0.06).

CONCLUSION

LSV is valuable in reducing the incidence of postoperative hydrocele, with similar recurrence and catch-up growth rates as LNSV. A series of RCTs are warranted to explore the efficacy of LSV in the management of varicocele in children and adolescents.

Proteomic analysis of inviable salmonid hybrids between female masu salmon Oncorhynchus masou masou and male rainbow trout Oncorhynchus mykiss during early embryogenesis

Early embryos of inviable hybrids between female masu salmon Oncorhynchus masou masou and male rainbow trout Oncorhynchus mykiss at 9, 12, 15 and 20 days after fertilization were examined for protein expression profiles. A total of 44 proteins, mostly down-regulated products of house-keeping genes and those involved in nucleic acid metabolism or chromatin replication, were identified in hybrid embryos by mass spectrometry analysis and protein database searching. The identified down-regulated proteins may be responsible for the inviability in the hybrids.

First Report of Leaf Spot of Houttuynia cordata Caused by Alternaria alternata in China

Houttuynia cordata is a perennial herbaceous plant (family Saururaceae) that is native to southern China, Japan, Korea, and Southeast Asia where it grows well in moist to wet soils. It is commonly used as a Chinese herbal medicine and as a vegetable. In North America and Europe it is also used as an ornamental. From September 2007 to November 2009, symptoms of leaf spot were found on H. cordata leaves in Dangyang County, Hubei, China, with the crop area affected estimated to be over 600 ha per year. Rhizome yield was reduced by 20% on average, with up to 70% yield losses in some fields during the autumn growing season. Lesions were initially small, brown, and oval or circular that developed into dark spots and sometimes formed target spots with white centers. These spots enlarged and overlapped, extending until the leaves withered entirely usually within 2 months. A fungus was consistently recovered from symptomatic leaf samples collected in October 2008 or 2009 with an average 90% isolation rate from ~60 leaf pieces that were surface sterilized with 0.1% mercuric chloride solution. Three isolates, HCDY-2, HCDY-3, and HCDY-4, were used to further evaluate characteristics of the pathogen. On potato dextrose agar, all cultures initially developed white colonies and the centers turned gray or brown after 4 days of incubation. Conidiophores were single or fasciculate, straight or knee curved, gray-brown with regular septa, and 42 to 61 × 4 to 5 μm. Conidia were obclavate or ovate, brown, and 26 to 38 × 12 to 20 μm with three to five transverse and one to three longitudinal or oblique septa. The tops of some conidia developed into secondary conidiophores, which were cylindrical, beige, and 5 to 17 × 3 to 5 μm. The pathogen was identified as Alternaria alternata based on descriptions in Simmons (3). Genomic DNA of HCDY-2 was extracted, and the rDNA-internal transcribed spacer sequence showed 99.6% identity to A. alternata (GenBank No. AY513941). Pathogenicity tests were performed with the three isolates by spraying conidial suspensions (1 × 10⁶ conidia/ml) containing 0.1% Tween 20 onto upper and lower surfaces of leaves of 40-day-old 15-cm high plants. There were 20 leaves from five replicate plants for each isolate. Control plants were treated with sterilized water containing 0.1% Tween 20 only. All plants were incubated with a 16-h photoperiod at 25°C and 90% relative humidity in an artificial climate chamber. Five days after inoculation, typical brown spots were observed on all inoculated leaves but no symptoms were seen on water-treated control plants. Koch's postulates were fulfilled by reisolation of A. alternata from diseased leaves. The pathogenicity tests were carried out twice. A survey of the literature revealed only a few fungal diseases associated with H. cordata (1,2,4), including Phyllosticta houttuyniae, Pseudocercospora houttuyniae, Rhizoctonia solani, and Sclerotium rolfsii. Although A. alternata is a cosmopolitan plant pathogen, it has not been reported on any species in the four genera in Saururaceae (Anemopsis, Gymnotheca, Houttuynia, and Saururus) (3). To our knowledge, this is the first report of A. alternata infecting H. cordata worldwide. References: (1) Y. L. Guo and W. X. Zhao. Acta Mycol. Sin. 8:118, 1989. (2) K. Sawada. Spec. Publ. Taiwan Univ. 8:138, 1959. (3) E. G. Simmons. Alternaria: An Identification Manual. The American Phytopathological Society, St. Paul, MN, 2007. (4) Y. Wu et al. J. Changjiang Vegetables (In Chinese) 2:19, 2007.

