Nickel Catalyzed Olefin Oligomerization and Dimerization.

Brought to life more than half a century ago and successfully applied for high-value petrochemical intermediates production, nickel-catalyzed olefin oligomerization is still a very dynamic topic, with many fundamental questions to address and industrial challenges to overcome. The unique and versatile reactivity of nickel enables the oligomerization of ethylene, propylene, and butenes into a wide range of oligomers that are highly sought-after in numerous fields to be controlled. Interestingly, both homogeneous and heterogeneous nickel catalysts have been scrutinized and employed to do this. This rare specificity encouraged us to interlink them in this review so as to open up opportunities for further catalyst development and innovation. An in-depth understanding of the reaction mechanisms in play is essential to being able to fine-tune the selectivity and achieve efficiency in the rational design of novel catalytic systems. This review thus provides a complete overview of the subject, compiling the main fundamental/industrial milestones and remaining challenges facing homogeneous/heterogeneous approaches as well as emerging catalytic concepts, with a focus on the last 10 years.

Prospective analysis between the therapy of immunosuppressive medication and allogeneic microchimerism after liver transplantation.

After liver transplantation, migration of donor-derived hematopoietic cells to recipient can be detected in peripheral blood. This state is termed microchimerism. The aim of this study was to investigate prospectively the presence of allogeneic microchimerism, the occurrence of acute cellular rejection and the level of immunosuppression in transplanted patients. Microchimerism occurrence between 10 days and 12 months after liver transplantation was analyzed in 47 patients aged between 15 and 65 by a two-stage nested PCR/SSP technique to detect donor MHC HLA-DR gene specifically. A pre-transplant blood sample was collected from each patient to serve as individual negative control. Microchimerism was demonstrated in 32 (68%) of the 47 patients; of these, only 10 patients (31.2%) presented rejection. Early microchimerism was observed in 25 patients (78.12%) and late microchimerism in 7 patients (21.8%). Among the patients with microchimerism, 14 were given CyA and 18 were given FK506. In the group without microchimerism, 12 patients were given CyA and 03 were given FK506. There was a significant association between the presence of microchimerism and the absence of rejection (p=0.02) and also between microchimerism and the type of immunosuppression used. Our data indicate that microchimerism and probably differentiation of donor-derived leukocytes can have relevant immunologic effects both in terms of sensitization of recipient and in terms of immunomodulation toward tolerance induction.

[Behavioral group-based therapy improves quality of life in men recovering from radical prostatectomy]. / Terapia grupal de comportamiento mejora la calidad de vida en hombres post prostatectomía radical.

BACKGROUND: This study evaluated the efficacy of 24-week, group-based, behavioral therapy in improving quality of life (QoL) among men treated for localized prostate carcinoma (PC) by means of radical prostatectomy (RP) who presented treatment-related dysfunctions: urinary incontinence (UI) and erectile dysfunction (ED). PATIENTS AND METHODS: Thirty men were assigned to 24-week behavioral group therapy. The intervention was designed to improve QoL by helping participants to identify and effectively manage stressful experiences. It focused on treatment-related sequelae from PC. Differences in variables were compared between the beginning and end of the study by means of Student's t test for paired samples. Multiple analysis was carried out by stepwise multiple linear regression following bivariate Pearson's correlation analysis. This was achieved for all predictors (i.e. general health perception, ED and UI impact) and relevant covariates (i.e. age, work/retirement status, alcohol addiction, attitude towards cancer and surgery, sexual satisfaction, and future plans). RESULTS: In all patients the time elapsed from surgery to attending the behavioral group therapy exceeded 24 months. There was no significant correlation between this time and the predictor variables. General health perception scores decreased by the end of the study (p = 0.000), as did the UI impact score (p = 0.023), thus denoting improvement in both factors. The difference in UI impact scores correlated negatively and significantly with both age (p = 0.04) and work/retirement (p = 0.05). Multiple stepwise regression showed that age was the most important variable (r2 = 26.0%). Considering age and work/retirement simultaneously, there was an increase of 10.3% (r2 = 36.3%). ED increased by the end of the study (p = 0.000), and the difference between the ED scores correlated positively and significantly with sexual satisfaction alone (p = 0.029), which signifies that previous sexual satisfaction had a positive influence over erectile dysfunction (r2 = 15.8%). CONCLUSION: 24-week behavioral group therapy was effective in improving the perceived QoL among men treated for PC. There were changes associated with the therapy, particularly the improvement in UI and ED.

