Acute moderate-intensity exercise induces vasodilation through an increase in nitric oxide bioavailiability in humans

BACKGROUND: Long-term moderate-intensity exercise augments endothelium-dependent vasodilation through an increase in nitric oxide (NO) production. The purpose of this study was to determine the effects of different intensities of acute exercise on hemodynamics in humans. METHODS: We evaluated forearm blood flow (FBF) responses to different intensities of exercise (mild, 25% maximum oxygen consumption [VO2max]; moderate, 50% VO2max; and high, 75% VO2max; bicycle ergometer, for 30 min) in eight healthy young men. The FBF was measured by using a strain-gauge plethysmography. RESULTS: After exercise began, moderate-intensity exercise, but not mild-intensity exercise, promptly increased FBF from 2.8+/-1.1 mL/min/100 mL to a plateau at 5.4+/-1.6 mL/min/100 mL at 5 min (P<.01) and increased mean arterial pressure from 84.7+/-11.8 mm Hg to a plateau at 125.7+/-14.3 mm Hg at 5 min (P<.01). Moderate-intensity exercise decreased forearm vascular resistance (FVR) from 29.2+/-5.4 to 16.8+/-3.2 mm Hg/mL/min/100 mL tissue (P<.01). The administration of NG-monomethyl-L-arginine, an NO synthase inhibitor, abolished moderate exercise-induced augmentation of vasodilation. Although we were not able to measure FBF during high-intensity exercise because of large body motion, high-intensity exercise markedly increased mean arterial pressure from 82.6+/-12.2 to 146.8+/-19.8 mm Hg. High-intensity exercise, but not mild-intensity or moderate-intensity exercise, increased plasma concentration of 8-isoprostane, an index of oxidative stress, from 24.1+/-10.8 to 40.2+/-16.7 pg/mL (P<.05) at 10 min after the end of exercise. CONCLUSIONS: These findings suggest that acute moderate-intensity exercise induces vasodilation through an increase in NO bioavailability in humans and that high-intensity exercise increases oxidative stress.     

Effects of Exercise Training in Patients with Chronic Heart Failure and Sleep Apnea

Study Objectives:

To test the effects of exercise training on sleep and neurovascular control in patients with systolic heart failure with and without sleep disordered breathing.

Design:

Prospective interventional study.

Setting:

Cardiac rehabilitation and exercise physiology unit and sleep laboratory.

Patients:

Twenty-five patients with heart failure, aged 42 to 70 years, and New York Heart Association Functional Class I-III were divided into 1 of 3 groups: obstructive sleep apnea (n = 8), central sleep apnea (n = 9) and no sleep apnea (n = 7).

Interventions:

Four months of no-training (control) followed by 4 months of an exercise training program (three 60-minute, supervised, exercise sessions per week).

Measures and Results:

Sleep (polysomnography), microneurography, forearm blood flow (plethysmography), peak VO_2, and quality of life were evaluated at baseline and at the end of the control and trained periods. No significant changes occurred in the control period. Exercise training reduced muscle sympathetic nerve activity (P < 0.001) and increased forearm blood flow (P < 0.01), peak VO₂(P < 0.01), and quality of life (P < 0.01) in all groups, independent of the presence of sleep apnea. Exercise training improved the apnea-hypopnea index, minimum O₂ saturation, and amount stage 3-4 sleep (P < 0.05) in patients with obstructive sleep apnea but had no significant effects in patients with central sleep apnea.

Conclusions.

The beneficial effects of exercise training on neurovascular function, functional capacity, and quality of life in patients with systolic dysfunction and heart failure occurs independently of sleep disordered breathing. Exercise training lessens the severity of obstructive sleep apnea but does not affect central sleep apnea in patients with heart failure and sleep disordered breathing.

Citation:

Ueno LM; Drager LF; Rodrigues ACT; Rondon MUPB; Braga AMFW; Mathias W; Krieger EM; Barretto ACP; Middlekauff HR; Lorenzi-Filho G; Negrão CE. Effects of exercise training in patients with chronic heart failure and sleep apnea. SLEEP 2009;32(5):637-647.     

Reconstruction of the first web space in symbrachydactyly using the reverse radial forearm flap

PURPOSE: To present a new approach for the reconstruction of severe first web contractures using a distally based reverse radial forearm flap in symbrachydactyly patients. METHODS: This study included 6 hands in 5 patients. Subjective evaluation included appearance, parent satisfaction (and patient satisfaction when appropriate), and ability to perform daily activities such as thumb-index grasp and pinch at follow-up evaluations. We measured the angle between the first and second rays using a goniometer at maximum radial abduction, and pinch and grasp strengths were evaluated as an objective assessment. RESULTS: The average follow-up period was 2 years. All parents and patients were happy with the aesthetic appearance. They were completely satisfied in their daily living activities. The average first web angle measurement was 56 degrees . An average of 39 degrees of improvement of web measurement was achieved. For the unilateral 4 patients, the average pinch strength measurement was 80% of the normal contralateral hand and the grip strength was 75% of the normal contralateral hand. CONCLUSIONS: The reverse radial forearm flap was found to be a safe and simple method in the reconstruction of severe first web contractures in symbrachydactyly patients. This method provided good coverage of appropriate thickness and skin quality, and supple soft tissue that filled the first web space. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.     

