Biological Behavior (biological + behavior)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Cytologic diagnosis of pancreatic endocrine tumors by endoscopic ultrasound-guided fine-needle aspiration: A review

DIAGNOSTIC CYTOPATHOLOGY, Issue 9 2006
Fuju Chang M.D., Ph.D.
Abstract Precise localization and diagnosis of pancreatic endocrine tumors (PETs) is important, because pancreatic PETs have different clinical and biological behavior and treatment modalities than do exocrine pancreatic tumors. In contrast to the much more common exocrine adenocarcinomas, cytologic studies of PET are relatively rare and many cytopathologists lack experience with the cytomorphologic features of these tumors. During the last 10 yr, endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) has matured into an accurate, highly sensitive, and cost-effective modality for the preoperative localization of pancreatic PETs. This has resulted in an increased number of PETs first sampled as cytology specimens. This manuscript focuses on the cytomorphologic features most suggestive of pancreatic PETs, differential diagnosis, and diagnostic pitfalls of PETs. The technical development of EUS-guided FNA and the ancillary studies for pancreatic PETs are also reviewed. The data summarized in this review indicate that EUS-FNA is a valuable method in the recognition of pancreatic PETs and in most cases cytopathologists could reach a correct diagnosis of these tumors, including their hormone producing capability on aspirated cytologic material. Diagn. Cytopathol. 2006;34:649,658. © 2006 Wiley-Liss, Inc. [source]


Estrogen and progesterone receptors in esophageal carcinoma

DISEASES OF THE ESOPHAGUS, Issue 4 2008
R. Kalayarasan
SUMMARY., Information is sparse and contradictory in the literature regarding the role of estrogen receptor (ER) and progesterone receptor (PR) in esophageal carcinoma. This study was conducted over a period of 18 months from September 2004 with the primary aim of determining the PR, ER alpha (ER,) and ER beta (ER,) status of esophageal carcinoma and normal esophageal mucosa (NEM). The receptor status was correlated with tumor type, tumor differentiation and tumor stage. A total of 45 patients with histologically proven squamous cell carcinoma (SCC) (n = 30) and adenocarcinoma (AC) (n = 15) were studied. Receptor status was detected by immunohistochemistry (IHC) and semiquantitative assessment was done by quick score method of endoscopic biopsy specimens. The mean age for SCC and AC were not significantly different. The gender ratio in favor of males was 3 : 2 for SCC and 4 : 1 for AC. None of the specimens from SCC or AC showed positivity for PR both in NEM and tumor tissue. Likewise none of the specimens were positive for ER, by IHC. The mean ER, score for AC was significantly higher than SCC. For SCC it was seen that ER, positivity in tumor cells increases with dedifferentiation and increasing tumor stage. This trend was seen for AC as well. ER, is over-expressed in poorly differentiated SCC and AC compared to NEM. Thus ER, may be a marker for poor biological behavior, that is dedifferentiation or higher stage of disease. In view of these findings we propose a large-scale prospective, longitudinal interventional study using selective estrogen modulators. [source]


Transfection of the c- erbB2/neu gene upregulates the expression of sialyl Lewis X, ,1,3-fucosyltransferase VII, and metastatic potential in a human hepatocarcinoma cell line

FEBS JOURNAL, Issue 12 2001
Fei Liu
The pCMV4 plasmid containing the cancer-promoting gene, c- erbB2/neu, was cotransfected into the human hepatocarcinoma cell line 7721 with the pcDNA3 vector, which contains the ,neo' selectable marker. Several clones showing stable expression of c- erbB2/neu were established and characterized by determination of c- erbB2/neu mRNA and its encoded protein p185. Expression of Lewis antigens and ,1,3-fucosyltransferases and the biological behavior of 7721 cells after c- erbB2/neu transfection were studied using mock cells transfected with the vectors pCMV4 and pcDNA3 as controls. SLex expression on the surface of mock cells was high, whereas expression of SDLex, Lex and SLea was absent or negligible. This is compatible with the abundant expression of ,1,3-fucosyltransferase VII, very low expression of ,fucosyltransferase III/VI, and almost absent expression of ,1,3-fucosyltransferase IV in the mock cells. After transfection of c- erbB2/neu, expression of SLex and ,1,3-fucosyltransferase VII were simultaneously elevated, but that of ,fucosyltransferase III/VI was not altered. The expression of both SLex and ,1,3-fucosyltransferase VII correlated positively with the expression of c- erbB2/neu in different clones, being highest in clone 13, medium in clone 6, and lowest in clone 7. In addition, the adhesion of 7721 cells to human umbilical vein endothelial cells (HUVECs) or P-selectin, as well as cell migration and invasion, were increased in c- erbB2/neu -transfected cells. These increases also correlated positively with the expression intensities of c- erbB2/neu, SLex and ,1,3-fucosyltransferase VII in the different clones, whereas cell adhesion to fibronectin correlated negatively with these variables. mAbs to SLex (KM93) and SDLex (FH6) significantly and slightly, respectively, abolished cell adhesion to HUVECs or P-selectin and cell migration and invasion. mAbs to SDLex and SLea did not suppress cell adhesion to HUVECs nor inhibit cell migration and invasion. Transfection of ,1,3-fucosyltransferase VII cDNA into 7721 cells showed similar results to transfection of c- erbB2/neu, and the increased adhesion to HUVECs, cell migration, and invasion were also inhibited significantly by KM93 and slightly by FH6. These results indicate that expression of ,1,3-fucosyltransferase VII and its specific product, SLex, and their capacity for cell adhesion, migration and invasion are closely related. Therefore, the c- erbB2/neu gene is proposed to be a metastasis-promoting gene, and its effects are at least partially mediated by the increased expression of ,1,3-fucosyltransferase VII and SLex. [source]


Electrospinning of Manmade and Biopolymer Nanofibers,Progress in Techniques, Materials, and Applications

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2009
Seema Agarwal
Abstract Electrospinning of nanofibers has developed quickly from a laboratory curiosity to a highly versatile method for the preparation of a wide variety of nanofibers, which are of interest from a fundamental as well as a technical point of view. A wide variety of materials has been processed into individual nanofibers or nanofiber mats with very different morphologies. The diverse properties of these nanofibers, based on different physical, chemical, or biological behavior, mean they are of interest for different applications ranging from filtration, antibacterial coatings, drug release formulations, tissue engineering, living membranes, sensors, and so on. A particular advantage of electrospinning is that numerous non-fiber forming materials can be immobilized by electrospinning in nanofiber nonwovens, even very sensitive biological objects such as virus, bacteria, and cells. The progress made during the last few years in the field of electrospinning is fascinating and is highlighted in this Feature Article, with particular emphasis on results obtained in the authors' research units. Specific areas of importance for the future of electrospinning, and which may open up novel applications, are also highlighted. [source]


