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Biomedical subjects

D Di Stefano

Publications and source records attributed to D Di Stefano.

At least 37 records · Page 2Linked to original sources
PubMed1994

Correlations between sinusoidal pressure and liver morphology in cirrhosis.

Twenty-three patients with cirrhosis (alcoholic, post-hepatitic and cryptogenetic), who underwent hepatic venous catheterization and hepatic biopsy, were included in a histopathologic study to identify morphologic features correlated with the values of corrected sinusoidal pressure. The alterations in acinar architecture were investigated by histomorphometry and could be described as: a) multiacinar fibrosis with partial persistence of normal afferent and efferent vascular structures; b) complex acinar fibrosis with partial persistence of afferent structures alone; and c) simple acinar and subacinar fibrosis with almost complete disappearance of normal vascular structures. A significant negative correlation (p < 0.05) was found between corrected sinusoidal pressure values and the percentage of portal spaces not involved in the process of bridging fibrosis, indicated as "residual portal spaces". Residual portal space evaluation can therefore be suggested as an easily quantifiable morphologic feature indicative of portal pressure.

Adolescent↗
PubMed1994

[Chronic gastritis and prostaglandins. Results of endoscopic screening].

An endoscopic screening was carried out during the period between July 1989 and December 1991 in the Municipality of Roccagorga (LT) in order to: a) evaluate the presence of various forms of gastritis and pre-cancerous lesions; 2) verify the effect of the administration of prostaglandins (Misoprostol) on the evolution of superficial chronic gastritis (CG). A total of 468 endoscopy were performed (17% of the population aged between 20 and 75 years old). 22% of the subjects examined were found to be endoscopically normal; 34% presented symptoms of mild esophagitis and 4% of moderate esophagitis. The prevalence of duodenal ulcer was 10.6% and gastric ulcer 3.4%. Gastric carcinoma was diagnosed in 6 patients (1.2%). 8.5% of patients were found to have atrophic CG and 15.3% superficial CG. Thirty-six patients with superficial CG were randomly divided into two groups: A) treated with Misoprostol 600 mg/day for 6 months; B) controls (placebo). The administration of Misoprostol did not influence the evolution of CG, whereas it caused a reduction in the incidence of type 1 intestinal metaplasia. Misoprostol also led to an improvement in dyspeptic symptoms. The results of the present study do not suggest a role of prostaglandins in the natural evolution of CG.

Adult↗
PubMed1992

Time-related interference of misoprostol with experimental gastric cancer formation induced by N-methyl-N'-nitro-N-nitrosoguanidine in the rat.

The purpose of this study was to investigate the effect of long-term misoprostol administration, at non-antisecretory doses, on N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)-induced gastric carcinogenesis. The incidence of gastric carcinomas and precancerous lesions was evaluated in 50 male 250-g Sprague-Dawley rats after 52 weeks of continuous oral administration of MNNG (120 mg/l; n = 20), MNNG plus misoprostol (2 mg kg-1 day-1; n = 20) or tap water (n = 10) (experiment 1), and in 30 rats treated with MNNG for 30 weeks followed by tap water (n = 15) or by misoprostol (n = 15) for 22 weeks; a third group (n = 10) received tap water only for 52 weeks (experiment 2). After sacrifice, gastric mucosal lesions were macroscopically evaluated and their histology obtained. MNNG consumption was comparable in all groups (6.5 +/- 1.1 mg rat-1 day-1). Misoprostol consumption was 180 +/- 0.25 mg kg-1 day-1 rat-1. In experiment 1 the incidence of gastric carcinomas was 60% in the MNNG group and 25% in the group treated with MNNG plus misoprostol (P less than 0.05). Cytotoxic and hyperplastic gastric mucosal lesions were also significantly reduced by misoprostol. In experiment 2 the incidence of carcinomas was 31% and 38.6% respectively. Misoprostol significantly decreased the incidence of gastric cancer formation when given from the beginning of the experiment. By contrast, when administered after 30 weeks of MNNG treatment it did not interfere with experimental gastric cancer formation. Exogenous prostaglandins are able to prevent the early MNNG-induced gastric mucosal lesions, thus interfering with gastric carcinogenesis.

