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Biomedical subjects

M Sibony

Publications and source records attributed to M Sibony.

At least 19 recordsLinked to original sources
PubMed2004

[Retroperitoneal fibrosis].

The rare occurrence of retroperitoneal fibrosis contrasts with the multitude of publications. Its clinical expression also contrasts with the severity of its repercussion on renal function. Now, diagnostic and therapeutic are more standardized to improve chances of preserving renal function. However, no surgical or medical therapy has been tested in a randomized, controlled trial. This article proposes an update of knowledge on this subject.

Diagnosis, Differential↗
PubMed2003

Proliferative myositis in a patient with AIDS.

We report a case of proliferative myositis in the right biceps of a 56-year-old man with acquired immune deficiency syndrome (AIDS). Imaging methods included sonography, computed tomography and magnetic resonance imaging. The diagnosis was made by a core-cut biopsy and fine needle aspiration biopsy with immunohistochemical analysis. The lesion disappeared after 2 months without treatment. It is particularly important to determine whether intramuscular masses arising in patients with AIDS are due to an infectious or malignant process.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Bisulfite genomic sequencing of microdissected cells.

Mapping of methylation patterns in CpG islands has become an important tool for understanding tissue-specific gene expression in both normal and pathological situations. However, the inherent cellular heterogeneity of any given tissues can affect the outcome and interpretation of molecular studies. In order to analyse genomic DNA methylation on a pure cell population from tissue sample, we have developed a simple technique of single-cell microdissection from cryostat sections which can be combined with bisulfite-mediated sequencing of 5-methylcytosine. We report here our results on the methylation status of the androgen receptor gene studied by bisulfite genomic sequencing on purified cells isolated from human testis.

Cells, Cultured↗
PubMed2000

L5 radicular pain related to a cystic lesion of the posterior longitudinal ligament.

A 35-year-old man with a long history of left L5 radicular pain was found to have an intraspinal cystic lesion causing radicular compression. Magnetic resonance imaging demonstrated a round lesion situated in the anterior epidural space, with uniform high signal intensity on T2-weighted sequences characteristic of a cystic lesion. During surgery a liquid-containing cyst originating from the posterior longitudinal ligament was punctured and resected. The histologic aspect was that of a ganglion cyst without synovial layers. The radiologic differential diagnoses are discussed.

Adult↗
PubMed2000

Organizing pneumonia related to common variable immunodeficiency. case report and literature review.

A 68-year-old woman suffering from common variable immunodeficiency (CVI) developed a typical picture of organizing pneumonia. Causative factors other than CVI were eliminated. Several antibiotic regimens failed to improve the patient's condition, while the clinical manifestations rapidly disappeared under steroid therapy, with complete radiological recovery, but relapsed after steroid withdrawal. Finally, organizing pneumonia was definitely demonstrated by pathological findings obtained by open lung biopsy. Interestingly, pathological examination exhibited two other well-known CVI-associated lesions, i.e. benign lymphoid hyperplasia and noncaseating granuloma. In view of reports in the literature, we speculate that these different histological patterns could have resulted in a spectrum of symptomatic CVI-associated pulmonary disorders that improved under steroid therapy.

Aged↗
PubMed1999

Neuropathic arthropathy: a forgotten diagnosis? Two recent cases involving the hip.

Two cases of neuropathic arthropathy of the hip are reported. One was the first manifestation of tabes dorsalis in a 74-year-old man, whereas the second occurred in a 47-year-old woman with a history of spina bifida and L2-L5 epidural lipoma. Radiographic joint destruction occurred within five and three months, respectively. The main clinical and radiological features of neuropathic arthropathy are reviewed, and diagnostic pitfalls are discussed. There are no specific laboratory tests or histologic findings. This now rare condition should be routinely considered in patients with severe joint destruction contrasting with minimal pain. The reasons for the decision to use trochanteric-iliac coaptation in one of our patients and a wait-and-see approach in the other are explained. The literature is reviewed. Ten cases treated by joint replacement have been reported. However, neither joint replacement nor arthrodesis seem capable of restoring satisfactory hip function.

Aged↗
PubMed1998

Angiotensin-converting enzyme and male fertility.

The angiotensin-converting enzyme (ACE; EC 3.4.15.1) gene (Ace) encodes both a somatic isozyme found in blood and several other tissues, including the epididymis, and a testis-specific isozyme (testis ACE) found only in developing spermatids and mature sperm. We recently used gene targeting to disrupt the gene coding for both ACE isozymes in mice and reported that male homozygous mutants mate normally but have reduced fertility; the mutant females are fertile. Here we explore the male fertility defect. We demonstrate that ACE is important for achieving in vivo fertilization and that sperm from mice lacking both ACE isozymes show defects in transport within the oviducts and in binding to zonae pellucidae. Males generated by gene targeting that lack somatic ACE but retain testis ACE are normally fertile, establishing that somatic ACE in males is not essential for their fertility. Furthermore, male and female mice lacking angiotensinogen have normal fertility, indicating that angiotensin I is not a necessary substrate for testis ACE. Males heterozygous for the mutation inactivating both ACE isozymes sire wild-type and heterozygous offspring at an indistinguishable frequency, indicating no selection against sperm carrying the mutation.

Animals↗
PubMed1998

A new model of endovascularly induced renal artery stenosis in normocholesterolemic versus hypercholesterolemic rabbits.

