Biomedical subjects
Publications and source records attributed to P Anderson.
We report on 3 individuals who describe aggressive thoughts and behaviors that frequently occurred in association with panic symptoms. It is theorized that the seemingly paradoxical emotions of fear and aggression may actually share a similar etiology. Of clinical interest, the subjects improved in both their panic and aggressive symptoms when they were treated with antidepressant medication.
Several T-cell structures are capable of generating intracellular signals linked to T-cell proliferation. Crosslinking of CD2, CD4 and CD45 with Ti/CD3 to several of these antigens can augment the minimal signal induced by antigen binding to the Ti/CD3 complex. Importantly, some of these regulatory structures (CD4, CD8 and CD45) are also expressed on subsets of T cells with distinct activation requirements and functional programs (helper, suppressor, suppressor-inducer and cytotoxic function). The CD4+ CD45RA+ (2H4+) subset responds well to self-Ia, poorly to soluble antigen and possesses suppressor-inducer function. A reciprocal subset CD4+ CD45RA- (4B4+) is preferentially activated by soluble recall antigens and possesses helper function. Each of these subsets can be distinguished by virtue of the differential expression of CD45 antigens. Importantly, the anti-2H4 antibody which reacts with a specific region near the N-terminus of two CD45 isoforms can effectively block its function. Crosslinking of CD4 with the Ti/CD3 complex preferentially activated the CD4+ CD45+ RA- subset, while soluble antibodies to CD2 preferentially affected the CD45 CD45RA+ subset. Thus, CD3 and CD4 more effectively synergize in the activation process on the CD4+ CD45RA- subset, a result consistent with the ability of this subpopulation to respond to recall antigens. The regulatory role of the CD4, CD8 and CD45 antigens may be mediated by an interactive network of protein-tyrosine phosphorylation and dephosphorylation. We have shown the CD4 and CD8 antigens to be associated with the T cell-specific protein-tyrosine kinase (p56lck). p56lck is a member of a family of protein-tyrosine kinases with an established ability to activate and transform mammalian cells. The CD4/CD8:p56lck complex is catalytically active as shown by its ability to phosphorylate various members of the Ti/CD3 complex. By contrast, the CD45 antigens possess protein-tyrosine phosphatase activity within their intracellular domains and are postulated to function by virtue of a regulatory interaction with CD4/CD8:p56lck and its potential substrates. Thus, the differences in the response of the CD4+ CD45RA+/- subsets to various stimuli and the expansion of T-cell subsets with distinct immunoregulatory programs may be governed by a pathway of tyrosine-mediated events.
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An instrument was developed to study the use of hospital beds and discharge arrangements of a cohort of 847 admissions to the John Radcliffe Hospital, Oxford, for a three week period during February-March 1986. For only 38% of bed days were patients considered to have medical, nursing, or life support reasons for requiring a provincial teaching hospital bed. The requirements for a bed in the hospital decreased with the patient's age and length of stay in hospital. For only a tenth of patients was the general practitioner concerned in discussions with hospital staff about the patient's discharge and less than one third of patients had been given more than 24 hours' notice of discharge. Several features might increase the proportion of bed days that are occupied by patients with positive reasons for being in hospital. Among these are an increased frequency of ward rounds by consultants, or delegating discharge decisions by consultants to other staff; providing diagnostic related protocols for planning the length of stay in hospital; planned discharges; and providing liaison nurses to help with communication with primary care staff.
To estimate the excess mortality due to alcohol in England and Wales death rates specific to alcohol consumption that had been derived from five longitudinal studies were applied to the current population divided into categories of alcohol consumption. Because of the J shaped relation between alcohol consumption and death the excess mortality used as a baseline was an alcohol consumption of 1-10 units/week and an adjustment was made for the slight excess mortality of abstainers. The number of excess deaths was obtained by subtracting the number of deaths expected if all the population had the consumption of the lowest risk group; correction for the total observed mortality in the population was made. This resulted in an estimate of 28,000 deaths each year in England and Wales as the excess mortality among people aged 15-74 associated with alcohol consumption.
Human T lymphocytes, metabolically labeled with 35S-cysteine and 35S-methionine, were reacted with the homobifunctional cross-linking reagent, dithiobis (succinimidyl propionate) (DSP). When detergent lysates from these cells were immunoprecipitated with a monoclonal antibody reactive with the CD8 antigen, a radiolabeled protein of approximately 44 kd was coprecipitated with the CD8 molecule. Immunoprecipitates from detergent lysates prepared without prior chemical cross-linking contained only the 33 kd CD8 molecule. Similar results were obtained when T lymphocytes or a cytotoxic T cell clone (T4T8Cl) were radiolabeled with 32P-orthophosphoric acid. The 44 kd CD8-associated protein was identified as the heavy chain of the class I major histocompatibility antigen by depletion in preclearing experiments with anti-class I MHC antibody and by peptide mapping. Further analyses indicated that the CD8-class I MHC association is due, in part at least, to disulfide bonding, which may be susceptible to cleavage during processing of cell lysates.
