Reproducibility of the Oxford classification of immunoglobulin A nephropathy, impact of biopsy scoring on treatment allocation and clinical relevance of disagreements: evidence from the VALidation of IGA study cohort.

BACKGROUND: The VALidation of IGA (VALIGA) study investigated the utility of the Oxford Classification of immunoglobulin A nephropathy (IgAN) in 1147 patients from 13 European countries. Methods. Biopsies were scored by local pathologists followed by central review in Oxford. We had two distinct objectives: to assess how closely pathology findings were associated with the decision to give corticosteroid/immunosuppressive (CS/IS) treatments, and to determine the impact of differences in MEST-C scoring between central and local pathologists on the clinical value of the Oxford Classification. We tested for each lesion the associations between the type of agreement (local and central pathologists scoring absent, local present and central absent, local absent and central present, both scoring present) with the initial clinical assessment, as well as long-term outcomes in those patients who did not receive CS/IS. RESULTS: All glomerular lesions (M, E, C and S) assessed by local pathologists were independently associated with the decision to administer CS/IS therapy, while the severity of tubulointerstitial lesions was not. Reproducibility between local and central pathologists was moderate for S (segmental sclerosis) and T (tubular atrophy/interstitial fibrosis), and poor for M (mesangial hypercellularity), E (endocapillary hypercellularity) and C (crescents). Local pathologists found statistically more of each lesion, except for the S lesion, which was more frequent with central review. Disagreements were more likely to occur when the proportion of glomeruli affected was low. The M lesion, assessed by central pathologists, correlated better with the severity of the disease at presentation and discriminated better with outcomes. In contrast, the E lesion, evaluated by local pathologists, correlated better with the clinical presentation and outcomes when compared with central review. Both C and S lesions, when discordant between local and central pathologists, had a clinical phenotype intermediate to double absent lesions (milder disease) and double present (more severe). CONCLUSION: We conclude that differences in the scoring of MEST-C criteria between local pathologists and a central reviewer have a significant impact on the prognostic value of the Oxford Classification. Since the decision to offer immunosuppressive therapy in this cohort was intimately associated with the MEST-C score, this study indicates a need for a more detailed guidance for pathologists in the scoring of IgAN biopsies.

Syndecan-1, Epithelial-Mesenchymal Transition Markers (E-cadherin/ß-catenin) and Neoangiogenesis-related Proteins (PCAM-1 and Endoglin) in Colorectal Cancer.

The Syndecan-1 protein plays a crucial role in cell proliferation, cell adhesion, cell migration and angiogenesis and, at the same time, its co-expression with E-cadherin is regulated during epithelial-mesenchymal transition (EMT). In colorectal cancer (CRC), the expression of syndecan-1, E-cadherin/ß-catenin complex is frequently disturbed. Angiogenesis is critical for the growth and metastatic spread of tumors. In the present study, we focused on the expression of these biological molecules and their prognostic significance in human CRC. Formalin-fixed paraffin-embedded surgical specimens from 69 patients with CRC were immunostained for syndecan-1, E-cadherin, ß-catenin, endoglin (CD105) and CD31 (platelet cell adhesion molecule (PCAM-1)). A significant association was found between syndecan-1 with E-cadherin (p<0.0001), as well with ß-catenin (p<0.0001). High ß-catenin expression appeared to reduce the risk of poor outcome. Endoglin microvascular density (MVD) count was correlated significantly with Dukes' stage (p<0.0001), vessel invasion (p<0.0001), lymph node metastasis (p=0.039), liver metastasis (p<0.0001), recurrence of disease (p=0.010) and poor survival rate (p<0.0001). Endoglin tumor epithelial cell expression was associated with E-cadherin, ß-catenin and syndecan-1 (p=0.001, p=0.068 and p=0.005, respectively). In conclusion, changes in the pattern of expression of syndecan-1, EMT markers, E-cadherin/ß-catenin, in association with endoglin (CD105), may be involved in tumor progression and prognosis of CRC patients. Further studies are needed to clarify the interaction between these proteins and tumor initiation and progression.

Biomarkers of head and neck cancer, tools or a gordian knot?

