miR-221/222 overexpession in human glioblastoma increases invasiveness by targeting the protein phosphate PTPµ.

Glioblastoma is the most frequent brain tumor in adults and is the most lethal form of human cancer. Despite the improvements in treatments, survival of patients remains poor. In order to identify microRNAs (miRs) involved in glioma tumorigenesis, we evaluated, by a miRarray, differential expression of miRs in the tumorigenic glioma LN-18, LN-229 and U87MG cells compared with the non-tumorigenic T98G cells. Among different miRs we focused our attention on miR-221 and -222. We demonstrated the presence of a binding site for these two miRs in the 3' untranslated region of the protein tyrosine phosphatase µ (PTPµ). Previous studies indicated that PTPµ suppresses cell migration and is downregulated in glioblastoma. Significantly, we found that miR-221 and -222 overexpression induced a downregulation of PTPµ as analyzed by both western blot and real-time PCR. Furthermore, miR-222 and -221 induced an increase in cell migration and growth in soft agar in glioma cells. Interestingly, the re-expression of PTPµ gene was able to revert the miR-222 and -221 effects on cell migration. Furthermore, we found an inverse correlation between miR-221 and -222 and PTPµ in human glioma cancer samples. In conclusion, our results suggest that miR-221 and -222 regulate glioma tumorigenesis at least in part through the control of PTPµ protein expression.

Classification of oligodendroglial tumors based on histopathology criteria is a significant predictor of survival--clinical, radiological and pathologic long-term follow-up analysis.

BACKGROUND: The clinical course of oligodendroglial tumors is variable and there is a lack of consensus with regard to precisely diagnose which minimal criteria are required to make a diagnosis of a high-grade oligodendrial tumor. The aims of the present study are to assess pathologic factors with prognostic significance, in addiction to clinical and neuroradiologic variables, in an attempt to identify reproducible histological parameters that are useful for classification of oligodendroglial tumors. METHODS: 80 oligodendroglial tumors diagnosed between 1977 and 2004 were analyzed. To make a diagnosis of anaplastic tumor we used reproducible parameters: endothelial proliferation, high cellularity, increased mitotic activity and necrosis. Oligoastrocytomas (mixed gliomas) were diagnosed when the astrocytic component was clearly identified as part of the neoplastic cell population. Survival univariate analysis was made constructing survival curves using Kaplan-Meier method and comparing subgroups by log-rank probability test. A Cox regression model was made for multivariable analysis. RESULTS: The histologic diagnosis was low-grade oligodendroglioma in 35 patients (43.75%), anaplastic oligodendroglioma in 23 patients (28.75%), low-grade oligoastrocytoma in 11 patients (13.75%) and anaplastic oligoastrocytoma in 11 patients (13.75%). Median overall survival of the whole series was 80 months. The median overall survival of oligodendroglioma, anaplastic oligodendroglioma, oligoastrocytoma and anaplastic oligoastrocytoma was 148, 105, 47 and 7 months, respectively (p < 0.0001). Multivariate analysis revealed that age, Karnofsky performance status, histological grade and histological diagnosis (oligodendroglioma vs. oligoastrocytoma) were independently associated with survival. CONCLUSIONS: Clear cut histopathological criteria (endothelial proliferation, high cellularity, mitotic activity and necrosis) allow to establish different oligodendroglial tumor entities with distinct survival outcome.

[Eccrine gland adenocarcinoma of the eyelid]. / Adenocarcinoma de glándulas ecrinas de los párpados.

PURPOSE/METHODS: Ocular adnexal malignant tumors with eccrine differentiation represent a rare group of neoplasms with a great invasive capacity. Authors present clinical findings in an eighty five years old patient who developed a progressive painless induration of both eyelids in his right eye. RESULTS/CONCLUSIONS: Microscopic examination of biopsy specimen suggested a primary eccrine sweat glands carcinoma of the eyelids after a thorough search for tumors. We also describe the surgical technique used for this treatment, as well as the current supportive therapies for these kinds of tumors.

