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Biomedical subjects

B M Jones

Publications and source records attributed to B M Jones.

At least 109 records · Page 6Linked to original sources
PubMed1992

Biphasic rise of serum immunoglobulins G and A and sex influence on serum immunoglobulin M in normal Chinese children.

A study was conducted on 751 healthy children from child health clinics, kindergartens and schools, and 80 normal adults to establish reference ranges for serum immunoglobulins (Ig) G, A and M concentrations in normal Chinese. Serum IgG, IgA and IgM concentrations were determined by nephelometry. Serum IgG and IgA were shown to have a significant rise during the preschool age as well as at puberty with a plateau phase in between. This biphasic maturation profile has not been reported in Caucasians and the reasons for the observed difference have yet to be elucidated. Serum IgM concentrations were shown to be higher in females than in males, reaching significance in most age groups beyond 4 years of age. The difference between the two sexes in Chinese was of similar magnitude as that reported for Blacks and Caucasians, that is, 30%. Our findings support the hypothesis that the human X chromosome may carry quantitative genes for IgM.

Adolescent↗
PubMed1992

Sample-stimulus discriminability and sensitivity to reinforcement in delayed matching to sample.

Five pigeons were trained in a delayed matching-to-sample task with red and green stimuli. The retention interval between sample-stimulus presentation and the availability of the choice stimuli was varied between 0.01 s and 12 s within each session. The probability of food produced by correct-red and correct-green responses was varied across conditions. Sample-stimulus discriminability and response bias were measured at four different retention intervals. The results of these analyses showed an interaction between the discriminability of the sample stimuli and the control exerted by differential reinforcement. At longer retention intervals, sample discriminability decreased and sensitivity of choice behavior to changes in the red/green reinforcer ratio increased. An analogous relation has been reported in conditional discriminations in which the physical disparity of stimuli has been varied. This correspondence suggests that increasing the delay between presentation of one of two stimuli and an opportunity to respond discriminatively to it may be functionally similar to increasing the physical similarity of the two stimuli.

Journal Article↗
PubMed1991

Parotid haemangioma in infants: MR imaging at 1.5T.

Parotid gland neoplasms are uncommon and account for less than 2% of human tumours. Haemangiomas account for about 50% of parotid tumours in infants and children compared to only 2% in adults. As the clinical course of infantile haemangiomas may be self limiting and the initial treatment is expectant, early and accurate diagnosis is essential. We report 3 cases of paediatric parotid haemangioma and discuss the Magnetic Resonance (MR) characteristics of these tumours. In two cases the diagnosis was proven histologically and in one case Computed Tomography (CT) was also performed.

Female↗
PubMed1991

Defective neutrophil and lymphocyte function in leucocyte adhesion deficiency.

We report a Chinese girl with the moderate phenotype of leucocyte adhesion deficiency (LAD), presenting with persistent omphalitis and recurrent soft tissue infections. She had subnormal adhesion-dependent neutrophil functions, such as chemotaxis and chemiluminescence response to a particulate stimulant (opsonised zymosan). Despite her adequate humoral response to documented herpes simplex virus type 1, parainfluenza type 2 and adenovirus infection in vivo, there was marked impairment in the generation of plaque-forming cells (PFC) driven by pokeweed mitogen (PWM) in vitro. IgM PFC were less severely affected than IgG and IgA PFC, probably because IgM production is less dependent on T cell help than IgA and IgG production. The patient's B cells and accessory cells had reduced function compared with the control subsets, while helper function of her CD4+ cells was virtually absent in the PWM-driven PFC assay. She also had marked defect in natural killer cell activity. The proliferation of her lymphocytes was normal to several plant lectins, including phytohaemagglutinin, concanavalin A and PWM, but markedly defective to OKT3.

Antigens, CD↗
PubMed1991

Aberrant T-regulation in rheumatoid arthritis and IgA nephropathy affects CD5+ and CD5- B lymphocytes equally.

T-suppressor function and T-helper function in healthy adults, elderly patients with non-immune diseases, and patients with rheumatoid arthritis (RA) and IgA nephropathy (IgAN) were titrated by adding graded concentrations of CD8+ cells to autologous CD8-depleted peripheral blood mononuclear cells (PBMC), or CD4+ cells to CD8- 4- PBMC, respectively. Following culture with pokeweed mitogen (PWM), numbers of CD5+ and CD5- immunoglobulin-secreting cells were determined using a combination of rosetting with anti-CD5-coated Dynabeads and reverse haemolytic plaque formation (Jones, 1990). Of 11 RA patients studied, eight had slightly reduced suppressor activity for CD5+ and CD5- IgM-secreting cells, and three with active disease and high serum levels of C-reactive protein, could not suppress IgG, IgA or IgM secretion by either B subset. Helper activity for both CD5+ and CD5- B cells was slightly but significantly increased in RA patients. One of eight patients with IgAN could not suppress IgG, IgA or IgM production by CD5+ or CD5- B cells, and all IgAN patients required strikingly fewer CD4+ cells for PWM-induced activation of CD5+ and CD5- B cells than controls. It was concluded that in two immunologically mediated diseases in which some patients have raised numbers of circulating CD5+ B cells, aberrant T-regulation affects CD5+ and conventional CD5- B cells equally.

