Relationship between surface area for adhesion and tensile bond strength--evaluation of a micro-tensile bond test

OBJECTIVES

The purpose of this study was to test the null hypothesis that there is no relationship between the bonded surface area of dentin and the tensile strength of adhesive materials.

METHODS

The enamel was removed from the occlusal surface of extracted human third molars, and the entire flat surface was covered with resin composite bonded to the dentin to form a flat resin composite crown. Twenty-four hours later, the bonded specimens were sectioned parallel to the long axis of the tooth into 10-20 thin sections whose upper part was composed of resin composite with the lower half being dentin. These small sections were trimmed using a high speed diamond bur into an hourglass shape with the narrowest portion at the bonded interface. Surface area was varied by altering the specimen thickness and width. Tensile bond strength was measured using custom-made grips in a universal testing machine.

RESULTS

Tensile bond strength was inversely related to bonded surface area. At surface areas below 0.4 mm2, the tensile bond strengths were about 55 MPa for Clearfil Liner Bond 2 (Kuraray Co., Ltd.), 38 MPa for Scotchbond MP (3M Dental Products), and 20 MPa for Vitremer (3M Dental Products). At these small surface areas all of the bond failures were adhesive in nature.

SIGNIFICANCE

This new method permits measurement of high bond strengths without cohesive failure of dentin. It also permits multiple measurements to be made within a single tooth.

Interleukin 1B and interleukin 1RN polymorphisms are associated with increased risk of gastric carcinoma

BACKGROUND & AIMS

Interleukin (IL)-1 gene cluster proinflammatory polymorphisms have been associated with development of gastric atrophy and with increased risk of gastric carcinoma. We aimed to determine the association between IL-1 loci polymorphisms and increased risk of gastric carcinoma in samples from a Portuguese population, and to find whether there was any relationship with the histologic types of gastric carcinoma.

METHODS

In a case-control study including 220 controls and 152 patients with gastric carcinoma (intestinal, 76; diffuse, 37; and atypical, 39), both the IL-1B-511 biallelic polymorphism and the IL-1RN penta-allelic variable number of tandem repeats were genotyped.

RESULTS

We found a significant association between the IL-1 polymorphisms and increased risk for tumor development in patients with intestinal-type gastric carcinoma. A trend towards an increased risk of tumor development was also observed in patients with diffuse-type gastric carcinoma. No significant relationship was observed in patients with atypical carcinoma. Carriers of IL-1B-511T and IL-1RN*2 homozygotes had increased risk for developing intestinal-type gastric carcinoma with odds ratios of 2.7 (95% confidence interval [CI], 1.5-4.9) and 3.1 (95% CI, 1.5-6.5), respectively. Statistical analysis showed an interaction between the 2 loci with the risk conferred by the IL-1B-511T allele substantially increased (odds ratio, 9.0; 95% CI, 3.5-23.0) in individuals homozygous for the IL-1RN*2 allele.

CONCLUSIONS

Our results provide further support to the association between IL-1 gene cluster proinflammatory polymorphisms and increased risk of gastric carcinoma. Furthermore, we found evidence pointing to the existence of a synergistic interaction between the IL-1B and IL-1RN polymorphisms.

E-cadherin gene (CDH1) promoter methylation as the second hit in sporadic diffuse gastric carcinoma

In diffuse gastric carcinoma, despite common E-cadherin gene (CDH1) mutations, tumors show absence of CDH1 loss of heterozigosity (LOH) in most cases. This observation challenges the classical two-hit model of tumor suppressor gene inactivation. In order to investigate whether or not CDH1 promoter methylation may function as the second hit we analysed a series of 23 sporadic gastric carcinomas for the presence of CDH1 mutations, CDH1 promoter methylation, LOH and E-cadherin expression. CDH1 mutations were detected in nine of the 16 (56.3%) diffuse gastric carcinomas and in none of the seven intestinal gastric carcinomas. In diffuse gastric carcinomas harboring CDH1 mutations, LOH was observed in a single case. Loss of plasma membrane E-cadherin expression was consistently found in all nine cases with CDH1 mutation, suggesting that tumors inactivated the remaining CDH1 allele via a different mechanism. CDH1 promoter methylation was observed in nine of the 16 (56.3%) diffuse-type gastric carcinoma cases, including six of the nine cases (66.7%) harboring CDH1 mutations. CDH1 promoter methylation was also seen in two (28.6%) intestinal-type cases. Our results show that CDH1 promoter methylation is the second hit in more than half of the sporadic diffuse gastric carcinoma cases harboring CDH1 mutations.

