Histological and immunohistochemical evaluation of mandibular bone tissue regeneration.

The purpose of the study was to perform an immunohistochemical and histological evaluation of samples taken from different bone regeneration procedures in atrophic human mandible. 30 patients (15 men and 15 women, age range of 35-60 years), non-smokers, with good general and oral health were recruited in this study and divided into three groups. The first group included patients who were treated with blood Concentration Growth Factors (bCGF), the second group included patients who were treated with a mixture of bCGF and autologous bone, while the third group of patients was treated with bCGF and tricalcium phosphate/hydroxyapatite (TCP-HA). Six months after the regenerative procedures, all patients undergone implant surgery, and a bone biopsy was carried out in the site of implant insertion. Each sample was histologically and immunohistochemically examined. Histological evaluation showed a complete bone formation for group II, partial ossification for group I, and moderate ossification for group III. Immunohistochemical analysis demonstrated a statistically significant difference between the three groups, and the best clinical result was obtained with a mixture of bCGF and autologous bone.

Heterogeneous vascular patterns in renal cell carcinomas.

The present study proposes a classification of renal cancer tumor blood vessels according to their morphology and maturation grade. We identified four vascular patterns: reticular, diffuse, fasciculated and trabecular. The reticular pattern was present in 63% of cases, being characterized by the predominance of mature CD34+/SMAct+ tumor vessels, highly interconnected. For this pattern, 74% of cases had vascular invasion, and a significant correlation was observed between tumor grade and immature state of tumor vessels (p = 0.022). The diffuse pattern was observed in 23% of cases and was characterized by non-interconnected vessels predominantly of mature CD34+/SMAct+ type and vascular invasion in 64% of cases. Only 8% of cases, had a fasciculate model of vessels distribution, all of them being of mature type, located in the connective axis of papillary renal tumors. For this pattern vascular invasion was found in 50% of cases. In 6% of cases a trabecular pattern was observed and the lowest rate of vascular invasion was registered. We defined here four distinct vascular patterns in renal cell carcinomas showing a strong impact on vascular invasion. A complete morphological and molecular characterization of tumor vessels would be beneficial in elucidating the mechanisms that underlie the ineffectiveness of antiangiogenic/antitumor therapies.

Circular anastomotic experimental fibrin sealant protection in deep colorectal anastomosis in pigs in a randomized 9-day survival study.

PURPOSE: The reported rate of clinically apparent anastomotic leakage (AL) in a low anterior resection of the rectum (LAR) (≤7 cm from the anal verge) using a circular double-stapled anastomosis (CDSA) without defunctioning stoma is up to 37.5 %. Since AL may result in life-threatening peritonitis, sepsis, and multiple organ failure, LAR and CDSA are regularly combined with defunctioning stoma. Accordingly, we now evaluated whether LAR and CDSA without defunctioning stoma but with extraluminal anastomotic application of an experimental fibrin sealant reduce the AL rate. This might prevent humans from defunctioning stoma increasing quality of life and decreasing surgical costs. METHODS: Forty 8-week-old pigs underwent LAR and CDSA in an end-to-end technique (descendo-rectostomy). Animals were randomized into a therapy and control group (gr.). The therapy gr. (n = 20) received an additional extraluminal circular application of an experimental fibrin sealant to the anastomosis. The objective was to assess the incidence of clinically apparent and non-clinically apparent leakage through the ninth postoperative day. Double-contrast barium CT radiographs of the colorectal region were performed on the ninth postoperative day or earlier, in case there were clinical signs of AL. All remaining animals were sacrificed on the ninth postoperative day and the anastomotic region was histopathologically analyzed. In case of earlier diagnosed AL, animals were sacrificed immediately. Blood samples were taken for complete blood count, chemistry, and coagulation profile prior to surgery and on the first, third, fifth, seventh, and ninth postoperative day. RESULTS: A circular extraluminal anastomotic application of an experimental fibrin protection decreased the rate of clinically and non-clinically apparent AL from 20 % (n = 4) in the control group to 5 % (n = 1) in the treatment group. Ulcerations were also observed in both gr. (control gr.-5 animals, therapy gr. -3 animals). All animals with AL showed necrosis surrounding the hole at the anastomoses. Three additional animals had a full wall defect at the anastomotic region that was blocked by the experimental fibrin sealant. The fibrin sealant was present at necropsy in all treated animals. CONCLUSION: Circular anastomotic protection with the experimental fibrin sealant blocked anastomotic full wall defects, preventing peritonitis and significantly reducing the AL rate from 25 to 5 %.

Mast cell phenotype in benign and malignant tumors of the prostate.

