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Biomedical subjects

J Floquet

Publications and source records attributed to J Floquet.

At least 37 records · Page 2Linked to original sources
PubMed1995

Use of cryomicrotomy to study gastric diffusion of amoxicillin in guinea pigs.

Cryomicrotomy has been used as a new technique for removing gastric mucosae from adult guinea pigs for the study of amoxicillin secretion across gastric mucosae. This method allowed a very regular thickness of the removed surface layer of mucosa to be obtained with good reproducibility. Gastric superficial mucosa concentrations and gastric juice concentrations of amoxicillin were determined 1, 2, and 4 h after intramuscular administration (50 mg/kg) in 21 guinea pigs by a microbiological method. No antibiotic was detected in gastric samples at 4 h, except for a low-level mucosal concentration in one animal, thus indicating the short time that amoxicillin is present in gastric samples.

Amoxicillin↗
PubMed1995

[Inflammatory myofibroblastic tumor of the lung with endobronchial, infiltrating, multifocal and recurrent form].

Pulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor, plasma cell granuloma) was reported most often as a single peripheral mass, successfully cured by surgery. A 14-year-old girl presented with a large left pulmonary mass involving and obliterating the main bronchus; there were angioinvasion and infiltration of mediastinum, hilar lymph nodes and pleura. Multiple, often tiny nodules were seen in the right lung. At microscopic examination, there were lymphocytic and plasmacytic infiltrates and borderline myofibroblastic proliferation with focal nuclear anaplasia. Smaller lesions were similar to organizing pneumonia. Disease was progressive in the remaining right lung after surgical resection and a two-month treatment with corticoids. The patient was then treated with chemotherapy. She was alive and well (twenty-month follow-up).

Adolescent↗
PubMed1994

[Lumbar intervertebral disk. Intervertebral disk-vertebral body pathways and discal vascularization].

We studied the disco-vertebral interface and the blood supply of the intervertebral disks L3-L4, L4-L5, and L5-S1 of 5 human adult columns. Moreover, in order to investigate the discal vasculature, infusion of Japanese ink was used in 2 other adult columns, as well as immuno-histological methods in the L5-S1 disk of 4 adults and 2 infants. Our study confirms the paucity of discal vasculature in adults, by contrast with that of infants, but shows numerous defects in the subchondral vertebral plate, which are filled by vascularised medullary soft tissue and are in contact with the cartilaginous discal end plate. By these contacts, nutrients could reach the intervertebral disk, as suggested by other works, and as is the case in other cartilaginous structures of the body.

Humans↗
PubMed1994

[Undifferentiated osteogenic carcinoma of the thyroid].

A case of osteogenic thyroid carcinoma in a 68 years old male patient is reported. The WHO histopathological classification of such exceptional tumor is reminded. A review of the literature and the treatment modalities are discussed. Several etiological hypotheses are discussed.

Aged↗
PubMed1994

[Tubulo-papillary tumors of the kidney. Clinical, histologic and cytogenetic aspects. 15 new cases].

Between 1987 and 1992, we operated on 15 patients with tubulopapillary tumours (TPT) of the kidney, corresponding to 10% of all renal cancers operated during this 5-year period, which brings the total number of published cases to 418. TPT differ from non-tubulopapillary tumours in several ways. The medical imaging findings may differ when the tumour is not necrotic (20 to 30% of cases). The histology differs not only in terms of the tumour architecture, but also by the frequent association (9/15 cases) with other ipsilateral or contralateral renal anomalies: 2 bilateral tumours, 3 tumours associated with multiple cysts and 4 multifocal tumours. These characteristics, combined with the finding of 12 familial cases suggest a genetic origin for TPT, especially as the genetic abnormalities detected (tri-or tetrasomy 17) differ from the anomalies usually detected in non-tubulopapillary tumours (anomalies of 3p and 5q). This study is the first to report familial cases of TPT. The prognosis of these tumours, generally better than that of non-tubulopapillary tumours, suggests the possibility of conservative surgery when the diagnosis can be established preoperative or at operation.

Adenocarcinoma, Papillary↗
PubMed1994

Experimental articular toxicity of aluminum compounds in vivo.

