[Inhibitory effect of Streptococcus mutans antisense vicK RNA regulating the cariogenicity of oral streptococci multi-species biofilm]

Objective: To investigate the regulative effects of Streptococcus mutans (Sm) antisense vicK RNA (ASvicK) on the multi-species biofilm formed by three common oral streptococci (Sm, Streptococcus sanguinis, and Streptococcus gordonii) (Sm+Ss+Sg). Methods: ASvicK over-expression strain was constructed by using a recombinant plasmid, and three-species biofilm UA159+Ss+Sg and ASvicK+Ss+Sg were cultured. The phenotypes of biofilms were detected by scanning electron microscopy (SEM). Crystal violet (CV) assay was used to detect biofilm biomass. Lactate kit and anthrone-sulfuric acid colorimetric assay were used to determine the abilities of lactic acid and exopolysaccharides production, respectively. The proportions of three-species and expression levels of the cariogenic-related genes in biofilms were detected by TaqMan fluorescence quantitative PCR and real-time fluorescence quantitative PCR. A biofilm demineralization model of human enamel slabs was further constructed, and the hardness of enamel surface was detected. Results: Compared to UA159+Ss+Sg, over-expression of ASvicK could inhibit biofilm formation and lactic acid production in ASvicK+Ss+Sg biofilm significantly decreased by 78.93% (P<0.001) and 62.23% (P<0.001), respectively. With ASvicK over-expression, the amounts of water-insoluble and-soluble glucoses in ASvicK+Ss+Sg biofilm were reduced respectively by 39.13% (P<0.001) and 68.00% (P<0.001). Compared to the UA159+Ss+Sg Group, the proportion of Sm, the cariogenic bacteria, showed 33.00% reduction (P<0.01) in Sm+Ss+Sg biofilm, and the gene expressions of cariogenic-relative genes vicK/X, gtfB/C/D, and ftf significantly decreased (P<0.05). The micro-hardness value of enamel slabs after demineralization by ASvicK+Ss+Sg biofilm was significantly increased to 183.84% (P<0.001). Conclusions: ASvicK over-expression could reduce the Sm proportion and weaken the cariogenicity of oral Streptococcus biofilm, thereby possibly slowing down the progression of caries.

[Standardized nomenclature of oral microorganisms in Chinese: the 2023 update]

Oral microbial community, as an important part of human microbial community, is closely related to oral and general health. Oral microbiological research has become the forefront of international microbiological research. Standardized and unified nomenclature for oral microorganisms in Chinese is of great significance to support the development of oral medicine research. Standardized translation of microbial names is the basis for writing canonical and authoritative professional textbooks and reference books, which helps students to accurately acquire the characteristics and classifications of oral microbes. Unified translation of oral microorganisms is also conducive to academic communication and cooperation, and plays an important role in oral health education and science popularization, which enables oral microbiology knowledge to be accurately disseminated to the public. Therefore, in order to standardize the words in scientific research, funding application, publications, academic exchanges and science popularization within the field of oral medicine, we have fully discussed and revised the Chinese names of oral microorganisms in 2017 edition and ones of newly discovered oral microbes, finally reaching a consensus to form the 2023 edition of Chinese names of oral microorganisms.

Functional characterization of a glutathione S-transferase in Trichinella spiralis invasion, development and reproduction

The purpose of this study was to determine the biological function of a Trichinella spiralis glutathione S-transferase (TsGST) in larval invasion and development by RNA interference (RNAi). The TsGST-specific siRNA 366 was transfected into T. spiralis muscle larvae (ML) via electroporation. At 1 day following transfection, the larval TsGST mRNA and protein expressions were reduced by 40.09 and 65.22 % (P < 0.05), respectively. The enzymatic activity of natural TsGST in siRNA-transfected ML was also suppressed by 45% compared with PBS group (P < 0.05). Silencing of the TsGST significantly inhibited the ability of larvae to invade intestinal epithelium cells (IECs) and isolated intestine. After challenge with siRNA-366-treated ML, the infected mice exhibited a 62.82% reduction of intestinal adult worms, and 65.03 % reduction of muscle larvae compared to the PBS group. Besides, the length of adults, newborn larvae and muscle larvae was significantly shorter than that of control siRNA and PBS group; the female fecundity of siRNA 366 group was lower than those of control siRNA and PBS group (P <  0.05). The results revealed that the specific RNAi significantly reduced the expression and enzymatic activity of TsGST, inhibited the larval invasive and developmental capacity, and impaired the female fecundity. The results further confirmed that TsGST plays a crucial role in the T. spiralis life cycle and it might be a potential molecular target for anti-Trichinella vaccines.

