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Biomedical subjects

M Antoine

Publications and source records attributed to M Antoine.

At least 91 records · Page 5Linked to original sources
PubMed1997

MDR1-Pgp 170 expression in human bronchus.

MDR1 P-glycoprotein (Pgp 170), a member of the adenosine triphosphate (ATP) binding cassette transporters, acts as an efflux pump for various hydrophobic agents, particularly for xenobiotics such as benzo(a)pyrene. It has also been shown to regulate cell-volume activated chloride channels. Pgp 170 could, therefore, be of particular importance in cellular mechanisms of defence in the airways and in the control of mucus layer composition. For these reasons, we evaluated the precise localization of Pgp 170 in human adult airways. Fresh non-neoplastic bronchial specimens were collected from 33 patients (26 smokers, four exsmokers and three nonsmokers) who underwent surgery for lung carcinoma. The presence of MDR1 messenger ribonucleic acid (mRNA) was demonstrated by reverse transcriptase chain reaction (RT-PCR) in bronchial epithelial cells collected by gentle scraping from either smokers, exsmokers or nonsmokers. Immunodetection of Pgp 170 using a panel of monoclonal antibodies (MRK16, JSB1, C219, C494) was performed either on cryostat or paraffin-embedded sections of histologically normal bronchial tissue. Pgp 170 was constantly detected with intense labelling at the apical surface of ciliated epithelial cells from the surface epithelium or ciliated collecting ducts, and on apical and lateral surfaces of serous cells from bronchial glands. No staining of mucus-secreting cells was observed. Pgp 170 was also demonstrated at the luminal surface of endothelial cells of bronchial capillaries. In conclusion, the expression of MDR1 P-glycoprotein in bronchial structures, particularly at the epithelial apical surface, suggests important roles for this transmembrane protein in human airways.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

[Primary pulmonary lymphoma].

There are three distinct clinico-anatomical entities today covered by the definition of a primary clonal pulmonary lymphoid proliferation. These are pulmonary lymphomas of B cell phenotype, of low grade malignancy, B cell lymphomas of high grade malignancy and finally lymphomatoid granulomatosis whose clonal characteristic is sometimes difficult to confirm. This general review aims to specify the pathophysiological, diagnostic, prognostic and therapeutic aspects of these different types. Low grade B cell lymphoma is the most common pulmonary lymphoma. Their development depends on mucosa associated lymphoid tissue. They are most often indolent and present as a chronic alveolar opacity. Their prognosis is excellent and the modalities of treatment are discussed (no therapy, surgery or monochemotherapy). High grade B cell pulmonary lymphomas are much rarer and may result from the transformation of a low grade lymphoma or arise in a particular situation such as imunodepression. Their prognosis is poor and the therapeutic possibilities depend most often on the underlying disease. The presence of lymphomatoid granulomatosis in this group of pulmonary lymphomas is debatable. The demonstration of a clonal character of this proliferation is practically never obtained and there is often extra pulmonary disease. The prognosis of this type of illness is extremely variable because certain studies have shown a cure using corticosteroids and cyclophosphamide whilst others have found that the disease is always fatal in spite of using strong polychemotherapy.

Humans↗
PubMed1997

Torsion of an intra-abdominal testicle in a neonate. Case report and review of the literature.

The thirty-ninth reported case of torsion of an intra-abdominal testicle is described in a neonate. The gonad was excised as is recommended because of the high incidence of malignancy (60% of 37 cases). Torsion of an intra-abdominal testicle should be considered where an abdominal mass with calcification is found in an infant with undescended testis. Ultrasonography improves the diagnostic accuracy in infants because of the cystic nature of these masses in this age group.

Cryptorchidism↗
PubMed1997

[Multicentric Castleman's disease with mediastinal involvement in a patient with HIV infection].

Castleman's disease is most often seen by a thoracic physician as a mediastinal tumour which is discovered fortuitously and whose surgical excision leads to a cure. We report a case of a patient of 30 who was seropositive for HIV and was suffering from Castleman's disease initially localised to the mediastinum. The disease was associated with a cutaneous and bronchial Kaposi sarcoma. The mediastinal disease, associated with cutaneous and bronchial Kaposi sarcoma, was marked by evolving in a multicentric manner. We review the histological definition and recent data concerning the pathophysiology and the diagnostic and therapeutic management of this disorder and the very varied clinical expression.

