Diaphragm remodeling associated with chronic obstructive pulmonary disease (COPD) consists of a fast-to-slow fiber type transformation as well as adaptations within each fiber type. To try to explain disparate findings in the literature regarding the relationship between fiber type proportions and FEV1, we obtained costal diaphragm biopsies on 40 subjects whose FEV1 ranged from 118 to 16% of the predicted normal value. First, we noted that our exponential regression model indicated that changes in FEV1 can account for 72% of the variation in the proportion of Type I fibers. Second, to assess the impact of COPD on diaphragm force generation, we measured maximal specific force generated by single permeabilized fibers prepared from the diaphragms of two patients with normal pulmonary function tests and two patients with severe COPD. We noted that fibers prepared from the diaphragms of severe COPD patients generated a lower specific force than control fibers (p < 0.001) and Type I fibers generated a lower specific force than Type II fibers (p < 0.001). Our finding of an exponential relationship between the proportion of Type I fibers and FEV1 accounts for discrepancies in the literature. Moreover, our single-fiber results suggest that COPD-associated diaphragm remodeling decreases diaphragmatic force generation by adaptations within each fiber type as well as by fiber type transformations.

Background/Objective: To determine whether 9 weeks of locomotor training (LT) results in changes in muscle strength and alterations in muscle size and activation after chronic incomplete spinal cord injury (SCI). Study Design: Longitudinal prospective case series. Methods: Five individuals with chronic incomplete SCI completed 9 weeks of LT. Peak isometric torque, torque developed within the initial 200 milliseconds of contraction (Torque 200), average rate of torque development (ARTD), and voluntary activation deficits were determined using isokinetic dynamometry for the knee-extensor (KE) and plantar-flexor (PF) muscle groups before and after LT. Maximum muscle crosssectional area (CSA) was measured prior to and after LT. Results: Locomotor training resulted in improved peak torque production in all participants, with the largest increases in the more-involved PF (43.9% 6 20.0%), followed by the more-involved KE (21.1% 6 12.3%). Even larger improvements were realized in Torque 200 and ARTD (indices of explosive torque), after LT. In particular, the largest improvements were realized in the Torque 200 measures of the PF muscle group. Improvements in torque production were associated with enhanced voluntary activation in both the KE and ankle PF muscles and an increase in the maximal CSA of the ankle PF muscles. Conclusion: Nine weeks of LT resulted in positive alterations in the KE and PF muscle groups that included an increase in muscle size, improved voluntary activation, and an improved ability to generate both peak and explosive torque about the knee and ankle joints.

Study design: Longitudinal intervention case series. Objective: To determine if a 12-week resistance and plyometric training program results in improved muscle function and locomotor speed after incomplete spinal cord injury (SCI). Setting: University research setting. Methods: Three ambulatory individuals with chronic (18.772.2 months post injury) motor incomplete SCI completed 12 weeks of lower extremity resistance training combined with plyometric training (RPT). Muscle maximum cross-sectional area (max-CSA) of the knee extensor (KE) and plantar flexor (PF) muscle groups was determined using magnetic resonance imaging (MRI). In addition, peak isometric torque, time to peak torque (T 20-80 ), torque developed within the initial 220 ms of contraction (torque 220 ) and average rate of torque development (ARTD) were calculated as indices of muscle function. Maximal as well as selfselected gait speeds were determined pre-and post-RPT during which the spatio-temporal characteristics, kinematics and kinetics of gait were measured. Results: RPT resulted in improved peak torque production in the KE (28.974.4%) and PF (35.079.1%) muscle groups, as well as a decrease in T 20-80 , an increased torque 220 and an increase ARTD in both muscle groups. In addition, an increase in self-selected (pre-RPT ¼ 0.77 m/s; post-RPT ¼ 1.03 m/s) and maximum (pre-RPT ¼ 1.08 m/s; post-RPT ¼ 1.47 m/s) gait speed was realized. Increased gait speeds were accompanied by bilateral increases in propulsion and hip excursion as well as increased lower extremity joint powers. Conclusions: The combination of lower extremity RPT can attenuate existing neuromuscular impairments and improve gait speed in persons after incomplete SCI.