Head and neck tumors comprise a wide spectrum of heterogeneous neoplasms for which biomarkers are needed to aid in earlier diagnosis, risk assessment and therapy response. Personalized medicine based on predictive markers linked to drug response, it is hoped, will lead to improvements in outcomes and avoidance of unnecessary treatment in carcinoma of the head and neck. Because of the heterogeneity of head and neck tumors, the integration of multiple selected markers in association with the histopathologic features is advocated for risk assessment. Validation of each biomarker in the context of clinical trials will be required before a specific marker can be incorporated into daily practice. Furthermore, we will give evidence that some proteins implicated in cell-cell interaction, such as CD44 may be involved in the multiple mechanism of the development and progression of laryngeal lesions and may help to predict the risk of transformation of the benign or precancerous lesions to cancer.

Pleomorphic hepatocellular carcinoma following consumption of hypericum perforatum in alcoholic cirrhosis.

Hepatocellular carcinoma (HCC) often develops in patients with underlying liver disease, yet HCC with syncytial giant cells (SGCs) is extremely rare. Herein, we report a 55-year-old man with a 6-year history of alcoholic cirrhosis who during his regular checkup presented with marked elevation of alpha-fetoprotein. Clinical examination and imaging analyses revealed a tumor-like lesion in segment 4 of the liver, which was removed by limited wedge resection. Histological analysis by hematoxylin and eosin staining indicated pleomorphic and atypical nodules, with some SGCs, embedded within the boundaries of the neoplastic lesion. The adjacent liver parenchyma showed microvesicular steatosis, pericellular fibrosis, and moderate hemosiderin accumulation (grade 2, as determined by Prussian blue iron stain) in hepatocytes and Kupffer cells but no copper accumulation (as determined by orcein stain). Immunohistochemical analysis showed hepatocyte antigen-positive staining for the neoplastic cells and SGCs. The diagnosis was made for cirrhosis-related HCC with SGCs. The previous reports of pleomorphic HCC have featured osteoclast-like (i.e., mesenchymal type) giant cells, making this case of epithelial type giant cells very rare. The patient's 6-month history of hypericum perforatum/St John's wort self-medication may have prompted the cirrhosis or HCC progression or the unusual SGC manifestation.

Spinal cord early ischemic preconditioning activates the stabilized fraction of ß-catenin after thoracoabdominal aortic occlusion in pigs.

BACKGROUND: Paraplegia after thoracoabdominal aortic surgery is a devastating complication attributed to motor neurons loss and dysfunction, due to spinal cord ischemia. ß-Catenin is a protein that has been associated with cell survival and healing and many studies have correlated this protein with late ischemic preconditioning (IPC). Herein we investigate the potential contribution of ß-catenin in an early IPC animal model, and its relationship with heat shock protein 70 (Hsp70), suggesting a possible role of this protein as a first window of protection. METHODS: A total of 42 pigs were used in an experimental thoracoabdominal aortic occlusion model. Twelve animals were used for neurologic evaluation and were randomly assigned to 2 groups (A and B). The remaining 30 animals were used in experiments for biologic measurements and innunohistochemical studies, and were randomly assigned to 5 groups (1-5). Western blotting analysis and immunoprecipitations were performed to study the levels of ß-catenin and its binding relationship with Hsp70. The cellular distribution of ß-catenin at various time-points was investigated by immunohistochemical studies. RESULTS: According to neurologic evaluation, the animals in the IPC+ischemia group had significantly better neurologic scores compared with those in the ischemia group, indicating a protective role for IPC. The biologic measurements demonstrated a significant (P=0.03) increase in ß-catenin levels and translocation of the protein in the nucleus at the end of ischemic preconditioning. CONCLUSIONS: Our results suggest a significant role of ß-catenin in early IPC protection of spinal cord after thoracoabdominal occlusion, as IPC seems to trigger the activation of the ß-catenin stabilized fraction and, thus, its survival pathway.

Predictive role of thymidine phosphorylase expression in patients with colorectal cancer and its association with angiogenesis-related proteins and extracellular matrix components.

