The role of K-RAS and B-RAF mutations as biomarkers in metastatic colorectal cancer.

PURPOSE: Unlike cetuximab, there is a paucity of biomarkers for bevacizumab as predictors of outcome in metastatic colorectal cancer (mCRC) patients. Obviously exploring the worth of some potential markers in this setting is warranted. The purpose of this study was to investigate the predictive value of the presence of K-RAS and B-RAF mutations on the outcome of patients with mCRC treated with FOLFIRI and bevacizumab combination therapy. METHODS: A total of 172 patients with mCRC were evaluated. K-RAS and B-RAF mutations were analyzed by quantitative PCR. Median progression-free survival (PFS) and overall survival (OS) were compared utilizing chi-square and Mann-Whitney U tests, respectively. RESULTS: Forty-four percent (N=77) of the patients were found to harbor K-RAS mutations and 6 (7.5%) were positive for B-RAF mutations. In baseline no difference in PFS and OS was observed between the groups with or without K-RAS mutation. No relationship was established between K-RAS and B-RAF mutation status and baseline CEA and CA19-9 tumor markers levels. CONCLUSION: K-RAS and B-RAF mutations do not seem to be predictive of treatment outcome as potential biomarkers for bevacizumab therapy in mCRC. However, not only the presence of K-RAS and B-RAF mutations but also the different biological behavior of the various subtypes of mutations should be considered as potential determinants in the final outcome of this disease.

An alternative sutureless repair technique with amelogenin for duodenal perforation.

BACKGROUND: Among the various sutureless techniques, fibrin glue has proved to be effective in the treatment of peptic ulcer perforation as an alternative to classical suture repair. Albeit rare, a potential disadvantage of fibrin glue use is viral transmission or anaphylaxis. The aim of this study is to introduce a new technique for the closure of duodenal perforation using a novel recombinant enamel protein called amelogenin. METHODS: In this case-control experimental study, 32 adult male Wistar Albino rats weighing 250-300 g were randomly divided into four groups, each containing 8 rats. Duodenal perforation of 0.2 cm were performed in the postpyloric region in all rats. Each group received primary repair, primary repair with omentoplasty, fibrin glue, and amelogenin, respectively. All animals were killed on the postoperative day five and the bursting pressure measurements, hydroxyproline levels and histopathologic values of the wound site were evaluated. RESULTS: Bursting pressure levels of the fibrin glue and amelogenin groups were significantly lower than the primary repair and primary repair with omentoplasty groups (P < 0.05) However, no significant difference existed between the fibrin glue and amelogenin groups in this respect (P > 0.05). There was also no statistically significant difference among all groups regarding tissue hydroxyproline levels and histopathologic values (P > 0.05). CONCLUSION: Application of amelogenin as an alternative sutureless repair technique did not improve wound healing in this animal model of duodenal perforation.

Icodextrin and Seprafilm do not interfere with colonic anastomosis in rats.

BACKGROUND: Physical barriers and instilled solutions have been studied to prevent intra-abdominal adhesions. However, undesirable side effects of these substances on the healing of intestinal anastomoses may limit their use. This study was designed to compare the effects of antiadhesives on the healing of colonic anastomosis in rats. METHODS: Sixty female Sprague-Dawley rats were divided into 3 groups of 20. The animals received isotonic saline and 7.5% icodextrin, intraperitoneally after standard left colonic anastomosis. In group 3, Seprafilm was wrapped around the anastomosis and also laid over the abdominal viscera. Half of the animals from each group were killed on postoperative day (POD) 4 and the remaining half on POD 21. Adhesion scoring, bursting pressure and tissue hydroxyproline measurements and histopathological assessment were performed. RESULTS: Mean hydroxyproline levels were significantly higher in groups receiving icodextrin and Seprafilm compared with the control group, whereas mean bursting pressures were significantly higher in the group that received icodextrin (p < 0.05). Intraperitoneal administration of icodextrin resulted in significant reduction of adhesion formation on POD 21 (p < 0.05). CONCLUSIONS: Seprafilm does not prevent formation of adhesions as much as icodextrin does, but its effect on the healing of colonic anastomoses is similar.

Prevalence of Helicobacter pylori vacA, cagA, cagE, iceA, babA2 genotypes and correlation with clinical outcome in Turkish patients with dyspepsia.

