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Biomedical subjects

A M Wilson

Publications and source records attributed to A M Wilson.

At least 109 records · Page 6Linked to original sources
PubMed1998

Effects of intranasal corticosteroids on adrenal, bone, and blood markers of systemic activity in allergic rhinitis.

BACKGROUND: Intranasal corticosteroids are regarded as the first-line treatment for allergic rhinitis, but few studies have directly compared their systemic effects. OBJECTIVE: The purpose of this study was to compare the systemic bioactivity of aqueous formulations of intranasal budesonide, mometasone furoate (MF), and triamcinolone acetonide (TAA) in terms of adrenal, bone, and white blood cell markers. METHODS: Twenty patients with allergic rhinitis, mean age (SE) 35.7 (3.5) years were studied in a single-blind, randomized, 4-way crossover design, with treatments separated by 7-day washout periods, comparing placebo with budesonide 200 micro(g) once daily, MF 200 micro(g) once daily, and TAA 220 micro(g) once daily. After 5 days of treatment at steady-state, serial blood and urine samples were taken for 24 hours. Collective and fractionated measurements (daytime, overnight, and 8 AM) were done on plasma cortisol and urine cortisol/creatinine excretion. Plasma osteocalcin and blood eosinophil counts were measured at 8 AM. RESULTS: There was no significant difference between placebo and the active treatments with any of the markers of adrenal suppression. Mean values (SE) for 24-hour area under the curve plasma cortisol (nmol/L.hr) were placebo, 6312.9 (564.4); budesonide, 5908.8 (496.8); MF, 6374.1 (509.9); and TAA, 6239.2 (552.0). Twenty-four hour urinary cortisol/creatinine ratio (nanomoles per millimoles) showed placebo, 9.2 (0.5); budesonide, 8.5 (0.5); MF, 8.6 (0.4); and TAA, 8.6 (0.4). The diurnal circadian rhythm was unaffected, and there were only occasional patients with abnormally low cortisol values. There was also no suppression in terms of osteocalcin (placebo, 1.27 nmolL; budesonide, 1.22 nmol/L; MF, 1.33 nmol/L; and TAA, 1.24 nmol/L) and blood eosinophil count (placebo, 0.29 x 10(9)/L; budesonide, 0.27 x 10(9)/L; MF, 0.25 x 10(9)/L; and TAA, 0.24 x 10(9)/L). CONCLUSION: Neither budesonide, MF, nor TAA produced significant systemic suppression of adrenal, bone, or white blood cell markers at the doses studied. This reflects the good safety profile of these aqueous intranasal formulations when taken at clinically recommended doses.

Administration, Intranasal↗
PubMed1998

Effects of repeated once daily dosing of three intranasal corticosteroids on basal and dynamic measures of hypothalamic-pituitary-adrenal-axis activity.

BACKGROUND: Intranasal corticosteroids are regarded as the first-line treatment for allergic rhinitis, but few studies have directly compared their systemic effects. OBJECTIVE: We sought to compare the hypothalamic-pituitary-adrenal (HPA)-axis suppression with three intranasal corticosteroids in terms of basal and dynamic adrenocortical activity. METHODS: Sixteen healthy volunteers (mean age, 30.7 years) were studied in a single-blind, randomized, four-way crossover study comparing placebo with 200 microg/day fluticasone propionate (FP), 220 microg/day triamcinolone acetonide (TAA), and 336 microg/day beclomethasone dipropionate (BDP). After 4 days of treatment, an overnight urine collection was taken for cortisol and creatinine excretion starting at 10 PM (14 hours after the fourth dose), and blood was taken for serum cortisol at 8 AM (24 hours after the fourth dose) and after stimulation with adrenocorticotrophic hormone (ACTH) (0.5 microg). RESULTS: For overnight urinary cortisol excretion compared with placebo (20.8 nmol), there was a significant (p < 0.05) degree of suppression with FP (11.8 nmol) but not with TAA (16.0 nmol) or BDP (16.5 nmol). In terms of fold difference (95% CI for difference) from placebo, this amounted to 1.75-fold (1.01 to 3.03) for FP (43% suppression), 1.30-fold (0.75 to 2.25) for TAA (23% suppression), and 1.26-fold (0.73 to 2.18) for BDP (21% suppression). There was also a trend towards suppression of overnight urinary cortisol/creatinine excretion, but this was not statistically significant (placebo, 5.2 nmol/mmol; TAA, 5.0 nmol/mmol; BDP, 4.3 nmol/mmol; and FP, 4.3 nmol/mmol). Values for serum cortisol before and after ACTH stimulation showed no significant suppression. CONCLUSION: Suppression of overnight urinary cortisol occurred with intranasal FP (43%), TAA (23%), and BDP (21%), although this was only statistically significant with FP. None of the drugs were associated with blunting of the response to ACTH stimulation. Further studies are indicated to establish whether the systemic effects of inhaled and intranasal corticosteroids are additive.

