A structurally aberrant immunoglobulin paraprotein in a patient with multiple myeloma and corneal crystal deposits.
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Cornea↗
Biomedical subjects
M G Scott
Publications and source records attributed to M G Scott.
Immunologic and clinical status of blood donors with subnormal levels of IgG2.
To determine the immunologic and clinical status of individuals from a general population with subnormal levels of IgG2, we prospectively studied 37 of 312 blood donors with low IgG2 levels identified among 8015 donors. We examined (1) G2m(23) allotypes, (2) levels of other IgG subclasses and immunoglobulin classes, (3) composition of peripheral leukocyte populations, (4) responses to two carbohydrate antigen vaccines, (5) in vitro secretion of IgG subclasses by isolated lymphocytes after mitogen stimulation, and (6) clinical histories. We found that most (90%) individuals with subnormal IgG2 levels had G2m(23)- allotypes, whereas only 30% of the unselected donors had G2m(23)-. When individuals were separated according to their G2m(23) allotype, we found that IgG2 "normal" range for individuals with G2m(23)- allotype is 35% lower than for individuals with G2m(23)+ allotype. Individuals who had G2m(23)- allotype and had IgG2 levels greater than or equal to 0.8 but less than 1.3 gm/L had no other immunologic abnormalities. In contrast, the individuals with G2m(23)+ allotype and with IgG2 levels less than 1.3 gm/L and the individuals with G2m(23)- allotype and with IgG2 levels less than 0.8 gm/L often had additional immunologic abnormalities, including IgA and/or IgG4 deficiency and decreased in vitro expression of IgG2 subclass. None of these individuals had a clinical history remarkable for recurrent infections. Thus, subnormal IgG2 levels interpreted with G2m(23) corrected normal ranges may be a marker of other immunologic abnormalities but taken alone probably have little clinical significance in a general healthy population.
Antigens↗
Subnormal serum concentrations of IgG2 in children with frequent infections associated with varied patterns of immunologic dysfunction.
To characterize more fully the immunologic basis for increased susceptibility to infection in patients with low serum concentrations of IgG2, we identified eight infection-prone children, 1 to 2 years of age, with serum IgG2 concentrations greater than 2 SD below the mean for age and followed their serologic and clinical courses for 1 to 3 years. Two of the eight children became clinically and immunologically normal and may have had transient IgG2 deficiency with an exaggerated developmental delay of this late-maturing subclass. The remaining six subjects had persistently subnormal or low-normal serum IgG2 levels and continued to experience frequent infections. All six of these children responded poorly to Haemophilus influenzae type b (Hib) polysaccharide, and four of six responded poorly to Streptococcus pneumoniae type 3 polysaccharide. Both IgG1 and IgG2-specific antibody responses to these vaccines were abnormal. Three of these six children also responded poorly to tetanus toxoid, an antigen that normally induces a predominant IgG1 response. Although five of these six children produced antibodies in response to Hib polysaccharide protein conjugate vaccine, three of four given Hib oligosaccharide CRM conjugate vaccine required booster doses to respond, a pattern of response characteristic of infants less than 6 months of age. Further, although serum concentrations of IgG1 were normal, peripheral blood mononuclear cells from four of six children tested produced extremely small amounts of IgG1 and IgG3 as well as IgG2. Finally, varied patterns of abnormalities of IgG, IgA, IgM, and IgG4 became apparent in five of the six children with persistently low serum IgG2 values. This study demonstrates that subnormal serum concentrations of IgG2 may be associated with varied patterns of immunologic dysfunction, some of which are evolving and may be responsible for increased susceptibility of these children to infection.
Adolescent↗
Bactericidal and opsonic activity of IgG1 and IgG2 anticapsular antibodies to Haemophilus influenzae type b.