Adenocarcinoma↗
PubMed1992

Interphasic nucleolar organizer regions expression and cell kinetics evaluation during gastric carcinogenesis induced by nitrosoguanidine in the rat.

An increased number of interphasic nucleolar organizer regions containing ribosomal cistrons associated with argyrophilic proteins (AgNORs) has been described in human malignant tumor cells. In this study variations in AgNOR numbers have been compared with changes of cell kinetics, evaluated by the mitotic count (MC) and bromodeoxyuridine labeling index (BrdU LI), during gastric carcinogenesis induced with N-methyl-N'-nitro-N-nitrosoguanidine (NG) in rats. Significant differences (2 P < 0.005) in AgNOR mean numbers, evaluated in the antral isthmic cells, in MC mean values and BrdU LI, evaluated in the whole antral cellular population, were found when comparing areas of acute gastritis, atrophy and hyperplasia in NG-treated rats with the normal mucosa in controls. No differences were observed in MC and BrdU LI between normal antrum and carcinoma cells which showed an AgNORs mean number lower than in the isthmic cells of controls (2 P < 0.005). Moreover, significant correlations were found comparing changes in AgNOR numbers with MC (r = 0.89, P < 0.001) and BrdU LI (r = 0.66, P < 0.001) in different lesions. These data show that evaluation of AgNOR numbers does not allow the identification of malignant cells in NG-induced gastric carcinoma. However AgNOR quantification seems to be a reliable index of cell kinetics and related well with the cellular dividing fraction.

Adenocarcinoma↗
PubMed1992

Surgical treatment of Krukenberg tumours: case reports and clinical consideration.

The authors present 4 cases of Krukenberg tumour of the ovary, secondary to carcinoma of the stomach (3 cases) and carcinoma of the breast (1 case). Pathologically it is characterized by the presence of typical signet ring cells and a diffuse infiltration of the stroma that gives the appearance of a sarcoma. Clinical data, computed tomography (CT) and sonographic findings in these four cases are analyzed. A review of the literature concerning this condition is provided and the treatment of the disease is discussed emphasizing the role of prophylactic oophorectomy.

Adenocarcinoma↗
PubMed1991

A comparative study of histopathology, hormone receptors, peanut lectin binding, Ki-67 immunostaining, and nucleolar organizer region-associated proteins in human breast cancer.

The current study was performed on 71 cases of human female breast cancer and compares the results of five morphologic methods developed for the detection of estrogen receptors (ER), progesterone receptors (PgR), lectin Peanut agglutinin (PNA) binding sites, monoclonal antibody Ki-67 immunoreactivity, and the mean number of argyrophilic nucleolar organizer regions (Ag-NOR). All the parameters were evaluated on serial cryostat sections representative of a closely related, if not identical, neoplastic population. A significant positive correlation was found between the occurrence of estrogen, progesterone, and peanut receptors and between Ki-67 immunoreactivity, mean number of NOR, and mitotic index. Furthermore, ER, PgR, and PNA receptors showed a significant, inverse correlation with Ki-67 immunoreactivity, mitotic index, and mean number of Ag-NOR. These results provide further data that support the hypothesis that (1) progesterone and PNA receptors are estrogen-induced and indicate a metabolic response of the target cells to functioning estrogen receptors; (2) the mean number of NOR reflects the cell kinetics of the tumor; and (3) metabolic differentiation of neoplastic cells is inversely correlated to the proliferation index.

Antibodies, Monoclonal↗
PubMed1991

Expression of interphasic nucleolar organizer regions in normal, dysplastic and neoplastic colorectal mucosa.

