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Biomedical subjects

M Humphreys

Publications and source records attributed to M Humphreys.

At least 37 records · Page 2Linked to original sources
PubMed1996

Wolcott-Rallison syndrome associated with congenital malformations and a mosaic deletion 15q 11-12.

Wolcott-Rallison syndrome is a rare autosomal recessive condition first described in 1972. It is characterised by diabetes mellitus which arises in early infancy and multiple epiphyseal dysplasia. We describe an affected girl who had recurrent episodes of hepatic failure for which no obvious cause was found. Post-mortem examination revealed abnormal pancreatic histology and congenital abnormalities of the central nervous and cardio-respiratory systems which have not been previously described in this condition. She also demonstrated a deletion at 15q 11-12 in 65% of her cells.

Abnormalities, Multiple↗
PubMed1992

Serum levels of vitamin A and retinol binding protein in chronic renal patients treated by continuous ambulatorial peritoneal dialysis.

The possible causes and consequences of hypervitaminosis A and retinol binding protein (RBP) levels were investigated in patients with chronic renal disease submitted or not to dialysis treatment. The study was conducted on 20 patients divided into two groups: 10 patients with chronic renal failure (CRF) treated by continuous ambulatorial peritoneal dialysis (CAPD), and 10 CRF patients with no dialysis treatment. Ten normal subjects formed the control group. Retinol levels were determined by HPLC, and RBP levels by immunoassay in plasma and in post-dialysis fluid at different periods of time. Laboratory tests were carried out on all subjects, and dietary history was taken. Patients on dialysis had higher retinol levels than untreated patients. Retinol levels were found to be correlated with RBP levels. Serum retinol and RBP levels did not vary with diet, age or time of disease, dialysis group or time of dialysis, nor were they correlated with the levels measured in the dialysis fluid (CAPD). There was no significant correlation in retinol levels between chronic patients and controls. It is suggested that vitamin A and RBP clearances during dialysis do not accompany urea or creatinine clearance. Hypervitaminosis A did not show any toxic effect.

Adult↗
PubMed1990

Bioassay of interleukin-1 in serum and plasma following removal of inhibitory activity with polyethylene glycol.

Serum and plasma normally inhibit the responsiveness of the indicator cells used in bioassays for interleukin-1 (IL-1). A precipitation step with 12% polyethylene glycol (PEG) was found to remove material responsible for such inhibition. The IL-1 bioassay could be performed in the presence of a 3% concentration of PEG and recovery of added natural IL-1 from plasma or serum was essentially complete.

Animals↗
PubMed1990

Contact hypersensitivity induces plasma interleukin 6.

Previous studies in this laboratory have revealed that elicitation reactions in contact-sensitized mice correlate closely with elevations in the serum concentration of acute-phase proteins. Regulation of the hepatic synthesis of acute-phase proteins is one of the many biological functions ascribed to interleukin 6 (IL-6). We now provide evidence that contact reactions are also associated with a rapid and substantial increase in the plasma concentration of IL-6. Quantitative assessment of plasma IL-6 may provide a useful serological method for the evaluation of experimental allergic contact dermatitis in mice, and possibly in other species.

Animals↗
PubMed1990

Production of interleukin-1 by draining lymph node cells during the induction phase of contact sensitization in mice.

Biologically active interleukin-1 (IL-1) has been detected in supernatants of draining lymph node cells isolated from contact-sensitized mice. Induction of IL-1 was dependent upon the concentration of sensitizer applied and occurred within 2 hr of exposure. The IL-1 activity could not be attributed to other interleukins and was neutralized by a specific antiserum. Reduced concentrations of IL-1 were produced by cells isolated from the draining nodes of mice that had been pre-exposed to the sensitizer. Since IL-1 has the potential to influence several aspects of lymphocyte activation, the production of significant concentrations of biologically active IL-1 by draining lymph node cells indicates that it is likely to play an important role in the afferent phase of contact sensitization.

Animals↗
PubMed1989

Simple, sensitive and specific bioassay of interleukin-1.

This paper describes a convenient method for the culture of sub-lines of the murine T cell cloned line, D10.G4.1, and the use of these lines in a highly sensitive and specific bioassay for interleukin-1 (IL-1). The cells are cultured with IL-1, interleukin-2 (IL-2), and concanavalin A (ConA), in the absence of feeder cells or antigen. Assays are routinely carried out in the presence of saturating IL-2, which enhances sensitivity and ensures that further IL-2 will not give false positives. Addition of interleukin-4 (IL-4) has a similar effect and can be used together with IL-2 where there is a potential for interference from either cytokine. The assay is not affected by high concentrations of human interleukin-6 or tumour necrosis factor-alpha (TNF-alpha) and only minimally affected by high concentrations of murine TNF-alpha.

Animals↗
PubMed1988

Cytokines in synovial fluid. I. The presence of biologically active and immunoreactive IL-1.

Using a sensitive IL-1-dependent T cell clone we estimated interleukin 1 (IL-1)-like activity in a variety of synovial fluids (SF). Although we demonstrate that SF contains potent inhibitors of endogenous and exogenous IL-1 we were able to estimate that samples from rheumatoid arthritis, osteoarthritis and other arthritides contain the equivalent of tens or hundreds of picograms of IL-1 per millilitre, when compared to a standard IL-1 preparation. Although there was some correlation between these results and those obtained using a radio-immunoassay (RIA) for IL-1 beta, the RIA indicated that IL-1 was present in the nanogram range. The results suggest that the importance of inhibitors of IL-1 in SF merits particular attention and that it is also important to consider the bioactivity of cytokines which may be detected by physical methods.

Arthritis↗
PubMed1987

Reflex sympathetic dystrophy: electronic thermography as an aid in diagnosis.

Reflex sympathetic dystrophies can be distressing conditions for patients as well as physicians. In the full-blown case, the diagnosis is easy to make; however, many more subtle forms of reflex sympathetic dystrophy exist. In the full-blown case, diagnosis may be quite simple when the physical findings are present. In the more subtle forms, however, one must have a high index of suspicion in order to make the diagnosis. Clinical testing, such as stellate ganglion blocks, may or may not be helpful. Electronic infrared thermography emerges as a helpful tool in the aid to diagnosis. We have presented several cases in order to illustrate this.

Adult↗