Cytogenetic analysis of 101 skull base tumors

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 5 2008
Ziv Gil MD
Abstract Background. Skull base tumors are rare neoplasms and the cytogenetic data on these tumors are limited. The authors cytogenetically analyzed a large series of tumors and compared the findings with patients' pathologic data. Methods. The karyotypes of pathologically confirmed samples of 101 patients, who were operated for oncological extirpation of tumors, were analyzed using G-banding and spectral-karyotyping techniques. Results. Of the 67 malignant tumors, 32 (48%) had chromosomal aberrations, some with complex numerical and structural chromosomal anomalies. Recurrent chromosomal breakpoints were identified in squamous cell carcinomas, adenoid cystic carcinomas (ACCs), sinonasal undifferentiated carcinomas, chordomas, and sarcomas. Specific breakpoints established the diagnosis of various soft tissue sarcomas. Novel chromosomal aberrations were found in various other malignant and benign tumors. Conclusion. This study highlights the value of cytogenetic analysis for diagnosis of skull base tumors. The data add further information on the biological behavior of these rare neoplasms. © 2007 Wiley Periodicals, Inc. Head Neck, 2008 [source]


Her-2/neu and EGFR tyrosine kinase activation predict the efficacy of trastuzumab-based therapy in patients with metastatic breast cancer

INTERNATIONAL JOURNAL OF CANCER, Issue 5 2006
Gernot Hudelist
Abstract Her-2/neu overexpression in human breast cancer leads to an aggressive biological behavior and poor prognosis. Although the anti-Her-2/neu antibody trastuzumab (Herceptin®) has become a valuable therapeutic option for patients with Her-2/neu -overexpressing breast cancer, many patients do not benefit from this therapy. To evaluate the effect of receptor activation on tumor response, we have investigated the phosphorylation status of Her-2/neu and EGFR in 46 Her-2/neu -overexpressing tumor samples from trastuzumab-treated metastatic breast cancer patients by immunohistochemistry. Activated (p)tyr-1248 Her-2/neu was detected in 9 of 46 breast cancers (20%), and activated (p)tyr-845 and (p)tyr-1173 EGFR were both present in 6 tumors (13%) while EGFR was present in 16 cases (35%). ptyr-1248 Her-2/neu showed a trend to correlate with increased response to trastuzumab (p = 0.063), while ptyr-845, ptyr-1173 EGFR and EGFR did not. The presence of ptyr-1248 Her-2/neu and ptyr-845 or ptyr-1173 EGFR, however, was a strong predictor of both response to trastuzumab-based treatment (OR = 8.0, p = 0.021 and OR = 8.0, p = 0.021) and clinical benefit (OR = 5.47, p = 0.041 and OR = 6.22, p = 0.028 multivariate logistic regression analysis). Furthermore, ptyr-845 EGFR and ptyr-1248 Her-2/neu were both independent predictors of progression-free survival (RR = 0.21, p = 0.01 and RR = 0.45, p = 0.026, multivariate analysis). Patients with ptyr-845 EGFR positive tumors also tended toward increased overall survival (RR = 0.17, p = 0.082). Taken together, we have demonstrated that the determination of activated EGFR improves the utility of ptyr-1248 Her-2/neu staining in predicting the clinical outcome of patients undergoing trastuzumab treatment. We hypothesize that the activation state of both Her-2/neu and EGFR are key determinants for trastuzumab efficacy. © 2005 Wiley-Liss, Inc. [source]


Chemokine receptor expression in non-melanoma skin cancer

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 7 2008
Jeff Basile
Background:, Previous studies suggest that chemokines and chemokine receptors have a role in the metastatic process. A correlation exists between the specific expression of these chemoattractive, pro-inflammatory cytokines and the ability of cancer to disseminate. Prior studies have shown that in metastatic melanoma and squamous cell carcinoma of the head and neck upregulation of CXC (,) chemokine receptor (CXCR)4 and CC (,) chemokine receptor (CCR)7 expression is accompanied by downregulation of the chemokine receptor CCR6. However, the expression patterns of CCR6, CCR7 and CXCR4 in non-melanoma skin cancer have yet to be elucidated. Methods:, The expression patterns of CCR6, CCR7 and CXCR4 were determined using an immunohistochemical approach on formalin-fixed, paraffin-embedded normal, pre-cancerous actinic (solar) keratosis, squamous cell carcinoma and basal cell carcinoma tissues. Results:, Analysis of chemokine receptor expression showed downregulation of CCR6 and upregulation of CCR7 and CXCR4 in potentially metastatic non-melanoma skin cancer, invasive squamous cell carcinoma, but this pattern did not exist in non-melanoma skin cancer with no metastatic potential, basal cell carcinoma; or actinic keratosis, when compared with normal skin. Conclusions:, Chemokine receptor expression may influence the biological behavior of non-melanoma skin cancer. The exact mechanism by which this occurs requires further study. [source]


Cyclooxygenase-2 expression in dermatofibroma and dermatofibrosarcoma protuberans

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2008
Neta Adler
Background:, Dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) occasionally resemble each other histologically but differ in histogenesis and biological behavior. This study sought to determine if these lesions can be differentiated by the quantity or quality of expression of cyclooxygenase-2 (COX-2), an enzyme associated with both reactive and neoplastic processes. Patients and methods:, Formalin-fixed and paraffin-embedded samples from 20 DFs and 20 DFSPs were stained immunohistochemically with antibodies directed against COX-2. Staining was evaluated semiquantitatively for percentage and intensity using a three-tiered system. DFs were graded and analyzed by cellularity. Findings within the tumors were compared with fibrocyte staining in adjacent tissue. The results were analyzed. Results:, Nineteen DFs (95%) and 15 DFSPs (75%) were immunopositive for COX-2; this difference was not statistically significant. Highly cellular DFs showed more widespread (p = 0.0039; r = 0.614) and more intense (p = 0.0586; r = 0.429) staining than less cellular DFs and more prominent staining in adjacent fibroblasts (p = 0.044; r = 0.608). Conclusions:, COX-2 immunostaining does not distinguish DFs from DFSPs. However, the enzyme is expressed more widely and more intensely in more cellular, possibly younger, DFs. The prominent expression of COX-2 in DFSP may have clinical implications for treatment with COX-2 inhibitors in tumors that are not amenable to surgery. [source]