Antibody Formation↗
PubMed1991

CD5+ B-lymphocytes are as dependent on T-helper cells and as responsive to T-suppressor cells in pokeweed mitogen-stimulated activation as conventional CD5- B-lymphocytes.

Pokeweed mitogen (PWM)-stimulated cultures were established with varying numbers of CD4+ or CD8+ cells and CD5+ immunoglobulin-secreting cells were subsequently identified using a combination of haemolytic plaque formation and rosetting with immunobeads coated with anti-Leu-1. It was found that CD5+ and CD5- B-cells required similar numbers of CD4+ cells for half-maximum plaque-forming cell (PFC) induction and that 50% suppression of both CD5+ and CD5- PFC occurred with similar numbers of CD8+ cells. Suppression of both CD5+ and CD5- PFC could occur when T-helper signals were supplied by a PWM-stimulated culture supernatant, indicating that both subsets could be directly suppressed by CD8+ cells rather than by indirect suppression of T-helper cells. It is concluded that CD5+ B-cells are as responsive to T-regulatory influences as conventional CD5- B-cells.

Adult↗
PubMed1991

The susceptibility of organisms associated with bacterial vaginosis to spermicidal compounds, in vitro.

OBJECTIVES: Bacterial vaginosis (BV) is a prevalent vaginal infection that is now regarded as a risk factor in more serious pelvic and obstetric complications. Spermicides are known to have antimicrobial activity against other sexually transmitted diseases and the aim of this study was to test whether the causative organisms of BV were also susceptible to spermicides, in vitro. DESIGN: Minimal Inhibitory Concentrations of five spermicidal compounds were determined for the organisms associated with BV, in an agar dilution technique. LOCATION: The Department of Experimental and Clinical Microbiology, University of Sheffield Medical School, UK. SPERMICIDES AND ORGANISMS: Nonoxynol-9, Nonoxynol-11, Docusate sodium, Benzalkonium chloride and Menfegol were tested against 20 strains each of Gardnerella vaginalis, Bacteroides and Mobiluncus organisms, isolated from patients with BV who attended the Department of Genitourinary Medicine, the Royal Hallamshire Hospital, Sheffield. MAIN OUTCOME MEASURES: The susceptibility of BV-associated organisms to spermicidal compounds, in vitro. RESULTS: G vaginalis, Mobiluncus spp, Bacteroides bivius and Bacteroides disiens were all susceptible to the five spermicides tested, with MICs ranging between less than or equal to 19 and 5000 mg/l (0.0019%-0.5%). CONCLUSION: The concentrations of spermicides incorporated in contraceptive preparations are usually between 3% and 8%, which are far in excess of the MICs found for BV organisms. Their usage could exert a significant antimicrobial effect and be a useful prophylactic in preventing the infection.

Bacteria, Anaerobic↗
PubMed1991

Dr Paul Tessier.

Explore the source record for details and available documents.

Craniofacial Dysostosis↗
PubMed1990

Evaluation of CD5 and other differentiation antigens on human immunoglobulin-secreting cells using a combination of immunobead rosetting and reverse haemolytic plaque formation.

This paper describes a new method, with high specificity and sensitivity, for evaluating cell surface markes such as differentiation antigens and cytokine receptors on immunoglobulin-secreting cells. Mononuclear cells, freshly derived from peripheral blood or following stimulation in vitro with pokeweed mitogen or Staphylococcus aureus Cowan I, are partially depleted of T cells and monocytes using immunomagnetic beads (Dynabeads) coated with anti-CD2. The cells are incubated with Dynabeads coated with monoclonal antibody against the cell marker under investigation and then used in a protein A haemolytic plaque assay. Plaque-forming cells (PFC) with (marker-positive) and without (marker-negative) attached beads can be readily enumerated. Values are given for percentages of IgG-, IgA- and IgM-PFC bearing CD19, CD38, CD25 and CD5.

ADP-ribosyl Cyclase↗
PubMed1990

Infected sternotomy wounds.

Three babies who developed infection in their median sternotomy wounds are reported. In one child, a retrosternal abscess was drained and in the other two cases, the wounds dehisced. The wound cavities were filled with a rectus abdominis myocutaneous island flap and in each case, the wounds healed primarily. Early flap repair resolved the infection, shortened the hospital stay and provided protection to the exposed mediastinum.

Abdominal Muscles↗
PubMed1990

Intracranial volume in children with craniosynostosis.

The intracranial volume of 104 children with craniosynostosis was measured. Premature fusion of skull sutures is thought to deny the growing brain room to expand, but contrary to traditional teaching the intracranial volume of such children is often within normal limits.

Cephalometry↗
PubMed1990

Mutilating palmoplantar keratoderma with periorificial keratotic plaques (Olmsted's syndrome).

We report the case of a boy, now aged 4 years, with a progressive, painful and disabling palmoplantar keratoderma, associated with well-defined hyperkeratotic plaques around the mouth and nostrils. His mother has an identical palmoplantar keratoderma. The palmoplantar keratoderma failed to improve with etretinate, but considerable benefit resulted from full-thickness excision of the skin of both palms, followed by skin grafting. We believe that he has a distinctive but extremely rare form of hereditary palmoplantar keratoderma, first described by Olmsted.

Child, Preschool↗