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Biomedical subjects

A M Lavezzi

Publications and source records attributed to A M Lavezzi.

46 records · Page 3Linked to original sources
PubMed1984

Application of the Giemsa-11 technique in cytogenetic analysis of leukemic patients.

Cultures of bone marrow obtained from patients with various forms of leukemia have been stained by the Giemsa-11 technique. The results suggest that this method can be utilized for the constant monitoring of numerical and structural anomalies in chromosome 9. Furthermore, by varying the pH, this technique can be applied not only to freshly prepared slides but also to stained preparations stored for many months.

Azure Stains↗
PubMed1983

The bone marrow karyotype in seventeen cases of refractory anemia with excess of blasts (RAEB).

The bone marrow karyotype was studied in 17 patients affected by refractory anemia with excess of blasts (RAEB). A cytogenetic finding common to nearly all the cases is hypodiploidy, present in even quite high percentages. In 3 patients were identified the same interstitial deletion of the long arm of a chromosome 5, present in a percentage varying between 30% and 65%. The presence of this chromosomal anomaly appears to correspond to a slower development of the illness and transformation into acute leukemia seems rare or delayed.

Adult↗
PubMedDate not supplied

Prognostic significance of different biomarkers in non-small cell lung cancer.

The purpose of our study was to examine the prognostic significance of different biomarkers [DNA content, proliferating cell nuclear antigen labeling index (PCNA-LI), p53 mutation and apoptosis], in 152 surgically resected non-small cell lung cancer (NSCLC). The ploidy was carried out by densitometry; PCNA-LI, p53 and apoptosis were determined with immunohistochemistry. The results were correlated to histology, stage and patient survival. A considerable variability of the PCNA indices, ranging from 0 to 33.5% with a mean value of 7.0%, was found. DNA evaluation showed a prevalence of aneuploid tumors (62%) with a DNA index >1. Overexpression of p53 protein and apoptotic positivity were observed in low percentages of cases (16% and 32% respectively). Only stage and PCNA-LI were found to be significant prognostic factors on multivariate analysis. PCNA was superior to stage in predicting shortened survival of patients with NSCLC. PCNA immunostaining can be applied on a routine basis in formalin-fixed, paraffin-embedded samples of NSCLC to predict patient prognosis and thus to identify patients in need of additional postoperative therapies.

Adult↗
PubMedDate not supplied

PCNA immunostaining as a valid alternative to tritiated thymidine-autoradiography to detect proliferative cell fraction in transitional cell bladder carcinomas.

BACKGROUND: The thymidine labeling index (T-LI) evaluated with the autoradiographic technique on fresh specimens is the most objective and specific marker of tumor proliferative cell fraction. In this study we investigated T-LI and PCNA expression in 68 cases of transitional cell bladder carcinomas in order to evaluate whether PCNA immunostaining in paraffin sections could be a valid alternative to autoradiographic methods for cell kinetic detection. Immunohistochemistry was applied after different fixatives: usual formalin, neutral 4% buffered formalin and Bouin. The results revealed that only in buffered formalin-fixed tumor specimens, considering the most darkly stained cells, the PCNA-LI in all cases overlapped with T-LI. Higher values than those observed with autoradiography were detected in PCNA values obtained after usual formalin fixation whereas no or faint PCNA staining was seen in material fixed in Bouin. Thus, only cells with strong PCNA staining can be considered as significant in evaluating the proliferative activity in transitional cell bladder carcinoma. By using immunohistochemical methods it should thus be possible to overcome many of the inherent difficulties of autoradiography and likewise to obtain accurate and significant information on the biological aggressiveness of bladder tumors and consequently of patient prognosis.

Acetic Acid↗
PubMedDate not supplied

The role of different biomarkers (DNA, PCNA, apoptosis and karyotype) in prognostic evaluation of superficial transitional cell bladder carcinoma.

BACKGROUND: In order to clarify the variable behaviour of transitional cell bladder carcinomas (TCBC) with same clinico-pathologic pattern, we investigated the prognostic significance of various biomarkers (PCNA, DNA, apoptosis, karyotype). MATERIALS AND METHODS: We studied 177 superficial TCBC (stage T1) undergoing transurethral resection (TUR). Analysis of biological indicators was performed on serial paraffin sections: DNA by static cytometry, karyotype by fluorescence in situ hybridisation (FISH), PCNA and apoptosis by immunohistochemistry. RESULTS: The most salient results are represented by prevalence of diploidy (56%), a mean PCNA labeling index (PCNA-LI) of 8.2%, nonrandom trisomies and tetrasomies of chromosome 7, and a high presence of apoptosis (in 72% of cases). These data were not related to histological grading. Multivariate analysis showed that only PCNA-LI is a an independent prognostic marker for patient survival (p = 0.01). Besides, we observed a worse prognosis in the presence of both very high PCNA indices and low or absent apoptosis. CONCLUSIONS: The results of this study suggest that tumor prognostic potential in TCBC should be evaluated on the basis of the association between PCNA cell kinetics and cell apoptosis information.

Aged↗
PubMedDate not supplied

Role of somatostatin and apoptosis in breathing control in sudden perinatal and infant unexplained death.

