Disease-specific changes in equine ground reaction force data documented by use of principal component analysis

OBJECTIVE

To assess the force plate as a diagnostic aid in equine locomotor abnormalities, particularly for abnormalities such as navicular disease that do not have specific diagnostic criteria.

ANIMALS

17 Thoroughbreds without observable locomotor abnormalities (group A), 6 Thoroughbreds with superficial digital flexor tendon injury (group B), and 8 Thoroughbreds with navicular disease (group C).

PROCEDURE

Using a force plate, ground reaction force patterns were recorded at the trot. Peak limb vertical force and force/time curve parameters were derived from 4 identifiable points at the beginning and end of vertical and craniocaudal horizontal plots. Principal component analysis (PCA) of group-A data was undertaken on beginning and end of stride data, and the first 2 components were represented graphically. The PCA rotation matrices were applied to equivalent data for horses of groups B and C.

RESULTS

Asymmetry of peak vertical force (PVF) could not be differentiated among groups A, B, and C. Values for group-B horses, however, were significantly outside mean group-A values on the PCA plot for beginning of stride phase variables. Group-B data were within the group-A range for end of stride phase variables. Values for group-C horses were significantly outside the group-A range for beginning of stride phase variables and were outside mean group-A values for end of stride phase variables.

CONCLUSIONS

PCA of force/time data provides a sensitive method to evaluate the force/time curve associated with 2 specific injury/disease processes.

CLINICAL RELEVANCE

Horses alter weight-bearing in biomechanically distinct ways, thus creating potential for the force plate to become an important diagnostic and prognostic tool.

Long-term safety and efficacy of zafirlukast in the treatment of asthma: interim results of an open-label extension trial

BACKGROUND

Current guidelines recommend anti-leukotriene agents as alternative treatments for mild persistent asthma; however, information on their long-term safety and efficacy is needed.

OBJECTIVE

To evaluate long-term safety and efficacy of and compliance with oral zafirlukast (Z; 20 mg BID) during the first 39 weeks of ongoing, multicenter, open-label extension (OLE) of a previously reported 13-week, randomized (2:1), double-blind (DB), placebo (P)-controlled trial in mild-to-moderate asthmatic patients treated previously with beta2-agonists alone.

METHODS

Patients (12 to 76 years; FEV1 > or = 55% predicted) elected to enter OLE after completing the DB trial. Safety evaluated by adverse events (AEs), laboratory tests, and physical and electrocardiographic examinations. Efficacy assessed by spirometry measurements [FEV1, FEV1 % predicted, personal-best (post-bronchodilator) FEV1] and treatment failure rates. Compliance was calculated as percentage of treatment dispensed. After a visit at OLE week 3 (week 16), patients had visits every 12 weeks.

RESULTS

A total of 443 patients (nz-->z = 310, np-->z = 133) entered the OLE. Results through the OLE period showed that 80% of patients overall reported AEs. Of patients randomized to Z and P during DB period, 68% and 67%, respectively, reported AEs during quarter I (Q1); percentage of Z-treated patients reporting AEs during the OLE ranged from 66% (Q2) to 44% (Q4). Review by quarters showed occurrence of AEs in Z-treated groups (Q2-4) was similar to that in P group (Q1). Compared with baseline (week 0), modest yet significant improvements (P < or = .02) in all spirometry measurements were noted in Z --> Z and P --> Z groups at OLE week 3, with sustained effects noted during OLE period. Treatment failure rates during OLE ranged from 7.2% (Q2) to 3.3% (Q4). Mean compliance ranged from 98% (OLE week 3) to 95% (OLE week 39).

CONCLUSIONS

Long-term treatment with zafirlukast was safe and well tolerated in asthmatic patients. Sustained efficacy and asthma control and good compliance were observed over extended treatment period. Results demonstrate long-term safety and effectiveness of and compliance with this anti-leukotriene agent.

Dose response with fluticasone propionate on adrenocortical activity and recovery of basal and stimulated responses after stopping treatment

OBJECTIVE

To evaluate the dose-response relationship for adrenocortical activity with fluticasone propionate (FP) and to assess basal and dynamic markers after stopping treatment for 3 days.