Trichinella spiralis: RNAi-mediated silencing of serine protease results in reduction of intrusion, development and fecundity

In previous studies, a Trichinella spiralis serine protease (TsSP) was identified in excretion/secretion (ES) products from intestinal infective L1 larvae (IIL1) using immunoproteomics. The complete cDNA sequence of TsSP gene was 1372 bp, which encoded 429 amino acids with 47.55 kDa. The TsSP was transcribed and expressed at all T. spiralis life cycle phases, as well as mainly located at the cuticle and stichosome of the parasitic nematode. Recombinant TsSP bind to intestinal epithelial cells (IEC) and promoted larva invasion, however, its exact function in invasion, development and reproduction are still unknown. The aim of this study was to confirm the biological function of TsSP during T. spiralis invasion and growth using RNA interference (RNAi) technology. The results showed that on 1 day after electroporation using 2.5 µM siRNA156, TsSP mRNA and protein expression of muscle larvae (ML) was suppressed by 48.35 and 59.98%, respectively. Meanwhile, silencing of TsSP gene by RNAi resulted in a 61.38% decrease of serine protease activity of ML ES proteins, and a significant reduction of the in vitro and in vivo invasive capacity of IIL1 to intrude into the IEC monolayer and intestinal mucosa. When mice were infected with siRNA 156-transfected larvae, adult worm and muscle larva burdens were decreased by 58.85 and 60.48%, respectively. Moreover, intestinal worm growth and female fecundity were evidently inhibited after TsSP gene was knockdown, it was demonstrated that intestinal adults became smaller and the in vitro newborn larval yield of females obviously declined compared with the control siRNA group. The results indicated that knockdown of TsSP gene by RNAi significantly reduced the TsSP expression and enzymatic activity, impaired larvae intrusion and growth, and lowered the female reproductive capacity, further verified that TsSP might participate in diverse processes of T. spiralis life cycle, it will be a new prospective candidate molecular target of anti-Trichinella vaccines.

Binding of elastase-1 and enterocytes facilitates Trichinella spiralis larval intrusion of the host's intestinal epithelium

Elastase-1 is one member of serine protease family, distributes in organisms widely and plays a crucial role in the invasion and development of Trichinella spiralis. In order to identify the binding of T. spiralis elastase-1 (TsEla) with host's intestinal epithelial cells (IECs) and its role in Trichinella larval intrusion, TsEla gene was cloned and expressed in our previous study. The recombinant TsEla (rTsEla) has the enzymatic activity to degrade specific peptide substrate. A specific binding between rTsEla and IECs was detected by Far Western blot and ELISA. In an in vitro invasion assay, rTsEla promoted the larval intrusion, whereas anti-rTsEla serum inhibited the larval penetration. The larval intrusion was also suppressed after the silencing of TsEla by siRNA. Silencing of TsEla gene by siRNA-291 meditated RNA interference suppressed TsEla protein expression, reduced the worm infectivity, development and reproductive capacity. These results indicated that TsEla plays an important role in the T. spiralis intrusion of host's intestinal epithelia, and it could be a prospective vaccine molecular target against T. spiralis infection.

