Search PubMed⌕ Search

Biomedical subjects

P Bossi

Publications and source records attributed to P Bossi.

At least 19 recordsLinked to original sources
PubMed1997

[Tuberculous meningitis: clinical, biological and x-ray computed tomographic comparison between patients with or without HIV infection].

OBJECTIVES: Determine possible differences in clinical manifestations, laboratory findings and neuroimaging results in tuberculous meningitis patients with and without HIV infection. PATIENTS AND METHODS: We retrospectively reviewed data of 38 patients with positive cerebrospinal fluid cultures for Mycobacterium tuberculosis who were hospitalized in 3 university hospitals in Paris over the last 11 years. RESULTS: There were 24 HIV-infected patients and 14 without HIV infection. Mean CD4 lymphocyte count was 103 +/- 180/mm3 in the HIV group. Age (median age = 33 years for the HIV group vs. 53 for the non-HIV group), sex ratio (3 vs. 0.75), and prior history of tuberculosis (46% vs. 43%) were similar in both groups. Clinical presentation was similar for headache (83% in HIV group vs. 50% in non-HIV group; p = 0.02) and confusion (54% vs. 93% in non-HIV group p = 0.05). Serum natremia (mmol/l) (131 +/- 5 vs. 125 +/- 8; p = 0.024), white blood cell count (x 10(9)/l) (5.8 +/- 4.7 vs. 10.7 +/- 1.7; p = 0.37) and erythrocyte sedementation rate (mm/h) (68 +/- 34 vs. 31 +/- 35; p = 0.003) were significantly different in the 2 groups. Median cerebrospinal fluid findings were similar in the 2 groups: leukocytes (x 10(6)/l) (375 +/- 860 vs 218 +/- 250), glucose (mmol/l) (2.3 +/- 0.9 vs 2.7 +/- 1.9) and protein (g/l) (3.8 +/- 7.1 vs. 2.6 +/- 1.6). CT-scans of the brain were similar in the 2 groups. Mortality during hospitalization was similar (42% vs 36%; NS). CONCLUSION: HIV infection appears to have little impact on the presentation of tuberculous meningitis.

Adult↗
PubMed1997

p53 protein accumulation and p53 gene mutation in esophageal carcinoma. A molecular and immunohistochemical study with clinicopathologic correlations.

BACKGROUND: p53 gene mutation and p53 protein accumulation are common in human cancer. However, their clinical significance is controversial and p53 accumulation may not correlate with gene mutation. The current study investigates the occurrence of p53 alterations in esophageal carcinoma, the correlation between the analyses at the gene and protein level, and their prognostic significance. METHODS: A series of 74 esophageal carcinomas (46 squamous cell carcinomas, 21 Barrett's adenocarcinomas, and 7 undifferentiated carcinomas) was studied by single strand conformation polymorphism (SSCP) analysis and immunohistochemistry (IHC) to detect p53 mutation and accumulation, respectively. RESULTS: p53 mutations in exons 5-8 were detected in 53% of the carcinomas whereas p53 accumulation was observed in 57% of cases. Comparing SSCP and IHC, there were 27 discordant cases (38%). Overall, only 20 tumors (27%) did not display p53 mutation and/or p53 accumulation. No associations were found between p53 aberrations and clinicopathologic parameters, including patients age and gender tumor type, stage, and grade. p53 protein accumulation and p53 gene mutation were not related to patient survival by univariate or multivariate analysis in esophageal carcinomas. CONCLUSIONS: p53 aberrations are very common in esophageal carcinomas. However, p53 gene mutation and p53 protein accumulation have a significant discordance, suggesting that p53 function may be inactivated by mechanisms other than mutation. p53 aberrations do not independently predict prognosis in esophageal tumors.

Adenocarcinoma↗
PubMed1995

Angiogenesis in colorectal tumors: microvessel quantitation in adenomas and carcinomas with clinicopathological correlations.

