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S Staibano

Publications and source records attributed to S Staibano.

At least 37 records · Page 2Linked to original sources
PubMed2001

Variations of proline-rich kinase Pyk2 expression correlate with prostate cancer progression.

Proline-rich kinase 2 (Pyk2), also known as CAKbeta (cell adhesion kinase beta), is a cytoplasmic tyrosine kinase that is structurally related to focal adhesion kinase. Pyk2 is expressed in different cell types including brain cells, fibroblasts, platelets, and other hemopoietic cells. Pyk2 is rapidly tyrosine phosphorylated in response to diverse extracellular signals acting via different post receptor pathways. We have investigated whether this protein kinase is functionally expressed in normal and neoplastic prostate tissues. In this study, we demonstrate that Pyk2 is expressed only in normal epithelial prostate tissue and in benign prostatic hyperplasia, whereas its expression progressively declines with an increasing grade of malignancy of prostate cancer.

Enzyme Activation↗
PubMed2001

Facial granulomatous diseases: a study of four cases tested for the presence of Mycobacterium tuberculosis DNA using nested polymerase chain reaction.

The histopathologic diagnosis of cutaneous tuberculosis (CTB) is often troublesome, because there are several other entities (tuberculids, demodicidosis, granulomatous rosacea, and acne agminata) that may display granulomatous inflammation with caseation necrosis. The current study describes four cases of granulomatous disease of the face. The final diagnosis (assessed on the basis of the clinical response to therapy) was CTB in three cases and granulomatous rosacea in one case. Histologically, epithelioid granulomas were a constant feature; in one case of CTB, they displayed a palisading (granuloma annulare-like) arrangement. Caseation necrosis was a prominent feature only in the case of granulomatous rosacea. Routinely processed biopsy specimens were evaluated with nested polymerase chain reaction (nPCR) for Mycobacterium tuberculosis (MBT) DNA. The correlation between nPCR results and clinical outcome was less than optimal; in fact, one case showed an excellent clinical response to the antituberculous drug therapy despite the absence of MBT DNA amplification. In granulomatous diseases of the face, the importance of evaluating not only nPCR but the overall clinicopathologic picture so as to avoid diagnostic misinterpretations is emphasized.

Adult↗
PubMed2001

In vivo and in vitro studies of cytosolic phospholipase A2 expression in Helicobacter pylori infection.

Modifications of mucosal phospholipids have been detected in samples from patients with Helicobacter pylori-positive gastritis. These alterations appear secondary to increased phospholipase A2 activity (PLA2). The cytosolic form of this enzyme (cPLA2), normally involved in cellular signaling and growth, has been implicated in cancer pathogenesis. The aim of this study was to investigate cPLA2 expression and PLA2 activity in the gastric mucosae of patients with and without H. pylori infection. In gastric biopsies from 10 H. pylori-positive patients, cPLA2 levels, levels of mRNA as determined by reverse transcriptase PCR, levels of protein as determined by immunohistochemistry, and total PLA2 activity were higher than in 10 H. pylori-negative gastritis patients. To clarify whether H. pylori had a direct effect on the cellular expression of cPLA2, we studied cPLA2 expression in vitro with different human epithelial cell lines, one from a patient with larynx carcinoma (i.e., HEp-2 cells) and two from patients with gastric adenocarcinoma (i.e., AGS and MKN 28 cells), incubated with different H. pylori strains. The levels of cPLA2, mRNA, and protein expression were unchanged in Hep-2 cells independently of cellular adhesion or invasion of the bacteria. Moreover, no change in cPLA2 protein expression was observed in AGS or MKN 28 cells treated with wild-type H. pylori. In conclusion, our study shows increased cPLA2 expression and PLA2 activity in the gastric mucosae of patients with H. pylori infection and no change in epithelial cell lines exposed to H. pylori.

Adult↗
PubMed2001

Epiluminescence microscopy for port-wine stains: pretreatment evaluation.

