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Biomedical subjects

N Bourgeois

Publications and source records attributed to N Bourgeois.

At least 19 recordsLinked to original sources

The vaccinia virus mRNA (guanine-N7-)-methyltransferase requires both subunits of the mRNA capping enzyme for activity.

Plasmid vectors capable of expressing the large and small subunits of the vaccinia virus mRNA capping enzyme were constructed and used to transform Escherichia coli. Conditions for the induction of the dimeric enzyme or the individual subunits in a soluble form were identified, and the capping enzyme was purified to near homogeneity. Proteolysis of the capping enzyme in bacteria yields a 60-kDa product shown previously to possess the mRNA triphosphatase and guanyltransferase activities (Shuman, S. (1990) J. Biol. Chem. 265, 11960-11966) was isolated and shown by amino acid sequence analysis to be derived from the NH2 terminus of D1R. The individual subunits lacked methyltransferase activity when assayed alone. However, mixing the D1R and D12L subunits permitted reconstitution of the methyltransferase activity, and this appearance in activity accompanied the association of the subunits. In contrast, mixing the D12L subunit with the D1R-60K proteolytic fragment failed to yield methyltransferase activity or result in a physical association of the two proteins. These results demonstrate that the methyltransferase active site requires the presence of the D12L subunit with the carboxyl-terminal portion of the D1R subunit. Furthermore, since the mRNA triphosphatase and guanyltransferase active sites reside in the NH2-terminal domain of the D1R subunit, and the methyltransferase activity is found in the carboxyl-terminal portion of this subunit and D12L, there must be at least two separate active sites in this enzyme.

Chromatography

Hypersensitivity with hepatotoxicity to mesalazine after hypersensitivity to sulfasalazine.

A 21-year-old woman with Crohn's disease of the colon developed a skin rash after 3 weeks of treatment with sulfasalazine. Administration of sulfasalazine was discontinued. When mesalazine was instituted 1 week later, she developed a severe hypersensitivity reaction characterized by fever, diarrhea, skin rash with subsequent desquamation, marked atypical lymphocytosis, and severe hepatotoxicity. Recovery was complete. The clinical and biological features as well as liver pathology of this case bear a striking resemblance to earlier reports of hypersensitivity reaction with severe hepatotoxicity to sulfasalazine. The authors urge caution when mesalazine is given to a patient with known hypersensitivity to sulfasalazine.

Adult

Factors related to early mortality in cirrhotic patients bleeding from varices and treated by urgent sclerotherapy.

Variceal haemorrhage in cirrhotic patients carries a high early mortality even when balloon tamponade or emergency sclerotherapy are applied. The aim of this study to identify patients dying within six weeks of their first variceal haemorrhage. One hundred and twenty one patients with parenchymal cirrhosis presenting with the first variceal bleeding episode between June 1983 and December 1988 were studied. Nineteen patients were excluded for various reasons. Emergency sclerotherapy was carried out in cases of active bleeding or where there were endoscopic signs of recent bleeding, and then regularly repeated afterwards. Of the 24 variables studied and included in a multivariate analysis using a logistic regression model, three had an independent prognostic value: encephalopathy, prothrombin time, and the number of blood units transfused within the 72 hours of time zero. The subsequent regression equation was able to predict 89% of the patients who will die and 97% of the patients who will still be alive six weeks after their first variceal haemorrhage treated by sclerotherapy. Pugh score was less discriminatory than these last three variables in terms of accuracy of adjustment, goodness of fit to the model, receiver operating characteristic curves, and percentage correct prediction. To measure the accuracy of the prediction rule, our model was applied to another series of 28 cirrhotic patients admitted with their first variceal bleeding during the next period (January 1989 to May 1990). Death and survival were correctly predicted in respectively 82% and 94% of the cases. The use of this score is recommended for the selection of patients with high early mortality after variceal bleeding despite sclerotherapy, and for the design of new therapeutic trials.

Acute Disease

Acardiac amorphous twin with prune belly sequence in the co-twin.