Percutaneous biopsies were taken from the right vastus lateralis (VL), tibialis anterior (TA), soleus (Sol), and lateral gastrocnemius (LG) muscles of eight recreationally active adult males. Approximately 60 fibers in each sample were analyzed for their type (I, IIa, or IIx), cross‐sectional area (CSA), and succinic dehydrogenase (SDH), alpha glycerol phosphate dehydrogenase (GPDH) and calcium‐activated actomyosin adenosine triphosphatase (qATPase) activities. This was done to test the hypothesis that metabolic enzyme activities are more reflective of the functional diversity among human locomotor muscles than fiber type composition. The results showed that enzymatic characteristics differed more or less than expected between muscles of the same or different fiber type. For example, the relative CSA occupied by fast fibers was only about 50% greater in the mixed (LG and VL) than in the slow (Sol and TA) muscles (57 vs. 38%). At the same time, average fiber SDH activity and fiber type specific SDH:qATPase*%CSA, both used as estimates of fatigue resistance, were greater in Sol and LG than in TA and VL. As a result, the two slow muscles and the two mixed muscles had different values, and a mixed muscle (LG) had higher values than a slow muscle (TA). The findings suggest that differences in enzymatic profile, more than fiber type composition, afford human locomotor muscles the capacity to perform their purportedly divergent functional tasks. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 387–393, 2001

No abstract

Additional research is needed to understand the mechanism of effect and to identify the factors that mediate response to exercise interventions, specifically the optimal dose of exercise and timing of language intervention with exercise. ClinicalTrials.gov identifier: NCT01113879.

A 3½-year-old male Shih Tzu dog was examined by a referring veterinarian at the University of Georgia Veterinary Medical Teaching Hospital, Athens, GA, for chronic exercise intolerance since 6 months of age and coughing of 4 months' duration. The dog's medical history included mild seborrhea sicca and seasonal atopic dermatitis, treated with dietary modification and parenteral triamcinolone injections every 2-3 months. The dog had been treated with a 2-week course of tetracycline (15 mg/kg PO q8h) 3 months before examination for lethargy, fever, and weakness in conjunction with high serum immunoglobulin G titers to Borrelia burgdorferi (1,024; reference range, Ͻ256) and Rickettsia rickettsii (128; reference range, Ͻ64). The dog also received amoxicillin and clavulanate (20 mg/ kg PO q12h) for 10 days 4 months before referral and enrofloxacin (5 mg/kg, PO q12h) for 10 days 7 weeks before referral. No improvement was seen with any of these therapies. Hematologic abnormalities present during this time included a persistent neutrophilic leukocytosis with an inconsistent lymphocytosis and eosinophilia.At the time of referral, examination revealed the dog to be bright, alert, and responsive. Rectal temperature was slightly high (102.8ЊF [39.3ЊC]; reference range, 99.5-102.5ЊF [37.5-39.2ЊC]). The dog had a normal pulse rate (130 beats/min; reference range, 110-130 beats/min) and increases in respiratory rate (50 breaths/min; reference range, 15-30 breaths/min). Lung sounds were increased in intensity, and the dog had an easily induced dry, hacking cough.Abnormalities on hematologic testing included a leukocytosis (23.4 ϫ 10 3 cells/L; reference range, 5.1-13.0 cells/L) with a mature neutrophilia (18.3 ϫ 10 3 cells/L; reference range, 2.9-12.0 cells/L) and eosinophilia (2.1 ϫ 10 3 cells/L; reference range, 0.0-1.3 cells/L). Serum total protein (7.6 g/dL; reference range, 5.4-7.5 g/dL) and globulin concentrations (4.2 g/dL; reference range, 1.9-5.3 g/dL) were increased. Urinalysis was within normal limits. Fundic examination revealed no abnormalities. An interstitial lung pattern was seen on thoracic radiographs ( Fig 1A,B). No parasite ova were seen in feces examined by Sheather flotation or Baermann extraction. Cytologic findings of a transtracheal washing were of a moderate amount

Background-Despite extensive investigations some patients with suspected lung cancer may undergo thoracotomy without preoperative histological proof of malignancy. A questionnaire on the use of histological examination of peroperative frozen sections in such patients was sent to 50 thoracic surgeons. Replies were received from 41 surgeons and indicated an absence of consensus on the usefulness of histological examination of frozen sections in this context, confirming the need for this study. Methods-During one year 60 consecutive patients undergoing thoracotomy for suspected lung cancer without a prior histological diagnosis were studied prospectively. At thoracotomy the surgeon assessed the lesion macroscopically and a verdict on whether it was malignant was recorded. A biopsy specimen was then taken for examination of a frozen section and the result recorded. The appropriate operation was performed and the surgeon's verdict and the report on the frozen section were compared with the definitive histological diagnosis based on a paraffin section. Results-Of 50 malignant lesions, 43 were identified by the surgeon and 47 by examination of the frozen section (sensitivity 86% and 94% respectively). Of 10 benign lesions, four were identified by the surgeon and nine by examination of the frozen section (specificity 40% and 90% respectively). Conclusions-Clinical and macroscopic assessment at thoracotomy are inferior to examination of frozen sections in suspected lung cancer, particularly where