PubMed Health⌕ Search

Biomedical subjects

D J Lyons

Publications and source records attributed to D J Lyons.

17 recordsLinked to original sources
PubMed1992

Chemical inactivation of the Kveim reagent.

In an attempt to identify the nature of the active principle, Kveim reagent was exposed to chemical fractionating agents. Thirty-one patients with sarcoidosis underwent simultaneous intradermal injection with fractionated and unfractionated Kveim material. Kveim reagent was stable in the presence of DNAse, RNAse, pronase, 95% phenol, neutral detergent, and to lipid extraction with chloroform-methanol. Kveim reagent was also stable in the presence of both 8 M urea (8MU) and 2-mercaptoethanol (2ME) when used alone. When both these agents were used together, Kveim reagent was inactivated. Fourteen patients had a positive test to unfractionated Kveim reagent; of these, only 2 gave a positive response to material fractionated by exposure to 8MU and 2ME. Simultaneous exposure to 8MU and 2ME was more likely to inactivate Kveim reagent (10/10 tests) than sequential exposure to 8MU and 2ME (2/4 tests). Chemical analysis of the fractionated material showed that it retained granuloma-generating activity despite the lack of carbohydrates. Protein loss in terms of total and relative amino acid composition was progressive and non-specific throughout processing. These results are consistent with a protein-active principle which is dependent on three-dimensional structure.

Chemical Fractionation↗
PubMed1992

Lymphocyte macrophage interactions: peripolesis of human alveolar macrophages.

Peripolesis is a phenomenon in which a lymphocyte attaches itself to another cell, usually a macrophage or veiled cell, and proceeds to circle around it. In emperipolesis, a related phenomenon, the lymphocyte invaginates the target cell so deeply that it appears to be intracytoplasmic. Lung cells in bronchoalveolar lavage fluids from 20 patients were observed in the living state and filmed. Peripolesis of the alveolar macrophages was recorded in six cases. These patients included one case each of carcinoma of the bronchus, tuberculosis, sarcoidosis and asthma, while two patients had no detectable lung disease. Five out of the six positive cases were females. In every instance there was a high number of lymphocytes in the washing. The peripolesed macrophages were not injured, but temporary alteration of the cell membrane was noted in a minority of film sequences. The peripolesing cells were also examined by transmission and scanning electron microscopy. The lymphocyte was found to be closely attached to the surface of the macrophage, with no invagination and its ultrastructure was that of a small lymphocyte. Peripolesis is probably a physiological mechanism concerned with regulation of the immune response in the lung.

Adult↗
PubMed1991

Ulcerative jejunitis: are we missing cases?

We present two cases of ulcerative jejunitis unassociated with coeliac disease. The condition is probably being underdiagnosed especially since the reduction in the investigative laparotomy.

Adult↗
PubMed1991

Sarcoidosis: in search of Kveim reactivity in vitro.

Granuloma formation in patients with sarcoidosis may be evoked by the intradermal injection of homogenised sarcoid tissue (the Kveim reaction). Attempts to demonstrate an in vitro counterpart of the reaction have been unsuccessful. The cytokine interleukin-2 (IL-2) enhances immune responses in vivo and in vitro. We report here an attempt to amplify the Kveim reaction by the addition of IL-2. We studied the effect of Kveim reagent on the proliferative responses of peripheral blood mononuclear cells (PBMC) in the presence or absence of exogenous IL-2. Twenty-eight patients were studied and 14 healthy subjects served as controls. PBMC were cultured, in vitro, in the presence of Kveim reagent. Recombinant IL-2 or both of these combined. Proliferative responses were measured by [3H]-thymidine incorporation. The response of patients' PBMC in the presence of Kveim reagent at a dilution of 1:40 was significantly below the unstimulated response (P less than 0.01). Kveim reagent at a dilution of 1:40 also inhibited the proliferative response of patients PBMC to IL-2 (P less than 0.005); greater dilutions (1:100 and 1:1000) of Kveim reagent were not inhibitory. Responses of PBMC from control subjects (both unstimulated and IL-2 generated) were reduced in the presence of Kveim reagent, however, these reductions were not statistically significant.

Adult↗
PubMed1991

Search for a retroviral cause for sarcoidosis: no evidence from peripheral blood studies.

Twenty six patients with sarcoidosis of recent onset or with severe progressive disease were studied for evidence of retroviral infection. Peripheral blood mononuclear cells (PBMC) were cultured in vitro and stimulated with phytohaemagglutinin and interleukin-2. Induction of syncytia (SI) and production of reverse transcriptase (RT) were sought as indicators of possible retroviral infection. PBMC from two patients showed syncytia formation and in one of these two there was associated production of low levels of reverse transcriptase. The remaining patients showed neither RT nor SI activity. The predominantly negative results of this study indicate that sarcoidosis is unlikely to be of retroviral aetiology; however, cell populations from sites of active disease should be studied before drawing this conclusion.