PATIENTS AND DESIGN

Fourteen asthmatic patients were recruited: mean age 33.3 years, forced expiratory volume in 1 s (FEV1): 91.3% predicted, forced mid expiratory flow rate (FEF25-75): 58.1% predicted. A single blind study design was used comparing a placebo run-in with sequentially low, medium and high doses of FP and a placebo washout. All active treatments, placebo and washout were each for 3 days. FP was given at steady-state with twice daily divided dosing at 0800 h and 2200 h at doses of 375 micrograms, 875 micrograms, and 1750 micrograms per day.

MEASUREMENTS

A 100 micrograms i.v. bolus hCRF test was performed at 0800 h after the run-in and washout periods. Blood samples were taken for 0800 h serum cortisol and osteocalcin as well as an overnight 10 h urine collection for cortisol/creatinine excretion after the run-in period, each dose of active treatment and washout.

RESULTS

For serum cortisol (pre and post hCRF stimulation) there was no significant difference between placebo and washout values. Mean (SE) cortisol (nmol/1) values pre hCRF were run-in: 644.5 (59.7), washout: 550.3 (42.8) and post hCRF were run-in: 690.9 (42.9), washout: 719.1 (43.8). There was a significant (P < 0.05) difference between run-in vs medium and high doses for 0800 h serum cortisol, overnight urinary cortisol and overnight urinary cortisol/creatinine excretion; and vs high dose for serum osteocalcin. The fold difference (95% CI for difference) between run-in and high dose was: 2.2 (1.5-3.2) for overnight urinary cortisol, 2.5 (1.5-4.1) for overnight urinary cortisol/creatinine, 2.0 (1.1-3.6) for serum cortisol, and 1.2 (1.1-1.3) for serum osteocalcin.

CONCLUSION

Fluticasone propionate exhibited dose related adrenal suppression with treatment. The suppressive effects of fluticasone propionate on adrenocortical activity were greater than those observed on osteocalcin.

Health promoting behaviors of African-American registered nurses

The purposes of this study were: (1) to describe the health promoting behaviors of African-American nurses, (2) to add to the health promotion data base for African-American women, and (3) to pilot test a self-administered questionnaire developed by the investigators for use in a larger study of the health-promoting behaviors of middle class African-American women. The sample consisted of 49 African-American registered nurses recruited from members of a nursing sorority. Selected criteria for the subjects were female, college graduate, and a middle class standard of living. A self-administered questionnaire was used to assess the likelihood of engaging in health-promoting behaviors. Descriptive statistics were used to describe the findings in terms of frequency and percentage distribution. The results indicated that the African-American nurses had high percentages of adherence to the following health-promoting behaviors: minimal alcohol consumption, avoidance of smoking, cholesterol screening, assessment of blood sugar levels, monthly breast self-examination, pap smears, mammogram screening and regular measurement of blood pressure. Lower percentages of adherence were reported for two health-promoting behaviors: diet and exercise. Results of this study support the need for the incorporation of diet and exercise into all health promotion intervention programs for African-American women. Implications include additional research to validate the findings of this study.

24 hour and fractionated profiles of adrenocortical activity in asthmatic patients receiving inhaled and intranasal corticosteroids

BACKGROUND

As both rhinitis and asthma are allergic conditions, they frequently occur together. The objective of this study was to assess the diurnal adrenocortical activity in asthmatics receiving inhaled (inh) and intranasal (n) formulations of two different corticosteroids, fluticasone propionate (FP) and triamcinolone acetonide (TAA), both given at clinically recommended doses.

METHODS

Twelve stable moderately severe asthmatic subjects of mean age 23.9 years and mean forced expiratory volume in one second (FEV1) 84% predicted were recruited into a randomised placebo (PL) controlled two-way crossover study comparing nPL + inhPL, nPL + inhFP (880 micrograms bid), and nFP (200 micrograms once daily) + inhFP (880 micrograms bid) with nPL + inhPL, nPL + inhTAA (800 micrograms bid) and nTAA (220 micrograms once daily) + inhTAA (800 micrograms bid), each given for five days with a 10 day washout period. Twenty four hour integrated and fractionated (overnight, 08.00 hours, daytime) serum cortisol levels and urinary cortisol/creatinine excretion were measured.