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The aggregation of a specific class of lymphocyte surface molecules results in patching, capping, and surface modulation of the aggregated ligand. Both CD4, an associative recognition structure found on helper T lymphocytes, and CD3, a component of the T cell receptor complex, are members of this functional subgroup. When 125I-labeled monoclonal antibodies reactive with either CD4 (19Thy 5D7) or CD3 (RW24B6) were bound to T lymphocytes, the subsequent addition of goat anti-mouse Ig resulted in their rapid, temperature-dependent internalization. Whereas the binding of 125I-19Thy 5D7 (anti-CD4) was inhibited by greater than 90% in the presence of unlabeled 19Thy 5D7, no inhibition occurred in the presence of unlabeled antibody reactive with CD3 (RW28C8). We took advantage of the fact that these antibodies were of different isotypes (19Thy 5D7:IgG2a; RW28C8:IgGl) to determine whether the internalization of CD3 induced the comodulation of CD4. T lymphocytes preincubated with 125I-19Thy5D7 (anti-CD4) and unlabeled RA28C8 (anti-CD3) were treated with goat anti-mouse IgGl under conditions shown to quantitatively internalize CD3. After 1 h at 37 degrees C, T lymphocytes had internalized 10.5 +/- 2.6% (n = 3) of their antibody-bound cell surface CD4. After similar incubations with media alone or with goat anti-mouse IgGl in the absence of prebound RW28C8 (anti-CD3), no internalization of CD4 could be detected. Control antibodies reactive with CD45R (2H4, IgGl) also failed to induce the internalization of CD4. Similar results were obtained by using a helper T cell clone (T4C1) that internalized 9.6 +/- 2.8% (n = 3) of its antibody-bound cell surface CD4 in response to CD3 modulation. In a reciprocal experiment, 125I-anti-CD3 (RW24B6, IgG2b) was preincubated with T4Cl cells together with unlabeled anti-CD4 (12T4D11, IgG1) prior to the addition of goat anti-mouse IgGl. The quantitative modulation of CD4 induced the co-internalization of 4.6 +/- 0.6% (n = 3) of cell surface CD3. These results suggest that approximately 5% of the CD3:T cell receptor complexes on helper T lymphocytes are specifically associated with CD4. Furthermore, our results suggest that an average of two CD4 molecules associate with each CD3:T cell receptor complex.
General practitioners will have an increasingly important role in the management of patients with the acquired immune deficiency syndrome (AIDS) and infections with human immunodeficiency virus (HIV) as the numbers of cases increase. Altogether 280 general practitioners working in Oxfordshire were sent a postal questionnaire inquiring about their education, knowledge, current practice, and attitudes in relation to managing infections with HIV. Of the 235 (84%) general practitioners who replied, nine out of 10 were giving advice about infection with HIV to their patients. One in two were testing patients for such infection, and one in four were caring for infected patients. Nevertheless, uncertainty remained about the risks of transmission of infection with HIV and general practitioners' knowledge of educational activities for their patients could be improved. The introduction of a facilitator to work with general practitioners in managing patients with AIDS or infection with HIV is planned, especially to help general practitioners develop the skills needed for prevention.
CD4 cell subsets, CD4+CD45R+ (CDw29-) cells and CD4+CD45R- (CDw29+) cells, can be differently triggered by various stimuli and possess distinct functions. In the present study, cell activation in CD4+CD45R+ and CD4+CD45R- subsets mediated by CD3-Ti antigen-receptor complex or CD2 molecule were examined by using anti-CD3 antibody or pairs of anti-CD2 antibodies (anti-T11(2) and anti-T11(3) antibodies). The results showed that CD4+CD45R+ cells were preferentially activated through the CD2 pathway, whereas both subsets were equally activated through the CD3-Ti antigen-receptor pathway when a second signal such as monocytes or interleukin 2 was present. The different responsiveness of CD4+CD45R+ and CD4+CD45R- subsets through the CD2 molecule did not appear to be due to differences in the distribution or number of T11(2) and T11(3) determinants. These data suggest that some part of the functional diversity of CD4 cell subsets might be explained by the differences in cell activation through the CD2 molecule.
An i.v. infusion of mannitol was given over 15 min to 12 patients before they underwent intracranial surgery under general anesthesia. Samples of blood, CSF and urine were taken over 4 h. Mannitol disappeared from plasma in a bi-exponential manner. The mean maximal plasma concentration was 4.08 mg/ml at 15 min, and at 4 h it had declined to 0.53 mg/ml. The mean distribution rate constant was 11.2 h-1, corresponding to a plasma distribution half-life of 0.11 h. The mean elimination rate constant was 0.41 h-1, the plasma half-life was 2.2 h, the central distribution volume was 16.3 l, and total plasma clearance was 100.4 ml/min. The mean concentration of mannitol in CSF during the 4 h period increased up to 0.10 mg/ml. There were marked interindividual differences in the concentration ratio blood/CSF, and the CSF concentration varied 7.5 fold between patients. Optimal use of mannitol during neurosurgery requires further prolonged study of its pharmacokinetics.