Functional analysis of Trichinella spiralis serine protease 1.2 by siRNA mediated RNA interference

A T. spiralis serine protease 1.2 (TsSP1.2) was identified in the muscle larvae (ML) and intestinal larvae surface/excretory-secretory (ES) proteins by immunoproteomics. The aim of this study was to determine the TsSP1.2 function in the process of T. spiralis intrusion, growth and reproduction by using RNA interference (RNAi). RNAi was used to silence the expression of TsSP1.2 mRNA and protein in the nematode. On 2 days after the ML were electroporated with 2 µM of TsSP1.2-specific siRNA 534, TsSP1.2 mRNA and protein expression declined in 56.44 and 84.48%, respectively, compared with untreated ML. Although TsSP1.2 silencing did not impair worm viability, larval intrusion of intestinal epithelium cells (IEC) was suppressed by 57.18% (P < 0.01) and the suppression was siRNA-dose dependent (r = 0.976). Infection of mice with siRNA 534 transfected ML produced a 57.16% reduction of enteral adult burden and 71.46% reduction of muscle larva burden (P < 0.05). Moreover, silencing of TsSP1.2 gene in ML resulted in worm development impediment and reduction of female fertility. The results showed that silencing of TsSP1.2 by RNAi inhibited larval intrusion and development, and reduced female fecundity. TsSP1.2 plays a crucial role for worm invasion and development in T. spiralis life cycle, and is a potential vaccine/drug target against Trichinella infection.

[Dedifferentiated liposarcoma with inflammatory myofibroblastic tumor-like features: a clinicopathological analysis of five cases]

Objective: To investigate the clinicopathological features, diagnosis and differential diagnosis of dedifferentiated liposarcoma (DDLPS) with inflammatory myofibroblastic tumor (IMT)-like features. Methods: Five cases of DDLPS with IMT-like features were collected from the First Affiliated Hospital of Nanjing Medical University, the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine and the First People's Hospital of Qinzhou between 2013 and 2018. EnVision method and fluorescence in situ hybridization (FISH) were used to detect the immunophenotype of the tumor cells and the profile of MDM2 gene amplification respectively. Results: All five cases were male and the median age was 61 (range 53 to 65) years. The clinical symptoms were mainly related to the space-occupying lesions. The tumors were located in duodenal mesentery (two cases), intestinal wall (one case), retroperitoneum (one case), and spermatic cord (one case). Grossly, the tumors were not well encapsulated, ranging from 3 to 13 cm (median 6.7 cm) in diameter, with tan to gray and firm cut surface. Histologically, the dedifferentiated component closely resembled inflammatory myofibroblastic tumor (IMT), with spindle/polygonal/stellate-shaped cells arranged in storiform, sheet-like, or random pattern, with varying degrees of chronic inflammation and fibrosis. All three major patterns seen in IMT (myxoid, cellular and hypocellular fibrous) were observed, the hypocellular fibrous pattern was the most common. Well-differentiated liposarcomatous component was found in the peripheral areas of all the tumors. One case had high grade dedifferentiated component. Four cases were strongly positive for MDM2 and p16. Two cases were positive for SMA, and one case was focally positive for desmin and one for CD34. None of the cases stained for ALK-1. FISH demonstrated MDM2 gene amplification in all five cases. Clinical follow-ups were available in all five cases and the interval ranged from 3 to 66 months (median 23 months). Two patients developed recurrences and one patient had metastasis. The remaining two patients were alive with no evidence of tumor recurrence at 3 and 14 months after surgery respectively. Conclusions: DDLPS with IMT-like features is a more aggressive neoplasm than its histological mimic (IMT), and should not be misdiagnosed as other intermediate or low-grade malignant tumors, such as IMT, sclerosing liposarcoma, inflammatory liposarcoma, aggressive fibromatosis, solitary fibrous tumors, low-grade myofibroblastic sarcoma, and low-grade fibrosarcoma.

Molecular characterization of Trichinella spiralis galectin and its participation in larval invasion of host's intestinal epithelial cells