BACKGROUND: Port-wine stains (PWSs) are characterized by an increased number of ectatic vessels. The treatment of choice is the use of some lasers such as pulsed dye lasers. However, some lesions are nonresponsive to laser treatment. Perhaps the vessels' depth and diameter and the thickness of the vessel wall are important factors influencing the effectiveness of the laser treatment. METHODS: To investigate whether epiluminescence microscopy (ELM) could be useful in determining the effectiveness of laser treatment of PWSs, we studied a group of patients with PWSs using both ELM and histological analysis. RESULTS: A correlation existed between a gray-whitish veil seen by ELM and the vessel depth judged by histology: when the veil was absent, the vessels were always found to be located only in the upper third of the dermis. CONCLUSION: We think that the gray-whitish veil is a distinctive dermoscopic feature that is able to differentiate between superficial vessels (absence of veil) and deeper vessels (presence of veil).

Adolescent↗
PubMed2001

Superficial black network: an additional dermoscopic clue for the diagnosis of pigmented spindle and/or epithelioid cell nevus.

Dermoscopy is a valuable method for improving the diagnostic accuracy of pigmented skin lesions. Specific dermoscopic criteria have been described for differentiating pigmented spindle and/or epithelioid cell nevi (SECN; Spitz nevi and Reed nevi) from cutaneous melanomas. In the present study, we report an additional dermoscopic feature of SECN, namely a distinctive type of pigment network, described as superficial black network, which was observed in 10.5% of SECN. Histopathologically, this network corresponds to focal areas of pigmented parakeratosis, producing a black reticulated appearance on the horizontal plane.

Adolescent↗
PubMed2001

DNA ploidy and cyclin D1 expression in basal cell carcinoma of the head and neck.

Basal cell carcinomas (BCCs) may be subdivided into primary with a favorable biologic course (BCC1) and recurrent and/or metastatic (BCC2). No clear association between primary tumor location, histologic subtype, or other clinicopathologic variables and predisposition for BCC2 has been found. Histopathologic criteria are limited for prognostication. To identify prognostic factors useful for planning therapy, we studied cyclin D1 immunohistochemical expression, DNA ploidy, and epiluminescence light microscopic (ELM) patterns in 60 cases of BCC (30 BCC1 and 30 BCC2) in the head and neck region, half of which were hyperpigmented. Cyclin D1 was absent in 27 cases, expressed at low level in 4 cases, and overexpressed in 30 cases. Seven BCCs were euploid, 28 exhibited a mixed cellular population, and 25 were aneuploid. Among aneuploid tumors, hypodiploidy was found in 12. Among the 30 pigmented carcinomas, only 15 showed a typical ELM pattern. No association between pigmentation and more aggressive biologic behavior of BCC was found. These results and follow-up data seem to indicate that an unfavorable outcome can be predicted by hyperexpression of cyclin D1, aneuploidy, and an atypical ELM pattern for pigmented cases. A definite hypodiploid peak was associated with worse prognosis. The analysis of cyclin D1 expression and DNA ploidy may help identify BCC with an aggressive phenotype and a poor clinical outcome.

Basal Cell Carcinoma↗
PubMed2001

P53 and hMSH2 expression in basal cell carcinomas and malignant melanomas from photoexposed areas of head and neck region.

Ultraviolet (UV) radiation plays a pivotal role in skin damage and photocarcinogenesis. The basic mechanism of phototoxicity lies in DNA damage, and involves mutation of tumor suppressor genes, oncogenes and genes directly involved in the control of the stability of genome, such as the mismatch repair (MR) genes. The goal of this study was to evaluate the role of p53 and hMSH2 in the UV-related carcinogenetic process. An immunohistochemical study for p53 and hMSH2 was performed in a series of 43 basal cell carcinomas (BCC) and 60 melanomas (MM) from photoexposed areas of head and neck region, comparing the findings with follow-up. A deregulated p53 expression characterized less differentiated, more aggressive BCC (BCC2) but not the well-differentiated ones (BCC1). The hMSH2 protein was present, though expressed at varying levels, in 18 out of 21 BCC1 cases and in 4 out of 22 BCC2. In the remaining 3 cases of BCC1 and 18 cases of BCC2, a complete absence of hMSH2 expression was found, correlating directly with the presence of recurrence and/or death of the disease in case of melanoma (p<0.05). Overall, the expression of hMSH2 correlated inversely with the p53 overexpression (p<0.01). In MM, p53 was found overexpressed in 81.6% of the cases, and this correlated positively with the level of infiltration and with the presence of relapses (p<0.01) or metastasis (p<0.01) and inversely with the disease-free interval (p<0.05). These results are in agreement with the reported association between p53 deregulation and a more aggressive cancer phenotype. The evaluation of the expression of p53 and hMSH2 could improve the management of patients with BCC and MM, and could have a role also in the evaluation of the early cutaneous photo-inducted damage, contributing to the identification of presymptomatic patients predisposed to the development of UV-related new skin tumors, who could become candidates for chemoprevention trials.