Adenocarcinoma de glándulas ecrinas de los párpados / Eccrine sweat glands carcinoma of the eyelid

Objetivo/métodos: Los tumores malignos de anejos oculares con diferenciación ecrina constituyen un raro grupo de neoplasias con gran capacidad infiltrativa. Los autores presentan los hallazgos clínicos y curso evolutivo en un paciente de 85 años que debutó con una induración indolora y progresiva de ambos párpados del ojo derecho. Resultados/conclusiones: El estudio histopatológico de la biopsia sugirió el diagnóstico de adenocarcinoma de glándulas ecrinas de párpado, aceptándose su origen primario al no evidenciarse otras tumoraciones en el rastreo sistémico. Se describe además, la técnica quirúrgica utilizada para su tratamiento, así como las terapias adyuvantes actuales para este tipo de tumores (AU)

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Melanoma del borde libre del párpado: manejo clínico y estudio onco-patológico / Melanoma of the eyelid margin: clinical management and oncopathological survey

Objetivo/Métodos: Presentamos el caso de un paciente varón de 57 años con una tumoración muy pigmentada del borde libre del párpado superior del ojo derecho, de dos meses de evolución, que tras su escisión y estudio anatomopatológico resultó ser un melanoma nodular. Resultados/Conclusiones: Exponemos el tratamiento y manejo clínico de esta infrecuente patología, así como las diferencias en cuanto a su localización en el párpado, y por tanto de cara al pronóstico, que se plantean entre ésta y otras formas de presentación (AU)

Linfoma de la zona marginal de conjuntiva: características clínico-patológicas / Conjunctival marginal zone lymphoma: clinical and pathological features

Objetivo/métodos: Presentamos el caso de una mujer de 66 años con una tumoración rosada en la conjuntiva bulbar temporal del ojo izquierdo de 7 meses de evolución, sin respuesta al tratamiento tópico instaurado. Se realizó biopsia y estudio inmunohistoquímico para confirmar el diagnóstico. Resultados/conclusiones: La biopsia mostró un linfoma B de bajo grado compatible con linfoma de la zona marginal, correspondiente a la antigua denominación de linfoma derivado del 'tejido linfoide asociado a mucosas' (MALT). Los linfomas conjuntivales no son frecuentes y la mayoría son linfomas de la zona marginal. Es importante su diferenciación de otros linfomas de anejos oculares por su baja asociación con enfermedad extraocular y su pronóstico más favorable (AU)

p27KIP1 is abnormally expressed in Diffuse Large B-cell Lymphomas and is associated with an adverse clinical outcome.

Cell cycle progression is regulated by the combined action of cyclins, cyclin-dependent kinases (CDKs), and CDK-inhibitors (CDKi), which are negative cell cycle regulators. p27KIP1 is a CDKi key in cell cycle regulation, whose degradation is required for G1/S transition. In spite of the absence of p27KIP1 expression in proliferating lymphocytes, some aggressive B-cell lymphomas have been reported to show an anomalous p27KIP1 staining. We analysed p27KIP1 expression in a series of Diffuse Large B-cell Lymphoma (DLBCL), correlating it with the proliferative index and clinical outcome, to characterize the implications of this anomalous staining in lymphomagenesis in greater depth. For the above mentioned purposes, an immunohistochemical technique in paraffin-embedded tissues was employed, using commercially available antibodies, in a series of 133 patients with known clinical outcomes. Statistical analysis was performed in order to ascertain which clinical and molecular variables may influence outcome, in terms of disease-free survival (DFS) and overall survival (OS). The relationships between p27KIP1 and MIB-1 (Ki-67) were also tested. An abnormally high expression of p27KIP1 was found in lymphomas of this type. The overall correlation between p27KIP1 and MIB-1 showed there to be no significant relationship between these two parameters, this differing from observations in reactive lymphoid and other tissues. Analysis of the clinical relevance of these findings showed that a high level of p27KIP1 expression in this type of tumour is an adverse prognostic marker, in both univariate and multivariate analysis. These results show that there is abnormal p27KIP1 expression in DLBCL, with adverse clinical significance, suggesting that this anomalous p27KIP1 protein may be rendered non-functional through interaction with other cell cycle regulator proteins.

