Transcriptomic Profiling of Rectus Abdominis Muscle in Women with Gestational Diabetes-Induced Myopathy: Characterization of Pathophysiology and Potential Muscle Biomarkers of Pregnancy-Specific Urinary Incontinence.

Gestational diabetes mellitus (GDM) is recognized as a "window of opportunity" for the future prediction of such complications as type 2 diabetes mellitus and pelvic floor muscle disorders, including urinary incontinence and genitourinary dysfunction. Translational studies have reported that pelvic floor muscle disorders are due to a GDM-induced-myopathy (GDiM) of the pelvic floor muscle and rectus abdominis muscle (RAM). We now describe the transcriptome profiling of the RAM obtained by Cesarean section from GDM and non-GDM women with and without pregnancy-specific urinary incontinence (PSUI). We identified 650 genes in total, and the differentially expressed genes were defined by comparing three control groups to the GDM with PSUI group (GDiM). Enrichment analysis showed that GDM with PSUI was associated with decreased gene expression related to muscle structure and muscle protein synthesis, the reduced ability of muscle fibers to ameliorate muscle damage, and the altered the maintenance and generation of energy through glycogenesis. Potential genetic muscle biomarkers were validated by RT-PCR, and their relationship to the pathophysiology of the disease was verified. These findings help elucidate the molecular mechanisms of GDiM and will promote the development of innovative interventions to prevent and treat complications such as post-GDM urinary incontinence.

Preoperative Oral Carbohydrate Reduces Postoperative Insulin Resistance by Activating AMP-Activated Protein Kinase after Colorectal Surgery.

BACKGROUND: Postoperative insulin resistance (PIR) is a common response after colorectal surgery and an independent risk factor for recovery. Preoperative oral carbohydrate (POC) has been known to reduce PIR. Herein, we investigated whether its mechanism of action involves AMP-activated protein kinase (AMPK) and mTOR/S6K1/insulin receptor substrate-1 (IRS-1) pathways. METHODS: Patients undergoing colorectal cancer resection were randomly assigned to a POC, fasting, or placebo group. The exclusion criteria were association with diseases or intake of medication affecting insulin sensitivity. Pre- and postoperative insulin resistance, and protein phosphorylation of AMPK, mTOR, and IRS-1 in the rectus abdominis muscle were evaluated. RESULTS: From January 2017 to December 2017, 70 patients were randomized and 63 were evaluated. No difference was found in the clinical and operative characteristics among the 3 groups. In the POC group, the levels of blood glucose, blood insulin, and homeostasis model assessment of insulin resistance were significantly lower in the POC group than the fasting and placebo groups, and the insulin sensitivity index was significantly higher. The phosphorylation of AMPK in the POC group was significantly higher than that in the other 2 groups, whereas the phosphorylation of mTOR and IRS-1 was significantly lower. CONCLUSION: PIR involves AMPK and mTOR/S6K1/IRS-1 pathways. POC reduces PIR by the stimulation of AMPK, which suppresses the phosphorylation of mTOR/IRS-1 and attenuates PIR after colorectal resection.

Abdominal Wall Endometriosis: Myofibroblasts as a Possible Evidence of Metaplasia: A Case Report.

In this study, we report about a patient with extra-uterine endometriosis (EM) in the abdominal wall muscle with evident metaplasia based on the abundant alpha smooth muscle actin (ASMA)-expressing myofibroblasts. Laparotomy excision of the abdominal wall EM was done following ultrasonographic evidence of a hypodense swelling in the right rectus abdominis, which was confirmed by MRI. Immunohistochemistry staining for ASMA and collagen I was done, with the results confirming that endometriotic stromal cells expressed both. Anterior abdominal wall endometriosis was suspected because of the patient's history of recurrent EM combined with the cyclic nature of symptoms. MRI is useful in determining the extent of the disease. In case of persisting symptoms even under hormonal treatment, surgical excision is mandatory. The expression of both ASMA and collagen I in and around EM lesions supports the notion of the metaplastic process in the course of disease development.

Impaired mitochondrial oxidative phosphorylation and supercomplex assembly in rectus abdominis muscle of diabetic obese individuals.

