Increase in urinary leukotriene LTE4 levels in acute asthma: correlation with airflow limitation.

BACKGROUND: Leukotrienes play a key role in the pathophysiology of chronic asthma. Activation of leukotriene pathways is accompanied by rises in detectable urinary levels of leukotriene E4 (LTE4). The relationship between urinary LTE4 levels and factors associated with acute asthma has not been determined. METHODS: Adults aged 15-54 years presenting with moderate to severe acute asthma were evaluated at emergency departments in 16 US sites. Forced expiratory volume in 1 second (FEV1) was measured during the first 60 minutes after arrival and at specified times until discharge or admission. Urine samples for measurement of LTE4 levels were obtained either on arrival at the study site and/or before discharge. Patients were seen 2 weeks later for follow up, at which time repeat FEV1 measurements and urine samples for LTE4 were obtained. RESULTS: One hundred and eighty four patients were evaluated; LTE4 results from both the acute and follow up periods were available for analysis in 146. Urinary LTE4 levels were increased during asthma exacerbations compared with levels obtained 2 weeks later (geometric means 111.7 and 75.6 pg/mg creatinine, respectively, mean percentage change -32.3; 95% confidence interval (CI) for the mean percentage change -39.6 to -24.3, p<0.001). The correlation between improvement in FEV1 and decline in LTE4 over the 2 week interval was significant (p<0.001, r=0.43). CONCLUSIONS: Activation of leukotriene pathways in acute asthma is correlated with the degree of airflow obstruction, and resolution of the asthma exacerbation is associated with a reduction in leukotriene levels.

Incidence of nonvertebral fractures in relation to time on treatment and bone density in glucocorticoid-treated patients: a retrospective approach.

The effects of duration of treatment and bone mineral density (BMD) on nonvertebral fracture in 560 glucocorticoid users were examined by using baseline and retrospective data from 2 parallel studies assessing the efficacy and safety of alendronate therapy. Baseline spine and hip BMD were significantly (P < 0.01) lower with increased time spent receiving glucocorticoids. Forty-three patients (7.7%) had experienced at least 1 nonvertebral fracture after starting glucocorticoid treatment. The hazard function for nonvertebral fracture occurrence increased significantly (P < 0.01) with time spent receiving glucocorticoids: fracture incidence per 1,000 person-years on glucocorticoids was 18 (< 5 years), 31 (5-10 years), and 35 (> 10 years). Patients with a history of nonvertebral fractures after starting glucocorticoid treatment had significantly lower lumbar spine (P < 0.01) and hip (< 0.01) BMD value than those without fractures. This retrospective analysis suggests that a BMD measurement of spine and hip may identify risk for nonvertebral fractures in a heterogeneous population of glucocorticoid users.

Comparison of rofecoxib, celecoxib, and naproxen on renal function in elderly subjects receiving a normal-salt diet.

BACKGROUND: This study compared directly the renal effects of two selective cyclooxygenase (COX)-2 inhibitors (rofecoxib and celecoxib) with naproxen (dual COX-1/COX-2 inhibitor) and placebo in healthy elderly subjects on a sodium-replete diet. METHODS: A total of 67 elderly subjects stabilized in the clinic for weight and urinary sodium on a controlled 200-mEq sodium diet were randomized in a double-blind fashion to receive rofecoxib, 25 mg daily (n = 17); celecoxib, 200 mg twice daily (n = 17); naproxen, 500 mg twice daily (n = 17); or matching placebo (n = 16) for 28 days. Subjects were sequestered in the clinic for the first 14 treatment days on the controlled diet. RESULTS: Daily urinary sodium excretion during the first 72 hours of treatment (primary endpoint) significantly decreased in rofecoxib, celecoxib, and naproxen groups compared with baseline (P < or =.05). Rofecoxib and celecoxib decreases in urinary sodium excretion rates that were comparable with each other, on the basis of predefined boundaries (-39.5 versus -27.1 mEq/d, respectively) and to naproxen (-40.6, mEq/d). Rofecoxib, celecoxib, and naproxen increased mean systolic blood pressure to a similar degree (3.4, 4.3, and 3.1 mm Hg, respectively, versus -1.3 mm Hg for placebo) after 14 days of treatment; small changes also occurred in diastolic blood pressure (0.3, 0.8, and -0.4 mm Hg, respectively, versus -1.4 mm Hg for placebo). Changes from baseline in creatinine clearance, body weight, and urinary potassium excretion among active treatments were similar. After 28 days of treatment, findings were generally consistent with those at 14 days. No subject reported edema or discontinued treatment as the result of an adverse experience. CONCLUSION: In healthy elderly subjects on a sodium-replete diet, the COX-2 inhibitors rofecoxib and celecoxib did not differ from a nonselective nonsteroidal anti-inflammatory drug (naproxen), in influencing renal function as measured by urinary sodium excretion, systolic and diastolic blood pressure, creatinine clearance, or weight change.