Prospective evaluation of rapid point-of-care tests for the diagnosis of acute leptospirosis in dogs.

The early diagnosis of acute leptospirosis is still a major challenge in dogs. The aim of this prospective study was to evaluate the suitability of two in-clinic tests detecting anti-leptospiral IgM and IgG antibodies in diagnosing canine leptospirosis. The performances of the two rapid tests were compared to the microscopic agglutination test (MAT) carried out on acute sera and to diagnostic criteria adopted in this study to confirm leptospirosis infection (MAT upon admission, convalescent MAT and quantitative real-time PCR on blood and/or urine). The dogs were enrolled on the basis of reported exposure to known risk factors and clinical presentation (acute kidney injury and/or systemic inflammatory response syndrome with multi-organ damage). Eighty-nine dogs included in the study were sub-grouped on the basis of the results of the diagnostic criteria adopted: (1) confirmed leptospirosis cases (42/89 dogs); (2) negative leptospirosis cases (36/89 dogs); and (3) unconfirmed leptospirosis cases (11/89 dogs). The results supported the usefulness of the two rapid diagnostic tests as a first in-clinic screening tool for suspected leptospirosis; positive results in the in-clinic tests in dogs with suggestive clinical and laboratory signs strongly indicated acute leptospirosis, while negative results required additional diagnostic investigation to exclude the infection. Confirmatory tests recommended for canine leptospirosis are still necessary in addition to the use of rapid in-clinic tests.

Allelic frequencies of the 35delG mutation of the GJB2 gene in different Brazilian regions.

Mutations in the GJB2 gene, which encodes the protein connexin 26, are a major cause of autosomal recessive deafness. The most frequent mutation, 35delG, has a carrier frequency as high as 4% in some countries, and this frequency varies in different ethnic groups. Most of the Brazilian population results from interethnic crosses of people from three continents (European, African, and Amerindian), and the proportion of each varies according to the geographical region of the country. To verify if the different ethnic composition of Brazilian regions leads to variable 35delG carrier frequencies, we performed the screening of the 35delG mutation using DNA from dried-blood filter paper samples obtained from 1,856 newborns from 10 cities in different regions. The 35delG mutation was found in 25 individuals (1.35%), indicating an overall carrier frequency of 1:74. This frequency was 1:47 in the north, 1:64 in the southeast, 1:85 in the south and 1:124 in the northeast, but these differences were not significant. The overall frequency of the 35delG allele was estimated as 0.0067, and comparison between expected and observed genotype frequencies indicates that the population is in Hardy-Weinberg equilibrium.

Molecular mechanisms associated with donor-specific microchimerism in peripheral blood of Brazilian patients after liver transplantation.

A large number of studies in liver transplantation have demonstrated allogeneic microchimerism. The clinical and immunologic implications of this finding remain inconclusive, just as the influence of HLA mismatch and donor alloreactivity also are controversial. The present study analyzed the presence of allogeneic microchimerism in liver transplant recipients in relation to donor leukocyte kinetics and rejection episodes. The study was extended to determining the influence of immunogenetic factors in patients after liver transplantation. The presence of allogeneic microchimerism was analyzed on peripheral blood of 50 recipients. DNA extracted from the samples was subjected to typing for HLA-DRB1 and -DQB1 alleles by polymerase chain reactions using sequence-specific primers (PCR/SSP). Microchimerism was identified by nested PCR/SSP. Microchimerism was detected in 72% of patients. There was significant effect of microchimerism on rejection episodes (P=.002), while HLA mismatches did not show significance for one or two mismatches (P=.98). Allogeneic microchimerism detected in the majority of liver transplant patients was observed to be significantly associated with rejection episodes.

Urinary tract involvement in EEC syndrome: a clinical study in 25 Brazilian patients.

We have evaluated 25 patients (14 isolated and 11 familial cases) with the EEC syndrome for genitourinary (GU) tract anomalies through intravenous pyelogram (IVP), voiding urethrocystography, and sonographic examination. Fifty-two percent of the patients (7 isolated and 6 familial cases) had involvement of the urinary tract, with no significant difference between isolated and familial cases. The present data seem to reflect the best estimate of the prevalence of genitourinary anomalies in patients with the EEC syndrome.