Expression of angiogenic factors during distraction osteogenesis

Distraction osteogenesis is a unique and effective way to treat limb length inequality resulting from congenital and posttraumatic skeletal defects. However, despite its widespread clinical use, the cellular and molecular mechanisms by which this surgical treatment promotes new bone formation are not well understood. Previous studies in distraction osteogenesis have noted increased blood flow and vessel formation within the zone of distraction. These observations suggest that distraction osteogenesis may be driven in part by an angiogenic process. Using immunohistological analysis, the expression of two different angiogenic factors (VEGF and bFGF) was shown to localize at the leading edge of the distraction gap, where nascent osteogenesis was occurring. These cells were spatially adjacent to new vessels that were identified by staining for factor VIII. Microarray analysis detected maximal mRNA expression for a wide variety of angiogenic factors including angiopoietin 1 and 2, both Tie receptors, VEGF-A and -D, VEGFR2, and neuropilin 1. Expression of these factors was found to be maximal during the phase of active distraction. Expression of mRNA for extracellular matrix proteins and BMPs was also maximal during this period. A comparison between the patterns of gene expression in fracture healing and distraction osteogenesis revealed similarities; however, the expression of a number of genes showed selective expression in these two types of bone healing. These data suggest that bone formation during distraction osteogenesis is accompanied by the robust induction of factors associated with angiogenesis and support further investigations to elucidate the mechanisms by which angiogenic events promote bone repair and regeneration.

A randomized trial comparing radiation therapy versus concomitant radiation therapy and chemotherapy in carcinoma of the thoracic esophagus

From September 1982 to December 1985, 59 previously untreated patients with Stage II squamous cell carcinoma of the thoracic esophagus were randomly assigned to receive radiation therapy (RT) alone versus the concomitant use of RT and chemotherapy (CT) with 5-fluorouracil (5-FU), mitomycin C, and bleomycin (RT + CT). Thirty-one patients were randomized to the RT regimen and 28 to the RT + CT regimen. The complete local response rate was 58% for the RT group and 75% for the RT + CT group (P = 0.77). The median duration of response was 8 months for both groups. The overall 5-year survival rates were 6% and 16% (P = 0.16) for the RT and RT + CT groups, respectively. Acute toxicities were more pronounced in the RT + CT group. This clinical trial did not detect a difference in outcome with combined-technique therapy. This result must be interpreted with caution because of the small number of patients entered in this trial. Confirmation of the value or lack of value for combined therapy will require additional larger clinical trials.

Large genomic deletions of SMAD4, BMPR1A and PTEN in juvenile polyposis

BACKGROUND/AIMS

Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder characterised by multiple gastrointestinal juvenile polyps and an increased risk of colorectal cancer. This syndrome is caused by germline mutation of either SMAD4 or BMPR1A, and possibly ENG. PTEN, originally linked to Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome, has also been associated with JPS. By direct sequencing, germline mutations are found in only 30-40% of patients with a JPS phenotype. Therefore, alternative ways of inactivation of the known JPS genes, or additional genes predisposing to JPS may be involved. In this study, a comprehensive genetic analysis of SMAD4, BMPR1A, PTEN and ENG is performed through direct sequencing and multiplex ligation-dependent probe amplification (MLPA) in JPS patients.