The monoclonal antibodies anti-2H4 and anti-4B4 identify the suppressor-inducer (CD4+2H4+) and helper-inducer (CD4+4B4+) subpopulations of CD4 (T4+) lymphocytes, respectively. The cell surface phenotype of peripheral blood lymphocytes and synovial fluid lymphocytes in patients with rheumatoid arthritis and other inflammatory joint diseases was analyzed by use of these and other well-characterized anti-T-cell monoclonal antibodies. In the synovial fluid of patients with rheumatoid arthritis, there was a markedly decreased percentage of T4+2H4+ suppressor-inducer cells (3.1 +/- 1 percent) and an increased percentage of T4+4B4+ helper-inducer cells (29.1 +/- 9 percent) as compared with the proportions found in the peripheral blood of normal individuals (T4+2H4+: 19.0 +/- 6 percent, T4+4B4+: 23.0 +/- 7 percent). Moreover, patients with other chronic and acute inflammatory joint diseases exhibited highly similar synovial T-cell findings to those of the patients with rheumatoid arthritis (T4+2H4+: 4.2 +/- 3 percent, T4+4B4+: 33.1 +/- 9 percent). In contrast, there were no significant differences between the normal control subjects and patients with rheumatoid arthritis in the percentage of T4+2H4+ cells in peripheral blood lymphocytes, nor were there significant differences between normal control subjects, patients with rheumatoid arthritis, and patients with other joint diseases (osteoarthritis, gout, B27+ spondyloarthropathy, and psoriatic arthritis) in the number of T4+4B4+ cells or in the T4/T8 ratio of peripheral blood lymphocytes. However, very low numbers of T4+2H4+ (suppressor-inducer) peripheral blood lymphocytes were seen in a subgroup of patients, including five of seven with Reiter's syndrome and several patients with systemic rheumatic disease syndromes. In addition, although the percentage of T4+2H4+ cells in peripheral blood lymphocytes of patients with osteoarthritis (13.7 +/- 7 percent) and gout (14.3 +/- 7 percent) was decreased compared with that of normal controls (19.0 +/- 6 percent) (osteoarthritis versus normal controls p less than 0.025), this difference appeared to reflect alterations due to age rather than disease. Consistent with the phenotypic changes observed, synovial T cells were also functionally defective, since autologous mixed lymphocyte reaction-activated T4 cells from the synovial fluid of patients with rheumatoid arthritis failed to exhibit suppressor-inducer activity.(ABSTRACT TRUNCATED AT 400 WORDS)
T lymphocyte proliferation can be triggered through interactions with either CD3:Ti, the target of antigen-specific activation, or CD2, the target of an antigen-independent activation pathway. Sepharose-immobilized antibody reactive with CD3 was used to aggregate the T cell receptor complex resulting in T lymphocyte activation. When CD3 was simultaneously crosslinked with CD2 using Sepharose beads coupled to antibodies directed at both determinants, T cell proliferation was markedly enhanced (stimulation index = 8- to 11-fold). A smaller enhancement was induced when CD3 was crosslinked with several other functionally relevant T cell surface molecules. The relative mitogenic potency of the accessory molecules tested was CD2 greater than CD4 greater than CD8 greater than 2H4. Little or no increased proliferation resulted from crosslinking CD3 with class I or class II major histocompatibility antigens. The added proliferation induced by CD3: CD2 crosslinking did not occur in the presence of soluble antibodies directed against CD2. Human thymocytes, the majority of which express both CD3 and CD2, were similarly activated by Sepharose-immobilized antibodies. Our results suggest that specific interactions between T cell surface molecules may play a role in the regulation of lymphocyte activation.
We have investigated the direct labeling of antibodies with gold isotopes as an alternative to iodine and chelated metals for antibody guided therapy. Both 199Au and 195Au complex anions in citrate-buffered solutions (pH 3.8-7.2) are rapidly bound to sheep polyclonal anti-CEA with high efficiency. After purification by gel filtration, the antibody retained 80% of the bound gold for upto 6 days at 4 degrees C and was reactive with its target antigen in a solid phase assay. Incubation with the gold binding substance D-penicillamine reduced labeling efficiency and stability.
The isolated capsular polysaccharide induces antibody protective against invasive infections by H. influenzae b. Maturation of responsiveness is slow such that infants are not protected. Several protein-coupled versions of the antigen are being tested for immunogenicity in early infancy. The relation of structure to immunogenicity is not completely defined, but all induce a booster-type antibody response with protective potential. Primary vaccination in infancy appears to mimic natural priming, activating clones of B lymphocytes that can later be restimulated by uncoupled polysaccharide. Prospects appear good for immunizing normal infants and also children with immunoregulatory defects predisposing to infection.
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