Anomalous high p27/KIP1 expression in a subset of aggressive B-cell lymphomas is associated with cyclin D3 overexpression. p27/KIP1-cyclin D3 colocalization in tumor cells.

p27 cyclin-dependent kinase inhibitor downregulation is essential for transition to the S phase of the cell cycle. Thus, proliferating cells in reactive lymphoid tissue show no detectable p27 expression. Nevertheless, anomalous high p27 expression has been shown to be present in a group of aggressive B-cell lymphomas with high proliferation index and adverse clinical outcome. This suggests that abnormally accumulated p27 protein has been rendered functionally inactive. We analyzed the causes of this anomalous presence of p27 in a group of aggressive B-cell lymphomas, including 54 cases of diffuse large B-cell lymphomas and 20 Burkitt's lymphomas. We simultaneously studied them for p27, cyclin D3, cyclin D2, cyclin D1, and cyclin E expression, because it has been stated that high levels of expression of cyclin D1 or E lead to increased p27 levels in some cell types. A statistically significant association between p27 and cyclin D3 expression was found for the group as a whole. Additionally, when dividing the cases according to the level of expression of cyclin D3 by reactive germinal centers, it was observed that cases with stronger cyclin D3 expression also show higher p27 expression. The relationship between both proteins was also shown at a subcellular level by laser confocal studies, showing that in cases with high expression of both proteins there was a marked colocalization. Additional evidence in favor of p27 sequestration by cyclin D3 was provided by coimmunoprecipitation studies in a Burkitt's cell line (Raji) showing the existence of cyclin D3/p27 complexes and the absence of CDK2/p27 complexes. These results could support the hypothesis that there are cyclin D3/p27 complexes in a subset of aggressive B-cell lymphomas in which p27 lacks the inhibitory activity found when it is bound to cyclin E/CDK2 complexes. This interaction between both proteins could lead to an abnormal nuclear accumulation, detectable by immunohistochemical techniques.

Loss of p16 protein expression associated with methylation of the p16INK4A gene is a frequent finding in Hodgkin's disease.

p16 protein binds and inactivates cyclin D-CDK4/6 complexes, stopping the cell cycle at the G1/S boundary. Loss of p16 expression is found frequently in human cancer tissues, often resulting from allelic loss or promoter region hypermethylation in non-Hodgkin's lymphomas. Hodgkin's disease has been shown to be a monoclonal neoplasm of B-cells in which a majority of cells are cycling. In the attempt to identify hypothetical CDK inhibitor inactivation that could explain the accumulation of proliferating cells, we decided to focus on the p16INK4A gene. To determine whether inactivation of this gene is implicated in the development of Hodgkin's disease, we immunostained 40 cases with a monoclonal antibody for the p16 protein. At the same time, we used a methylation-specific PCR technique to determine the methylation status of exon 1 of the p16INK4A gene in 23 cases in this series. Loss of p16 expression was found in 30 of 37 cases (absence of expression in most Hodgkin's/Reed-Sternberg cells, with a normal scattered pattern of p16 expression in the reactive background). Only seven samples showed nuclear p16 expression in a significant proportion of large tumoral cells. In agreement with this finding, hypermethylation of p16INK4A gene was found in 14 of 23 cases by PCR. All the p16 cases found positive by immunohistochemistry also showed unmethylated DNA. These results show that loss of p16 protein expression is usually observed in Hodgkin's/Reed-Sternberg cells in Hodgkin's disease, frequently associated with p16INK4A gene hypermethylation. The high frequency of abnormal methylation found in this study suggests that this genetic event may play an important role in the pathogenesis of the disease.

Oncogene expression in tumour cells of pediatric Hodgkin's disease in Argentina--correlation with Epstein Barr virus presence.

