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Biomedical subjects

J R Hobbs

Publications and source records attributed to J R Hobbs.

At least 37 records · Page 2Linked to original sources
PubMed1991

A double-blind placebo-controlled study of thymostimulin (TP-1) for the treatment of atopic eczema.

Twenty-nine patients with severe atopic eczema were entered into a randomized double-blind, placebo-controlled trial of the polypeptide thymus extract, thymostimulin (TP-1). The treatment period was 10 weeks with a subsequent follow-up period of up to 1 year. Of the 18 patients receiving TP-1 and the 11 patients on the placebo, 15 and 11 patients, respectively, were fully evaluable. There was no significant difference in either clinical or immunological status between the two treatment groups at baseline. At the 3-month follow-up clinic visit there was a statistically significant difference in the total clinical score, calculated as a percentage of baseline, in favour of the TP-1-treated patients. This difference was not maintained in the subsequent follow-up period and was not accompanied by an improvement in the patient's subjective well-being. There was no significant difference between the treatment groups with respect to the immunological parameters as measured at the 3-month clinic visit.

Adjuvants, Immunologic↗
PubMed1991

Cytokine induction of neopterin production.

The pteridine neopterin is a marker of immunological activation and has been shown to be a useful marker of graft-versus-host disease (GVHD) in bone marrow transplant patients. High levels of both neopterin and interferon-gamma (IFN-gamma) were produced in vitro during mixed lymphocyte responses, which may be considered to be a model of the primary events leading to GVHD. Neopterin was shown to be produced by monocytes in response to stimulation with IFN-gamma, but not other cytokines. However, the interleukins IL-1 alpha, IL-1 beta, IL-2, and tumour necrosis factor (TNF) alpha and beta, but not IL-6, stimulated neopterin production by unfractionated peripheral blood mononuclear cells (PBMC), and culture supernatants from PBMC stimulated with IL-1 alpha, IL-1 beta, IL-2 and IL-6, but not TNF-alpha or TNF-beta induced neopterin production following transfer to fresh monocyte cultures. It therefore appears that cytokines may generate neopterin by induction of IFN-gamma, by synergy with low levels of induced IFN-gamma, or by non-IFN-gamma-dependent mechanisms.

Biopterins↗
PubMed1991

Overestimation of monoclonal immunoglobulin by immunochemical methods.

A comparison of paraprotein estimation by scanning densitometry with corresponding immunoglobulin concentration measured by rate immunonephelometry, fixed-time immunonephelometry and kinetic immunoturbidimetry using a large number of sera has indicated overestimation of the immunoglobulin by liquid phase immunoassays in the presence of a monoclonal component. The effect was seen with all three major immunoglobulin isotypes but was most marked with IgM paraproteins when measured by kinetic nephelometry. The overestimations could not be explained by presence of rheumatoid factors or immune complexes in the serum samples, or by non-parallelism, over a range of dilutions, of the reaction of sample and calibrant with the antiserum. The source and species of antiserum used was a major contributory factor.

Antibodies, Monoclonal↗
PubMed1991

Plasma neopterin as an adjunct to C-reactive protein in assessment of infection.

C-reactive protein (CRP) concentrations are increased in plasma in people with inflammatory conditions and bacterial infections. Plasma neopterin concentrations are increased in people with bacterial septicemias, viral infections, and graft vs host disease. Plasma concentrations of CRP and neopterin were measured daily in 21 bone-marrow transplant (BMT) patients, 64 patients in intensive-care units (ICU), and 12 patients with squamous cell carcinoma of the head and neck (HN). In the BMT patients, plasma neopterin measurements in addition to CRP measurements allowed infectious episodes to be distinguished from graft vs host disease. In the ICU patients, increased concentrations of CRP were not specific for infection and the additional plasma neopterin measurements did not improve this specificity. In all three patient groups, the derivation of a neopterin/CRP ratio was of no clinical use. These three groups of patients showed patterns of CRP and neopterin concentrations characteristic of their underlying diseases, the BMT patients with the immunological activation of graft vs host disease showed predominantly increased concentrations of plasma neopterin, ICU patients with infectious and inflammatory conditions had increased concentrations of both CRP and neopterin in plasma, and the HN group with localized inflammation showed increased plasma concentrations of CRP without increases in neopterin.

Adolescent↗
PubMed1990

Displacement bone marrow transplantation for some inborn errors.

The initial simple bone marrow transplants for genetic immunodeficiency diseases could hardly be rejected by the host, but required matched sibling donors, only available for about 1 in 5 patients. Improved inductions enabled alternative donors from the family or unrelated volunteers to be used. Measurement of the extent of engraftment by donor cell markers or their normal enzymes showed the need for displacement, which aims to obtain 100% donor-type marrow so that the future immune responses of the recipient become those of the donor and tolerant to donor cells or their products. Immunoprophylaxis can prevent residual host immune cells from surviving to impair the graft. The concept of DBMT with immunoprophylaxis has evolved either to replace abnormal host cells or to confer a component transferable from donor cells to deficient host tissues. Within 10 years over 40 previously fatal genetic diseases have been satisfactorily corrected and seven partially corrected, but for five there has been inadequate delivery of component to genetically defective tissues such as heart, cartilage and brain. The principles can be applied to some 40 other genetic diseases for which no suitable alternative treatments yet exist.

Bone Marrow Transplantation↗
PubMed1990

Staphylococcal opsonization and anti-Staphylococcus aureus IgG subclass antibodies in patients with severe or recurrent S. aureus infections.

Opsonization of Staphylococcus aureus (Oxford strain) and specific IgG subclass antibodies against formalised staphylococci were measured in plasmas from 27 patients with significant S. aureus infections and 35 healthy adults and 15 children. There were no statistically significant differences in the IgG2 and IgG4 levels between two groups and IgG3 was not detected, but the median plasma IgG1 level was significantly higher in patients with staphylococcal infections (P less than 0.00003). The concentration of IgG2 anti-S. aureus antibodies was 25-47 times greater than that of IgG1. If plasmas were decomplemented, the raised IgG1 levels were associated with increased opsonophagocytosis by normal neutrophils (P less than 0.0002).

Abscess↗
PubMed1988

Effects of beta endorphin on specific immune responses in man.

Synthetic human beta endorphin shows a biphasic effect on the production of specific anti-herpes viral antibodies in vitro. At higher concentrations antibody production is reduced, at lower concentrations it is enhanced. In a proportion of donors whose cells do not produce specific antibody when cultured with antigen alone, the lower concentrations of beta endorphin allow antigen-driven specific antibody production to occur. Specific anti-herpes viral antibodies are also made by natural killer (NK) cell-depleted populations from the same non-producer donors. beta endorphin also exerts biphasic effects on NK, although the direction of the modulation is a mirror image of the effects on antibody production. This suggests that the immunomodulatory actions of beta endorphin on specific immune responses are mediated in part by effects on NK suppressor-inducer cells.

Antibodies, Viral↗