AIMS/HYPOTHESIS: Skeletal muscle mitochondrial dysfunction has been documented in patients with type 2 diabetes mellitus; however, specific respiratory defects and their mechanisms are poorly understood. The aim of the current study was to examine oxidative phosphorylation and electron transport chain (ETC) supercomplex assembly in rectus abdominis muscles of 10 obese diabetic and 10 obese non-diabetic individuals. METHODS: Twenty obese women undergoing Roux-en-Y gastric bypass surgery were recruited for this study. Muscle samples were obtained intraoperatively and subdivided for multiple analyses, including high-resolution respirometry and assessment of supercomplex assembly. Clinical data obtained from referring physicians were correlated with laboratory findings. RESULTS: Participants in both groups were of a similar age, weight and BMI. Mitochondrial respiration rates were markedly reduced in diabetic vs non-diabetic patients. This defect was observed during maximal ADP-stimulated respiration in the presence of complex I-linked substrates and complex I- and II-linked substrates, and during maximal uncoupled respiration. There were no differences in fatty acid (octanoyl carnitine) supported respiration, leak respiration or isolated activity of cytochrome c oxidase. Intriguingly, significant correlations were found between glycated haemoglobin (HbA1c) levels and maximal respiration or respiration supported by complex I, complex I and II or fatty acid. In the muscle of diabetic patients, blue native gel electrophoresis revealed a striking decrease in complex I, III and IV containing ETC supercomplexes. CONCLUSIONS/INTERPRETATION: These findings support the hypothesis that ETC supercomplex assembly may be an important underlying mechanism of muscle mitochondrial dysfunction in type 2 diabetes mellitus.

[The role of Foxo1 and ubiquitin-proteasome system markers in muscle atrophy caused by chronic kidney disease].

OBJECTIVE: To identity whether there is muscle atrophy phenomenon in end-stage kidney disease patients and to detect the level of transcription factor Foxo1 and the activity of ubiquitin-proteasome system. METHODS: Twenty-two patients in chronic kidney disease (CKD) stage 5 were selected and their mean muscle cross sectional area was measured. mRNA and protein levels of Foxo1, Atrogin-1, MuRF1 in rectus abdominis biopsies obtained from consecutive patients were detected. Control biopsies were obtained from 8 healthy subjects during elective surgery for abdominal wall hernias and 6 subjects during elective surgery for adenomyosis. RESULTS: Compared with the control group, cross sectional area of muscle fibers decreased and the transcription and protein levels of Foxo1, Atrogin-1, MuRF1 were upregulated in CKD group (P < 0.05). Protein level of p-Foxo1 decreased in CKD group (P < 0.05). CONCLUSION: There exist muscle atrophy phenomenon in CKD patients, which may associate with the upregulation of Foxo1 and activation of ubiquitin-proteasome system.

MuRF-1 and p-GSK3ß expression in muscle atrophy of cirrhosis.

BACKGROUND: Chronic diseases, including cirrhosis, are often accompanied by protein-energy malnutrition and muscle loss, which in turn negatively affect quality of life, morbidity and mortality. Unlike other chronic conditions, few data are available on the molecular mechanisms underlying muscle wasting in this clinical setting. AIMS: To assess mechanisms of muscle atrophy in patients with cirrhosis. METHODS: Nutritional [subjective global assessment (SGA) and anthropometry] and metabolic assessment was performed in 30 cirrhotic patients awaiting liver transplantation. Rectus abdominis biopsies were obtained intraoperatively in 22 cirrhotic patients and in 10 well-nourished subjects undergoing elective surgery for non-neoplastic disease, as a control group. Total RNA was extracted and mRNA for atrogenes (MuRF-1, Atrogin-1/MAFbx), myostatin (MSTN), GSK3ß and IGF-1 was assayed. RESULTS: A total of 50% of cirrhotic patients were malnourished based on SGA, while 53% were muscle-depleted according to mid-arm muscle area (MAMA<5th percentile). MuRF-1 RNA expression was significantly increased in malnourished cirrhotic patients (SGA-B/C) vs. well-nourished patients (SGA-A) (P = 0.01). The phosphorylation of GSK3ß was up-regulated in cirrhotic patients with hepatocellular carcinoma (HCC) vs. patients without tumour (P < 0.05). CONCLUSIONS: Muscle loss is frequently found in end-stage liver disease patients. Molecular factors pertaining to signalling pathways known to be involved in the regulation of muscle mass are altered during cirrhosis and HCC.

Pathological effects of processed bovine pericardial scaffolds--a comparative in vivo evaluation.

