[Colorectal polyps: update on diagnosis]

Histological diagnosis determines the clinical behavior of colorectal polyps. Recently new types of polyps have been described and the classification has become wider and more complex. Our aim is update the current concepts in the knowledge of colorectal polyps.

[Increase of intraepithelial lymphocytes in patients with irritable bowel syndrome]

Several studies have shown increased numbers of intraepithelial lymphocytes (IEL), mast cells, enterochromaffin cells in colonic mucosa of patients with Irritable Bowel Syndrome (IBS). Many of these findings are based is based on immunohistochemistry results, which is not available in general hospitals. Our objective is to study the histological findings observed in colon biopsies from patients with IBS compared with a group without IBS, using only histochemistry. Twenty five (25) patients were included: 16 with IBS and 9 without IBS. We found increased numbers of IEL in patients with IBS (p=0,002). A group of patients with IBS (41.9%) who fulfilled histological criteria for lymphocytic colitis were excluded. There was no significant difference in mast cells, enterochromaffin cells or eosinophils.

Low serological positivity in patients with histology compatible with celiac disease in Perú

OBJECTIVE

To study the frequency of positive serology for celiac disease (CD) in patients with duodenal biopsies suggestive of this disease.

MATERIAL AND METHODS

Cross sectional study. We included patients with duodenal biopsies histologically compatible with CD and antigliadin, antiendomysial and IgA antitransglutaminase antibodies. We defined a "case" of CD if there was a positive biopsy and either antiendomisial or antitransglutaminase positive antibodies.

RESULTS

Thirty one patients were included in our study. Six were antiendomysial positive and 5 antitransglutaminase positive while the antigliadin was positive in 14 cases. Therefore, out of 31 patients only 10 had a serology compatible with CD and only one had positive both antibodies, antiendomysial and antitransglutaminase.

CONCLUSIONS

a) We have found that most of the duodenal biopsies compatible with CD are not diagnosed with positive serology; and b) we found a low correlation between serological diagnostic tests.

[Inflamatory polyps of the colon an evaluation]

AIM

We report our experience with Inflammatory Polyps of the Colon.

METHODS

Retrospective study including all polyps diagnosed at the Arias Stella Pathology Institute, Lima in the year 2008. Inflammatory polyps were diagnosed as polyp composed of reactive epithelium without dysplasia, inflamed granulation tissue.

RESULTS

We found 887 polyps of which 2.3% were inflammatory polyps. One out of three were located in the sigmoid colon, and 63% had no underlying colonic disease.

CONCLUSION

Inflammatory polyps are rare among colonic polyps and most patients have no accompanying colonic disease.

[Immunoexpression of p53 and cyclin D1 in adenomas of the gallbladder]

INTRODUCTION

Gallbladder adenomas are infrequent neoplasms whose relation to adenocarcinoma is not well understood. It has been suggested that adenomas and adenocarcinomas follow different molecular pathways.

MATERIAL AND METHODS

This is a comparative, cross-sectional study in which we compared p53 and D1 cyclin expression in adenomas and adenocarcinomas of the gallbladder.

RESULTS

We included 12 cases in each group. Expression of p53 occurred in 83.3% of adenocarcinomas and in 16.6% of adenomas (p = 0.003). D1 cyclin was expressed in a similar number of adenomas and adenocarcinomas.

CONCLUSION

Our results support the hypothesis that p53 is an important step in the pathogenesis of adenocarcinomas but not of adenomas of the gallbladder. D1 cyclin is apparently a common pathway involved in the genesis of both tumors.

[Colon biopsy--histological characteristics in different types of chronic colitis]

In the last few years a variety of new forms of chronic colitis have been described with defined histological characteristics. It is important both for the gastroenterologists and pathologists to be acquainted with this new clinic pathological entities. The present article is a review of the anatomo-pathological characteristics of the different types of colitis.

[E-cadherin molecular expresion in the diffuse and intestinal types of gastric adenocarcinoma. A report from Lima, Peru]

OBJECTIVE

Signet ring carcinoma of the stomach is well known to be more aggressive and infiltrating than adenocarcinoma. Different studies have proposed that signet ring cell carcinoma would be more infiltrating because of the loss of E-cadherin expression, this cadherin is a class of protein cell membrane protein which plays an important role in cell-adhesion.