METHODS

Archival material of 29 patients with JPS from 27 families was collected. Direct sequencing and MLPA analysis were performed to search for germline defects in SMAD4, BMPR1A, PTEN and ENG.

RESULTS

A germline defect in SMAD4, BMPR1A or PTEN was found in 13 of 27 (48.1%) unrelated JPS patients. Nine mutations (33.3%) were detected by direct sequencing, including six (22.2%) SMAD4 mutations and three (11.1%) BMPR1A mutations. MLPA identified four additional patients (14.8%) with germline hemizygous large genomic deletions, including one deletion of SMAD4, one deletion of exons 10 and 11 of BMPR1A, and two unrelated patients with deletion of both BMPR1A and PTEN. No ENG gene mutations were found.

CONCLUSION

Large genomic deletions of SMAD4, BMPR1A and PTEN are a common cause of JPS. Using direct sequencing and MLPA, a germline defect was detected in 48.1% of JPS patients. MLPA identified 14.8% (4/27) of these mutations. Since a substantial percentage of JPS patients carry a germline deletion and MLPA is a reliable and user-friendly technique, it is concluded that MLPA is a valuable adjunct in JPS diagnosis.

First diabetes prevalence study in Portugal: PREVADIAB study

AIMS

Diabetes is a growing worldwide problem. Ascertaining its prevalence is vital as a starting point to establish and measure the success of health interventions. This study aimed to determine the prevalence of Type 2 diabetes and 'pre-diabetes', defined as impaired fasting glucose and impaired glucose tolerance, in the Portuguese population aged between 20 and 79 years.

METHODS

Considering the number of inhabitants between 20 and 79 years old, statistical units were selected that were representative regionally and nationally. The total sample comprised 5167 subjects. National prevalence was calculated. Analyses were performed on all those without previously known diabetes using World Health Organization reference diagnostic criteria.

RESULTS

We found a diabetes prevalence of 11.7% (95% confidence interval 10.8-12.6%), with a significant difference between men (14.2%; 95% confidence interval 12.5-15.5%) and women (9.5%; 95% confidence interval 8.5-10.6%). While 6.6% of the subjects had previously been diagnosed with diabetes, 5.1% were undiagnosed. By age groups, 2.4% of the population between 20 and 39 years, 12.6% of people from 40 to 59 years old and 26.3% of those aged between 60 and 79 years had diabetes. Prevalence of 'pre-diabetes' (impaired fasting glucose, impaired glucose tolerance or both) in the population was 23.3%.

CONCLUSIONS

Diabetes has a high prevalence in Portugal. If 'pre-diabetes' is also considered, about one-third (34.9%) of the population aged 20-79 years is affected. A greater number of males were found to have diabetes. We detected a high percentage of people with undiagnosed diabetes (43.6%).

Complete nucleotide sequence of yellow fever virus vaccine strains 17DD and 17D-213

The complete nucleotide sequence of the genome from two yellow fever (YF) virus vaccine strains, 17DD and 17D-213, has been determined. Comparison of these sequences with those of other YF viruses including the parental virulent Asibi strain allowed the identification of 48 nucleotide sequence differences which are common to all 17D substrains. This is a significant reduction from the 67 nucleotide changes originally reported as being 17D-specific and potentially related to viral attenuation. The 48 changes are scattered throughout the genome, 26 of which are silent and 22 led to amino acid substitutions. These 22 changes are bona fide candidates to test by mutating the infectious YF cDNA to investigate their role in viral attenuation.