Angiogenesis is a crucial step in tumor growth and progression. Its quantitation by microvessel counting is of prognostic value in several types of malignancies. Scarce data are available on angiogenesis in gastrointestinal tumors. We studied 36 adenomas and 178 large bowel carcinomas to evaluate the onset of angiogenesis in colorectal tumorigenesis and to assess the prognostic significance of microvessel quantitation. Endothelial cells were immunostained with an anti-CD31 mAb; in each case three microscopic fields (x 200) with the highest number of microvessels were counted: the average value of the three fields was used to evaluate the significance of microvessel density (MVD). MVD of normal mucosa (41 cases) served as controls. MVD was 42 +/- 10 in the normal mucosa, 64 +/- 10 in adenomas, and 115 +/- 39 in carcinomas (normal versus adenomas, P < 0.001; adenomas versus carcinomas, P < 0.0001). The transitional mucosa adjacent to carcinomas displayed intermediate levels of MVD (89 +/- 23; P < 0.001 versus adenomas; P < 0.001 versus carcinomas). High MVDs were not associated with metastases, disease stage, and patient survival. The data indicate that angiogenesis is an early, critical step in colorectal tumorigenesis. MVD, however, does not provide significant prognostic information in colorectal cancer patients.

Adenocarcinoma↗
PubMed1995

[Clinical and paraclinical diagnosis of AIDS neurologic lesions].

Seventy to eighty percent of HIV-infected patients exhibit neurological disorders at an advanced stage of the disease. In almost 90% of cases anatomical examination of brains shows histological lesions. Even when often reversible neurological disorders occur during the HIV primary infection, most of the manifestations of central nervous system (CNS) damage remains the prerogative of severe immunodepression. The principal CNS lesions associated with HIV infection are presented here with the clinical and biological elements that lead to the diagnosis. Cerebral toxoplasmosis holds a privileged place in these manifestations since it responds to an efficient curative and prophylactic treatment with a well-codified medical care based on the test treatment. Biological data, therefore, only have a contributing value. HIV encephalopathy is frequent, but the dementia syndrome is less frequent than the finding of associated imaging and pathological anatomy: atrophy and lesions of the white matter. Thus, the dementia complex is an elimination diagnosis. Cryptococcosis must be systematically considered, not only in patients with meningeal symptoms and headaches, but also with those with isolated fever. The demonstration of cryptococcus and cryptococcic antigen in the CSF has an almost absolute diagnostic value; imaging plays a very small diagnostic role, looking for an exceptional cryptococcoma. Multifocal progressive leukoencephalopathy benefits from the accuracy of MRI, and the diagnosis is usually based on clinical data, MRI and evidence of the virus in the CSF by PCR, even though the only mean of obtaining full proof is, in theory, stereotaxic biopsy. Primary cerebral lymphoma is the diagnostic alternative to toxoplasmosis.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS Dementia Complex↗
PubMed1994

Cytoplasmic accumulation of p53 protein: an independent prognostic indicator in colorectal adenocarcinomas.

BACKGROUND: Aberrations of the p53 gene (also known as TP53) frequently lead to the synthesis of mutant proteins that accumulate in the nuclei and/or cytoplasm of neoplastic cells. Intracellular p53 protein accumulation may be an unfavorable prognostic parameter in breast, lung, ovarian, gastric, and colorectal cancers. Specific classes of p53 gene mutations, assayed by characteristic subcellular p53 protein accumulation patterns, may be useful prognostic indicators. PURPOSE: The prognostic value of nuclear and cytoplasmic p53 protein accumulation in the tumor cells of patients with colorectal carcinoma was studied. METHODS: Antibodies PAb 1801 and CM1 were used for immunocytochemical assay of nuclear and cytoplasmic p53 protein accumulation in a retrospective series of colorectal carcinoma samples obtained from 206 patients who were followed for at least 5 years. Results were correlated with the following clinicopathologic parameters: patient sex and age; tumor site, stage, and grade; and DNA ploidy status of the tumors. Overall survival and disease-free survival were analyzed with the Kaplan-Meier method. Differences in distributions were analyzed using the Mantel-Cox method. Multivariate analysis was performed with the Cox proportional hazards model. RESULTS: Immunostaining with PAb 1801 revealed nuclear p53 accumulation in 46% (95) of 206 cases, whereas CM1 immunostaining of 197 cases showed nuclear and cytoplasmic p53 accumulation in 33% (65 cases) and 50% (99 cases) of the cases, respectively. In univariate analysis, both nuclear p53PAb 1801 and cytoplasmic p53CM1 protein accumulations were significantly associated with poor overall survival (P = .0198 and P = .0017, respectively) and with disease-free survival (P = .004 and P = .0016, respectively). When patients were analyzed according to site of their tumors, nuclear p53PAb 1801 protein accumulation was statistically significant only in the right colon (P = .027), whereas cytoplasmic p53CM1 protein accumulation was statistically significant in the left colon and rectum (P = .0016). In multivariate analysis, only cytoplasmic p53CM1 protein accumulation was associated with poor overall survival and with disease-free survival (P = .006 and P = .002, respectively). With the addition of DNA ploidy status, however, cytoplasmic p53CM1 protein accumulation remained significant only for disease-free survival (P = .035). In patients with tumors of the left colon and rectum, cytoplasmic p53CM1 protein accumulation was the most significant prognostic indicator for overall survival (P = .007) and disease-free survival (P = .002) after disease stage. CONCLUSION: Cytoplasmic p53CM1 protein accumulation, but not nuclear p53PAb 1801 protein accumulation, is an independent prognostic parameter in patients with colorectal carcinomas. IMPLICATIONS: Cytoplasmic p53CM1 accumulation may be a useful indicator of patients at high risk for disease recurrence who may benefit from aggressive adjuvant therapy.

