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Biomedical subjects

M G Harries

Publications and source records attributed to M G Harries.

At least 19 recordsLinked to original sources
PubMed1992

Dietary calcium as a statistical determinant of spinal trabecular bone density in amenorrhoeic and oestrogen-replete athletes.

A study investigating the relationship between spinal trabecular bone density (measured by QCT), dietary calcium (measured by questionnaire) and menstrual status in 67 elite female athletes was undertaken. Twenty-five athletes were amenorrhoeic, 27 eumenorrhoeic and 15 were taking an oral contraceptive. The mean bone density was significantly lower (P less than 0.0001) in the amenorrhoeics (168 mg/cm3; 95% confidence interval 154-182) than in the eumenorrhoeics (211 mg/cm3; 197-224) and oral contraceptive takers (215 mg/cm3; 197-233). There was also a significant positive linear correlation between trabecular bone density. However, factors with which calcium intake may be linked, such as energy intake and expenditure, were not measured and therefore it is possible that this relationship is indirect. Further studies on the relationship between dietary calcium and bone mineral density in young women are needed.

Adolescent↗
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

Different training patterns and bone mineral density of the femoral shaft in elite, female athletes.

The effects of sporting activity and of menstrual status on the bone mineral content of the femoral mid-shaft were investigated. The cohort consisted of 67 elite, female athletes comprising 21 runners, 36 rowers, and 10 dancers. Twenty five of these athletes were amenorrhoeic, 27 eumenorrhoeic, and 15 were taking the oral contraceptive. The bone mineral content was also measured in 13 eumenorrhoeic, sedentary women. The mean (95% confidence interval) bone mineral content in the runners was 1.51 (1.47 to 1.55) g/cm2, which was significantly higher than in the rowers, dancers, and sedentary controls whose values were 1.43 (1.40 to 1.47), 1.39 (1.33 to 1.45), and 1.40 (1.34 to 1.45) g/cm2 respectively. There was no significant difference in the bone mineral content between the amenorrhoeic, eumenorrhoeic, and oral contraceptive taking athletes. These results may have implications for devising exercise strategies to reduce the possibility of fractures in later life.

Adult↗
PubMed1985

Didymella exitialis and late summer asthma.

4 patients in whom Didymella exitialis seemed to be an important cause of their asthma were investigated. All 4 patients had immediate skinprick test reactions and specific IgE antibody to D exitialis and Alternaria alternata. Inhalation of a soluble extract of D exitialis provoked immediate asthmatic reactions in these 4, but not in a skin-prick-test-negative volunteer. Radioallergosorbent inhibition studies with D exitialis and A alternata showed self and cross inhibition, which suggested shared antigens. During summer, 1983, 1 of the 4 recorded peak expiratory flow rate (PEFR) twice a day. Spore counts of D exitialis and A alternata were made during this time. Falls in PEFR occurred when D exitialis spore counts increased, usually after a rainfall. Of 34 allergy clinic patients, 6 had skin-prick test reaction to both fungi, but 2 had reactions to A alternata only and 3 to D exitialis only, which suggests the existence of specific antigens. D exitialis seems to be a cause of late summer asthma. Its importance is not known, but allergy to it may contribute to asthma following thunderstorms.

Ascomycota↗
PubMed1985

Occupational asthma due to formaldehyde.

Bronchial provocation studies on 15 workers occupationally exposed to formaldehyde are described. The results show that formaldehyde exposure can cause asthmatic reactions, and suggest that these are sometimes due to hypersensitivity and sometimes to a direct irritant effect. Three workers had classical occupational asthma caused by formaldehyde fumes, which was likely to be due to hypersensitivity, with late asthmatic reactions following formaldehyde exposure. Six workers developed immediate asthmatic reactions, which were likely to be due to a direct irritant effect as the reactions were shorter in duration than those seen after soluble allergen exposure and were closely related to histamine reactivity. The breathing zone concentrations of formaldehyde required to elicit these irritant reactions (mean 4.8 mg/m3) were higher than those encountered in buildings recently insulated with urea formaldehyde foam, but within levels sometimes found in industry.

Adult↗
PubMed1984

Skin and radioallergosorbent tests in patients with sensitivity to bee and wasp venom.

Intradermal (ID) and prick tests with bee or wasp venom (Pharmalgen) have been performed on 102 subjects with a history of adverse reactions to stings and forty-six control subjects giving no such history. Venom was diluted 100, 10 and 1 microgram/ml for prick testing and 10(-2), 10(-2), 10(-3) and 10(-4) micrograms/ml for ID injections. In forty-six control subjects all were tested with the highest concentration of prick testing solution (100 micrograms/ml), eight (17%) had positive reactions, a similar reaction rate to that reported in control subjects using 10(-1) micrograms/ml ID. In our 102 test subjects skin tests were therefore regarded as positive only if the reaction was elicited by 10 micrograms/ml or less by prick test of 10(-2) micrograms/ml or less ID. In general the results with skin prick tests and ID tests were comparable when the prick solution was 1000 times the concentration of that used for ID testing. ID tests were positive in thirteen with negative skin prick, seven of whom had detectable antibodies when tested by RAST. Conversely four with a positive skin prick test (two of whom were RAST positive) were considered negative on ID testing. As judged either by RAST or skin tests it appeared that sensitivity diminished with the time interval from the last sting (P less than 0.001).

Bee Venoms↗
PubMed1984

Extrinsic allergic bronchiolitis in a bird fancier.