BACKGROUND: Thymidine phosphorylase (TYMP) is an angiogenic factor that has potent chemotactic activity for endothelial cells and is involved in 5-fluorouracil (5-FU) metabolism. In colorectal cancer (CRC), previous studies evaluating the relationship between TYMP expression and clinicopathological features have yielded inconsistent results. The aim of this study was to investigate the prognostic value of TYMP, its association with other angiogenic factors, proliferation markers and, to our knowledge, for the first time its relationship with extracellular matrix components. MATERIALS AND METHODS: Formalin-fixed, paraffin-embedded specimens from 97 patients with CRC were immunostained for TYMP, vascular endothelial growth factor (VEGF), microvascular density (CD34), proliferation marker (Ki-67), proliferating cell nuclear antigen (PCNA), p53 oncoprotein and extracellular matrix components (collagen type IV, fibronectin, tenascin and laminin). Survival curves were calculated with the Kaplan-Meier method. RESULTS: Immunoreactivity was observed in the cytoplasm (cyt) and nucleus (n) of the tumor cells, as well in the stroma (st), endothelium and tumor-associated macrophages. High TYMPcyt expression was observed in 7.2% of the cases, moderate in 22.7% and weak in 59.9%, while 10.3% were negative. High TYMPst expression was observed in 58.8% of the cases. TYMPcyt expression was correlated with the VEGF expression of tumor cells and VEGF expression of vessels (p=0.014 and p=0.022, respectively). TYMPst expression was correlated with VEGF expression and tenascin (p=0.014 and p=0.011, respectively). Patients with higher TYMPcyt expression had a more favorable overall survival (p=0.041) in univariate analysis compared to patients without TYMP expression. CONCLUSION: These findings suggest that TYMP plays an important role in angiogenesis, extracellular matrix remodeling and in the prognosis of patients with CRC, but further studies are needed to clearly define its role in CRC.

Association of syndecan-1 with angiogenesis-related markers, extracellular matrix components, and clinicopathological features in colorectal carcinoma.

Syndecan-1 is a transmembrane heparansulfate proteoglycan, which regulates cell proliferation, migration, angiogenesis, cell-to-cell and cell-to-extracellular matrix adhesion and may influence malignant cell behavior. We investigated the alterations of syndecan-1 expression in colorectal cancer and analyzed the relationship between clinicopathological parameters, proliferation indices, angiogenic markers, and extracellular matrix components. Syndecan-1 protein expression observed in the tumorous epithelium was high in 52/97 (53.6%) of the studied cases, moderate in 20/97 (20.6%), and weak in 5/97 (5.22%) of the cases, and there was strong stromal expression in 34.02% of the tumors. Syndecan-1 expression was statistically correlated to VEGF expression in tumor (p=0.001) and vessels (p=0.007). In addition, there was a borderline correlation between syndecan-1 expression and tenascin (p=0.053). Patients with weak staining reaction had a more unfavorable prognosis (p=0.032) in univariate analysis. These results indicate the implication of syndecan-1 in the remodeling and angiogenesis of colorectal cancer tissue, through interaction with other extracellular matrix components and VEGF, probably influencing the tumor progression and aggressiveness.

Immunohistochemical study of the epithelial-mesenchymal transition phenotype in cancer of unknown primary: incidence, correlations and prognostic utility.

BACKGROUND: The epithelial to mesenchymal transition (EMT) has been associated with metastatic dissemination and poor outcome in several solid tumour types. Our aim was to study its incidence and its prognostic significance in cancer of unknown primary (CUP). PATIENTS AND METHODS: One hundred tumour samples of CUP were loaded in tissue microarrays and were studied for immunohistochemical (IHC) expression of E-cadherin, N-cadherin, vimentin, the EMT transcription factor (SNAIL) and the stem cell marker octamer-binding transcription marker 4(OCT4). An EMT phenotype was defined as low expression of E-cadherin, expression of N-cadherin with/without vimentin with concomitant expression of SNAIL, as assessed by percentage of tumour cell staining. RESULTS: Among 100 CUP cases, the histological diagnosis was adenocarcinoma in 55, squamous carcinoma in 20 and undifferentiated carcinoma in 15, with a high grade seen in 46. Therapy consisted of palliative chemotherapy, mostly platinum based. The median progression-free survival and overall survival (OS) were 7 and 12 months respectively. Distributional studies resulted in selection of IHC cut-offs for E-cadherin (negative when expressed in <60% of tumour cells), N-cadherin, vimentin (positive when expressed in ≥40% of tumour cells), SNAIL (positive when stained in ≥80% of tumour cells). An EMT phenotype was observed in 8 cases (8.1%) and was strongly associated with poor OS (median OS EMT(-)=13 months vs. median OS EMT(+)=8 months, p=0.023). When we used staining intensity (H-Score), an EMT phenotype was observed in 16 patients and carried borderline adverse prognostic utility for outcome (median OS 9 vs. 14 months, p=0.07). The presence of the EMT phenotype correlated significantly with male gender, high grade and presence of visceral metastases (χ(2) p<0.05), while EMT mediator expression was correlated to high NOTCH 2/3 expression. Other factors, prognostic for poor survival, were male gender, PS≥2, non-platinum therapy (χ(2) p<0.05). CONCLUSION: EMT is infrequently seen in tumours of CUP. However, an adverse prognostic significance for patient outcome has been identified and may warrant studies of therapeutic targeting.