The objective of the present study was to assess the biocompatibility and regenerative potential of decellularized bovine pericardial scaffold in comparison with glutaraldehyde-treated and fresh bovine pericardial implants using short-term intramuscular implantation testing in a rat model. The inflammatory and immune responses were assessed using histopathological examination, special stains for connective tissue, histomorphometric evaluation, and immunohistochemistry. The decellularized pericardium showed an active tissue remodeling response with complete cellular invasion, minimum connective tissue encapsulation, extensive fibrovascular tissue formation, and collagen deposition. On the contrary, the glutaraldehyde-treated pericardial implants showed incomplete degradation and cellular invasion, while the fresh pericardial implants elicited a severe foreign body reaction. The results of immunohistochemical staining revealed a minimum T helper (CD4+) lymphocyte response in decellularized pericardial implants compared with its glutaraldehyde-treated and fresh counterparts. The decellularized bovine pericardium was better accepted as a prosthetic scaffold, which permitted maximum collagen deposition and active tissue remodeling by invading host cells and showed good tissue integration in vivo compared with glutaraldehyde-treated and fresh/untreated pericardium.

Fluid resuscitation of hemorrhagic shock with hemoglobin vesicles in Beagle dogs: pilot study.

Resuscitation of hemorrhagic shock requires volume replacement and restoration of oxygen metabolism. Artificial oxygen carriers that can both expand blood volume and deliver oxygen have been developed as resuscitation fluids. We employed hemoglobin vesicles (HbV), a cellular-type artificial oxygen carrier, in a Beagle dog hemorrhagic shock model to prove the efficacy of HbV. Hemorrhagic shock was introduced in splenectomized Beagle dogs by withdrawing 50% of circulating blood from the femoral artery. Shock was maintained for 60 minutes before isovolemic resuscitation with HbV dispersed in 5% albumin in saline (HbV), lactated Ringer's solution (LR), 5% human serum albumin in saline (HSA), or autologous shed blood (ASB). One animal in the LR group died 150 min after resuscitation. All other animals survived 4 h of the experiment. The mean arterial pressure remained significantly lower in the LR group than in the HbV group but did not differ significantly among the HbV, Alb, and ASB groups. Immediately after resuscitation, the HbV group showed a significantly higher mean pulmonary arterial pressure, which decreased within 10 minutes to the baseline level. The cardiac output was significantly higher in the Alb group than in the others, indicating compensation for low oxygen delivery per unit blood. The post-resuscitation hematocrit was 36% in the ASB group and decreased in the other groups (20-22%). Serum chemistry data from the HbV group were unremarkable. HbV contributed 32% of the post-resuscitation oxygen delivery. Collectively, HbV is comparable to ASB and HSA as a resuscitation fluid and is an effective oxygen carrier.

Basal protein synthesis rates differ between vastus lateralis and rectus abdominis muscle.

BACKGROUND: In vivo muscle protein synthesis rates are typically assessed by measuring the incorporation rate of stable isotope labelled amino acids in skeletal muscle tissue collected from vastus lateralis muscle. It remains to be established whether muscle protein synthesis rates in the vastus lateralis are representative of muscle protein synthesis rates of other muscle groups. We hypothesized that post-absorptive muscle protein synthesis rates differ between vastus lateralis and rectus abdominis, pectoralis major, or temporalis muscle in vivo in humans. METHODS: Twenty-four patients (62 ± 3 years, 42% female), scheduled to undergo surgery, participated in this study and underwent primed continuous intravenous infusions with l-[ring-13 C6 ]-phenylalanine. During the surgical procedures, serum samples were collected, and muscle tissue was obtained from the vastus lateralis as well as from the rectus abdominis, pectoralis major, or temporalis muscle. Fractional mixed muscle protein synthesis rates (%/h) were assessed by measuring the incorporation of l-[ring-13 C6 ]-phenylalanine into muscle tissue protein. RESULTS: Serum l-[ring-13 C6 ]-phenylalanine enrichments did not change throughout the infusion period. Post-absorptive muscle protein synthesis rates calculated based upon serum l-[ring-13 C6 ]-phenylalanine enrichments did not differ between vastus lateralis and rectus abdominis (0.032 ± 0.004 vs. 0.038 ± 0.003%/h), vastus lateralis and pectoralis major, (0.025 ± 0.003 vs. 0.022 ± 0.005%/h) or vastus lateralis and temporalis (0.047 ± 0.005 vs. 0.043 ± 0.005%/h) muscle, respectively (P > 0.05). When fractional muscle protein synthesis rates were calculated based upon tissue-free l-[ring-13 C6 ]-phenylalanine enrichments as the preferred precursor pool, muscle protein synthesis rates were significantly higher in rectus abdominis (0.089 ± 0.008%/h) compared with vastus lateralis (0.054 ± 0.005%/h) muscle (P < 0.01). No differences were observed between fractional muscle protein synthesis rates in vastus lateralis and pectoralis major (0.046 ± 0.003 vs. 0.041 ± 0.008%/h) or vastus lateralis and temporalis (0.073 ± 0.008 vs. 0.083 ± 0.011%/h) muscle, respectively. CONCLUSIONS: Post-absorptive muscle protein synthesis rates are higher in rectus abdominis when compared with vastus lateralis muscle. Post-absorptive muscle protein synthesis rates do not differ between vastus lateralis and pectoralis major or temporalis muscle. Protein synthesis rates in muscle tissue samples obtained during surgery do not necessarily represent a good proxy for appendicular skeletal muscle protein synthesis rates.