Serum leptin levels after bariatric surgery across a range of glucose tolerance from normal to diabetes.

BACKGROUND: A longitudinal, clinical intervention study with bariatric surgery was done to investigate the relationship between leptin levels, BMI, and insulin during weight loss across a range of glucose tolerance from normal to diabetes. METHODS: 43 morbidly obese patients (BMI: 42-75 kg/m2) undergoing vertical banded gastroplasty Roux-en-Y gastric bypass (VBG-RGB), were divided into 3 groups: 21 normal (NGT), 12 impaired glucose tolerance (IGT) and 10 type 2 diabetes (DM). Leptin, insulin, glucose, lipids and uric acid were measured at baseline and 2, 4, 6, and 12 months following surgery. RESULTS: BMI fell from 54.1 +/- 9.1 to 34.6 +/- 6.3 kg/m2, similarly in all groups. Leptin decreased from 73.9 +/- 8.7 to 16.9 +/- 10.2 ng/ml and was strongly correlated with BMI during 1-year follow-up (r = 0.78; p < 0.001). Linear univariate analysis for repeated evaluation showed a positive correlation between leptin and glucose, triglycerides, uric acid, and insulin. Multivariate regression analysis indicated that BMI was independently correlated with the decrease in leptin (p < 0.001), accounting for 66% of the variance in leptin levels during weight loss. These results were found in the NGT and IGT groups. In the DM group, a small additional influence in leptin levels was attributed to glucose decrease. CONCLUSIONS: A strong link between leptin and BMI was found after surgery. BMI was the main determinant of the decrease of leptin. In these patients submitted to bariatric surgery, ranging from normal glucose tolerance to diabetes, changes in insulin levels and metabolic parameters, except for glucose in the DM group, did not appear to be correlated with changes in leptin levels.

The value of PCNA and AgNOR staining in endoscopic biopsies of gastric mucosa.

The aim of the present study was to examine the usefulness of the quantification of PC10-positive-cells and of Argyrophilic Nucleolar Organizer Regions (AgNORs) in gastric biopsies for the identification of gastric mucosal proliferative lesions. Fifty seven paraffin-embedded endoscopic biopsies were classified into four histologic groups: normal, inflammatory, dysplastic and neoplastic mucosa. The percentage of PC10-positive cells was determined by immunohistochemistry. The AgNOR parameters determined included the total number of all identifiable silver precipitations in the nucleus, the mean number of silver precipitations per cluster, and the presence of morphologically heterogenous silver precipitations. Group comparisons were performed using the Kruskall Wallis and Dunn non-parametric tests with a significance level of 5%. A discriminant analysis (followed by the jack-knife procedure) was performed using the three AgNOR parameters plus the percentage of PCNA-positive cells as the independent variables and histological groups as the dependent variable. All three AgNOR parameters, as well as the percentage of PCNA-stained nuclei, showed their highest values in the carcinoma group. However, no good differentiation among the four histologic groups was obtained using only one of these parameters, since there was always considerable overlap among them. By combining all the parameters in a linear discriminant analysis, we obtained a correct classification in 48 out of 57 cases. Within the classification errors there was only one false positive carcinoma, which was in fact a dysplasia and only one false negative carcinoma erroneously classified as dysplasia. The number of cells with heterogenous AgNORs was the most important parameter for the discriminant analysis. No correlation between PCNA values and the AgNOR parameters could be found, thus indicating that they do not represent the same phenomenon in the cell cycle. We concluded that the use of a combination of various proliferation parameters in a linear discriminant analysis may be helpful for differentiating gastric mucosal lesions. The peculiar AgNOR morphology is an important variable which should be taken in consideration in quantitative studies. PCNA and AgNORs seem to represent different physiological phenomena in the cell cycle.

Prostate elastosis: a microscopic feature useful for the diagnosis of postatrophic hyperplasia.