Adult↗
PubMed2000

Nuclear DNA content-derived parameters correlated with heterogeneous expression of p53 and bcl-2 proteins in clear cell renal carcinomas.

BACKGROUND: p53 and bcl-2 are two key genes involved in cell cycle and cell death regulation. Altered expression or mutation of these genes has been found in human cancers and also has been identified in clear cell renal carcinoma (RCC). Their role in RCC progression, however, is still unclear. By contrast, the prognostic significance of ploidy and S-phase fraction (SPF) have been studied extensively in RCC. To better characterize the biologic role of p53 and bcl-2 oncoproteins in RCC, we offer a multisample correlative analysis of the expression of these two proteins with ploidy and SPF. METHODS: Ploidy and SPF along with p53 and bcl-2 expression were analyzed in 296 specimens, selected by multiple sampling of 33 consecutive operable RCCs. The expression of p53 and bcl-2 proteins was studied by immunohistochemistry, and SPF and tumor ploidy were studied by flow cytometry. RESULTS: In our study, 4 of 32 (12.5%) were found to be diploid, and 28 of 32 (87.5%) cases showed an abnormal DNA content. Among the aneuploid tumors, 14 of 28 (50%) were multiploid. Heterogeneous DNA content was detected in 21 of 32 (65.6%) tumors and was correlated with the more advanced Robson stage tumor (P = 0. 03). Intratumor heterogeneity also was detected for p53 and bcl-2 protein expression. Expression of p53 protein correlated with the lack of bcl-2 protein expression (P = 0.0032), aneuploidy (P < 0. 0001), and high SPF (P = 0.0006), whereas bcl-2 expression was associated with a normal DNA content (P < 0.0001) and low SPF (P = 0. 035). CONCLUSIONS: Within each RCC, p53 and bcl-2 expression is markedly heterogeneous. Our results depicted a scenario in which bcl-2 protein, expressed by normal renal parenchyma, is still present in euploid cell clones of RCC but disappears during the progression of renal neoplasm toward a more aggressive phenotype characterized by overexpression of p53 protein, aneuploidy, and high SPF.

Adenocarcinoma, Clear Cell↗
PubMed2000

PCNA in the testis of the frog, Rana esculenta: a molecular marker of the mitotic testicular epithelium proliferation.

Proliferating cell nuclear antigen (PCNA) plays an essential role in nucleic acid metabolism as a component of the replication and repair machinery. This toroidal-shaped protein encircles DNA and can slide bidirectionally along the duplex. One of the well-established functions for PCNA is its role as the processing factor for DNA polymerase delta and epsilon. It has become apparent that PCNA interacts with proteins involved in the cell cycle. The PCNA interactions with different cellular proteins and the importance of these interactions are also discussed. To examine the different mitotic testicular epithelium proliferation during the annual discontinuous frog (Rana esculenta) spermatogenesis, the temporal and the spatial PCNA expression are described and give a useful endogenous molecular marker.

Animals↗
PubMed2000

Primary non-Hodgkin's lymphoma of the jaws: immunohistochemical and genetic review of 10 cases.