Montelukast for treating seasonal allergic rhinitis: a randomized, double-blind, placebo-controlled trial performed in the spring.

BACKGROUND: Cysteinyl leukotrienes are important proinflammatory mediators believed to have a role in allergic rhinitis. OBJECTIVE: This multicentre, randomized, double-blind, placebo- and active-controlled trial evaluated the effectiveness and tolerability of montelukast, a cysteinyl leukotriene receptor antagonist, for treating patients with seasonal allergic rhinitis. METHODS: After a 3- to 5-day, single-blind placebo run-in period, 1302 male and female patients (aged 15-81 years) with active allergic rhinitis symptoms were randomly assigned to receive montelukast 10 mg (n = 348), loratadine 10 mg (n = 602), or placebo (n = 352) administered once daily at bedtime for 2 weeks during the spring allergy season. RESULTS: Mean patient characteristics and symptom scores at baseline were similar for the three treatment groups. The primary end-point, daytime nasal symptoms score (mean of nasal congestion, rhinorrhea, nasal pruritus, and sneezing scores; 0-3 scale), improved from baseline during treatment by (least squares mean, 95% confidence interval) - 0.37 (- 0.43, - 0.31), - 0.47 (- 0.52, - 0.43), and - 0.24 (- 0.29, - 0.18) in the montelukast, loratadine, and placebo groups, respectively (P < or = 0.001 comparing each active treatment with placebo). Mean changes from baseline in all other diary-based scores, including night-time and eye symptom scores, were significantly greater for each active treatment than for placebo. The rhinoconjunctivitis quality of life overall score improved significantly with montelukast and with loratadine as compared with placebo. Montelukast and loratadine showed a safety profile comparable to that of placebo. CONCLUSION: Montelukast is well tolerated and provides improvements in daytime and night-time symptoms, as well as quality of life parameters, for patients with seasonal allergic rhinitis.

Two-year effects of alendronate on bone mineral density and vertebral fracture in patients receiving glucocorticoids: a randomized, double-blind, placebo-controlled extension trial.

OBJECTIVE: To evaluate the continued efficacy and safety of alendronate (ALN) for up to 2 years in patients receiving glucocorticoids. METHODS: This is a 12-month extension of a previously completed 1-year trial of daily ALN, performed to evaluate the effects of ALN over a total of 2 years in 66 men and 142 women continuing to receive at least 7.5 mg of prednisone or equivalent daily. All patients received supplemental calcium and vitamin D. The primary end point was the mean percentage change in lumbar spine bone mineral density (BMD) from baseline to 24 months. Other outcomes included changes in hip and total body BMD, biochemical markers of bone turnover, radiographic joint damage of the hands, and vertebral fracture incidence. RESULTS: The mean (+/-SEM) lumbar spine BMD increased by 2.8 +/- 0.6%, 3.9 +/- 0.7%, and 3.7 +/- 0.6%, respectively, in the groups that received 5 mg, 10 mg, and 2.5/10 mg of ALN daily (P < or = 0.001) and decreased by -0.8 +/- 0.6% in the placebo group (P not significant) over 24 months. In patients receiving any dose of ALN, BMD was increased at the trochanter (P < or = 0.05) and maintained at the femoral neck. Total body BMD was increased in patients receiving 5 or 10 mg ALN (P < or = 0.01). These 2 dose levels of ALN were more effective than placebo at all sites (P < or = 0.05). Bone turnover markers (N-telopeptides of type I collagen and bone-specific alkaline phosphatase) decreased 60% and 25%, respectively, during treatment with ALN (P < or = 0.05). There were fewer patients with new vertebral fractures in the ALN group versus the placebo group (0.7% versus 6.8%; P = 0.026). The safety profile was similar between treatment groups. CONCLUSION: Alendronate is an effective, well-tolerated therapy for the prevention and treatment of glucocorticoid-induced osteoporosis, with sustained treatment advantages for up to 2 years.