Expression of organic anion-transporting polypeptides 1B3, 1B1, and 1A2 in human pancreatic cancer reveals a new class of potential therapeutic targets.

BACKGROUND: Organic anion-transporting polypeptides (OATPs) are influx transporters that mediate intracellular uptake of selective endogenous and xenobiotic compounds. Identification of new molecular targets and discovery of novel targeted therapies is top priority for pancreatic cancer, which lacks any effective therapy. MATERIALS AND METHODS: We studied expression of OATP 1A2, 1B1, and 1B3 in pancreatic cancer tissue and in cell lines. Formalin-fixed paraffin-embedded biopsy material of 12 human pancreatic cancers was immunohistochemically assessed for protein expression of the three studied influx transporters. Immunohistochemistry was evaluated by experienced pathologists and quantified by use of an automated image analysis system. BxPC-3 and MIA PaCa-2 pancreatic cancer cell lines were used to quantify transcripts of OATP 1B1 and 1B3. RESULTS: OATP 1A2, 1B1, and 1B3 proteins were found ubiquitously expressed in all studied cases. Quantification performed by HistoQuest system revealed that mean intensity was 53 for 1A2, 45 for 1B1, and 167 for OATP 1B1/1B3 on a range scale 0-250 units. At mRNA level, 1B1 and 1B3 were overexpressed in both studied cancer cell lines but not in normal pancreatic tissue. CONCLUSION: OATPs 1A2, 1B1, and 1B3 are highly expressed in pancreatic adenocarcinoma. We suggest that expression of these transporters in pancreatic cancer justify research efforts towards discovery of novel therapeutics targeting OATPs.

Findings of an experimental study in a rabbit model on posterior capsule opacification after implantation of hydrophobic acrylic and hydrophilic acrylic intraocular lenses.

PURPOSE: Study on cell growth on the posterior capsule after implantation of hydrophobic acrylic (Acrysof SA 60 AT) and hydrophilic acrylic (Akreos Disc) intraocular lenses (IOL) in a rabbit model and comparison of posterior capsule opacification (PCO). METHODS: Phacoemulsification was performed in 22 rabbit eyes, and two different IOL types (Acrysof SA60 AT and Akreos Disc) were implanted. These IOLs had the same optic geometry (square edged) but different material and design. Central PCO (CPCO), peripheral PCO (PPCO), Sommering's ring (SR) formation, type of growth, extension of PCO, cell type, inhibition, and fibrosis were evaluated three weeks after surgery. Histological sections of each globe were prepared to document the evaluation of PCO. RESULTS: No statistically significant difference was observed between a hydrophobic acrylic IOL and a hydrophilic acrylic IOL in relation to the CPCO, PPCO, type of growth, extension, cell type, inhibition, and fibrosis. Statistically significant difference was observed in relation to the formation of SR with Acrysof SA 60 AT group presenting more SR than Akreos Disc group. CONCLUSION: PCO was not influenced by the material of the IOL or the design of the haptics of the IOLs we studied.

The lipophilic extract of Hypericum perforatum exerts significant cytotoxic activity against T24 and NBT-II urinary bladder tumor cells.