PURPOSE: Non-Hodgkin's lymphoma (NHL) comprises a group of malignant lymphoproliferative diseases characterized by clonal expansion of lymphocytes at various levels of ontogenetic development. The aim of this study was to review the immunohistochemical and cytogenetic features of 10 cases of NLH of the jaws to determine their respective derivation. PATIENTS AND METHODS: Histopathologic and immunohistochemical review of 10 cases of large-cell lymphomas of the jaws, together with Southern blot analysis of 2 of the cases, was performed and results compared with the findings in the literature. RESULTS: In the 10 cases studied, the average age of onset of the NHL was 51 years, with a male-to-female ratio of 3:2. Tumefaction was the first clinical sign of disease. Eight of 10 cases were high-grade, large-cell NHLs, centroblastic type. Two cases were high-grade, large-cell NHL, immunoblastic type. CONCLUSION: The immunohistochemical and Southern blot data remain the principal laboratory aids in the diagnosis and characterization of NHL, and they provide critical information for guiding clinicians to the appropriate treatment protocol for these malignancies.

Adult↗
PubMed2000

p53, cyclin-D1, PCNA, AgNOR expression in squamous cell cancer of the lip: a multicenter study.

BACKGROUND: The development of squamous cell carcinoma of the lower lip is an interesting model of photocarcinogenesis because of the structural and topographic characteristics of the lips. The purpose of this study was to evaluate the expression of immunohistochemical markers on the lips of patients with lower lip squamous cell carcinoma (LLSCC), compared with a control population. METHODS: Of the 98 subjects involved in the study, 58 were suffering from squamous cell carcinoma of the lower lip. The remaining 40 acted as a control. The case studies were taken from six university and hospital dermatology and plastic surgery departments. Questionnaires were administered to assess the risk factors for LLSCC. The cases involving squamous cell carcinoma underwent surgical excision and punch biopsy specimens were obtained from 20 control patients. Tissues were prepared in 5-microm-thick sections to carry out the following immunohistochemical study: PCNA, p53, AgNOR, cyclin-D1, bcl-2. RESULTS: The lower lip was the predominant location of squamous cell carcinoma, with the following factors playing important roles: chronic sun exposure, history of smoking, alcohol use and familial risk of cutaneous tumors. The male/female ratio in our survey was 5:1. The p53 protein was positive in approximately 50% of SCC cases and in 20% of controls. This protein is mostly associated with chronically photoexposed skin areas. AgNOR positivity increased with the loss of cellular differentiation; a progressive increase in size and a poorly defined shape were evident in poorly differentiated carcinomas. CONCLUSIONS: The results of this multicenter study showed that there is a noticeable difference in the expression of PCNA, p53, cyclin-D1, and AgNOR in tissues from patients with LLSCC and controls.

Aged↗
PubMed2000

Estradiol-induced mitogen-activated protein kinase (extracellular signal-regulated kinase 1 and 2) activity in the frog (Rana esculenta) testis.

Several lines of evidence support a key role of estradiol-17beta (E(2)) in male fertility. We have used a non-mammalian vertebrate model, the frog Rana esculenta, to investigate the regulation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) activity in the testis during the annual sexual cycle and to study whether E(2 )exerts a role in spermatogenesis through the regulation of ERK1/2 activity. ERK1/2 proteins are present in the cytoplasm and nucleus of the primary and secondary spermatogonia (SPG), and in the nucleus of primary spermatocytes. The annual E(2) profile shows a progressive increase during active spermatogenesis with a peak in the month of June. In parallel, ERK1/2 are highly phosphorylated during the period of active spermatogenesis (from April to July) compared with the regressive period (September/October) and winter stasis (from November to March). E(2) treatment induces the proliferation of primary SPG, possibly via the activation of ERK1/2, and this effect is counteracted by the anti-estrogen ICI 182-780.

Animals↗
PubMed1999

Modulation of in vivo growth of thyroid tumor-derived cell lines by sense and antisense vascular endothelial growth factor gene.