OBJECTIVES: To obtain basic information about the expression of somatostatin in the human central nervous system and, in particular, to evaluate its possible involvement in unexplained perinatal and in sudden infant death syndrome. MATERIAL: Sixty-seven brainstems from subjects aged from 30 gestational weeks to 12 postnatal months, dying of both known and unknown causes, were selected for this study. The unexplained deaths included 17 sudden intrauterine deaths, 5 sudden neonatal deaths and 28 sudden infant deaths. METHOD: All brainstems were fixed in 10% phosphate-buffered formalin, processed and embedded in paraffin, according to our protocol available on the web site: http://users.unimi.it/-pathol/sids/riscontro_diagnostico_e.html. The distribution of the somatostatin in the brainstem was studied by immunohistochemistry on serial sections. RESULTS: We observed an intense somatostatin positivity in many brainstem nuclei prevalently involved in the respiratory activity (parabrachial/Kölliker-Fuse complex, locus coeruleus, hypoglossus nucleus, dorsal vagus motor nucleus, tractus solitarii nucleus, ambiguus nucleus, reticular formation) in stillbirths. In 10 fetuses with unexplained death the neurons of the hypoglossus nucleus were somatostatin-negative. In the postnatal deaths, we observed immunopositivity in the ventrolateral and ventral subnuclei of the tractus solitarii nucleus. Besides, in 15 sudden infant death victims and in 1 control case, somatostatin-positive neurons were also present in the hypoglossus nucleus. In 10 of these 15 cases, a high apoptotic index was also reported. CONCLUSIONS: We suggest that abnormalities in the distribution of SS in the hypoglossus nucleus before and after birth may contribute to the induction of both fatal breathing in prenatal life and abnormal ventilatory control after birth leading to irreversible apnea.

Apoptosis↗
PubMedDate not supplied

PCNA--a cell proliferation marker in vocal chord cancer. Part I: Premalignant laryngeal lesions.

Laryngeal hyperkeratotic lesions can progress to fully developed malignant carcinoma in some cases. These premalignant lesions are proliferative disorders whose potential for further tumour progression is perhaps difficult to assess by mere histology. Immunostaining with PCNA, a protein correlated with cell proliferation, has been used to study tissue behavior in 30 cases of premalignant laryngeal vocal chord lesions treated by epithelial stripping in microlaryngoscopy, 15 of whom had no progression and 15 had recurrence and final development of full malignancy. The results showed a statistically significantly higher PCNA-index in the cases which underwent further tumour progression towards malignancy. PCNA testing may thus be suggested as a marker for tumour progression potential and help in determining clinical treatment choices.

Humans↗
PubMedDate not supplied

PCNA--a cell proliferation marker in vocal cord cancer. Part II: Recurrence in malignant laryngeal lesions.

Laryngeal squamous cell carcinoma constitutes the most frequent carcinoma found in the head and neck region. A precise prediction for recurrence potential cannot be done on site, treatment and histologic grading. Since Proliferating Cell Nuclear Antigen (PCNA) and DNA-cytometry have shown a good correlation between premalignant lesions and their progressive potential towards full-fledged carcinoma in the larynx as described in part I of this work, we have analyzed the PCNA index and DNA cytometry in specimen taken from vocal chord carcinomas with a 5-year follow-up, in order to assess its relationship with the presence or absence of tumour progression. 42 cases with (21) and without (2) recurrence have been examined. The DNA-index ranged from 1.01 to 1.43 (mean 1.10) in the group without and from 1.02 to 1.59 (mean 1.38) in the group with recurrent carcinoma (p = 0.002). The PCNA-index ranged from 0.00% to 18.90% (mean 6.97%) in the nonrecurrent group and from 0.00 to 3g.50% (mean 16.35%) in the patients with recurrence (p = 0.001). Both indices also correlated in a highly significant way. From these data emerges a highly significant correlation between the cytometric indices of cell proliferation and PCNA immunostaining. Furthermore the high correction between PCNA and DNA-index is of special interest for single case assessment. High DNA aberration and PCNA-index in vocal chord carcinoma may indicate a higher cellular aggressiveness of the tumour, resulting in a greater overall risk of metastases and local recurrences. Our results support the thesis that the indices of cellular proliferation within some cancers can define subsets of patients of high risk and help in isolating a population in which a more aggressive clinical protocol may be proposed.

Analysis of Variance↗
PubMedDate not supplied

Prognostic significance of different biological markers (DNA index, PCNA index, apoptosis, p53, karyotype) in 126 adenocarcinoma gastric biopsies.

BACKGROUND: The different clinical evolution of gastric adenocarcinomas with the same clinico-pathologic characteristics prompted the authors to investigate the prognostic significance of different biological markers. METHODS: One hundred twenty-six preoperative cancer gastric biopsies, selected according the stage evaluated after following gastrectomy, were examined for DNA content by means the static cytometry, proliferating cell nuclear antigen (PCNA), p53 mutation, apoptosis by immunohistochemistry and karyotype using fluorescence in situ hybridization (FISH) techniques. RESULTS: The gastric cancers, ail belonging at stage III, were adenocarcinomas histologically typed as: 26 well differentiated (G1), 45 moderately differentiated (G2), 43 poorly differentiated (G3) and 12 of undifferentiated type with signet-ring cells. The tumours showed a prevalence of diploidy (68%), a mean PCNA-LI of 4.8%, trisomy of chromosome 7 in 40% of the cases, low presence of apoptosis (30%) and p53 mutation (17%). Only apoptosis was significantly correlated to histological diagnosis (p = 0.009). A multivariate analysis showed that the DNA content and PCNA-LI were the only independent prognostic markers for survival (p = 0.005 and p = 0.0002 respectively). CONCLUSIONS: The evaluation of these two biological variables, especially of the PCNA index, on gastric cancer biopsies may be useful in predicting the aggressiveness of each tumor and in identifying patients in need of additional perioperative therapies.

Adenocarcinoma↗