Induction of Muscle Hypertrophy in Rats through Low Intensity Eccentric Contraction

[Purpose] The purpose of this study was to examine whether a low intensity exercise using an eccentric contraction would result in skeletal muscle hypertrophy in rats. [Subjects and Methods] Eighteen female Wistar rats were used in this study. The rats were randomly divided into three groups. The control group performed no exercise. The level group ran on a treadmill on a 0° incline. The downhill group ran on a treadmill on a −16° incline. The two exercise groups ran on a treadmill at 16 m/min for 90 minutes, once every three days for a total of twenty sessions. [Results] The muscle wet weights, the relative weight ratios, and the muscle fiber cross-section minor axes of the downhill group were significantly larger than those of the control and level groups. There were no differences in the muscle wet weights, the relative weight ratios, and the muscle fiber cross-section minor axes between the control group and the level group. [Conclusion] The stimulation from the low intensity eccentric contraction may have produced enough mechanical stress to induce muscle hypertrophy without the over-stressing that might have produced muscle fiber damage. These results indicate that this technique may be an effective method of inducing hypertrophy in skeletal muscle.Key words: Eccentric contraction, Low intensity exercise, Muscle hypertrophy     

Effect of Skin Resection on the Improvement of Joint Contractures in Rats

The effect of skin resection on joint contracture was determined by comparing the first measurement of range of motion after cast removal and the second measurement after the skin resection. This study aimed to verify that both the joint movement during the measurement and skin affect range of motion. [Subjects] Twelve female Wistar rats were used. [Methods] The right hind limb ankle of each rat was immobilized in complete plantar flexion in a cast. In the resection group (n = 6), the skin of the right hind limb ankle was removed surgically, but not in the non-resection group (n = 6). In the resection group, the first measurement of the dorsiflexion angle was obtained after the cast was removed, and the second measurement was obtained after skin resection. In the non-resection group, both measurements of the dorsiflexion angle were obtained soon after the cast was removed. [Results] Compared with the non-resection group, the resection group showed a significant increase between the first and second measurements of range of motion. [Conclusion] These results show that range of motion is substantially affected by skin, in addition to joint movement, during measurement.Key words: Joint contracture, Skin, Rat     

Impact of laparoscopic liver resection for hepatocellular carcinoma with F4-liver cirrhosis

Background

Although the utility of laparoscopic liver resection for hepatocellular carcinoma (HCC) has been recognized in recent years, the impact of the laparoscopic liver resection for HCC with complete liver cirrhosis (F4) is still unknown.

Methods

Retrospective analysis of 56 patients who underwent partial hepatectomy for HCC (3 cm or smaller in a diameter) and had complete liver cirrhosis (F4) diagnosed histologically was performed. Of the 56 patients, partial hepatectomy was performed under laparotomy in 28 patients (laparotomy group) or under laparoscopy in 28 patients (laparoscopy group). Perioperative outcome was analyzed in the two groups.

Results

There were no significant differences in the results of the preoperative liver function tests and the operation time between the two groups. The intraoperative blood loss was lower in the laparoscopy group than the laparotomy group (p = 0.0003). The incidence of the postoperative complications was significantly higher in the laparotomy group (20/36 patients) than in the laparoscopy group (3/28 patients, p < 0.0001). The incidences of surgical site infection, especially incisional infection, and intractable ascites were significantly higher in the laparotomy group than in the laparoscopy group (p = 0.0095, p < 0.0001, respectively). The proportions of patients who were classified into Clavien’s grade I and IIIa were higher in the laparotomy group than in the laparoscopy group (p = 0.0043, p = 0.051, respectively). The duration of the postoperative hospital stay was significantly shorter in the laparoscopy group than in the laparotomy group (p < 0.0001).

Conclusions

The postoperative morbidity, such as surgical site infection and intractable ascites, decreased by the induction of laparoscopic liver resection in patients with liver cirrhosis. As the results, the necessity of invasive treatment for postoperative complications decreased and the duration of the postoperative stay was shortened.     

High resolution SPECT imaging for visualization of intratumoral heterogeneity using a SPECT/CT scanner dedicated for small animal imaging

Objectives

Tumor interiors are never homogeneous and in vivo visualization of intratumoral heterogeneity would be an innovation that contributes to improved cancer therapy. But, conventional nuclear medicine tests have failed to visualize heterogeneity in vivo because of limited spatial resolution. Recently developed single photon emission computed tomographic (SPECT) scanners dedicated for small animal imaging are of interest due to their excellent spatial resolution of <1?mm, but few studies have focused on the evaluation of intratumoral heterogeneity. We investigated the optimal conditions related to high resolution imaging of heterogeneous tumor interiors using a small animal SPECT scanner.

Methods

The conditions related to SPECT/CT visualization of heterogeneous tumor interiors were investigated using phantoms with ¹¹¹In and simulations of actual small animal imaging. The optimal conditions obtained were validated by in vivo imaging of sarcoma 180-bearing mice.

Results

Larger number of counts must be obtained within limited acquisition time to visualize tumor heterogeneity in vivo in animal imaging, compared to cases that simply detect tumors. At an acquisition time of 30?min, better image quality was obtained with pinhole apertures diameter of 1.4?mm than of 1.0?mm. The obtained best spatial resolution was 1.3?mm, it was acceptable for our purpose, though a little worse than the best possible performance of the scanner (1.0?mm). Additionally, the reconstruction parameters, such as noise suppression, voxel size, and iteration/subset number, needed to be optimized under the limited conditions and were different from those found under the ideal condition. The minimal radioactivity concentration for visualization of heterogeneous tumor interiors was estimated to be as high as 0.2?C0.5?MBq/mL. Liposomes containing ¹¹¹In met this requirement and were administered to tumor-bearing mice. SPECT imaging successfully showed heterogeneous ¹¹¹In distribution within the tumors in vivo with good spatial resolution. A threshold of 0.2?MBq/g for clear visualization of tumor heterogeneity was validated. Autoradiograms obtained ex vivo of excised tumors confirmed that the in vivo SPECT images accurately depicted the heterogeneous intratumoral accumulation of liposomes.

