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Biomedical subjects

H R Colten

Publications and source records attributed to H R Colten.

At least 181 records · Page 10Linked to original sources
PubMed1976

Homozygous human C3 deficiency. The role of C3 in antibody production, C-1s-induced vasopermeability, and cobra venom-induced passive hemolysis.

Studies of the family of a patient with marked deficiency of the third component of complement (C3) demonstrated that the patient was homozygous for a blank allele at the C3 locus, C3-. Metabolic studies with purified radiolabeled C3 in the patient revealed a mildly elevated fractional catabolic rate and a markedly reduced synthesis rate, consistent with a lack of C3 synthesis as the patient's primary defect. There was also a mild increase in the rate of conversion of purified C3 added to her serum and incubated at 37 degrees C in vitro. Major blood group-compatible erythrocytes from a patient with paroxysmal nocturnal hemoglobinuria had the same shortened survival in the C3-deficient patient as in a normal control. Although no leukocytosis developed in the patient in spontaneous infection by pyogenic organisms, there was a normal leukocytosis in response to the injection of thyphoid vaccine. The intradermal injection of C-1s, which produces a marked increase in vasopermeability in the skin of normal subjects, produced no definite change in the patient, possibly implicating C3 or a protein in the alternative pathway as the normal mediator of this response. The patient's serum exhibited near-normal immune adherence activity, confirming the lack of requirement of C3 for this function. C5 inactivation and passive hemolysis of unsensitized guinea pig erythrocytes occurred normally in C3-deficient serum on incubation with cobra venom factor, indicating that C3 is not required for these reactions. The patient's humoral antibody response to both protein and carbohydrate antigens was entirely normal, making it unlikely that C3 is required for antigen processing.

Alleles↗
PubMed1976

Liver in alpha1-antitrypsin deficiency: morphologic observations and in vitro synthesis of alpha1-antitrypsin.

In an effort to characterize the hepatic abnormality in patients with alpha1-antitrypsin deficiency, three unrelated children with the disorder (Pi types ZZ and SZ), two heterozygous parents (Pi type MZ), and three normal subjects (Pi type MM) were studied. As expected, the livers of the ZZ- and SZ-deficient subjects showed abnormal accumulation of alpha1-antitrypsin in the cisternae of the rough endoplasmic reticulum as judged by immunofluorescent and electron microscopic studies. Their parents (MZ phenotype) demonstrated identical although less extensive hepatic abnormalities. Short term cultures of liver tissue in the presence of radiolabeled amino acids showed both synthesis and release of alpha1-antitrypsin in normal control subjects and in the patients with the Z protein. Radiolabeled intracellular alpha1-antitrypsin could not be found. These studies demonstrate synthesis of alpha1-antitrypsin by the livers of normal and genetically deficient subjects in vitro, and suggest several possible mechanisms for alpha1-antitrypsin deficiency.

Adult↗
PubMed1975

Immediate hypersensitivity to hog trypsin resulting from industrial exposure.

Clinical, immunologic and psysiologic studies were undertaken to establish the role of hog trypsin dust in four cases of occupational asthma and to define the mechanism of this respiratory disease. Objective evidence was obtained that these patients, but not their asymptomatic co-workers, were allergic to trypsin, and that this fact accounted for their respiratory symptoms. Direct skin testing, passive transfer of IgE antibodies, antigen-mediated histamine release from peripheral blood leukocytes and airway obstruction in response to inhalation challenge indicated IgE-mediated, Type I hypersensitivity. These effects were induced by inactivated trypsin and were therefore independent of tryptic enzymatic activity. The data suggested that periodic skin testing for immediate sensitivity to organic dust would be an inexpensive and convenient screening procedure for early detection and prevention of some types of occupational asthma.

Aerosols↗
PubMed1975

Cooperation between human thymus-derived and bone marrow-derived lymphocytes in the antibody response to ragweed antigen E in vitro.

Human T lymphocytes from patients with ragweed hay fever, when exposed to ragweed antigen E (AgE) in vitro, produced an activity that, in the presence of antigen, induced B cells from AgE-sensitive donors to synthesize and secrete IgE and IgG antibodies to AgE. Anti-AgE specificity was assessed both in vitro and in vivo. B lymphocytes from ragweed-sensitive individuals exposed in vitro to AgE alone failed to transform or to secrete antibody to AgE. The T cells activity had no effect on B cells of individuals not sensitive to AgE. The results of this study suggest that the human reaginic antibody response requires T and B cell cooperation. The experimental approach used may be a useful model for the investigation of the antibody responses of allergic individuals.

Adult↗
PubMed1975

Complement biosynthesis in vitro by rat hepatoma cell strains.

Four separate rat hepatoma strains were examined for their capacity to synthesize complement (C). None of the strains synthesized detectable amounts of the first components (C-1), and only one strain (7800C-1) produced the fourth component (C4). However, each of the strains synthesized significant amounts of biologically active C-2 and C-3. Three of the four strains also produced C-5 and the natural inhibitor of C-1 (C1 INH). Two control rat cell strains (fibroblast and pituitary) did not synthesize any detectable C components. Production of C, studied extensively in 7800C-1 and H-4, was reversibly inhibited by cycloheximide (2 mug/ml) and [ 14-C ] amino acids were incorporated into C-2, C-3, and C-1 INH. As assessed by gel filtration, the elution positions of the C components synthesized by the cells in culture were similar to those of the corresponding proteins in normal rat serum. Hydrocortisone (10-6 to 10-7 M) stimulated the production of C-3 by H-4 but C-2 and C-5 production were not affected. These C-producing hepatoma cells may prove useful for studies of the control of C biosynthesis.

Animals↗
PubMed1972

In vitro synthesis of a regulator of mammalian gene expression.

Peritoneal cells isolated from guinea pigs homozygous for a deficiency of the fourth component of complement (C4), produce in vitro a factor that induces the synthesis and secretion of functionally active human C4 by a human cell. This factor appeared to switch on production of C4 in the responsive cell without affecting total protein synthesis. The regulator factor is not species specific, inasmuch as guinea pig regulator affected a corresponding human gene function. Both synthesis of the factor and the response to it were inhibited by actinomycin D. The amount of regulator recovered from genetically deficient cells was about 5-10 times that recovered from normal guinea pig cells.

Amino Acids↗