Complement-mediated bactericidal and opsonic activity of IgG1 and IgG2 antibodies to Haemophilus influenzae type b polysaccharide (polyribosyl ribitol phosphate [PRP]) were investigated. The antibody sources were IgG1 or IgG2 subclass polyclonal antibody fractions prepared by immunoabsorption of sera from adults immunized with PRP or PRP-diphtheria toxoid conjugate vaccine or clonally purified anti-PRP antibodies from eight adults immunized with PRP vaccine. In bactericidal assays using an inoculum of 3 x 10(3) colony-forming units (cfu)/ml, twofold lower concentrations of IgG1 compared with IgG2 antibody were required for 50% killing. With approximately 10(6) cfu/ml, IgG1 antibody killed 3 logs more of bacteria than were killed by comparable concentrations of IgG2 antibody. The IgG1 antibody also required lower concentrations of complement than did the IgG2 antibody for comparable bacteriolytic activity. Clonally purified IgG1 and IgG2 anti-PRP antibodies from most individuals showed similar relative differences in bactericidal activity. IgG1 anti-PRP antibody was also more efficient than IgG2 anti-PRP antibody in enhancing the uptake of radiolabeled type b H. influenzae by human polymorphonuclear leukocytes in the presence of complement and in protecting infant rats from developing bacteremia. However, the differences in opsonic or protective activity of the two subclasses were smaller than the differences in bactericidal activity. Thus, IgG1 anti-PRP antibody is functionally more effective than IgG2 antibody, but it is likely that both subclasses can confer protection against disease.
Animals↗
Characterization of monoclonal antibodies against ovine prolactin: suitability for use in immunocytochemical analysis of rat prolactin.
The aim of this study was to identify a monoclonal antibody (MAb) suitable for use in the immunocytochemical localization of prolactin in rat tissues. We took advantage of the conservation of certain amino acid sequences in prolactin among species by examining the crossreactivity patterns of five MAb, originally generated to ovine prolactin, with rat prolactin by enzyme-linked immunoassay (ELISA), Western blot analysis, and immunocytochemistry. Two of five antibodies (17D9 and 6F11) showed reactivity with 100 ng of immobilized rat prolactin (NIH RP-3) by ELISA, 6F11 reacting more strongly than 17D9. Only 6F11 reacted with prolactin in lysates of GH4C1 rat pituitary tumor cells by Western blot analysis. When we examined the crossreactivity of the MAb with rat prolactin in monolayer cultures of GH4C1 cells by indirect immunofluorescence, we found that both 17D9 and 6F11 reacted strongly with the cultures. The distribution of staining with 17D9 or 6F11 was coincident with staining with a polyclonal antiserum to rat prolactin. Preabsorption of the antibodies with a 20-fold excess of purified rat prolactin abolished the staining of GH4C1 cell cultures with either antibody. Therefore, we have selected from a series of MAb raised to ovine prolactin two antibodies (17D9 and 6F11) that react specifically with rat prolactin in immunocytochemical studies, whereas 6F11 also reacts strongly with rat prolactin by ELISA and Western blot analysis.
Animals↗
Clinical and immunologic characteristics of healthy children with subnormal serum concentrations of IgG2.
To understand the relevance of subnormal serum concentrations of IgG2, we measured IgG2 in serum of 575 healthy children and identified 11 with concentrations greater than 2 SD less than the mean for age. The levels of IgG2 present were similar to those found in symptomatic children with IgG2 subclass deficiency associated with antibody deficiency. The 11 children ranged in age from 1 to 14 y (mean = 5.7). Detailed clinical information was available on 10 of the 11 children and each was matched for age with two controls. The median number of visits/y to the doctor for infectious illnesses was identical for the two groups (1.0). Nine of the children with subnormal IgG2 were followed for 1 to 5 y (mean = 2.3). All nine children had normal serum concentrations of IgA, IgG1, IgG3, and IgG4 but seven had persistently subnormal or low-normal serum IgG2 concentrations. One of these seven children also had a subnormal serum concentration of IgG, and one had subnormal IgM. Antibody responses to Haemophilus b polysaccharide vaccine were normal in five of six who were immunized. In vitro secretion of Ig by mitogen-stimulated peripheral blood mononuclear cells was measured in six of seven children with persistently subnormal or low-normal IgG2; five showed decreased secretion of IgG2, and two of the five also had subnormal secretion of IgG1 and IgG3. An important implication of this study is that the subnormal concentrations of serum IgG2 found in infection-prone children are not a sufficient explanation for their increased susceptibility to infection.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Production, characterization and use of five monoclonal antibodies to human IL-4.
