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Biomedical subjects

F Paraf

Publications and source records attributed to F Paraf.

At least 19 recordsLinked to original sources
PubMed1998

Expression of CD44 in premalignant and malignant Barrett's oesophagus.

AIMS: To establish the prevalence of CD44 protein expression in a large surgical series of Barrett's adenocarcinoma and associated preneoplastic lesions and to correlate this expression with clinicopathological data and prognosis. METHODS AND RESULTS: CD44H and variants (V4/V5, V6) expression was detected by immunohistochemistry in formalin-fixed, paraffin wax tissue samples of Barrett's mucosa (50) and Barrett's adenocarcinoma (73) obtained from surgical resections from 73 patients. This expression was correlated with pathological features of the tumour and prognosis. CD44H and V6 expression was found in 62% and 55% of Barrett's specialized mucosa negative for dysplasia and in 70% and 63% of Barrett's adenocarcinoma, respectively. CD44H and V6 expression was restricted to the lower part of the crypts in Barrett's specialized mucosa negative for dysplasia and reached the upper part of the crypts in high-grade dysplasia. A significant relation was found between CD44V6 expression and depth of tumour invasion in the oesophageal wall (P = 0.05), neoplastic vascular invasion (P = 0.0001), neoplastic perineural invasion (P = 0.0004) and stage in Rosenberg's classification (P = 0.02). Cancers with CD44V6 expression had a significantly poorer prognosis (5-year survival: 17%) than those without (5-year survival: 44%) (P = 0.02) in univariate analysis. However, multivariate analysis showed that CD44V6 expression had no independent prognostic value when tumour invasion and lymph node involvement were taken as explanatory variables. CONCLUSION: CD44H and V6 are frequently expressed in Barrett's oesophagus. The pattern of expression that we observed from mucosa negative for dysplasia to adenocarcinoma suggests that CD44H and V6 may be involved in the carcinogenesis of Barrett's mucosa. CD44V6 expression in adenocarcinoma is correlated to aggressive pathological features.

Adenocarcinoma↗
PubMed1998

Intraoperative localization of neuroblastoma in children with 123I- or 125I-radiolabeled metaiodobenzylguanidine.

BACKGROUND: This study describes a novel method of intraoperative localization of neuroblastoma with a gamma-detecting probe, to detect in situ tumor binding of radiolabeled 123I- or 125I-metaiodobenzylguanidine (MIBG) and improve the quality of tumor resection. METHODS: Fifty-eight children underwent 66 surgical procedures with intraoperative detection of radiolabeled MIBG. All patients with positive MIBG scintiscans at diagnosis were included in the study. A tumor/background ratio exceeding 2:1 at the time of operation was considered positive, indicating a significant uptake of MIBG, compatible with the presence of malignant cells. The surgeons were requested to evaluate the contribution of the method to the surgical procedure. Sensitivity and specificity of the method with either 123I-labeled MIBG or 125I-labeled MIBG, on the basis of correlations between probe findings and pathologic analysis of 288 resected specimens, were determined. RESULTS: Intraoperative detection was helpful in 65% of surgical procedures, allowing a better definition of tumor limits and extension to locoregional nodes or detection of small and nonpalpable tumors in sites with difficult surgical access, especially during operation for relapse. The detection was not contributory in 35% of the procedures (well-localized tumors, thoracic neuroblastoma for technical reasons, highly differentiated tumors as ganglioneuroma, and tumors with mainly necrosis or fibrosis). The sensitivity of 123I and 125I was the same (91% and 92%), but the specificity of 125I (85%) was significantly higher than that of 123I (55%) (p < 0.005). CONCLUSIONS: First, this study demonstrates the feasibility of intraoperative detection, with radiolabeled MIBG, of neuroblastoma in children. We advocate the use of 125I rather than 123I. Second, the method is useful to improve the quality of macroscopic resection in widespread neuroblastoma with nodal involvement, in sites with difficult access, and in operations for relapse.

3-Iodobenzylguanidine↗
PubMed1997

Brain tumor-polyposis syndrome: two genetic diseases?