Vascular endothelial growth factor A (VEGF) is a potent mitogen for endothelial cells in vitro and promotes neo-angiogenesis in vivo. VEGF overexpression occurs in most human malignancies including thyroid carcinomas in which elevated VEGF expression is associated with a high tumorigenic potential. To investigate the role of VEGF in angiogenesis associated with development of thyroid carcinomas, we constitutively expressed VEGF121 into a poorly tumorigenic cell line (NPA) expressing minimal levels of endogenous VEGF. Here we report that VEGF overexpressing NPA cells showed the same growth potential as untransfected NPA in vitro but formed well-vascularized tumors when injected subcutaneously into nude mice with markedly reduced latency compared to parental cells. A complementary approach was to suppress VEGF expression in a highly tumorigenic anaplastic cell line (ARO) by the transfection of an antisense construct. Antisense-transfected ARO cells expressed reduced constitutive levels of VEGF, showed the same growth potential as untransfected ARO cells in vitro and formed small tumors characterized by minimal vascularization, extensive necrosis and longer latency compared to parental or vector-transfected ARO cells in vivo. Finally, we investigated the expression of both VEGF tyrosine kinase receptors (Flt-1 and Flk-1/KDR) in tumor specimens by RT - PCR. Expression of (Flt-1 and Flk-1/KDR) was low in tissue specimens derived from NPA tumors, but was found enhanced in NPA VEGF tumors; conversely, the expression of VEGF receptors was high in tissue specimens derived from ARO tumors but was decreased in tumors derived from VEGF depleted ARO cells. These results clearly demonstrate that VEGF indirectly promotes the growth of thyroid tumors by stimulating angiogenesis.

Animals↗
PubMed1999

Prognostic value of apoptotic index in cutaneous basal cell carcinomas of head and neck.

Basal cell carcinoma (BCC) is the most common type of human cancer, often locally invasive, and following a benign clinical course. However, a proportion of BCCs do recur after treatment, causing extensive local tissue destruction, seldom metastasizing. Morphological methods to unequivocally distinguish the aggressive forms of these tumors (BCC2) from the ordinary ones (BCC1) have so far been lacking. Apoptosis, or programmed cell death, is thought to be important for the death of tumor cells in various stages of carcinogenesis. We analyzed the extent of apoptosis in BCCs of head and neck in a morphological, morphometric, and electron-microscopic study, to estabilish on a retrospective basis, the relative frequency of recurrence of tumors showing different apoptotic rates. We found that BCC1 showed lower apoptotic index (AI) than BCC2 [BCC1: AI from 2.03 to 10.45% (mean value: 5.98%) BCC2: AI from 21. 91 up to 43.82% (mean value: 39.82%)]. The morphometric analysis of both BCC1 and BCC2 revealed significant differences between the values concerning nuclear area, length, perimeter, and roundness of the apoptotic cells with respect to the 'viable' neoplastic cells. Electron-microscopy confirmed that the features of morphological apoptotic cells were characteristic of programmed cell death. We hypothesized that low apoptotic rates in BCC1 could be indicative of a good prognosis. In fact, this corresponded to an 'expansive' but not still invasive neoplastic state. In this phase, however, the tumor cells may constitute the target for genetic changes triggered by enviromental physical or chemical mutagenic agents, such as UV rays. BCC2, then, could be the result of newly selected mutated neoplastic cellular clones, with more aggressive biological behavior. The high apoptotic level found in BCC2 could thus be used as an indirect alarm signal from pathologists. This hypothesis seems to be supported by most of the current data in the literature and by the clinical outcome of BCC2 of our series. In our opinion, routine evaluation of apoptosis in BCCs could be proposed to facilitate their sub-classification, contributing toward the evaluation of the prospective outcome of the individual patients.

Adult↗
PubMed1999

Dermatoscopic pitfalls in differentiating pigmented Spitz naevi from cutaneous melanomas.

Epiluminescence microscopy (ELM, skin surface microscopy, dermoscopy, dermatoscopy) is a valuable method for improving the diagnostic accuracy in pigmented skin lesions. Specific ELM criteria are already recognized for differentiating pigmented Spitz naevi (PSN) from cutaneous melanomas (CM). Our purpose was to describe the ELM appearance of a series of PSN with emphasis on PSN and CM with overlapping features. Thirty-six consecutive patients with PSN, and three cases of CM (selected from a larger database) exhibiting ELM 'spitzoid' features, were evaluated clinically, dermatoscopically and histopathologically. Most PSN (27 of 36; 75%) displayed two typical ELM patterns, namely, the starburst (19 of 36; 53%) or the globular pattern (eight of 36; 22%), which were correlated to different histopathological findings. In nine of 36 (25%) PSN, atypical ELM features which are more commonly seen in CM were observed. These PSN with an atypical pattern were characterized by an uneven distribution of colours and structures, and an irregular diffuse pigmentation resembling blue-white veil or irregular extensions (black blotches). These atypical lesions mostly occurred in children and showed no history of growth. In contrast, in three examples of CM, the typical ELM criteria of malignancy were less recognizable and either the characteristic starburst or globular pattern usually seen in PSN was present. These three lesions occurred in adults and had a recent history of change in colour, shape or size. The overlap in ELM features of some PSN and CM represents a major diagnostic pitfall when ELM examination is considered alone. In these atypical cases, clinical history including the age of the patient may be the only clue to enable a correct diagnosis.

