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J Pradel

Publications and source records attributed to J Pradel.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Value of percutaneous hepatic biopsy in the diagnosis of presumed benign tumors of the liver].

The purpose of this study was to assess the accuracy of guided hepatic biopsy (GHB) and imaging techniques for presumed benign liver tumours and to determine their impact on surgical treatment. The study was carried out retrospectively in a surgical series of 15 consecutive patients with presumed benign liver tumours. The final diagnosis was 8 cases of focal nodular hyperplasia (FNH), 6 hepatic adenomas (HA) and one association FNH-HA. No morbidity was related to guided hepatic biopsy. All FNH detected on radiologic imaging or pathological examination of the biopsy specimen were true positive diagnoses. This study demonstrates that combined results of imaging techniques and percutaneous GHB could correctly diagnose three quarters of FNH before surgery. GHB is also useful when MRI imaging is indeterminate allowing a conservative approach for undiagnosed FNH.

Adenoma, Liver Cell↗
PubMed1995

Genetic and molecular analysis of terminal deletions of chromosome 3R of Drosophila melanogaster.

Terminal deletions of chromosome 3R are induced at a high frequency (3.2 x 10(-3)) by irradiating 45-4 Drosophila melanogaster females with a low dose of X-rays. The 45-4 line carries a white transgene inserted at 16 kb from the terminus and is homozygous for the mu-2 mutation, a gene involved in the repair of double-strand DNA breaks. Four of the 51 recovered deleted strains have lost modulo, the distalmost essential gene on chromosome 3R. Breakpoints of 22 deletions have been localised in a single hybridisation step, using pulsed-field gel electrophoresis to separate genomic DNA fragments obtained from digestion with a rare-cutter restriction enzyme. Breaks do not occur at random, but are rather clustered in three susceptible chromosomal domains. Backcross experiments resulting in transheterozygous (deleted chromosome/45-4) animals indicate that the activity of the white transgene is enhanced when the DNA break has occurred proximal to a critical position. This suggests that homologous chromosomal pairing distal to the critical position results in the definition of a more compact chromatin structure and, due to position effect, in the silencing of white.

Animals↗
PubMed1995

Role of CT in the acute nontraumatic abdomen.

The diagnostic workup of the acute abdomen always begins with a precise clinical history, a complete physical examination, and careful reading of plain films. Commonly performed additional imaging studies include contrast examination and, more recently, ultrasound. CT offers the advantage of allowing a comprehensive diagnostic evaluation of both solid and hollow viscera in neoplastic as well as in inflammatory and vascular disorders.

Abdomen, Acute↗
PubMed1995

Conservative surgery for low rectal carcinoma after high-dose radiation. Functional and oncologic results.

OBJECTIVE: Using a prospective, nonrandomized study, the authors evaluated the morbidity and functional and oncologic results of conservative surgery for cancer of the lower third of the rectum after high-dose radiation. SUMMARY BACKGROUND DATA: Colo-anal anastomosis has made sphincter conservation for low rectal carcinoma technically feasible. The limits to conservative surgery currently are oncologic rather than technical. Adjuvant radiotherapy has proven its benefit in terms of regional control, with a dose relationship. METHODS: Since June 1990, 27 patients with distal rectal adenocarcinoma were treated by preoperative radiotherapy (40 + 20 Gy delivered with three fields) and curative surgery. The mean distance from the anal verge was 47 mm (27-57 mm), and none of the tumors were fixed (15 T2, 12 T3). RESULTS: Mortality and morbidity were not increased by high-dose preoperative radiation. Twenty-one patients underwent conservative surgery (78%-17 total proctectomies and colo-anal anastomoses, 4 trans-anal resections). After colo-anal anastomosis, all patients with colonic pouch had good results; two patients had moderate results and one patient had poor results after straight colo-anal anastomosis. With a mean follow-up of 24 months, the authors noted 1 postoperative death, 2 disease-linked deaths, 1 controlled regional recurrence, 2 evolutive patients with pulmonary metastases, and 21 disease-free patients. CONCLUSIONS: These first results confirm the possibility of conservative surgery for low rectal carcinoma after high-dose radiation. A prospective, randomized trial could be induced to determine the real role of the 20 Gy boost on the sphincter-saving decision.

Adenocarcinoma↗
PubMed1995

DWnt-4, a novel Drosophila Wnt gene acts downstream of homeotic complex genes in the visceral mesoderm.