Adult↗
PubMed1997

[Pulmonary mucormycosis in a leukemia patient. Diagnostic and therapeutic difficulties].

The observation of pulmonary mucormycosis occurring in a patient presenting with aplasia induced therapeutically during treatment for acute myeloblastic leukaemia, has led to a review of the characteristics of this rare opportunistic fungal infection: it occurs in a particular condition; the clinical manifestations are characterised by the thrombotic character and the rapidly necrosing nature of the histological lesions; the diagnosis is usually very difficult to make and is linked to the rarity of the pathology and the frequently negative mycological specimens apart from tissue biopsies; the value of a medicosurgical therapeutic strategy on which the prognosis of the infection depends.

Amphotericin B↗
PubMed1997

[Stereotactic core biopsy of breast microcalcifications. Aid to diagnosis?].

We assessed the accuracy with which stereotactic core biopsy of breast microcalcifications helps to justify follow-up or indicate required surgical planning. Eighty-nine patients underwent stereotactic breast biopsy performed with large core needles. Histopathologic findings of microbiopsies were correlated with radiological findings, with follow up and with surgical findings. Agreement between radiological and histopathologic findings on biopsies was obtained in 86% for benign results. Even in the case of benign radiological findings, the histological results of microbiopsies required a surgical biopsy justified in 10% of cases. Radiologically suspicious or malignant microcalcifications were correlated with 35% benign and 65% malignant histologies on biopsies. The positive predictive value, negative predictive value and accuracy were respectively 93%, 86% and 95%. Invasive lesions were found on microbiopsies in 39% of excised malignant lesions. Multifocal lesions were proved on microbiopsies in 50% of all excised carcinomas. Microbiopsies help to disclose malignant lesions undetected on radiological analysis, and may obviate diagnostic surgical biopsy in many cases.

Adult↗
PubMed1996

[From pseudolymphomas to primary pulmonary lymphomas of MALT type].

Primary lung lymphomas are uncommon and the use of immunohistochemical and molecular biological techniques have widely contributed to their understanding. Generally, they are of low grade malignancy and most develop from mucosa-associated lumphoid tissue (MALT). Cellular analyses of samples obtained routinely by endoscopy (transbronchial biopsy or bronchoalveolar lavage) will probably enable the clinician to avoid invasive diagnostic procedures, such as surgical lung biopsy. Treatment of limited forms is usually surgical. As to bilateral forms or those with lesions of other mucosae e.g. gut, the best therapeutic strategy remains to be defined.

Diagnosis, Differential↗
PubMed1996

Ca2+/calmodulin kinase types II and IV regulate c-fos transcription in the AtT20 corticotroph cell line.

In the corticotroph cell line AtT20, Ca2+ stimulates c-fos mRNA and nuclear c-fos protein accumulation. We show that Ca2+ stimulates transcription of a chloramphenicol-acetyl-transferase reporter gene driven by the c-fos promoter. This effect is mimicked by both constitutively active Ca2+/calmodulin-dependent protein kinase types II (CamK II) and IV (CamK IV). The effects of CamK IV are synergistic with those obtained by cAMP stimulation, whereas CamK II-dependent transcription is not further stimulated. Deletion of the distal promoter sequence revealed that CamK IV, and to a lesser extent CamK II, activate a cis-acting element(s) located between -99 and -53 bp prior to the transcription initiation site. Moreover, CamK II further stimulates transcription through the fos AP1-like element. CamK IV has a lower effect on this element but represses the serum response element. The latter observation might account for the lower transcriptional effects of CamK IV on the full length c-fos promoter.

Animals↗
PubMed1996

Steroid administration in heart and heart-lung transplantation: is the timing adequate?