BACKGROUND: Elastosis of the prostate may be seen on needle biopsy and radical prostatectomy specimens, but its significance is unknown. Prostatic atrophy (or postatrophic hyperplasia) is one of the most frequent mimics of prostatic adenocarcinoma. OBJECTIVE: To observe the frequent occurrence of elastosis of the prostate stroma in areas of postatrophic hyperplasia. DESIGN: A step-section method was used to cut the posterior lobe (or peripheral zone) in coronal planes at intervals of 0.3 to 0.5 cm in 100 consecutive autopsy specimens of men older than 40 years. Elastosis was detected because of a basophilic tinge of the stroma on hematoxylin-eosin stain and confirmed using elastic fiber stains. Presence of elastosis correlated with the following variables: age, prostatic atrophy (simple, hyperplastic, or sclerotic), local arteriosclerosis, histologic carcinoma, high-grade prostatic intraepithelial neoplasia, benign or malignant nephrosclerosis, generalized atherosclerosis, nodular prostatic hyperplasia, and acute inflammation. For statistics, a stepwise linear regression method adjusted for age was used. RESULTS AND CONCLUSIONS: Elastosis was found in 65 of the prostates examined and was significantly more frequent with increasing age (P <.001), prostatic atrophy (P <.001), and local arteriosclerosis (P <.02). There was no significant relation to histologic carcinoma, high-grade prostatic intraepithelial neoplasia, benign or malignant nephrosclerosis, generalized atherosclerosis, nodular prostatic hyperplasia, and acute inflammation. The correlation with local arteriosclerosis favors a possible role of ischemia to its etiopathogenesis. The absence of correlation to neoplastic and preneoplastic lesions and the striking spatial relationship of elastosis to prostatic atrophy (or postatrophic hyperplasia) add a new microscopic feature for the diagnosis of this latter lesion, helping in the differential diagnosis with prostate adenocarcinoma.

Cerebral atrophy related to corticotherapy in systemic lupus erythematosus (SLE).

The aim of this study was to evaluate the frequency and intensity of cerebral atrophy using CT scanning and the possible relation to corticosteroid therapy or disease in systemic lupus erythematosus (SLE) and to analyse the relationships between cerebral atrophy and activity disease and neuropsychiatric manifestations in lupus patients. We studied 107 consecutive SLE patients (American Rheumatology Association 1982 criteria) who were taking steroid drugs at the time and not selected for any particular manifestation (group 1). A complete clinical, neurological and laboratory evaluation was performed. The American College of Rheumatology's classification for neuropsychiatric manifestations and SLE disease activity index for activity were employed. Group 2 comprised 39 non-SLE patients with oral chronic steroid use (1 mg/k/day for more than 3 consecutive months); 50 normal individuals were the controls (group 3). There were no demographic differences between the groups. Brain CT was performed in all individuals and the frequency and the intensity (minimal, moderate and severe) of atrophy analysed, through well-defined measures and indices, by two neuroradiologists. Cerebral atrophy was significantly more frequent in groups 1 and 2 than in group 3, but with no significant difference between groups 1 and 2. The severity of cerebral atrophy was significantly higher in SLE patients (p<0.05), independent of steroid dose or duration of disease. In both groups no patient presented severe atrophy. Lupus patients with and without cerebral atrophy presented neuropsychiatric manifestations and activity disease in a similar proportion. The more frequent neuropsychiatric manifestation in lupus patients with cerebral atrophy was seizures (p<0.05). Chronic glucocorticoid therapy was responsible for cerebral atrophy, with a comparable incidence in both lupus and non-lupus patients compared to age and gender-matched normal subjects untreated with glucocorticoids. The disease activity was not related to cerebral atrophy in group 1 and seizures were the neurologic manifestation related to cerebral atrophy. The severity of the cerebral atrophy was independent of steroid dose, or duration of treatment. Moreover, the disease itself contributes to the severity of this process, but not to the development of cerebral atrophy.

Development of donor-specific microchimerism in liver transplant recipient with HLA-DRB1 and -DQB1 mismatch related to rejection episodes.

Migration of donor-derived cells to recipient tissues after liver transplantation has been suggested as a mechanism to induce and maintain allograft tolerance, although important issues remain including acute rejection posttransplantation mortality, and complications related to immunosuppressive therapy. We therefore examined the relation of rejection to chimerism based upon recipient and donor mismatch of HLA-DRB1 and -DQB1 alleles. Laboratory analysis of peripheral blood was performed before and 10 days to 16 months after liver transplantation in 32 recipients, using ganglion or spleen cell samples of respective donors. DNA was extracted for HLA-DRB1 and DQB1 allele typing using polymerase chain reactions with sequence-specific primers (PCR-SSP). Microchimerism was analyzed through nested PCR. Our results confirmed that patients with one or two mismatched HLA-DRB1 and-DQB1 alleles showed microchimerism and no rejection (P <.05). Microchimerism was present in 71.88% of the patients, and a significant association of rejection P <.05 was found when microchimerism was correlated to graft rejection. These results suggest that the presence of microchimerism may be associated with acceptance, tolerance and survival of the allograft.