The aim of this study was to study the molecular characteristics of Trichinella spiralis galectin (Tsgal) and interactions between Tsgal and host's intestinal epithelial cells (IECs). The functional domain of Tsgal was cloned and expressed in an E. coli system. The Tsgal was 97.1% identity to the galectin of T. nativa and 20.8% identity to the galectin-8 of humans. Conserved domain analysis revealed that Tsgal belongs to TR-type galectin and has two carbon recognized domain. The rTsgal with 29.1 kDa could be recognized by T. spiralis-infected mice at 42 days post-infection (dpi). The transcription and expression of Tsgal gene was detected by RT-PCR and Western blotting in all T. spiralis developmental stages (intestinal infective larvae, adult worms, newborn larvae, and muscle larvae). The IFA results revealed that Tsgal was mainly located at the cuticles and stichosomes of T. spiralis larvae (ML, IIL and NBL). The rTsgal had hemagglutinating function for erythrocytes from human, rabbit and mouse. The results of Far Western blot and confocal microscopy indicated there was specific binding between rTsgal and IECs, and the binding was located the membrane and cytoplasm of the IECs. Out of four sugars (sucrose, glucose, lactose and maltose), only lactose was able to inhibit the rTsgal agglutinating role for human type B erythrocytes. Moreover, the rTsgal could promote the larval invasion of IECs, while the anti-rTsgal serum inhibited the larval invasion. These results demonstrated that Tsgal might participate in the T. spiralis invasion of intestinal epithelium in early infection stage.

Effects of Astragalus glycoprotein on Th17/Treg cells in mice with collagen-induced arthritis

In this study of Th17/Treg cells, the therapeutic effect of Astragalus glycoprotein on collagen-induced arthritis in mice (CIA) was explored, and a basis for the clinical treatment of rheumatoid arthritis is provided. Sixty mice were selected for the establishment of a CIA mouse model, and were then randomly divided into a CIA model group, a hydrocortisone control group, a low, medium, and high dose group of Astragalus glycoprotein, respectively. The same number of control groups with same number of mice was established and after basic immunization, intraperitoneal injections were given once daily for two weeks in the treatment. At the end of the treatment, the mice in each group were selected and the proportion of Th17/Treg cells was detected by flow cytometry. The expression and positive expression of RORt, Foxp3, P-STAT3 and P-STAT5 protein were detected by Western blot and immunohistochemistry. Astragalus glycoprotein was shown to potentially improve the diet and mental state, reduce the arthritis index score and improve the pathological state of synovial membranes in the mice. Moreover, flow cytometry results showed that, compared with the CIA model group, the proportion of Th17 cells in the four other groups of mice decreased, while the proportion of Treg cells increased. This difference was statistically significant (P less than 0.05). From the experiment, the following conclusions were drawn: Astragalus glycoprotein can reduce Th17 cells and their transcription factors in the peripheral blood of CIA mice, up-regulate Treg cells and their transcription factors, and correct the balance of Th17/Treg cells so as to achieve an effective of treatment for CIA mice.

Metagenomic analysis of oral microbiome in young children aged 6-8 years living in a rural isolated Chinese province

BACKGROUND

The mixed dentition is an important transition period from primary teeth to permanent teeth. However, the caries prevalence of first permanent molar in mixed dentitions was about 30%, which almost represent the caries rate of permanent teeth in this period of time. Therefore, we assessed the oral bacterial profiles in young children (age 6-8) with mixed dentition with or without first molar caries for providing the research basis of caries etiology.

METHODS

We collected samples of supragingival plaque and saliva from the children living in Guizhou, a rural isolated province in China. Then, we performed DNA extraction and purification followed by 454 pyrosequencing of the V1-V3 hypervariable regions of the 16S rRNA and compared our results with those of previous research.

RESULTS

(i) We analyzed 48,320 unique sequences that represented 18 phyla, 29 classes, 44 orders, 74 families, 129 genera, 15,003 species-level OUT in plaque and saliva samples; (ii) longitudinally, there was the "healthy core microbiome" between healthy deciduous dentition and early mixed dentition, for example, Neisseria, Porphyromonas, Selenomonas etc.; (iii) horizontally, there also existed the "healthy core microbiome" in early mixed dentition, for example, Neisseria, Streptococcus, Prevotella etc.; (iv) the dominant bacteria detected by Lefse in caries group including Actinomycetaceae, Streptobacillus (p < 0.05) and those in caries-free group including Gammaproteobacteria, Pasteurellaceae, Aggregatibacter, Chloroflexi, (p < 0.05).

CONCLUSIONS

The oral cavity is a highly heterogeneous ecosystem with the "healthy core microbiome" in children, although microbial composition shifts along with aging. In addition, the abundance and diversity of microbiota vary between caries and caries-free groups verify the ecological plaque hypothesis.

