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Biomedical subjects

J Floquet

Publications and source records attributed to J Floquet.

At least 19 recordsLinked to original sources
PubMed2001

Phytosterols have an unfavourable effect on bacterial activity and no evident protective effect on colon carcinogenesis.

The effects of physiological dietary phytosterol supplements on intestinal microflora activity and faecal sterols and their capacity to protect rats fed a normal or high saturated fatty-acid diet against tumour development were studied. A group of 80 female Wistar rats were fed an 8% lipid diet for 4 weeks (adaptation period) and then randomly assigned in a factorial experimental design study to diets containing 8% or 24% hydrogenated coconut oil, with or without a 24-mg/day/rat phytosterol supplement. They were instilled intrarectally with saline or methyl-nitroso-urea (MNU). Faecal sterol output was analysed for one week each month. Pathological analysis was done at the end of the 30-week experiment. Animals treated with MNU and given phytosterol supplements had tumour frequencies (8/20) similar to those not fed phytosterols (11/20). The fat-supplemented diet had no significant influence. Colonic glands were found in area of lymphoid follicles in all the groups, but were more frequent in rats on high-fat diets (P < 0.01). The coprostanol and the cholesterol excretion of the phytosterol-supplemented rats was significantly enhanced. Therefore phytosterols have an unfavourable effect on bacterial activity. These data confirm the capacity of phytosterols to decrease cholesterol absorption, but indicate that a large excess of phytosterol must be avoided until further research on its effects on carcinogenesis has been done.

Animals↗
PubMed1999

Influence of a high-calcium carbonate diet on the incidence of experimental colon cancer in rats.

This study was done to determine whether a high dietary calcium carbonate concentration could protect against colon tumors in rats. Female Wistar rats were randomly assigned to one of four groups and maintained on an 8% lipid diet for an adaptation period of four weeks. All groups were then fed a 24% lipid diet (sunflower oil), with (Groups 2 and 4) or without (Groups 1 and 3) a 1.5% calcium carbonate supplement. They were intrarectally instilled with saline (Groups 1 and 2) or nitrosomethylurea (NMU) (Groups 3 and 4). Fecal sterol output and pH were analyzed for one week each month. Histological analysis was done at the end of the 32-week experiment. No tumors were found in the non-NMU-treated animals. The NMU-treated rats had tumors: 31% in Group 3 and 30% in Group 4. The calcium carbonate supplement had no effect on this incidence. The lipid and cholesterol excretions of the calcium carbonate-supplemented rats were significantly enhanced. The coprostanol output was not altered, although its fecal concentration of the calcium-supplemented rats was decreased. Although neither lipid overload nor NMU treatment altered the fecal pH, it was significantly increased in both calcium carbonate-supplemented groups. These findings suggest that additional calcium as carbonate has no effect on colon tumor incidence, although the fecal composition is altered. The increased pH of the feces due to the carbonate could have the opposite effect to calcium.

Animals↗
PubMed1999

Gerstmann-Sträussler-Scheinker disease and the French-Alsatian A117V variant.

Gerstmann-Sträussler-Scheinker disease is a rare familial form of prion disease. This autosomal dominant disorder is constantly associated with a point mutation on the PrP gene. Eight mutations affecting respectively codons 102, 105, 117, 145, 202, 212 and 218, have been so far described. Symptoms are variable and include ataxia and dementia. They generally appear between the fourth and sixth decade. Mean duration of the disease (5 years) is on the whole longer than that of other familial forms of prion diseases. Gerstmann-Sträussler-Scheinker disease is neuropathologically characterized by the presence of numerous multicentric or unicentric PrP amyloid deposits widespread throughout the encephalon. Spongiform change is inconstant. Neurofibrillary tangles have been described in some families. Clinicopathological features show considerable variability. Pathogenesis of amyloidosis and associated lesions as well as factors underlying the phenotypic polymorphism of the disease remain only partially known.

Adult↗
PubMed1999

[112 cases of sporadic and genetically determined pheochromocytoma: a comparative pathologic study].

The aim of this study was to compare 64 genetically determined pheochromocytomas (PH) (49 MEN IIa, 3 MEN IIb, 6 Von Recklinghausen diseases, 1 von Hippel-Lindau disease, 5 familial pheochromocytomas) and 48 sporadic PH. Genetically determined PH were more often observed among men and more frequently bilateral and multicentric than sporadic PH. Sporadic tumors had more often adrenal capsular invasion, necrosis and pseudocysts. Genetically determined PH were more differentiated with an insular pattern, hyaline globules and a higher percentage of polyhedric cells. Sporadic tumors were less differentiated with more frequently a diffuse pattern and small cells. Adrenal medullar hyperplasia was significantly associated with genetically determined PH. Adrenal cortical hyperplasia was not associated with a particular type of PH. The PS100 and chromogranin immunodetection was equivalent in both groups.