We describe five murine monoclonal antibodies that are specific for human IL-4. At least three spatially distinct epitopes on the hIL-4 molecule are recognized by this panel of antibodies which allowed development of a sensitive sandwich EIA specific for hIL-4. The EIA is capable of detecting 200 pg/ml of hIL-4 and exhibits no detectable crossreactivity to seven other human cytokines examined. In addition to the EIA these antibodies are also useful in a number of other techniques for investigating hIL-4. Recombinant hIL-4 can be easily and efficiently purified by affinity chromatography using these mAbs. Western blotting with two of the antibodies detects as little as 1.8 ng/ml of hIL-4 in a 50 microliters sample. Finally, we present a method for cytoplasmic localization of hIL-4 by a fluorescence staining method utilizing a hIL-4 specific mAb.
Animals↗
Positive interferences with the Ektachem total CO2 assay from therapy with topical cerous nitrate.
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Administration, Topical↗
Clonal characterization of the human IgG antibody repertoire to Haemophilus influenzae type b polysaccharide. III. A single VKII gene and one of several JK genes are joined by an invariant arginine to form the most common L chain V region.
To characterize the L chain V region repertoire of IgG anti-Haemophilus influenzae type b capsular polysaccharide (Hib-PS) antibodies, clonal antibodies were purified from immune serum and internal amino acid sequences of VKII anti-Hib-PS L chains obtained. We examined VKII L chains because it is the most common VL family expressed in the anti-Hib-PS response. Comparison of VKII amino acid sequences, including the entire CDR2 and CDR3 regions, of five anti-Hib-PS clonal antibodies from four unrelated individuals revealed complete identity with the exception of a single CDR3 residue from one antibody. When the sequence of these antibodies was compared with known VKII genes and myeloma proteins, it was found to be identical to the human VKII gene, A2, whose genomic sequence is presented here. In addition, all five of the VKII anti-Hib-PS antibodies examined contain an arginine inserted at the V-J junction. Finally, in contrast to the extraordinary homology of the VKII-encoded residues, there is variability in the JK gene utilization by these antibodies. These results demonstrate that the most common L chain V region in IgG anti-Hib-PS antibodies is the product of a single germ-line gene. The invariant arginine insertion suggests that this residue has an important role in Ag binding.
Amino Acid Sequence↗
Clonal characterization of the human IgG antibody repertoire to Haemophilus influenzae type b polysaccharide. II. IgG antibodies contain VH genes from a single VH family and VL genes from at least four VL families.
To define the V gene family repertoire of human IgG anti-Haemophilus influenzae type b polysaccharide antibodies, we purified six IgG1 and nine IgG2 anti-Hib-PS antibodies to monoclonality from immune serum of six individuals and performed N-terminal amino acid sequence analysis. Of the 15 clonal antibodies we examined, all H chain V regions were of the VHIII family. In contrast, the L chains of these antibodies were clearly from at least four different VL families; VKI, VKII, VKIII, and V lambda. Interestingly. VL family expression correlated with the cross-reactivity of these antibodies to the capsular carbohydrate of Escherichia coli K100. VKII antibodies did not cross-react, whereas antibodies expressing V lambda, VKI, or VKIII generally cross-reacted. We conclude that L chain V regions are very important contributors to the limited heterogeneity in this antibody repertoire.
Adult↗
Clonal characterization of the human IgG antibody repertoire to Haemophilus influenzae type B polysaccharide. Demonstration of three types of V regions and their association with H and L chain isotypes.