The molecular phenotypic heterogeneity of mast cells (MCs) makes them attractive as potential therapeutic targets in anti-cancer adjuvant therapy. Mast cell aggregations observed in tumors suggested their involvement in tumor pathogenesis. Despite several studies using mast cell tryptase, MCs' involvement in the progression of prostate tumors has not been demonstrated. The aim of our study was to identify and quantify the phenotypic heterogeneity of MCs in prostate lesions. Our study included 7 cases of normal prostate, 25 cases of benign epithelial hyperplasia and 64 cases of prostate carcinoma. MCs were immunohistochemically assessed using three markers: tryptase, chymase and CD117. Two immunophenotypes of MCs were identified in benign lesions: tryptase+/CD117+/chymase- and tryptase-/chymase+/CD117+, located in peritumoral areas. Intratumoral MC phenotype of malignant lesions was characterized by tryptase+/chymase+/CD117+, while in the peritumoral areas three different MCs phenotypes were identified: tryptase+/chymase+/CD117-, tryptase+/CD117+/chymase- and chymase+/CD117+/tryptase-. Our results suggest the correlation of chymase positive MCs of the peritumoral areas and CD117 positive MCs of the intratumoral areas with tumor grade.

Behavior of the P1.HTR mastocytoma cell line implanted in the chorioallantoic membrane of chick embryos.

The P1.HTR cell line includes highly transfectable cells derived from P815 mastocytoma cells originating from mouse breast tissue. Despite its widespread use in immunogenic studies, no data are available about the behavior of P1.HTR cells in the chick embryo chorioallantoic membrane model. The objective of the present investigation was to study the effects of P1.HTR cells implanted on the chorioallantoic membrane of chick embryos. We inoculated P1.HTR cells into the previously prepared chick embryo chorioallantoic membrane and observed the early and late effects of these cells by stereomicroscopy, histochemistry and immunohistochemistry. A highly angiotropic and angiogenic effect occurred early after inoculation and a tumorigenic potential with the development of mastocytoma keeping well mast cells immunophenotype was detected later during the development. The P1.HTR mastocytoma cell line is a good tool for the development of the chick embryo chorioallantoic membrane mastocytoma model and also for other studies concerning the involvement of blood vessels. The chick embryo chorioallantoic membrane model of mastocytoma retains the mast cell immunophenotype under experimental conditions and could be used as an experimental tool for in vivo preliminary testing of antitumor and antivascular drugs.

Behavior of the P1.HTR mastocytoma cell line implanted in the chorioallantoic membrane of chick embryos

The P1.HTR cell line includes highly transfectable cells derived from P815 mastocytoma cells originating from mouse breast tissue. Despite its widespread use in immunogenic studies, no data are available about the behavior of P1.HTR cells in the chick embryo chorioallantoic membrane model. The objective of the present investigation was to study the effects of P1.HTR cells implanted on the chorioallantoic membrane of chick embryos. We inoculated P1.HTR cells into the previously prepared chick embryo chorioallantoic membrane and observed the early and late effects of these cells by stereomicroscopy, histochemistry and immunohistochemistry. A highly angiotropic and angiogenic effect occurred early after inoculation and a tumorigenic potential with the development of mastocytoma keeping well mast cells immunophenotype was detected later during the development. The P1.HTR mastocytoma cell line is a good tool for the development of the chick embryo chorioallantoic membrane mastocytoma model and also for other studies concerning the involvement of blood vessels. The chick embryo chorioallantoic membrane model of mastocytoma retains the mast cell immunophenotype under experimental conditions and could be used as an experimental tool for in vivo preliminary testing of antitumor and antivascular drugs.

Prox 1, VEGF-C and VEGFR3 expression during cervical neoplasia progression as evidence of an early lymphangiogenic switch.

Prox1 is a key regulator of lymphatic endothelial cell commitment during embryonic development. No correlations between Prox1 and VEGF-C/VEGFR3 expression in cervical cancer has been done until now. The aim of the present study was to evaluate the peculiarities of Prox1, VEGF-C and VEGFR3 expression during uterine cervix neoplasia progression. Material and methods. One hundred and four specimens taken from women with macroscopically detectable lesions were classified by histopathology and analyzed by immunohistochemistry for Prox1, VEGFR3 and VEGF-C expression. Results. The presence of Prox1 nuclear expression was detected starting from CIN2 and CIN3 lesions to microinvasive carcinoma, in the nuclei of lymphatic and venous endothelial cells and scattered stromal cells. All Prox1 positive lymphatic vessels were positive for VEGFR3. A significant correlation was found between expression of VEGF-C in tumor cells and nuclear density of Prox1 positive lymphatic cells (p=0.044). Conclusion. The commitment of Prox1 positive cells through a lymphatic lineage is an early event for cervical neoplastic progression, being present starting with intraepithelial cervical lesions, and is strongly associated with VEGFR3 and VEGF-C expression. These findings suggest an early active lymphangiogenesis during cervical neoplasia progression and explain, in part, the early presence of lymph node metastasis in cervical cancer. By the detection of Prox1 expression in lymphatic and venous endothelial cells, and also in stromal cells, it has been suggested that there are at least three different mechanism of lymph vessel development during cervical neoplasia progression.

