Search PubMed⌕ Search

Biomedical subjects

M Legrand

Publications and source records attributed to M Legrand.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

Isolation and characterization of a proteinaceous inhibitor of microbial proteinases induced during the hypersensitive reaction of tobacco to tobacco mosaic virus.

A proteinase inhibitor is strongly induced in tobacco leaves reacting hypersensitively to tobacco mosaic virus. The tobacco inhibitor is highly active against four different serine endoproteinases of fungal and bacterial origin (EC 3.4.21.14) but inhibits poorly two serine endoproteinases of animal origin, trypsin (EC 3.4.21.4) and chymotrypsin (EC 3.4.21.1). The inhibitor has been purified to homogeneity by successive steps of conventional and high-performance liquid chromatography. When electrophoresed under denaturing conditions, it behaves as a small polypeptide with a molecular weight of about 6,000. From its amino acid composition and NH2-terminal amino acid sequence analysis, it appears that the inhibitor belongs to the potato inhibitor I family. A polyclonal antiserum was raised against the purified tobacco inhibitor and was used in immunoblotting experiments to follow inhibitor accumulation during the hypersensitive reaction of tobacco to tobacco mosaic virus. The inhibitor is highly efficient and might represent a potent fungicide and/or bactericide to be used in plant biotechnology.

Amino Acid Sequence↗
PubMedDate not supplied

Regulation of enzymes involved in lignin biosynthesis: induction of O-methyltransferase mRNAs during the hypersensitive reaction of tobacco to tobacco mosaic virus.

The mRNAs encoding orthodiphenol-O-methyltransferases (OMTs; EC 2.1.1.6), which are involved in the biosynthesis of lignin precursors, are highly induced in tobacco leaves during the hypersensitive reaction to tobacco mosaic virus (TMV). OMT messengers were fractionated on a sucrose gradient and translated in vitro. Protein A-Sepharose columns adsorbed with specific antisera raised against purified OMTs were used to select translation products, and the translatable activity of OMT mRNA was measured at different stages of infection. Oligonucleotides derived from peptide sequences of purified OMT I were used to prime polymerase chain reactions; total RNA was used as template to allow the isolation of an OMT I clone. RNA blots, hybridized with the OMT I probe, revealed a unique messenger of 1.7 kb. The kinetics of accumulation of OMT I mRNAs during the hypersensitive reaction to TMV parallels the kinetics of translation and suggests that an increase in mRNA controls the increase in the rate of enzyme synthesis. In healthy plants, RNA blot hybridization showed that the steady-state level of OMT I mRNA is very high in vascular tissue compared to the level measured in leaves.

Amino Acid Sequence↗
PubMedDate not supplied

Collagen I and III and mechanical properties of conduit arteries in rats with genetic hypertension.

Conduit arteries of hypertensive rats are thicker and stiffer than those of normotensive controls. The possible role played by collagen type I and II subtypes in the mechanism of arterial stiffness remains unknown. The carotid and aortic arterial wall of rats of Japanese (Wistar-Kyoto and spontaneously hypertensive rats) and Lyon (normotensive and hypertensive rats) origin were studied. The stiffness of the carotid wall material (ultrasound), the histomorphometry of the aortic wall with the content in collagen I and III subtypes and their corresponding mRNA were analyzed. Independently of hypertension, the Japanese group differed from the Lyon group by a stiffer carotid wall material at any given value of wall stress; a lesser degree of aortic hypertrophy with a higher percentage of elastin, and a higher density of collagen III but not of collagen I. All other hemodynamic and histomorphometric parameters were affected by both the origin of the rats (Japanese vs. Lyon) and the presence of hypertension. Large artery stiffness in genetically hypertensive rats was not only influenced by hypertension itself, but also by differences in the contents of collagen subtypes which are also found in their corresponding normotensive controls.

Animals↗
PubMedDate not supplied

An in vivo pharmacokinetic/pharmacodynamic model for antiretroviral combination.