Acid suppression with ranitidine plus oral triple therapy improves ulcer healing but not Helicobacter pylori eradication.

BACKGROUND/AIMS: To evaluate whether the addition of 2 weeks of ranitidine to a 1-week oral triple therapy (OTT) regimen improved ulcer healing and H. pylori eradication. METHODOLOGY: Two hundred and eleven consecutive patients with an endoscopic diagnosis of active duodenal ulcer (DU) and a positive antrum biopsy for H. pylori were enrolled. Those attending the Hospital Vera Cruz (Group A, n=142) received a 14-day course of ranitidine (150 mg after breakfast and dinner) plus a 1-week OTT, consisting of bismuth subcitrate, (240 mg after the 3 meals), tetracycline (500 mg, 10 min before the three meals and at bedtime), and furazolidone (200 mg after breakfast and dinner). Patients from the Hospital das Clinicas (Group B, n=69) received the same OTT as Group A but without ranitidine. Patients underwent endoscopy again on average 40 days (range: 30-60 days) after completing therapy in order to assess ulcer healing and H. pylori status. RESULTS: Both schedules were equally efficient in eradicating H. pylori with 90% (128/142) eradication in group A, and 84% (58/69) in group B (p=0.2). In contrast, the addition of ranitidine to OTT improved ulcer healing when compared with OTT alone (96%, 137/142, vs. 70%, 48/69; p<0.001). CONCLUSIONS: Our results demonstrate that the association of acid suppression, obtained with 2 week ranitidine administration with OTT improved ulcer healing but did not enhance H. pylori eradication.

Nucleolar organiser regions of mesothelial and carcinomatous cells in effusions.

The AgNor reaction was performed on effusions and peritoneal washings, and the silver dots were counted on normal or reactive mesothelial cells vs. carcinomatous cells, ascertained by previous HE staining. The mean values were 1.64 for the former (n = 20) and 4.90 for the latter (n = 10). The intersection between the two group distributions was 2.78, leaving a chance of only 0.65% for a false-positive result. The method may thus be helpful in the interpretation of doubtful cytological cases.

A clinical, epidemological, laboratorial, histological and ultrasonographical evaluation of anti-HCV EIA-2 positive blood donors.

Between 1992 and 1997, 790 blood donors with anti-HCV EIA-2 strongly reagent (relationship between the sample optical density/cut-off > 3) detected at the blood bank serological screening, were evaluated in ambulatory environment. They were all negative for Chagas disease, syphilis, hepatitis B (HBsAg) and AIDS. Blood samples were collected at the first ambulatorial evaluation, for hemogram, biochemical tests and new serological tests for HCV (anti-HCV EIA-2). In blood samples of 226 repeatedly reagent anti-HCV EIA-2 blood donors, supplementary "immunoblot" test for HCV (RIBA-2) was used. In 209 donors, the presence of HCV-RNA was investigated by the PCR test. The abdominal ultrasonography was realized in 366 donors. In 269 patients liver biopsy was performed for the histopathological study. The follow-up of blood donors showed that 95.6% were repeatedly EIA-2 reagent, 94% were symptomless and denied any hepatitis history, with only 2% mentioning previous jaundice. In 47% of this population at least one risk factor has been detected for the HCV transmission, the use of intravenous drugs being the main one (27.8%). Blood transfusion was the second factor for HCV transmission (27.2%). Hepatomegaly was detected in 54% of the cases. Splenomegaly and signs of portal hypertension have seldom been found in the physical examination, indicating a low degree of hepatic compromising in HCV. Abdominal ultrasound showed alterations in 65% of the subjects, being the steatosis the most frequent (50%). In 83. 5% of the donors submitted to the liver biopsy, the histopathological exam showed the presence of chronic hepatitis, usually classified as active (89%) with mild or moderate grade in most of the cases (99.5%). The histopathological exam of the liver was normal in 1.5% of blood donors. The RIBA-2 test and the HCV-RNA investigation by PCR were positive in respectively 91.6 and 75% of the anti-HCV EIA-2 reagent donors. The HCV-RNA research was positive in 82% of the RIBA-2 positive subjects, in 37.5% of the indeterminate RIBA-2 donors and in 9% of the negative RIBA-2 donors. Chronic hepatitis has also been observed in 50% of the histopathological exams of the anti-HCV EIA-2 reagent donors which were indeterminate RIBA-2. Among 18 blood donors with minimal changes histopathological exam 11 (61%) were HCV-RNA positive. Our blood donors anti-HCV reagent generally had clinical, laboratorial and histopathological features observed in patients with chronic HCV hepatitis and a high proportion could be identified in interviews and medical evaluation realized in blood blanks. Generally, these HCV infected donors are identified and discharged only by the serological tests results.