Interaction between estrogens and androgen receptor genes microsatellites, prostate-specific antigen and androgen receptor expressions in breast cancer.

The role of estrogen and androgen receptors signaling in breast cancer is widely accepted, but the interrelations between them are not well understood. It was suggested that PSA could be a marker of endogenous balance between androgens and estrogens. In this context, we intended to investigate the potential of relationship between polymorphic tandem repeats (CAG, TA and CA) in AR (androgen receptor), ERalpha (estrogen receptor alpha) and ERbeta (estrogen receptor beta) genes and the immunoexpression of PSA and AR proteins. We assessed also the possible influences of CAG, TA, and CA variables and other available prognostic factors (ER, PR, AR, HER2/neu, PSA expression, and nodal status) on disease-free survival. We assessed the polymorphic tandem repeats lengths by genotyping, followed by high-resolution denaturing polyacrylamide gel electrophoresis in 163 breast cancers. Immunohistochemistry was performed to assess the expressions of AR, PSA, ER, PR and HER2/neu proteins. Our results showed that PSA was correlated with the length of CA repeats in the 3'-untranslated region of ERbeta, shorter CA repeats being correlated with PSA expression (p=0.03). AR immunoexpression was correlated with CAG repeats on AR gene, higher number of repeats being linked to a higher AR immunoexpression (p=0.04). Performing logistic regression to investigate relationships with prognosis, we observed that PSA immunoexpression (p=0.004), the nodal status (p-<0.001) and marginally, longer TA repeats (p=0.05) were correlated with increased disease-free survival. AR expression presented a low statistical value (p=0.054) in predicting evolution and was not entered into the multivariate regression analysis. Altogether, our findings supports the hypothesis that estrogens, through both alpha and beta-receptors variants are mediating the AR signaling pathway.

Podoplanin expression in advanced-stage gastric carcinoma and prognostic value of lymphatic microvessel density.

In gastric cancer, lymph node metastasis is a major prognostic factor. Tumor lymphangiogenesis promotes metastasis in experimental models, but in human tumors data about the presence and clinical significance of lymphatic vessels in the tumor area are controversial. We investigated 70 patients with advanced-stage gastric carcinoma and the pathological examination showed 40 cases with intestinal subtype and 30 cases with diffuse subtype. Forty three from 70 cases had regional lymph node metastasis. Additional slides were stained with an antibody against podoplanin, and lymphatic microvessel density (LMVD) was evaluated in the tumoral and peritumoral areas. Lymphatic vessels were identified in tumor area in all cases and LMVD was higher in the peritumoral than in the tumor area. Podoplanin-positive vessels in tumor area were usually small, with narrow lumen. A significant correlation was found between LMVD and stage of the tumor (p<0.002) and lymph node metastasis (p<0.031), but not with the pathological subtype and grade of the tumor. We found tumor cells in the lumen of lymphatic vessels in 11 cases, whereas tumor cells expressing podoplanin were found in 4 cases of less differentiated diffuse subtype gastric carcinoma. In conclusion, our results suggest that LMVD predicts tumor stage and lymph node metastasis, and podoplanin-positive tumor cells select a subgroup of tumors with high potential of invasion and metastasis.

Immunohistochemical expression of vascular endothelial growth factor (VEGF) does not correlate with microvessel density in renal cell carcinoma.