OBJECTIVE: To investigate the articular toxicity of 2 aluminum derivatives, one insoluble (hydroxide) and/or the other soluble (lactate), after a single administration in rabbits and rats. METHODS: First, aluminum levels in plasma, urine, synovial tissue, liver and kidney were measured in saline treated rabbits and 1 to 2 days after an articular injection of 75 mg of aluminum compounds into their right knee. The methodology used was argon plasma emission spectrometry. Thereafter, the joint toxicity of aluminum lactate at the same dose regimen was evaluated for 2 days by a qualitative histological examination of synovial tissue and articular surfaces and a colorimetric assay (1,9-DMB) of patellar articular cartilage proteoglycan content. Secondly, the single injection of 50 mg of aluminum derivatives as an inducer of inflammation was studied in the rat subcutaneous air pouch, a model for a synovial-like space. Leukocytes and eicosanoids levels were measured in pouch washout fluids from 1 to 72 h after injection. RESULTS: After injection into rabbit knee, aluminum lactate largely distributed within the body while hydroxide remained locally. However, aluminum lactate resulted in perivascular edema, sparse infiltration of inflammatory cells in the synovium and a hemorrhagic effusion. Proliferation of the synovial cell layer coexisted with an apparent loss of proteoglycan in superficial zones of tibial and femoral cartilages when patellar proteoglycan content remained unchanged. Aluminum hydroxide did not affect joint structures. In the air pouch experiment, aluminum lactate increased prostaglandin E2 (PGE2) levels from 3 to 10 h after its injection and less intensively leukotriene B4 (LTB4) levels after 6 h, in the absence of leukocytes migration into the cavity. In contrast, aluminum hydroxide increased leukocytes count in pouch-washout fluid from 3 to 24 h after its injection when PGE2 and LTB4 levels were little modified. CONCLUSION: Although some differences attributable to dissimilarities in the experimental model used, aluminum compounds, even in a soluble form, may damage joint structures either directly or through stimulating the secretion of eicosanoids by synovial-like cells.

Aluminum Compounds↗
PubMed1993

Subcellular localization of cytochrome P450, and activities of several enzymes responsible for drug metabolism in the human brain.

We studied the subcellular distribution of cytochrome P450 and related monooxygenase activities in six regions of human brains removed at autopsy. The content of total cytochrome P450 was found to be at least nine times higher in the mitochondrial fraction than in the microsomes in all the regions studied. However, cytochrome P450-dependent enzymatic activities which are representative of different isoforms metabolizing exogenous molecules exhibited a microsomal prevalence, a situation previously observed in rat brain. The other drug-metabolizing enzymes catalysing functionalization and conjugation reactions, presented the following characteristics in human brain: (i) a low activity of NADPH-cytochrome P450 reductase, which also catalyses the reduction of some xenobiotics; (ii) a high specific activity of the membrane-bound epoxide hydrolase; (iii) among the enzymes catalysing conjugation reactions, 1-naphthol-UDP-glucuronosyltransferase activity was barely or not detectable, whereas the mean glutathione-S-transferase activity was 15 times higher than the activity measured in rat brain. The presence of several drug-metabolizing enzyme activities in human brain microvessels, and particularly the high activity of epoxide hydrolase, suggests a participation of these enzymes in the metabolic blood-brain barrier.

Aged↗
PubMed1993

Osteogenic anaplastic carcinoma of the thyroid.

An unusual osteogenic anaplastic carcinoma of the thyroid developed in a 68-year-old man and showed follicular and osteosarcomatous components. Seven months after surgery and 70 mCi 131I treatment, a local tumor recurrence was found and showed an intense uptake of 99mTc-MDP on the bone scan. After a second operation, pathologic and immunostaining analysis revealed no more thyroid carcinoma but only osteosarcomatous cells. Chemotherapy was ineffective and the patient died with diffuse pulmonary metastases 26 months after the diagnosis. The importance of osteogenic sarcomatous differentiation is proven by the bone scan. Osteosarcoma of the thyroid is a rare but well known tumor. Usually these tumors do not contain any cells originating from the thyroid epithelium and only comprise sarcomatous components. Ten cases of undifferentiated carcinoma of thyroid origin with osteogenic component have been reported. These tumors have been recently included in undifferentiated carcinomas in the second edition of the WHO classification. The evolution and pathologic findings favor the hypothesis of a transdifferentiation of the thyroid cell into osteogenic cells.

Aged↗
PubMed1993

[Olfactory esthesioneuroma (esthesioneuroblastoma). A pathologic study of 7 cases].

With an histological, immunohistochemical study of 7 cases of olfactory esthesioneuromas (4 of them had an ultrastructural study), our purpose was to revise the problem of the too often ambiguous terminology and of the different histological lower classes classifications of these tumors. Our own results and the literature demonstrate that they are polymorphic. In standard histology, they are often right diagnosed but an immunohistochemical study can be useful and an ultrastructural study absolutely necessary for a reliable diagnosis. For an easier nomenclature, we advise to use only one terminology for these tumors = olfactory esthesioneuroma. But, because of their important polymorphism, we keep to an histological lower classes classification according to their degree of differentiation in light microscopy: well differentiated tumors (old esthesioneuroepitheliomas), moderately differentiated tumors (old esthesioneurocytomas), poorly differentiated tumors (old esthesioneuroblastomas and so on described as neuro-endocrine carcinomas by Silva and al).

Adolescent↗
PubMed1993

[Value of skin fibroblasts in culture for the diagnosis of mitochondrial cell dysfunction. Apropos of 5 cases with cytochrome c oxidase deficiency].

