Localization of muscle damage within the quadriceps femoris induced by different types of eccentric exercises.

This study examined localization of muscle damage within the quadriceps femoris induced by different types of eccentric exercises by using transverse relaxation time (T2 )-weighted magnetic resonance imaging (MRI). Thirty-three young males performed either of the following three exercises: single-joint eccentric contraction of the knee extensors (KE), eccentric squat (S), or downhill walking (DW) (n=11/exercise). KE and S consisted of 5-set×10-lowering of 90% one-repetition maximum load. DW was performed for 60 minutes with -10% slope, 6 km/h velocity, and 20% body mass load carried. At pre- and 24-, 48-, and 72-hours post-exercise, T2 -MRI was scanned and T2 values for the rectus femoris (RF), vastus intermedius (VI), vastus lateralis (VL), and vastus medialis (VM) at proximal, middle, and distal sites were calculated. Additionally, soreness felt when static pressure was applied to these sites and maximal isometric knee extension torque were measured. Maximal torque significantly (P<.05) decreased (7%-15%) at 24-48 hours after all exercises. T2 significantly increased (3%-9%) at 24-72 hours after all exercises, with heterogeneities within the muscles found in each exercise. Effect size and peak change of T2 , as well as soreness, overall indicated that the proximal RF after KE and middle VM after S and DW were most affected by these exercises. The VL did not show any significant T2 increase after all exercises. These results suggest that muscle damage specifically localizes at the proximal RF by KE and at the middle VM by S and DW, while the VL is least damaged regardless of the exercises.

Intra-abdominal Pressure and Trunk Muscular Activities during Abdominal Bracing and Hollowing.

This study examined the difference in intra-abdominal pressure (IAP) between abdominal bracing and hollowing in relation to trunk muscular activities. IAP with a pressure transducer placed in the rectum and surface electromyograms for rectus abdominis, external oblique, internal oblique, and erector spinae during the 2 tasks were obtained in 7 young adult men. The difference between IAP at rest and its peak value (ΔIAPmax) showed high intra- and inter-day repeatability, and was significantly greater in abdominal bracing (116.4±15.0 mmHg) than in abdominal hollowing (9.9±4.5 mmHg). The trunk muscular activities at ΔIAPmax were significantly higher in abdominal bracing than in abdominal hollowing, and in the internal oblique than in the other 3 muscles. In both abdominal bracing and hollowing, the changes in IAP during the tasks were linearly correlated with those in trunk muscular activities, but the slope of the regression line for the relationship differed between the 2 tasks. The current results indicate that 1) abdominal bracing is an effective maneuver to elevate IAP compared with abdominal hollowing, and 2) in the 2 tasks, the changes in IAP are linked with those in trunk muscular activities, but the association is task-specific.

Low-load Slow Movement Squat Training Increases Muscle Size and Strength but Not Power.

We tested a hypothesis that low-load squat training with slow movement and tonic force generation (LST) would increase muscle size and strength but not necessarily power. Healthy young men were assigned to LST [50% one-repetition maximum (1-RM) load, 3 s for lowering/lifting without pause: n=9] or low-load normal speed (LN: 50% 1-RM load, 1 s for lowering/lifting with 1-s pause; n=7) groups. Both groups underwent an 8-week squat training program (10 repetitions/set, 3 sets/day, and 3 days/week) using the assigned methods. Before and after the intervention, quadriceps femoris muscle thickness, maximal torque during isometric hip extension and knee extension, 1-RM squat, lifting power from squatting position and rate of electromyography rise (RER) in knee extensors during the task, leg extension power and vertical jump height were measured. After the intervention, the LN group showed no changes in all the variables. The LST group significantly (P<0.05) increased muscle thickness (6-10%), isometric hip extension torque (18%) and 1-RM squat (10%), but not isometric knee extension torque, lifting power and RER, leg extension power and vertical jump height. These results suggest that LST can increase muscle size and task-related strength, but has little effect on power production during dynamic explosive movements.

Muscular adaptations to short-term low-frequency downhill walking training.

This study examined muscular adaptations of knee extensors following short-term low-frequency downhill walking training. 22 young males (training group: TG, n=12; control group: CG, n=10) participated. TG conducted 40-min downhill treadmill walking (load: 10% of body mass, gradient: 28%, velocity: 5 km/h) 1 session/week for 4 weeks. Before and after the intervention, muscle thickness of knee extensors and maximal knee extension torques in eccentric (- 120, - 60, - 30°/s), isometric (0°/s), and concentric (30, 60, 120, 240°/s) conditions were measured. For TG, muscle damage markers were also measured before and up to 72 h following each session. After the intervention, CG did not show any changes in all variables. TG had significant increases in maximal knee extension torques at all angular velocities, with higher relative gains in eccentric torques (+ 24% on average) than isometric (+ 13%) and concentric (+ 12% on average) torques. No changes were found in the muscle thickness. Although considerable muscle damage was observed after the first training session in TG, the magnitudes of changes in all markers following the second to fourth sessions were minimal. These results indicate that even with relatively short-term and low-frequency, downhill walking training can increase the strength capacity of knee extensors, especially in eccentric strength.

Effect of short-term maximal voluntary co-contraction training on neuromuscular function.