Administration, Intranasal↗
PubMed1998

Exercise-related alterations in crimp morphology in the central regions of superficial digital flexor tendons from young thoroughbreds: a controlled study.

Injury to the core of the mid-metacarpal region of the superficial digital flexor tendon in Thoroughbred racehorses is a very frequent but poorly understood condition. It has been suggested that subclinical changes induced by galloping exercise weaken the collagen in this region of the tendon, predisposing it to rupture. The longitudinally arranged collagen fibrils in tendon follow a planar waveform, termed the crimp. Fibril bundles with a smaller crimp angle fail at a lower level of strain than those with a larger crimp angle. This study tested the hypothesis that a specific 18 month exercise programme would result in significant reduction of collagen fibril crimp angle and period length in the core region of the superficial digital flexor tendon of young Thoroughbreds (21 +/- 1 months), compared to the normal change in these parameters with age. Central region crimp angle and length were significantly lower in exercised horses than in control horses (P < 0.05). The crimp angle was significantly lower in this central region than in the peripheral region of the tendon in 4 of the 5 exercised horses, as was the crimp length in 3 of the 4 horses. The crimp angle in the peripheral region was significantly greater in exercised horses than in the controls (P < 0.05), which may indicate functional adaptation due to differing mechanical environment between the 2 tendon regions. The results of this study supported previous evidence that galloping exercise modifies normal age-related changes in crimp morphology in the core of the superficial digital flexor tendon. Such changes are indicative of microtrauma and would be detrimental to tendon strength.

Aging↗
PubMed1998

The effect of foot imbalance on point of force application in the horse.

Foot imbalance is believed to be a common cause of musculoskeletal injury in the horse; its biomechanical effects are, however, poorly understood. Wedges (angle 3.7 and 5 degrees) were attached to modified shoes to elevate one aspect of both front feet of Thoroughbred-type horses. The point of force application during weightbearing was determined at trot using a forceplate system. A total of 8 horses were studied with a minimum of 4 providing data for each wedge condition. The results demonstrated that application of a standard steel horse shoe to a balanced foot has minimal effect on the point of force trace through stance. Alteration of mediolateral hoof balance resulted in a displacement of point of force application by about 10 mm in the direction of the wedge throughout stance. Elevation of the heels delayed unloading of the heels and elevation of the toe advanced unloading. Reassessment 24 h after shoeing showed minimal change in the point of force trace. This work demonstrates that a horse is unable to compensate for an acute foot imbalance by redistributing the load under the foot. The higher loads in the elevated region are likely to have a detrimental effect on the hoof structure and horn growth in that part of the hoof.

Animals↗
PubMed1998

Effects of low and high doses of inhaled flunisolide and triamcinolone acetonide on basal and dynamic measures of adrenocortical activity in healthy volunteers.