Wnt genes encode putative cell signalling proteins which play crucial roles during development. From a library of DNA fragments associated, in vivo, with Ultrabithorax proteins, we isolated a novel Drosophila Wnt gene, DWnt-4. Neither a paralog nor an ortholog of the gene exist in the current repertoire of full-length Wnt sequences. DWnt-4 maps close (30 kb) to wingless, suggesting that the two Wnt genes derive from a duplication that occurred early in evolution, since they are significantly diverged in sequence and structure. Developmental expression of DWnt-4 partially overlaps that of wingless. The gene is transcribed following a segment polarity-like pattern in the posterior-most cells of each parasegment of the ectoderm, and at two locations that correspond to parasegments 4 and 8 of the visceral mesoderm. The control of DWnt-4 expression in the visceral mesoderm involves a network of regulatory molecules that includes Ultrabithorax and other proteins from the homeotic complex (HOM-C), as well as the TGF-beta decapentaplegic gene product.

Animals↗
PubMed1995

wingless and DWnt4, 2 Drosophila Wnt genes, have related expression, regulation and function during the embryonic development.

The multigenic Wnt family encode secreted signalling molecules with important regulatory functions in various developmental processes. This paper reports an analysis of the relationships, in terms of structure, expression and function, that exist between the Drosophila genes wingless, the orthologue of the mammalian Wnt1 proto-oncogene, and DWnt4, a new member of the Wnt family. The 2 genes are physically clustered, are transcribed in overlapping embryonic territories under the control of the same regulatory molecules. Co-expression and co-regulation suggest first, that the close physical linkage results from the sharing of cis-control elements and second, that the 2 Wnt signals cooperate in developmental patterning events. Antisense RNA experiments revealed that signalling by DWnt4 is essential for cells from the anterior compartment of each parasegment to adopt a denticled fate. We propose that wingless and DWnt4 achieve opposite, but complementary functions in intrasegmental cell patterning of the embryonic ectoderm.

Animals↗
PubMed1994

CNRS defended.

Explore the source record for details and available documents.

France↗
PubMed1994

The modifier of variegation modulo gene acts downstream of dorsoventral and HOM-C genes and is required for morphogenesis in Drosophila.

Growing evidence involves chromatin structural flexibility in gene regulation during development. modulo is a dominant suppressor of position effect variegation, suggesting the participation of its product in the assembly of higher order chromatin structures. Here we report the patterns of modulo expression and regulation during embryogenesis, analyzed in correlation with phenotypical defects resulting from the amorphic mutation of the gene. Zygotic expression of modulo depends on the activity of genes which pattern the embryo along dorsoventral and anteroposterior axes and specify diversified morphogenesis, dorsal and the mesoderm-specific genes twist and snail direct modulo expression in the presumptive mesoderm. The homeotic genes Sex combs reduced and Ultrabithorax positively regulate the gene in the ectoderm of parasegment 2 and abdominal mesoderm, respectively, modulo mutants exhibit aberrant morphogenesis of tissues originating from those embryonic primordia which normally express the gene, but do not show defect in cell fate specification. We propose that down-stream of pattern-forming genes modulo controls, via chromatin structural changes, genes critical for the process of morphogenesis of several tissue types.

Animals↗
PubMed1994

Current CT/MRI examination of the upper intestinal tract.

When properly performed, CT of the abdomen can provide valuable information about mural diseases of the alimentary tract. It can demonstrate the digestive origin of an abdominal mass, categorize a given lesion on the basis of its specific CT appearance and any associated CT findings, assess the extramural spread of gastrointestinal lesion, guide various interventional procedures (biopsy, drainage) and follow a patient's response to therapy.

Crohn Disease↗
PubMed1994

Hemodynamic changes after transcatheter arterial embolization of hepatocellular carcinomas.

PURPOSE: To evaluate the serial hemodynamic changes that occur after transcatheter arterial embolization (TAE) of hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: Twenty patients with HCCs treated with TAE were evaluated with color and duplex Doppler sonography before, immediately after, and 2 days after TAE. The changes in hepatic artery and portal vein velocity and flow were evaluated. RESULTS: The portal venous velocity and flow did not change significantly after TAE. The peak systolic velocity in the proximal hepatic artery decreased significantly (P < .01) immediately after TAE then returned to baseline values 2 days after TAE; the resistance index of the proximal hepatic artery increased significantly (P < .01) immediately after embolization, then returned to baseline values 2 days after TAE. Arterial signal in the distal hepatic artery, generally absent immediately after TAE, could be recorded 2 days after. CONCLUSION: There is a rapidly reversible decrease in hepatic arterial flow induced by embolization, without any change in portal venous flow.

Adult↗
PubMed1993

[Failure factors of guided puncture of hepatic masses].