The aim of present study was to investigate the relationship between the immunohistochemical expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) assessed by CD31 and endoglin (CD105) in renal cell carcinoma (RCC). Specimens from 45 cases of RCC. were formalin-fixed, paraffin embedded, and sections were stained with H&E. Additional sections from each case were stained for VEGF, CD31, CD105, and alpha smooth muscle cell actin (SMA). VEGF immunohistochemical expression was estimated as negative (0), weak positive (+1), moderate positive (+2), and intense positive (+3). Microvessel density (MVD) was estimated on 5 hot spots (x400) from each case, and the arithmetic media was the final result. MVD was separately calculated on slides stained with CD31 and CD105. The rate between mature and immature blood vessels was calculated on slides stained with CD31/CD105/SMA. Statistic analysis was performed with SPSS10.0. The immunoreaction for VEGF was positive in epithelial cells of the renal tubules, and occasionally, in endothelial cells. In RCC, tumor cells were positive in 34 from 45 cases (75.5%). 11 cases were negative, 14 were slightly positive (+1), 13 moderate (+2), and 7 intense (+3). No relationship was found between the expression of VEGF and pathological form and nuclear grade, excepting for the chromophilic variant (3 cases, all positive). CD31 was positive in all cases, and CD105 in 39 cases. The mean values of MVD on slides stained for CD31 and CD105 were: 31.68 (range 9.8-60.2)/20.66 (range 4.2-52.8). The rate CD31/SMA positive blood vessels was 1/0.62. VEGF was expressed in 75.5% of 45 cases with RCC, and the mean value of MVD CD31/CD105 was 31.68/20.66. The immunohistochemical expression of VEGF does not correlate with MVD performed on slides stained for both CD31 and endoglin. The majority of blood vessels in the tumor area are of mature type, with perivascular cells positive for SMA.

Prostate-specific antigen value as a marker in breast cancer.

The immunoexpression of prostate-specific antigen in breast cancers has been well established, but the role of this extra-prostate PSA appears to be a complex, poorly understood and of doubtful prognostic value. In this context, our aim was to evaluate PSA in breast carcinomas and to compare the results with several established prognostic markers of breast cancer: estrogen and progesterone receptors status, HER2/neu status, histological type of tumor, grade of differentiation, stage, tumor size, nodal and menopausal status. We have immunohistochemically assessed 53 breast carcinomas for PSA, ER, PR and oncoprotein HER2/neu status. The relationship between the clinical and histopathological markers was analyzed by chi-square test. In the present study PSA was expressed in 60.3% of cases, and we have found a significant correlation with the histological type and HER2/neu negative status in premenopausal women. No statistically significant difference was found between PSA positivity and menopausal status of the patients, nodal status, estrogen and progesterone receptors, HER2/neu status in postmenopausal patients, tumor size or histological grade. We conclude that in our study PSA can not be considered as a valuable independent prognostic factor in breast carcinoma. As long as the majorities of PSA positive carcinomas were small in size, early stage, better and moderately differentiated, HER2/neu negative and 70% of ER/PR positive carcinomas expressed PSA, it might be useful as a marker for a subset of breast cancers with better prognosis, which could respond to endocrine therapy, in correlation with other prognostic markers.

Thymus and thymoma: what's new?

The thymus is the prototype of lymphoid and epithelial organ that consists of lymphoid and epithelial cells. In spite of remarkable progresses made in the field of the immunohistochemical characterisation of the thymus parenchyma, the diagnosis of thymoma largely depends on the interpretation of conventional morphologic aspects. Histogenesis of this organ is a multi-step process, and many stages reproduce lesions and changes found in the adult thymus. The normal structure and its variants are extremely helpful to differentiate normal from pathologic aspects. Particular aspects of the thymus structures were shown in myasthenia gravis, despite the behaviour of thymoma in these patients is not clearly understood. Authors performed a detailed description of the conventional pathology of the thymoma, based on the new classifications, recently adopted. The immunohistochemical profile could be helpful in the diagnosis of many cases, and also seems to be useful in prediction of invasion that is the most important criterion in prognosis.

Overexpression of cytokeratin 34beta E12 in thymoma: could it be a poor prognosis factor?

We included in our study nine normal human thymuses and sixteen thymomas (1 type A, 2 type AB, 3 type B1, 3 type B2, 5 type B3 and 2 type C). The 25 patients were between 7 days and 75 years old, and were submitted to open surgery for correction of congenital heart defects or for mediastinal tumor mass. Biopsies were formalin fixed for 24 hours and then embedded in paraffin using routine procedure. Five micrometers step sections were mounted on silanized slides. Slides from each case were stained with haematoxylin and eosin method for morphological diagnosis. Additional sections were immunostained using monoclonal antibodies against high molecular weight cytokeratin clone 34beta E12. We found a very strong positive reaction for this type of cytokeratin in thymomas type B2, B3 and inconstant in type C comparative with normal thymus. Also, the number and distribution of positive epithelial cells in normal thymus versus thymomas were different. We found positive cells into capsular vessels of thymomas. This could be an invasion marker for apparent encapsulated thymomas. Strong positive reaction in almost all epithelial cells of thymomas types mentioned above was correlated in part with invasion. We concluded that expression of 34beta E12 cytokeratin is a useful marker for thymomas with high grade of malignacy, correlated with vascular and capsular invasion.