BACKGROUND: Distinct virulence factors of Helicobacter pylori have been associated with clinical outcome of the infection; however, considerable variations have been reported from different geographic regions and data on genotypes of Turkish H. pylori isolates are sparse. AIM: To determine the prevalence of specific genotypes of H. pylori in Turkish patients with dyspepsia. MATERIALS AND METHODS: Ninety-three H. pylori-positive patients [30 with non-ulcer dyspepsia (NUD), 30 with duodenal ulcer (DU), and 33 with gastric cancer (GC)] who were admitted to our endoscopy unit due to dyspepsia were enrolled in the study. H. pylori infection was confirmed in all patients by histology and rapid urease test (RUT). The presence of vacA alleles, cagA, cagE, iceA, and babA2 genotypes were determined by polymerase chain reaction (PCR). Chi-squared test and Fisher's exact test were used for statistical comparisons and multivariate regression analysis was performed to find out independent predictors of different clinical outcomes. RESULTS: Turkish strains examined predominantly possessed the vacA s1,m2 (48.4%) and s1,m1 (40.7%) genotypes. The vacA s1a genotype was detected in 66.7, 96.4, and 87.9% of isolates from patients with NUD, DU, and GC, respectively, and its presence was significantly associated with that of DU (p = .004), GC (p = .043), and cagA gene (p = .021). None of the cases was found to harbor the s1c genotype. The frequencies of the cagA and cagE genes among studied isolates were 73.6 and 59.3%, respectively. The cagA gene was significantly associated with the presence of DU (p = .004) and GC (p = .003), and the cagE gene, too, was significantly associated with the presence of DU (p = .002) and GC (p = .000). All H. pylori isolates possessed the iceA gene. In all, 68 isolates (74.7%) were positive for iceA1 and 23 (25.3%) for iceA2. The frequency of icea1 gene was significantly higher in cases with GC (85%) than in cases with NUD (60%) (p = .026). The frequency of babA2 gene was 23.3, 46.4, and 87.9% in isolates of patients with NUD, DU, and GC, respectively. When compared to cases with NUD (p = .000) and DU (p = .000), the presence of babA2 gene was significantly higher in cases with GC. Multivariate regression analysis disclosed cagE (p = .006) and vacA s1a (p = .027) genotypes to be independent predictors of DU and babA2 (p = .000) and cagE (p = .013) genotypes to be independent predictors of GC. CONCLUSIONS: H. pylori vacA s1a, cagA, cagE genotypes have significant relations with the presence of DU and GC, and iceA1, babA2 with GC in Turkish patients with dyspepsia, whereas cagE and vacA s1a genotypes are independent predictors of DU, and babA2 and cagE genotypes are independent predictors of GC.

Correlation of endothelial nitric oxide synthase and vascular endothelial growth factor expression with malignancy in patients with astrocytic tumors.

PURPOSE: Many characteristics of malignant brain tumors (increased vascular permeability, vasodilatation, neovascularisation and free radical injury to the tumor and adjacent normal tissues) are believed to be mediated by nitric oxide (NO) synthetized by endothelial NO synthase (eNOS). Overexpression of vascular endothelial growth factor (VEGF) is associated with several central nervous system (CNS) diseases and tumors. Our aim was to study immunohistochemically the coexpression of eNOS and VEGF in astrocytic tumors and to analyse their possible correlation with tumor grade, angiogenesis and proliferation index. MATERIALS AND METHODS: Sections from 120 randomly selected patients with supratentorial astrocytic tumors [38 glioblastomas (GB), 22 anaplastic astrocytomas (AA) and 20 low-grade astrocytomas (LA)], also including oligodendrogliomas (n=20) and mixed oligoastrocytomas (n=20), were immunostained with monoclonal antibodies for eNOS and VEGF using the avidin-biotin method. The proliferative potential was assessed as the MIB-1 staining index for tumor cells. RESULTS: There was positive correlation between eNOS and VEGF expressions and histological grade (p<0.05) in terms of intensity and extent of immunoreactivity distribution. Oligodendrogliomas showed significantly less VEGF and eNOS immunoreactivity compared to pure astrocytomas (p<0.05). CONCLUSION: Overexpressions of eNOS and VEGF in astrocytic tumors were significantly correlated with histological grade, proliferative potential and malignant transformation. The expression of VEGF in a necrotic and ischemic tumor such as GB is more intense and diffuse than low-grade astrocytomas. These findings suggest that eNOS overexpression in tumor vasculature would be precipitated by transformation into an angiogenic phenotype in the process of neovascularisation in astrocytic tumors.

Evaluation of two enzyme immunoassays for detecting Helicobacter pylori in stool specimens of dyspeptic patients after eradication therapy.