PURPOSE AND DESIGN: This report presents a comprehensive and statistical analysis of the brain tumor-polyposis (BTP) cases referred to as Turcot's syndrome in the literature. RESULTS: BTP patients encompass a heterogeneous group that can be classified into two statistically distinct clinical entities based on phenotype of the polyps (P = .0001), presence of colorectal cancer (P = .0001), type of brain neoplasm, ie, glioma or medulloblastoma (P = .0001), presence of skin lesions (P = .0004) and cafe-au-lait spots (P = .0008), as well as consanguinity (P = .0135). CONCLUSION: The first entity (BTP syndrome type 1) consists of patients who have glioma and colorectal adenomas without polyposis (non-FAP cases), and their siblings with glioma and/or colorectal adenomas. For these patients, we show that the patient's age at malignant glioma occurrence is less than 20 years (50 to 80 years in the general population), which strongly supports the existence of an underlying genetic cause. The neoplasms of these patients show DNA replication errors, which suggests a relationship with hereditary nonpolyposis colorectal cancer (HNPCC), a disease characterized by germline alterations in DNA mismatch repair genes. The second entity (BTP syndrome type 2) consists of patients with a CNS tumor that occurs in a familial adenomatous polyposis kindred (FAP cases). These patients carry germline mutations in the APC gene, which suggests that mutations in this gene might predispose to brain tumors. Risk analysis shows increased incidence of medulloblastoma in FAP patients, but APC mutations are not found in sporadic glioma or medulloblastoma. Therefore, further investigations should establish whether the occurrence of medulloblastoma in an FAP family represents a variant of FAP.

Adenomatous Polyposis Coli↗
PubMed1997

[Familial adenomatous polyposis and thyroid cancer].

Familial adenomatous polyposis may exhibit extracolonic tumors which include thyroid carcinoma. It has been recently suggested that thyroid carcinomas associated with familial adenomatous polyposis show distinct histologic features different from sporadic follicular or papillary thyroid carcinomas. We report a case of thyroid carcinoma in a young girl affected by familial adenomatous polyposis, whose thyroid tumor exhibited some of these features. This finding confirms the peculiar histologic phenotype of the thyroid carcinomas associated with familial adenomatous polyposis. Alterations of the APC gene responsible for familial adenomatous polyposis may play a role in the development of these thyroid cancers.

Adenomatous Polyposis Coli↗
PubMed1997

[Subadventitial cyst of the popliteal artery. Non-invasive explorations. Anatomo-pathologic data].

Subadventitial cyst of the popliteal artery is a well known entity. We report a new case and the diagnostic and therapeutic advantages of noninvasive explorations. Transcutaneous duplex-scan provided diagnosis and showed cystic formations in contact with a segmentary occlusion of the popliteal artery. Magnetic resonance imaging (MRI) evidenced communication between the cysts and the articular capsule of the knee joint. Surgical exeresis confirmed the communication with the synovial fluid. This observation demonstrated: i) the contribution of duplex-scan for the diagnosis of adventitial cysts and arterial consequences; ii) the contribution of MRI in identifying communication with the synovial fluid; iii) the presence of arterial wall lesions (necrosis of the media) would favor no conservative treatment.

Humans↗
PubMed1997

[Localization of a tumor suppressor gene distal to D22S270 in colorectal cancers].

Recurrent allelic losses on chromosome 22q have been reported in colorectal cancer, distal to the NF2 gene, suggesting that another tumor suppressor gene might be involved. We report here the typing of 256 sporadic colorectal tumors and 18 colonic cancer cell lines using a set of chromosome 22 polymorphisms, ranging from 20 to 45. A panel of somatic cell hybrids, that allows to distinguish 11 bins in the 22q13 region, was used to localize 19 of the 45 selected markers and the putative tumor suppressor gene BZRP. Allelic-loss was observed in 43% of tumors. The minimal region of deletion that could be determined, telomeric to locus D22S270, refines significantly the position of the gene. The localization of the BZRP gene in this region led to a systematic screening for somatic point mutation. Direct sequencing of its coding sequence in 36 tumors hemizygous for chromosome 22 allowed the identification of three polymorphisms but failed to detect somatic mutation.

Adenocarcinoma↗
PubMed1996

Pituitary adenylate cyclase activating peptide and its receptors are expressed in human neuroblastomas.

Vasoactive intestinal peptide (VIP) has been considered as an autocrine growth factor in neuroblastomas. Pituitary adenylate cyclase activating polypeptides (PACAPs) are newly recognized members of the VIP family of neurohormones. As compared to VIP, PACAP has been reported to be biologically more potent and more efficient in tissues expressing selective PACAP receptors rather than common VIP/PACAP receptors. PACAPs and VIP interact with the same affinity and stimulate adenylate cyclase activity with the same efficacy and potency on the VIP receptors, but PACAPs act also on a more selective PACAP receptor that also recognizes VIP but with a 100- to 1,000-fold lower affinity. Thus, depending on the type of receptors expressed at a cell surface, PACAP may be more potent and efficient than VIP. The capacity of 22 surgical specimens of neuroblastomas and of 5 established cell lines to synthesize PACAP and VIP and to synthesize and express PACAP receptors and VIP receptors was studied. Using the reverse transcriptase-polymerase chain (RT-PCR) method with specific primers, we detected the mRNAs coding for PACAP and VIP in 19 and 3 out of 22 samples, respectively. PACAP mRNA was expressed in 3 of the 5 cell lines studied and VIP mRNA in 4. Using the same techniques, PACAP and VIP receptors mRNA were detected in 21, and 13 of the 22 tumor samples and in 5 and 1 of the cell lines studied, respectively. The expression of the PACAP receptor was demonstrated by direct binding studies and/or by the relative potency of PACAPs and VIP to stimulate adenylate cyclase activity in 16 of the 22 tumors and in all the cell lines. In addition, there was no correlation between tumor stage and the expression of mRNA coding for the peptides and the receptors. The present results demonstrated that PACAP could also be a candidate as an autocrine regulator of neuroblastoma which a higher activity than VIP.

