Search PubMed⌕ Search

Biomedical subjects

B Anderson

Publications and source records attributed to B Anderson.

At least 361 records · Page 20Linked to original sources
PubMed1981

Calcium-dependent prolonged effects on melanophores of [4-norleucine, 7-D-phenylalanine]-alpha-melanotropin.

A single injection of the melanotropin analog [4-norleucine, 7-D-phenylalanine]-alpha-melanotropin into frogs (Rana pipiens) caused near maximum darkening of the skins of the frogs for at least 6 weeks. Injections of the natural hormone alpha-melanotropin or of the analog [Nle4]-alpha-melanotropin also caused darkening, but this effect lasted only a few days. Morphological examination of the skins of frogs injected with [Nle4, D-Phe7]-alpha-melanotropin revealed that both dermal and epidermal melanophores were dispersed during the entire 6-week period. In vitro [Nle4, D-Phe7]-alpha-melanotropin also causes prolonged darkening of the skin of the lizard Anolis carolinensis. In the absence of the melanotropin, skins previously darkened with the analog could be lightened by removal of calcium from the incubation medium but could then be redarkened by adding calcium. The cycle could be repeated indefinitely without addition of melanotropin. These results demonstrate the role of calcium in receptor signal transduction and the prolonged biological effects of [Nle4, D-Phe7]-alpha-melanotropin long after its removal from the assay medium.

Animals↗
PubMed1981

Effects of level of dietary glutamic acid and thiamin on food intake, weight gain, plasma amino acids, and thiamin status of growing kittens.

Specific pathogen-free kittens were individually fed purified amino acid diets containing 4.4 mg of thiamin and 3.0, 4.5, 6.0, 9.0 or 12.0% glutamic acid (Glu) in a balanced 5 x 5 latin square design. Kittens fed either the 9.0% followed by the 12.0% glutamate diets or vice versa developed severe clinical signs of thiamin deficiency and two kittens died. Other affected kittens given 5 mg additional thiamin per day for 3 days promptly recovered. In a subsequent experiment, the effect of a diet containing 12.0% glutamic acid with either 4.4 or 25.0 mg thiamin per kilogram diet was compared with a diet containing 3.0% glutamic acid with either 0.0 or 4.4 mg thiamin per kilogram. Kittens fed the diet containing the high level of glutamic acid with 4.4 mg thiamin exhibited depressed food intake and body weight gain and an elevated level of plasma glutamic acid compared to diets containing 3.0% glutamic acid. Red blood cells from this group of kittens also showed a transitory incomplete saturation of transketolase with thiamin pyrophosphate. Kittens fed the high glutamate diets vomited occasionally during the 1st month of the dietary regimen. Although increased thiamin (25 mg/kg diet) decreased the severity of the adverse effects of the high glutamate diet, maximal growth was not obtained in kittens fed the high glutamate, high thiamin diet.

Amino Acids↗
PubMed1981

Synovial cell antigens--production of heterologous anti-human synovial cell sera and general reactivities of the antisera.

Antisera to cultured human synovial cells were produced in several rabbits by a variety of immunization procedures. The antisera were assayed by a number of immunologic techniques for specificities against live synovial and other fibroblastic cell lines and against additional antigen sources including human serum and synovial fluid, and fetal calf serum. While the antisera reacted well and with the same titers to all synovial cell lines, reactivities varied with several nonsynovial cell lines showing that synovial tissue-derived cells are antigenically different from other tissue fibroblastic cell strains. Also, the major antigens cross-reactive between synovial and certain other fibroblastic cell lines were partially defined as those in or cross-reactive with fetal calf serum and human serum or plasma components. The differential reactivities of the antisera demonstrated that the antibody specificity populations were markedly affected by the immunization manipulations. Methods for analyzing those differences are presented by defining specificity and reactivity indices. The antisera to the synovial cells distinguished 7 electrophoretically distinct reactivities in human serum or plasma, synovial fluid, and in fetal calf serum. 1 antigen was identified as fibronectin, 3 as components of fetal calf serum and 3 additional unidentified human serum cross-reactive antigens.

Antigens↗
PubMed1981

Synovial cell antigens - differences of antigen compositions between rheumatoid arthritic (RA)- and non-RA-derived synovial cells detected with anti-synovial cell sera.

