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Biomedical subjects

S R Pinnell

Publications and source records attributed to S R Pinnell.

At least 73 records · Page 4Linked to original sources
PubMed1980

Procollagen I synthesis in human skin fibroblasts: effect on culture conditions on biosynthesis.

Human skin fibroblast culture promises to be a useful system for the investigation of the regulation of collagen biosynthesis and the study of abnormalities in collagen biosynthesis in connective tissue disorders. The effect of culture conditions on procollagen I biosynthesis has been determined. Optimal conditions for collagen biosynthesis were: 10% dialyzed heat-inactivated fetal calf serum, 0.15 mM ascorbate, and 0.078 mM beta-aminopropionitrile. Newly synthesized procollagen I accumulated in the medium at a linear rate for 18 hr. Preincubation of cells in labelling media for 4 hr before adding radioactive proline enhanced synthesis. Collagenase digestion was used to study overall collagen biosynthesis. 94% of all collagen synthesized was found in the medium, and 6% in the cell pellet. Under optimal conditions, collagen comprised 24% of all protein in the medium, and 14% of protein produced by the whole culture.

Adolescent↗
PubMed1979

Altered collagen composition in a prolapsing mitral valve with ruptured chordae tendineae.

A patient presented with mitral valve prolapse, ruptured chordae tendineae, severe mitral regurgitation and congestive heart failure. Pathologic studies demonstrated myxomatous changes of both mitral leaflets. Collagen analysis of the valve and of the chordae tendineae revealed the presence of type I collagen in normal quantities and a striking absence of type III and AB collagens. The altered collagen in this patient's mitral valve probably contributed to the development of his mitral valve disorder.

Chordae Tendineae↗
PubMed1979

Levamisole and agrandulocytosis.

Levamisole, originally developed as an anthelmintic, is used in the treatment of many disorders. Severe side-effects have been noted by some investigators, and a case is presented herein of levamisole-induced agranulocytosis.

Adult↗
PubMed1979

Hereditary C2 deficiency associated with cutaneous lupus erythematosus: clinical, laboratory, and genetic studies.

Selective congenital deficiency in the second component of complement has been described in association with lupus erythematosus (LE) and other connective tissue disorders. We identified a 59-year-old woman with a 13-year history of cutaneous LE and no detectable serum C2. The patient's photosensitivity, large polycyclic erosive cutaneous lesions, lack of renal disease, paucity of serological findings, and high incidence of bacterial infection is consistent with previously described patients with this association. Uniquely, the patient demonstrated secondary infection with Staphylococcus aureus and Trichophyton rubrum in the skin lesions themselves. Immunologic studies disclosed depression in both humoral and cellular immunity. Moderation in her clinical disease and immunologic measurements has been observed after treatment with levamisole hydrochloride. Immunogenetic studies of the patient's four-generation kindred was consistent with an autosomal recessive inheritance of C2 deficiency genetically linked to HLA, segregating with the B18 allele. Mixed lymphocyte culture determinations reinforce evidence for linkage between the HLA-D locus and the trait for C2 deficiency.

Complement C2↗
PubMed1978

Inherited human collagen lysyl hydroxylase deficiency: ascorbic acid response.

A patient is described with congenital hypotonia, lax joints, friable skin, hemorrhagic scars, high-arched palate, and borderline microcornea. Acid hydrolyzed whole skin collagen had a reduced hydroxylysine content of 0.5 residues per 1,000 as compared to 5.1 +/- 0.7 in control skin. Collagen lysyl hydroxylase in dialyzed subcellular fractions of cultured skin fibroblasts required L-ascorbate as a principal cofactor. Activity of this enzyme in cultured skin fibroblasts derived from this patient, his father, and mother were 17%, 66%, and 39% of control values, respectively. Collagen prolyl hydroxylase activity was normal. Pharmacologic amounts of oral vitamin C (4 gm/day) produced an increase and withdrawal resulted in abrupt diminution of urinary excretion of hydroxylysine. Over a two-year period the patient's wound healing and muscle strength improved and corneal diameter increased. Hydroxylysine content of the skin did not increase.

Ascorbic Acid↗
PubMed1978

Double-blind study of levamisole in aphthous stomatitis.

Sixty-five patients with recurrent aphthous stomatitis participated in a double-blind study to evaluate levamisole. Nineteen of 34 patients improved on levamisole and only five of 31 patients improved on placebo (P less than 0.004, chi-square with two degrees of freedom). After breaking the code and switching placebo patients to levamisole and non-responders to an alternate dosage schedule, 46 of 60 patients noted clinical improvement.