The antibody response to Haemophilus influenzae type b polysaccharide (Hib-PS) is pauciclonal but can vary between different individuals. To estimate the size of this antibody repertoire we examined the constant and V regions of human IgG anti-Hib antibodies from 14 individuals at the clonal level using various serologic and IEF methods. Examination of H chains showed that 11 of 14 individuals produced both IgG1 and IgG2 antibodies, two individuals produced only IgG2 and one individual produced only IgG1 antibody. All 14 individuals produced kappa-containing antibody clones and three persons also produced significant lambda-containing antibody clones. V region heterogeneity was examined by comparing cross-reactivity of anti-Hib-PS antibodies to the capsular polysaccharide of Escherichia coli K100 carbohydrate (K100 CHO). These studies showed that clones of IgG anti-Hib-PS antibodies cross-reactive with K100 CHO were present in 5 of 14 (36%) individuals and also revealed at least three types of V regions among these antibodies. The first type has no cross-reaction with K100 CHO and was found in 13 of the 14 individuals. The second type, found in three of 14 individuals, cross-reacts with K100 CHO and uses a lambda L chain V region. The third type, found in 2 of 14 individuals, cross-reacts with K100 CHO and uses a kappa L chain V region. Although the lambda type V region was found only in association with IgG2, the other two V region types associate with both IgG1 and IgG2. Thus, five IgG antibody clones are serologically discernable. An individual generally responds to Hib-PS by expressing several clones selected from these discernable antibody clones. Indeed, we can observe six individual response patterns among these 14 individuals and conclude that considerable variability in individual responses to Hib-PS can be achieved with very few V regions.
Adult↗
Haemodynamic and pharmacokinetic evaluation of alfuzosin in man. A dose ranging study and comparison with prazosin.
In an open dose ranging study with random inclusion of placebo, alfuzosin (alpha 1-adrenoceptor antagonist) 1, 2.5 and 5 mg was administered to 6 healthy volunteers, 3 of the volunteers received 10 mg alfuzosin. Supine systolic blood (SBP) pressure was not reduced by alfuzosin although significant increases occurred in supine heart rate (HR) after 2.5 and 5 mg. In the standing position, SBP was reduced at 2 and 4 h with 5 mg alfuzosin; significant increases in HR occurred following 1, 2.5 and 5 mg at 2, 4, 6 and 8 h after administration. Exercise SBP was not reduced; diastolic blood pressure was significantly reduced at 4 and 6 h with 5 mg alfuzosin. More marked effects were seen in the 3 subjects who received 10 mg alfuzosin. After 1 and 5 mg, tmax ranged from 1-2 h; Cmax (4.1 to 20.8 ng.ml-1; AUC (0-24) 20 to 132 ng.ml-1.h (1 and 5 mg respectively) increased progressively with dose indicating dose dependent kinetics; no significant changes occurred in the visual analogue scale for sedation. A comparison of alfuzosin 5 mg, prazosin 1 mg and placebo each administered for 4 days, indicated that alfuzosin did not significantly reduce standing SBP on either Day 1 or Day 4; prazosin reduced SBP at 2 and 4 h on Day 1 and 6 h on Day 4 compared to placebo. Standing HR was increased by alfuzosin at 2 h on Day 1 and Day 4; increases occurred with prazosin at 2, 4, 6 and 8 h on Day 1 and 6 h on Day 4.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Mitogen-induced human IgG subclass expression. II. IgG1 and IgG3 subclasses are preferentially stimulated by a combination of Staphylococcus aureus Cowan I and pokeweed mitogen.
Mitogens generally stimulate human IgG subclass production in amounts proportional to their abundance in serum (IgG1 greater than IgG2 greater than IgG3 greater than IgG4). We report here that a combination of Staphylococcus aureus Cowan strain I and pokeweed mitogen consistently stimulates human peripheral blood lymphocytes in vitro to preferentially produce more IgG1 and IgG3 than IgG2. This preferential stimulation can be measured by increases in the number of immunoblasts (cells with detectable cytoplasmic immunoglobulin) as well as in secreted immunoglobulin. The preferential stimulation pattern is established by the fourth day of culture and is maintained at least until the tenth day. Removal of T cells and subsequent stimulation of B cells with S. aureus Cowan I and interleukin 1 (IL-1) interleukin 2 (IL-2), interleukin 4 (IL-4), or interferon-gamma (IFN-gamma) failed to enhance any IgG subclass production, indicating the requirement for multiple lymphokines in IgG subclass production. The significance of these findings is discussed with respect to B-cell regulatory molecules and the coordinate expression of IgG subclasses.
Enzyme-Linked Immunosorbent Assay↗
Audiovisual demonstration for patient counselling in the use of pressurised aerosol bronchodilator inhalers.