Silver-binding nucleolar organizer region (Ag-NOR) expression in interphasic nuclei was studied in normal, dysplastic and neoplastic colorectal mucosa at the light microscope level and by means of an image analyser (IBAS II). Both methods showed a progressive increase in the mean number of Ag-NOR sites per nucleus from mild dysplasia to invasive carcinoma. Ag-NOR counts differed significantly in the various classes of lesions (P less than 0.001), except between moderate and severe dysplasia (P greater than 0.05). Severe dysplasia showed a mean number of NORs lower than that for invasive carcinoma though an overlap in the respective frequency distributions was observed. The mean of the variances of the mean dot areas per cell nucleus (pooled variance) also showed a step-wise increase from normal to neoplastic lesions, indicating a greater variability in NOR size as a characteristic of malignant cells. A similar increase was observed in the percentage of nuclear area occupied by Ag-NORs. The mean area per silver-stained dot was also measured in the different classes of lesions by IBAS II. Data obtained showed no significant differences among the values. In conclusion, the wide overlap between the frequency distributions does not allow consideration of the Ag-NOR count alone to be a reliable marker of malignant transformation in a single cell. It appears that the study of Ag-NOR number needs to be evaluated together with dot anisometry in order to be a useful criterion in distinguishing the biological behaviour of neoplastic lesions in colorectal mucosa.

Colon↗
PubMed1991

MR imaging of renal transplant rejection.

The results of 62 consecutive MR examinations were correlated with the subsequent clinical course and histologic results. Twenty-six cases of rejection showed a marked diminution of cortico-medullary differentiation (CMD). The renal parenchymal vascular pattern and visibility of renal sinus fat were not markedly altered in rejection and there was no difference between normal and rejected allograft shape. The ability of MR imaging to diagnose renal transplant rejection is only based on CMD, which, however, is non-specific. In 2 cases of severe acute rejection, T2 weighted images showed an abnormal signal intensity of the cortex due to renal infarction. Our preliminary results in 8 patients with Gd-DOTA injection showed 2 cases with necrosis seen as areas with absent contrast enhancement. This technique seems to be promising in the detection of perfusion defects.

Adult↗
PubMed1990

[Cancer of the kidney: venous staging using magnetic resonance imaging].

Venous tumor invasion in 42 renal cell carcinomas was evaluated by MRI. A correct diagnosis of renal vein and inferior vena cava (IVC) involvement was made in 14 of 17 tumors: 1 false negative diagnosis of right renal vein invasion was due to a double renal vein in which the inferior vein (identified by MRI) was not involved; 2 cases of IVC involvement were understaged (1 case of suprahepatic extension) or not identified (the false negative of renal vein invasion previously described). One false positive (among 31 tumors without venous invasion) was reported in a case of a large tumor in which the compressed but free right renal vein was overevaluated by MRI.

Carcinoma, Renal Cell↗
PubMed1990

[Extracorporeal lithotripsy of urinary calculi. Results and radiologic criteria of effectiveness. Apropos of 700 cases].

The results of extracorporeal shock wave lithotrity (Dornier lithotriptor) for 700 cases of urinary calculi have been reviewed and correlated with the radiological features of the calculi in order to define some predictive radiological criteria of effectiveness. The calculi were broken up in 74.5% of all cases, complete destruction (no residual fragment) was achieved in 34.5% and partial destruction in 40% of cases. The rate of failure (failure to break up or scatter the calculus) is 8.9%. Complications were observed in 2.6% of all cases, a second session of lithotrity or a surgical operation was required in 4.8% of cases (evolution lost to follow-up: 9.2%). The comparison of these results with the radiological data obtained before lithotrity allows distinguishing 2 categories of calculi: 1) Calculi with a favorable prognosis: single, smaller than 1 cm, pyelic, not very opaque and heterogeneous, located in normal-sized cavities; 2) calculi with a poor prognosis: multiple, larger than 2 cm, lower calyceal or ureteral, very opaque and homogeneous, located within dilated cavities.

Adolescent↗
PubMed1988

Mediastinal angiofollicular lymph node hyperplasia, hyaline-vascular type with mucocutaneous manifestations.

A never previously reported association between mediastinal angiofollicular lymph node hyperplasia (ALNH) of the hyaline vascular type and mucocutaneous manifestations in a twenty-one-year-old man is described. Mucocutaneous lesions, unresponsive to medical therapy, promptly disappeared after resection of the mediastinal mass, indicating, as suggested for the plasmacell type, a close relationship between the systemic manifestations and ALNH.