[Cloning and expression analysis of two pro-inflammatory cytokines, IL-1β and its receptor, IL-1R2, in the Asian swamp eel Monopterus albus]

Interleukin-1β (IL-1β) is the prototypic pro-inflammatory cytokine, whose functions are mediated through interaction with its receptors (IL-1R1 and IL-1R2). Herein, we cloned the full-length cDNA and genomic DNA of IL-1β and IL-1R2 in the Asian swamp eel (Monopterus albus). The eel IL-1β cDNA encodes a putative polypeptide of 246 amino acids. The protein sequence includes a typical IL-1 family signature, but lacked an interleukin-converting enzyme cleavage site. The genomic DNA of eel IL-1β was 2520 bp and comprised five exons and four introns. The eel IL-1R2 cDNA encoded a putative propeptide of 423 amino acid residues, comprising a signal peptide, a transmembrane region and two Ig-like domains in the extracellular region. Similar to other vertebrates, the genomic DNA of the eel IL-1R2 has nine exons and eight introns. Real-time PCR analysis indicated that IL-1β and IL-1R2 were constitutively expressed in all tissues, especially in the liver and immune-related organs. After infection with Aeromonas hydrophila, the transcript levels of IL-1β and IL-1R2 were induced in the head kidney and spleen, reaching their highest levels at 6 h post injection. In vitro, IL-1β and IL-1R2 mRNA levels were also upregulated rapidly at 1h post infection with A. hydrophila. Furthermore, acanthocephalan Pallisentis (Neosentis) celatus could induce the expression of both genes in the head kidney and intestine. In infected intestines, the transcript levels of IL-1β and IL-1R2 were increased by 21.4-fold and 20.8-fold, respectively, relative to the control. The present study indicated that IL-1β and IL-1R2 play an important role in inflammation and host defense, especially in the antiacanthocephalan response.

[Comparative study of total hip arthroplasty with subtrochanteric osteotomy for treating Hartofilakidis types C1 and C2 developmental dysplasia of the hip]

OBJECTIVE

To compare efficacies and complications of total hip arthroplasty (THA) with subtrochanteric osteotomy for treating patients with Hartofilakidis types C1 and C2 developmental dysplasia of the hip (DDH).

METHODS

Retrospective analysis was performed in 32 patients with DDH who underwent THA. These patients were divided into two groups according to Hartofilakidis classification, 17 patients in type C1 and 15 in type C2. Their HSS and WOMAC scores, leg length discrepancy (LLD), hip joint image data and complications were evaluated.

RESULTS

HSS scores in type C1 was changed from preoperative 43.7±4.6 to postoperative 87.2±7.1 (P<0.001), together with WOMAC scores 43.6±4.3 to 87.5±6.7 (P<0.001). HSS scores in type C2 was changed from preoperative 44.4±5.4 to postoperative 86.5±8.0 (P<0.001), together with WOMAC scores 44.1±4.1 to 86.7±8.1 (P<0.001). Four cases in type C2 and one case in type C1 presented intraoperative fracture which all healed during the postoperative follow-up. The postoperative X-ray films showed that the joint prosthesis location was satisfactory, the surrounding bone was not dissolved and the bone at femur osteotomy site healed with no infection.

CONCLUSION

For unilateral high dislocation DDH patients, THA with femur osteotomy can be effective and safe. No significant differences were found between types C1 and C2, however intraoperative fracture in type C2 should be paid attention to.