RESULTS

For 24 hour and fractionated serum cortisol levels and corrected urinary cortisol/creatinine excretion there were significant (p < 0.05) differences between all active treatments and placebo. For 24 hour integrated serum cortisol levels the ratio between inhaled TAA and FP was 2.3 fold (95% CI 1.2 to 4.3), and for 24 hour urinary cortisol/creatinine excretion the ratio was two-fold (95% CI 1.2 to 3.4). For 24 hour urinary cortisol excretion, with all active treatments, individual abnormal low values of < 40 nmol (< 14.4 micrograms) occurred in 17/24 with FP compared with 4/24 with TAA (p < 0.0005). The 24 hour serum cortisol profile was flattened by FP but not with TAA. The addition of nasal corticosteroid did not produce further significant suppression of mean cortisol values, although with intranasal FP there were three more abnormal values for 24 hour urinary cortisol excretion than with inhaled FP alone.

CONCLUSIONS

Both inhaled FP and TAA caused significant suppression of adrenocortical activity which was twice as great with FP, the latter being associated with significantly more individual abnormal values and loss of the normal diurnal circadian rhythm. Fractionated serum cortisol levels and urinary cortisol/creatinine excretion were as sensitive as the respective integrated 24 hour measurements. Although the addition of intranasal formulations did not produce further significant suppression of mean values, there were more individual abnormal cortisol values associated with the addition of intranasal FP.

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.

Dose-response comparison of systemic bioactivity with inhaled budesonide and triamcinolone acetonide in asthmatic adults

BACKGROUND

Budesonide (BUD) has recently been licensed for treatment of asthma in the United States, whereas triamcinolone acetonide (TAA) has been used for many years.

OBJECTIVE

We sought to evaluate the dose-response effect of inhaled BUD and TAA in terms of adrenal, bone, and blood markers.

METHODS

Twelve asthmatic subjects (mean age, 32 years; mean FEV1, 91% of predicted value) were studied in a randomized design comparing 3 days of treatment with placebo and low (200 micrograms twice daily), medium (400 micrograms twice daily), and high (800 micrograms twice daily) doses of BUD (Pulmicort Turbuhaler, 100 micrograms) and TAA (Azmacort integrated actuator/spacer, 100 micrograms) with a 7-day period at crossover, when patients received their usual inhaled corticosteroid therapy. Measurements were made at 8 am for serum cortisol, osteocalcin, and blood eosinophils. Measurements were also made for overnight urinary cortisol/creatinine excretion.

RESULTS

For all measurements there were no significant differences between the 2 treatments at any dose level. Ratios between BUD and TAA (95% CI) at the highest dose levels were as follows: 8 am serum cortisol, 1.08-fold (0.63 to 1. 85); urinary cortisol, 1.09-fold (0.63 to 1.86); eosinophils, 0. 98-fold (0.69 to 1.38); and osteocalcin 1.05-fold (0.78 to 1.41). There was no evidence of a significant overall dose-response effect for any parameter of hypothalamo-pituitary-adrenocortical axis activity, with neither drug being significantly different from placebo at any dose. For the 3 dose levels of both drugs, total abnormal low values for 8 am serum cortisol (ie, <5.4 micrograms/dL [<150 nmol/L]) showed 2 of 36 for BUD and 2 of 36 for TAA. There was also no significant overall dose-response effect for eosinophils or osteocalcin, although both drugs were significantly (P <.05) different from placebo at the highest dose: eosinophils (x10(9)/L), placebo: 0.36, TAA: 0.24, and BUD: 0.23; and osteocalcin (nmol/L), placebo: 1.04, TAA: 0.73, and BUD: 0.77.

CONCLUSION

There were no significant differences in the systemic bioactivity profiles, in terms of adrenal, blood, and bone markers, between BUD administered by means of Turbuhaler and TAA administered by means of an integrated actuator/spacer in a dose range of 400 micrograms to 1600 micrograms/day. Both drugs exhibited a significant degree of detectable systemic bioactivity but only at the highest dose of 1600 micrograms/day for effects on eosinophil count and osteocalcin.

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.

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.

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.