A number of antisera were produced in rabbits immunized with cultured synovial tissue-derived cells. The synovial cells were injected utilizing a variety of immune manipulations in order to elicit different antibody specificities and to enhance antibodies that may differentiate antigens of rheumatoid arthritic and nonrheumatoid arthritic synovial tissue-derived cells. The major sources of antigens common to both rheumatoid and nonrheumatoid cells were cross-reactive with normal human serum, nonrheumatoid synovial fluids and fetal calf serum components. Adsorptions with the latter antigen sources yielded different antisera with greater differential reactivities to either rheumatoid or nonrheumatoid synovial cells. Crossed immunoelectrophoretic analyses of extracts of the synovial cells using unabsorbed antisera differentiated five electrophoretically distinct antigens with various quantitative differences of the antigens being noted between the rheumatoid and nonrheumatoid extracts. The results suggest that several antigens are quantitatively differentially expressed on rheumatoid-derived synovial cell strains compared to synovial strains of nonrheumatoid origin.

Animals↗
PubMed1981

Binding of fibronectin to Clq; inhibition of binding by aggregated IgG.

Fibronectin was shown to bind to C1q using alkaline phosphatase conjugated fibronectin and C1q coated polystyrene tubes. The binding of the alkaline phosphatase conjugated fibronectin to C1q was dose dependent and inhibited by fibronectin and by the sulfated polymers heparin and chondroitin sulfate. The fibronectin interaction was inhibited only slightly by gelatin indicating that the fibronectin-gelatin interaction was different from that with C1q. Heat aggregated IgG blocked the binding of fibronectin to C1q and fibronectin inhibited the binding of aggregated IgG to C1q. These results suggest that fibronectin may be a factor affecting the determination of immune complexes in serum specimens by C1q binding assays.

Alkaline Phosphatase↗
PubMed1981

Fibronectin associated with Clq in a Clq isolation procedure.

The complement component Clq, prepared by euglobulin precipitation of serum to which EDTA or EGTA had been added, contained fibronectin (FN) as detected by radioimmunoassay and immunodiffusion methods. The FN contents of the Clq preparations varied between 3 and 29% by weight of the Clq contents. Adsorptions of sera with polymerized IgG (an absorbent for Clq) in the presence or absence of EDTA removed all detectable Clq and between 12 and 95% of the FN. In a similar manner, adsorptions of sera and Clq preparations with insolubilized gelatin (to which FN will bind) reduced greatly or removed completely the FN component but also strikingly reduced the Clq contents. High salt concentration or the addition of EDTA did not alter the gelatin absorption results indicating that the association was not sensitive to high ionic condition and that Clq was equally bound as Clq or as the Cl complex. The results suggest that FN and Clq bind individually to both gelatin and IgG or that FN and Clq co-associate, accounting for removal of one component when the other is bound to its expected adsorbent.

Antigen-Antibody Reactions↗
PubMed1981

Subsequent physical and mental development in infants with positive contraction stress tests.

Little knowledge exists concerning long-term sequelae in children born of pregnancies complicated by chronic uteroplacental insufficiency. This follow-up study evaluates 12 children with positive contraction stress tests (CSTs) 5.5 months to 4.75 years following birth. Subsequent physical growth was uniformly normal in the four infants classified as appropriate for gestational age at birth; however, continued postnatal growth deficiency was present in 50% of the eight infants who suffered from intrauterine growth retardation. No major neurologic abnormalities were detected, and 10 of the 12 displayed normal mental and motor function, as determined by the Denver Developmental Screening Test, Bayley Scales of Infant Development and Wechsler Preschool and Primary Scale of Intelligence. Two of the 12 infants were depressed at birth and had serious neonatal complications. These were the only two children who scored poorly on the Bayley test. Although no conclusions regarding minimal brain dysfunction can be made, the majority of infants with positive CSTs demonstrate grossly normal neurologic and psychologic development.

Apgar Score↗
PubMed1981

Fibronectin in von Willebrand's disease and thrombasthenia: role in platelet aggregation.

Fibronectin is involved in cell-cell and cell-substratum adhesion processes. Since von Willebrand's disease and thrombasthenia are characterized, respectively, by platelet-substratum and platelet-platelet adhesion anomalies, we investigated the state of fibronectin in platelets and plasma of these two disorders as well as the role of plasma fibronectin in platelet aggregation. The levels of platelet and plasma fibronectin in three cases of von Willebrand's disease and in three cases of thrombasthenia did not show statistically significant differences as compared with the normal controls. Immunofluorescent staining intensity and patterns of disease-derived and normal platelets, studied with anti-fibronectin antibodies, were similar. Furthermore, 125I-labeled protein A binds to anti-fibronectin-treated platelets from the two diseases investigated in the same fashion as in normal controls. No role for plasma fibronectin was detected in platelet aggregation induced by ADP, thrombin, collagen, epinephrine, and arachidonic acid. Thus our results do not indicate a direct quantitative role of fibronectin in the adhesion anomalies encountered in these diseases. However, fibronectin may still be important to platelet adhesion and normal hemostasis processes through interactions with the plasma von Willebrand factor and the membrane glycoproteins IIb and III, which have been shown to be deficient in von Willebrand's disease and thrombasthenia, respectively.