Effect of Tanshinone IIA intrathecal injections on pain and spinal inflammation in mice with bone tumors

The study aimed to investigate the effect of intrathecal injections of Tanshinone IIA on thermal hyperalgesia in a mouse model of bone cancer-pain. Spinal IL-1β, IL-6, TNF-α expression levels were analyzed. C3H/HeNCrlVr male mice were assigned to groups that either received dose-dependent injections of Tanshinone IIA, or the DMSO + Sham, Tanshinone IIA + Sham, DMSO + Tumor, and Control groups. Paw withdrawal thermal latency (PWTL) was measured with a radiant heat stimulus and mRNA expression levels were determined using real-time PCR. Fourteen days post-injection, PWTL in the DMSO + Tumor group was lower than that in the controls (P < 0.05). Twenty-one days post-injection, compared with the Control group, there was no significant difference in PWTL and IL-1β, IL-6, and TNF-α expression levels between the Tanshinone IIA + Sham and DMSO + Sham groups (P > 0.05). PWTL in the DMSO + Tumor group was significantly lower than the Control group (P < 0.05), while the expression levels of IL-1β, IL-6, and TNF-α were significantly higher than controls. Compared with the DMSO + Tumor group, PWTLs were higher in the Tanshinone IIA - 20-μg and 40-μg groups, while expression levels of IL-1β, IL-6, and TNF-α were significantly lower (P < 0.05). These measures were not significantly different between the Tanshinone IIA 10 μg and the DMSO + Tumor groups (P > 0.05). In conclusion, Tanshinone IIA may inhibit the release of inflammatory cytokines, such as, IL-1 β, IL-6 α, TNF-α.

Effect of calcitonin on anastrozole-induced bone pain during aromatase inhibitor therapy for breast cancer

This study aimed to investigate calcitonin as an effective therapy for osteoporosis in patients with bone pain during the anastrozole treatment of breast cancer. Ninety-one patients, who were on anastrozole treatment for breast cancer and also suffered anastrozole-induced bone pain, were randomly divided into two groups: the calcitonin group received salmon calcitonin and Caltrate D, and the control group received Caltrate D. All patients were evaluated by the visual analogue scale (VAS) and underwent the dual energy x-ray absorptiometry test for bone mineral density (BMD), and serum osteocalcin (BGP), alkaline phosphatase (ALP), calcium (Ca), and phosphorus (P) were measured at three months before and after the treatment. Significant differences in serum Ca, P, BGP, and ALP were found in each group between before and after treatment (P < 0.05), while no differences between the calcitonin and control groups were found. No difference was observed in femur BMD between the two groups, or between before and after treatment in each group. There was a significant difference in spine BMD between before and after treatment in the control group (P < 0.05) but not in the calcitonin group, while no difference was found between the calcitonin and control groups. Futhermore, VAS score significantly declined in each group after treatment (P < 0.05), but much more in the calcitonin group than the control group (P < 0.05). Our finding suggests that calcitonin may alleviate bone pain during the anastrozole treatment of breast cancer but has no effect on bone loss during cancer treatment.

Microbial diversity in the oral cavity of healthy Chinese Han children

OBJECTIVE

This study aimed to identify the oral microbial diversity of healthy Chinese Han children.

METHODS

Dental plaques were sampled from the oral cavity of ten healthy Chinese Han children. The oral microbiome was examined using the 16S rRNA-based Human Oral Microbe Identification Microarray. The microbial diversity and similarity were analyzed using the Chao-Jaccard similarity index.

RESULTS

A total of 112 species, which belonged to nine bacterial phyla and 41 genera, were detected. Each individual harbored an average of 54.1 microbial species (ranging from 37 to 69) and 26.2 genera (ranging from 21 to 31), with interindividual variations both at the species and genus level. Thirteen genera were conserved among all individuals. The Chao-Jaccard similarity index averages, at the genus and species level, were 0.642 (ranging from 0.485 to 0.871) and 0.506 (ranging from 0.338 to 0.676), respectively, suggesting that the healthy oral community was more conserved at the genus level than at the species level.

CONCLUSION

Although there was interindividual variation in the oral microflora, some bacterial genera were conserved among individuals, supporting the existence of a core microbiome in the oral cavity of healthy Chinese Han children.

Microbial profiles in saliva from children with and without caries in mixed dentition

OBJECTIVE

The purpose of this study was to determine the bacterial profiles in saliva of the isolated children for studying caries etiology.

MATERIALS AND METHODS

  Samples were collected from isolated children from 6 to 8years old including 20 caries-free (dmfs=0) (healthy) and 30 caries-active individuals (dmfs>8) (patients). 16S rRNA genes were amplified by PCR from bacterial DNA of saliva sample and labeled via incorporation of Cy3-dCTP in second nested PCR. After hybridization of labeled amplicons on HOMIM, the microarray slides were scanned and original data acquired from professional software.