The relationships among lemons, limes and citron: a chromosomal comparison

Lemons, limes and citron constitute a group of closely related Citrus species, whose species delimitations and taxonomic relationships are unclear. In order to identify karyotypic similarities and species relationships within this group, the CMA+/DAPI- banding pattern and the distribution of the 5S and 45S rDNA sites of 10 accessions of lime, lemon, and citron were investigated. The four cultivars of C. limon analyzed showed the same pattern of CMA+ bands and rDNA sites, suggesting that they originated from a single germplasm, later differentiated by distinct somatic mutations. The lemons C. jambhiri, C. limonia and C. volkameriana displayed karyotypes very similar to each other, but they differed from C. limon by the absence of a single chromosome with one band in each telomere. The limes, C. aurantifolia and C. limettioides, seemed less related to each other and exhibited different heteromorphic chromosome pairs. In C. aurantifolia, the presence of a chromosome type unknown in all other Citrus species cytologically known so far supports the assumption that this accession may be derived from a hybrid with a species from the subgenus Papeda or from another genus. Citrus medica was the only homozygous accession of this group and all of its chromosome types were clearly represented in limes and lemons, some of them forming heteromorphic pairs. The analysis of the distribution of rDNA sites allowed a further refinement of the comparison among accessions. The lemons and limes were heterozygous for all rDNA sites, whereas C. medica was entirely homozygous. These data support the hypothesis that C. medica is a true species while the other nine accessions are hybrids.

Flexible nanofilms coated with aligned piezoelectric microfibers preserve the contractility of cardiomyocytes

The use of engineered cardiac tissue for high-throughput drug screening/toxicology assessment remains largely unexplored. Here we propose a scaffold that mimics aspects of cardiac extracellular matrix while preserving the contractility of cardiomyocytes. The scaffold is based on a poly(caprolactone) (PCL) nanofilm with magnetic properties (MNF, standing for magnetic nanofilm) coated with a layer of piezoelectric (PIEZO) microfibers of poly(vinylidene fluoride-trifluoroethylene) (MNF+PIEZO). The nanofilm creates a flexible support for cell contraction and the aligned PIEZO microfibers deposited on top of the nanofilm creates conditions for cell alignment and electrical stimulation of the seeded cells. Our results indicate that MNF+PIEZO scaffold promotes rat and human cardiac cell attachment and alignment, maintains the ratio of cell populations overtime, promotes cell-cell communication and metabolic maturation, and preserves cardiomyocyte (CM) contractility for at least 12 days. The engineered cardiac construct showed high toxicity against doxorubicin, a cardiotoxic molecule, and responded to compounds that modulate CM contraction such as epinephrine, propranolol and heptanol.

Heterogeneity in envelope protein sequence and N-linked glycosylation among yellow fever virus vaccine strains

We have compared the deduced envelope (E) protein sequences of two biologically well-characterized yellow fever (YF) virus vaccine strains. The 17DD strain has been produced in Brazil for more than 50 years and used to successfully vaccinate millions of people worldwide. The 17D-213 is a candidate vaccine strain produced in tissue culture which has previously passed the monkey neurovirulence assay for testing human YF vaccines. Nucleotide sequence analysis of polymerase chain reaction-amplified cDNA revealed a number of mutations which were strain- and substrain-specific. A major difference of 17DD and 17D-213 as compared to 17D-204 and Asibi was the existence of a potential N-linked glycosylation site located at amino acid residues 153 and 151 of 17DD and 17D-213, respectively. These acceptor sites are apparently utilized for the addition of high-mannose carbohydrate chains as shown by endoglycosidase analyses of immunoprecipitated E proteins. Glycosylated E protein is also used to assemble YF vaccine virions. This work and eventual complete nucleotide sequence analysis of both vaccine strains should help to define possible changes involved in YF virus attenuation and allow their biological importance to be determined using a recently developed system for generating YF virus from cDNA. In addition, these data provide an estimate on the extent of genetic variability among YF 17D seeds and vaccines.

Linkage between polymorphisms in the prostate specific antigen ARE1 gene region, prostate cancer risk, and circulating tumor cells

BACKGROUND

The prostate specific antigen (PSA) gene has a polymorphic androgen response element (ARE) sequence with two alleles, A and G. PSA A-allele carriers have higher serum PSA levels in healthy men (HM).

METHODS

We analysed DNA samples from 278 (556 alleles) unrelated individuals, 127 HM and 151 prostate cancer (PC) patients, for PSA ARE1 genotypes.