Cutaneous composite hemangioendothelioma with satellitosis and lymph node metastases

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 2 2008
Luis Requena
The term hemangioendothelioma has been used in recent years to name a heterogeneous group of vascular neoplasms, intermediate in both biological behavior and histopathologic appearance between benign tumors (hemangiomas) and frankly malignant tumors (angiosarcomas). Thus, within the spectrum of hemangioendothelioma have been successively included epithelioid hemangioendothelioma, spindle cell hemangioendothelioma, retiform hemangioendothelioma, kaposiform hemangioendothelioma, polymorphous hemagioendothelioma of the lymph nodes, papillary intralymphatic angioendothelioma (PILA) and composite hemangioendothelioma. The latter is a vascular neoplasm showing varying combinations of benign, low-grade malignant and malignant vascular components. We herein report a case of composite hemangioendothelioma showing a combination of retiform hemangioendothelioma, epithelioid hemangioendothelioma, spindle cell hemangioma and PILA. The neoplasm showed a more aggressive behavior than other reported cases of composite hemangioendothelioma and it developed satellitosis and metastases to the inguinal lymph nodes. Neoplastic cells expressed immunoreactivity for Prox-1, supporting a lymphatic line of differentiation. [source]


Primary Cutaneous Carcinosarcoma (PCCS0 Aka Metaplastic Carcinoma)

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005
Ramin Ram
We describe a case of PCCS in a 73 year-old male who presented with a rapidly growing tumor of 6 months duration on the right ear. Clinical examination revealed a 5 × 4 × 4-cm ulcerated, crusted, exophytic tumor on the superior aspect of the helix. Histologically, the mass revealed a biphasic tumor with malignant epithelial and mesenchymal components. The epithelial component consisted of a few foci of basal cell carcinoma (BCC). The majority of the tumor was composed of osteogenic sarcoma and malignant fibrous histiocytoma (MFH). An intricate transition of BCC into sarcoma was noted in a few foci. Atypical mitosis and necrosis were common. The BCC and tumor giant cells in the MFH area showed positive immunoreaction for cytokeratin and CD68 respectively. The tumor was negative for S-100 protein, HMB-45, muscle actins, chromogranin, and synaptophysin. In conclusion, a PCCS growing predominantly as osteosarcoma and MFH is reported. Although the exact histogenesis of PCCS is unknown, primitive mesenchymal cells of the dermis, surrounding the follicular units, are capable of pluripotent differentiation and are likely the source of origin of the sarcoma. The known aggressive biological behavior warrants wide excision and given the rare reports of metastasis and death, regular follow-up is required [source]


Merkel cell carcinoma: a clinicopathologic study with prognostic implications

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 3 2004
Ryan T. Mott
Background:, Merkel cell carcinoma (MCC) is a frequently aggressive neuroendocrine malignancy of the skin that presents in sun-exposed areas on elderly patients. Although originally described over 30 years ago, many aspects of MCC remain to be defined. Of particular importance is the need to identify prognostic factors capable of predicting the biological behavior of these tumors. Knowledge of these factors may help in determining which patients require more aggressive treatment regimens. In this study, we examined 25 cases of MCC with an attempt to identify clinical, histopathological, or immunohistochemical features capable of predicting disease outcome. Methods:, Features that we evaluated in each case included age, gender, race, tumor location, tumor size, depth of invasion, growth pattern, lymphocytic infiltration, mitotic activity, ulceration, necrosis, vascular invasion, and perineural invasion. In addition, we examined neural cell adhesion molecule and cytokeratin-20 expression using immunohistochemical methods. Results:, We found that most patients were males (84%) with an average age of 74 years. The tumors were located on the head and neck (68%) and upper extremities (32%). Overall, 64% of the patients developed metastatic disease to regional lymph nodes or distant sites (average follow-up time of 21 months). Local recurrence was also common, occurring in 29% of the patients. The overall 1- and 2-year survival rates were 80 and 53%, respectively. Histopathological examination revealed tumors with an average size of 7.2 mm. Common features included invasion into the subcutaneous adipose tissue, solid growth pattern, tumor necrosis, and vascular and perineural invasion. Findings that had a statistically significant correlation with poor outcome included tumor size ,5 mm (p = 0.047), invasion into the subcutaneous adipose tissue (p = 0.005), diffuse growth pattern (p = 0.040), and heavy lymphocytic infiltration (p = 0.017). The remaining findings, including the immunohistochemical results, did not correlate with disease outcome. Using logistic regression models, we show that depth of invasion and degree of lymphocytic infiltration are strong predictors of disease outcome. Conclusions:, The current controversies regarding the treatment of early-stage MCC (i.e., localized disease) underscore the importance of identifying clinicopathological features capable of predicting tumor behavior. In this study, we have identified several prognostic features in MCC. Perhaps, these features may prove useful in identifying patients who require more aggressive treatment regimens. [source]


Expression of VEGF and its receptors Flt and KDR in gastric cancer

JOURNAL OF DIGESTIVE DISEASES, Issue 4 2001
Dongping Liu
OBJECTIVE: The purpose of the present study was to investigate the correlation between the expression of vascular endothelial growth factor (VEGF), the expression of its receptors, Flt and KDR, and the biological behavior of gastric cancer. METHODS: Sixty cases of gastric cancer that had been diagnosed by surgery and pathology were studied with the method of semiquantitative reverse transcriptase,polymerase chain reaction (RT-PCR), to determine the expression of VEGF, Flt and KDR in gastric cancer tissue. RESULTS: The positive rates of VEGF, Flt and KDR in gastric cancer were 73.3, 86.7 and 80.0%, respectively. In pericancerous tissue, the rates were 43.3, 33.0 and 30.0%, respectively. There were significant differences between the groups with and without lymph node metastasis (P < 0.01). For gastric cancer patients with lymphatic metastasis, the positive rates for VEGF, Flt and KDR were 90.3, 80.6 and 96.8%, respectively; for patients without lymphatic metastasis, the rates were 51.7, 41.3 and 55.1%; there were significant differences between the groups with and without lymph node metastasis (P < 0.01). The positive rates of VEGF and KDR in well-differentiated gastric cancer were 40.0 and 46.7%, markedly lower than those of the poorly differentiated and undifferentiated gastric cancer groups. The rate of positive expression of Flt in the well-differentiated gastric cancer group was 73.3%. There was no significant difference between this rate and that of the poorly differentiated and undifferentiated groups (87.5%). The positive expression of VEGF, Flt and KDR was unrelated to the depth of infiltration. CONCLUSIONS: There are some correlations between VEGF, Flt and KDR and the biological behavior of gastric cancer. Knowing where they are expressed at high rates may be of help in evaluating the prognosis of gastric cancer. [source]


