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Biomedical subjects

B M Jones

Publications and source records attributed to B M Jones.

At least 163 records · Page 9Linked to original sources
PubMed1985

A case of invasive penicilliosis in Hong Kong with immunologic evaluation.

A 53-yr-old Chinese sailor developed prolonged pyrexia with unresolved lobar pneumonia, cervical lymphadenopathy, generalized subcutaneous abscesses, and pericardial effusion. Penicillium marneffei was isolated from pericardial fluid and subcutaneous pus and was demonstrated on histologic sections of lymph nodes and lung tissue. The penicilliosis was treated successfully with amphotericin B, ketoconazole, and 5-fluorocytosine. Subsequently, he also developed other T-lymphocyte-related opportunistic infections such as disseminated cutaneous herpes zoster and chronic osteomyelitis of sternum caused by Salmonella typhimurium. He was also a chronic carrier of cytomegalovirus. Further investigations showed that he had persistent depression of T-lymphocyte function and enhancement of B-lymphocyte activity, the cause of which was undetermined.

Abscess↗
PubMed1985

Exposure to human T-lymphotropic virus type III/lymphadenopathy-associated virus and immunologic abnormalities in asymptomatic homosexual men.

Immunologic and serologic studies were done in 120 homosexual men who reportedly had no symptoms related to the acquired immunodeficiency syndrome. Forty-nine men (41%) had antibody to the retrovirus human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV), and 37 (31%) had an abnormal T-cell subset ratio and other immunologic abnormalities. These abnormalities were almost exclusively confined to men seropositive for the retrovirus. Multivariate statistical analysis showed that exposure to HTLV-III/LAV was the single best predictor of T-cell (and other) immunologic abnormalities. Sexual practice, particularly receptive anal intercourse, predicted exposure to HTLV-III/LAV but was not independently related to T-cell abnormalities. The association of other microbial serologic findings with HTLV-III/LAV seropositivity or T-cell changes was a coincidental function of sexual activity. Immunologic abnormalities in asymptomatic homosexual men are mostly related to exposure to HTLV-III/LAV.

Antibodies, Viral↗
PubMed1985

Neutralization of T-replacing factor by T8-positive lymphocytes: an important suppressor mechanism operating in the regulation of polyclonal B-cell activation.

Pokeweed mitogen (PWM)-induced B-cell activation was entirely abrogated by pre-treating peripheral mononuclear cells (PBM) with T4 (anti-T-helper-inducer subset) or T11 (anti-sheep erythrocyte receptor, ie. anti-pan-T-cell) monoclonal antibody plus complement. Immunoglobulin secretion was restored in T11- but not T4- cultures by adding the culture supernatant from PWM-stimulated PBM (T-replacing factor, TRF). Since T8+ (T-suppressor-cytotoxic subset) cells were present in high concentrations in T4- but absent from T11- cultures, it appeared that these cells could inhibit B-cell activation by PWM plus TRF and that suppression could occur in the absence of T4+ cells. Incubation of TRF with purified, unstimulated T8+ cells prior to addition to T11- cultures abrogated subsequent PWM-induced B-cell activation, whereas T8- PBM had no effect on TRF. T8+ cells did not secrete suppressor factors during incubation with TRF. Absorption of one or more of the factors required for B-cell growth and differentiation by T8+ cells appears to be an important suppressor mechanism operating in the PWM system.

Adult↗
PubMed1985

Predicting the fate of free tissue transfers.

Accurate and objective assessment of blood flow in microvascular free tissue transfers both at the time of surgery and during the postoperative period is vital. An experimental study is presented in which four methods of evaluating flow were tested in an animal model. Based on this work clinical free tissue transfers have been successfully monitored using an ultrasound Doppler flowmeter at operation and a laser Doppler flowmeter afterwards. The use of these instruments has significantly improved the reliability of microvascular reconstructions and greatly simplified their postoperative management.

Adolescent↗
PubMed1984

Comparison of T and B cell analyses on fresh and aged blood.

We have compared T and B cell analyses using whole blood, separated lymphocytes, and separated, frozen, then thawed lymphocytes to see how long blood can be kept before separation and analysis. We also examined the effect of various anticoagulants and the effect of diluting blood in culture media on T and B cell analysis over time. We found that the whole blood method is a very reliable method for T and B cell analysis, even 4 days after the blood is drawn, provided that heparin or ACD is the anticoagulant used. Separated lymphocytes and cryopreserved lymphocytes from blood that was separated within 24 h of collection was satisfactory; however, results were less consistent if separation was delayed more than 24 h. For lymphocyte separation, blood collected in heparin or ACD held up better over time than did blood collected in EDTA, and dilution with either RPMI 1640 or McCoy's medium gave better lymphocyte separation in older blood.

Antibodies, Monoclonal↗
PubMed1984

Surgical treatment of radiation-induced scalp lesions.

The treatment of scalp lesions induced by ionising radiation in four patients is described. In each case the technique used was different. Three required several operations and a prolonged hospital stay. The fourth patient, in whom a free flap was used, underwent a single operation. In selected patients with reasonable general health free tissue transfer may provide the best solution to such difficult management problems.

Aged↗
PubMed1984

Identification of B-cell and T-helper-cell defects, and of suppressor cell hyperactivity, in humoral immunodeficiency.

Methods are described for distinguishing between intrinsic B-cell defects, T-helper-cell defects, and suppressor cell hyperactivity in patients who fail to secrete immunoglobulin when peripheral blood mononuclear cells are stimulated with pokeweed mitogen. Control cells which respond to pokeweed mitogen are made unresponsive by depleting B cells or OKT4+ cells, and the missing subset, purified from the patient's peripheral blood mononuclear cells, is added back to examine its functional activity. Alternatively, hyperactivity of OKT8+ putative suppressor T cells or suppressor monocytes is evaluated by depleting these populations from the patient's peripheral blood mononuclear cells. Four patients who produced few plaque-forming cells in response to pokeweed mitogen were investigated: two had intrinsic B-cell deficiencies, one had T-helper-cell deficiency, and one had T-suppressor-cell hyperactivity.