RESULTS

The analysis of the frequencies from the 556 alleles indicates a significant overrepresentation of A-allele in the PC group under the age of 67 compared with the HM group (63.3% vs. 48.8%; P = 0.009). We found that men carrying two A-alleles have increased risk for PC onset under the age of 67 (odds ratio [OR] = 2.92; 95% confidence interval [CI], 1.10-7.86; P = 0.013). Multivariate logistic regression analysis confirmed this association (OR = 1.82; 95% CI, 1.03-3.22; P = 0.037). Furthermore, the homozygosity for the A-allele was associated with higher serum PSA levels (P = 0.027) and with the presence of circulating tumor cells in the blood of PC patients (P = 0.018).

CONCLUSION

Our results indicate that polymorphism in the PSA gene promoter may be an important biomarker for prostate cancer risk, especially for an earlier onset of PC.

Anterior Vocal Commissure Invasion in Laryngeal Carcinoma Diagnosis

BACKGROUND

Laryngeal carcinoma involving anterior vocal commissure (AVC) represents a great challenge for staging and treatment.

OBJECTIVES

To compare laryngoscopy and computed tomography (CT) scan efficiency in staging tumors extending to the AVC. We also analyzed the helicoidal axial CT scan accuracy in recognizing this larynx subregion invasion.

MATERIAL AND METHODS

Fifty-two glottic and supraglottic laryngeal squamous cell carcinoma patients with tumoral extension to the AVC were prospectively studied from August 2001 to August 2003 at the National Cancer Institute (Rio de Janeiro, Brazil). All patients underwent videolaryngoscopic examination and direct laryngoscopy for lesion extension analysis and biopsy. After AVC helicoidal axial CT scan with sagittal and coronal 1.0 mm thick reconstruction, patients were submitted to surgical treatment. The same pathologist analyzed all surgical specimens.

RESULTS

When compared with pathologic stage, clinical endoscopic classification was correct in 40.38% of cases (40% for T1, 29.41% for T2, 46.43% for T3, and 50% in T4). Helicoidal axial CT scan accuracy for AVC tumors was 75% (P = .0001), being more important for T2 (62.50%), T3 (73.91%), and T4 (88.24%) lesions. Identification of radiologic signs described as gross radiologic anterior commissure involvement (GRACI) increased radiologic image staging accuracy to over 96%.

CONCLUSIONS

Endoscopic evaluation understaged tumors in all clinical stages but really T1. Helicoidal axial CT scan reformatted to 1.0 mm thick played an important role in correctly staging more advanced AVC laryngeal tumors. Radiologic signs, here identified as GRACI, may be very helpful for tomographic staging and patient treatment.

Genetic defects underlying Peutz-Jeghers syndrome (PJS) and exclusion of the polarity-associated MARK/Par1 gene family as potential PJS candidates

LKB1/STK11 germline inactivations are identified in the majority (66-94%) of Peutz-Jeghers syndrome (PJS) patients. Therefore, defects in other genes or so far unidentified ways of LKB1 inactivation may cause PJS. The genes encoding the MARK proteins, homologues of the Par1 polarity protein that associates with Par4/Lkb1, were analyzed in this study because of their link to LKB1 and cell polarity. The genetic defect underlying PJS was determined through analysis of both LKB1 and all four MARK genes. LKB1 point mutations and small deletions were identified in 18 of 23 PJS families using direct sequencing and multiplex ligation-dependent probe amplification analysis identified exon deletions in 3 of 23 families. In total, 91% of the studied families showed LKB1 inactivation. Furthermore, a MARK1, MARK2, MARK3 and MARK4 mutation analysis and an MARK4 quantitative multiplex polymerase chain reaction analysis to identify exon deletions on another eight PJS families without identified LKB1 germline mutation did not identify mutations in the MARK genes. LKB1 defects are the major cause of PJS and genes of the MARK family do not represent alternative PJS genes. Other mechanisms of inactivation of LKB1 may cause PJS in the remaining families.