Prostate volume and serum prostate-specific antigen as predictors of acute urinary retention. Combined experience from three large multinational placebo-controlled trials.

OBJECTIVES: We evaluated prostate volume and prostate-specific antigen (PSA) as predictors of acute urinary retention (AUR) in men with benign prostatic enlargement (BPE). METHODS: Data were pooled from 3 identical 2-year, multinational, multicenter, non-US, placebo-controlled finasteride trials in 4,222 men with BPE and no evidence of prostate cancer. RESULTS: The 2-year incidence of spontaneous AUR was higher in placebo patients with enlarged prostates (4.2% in men with prostate volume > or =40 ml vs. 1.6% in the <40 ml group) and higher PSA levels (3.9% in men with PSA > or =1.4 ng/ml vs. 0.5% in the <1.4 ng/ml group) at baseline. Finasteride reduced AUR incidence by 61% in men with larger prostates, by 63% in men with higher PSA levels, and by 47% in men with smaller prostates, compared with placebo. CONCLUSIONS: BPE patients with larger prostate volumes, higher PSA levels and no evidence of prostate cancer have an increased risk of developing AUR and therefore derive the greatest benefit from the risk reduction seen with finasteride therapy.

Effects of alendronate on bone quality and remodeling in glucocorticoid-induced osteoporosis: a histomorphometric analysis of transiliac biopsies.

Effects of alendronate (ALN) on bone quality and turnover were assessed in 88 patients (52 women and 36 men aged 22-75 years) who received long-term oral glucocorticoid exposure. Patients were randomized to receive oral placebo or alendronate 2.5, 5, or 10 mg/day for 1 year and stratified according to the duration of their prior glucocorticoid treatment. Transiliac bone biopsies were obtained for qualitative and quantitative analysis after tetracycline double-labeling at the end of 1 year of treatment. As previously reported in glucocorticoid-induced osteoporosis, low cancellous bone volume and wall thickness were noted in the placebo group as compared with normal values. Alendronate treatment was not associated with any qualitative abnormalities. Quantitative comparisons among the four treatment groups were performed after adjustment for age, gender, and steroid exposure. Alendronate did not impair mineralization at any dose as assessed by mineralization rate. Osteoid thickness (O.Th) and volume (OV/BV) were significantly lower in alendronate-treated patients, irrespective of the dose (P = 0.0003 and 0.01, respectively, for O.Th and OV/BV); however, mineral apposition rate was not altered. As anticipated, significant decreases of mineralizing surfaces (76% pooled alendronate group; P = 0.006), activation frequency (-72%; P = 0.004), and bone formation rate (-71%; P = 0.005) were also noted with alendronate treatment. No significant difference was noted between the changes observed with each dose. Absence of tetracycline label in trabecular bone was noted in approximately 4% of biopsies in placebo and alendronate-treated groups. Trabecular bone volume, parameters of microarchitecture, and resorption did not differ significantly between groups. In conclusion, alendronate treatment in patients on glucocorticoids decreased the rate of bone turnover, but did not completely suppress bone remodeling and maintained normal mineralization at all alendronate doses studied. Alendronate treatment did not influence the osteoblastic activity, which is already low in glucocorticoid-induced osteoporosis.

Continued improvement in pressure-flow parameters in men receiving finasteride for 2 years. Finasteride Urodynamics Study Group.

