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Biomedical subjects

B Knox

Publications and source records attributed to B Knox.

11 recordsLinked to original sources
PubMed1992

Two consecutive thunderstorm associated epidemics of asthma in the city of Melbourne. The possible role of rye grass pollen.

OBJECTIVE: To document the clinical impact and identify the meteorological and environmental circumstances surrounding two epidemics of asthma exacerbations associated with thunderstorms in the city of Melbourne and to find a possible aetiology for these events. DESIGN: Collection of meteorological and environmental data from the Victorian Bureau of Meteorology and the Environment Protection Authority; collection of clinical data from metropolitan emergency departments and the Victorian Ambulance Service; and study of a cohort of affected patients with asthma and a control group of asthmatics who were not affected by the storms. SETTING: Tertiary institution. PATIENTS: Twelve storm-affected patients with asthma and 16 asthmatics not affected by the storms. INTERVENTION: Administration of a questionnaire, medical interview, pulmonary function tests and skin prick tests with common allergens. MAIN OUTCOME AND RESULTS: Both epidemics caused a major increase in the number of hospital attendances and admissions because of asthma exacerbation (five to ten fold rise). These events could not be related to atmospheric pollution or specific meteorological features of the storms. Patients affected by the second storm were significantly more likely to suffer from hay fever (P less than 0.05), rye grass pollen allergy (P less than 0.05) and allergy to rainfall released rye grass starch granules (P less than 0.025). CONCLUSIONS: Late spring thunderstorms in the city of Melbourne can trigger epidemics of asthma attacks. The seasonal nature of the phenomenon and the pattern of allergic responses found in affected patients suggest a possible aetiological role for rye grass pollen.

Air Pollution↗
PubMed1989

Transdermal oestrogen for postmenopausal women: a double blind crossover comparative study with ethinyl oestradiol.

A double blind crossover study of transdermal oestradiol (50 micrograms/day) and ethinyl oestradiol (20 micrograms/day) was conducted with 25 postmenopausal women. Transdermal oestradiol increased circulating levels of oestradiol and oestrone. Both preparations favourably improved patients' symptoms and vaginal cytology, lowered gonadotrophin levels and urinary calcium loss and gave a satisfactory menstrual pattern. Transdermal oestradiol had no effect on measures of hepatic function whereas oral ethinyl oestradiol significantly altered levels of sex hormone binding globulin, plasma renin substrate and lipoproteins. Transdermal oestradiol has a comparable beneficial effect on postmenopausal symptoms to ethinyl oestradiol without the adverse effects on hepatic proteins.

Administration, Cutaneous↗
PubMed1987

Purification of the surface cAMP receptor in Dictyostelium.

We have previously identified and demonstrated reversible ligand-induced modification of the major cell surface cAMP receptor in Dictyostelium discoideum. The receptor, or a subunit of it, has been purified to homogeneity by hydroxylapatite chromatography followed by two-dimensional preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purification was monitored by following 32Pi incorporated by photoaffinity labeling with 8-azido-[32P]cAMP or by in vivo labeling with 32Pi. Two interconvertible forms of the receptor, designated R (Mr 40,000) and D (Mr 43,000), co-purified. Two-dimensional peptide maps of independently purified and 125I-iodinated R and D forms of the receptor were nearly identical but did have several distinct peptides. The estimated 6000-fold purification required is consistent with the number of cell surface binding sites assuming there are not multiple binding sites/polypeptide. In the accompanying article we report the generation of a monospecific polyclonal antiserum which has helped to further elucidate the physical properties and developmental regulation of the cAMP receptor.

Affinity Labels↗
PubMed1985

Cyproterone acetate as initial treatment and maintenance therapy for hirsutism.

Thirty-four patients with hirsutism were treated for 9 months with 100 mg cyproterone acetate (CA) given on days 5-15 of the menstrual cycle together with a combination oral contraceptive containing 2 mg CA and 50 micrograms ethinyloestradiol (Diane) given on days 5-25 of the cycle. After 9 months treatment patients were randomised to a 12 month double-blind cross-over trial comparing Diane plus 25 mg CA with Diane plus placebo, to test the efficacy of low-dose CA as maintenance therapy. Thirty-one patients (92%) experienced moderate or good subjective improvement in hirsutism on high-dose CA, associated with a 40% mean overall improvement in objective hirsutism grade and 13% overall reduction in hair growth rate measured by a photographic technique. Minor or moderate side effects were experienced by 64% of patients and severe side effects by 11% at this dosage. There was a mean subjective relapse rate of 33% when patients were changed to low dose CA, and relapse rates were not significantly different between the two regimens with 28% relapsing on 25 mg CA + Diane and 48% on placebo and Diane (P less than 0.05). Despite significant subjective relapse with low-dose treatment there was no significant deterioration in objective hirsutism grade or hair growth rate determined photographically. Levels of plasma testosterone, sex hormone binding globulin, free testosterone (derived) and androstenedione fell significantly on high dose CA and this reduction was maintained during low dose therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1978

Congenital ataxia and tremor with cerebellar hypoplasia in piglets borne by sows treated with Neguvon vet. (metrifonate, trichlorfon) during pregnancy.

In 1976--77 The State Veterinary Serum Laboratory received new-born pigs which had shown nervous disorders immediately after birth. In all the cases the sows had been treated with Nevugon vet. (metrifonate, trichlorfon) during pregnancy. In the majority of the affected litters the morbidity and lethality were 100 per cent. Analysis of the breeding data from some of the herds suggested that the period during which the fetuses are sensitive is rather narrow, i.e., approximately from day 45 to day 63. The disease was reproduced experimentally and it was concluded that oral treatment of pregnant sows with Neguvon vet. about the middle of the gestation period can result in severe nervous disorders in the piglets. Clinically the disease is characterized by ataxia and tremor, and corresponding to that there is a pronounced hypoplasia of the cerebellum and also a reduction in the size of the spinal cord.

Abnormalities, Drug-Induced↗