Apoptosis in canine distemper

Canine distemper is a systemic viral disease characterized by immunosuppression followed by secondary infections. Apoptosis is observed in several immunosuppressive diseases and its occurrence on canine distemper in vivo has not been published. In this study, the occurrence of apoptosis was determined in lymphoid tissues of thirteen naturally infected dogs and nine experimentally inoculated puppies. Healthy dogs were used as negative controls. Samples of lymph nodes, thymus, spleen and brain were collected for histopathological purposes. Sections, 5 microm thick, of retropharingeal lymph nodes were stained by HE, Shorr, Methyl Green-Pyronin and TUNEL reaction. Shorr stained sections were further evaluated by morphometry. Canine distemper virus nucleoprotein was detected by immunohistochemistry. Retropharingeal lymph nodes of naturally and experimentally infected dogs had more apoptotic cells per field than controls. In addition, DNA from thymus of infected dogs were more fragmented than controls. Therefore, apoptosis is increased in lymphoid depletion induced by canine distemper virus and consequently play a role in the immunosuppression seen in this disease.

Prevalence of obesity among Portuguese children (6-8 years old) using three definition criteria: COSI Portugal, 2008

INTRODUCTION

Previous studies place Portugal among the five countries with the highest prevalence of childhood obesity in Europe. This paper describes the prevalence of thinness, overweight and obesity in Portuguese children of 6-8 years of age, based on the first data collection from Childhood Obesity Surveillance Initiative Portugal, which took place during the 2007/2008 school year.

METHODS

This study uses a semi-longitudinal design with repeated cross-sectional national representative samples. Specific prevalence of overweight (including obesity) and obesity was determined using three different diagnostic criteria. Across the seven geographic regions, 3765 children were enrolled from 181 schools; 50.3% of participants were males.

RESULTS

Using the International Obesity Task Force reference, the prevalence of thinness, overweight and obesity were 4.8%, 28.1% and 8.9%, respectively; using the Center for Disease Control and Prevention reference they were 2.1%, 32.2% and 14.6%, respectively; and according to the World Health Organization reference, they were 1.0%, 37.9% and 15.3%, respectively. Univariate analysis showed a higher risk of obesity in older children, in boys and in the Azores region. The islands of Madeira and the Azores were the regions with the highest prevalence of overweight at 39.4% and 46.6%, respectively, and Algarve was the one with the lowest (21.4%).

CONCLUSION

These findings demonstrate the need for urgent action in Portugal and provide policy-makers with comprehensive and detailed information to assist with this.

Papillomaviruses: a systematic review

In the last decades, a group of viruses has received great attention due to its relationship with cancer development and its wide distribution throughout the vertebrates: the papillomaviruses. In this article, we aim to review some of the most relevant reports concerning the use of bovines as an experimental model for studies related to papillomaviruses. Moreover, the obtained data contributes to the development of strategies against the clinical consequences of bovine papillomaviruses (BPV) that have led to drastic hazards to the herds. To overcome the problem, the vaccines that we have been developing involve recombinant DNA technology, aiming at prophylactic and therapeutic procedures. It is important to point out that these strategies can be used as models for innovative procedures against HPV, as this virus is the main causal agent of cervical cancer, the second most fatal cancer in women.