A new category of oncogenes regulating apoptosis, p53 and bcl-2, and the Epstein Barr virus (EBV) latent membrane protein-1 (LMP-1) have been related to Hodgkin's disease (HD) pathogenesis. We attempt to determine p53, mdm2, p21waf-1, bcl-2 and LMP-1 immunohistochemical expression in tissue sections from formalin-fixed, paraffin-embedded lymph node biopsies of pediatric HD. P53 was detected in the nucleus of Reed Sternberg cells and their variants (H-RS) in 68% of the HD cases. However, there was no statistically significant association with either clinical stages or with histological subtypes. P21waf-1, an indirect marker of p53 functional status, showed nuclear labelling of H-RS in all the studied cases. MDM2 co-expressed with p53 in 62% of the cases, suggesting that both proteins regulate one another, in HD by a self regulatory loop. Bcl-2 cytoplasmatic expression in H-RS was demonstrated in 65% of the cases. There was co-expression of bcl-2 and p53 in 51%, but it failed to correlate with a poor prognosis. LMP-1 labelling was shown in 51% of the cases, disclosing a statistically significant association with the under 6-year group (p = 0.005, Fisher's exact test). Since LMP-1 induces the expression of bcl-2 in vitro, the relation of both proteins was analysed and found to co-express in 15/37 cases, with a statistically significant association only in the under 6-year group (p = 0.001, Fisher's exact test). Abnormal accumulation of these oncoproteins in tumour cells could play a role in the pathogenesis of a subset of pediatric HD.

Clinical outcome in diffuse large B-cell lymphoma is dependent on the relationship between different cell-cycle regulator proteins.

PURPOSE: The goal of this work was to perform a comprehensive exploration of the relationship between the clinical outcome of diffuse large B-cell lymphoma (DLBCL) and the expression of a panel of tumor suppressor and oncogenic proteins, which includes some cell-cycle regulator proteins involved in the p53 pathway. PATIENTS AND METHODS: To this end, we collected the clinical data of 141 patients with DLBCL and immunohistochemically analyzed diagnostic tumoral tissue from each patient for the presence of Ki67 (MIB1, Immuno-tech, Marseille, France), bcl2, p53, p21/WAF1, MDM2, and retinoblastoma (Rb) proteins. RESULTS: The results show that several proteins are associated with some of the clinical traits analyzed. Multivariate analysis showed that an extended overall survival (OS) time was associated with low growth fraction, high Rb protein, and low MDM2 expression, as well as with known clinical parameters. The probability of inducing a complete remission (CR) was only associated with clinical parameters, although univariate study showed that a low growth fraction was associated with a higher probability of inducing a CR. Univariate study of disease-free survival (DFS) showed that tumors with high bcl2 expression and nodal origin have a shorter DFS time, although multivariate study only confirmed the adverse effect of bcl2 expression. CONCLUSION: Taking all these results into consideration, it seems that although the overall outcome for patients with DLBCL is decided by a combination of different clinical and biologic variables, the expression of some of these cell-cycle regulator proteins appears to be specifically associated with the different clinical features of tumors.

Cyclin-dependent kinase inhibitor p27KIP1 in lymphoid tissue: p27KIP1 expression is inversely proportional to the proliferative index.

Cell cycle progression is regulated by the combined action of cyclins, cyclin-dependent kinases (CDKs), and CDK inhibitors (CDKIs). p27KIP1, which has a high degree of similarity with p21WAF1, is a general CDKI thought to be involved in G1 arrest in response to agents that inhibit cell cycle progression. The aims of this study were 1) to establish the pattern of expression of p27KIP1 protein in nontumor lymphoid tissue, 2) to determine whether p27KIP1 is involved in lymphomagenesis, and 3) to address the possible relationship between p27KIP1 and p21WAF1 expression in reactive and tumor lymphoid tissue. p27KIP1 protein was found to be mainly present in quiescent lymphocytes in reactive lymphoid tissue as well as in peripheral blood lymphocytes, with an inverse expression for p27KIP1 and Ki-67 proteins. The same p27KIP1 expression pattern was observed in lymphomas, independently of histological type; small resting cells were p27KIP1 positive, and large proliferating cells were p27KIP1 negative. Therefore, tumors with a low proliferative index were mostly positive, whereas tumors characterized by a higher growth fraction bad low p27KIP1 protein levels. An unexpected finding was the existence of a group of six cases of high-grade lymphomas (three diffuse large B-cell lymphomas and three Burkitt's lymphomas) with homogeneously strong staining for p27KIP1 protein. All 6 of these cases belong to a group of 28 cases characterized by blockage of the p53 tumor suppressor pathway, as determined by genetic (p53 mutation) or immunophenotypic studies (p53+/p21-). p27KIP1 expression was not seen in any case of aggressive non-Hodgkin's lymphoma with an intact p53 pathway. The results indicate that p27KIP1 is down-regulated in lymphomas with a high proliferative index, although it is highly expressed in high-grade lymphomas with defects in the p53 pathway.

