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Biomedical subjects

M L Dumas

Publications and source records attributed to M L Dumas.

16 recordsLinked to original sources
PubMed1994

Inactivation of hepatitis C virus in low pH intravenous immunoglobulin.

The safety from hepatitis C virus of intravenous immunoglobulin prepared by the cold ethanol method of Cohn-Oncley is demonstrated by clearance through the manufacturing process of 9 x 10(6) plaque-forming units of bovine viral diarrhea virus used as a surrogate for hepatitis C virus. Incubation of the intravenous immunoglobulin in its final formulation at pH 4.25 for 21 days at 21 degrees C caused a 10,000-fold decrease in bovine viral diarrhea virus intentionally added and complete inactivation of 1000 chimpanzee infectious doses per ml of hepatitis C virus.

Animals↗
PubMed1992

Anti-tumor necrosis factor receptor and tumor necrosis factor agonist activity by an anti-idiotypic antibody.

Tumor necrosis factor (TNF) is a cytokine which, among other properties, is a principle mediator of inflammation and septic shock. It acts upon target cells by binding to specific cell surface receptors. A10G10 is a murine monoclonal antibody which recognizes human TNF and neutralizes its activity. A rabbit polyclonal antibody directed at the antigen-binding site of A10G10 was raised and affinity purified over an A10G10 column. The resultant anti-idiotypic antibody recognized not only A10G10 but also both TNF receptors. It showed TNF agonist activity in two different TNF bioassays, and competed with several anti-TNF receptor monoclonal antibodies and TNF itself for binding to cells. These results represent an example of a method for obtaining antibodies to a ligand-specific receptor in the absence of the receptor itself.

Animals↗
PubMed1991

[Transitory acute kidney insufficiency and insulin-dependent after treatment of kala-azar with pentamidine and N-methylglucamine antimony].

Azotemia and diabetes mellitus are now well-known adverse reactions associated with Pentamidine treatment, especially since its prescription in case of Pneumocystis carinii pneumonia. We report the case of a 2 year-old boy, treated for kala-azar with pentamidine and N-methyl glucamine antimoniate who developed adverse effects, characterized by a nephrotic syndrome associated with the classic acute tubular necrosis, and transient diabetes mellitus.

Acute Kidney Injury↗
PubMed1984

A preparation of modified immune serum globulin (human) suitable for intravenous administration. Further characterization and comparison with pepsin-treated intravenous gamma globulin.

Numerous methods have been used in previous attempts to prepare a human gamma globulin solution suitable for intravenous administration. These include fractionation schemes, enzyme digestion, manipulations of pH, and various combinations of these methods. The selective reduction and alkylation process that we have developed for Gamimune causes a controlled and reproducible modification of a limited number of disulfide bonds in the hinge region of IgG, resulting in a functional antibody molecule of undiminished molecular weight and possessing complement-binding properties suitable for intravenous administration. Subtle changes in molecular structure or properties that may be caused by trace enzyme hydrolysis or extremes of pH and temperature are avoided. The biochemical characterization of immune globulin intravenous (Gamimune) is described herein, and the attributes of this chemically modified IgG are compared with some of the other intravenous gamma globulin preparations.

Chemical Phenomena↗
PubMed1984

Detection of IgG-associated determinants in reduced and alkylated preparations of human IgG3 by monoclonal antibodies.

Using classical typing antisera, previous experiments have failed to demonstrate IgG3 in partially reduced and alkylated preparations of human IgG intended for intravenous application (IGIV). To establish that IgG3 is actually present in such preparations, we designed an enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies as solid-phase reagents and protein A-purified IgG3 as antigen. Three different samples of reduced and alkylated antigen were used: (1) IgG3 isolated from a ready-for-infusion IGIV; (2) IgG3 which was purified from an intramuscular (Cohn fraction II) IgG solution before being subjected to a mild reduction and alkylation procedure, and (3) completely reduced and alkylated IgG3. The reduction and alkylation procedure did not affect the solubility of IgG3, indicating that IGIV prepared in this manner should contain normal quantities of IgG3. In the ELISA, solid-phase monoclonals which were cross-reactive with multiple IgG subclasses clearly reacted with reduced and alkylated IgG3. Furthermore, there was no substantial difference between the quantities of modified and native antigen required for 50% maximal ELISA signal. In contrast, solid-phase monoclonals with IgG3-restricted specificity did not recognize reduced and alkylated material. These results indicate that IGIV prepared by reduction and alkylation has a normal IgG3 content and confirm that some IgG3-specific determinants are altered by the modification procedure.

Alkylation↗
PubMed1982

[Membranous glomerulonephritis in two brothers associated in one with tubulo-interstitial disease, Fanconi syndrome and anti-TBM antibodies (author's transl)].

Anatomical and immunological studies were performed in two brothers with membranous glomerulonephritis. The older child presented with renal failure, Fanconi syndrome and anti-TBM antibody in his plasma. Renal biopsy revealed severe tubulo-interstitial disease with membranous glomerulonephritis. Because of rapidly progressive renal insufficiency the patient was started on hemodialysis. A cadaver renal allotransplantation was performed without success. Renal transplant biopsy showed severe lesions of vascular rejection without recurrence of the primary disease. The younger child was examined at six months for a nephrotic syndrome with mild renal insufficiency, and died at nine months. Anti TBM antibodies were not detected in his serum. The patient's mother presented with asymptomatic proteinuria, and anti TBM antibodies in her plasma. In the same family the uncle died at 3 months with a steroid resistant nephrotic syndrome. The relationships between the familial membranous glomerulonephritis and the tubulo interstitial disease are discussed.

Autoantibodies↗
PubMed1978

Characterization of human angiotensinogen.

In this study of the physical and chemical properties of human angiotensinogen were determined. Human angiotensinogen is a glycoprotein containing 14% carbohydrate. The molecular weight as determined by sedimentation equilibrium studies was 56,800. A higher molecular weight was obtained on sodium dodecyl sulfate electrophoresis. Ferguson-type plots indicated that angiotensinogen is another glycoprotein which behaves anomalously on sodium dodecyl sulfate electrophoresis. The COOH-terminal amino acid was found to be serine while two NH2-terminal amino acids, alanine and aspartic acid (or asparagine), were detected. The specific angiotensin I content of angiotensinogen preparations can vary considerably with no effect on the apparent homogeneity of the isolated protein. A protein with negligible angiotensin I content has been obtained from a preparation of human angiotensinogen. The COOH-terminal amino acid of this protein was serine while the only NH2-terminal amino acid detected was alanine.

Amino Acids↗
PubMed1977

Purification of human angiotensinogen.

A four-step method for the purification of human angiotensinogen has been devised. The four steps are: (1) removal of albumin by affinity chromatography on blue dextran-Sepharose, (2) chromatography on DEAE-Sephadex, (3) chromatography on hydroxylapatite, and (4) chromatography on DEAE-cellulose. This method is capable of producing 8 mg of purified angiotensinogen from 150 ml of plasma with 33% overall recovery of renin-releasable angiotensin I. The angiotensinogen appears homogeneous by immunochemical and ultracentrifugal techniques. The N-terminal amino acids have been determined to be alanine and aspartic acid or asparagine.

Angiotensinogen↗