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Biomedical subjects

C Brown

Publications and source records attributed to C Brown.

At least 397 records · Page 22Linked to original sources
PubMed1988

Identification and expression of a human cytomegalovirus glycoprotein with homology to the Epstein-Barr virus BXLF2 product, varicella-zoster virus gpIII, and herpes simplex virus type 1 glycoprotein H.

An open reading frame with the characteristics of a glycoprotein-coding sequence was identified by nucleotide sequencing of human cytomegalovirus (HCMV) genomic DNA. The predicted amino acid sequence was homologous with glycoprotein H of herpes simplex virus type 1 and the homologous protein of Epstein-Barr virus (BXLF2 gene product) and varicella-zoster virus (gpIII). Recombinant vaccinia viruses that expressed this gene were constructed. A glycoprotein of approximately 86 kilodaltons was immunoprecipitated from cells infected with the recombinant viruses and from HCMV-infected cells with a monoclonal antibody that efficiently neutralized HCMV infectivity. In HCMV-infected MRC5 cells, this glycoprotein was present on nuclear and cytoplasmic membranes, but in recombinant vaccinia virus-infected cells it accumulated predominantly on the nuclear membrane.

Amino Acid Sequence↗
PubMed1988

Reaction of antibodies to rheumatoid arthritis nuclear antigen with a synthetic peptide corresponding to part of Epstein-Barr nuclear antigen 1.

Antibodies to rheumatoid arthritis nuclear antigen (RANA) are detected by immunodiffusion (ID) and immunofluorescence (IF), though reports of the identity of the antigen(s) have been conflicting. In this study it is shown conclusively that ID and IF anti-RANA react with epitopes on Epstein-Barr nuclear antigen 1 (EBNA-1) and that the major epitope detected by immunofluorescence is represented by a synthetic peptide, P62, corresponding to part of EBNA-1. In an enzyme linked immunosorbent assay (ELISA) anti-P62 antibodies in 35 rheumatoid arthritis sera were threefold higher than those of 35 age and sex matched controls, with the highest levels occurring in young patients with active joint disease.

Adult↗
PubMed1988

Managing women with human papillomavirus changes in cervical cytology.

Of 86 women with cervical cytological evidence of human papillomavirus (HPV) infection who underwent colposcopy, 55 yielded histological confirmation of HPV infection and 17 of them had cervical intraepithelial neoplasia (CIN). Of 51 women followed up six months after cryotherapy of their cervical lesions, 46 showed no evidence of HPV infection in their cervices. Of the patients with CIN lesions, only one out of the 16 followed up had persistent CIN II six months after treatment, which gave a clearance rate of 94% for early CIN lesions treated by this method. Of 62 sexual partners examined, 48 had sexually transmitted infections, 38 of them genital warts. The use of colposcopy with directed punch biopsy is a practical way of managing patients whose cervical smears suggest HPV infection. Cryotherapy is effective in treating histologically confirmed cervical HPV and associated minor CIN lesions. Contact tracing and screening for other sexually transmitted diseases is an integral part of managing genital warts.

Adolescent↗
PubMed1988

Corticotropin-releasing factor levels in the peripheral plasma and hypothalamus of the rat vary in parallel with changes in the pituitary-adrenal axis.

Impressive evidence has emerged indicating that immunoassayable and bioassayable CRF, which is immunoneutralizable, is present not only in the hypothalamus but in many peripheral tissues as well. Using highly specific and sensitive RIAs and immunoaffinity chromatography to investigate whether this extrabrain CRF circulates in the rat, we found low but clearly measurable levels in peripheral plasma (mean, 11.4 +/- 0.8 pg/ml). Immunological findings were corroborated by fast protein liquid chromatography, which resolves peptides by both hydrophobicity and ionic charge. With this approach the major immunoreactive peak was eluted at the position of synthetic rat CRF standard. To assess whether levels of peripheral plasma CRF-like immunoreactivity (CRF-LI) vary in parallel with those of hypothalamic CRF-LI, we performed studies with low and high dose dexamethasone administration and withdrawal, adrenalectomy, and hypophysectomy. Seven days after oral administration of dexamethasone, there was a decrement in the levels of peripheral plasma and hypothalamic CRF-LI. Depending on the dose, recovery was also found 7 days after cessation of the treatment. After either adrenalectomy or hypophysectomy, there were increments in the levels of CRF-LI in both peripheral plasma and hypothalamus. Thus, concentrations of CRF-LI in the peripheral plasma and in the hypothalamus vary in parallel in response to alterations in the pituitary-adrenal axis.