Adolescent↗
PubMed1977

Inhibition of lysyl hydroxylase by catechol analogs.

Catechol analogs inhibit the activity of lysyl hydroxylase (peptidyllysine, 2-oxyglutarate: oxygen 5-oxidoreductase, EC 1.14.11.4), a microsomal enzyme which catalyzes the transformation of certain lysyl residues in collagen to hydroxylysine. Chick embryo lysyl hydroxylase activity was measured by specific tritium release as tritiated water from an L-[4,5-3H]lysine-labelled unhydroxylated collagen substrate prepared from chick calvaria. Catechol analogs did not bind irreversibly to either enzyme or substrate, as full activity was restored with dialysis. Addition of excess cofactor, Fe2+, ascorbic acid, or alpha-ketoglutarate, did not affect inhibition. Kinetic analysis revealed that with respect to collagen substrate, catechol demonstrated a noncompetitive type of inhibition with a Ki of 15 muM.

Animals↗
PubMed1977

Isolation of type III collagen from human adult parenchymal lung tissue.

The isolation and characterization of type III collagen from adult human lung parenchyma are described. The identity of this molecule as type III collagen has been established on the basis of (a) demonstration of intramolecular disulfide cross-links in the helical portion of the molecule, (b) amino acid analysis characteristic for type III collagen, and (c) composition and size of isolated cyanogen bromide peptides alpha1(III)-CB3, alpha1(III)-CB5, and alpha1(III)-CB8. The molecular weight of lung alpha1(III) was determined as 93 000 by Agarose chromatography, but its electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gels was slower than that of type I alpha chains which also have a molecular weight of 93 000.

Adult↗
PubMed1977

Generalized microsporum audoninii infection and depressed cellular immunity associated with a missing plasma factor required for lymphocyte blastogenesis.

Described herein is a 15 year old girl with a generalized, possibly systemic Microsporum audouinni infectin associated with anergy and defective lymphocyte transformation as a consequence of a deficiency of an uncharacterized plasma factor. Intravenous administration of plasma, obtained from normal donors, has produced consistent although incomplete clinical improvement. Defective lymphocyte transformation to M. audiouinii antigen cultured in autologous plasma became normal after infusions of normal plasma were instituted. Systemic administrations of griseofulvin, clotrimazole and miconazole produced transient and incomplete clinical improvement. Clearing of the cutaneous infection and stabillization of the neurologic status was finally achieved with plasma infusions combined with parenterally administered amphotericin B.

Adolescent↗
PubMed1977

In vitro inhibition of collagen cross links by catechol analogs.

Catechol analogs inhibit the formation of hydroxylysine-derived intermolecular collagen cross links in tissue cultures of chick embryo calvaria. Formation of intermolecular collagen cross links was measured following incorporation of [14C]lysine, reduction with sodium borohydride, and elution from an ion exchange column with a pyridine-formate gradient. Cultures grown in the presence of 10(-3) M catechol, 10(-3) M dopamine, 10(-3) M L-dopa, or 10(-3) M D,L-serine-(2,3,4-trihydroxybenzyl)-hydrazide demonstrated between 43 and 84% inhibition of hydroxylysine formation. Collagen biosynthesis was not diminished in these cultures as compared to controls without additions or with beta-aminopropionitrile when measured by collagenase digestion. The formation of hydroxylysine-derived intermolecular cross links was inhibited 34 to 93% for 5,5'-dihydroxylysinonorleucine and 7 to 71% for 5-hydroxylysinonorleucine. The catechol analogs also inhibit the activity of lysyl hydroxylase as measured by specific tritium release as triated water from an L-[4,5-3H]lysine-labeled unhydroxylated collagen substrate prepared from chick calvaria. Since catechol analogs inhibit the formation of hydroxylysine in a cell-free assay, these compounds must pass into the cells of calvaria in this culture system to inhibit intracellular hydroxylysine formation and subsequently to diminish the reducible intermolecular cross links of the newly synthesized collagen.

Aminopropionitrile↗
PubMed1977

Urinary excretion of hydroxylysine and its glycosides as an index of collagen degradation.