Anomalous retinoblastoma protein expression in Sternberg-Reed cells in Hodgkin's disease: a comparative study with p53 and Ki67 expression.

Retinoblastoma (Rb) tumour-suppressor protein plays a critical role in cell cycle control. Rb inactivation is a frequent phenomenon in tumours of different cell lineages, in which the absence of Rb protein has been considered to be a marker of Rb disregulation. We used modern immunohistochemical techniques to study the expression of Rb protein in a large series of 130 patients with Hodgkin's disease. Simultaneously, Western blot was used to analyse a more restricted group (12 patients) to confirm the immunohistochemical results and to clarify the phosphorylation status of Rb protein. As the level of Rb expression varied according to cell cycle stage, we also performed immunostaining for Ki67, a protein present in proliferating cells. To make comparison possible, we first characterised the amount and phosphorylation status of Rb protein in reactive lymphoid tissue and phytohaemagglutinin (PHA)-stimulated lymphocytes. The presence of p53 in Sternberg-Reed cells was also included in the study, as both proteins (p53 and Rb) have been found to be closely associated in cell cycle control. PHA-stimulated peripheral blood lymphocytes showed a parallel increase in Rb and cell cycle progression, together with progressive Rb phosphorylation. In reactive lymphoid tissue there was also a clear correlation between Rb expression and the Ki67 proliferation index (R = 0.96, P = 0.038). When analysing Hodgkin's disease samples, a clear difference emerges between cases of nodular lymphocyte predominance, which preserve the relationship between Rb and Ki67 expression (r = 0.8727, P = 0.000), and classical forms of Hodgkin's disease (nodular sclerosis and mixed cellularity), which display a strong deviation from this pattern. Two main anomalies were found: (1) One group of 21/130 cases with partial or total loss of Rb protein expression, which could reflect the existence of genetic alterations, or an altered transcriptional or translational regulation of Rb gene. (2) Another group with an abnormally high Rb/Ki67 ratio, which could support conflicting interpretations: (i) excess Rb protein for controlling cell cycle progression; or (ii) adhesion of Rb protein to other cellular or viral proteins, such as p53 and MDM2. The results of this study indicate an anomalous pattern of expression of Rb in classical forms of Hodgkin's disease, and suggest the possibility of undertaking functional studies (E1A adhesion, p16 expression) with the aim of better characterising the status of Rb protein, and correlating these findings with clinical course in Hodgkin's disease patients.

MDM2 and p21WAF1/CIP1, wild-type p53-induced proteins, are regularly expressed by Sternberg-Reed cells in Hodgkin's disease.

Mutations in the p53 tumour suppressor gene are the most common genetic alteration found in human cancers. Most of them are accompanied by stabilization of the protein, which renders it detectable through immunohistochemical techniques. Although p53 expression is a very common finding in Hodgkin's disease (HD), the status of the p53 gene is scarcely known, due to the difficulty in sequencing this gene in a lesion in which tumour cells are thought to constitute a very minor subpopulation, diluted in a background of supposedly benign cells. The pattern of expression of two downstream p53 proteins (MDM2 and p21 WAF1/CIP1, was studied as an indirect way of assessing p53 gene status. MDM2 is a wild-p53 inducible protein which may form a complex with p53, abrogating its function, as has been found in human sarcomas and other malignancies. p21WAF1/CIP1 is another protein inducible by wild-type p53, involved in inhibiting cell-cycle progression, through binding to cyclin/cyclin-dependent-kinase complexes. MDM2 and p21WAF1/CIP1 immunostaining was detected in all the cases analysed, independently of histological type, and were mainly present in Sternberg-Reed and Hodgkin (H & SR) cells. These immunohistochemical results were confirmed by Western blotting. To study the cause of MDM2 protein accumulation, MDM2 mRNA expression was also investigated by reverse transcription polymerase chain reaction (RT-PCR). The results show the presence of MDM2 transcripts in all cases of HD, albeit at lower levels than those found in reactive lymphoid tissue. These results seem to support the hypothesis that p53 is transcriptionally active in at least some of the H & SR cells in HD, and is able to induce MDM2 and p21WAF1/CIP1 protein expression.

p53 and bcl-2 expression in high-grade B-cell lymphomas: correlation with survival time.

