Basement membrane recovery process in rat soleus muscle after exercise-induced muscle injury.

Purpose: Collagen IV is a component of the basement membrane (BM) that provides mechanical support for muscle fibers. In addition, transcription factor 4 (TCF4) is highly expressed in muscle connective tissue fibroblasts and regulates muscle regeneration. However, the expression of collagen IV and TCF4 (+) cells in response to exercise-induced muscle injury is not well known. Here, we investigated the expression and localization of collagen IV and TCF4 (+) cells during the recovery process after muscle injury induced by different exercise loads.Materials and Methods: Muscle injury was observed in the soleus muscle of young Wistar rats after 12 or 18 sets-downhill running (DR) on a treadmill. After running, the rats were permitted to recover for a period of 0.5 days, 2 days, or 7 days.Results: Ectopic localization of collagen IV in injured muscle fibers was observed after DR, and the number increased at 0.5 days after 18 sets DR and at 2 days after 12 or 18 sets DR as compared to the number observed at baseline. BM disruption was observed after DR. TCF4 (+) cells appeared in the inside and around injured muscle fibers at 0.5 day of recovery. After 18 sets DR, TCF4 (+) cells were more abundant for a longer period than that observed after 12 sets DR.Conclusions: DR induces BM disruption accompanied by muscle fiber damage. It is possible that BM destruction may be accompanied by muscle damage and that TCF4 (+) cells contribute to muscle fiber and BM recovery.

Differences in capillary architecture, hemodynamics, and angiogenic factors in rat slow and fast plantarflexor muscles.

INTRODUCTION: The capillary architecture in skeletal muscles is unique in that it has anastomoses that interconnect individual capillaries. METHODS: We used new techniques to measure velocity of red blood cells (V(RBC) ) in both capillaries and anastomoses in situ. The volume of capillaries/anastomoses was determined, and the levels of several angiogenic regulators were compared between the soleus and the superficial gastrocnemius (LG(sup) ). RESULTS: The V(RBC) in both capillaries and anastomoses was slower in soleus than in LG(sup) . The numbers of capillaries and anastomoses were higher, diameter of capillaries smaller, and tortuosity greater in soleus than in LG(sup) . Consequently, the capillary/anastomoses volume was larger in soleus than in LG(sup) . Furthermore, several angiogenic regulators (HIF-1α, VEGF, Flt-1, KDR, angiopoietin-1 and -2, and Tie-2) were higher in soleus than in LG(sup) . CONCLUSION: The differences in microvascular architecture, V(RBC) , and levels of angiogenic regulators between soleus and LG(sup) reflect the greater oxygen demands of the highly active soleus muscle.

Abnormalities in the fiber composition and capillary architecture in the soleus muscle of type 2 diabetic Goto-Kakizaki rats.

Type 2 diabetes mellitus is linked to impaired skeletal muscle glucose uptake and storage. This study aimed to investigate the fiber type distributions and the three-dimensional (3D) architecture of the capillary network in the skeletal muscles of type 2 diabetic rats. Muscle fiber type transformation, succinate dehydrogenase (SDH) activity, capillary density, and 3D architecture of the capillary network in the soleus muscle were determined in 36-week-old Goto-Kakizaki (GK) rats as an animal model of nonobese type 2 diabetes and age-matched Wistar (Cont) rats. Although the soleus muscle of Cont rats comprised both type I and type IIA fibers, the soleus muscle of GK rats had only type I fibers. In addition, total SDH activity in the soleus muscle of GK rats was significantly lower than that in Cont rats because GK rats had no high-SDH activity type IIA fiber in the soleus muscle. Furthermore, the capillary diameter, capillary tortuosity, and microvessel volume in GK rats were significantly lower than those in Cont rats. These results indicate that non-obese diabetic GK rats have muscle fiber type transformation, low SDH activity, and reduced skeletal muscle capillary content, which may be related to the impaired glucose metabolism characteristic of type 2 diabetes.

PGC-1α mRNA level and oxidative capacity of the plantaris muscle in rats with metabolic syndrome, hypertension, and type 2 diabetes.