Clinicopathological features and immunohistochemical expression of p53, Ki-67, Mcm-2 and Mcm-5 in proliferative verrucous leukoplakia

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 6 2010
Adriele Ferreira Gouvêa
J Oral Pathol Med (2010) 39: 447,452 Background:, Proliferative verrucous leukoplakia (PVL) is a distinct and aggressive type of oral leukoplakia which affects elderly women without risk behavior and presents high rates of malignant transformation. The objective of the present study was to evaluate the clinicopathological characteristics and the distribution of cell proliferation markers, aiming to elucidate the distinct biological behavior of the PVL. Methods:, Clinical and microscopical features of 12 patients with PVL were reviewed. Immunohistochemical analysis for p53, Ki-67, Mcm-2 and Mcm-5 were performed and the data were correlated. Results:, All patients were women, above 50 years of age, 91.7% were non-smoker and 100% were non-habitual drinker. Alveolar ridge (66.6%), tongue (50%) and buccal mucosa (41.6%) were the most affected sites. Four patients developed squamous cell carcinoma (SCC). The immunohistochemical findings showed higher positivity for p53, Ki-67, Mcm-2 and Mcm-5 in SCCs. However, some patients with mild or moderate dysplasia, specially the patients who developed SCC, presented high expression of Mcm-2 and Mcm-5. Conclusions:, High immunoexpression of Mcm-2 and Mcm-5 in mild and moderate dysplasia could be helpful to predict the malignant transformation of PVL. [source]


Immunohistochemical evidence of PTEN in oral squamous cell carcinoma and its correlation with the histological malignancy grading system

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 7 2002
Cristiane Helena Squarize
Abstract PTEN is a tumor suppressor gene that encodes a dual phosphatase protein capable of modulating membrane receptors and interaction of the cell and extracellular stimuli. PTEN regulates cell physiology such as division, differentiation/apoptosis and also migration and adhesion. The expression of PTEN was evaluated by immunohistochemistry in OSCC and compared to a well-established histological malignancy grading system. The well-differentiated OSCC were 59.1% and poorly differentiated were 40.9%. According to PTEN expression, the cases were 45.5% positive (the entire tumor showed stained), 22.7% mixed (both negative and positive cells were present) and 31.8% negative (no staining was seen in the tumor cells). PTEN expression in OSCC was related to the malignancy grade (P < 0.0005). Aggressive tumors with a high score of malignancy did not express PTEN, and clearly, the PTEN expression was present in the epithelium adjacent to the tumor. Negative cells were in the invasion border of the tumor. This result suggests that PTEN is related to histologic pattern and biological behavior of OSCC and may be a used as a prognostic marker in the future. The role of PTEN during carcinogenesis and as a biomarker should be further investigated. [source]


MIB-1 immunolabeling: A valuable marker in prediction of benign recurring meningiomas

NEUROPATHOLOGY, Issue 5 2007
Mahesha Vankalakunti
Histological analysis has limited value to predict biological behavior of meningiomas. We investigated the utility of cell proliferative indicator in the evaluation of histologically benign meningiomas. We selected 25 benign non-recurrent meningiomas, 15 benign recurrent meningiomas after complete surgical resection, 30 atypical meningiomas, and 15 anaplastic meningiomas out of 384 cases studied. MIB-1 Labeling Index was evaluated by two methods: Highest Labeling Index (HLI) and Random Labeling Index (RLI). There was no dependable histological parameter to predict recurrence among benign-looking meningiomas. HLI had significant difference when compared with RLI in all categories. The mean MIB-1 HLI values ± SD were 3.47 ± 2.0% for benign meningiomas, 5.08 ± 4.0% for atypical meningiomas and 11.66 ± 7.06% for anaplastic meningiomas. In comparison, the mean MIB-1 HLI of benign non-recurrent meningiomas were 2.66 ± 1.7% and with recurrence were 4.21 ± 2.78% (P = 0.0339). Using receiver operating characteristic, it was seen that neoplasm recurred with the MIB-1 HLI of > 2.6 having the sensitivity of 64.6% and specificity of 68% among benign (grade I) meningiomas. MIB-1 positive tumor cells were maximally aggregated at the periphery of excised specimen. MIB-1 HLI, integrated with standard histopathology can provide better information about the disease biological nature in benign meningiomas. [source]


Chordoid meningioma: Rare variant of meningioma

NEUROPATHOLOGY, Issue 3 2004
Özlem Özen
Chordoid meningioma is a rare variant of meningioma that bears a striking histological resemblance to chordoma and has greater likelihood of recurrence. Although most meningiomas occur in the intracranial, orbital and intravertebral cavities, rare meningiomas have been reported in extracranial organs; thus, it is important to be able to distinguish them from other neoplasms that have similar histology but different biological behavior and therapies. A case of chordoid meningioma in a 48-year-old woman who did not have Castleman's syndrome is described in the present report. The patient presented with a mass in her left frontoparietal region, and had been suffering from headaches for many years. Magnetic resonance imaging of the brain demonstrated an expansive lytic lesion in the squamous portion of the left temporal bone. The lesion extended in both directions. Histological examination of the surgical specimen revealed a tumor composed of cords and nests of eosinophilic vacuolated cells embedded in a myxoid matrix. A typical meningiomatous pattern was observed focally, and positive staining of the tumor cells for vimentin and epithelial membrane antigen confirmed the diagnosis of chordoid meningioma. [source]


Benign myoepithelioma of the breast: Origin and development

PATHOLOGY INTERNATIONAL, Issue 6 2009
Hajime Hikino
A case of benign myoepithelioma of the breast in a 55-year-old woman is described. The tumor was a well-circumscribed solid mass, measuring 13 × 12 mm. Histopathology indicated that the tumor was composed of entirely myoepithelial cells, which was confirmed by immunoreactivity to calponin and S-100. There was no ductal differentiation in the tumor, and staining for pan-cytokeratin and epithelial membrane antigen was weak and negative, respectively. Although the biological behavior of the tumor remains to be ascertained, the tumor was considered to be myoepithelioma with benign features due to mild nuclear pleomorphism, sparse mitotic figures, low Ki-67 labeling index and low S-phase fraction. Diagnostic confusion between benign myoepithelioma and other myoepithelial-rich cell tumors is possible. Considering the classification of myoepithelial tumor in the salivary glands, benign myoepithelioma of the breast may possess a different development process from adenomyoepithelioma. [source]