B-cell high-grade lymphomas are heterogeneous in terms of histology, clinical presentation, treatment response and prognosis. As bcl-2 and p53 gene deregulations are frequently involved in several types of lymphoid malignancies, we aimed our investigation at the study of the relation between bcl-2 and p53 expression and survival probability in a group of 119 patients with B-cell high-grade lymphoma. These were obtained from the Virgen de la Salud Hospital, Toledo, Spain (73 cases), John Radcliffe Hospital, Oxford, UK (31 cases), and the Istituto Nazionale dei Tumori, Milan, Italy (15 cases). The relation between bcl-2 protein expression and survival was small, depending on the primary localisation of the tumour (in lymph node of mucosae), and lacked a significant correlation with overall survival. In contrast with this, p53 expression was related to survival probability in our series, this relation being both significant and independent of histological diagnosis. p53-positive patients showed a sudden decrease in life expectancy in the first months after diagnosis. Multivariant regression analysis confirmed that the only parameters significantly related with survival were extranodal origin, which is associated with a better prognosis, and p53 expression, which indicates a poor prognosis. Simultaneous expression of bcl-2 and p53 was associated with a poorer prognosis than p53 alone. This is particularly significant for large B-cell lymphomas presenting in lymph nodes. The cumulative poor effect of both p53 and bcl-2 in large B-cell lymphomas, which is more significant in nodal tumours, could confirm the existence of a multistep genetic deregulation in non-Hodgkin's lymphoma. This indicates that the genetic mechanisms controlling apoptosis and their disregulation are critical steps in the progression of lymphomas.

[Outbreak of rubella in Puerto de Santa María (Cádiz)]. / Estudio de un brote de rubéola en el Puerto de Santa María (Cádiz).

OBJECTIVE: To find the frequency of cases of German measles and its spread according to the variables of age, gender, the position regarding vaccination and time; to identify groups at risk in line with the above variables and find out how efficacious vaccination is. DESIGN: Crossover, descriptive study. SETTING: Catchment area of the Pinillo Chico Health Centre in Puerto de Santa María (Cádiz). PATIENTS AND OTHER PARTICIPANTS: Between March and June, 1991, there was an outbreak of 175 cases of German measles in our catchment area. We included in the study 149 of these, for whom an epidemiological index card had been filled out. Cases were defined in line with the CDC criteria of a probable or confirmed case. The frequency of cases for the different groups were calculated and compared using the Chi squared test. MAIN MEASUREMENTS AND RESULTS: More than 95% of those affected were aged between 15 months and 26 years (average age 13). There were only significant gender differences, in proportion to the general population, for the 9 to 11 age-group for girls and 12 to 16 for boys. The frequency of cases was significantly greater in males than in females in the 12 to 16 and 17 to 21 age-groups (p < 0.05); and in females than males in the 9 to 11 group (p < 0.05). The frequency of cases between those vaccinated and those not vaccinated also showed significant differences for all the age and gender groups (p < 0.05). Efficacy of vaccination was 81.51%, being over 70% in all age groups. CONCLUSIONS: Studying outbreaks at the Primary Care level assists the identification of susceptible groups and planning of a course of action.

Model system for optimising mRNA non-isotopic in situ hybridisation: riboprobe detection of lysozyme mRNA in archival gut biopsy specimens.

The aim of this study was to optimise conditions for mRNA detection by nonisotopic in situ hybridisation (NISH) using biotinylated and digoxigenin labelled riboprobes. Because lysozyme gene transcripts are present at high concentrations in Paneth and other alimentary cells, archival gut biopsy specimens were chosen as a model system for these experiments. Most of the variables in NISH, from unmasking of mRNA, to its ultimate detection by peroxidase or alkaline phosphatase based detection systems, were examined in detail. The most important findings were that simultaneous heating of tissue targets and riboprobes at 95 degrees C for 15 minutes before hybridisation at 50 degrees C for two hours gave the most intense signal for lysozyme mRNA in Paneth cells, Brunner's glands, and lamina propria macrophages; digoxigenin labelled riboprobes gave a higher signal to noise ratio than their biotinylated counterparts, and probes 600 base pairs long were superior to shorter probes. It is concluded that the mRNA NISH method may be generally useful for detecting gene transcription in archival clinical biopsy specimens.