Adrenalectomy↗
PubMed1988

Musculoskeletal symptoms related to arthropathy in patients receiving dialysis.

We evaluated musculoskeletal complaints related to arthropathy in 28 patients with end stage renal failure receiving maintenance dialysis. Twenty-three of 28 patients had arthritic complaints and 14 had an arthropathy. Six of 14 patients with arthropathy had a pattern resembling calcium pyrophosphate dihydrate deposition (CPPD) disease, 4 patients had moderately severe osteoarthritis, 3 had calcific periarthritis, and 1 patient had acute arthritis with intermittent pain and swelling. Factors which predispose to metabolic arthropathies were observed as follows: 29% elevated ferritin; 39% history of hyperparathyroidism; 68% elevated parathormone; 54% hyperphosphatemia; 36% hypercalcemia, 29% HLA haplotypes A3, B7, or B14; and 60% hyperaluminemia. The arthropathy group had more abnormalities per patient (mean 3.6) than the group without arthropathy (mean 2.7) (p less than 0.05). Our data suggest that (1) arthritic complaints occur frequently in patients receiving dialysis; (2) arthropathy accounted for 61% of the complaints; (3) 43% of patients with arthropathy had CPPD-type; (4) renal osteodystrophy caused 17% of arthritic complaints; and (5) in patients receiving dialysis, there is a high incidence of metabolic abnormalities that are known to be associated with arthropathy.

Adult↗
PubMed1988

Heparin-induced thrombocytopenia: laboratory studies.

This report describes studies into the pathophysiology of heparin-induced thrombocytopenia. The IgG fraction from each of nine patients with heparin-induced thrombocytopenia caused heparin-dependent platelet release of radiolabeled serotonin. Both the Fc and the Fab portions of the IgG molecule were required for the platelet reactivity. The platelet release reaction could be inhibited by the Fc portion of normal human or goat IgG, and patient F(ab')2, but not F(ab')2 from healthy controls. These results suggested that the Fab portion of IgG binds to heparin forming an immune complex and the immune complexes initiate the platelet release reaction by binding to the platelet Fc receptors. To directly challenge this hypothesis, we preincubated the serotonin-labeled platelets with the monoclonal antibody against the platelet Fc receptor (IV.3). This monoclonal antibody completely inhibited the release reaction caused by heparin and patient sera, as well as heat aggregated IgG, but did not block collagen or thrombin-induced platelet release. Heparin-dependent platelet release also could be inhibited in vitro by the addition of monocytes and neutrophils, but not by red cells, presumably because the Fc receptors on the phagocytic cells have a higher binding affinity for IgG complexes than do platelets. Platelets from patients with congenital deficiencies of specific glycoproteins Ib and IX (Bernard-Soulier syndrome) and IIb and IIIa (Glanzmann's thrombasthenia) displayed normal heparin-dependent release indicating that the release reaction did not require the participation of these glycoproteins. These studies indicate that heparin-induced thrombocytopenia is an IgG-heparin immune complex disorder involving both the Fab and Fc portion of the IgG molecule.

Antibodies, Monoclonal↗
PubMed1987

Growth hormone-releasing factor releases ACTH from an AtT-20 mouse pituitary tumor cell line but not from normal pituitary cells.