Adult↗
PubMed1984

Trifluoperazine inhibits formation of adhesion plaque complexes and cell sorting in aggregates of fibroblasts.

Trifluoperazine (TFP) at 5 microM completely blocks the formation of adhesion plaque complexes (adhaerens junctions) between aggregating fibroblasts; the drug at this same concentration did not prevent the cells from producing aggregates of normal size and appearance. Implicit in this finding is that aggregation does not rely on adhesion plaque complex formation. When thymidine-3H labelled 16C and unlabelled BHK fibroblast cells were experimentally combined to form aggregates in which the cells were initially uniformly distributed, the 16C cells, which produced adhesion plaque complexes within minutes and in greater numbers than did BHK cells, congregated in an internal position after the aggregates had been cultured for 12h. This redistribution of the cells, indicated by the positioning of the labelled 16C nuclei, did not occur when the aggregates were exposed to TFP. Thus cell sorting, unlike aggregation, seems to be reliant on the formation of adhesion plaque complexes.

Animals↗
PubMed1984

Monitors for the cutaneous microcirculation.

Scientific evidence is not yet sufficient to justify a large expenditure on equipment simply for clinical monitoring. Despite reservations about reliability, thermometry certainly appears the most cost-effective technique. It is of particular value in monitoring digits. Since these are end organs, spurious information arising because of heat conducted from deep tissues is eliminated, and multiple digits are easily monitored simultaneously. Implantable systems providing direct information relating to the condition of a microanastomosis may eventually prove more versatile and effective clinically than externally applied techniques, although the physiological information which they provide is limited.

Blood Flow Velocity↗
PubMed1984

Accumulation and release of isoferritins during incubation in vitro of human peripheral blood mononuclear cells.

Ferritin concentration has been measured in peripheral blood mononuclear cells and in the incubation medium following in vitro culture. Antibodies to both heart and spleen ferritin were used. Mononuclear cells cultured in medium containing about 12 mumol Fe/l accumulate ferritin rapidly with an increase in the heart:spleen ferritin ratio from 3:1 to about 10:1. Higher concentrations of iron (100 mumol/l) produce an even greater effect. The accumulation of ferritin is prevented by the addition of desferrioxamine (2 mmol/l) to the incubation medium. Accumulation of ferritin appears to take place largely in monocytes. Phagocytosis of red blood cells also causes rapid accumulation of ferritin but without any change in the heart:spleen ratio. Small amounts of both spleen and heart type ferritin are released during incubation in an iron containing medium and following phagocytosis of red blood cells. Some concanavalin A binding ferritin is also released suggesting that phagocytic cells may be a source of the concanavalin A binding ferritin found in normal plasma.

Cells, Cultured↗
PubMed1984

Immunoregulatory subsets of the T helper and T suppressor cell populations in homosexual men with chronic unexplained lymphadenopathy.

Unexplained, generalized lymphadenopathy in homosexual men, which can be a prodrome to the acquired immunodeficiency syndrome, is associated with impaired cell-mediated immunity, a low ratio of T helper-inducer to T suppressor-cytotoxic cells (defined by the T4 and T8 monoclonal antibodies), and hypergammaglobulinemia. We performed double-marker studies on T cells by using a panel of monoclonal antibodies (Ia, T17, TQ1, and Leu-8), which reportedly detect activation or functional subsets of the T4 and T8 T cell populations. The T4:TQ1- or T4:Leu-8- subset, which is the major helper subset for B cell responses, is normally represented in lymphadenopathy patients. A depression in the reciprocal subset, T4:TQ1+ or T4:Leu-8+, accounts for the T4 T cell defect. Similarly, the TQ1 and Leu-8 markers delineate the abnormality of T8 T cells: the T8:TQ1- or T8:Leu-8- subset is elevated, whereas the T8:TQ1+ or T8:Leu-8+ subset is normally represented. We found no evidence of excessive activation of T4 T cells by using the T17 or Ia monoclonal antibodies. We did find an overall increase in Ia-positive T cells; however, this was due to increased T8:Ia+ cells. In functional studies, immunoglobulin production induced by pokeweed was subnormal. Most lymphadenopathy patients had normal T helper cell function when combined with normal B cells. The dampened pokeweed responses could be partially explained by depression of the T4:TQ1+ (or T4:Leu-8+) subset (which has minor help-associated function) and/or greater than expected suppression. However, subnormal pokeweed responses could not be totally explained by immunoregulatory T cell abnormalities because we also found an intrinsic defect in the B cell responses of lymphadenopathy patients.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Differential thermometry as a monitor of blood flow in skin flaps.

An instrument for monitoring the blood flow in skin flaps by temperature measurement is described. This compares the temperature of the flap with adjacent normal skin. An experimental assessment of the technique is presented. Although many of the problems associated with absolute temperature measurement were eliminated, the reaction to circulatory change within a flap was slow. However, with further refinement, the principle may have a place in clinical practice, especially in replantation surgery.

Animals↗
PubMed1983

Monitoring skin flaps by colour measurement.

A technique based on reflection spectrophotometry has been tested for use as a monitor of the cutaneous circulation in experimental skin flaps. A very rapid indication was given of either arterial or venous insufficiency in a previously healthy flap. Post-operative monitoring produced characteristic traces for successful and unsuccessful free flaps. The ability of this method to discriminate between a satisfactory flap, an arterial failure, and a venous failure was highly significant (P less than 0.001).

Animals↗