Adult↗
PubMed1990

Chronic anaemia in an Irish gastroenterology unit: one hundred consecutive cases.

One hundred consecutive patients presenting with anaemia of at least 4 wks' duration were studied. This represents 3% of all patients seen at a medical service with a gastroenterology subspecialty interest. Forty-three men and 57 women were included; the mean age was 60 (SD 18) yr. Iron deficiency was the principal cause of anaemia in 49% of cases. Blood loss from the gastrointestinal tract was the most frequent cause of iron deficiency and was predominantly from the upper gastrointestinal tract. Patients in whom iron deficiency was the sole cause of anaemia all had a microcytic hypochromic blood profile; however, serum iron and iron binding capacity correlated poorly with the severity of anaemia. Chronic disease was the principal cause of anaemia in 39% of patients.

Adult↗
PubMed1990

What's in a relationship? Sarcoidosis and tuberculosis.

The relationship between the two granulomatous diseases sarcoidosis and tuberculosis is reviewed. Data from 14 published case series are presented in the form of a figure which indicates that case series collected earlier in time and with a high proportion of non-white patients show a higher prevalence of tuberculosis. This high prevalence was also found in other chronic diseases such as diabetes and rheumatoid arthritis. The more frequent presence of mycobacteria in sarcoid than in control tissue, the parallel changes in the prevalence of sarcoidosis and tuberculosis in a community and the presence of myocbacteria on culture if pursued with sufficient aggression, are consistant with a mycobacterial aetiology. Recent developments in the immunology of the two diseases are reviewed.

Humans↗
PubMed1989

A case of Graves' disease associated with autoimmune haemolytic anaemia.

This report describes simultaneous autoimmune thyrotoxicosis and autoimmune haemolytic anaemia. Autoimmune haematological abnormalities should be excluded in patients with Graves' disease and thyroid function and thyroid antibody status should be evaluated in patients with autoimmune haemolytic anaemia.

Adolescent↗
PubMed1988

Defective cell mediated immunity in sarcoidosis: effect of interleukin-2.

Interleukin-2 has been reported to enhance the immune response in diseases characterised by defective cell mediated immunity. The effect of exogenous recombinant interleukin-2 was studied on the proliferative and cytotoxic responses of peripheral blood mononuclear cells from 39 patients with sarcoidosis and 14 healthy control subjects. The proliferative response to purified protein derivative was smaller in patients than in control subjects (p less than 0.001) whereas the response to 80 U interleukin-2 alone and to purified protein derivative and interleukin-2 did not differ significantly between the two groups. In addition, in eight patients but no control subjects tritiated thymidine incorporation induced by the combination of purified protein derivative and interleukin-2 was more than twice the sum of that induced by purified protein derivative and interleukin separately. Cytotoxic activity occurring spontaneously and induced by purified protein derivative and interleukin-2 in blood mononuclear cells was significantly less for patients with sarcoidosis than for control subjects (p less than 0.05 spontaneous, less than 0.001 purified protein derivative induced, less than 0.02 interleukin induced). Synergism between antigen and interleukin did not occur with respect to the cytotoxic response in either patients or controls. Defective interleukin-2 production may contribute to, but does not entirely explain, the functional abnormalities of peripheral blood lymphocytes from patients with sarcoidosis.

Adult↗
PubMed1986

Contribution of ethanol and cigarette smoking to pulmonary dysfunction in chronic alcoholics.

Ethanol is claimed to have a specific damaging effect on the lung and to be at least partially responsible for pulmonary dysfunction in alcoholics. Adequate allowance for the damaging effects of cigarette smoking has not, however, been made hitherto. Pulmonary function studies were undertaken in 27 alcoholic subjects. Although there was a high prevalence of symptoms and abnormalities of pulmonary function, these were largely confined to current smokers: most of those who had never smoked and the ex-smokers who were symptom free and had normal pulmonary function. A case controlled study of alcoholics and matched controls showed no significant difference in pulmonary function between the two groups. It is concluded that the high prevalence of respiratory disease in alcoholics is largely attributable to their smoking habits: no evidence of a specific pulmonary toxic effect of ethanol was identified in the study.

Adult↗
PubMedDate not supplied

Assay of calcium borogluconate veterinary medicines for calcium gluconate, boric acid, phosphorus, and magnesium by using inductively coupled plasma emission spectrometry.

An inductively coupled plasma spectrometric method is described for the determination of 4 elements (Ca, B, P, and Mg) in calcium borogluconate veterinary medicines. Samples are diluted, acidified, and sprayed directly into the plasma. Reproducibility relative confidence intervals for a single sample assay are +/- 1.4% (calcium), +/- 1.8% (boron), +/- 2.6% (phosphorus), and +/- 1.4% (magnesium). The total element concentrations for each of 4 elements compared favorably with concentrations determined by alternative methods. Formulation estimates of levels of calcium gluconate, boric acid, phosphorus, and magnesium salts can be made from the analytical data.

Animals↗