Adolescent↗
PubMed1999

Potentially malignant and malignant lesions of the lip. Role of silver staining nucleolar organizer regions, proliferating cell nuclear antigen, p53, and c-myc in differentiation and prognosis.

The cellular changes leading to carcinoma of the lip are still not completely understood. This study was carried out on 44 malignant and potentially malignant lesions of the lower lip [30 squamous cell carcinomas (SCC), 7 actinic cheilitis, 3 leukoplakias, and 4 nodal metastases from lower lip SCC]. Silver-stained nucleolar organizer regions (AgNORs) and the immunohistochemical expression of proliferating cell nuclear antigen (PCNA), p53, and c-myc were evaluated on formalin-fixed, paraffin-embedded sections. The results indicate that the size and numbers of AgNORs and the percentage of PCNA-positive cells are sensitive parameters for discriminating between potentially malignant lesions and SCC, and for the prognostic sub-typing of lower lip SCC. Furthermore, while p53 positivity was found more frequently in high-grade carcinomas, p53-positive cellular clones were also found in some potentially malignant lesions, a finding probably related to ultraviolet-related cellular damage. These p53-positive lesions could be considered at higher risk of progression to malignancy than the p53-negative ones, although there is no evidence for this as yet. c-myc positivity was found only in some high-grade carcinomas and metastases, and appeared correlated with the later phases of lip carcinogenesis. The combined evaluation of the proliferation status, together with the changes in p53 and c-myc oncoproteins, might constitute useful markers for the prognostic evaluation of potentially malignant, as well as malignant, lesions of the lip.

Adolescent↗
PubMed1999

Effect of Helicobacter pylori infection and its eradication on cell proliferation, DNA status, and oncogene expression in patients with chronic gastritis.

BACKGROUND: Helicobacter pylori, the main cause of chronic gastritis, is a class I gastric carcinogen. Chronic gastritis progresses to cancer through atrophy, metaplasia, and dysplasia. Precancerous phenotypic expression is generally associated with acquired genomic instability. AIM: To evaluate the effect of H pylori infection and its eradication on gastric histology, cell proliferation, DNA status, and oncogene expression. METHODS/SUBJECTS: Morphometric and immunohistochemical techniques were used to examine gastric mucosal biopsy specimens from eight controls, 10 patients with H pylori negative chronic gastritis, 53 with H pylori positive chronic gastritis, and 11 with gastric cancer. RESULTS: All patients with chronic gastritis were in a hyperproliferative state related to mucosal inflammation, regardless of H pylori infection. Atrophy was present in three of 10 patients with H pylori negative chronic gastritis and in 26 of 53 with H pylori positive chronic gastritis, associated in 18 with intestinal metaplasia. DNA content was abnormal in only 11 patients with atrophy and H pylori infection; eight of these also had c-Myc expression, associated in six cases with p53 expression. Fifty three patients with H pylori positive chronic gastritis were monitored for 12 months after antibiotic treatment: three dropped out; infection was eradicated in 45, in whom cell proliferation decreased in parallel with the reduction in gastritis activity; atrophy previously detected in 21/45 disappeared in five, regressed from moderate to mild in nine, and remained unchanged in seven; complete metaplasia disappeared in 4/14, and markers of genomic instability disappeared where previously present. In the five patients in whom H pylori persisted, atrophy, metaplasia, dysplasia, and markers of genomic instability remained unchanged. CONCLUSIONS: Chronic H pylori infection seems to be responsible for genomic instability in a subset of cases of H pylori positive chronic atrophic gastritis; eradication of H pylori infection can reverse inflammation and the related atrophy, metaplasia, and genomic instability.

Adult↗