Hypericum perforatum L. (St. John's wort) is a medicinal plant used for many pathologies, especially for the treatment of mild to moderate depression. In the present study we have investigated the cytotoxic activity of the locally collected (Epirus region) Hypericum perforatum L. against cultured T24 and NBT-II bladder cancer cell lines. The lipophilic extract of the herb, prepared using petroleum ether, induced apoptosis displaying LC(50) values at concentrations as low as 4 and 5 microg/mL. A fraction of this extract displayed 60 % cell growth inhibition at a concentration of 0.95 microg/mL. Evaluating the importance of various biologically active components of the extract, it was found that hypericins (hypericin, pseudohypericin, etc.) were identified only in the methanolic (lipophobic) extract of the herb, and not in the active lipophilic extract. In addition, hyperforin concentrations in the lipophilic extract and its most active fraction, were 0.94 microg/mL, and 0.17 microg/mL, respectively, while the active cytotoxic concentration of pure hyperforin appeared in the range of 1.8 microg/mL - 5.0 microg/mL. Therefore, pure hyperforin does not seem to contribute significantly to the cytotoxicity activity. Chlorophylls were identified in low, not significantly different, concentrations in all extracts and fractions and were not correlated to the biological activity. Owing to the combination of significant cytotoxic activity, natural abundance and low toxicity, the lipophilic extract of Hypericum perforatum holds the promise of being an interesting, new, antiproliferative agent against bladder cancer that deserves further investigation.

Inflammatory bowel disease-related dysplasia and cancer: A referral center study in northwestern Greece.

BACKGROUND: An increased risk of colorectal cancer in ulcerative colitis (UC) and Crohn's disease (CD) has been reported. No data on inflammatory bowel disease (IBD)-related dysplasia and cancer is available in Greece, where the disease profile seems to be milder than that of northern Europe. METHODS: A study was conducted of 215 IBD patients (182 with UC, 33 with CD) from a referral center. Patients were followed up for 3-18 years. The prevalence of cancer and dysplasia among the IBD patients who were diagnosed in northwestern Greece was analyzed and registered. Statistical analysis was performed assuming that this IBD cohort had the same risk of developing malignancies as the general population in Greece. RESULTS: Six of the 215 patients in this IBD cohort had cancer, and 20 of 126 patients for whom bowel biopsies were available had dysplasia. Three of these cases were high-grade dysplasia. There was no significant difference in the numbers of calculated and expected cases of IBD-related cancer at any sites except for the skin [2.7 vs. 2.0]. CONCLUSIONS: This IBD cohort did not appear to have an increased risk of cancer during the time period studied. It would be interesting to re-assess the risk after the second and third decades of follow-up.

A clinicopathological study of the expression of extracellular matrix components in urothelial carcinoma.

OBJECTIVE: To measure the immunohistochemical expression of the extracellular matrix (ECM) components tenascin, fibronectin, collagen type IV and laminin in urothelial carcinomas, and to correlate their expression with clinicopathological features to clarify the prognostic value of these molecules and their role in tumour progression. MATERIALS AND METHODS: Tumour specimens obtained during transurethral resection of bladder tumour (TURBT) from 103 patients (82 men and 2 1 women, mean age 66.7 years, range 27-89) were studied retrospectively. The expression of tenascin, fibronectin, collagen type IV and laminin was correlated with clinicopathological features (tumour grade and stage, multiplicity, simultaneous in situ component, the proliferative activity as estimated by the two proliferation associated indices, Ki-67 and proliferating cell nuclear antigen, the recurrence rate, and the progression of invading tumour). Specimens investigated for tenascin expression from patients with superficial bladder cancers were categorized into 28 treated by TURBT only and 53 who had TURBT followed by intravesical instillations of interferon. RESULTS: Cytoplasmic tenascin expression was detected in tumour cells in 20% of specimens. Tenascin was expressed in the tumour stroma in 76% of specimens, and was positively correlated with tumour grade and stage. Stromal tenascin expression was positively correlated with proliferative activity, and with the expression of fibronectin and collagen type IV. Fibronectin was expressed in the tumour stroma in 89% of specimens and was positively correlated with tumour stage, proliferative activity, and expression of collagen type IV and laminin. Collagen type IV was expressed in 93% of specimens, and was positively correlated with tumour grade and stage. Laminin was expressed in 78% of specimens and had no significant correlation with the clinicopathological features. Patients treated with TURBT alone and who had low levels of tenascin had a longer tumour-free interval than those with high levels of tenascin. CONCLUSION: Levels of tenascin might be valuable for predicting the risk of early recurrence. The expression of tenascin, fibronectin and collagen type IV seems to be correlated with more aggressive tumour behaviour. Furthermore, their interrelationships could indicate that they are involved in the remodelling of bladder cancer tissue, probably influencing tumour progression.