Beneficial effect of fibronectin administration on chronic nephritis in rats.

We studied the effect of fibronectin (FN) on the course of chronic nephritis (induced by daily injections of ovalbumin) and on the clearance and catabolism of immune complexes in Wistar rats. Rats with chronic nephritis were treated with FN (2.5 mg/kg/48 hours) for 15 days after proteinuria was first detected. In rats with untreated nephritis, urinary protein levels increased from 40 +/- 22 mg/day (mean +/- SD) to 339 +/- 68 mg/day during the 15 days of the study (P less than 0.0005). This statistically significant increase was not observed in rats treated with FN (mean +/- SD 58 +/- 46 mg/day to 124 +/- 112 mg/day). Rats treated with FN showed a higher total serum protein level than did the untreated animals (mean +/- SD 6.4 +/- 0.3 gm/dl versus 5.1 +/- 0.5 gm/dl; P less than 0.0125), as well as a significant reduction in mesangial and glomerular basement membrane deposits. Untreated nephritic rats demonstrated delayed plasma clearance of 125I-labeled aggregated IgG (plasma half-life [T1/2] 3.03 +/- 0.6 minutes) and less catabolism of these aggregates at 30 minutes (mean +/- SD 15 +/- 1.7%) than did the normal rats (T1/2 1.5 +/- 0.2 minutes, 22 +/- 2.8%, respectively; P less than 0.0005). Both parameters were within normal limits in the FN-treated rats (T1/2 1.6 +/- 0.4 minutes, 22 +/- 6%, respectively). In vitro, FN induced a significant increase in aggregated IgG catabolism by Kupffer cells and peritoneal macrophages from normal rats. These results show that FN reduces the proteinuria and histologic lesions of chronic nephritis in rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Interstitial mononuclear cell infiltrates in experimental nephrosis: effect of PAF antagonist.

Rats receiving a single injection of either aminonucleoside of puromycin (PAN, 10 mg/100 g) or Adriamycin (ADR, 7.5 mg/kg) develop heavy proteinuria and tubulointerstitial nephritis. Interstitial mononuclear cells were markedly more intense in PAN- than in ADR-treated rats. The composition of cell infiltrates was characterised in frozen kidney sections using an immunoperoxidase staining method and a panel of specific monoclonal antibodies. The severe mixed cellular lesions observed in the PAN model on day 14 were dominated by ED1+ macrophages, OX6+ Ia-interstitial and OX8+ T-cytotoxic/suppressor cell surface markers. A similar but more discrete ADR-interstitial cell accumulation was observed on day 11 of the experiment. A correlation existed in the PAN model between the severity of interstitial nephritis and the degree of proteinuria. In contrast, there was no such correlation in ADR nephrosis. Administration of PAF antagonist (BN 52021), started on the first day and continued throughout the 4 weeks of the experiment, induced in both ADR and PAN-treated rats a partial reduction in the number of interstitial cell infiltrates. Glomeruli from normal control rats incubated with 3H acetate, substrate for lyso-PAF: acetyl-CoA acetyltransferase and ADR stimulated PAF generation. Although the precise mechanism of interstitial cell accumulation in these two models of nephrosis are still unknown, our results suggest that PAF could be an important factor involved in interstitial cell recruitment.

Mesangial proliferative glomerulonephritis with unusual intramembranous granular dense deposits.

We have studied two patients with histories of upper respiratory tract infection. Hematuria and proteinuria were the presenting renal symptoms in one patients and an acute nephritic syndrome in the other. Serological findings disclosed depression of total hemolytic complement activity with low levels of C3 and the presence of C3Nef activity. Light microscopy showed diffuse mesangial cell proliferation. By immunofluorescence, diffuse deposits of C3 were found in the glomeruli. Ultrastructural studies revealed segmental thickening of the glomerular basement membrane due to the deposition of granular electron-dense deposits in a laminar pattern. We suggest that our cases may represent a variant of hypocomplementemic glomerulonephritis or perhaps the early stages of dense deposit disease.