Incidental calcifying fibrous tumor of the stomach presenting as a polyp

PATHOLOGY INTERNATIONAL, Issue 4 2006
Gülsüm Özlem Elpek
Calcifying fibrous tumor (CFT) is an uncommon lesion of uncertain cause and pathogenesis that has a unique histological appearance. These lesions are described mainly in the subcutaneous or deep soft tissues, followed by subserosal locations. Intrinsic visceral CFT is extremely rare. Herein is described a rare case of CFT that involved the gastric wall, along with a review of the literature. An incidental small polypoid lesion was excised during urgent surgery for penetrating injury at the lesser curvature in a 25-year-old man, previously healthy. The lesion was a well-demarcated, small (10 mm) tumor that occupied the submucosa. The characteristic histopathological features and the presence of spindle cells that express factor XIIIa allowed a diagnosis of CFT to be made. The present case and the review revealed that, despite their frequent subperitoneal location, intra-abdominal CFT might present as intrinsic visceral lesions and might be found incidentally. These lesions tend to be smaller when compared to their symptomatic counterparts. The diffuse factor XIIIa expression in CFT might be useful to differentiate this entity from other intra-abdominal soft-tissue tumors in problematic cases. Although rarity of intrinsic visceral CFT necessitates new cases to determine their exact biological behavior, the present case highlights their presence in the stomach as a symptomless small polypoid lesion. [source]


Comedonecrosis is an unfavorable marker in node-negative invasive breast carcinoma

PATHOLOGY INTERNATIONAL, Issue 8 2003
Hiroshi Yagata
Breast carcinoma is usually accompanied by an invasive component with an intraductal component, and each component shows different morphological features. We evaluated whether the presence or absence of comedonecrosis is correlated with prognosis and biological features in node-negative invasive breast carcinoma. Ninety-four node-negative breast carcinomas with an intraductal component were classified into two types: comedo type (n = 36) showing comedonecrosis partly or extensively in the intraductal component, and non-comedo type (n = 58) showing either an absence or small foci of necrosis. The Kaplan,Meier method was used to calculate disease-free survival. Immunohistochemical examination for p53 and HER-2 was conducted on the comedo (n = 35) and non-comedo (n = 47) type tumor specimens. Disease-free survival was significantly shorter in the comedo type than in the non-comedo type (P = 0.019). The expression of p53 was observed in 16 (45.7%) of the 35 comedo type cases, but only in two (4.3%) of the 47 non-comedo type cases (P < 0.0001). HER-2 overexpression was observed in seven (20.0%) of the 35 comedo type cases, while none of the 47 non-comedo type cases overexpressed HER-2 (P < 0.0001). These results suggest that the presence of comedonecrosis may be predictive of an unfavorable prognosis with aggressive biological behavior in node-negative invasive breast carcinoma. [source]


Microsatellite instability of papillary subtype of human gastric adenocarcinoma and hMLH1 promoter hypermethylation in the surrounding mucosa

PATHOLOGY INTERNATIONAL, Issue 4 2001
Rong-Jun Guo
Gastric cancer has striking heterogeneity in histological pattern, cellular phenotype, genotype, biomarkers, and biological behavior. We focused on the specific morphological papillary phenotype of gastric adenocarcinoma and attempted to identify its distinct molecular characteristics. In our comparative study, early stage papillary (papillary-dominant) gastric cancer showed a significantly higher and more widespread high-frequency microsatellite instability (MSI-H) than other morphological types. Analysis of mutations in a panel of five putative microsatellite instability (MSI)-associated genes in the MSI-H cases revealed that papillary or papillary-dominant cancer displays a unique profile of mutations compared to profiles previously reported in gastric cancer. Immunohistochemical staining and methylation analysis revealed that silencing of hMLH1 by methylation in its promoter region was responsible for the failure of mismatch repair in papillary-type gastric cancer, whereas aberrant promoter methylation of hMLH1 was not found in any cases without the unique mutator phenotype. Promoter hypermethylation of the hMLH1 genes was found to a lesser degree in the adjacent non-tumor mucosa in four of the 10 cases with tumor having the mutator phenotype. Microsatellite instability itself could not be detected in the adjacent non-tumor mucosa. Inactivation of hMLH1 expression by promoter hypermethylation may be an early event in carcinogenesis of this type of gastric cancer, preceding the development of the clear MSI phenotype of papillary carcinoma. [source]


Nodular melanomas: Analysis of the casistic and relationship with thick melanomas and diagnostic delay

THE JOURNAL OF DERMATOLOGY, Issue 10 2008
Roberto BETTI
ABSTRACT The present study aimed to: (i) define thick melanomas related to nodular melanomas and other melanoma subgroups; and (ii) establish diagnostic delay in relation to the biological behavior of these melanomas and prevention programs. Cutaneous primary melanomas were studied. Nodular melanoma (NM), lentigo maligna melanoma (LMM) and superficial spreading melanoma (SSM) were selected. A further category named vertical growth melanoma (VGM) was also utilized. Analysis for sex, age, different values of thickness (1,2 mm, >2 mm; 1,3 mm, >3 mm; >4 mm), delay to diagnosis and patterns of detection were performed in all of the different subtypes. Eighty-seven patients with melanomas more than 1 mm of Breslow's thickness out of 506 melanoma were collected. Twenty-six were nodular cases, 39 SSM, five LMM and 17 VGM. Of those patients with NM, 42% had a thickness of more than 1,2 mm, 34% of 2,4 mm, 23% of more than 4 mm; and 54% with 1,3, 46% with more than 3 mm; and 58% with more than 2 mm. Even considering different values of thickness of more than 1 mm, a delay to diagnosis was significantly lower in NM (4.79 months) than in other subgroups. The value of more than 1 mm of Breslow's thickness may be sufficient to consider a melanoma to be thick. The lower diagnostic delay of NM suggests that they represent faster growing lesions probably with a different biological behavior than other melanoma subtypes. VGM should not be confused with NM, having a longer delay and different clinical features compared with the latter. They represent an area of diagnostic carelessness than potentially be improved. [source]