Adrenal Cortex↗
PubMed1998

Medullary thyroid carcinoma: search for histological predictors of survival (109 proband cases analysis).

A group of 13 pathologists belonging to the French Calcitonin Tumor Study Group (GETC: Groupe d'Etude des Tumeurs à Calcitonine) examined the histological slides and medical records of 109 proband cases of medullary thyroid carcinoma (MTC) diagnosed on clinical features. The cases belonged to the various forms of the disease (80 sporadic and 29 familial MTC). The aim of the study was to detect histological predictors for survival by comparing morphological data from patients killed by the disease versus the others. Twenty-seven histological parameters were considered, including cellular heterogeneity, shape of the cells, and cytoplasmic characteristics. Other parameters such as sex, age, and phenotype of the disease were also studied. First, predictive parameters of interest on survival function were selected by univariate analysis (Mantel-Cox test). Then, the extracted parameters were tested in a multifactorial analysis using the Cox's forward stepping proportional hazard model. Five parameters were significantly associated with a lower survival function: presence of necrosis in the tumor (P = .001), squamous pattern (P = .002), age over 45 years (P = .004), presence of oxyphil cells in the tumor and absence of cells with intermediate cytoplasm (P = .025), less than 50% of calcitonin immunoreactive cells in the tumor (P = .04).

Adolescent↗
PubMed1997

Assessment of articular cartilage and subchondral bone: subtle and progressive changes in experimental osteoarthritis using 50 MHz echography in vitro.

The main objectives of this work were to demonstrate the potential of 50 MHz echography for assessing initial and progressive morphological and structural changes of articular cartilage and bone developed in an experimental model of osteoarthritis (OA). Degenerative lesions were induced in rat knees by the unilateral intra-articular injection of a 3 mg dose of mono-iodo-acetic acid. To assess the lesion progression, the animals (n = 30) were sacrificed at different time intervals up to 8 weeks after the injection. Three-dimensional echographic data were acquired in vitro on patellar cartilage and bone at various stages of the remodeling process using a scanning ultrasound microscope. Changes involving the OA cartilage characteristics are discussed relative to those of the contralateral control joint which received a placebo. Images of control cartilage showed a smooth hyperechoic articular surface and an echoic matrix. The cartilage thickness was 266 +/- 44 microns (mean +/- SD) in the central region of the tissue. The precision of ultrasonic thickness measurements was better than 1.3%. First changes in cartilage internal structure and subchondral bone appeared on ultrasound images 3 days after the injection and were even more evident by day 7. They resulted in a slight thinning of the cartilage, a 30% increase of its internal structure echogenicity, and the appearance of echoic zones in subchondral bone. Histologic findings confirmed chondrocyte depletion and degeneration, decrease of matrix proteoglycans, and fibrovascular connective tissue proliferation at the subchondral plate. Progressive and severe lesions at both bone and cartilage surface and internal structure were assessed and correlated to histologic features. These results show that high resolution echography is sensitive to subtle and progressive osteochondral remodeling. This technique has the potential to be used for intra-articular quantitative imaging and assessment of early changes in bone and cartilage structure associated with natural human disease.

Animals↗
PubMed1997

[Extra-cardiac rhabdomyoma of the fetal type].

Rhabdomyomas are benign tumors of striated muscle. They are distinguished by topographic data: cardiac or genital and by histological criteria: foetal or adult type. The foetal type is the most heterogeneous, with either a majority of immature cells or a mixture of maturing elements. This diversity has led to distinguish immature (or standard) foetal Rhabdomyomas from intermediate foetal Rhabdomyomas. One observation of this last type is reported. The authors highlight the essential characteristics of foetal Rhabdomyomas, however the exact meaning remains unclear: an anomaly in the differentiation of the striated muscle? or a true tumoral process through genetic anomaly?

Fetal Diseases↗
PubMed1996

Water-jet dissection in renal surgery: experimental study of a new device in the pig.