A patient in whom a severe systemic illness was characterised by weight loss, arthralgia and breathlessness was exposed to her pet bird. This pragmatic approach reproduced the features of her illness. The changes that occurred in her pulmonary physiology and histology differed from those seen in extrinsic allergic alveolitis in many important respects.

Adult↗
PubMed1984

A comparison of an aqueous and a pressurized nasal spray of beclomethasone dipropionate in the management of seasonal rhinitis.

A multi-centre, double-blind, parallel group study was carried out in 38 patients with seasonal rhinitis to compare a new aqueous nasal spray of beclomethasone dipropionate with the conventional pressurized nasal spray. Beclomethasone dipropionate (200 micrograms) was administered twice daily for a treatment period of 2 weeks. Both treatments were found to be equally effective and well tolerated. It is suggested, therefore, that the new aqueous nasal spray provides an alternative method of intranasal administration of the steroid for patients who may prefer an aqueous product.

Administration, Intranasal↗
PubMed1983

Antibodies to purified bee venom proteins and peptides. I. Development of a highly specific RAST for bee venom antigens and its application to bee sting allergy.

IgE antibodies to purified proteins and peptides from honeybee venom have been measured by the RAST. Trace amounts (less than 0.1%) of the major venom protein phospholipase A2 (PLA2) grossly distorted the measurement of IgE antibody to the other venom proteins, acid phosphatase (Acid P) and hyaluronidase (HYAL), and overemphasized their importance. Reduction of antigen coupled to the cellulose paper discs, which were used in the assay, diluted out the contaminating PLA2 without apparent loss in sensitivity. The reduction of disc-bound antigen increased the competition between IgE and IgG antibodies but did not affect measurement of IgE antibodies in sera taken from 35 untreated patients who had a history of general allergic reactions to bee stings. In 54% of sera from bee venom--allergic patients, the greatest IgE antibody response was to PLA2. In all, IgE antibodies to PLA2 were present in 91% of these sera. IgE antibodies to Acid P, HYAL, or melittin were present in 60%, 51%, and 31% of sera, respectively, and accounted for the highest level of binding in 17%, 17%, and 6% of these. Only 6% of sera were positive for whole venom but negative for the isolated antigens. A low level of IgE antibody was found to peptide 401 in 6% of sera. No IgE antibodies were found to apamin. While confirming the central role played by PLA2 in bee sting allergy, these results show that other venom components are also important in some patients.

Acid Phosphatase↗
PubMed1983

Antibodies to purified bee venom proteins and peptides. II. A detailed study of changes in IgE and IgG antibodies to individual bee venom antigens.

Antibodies to individual bee venom antigens were studied in detail in nine bee sting-allergic patients who received venom immunotherapy without side effects, in two patients who failed to reach maintenance, and in two whose sensitivity returned. The study was confined to patients who had IgE antibodies to at least one of four purified bee venom antigens at the start of treatment. IgE and IgG antibodies to phospholipase A2 (PLA2), hyaluronidase (HYAL), and acid phosphatase (ACID P) and IgE antibodies to melittin (MEL) were measured, and changes in the antibody levels were followed during bee venom immunotherapy. Two contrasting patterns of antibody response were seen in the nine successfully treated patients. In five patients there was a rise in serum IgG antibodies to the same antigens as the IgE antibodies. In two patients' serum IgE antibody to HYAL or ACID P fell without a marked IgG antibody response to these antigens, although high levels of IgG antibody to PLA2 were present in both. Although the first pattern is consistent with a "blocking" role for IgG antibody, clearly the second is not. Not all patients can be conveniently divided into these two categories, and two patients did not show any significant change in either IgG or IgE antibody but were nevertheless able to tolerate the maintenance dose of 100 micrograms of venom. Two patients who failed to reach the maintenance dose of 100 micrograms because of their allergic reactions to the injections of venom were distinguished by (1) very high serum IgE antibody and (2) a low ratio of IgG/IgE antibody. Passive immunization with IgG antibody from a hyperimmune beekeeper was, however, protective in these patients, although it did not raise their overall serum IgG antibody level very much. We are unable to explain either the failure of conventional therapy or the beneficial effect of passive immunization in these two patients. Two bee sting--allergic beekeepers lost their sensitivity to stings, but later, when their sera contained IgE antibody to another bee venom antigen, they reacted to stings and inhalation of beehive dander. These data suggest that either falling IgE antibody or IgG- "blocking" antibody could be responsible for providing clinical protection to bee venom--allergic subjects. Renewed clinical sensitivity was observed when the IgE response was modulated, with patients making IgE antibody first to one antigen and then to another.

Acid Phosphatase↗
PubMed1983

Portable ventilators under field conditions.

Twenty-eight field rescue units using mechanical ventilators were questioned about the incidence of practical difficulties encountered with their equipment. Eleven (39%) had used the equipment in an emergency. Sixty-one separate incidents were recorded, in 48 oxygen therapy alone was given but in 13 the equipment was used to ventilate the patients' lungs. Seven units (25%) experienced some sort of practical difficulty. Six units complained of trouble with servicing, five of which were frustrated by delays with replacement oxygen cylinders.

Emergencies↗
PubMed1981

Role of bronchial irritant receptors in asthma.

Sulphur dioxide inhaled at low concentration had no detectable effect on forced expiratory volume in one second in non-asthmatic atopic controls, but it induced asthma and increased bronchial reactivity in nine symptomless atopic and non-atopic asthmatic patients. This increased reactivity was inhibited by sodium cromoglycate (SCG) and partly inhibited by atropine. This suggests that SCG, in addition to its ability to stabilise mast cells, may also act on bronchial irritant receptors or directly on smooth muscle in asthmatic patients.

Adolescent↗