PubMed Health⌕ Search

Biomedical subjects

J G Curd

Publications and source records attributed to J G Curd.

12 recordsLinked to original sources
PubMed1992

Atlantoaxial lateral mass osteoarthritis. A frequently overlooked cause of severe occipitocervical pain.

Localized C1-C2 lateral mass osteoarthritis is a degenerative disorder of the upper cervical spine that has a natural history markedly different from that of degenerative afflictions of the lower cervical spine. Atlantoaxial lateral mass arthritis is a distinct cause of occasionally severe occipitocervical pain in elderly persons. In this series, the diagnosis was suggested by the medical history of nine elderly patients who presented with severe occipitocervical pain (frequently diagnosed as occipital neuralgia). Physical examination demonstrated marked restriction of rotation of the cervical spine to the affected side, and localized tenderness unilaterally at the occipitocervical junction. The diagnosis was confirmed by plain radiographs of the C1-C2 articulation (open-mouth view), demonstrating marked, usually unilateral joint-space narrowing, osteophyte formation, and subchondral sclerosis. Bone scanning demonstrated focal uptake unilaterally at the occipitocervical junction. Additional imaging studies, including computed tomography, magnetic resonance imaging, or cervical myelogram, were performed to rule out coexisting intraspinal pathology. Conservative treatment was usually successful; however, C1-C2 arthrodesis was successful for severe occipitocervical pain due to atlantoaxial lateral mass arthritis not responsive to conservative treatment.

Aged↗
PubMed1991

Autoantibodies to native myeloperoxidase in patients with pulmonary hemorrhage and acute renal failure.

Sera from 245 patients were screened by indirect immunofluorescence for perinuclear/nuclear staining (P-ANCA) of ethanol-fixed neutrophils, a staining pattern which is associated with the presence of antibodies to myeloperoxidase. Using immunoblot and immunoprecipitation techniques on 15 P-ANCA-positive sera, 13 patients demonstrated antibody to purified or native myeloperoxidase but not to denatured myeloperoxidase. In patients with P-ANCA, the most frequent reason for medical attention was hemoptysis (8/13; 62%). Of the 15 sera with P-ANCA, acute renal failure was identified in 9 patients (60%). Five patients (33%) had both. All patients (eight of eight) with hemoptysis had antibodies which bound functional MPO as compared to three of seven P-ANCA-positive patients without hemoptysis (P less than 0.001), suggesting that antibodies which recognize conformational sites on native myeloperoxidase occur in a subgroup of patients with alveolar hemorrhage as their presenting clinical sign. These findings may provide insight into the disease process associated with P-ANCA. We further identify a subgroup of patients with a severe pulmonorenal syndrome and antibodies recognizing native myeloperoxidase.

Acute Kidney Injury↗
PubMed1990

Potent toxicity of 2-chlorodeoxyadenosine toward human monocytes in vitro and in vivo. A novel approach to immunosuppressive therapy.

Lymphoid cells were thought to be uniquely susceptible to excess 2'-deoxyadenosine (dAdo), when exposed to inhibitors of adenosine deaminase (ADA). However, we now find that human monocytes are as sensitive as lymphocytes to dAdo or to the ADA-resistant congener 2-chloro-2'-deoxyadenosine (CldAdo). Monocytes exposed in vitro to CldAdo, or to dAdo plus deoxycoformycin rapidly developed DNA strand breaks. Both the DNA damage and the toxicity of CldAdo or dAdo toward monocytes were blocked by deoxycytidine, but not by inhibitors of poly(ADP-ribose) polymerase. A partial decrease in RNA synthesis and a gradual decline of cellular NAD were early biochemical events associated with monocyte DNA damage. Low CldAdo concentrations (5-20 nM) inhibited monocyte phagocytosis and reduced the release of interleukin 6. Higher CldAdo concentrations led to a dose- and time-dependent loss of monocyte viability. Circulating monocytes disappeared within 1 wk in patients with cutaneous T cell lymphoma or with rheumatoid arthritis during continuous CldAdo infusion. The marked sensitivity of human monocyte function and survival to CldAdo in vitro, together with the monocyte depletion in patients receiving CldAdo chemotherapy, suggests that CldAdo or other dAdo analogues offer a novel therapeutic strategy for chronic inflammatory and autoimmune diseases characterized by inappropriate monocyte deployment or function.