The association between ulnar length and forearm movement in patients with multiple osteochondromas

PURPOSE: To determine the relationship between the length of the ulna as a proportion of height (proportional ulnar length [PUL]), forearm and wrist ranges of motion, and degree of observable deformity in people with hereditary multiple exostoses. METHODS: One hundred forty-two people with hereditary multiple exostoses were examined; 35 were under the age of 15 years and therefore were presumed to be skeletally immature. Elbow, forearm, and wrist motion were measured, and the radius and ulna were palpated for osteochondromas. Ulnar length was estimated as a proportion of height (PUL) in skeletally immature subjects. The relationships between total active motion, number of palpable osteochondromas, and proportional length were examined for one randomly selected limb from each subject. RESULTS: A negative correlation was found between the number of palpable osteochondromas and range of forearm rotation. The degree of forearm motion in those under the age of 15 years was directly related to PUL and indirectly related to the number of palpable osteochondromas. Children whose PUL is within the normal range have a normal range of motion. CONCLUSIONS: In a child with hereditary multiple exostoses affecting the forearm, the PUL is associated with the range of movement and deformity, and it can be a useful adjunct in deciding the appropriate management.     

Release of the transverse carpal ligament alone is associated with elevated pressure beneath the distal volar forearm fascia in a cadaver model of carpal tunnel syndrome

PURPOSE: The purpose of this study is to determine whether release of the distal volar forearm fascia (DVFF) is necessary at the time of median nerve decompression for carpal tunnel syndrome. METHODS: Five fresh-frozen cadaver specimens were mounted vertically with the hand dependent and a 2.27-kg weight suspended from the fingers. A pressure sensor wire was used to measure pressures starting just distal to the transverse carpal ligament (TCL). The wire was withdrawn proximally in 5-mm increments and into the forearm until pressure was below 10 mm Hg. An incision in the forearm was extended distally until the pressure sensor was found. The distance from this point to the distal volar wrist crease was measured. The TCL was released, keeping the DVFF intact, and the experiment was repeated. Paired t-tests determined whether there were statistically significant differences between measurements before and after TCL release. RESULTS: Average peak pressure under the intact TCL was 57.8 +/- 10.1 mm Hg. Average peak pressure under the DVFF with the TCL intact was 61.2 +/- 43.6 mm Hg. Following release of the TCL, average peak pressure beneath the TCL significantly decreased to 14.0 +/- 9.0 mm Hg, whereas average peak pressure at the intact DVFF increased to 64.8 +/- 48.7 mm Hg. Average locations where DVFF pressure became less than 10 mm Hg with an intact TCL and with released TCL were 4.30 +/- 1.8 cm and 4.00 +/- 1.8 cm proximal to the distal volar wrist crease, respectively. There was no significant difference between DVFF pressures before or after TCL release. CONCLUSIONS: In a cadaver model of carpal tunnel syndrome, release of the TCL alone is associated with persistent pressures >30 mm Hg in the region of the DVFF. Release of the TCL did not significantly change the location of the pressure drop-off under the DVFF.     

Treating Displaced Distal Forearm Fractures in Children

Abstract Purpose:  Distal forearm fractures are among the most common fractures in children. In the past few years the option of percutaneous pinning has gained more attention in the treatment of unstable fractures. However, it remains unclear in which cases a fracture or its reduction should be considered unstable. Study Design:  In order to evaluate which type of fractures profit most from additional pinning after closed reduction, we performed a retrospective analysis of 225 consecutive cases using the recently published AO pediatric classification of long bone fractures. Results:  After closed reduction, position in the cast was lost in 23% of the cases. The proportion of unstable reductions was much higher in completely displaced fractures. The amount of dislocation was more important than the type of fracture according to the AO classification proposal. Conclusions:  Fully displaced fractures should always be reduced in a setting with pins immediately available. If anatomical reduction cannot be achieved, pinning is advocated. The AO proposal for pediatric long bone fracture classification could be a useful tool to render the diverse studies more comparable. However, the important feature of complete versus subtotal displacement is lacking.     

Forearm gangrene following distraction injury at elbow in a neonate

Gangrene of limbs in newborn is extremely rare. A number of aetiological factors may account for such type of situation. We describe herewith a case of gangrene of forearm in newborn following distraction injury to the physis of elbow and vessels of forearm by excessive pull on upper limb during difficult delivery.     

Ulnar versus radial forearm flap in head and neck reconstruction: an experimental and clinical study.

BACKGROUND: To consider the pros and cons of the microvascular ulnar forearm flap compared with its radial counterpart, this study compares the use of these two flaps for head and neck reconstruction. METHODS: In 75 patients, 51 ulnar and 24 radial forearm flaps were used. Both groups were compared regarding flap dissection, suitability of the flap for the recipient region, complication rate, and secondary morbidity in the donor region. Furthermore, in 40 healthy volunteers, the thickness of the subcutaneous tissue layer was measured by use of ultrasonography. RESULTS: Flap survival rate, respectively wound healing, in the recipient region showed no differences. Clinical and experimental results demonstrated a thinner subcutaneous layer in the ulnar aspect of the forearm. Compared with its radial equivalent, closure of the ulnar donor side by skin grafting resulted in a significantly lower complication rate. CONCLUSIONS: The ulnar forearm flap is favored because of the less hairy skin of the ulnar forearm region, the thinner layer of subcutaneous tissues, and the more conveniently located donor area. The ulnar forearm pedicle is long compared with alternative transplants but shorter than the radial equivalent.     

48例前臂桡侧皮瓣移植供区术前与术后功能的对比研究

目的 探讨前臂桡侧皮瓣移植术后供区功能障碍的原因及预防措施，方法 对４８例头颈部缺损行前臂桡侧皮瓣重建病人的供区手臂功能进行术前与术后的对比研究，感觉功能评价参照ＢＭＲＣ标准并计百分比，运动功能评价采用配对ｔ检验，结果 术后早期，９３．７５％病人的桡神经分布区以及５０．００％病人的正中神经分部区感觉功能在Ｓ４以下，至术后１ａ时，９２．８６％病人的桡神经分布区的感觉功能恢复至Ｓ３以上，正中神经分布区