This study was carried out to assess the failure factors of guided hepatic mass puncture in 320 biopsies. Results of the puncture, follow-up or surgery allowed us to divide 320 biopsies into true positives or false negatives. Compared with the group of true positive diagnosis, the group of false negative diagnosis revealed a significantly higher percentage either of lesions less than 2 cm (52.5% versus 34%), of benign tumors (19% versus 5%), or of pseudotumors (24% versus 1.5%). Compared with the group with cytology and histology diagnosis, the group in which only histology established the diagnosis revealed a significantly higher percentage of hepatocellular carcinoma (52.5% versus 34%) and of benign tumors (21% versus 0%). A diameter less than 2 cm, a histology of benign tumors or pseudotumors, are failure factors of guided biopsy. The use of histology is useful for the diagnosis of benign tumors and increases the accuracy of diagnosis for hepatocellular carcinoma.

Biopsy, Needle↗
PubMed1992

Homeotic control in Drosophila; the scabrous gene is an in vivo target of Ultrabithorax proteins.

The regulatory functions of transcription factors encoded by the Ultrabithorax (Ubx) gene initiate genetic programmes essential for segmental identity and morphogenesis in Drosophila. Based on the formation of DNA-protein adducts in intact nuclei and immunoselection procedure, we cloned genomic targets for Ubx proteins. One clone was studied in detail. It encompasses parts of the last intron and exon of the scabrous (sca) gene, which encodes a secreted protein involved in cellular communication during neurogenesis. Five motifs, presenting the ATTA core, which is shared by most homeodomain binding sites, were found in the nucleotide sequence of this clone. We detail here the dynamic pattern of sca transcript accumulation during embryogenesis and show that mutation of Ubx results in the ectopic transcription of sca in the first abdominal segment. We propose that a direct interaction of Ubx with cis-acting elements in sca negatively regulates the gene. Transcript localization in several combinations of deficiencies in the Bithorax complex (BX-C) indicates that sca is downregulated by abdominal A (abdA) and Abdominal B (AbdB), and suggests that it is a common target of the three genes of BX-C.

Animals↗
PubMed1992

Cell lineage-specific expression of modulo, a dose-dependent modifier of variegation in Drosophila.

Variegation in Drosophila is a manifest illustration of the important role played by chromatin structure in gene expression. We have isolated mutants of modulo (mod) and shown that this gene is a dominant suppressor of variegation. Null mutants are recessive lethal with a melanotic tumour phenotype. The mod protein directly binds DNA, which indicates that it may serve to anchor multimeric complexes promoting chromatin compaction and silencing. Using a specific monoclonal antibody we examined by immunocytochemistry the accumulation pattern of mod protein during embryogenesis. The protein is first detected before the blastoderm cellularization in all somatic nuclei, precisely when pericentromeric heterochromatin becomes visible. After the first cell division, mod protein is expressed in lineages of specific embryonic primordia. Based on its dominant phenotype, expression pattern and DNA-binding activity of its product, we propose that mod regulates chromatin structure and activity in specific cell lineages.

Animals↗
PubMed1992

Acute abdomen of unknown origin: impact of CT on diagnosis and management.

A prospective study was performed including 40 patients with an acute abdominal syndrome presenting difficulties in defining the etiology. All patients underwent an emergency computed tomographic (CT) scan. The CT scan made the syndrome's diagnosis in 95% of cases and it permitted the detection of a lesion in 57.5% of cases. The diagnostic impact of CT scan was significant (p less than 0.01). The value and the specific contribution of CT in various diseases were analyzed. CT allowed appropriate therapeutic decisions in 95% of cases where clinical examination performance was positive in only 60% of cases. We had two negative CT results leading to an inappropriate therapeutic decision; it consisted of two cases of undiagnosed appendicitis. CT modified the primary therapeutic strategy in 30% of cases and avoided seven laparotomies.

Abdomen, Acute↗
PubMed1991

[The posterior interparietoperitoneal spaces or retroperitoneal spaces. 1: Normal topographic anatomy].

The posterior spaces between the wall and peritoneum or extraperitoneal spaces are located between the visceral retrocolic and retro-duodenopancreatic fascias anteriorly and the parietalis fascia posteriorly. They were studied using an anatomic and computed tomographic comparison. The propria fascia (lateroconal fascia) divided into the anterior and posterior layers of the perirenal fascia. The fascias delimitate two anterior and posterior pararenal spaces around the kidney compartment and two anterior and posterior perirenal spaces in the compartment itself. These spaces extended above and below the renal compartment from the diaphragm to the pelvis. These large spaces composed of fat and organs can assume the guided migration of pathologic processes or their spread according to the importance of the fascias barriers. They below to the genito-urinary region. The extraperitoneal spaces are related anteriorly to the retroperitoneal alimentary organs: duodenum, pancreas, ascending and descending colon depending of the alimentary region. They are related posteriorly with the abdominal wall and its own fat. The individuality and the interdependance of these three territories (alimentary, genito-urinary and abdominal wall) and their consequences for pathologic CT scan imaging will be discussed in the second part of this paper.

Humans↗