The use of video as a method of instructing subjects on correct inhaler technique was compared with the written and personal instruction of 150 volunteer subjects with no previous experience of such a device. Video was found to be as effective as personal tuition by a pharmacist and significantly (P less than 0.05) superior to the manufacturer's package insert in teaching correct inhaler technique. The technique was assessed by a panel of five investigators in each case and was found to deteriorate over a 2-week period regardless of the instruction method. The video, which was prepared 'in-house', was then assessed in both the hospital out-patient and the general practice pharmacy settings. Asthmatic patients found the video useful at identifying mistakes they were making and felt that this approach to their education should be more widely available.
Adolescent↗
More on "hook effects" in immunometric assays for prostate-specific antigen.
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Adenocarcinoma↗
Hormonal evaluation of female infertility and reproductive disorders.
Performance of the male and female reproductive systems reflects the orderly operation of the hypothalamic-pituitary-gonadal axis. Aberrant operation of this axis can result in many different reproductive disorders, including various forms of infertility. Proper evaluation of these disorders involves a multifaceted diagnostic approach, which includes a critical contribution from the clinical laboratory. This adjunctive testing, involving the measurements of peptide and sex-steroid hormone concentrations, allows the clinician to biochemically "dissect" the hypothalamic-pituitary-gonadal axis and ascertain the presence as well as location of the specific defect. In practice, the specific tests utilized during the evaluation of a patient depend upon the underlying disorder. Typically, in evaluating the reproductive disorders discussed in this review, a primary battery of tests is obtained that reflects the initial clinical presentation and physical examination. The results of these initial studies then dictate any secondary testing required to complete the evaluation. Such an approach, in use at our institution, is provided in Table 5. Although this discussion has concentrated on the laboratory assessment of the female reproductive system, it is important to remember the special case of infertility, where couples, in general, are evaluated together by the clinician. The cause of infertility can reside with the female, the male, or, in the cases of immunological "incompatibilities," a combination of the male and the female. As such, rigorous schemes for evaluating male reproductive disorders (1, 3, 89-94) and immunological incompatibilities (95-98) have been developed, and the information derived from such testing represents a critical contribution to establishing the etiology of a couple's infertility. Although the laboratory assessment of peptide and sex-steroid hormone concentrations clearly plays a pivotal role in the evaluation of reproductive disorders, these diagnostic tools probably will continue to change and improve in the years to come. Such changes will probably occur as the finer details of the operation of the hypothalamic-pituitary-gonadal axis become known. With this improved knowledge, we should have the capacity to design assays that will allow more clinically refined and biochemically precise means of diagnosing and treating specific reproductive disorders.
Adult↗
Out of the fire and into the frying pan: thoughts in anticipation of a new contract.
In anticipation of the government's review of the National Health Service an inner city doctor considers some of the issues raised by a contract which will challenge the general practitioner to manage a budget for both primary and secondary care and will require standards of care to be audited. There will be difficult clinical, management and ethical problems ahead, but these are capable of being solved. Such a contract holds out the prospect of enhanced health care for patients and a more fulfilled professional life for general practitioners.
Budgets↗
Measurement of cyclosporine concentrations in whole blood: HPLC and radioimmunoassay with a specific monoclonal antibody and 3H- or 125I-labeled ligand compared.
We compared cyclosporine concentrations in whole blood as measured by HPLC and by RIA with a monoclonal antibody specific for cyclosporine with 3H- or 125I-labeled cyclosporine ligand. The 3H-RIA kit slightly underestimated cyclosporine concentrations (greater than 600 micrograms/L) in comparison with HPLC. Over a wide range of concentrations, cyclosporine measured with the 125I-RIA kit correlated well with HPLC (slope = 0.99, n = 301, r = 0.98), observed for samples from recipients of kidney, heart, or liver allografts (respective slopes: 1.01, 0.93, and 1.00). The 125I-RIA standard curve was linear to 1000 micrograms of cyclosporine per liter. Inter- and intra-assay CVs for 125I-RIA measurements of cyclosporine were less than or equal to 7%. Evidently, the 125I-RIA kit involving a monoclonal antibody specific for cyclosporine is equivalent to the HPLC assay and can replace it for therapeutic drug monitoring of cyclosporine therapy.
Antibodies, Monoclonal↗