OBJECTIVES: To assess the long-term effects of finasteride on pressure-flow parameters in men with urodynamically documented bladder outflow obstruction (BOO). METHODS: One hundred twenty-one men with benign prostatic enlargement (BPE) and lower urinary tract symptoms (LUTS) underwent a pressure-flow study (PFS) at 1 of 11 clinical centers. The PFS technique was standardized, and all tracings were read by a single reader unaware of the treatment group. Patients who were obstructed according to a modified Abrams-Griffiths nomogram were randomized to 5 mg finasteride (n = 81) or placebo (n = 40) for 12 months; all patients continuing into an open extension received finasteride during the second 12 months of therapy. Results of the initial 12-month study demonstrated the benefit of finasteride treatment on PFS parameters. To examine the continuing effects over time, an analysis of the data from 54 patients who completed 24 months of treatment with finasteride is provided. RESULTS: Detrusor pressure at maximum flow (PdetQmax) continued to decrease during the second 12 months of therapy (decreases of 5.3 and 11.7 cm H2O at months 12 and 24, respectively). The percentage of patients obstructed by Abrams-Griffiths classification decreased from 76.2% at baseline to 66.7% at month 12 and 59.6% at month 24. An intention-to-treat analysis yielded similar results. CONCLUSIONS: Finasteride improves urodynamic measures of obstruction in men with BPE and LUTS, with continued improvement during the second 12 months of therapy.

Improvement of pressure flow parameters with finasteride is greater in men with large prostates. Finasteride Urodynamics Study Group.

PURPOSE: We assess the effect of finasteride, a 5alpha-reductase inhibitor, on objective voiding parameters in men with lower urinary tract symptoms and benign prostatic enlargement on digital rectal examination (known as clinical benign prostatic enlargement) in a double-blind placebo controlled multicenter study using strict standard pressure flow study techniques. MATERIALS AND METHODS: A modification of the Abrams-Griffiths nomogram was used by 1 reader to ensure that all patients met objective criteria for bladder outlet obstruction at baseline. After performing a pressure flow study patients with obstruction were randomized 2:1 to receive 5 mg. finasteride (81) or placebo (40) daily. A second pressure flow study was performed at month 12. At baseline and month 12 free urinary flow studies and transrectal ultrasound were performed, and International Prostate Symptom Score questionnaires were completed. Patients were treated between May 1994 and July 1996. RESULTS: Finasteride caused a significant decrease (-8.1 cm. water) in detrusor pressure at maximum flow (p <0.05 versus placebo p = 0.02), increase (+1.1 ml. per second) in maximum flow rate (p <0.05 versus placebo p = 0.02) and decrease (-22.8%) in prostate volume (p <0.05 versus placebo p <0.001). Men with prostates larger than 40 cc had greater improvement in detrusor pressure at maximum flow (between group difference -14.5 cm. water, 95% confidence interval -26.2 to -2.6, p = 0.02) and maximum flow rate (mean treatment effect +1.6 ml. per second, 95% confidence interval -0.2 to 3.0, p = 0.02) compared to those with prostates 40 cc or less (between group differences not significant). CONCLUSIONS: Finasteride treatment resulted in improvements in urodynamic parameters, which were greater in men with large prostates.

Repeated pressure-flow studies in the evaluation of bladder outlet obstruction due to benign prostatic enlargement. Finasteride Urodynamics Study Group.

Test-retest reliability of repeated voids in pressure-flow studies and the influence on maximum flow rate (Q(max)pQ), detrusor pressure at maximum flow rate (p(det)Qmax), voided volume, and residual urine were studied. Also the agreement in interpretation of pressure-flow tracings between investigators and a single blinded central reader acting as a quality control center (QCC) were assessed. In addition, correlations between p(det)Qmax and patient age, International Prostate Symptom Score (IPSS), free maximum flow rate (Qmax), and prostate volume were calculated. Using suprapubic pressure recording, 216 men with lower urinary tract symptoms (LUTS) due to benign prostatic enlargement (BPE) were investigated in 11 centers. In each pressure-flow study, three sequential voids were performed, and quality controlled recordings were analyzed for Q(max)pQ and p(det)Qmax by the QCC. Trans rectal ultrasound was used to measure the prostate volume. Mean Q(max)pQ did not change, but p(det)Qmax decreased significantly in the second and third sequential voids. Using the Abrams-Griffiths nomogram definition of obstruction, 125 patients (67%) were classified as obstructed from the first void, but only 111 patients (59%) from the third void. The agreement between the investigator assessment and that of a single blinded reader was good. There was no significant correlation between p(det)Qmax and patient age, IPSS, and Qmax, whereas a modest correlation was found between p(det)Qmax and prostate volume. In summary, there was no significant change in Q(max)pQ, but p(det)Qmax decreased for the three consecutive voids, which can be explained by a decrease in outlet resistance. The agreement between the investigator and QCC interpretations shows the value of a standardized technique, supporting the feasibility of multicenter urodynamic studies. There is a modest, but statistically significant, correlation between detrusor pressure and prostate size, supporting the hypothesis that prostate size is a contributing factor in symptomatic BPH.

