Biomedical subjects

K Tse

Publications and source records attributed to K Tse.

7 recordsLinked to original sources

PubMed1996

Once daily mometasone furoate aqueous nasal spray is as effective as twice daily beclomethasone dipropionate for treating perennial allergic rhinitis patients.

BACKGROUND: Perennial allergic rhinitis is chronic and persistent, may lead to a constellation of secondary complaints including sinusitis, mouth-breathing, and some symptoms resembling a permanent cold, and often requires constant medical intervention. Well-tolerated nasal corticosteroids, alone or in combination with antihistamines, have been found to be very effective in treating this condition. OBJECTIVE: To compare the effectiveness and tolerability of mometasone furoate aqueous suspension, a new once daily nasal spray, to placebo vehicle and to beclomethasone dipropionate, administered twice daily, in patients with perennial allergic rhinitis. METHODS: This was a randomized, double-blind, placebo-controlled, double-dummy, parallel group study, in 427 patients age 12 years and older at 24 centers in Canada and Europe. Patients allergic to at least one perennial allergen, confirmed by medical history, skin testing, and adequate symptomatology were eligible to receive one of the following regimens for 3 months: mometasone furoate, 200 micrograms only daily; beclomethasone dipropionate, 200 micrograms twice daily (400 micrograms total dose); or placebo vehicle control. The primary efficacy variable was the change from baseline in total AM plus PM diary nasal symptom score over the first 15 days of treatment. RESULTS: Three hundred eighty-seven patients were valid for efficacy. For the primary efficacy variable, mometasone furoate was significantly (P < or = .01) more effective than placebo and was indistinguishable from beclomethasone dipropionate. Similar trends were seen among individual symptoms, physician symptom evaluations, and therapeutic response. There was no evidence of tachyphylaxis. All treatments were well tolerated. CONCLUSIONS: Mometasone furoate nasal spray adequately controls symptoms of perennial allergic rhinitis, offers the advantage of once daily treatment, and is well tolerated.

Administration, Intranasal↗

PubMed1994

Characterization of natural toxins with inhibitory activity against serine/threonine protein phosphatases.

Recent studies suggest that the ability to inhibit the activity of certain serine/threonine protein phosphatases underlies the toxicity of several natural compounds including: okadaic acid, microcystin-LR, nodularin, calyculin A and tautomycin. To characterize further the actions of these toxins, this study compares the inhibitory effects of okadaic acid, chemical derivatives of okadaic acid, microcystin-LR, microcystin-LA, nodularin, calyculin A and tautomycin on the activity of serine/threonine protein phosphatases types 1 (PP1), 2A (PP2A) and a recently identified protein phosphatase purified from bovine brain (PP3). This study shows that, like PP1 and PP2A, the activity of PP3 is potently inhibited by okadaic acid, both microcystins, nodularin, calyculin A and tautomycin. Further characterization of the toxins employing the purified catalytic subunits of PP1, PP2A and PP3 under identical experimental conditions indicates that: (a) okadaic acid, microcystin-LR, and microcystin-LA inhibit PP2A and PP3 more potently than PP1 (order of potency PP2A > PP3 > PP1); (b) nodularin inhibits PP1 and PP3 at a similar concentration that is slightly higher than that which affects PP2A, and (c) both calyculin A and tautomycin show little selectivity among the phosphatases tested. This study also shows that the chemical modification of the (C1) carboxyl group of okadaic acid can have a profound influence on the inhibitory activity of this toxin. Esterification of okadaic acid, producing methyl okadaate, or reduction, producing okadaol, greatly decreases the inhibitory effects against all three enzymes tested. Further reduction, producing 1-nor-okadaone, or acetylation, producing okadaic acid tetraacetate, results in compounds with no inhibitory activity. In contrast, the substitution of alanine (-LA) for arginine (-LR) in microcystin has no apparent effect on the inhibitory activity against PP1, PP2A or PP3.

Animals↗

PubMed1991

Differences in mediator release between allergic rhinitis and asthma.

To determine why patients with allergic rhinitis alone differ in their airway response to inhaled allergen compared to patients with allergic asthma, bronchial lavage was performed in 10 subjects with allergic asthma and in five subjects with allergic rhinitis, before and after inhalation challenge with antigen to produce an immediate asthmatic reaction. Before antigen challenge, the subjects with asthma had higher absolute neutrophil counts in the lavage fluid. After antigen challenge, the subjects with asthma released significant amounts of bronchoconstrictive mediators, such as histamine and thromboxane B2 into the lavage fluid, whereas subjects with rhinitis alone did not. There was also a significant increase in prostaglandin E2 in the subjects with asthma after antigen challenge. Nonimmunologic bronchoconstriction with methacholine inhalation challenge in six other subjects with asthma did not demonstrate an increase in any of the lavage fluid mediator levels that were measured. A positive correlation was found between methacholine provocative concentration causing a 20% drop in FEV1 and the concentration of prostaglandin E2 in the lavage fluid before challenge. The significance of this observation has yet to be determined. The results suggest that subjects with allergic asthma differ from subjects with rhinitis alone in their capacity to release more mediators into the airways on antigen challenge. It is not known whether this increase in mediators is due to increase in the number of mast cells in the airways or due to increase in mediator releasability from the mast cells of subjects with asthma.

Adult↗

PubMed1991

Okadaic acid inhibits PDGF-induced proliferation and decreases PDGF receptor number in C3H/10T1/2 mouse fibroblasts.

Okadaic acid is both a potent inhibitor of protein serine/threonine phosphatases and a tumor promoter in the mouse skin model. We have previously shown that at non-toxic nanomolar concentrations okadaic acid reversibly inhibits induction (promotion) by PDGF of transformed cells by the 'complete' and 'two-stage' protocols in the C3H/10T1/2 mouse fibroblast transformation assay. In the present study we have demonstrated that treatment of confluent and proliferatively quiescent C3H/10T1/2 mouse fibroblasts with low doses of okadaic acid inhibits the platelet-derived growth factor (PDGF)-induced mitogenic response. This inhibition is accompanied by a loss of PDGF binding sites, a decreased PDGF-induced phosphatidylinositol turnover and a decrease in the PDGF-induced intracellular calcium signal. The decrease in the PDGF-generated intracellular signalling processes represents a mechanism by which okadaic acid inhibits PDGF-induced proliferation and the promotion of in vitro neoplastic transformation by PDGF.

Animals↗

PubMed1990

Dilemmas in counselling: the EEC syndrome.

A family with the EEC syndrome is reported. Two sibs have the classical form of the condition with ectrodactyly, ectodermal dysplasia, and clefting. Their mother, however, has only minimal evidence, with preaxial polydactyly of the right hand and duplication of the terminal phalanx of the second toe of the left foot with 3/4 syndactyly. The dilemmas faced by the genetic counsellor are discussed in this variable autosomal dominant condition.

Abnormalities, Multiple↗

PubMed1988

Congenital absence of insulin-secreting cells.

A male infant was diagnosed as having diabetes mellitus 1 d after birth and died on the third day. Histological examination of the pancreas showed small and inconspicuous islets of Langerhans that were completely devoid of insulin-secreting cells. There was no evidence of insulitis.

Diabetes Mellitus↗

PubMed1982

Epidural morphine.

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Epidural Space↗