We describe a twin with acardia acephalus or "Twin Reversed Arterial Perfusion Sequence" and prune belly sequence in the co-twin. In a former quite similar case a prune belly appearance of the co-twin of an acardiac fetus was found to be secondary to the ascites caused by cardiac failure. In the present case, we are dealing with the prune belly sequence as a separate condition, given the fact there were no signs of ascites or cardiac failure. We also found associated anomalies: agenesis of the left ureter and kidney, dysplastic right kidney and anal atresia. Urinary tract obstruction has never been described in the co-twin of an acardiac amorphous fetus.

Diseases in Twins

Management of dysphagia in suspected esophageal motor disorders.

Fifty-three patients suffering from dysphagia because of suspected esophageal motor disorders were treated by pneumatic dilatation using the Rider-Moeller technique. Fifteen had achalasia demonstrated by manometric studies. Forty-nine of them had remarkable clinical improvement after the procedure. During the mean period of follow-up (average 5 years, range 1-11), 75% of the patients needed a new dilatation, with a delay of two years. The results of the dilatation were excellent or good in 80% of the cases. Early complications consisted in two esophageal perforations surgically treated. There was no mortality. We did not observe late complications of the procedure. We conclude that pneumatic dilatation should be the initial procedure in the treatment of dysphagia in suspected esophageal motor disorders.

Aged

Comparison of cell growth in different parts of breast cancers.

This study was performed to answer the question: which parts of breast cancers are active in terms of proliferation as measured by the Ki-67 antibody and in terms of cell division as measured by the mitotic index. Forty-six breast samples were studied, including 34 breast cancers and 12 benign conditions. The intraductal component of infiltrating breast cancers showed a significantly lower proliferation index than the infiltrating component. The cells at the periphery of infiltrating tumour strands showed a higher proliferation activity than the cells in the core. These findings suggest that infiltration advances through preferential active growth of the cells at the invasion front.

Antigens, Surface

The presence of a type IV collagen skeleton associated with periductal elastosis in breast cancer.

Using serial sections of frozen and AFA-fixed tissues from 34 breast cancers, we studied the presence of basement membrane material in the areas of elastosis. Various amounts of type IV collagen but not of laminin were demonstrated in areas of periductal elastosis. In some tumors, type IV collagen accumulated beneath the basement membrane. Periductal elastosis in areas of extensive fibrosis showed focal type IV collagen immunoreactivity, indicating remnants of ducts. Interstitial elastosis corresponded with weak type IV collagen reactivity. Each tumor showed type IV collagen immunostaining of the elastotic areas, with various degrees of intensity. Negative crossreactivity of the type IV collagen antibody with elastin was verified in skin biopsies with solar elastosis. Pre-incubation of the antibody with large amounts of elastin demonstrated an identical immunoreactivity. The specificity of the antibody was confirmed by ELISA and by Western blot analysis. To explain the periductal elastosis, we propose the following hypothesis. Excessive production of basement membrane material by the epithelial cells of the ducts leads to formation of a type IV collagen skeleton. This skeleton can act as the matrix for a secondary deposition of elastic material.

Basement Membrane

Use of somatostatin for complications occurring after liver transplantation.

Somatostatin can be helpful after liver transplantation in some well-defined indications. In uncontrolled digestive haemorrhage, a short course of somatostatin therapy can be of great help in controlling the acute bleeding and to avoid emergency laparotomy. Somatostatin could also be helpful in bilio-pancreato-intestinal fistula, but in this case its advantage over elective surgical treatment remains to be confirmed.

Acyclovir

Large basophilic cells in the bone marrow in iron deficiency anemia.

Many large cells with a strongly basophilic cytoplasm and large nuclei with a delicate chromatin pattern and large nucleoli were studied in 1 mu sections of core biopsies in 8 patients with iron deficiency anemia and in 5 patients with pernicious anemia. In 2 normal controls these cells were rare. Possible features of granulocytic differentiation were assessed with the Giemsa stain and with the naphtol-ASD-chloroacetate esterase reaction which is indicative of early granule formation: the large cells were constantly negative. In thin sections the morphological appearances of the large basophilic cells are rather similar in such different haematological disorders as pernicious anemia or iron deficiency anemia. A clear difference can be demonstrated by karyometry, which shows that the large basophilic cells in pernicious anemia are significantly larger than those in iron deficiency anemia or in the normal control.