BACKGROUND: The release of cytokines after cardiopulmonary bypass may play an important role in postoperative morbidity. The release of proinflammatory cytokines, such as tumor necrosis factor alpha, interleukin (IL)-6 and IL-8, is even greater in patients undergoing heart transplantation (HTx) than coronary artery grafting. We tested the hypothesis that in HTx patients the earlier administration of steroids, before rather than after cardiopulmonary bypass as usual, can reduce the inflammatory response. METHODS: In 20 consecutive patients who underwent HTx or heart-lung transplantation (HLTx), plasma levels of tumor necrosis factor alpha, IL-6, IL-8, and anti-inflammatory cytokine IL-10 were measured before heparin administration, at aortic cross-clamping and declamping, and 0.5, 1, 1.5, 2, 4, 12, and 24 hours after aortic declamping. In 10 patients (group I, 6 HTx and 4 HLTx), 500 mg of methylprednisolone was first given as usual at 1.5 hours after aortic declamping (at the end of cardiopulmonary bypass). In the next 10 patients (group II, 6 HTx and 4 HLTx), the first doses of methylprednisolone were given 1 hour before operation. In both groups, 125 mg of methylprednisolone were given every 8 hours thereafter during the first postoperative day. RESULTS: The ischemic time and cardiopulmonary bypass time were similar in the two groups (166 +/- 16 minutes versus 157 +/- 13 minutes, and 192 +/- 21 minutes versus 186 +/- 20 minutes, respectively, mean +/- standard error of the mean). At 30 minutes after aortic declamping and throughout the next 4 hours, tumor necrosis factor alpha levels were significantly lower in group II than in group I (all p < 0.03). Interleukin-8 values 1 hour after declamping were also lower in group II than in group I (49 +/- 15 pg/mL versus 130 +/- 38 pg/mL, p < 0.02). Interleukin-10 levels were significantly higher in group II than in group I from 30 minutes after declamping through 2 hours after (all p < 0.03). Interleukin-6 levels were similar in the two groups. CONCLUSIONS: Earlier steroid administration in the immunosuppressive protocol for HTx or HLTx may be preferable to reduce the inflammatory response to cardiopulmonary bypass, as reflected by a lower production of tumor necrosis factor alpha and IL-8, and a greater release of IL-10.

Adult↗
PubMed1996

[Microangiopathic hemolytic anemia associated with uterine sarcoma: report of a case. Review of the literature].

Microangiopathic hemolytic anemia (MAHA) is a rare but severe complication of neoplastic disease. The diagnosis of thrombotic microangiopathy is based on a triad of a hemolytic anemia with schistocytes, thrombocytopenia, and renal failure. Carcinoma-associated MAHA and chemotherapeutic-induced MAHA have been described. Because of differences concerning prognosis and treatment it is important for the clinician to distinguish these two syndromes. However, to our knowledge, this is the first case of a sarcoma-associated thrombotic microangiopathy.

Anemia, Hemolytic↗
PubMed1996

Human cytokine responses to cardiac transplantation and coronary artery bypass grafting.

Cardiac surgery with cardiopulmonary bypass triggers an inflammatory response involving proinflammatory cytokines such as tumor necrosis factor-alpha, interleukin-6, and interleukin-8. To elucidate the pathophysiology of this cytokine response, we explored the possible differences in cytokine responses between patients undergoing heart transplantation and those undergoing coronary artery bypass grafting. Plasma levels of tumor necrosis factor-alpha, interleukin-6, interleukin-8, and interleukin-10 were measured in eight patients undergoing heart transplantation (mean age 44 years) and eight patients undergoing coronary artery bypass grafting (mean age 61 years). Duration of cardiopulmonary bypass and ischemic time were both longer in the heart transplantation group than in the coronary artery bypass grafting group (133 +/- 26 min vs 100 +/- 31 min, p < 0.05, and 130 +/- 47 min vs 58 +/- 21 min, p < 0.005, respectively). Samples were collected before heparin administration, at aortic crossclamping and declamping, and at 0.5, 1, 1.5, 2, 4, 12, and 24 hours after declamping. Tumor necrosis factor-alpha levels were significantly higher 30 minutes after aortic declamping in the heart transplantation group than in the coronary artery bypass grafting group (68 +/- 30 vs 18 +/- 5 pg/ml, p < 0.05). Interleukin-6 and interleukin-8 levels were also significantly higher 90 minutes after declamping in patients undergoing heart transplantation than in those undergoing coronary artery bypass grafting (310 +/- 63 vs 169 +/- 24 pg/ml, p < 0.05, and 73 +/- 17 vs 24 +/- 5 pg/ml, p < 0.01, respectively). Furthermore, interleukin-6 and interleukin-8 values 90 minutes after declamping were significantly correlated with the ischemic time (r = 0.72 and r = 0.82, respectively, both p < 0.05). Interleukin-10 levels in both groups rose to reach a peak value of around 115 pg/ml 1 hour after declamping. Patients undergoing heart transplantation exhibited a second peak of tumor necrosis factor-alpha, interleukin-8, and interleukin-10 levels 12 hours after declamping, probably related to the administration of rabbit antihuman thymocyte immunoglobulin (Thymoglobuline) 3 hours after declamping. Interleukin-6 levels decreased more significantly 12 and 24 hours after declamping in patients undergoing heart transplantation, probably related to methylprednisolone therapy. In conclusion, cardiopulmonary bypass is associated with the production of both proinflammatory and antiinflammatory cytokines. The production of proinflammatory cytokines in patients undergoing heart transplantation is higher than that in patients undergoing coronary artery bypass grafting, and this increase could be related to the longer duration of ischemia in the former group. The later course of cytokine levels after heart transplantation may be further influenced by immunosuppressive therapy.

