Prevalence and correlates of vertebral fractures in adults with cystic fibrosis.

INTRODUCTION: Osteoporosis associated with cystic fibrosis (CF) is becoming increasingly important as the life expectancy of patients continues to increase. MATERIALS AND METHODS: We studied 191 adults with CF (18-50 years old; 100 men, 91 women). Total body, lumbar spine, and total proximal femur bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry, and lateral spinal radiographs were taken for assessment of vertebral fractures. A range of anthropometric, clinical and biochemical variables were evaluated as potential correlates. RESULTS: BMD T score values at the lumbar spine lower than -2.5 SD were observed in 27.3% and 11.2% of male and female patients, respectively. These proportions fell to 14% and 9.9% for total hip and 10.4% and 12.1% for total body, in men and women, respectively. Vertebral deformities were identified in 26.7% of the patients with a slightly higher prevalence in males (32%) than in females (21%, P = 0.058). Multiple vertebral deformities were observed in 12% and 7.7% of men and women, respectively. BMD values were significantly related to body weight, FEV1, age of puberty and occasionally to cumulative steroid dose in both genders. BMD values were also significantly related with serum albumin, IgG and cholinesterase. Serum estradiol levels were found below the normal range in 23% of the women and 27% of the men, and was significantly related to femur BMD values in both women and men. Significantly lower serum estradiol and free testosterone levels were observed in men with vertebral fractures. Serum osteocalcin was below the normal range in 36% and urinary deoxypyridinoline above the normal range in 51% of the patients. CONCLUSIONS: This study indicates that osteoporosis is a common complication of CF, being related to disease progression and apparently due to both excess bone resorption and inadequate bone formation. Estradiol deficiency may have a significant role in the pathogenesis in both genders. Vertebral fracture prevalence is high and greater than expected from prevalent BMD values.

The effects of zygomatic complex fracture on masseteric muscle force.

The masseter muscle often has been implicated as a primary cause of postreduction displacement of the fractured zygomatic complex. However, this contention has never been proved. This study compared masseter muscle force in 10 male controls with that in 10 male patients who had sustained unilateral zygomaticomaxillary complex (ZMC) fractures. Calculation of muscle force was based on measured bite force, electromyogram, and radiographic determination of muscle vectors. It was found that the masseter muscle in patients with ZMC fractures developed significantly less force than masseter muscle in controls. Following fracture, the masseter force slowly increased, but at 4 weeks following surgery the majority of patients were still well below control levels. The results of this study cast uncertainty on the role of the masseter muscle in postreduction displacement of the fractured ZMC.

Reproducibility of data from a hand-held digital pulp tester used on teeth and oral soft tissue.

Controlled studies of the reproducibility of data from electronic pulp testing instruments are limited and contain few statistical analyses. The reproducibility of these readings is important if the instrument is to be used for determining differences in sensitivity. Twenty human subjects (16 male) were used in this study. One incisor, one premolar, one molar tooth with small or no restorations, and two gingival soft tissue positions from each upper and lower arch of each subject were stimulated with the Analytic Technology vitality scanner. This procedure was repeated twice with a 5-minute rest between each trial, for a total of three trials. Each subject was then seen again after a period of at least 3 days, at which time the trials were repeated. The collected data were grouped by trial, tooth position, and day. Paired t test analysis of both the absolute difference between any two trials on the same day and the average of the absolute differences between corresponding trials on days 1 and 2 showed no statistically significant differences (p greater than 0.05). Accommodation to the stimulus was evaluated by examining differences in the mean values between the three same-day trials. The Analytic Technology vitality scanner was found to be reproducible both for consecutive same-day trials and for corresponding trials on different days. No same-day trends in meter readings were noted.

Systemic and renal effects of a new angiotensin converting enzyme inhibitor, benazepril, in essential hypertension.

Seventeen essential hypertensive patients with normal renal function were treated with a new non-sulphydryl orally active angiotensin converting enzyme (ACE) inhibitor, benazepril, 10 mg given once or twice daily, according to diastolic blood pressure levels, for 6 weeks. In all patients, changes in blood pressure, systemic and renal hemodynamics, plasma renin activity and urinary aldosterone and albumin excretions were assessed at the end of a 2-week placebo run-in period and at the end of the study. Benazepril monotherapy controlled blood pressure well. No changes in cardiac output, heart rate or stroke volume were observed, while peripheral vascular resistance was significantly decreased (-11%, P less than 0.05). Plasma volume was unaltered. The glomerular filtration rate was stable, but effective renal plasma flow was increased because of the marked reduction in renal vascular resistance (-35%) and, therefore, the filtration fraction was decreased. Urinary albumin excretion remained unchanged. A significant increase in plasma renin activity (P less than 0.001) and a decrease in urinary aldosterone excretion were seen. No side effects were observed during the treatment period. In conclusion, our results suggest that benazepril alone is an effective antihypertensive agent in patients with essential hypertension. The blood pressure lowering effect is due mainly to systemic vasodilation and is observed up to 24 h after administration of the drug. The vasodilation appears to be more consistent in the renal than in the systemic circulation.