Immunohistochemical expression of cyclin D1, cyclin E, p21/waf1 and p27/kip1 in inflammatory bowel disease: correlation with other cell-cycle-related proteins (Rb, p53, ki-67 and PCNA) and clinicopathological features.

BACKGROUND AND AIMS: The expression patterns of cyclins D1 and E as well as cyclin-dependent kinase inhibitors p21/waf1 and p27/kip1 and their correlation with clinical parameters and other cell cycle regulators was investigated in inflammatory bowel disease (IBD). PATIENTS AND METHODS: These molecular markers were localized immunohistochemically using the monoclonal antibodies anti-cyclin D1 (DCS-6), anti-cyclin E (13A3), anti-p21 (4D10) and anti-p27 (1B4) in 70 patients with IBD, 30 patients with colorectal cancer and eight healthy subjects. Data were analyzed statistically using the software program. RESULTS: Cyclin D1 expression was higher in both UC and CD compared with the healthy control group. In addition, CD cyclin D1 expression was higher compared with UC cases and colorectal carcinomas. Cyclin D1 expression was correlated with disease activity and cell proliferation in UC cases. A positive relationship of cyclin D1 with p27/kip1 in both UC and CD was detected. Cyclin E expression was higher in UC, CD and carcinomas compared with healthy control group and its expression correlated with proliferative activity in both UC and CD cases. p21/waf1 expression was higher in IBD cases compared with that of the control group, while a decreased p21/waf1 expression in the group of carcinomas was noted. This expression was correlated with disease activity in UC and the proliferative activity in both UC and CD. The expression of cyclins D1 and E as well as p21/waf1 was also correlated with the existence of dysplastic lesions. A lower p27/kip1 expression in the group of carcinomas compared with IBD cases and healthy controls was found. CONCLUSIONS: The expression patterns of cyclin D1, cyclin E, p21/waf1 and p27/kip1 in IBD may indicate their contribution in epithelial cell turnover and their possible implication in IBD-related dysplasia-carcinoma.

Immunohistochemical study of apoptosis-related Bcl-2 protein and its correlation with proliferation indices (Ki67, PCNA), tumor suppressor genes (p53, pRb), the oncogene c-erbB-2, sex steroid hormone receptors and other clinicopathological features, in normal, hyperplastic and neoplastic endometrium.

The bcl-2 gene codes for a protein which functions to inhibit apoptotic cell death, that involves an intrinsic normal cell death program. Bcl-2 overexpression was originally described in a follicular lymphoma, but more recently bcl-2 expression has been observed in a variety of other human neoplasms. Variation in the frequency of apoptosis in hormone-sensitive tissues, such as the endometrium, is known to occur as a result of hormonal changes in both physiological and pathological circumstances. In this study we examined bcl-2 protein expression in a total of 170 samples of endometrial tissues (18 proliferative endometrium, 14 secretory endometrium, 35 adenomatous hyperplasia and 103 carcinomas). The results were compared with p53, pRb and c-erbB-2 proteins expression, estrogen and progesterone receptors status, with the proliferative activity and with clinicopathological features. The expression of bcl-2 protein was lower in the group of carcinomas, when compared with the cases of adenomatous hyperplasia (p < 0.0001), normal proliferative (p < 0.0001) and secretory endometrium (p = 0.07). In normal proliferative endometrium bcl-2 expression was correlated with PCNA (p = 0.026) and in secretory endometrium it was correlated with ER status (p = 0.042). In hyperplasias, bcl-2 was correlated with PCNA (p = 0.019) and the PR (p = 0.007) expression. In carcinomas, decreased bcl-2 expression was associated with increased tumor grade (p = 0.04). A positive relationship between bcl-2 expression and pRb, as well as PCNA score (p = 0.014 and p = 0.001, respectively), was also found. These results indicate that bcl-2 expression may play a role in the inhibition of apoptosis in endometrial carcinoma and its expression seems to be associated with tumor differentiation and cell proliferation.