Base Sequence↗
PubMed1996

Renal involvement in von Hippel-Lindau disease.

Renal involvement in von Hippel-Lindau (VHL) disease has emerged as the most prevalent cause of death in this hereditary disorder. In a group of 43 VHL patients (23 unrelated families) with renal lesions we examined whether severity of renal disease is affected by parental inheritance and VHL subtype (1, without pheochromocytoma; 2, with pheochromocytoma). We also tested whether and how nephron-sparing surgery could be applied. Renal involvement comprised multiple cysts and bilateral and multifocal carcinomas (RCC) which were detected by screening in 38 patients, at 30.5 (14 to 62) years of age. The severity of the renal disease was similar in VHL type 1 (79% of the pedigrees) and 2 (21%). It was not influenced by the sex of the carrier. Twenty-nine patients were operated on at a mean age of 33.6 years: 21 patients (28 kidneys or 61% of all operated kidneys) underwent nephron-sparing surgery, 4 had complete ablation of involved kidneys and thus required dialysis, 3 had uninephrectomy and 1 had cyst fenestration. Vascular thrombosis was the most severe early complication. It occurred in 4 of 9 kidneys treated by ex vivo surgery. During a median follow-up of 29 months, local recurrence occurred in 5 of 21 (24%) patients treated by nephron-sparing surgery, whereas 2 developed metastasis. Chronic renal failure (creatinine > 120 mumol/liter) affected 11 patients; in 9 of them, it was due to sequelae of surgery. In conclusion, screening of RCC and nephron-sparing surgery are of value in VHL patients. However, indications of ex vivo surgery should be drastically restricted and renal sequelae are not uncommon. Renal followup is required because of the risk of recurrence.

Adolescent↗
PubMed1996

Local staging of prostate cancer by endorectal MRI using fast spin-echo sequences: prospective correlation with pathological findings after radical prostatectomy.

OBJECTIVE: To evaluate the accuracy of endorectal magnetic resonance imaging (MRI) with fast spin-echo sequences in the local staging of clinically localized prostate cancer. PATIENTS AND METHODS: Seventy-one patients with a clinical T1 (18 patients) or T2 tumour (53 patients) underwent endorectal MRI 2-12 weeks before radical prostatectomy. Extraprostatic tumour was diagnosed if MRI showed signs of capsular penetration and/or invasion of the seminal vesicle and/or distal urethra or bladder neck. If the pathological examination showed a single positive margin with no periprostatic tissue, the tumour was classified as indeterminate and not as a T3 tumour. RESULTS: Of the 25 cases of capsular penetration. MRI correctly identified 10 (sensitivity 42%, specificity 100%). Of the 14 cases with seminal vesicle invasion, MRI correctly identified six (sensitivity 43%, specificity 100%), but showed other signs of extraprostatic tumour spread in seven of the eight unidentified cases. Overall, MRI identified 16 of the 30 patients (53%) with occult extraprostatic spread of tumour; there was only one false-positive result. The sensitivity, specificity and accuracy of MRI were 53, 96 and 74%, respectively. CONCLUSION: Endorectal MRI can reduce the rate of preoperative understaging from 42% to 22% and it can be used for a given individual because it can detect extraprostatic invasion with 96% specificity, ensuring that very few, if any, patients will be deprived of curative surgery.

Aged↗
PubMed1996

[Budd-Chiari syndrome secondary to post-traumatic stenosis of the inferior vena cava].

Budd-Chiari syndrome with inferior vena cava involvement is usually due to membranous obstruction; traumatic origin of inferior vena cava lesions is very rare. We report a case of Budd-Chiari syndrome in a 29 year-old man, 3 years after an abdominal trauma. Cavography showed 50% stenosis in the sushepatic portion of the inferior vena cava. After two unsuccessful percutaneous transluminal angioplasty procedures, a surgical resection of the stenotic vein was performed. The histological study of the stenotic segments showed that the three layers of the venous wall had been replaced by a dense fibrous tissue. No inflammation or thrombosis were found. This case of stenosis of the vena cava shows that histological examination can be used to assess the traumatic nature of the lesion, showing a different histological pattern from that of the membranous obstruction in which the basic structure of the venous wall is preserved.