The pig model was used for experiments with a new type of water-jet dissector, which produces high-pressure water by application of a gas and maintains the water fully sterile in a single-use delivery apparatus. The experiment was conducted ex vivo (14 kidneys) and in vivo to compare electric cautery section with water-jet dissection (5 vs 11 partial nephrectomies). Ex vivo study confirmed sparing of blood vessels and pelvicaliceal system. In vivo study did not show significant differences in blood loss but, the water-jet allowed precise dissection and tight closure of the excretory system. More frequent haemorrhages were noted on histological examination of the WJ group, but no coagulation necrosis. These are preliminary findings and further studies of long-term results may confirm the benefits of the absence of parenchymal necrosis and the definite advantage of precise closure of the pelvicaliceal system, as morbidity of partial nephrectomy is often related to secondary haemorrhages and urinary fistulae.

Animals↗
PubMed1996

[Actinomycosis and non-Hodgkin's malignant lymphoma: fortuitous association?].

Two cases of actinomycosis associated with non Hodgkin's lymphoma (NHL) are reported. In one case, low grade NHL was diagnosed many years after actinomycosis because of the persistence of abdominal lymphadenopathy in spite of antibiotic therapy. In the second case, hepatic metastasis were initially suspected until actinomycosis diagnosis was made by percutaneous liver biopsy under scanography. High grade NHL was diagnosed by laparotomy and liver biopsy performed 6 weeks after the onset of antibiotic therapy as no improvement in hepatic lesions was obtained. These two case reports outline the difficulties encountered in the diagnosis of actinomycosis and the indication of a repeat biopsy when actinomycosis does not respond to antimicrobial therapy because of the possibility of concomitant malignancy.

Actinomycosis↗
PubMed1996

Dietary calcium salts as protective agents and laminin P1 as a biochemical marker in chemically induced colon carcinogenesis in rats.

To evaluate the protective effect of different calcium forms against colon carcinogenesis, Wistar rats fed a high-fat diet (24%) were supplemented with different chemical forms of dietary calcium and were intrarectally instilled with N-methyl-N-nitrosourea (NMU). Supplemental calcium was administered at 1.5% mineral (w/w of total diet) complexed with either carbonate, gluconate, or lactate in Groups 2, 3, and 4, respectively. The tumor incidence of colon cancer was compared with a control group (Group 1), fed the same diet without supplemental calcium. Colon carcinoma incidence was 31, 33, 13, and 7% in Groups 1, 2, 3, and 4, respectively. Calcium had a significant protective effect against carcinogenesis, and the maximum protective effect was observed with gluconate and lactate forms. Laminin P1 blood level was measured as a tumor marker. Laminin P1 results were compared with the reference group (Group T), fed a standard diet and not NMU instilled. The serum laminin P1 level was significantly higher (p = 0.0001) in NMU-instilled Groups 1, 2, 3, and 4 (0.24 +/- 0.03, 0.93 +/- 1.43, 0.84 +/- 1.33, and 0.41 +/- 0.34 mU/ml respectively) than in the Reference Group T (0.10 +/- 0.05 mU/ml).

Animals↗
PubMed1996

Giant cell tumor of bone in children and adolescents.

Giant cell tumor of bone rarely affects children, in whom it is usually located in a metaphysis in contrast to the predominantly epiphyseal localization in adults. Five cases are reported, two at the femur, two at the fibula and one at the tibia. Plain film radiography and computed tomography are the most informative imaging studies. The differential diagnosis is with aneurysmal bone cyst and, in metaphyseal-epiphyseal forms, with chondroblastoma. Treatment usually consists in curettage of the tumor followed by filling of the cavity; however, more extensive resection is required in some cases.

Adolescent↗
PubMed1995

Evaluation of the Duke criteria versus the Beth Israel criteria for the diagnosis of infective endocarditis.

New diagnostic criteria for infective endocarditis (IE) have been proposed by the Duke University Endocarditis Service (Durham, NC) to update the widely used Beth Israel (Boston) criteria. We compared the Duke criteria with the Beth Israel criteria in a series of 115 consecutive patients with suspected IE who were hospitalized in a referral center. The diagnosis of IE was histologically and/or bacteriologically confirmed for 27 operated patients. If surgery had not been performed on these 27 patients, 22 vs. 12 would have been classified as having ¿clinically definite¿ and ¿probable¿ IE by the Duke vs. the Beth Israel criteria, respectively, whereas 0 vs. 5 would have been ¿rejected¿ by the Duke vs. the Beth Israel criteria, respectively. The improvement in sensitivity of the criteria from 44% (Beth Israel) to 82% (Duke) was statistically significant (P < .01). We confirm that the Duke criteria improve the sensitivity of diagnosis of IE. The specificity of these criteria should be further evaluated.

Adult↗