Medical-claims databases in the design of a health-outcomes comparison of quetiapine ('Seroquel') and usual-care antipsychotic medication

Treating schizophrenia is expensive. Preventing rehospitalization of patients with schizophrenia provides an attractive opportunity for cost savings, especially for patients with 'revolving-door' or multiple-episode schizophrenia. Reducing the occurrence of extrapyramidal symptoms and other adverse events associated with standard antipsychotic agents may increase compliance and reduce the rate of rehospitalization of patients with schizophrenia. Quetiapine ('Seroquel', ICI 204,636, Zeneca Pharmaceuticals) is a new dibenzothiazepine antipsychotic agent with a low propensity for extrapyramidal symptoms. We describe here a unique methodology to compare quetiapine with usual-care medications in real-world treatment settings. The trial objective is to determine if therapy with this new atypical antipsychotic agent can reduce the rate of rehospitalization and, therefore, treatment costs. Using two secondary medical-claims databases, we defined the minimal threshold for revolving-door status as 1.0 admission per year; this definition allows our trial to focus on the subpopulation of schizophrenic patients with the greatest potential for cost savings by either the new atypical antipsychotic quetiapine or usual-care therapy. We describe here the approach used in our trial.

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.

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.

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.

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.

Adrenocortical activity with repeated administration of one-daily inhaled fluticasone propionate and budesonide in asthmatic adults

OBJECTIVE

The aim of this study was to evaluate the steady-state effects of once-daily inhaled fluticasone propionate (FP) and budesonide (BUD) on adrenocortical activity in asthmatic patients.

METHODS

Ten asthmatic patients with a mean age of 31.2 years, a mean forced expiratory volume in 1 s (FEV1) of 91% predicted and a forced mid-expiratory flow (FEF25-75) of 62.3% predicted were studied in a single-blind randomised crossover design comparing placebo (PL), FP (375 microg per day and 750 microg per day) and BUD (400 microg per day and 800 microg per day) all given once daily for 4 days at each dose via a pressurised metered dose inhaler (pMDI) at 0800 hours. After 4 days of treatment, plasma cortisol was measured at 0800 hours (24 h after the last dose) and a 10-h overnight urine collection was taken, 14 h after the last dose (2200-0800 hours) for analysis of cortisol and creatinine excretion.

RESULTS

Plasma cortisol levels (nmol.l(-1), as geometric mean) at 0800 hours demonstrated a significant difference between the highest doses of FP and BUD (424.1 vs 510.3 nmol.l(-1), respectively) but not between the low doses (506.8 vs 514.9 nmol.l(-1); PL 532.2 nmol.l(-1)). For the highest dose FP (750 microg) this equated to 20% suppression of 0800 hours plasma cortisol. Likewise, for overnight urinary cortisol output (nmol.10 h(-1) as geometric mean), there was a significant difference at the high doses of FP and BUD (25.5 vs 38.2 nmol.10 h(-1)), but not at the low doses 31.3 vs 34.8 nmol.10 h(-1); PL 32.0 nmol.10 h(-1). For the overnight urinary cortisol/creatinine ratio (nmol.mmol(-1), as geometric mean) there was a similar trend; 4.5 vs 6.1 nmol.mmol(-1) for high dose and 5.6 vs 6.3 nmol.mmol(-1) for low dose; PL 5.9 nmol.mmol(-1).

CONCLUSION

Repeated doses of FP 750 microg once daily caused greater adrenal suppression than BUD 800 microg once daily, when comparing effects on plasma cortisol levels at 0800 hours, 24 h after the last dose, as well as effects on overnight urinary cortisol output. Neither FP 375 microg once daily nor BUD 400 microg once daily produced detectable adrenal suppression.

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.

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.

ATP loss with exercise in muscle fibres of the gluteus medius of the thoroughbred horse

Muscle ATP loss with exercise has implications both to the causes of fatigue and muscle damage. To study this at the single muscle fibre level, five trained thoroughbred horses performed consecutive 90 second gallops on an inclined treadmill followed by a final gallop to fatigue. Biopsies of the m. gluteus medius were taken at rest, post-exercise and during 24 hour recovery. Blood lactate was 20.0 mmol litre-1 or more, and plasma NH3 300-800 mumol litre-1, following the final gallop. Minimal changes occurred in the plasma markers, CK and AST. ATP loss with exercise was 32.2 (SD 12.2) per cent. Following exercise single fibre ATP contents showed a much broader distribution than at rest, with contents in some close to zero. Following five and 24 hour recovery, however, frequency distribution curves were close to those seen at rest. There was no difference in the ATP contents of types I, IIa and IIb at rest of with exercise or recovery. The results pointed to marked heterogeneity between individual fibres in their biochemical response with exercise, independent of fibre type.

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.

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.