Anemia, Hypochromic

Trichoderma viride infection in a liver transplant recipient.

A liver transplant recipient developed infection of a perihepatic haematoma due to Trichoderma viride. Before the infection was diagnosed, the patient received intense immuno-suppressive and prolonged antibacterial and anti-fungal therapies. Although the death of the patient was not directly related to the fungal infection, abundant quantities of this pathogen were recovered in the haematoma at post-mortem examination, despite previous surgical removal and treatment with amphotericin B and fluconazole.

Adult

[Prevention and treatment of digestive hemorrhage due to ruptured esophageal varices in patients with cirrhosis].

1) Emergency treatment. The best treatment remains endoscopic sclerotherapy, which controls the bleeding in 90% of the cases. Pharmacologic management stops the variceal hemorrhage in 80% of the cases and is indicated before endoscopic treatment can be performed. Intravenous somatostatin administration may be prolonged for 5 days, even more, and may thus prevent early rebleeding, which is not achieved neither by vasopressin nor by glypressin, which administration is restricted to 24 hours. Esophageal tamponade is useful to arrest a massive variceal bleeding, if vasoactive drugs are not available or not efficient, before endoscopic management. If the bleeding persists after 2 sclerotherapy sessions, an alternative treatment is mandatory: the patient should be sent to the surgeon for a portosystemic shunt if the operative risk is acceptable (child A and B) or should become a candidate for a transjugular intrahepatic stent shunt, especially if transplantation is considered afterwards. 2) Prevention of recurrent hemorrhage. A) Early (within 5 days after the initial bleeding). Somatostatin probably prevents early rebleeding, as do sclerotherapy. B) Late. B blockade (+ nitrates) or long-term sclerotherapy have the same efficacy. Their association may improve their results. 3) Prevention of the first bleeding episode. Propranolol decrease the risk of variceal rupture from 20% to 9% during the first year after the diagnosis of esophageal varices and is the only treatment which may be proposed to cirrhotics who did not yet bled form their varices.

Adrenergic beta-Antagonists

[Acute hepatitis and poisoning by Amanita phalloides].

We report the case of a 69-year-old woman who presented acute hepatitis due to Amanita Phalloides poisoning complicated of acute renal failure. Her clinical evolution was favorable under medical treatment whose actual modalities are discussed.

Acute Kidney Injury

[Emergency intrahepatic shunt via transjugular approach].

We report the case of a cirrhotic 65 year-old woman presenting with persistent and recurrent variceal hemorrhage in spite of endoscopic sclerotherapy with bucrylate, glypressin infusion and balloon tamponade. At the time of intrahepatic shunt placement via the transjugular route, Child-Pugh score was 14 (Child C category) and surgical variceal decompression or liver transplantation were contraindicated. At the end of the procedure, which included the placement of two Palmaz stents, varices were no more opacified and the wedge hepatic venous pressure gradient had decreased from 70%. Evolution of the patient was excellent with a permeable shunt after one month. Emergency placement of intrahepatic shunt with metallic stent has certainly a place in case of failure of initial management of variceal bleeding with pharmacotherapy, sclerotherapy or balloon tamponade.

Aged

Endoscopic treatment of esophagogastric varices.

We report our current management of variceal bleeding with endoscopic sclerotherapy. We emphasize the importance of resuscitation and of recording at time zero and within the first 72 hours clinical and laboratory indicators, as these influence the management of these patients. Primary sclerotherapy using Histoacryl for active bleeding and Ethoxysclerol for recent bleeding should be performed as soon as the patient is stable hemodynamically. As we have identified factors related to the severity of hemorrhage and of liver failure degree which can predict early failure of sclerotherapy, patients presenting with these findings should be, in the future, referred quickly toward alternative therapies among which non-surgical intrahepatic shunt appears a promising modality.

Cyanoacrylates