The objective of this study was to evaluate the effects of inhaled flunisolide (FN) and triamcinolone acetonide (TAA) on basal and dynamic adrenocortical activity. A randomized cross-over design was used, comparing placebo (PL), low (L) and high (H) doses of FN (Aerobid; 250 microg/actuation; without spacer; L, 1000 microg; H, 2000 microg/day), and TAA (Azmacort; 100 microg/actuation; with integrated actuator/spacer; L, 800 microg; H, 1600 microg/day). Each dose was given at 0800 and 2200 h for 3 days, and treatments were separated by a 10-day washout. Twelve normal volunteers (mean +/- SE age, 24.2 +/- 2.4 yr) were studied. After 3 days of treatment, blood samples were taken before ACTH stimulation at 0800 h (10 h after the sixth dose) and after ACTH (0.5 microg) stimulation for determination of serum cortisol. Overnight (starting at 2200 h on the third day of treatment) and early morning urine collections were taken for measurements of urinary cortisol corrected for creatinine excretion. For serum cortisol (pre- and post-ACTH stimulation), there was no significant difference compared with placebo for either drug. Post-ACTH cortisol (nanomoles per L) values were: PL, 666.3; H FN, 617.0; H TAA, 591.4; L FN, 699.2; and L TAA, 686.0. For overnight corrected urinary cortisol/creatinine excretion (nanomoles per mmol) compared with PL (6.4), there was a significant suppression (P < 0.05) at the high dose of both drugs (H FN, 2.6; H TAA, 2.3) but not at the low dose (L FN, 4.2; L TAA, 4.5). Likewise, values for early morning corrected urinary cortisol/creatinine (nanomoles per mmol) showed significant suppression (P < 0.05) only with high doses of both drugs (PL, 39.0; H FN, 26.5; H TAA, 26.6; L FN, 37.2; L TAA, 36.5). The following conclusions were reached. 1) Overnight and early morning corrected urinary cortisol/creatinine excretion was more sensitive at detecting adrenocortical suppression than basal 0800 h serum cortisol or response to 0.5 microg ACTH stimulation. 2) There were no significant differences between inhaled FN (without spacer) and TAA (with integrated actuator/spacer), which only produced detectable adrenocortical suppression at the highest recommended doses and was not associated with impaired adrenal reserve. 3) Even at the high dose, the suppression observed with both drugs is unlikely to be of clinical relevance.

Administration, Inhalation↗
PubMed1998

Systemic bioactivity profiles of oral prednisolone and nebulized budesonide in adult asthmatics.

STUDY OBJECTIVE: Because nebulized budesonide may be used as an alternative to maintenance oral prednisolone in the treatment of severe chronic asthma, it is important to compare these two drugs to determine their relative systemic bioactivity profiles in terms of effects on adrenal, bone, and hematologic markers. DESIGN: Twelve asthmatic patients (mean age; 34.7 years; mean FEV1; 88.3% predicted; mean forced expiratory flow between 25% and 75% of FVC, 54.8% predicted) were studied in a double-blind, double-dummy, randomized crossover design to compare placebo, low, medium, and high doses of nebulized budesonide given bid (1, 2, and 4 mg/d, respectively), and oral prednisolone given qd (5, 10, and 20 mg/d). All treatments and both placebos were given for 4 days at each dose level with a 7-day washout period between each treatment block with budesonide or prednisolone. All measurements were made at 8 AM after the last dose of each dose increment for plasma cortisol, serum osteocalcin, and blood eosinophil count. RESULTS: Regression analysis showed significant dose-related suppression with prednisolone for 8 AM plasma cortisol (p<0.0001), osteocalcin (p<0.05), and blood eosinophil count (p<0.0005), but not with budesonide. Compared with placebo, there were significant differences only with prednisolone, at the medium- and high-dose levels for all three markers. CONCLUSIONS: For all three systemic bioactivity markers (8 AM plasma cortisol, serum osteocalcin, and blood eosinophils), there was significant dose-related suppression with prednisolone but not with budesonide. Further long-term studies are required in more severe asthmatics in order to evaluate the therapeutic index.

Administration, Inhalation↗
PubMed1998

Effects of training on collagen fibril populations in the suspensory ligament and deep digital flexor tendon of young thoroughbreds.