2-Chloroadenosine↗
PubMed1979

Potassium iodide sensitivity in four patients with hypocomplementemic vasculitis.

During metabolism studies of radiolabeled proteins in 126 participants four patients were suspected of being sensitive to potassium iodide (Kl) because they repeatedly developed urticaria and other symptoms after Kl administration. Two of the four patients suspected of Kl sensitivity and 10 control patients were orally challenged with Kl to document and characterize Kl sensitivity and to evaluate the possible association(s) of Kl sensitivity with urticaria, hypocomplementemia, and vasculitis. The Kl challenges in the two sensitive patients precipitated urticaria, angioedema, polymyalgias, conjunctivitis, and coryza. One of these two patients also developed a severe systemic illness characterized by fever, headache, peritonitis, episcleritis, and pneumonitis. The four sensitive patients were strikingly similar in that they exhibited hypocomplementemia and dermal vasculitis associated with chronic urticaria or systemic lupus erythematosus, suggesting that other patients with similar clinical features may be sensitive to Kl and that Kl may precipitate severe systemic illness in them.

Adult↗
PubMed1978

Neoantigen of the membrane attack complex of human complement: Occurrence on peripheral blood leukocytes from patients with systemic lupus erythematosus.

Since complement activation and hematological abnormalities occur in systemic lupus erythematosus (SLE), the present study is an investigation of whether the membrane attack complex of complement might be bound to peripheral blood leukocytes (PBL) in vivo. Assembly of the membrane attack complex results in the generation of neoantigen (neoAg) which is complex-specific and not expressed by any of the individual complement proteins. FITC antiserum specific to neoAg was employed to detect the membrane attack complex on PBL from 7 normal donors, 12 patients with SLE, and 2 patients with rheumatoid arthritis (RA): 3 +/- 1% of normal, 25 +/- 13% of SLE, and 23 +/- 11% of RA PBL were positive. The majority of the neoAg positive PBL in SLE were polymorphonuclear neutrophils (PMN) as shown by adherence to plastic, phagocytosis of carbonyl iron, and differential cell counts. The PBL were greater than 98% viable as indicated by the trypan blue exclusion technique. These observations strongly suggest that the membrane attack complex may be bound to viable PBL in patients with SLE and RA, and further raise the possibility that the membrane attack complex, may have a function other than lysis.

Antigen-Antibody Complex↗
PubMed1978

Leukocyte complement: assembly of the membrane attack complex of complement by human peripheral blood leukocytes in the presence and absence of serum.

The specific neoantigenic determinants (neoAg) that are indicative of the assembled C5b-9 C complex are generated on the surface of peripheral blood leukocytes (PBL) during collection and processing of blood. Formation of neoAg on PBL could be prevented by collecting blood directly into 20 mM EDTA and, could be induced in vitro by adding autologous serum to isolated PBL that lacked neoAg. When neoAg was induced by the addition of serum containing 125I-labeled C8, the C8 was incorporated into a 23S complex which could be eluted from PBL. A mechanism for neoAg formation on PBL independent of exogenous serum factors was detected when PBL were placed into culture in serum-free medium. Results with metabolic inhibitors and 14C-leucine suggest that PBL can synthesize C5 and assemble the C5b-9 complex. The possible relevance of these findings to the understanding of mechanisms of cell-mediated cytotoxicity is discussed.

Antigens↗
PubMed1976

The NH2-terminal region of the beta chain of sickle hemoglobin. I. Synthesis and purification of oligopeptides.

Five peptides from the NH2-terminal region of the beta chain of hemoglobin S, betaS (1-13), betaS (3-13), betaS (1-8), betaS (4-10), And betaS (4-8), have been synthesized by a rapid solid phase method based on the Merrifield procedure. In addition, one peptide, betaS (3-13), has also been synthesized by the original Merrifield method. We have shown that the products of the two methods are comparable, that gel filtration is a useful method for removing truncated fragments of the desired oligopeptide, and that measurement of the efficiency of coupling at each step is an important adjunct to amino acid analysis in determining purity. Peptides of the purity achieved by these methods may be used to fractionate antibodies to the native hemoglobin S, in the characterization of antigen-binding properties of specific antibodies, and in other studies of peptide-protein interactions.