Adolescent↗
PubMed1996

Codon 12 Ki-ras mutation in non-small-cell lung cancer: comparative evaluation in tumoural and non-tumoural lung.

Ki-ras activation by point mutation on codon 12 has been reported in non-small-cell lung carcinomas and in various models of experimental lung tumours induced by chemical carcinogens. The cellular targets for carcinogenic compounds of tobacco smoke are usually considered to be the cells of the bronchial mucosa or alveolar epithelium. However, little is known about preneoplastic events in bronchopulmonary carcinogenesis. The hypothesis of the presence of widespread target cells containing Ki-ras mutation was investigated by evaluating concurrent neoplastic and non-neoplastic bronchial and alveolar samples from 51 patients with non-small-cell lung carcinomas. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method used can detect one cell with a mutation on codon 12 among 10(2) normal cells. In tumour samples, a mutation was detected in 20% of adenocarcinomas, but in none of the adenosquamous or squamous cell carcinomas. No mutation was detected in the non-neoplastic bronchial or parenchymal samples. When using an enriched PCR-RFLP method detecting one mutated allele among 10(3) normal alleles a mutation was detected in 23% of adenocarcinomas. In conclusion, Ki-ras activation by mutation on codon 12 was not observed in non-neoplastic bronchial or parenchymal tissues in patients with bronchopulmonary cancers and does not appear to be a genetic event present in non-malignant epithelial target cells exposed to tobacco smoke.

Carcinoma, Non-Small-Cell Lung↗
PubMed1996

Cytomegalovirus-induced alveolar hemorrhage in patients with AIDS: a new clinical entity?

We report five cases of alveolar hemorrhage associated with intravascular hemolysis in patients with AIDS. Cytomegalovirus was the only pathogen recovered from the lungs of these patients. There was evidence of multivisceral spread of the virus in all patients, and all had viremia. All had clinical, biological, and pathological features of pulmonary vasculitis, and the conditions of four improved with specific anti-cytomegalovirus therapy.

AIDS-Related Opportunistic Infections↗
PubMed1996

Diffuse panbronchiolitis in an Asian immigrant.

Diffuse panbronchiolitis (DPB) is a disease with chronic inflammation exclusively located in the region of the respiratory bronchiole. It is largely restricted geographically to the Far East, and cases in Western countries are exceptional, even among Asian immigrants. A patient of Asian origin with DPB who had been living in France for 10 years is described. Only re-examination of the initial open lung biopsy specimen after an eight year period allowed this rare disease to be diagnosed correctly. The known efficacy of low dose erythromycin in DPB was again confirmed after failure of long term high dose corticosteroid therapy administered before an accurate diagnosis had been made.

Adult↗
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↗
PubMed1996

[Role of microbiopsies in the therapeutic and diagnostic approach in cases of mammary microcalcification: preliminary results].

The increase of mammographies has lead to the discovery of more frequent mammary microcalcifications. Presently, about 30% of breast tumors are discovered from infraclinics lesions. Instead of the different classifications, the microcalcifications are the omnious sign with bad specificity. It is in the aim to improve the diagnostic etiology and the choice of therapy, that the directed microbiopsies on microcalcifications had been realized. After an orthogonal location and under local anesthesia, we performed at least six biopsies with a 2.1 mm (14 gauge) needle. This allowed recovery of malignant lesions during the control of microcalcifications and permitted considerable early operative treatment. In fact, a diagnostic and therapeutic advancement of 12 months as compared to a clinical diagnosis, permitting a 30% reduction of metastasis.

Adult↗