Mitochondrial respiratory chain dysfunction has been studied by two complementary methods using cultured skin fibroblasts from five patients with muscular cytochrome c oxidase (complex IV) deficiency: first, a screening test measuring lactate to pyruvate ratio (L/P) after supplementation of cultured cells; secondly, measurement of complex IV activity in whole cells. Respiratory chain defect (increased L/P ratio with decreased complex IV activity) was expressed in fibroblasts of four of the five patients. Our results show that skin fibroblasts can be helpful for biochemical diagnosis of mitochondrial respiratory chain defects.

Cells, Cultured↗
PubMed1992

[Experimental study of the trophic effects of reinnervation of pedicled muscle flaps].

Any transplanted muscle flap undergoes atrophy to an extent depending mainly on its innervation. Other factors such as the tension at rest and the duration of ischemia play a secondary role. An experimental study was carried out in rats to quantitatively assess the extent of atrophy according to the mode of transplant reinnervation. The gracilis muscle was used as an experimental model of pedicled flap after verifying the axial nature of its vasculature. Results were assessed after three months from a histological point of view and in terms of postoperative weight in four different groups of 13 rats. The first three groups reproduced situation encountered in clinic: intact nerve, sutured nerve, resected nerve. A graft sensory neurotization technique was implemented in the fourth group by diverting a neighboring sensory nerve. The best trophic results were obtained when the motor nerve remained continuous. The sensory neurotization technique did not significantly influence the trophic evolution after three months.

Animals↗
PubMed1992

Statistical analysis of histomorphological findings in medullary thyroid carcinoma: distinction between the different familial forms of the disease. G.E.T.C. Groupe d'Etude des Tumeurs a Calcitonine.

A multifactorial analysis of morphological findings was performed on 153 cases of medullary thyroid carcinoma (MTC). The aim of the study was to utilize histological criteria to discriminate between MTC associated with multiple endocrine neoplasia type 2A (MEN 2A) and that associated with the inherited MTC only syndrome. The presence of fusiform cells associated with several other markers seemed to be more predictive of MEN 2A. A comparison of inherited MTC only and sporadic MTC only showed fusiform cells to be significantly less common in inherited MTC only. These results suggest that the inherited MTC only syndrome is a distinct clinical and morphological entity. Further investigations are needed to confirm the findings and understand its implications.

Carcinoma↗
PubMed1992

Flow cytometric analysis of the cell cycle in chronic gastritis.

Flow cytometric cell cycle analysis was recorded in gastric biopsy specimens from patients with normal gastric mucosa (GM), superficial gastritis (SG) and chronic atrophic gastritis (CAG). Cell-cycle analysis showed significantly higher percentages of cells in S- and S+G2/M-phase in CAG than in SG and normal GM (P < 0.0001). Moreover, CAG with severe or moderate atrophy showed significantly higher percentages of cells in S-phase (P < 0.05) and S+G2/M-phase (P < 0.02) than CAG with mild atrophy in antrum. In fundus, even if this increase was observed, it did not reach statistical significance. Consideration of concomitant pathologic findings such as oesophagite, gastric or duodenal ulcer, duodenite or benign polyp allowed a better differentiation of CAG both in antrum and in fundus. Significantly higher S-phase was observed in CAG with severe or moderate atrophy than in CAG with mild atrophy (P < 0.05). No statistically significant results were observed in patients with normal gastric mucosa or chronic gastritis and a concomitant pathologic finding.

Cell Cycle↗
PubMed1991

Auto-immune spondylodiscitis associated with collagen induced arthritis in rats: high field MRI findings.

The spinal involvement of the tail was studied in Wistar Furth rats immunized with bovine native type II collagen. Focal caudal autoimmune spondylodiscitis occurred 5 weeks after sensitization, as assessed histopathologically. High field Magnetic Resonance Imaging (MRI) was useful in depicting these caudal abnormalities that were related to juxta-diskal enthesitis. The occurrence of such inflammatory enthesopathies could serve as an experimental approach for physiopathological and therapeutical studies of spondylarthropathies.

Animals↗
PubMed1991

Influence of muramyl dipeptide on established experimental arthritis in rats.

The effects of MDP, a potent inducer of cytokines, were studied in four batches of Wistar Furth rats with established experimental arthritis. Arthritic rats were given a daily sc injection of 10, 100, 200 or 400 micrograms MDP respectively. Muramyl dipeptide increased the severity of clinical events in a dose-dependent manner, with the exception of the 10 micrograms dose which was ineffective. The levels of anti-collagen antibodies were not however significantly enhanced by MDP. Radiological lesions and histological changes were maximal at high dosage regimens. Paradoxically, the acute phase reactive alpha 1 glycoprotein was little affected by MDP treatment.

Acetylmuramyl-Alanyl-Isoglutamine↗