Head and Neck Cancer: The Importance of Oxygen ,

THE LARYNGOSCOPE, Issue 5 2000
David J. Terris MD
Abstract Objectives To use recently introduced polarographic technology to characterize the distribution of oxygenation in solid tumors, explore the differences between severe hypoxia and true necrosis, and evaluate the ability to predict treatment outcomes based on tumor oxygenation. Study Design Prospective, nonrandomized trial of patients with advanced head and neck cancer, conducted at an academic institution. Methods A total of 63 patients underwent polarographic oxygen measurements of their tumors. Experiment 1 was designed to determine whether a gradient of oxygenation exists within tumors by examining several series of measurements in each tumor. Experiment 2 was an analysis of the difference in data variance incurred when comparing oxygen measurements using oxygen electrodes of two different sizes. Experiment 3 compared the proportion of tumor necrosis to the proportion of very low (,2.5 mm Hg) polarographic oxygen measurements. Experiment 4 was designed to explore the correlation between oxygenation and treatment outcomes after nonsurgical management. Results No gradient of oxygenation was found within cervical lymph node metastases from head and neck squamous cell carcinomas (P > .9). Tumor measurements achieved with larger (17 ,m) electrodes displayed smaller variances than those obtained with smaller (12 ,m) electrodes, although this difference failed to reach statistical significance (P = .60). There was no correlation between tumor necrosis and the proportion of very low (,2.5 mm Hg) oxygen measurements. There was a nonsignificant trend toward poorer locoregional control and overall survival in hypoxic tumors. Conclusions Hypoxia exists within cervical lymph node metastases from head and neck squamous carcinomas, but the hypoxic regions are distributed essentially randomly. As expected, measurements of oxygen achieved with larger electrodes results in lowered variance, but with no change in overall tumor mean oxygen levels. Polarographic oxygen measurements are independent of tumor necrosis. Finally, oxygenation as an independent variable is incapable of predicting prognosis, probably reflecting the multifactorial nature of the biological behavior of head and neck cancers. [source]


Impact of Morphology, MIB-1, p53 and MGMT on Outcome in Pilocytic Astrocytomas

BRAIN PATHOLOGY, Issue 3 2010
Craig Horbinski MD
Abstract Pilocytic astrocytoma (PA) is the most common glioma in the pediatric population. PAs can exhibit variable behavior that does not always correlate with location, yet at present there is no way to predict which tumors will be more aggressive. To address this problem, an institutional cohort of 147 PAs (118 with outcome data) from both cerebellar and noncerebellar locations (spine, diencephalon, midbrain, brainstem and cortex) was utilized. Parameters included quantification of characteristic morphologic variables as well as genes previously shown to be of relevance in high-grade gliomas, including MIB-1, p53 and MGMT. In this cohort, the classic biphasic appearance was most common in cerebellar tumors, whereas noncerebellar tumors were predominantly microcystic. Associations with outcome suggest that the presence of degenerative atypia may be a favorable factor in PAs. Oligodendroglial morphology and the absence of leptomeningeal invasion are adverse histologic factors, but only in cerebellar tumors. Conversely, MIB-1 proliferation index and p53 and MGMT expression do not correlate with outcome. Morphologic biomarkers thus do exist for PAs, but the utility of each biomarker varies according to location. These results suggest that PAs differ fundamentally according to location; therefore, biological behavior may not simply depend on extent of resection. [source]


Aberrant Hypermethylation of p14ARF and O6 -methylguanine-DNA Methyltransferase Genes in Astrocytoma Progression

BRAIN PATHOLOGY, Issue 1 2007
Takao Watanabe MD
The aim of the present study was to elucidate genetic alterations that are critically involved in astrocytoma progression. We characterized 27 World Health Organization grade II fibrillary astrocytomas which later underwent recurrence or progression, paying specific attention to the CpG island methylation status of critical growth regulatory genes. p14ARF and O6 -methylguanine-DNA methyltransferase (MGMT) hypermethylation represented frequent events (26% and 63%, respectively), which were mutually exclusive except in one case, with alternate or simultaneous methylation of these two genes occurring in 85% of our tumor series. Seventeen tumors (63%) contained TP53 mutations, which were closely related to the presence of MGMT methylation. Methylation of the p21Waf1/Cip1, p27Kip1 and p73 genes and homozygous deletion of the p16INK4a, p15INK4b and p14ARF genes were not detected in any of the primary low-grade tumors. The presence of p14ARF methylation at first biopsy was associated with shorter patient survival, whereas the presence of MGMT methylation carried a better clinical outcome after salvage therapy. Examination of 20 cases whose histological data for recurrent tumors were available revealed that malignant progression occurred in all of the tumors with p14ARF methylation but less frequently (50%) in the lesions with MGMT methylation. On analysis of their respective recurrent tumors, five of six patients whose primary low-grade tumors carried p14ARF methylation exhibited homozygous co-deletions of the p14ARF, p15INK4b and p16INK4a genes, which were restricted to glioblastoma as the most malignant end point. Our findings suggest that p14ARF hypermethylation and MGMT hypermethylation constitute distinct molecular pathways of astrocytoma progression, which could differ in biological behavior and clinical outcome. [source]


Search for new biomarkers of gastric cancer through serial analysis of gene expression and its clinical implications

CANCER SCIENCE, Issue 5 2004
Wataru Yasui
Gastric cancer is one of the most common human cancers and is the second most frequent cause of cancer-related death in the world. Serial analysis of gene expression (SAGE) is a powerful technique to allow genome-wide analysis of gene expression in a quantitative manner without prior knowledge of the gene sequences. SAGE on 5 samples of gastric cancer with different histology and clinical stages have created large SAGE libraries of gastric cancer that enable us to identify new cancer biomarkers. Commonly up-regulated genes in gastric cancer in comparison with normal gastric epithelia included CEACAM6, APOC1 and YF13H12. By comparing gene expression profiles of gastric cancers at early and advanced stages, several genes differentially expressed by tumor stage were also identified, including FUS, CDH17, COL1A1 and COL1A2, which should be novel genetic markers for high-grade malignancy. Regenerating gene type IV (REGIV) is one of the most up-regulated genes in a SAGE library of a scirrhous-type gastric cancer. In vitro studies using RegIV-transfected cells revealed that RegIV is secreted by cancer cells and inhibits apoptosis, suggesting that RegIV may serve as a novel biomarker and therapeutic target for gastric cancer. Production of RNA aptamers could be a useful approach to establish a detection system in blood. A custom-made array, named Ex-STO-MACHIP, consisting of 395 genes, including highly differentially expressed genes identified by our SAGE and other known genes related to carcinogenesis and chemosensitivity, is useful to study the molecular pathogenesis of gastric cancer and to obtain information about biological behavior and sensitivity to therapy in the clinical setting. Combined analyses of gene expression profile, genetic polymorphism and genetic instability will aid not only cancer detection, but also characterization of individual cancers and patients, leading to personalized medicine and cancer prevention. [source]


Stem cells and gastric cancer: Role of gastric and intestinal mixed intestinal metaplasia