The present study aimed to examine the effect of short-term training utilizing voluntary co-contraction with maximal efforts. 23 healthy young men (training group: TG, n = 13; control group: CG, n = 10) participated in this study. TG conducted a 4-week training program (3 days/week), which consisted of 4 s simultaneous maximal voluntary contractions of elbow flexors and extensors at 90° of the elbow joint, followed by 4 s muscle relaxation (10 repetitions/set, 5 sets/day). Before and after the intervention, maximal voluntary isometric and isokinetic torques and the muscle thicknesses of the elbow flexors and extensors were determined. The electromyograms (EMGs) of the 2 muscle groups during isometric maximal voluntary contraction (MVC) were also recorded. After the intervention, CG did not show any significant changes in all measured variables. In TG, significant increases were found in the agonist EMG activities during MVC, and maximal isometric and isokinetic torques of the elbow flexors and extensors, without significant changes in the muscle thicknesses and involuntary coactivation levels during MVC. The current results indicate that the training mode with maximal voluntary co-contraction is effective for improving the force-generating capabilities of the exercising muscles, without any increases in the level of involuntary coactivation during MVC.

Characterization and sensitivity to interleukin 2 and interferon alpha of leukemic cells from a patient with large granular lymphocytic leukemia associated with chronic active Epstein-Barr virus infection.

A patient presented with chronic large granular lymphocyte leukemia associated with chronic active Epstein-Barr virus infection (CAEBV). Cell cycle analysis revealed a minimal growth compatible with chronic lymphocytic leukemia After 5 months of treatment, the patient died from acute transformation of the leukemia. Cell harvested during chronic phase were analyzed for sensitivity to interleukin 2 (IL-2) and interferon alpha (IFN alpha) in vitro by means of surface phenotyping and cell cycle assay. IL-2 induced remarkable growth of the cells, whereas IFN alpha did not confer a growth advantage. Since IFN alpha was expected to have no growth induction effect on the leukemia cells, it was administered to the patient to treat the CAEBV.

Laparoscopic repair of a colonic perforation sustained during colonoscopy.

A patient who sustained a colonic perforation during therapeutic colonoscopy was treated successfully by laparoscopic repair. Laparoscopy was performed 5 h after polypectomy. Fecal matter was not identified in the peritoneal cavity. Local peritonitis was mild. The laceration was oversewn with five sutures using the extracorporeal endoscopic knot technique. The appendix epiploica was then anchored over the lesion. The postoperative recovery was rapid and uneventful. Laparoscopic surgery may become a useful tool for the safe, effective, and minimally invasive management of iatrogenic colonic perforation.

The proliferating cell nuclear antigen (PCNA) index correlates with the grade of cytologic atypia in well-differentiated early adenocarcinomas of the large intestine.

Well-differentiated colorectal adenocarcinomas are subclassified into carcinoma with high-grade atypia (CAH) and carcinoma with low-grade atypia (CAL) based on their cellular atypia. It is proposed that CAH and CAL are different in histologic prognostic factors and that the former should be regarded as carcinoma with high-grade malignancy and the latter as low-grade malignancy. In this study, the differences in cell-proliferative activity between CAH and CAL were examined using a monoclonal antibody to the proliferating cell nuclear antigen (PCNA). The PCNA index and mitotic index of 27 early colorectal carcinomas (9 CAL, 5 CAH, and 13 carcinomas with mixed low- and high-grade atypia) was evaluated in relation to their depth of invasion. In intramucosal lesions, both indices were higher in CAH (78%, 0.89%) than in CAL (68%, 0.47%; P < 0.01). In lesions invading into the submucosa, the PCNA and mitotic indices were also higher in CAH (75%, 0.65%) than in CAL (35%, 0.19%; P < 0.01). A significant correlation was observed between the PCNA index and the mitotic index in the mucosal lesions (P < 0.05). These results indicate that CAH has a higher proliferative activity than CAL, and support the current authors' proposal that CAH is a high-grade malignancy and CAL low-grade malignancy.

Laparoscopically assisted distal partial gastrectomy for early-stage gastric carcinomas.

Endoscopic mucosal resection (EMR) is now in clinical use for the management of small, early-stage gastric, carcinomas, although some patients are treated via laparotomy when the lesions are not suitable for, EMR due to their size, depth, and location. In many cases of invasive mucosal carcinoma with submucosal involvement, the regional lymph nodes along with the distal portion of the stomach must also be resected. In order to remove the whole resected specimen, a mini-laparotomy of appropriate length (5 cm) is performed which can be located at the optical port site after removing the laparoscope. By applying an abdominal wall elevator through the mini-laparotomy, direct vision is possible which facilitates resection of the regional lymph nodes and intestinal anastomosis. We describe our technique for laparoscopically assisted distal gastrectomy and present our early clinical results.

[Panpleuropneumonectomy for primary lung cancer patients with pleural dissemination].

Twelve patients of non-small cell lung cancer with carcinomatous pleuritis were subjected to panpleuropneumonectomy between June 1981 and December 1988. The median survival time was 13 months. One-year and 3-year survival rates were 52% and 26%, respectively. There was no significant difference in prognosis compared with the results of other modality therapies such as pleurodesis with talc and tube drainage for pleural effusion. After panpleuropneumonectomy the patients were divided into the group with only pleural dissemination and the one with pleural effusion. The median survival time in the group of pleural dissemination was 14 months. The three-year survival rate was 50%. The one patient survived for 51 months and the other for 45 months. The median survival time of patients with pleural effusion was 4 months without over 1-year survivor. The statistically significant difference was found between the two groups (p less than 0.05). We concluded that panpleuropneumonectomy is indicated only for the patients of non-small cell lung cancer with diffuse pleural dissemination and no pleural effusion.

Complete excision and panpleuropneumonectomy resulting in long-term survival for a teenager with invasive thymoma: report of a case.

An 18-year-old girl with invasive thymoma and pleural dissemination underwent a complete removal of the tumor with combined resection of the pericardium and a panpleuropneumonectomy of the left lung. At the time of writing, 70 months later, she was doing well under the classification of grade I performance status with no signs of recurrence. Thus, complete surgical removal of this tumor can prolong the survival time of patients with invasive thymoma and pleural dissemination.