OBJECTIVE: To determine the effect of a specific galloping exercise regimen on collagen fibril mass-average diameters (MAD) in the deep digital flexor tendon (DDFT) and suspensory ligament (SL) of young Thoroughbreds. ANIMALS: 12 Thoroughbred fillies, 21 +/- 1 (mean +/- SD) months old. PROCEDURE: 6 horses underwent a specific 18-month treadmill training program involving galloping exercise. The remaining 6 horses served as controls, undertaking low-volume walking exercise over the same period. Sections were excised from the midpoint of the DDFT and SL, and small strips were dissected from central and peripheral locations for each structure. Fibril diameters were measured from micrographs of transverse ultrathin sections, using a computerized image analysis program. An MAD value was calculated for the central and peripheral regions of the DDFT and SL for each horse. Values for both regions were compared between exercised and control horses. RESULTS: The MAD did not change significantly with exercise for either the DDFT or the SL. CONCLUSION: Loading of the DDFT as a result of this exercise regimen was not sufficient to stimulate collagen fibril hypertrophy, in keeping with current data that indicate this tendon, compared with the SL and superficial digital flexor tendon (SDFT), is subjected to low loads. Microtrauma, in terms of reduction in fibril MAD, may have occurred in the SL at a site different from that sampled. Another possibility is that, between the trot and the gallop, loading of the SL does not increase to the same extent as that of the SDFT.

Animals↗
PubMed1998

Inhaled corticosteroid therapy reduces the early morning peak in cortisol and aldosterone.

1. As mineralocorticoid and adrenocorticoid activity are both under the diurnal control of adrenocorticotropic hormone secretion, we aimed to evaluate whether the normal circadian rhythm of cortisol and aldosterone secretion was suppressed by inhaled corticosteroid therapy.2.Ten normotensive patients with mild-moderate asthma, mean age 24.0 (S.D. 9.8) years and mean arterial pressure 90.7 (9.8) mmHg, were studied in a double-blind, randomized crossover design comparing placebo with fluticasone propionate, 1000 microgram administered twice daily at 08:00 h and 20:00 h. After 5 days of repeated dosing at steady state, measurements were made of plasma cortisol and aldosterone at midnight and 08:00 h.3. With placebo there was a significant (P<0.05) difference between cortisol values at 08:00 h (588.6+/-83.8 nmol/l) and midnight (109.6+/-35.0 nmol/l), whereas after treatment with fluticasone propionate there was no significant difference between levels at 08:00 h (143.3+/-57.4 nmol/l) and midnight (64.3+/-22.3 nmol/l). For cortisol at 08:00 h there was also a significant (P<0.05) difference between placebo and fluticasone propionate. The same pattern was observed for aldosterone. Plasma aldosterone levels at 08:00 h after treatment with placebo (129.6+/-30.9 nmol/l) were significantly different (P<0. 05) to those seen at midnight (40.4+/-6.2 nmol/l). After treatment with fluticasone propionate, there was no significant difference between levels at midnight (55.4+/-11.7 nmol/l) and 08:00 h (64. 8+/-12.7 nmol/l).4. These results show that inhaled corticosteroid therapy abolishes the circadian rhythm of aldosterone and cortisol secretion. This may have possible implications for patients taking inhaled corticosteroids in terms of the beneficial cardiac effects of suppressing early morning aldosterone.

Administration, Inhalation↗
PubMed1997

Adrenal suppression with high doses of inhaled fluticasone propionate and triamcinolone acetonide in healthy volunteers.