NBCe1 in mouse and human ameloblasts may be indirectly regulated by fluoride

Enamel biomineralization results in a release of protons into the enamel matrix, causing an acidification of the local microenvironment. This acidification, which may be enhanced by more rapid mineral deposition in the presence of fluoride, must be neutralized by the overlying ameloblasts. The electrogenic sodium bicarbonate co-transporter NBCe1 has been localized in mouse ameloblasts, and has been proposed to have a role in matrix pH regulation. In this study, transcript analysis by PCR showed NBCe1-A present in human ameloblasts, whereas mouse ameloblasts expressed NBCe1-B. In situ hybridization and qPCR in mouse and fetal human incisors showed that NBCe1 mRNA was up-regulated as ameloblasts differentiated. Ingestion of 50 ppm fluoride resulted in an up-regulation of NBCe1 mRNA in maturation-stage mouse ameloblasts in vivo, as compared with controls. NBCe1 expression was up-regulated by low pH, but not by fluoride, in human ameloblast-lineage cells in vitro. The up-regulation of NBCe1 in vivo as enamel maturation and mineralization progressed provides evidence that NBCe1 participates in pH modulation during enamel formation. Up-regulation of NBCe1 in fluorosed maturation ameloblasts in vivo, with no effect of fluoride in vitro, supports the hypothesis that fluoride-enhanced mineral deposition results in acidification of the mineralizing enamel matrix.

Streptozotocin-induced diabetic rat-derived bone marrow mesenchymal stem cells have impaired abilities in proliferation, paracrine, antiapoptosis, and myogenic differentiation

BACKGROUND

Diabetes has been widely recognized as a major risk factor for cardiovascular disease. With the development of the regenerative medicine, autologous bone marrow-derived mesenchymal stem cells (BMSCs), transplantation can effectively improve cardiac function after myocardial infarction. However, the BMSCs used in most previous studies are derived from young or normal donors. Little is know about the biological characters change of BMSCs in diabetes mellitus.

METHODS

BMSCs were taken from the streptozotocin (STZ)-induced diabetic rats and normal control rats. Cell proliferation was evaluated by CCK-8 assay. Production of vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF)-1 were measured by enzyme-linked immunosorbent assay. Apoptosis under hypoxia and serum deprivation culture conditions were detected by Hoechst 33342 stain and flow cytometry. Myogenic differentiation, induced by 5-azacytidine was assessed by using immunocytochemical staining for the expression of sarcomeric α-actin and desmin.

RESULTS

Diabetic rat models were successfully induced by intraperitoneal injection of STZ. The proliferative abilities of BMSCs derived from diabetic rats decreased significantly compared with that from normal rats (P < .05). Similar results were also presented in the cytokines (VEGF and IGF-1) release (P = .02 and P < .01, respectively) that the ability of antiapoptosis and myogenic differentiation decreased obviously between diabetes group and the normal control group (P < .01).

CONCLUSION

BMSCs from STZ-induced diabetic rats could be successfully harvested and expanded in vitro culture condition; their morphology was very similar to normal control group, with minor changes. However, the proliferative and differentiation properties of diabetic BMSCs, as well as cytokine release and antiapoptosis ability, were significantly impaired.

Correlation between pancreatic tumor size as measured on 3D CT scan versus pathologic specimen: Impact on radiation treatment volume

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Background: Definition of the target volume for irradiation of pancreatic cancer (PCA) must balance coverage of micrometastatic disease with toxicity. To determine differences between radiographically defined tumors and true pathologic tumor specimens, we correlated the maximum tumor diameter (TD) of preoperatively imaged tumors with resected tumor specimens.

Methods: With IRB approval, a retrospective chart review of patients who underwent resection of PCA between 2006 and 2010 was conducted. 73 patients were identified with preoperative CT imaging and pathologic analysis of tumors. 70 of 73 patients had a preoperative 3D CT performed. The TD as measured by a radiologist (EF) on contrast CT and 3D CT reconstruction was compared with that measured by pathological analysis of the resected specimen.

Results: 70 patients underwent resection with preoperative CT imaging; 14.1% of these patients had CT performed >6 weeks prior to surgery. The mean (SD) pathologic maximum TD was 31.3 mm (11.3) with range 3 mm to 60 mm. Whereas TD was underestimated by 1.9 mm (1.7 SE) with CT relative to pathologic analysis, this difference was not statistically significant (paired t-test, p=0.27) with a correlation coefficient of 0.265. 3D CT imaging had a smaller mean difference with a mean 3D CT diameter 0.4 mm (1.76 SE) larger than the pathologic specimen (p=0.82) with correlation coefficient 0.222. However, the max TD on 3D CT imaging was on average 2.3 mm larger than on CT (p=0.016) with correlation coefficient 0.798. Of patients with R0 resections (N=48), CT underestimated path size by 3.1 mm (p=0.020), whereas 3D CT was slightly larger (0.1 mm, p=0.949). For R1 resections (n=22), both CT and 3D CT overestimated size (0.8 mm and 1.1 mm, respectively, p>0.5).

Conclusions: PCA TD is generally underestimated on CT imaging, yet better approximated with 3D CT. Improved correlation was seen between CT and pathologic specimens following R0 resection. Alternatively, R1 resection specimens were slightly overestimated by CT/3D CT imaging. As a result, clinical target volumes should be expanded accordingly during radiotherapy planning to properly account for these discrepancies in the gross tumor.