Conclusion

Intratumoral heterogeneity was successfully visualized under the optimized conditions using a SPECT/CT scanner.     

Predictive Factors for Change of Diabetes Mellitus Status After Pancreatectomy in Preoperative Diabetic and Nondiabetic Patients

Introduction

This study aimed to determine risk factors for exacerbation of diabetes mellitus (DM) after pancreatectomy.

Methods

Medical records of 167 patients with benign and malignant pancreaticobiliary diseases who underwent pancreaticoduodenectomy or distal pancreatectomy were retrospectively analyzed. DM was diagnosed by diabetic history or American Diabetes Association criteria. Worsened and improved DM after pancreatectomy was defined when treatment intensity or insulin/oral antidiabetic drug dosage increased or decreased, respectively, postoperatively. Long-standing DM was defined as a duration of >2 years.

Results

In 76 preoperative diabetic patients, worsened and improved DM was observed postoperatively in 46 (60.5 %) and 9 (11.8 %) patients, respectively. In 91 preoperative nondiabetic patients, 22 (24.2 %) developed new-onset DM after pancreatectomy. Multivariate logistic analysis of the preoperative diabetic patients demonstrated long-standing DM and malignancy as independent predictors for postoperative worsened DM. No patients with long-standing DM or insulin treatment experienced improved DM after pancreatectomy. Multivariate logistic analysis of the preoperative nondiabetic patients showed body mass index of ≥25 and hard pancreatic texture as independent risk factors for new-onset postoperative DM.

Conclusions

These results may enable preoperative evaluation of risk factors for worsened or new-onset DM after pancreatectomy and may help plan intensive care for patients at a high risk of postoperative worsened DM.     

Paraparesis after excision of intrathoracic meningoceles in a patient with neurofibromatosis

Intrathoracic meningocele associated with neurofibromatosis is a rarity. We treated a 16-year-old boy with neurofibromatosis, marked kyphoscoliosis, and two right-sided intrathoracic meningoceles. Because his chief complaints of cough and chest pain were thought to be caused by the meningoceles, resection of these lesions was performed prior to correction of the spinal deformity. On the day after the resection, complete paraplegia developed, followed by recovery to paraparesis. Decompressive lumbar puncture was performed, but intraspinal pressure was normal. Postoperative spinal cord damage and consequent paresis may have resulted from a loss of pressure buffering by the meningocele, which rendered the cord vulnerable to injury. The possibility of a similar unusual complication should be borne in mind when treating patients with intrathoracic meningocele associated with neurofibromatosis. Received: April 17, 2001 / Accepted: August 17, 2001     

Unique multipotent cells in adult human mesenchymal cell populations

We found adult human stem cells that can generate, from a single cell, cells with the characteristics of the three germ layers. The cells are stress-tolerant and can be isolated from cultured skin fibroblasts or bone marrow stromal cells, or directly from bone marrow aspirates. These cells can self-renew; form characteristic cell clusters in suspension culture that express a set of genes associated with pluripotency; and can differentiate into endodermal, ectodermal, and mesodermal cells both in vitro and in vivo. When transplanted into immunodeficient mice by local or i.v. injection, the cells integrated into damaged skin, muscle, or liver and differentiated into cytokeratin 14-, dystrophin-, or albumin-positive cells in the respective tissues. Furthermore, they can be efficiently isolated as SSEA-3(+) cells. Unlike authentic ES cells, their proliferation activity is not very high and they do not form teratomas in immunodeficient mouse testes. Thus, nontumorigenic stem cells with the ability to generate the multiple cell types of the three germ layers can be obtained through easily accessible adult human mesenchymal cells without introducing exogenous genes. These unique cells will be beneficial for cell-based therapy and biomedical research.     

Prevention of postoperative adhesions by a novel honeycomb-patterned poly(lactide) film in a rat experimental model

Intraperitoneal adhesion is a serious problem concerning abdominal surgery. This study evaluated the performance of a honeycomb-patterned poly(lactide) (HCPLA) film as a physical barrier for preventing postoperative adhesion. HCPLA films were prepared using dioleoylphosphatidylethanolamine (DOPE) or a copolymer of dodecylacrylamide and omega-carboxyhexylacrylamide (CAP) as a surfactant (HCPLA-DOPE and HCPLA-CAP, respectively). In an in vivo adhesion prevention experiment, male Sprague-Dawley rats underwent standard cecum abrasion before midline laparotomy. We placed 2 cm x 2 cm HCPLA and flat films on the gliding interfaces; untreated rats formed the control group. After 1 week, adhesion was scored from 0 to 4. No significant difference was observed in the scores among groups, but macroscopic differences in adhesion prevention were observed. The adhesive strength of HCPLA-DOPE (18.1 +/- 1.2 g) to skinless chicken breast was significantly higher than that of the flat film (15.2 +/- 0.8 g, p < 0.05). Further, the adhesion score after 1 week for the HCPLA-DOPE group (1.6 +/- 0.2) was significantly lower than that for the control group (3.0 +/- 0.3, p < 0.05) but comparable to that for the Seprafilm group (1.4 +/- 0.3). These results demonstrated the potential of HCPLA-DOPE as a physical barrier for preventing postoperative adhesion.