The aim of the current study was to assess the reliability of two enzyme immunoassays in detecting the Helicobacter pylori status of stool specimens of Turkish dyspeptic patients in the post-treatment period. Forty-eight patients with non-ulcer dyspepsia who were positive for H. pylori underwent a 1 week regimen of triple therapy. Stool samples of patients were obtained 2 and 6 weeks after eradication therapy and a [13C]urea breath test was performed 6 weeks after therapy in order to assess the reliability of mAb-based (Amplified IDEIA HpStAR, DakoCytomation) and polyclonal-antiserum-based (Premier Platinum HpSA, Meridian Diagnostics) stool antigen test kits and to compare their diagnostic accuracies. Using a minimum cutoff OD450 value of 0.19 for Amplified IDEIA HpStAR and 0.16 for Premier Platinum HpSA the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of the tests were determined 2 and 6 weeks after completion of eradication therapy. At both the second and the sixth week in the post-treatment period the diagnostic accuracy of Amplified IDEIA HpStAR was significantly better than the Premier Platinum's (75% versus 50%, S2=6.4; P=0.011, and 90% versus 69%, S2=6.316; P=0.012, respectively). In light of these findings the mAb-based Amplified IDEIA HpStAR has a high diagnostic accuracy for H. pylori infection in Turkish dyspeptic patients 6 weeks after completion of eradication therapy.

Comparison of two different stool antigen tests for the primary diagnosis of Helicobacter pylori infection in turkish patients with dyspepsia.

AIM: To assess the reliability of two different enzyme immunoassays in detecting the Helicobacter pylori status in stool specimens of Turkish patients with dyspepsia. MATERIALS AND METHODS: One hundred and fifty-one patients [74 with nonulcer dyspepsia (NUD), 64 with duodenal ulcer (DU) and 13 with gastric cancer] who were admitted to the endoscopy unit of Istanbul University, Cerrahpasa Medical Faculty for upper gastrointestinal endoscopy because of dyspepsia were enrolled in the study. Helicobacter pylori infection was confirmed in all patients by histology, rapid urease test and culture. A patient was classified as being H. pylori-positive if the culture alone or both the histology and the rapid urease test were positive and as negative only if all of these tests remained negative. Stool samples were obtained from patients to assess the reliability of a monoclonal (FemtoLab H. pylori) and a polyclonal (Premier Platinum HpSA) stool antigen test and to compare the diagnostic accuracies of these two tests. A chi2 test was used for statistical comparisons. RESULTS: Using cut-off values of 0.19 for FemtoLab H. pylori and 0.16 for Premier Platinum HpSA, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 93%, 90%, 98%, 68% and 93% for the monoclonal test and 84%, 67%, 94%, 40% and 81% for the polyclonal test, respectively. The sensitivity, specificity, negative predictive value and diagnostic accuracy of the monoclonal test were significantly greater than those of the polyclonal test (chi2 = 3.98; p < .05 for sensitivity and chi2 = 15.67; p = .000 for specificity, chi2 = 15.78; p = .000 for negative predictive value and chi2 = 6.37; p = .012 for diagnostic accuracy). The bacterial load did not affect the sensitivity of either test. CONCLUSIONS: The monoclonal FemtoLab H pylori test, using a cut-off 0.19, is a very sensitive, specific and easy to perform diagnostic tool for the primary diagnosis of H. pylori infection in Turkish patients with dyspepsia.

Verumontanum mucosal gland hyperplasia is associated with atypical adenomatous hyperplasia of the prostate.

BACKGROUND: Verumontanum mucosal gland hyperplasia (VMGH) and atypical adenomatous hyperplasia (AAH) are both small glandular proliferations that are histologically and topographically unique. METHODS: One hundred ten randomly selected, whole-mount, radical prostatectomy specimens were reviewed to assess independently the normal histology of the prostatic urethra and periurethral area and the association of AAH with other pathologic features, including VMGH. The degree of nodular hyperplasia was evaluated by total prostate weight for comparison purposes. RESULTS: Atypical adenomatous hyperplasia was found in 37 cases (33.6%) and was nearly always (32/37) associated with nodules of nodular hyperplasia. Verumontanum mucosal gland hyperplasia was present in 32 cases (29.1%; 21 with AAH, 11 without AAH). There was a significant association between presence of VMGH and AAH (P <.001, Fisher exact test). The degree of nodular hyperplasia was not significantly different between prostates with and without VMGH or AAH. CONCLUSIONS: These results suggest that AAH and VMGH occur more commonly in prostates when the other is also present.