We examined the fiber profiles and the mRNA levels of peroxisome proliferator-activated receptors (PPARα and PPARδ/ß) and of the PPARγ coactivator-1α (PGC-1α) in the plantaris muscles of 15-week-old control (WR), metabolic syndrome (CP), hypertensive (SHR), and type 2 diabetic (GK) rats. The deep regions in the muscles of SHR and GK rats exhibited lower percentages of high-oxidative type I and IIA fibers and higher percentages of low-oxidative type IIB fibers compared with WR and CP rats. The surface regions in the muscles of CP, SHR, and GK rats exhibited lower percentages of high-oxidative type IIA fibers and higher percentages of low-oxidative type IIB fibers compared with WR rats. The muscles of SHR and GK rats had lower oxidative enzyme activity compared with WR rats. The muscles of SHR rats had the lowest PPARδ/ß mRNA level. In addition, the muscles of SHR and GK rats had lower PGC-1α mRNA level compared with WR and CP rats. We concluded that the plantaris muscles of rats with hypertension and type 2 diabetes have lower oxidative capacity, which is associated with the decreased level of PGC-1α mRNA.

Effects of hyperbaric oxygenation on blood pressure levels of spontaneously hypertensive rats.

Five-week-old normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were subjected to hyperbaric oxygenation with an enhanced atmospheric pressure (950 mmHg) and an increased oxygen concentration (36%) for 6 h per day. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were monitored for 8 weeks of hyperbaric oxygenation period. After 8 weeks of hyperbaric oxygenation, the derivatives of reactive oxygen metabolites (dROMs) and biological antioxidant potentials (BAPs) were measured. After 5 weeks of hyperbaric oxygenation, the hyperbaric group of WKY exhibited lower SBP than the age-matched normobaric group, while there were no differences in the DBP between the normobaric and hyperbaric groups. After 3 and 7 weeks of hyperbaric oxygenation, the hyperbaric group of SHR exhibited lower SBP and DBP than the age-matched normobaric group. The hyperbaric groups of both WKY and SHR exhibited lower dROMs than the respective normobaric groups. There were no differences in BAPs between the normobaric and hyperbaric groups of WKY. In contrast, the hyperbaric group of SHR exhibited higher BAPs than the normobaric group. We conclude that the hyperbaric oxygenation conditions used in this study effectively repress hypertension.

Comparison of capillary architecture between slow and fast muscles in rats using a confocal laser scanning microscope.

The skeletal muscle is classified into 2 types, slow oxidative or fast glycolytic muscle. For further characterization, we investigated the capillary architecture in slow and fast muscles. The rat soleus and extensor digitorum longus (EDL) muscles were used as representatives of slow and fast muscles, respectively. To investigate capillary density, sections of both types of muscle were stained with alkaline phosphatase; the soleus muscle showed more intense reactivity, indicating that it had a denser capillary structure than the EDL muscle. We then injected fluorescent contrast medium into samples of both muscle types for light and confocal-laser microscopic evaluation. The capillary density and capillary-to-fiber ratio were significantly higher, and the course of the capillaries was more tortuous, in the soleus muscle than in the EDL muscle. Capillary coursed more tortuously in the soleus than in the EDL muscle. Succinate dehydrogenase (SDH) activity, an indicator of mitochondrial oxidative capacity, and vascular endothelial growth factor (VEGF) expression were also significantly higher in the soleus muscle. Thus, we conclude that slow oxidative muscle possess a rich capillary structure to provide demanded oxygen, and VEGF might be involved in the formation and/or maintenance of this highly capillarized architecture.

Thermal preconditioning prevents fiber type transformation of the unloading induced-atrophied muscle in rats.