STUDY OBJECTIVE: This study was conducted to compare the adrenal suppression of inhaled fluticasone propionate and triamcinolone acetonide in healthy volunteers, both given via their respective pressurised metered dose inhaler (pMDI) devices at high doses within the manufacturers recommended dose range. DESIGN: We used a single (investigator) blind, randomised, crossover design comparing a total daily dose of 1.625 mg fluticasone propionate delivered via a pMDI, 1.60 mg daily of triamcinolone acetonide delivered via a pMDI with integrated spacer, or placebo pMDI; each drug was given in two divided doses at 0800 hours and 2200 hours over a 24-h period. Each drug treatment was separated by a 1-week washout. PATIENTS: Twelve normal subjects mean age 27.5 years were studied. MEASUREMENTS: Blood samples were taken for 0800 hours plasma cortisol, i.e. 10 h following the second dose. Ten hour urine collections (2200 hours until 0800 hours) were taken for urinary cortisol and creatinine excretion. RESULTS: For the 0800 hours plasma cortisol (geometric mean, nmol.1(-1) compared with placebo (353) fluticasone propionate (138) produced significant (P < 0.05) suppression (2.57-fold difference), whereas triamcinolone acetonide (263) did not (1.34-fold difference). Fluticasone propionate produced a 1.91-fold greater adrenal suppression than triamcinolone acetonide (95% CI 1.10 to 3.33). Individual subjects with abnormally low 0800 hours cortisol values < 150 nmol.1(-1) (< 5.4 micrograms/dl) were n = 4 for fluticasone propionate and n = 0 for triamcinolone acetonide. Overnight urinary cortisol/creatinine ratio (geometric mean, nmol/mmol) did not show any difference between fluticasone propionate (1.48) and triamcinolone acetonide (1.60), with both producing significant suppression versus placebo (4.01): triamcinolone acetonide 2.50-fold difference (95% CI 1.45-4.24); fluticasone propionate 2.71-fold difference (95% CI 1.57-4.69). CONCLUSION: Fluticasone propionate 1.625 mg/day (pMDI) produced an approximately two-fold greater adrenal suppression of 0800 hours plasma cortisol than triamcinolone acetonide 1.60 mg per day (Oral Inhaler) when given twice daily, and one third of subjects with fluticasone had abnormally low 0800 hours cortisol values < 150 nmol.1(-1) (< 5.4 micrograms.dl-1. There were no differences between the drugs for urinary cortisol excretion. Further dose-ranging studies are required at steady-state in asthmatic subjects in order to see whether differences occur at lower doses on the steep part of the dose-response curve for both plasma and urinary cortisol suppression.

Administration, Inhalation↗
PubMed1997

The effect of burn blister fluid on fibroblast contraction.

Burns of the hand seem to be followed by more stiffness and contractures than other injuries. This study was aimed at examining whether burn exudate contributes to this difference. Five cell strains of human dermal fibroblasts were each treated with three samples of burn blister fluid and the effect compared with the rate of contraction of free floating fibroblast populated collagen lattices (FPCL). In addition, the response of fibroblasts from the dermis, fascia and peritendinous sheath of the hand to burn fluid were compared both in FPCLs and by the tensile forces they generated in the culture force monitor. Results of this study consistently show that the addition of burn fluid to culture medium stimulates fibroblasts to contract to a greater degree in the first 24-48 h. It is proposed that the presence of burn blister fluid provides materials which promote contraction. This in turn may contribute to the postburn stiffness seen clinically.

Adolescent↗
PubMed1997

Mental models, metaphors and their use in the education of nurses.

A great deal of nurses' confidence in the use of information technology (IT) depends both on the way computers are introduced to students in the college and how such education is continued and applied when they are practitioners. It is therefore vital that teachers of IT assist nurses to discover ways of learning to utilize and apply computers within their workplace with whatever methods are available. One method which has been introduced with success in other fields is the use of mental models and metaphors. Mental models and metaphors enable individuals to learn by building on past learning. Concepts and ideas which have already been internalized from past experience can be transferred and adapted for usage in a new learning situation with computers and technology. This article explores the use of mental models and metaphors for the technological education of nurses. The concepts themselves will be examined, followed by suggestions for possible applications specifically in the field of nursing and health care. Finally the role of the teacher in enabling improved learning as a result of these techniques will be addressed.

Computer-Assisted Instruction↗
PubMed1997

A prospective, randomized trial comparing continuous bladder drainage with catheterization at abdominal hysterectomy.