Corpora amylacea and heat shock protein 27 in Ammon's horn sclerosis.

Increased numbers of corpora amylacea have been observed in the resected mesial temporal lobe of many patients with complex partial seizures (CPS) and Ammon's horn sclerosis (AHS). Several heat shock proteins (HSPs) are induced by seizures and have been suggested as an etiologic factor in the formation corpora amylacea. We quantified corpora amylacea and HSP27-immunoreactive astrocytes in temporal lobe specimens from patients with CPS (28 AHS; 10 non-AHS) and in 5 autopsy controls. Corpora amylacea were increased in each sector of Ammon's horn in the AHS group, significantly so in CA1 and CA3 (p < 0.0001 and p = 0.0097, respectively), compared with the non-AHS group, although there was considerable variability among the specimens. We found HSP27 to be significantly but nonspecifically increased in the resected temporal lobe specimens from all patients with CPS, regardless of the underlying pathology. HSP27 was not, however, expressed within the corpora amylacea, and did not correlate with the number of corpora amylacea in any of the 9 mesial and lateral temporal lobe areas examined.

Levels of expression of p27KIP1 protein in human prostate and prostate cancer: an immunohistochemical analysis.

p27KIP1 is a member of the CIP/KIP family of cyclin-dependent kinase inhibitory proteins that negatively regulate cell proliferation. Recent studies reported decreased p27 expression in breast and colon carcinomas and found that the loss of p27 is associated with a poor prognosis. We report here the results of our immunohistochemical analysis of p27 in human prostate cancer. Formalin-fixed, paraffin-embedded, whole-mount sections of prostate cancer from 73 selected patients treated by radical retropubic prostatectomy were obtained from the Department of Pathology, The Methodist Hospital, Houston, Texas. Ten histologically normal and nine high-grade prostatic intraepithelia neoplasia foci were selected from these whole-mount sections, and nine cases of transplant donor prostates were chosen as controls. Also, 10 prostate cancer metastatic lymph nodes were used to compare with the primary cancer group. Sections were immunostained with a monoclonal antibody against p27 protein using the avidin-biotin complex immunohistochemical method. Immunoactivity was evaluated without knowledge of follow-up and recorded as the p27 labeling index (LI) (defined as the percentage of p27-positive cells among epithelia of the same category). The p27 (LI) in normal prostatic epithelia was 86.4+/-3.5% (the mean +/- the standard error of the mean). In contrast, the p27 immunoreactivity was significantly lower in cancers (LI: 43.5 +/-3.7%, P < .001) and in the high-grade prostatic intraepithelial neoplasia group (LI: 59.3 +/- 3.2%, P < .05). Expression of p27 in the metastatic lymph node group was significantly lower than in the other groups, including the prostate cancer cases and the cases of high-grade intraepithelial neoplasia (LI, 7.0%; P = .05). There was no association of the mean p27 LI with progression after radical prostatectomy. Nonrecurrent cases, with a mean follow-up time of greater than 5 years (n = 45), equalled 41.9%; recurrent cases, with a mean follow-up time of 18.3 months (n = 28), equalled 40.0%. The mean p27 LI was not associated with pathologic stage. Organ-confined specimens (n = 21) equalled 34.2%; cases of extraprostatic extension (n = 24) equalled 46.5%; and samples showing seminal vesicle involvement (n = 14) equalled 47.6%. In 14 cases with lymph node metastases, the mean p27 LI was 48.1% in the primary cancer (P = .2322). There was no association of the mean p27 LI with the Gleason score (P = .4747) nor with the clinical stage (P = .9914).

The fate of alloplastic materials placed under a burn scar: an experimental study.

The behavior, under burn scars, of three different alloplastic materials, silicone, Medpor and Proplast, was compared in an animal model. A standard burn wound was created in rats, and 3 months later silicone, medpor and proplast alloplasts were placed under the burn scar. The rats were followed for another 3 months and ulceration and/or alloplast exposure rates were evaluated. At the end of this period specimens were examined histologically for the thickness of the fibrous capsule around the implant, thickness of the overlying tissue, tissue ingrowth and vascularization of the implants. Ulceration and exposure occurred in 2 of the 12 Medpor, 2 of the 12 Proplast and none of the 12 silicone implants. Fibrous capsule was significantly thicker around the silicone implants. Tissue ingrowth and vascularization were most prominent in Medpor implants while thickness of the overlying tissue was maximum in Proplast implants. These findings suggest that complications with silicone implants may be less than with other porous implants when used under burn scarred tissue.