Muscle atrophy is accompanied by a slow-to-fast transformation of the slow muscle, e.g., the soleus muscle, which is characterized by a decrease in the expression of the slow myosin heavy chain (MyHC) isoform. Heat stress before hindlimb unloading, i.e., thermal preconditioning, has been shown to reduce the rate of disuse-induced muscle atrophy. The present study examined whether thermal preconditioning could prevent a slow-to-fast transformation of the MyHC isoform through the induction of heat-shock protein (HSP) 72. Thermally preconditioned rats (Heat + HU) were individually placed in an environmentally controlled heat chamber for 1 h before hindlimb unloading for 2 weeks (HU). Although the mean fiber cross-sectional areas of the soleus muscle decreased in the HU and Heat + HU group, the loss of myofibrillar protein was attenuated in the Heat + HU group. Furthermore, a slow-to-fast transformation of MyHC isoform was inhibited in the Heat + HU group with the overexpression of HSP72. These results indicate that thermal preconditioning before hindlimb unloading attenuates the decrease of the slow MyHC isoform in the soleus muscle. Therefore, thermal preconditioning provides a new approach to prevent disuse-induced fiber type transformation of skeletal muscle.

Effects of aging on basement membrane of the soleus muscle during recovery following disuse atrophy in rats.

Aging is known to lead to the impaired recovery of muscle after disuse as well as the increased susceptibility of the muscle to damage. Here, we show that, in the older rats, reloading after disuse atrophy, causes the damage of the muscle fibers and the basement membrane (BM) that structurally support the muscle fibers. Male Wistar rats of 3-(young) and 20-(older) months of age were subjected to hindlimb-unloading for 2weeks followed by reloading for a week. In the older rats, the soleus muscles showed necrosis and central nuclei fiber indicating the regeneration of muscle fibers. Furthermore, ectopic immunoreactivity of collagen IV, a major component of the BM, remained mostly associated with the necrotic appearance, suggesting that the older rats were impaired with the ability of repairing the damaged BM. Further, after unloading and reloading, the older rats did not show a significant alteration, although the young rats showed clear response of Col4a1 and Col4a2 genes, both coding for collagen IV. In addition, during the recovery phase, the young rats showed increase in the amount of Hsp47 and Sparc mRNA, which are protein folding-related factor genes, while the older rats did not show any significant variation. Taken together, our findings suggest that the atrophic muscle fibers of the older rats induced by unloading were vulnerable to the weight loading, and that attenuated reactivity of the BM-synthesizing fibroblast to gravity contributes to the fragility of muscle fibers in the older animals.

Regression of capillary network in atrophied soleus muscle induced by hindlimb unweighting.

Little is known about the mechanisms responsible for the adaptation and changes in the capillary network of hindlimb unweighting (HU)-induced atrophied skeletal muscle, especially the coupling between functional and structural alterations of intercapillary anastomoses and tortuosity of capillaries. We hypothesized that muscle atrophy by HU leads to the apoptotic regression of the capillaries and intercapillary anastomoses with their functional alteration in hemodynamics. To clarify the three-dimensional architecture of the capillary network, contrast medium-injected rat soleus muscles were visualized clearly using a confocal laser scanning microscope, and sections were stained by terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) and with anti-von Willebrand factor. In vivo, the red blood cell velocity of soleus muscle capillaries were determined with a pencil-lens intravital microscope brought into direct contact with the soleus surface. After HU, the total muscle mass, myofibril protein mass, and slow-type myosin heavy chain content were significantly lower. The number of capillaries paralleling muscle fiber and red blood cells velocity were higher in atrophied soleus. However, the mean capillary volume and capillary luminal diameter were significantly smaller after HU than in the age-matched control group. In addition, we found that the number of anastomoses and the tortuosity were significantly lower and TUNEL-positive endothelial cells were observed in atrophied soleus muscles, especially the anastomoses and/or tortuous capillaries. These results indicate that muscle atrophy by HU generates structural alterations in the capillary network, and apoptosis appears to occur in the endothelial cell of the muscle capillaries.

Anti-ribosomal P antibodies are associated with nephritis, vascular thrombosis and lymphocytopenia in patients with systemic lupus erythematosus.