Orbital metastasis from prostatic carcinoma.

A rare case of orbital metastasis from carcinoma of the prostate in a 76-year-old man who presented with pain in his left eye, mild proptosis and reduced visual acuity is reported. Cranial CT scanning demonstrated large bone metastases in the left orbit. The patient underwent orbital evisceration. The histopathological studies that were based on the morphological and immunohistochemical findings confirmed the histological diagnosis of orbital metastasis arising from prostatic carcinoma with neuroendocrine features.

Localization of an alkyl-acetyl-glycerol-CDP-choline: cholinephosphotransferase activity in submitochondrial fractions of Tetrahymena pyriformis.

Tetrahymena pyriformis contains platelet-activating factor (PAF) as a minor lipid, which is biosynthesized de novo. A dithiothreitol-insensitive CDP-choline:cholinephosphotransferase (AAG-CPT), which utilizes alkyl-acetyl-glycerol as a substrate, had been detected in both the mitochondrial and microsomal fractions of the protozoan. In the present report, localization of this enzyme in submitochondrial fractions was studied. Cell fractionation was evaluated with enzyme and morphological markers. In this respect, succinate dehydrogenase, NADPH:cytochrome c reductase, glucose-6-phosphatase, alkaline phosphatase, monoaminoxidase, and cytochrome c oxidase activities were investigated. In the presence of antimycin A, mitochondrial activity of NADPH-cytochrome c reductase, was increased, while the microsomal one was reduced. Cardiolipin was distributed in the inner mitochondrial membrane. Alkaline phosphatase was found exclusively in the cytosol of the protozoan. The main portion of the dithiothreitol-insensitive AAG-CPT was localized in the inner mitochondrial membrane. Our data indicate that mitochondria are able to produce PAF, which might be associated with their function.

Immunohistochemical HLA-DR antigen expression with lymphocyte subsets and proliferative activity in pterygium.

The immunohistochemical expression of HLA-DR antigen, CD8, CD4, CD68, S1OO, PCNA and Ki-67 was performed in order to investigate the role of immune mechanisms in pterygium, in correlation with proliferative activity. A series of 98 surgically-excised pterygia, 18 pingueculae and 20 normal conjunctivae, was studied by the avidin-biotin method, on formalin-fixed, paraffin-embedded tissue. HLA-DR antigen was abundantly expressed in pterygium epithelial cells, whereas almost no expression was found in pinguecula and normal conjunctiva. A high value of Ki-67 and PCNA expression coexisted in the same areas with HLA-DR antigen expression in pterygium and a statistically significant positive correlation resulted between them (p = 0.002). Aberrant infiltration of inflammatory cells (CD4, CD8, CD68, S100) was detected in pterygium, while lower densities were found in pinguecula and conjunctiva. The data suggest that immunopathological mechanisms may contribute in the pathogenesis of pterygium. In addition, the aberrant HLA-DR antigen expression seems to be correlated with the growth fraction of the lesion.

Heterotopic neo-osteogenesis from vascularized periosteum and bone grafts.

BACKGROUND: Periosteum is an osteogenic, flexible tissue. This study investigated the osteogenic potential of vascularized periosteal flaps in heterotopic conditions and compared it to the neo-osteogenesis from vascularized periosteal flaps combined with bone grafts with different properties (autologous and xenograft). METHODS: Vascularized periosteal flaps from the hindlimbs of 48 rabbits formed cylindrical pouches that were buried in muscles. The pouches were filled with autologous bone grafts (P/A group, n = 16), xenograft (P/X group, n = 16), or left empty (P/E group, n = 16). Specimens were harvested between 1 and 4 months and underwent radiographic, histologic, and histomorphometric evaluation. RESULTS: The total surface area was larger in the groups combined with bone grafts. Osseous apposition did not differ significantly in the P/A and P/X groups (p > 0.05). The central cavity contained hematopoietic cells (P/A), xenograft (P/X), or was absent (P/E). CONCLUSION: Vascularized periosteal flaps presented strong osteogenic capacity in heterotopic conditions. Combination with bone grafts resulted in larger specimens. The quality of neo-osteogenesis was not influenced by the different properties of combined bone grafts.