Effects of ACE inhibition in normotensive patients with chronic glomerular disease and normal renal function.

A double-blind, placebo-controlled study was carried out to assess the effects of a three-month treatment with a new ACE inhibitor, Benazepril (BNZ), on systemic and renal hemodynamics, and urine protein excretion, in 20 patients with chronic glomerulonephritis, normal blood pressure (130/83 +/- 16/10 mm Hg), and normal renal function (creatine clearance 106 +/- 25 ml/min). Treatments with placebo or BNZ were assigned randomly. A wide range of proteinuria lowering effect was observed in overall population (from 1 to 84%, average 34%). Following the arbitrary level of a 30% reduction, two well-matched subgroups (10 patients for each one) were obtained: "good responders" (average decrease 51%), and "poor responders" (average decrease 17%). The main distinctive feature between the two groups was a higher plasma renin activity level in good than in poor responders. A positive correlation between the fall in proteinuria and blood pressure was found. Although the decrease in blood pressure seems to represent the major factor in determining the reduction in proteinuria, a multiple correlation analysis showed that the most prominent role (71%) was attributable to the combined decrease in blood pressure and filtration fraction, and then also to the efferent arteriole dilatation. Our conclusion is that ACE inhibitors are capable of also reducing proteinuria in patients with renal disease with normal blood pressure, the effect being more pronounced in those exhibiting humoral, systemic and renal hemodynamic patterns, indicating a greater activity of circulating and renal renin angiotensin system.

Renal functional reserve in patients with essential hypertension: effect of inhibition of the renin--angiotensin system.

1. Urinary albumin excretion and the effect of an acute oral protein load (a meat meal) on glomerular filtration rate ('renal functional reserve') were evaluated in 15 essential hypertensive patients with preserved renal function and compared with 12 normal subjects. 2. Seven patients had microalbuminuria (greater than 30 mg/day) that was not correlated with blood pressure values. 3. After an oral protein load, an average increase of 20% in glomerular filtration rate (from 91 +/- 19 to 110 +/- 27 ml min-1 1.73 m-2 was found in the hypertensive patients. This change was not statistically different from that observed in normal controls (from 102 +/- 7 to 124 +/- 9 ml min-1 1.73 m-2). The glomerular response in hypertensive patients was independent of age, duration of hypertension, blood pressure, plasma renin activity, urinary albumin excretion and retinal vascular alterations. 4. All patients were re-evaluated after 6 weeks treatment with a new orally active angiotensin-converting enzyme inhibitor, benazepril. Systolic, diastolic and mean blood pressures were lowered in all the patients, but the drug did not affect the glomerular response to acute protein ingestion or the magnitude of urinary albumin excretion. 5. The findings of a normal 'renal functional reserve' and a lack of change in both urinary albumin excretion and the glomerular response after angiotensin-converting enzyme inhibition cast doubt on the existence of increased intraglomerular pressure in hypertensive patients.

Hysteresis in jaw positioning following lateral stretches.

The purpose of this study was to examine hysteresis of the masticatory system following brief, voluntary lateral positioning of the mandible. Hysteresis was studied in ten healthy subjects, as a function of both time and distance that the mandible was held laterally off the midline. So that the effects of distance of lateral stretch on hysteresis could be studied, subjects positioned their jaws to the left or right of the midline distances of 2, 4, 6, 8, and 10 mm for ten s. So that the effects of time could be studied, the distance of lateral stretch was held a constant 8 mm for durations of two, four, six, 12, 16, and 20 s. Following each voluntary lateral stretch, subjects relaxed the muscles using EMG biofeedback and allowed the mandible to reposition itself passively. Hysteresis was defined as the difference in the mandibular resting position between pre- and post-stretch recordings. Mean hysteresis effects ranged from 0.7 mm to 1.8 mm. Hysteresis effects were found to increase with both distance and time; after eight s, however, no additional effect of time was noted.

Design and construction of a pressure algometer.

A handheld pressure algometer is described for the measurement of pain-pressure thresholds. This instrument has a range of measurement of 0 to 16 N/cm2 and can be modified by changing contact points or springs. Technical specifications, a schematic diagram, application examples, and information concerning construction material availability are provided.