In the present study, anti-ribosomal P antibody in sera of patients with systemic lupus erythematosus was assayed using an enzyme-linked immunosorbent assay, and its association with clinical symptoms of the patients was analyzed. The presence of anti-ribosomal P antibody was associated with increased frequency of lupus nephritis in the presence of anti-DNA antibody, and was associated with increased frequency of vascular thrombosis in the presence of anti-beta2 glycoprotein I antibody and/or lupus anticoagulant. The level of anti-ribosomal P antibody correlated inversely with the peripheral lymphocyte counts.

Is bypass graft technique effective in arteriovenous graft?

BACKGROUND: Arteriovenous graft (AVG) requires percutaneous transluminal angioplasty (PTA) to maintain its patency; however, bypass graft technique is often chosen in cases requiring PTA again within 3 months. We retrospectively examined whether bypass graft technique is effective for AVG. METHODS: The sample patient population consisted of 50 patients who underwent bypass graft technique on the venous side of the AVG between April 2012 and March 2014. The primary and assisted patencies of the technique were calculated, and compared by the type and length of the bypass graft. Kaplan-Meier method and log-rank test were used for the calculation and comparison of the patency, respectively. p<0.05 was considered statistically significant. RESULTS: The reasons for surgery were thrombotic occlusion (27 cases), frequent PTA (15 cases) and others (8 cases). Frequent PTA was conducted within 3 months in 22 of 27 thrombotic occlusion cases (making 37/50, or 74%). Moreover, thrombectomy was required in 34 cases (68%). The 1-year primary and 1-year assisted patencies of the technique were 6.5% and 72.6%, respectively. When the endpoint was frequent PTA within 3 months after the technique, 1-year primary patency was 45.9%. CONCLUSIONS: The 1-year primary patency of the technique was poor, and patency was hard to maintain without the assistance of PTA. Given that frequent PTA was conducted in 74% of patients, it may be a cause for the poor patency. Many cases required thrombectomies, which have the disadvantage of being more invasive than PTA. We concluded that bypass graft technique is not valuable for cases that received frequent PTA.

Electromyographic analysis of a modified maneuver for quadriceps femoris muscle setting with co-contraction of the hamstrings.

A "quadriceps femoris muscle setting" is isometric quadriceps femoris exercise which can be widely used in early knee rehabilitation. However this exercise cannot obtain enough co-contraction of the hamstrings. Isolated quadriceps femoris contraction in knee extension imposes severe strain to anterior cruciate ligament. We succeeded in developing a simple training maneuver that is effective in obtaining co-contraction of the hamstrings--a modified maneuver for the quadriceps femoris muscle setting with the contralateral lower limb raised (MQS). In this study, we analyzed the effect of this maneuver by EMG quantification. Twenty-eight healthy young adult men performed sequential trials consisting of normal quadriceps femoris muscle setting (NQS) and MQS. Electromyographic activity was recorded from surface electrodes on the gluteus maximus, vastus medialis, rectus femoris, vastus lateralis, semitendinosus and biceps femoris (long head), and normalized to values derived from maximal isometric trials. The % maximal voluntary isometric contraction (%MVIC) of the vastus medialis, vastus lateralis and rectus femoris did not vary in the each maneuver. However, the %MVIC of the hamstrings varied significantly in the MQS. This study suggests that effective co-contraction of the hamstrings can be obtained in MQS by adjusting the load to the raised lower limb.

Suture line recurrence in jejunal pouch replaced after total gastrectomy for gastric cancer.

We report a case of suture line recurrence in a jejunal pouch, diagnosed 4 months after total gastrectomy for advanced gastric cancer. The jejunal pouch was made with a linear stapler, without intraluminal irrigation being carried out before anastomosis, and was replaced in an interposition fashion. We propose that the recurrence was caused by the implantation of exfoliated cancer cells in either the intraluminal mucus or on a contaminated stapling device.

High frequency of anti-ribosomal P antibody in patients with systemic lupus erythematosus-associated hepatitis.