Accidents, Traffic↗
PubMed1996

[Arterial fibromuscular dysplasia and Bourneville's tuberous sclerosis].

Tuberous sclerosis is an autosomal dominant disease characterized by the development of multiple hamartomas which involve mainly the skin, the brain, the kidneys, and the heart. Vascular involvement is uncommon, with essentially several reports of aortic aneurysm. The present case concerns a two and a half year-old girl with known tuberous sclerosis, who underwent a graft replacement of an abdominal aortic aneurysm revealed by hypertension, associated with a right nephrectomy for multiple renal angiomyolipomas and cysts. Microscopic examination of the aortic aneurysm and the right renal artery showed fibromuscular dysplasia. This case and the rare previous reports emphasize the possible vascular involvement in tuberous sclerosis, and suggest that arterial fibromuscular dysplasia may represent an additional manifestation of the disease.

Aortic Aneurysm↗
PubMed1996

Extensive spread of a squamous cell carcinoma in situ of the esophagus: an unusual case.

A case of extensive squamous cell carcinoma in situ along the esophageal height in a 58-yr-old female is presented. After subtotal esophagectomy, the course was favorable 11 months later. The pathological study of the specimen showed that the tumor was confined to the epithelium. The lesion was located diffusely along the entire esophageal height and one-third of its circumference. Neither foci of dysplasia or inflammatory erosions nor metastatic nodes were observed. Problems pertaining to the terminology, histopathological interpretation, pathogenesis, and management of such unusual lesion are reviewed. The necessity of large radical resection of the esophagus was validated upon histological confirmation that the resected stump is cancer free.

Carcinoma in Situ↗
PubMed1995

Expression of bcl-2 oncoprotein in renal cell tumours.

Expression of bcl-2 is associated with inhibition of apoptosis and extension of cell survival. The importance of apoptosis in relation to the development and progression of renal cell neoplasia remains undefined so far. In order to determine the expression of bcl-2 oncoprotein in normal and neoplastic renal cells, 37 renal tumours were investigated by immunolabelling, including 13 clear cell carcinomas, ten tubulopapillary carcinomas, four chromophobic renal cell carcinomas, and ten oncocytomas. Twenty-six samples of adjacent normal renal tissue served as controls. bcl-2 expression was correlated with cell proliferation activity as estimated by Ki67 antigen expression, and p53 protein expression in the tumour samples. The results demonstrate that in the normal kidney, positive bcl-2 immunostaining was present in glomerular parietal epithelial cells, in distal tubular cells, and in sparse proximal tubule cells. Renal cell tumours showed heterogeneous bcl-2 expression according to the tumour cell type. While the majority of carcinomas of clear cell type were usually negative or contained sparsely distributed positive cells, all tubulopapillary carcinomas were consistently positive for bcl-2. In oncocytomas and chromophobic carcinomas, there was a low percentage of bcl-2 immunoreactive tumour cells; some nuclear bcl-2 positivity was detected in one chromophobic tumour. These findings indicate variable bcl-2 oncoprotein expression in different types of renal cell tumours, with the highest level of expression in tubulopapillary carcinomas. No clear relationship was found between nuclear grade, cell proliferation activity, and level of bcl-2 expression. p53 protein was detected in only one tubulopapillary carcinoma.

Biomarkers, Tumor↗
PubMed1995

Clinicopathological relevance of the association between gastrointestinal and sebaceous neoplasms: the Muir-Torre syndrome.

The association between sebaceous neoplasms of the skin and visceral cancers, known as Muir-Torre syndrome, is described in three patients, including one with an extensive history of cancer in his family. The first patient, a 54-year-old man, developed multiple sebaceous adenomas, epitheliomas, and carcinomas in association with a colonic carcinoma 6 years after cardiac transplantation. Family history in this patient disclosed colon cancer in 17 relatives. The second patient was a 51-year-old man who had recurrent adenocarcinoma of the sigmoid colon, adenocarcinoma arising in Barrett's esophagus, and sebaceous epithelioma during a period of 15 years. The third patient was a 90-year-old man with a sebaceous adenoma followed 5 months later by adenocarcinoma of the sigmoid colon with liver metastases. Muir-Torre syndrome in 129 other patients published in the literature is reviewed. Although it is a rare disease, Muir-Torre syndrome requires recognition because skin lesions may be the first sign of the syndrome and this may lead to early diagnosis of associated visceral cancers. Moreover, because this syndrome appears to be inherited, family members should be screened for visceral cancer, especially colorectal adenocarcinoma.

Adenocarcinoma, Sebaceous↗