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Biomedical subjects

Alan M Levine

Publications and source records attributed to Alan M Levine.

14 recordsLinked to original sources

Cold air inhalation does not affect the severity of EIB after exercise or eucapnic voluntary hyperventilation.

INTRODUCTION: Exercise-induced bronchoconstriction (EIB) is thought to result from osmotic and thermal events of air conditioning during exercise at high ventilation rates. The purpose of this study was to evaluate lung function after exercise and eucapnic voluntary hyperventilation (EVH) while breathing both room-temperature and cold-temperature dry bottled air. METHODS: Twenty-two subjects were identified as EIB probable by a fall of >or=7% in forced expiratory volume in the first second of exhalation (FEV1) using a 6-min room-temperature EVH challenge (RTEVH; 22.0 degrees C). Subjects then randomly performed three 6-min challenges: cold-temperature EVH (CTEVH; -1 degrees C), room-temperature exercise (RTEX; 22.0 degrees C), and cold-temperature exercise (CTEX; -1 degrees C), with a period of at least 48 h observed between challenges. Spirometry was performed at baseline and at 5, 10, 15, and 20 min postchallenge. RESULTS: Reasonable agreement was found between challenge modes and room-temperature and cold-temperature challenges. Postchallenge percent falls in FEV1 were -15.21, -13.80, -13.12, and -10.69 for RTEVH, CTEVH, RTEX, and CTEX, respectively. RTEVH resulted in a significantly greater percent fall in FEV1 than CTEX (P=0.048); no other differences in FEV1 were observed. CONCLUSION: Similar postchallenge percent falls in FEV1 for room- and cold-temperature EVH and exercise suggest that dryness is essential to test conditions, as cold temperature did not have an additive effect to the EIB response.

Adult↗

Effects of cysteine donor supplementation on exercise-induced bronchoconstriction.

PURPOSE: Reactive oxygen/nitrogen species (ROS/RNS) in resident airway cells may be important in bronchoconstriction following exercise. Glutathione (GSH) is a major lung antioxidant and could influence pathological outcomes in individuals with exercise-induced bronchoconstriction (EIB). This study examined the effects of supplementation with undenatured whey protein (UWP) in subjects exhibiting airway narrowing following eucapnic voluntary hyperventilation (EVH), a surrogate challenge for diagnosis of EIB. UWP is a cysteine donor that augments GSH production. METHODS: In a randomized, double-blind, placebo-controlled study, 18 EIB-positive subjects (age: 25.2 +/- 9.01 yr; weight: 77.3 +/- 18.92 kg; height: 1.7 +/- 0.09 m) with post-EVH falls of > or =10% in FEV1 received 30 g UWP (TX) or casein placebo (PL)/d. Subjects performed 6-min EVH challenges before and after 4 and 8 wk of supplementation. Exhaled nitric oxide (eNO) was measured serially before spirometry and at 1-wk intervals. Spirometry was performed pre- and 5, 10, and 15 min postchallenge. RESULTS: Subjects exhibited significant mean improvement in postchallenge falls in FEV(1) from 0 wk (-22.6 +/- 12.22%) with TX at 4 (-18.9 +/- 12.89%, P < 0.05) and 8 wk (-16.98 +/- 11.61%, P < 0.05) and significant mean reduction in post-EVH peak falls in FEF(25-75) from 0 wk (-40.6 +/- 15.28%) with TX at 4 (-33.1 +/- 17.11%, P < 0.01) and 8 (-29.7 +/- 17.42%, P < 0.05) wk. No changes in FEV(1) or FEF(25-75) were observed in the PL group at any time point. Mean eNO for PL and TX groups at 0, 4, and 8 wk (46.8 +/- 31.33, 46.5 +/- 35.73, 49.3 +/- 37.12 vs 35.2 +/- 26.87, 29.1 +/- 17.26, 34.7 +/- 21.11 ppb, respectively) was not significantly different. CONCLUSIONS: UWP may augment pulmonary antioxidant capacity and be therapeutically beneficial in individuals exhibiting EIB, as postchallenge pulmonary function improved with supplementation. The lack of significant change in eNO suggests that the pulmonary function improvements from UWP supplementation are independent of eNO.