Adenocarcinoma↗
PubMed1993

p53 immunoreactivity in inflammatory and neoplastic diseases of the uterine cervix.

Immunoreactivity for the tumour suppressor gene product p53 is commonly found in many different human malignancies and few premalignant lesions. Data on cervical neoplasms, however, are still lacking. We retrospectively investigated p53 immunoreactivity in 92 lesions of the uterine cervix, including 44 cases of chronic cervicitis, 29 squamous intraepithelial lesions (SILs), and 19 invasive carcinomas. p53 immunoreactivity, confined to the basal cell layer, was detected in 74 per cent of cases showing chronic cervicitis and in all cases with low-grade SILs. Conversely, suprabasal and/or diffuse p53 immunoreactivity was exclusively demonstrated in 25 per cent of high-grade SILs and in 74 per cent of invasive carcinomas. The results of this investigation document a high prevalence of p53-immunoreactive malignant tumours of the uterine cervix. In high-grade SILs, p53-immunoreactive cells paralleled the height of involvement by dysplastic changes within the squamous epithelium. A prolonged half-life of the protein is the most likely explanation for the occurrence of p53 immunoreactivity in neoplastic cells. The unexpected finding of p53-immunoreactive cells in inflammatory lesions, though possibly related to an increased proliferation rate of the basal cell compartment, requires further study and underlines the need for a careful approach to p53 immunocytochemistry.

Adenocarcinoma↗
PubMed1993

p53 accumulation in ovarian carcinomas and its prognostic implications.

Intranuclear p53 accumulation is a common finding in many different human tumors and is associated with a worse prognosis in breast, colon, and lung carcinomas. We immunostained a series of common epithelial ovarian cancers to assess (1) the prevalence of p53 accumulation and its clinicopathologic correlations, and (2) its prognostic implications. The study population comprised 98 patients (83 with follow-up data). A variable degree of p53 immunoreactivity, strictly confined to the neoplastic cells, was detected in 54 tumors (55%). Among these tumors there were 10 low expressors (1% to 10% immunoreactive tumor cells), 16 moderate expressors (10% to 50% immunoreactive cells), and 28 high expressors (> 50% immunoreactive cells). The prevalence of p53 immunoreactivity did not show any association with the histologic type of the tumors or with the disease stage at presentation. p53 Accumulation, however, was significantly more prevalent among poorly differentiated tumors (P = .0059, by analysis of variance). Life table analysis demonstrated that patients with tumors showing moderate and high p53 expression had worse disease-free and adjusted lengths of survival (P = .0011 and P = .0025, respectively, by Mantel-Cox). The patients with "early stage" disease (stages I and II) and p53 accumulation showed a trend toward shorter length of survival, but this did not reach statistical significance. However, patients with "advanced stage" disease (stages III and IV) and moderate or high p53 accumulation had a poorer prognosis (P = .0154 and P = .0171, for disease-free and adjusted length of survival, respectively). These results suggest that p53 accumulation occurs more frequently in tumors with aggressive behavior and that p53 immunoreactivity may have a prognostic role in certain subsets of patients with ovarian carcinoma.

Adult↗