Urimary excretion of hydroxyprolin (Hyp) is one index of total collagen degradation, from all sources. Since some of the Hyp released from collagen may be further metabolized before it is excreted, other markers are necessary to measure collagen breakdown. Excretion of the glycosides of hydroxylysine (Hyl), glucosyl galactosyl hydroxylysine (Hy1[Gl)cGa1]), and galactosyl hydroxylysine (Hyl[Ga)]), more accurately reflects collagen metabolism since these products occur in specificratios in different tissue collagens and are themselves metabolized only to a minor degree. The ratios of total Hy1/Hyp and Hyl(GlcGal)/Hyl(Ga1) were measured in the urine of norma. subjects and of patients with Paget's disease of bone, hyperphosphatasia, and extensive thermal burns. In patients with extensive thermal burns the pattern of urinary Hy1 and its glycosides was consistent with degradation of collagen in dermis and fascia. When bone collagen degradation was dominant, the pattern of urinary metabolites reflected that source. Pagetic bone collagen has an amino acid composition similar to normal bone and Hy1(G1cGa1/Hyl(G1) of 0.396-0.743,vs. normal of 0.474+/-0.088. In untreated patients with severe Paget's disease of bone or hyperphosphatasia (urinary Hyp greater than 2.0 micronmol/mg creatinine) urinary Hyl/Hyp averaged 0.052+/-0.042 (0.042+/-0.009 in normal bone) and Hy1(G1cGa1)/Hy1(Ga1) 0.601+/-0.017 (0.47+/-0.009 in normal bone). When bone resorption was decreased sufficiently with calcitonin or disodium etidronate in these patients, both the urinary ratios of Hy1/Hyp and Hy1(G1cGa1)/Hyl(Gal) rose. In normal subjects treated with calcitonin and excreting relatively little Hyp, the ratio of Hy1/H)P approached 0.7 and Hy1(G1ycGa1)/Hy1(Ga1) approached 3.5. There increased ratios reveal the existence of a source of collagen breakdown other than skin or bone. The first subcompoent of complement, Clq, which has collagen-like sequences, relatively high amounts of Hy1, and most of the glycosylated Hy1 as Hy1(G1cGa1), could be the source of these metabolites.

Adolescent↗
PubMed1977

In vitro inhibition of chick embryo lysyl hydroxylase by homogentisic acid. A proposed connective tissue defect in alkaptonuria.

Homogentisic acid inhibits the in vitro activity of chick embryo lysyl hydroxylase, a microsomal enzyme which catalyzes the transformation of certain lysyl residues in collagen to hydroxylysine. Chick embryo lysyl hydroxylase activity was measured as specific tritium release as tritium water from a [4,5-(3)H]lysine-labeled unhydroxylated collagen substrate prepared from chick calvaria. Kinetic studies revealed a linear, noncompetitive type of inhibition with respect to collagen substrate with a Ki of 120-180 muM. The inhibition by homogentisic acid was reversible in that enzyme activity could be restored after dialysis of preincubated mixtures of homogentisic acid with enzyme or substrate. The inhibition by homogentisic acid was competitive with respect to ascorbic acid, and the addition of reducing agents, such as ascorbic acid or 1,4-dithiothreitol, protected lysyl hydroxylase activity from homogentisic acid inhibition.In organ cultures of embryonic chick calvaria, biosynthesis of hydroxylysine-derived intermolecular collagen cross-links was inhibited in a dose-dependent manner by 0.5-5 mM homogentisic acid. Because homogentisic acid inhibits the formation of hydroxylysine in a cell-free assay and in organ cultures, this compound must pass into the cells of calvaria to inhibit intracellular hydroxylysine formation and subsequently to diminish the reducible intermolecular cross-links of the newly synthesized collagen. We propose that the inhibition of lysyl hydroxylase and the resulting hydroxylsine-deficient, structurally modified collagen may be clinically significant in the defective connective tissue found in alkaptonuric patients.

Alkaptonuria↗
PubMed1972

Lysyl-protocollagen hydroxylase deficiency in fibroblasts from siblings with hydroxylysine-deficient collagen.

Cell culture studies were performed on members of a family in which two sisters, ages 9 and 12, have a similar disorder characterized clinically by severe scoliosis, joint laxity and recurrent dislocations, hyperextensible skin, and thin scars. The skin collagen from the sisters was markedly deficient in hydroxylysine, but other amino acids were present in normal amounts. Hydroxylysine in collagen from fascia and bone was reduced to a lesser extent. Since the most likely explanation for the hydroxylysine deficiency was a reduction in enzymatic hydroxylation of lysine residues in protocollagen, we measured the activity of lysyl-protocollagen hydroxylase in crude lysates of cultured skin fibroblasts. Enzyme activities in the two affected children were 14 and 10% of controls, whereas the activity was about 60% of normal in the mother, a pattern most consistent with autosomal recessive inheritance. The mutant enzyme demonstrated the same cofactor requirements as that from normal cells. Deficiency of lysyl-protocollagen hydroxylase is the first inborn error of human collagen metabolism to be defined at the biochemical level.

Adolescent↗