Blood Platelets↗
PubMed1981

Preparation and specificities of antisera to the amino-terminal sequence of the carcinoembryonic antigen.

A tetracosapeptide (peptide-24) corresponding to the amino-terminal sequence of the carcinoembryonic antigen (CEA) was synthesized and characterized. Antisera were produced to the peptide-24, and a radioimmunoassay was developed utilizing peptide-24 with a tyrosine residue on the amino-terminal end (Tyr-peptide-24). Inhibitions of anti-peptide-24-125I-Tyr-peptide-24 complex formation were done with several preparations of CEA and the normal cross-reacting antigen. The extent of cross-reactivities was low, one CEA preparation requiring a 250-fold molar quantity greater than peptide-24 to obtain the same degree of inhibition. Attempts to degrade the CEAs and normal cross-reacting antigens in order to possibly expose the amino-terminal ends for reactivity with antibody did not result in any great increase in inhibitory capacity. It was concluded that either the conformations of the antigenic determinant(s) of the peptide-24 and of the amino-terminal end of CEA were sufficiently different to result in little cross-reacting antigen are blocked for reactivity with antibody by other portions of the molecule.

Amino Acid Sequence↗
PubMed1981

Excretion of carcinoma products in irradiated C3H/He mice.

Local low-dose (200 rads) gamma-irradiation to both kidneys impaired the excretion of 3H-labeled tumor products and reduced the survival time of mice carrying carcinomas in the ascites form. Daily i.p. injections of cell-free ascites fluid into tumor-free mice for 3 weeks resulted in the death of 25 of 180 irradiated animals, with no deaths among 180 injected unirradiated controls. The only histologically visible effects of irradiation of the kidneys during ascites tumor growth or during i.p. injections of cell-free ascites fluid was a cloudy swelling of the tubular epithelium in the renal cortex together with excessive protein in the tubular lumens.

Animals↗
PubMed1980

Connective tissue activation. XVII. Radioimmunoassay of a human platelet derived connective tissue activating peptide (CTAP-III) and specificities of anti-CTAP-III sera.

The platelet-derived connective tissue activating peptide (CTAP-III) has been shown to be an important factor stimulating the metabolism and proliferation of human connective tissue cell strains, including synovial tissue cells. The quantities of CTAP-III affecting the cellular changes and the amounts of various biologic fluids and tissues are small. The objectives of this study were to develop a radioimmunoassay (RIA) for CTAP-III and to ascertain the specificities of the anti-CTAP-III sera reagents. The antisera were shown not to cross-react with a number of polypeptide hormones. However, two other platelet proteins, beta-thromboglobulin and low affinity platelet factor-4, competed equally as well as CTAP-III for anti-CTAP-III antibodies in the RIA system. Thus, the three platelet proteins are similar or identical with respect to those portions of the molecules constituting the reactive antigenic determinants. The levels of material in normal human platelet-free plasma that inhibited anti-CTAP-III--125I-CTAP-III complex formation were determined to be 34 +/- 13 (S.D.) ng/ml.

Animals↗
PubMed1980

Reisolation of immunoreactive radioiodinated antigens using glutaraldehyde-insolubilized antibody preparations.

Radioiodination of antigens for use in radioimmunoassay can result in substantial losses of antigenic reactivity with the corresponding antibody and antisera preparations. We describe a method whereby antigens iodinated with the chloramine-T procedure are bound to and eluted from glutaraldehyde-insolubilized antibody. Unfractionated antisera, an ammonium sulfate precipitated fraction or the IgG fraction of antisera may be used as insolubilized immunoadsorbents. The method has been applied for the reisolation of a radioiodinated peptide, a low molecular weight protein and the fibronectin molecule. The total binding of 125I-antigens to antibody in radioimmunoassays can be increased from such low amounts before reisolation that the assay is not feasible, to 85% above background binding, after adsorption and elution from the insolubilized antibody preparations.

Adsorption↗