Remo Vernillo

Fast-atom bombardment mass spectrometry for mapping of endogenous methylated purine bases in urine extracts.

Fast-atom bombardment (FAB) mass spectrometry, linked with tandem mass spectrometry (MS/MS), was employed for the identification of methylated purine bases in four urinary extracts of healthy subjects and fourteen urinary extracts of patients bearing colorectal tumors. In order to obtain an easy structural identification of the species present in urinary extracts, the MS/MS spectra of MH+ species of twenty nine diagnostically relevant purine bases were studied. Even if definitive quantitative data cannot be obtained by this approach, FAB mass spectra of urine extracts lead to a readily reproducible mapping of endogenous purine bases, allowing a distinction between healthy and sick subjects. Bases such as 9-ethyladenine, N6-2-isopentenyladenine and N6-benzyladenine were detected only in urine samples of colorectal tumor bearing patients. The detection in urine of compounds such as 7-methylguanine and 1-methylguanine, and their increase in the urine of colorectal tumor bearing patients, has been justified either by a more rapid turnover of nucleic acids in tumor tissue or by an increase in the extent of their methylation. The obtained results indicate that the method can be employed for diagnostic purposes.

Immunohistochemical expression of p53 and Ki67 in colorectal adenomas and prediction of malignancy and development of new polyps.

The aim of this study was to investigate the immunohistochemical expression of p53 and Ki67 in colorectal adenomas in order to clarify their significance as indicators of malignancy and development of new polyps. Seventy-eight polyps were removed from 51 patients and examined. Twenty-nine patients (56.9%) had adenomas with low-grade atypia (13 of them developed new polyps at 3-year follow-up) and 22 (43.1%) had adenomas with high-grade atypia (6 of them developed new polyps at 3-year follow-up). We tested the association between p53 and Ki67 expression and various clinicopathological variables, and regression analysis was performed to identify the risk factors for malignancy and development of new adenomas. A significant correlation between the grade of atypia and p53 immunoreactivity was observed. Ki67 expression was not related to atypia and no correlation was found between p53 and Ki67 immunoreactivity. Regression analysis showed that size (p=0.0002) and p53 staining (p=0.0111) were the selected factors related to malignant transformation, whereas the number of synchronous primary polyps emerged as the only predictive factor of development of new adenomas, although without statistical significance. The expression of biological markers may be in future added to the currently examined features of polyps; however, further studies are needed to better define their predictive value.

Serum ferritin in colorectal cancer patients and its prognostic evaluation.

The aim of this study was to investigate the relationship between preoperative serum ferritin levels, clinico-pathological parameters and survival analysis of patients with colorectal cancer. Ninety-four patients (57 males) with a mean age of 65 years (39-87 years) underwent 63 curative and 31 palliative operations. Follow-up was at least 5 years. Patients were categorized with normal (30-215 ng/mL in men and 11-148 ng/mL in women), low, or high serum ferritin levels. Prognostic evaluation was undertaken with stratified survival analysis and Coxs regression model. Twenty-nine of the patients (30.9%) had raised ferritin levels and 14 (14.9%) had low values. Comparisons of the survival curves showed significant differences in stage C disease; specifically, patients with either low or high ferritin levels had a shorter survival than patients with normal levels. Patients who underwent palliative surgery and had high ferritin serum values also had a shorter survival. In multivariate analysis, the variables with a negative effect on survival were stage, serum ferritin levels and age. Our data suggest that patients with advanced colorectal cancer having normal preoperative serum ferritin levels may have a better prognosis, although the prognostic value related to this association requires further investigation.

Ultrastructural study of enteric ganglia in three patients with Rett syndrome

In order to verify whether a pseudo-obstruction syndrome was associated with morphological changes in enteric ganglia, we performed an ultrastructural study on rectal biopsy specimens in three patients with Rett syndrome. Features of enteric neurons, detected to a different extent in all three biopsy specimens, included an abnormal dilatation of endoplasmic reticulum with a disorganization of cisternae of the Golgi apparatus, and masses of unidentified electron-dense granulo-filamentous material, probably of lipidic origin, observed in the perikaryon. Large electron-lucent membrane-bound vacuoles were found mostly within satellite glial cells. Sometimes, the axon terminals were swollen and showed intraxonal vacuolization. We conclude that the reported findings do not represent a specific sign of degeneration and do not constitute a significant morphological marker of disease.

Immunohistochemical Analysis of P185 and ASL Activity in Pre-Neoplastic Lesions and Intestinal Mucosa of Human Subjects

Colorectal cancer is the second neoplasia in terms of incidence and mortality (after lung-cancer in men and breast cancer in women), with 20,000 new cases in Italy every year and 10,000 deathes. The starting point of the multiphasic process leading to colorectal cancer (somatic and inherited genetic alterations which involve activation of onco-genes and inactivation of oncosuppressor genes) seems to be adenomatous polyposis. Since mortality due to colorectal cancer is high in our country, new perspectives for early diagnosis and chemotherapy, based on molecular and biochemical patterns at different stages of the pathological process, are needed.