Gut microbiome modulation during treatment of mucositis with the dairy bacterium Lactococcus lactis and recombinant strain secreting human antimicrobial PAP

Mucositis is an inflammatory condition of the gut, caused by an adverse effect of chemotherapy drugs, such as 5-fluorouracil (5-FU). In an attempt to develop alternative treatments for the disease, several research groups have proposed the use of probiotics, in particular, Lactic Acid Bacteria (LAB). In this context, the use of recombinant LAB, for delivering anti-inflammatory compounds has also been explored. In previous work, we demonstrated that either Lactococcus lactis NZ9000 or a recombinant strain expressing an antimicrobial peptide involved in human gut homeostasis, the Pancreatitis-associated Protein (PAP), could ameliorate 5-FU-induced mucositis in mice. However, the impact of these strains on the gut microbiota still needs to be elucidated. Therefore, in the present study, we aimed to characterize the effects of both Lactococci strains in the gut microbiome of mice through a 16 S rRNA gene sequencing metagenomic approach. Our data show 5-FU caused a significant decrease in protective bacteria and increase of several bacteria associated with pro-inflammatory traits. The Lactococci strains were shown to reduce several potential opportunistic microbes, while PAP delivery was able to suppress the growth of Enterobacteriaceae during inflammation. We conclude the strain secreting antimicrobial PAP was more effective in the control of 5-FU-dysbiosis.

Glycosylation and secretion of yellow fever virus nonstructural protein NS1

The flavivirus genome codes for structural and nonstructural proteins which are produced from a common polyprotein precursor by proteolytic processing. The nonstructural protein NS1 is hypothesized to be involved in virus assembly and maturation as well as in protective immunity. This paper describes the synthesis of several forms of yellow fever (YF) virus NS1 protein during virus cultivation in vitro. These include cell-associated and secreted NS1 forms, the major difference among these being their N-linked glycosylation status. High-mannose and complex (or hybrid)-type moieties were identified on YF NS1 by analysis with endoglycosidases of known specificity. These studies are the basis for a systematic approach to determining the role of NS1 in the virus cycle and possibly in pathogenesis.

The expression of the proteins of equine herpesvirus 1 which share homology with herpes simplex virus 1 glycoproteins H and L

Several expression systems were used in studies aimed at characterizing the equine herpesvirus 1 (EHV-1) glycoprotein H and L homologues of HSV-1 (EHV-1 gH and gL) and the products were compared to the authentic proteins synthesized in virus infected cells. Using an in vitro transcription/translation system two gH species were detected (an unprocessed 89 kDa and a processed 116 kDa product). Three low molecular weight proteins were found in the case of gL (21.8 kDa, 22.9 kDa and 26.9 kDa) and these showed a slight reduction in mobility on the addition of microsomal membranes to the reactions. A gL fusion protein was produced in pGEX-2T, expression being confirmed by Western blotting using a gL-specific antiserum raised against a peptide incorporating the 13 carboxyl terminal amino acids of the protein. A gH specific peptide antiserum precipitated both gH and two smaller proteins from EHV-1 infected cells thought to be two forms of gL. Insect cells infected with gH or gL baculovirus recombinants were used to vaccinate C3H (H-2k) mice. Some protection against EHV-1 infection was conferred to the gH inoculated mice. The results will enable further studies on the importance of the gH and gL interaction in the pathogenesis of EHV-1 to be evaluated and their potential in contributing to a subunit vaccine to be assessed.

Development of a differential multiplex PCR assay for equine herpesvirus 1 and 4 as a diagnostic tool

In this study, a multiplex polymerase chain reaction (PCR) procedure was developed for differentiation of strains and field isolates of equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4). Specific oli-gonucleotide primers were combined to amplify the thymidine kinase (TK) gene region of EHV-1 and EHV-4, which would yield fragments of different lengths for each virus in the same amplification reaction. The specificity of the largest PCR amplicon for EHV-4 was confirmed by restriction digestion with HindIII. The multiplex PCR proved to be a fast and sensitive method for typing EHV-1 and EHV-4 isolates and for detection and differentiation of both viruses in field samples in which infectious virus is no longer available. The sensitivity was improved by combining cycling optimization and visualization of PCR products in ethidium bromide and silver-stained acrylamide gels.

Loss of CDC4/FBXW7 in gastric carcinoma

Background: CDC4/FBXW7, encoding a ubiquitin ligase, maps to 4q32 and has been implicated as a tumor suppressor gene and therapeutic target in many tumor types. Mutations in colonic adenomas, and the frequent losses on 4q described in gastric cancer prompt speculation about the role of CDC4/FBXW7 in gastric carcinogenesis.