Administration, Oral↗

Airway narrowing measured by spirometry and impulse oscillometry following room temperature and cold temperature exercise.

STUDY OBJECTIVE: The efficacy of using impulse oscillometry (IOS) as an indirect measure of airflow obstruction compared to spirometry after exercise challenges in the evaluation of exercise-induced bronchoconstriction (EIB) has not been fully appreciated. The objective was to compare airway responses following room temperature and cold temperature exercise challenges, and to compare whether IOS variables relate to spirometry variables. DESIGN: Spirometry and IOS were performed at baseline and for 20 min after challenge at 5-min intervals. SETTING: Two 6-min exercise challenges, inhaling either room temperature (22.0 degrees C) or cold temperature (- 1 degrees C) dry medical-grade bottled air. At least 48 h was observed between these randomly assigned challenges. PARTICIPANTS: Twenty-two physically active individuals (12 women and 10 men) with probable EIB. INTERVENTIONS: Subjects performed 6 min of stationary cycle ergometry while breathing either cold or room temperature medical-grade dry bottled air. Subjects were instructed to exercise at the highest intensity sustainable for the duration of the challenge. Heart rate and kilojoules of work performed were documented to verify exercise intensity. MEASUREMENTS AND RESULTS: Strong correlations were observed within testing modalities for post-room temperature and post-cold temperature exercise spirometry and IOS values. Spirometry revealed no differences in postexercise peak falls in lung function between conditions; however, IOS identified significant differences in respiratory resistance (p < 0.05), with room temperature-inspired air being more potent than cold temperature-inspired air. CONCLUSIONS: Correlations were found between spirometric and IOS measures of change in airway function for both exercise challenges, indicating close equivalency of the methods. The challenges appeared to elicit the EIB response by a similar mechanism of water loss, and cold temperature did not have an additive effect. IOS detected a difference in degree of response between the temperatures, whereas spirometry indicated no difference, suggesting that IOS is a more sensitive measure of change in airway function.

Adult↗

The art and science of reviewing manuscripts for orthopaedic journals: Part I. Defining the review.

The peer review process is integral to the functioning of all scientific journals and plays a pivotal role in the publication of new scientific material. Timeliness, freedom from bias, and proper review etiquette are essential for an effective review. Each type of scientific article demands a slightly different reviewing technique. Clinical research articles require that a proper question be asked and that the study methodology allows the question to be answered effectively. All studies dealing with human subjects need to be approved by the Institutional Review Board. Clinical review articles have specific criteria to determine how they should be constructed and when they should be published, whereas basic science research articles should be evaluated for their experimental method as well as the relevance of the conclusions to the data. Finally, case reports have an important place in the scientific literature, but the rationale for publishing any individual case needs to be clearly established.

Clinical Trials as Topic↗

The art and science of reviewing manuscripts for orthopaedic journals: Part II. Optimizing the manuscript: practical hints for improving the quality of reviews.

Manuscripts submitted to musculoskeletal journals have several key components that need to be critically evaluated. There are specific methods to assess the abstract, illustrations, references, and other major elements of a manuscript under review. If each of these elements is assessed methodically, not only does the quality of the review improve, but it becomes more useful for the journal editor. Additionally, the method in which the review is conveyed has a marked impact on its usefulness. There should be a concise evaluation of the entire work, stating whether a publication should or should not be pursued. For poor manuscripts, several bulleted points that indicate the fatal flaw(s) are sufficient, but for good manuscripts, a systematic itemization of weaknesses will improve the quality of the manuscript. Reviews should not be derogatory and should be prompt and to the point.

Humans↗

Thoracoscopic approach for spine deformities.