OBJECTIVE: To compare the infection rate and post-operative morbidity between in-dwelling urinary catheterization and 'in-out' catheterization at the time of routine total abdominal hysterectomy. PATIENTS AND METHODS: The study comprised 100 patients who were blindly randomized to have either an indwelling Foley catheter or an 'in-out' catheterization at the time of surgery. Follow-up data on the retention of urine, urinary symptoms and infection were obtained. RESULTS: Of the 95 patients with complete data, 36% of those undergoing in-out catheterization had urinary retention after operation, requiring bladder emptying, compared with 4% of those receiving an indwelling catheter (P < 0.001). In addition, 29% of the catheterized group had urinary tract bacteriuria compared with 13% of the uncatheterized group (P < 0.025). CONCLUSION: This randomized controlled trial showed that in-out urinary catheterization at the time of routine abdominal hysterectomy was associated with a significantly higher incidence of post-operative urinary retention compared with in-dwelling catheterization, and may have implications for long-term bladder function.

Adult↗
PubMed1997

Modulation of cholestane-3 beta,5 alpha,6 beta-triol toxicity by butylated hydroxytoluene, alpha-tocopherol and beta-carotene in newborn rat kidney cells in vitro.

Cholesterol oxidation products (COP) have been reported to influence vital cellular processes such as cell growth, cell proliferation, membrane function and de novo sterol biosynthesis. The objectives of the present study were: (1) to develop an in vitro model using newborn rat kidney (NRK) cells to investigate the actions of COP; (2) to investigate the effect of COP on cell viability, endogenous antioxidant enzymes activities, i.e. superoxide dismutase (EC 1.15.1.1; SOD) and catalase (EC 1.11.1.6; CAT), and the extent of lipid peroxidation in this model; (3) to determine whether the addition of 100-1000 nM-alpha-tocopherol, beta-carotene or butylated hydroxytoluene (BHT) could protect against COP-induced cytotoxicity. NRK cells were cultured in the presence of various concentrations (5-50 microM) of cholesterol or cholestane-3 beta,5 alpha,6 beta-triol (cholestantriol) for a period of 24 h. Cholesterol over the range 5-50 microM did not induce cytotoxicity as indicated by the neutral-red-uptake assay or the lactate dehydrogenase (EC 1.1.1.27)-release assay. However, cell viability was compromised by the addition of > 10 microM-cholestantriol (P < 0.05). The addition of beta-carotene (100-1000 nM) did not increase cell viability significantly in cholestantriol-supplemented cells. However, the addition of alpha-tocopherol (1000 nM) and BHT (1000 nM) significantly increased percentage cell viability above that of the cholestantriol-supplemented cells but not back to control levels. SOD and CAT activities in NRK cells significantly decreased (P < 0.05) following incubation with cholestantriol. The addition of > 750 nM-alpha-tocopherol, beta-carotene or BHT returned SOD and CAT activities to that of the control. Lipid peroxidation was significantly induced (P < 0.05) in the presence of cholestantriol. Supplementation of the cells with alpha-tocopherol (250, 500 or 1000 nM) or BHT (750 or 1000 nM) resulted in a reduction in the extent of lipid peroxidation (P < 0.05). The addition of beta-carotene over the concentration range of 250-1000 nM did not reduce lipid peroxidation significantly compared with cells exposed to cholestantriol alone. These findings suggest that addition of exogenous antioxidants may be beneficial in the prevention of COP-induced toxicity in vitro.

Animals↗
PubMed1997

Comparison of collagen fibril populations in the superficial digital flexor tendons of exercised and nonexercised thoroughbreds.

This study was undertaken to test the hypothesis that collagen fibrils, the submicroscopic units of strength in tendon, would hypertrophy in response to a specific defined training programme. Fibril diameters were measured in central and peripheral regions of superficial digital flexor tendon (SDFT) samples from five 18-month-old horses which underwent a subsequent 18 month training programme and 6 age- and sex-matched controls. Central region fibrils from the trained horses had a mass-average diameter (MAD) of 105.3 nm, which was significantly lower (P < 0.01) than that of 131.7 nm for the same region in the control horses. This reduction in fibril diameter in the region of tendon which is predisposed to injury was interpreted as evidence of microtrauma, as it implies the region is weakened by the training regimen. Repeated episodes of microtrauma may accumulate and eventually result in degenerative lesions and clinical tendonitis.

