PubMed Health⌕ Search

Biomedical subjects

R Ali

Publications and source records attributed to R Ali.

At least 163 records · Page 9Linked to original sources
PubMed1984

Identical specificity of lupus antibodies and antibodies elicited in rabbits against Sm and RNP antigens.

Rabbits immunized with purified Sm and RNP small nuclear ribonucleoproteins (snRNPs) produced precipitating and hemagglutinating antibodies against these antigens. These antibodies had immunological specificity identical to the naturally occurring SLE anti-Sm/RNP antibodies as demonstrated by immunoprecipitation results and studies involving the characterization of immunoaffinity purified antigens isolated from the rabbit immune and SLE anti-Sm/RNP IgG affinity columns.

Animals↗
PubMed1984

Antibodies from patients with mixed connective tissue disease react with heterogeneous nuclear ribonucleoprotein or ribonucleic acid (hnRNP/RNA) of the nuclear matrix.

The sera of patients with mixed connective tissue disease (MCTD) have high titers of antibodies directed against nuclear U1-ribonucleoprotein (U1-RNP). This antigen is easily extracted from nuclear preparations with physiologic saline and from tissue sections with 0.1 HCl, leaving the nucleic acids and nuclear matrix behind. When U1-RNP is extracted from HEp-2 cells with 0.1 N HCl, the sera of 32/32 patients with MCTD react with another antigen that is exposed by the extraction procedure. This antigen is not destroyed by trypsin and deoxyribonuclease 1 treatment but is sensitive to both purified ribonuclease A and purified micrococcal nuclease. Absorption studies showed that the antibody reacting with this antigen cannot be absorbed by sheep red blood cells coated with extracts of rabbit thymus that contain U1-RNP. Radioimmunoassay showed that the reaction of the unadsorbed antibody was with heterogeneous nuclear ribonucleoprotein or ribonucleic acid (hnRNP/RNA) and not with transfer RNA or ribosomal RNA. The hnRNP/RNA antigen is demonstrated as discrete particles in the internucleolar chromatin of interphase cells, but in metaphase cells the antigen is diffusely dispersed. The distribution, solubility, and biochemical characteristics suggest that the antigenic moiety is part of the nuclear matrix. Therefore, MCTD sera contain antibodies that react with at least two species of nuclear RNP: small nuclear RNP (snRNP), as described by others, and a high m.w. hnRNP/RNA bound to the nuclear matrix.

Animals↗
PubMed1984

Fluorometric assay for anti-DNA antibodies: use of ethidium bromide as intercalating dye.

Autoantibodies against double-stranded DNA in the sera of patients with various autoimmune diseases have been examined by fluorometric assay using ethidium bromide as intercalating dye. Forty-three per cent of SLE patients, 14% of SLE patients with overlapping PSS, 20% of PSS patients and none of the RA and SS patients were positive for anti-DNA antibodies. The method was found to be more sensitive than immunoprecipitation techniques and comparable with the hemagglutination assay. The technique is simple, sensitive, specific and can be employed for the detection of low concentration of anti-DNA antibodies.

Autoantibodies↗
PubMed1983

Purification and identification of antigenic polypeptides of Sm and RNP antigens of goat liver.

A ribonucleoprotein complex containing Sm and RNP antigenic activity was isolated from goat liver. The sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed the complex to contain four major polypeptides of 80,000, 70,000, 30,000 and 14,000 molecular weights. When the gels were probed for antigenic polypeptides by an enzyme-linked immunosorbent assay and fluorescent antibody method, anti-Sm sera were found to react with polypeptides of 14,000 and 30,000 molecular weights whereas anti-RNP sera recognized 70,000 and 80,000 molecular weight polypeptides with minor reactivity in the polypeptide of 14,000 molecular weight. Sera containing antibodies to both Sm and RNP reacted with all the four polypeptides.

Animals↗
PubMed1983

Enzyme-linked immunosorbent assay for anti-DNA antibodies using fluorogenic and colorigenic substrates.

An enzyme-linked immunosorbent assay is described for the assay of anti-DNA antibodies. The method employs plastic surface for immobilization of the antigen and alkaline phosphatase-linked rabbit anti-human IgG for the detection of immune complex using PNP-P and 4MU-P as substrates. The sensitivity of the assay increased by as much as 16-fold when fluorogenic substrate was used instead of conventional PNP-P and could therefore be employed for the detection of low avidity antibodies. Using PNP-P as substrate 57% of SLE patients were positive for DNA antibody, but if 4MU-P was introduced as substrate, 71% gave a positive response. Moreover, using a fluorogenic substrate, it was possible to minimise the amount of antigen (2 nM bp). The technique is simple, reproducible and of high sensitivity.