[Community genetics and hemophilia in a Brazilian population]. / Genética comunitária e hemofilia em uma população brasileira.

Hemophilia is an important hemorrhagic disease in Brazil, affecting about 1 out of every 10,000 males. Patient's self-perception of hemophilia and interaction with the community are relevant to the clinical management of this disease. We investigated several social, psychological, and community aspects of hemophilia in a Brazilian population (Campinas, São Paulo State), interviewing 30 hemophiliac males, a control sample comprised of 73 non-hemophiliac brothers, and 641 individuals from the community. According to our results, more severe social disability in the hemophiliac patient was related to economic factors, mainly unemployment; however, no difference was found in relation to marital status, reproduction, or education. Self-perception of changes in health and lifestyle by individuals with hemophilia showed frequent self-stigmatization, along with depression, anxiety, and insecurity. The community showed a widespread lack of familiarity with hemophilia (49%), viewing people with hemophilia with the kinds of prejudices often observed in relation to people with infectious diseases, like AIDS. The paper concludes by recommending that a community-based program be implemented to improve the social adjustment status of individuals with hemophilia.

Bone mineral density, vitamin D and anticonvulsant therapy.

UNLABELLED: The aim of this study was to assess bone mineral density and vitamin D metabolism in patients on chronic anticonvulsant therapy. METHODS: Sixty-nine men, outpatients on chronic anticonvulsant therapy, who had been treated for at least 5 years, were studied, comparing them to thirty healthy controls. Bone mineral density was measured as well as serum levels of calcium, ionized calcium, alkaline phosphatase, PTH, 25-hydroxycholecalciferol and 1, 25-dihydroxycholecalciferol. RESULTS: No differences in bone mineral density, serum levels of vitamin D and intact-PTH were observed between patients and controls. Bone mineral density was not associated with chronic anticonvulsant therapy. CONCLUSION: Those adult patients who were on chronic anticonvulsant therapy and who lived in low latitude regions had normal bone mineral density as well as vitamin D serum levels.

Immunohistochemical study of basement membrane collagen IV in uterine cervix carcinoma.

CONTEXT: The integrity of basement membrane (BM) is damaged during the evolution of a benign or potentially malignant lesion into a malignant one, in which it may undergo several degrees of discontinuity as a necessary condition for the invasive process. Immunostaining for collagen IV, which is exclusively found in BM, has been used to evaluate its formation in neoplastic and benign lesions of several organs. OBJECTIVE: To investigate BM continuity pattern in squamous carcinoma "in situ" (CIS), microinvasive (MIC) and invasive (IC) squamous cell carcinoma of the uterine cervix, and to find out if BM expression could be useful in the diagnosis of early stromal invasion (MIC). DESIGN: Archival material between 1988 and 1993 was studied at the Pathological Anatomy Department-Unicamp. PROCEDURES: The selected cases, previously formalin fixed and paraffin embedded, were reviewed retrospectively by submitting them to immunohistochemical study via the avidin-biotin-peroxidase method using a monoclonal antibody anticollagen IV. RESULTS: In all, 17 cases of CIS, 16 of MIC and 21 of IC were evaluated. All IC cases showed evident BM discontinuity, either focal or diffuse. In the CIS group, a continuous BM pattern was predominant, being focally disrupted in only 2/17 cases (11.8%). The MIC group showed an intermediate pattern, but with a clear tendency to BM discontinuity in 10/16 cases (62.5%). Inflammatory infiltrate, a variable also studied, cannot be considered responsible for BM discontinuity, since there was no statistical correlation between them. CONCLUSION: We conclude that immunostaining for collagen IV may contribute to the diagnosis of stromal invasion by BM discontinuity.