Hepatic manifestations are a common phenomenon in patients with systemic lupus erythematosus (SLE). However, their cause may be difficult clinically to determine. A significantly increased frequency of anti-ribosomal P antibody has recently been found in patients with SLE-associated hepatitis. Thus, we examined the prevalence of anti-ribosomal P antibody and clinical differences between anti-ribosomal P antibody positive and negative SLE patients with liver dysfunction using ELISA kits against recombinant ribosomal P0 protein. Sera of 61 patients with SLE and 20 patients with autoimmune hepatitis (AIH) were assayed. Of 34 SLE patients with liver dysfunction, anti-ribosomal P antibody was detected in 15 (44.1%), consisting of 11 (68.8%) of 16 patients with SLE-associated hepatitis, 2 (28.6%) of 7 patients with fatty liver, 1 (16.7%) of 6 patients with drug-induced hepatitis, and 1 (20.0%) of 5 patients with SLE complicated by AIH. This antibody was not detected in patients with AIH. Except for those with SLE-associated hepatitis, anti-ribosomal P antibody positive patients were complicated by renal dysfunction and CNS lupus. The positive rate of anti-ribosomal P antibody was significantly higher in patients with SLE-associated hepatitis (68.8%) than in patients with SLE complicated by AIH (20%) ( [Formula: see text] ) and AIH (0%) ( [Formula: see text] ). These findings suggest that anti-ribosomal P antibody may be a useful marker of SLE-associated hepatitis to differentiate it from AIH and other liver dysfunctions in SLE patients without renal dysfunction or CNS lupus.

Clinicolaboratory characteristics of patients with primary biliary cirrhosis associated with CREST symptoms.

Aims: Patients with primary biliary cirrhosis (PBC) occasionally suffer complications from other autoimmune diseases. When PBC was associated with calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly and telangiectasias (CREST) symptoms, it has been proposed that it is a distinct clinical entity. This study aimed to investigate whether PBC associated with CREST symptoms is a distinct disease complex. Method: Clinicolaboratory data, HLA type of leukocytes and disease prognosis were compared between 31 patients with PBC associated with CREST symptoms and 68 patients with PBC alone. Results: The characteristic findings and significant differences observed in patients with PBC associated with CREST symptoms compared with PBC alone are as follows: all women with older age with milder clinical features of both PBC (asymptomatic PBC in 84%) and CREST syndrome (incomplete CREST in 81%), more frequent occurrence of esophageal varices (28.6 vs. 9.3%), better prognosis (87.5 vs. 45.5% in 10 years survival), lower serum levels of AST (39.8 vs. 63.6 IU/l) and IgM (460 vs. 676 mg/dl), higher prevalence of discrete speckled pattern of antinuclear antibodies (93.5 vs. 12.3%), higher median titers of anti-CENP-B antibodies (1.22 vs. 0.31), lower median titers of antimitochondrial antibody (1:80 vs. 1:160), and a higher prevalence of HLA-DR9 (54.5 vs. 24.3%). Conclusion: These findings support the presence of a subgroup in PBC as PBC associated with CREST symptoms.

Elderly onset rheumatoid arthritis complicated by polymyalgia rheumatica.

We report herein the case of a 70-year-old patient with elderly onset rheumatoid arthritis associated with severe muscle pain in shoulder and pelvic girdle. The patient revealed erosive polyarthritis with high titers of rheumatoid factor. Muscle pain started one month after the onset of rheumatoid arthritis followed by muscle weakness and muscle atrophy. Synovial effusion and edema in the soft tissue outside of the articular capsule in the knee joint were confirmed ultrasonographically. Administration of prednisolone at 20 mg/day dramatically abolished the muscular manifestations. The coexistence of an early stage of elderly onset rheumatoid arthritis and polymyalgia rheumatica was considered due to the presence of seropositive erosive arthritis and severe muscle manifestations at the same time.

An anti-nuclear antibody-negative patient with systemic lupus erythematosus (SLE) accompanied with anti-ribosomal P antibody (anti-P).