CANCER SCIENCE, Issue 2 2003
Masae Tatematsu
All of the different types of stomach epithelial cells are known to be derived from a single progenitor cell in each gland. Similarly, cancers develop from single cells, based on data from clonality analysis in C3H/HeN , BALB/c chimeric mice. Using gastric and intestinal epithelial cell markers, intestinal metaplasia (IM) can be divided into two major types: a gastric and intestinal (GI) mixed type, and a solely intestinal (I) type. Ectopic expression of Cdx genes and down-regulation of Sox2 in isolated single GI mixed IM glands suggests abnormal differentiation of stem cells that can produce both gastric (G) and I type cells. Similarly, phenotypic expression of gastric cancer cells of each histological type can be clearly classified into G and I type epithelial cells. The heterogeneity of phenotypic expression of gastric cancer cells in individual cancers is assumed to reflect this intrinsic potential for differentiation in two directions. Gastric cancers at early stages, independent of the histological type, mainly consist of G type cells, and phenotypic shift from G to I type expression is clearly observed with progression. The data thus suggest IM may not be a preneoplastic change in gastric carcinoma, but rather that cells of the I type may appear independently in the gastric mucosa in IM and in gastric cancers. Intestinalization of gastric mucosa and cancer cells may represent a kind of homeotic transformation. Whether disturbance of the regulation of Sox2 and Cdx genes may be of importance to the biological behavior of gastric cancers should therefore be clarified in future studies. (Cancer Sci 2003; 94: 135,141) [source]


Pharmaceutical and Biomedical Differences between Micellar Doxorubicin (NK911) and Liposomal Doxorubicin (Doxil)

CANCER SCIENCE, Issue 10 2002
Yoshihisa Tsukioka
The stability and biological behavior of an in vitro system of doxorubicin (DXR) entrapped in NK911, polymer micelles, was examined and compared with those of DXR entrapped in Doxil, polyethylene-glycol-conjugated liposomes. The fluorescence of DXR inside micelles or liposomes in an aqueous solution is known to be strongly quenched by the outer shells of the micellar or liposomal formation. Thus, by measuring the fluorescence intensity of DXR released from NK911 or Doxil, we could determine the stability of the micellar or liposomal DXR formation. Furthermore, NK911 was found to be less stable than Doxil in saline solution. In drug distribution experiments using an in vitro solid tumor model, when spheroids formed from two human colonic cancer lines, HT-29 and WiDr, and a human stomach cancer line, MKN28, were exposed to NK911, DXR was distributed throughout the spheroids, including their center. On the other hand, when the spheroids were exposed to Doxil, DXR was distributed only to the surface of the spheroids. It has been suggested that Doxil can deliver DXR to a solid tumor more efficiently than NK911 via the EPR (enhanced permeability and retention) effect, because Doxil may be more stable in plasma than NK911. On the other hand, DXR packed in NK911 may be distributed by diffusion to cancer cells distant from the tumor vessel, because NK911 can leak out of the tumor vessel and may be able to release free DXR more easily than Doxil. It has been suggested that drug carrier systems such as liposomes and micelles should be selected appropriately bearing in mind the characteristics of the tumor vasculature and the tumor interstitium. [source]


Injectable calcium phosphate cement as a filler for bone defects around oral implants: an experimental study in goats