RESULTS

Collectively, 94 bacterial species or clusters representing six bacterial phyla and 30 genera were detected. A higher bacterial diversity was observed in patients than in healthy samples. Statistical analyses revealed eight species or clusters were detected more frequently in diseased patients than in healthy samples, while six different species were detected more frequently in healthy as compared to diseased patients.

CONCLUSION

The diversity of microbe within saliva derived from isolated population increased in caries-active status, and there are some bacteria in salivary flora can be as candidate biomarkers for caries prognosis in mixed dentition. The imbalances in the resident microflora may be the ultimate mechanism of dental caries.

An innovative approach to synthesize highly-ordered TiO2 nanotubes

An innovative route to prepare highly-ordered and dimensionally controlled TiO2 nanotubes has been proposed using a mild sonication method. The nanotube arrays were prepared by the anodization of titanium in an electrolyte containing 3% NH4F and 5% H2O in glycerol. It is demonstrated that the TiO2 nanostructures has two layers: the top layer is TiO2 nanowire and underneath is well-ordered TiO2 nanotubes. The top layer can easily fall off and form nanowires bundles by implementing a mild sonication after a short annealing time. We found that the dimensions of the TiO2 nanotubes were only dependent on the anodizing condition. The proposed technique may be extended to fabricate reproducible well-ordered TiO2 nanotubes with large area on other metals.

LYRIC/AEG-1 overexpression modulates BCCIPalpha protein levels in prostate tumor cells

LYRIC/AEG-1 is a unique protein that has been shown to promote tumor cell migration and invasion through activation of the transcription factor NF-kappaB. We performed yeast two-hybrid screening to detect LYRIC/AEG-1 associated proteins, and identified BCCIP, a CDKN1A and BRCA2-associated protein involved in cell cycle regulation and DNA repair. Here, we demonstrate association between LYRIC/AEG-1 and BCCIP in mammalian cells, and define the region of interaction. Co-expression of the two proteins resulted in decreased levels of BCCIPalpha, an effect partially abrogated by proteasome inhibition. A truncated LYRIC/AEG-1 construct lacking the interaction region did not alter BCCIPalpha protein levels. Coincidentally, it was observed that overexpression of BCCIPalpha in DU145 prostate tumor cells induced an apparent neuroendocrine differentiation. In summary, our data suggest LYRIC/AEG-1 is a negative regulator of BCCIPalpha, promoting proteasomal degradation either through direct interaction, or potentially through an indirect mechanism involving downstream effects of the NF-kappaB signaling pathway.

Attenuation of cell migration and induction of cell death by aged garlic extract in rat sarcoma cells

Previous studies have shown that aged garlic extract suppresses cancer growth and enhances immune system against cancer, and yet little is known about inhibition of the cancer cell migration. In this study we investigated whether the aged garlic extract inhibits growth and migration of rat sarcoma tumor cells. The suppression of tumor cell growth was demonstrated by counting the cell number in three groups (control, cultured with 10 mg/ml, 20 mg/ml of aged garlic extracts) after culturing for 3 days and 5 days. The results showed that aged garlic extract inhibited the growth of rat sarcoma cancer cells in a dose-dependent manner, compared to the numbers of the cells grown in control group. The inhibition of tumor cell migration was examined by measuring the distance of trails left behind by the tumor cells when they passed through the polybeads overnight in four groups (control, 5 mg/ml, 10 mg/ml, 20 mg/ml aged garlic extracts). The average distance of trails in control group was 7.44 mm, whereas the average distance of cell movement is only 2.48 mm when treated with the highest concentration (20 mg/ml) of the aged garlic extract. The results also showed that the inhibitory effect of aged garlic extracts on tumor cell migration was dose-dependent. This is the first report to show that the aged garlic extract inhibits rat sarcoma cell migration, a critical feature of tumor cell metastasis. It can be thus envisioned that if tumor cell metastasis could be attenuated if not completely stopped, it would be possible to stabilize the tumor in the local area for surgical removal. The results suggest that garlic, as a natural plant, unlike other cancer treatment methods, may play a role in fighting cancer without significant side effects.