METHODS

We carried out a transversal comparative study, in order to measure the E-cadherin expression in 10 cases of signet ring cell and in 10 cases of adenocarcinoma, with help of immunohistochemistry.

RESULTS

We found a bigger expression of E-cadherin in adenocarcinomas (100%) than signet ring cell carcinoma (40%), this difference was significative using Fisher test (p = 0,011). The loss of E-cadherin would explain the bigger infiltrating capacity in comparison to adenocarcinoma.

Accumulation and transformation of DSP toxins in mussels Mytilus galloprovincialis during a toxic episode caused by Dinophysis acuminata

The time course of several outbreaks of the diarrhetic shellfish poisoning (DSP) producer Dinophysis acuminata and the consequent kinetic of accumulation and loss of toxins in mussels Mytilus galloprovincialis feeding on them was studied. Samples of mussels and seawater were frequently (2-3 times a week) collected from a raft in the Ri;a de Vigo. DSP toxins content of mussels and water was analyzed by HPLC-FD and phytoplankton was quantified in an inverted light microscope. Only okadaic acid (OA) and some of its conjugated forms (OA CF), estimated by enzymatic hydrolysis, were found in the plankton samples obtained, comprised mainly of D. acuminata cells. The main accumulated form in mussels was OA reaching a maximum of 10.1 microg OA g(-1) in the digestive gland (d.g.) in 16 days, falling below the quarantine level (ca. 2 microg OA g(-1) d.g.) by 45 days. The low polarity conjugated forms (LPCF), estimated by hexane extraction, accounted for 6.2% of the total toxin burden of the mussels. To quantify the rates of the processes involved in the accumulation, transformation and loss of the toxins, two dynamic models, a one-compartment and a two-compartment, including OA and its conjugated forms as variables were designed and implemented. The one-compartment model provided a good fit to the OA and LPCF actual data (r(2)=0.92 and r(2)=0.94, respectively). The two-compartment model did not fit the data markedly better than its one-compartment counterpart (r(2)=0.93 and r(2)=0.95, for OA and LPCF, respectively). High hydrolysis rates were estimated for most of the OA CF, which means that these forms came largely from the ingested plankton. The low estimated acylation rates support the previous point and suggest that the formation of LPCF by direct acylation of the OA is of little importance in M. galloprovincialis. Only in cases where the intoxication period is very long, can the formed acyl-derivatives be important, because they seem to accumulate for a long time in the mussels, as suggested by the low hydrolysis and depuration rates estimated from model fitting.

Seasonal changes in blood parameters in the bat species Rhinolophus ferrumequinum and miniopterus schreibersi

Intersexual and seasonal comparisons of erythrocyte number, hematocrit, and hemoglobin concentration were conducted for two old world temperate bats, Rhinolophus ferrumequinum and Miniopterus schreibersi. Both species had many small erythrocytes and elevated hemoglobin concentrations. Seasonal differences in erythrocyte count, hemoglobin concentration, and mean cell volume were found in each species. The increase in the number of small erythrocytes in the warm season may be related to heightened activity of the bats during this period. High blood-oxygen capacities associated with high hemoglobin concentrations and hematocrit values increase oxygen delivery to tissues in species with small body size and high metabolic rates.

Hematological data and hemoglobin components in bats (Vespertilionidae)

1. Statistically significant variations were observed in the RBC counts and Hb concentration in pregnant females of Pipistrellus pipistrellus. 2. Basic hematological values in 59 animals of five species of insectivorous bats were estimated. 3. Electrophoretic separation of the hemoglobins of Plecotus austriacus, Myotis nattereri and Myotis myotis showed two components, whereas in Miniopterus schreibersi and Pipistrellus pipistrellus appeared three and four components, respectively.

Hemoglobin and oxygen: different affinities in two species of rodents (Mus musculus and Pitymys duodecimcostatus)

Five different hemoglobins have been demonstrated by polyacrylamide-gel disk electrophoresis in the species Mus musculus. Oxygen affinities of hemoglobin (P50) from Mus musculus and Pitymys duodecimcostatus hemolysates were determined at pH 7.4 and 37 degrees C. Values obtained for delta log P50/delta pH in hemolysates from both species point out a more pronounced Bohr effect in Pitymys duodecimcostatus.