Methods: We assessed the role of CDC4/FBXW7 in gastric cancer, through loss of heterozygosity (LOH) and multiplex ligation-dependent probe amplification (MLPA) on 47 flow-sorted gastric carcinomas including early-onset gastric cancers (EOGC) and xenografted conventional gastric carcinomas. Ploidy analysis was carried out on 39 EOGCs and immunohistochemistry of CDC4/FBXW7 and its substrates c-myc, c-jun, Notch and cyclin E was performed on 204 gastric carcinomas using tissue microarrays (TMAs). Sequence analysis of CDC4/FBXW7 was carried out on gastric carcinoma cell lines and xenografts.

Results: Loss of heterozygosity of CDC4/FBXW7 occurred in 32% of EOGCs, and correlated with loss of expression in 26%. Loss of expression was frequent in both EOGC and conventional gastric cancers. No CDC4/FBXW7 mutations were found and loss of CDC4/FBXW7 did not correlate with ploidy status. There was a significant correlation between loss of CDC4/FBXW7 expression and upregulation of c-myc.

Conclusions: Loss of CDC4/FBXW7 appears to play a role in both EOGC and conventional gastric carcinogenesis, and c-myc overexpression is likely to be an important oncogenic consequence of CDC4/FBXW7 loss.

Phenotypic analysis of yellow fever virus derived from complementary DNA

A thorough phenotypic characterization of yellow fever (YF) virus generated from cDNA is a necessary prerequisite for mapping virulence/attenuation determinants and exploring the potential of YF attenuated virus 17D as a carrier for heterologous protective epitopes. In this study, YF virus was produced from 17D cDNA clones after lipofectin-mediated RNA transfection of certified primary cultures of chicken embryo fibroblasts (YFiv5.2/SL). This virus was passaged once in embryonated chicken eggs according to current YF vaccine manufacture methodology to produce the experimental virus (YFiv5.2/VL). These viruses were characterized in established monkey neurovirulence safety tests and quantitative clinical and histologic scores were derived for each virus. The experimental vaccine viruses (YFiv5.2/SL and VL) compared favorably with another well-known YF vaccine strain (17DD) used as control virus for the histologic score. Although slightly higher clinical neurovirulence was observed for YFiv5.2 as compared with the 17DD virus, it should not preclude the use of YFiv5.2 for mapping YF virus virulence determinants.

Non-surgical treatment of peri-implant pathology

INTRODUCTION

Peri-implant pathologies consist of an inflammatory process affecting the soft and hard tissues surrounding the implants. Chlorhexidine is considered the gold standard antiseptic, with a large variety of choice in administration. In this study, a protocol for the irrigation of peri-implant pockets with a chlorhexidine gel, using a plastic needle for the delivery of the product into the peri-implant pockets is described.

STUDY PARTICIPANTS AND METHODS

Nine patients with at least one implant presenting peri-implant pathology (inflamed soft tissue associated with bone loss around the implant) were enrolled in this prospective clinical study, and followed-up for 1 year, where clinical parameters such as modified plaque index, modified bleeding index, probing pocket depths, attachment levels were assessed at baseline, 1 month, and 1 year after implementation of the treatment protocol.

RESULTS

Treatment success was achieved in eight of the nine patients (and in 11 of the 13 implants) according to the success criteria adopted by the authors of this study.

DISCUSSION

Infection control lies at the heart of peri-implant treatment. The control of three factors such as optimal diagnosis, removal of the aetiological factor of the disease (proper removal of debris and decontamination of the peri-implant sulcus/pocket) and a good patient's oral hygiene self-care represents the key to success, resulting in good treatment outcomes when managing peri-implant pathologies. The protocol used (irrigation of peri-implant pockets with chlorhexidine gel delivered by a plastic needle) is considered to be of utility.