Genetic Variability of Canadian Populations of the Sapstain Fungus Ophiostoma piceae

ABSTRACT Genetic diversity was studied in seven Canadian populations of Ophiostoma piceae, the most prevalent sapstain fungus in Canadian softwoods. A total of 239 single-spore isolates were recovered following a systematic survey of sapstain fungi in logs and lumber at seven selected sawmills in six Canadian provinces (British Columbia, Alberta, Saskatchewan, Ontario, Québec, and New Brunswick). Sampling was carried out on five commercially important softwood species: balsam fir (Abies balsamea), white spruce (Picea glauca), black spruce (Picea mariana), jack pine (Pinus banksiana), and lodgepole pine (Pinus con-torta var. latifolia). The A and B mating types occurred at equal frequency (MAT A/ MAT B = 1.00:1.13) over all populations. Pseudo-allelic frequencies were estimated at each of 24 putative genetic loci by scoring for presence or absence of random amplified polymorphic DNA fragments generated by five primers. A total of 237 haplotypes were found among the 239 isolates, revealing a high level of genotypic diversity among isolates. Total gene diversity (H(T) = 0.414) was mostly attributable to diversity within populations (H(S) = 0.369). Thus, only 11.2% of the total variability was attributable to frequency differences among populations. An analysis of molecular variance revealed that most genetic variability occurred within subpopulations within mills (84.3%; P < 0.001), whereas low but statistically significant levels of genetic differentiation were also observed among subpopulations within populations (5.4%; P < 0.001) and among populations (10.3%; P < 0.001). Estimates of Nei' genetic distances were not correlated with geographic distances among sampling locations (r = -0.092; P = 0.310), although principal component analysis indicated that subpopulations located east of Saskatchewan were grouped on the same side of the second principal component axis. Overall, results suggest moderate genetic differentiation of O. piceae in Canada, which is consistent with the observation that sexual reproduction is frequently observed in this fungus.

Participation of ATM in insulin signalling through phosphorylation of eIF-4E-binding protein 1

One of the critical responses to insulin treatment is the stimulation of protein synthesis through induced phosphorylation of the eIF-4E-binding protein 1 (4E-BP1), and the subsequent release of the translation initiation factor, eIF-4E. Here we report that ATM, the protein product of the ATM gene that is mutated in the disease ataxia telangiectasia, phosphorylates 4E-BP1 at Ser 111 in vitro and that insulin treatment induces phosphorylation of 4E-BP1 at Ser 111 in vivo in an ATM-dependent manner. In addition, insulin treatment of cells enhances the specific kinase activity of ATM. Cells lacking ATM kinase activity exhibit a significant decrease in the insulin-induced dissociation of 4E-BP1 from eIF-4E. These results suggest an unexpected role for ATM in an insulin-signalling pathway that controls translation initiation. Through this mechanism, a lack of ATM activity probably contributes to some of the metabolic abnormalities, such as poor growth and insulin resistance, reported in ataxia telangiectasia cells and patients with ataxia telangiectasia.

A genetic survey of the pathogenic fungus Ophiostoma ulmi across a Dutch elm disease front in western Canada

The natural population structure of the Dutch elm pathogen Ophiostoma ulmi was determined from isolated collected from across a Western Canadian disease front through an analysis of restriction-site polymorphisms in the ribosomal DNA repeat, length mutations in the mitochondrial genomes, and through DNA fingerprinting of the nuclear genomes using a minisatellite DNA probe. The 8.8-kbp rDNA repeat was selected from a genomic library, and restriction-site and genic maps were constructed for the nonaggressive and aggressive subgroups of O. ulmi. There were only three restriction-site differences that distinguished these two subgroups and no intrasubgroup variation was detected. All of the isolates collected from the disease front were of the aggressive subgroup and were represented by two distinct nuclear and four mitochondrial genotypes. The minority of the isolates were of a single genotype (type A nuclear DNA; type I mtDNA), indicating the presence of a single very large clone extending across much of Manitoba and into Saskatchewan.