BACKGROUND: We reviewed our experience using anterior thoracoscopic procedures in the correction of severe idiopathic scoliosis and kyphotic deformities to evaluate the feasibility and effectiveness of such procedures. STUDY DESIGN: Twenty-four patients who underwent thoracoscopic surgical correction of the spine between March 1995 and December 2001 were retrospectively reviewed. A team consisting of one orthopaedic surgeon and one thoracic surgeon performed anterior thoracoscopic soft tissue release, disc excision, and bone grafting followed on the same day with posterior instrumentation and correction of deformity. RESULTS: There were 16 female and 8 male patients, with a median age of 16 years (range 11 to 47 years) with idiopathic scoliosis (20 patients) or kyphotic deformity (4 patients). The average time for the thoracoscopy was 125 minutes (range 60 to 175 minutes). Blood loss averaged 135 mL (range 20 to 350 mL), and a median number of five discs (range two to eight) were excised. The median ICU time was 2 days (range 1 to 8 days), and the median length of hospital stay was 6 days (range 4 to 11 days). One patient required conversion to an open procedure because of arterial bleeding from the cancellous bone (T5). Postoperative complications occurred in four patients (atelectasis, pneumothorax, pneumonia, and wound infection in one patient each). All patients had an uneventful hospital course after treatment. CONCLUSIONS: Thoracoscopic anterior procedures can be used safely and effectively in the treatment of idiopathic scoliosis and kyphotic deformity. This minimally invasive approach might decrease procedure-related trauma, operative time, blood loss, and length of hospitalization and may also alleviate postthoracotomy pain.

Adolescent↗

Imaging of soft-tissue myxoma with emphasis on CT and MR and comparison of radiologic and pathologic findings.

PURPOSE: To determine the imaging characteristics of soft-tissue myxoma, with emphasis on computed tomographic (CT) and magnetic resonance (MR) imaging findings and pathologic comparison. MATERIALS AND METHODS: Records of 45 pathologically confirmed soft-tissue myxomas in 44 patients were retrospectively reviewed. Patient demographics and radiographs (n = 20), bone scintigrams (n = 2), angiograms (n = 3), and ultrasonographic (US) (n = 6), CT (n = 14), and MR images (n = 33) were evaluated by two musculoskeletal radiologists with agreement by consensus for lesion location, lesion size, and intrinsic characteristics. RESULTS: Soft-tissue myxoma more commonly affected women (59%; average age 52 years) and manifested as a slowly enlarging (64%) painful (51%) mass. Lesions were most frequently intramuscular (82%) and involved the thigh (51%). An appearance similar to that of a cyst was seen at CT (at which the lesions demonstrated low attenuation) and at MR imaging (at which the lesions demonstrated markedly high signal intensity on T2-weighted images) in all cases because of the high water content of mucin that was seen histologically. The true solid architecture of these lesions was best depicted in all cases at US (at which the lesions were hypoechoic, not anechoic) and on MR images obtained with contrast material (at which the lesions demonstrated internal enhancement). A small amount of tissue similar to fat surrounding these intramuscular myxomas (71% at MR imaging) corresponded histologically (70%) to atrophy of surrounding muscle. CONCLUSION: Soft-tissue myxoma often demonstrates characteristic US, CT, and MR imaging findings, including intramuscular location, intrinsic high water content, and a surrounding rim of fat.

Adolescent↗

Impulse oscillometry is sensitive to bronchoconstriction after eucapnic voluntary hyperventilation or exercise.

Airway responses were compared following 6-minute eucapnic voluntary hyperventilation and 6-minute exercise challenges by examining resting and post-challenge impulse oscillometry and spirometry variables. Twenty-two physically active individuals with probable exercise-induced bronchoconstriction took part in this study. Impulse oscillometry and spirometry were performed at baseline and for 20 minutes post-challenge at 5-minute intervals. High correlation was found between the two measures of change in airway function for both methods of challenge. Impulse oscillometry detected a difference in degree of response to the challenges, whereas spirometry indicated no difference, suggesting that impulse oscillometry is a more sensitive measure of change in airway function.

Adolescent↗

Fluoroquinolones.

Explore the source record for details and available documents.

Anti-Infective Agents↗

Pediatric soft-tissue tumors.

Soft-tissue tumors in children (<18 years) are a heterogeneous group of lesions. Masses may be asymptomatic or associated with pain or discomfort. Although most lesions are benign, developing an appropriate differential diagnosis requires knowledge of the clinical and radiographic characteristics of tumors and tumorlike conditions in children. A thorough history and physical examination, followed by appropriate imaging studies, when indicated, can establish a correct diagnosis and help determine appropriate treatment recommendations.

Adolescent↗