Alendronate for the prevention and treatment of glucocorticoid-induced osteoporosis. Glucocorticoid-Induced Osteoporosis Intervention Study Group.

BACKGROUND: Osteoporosis is a common complication of long-term glucocorticoid therapy for which there is no well-proved preventive or restorative treatment. METHODS: We carried out two 48-week, randomized, placebo-controlled studies of two doses of alendronate in 477 men and women, 17 to 83 years of age, who were receiving glucocorticoid therapy. The primary end point was the difference in the mean percent change in lumbar-spine bone density from base line to week 48 between the groups. Secondary outcomes included changes in bone density of the hip, biochemical markers of bone turnover, and the incidence of new vertebral fractures. RESULTS: The mean (+/-SE) bone density of the lumbar spine increased by 2.1+/-0.3 percent and 2.9+/-0.3 percent, respectively, in the groups that received 5 and 10 mg of alendronate per day (P<0.001) and decreased by 0.4+/-0.3 percent in the placebo group. The femoral-neck bone density increased by 1.2+/-0.4 percent and 1.0+/-0.4 percent in the respective alendronate groups (P<0.01) and decreased by 1.2+/-0.4 percent in the placebo group (P<0.01). The bone density of the trochanter and total body also increased significantly in the patients treated with alendronate. There were proportionally fewer new vertebral fractures in the alendronate groups (overall incidence, 2.3 percent) than in the placebo group (3.7 percent) (relative risk, 0.6; 95 percent confidence interval, 0.1 to 4.4). Markers of bone turnover decreased significantly in the alendronate groups (P<0.001). There were no differences in serious adverse effects among the three groups, but there was a small increase in nonserious upper gastrointestinal effects in the group receiving 10 mg of alendronate. CONCLUSIONS: Alendronate increases bone density in patients receiving glucocorticoid therapy.

Comparison of finasteride (Proscar) and Serenoa repens (Permixon) in the inhibition of 5-alpha reductase in healthy male volunteers.

A total of 32 healthy male volunteers (age range 20-30 years) were enrolled in a 1-week open, randomized, placebo-controlled study comparing finasteride (Proscar), a 5 alpha-reductase inhibitor, with Permixon, the plant extract of Serenoa repens. The objective of the study was to evaluate the effect of single and multiple doses of the drugs on the inhibition of 5 alpha-reductase as assessed by serum dihydrotestosterone level determination. Following baseline measurements on day 1, the subjects were randomized to finasteride 5 mg once a day (n = 10), Permixon 80 mg x 2 twice a day (n = 11), or to placebo once a day (n = 11) for 7 days. Serum testosterone and dihydrotestosterone levels, were determined on day 1 (baseline and 12 h) and on days 2 (24 h), 3 (48 h), 4 (72 h), 6 (120 h), and 8 (168 h). After 12 h, a single dose of finasteride 5 mg reduced the serum dihydrotestosterone level by 65% (p < or = 0.01). The decreases ranged from -52 to -60% with multiple doses of finasteride 5 mg once a day (p < or = 0.01). As in the placebo group, there was no effect of Permixon on the serum dihydrotestosterone level. No significant difference was detected between finasteride and Permixon or between finasteride and placebo with respect to serum testosterone, except on days 3 and 6, respectively (p < or = 0.05). However, the corresponding serum testosterone levels remained within the normal ranges. These data confirm the efficacy of finasteride as inhibitor of 5 alpha-reductase.(ABSTRACT TRUNCATED AT 250 WORDS)

On the role of variable incubation periods in simple epidemic models.

The paper formulates a simple stochastic model which can be used to describe the early spread of an epidemic in a large population. Comparison of the behaviour of the epidemic under different assumptions for the distribution of the incubation period are made using the concept of partial ordering between random variables. It is shown that the process describing the infectious contacts between individuals has a major effect on the comparison of the different models. These results have important implications for modelling the AIDS epidemic.