Aging↗
PubMed1997

Dose-response effect for adrenal suppression with repeated twice daily inhaled fluticasone propionate and triamcinolone acetonide in adult asthmatics.

A single blind randomized crossover trial was performed comparing placebo (PL); low (L), medium (M) and high (H) doses of fluticasone propionate (FP) L: 330 microg, M: 770 microg, H: 1,540 microg per day and triamcinolone acetonide (TAA) L: 400 microg, M: 800 microg, H: 1,600 microg per day. Each drug was given twice daily over a total of 9 d, with 3 d for each dose level. Each 9-d drug sequence was preceded by a 3-d placebo, and was separated by a 12-d washout period. Twelve mild-to-moderate, stable adult asthmatics, mean (SEM) age, 34.3 (2.9) yr, mean FEV1: 82.1 (2.0) % predicted, and FEF25-75%: 53.6 (5.5) % predicted, receiving up to 400 microg of inhaled corticosteroid per day, were studied. After each 3-d treatment period, blood samples were taken for 8:00 A.M. serum cortisol. Ten-hour overnight urine collections were taken for measurement of urinary cortisol and corrected for creatinine excretion, starting at 10:00 P.M. following the sixth dose. For 8:00 A.M. serum cortisol compared with PL there was significant (p < 0.001) dose-related suppression with FP but not with TAA, which amounted to a 2.03-fold ratio for H FP versus H TAA. For corrected urinary cortisol/creatinine excretion, there was a significant (p < 0.005) dose-related suppression for FP but not for TAA. This amounted to a 1.9-fold ratio for H FP versus H TAA. For doses < 1,000 microg/d, the number of individual results with an abnormal low urinary cortisol value (< 10 nmol/10 h) were: 10/24 for FP versus 3/24 for TAA (p < 0.005). In conclusion, for 8:00 A.M. serum cortisol and overnight corrected urinary cortisol/creatinine excretion, there was significant dose-related suppression with FP but not with TAA. For both of these parameters at the highest dose of both drugs, this amounted to a two-fold ratio in suppression.

Administration, Inhalation↗
PubMed1997

The effect of exercise-induced localised hyperthermia on tendon cell survival.

Tendons that store energy during locomotion, such as the equine superficial digital flexor tendon (SDFT) and human Achilles tendon, suffer a high incidence of central core degeneration which is thought to precede tendon rupture. Although energy storage contributes to the efficiency of locomotion, tendons are not perfectly elastic and some energy is lost in the form of heat. Recent studies have shown that the central core of equine SDFT reaches temperatures as high as 45 degrees C during high-speed locomotion. In this study, we test the hypothesis that hyperthermia causes tendon cell death and results in tendon central core degeneration. Tendon fibroblasts cultured from the core of the equine SDFT were subjected to a temperature of 45 degrees C in an in vitro system for 0-180 min, and cell survival fraction was measured and compared with that for equine dermal fibroblasts and a commercial rat kidney fibroblast cell line (NRK 49F). Tendon fibroblasts were significantly more resistant to hyperthermia than NRK 49F cells after 30, 45 and 60 min of heating and significantly more resistant than dermal fibroblasts after 45 and 60 min of heating. After 10 min of heating at 45 degrees C, the tendon fibroblast cell survival fraction was 91 +/- 4%, whereas heating for 10 min at 48 degrees C resulted in a drop in the cell survival fraction to 22 +/- 4%. In conclusion, while temperatures experienced in the central core of the SDFT in vivo are unlikely to result in tendon cell death, repeated hyperthermic insults may compromise cell metabolism of matrix components, resulting in tendon central core degeneration.

Animals↗