Myokines in treatment-naïve patients with cancer-associated cachexia.

Cancer-associated cachexia is a complex metabolic syndrome characterized by weight loss and systemic inflammation. Muscle loss and fatty infiltration into muscle are associated with poor prognosis in cancer patients. Skeletal muscle secretes myokines, factors with autocrine, paracrine and/or endocrine action, which may be modified by or play a role in cachexia. This study examined myokine content in the plasma, skeletal muscle and tumor homogenates from treatment-naïve patients with gastric or colorectal stages I-IV cancer with cachexia (CC, N = 62), or not (weight stable cancer, WSC, N = 32). Myostatin, interleukin (IL) 15, follistatin-like protein 1 (FSTL-1), fatty acid binding protein 3 (FABP3), irisin and brain-derived neurotrophic factor (BDNF) protein content in samples was measured with Multiplex technology; body composition and muscle lipid infiltration were evaluated in computed tomography, and quantification of triacylglycerol (TAG) in the skeletal muscle. Cachectic patients presented lower muscle FSTL-1 expression (p = 0.047), higher FABP3 plasma content (p = 0.0301) and higher tumor tissue expression of FABP3 (p = 0.0182), IL-15 (p = 0.007) and irisin (p = 0.0110), compared to WSC. Neither muscle TAG content, nor muscle attenuation were different between weight stable and cachectic patients. Lumbar adipose tissue (AT) index, visceral AT index and subcutaneous AT index were lower in CC (p = 0.0149, p = 0.0455 and p = 0.0087, respectively), who also presented lower muscularity in the cohort (69.2% of patients; p = 0.0301), compared to WSC. The results indicate the myokine profile in skeletal muscle, plasma and tumor is impacted by cachexia. These findings show that myokines eventually affecting muscle wasting may not solely derive from the muscle itself (as the tumor also may contribute to the systemic scenario), and put forward new perspectives on cachexia treatment targeting myokines and associated receptors and pathways.

Specific fibre composition and metabolism of the rectus abdominis muscle of bovine Charolais cattle.

BACKGROUND: An important variability of contractile and metabolic properties between muscles has been highlighted. In the literature, the majority of studies on beef sensorial quality concerns M. longissimus thoracis. M. rectus abdominis (RA) is easy to sample without huge carcass depreciation and may appear as an alternative to M. longissimus thoracis for fast and routine physicochemical analysis. It was considered interesting to assess the muscle fibres of M. rectus abdominis in comparison with M. longissimus thoracis (LT) and M. triceps brachii (TB) on the basis of metabolic and contractile properties, area and myosin heavy chain isoforms (MyHC) proportions. Immuno-histochemical, histochemical, histological and enzymological techniques were used. This research concerned two populations of Charolais cattle: RA was compared to TB in a population of 19 steers while RA was compared to LT in a population of 153 heifers. RESULTS: RA muscle had higher mean fibre areas (3350 microm(2) vs 2142 to 2639 microm(2)) than the two other muscles. In RA muscle, the slow-oxidative fibres were the largest (3957 microm(2)) and the fast-glycolytic the smallest (2868 microm(2)). The reverse was observed in TB muscle (1725 and 2436 microm(2) respectively). In RA muscle, the distinction between fast-oxidative-glycolytic and fast-glycolytic fibres appeared difficult or impossible to establish, unlike in the other muscles. Consequently the classification based on ATPase and SDH activities seemed inappropriate, since the FOG fibres presented rather low SDH activity in this muscle in comparison to the other muscles of the carcass. RA muscle had a higher proportion of I fibres than TB and LT muscles, balanced by a lower proportion either of IIX fibres (in comparison to TB muscle) or of IIA fibres (in comparison to LT muscle). However, both oxidative and glycolytic enzyme activities were lower in RA than in TB muscle, although the LDH/ICDH ratio was higher in RA muscle (522 vs 340). Oxidative enzyme activities were higher in RA than in LT muscle, whereas glycolytic enzyme activity was lower. In RA muscle, contractile and metabolic properties appeared to be less well-correlated than in the two other muscles. CONCLUSIONS: RA muscle has some particularities in comparison to the LT and TB muscles, especially concerning the unusual large cross-section surface of SO fibres and the very low oxidative activity of intermediate IIA fibres.