PURPOSE: The objective of this study was to investigate the pharmacokinetic/pharmacodynamic properties of an antiretroviral therapy in HIV-infected patients. METHOD: Eight HIV-infected patients received zidovudine, lamivudine, and indinavir as their first antiretroviral treatment. Pharmacokinetic data were analyzed separately using a one-compartmental model with first-order absorption, and the individual estimates were used to simulate drug concentrations. To determine the relationship between drug concentrations and the antiviral effect, an in vitro E(max) model was tested. Alternatively, a dynamic model was built describing the viral and cellular pathophysiology, including the turnover of viral replication in infected cells and the production of virus under treatment. RESULT: The E(max) model fit poorly the experimental data. The complex model was not identifiable with the data available in this study, however a simplified model allowed us to estimate the pharmacodynamic parameters reflecting the decrease of both infected cells and viral load under antiretroviral treatment. CONCLUSION: Using potent highly active antiretroviral therapy, the treatment was so effective that it was not possible to estimate the parameters of the relationship between drug concentrations and the reduction of viral load. Even if the relationship does exist, the direct response model of antiretroviral agents cannot be demonstrated, however the simplified model provides an understanding of the synergy of such a combination and offers suggestions as how to prevent the emergence of viral resistant strains.

Adult↗
PubMedDate not supplied

Analysis of factors influencing long-term survival after surgical resection for oesophageal squamous cell carcinoma.

OBJECTIVE: We evaluated prognostic factors in 34 patients discharged from hospital after surgical resection for oesophageal squamous cell carcinoma. MATERIAL AND METHODS: There were 22 males and 12 females; mean age was 59.3 years (range 42-77 years). Preoperative neoadjuvant treatment consisted in chemotherapy alone in three patients and in combined radiochemotherapy in 14. Digestive continuity was restored with a gastric transplant in 26 patients and a colonic graft in 8. Surgery was curative in 28 patients and palliative in 6. There were three stage I, 14 stage II, 13 stage III, and 4 stage IV diseases. In 19 patients the lymph nodes were invaded. The tumour was well differentiated in 17 patients, moderately in 9, and poorly in 8. RESULTS: Follow-up ranged from 2 to 100 months. Overall median postoperative survival was 21 months. By univariate analysis, factors influencing survival were curative surgery (p = 0.04), stage (p = 0.006), and nodal involvement (p = 0.0003). Nodal involvement was an independent prognostic factor by multivariate analysis (p = 0.0002). Patient age and sex, perioperative transfusion, digestive transplant, tumour local extension, grade of differentiation, and distant metastasis did not influence survival. Also, we did not observe any significant benefit of preoperative or postoperative chemotherapy or radiochemotherapy. CONCLUSIONS: Nodal involvement was the most important prognostic factor influencing survival. Therefore, an earlier diagnosis of oesophageal cancer in a less advanced stage is important to improve survival rates. Our study could not confirm the benefit of neoadjuvant therapy in terms of late survival.

Adult↗
PubMedDate not supplied

Combined treatment of liver failure and hepatorenal syndrome with orthotopic liver transplantation.

Hepatorenal syndrome (HRS) is a severe complication of liver failure with high mortality. The pathogenesis of this reversible functional renal failure is not yet clearly understood. Diagnosis is based upon the association of clinical and biological criteria. A patient was admitted to our institution for severe liver failure secondary to an exacerbation of cirrhosis, where he developed a fulminant hepatorenal syndrome. Both, the renal and hepatic failure were successfully treated by orthotopic liver transplantation. Special attention was paid to the immunosuppressive treatment with Cyclosporine whose use, we believe, should be delayed until function has partially recovered.

Hepatorenal Syndrome↗
PubMedDate not supplied

[Spontaneous pneumomediastinum].

Spontaneous pneumomediastinum is a relatively rare disease, the clinical signs of which may be misleading, and the physiopathology is still unknown. The authors report 7 cases collected over a period of 3 years and note the etiology, the clinical findings and the X-ray findings. The disease often affectsyoung sybjects, without any sex predominance. The initial symptom is thoracic pain and is often accompanied by dispnea. Subcutaneous emphysema only appears secondarily and may be mild. The association with pneumothorax is not rare. Among the etiological circumstances, pneumomediastinum often occurs after an effort or a respiratory infection with dyspnea. The diagnosis depends on the discovery of subcutaneous emphysema and on radiological signs in A.P. and lateral chest views. Treatment should be as conservative as possible in the usual benign forms. It should be limited to bed rest, analgesics and sedatives. In severe cases, supra-sternal drainage permits decompression of the mediastinum. The physiopathological mechanisms are discussed, but the usually accepted theory is rupture of an alveolus into the pulmonary interstitial tissue. The pressure gradient necessary for this rupture may be due to variations in alveolar or vascular pressure.