Corticotropin-releasing factor (CRF) and both human pancreatic growth hormone-releasing factor (hp-GRF) and rat hypothalamic GRF (rh-GRF) stimulated ACTH release from neoplastic AtT-20 mouse pituitary tumor cells in a dose-dependent fashion, with CRF inducing a 10-fold increase and GRF a maximal increment of approximately one-half that of CRF. Neither rh-GRF nor hp-GRF induced ACTH release in normal anterior pituitary cells. Pretreatment with either dexamethasone or somatostatin prior to the addition of rh-GRF inhibited the increase in ACTH release. Both ovine CRF and rh-GRF stimulated adenosine 3,5-monophosphate production in AtT-20 cells. The weak but clearly discernible effect of GRF on ACTH release from AtT-20 cells may be due to an abnormality in the AtT-20 cell receptor.

Adrenocorticotropic Hormone↗
PubMed1987

Oral hairy leukoplakia. A distinctive marker of human T-cell lymphotropic virus type III (HTLV-III) infection.

Oral hairy leukoplakia (HL) is a newly described lesion occurring principally on the lateral borders of the tongue in immunosuppressed homosexual men infected with human T-cell lymphotropic virus type III (HTLV-III). Clinically, HL appears as a slightly raised, poorly demarcated lesion with a corrugated or "hairy" surface. Histologically, the lesion is characterized by keratin projections on the surface (which often resemble hairs), parakeratosis, and acanthosis. In addition, large pale-staining cells with pyknotic nuclei are seen in the upper stratum malpighii, which appear similar to the koilocytes described in uterine condylomata. Candida organisms are frequently observed on the lesion surface. Little, if any, subepithelial inflammation is present. Human papillomavirus and Epstein-Barr virus have been identified in biopsy specimens from lesions of oral HL. The association of this lesion in patients with HTLV-III infection has been established. We saw a patient with HTLV-III infection and HL, in whom the immunochemical and ultrastructural findings revealed the presence of a mixed viral infection. Because oral HL may be of diagnostic value as an early indicator of HTLV-III infection, awareness of its characteristic clinical, histologic, immunochemical, and ultrastructural features is important.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Citizen participation in police crisis intervention activities.

A naturalistic experiment tested the proposition that police time could be saved in nondangerous crisis intervention calls through the use of citizen participants. Results showed that police officers who used citizen intervention spent less time per call than officers who did not. However, police time was not saved in family disturbance calls. Family disturbance control group calls were rated by police as having a higher degree of physical danger present than other calls.

Adult↗
PubMed1987

Studies on the mechanism of bowel disturbance in ulcerative colitis.

The transit of a radiolabeled meal through the gastrointestinal tract and stool output were measured in 62 patients with ulcerative colitis, subdivided according to the activity and extent of their disease. The results were compared with those from 20 sex-matched normal subjects. Mouth-to-cecum transit was significantly slower than normal in all patient groups although gastric emptying was normal. Whole gut transit was not accelerated in any group of patients. An abdominal x-ray taken 48 h after ingesting the meal showed that patients with active colitis had proximal colonic stasis, whereas transit through the rectosigmoid region was rapid. Stool weights and frequencies were higher in patients with active colitis than in patients with quiescent disease. Patients with active colitis also passed smaller amounts of stool during each bowel movement, suggesting that they experienced a desire to defecate at lower rectal volumes. These results indicate that (a) diarrhea in ulcerative colitis is associated with rectosigmoid irritability rather than rapid transit and (b) caution should be used when treating active colitis with antidiarrheal drugs that could further retard proximal colonic transit.

Colitis, Ulcerative↗
PubMed1987

Inflammatory acquired oral hyperpigmentation: association with melanophages demonstrating phenotypic characteristics of antigen presenting cells and activated monocytes.

A case of a 30-year-old black woman who developed acute, extensive intraoral hyperpigmentation is reported. Its relationship to previously described entities is discussed. The condition was associated with the presence of melanophages both in the submucosa and in the oral epithelium. The melanophages displayed phenotypic markers of a population of intraepidermal melanophages previously described as potent T cell-activating, antigen presenting cells (T6- DR+ OKM5+ OKM1-) and of activated monocytes (Mo3e+), as well as other monocyte-macrophage markers (Mono 1 and My7). The distinct phenotype of these melanophages suggests that they could play an active role in the promotion of inflammatory disease.

Adult↗