Alkaline Phosphatase↗
PubMed1983

Spectrophotometric assay for the detection of antibodies to DNA.

A spectrophotometric assay for the detection of anti-DNA antibodies in the sera of patients with various connective tissue diseases is described. The sensitivity of the method was compared with hemagglutination and enzyme-linked immunosorbent assay. The method is convenient, specific and suitable for use in clinical laboratories where facilities for radioimmunoassay do not exist.

Antigen-Antibody Reactions↗
PubMed1983

Nutritional survey of Bangladeshi children aged under 5 years in the London borough of Tower Hamlets.

The main deficiencies in the diet of Bangladeshi infants and children are vitamin D, iron, and later, calories. Protein intake is a little low in some, but in general is satisfactory. Calcium and vitamin C intakes are adequate. The proportions of food are often inappropriate, mainly because of a high carbohydrate intake. Weaning tends to be late, with predominant milk drinking, even into the second year of life. Convenience baby foods, containing mainly carbohydrate are the major components of the diet until well into the second and third years of life, without the conversion to family food seen in white children. Vitamin D is given to fewer than half the children. It may be given to fewer still if the observation that bottles were often unopened is true for many families.

Ascorbic Acid↗
PubMed1983

Enzyme-linked immunosorbent assay for detection of antibodies to extractable nuclear antigens in systemic lupus erythematosus, with nylon as solid phase.

In this enzyme-linked immunosorbent assay (ELISA) for detection of antibodies against extractable nuclear antigens (ENA) in sera of patients with systemic lupus erythematosus (SLE), nylon is used as solid phase for antigen binding instead of the commonly used polystyrene surface. Optimal conditions for activation of the nylon beads, antigen coating, and other relevant factors have been investigated. We compared the incidence of anti-ENA antibodies in SLE, using chromogenic and fluorogenic enzyme substrates. Of SLE patients, 54% were positive for anti-ENA antibodies when chromogenic substrate was used as compared with 68% for fluorogenic substrate. Antibody activity against Sm and RNP antigens was distinguished on the basis of ribonuclease sensitivity of the RNP antigen. The method described offers advantages such as decreased background activity, increased surface area, facility for prolonged storage of antigen-coated solid phase, and miniaturization of the assay.

Antibodies↗
PubMed1978

Effects of ultraviolet irradiation and postirradiation incubation on heterogenous nuclear RNA size in murine cells.

We have analyzed the decrease in synthesis of individual size classes of heterogeneous nuclear RNA (hnRNA) in ultraviolet (UV)-irradiated Merwin plasmacytoma (MPC-11) cells at various times of postirradiation incubation. HnRNA from nonirradiated control cells is distributed over a wide range from approximately 60S to 5S, with 42S RNA carrying more label than any other size class. HnRNA from UV-irradiated cells shows a dose-dependent shift in size distribution toward lower molecular weight. The size distribution of hnRNA synthesized after prolonged times of postirradiation incubation is restored toward normal, i.e., synthesis of long RNA molecules increases relative to the synthesis of short ones. Analysis of the total number of hnRNA chains synthesized during a 20-min [(3)H]uridine pulse shows a considerable reduction in their number with increasing UV dose. Murine cell lines are excision-repair-deficient but capable of post replication repair inhibited by caffeine. HnRNA transcripts of cells incubated in its presence were studied. The caffeine, which has no effect on hnRNA size in control cells, inhibits to a considerable extent the restoration of full-length transcripts during postirradiation incubation. The lack of excision repair in MPC-11 was confirmed by the analysis of pyrimidine dimers in trichloracetic acid-insoluble and soluble fractions within 8 h of postirradiation incubation.The size of parental and daughter strand DNA in UV-irradiated cells was correlated with RNA transcript size. The parental DNA in these experiments does not change its size as a consequence of UV exposure and postirradiation incubation. In contrast, daughter DNA strands are short in UV-irradiated cells and they increase in size during postirradiation incubation to reach the size of parental strands after 8 h.

Animals↗
PubMed1977

Reducing the pill swill: an audit of clinical pharmacy.

A drug surveillance programme involving pharmacists in a general medical ward has been shown to reduce the number of drugs prescribed to patients and also to reduce the number of dispensing errors. The evidence presented suggests that continuing involvement of pharmacists in patient care at the ward level is required to maintain the improved prescribing habits.

Drug Prescriptions↗