Adult↗
PubMed1988

[Aberrant papillae. Apropos of 47 personal cases. Review of the literature].

Based on a personal series of 47 cases of aberrant papillae and a review of the literature, the authors stress the relative frequency of this anomaly and the almost constant possibility of making the diagnosis by means of intravenous pyelography on the basis of the following signs: regular, round or oval filling defect, surrounded by a fine opaque halo which separates it from the surrounding urine; or a notch with a regular arc-shaped border prolonged towards the exterior at its two extremities by a small spur. This spur, like the halo on the frontal view, corresponds to the presence of a small fornix at the insertion of the wall into the papilla. In doubtful cases, the persistence and stability of the image on repeated films constitutes a valuable diagnostic element. Haematuria is not more frequent in cases of aberrant papillae than in the overall population seen in a urological radiology department; in most cases, it is unrelated to this papilla. Only exceptional cases presenting with bleeding from the papilla may raise diagnostic problems due to the irregular contours of this papilla as a result of the vascular dysplasia responsible or the presence of clots. However, the finding of an opaque halo at the periphery of the filling defect or a spur at the extremities of the notch should draw attention, suggest the diagnosis and prohibit any aggressive management.

Female↗
PubMedDate not supplied

Intraoperative diagnosis of nervous system lesions.

OBJECTIVE: To determine the accuracy of comparative cytologic and frozen section intraoperative diagnosis in neuropathology and the relevance of diagnostic accuracy during both craniotomic and stereotactic biopsies and to provide further data on rare and/or diagnostically controversial lesions. STUDY DESIGN: Both cytologic and frozen section preparations were employed in the intraoperative diagnosis of 85 consecutive central and peripheral nervous system lesions obtained from classical surgery (70 samples, 4 of which were intramedullary) and stereotactic biopsies (15 samples). RESULTS: Combining cytologic and frozen section details allowed a fair diagnosis in 81 cases (95.29%), confirmed on paraffin sections. In the remaining cases intraoperative misdiagnosis was due to technical-staining defects (1 case); absence of tumor differentiation, resolved only by ultrastructural examination (2 cases); and marked tumor heterogeneity, resolved by wide tissue sampling and immunohistochemistry (1 case). CONCLUSION: Besides providing a general description of cytologic and frozen section criteria useful in intraoperative diagnostic neuropathology and adding further details about some problematic and/or rare entities, our work confirmed: (1) the usefulness of comparative cytologic and frozen section examination in the intraoperative diagnosis of central nervous system lesions, (2) the relevance of the accuracy of intraoperative diagnosis during both craniotomy and stereotaxis, including intramedullary samples; and (3) the importance of fair "conduct" in intraoperative neuropathology, always comparatively considering morphologic and clinicoradiologic data.

Central Nervous System↗
PubMedDate not supplied

Value of cytology as an adjunctive intraoperative diagnostic method. An audit of 2,250 consecutive cases.

OBJECTIVE: To evaluate the role of intraoperative cytology (IC) in the improvement of diagnostic accuracy obtained by frozen section (FS) alone. STUDY DESIGN: Comparison of 2,250 intraoperative cytologies performed along with frozen sections, with the final diagnoses achieved on paraffin sections. RESULTS: In 18 cases the diagnoses were deferred until the paraffin sections at the time of intraoperative consultation. The diagnostic accuracy in distinguishing benign from malignant lesions by combined intraoperative cytology and frozen section was 99.2%. The accuracy rate is significantly higher than that reported in large series based on frozen section preparations alone. Sensitivity and specificity were, respectively, 98.2% and 100%. The diagnostic accuracy of each technique alone was 94.9% for FS (sensitivity 89.9%, specificity 97.9%) and 96% for IC (sensitivity 94.9%, and specificity 96.8%). Although specific diagnoses were more frequently formulated on the bases of frozen section examination, FSs were not diagnostic in 113 case in which cytology allowed a specific diagnosis. CONCLUSION: Our results emphasize the increasingly important diagnostic role of intraoperative cytology as an adjunct to frozen section. The approach does have limitations.

Breast Neoplasms↗