Amino Acid Sequence↗
PubMed1976

Probability analysis of the interaction of antibodies with multideterminant antigens in radioimmunoassay: application to the amino terminus of the beta chain of hemoglobin S.

A simple theory, based on probability, is developed for the analysis of the interaction of multideterminant antigens with multispecific antisera in radioimmunoassays. The theory is completely general except for the assumptions that the determinants be unique and bind antibodies independently of one another. The analysis shows that the shape of the curve of bound/free as a function of the antigen concentration is very sensitive to the multiplicity of determinants. The predictive ability of the theory is illustrated for the case of antibodies to subregions of the N-terminal third of the beta chain of sickle hemoglobin, studied using antisera fractionated on affinity chromatographic columns of synthetic peptides. The implications for obtaining quantitative binding data by radioimmunoassay for natural antigens, which almost universally have more than one antigenic determinant on the same molecule, are discussed.

Amino Acid Sequence↗
PubMed1976

Antibodies to an NH2-terminal fragment of betaS globin. I. Preparation and radioimmunoassay.

Polypeptide fragments corresponding to the NH2-terminal 55 amino acids of betaS and betaA globins were prepared by cyanogen bromide treatment of globin and isolated by gel filtration on Sephadex G-50. Sheep were immunized with the isolated NH2-terminal fragments, and one of these sheep produced precipitating antibodies to the NH2-terminal fragment of betaS globin. These antibodies also reacted with betaA and betaS globin and hemoglobins A and S, as shown by immunodiffusion and quantitative precipitation studies. A radioimmunoassay was developed using the radioiodinated NH2-terminal fragment as tracer, and dextran-coated charcoal for separating bound and free peptide. The radioimmunoassay was used to characterize the interaction of the antibodies and the NH2-terminal fragment of betaS globin.

Amino Acids↗
PubMed1976

Antibodies to an NH2-terminal fragment of betaS globin. II. Specificity and isolation of antibodies for the sickle mutation.

The immunochemical specificity of an antiserum produced to an NH2-terminal 55-residue polypeptide fragment of the betaS globin, betaS(1-55), was analyzed with a radioimmunoassay using the radioiodinated fragment as a tracer. These studies show that most of the antibodies have comparable reactivity with betaS(1-55), betaA(1-55), betaS globin, betaA globin, HbS, and HbA. However, the antiserum contains some antibodies which react only with the species derived from HbS. These "S" -specific antibodies were isolated by absorption of the serum on a column of betaA(1-55) coupled covalently to Sepharose. The S-specific antibodies have markedly diminished reaction with betaA(1-55) and HbA. The S specificity was localized to the valine substitution at position 6 of the beta globin, as shown by inhibition of the binding of the radiolabeled fragment to S-specific antibodies by the synthetic peptide betaS(1-13). These antibodies, which appear monospecific, can be used to study the conformation of the NH2-terminal region of the beta chain of HbS.

Amino Acid Sequence↗
PubMed1975

Isolation of antibodies specific to sickle hemoglobin by affinity chromatography using a synthetic peptide.

Antibodies to hemoglobin have been studied with a radioimmunoassay which employs [14C]carbamylated (= carbamolyated) hemoglobin S. An antiserum raised against hemoglobin S, which initially discriminated poorly between hemoglobins S and A, was fractionated by absorption to a column of Sepharose to which a synthetic peptide corresponding to the first 13 amino-acid residues of the beta chain of sickle hemoglobin had been covalently bound. A subpopulation of the antiserum was eluted from this column with 4 M guanidine - HC1. These antibodies showed binding to hemoglobin S but not to hemoglobin A and this interaction could be inhibited by the synthetic peptide. These antibodies, of demonstrated fine structural specificity, may be useful in the detection of sickle hemoglobin and in the study of its structure in solution.

Amino Acids↗