Adolescent↗
PubMedDate not supplied

[Surgical treatment of incarcerated inguino-crural hernia with interposition of a preperitoneal prosthesis].

For the last four years, 17 inguinal and femoral strangulated hernias have been treated at our institution by a median subumbilical incision. In all cases, a prosthesis has been placed by preperitoneal approach. An intestinal resection for irreversible necrosis has been performed in five patients. This procedure gives good control of the herniated organs, allows easy intestinal resection and good management of unforeseeable situations. The surgical exploration of the other hernial orifices and, if needed, their simultaneous treatment can be performed. Intestinal resection does not represent, in our opinion, an absolute contra-indication to the implantation of a prosthesis. In our study, the morbidity does not seem to be increased.

Adult↗
PubMedDate not supplied

[Ileo-anal pouch anastomosis: results in ulcero-hemorrhagic rectocolitis and in familial adenomatous polyposis].

Two hundred twenty-four ileal pouch-anal anastomoses have been made, 122 for ulcerative colitis and 102 for familial adenomatous polyposis. All the patients had a J pouch and a diverting temporary ileostomy. Mortality was 0.5%. Twenty-eight % of the patients with ulcerative colitis and 24% of the patients with familial adenomatous polyposis had various postoperative complications. Seventy-two patients with ulcerative colitis had a follow-up of more than one year. They had a mean of 4.6 stools per 24 hours; 84% had a normal day-time continence and 70% a normal nocturnal continence. Sixty-nine patients with familial adenomatous polyposis had a follow-up of more than one year. They had a mean of 4.1 stools per 24 hours; 93% had a normal daytime continence and 91% a normal nocturnal continence. In conclusion, ileal pouch-anal anastomosis can be made safely, with good functional results.

Adenomatous Polyposis Coli↗
PubMedDate not supplied

[Leiomyosarcoma of the inferior vena cava: literature review and surgical treatment. Apropos of 2 retrohepatic localizations].

Two cases of leiomyosarcoma of retrohepatic inferior vena cava are reported. The two patients are women and are currently alive with metastases one, seven years, and the other one year postoperatively. Leiomyosarcoma of inferior vena cava s a rare tumor which has an unexplained predilection for women. Clinical symptoms are non specific and depend mostly on the segment of the vessel involved. Preoperative diagnosis is based on ultrasonography, computed tomography and cavography. Although the prognosis is poor due to local recurrence and metastasis, we recommend an aggressive approach by radical tumor resection and caval reconstruction.

Angiography↗
PubMedDate not supplied

[Eosinophilic pleurisy. Apropos of 35 cases].

Eosinophilic pleuritis are inflammatory effusions containing more than 10% of eosinocytes. More frequent in men, the course of illness is acute our subacute but pleural sequelae are seldom. They can be due to all inflammatory process, thoracic trauma, tuberculosis and viral diseases are predominant. Unexplained etiology represents 25% of cases, so "called autonomous pleuritis". Pleural eosinophilia could be explained by eosinophilotactic action of red cells or by activating products induced during hypersensibility reaction.

Adult↗
PubMedDate not supplied

[Polyvascular patients. Retrospective study of 4200 vascular patients operated on between 1980 and 1986].

Polyvascular patients. Among a consecutive series of 4200 patients submitted to vascular surgery, a group of 292 people operated on, in at least two anatomically and physiologically different sites, is individualized as polyvascular patients. A subgroup is characterized by simultaneous procedures in two separated fields; 32 have benefited in the same time from carotid and coronary procedures, i.e., 0.6% of all coronary patients and 2% of all carotid patients. The carotid-coronary group exhibited a more severe anatomical disease both in the carotid and the coronary vasculatures. Apart from simultaneously operated patients, others were sequentially treated over a 7 years period: people with carotid (25%) or visceral (40%) arterial disease were more prone to become polyvascular. Polyvascular patients differ from monovascular patients in that hypertension is more frequent and more severe, mean cholesterol level higher and incidence of severe hypercholesterolemia more frequent.

Aortic Diseases↗