RATIONALE AND OBJECTIVES: The authors determine the feasibility of creating renal artery stenosis by overdilatation and deendothelialization and compare the model in normocholesterolemic versus hypercholesterolemic rabbits. METHODS: Thirty male New Zealand White rabbits were randomized into two groups: group A (n = 15) was fed a normal diet and group B (n = 15) was fed a cholesterol-rich diet 4 weeks before stenosis induction. An aortogram was performed, then the right renal artery was overdilated with an angioplasty balloon-catheter, and deendothelialized. After 6 weeks, groups A and B were compared by angiographic and pathologic study. RESULTS: Comparison of group A versus group B showed that 12 arteries (80%) versus 6 (40%) were angiographically stenotic (P < 0.05); 14 (93%) versus 12 (80%) contained neointima (NS), 12 (80%) versus 3 (20%) showed medial disorganization (P < 0.01), and 9 (60%) versus 2 (13%) presented adventitial fibrosis (P < 0.01). CONCLUSIONS: A new model of endovascularly induced renal artery stenosis has been developed in rabbits. Medial proliferation and adventitial fibrosis are more frequent in normocholesterolemic rabbits.

Angiography↗
PubMed1997

Adrenocorticotropin-producing pituitary carcinoma with liver metastasis.

We report here the extremely rare case of a twenty-eight year-old woman with a metastatic ACTH-secreting pituitary carcinoma. This is the thirteenth case to be described in the literature. Ten years ago Cushing's disease was diagnosed. After pituitary surgery, then bilateral adrenalectomy, a Nelson's syndrome appeared. The particularly extensive pituitary secondary development led to several pituitary surgical procedures, radiotherapy, and octreotide treatment. Eight years after Cushing's disease was diagnosed, liver tumors were discovered. Pathological examination and ACTH immunostaining demonstrated the secretory nature of these metastases. The lack of ectopic tumor, the LPH/ACTH equimolar ratio and a study of the plasma proopiomelanocortin derivatives by HPLC showed that the ACTH secretion originated in pituitary tissues (in situ and liver metastases). The processing of POMC seems thus to be normal in this kind of tumor and metastases. Intact POMC levels were very high, indicating an aggressive tumor, and ACTH/LPH production was paradoxically stimulated by octreotide. This case is also exceptional because of the slow development of the disease, which may be due to the complementary hepatic chemoembolization treatment.

Adrenocorticotropic Hormone↗
PubMed1996

Predictive score for the development of hepatocellular carcinoma and additional value of liver large cell dysplasia in Western patients with cirrhosis.

The aim of this study was to identify high-risk patients for hepatocellular carcinoma (HCC). Among 151 patients with histologically proven cirrhosis hospitalized from 1987 to 1990 and prospectively followed-up until June 1994, 31 developed HCC. We assessed the predictive value of 22 variables recorded at enrollment for HCC occurrence by the log rank test and the Cox proportional hazards model. Six clinical and biological variables summarized predictive information of HCC: age > or = 50 years (P = .01), male (P = .01), large esophageal varices (EV) (P = .03), prothrombin activity < 70% (P = .04), serum alpha-fetoprotein (AFP) > or = 15 ng/L (P = .06), and anti-hepatitis C virus antibodies (P = .08). A clinicobiological predictive score identified two groups of patients at low (n = 67; 3-year cumulative incidence, 0%) and high risk for HCC (n = 84; 3-year cumulative incidence, 24%). The predictive value of this score was confirmed using an independent population of 49 patients with cirrhosis. Furthermore, liver large-cell dysplasia (LCD) had an additional predictive value in high-risk patients (P = 10(-4), which thus helped to define a subgroup at very high risk for HCC (n = 12; 3-year cumulative incidence, 72%). In Western patients with cirrhosis, a limited number of usual variables can identify a group of patients at high risk for HCC. Among these patients, liver biopsy allows for the determination a subgroup of patients at very high risk for HCC requiring intensive screening or preventive measures.

Age Factors↗
PubMed1996

[Effect of microwave pretreatment on the detection of Epstein-Barr virus EBER RNA's using in situ hybridization].

We have tested the influence of microwave pretreatment of tissue sections on in situ hybridization applied to the detection of Epstein-Barr virus-encoded small RNAs (EBER). To this end, different protocols have been tested on slides of 4 lymph node lymphomas: microwave pretreatment, proteinase K pretreatment, microwave followed by proteinase K and no pretreatment. To compare the sensitivity of each technique, several dilutions of oligoprobes were used. Hybrids have been detected by immunohistochemistry. The analysis of the nuclear stainings obtained shows an enhancement of the sensitivity in protocols using microwaves.

Endopeptidase K↗
PubMed1995

Enhancement of mRNA in situ hybridization signal by microwave heating.

BACKGROUND: Optimization of in situ hybridization protocols is of real interest when trying to detect small amounts of mRNA or when using low concentrations of probes. To enhance the hybridization signal, we have developed a modification of an in situ hybridization (ISH) protocol with radiolabeled cRNA probes. The detailed protocol of ISH used for paraffin sections is also described. EXPERIMENTAL DESIGN: In microwave (MW) heating, the tissue sections are heated in a sodium citrate buffer (0.01 M, pH 6). The effects of the pretreatment with MW were studied on kidneys and adrenals of young rats and on human pathologic samples using [35S]-RNA probes complementary to the mRNAs of some components of the renin angiotensin system. RESULTS: The heating pretreatment with the MW permitted us to obtain an enhancement of the hybridization signal, especially when using low doses of radioactive probes. This enhancement could be evaluated to 60 to 120% by computer-assisted quantification of the signal. Furthermore, the histologic structures and the staining with toluidine blue were not impaired by the heating treatment. CONCLUSIONS: The enhancing effect of the hybridization signal obtained using MW allows shorter autoradiographic exposure times and/or the use of lower concentrations of radioactive probes for the detection of mRNA or the detection of mRNA expressed at the threshold of detection with usual protocols.

Adrenal Glands↗