CLINICAL ORAL IMPLANTS RESEARCH, Issue 3 2002
Luca Comuzzi
Abstract: The aim of this study was to evaluate the clinical applicability and biological behavior of a newly developed injectable calcium phosphate (Ca-P) cement as bone filler for gaps around oral implants. Twenty-four step-like implants, creating gaps of 1 and 2 mm, were inserted into the trabecular bone of the medial femoral condyles of six goats. Four different situations were tested: (1) implant + gaps; (2) implant + gaps, but covered with a polylactic acid membrane; (3) implant + gaps that were filled with Ca-P cement; and (4) implant + gaps that were filled with Ca-P cement and covered with a membrane. All implants were left in place for 12 weeks. Histological and quantitative histomorphometrical measurements demonstrated that implants + gaps had generally poor bone contact at the implant base. Furthermore, fibrous encapsulation was observed in the gap part. In contrast, the presence of a membrane promoted bone ingrowth into the gap and also the bone contact at the implant base. Injection of Ca-P cement resulted in an almost complete filling of the gaps around the implant. The cement surface was completely covered by bone. Active resorption and remodeling of cement particles was observed, suggesting a pattern of slow resorption associated with full replacement with newly formed bone. Additional use of a membrane did not result in adjunctive benefits. Bone-to-implant contact at the implant base was comparable with the implants provided only with a membrane. In conclusion, the Ca-P cement used here showed excellent clinical handling properties combined with a superior bone behavior. On the other hand, the degradation rate of the material was still very slow. This current characteristic can hamper the final clinical applicability of the material as gap filler for periimplant or periodontal defects. Résumé Le but de l'étude présente a été d'évaluer l'application clinique et le comportement biologique d'un nouveau ciment de calcium de phosphate injectable (Ca-P) comme comblement osseux pour les cavités autour des implantes dentaires. Vingt-quatre implants créant des cavités de 1 et 2 mm ont été insérés dans l'os trabéculaire des condyles fémoraux moyens de six chèvres. Quatre situations différentes ont été testées: 1) implant + cavités; 2) implant = cavités recouvertes par une membrane en acide polylactique, 3) implant + cavités comblées par le ciment Ca-P et 4) implant + cavités comblées par le ciment Ca-P et recouvertes par une membrane. Tous les implants ont été laissés in situ pendant douze semaines. Les mesures histologiques et quantitatives histomorphométriques ont démontré que les implants + cavités avaient généralement un contact osseux pauvre au niveau de la base implantaire. De plus, une encapsulation fibreuse était observée dans la partie cavité. Par contre, la présence d'une membrane favorisait la croissance osseuse dans la cavité ainsi que le contact osseux à la base de l'implant. L'injection du cément Ca-P résultait en une réparation quasi complète des cavités autour de l'implant. La surface cémentaire était complètement recouverte d'os. La résorption active et le remodelage des particules de cément étaient observés, ce qui suggérait un système de résorption lente associéà un remplacement complet par de l'os néóformé. L'usage additionnel d'une membrane ne s'accompagnait pas de bénéfice supplémentaire. Le contact os/implant à la base de l'implant était comparable à celui des implants installés seulement avec une membrane. En conclusion, le ciment Ca-P possèdait des propriétés cliniques excellentes combinées à un comportement osseux supérieur. Par contre le taux de dégradation du matériel était toujours très lent. Cette caractéristique pourrait gêner l'application clinique finale de ce matériel en tant que comblement des cavités autour des implants ou dans les lésions parodontales. Zusammenfassung Das Ziel dieser Studie war es, die klinische Anwendbarkeit und das biologische Verhalten eines neu entwickelten injizierbaren Kalziumphosphatzements (Ca-P) als Knochenfüller bei oralen Implantaten auszuwerten. Vierundzwanzig stufenförmige Implantate, welche Defekte von 1 und 2 mm kreieren, wurden in den trabekulären Knochen der medialen femoralen Kondylen von 6 Ziegen eingesetzt. Vier verschiedene Situationen wurden getestet: 1) Implantat + Defekte; 2) Implantat + Defekte, aber bedeckt mit einer Membran aus Polimilchsäure; 3) Implantat + Defekte, welche mit Ca-P-Zement gefüllt wurden; 4) Implantat + Defekte, welche mit Ca-P-Zement gefüllt und mit einer Membran bedeckt wurden. Alle implantate wurden 12 Wochen belassen. Histologische und quantitative histomorphometrische Messungen zeigten, dass Implantate + Defekte generell schlechten Knochenkontakt an der Implantatbasis aufwiesen. Ausserdem wurde eine fibröse Einkapselung im Bereich der Defekte beobachtet. Im Gegensatz dazu bewirkte die Präsenz einer Membran das Einwachsen von Knochen in die Defekte und der Knochenkontakt an der Implantatbasis wurde gefördert. Die Injektion von Ca-P-Zement resultierte in einer fast kompletten Auffüllung der Defekte um die Implantate. Die Zementoberfläche war völlig mit Knochen bedeckt. Es konnte eine aktive Resorption und eine Remodellierung der Zementpartikel beobachtet werden. Dies lässt ein Muster mit langsamer Resorption assoziiert mit komplettem Ersatz durch neugebildeten Knochen vermuten. Die zusätzliche Verwendung einer Membran brachte keine weiteren Vorteile. Der Knochen-/Implantat-Kontakt an der Implantatbasis war vergleichbar mit den Implantaten, die nur mit einer Membran abgedeckt worden waren. Zusammenfassend kann festgehalten werden, dass der verwendete Ca-P-Zement eine exzellente Handhabung kombiniert mit ausserodentlichem Knochenverhalten zeigte. Andererseits war die Zersetzungsrate des Materials immer noch sehr Gering. Diese momentanen Eigenschaften können letztendlich die klinische Anwendbarkeit des Materials als Defektfüller bei periimplantären und parodontalen Defekten behindern. Resumen La intención del presente estudio fue evaluar la aplicabilidad clínica y el comportamiento biológico de un cemento recientemente desarrollado de fosfato de calcio (Ca-P) como relleno óseo para huecos alrededor de los implantes orales. Se insertaron veinticuatro implantes del tipo escalón creando huecos de 1 y 2 mm en el hueso trabecular de los cóndilos femorales mediales de 6 cabras. Se probaron cuatro situaciones diferentes: 1) implantes + huecos; 2) implantes + huecos, pero cubiertos con una membrana de ácido poliláctico; 3) implantes + huecos que se rellenaron con cemento de Ca-P; y 4) + huecos que se rellenaron con cemento de Ca-P y se cubrieron con una membrana. Todos los implantes se dejaron en su lugar durante 12 semanas. las mediciones histológicas e histomorfométricas cuantitativas demonstraron que los implantes + huecos tuvieron generalmente un contacto óseo pobre en la base del implante. Posteriormente, se observó una encapsulación fibrosa en la parte del hueco. En contraste, la presencia de la membrana promocionó el crecimiento óseo hacia el hueco y también el contacto óseo en la base del implante. La inyección de cemento Ca-P resultó en un casi completo relleno de los huecos alrededor del implante. La superficie del cemento se cubrió completamente de hueso. La reabsorción activa y la remodelación de las partículas de cemento fueron observadas, lo cual sugiere un patrón de reabsorción lenta asociada con una completa sustitución con hueso neoformado. El uso adicional de la membrana no resultó en beneficios adicionales. El contacto hueso implante en la base del implante fue comparable con los implantes que solo tenían la membrana. En conclusión, el uso de cemento de Ca-P mostró excelentes propiedades de manejo clínico combinado con un superior comportamiento óseo. Por otro lado, el índice de degradación del material fue muy lento. Estas características actuales pueden estorbar la aplicabilidad clínica final del material como rellenador de huecos alrededor de defectos periodontales o perimplantarios. [source]


Synchronous hepatic, mesenteric and pulmonary Epstein,Barr virus-associated smooth muscle tumors in a renal transplant recipient

CLINICAL TRANSPLANTATION, Issue 5 2010
T. Al Hussain
Al Hussain T, Haleem A, Alsaad KO. Synchronous hepatic, mesenteric and pulmonary Epstein,Barr virus-associated smooth muscle tumors in a renal transplant recipient. Clin Transplant 2010. DOI: 10.1111/j.1399-0012.2009.01206.x © 2010 John Wiley & Sons A/S. Abstract:, Epstein,Barr virus-associated smooth muscle tumors (EBV-SMT) are distinct lesions that occur in immunocompromised patients. EBV-SMT following solid organ transplantation are rare and generally have an indolent biological behavior. Post-transplant EBV-SMT have been reported in various anatomical locations. This report describes a synchronous and multicentric development of EBV-SMT in liver, mesentery, and lung of a 33-yr-old male patient, 10 yr after a deceased allograft renal transplantation. The hepatic and mesenteric tumors were available for study. These tumors were composed of bland looking, desmin-positive, spindle-shaped cells which showed a strong nuclear staining for EBV with in situ hybridization technique. A literature review of post solid organ transplant EBV-SMT in the liver and lung, particularly regarding their pathogenesis, synchronicity and biological behavior would be provided. [source]


Layer-By-Layer Assembly of ,-Estradiol Loaded Mesoporous Silica Nanoparticles on Titanium Substrates and Its Implication for Bone Homeostasis

ADVANCED MATERIALS, Issue 37 2010
Yan Hu
Drug-loadingmesoporous silica nanoparticles that serve as a nanoreservoir-type drug-delivery system are successfully attached to titanium substrates via the layer-by-layer assembly technique (see scheme). The obtained structure demonstrates great potential for regulating the biological behaviors of osteoblasts/ steoclasts in order to maintain bone homeostasis. The approach we present here may have wide applications in implant technology, tissue engineering, and regenerative medicine. [source]