We report a case of an anti-nuclear antibody (ANA)-negative patient with systemic lupus erythematosus (SLE) accompanied with anti-phospholipid antibody syndrome (APS) and lupus nephritis (LN). Histological examination of placenta obtained by an artificially-induced abortion revealed multiple thromboses in the placental villi. Histology of biopsied kidney tissue revealed minimal change with deposits of immunoglobulin and complement. Anti-ribosomal P antibodies (anti-P) and lupus anticoagulant (LAC) were positive and anti-double stranded DNA antibody (anti-DNA) showed only a slightly positive titer in her serum. The intensity of proteinuria of the patient was correlated with the anti-P, but not anti-DNA titers.

Prospective study of a high-intensity interferon-alpha regimen for chronic hepatitis C virus genotype 1b infection.

BACKGROUND/AIMS: To evaluate efficacy of high-intensity interferon administration for patients chronically infected with hepatitis C virus genotype 1b, we administered interferon-alpha with different regimens according to viral load. METHODOLOGY: Eighty-eight patients with hepatitis C virus genotype 1b were treated with recombinant interferon alpha-2b. The 70 patients with pretreatment hepatitis C virus RNA concentration > or = 10(6) copies/mL were given 10(7) units of interferon daily for the first 8 weeks and then three times weekly for 16 weeks (group A). The 18 patients with smaller pretreatment hepatitis C virus RNA concentration received the same dose daily for the first 2 weeks and then three times weekly for 14 weeks (group B). We analyzed tolerance of therapy, responses, and long-term outcome in the two groups. RESULTS: Fifteen of 70 patients (21.4%) in group A could not continue treatment and dropped out, while all patients in group B completed the entire course of therapy. The rate of sustained response in group A was 10.0%, being significantly less than in group B (72.2%; p < 0.0001). However, 12 patients in group A showed a biochemical sustained response despite presence of viremia. Long-term outcome did not differ between groups. CONCLUSIONS: Many patients could not tolerate high-intensity therapy, which showed the limitation of tolerance of patients receiving interferon monotherapy. High-intensity therapy could not improve eradication of hepatitis C virus in patients with high pretreatment hepatitis C virus RNA concentration. However, this therapy may increase the rate of sustained biochemical response, improving long-term outcome.

Incidence of hepatocellular carcinoma in chronic hepatitis C after interferon therapy.

BACKGROUND/AIMS: We investigated the rate of occurrence and the risk factors for hepatocellular carcinoma in chronic hepatitis C patients who received interferon therapy. METHODOLOGY: We followed 413 chronic hepatitis C patients for more than 6 years after interferon therapy and assessed the following patient characteristics: age, sex, platelet count, response to interferon, hepatitis C virus RNA level, hepatitis C virus genotype, liver histology, and changes in serum alanine aminotransferase levels. RESULTS: Hepatocellular carcinoma was found in 21 patients after interferon therapy. The factor most related to the occurrence of hepatocellular carcinoma was changes in serum alanine aminotransferase levels (univariate analysis, P < 0.0001; multivariate analysis, P = 0.0013), followed by age (univariate analysis, P = 0.0003; multivariate analysis, P = 0.0029). A significant difference was observed in the platelet count and response to interferon based on univariate analysis alone (P = 0.0096, P = 0.0241, respectively), however no significant differences were noted in the other factors. The course of serum alanine aminotransferase levels following interferon therapy rather than the eradication of hepatitis C virus was found to be the factor most profoundly involved in liver carcinogenesis. CONCLUSIONS: Even if interferon therapy fails to eradicate the hepatitis C virus, maintaining low serum alanine aminotransferase levels post-interferon therapy would reduce the risk of hepatocellular carcinoma in chronic hepatitis C.

A case of polyarteritis nodosa limited to lower legs with a high titer of MPO-ANCA under precedence of idiopathic pulmonary fibrosis.

A 58-year-old man with a 15-year history of idiopathic pulmonary fibrosis was hospitalized for rapid progression of muscle weakness to bilateral foot drop. Although laboratory data revealed high titers of myeloperoxidase anti-neutrophil cytoplasmic antibody (489 EU), the patient was diagnosed as polyarteritis nodosa limited to the lower portions of the legs. Despite of the treatment with large doses of corticosteroids and cyclosporin A, his symptoms barely improved during the following two months.