No significant financial relationships to disclose.

NPC-1C: A novel, therapeutic antibody to treat pancreas and colorectal cancers

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Background: NPC-1C (ensituximab) is a chimeric monoclonal antibody being developed as a novel biologic treatment for pancreatic and colorectal cancers. This antibody was selected from a panel of hybridomas generated from mice immunized with semi-purified membrane-associated proteins derived from biologically screened, pooled human allogeneic colon cancer tissues. The NPC-1C epitope appears to be expressed specifically by human colon and pancreatic tumor tissues and cell lines.

Methods: Antitumor activity was established in vitro by measuring ADCC with a standard 4-hour 111-Indium release assay on pancreatic and colorectal cancer cell lines. In vivo antitumor efficacy of NPC-1C was tested using pre-established subcutaneous human pancreatic tumor xenograft models.

Results: In vitro, the NPC-1C antibody exhibits ADCC activity specifically against human colon and pancreatic tumor cells, but not against control tumor cell lines. The in vivo data showed significant, and reproducible, antitumor action, including some complete tumor regressions. The clinical application for this antibody was bolstered by several examples of human tumor tissues stained with biotin-conjugated NPC-1C that showed a strong correlation of NPC-1C staining against pancreatic and colon tumors. Approximately 45% of tumors stained strongly positive. The staining pattern was typical of elaborated mucin expression, but also showed cytoplasmic and cell membrane staining.

Conclusions: A phase I open label, multicenter dose escalation clinical trial with NPC-1C is currently accruing patients with advanced pancreatic and colorectal cancer who are refractory to standard therapy. The primary objectives of the phase I clinical trial are to determine the safety and tolerability of escalating doses of NPC-1C monoclonal antibody therapy and to assess pharmacokinetics and select immune responses to the antibody at each dose level. Secondary objectives are to evaluate evidence of clinical benefit and to explore the immunologic correlates associated with administration of NPC-1C. Results from this trial will determine the minimum standard dosage levels to be used in further trials.

[Table: see text]

COX-1(+/-)COX-2(-/-) genotype in mice is associated with shortened time to carotid artery occlusion through increased PAI-1

BACKGROUND

We found a high incidence of thrombotic deaths in COX-1(+/-)COX-2(-/-) mice and sought to define the mechanism of these events. The cyclooxygenase products thromboxane A(2) and prostacyclin are important in the regulation of coagulation but their role in fibrinolysis is largely unexplored. PAI-1 blocks fibrinolysis by inhibiting plasminogen activator.

AIM

Our objective was to explain the mechanism of increased thrombosis associated with the COX-1(+/-)COX-2(-/-) genotype.

METHODS

Carotid artery occlusion times were measured after photochemical injury. PAI-1 levels were measured in the plasma by ELISA. PAI-1 levels in the aorta were measured by RT-PCR and Western blotting. Urinary metabolites of Thromboxane A(2) and prostacyclin were measured by ELISA.

RESULTS

The COX-1(+/-)COX-2(-/-) genotype is associated with a decreased time to occlusion in the carotid artery thrombosis model (30 ± 5 minutes vs 60 ± minutes in wild type, p<.001). The COX-1(-/-)COX-2(+/+), COX-1(+/-)COX-2(+/-) and COX-1(+/-)COX-2(+/+) all had occlusion times similar to wild type. COX-1(+/+)COX-2(-/-) had a prolonged occlusion time. COX-1(+/-)COX-2(-/-) had increased PAI-1 levels in the plasma and aorta and with a prolonged euglobulin lysis time (37.4 ± 10.2 hours vs 15.6 ± 9.8 hours in wild type, p<.004). The decreased time to occlusion in the COX-1(+/-)COX2(-/-) mice was normalized by an inhibitory antibody to PAI-1 whereas the antibody had no effect on the time to occlusion in wild type mice.

CONCLUSION

The COX-1(+/-)COX-2(-/-) genotype is associated with a shortened time to occlusion in the carotid thrombosis model and the shortened time to occlusion is mediated through increased PAI-1 levels resulting in decreased fibrinolysis.

Anti-acrolein treatment improves behavioral outcome and alleviates myelin damage in experimental autoimmune encephalomyelitis mouse

Oxidative stress is considered a major contributor in the pathology of multiple sclerosis (MS). Acrolein, a highly reactive aldehyde byproduct of lipid peroxidation, is thought to perpetuate oxidative stress. In this study, we aimed to determine the role of acrolein in an animal model of MS, experimental autoimmune encephalomyelitis (EAE) mice. We have demonstrated a significant elevation of acrolein protein adduct levels in EAE mouse spinal cord. Hydralazine, a known acrolein scavenger, significantly improved behavioral outcomes and lessened myelin damage in spinal cord. We postulate that acrolein is an important pathological factor and likely a novel therapeutic target in MS.