Neuromuscular junctions are stable in patients with cancer cachexia.

Cancer cachexia is a major cause of patient morbidity and mortality, with no efficacious treatment or management strategy. Despite cachexia sharing pathophysiological features with a number of neuromuscular wasting conditions, including age-related sarcopenia, the mechanisms underlying cachexia remain poorly understood. Studies of related conditions suggest that pathological targeting of the neuromuscular junction (NMJ) may play a key role in cachexia, but this has yet to be investigated in human patients. Here, high-resolution morphological analyses were undertaken on NMJs of rectus abdominis obtained from patients undergoing upper GI cancer surgery compared with controls (N = 30; n = 1,165 NMJs). Cancer patients included those with cachexia and weight-stable disease. Despite the low skeletal muscle index and significant muscle fiber atrophy (P < 0.0001) in patients with cachexia, NMJ morphology was fully conserved. No significant differences were observed in any of the pre- and postsynaptic variables measured. We conclude that NMJs remain structurally intact in rectus abdominis in both cancer and cachexia, suggesting that denervation of skeletal muscle is not a major driver of pathogenesis. The absence of NMJ pathology is in stark contrast to what is found in related conditions, such as age-related sarcopenia, and supports the hypothesis that intrinsic changes within skeletal muscle, independent of any changes in motor neurons, represent the primary locus of neuromuscular pathology in cancer cachexia.

Decreased placental and muscular expression of the fibroblast growth factor 19 in gestational diabetes mellitus.

AIMS/INTRODUCTION: Fibroblast growth factor (FGF)19 has been shown to improve glycemic homeostasis and lipid metabolism in animal models. In humans, decreased FGF19 level has been described in diabetes. The present study aimed to investigate the expression of FGF19 in gestational diabetes mellitus (GDM) patients. MATERIALS AND METHODS: Samples for measurement were obtained from 20 women with GDM and 25 healthy controls. The messenger ribonucleic acid (mRNA) and protein expression levels of FGF19, FGF21 and co-receptor ß-klotho (KLB) in the placenta, rectus muscle and subcutaneous fat tissues were quantified by real-time quantitative polymerase chain reaction, western blot and immunohistochemistry, respectively. RESULTS: Women with GDM had significantly lower mRNA and protein expressions of FGF19 than control women in the placenta (mRNA 0.33 ± 0.05 vs 0.72 ± 0.09; protein 0.34 ± 0.13 vs 0.85 ± 0.20) and rectus muscle (mRNA 0.83 ± 0.11 vs 1.28 ± 0.19; protein 0.78 ± 0.24 vs 1.23 ± 0.39). However, there were no significant differences between GDM women and controls with respect to the expression levels of FGF21 and ß-klotho in the placenta and rectus muscle. There were almost no detectable FGF19 and FGF21 expressions in subcutaneous fat tissue. Furthermore, ß-klotho expression levels were not different between the GDM and control group in subcutaneous fat. CONCLUSIONS: FGF19 expressions are decreased in the placenta and rectus muscle of women with GDM. This might contribute to the pathophysiology or development of GDM.

Initiation factors for translation of proteins in the rectus abdominis muscle from patients on overnight standard parenteral nutrition before surgery.

Previous studies have provided conflicting conclusions concerning the efficacy of improving protein balance in patients by standard intravenous nutrition [TPN (total parenteral nutrition)], which is either explained by suboptimal nutritional regimens or insensitive clinical methods. The aim of the present study was therefore to evaluate the effects on the initiation of translation of skeletal muscle proteins by standard overnight TPN. A total of 12 patients who underwent standard surgery were included. TPN was provided as an all-in-one treatment by constant infusion [0.16 gN.kg(-1) of body weight.day(-1) (30 kcal.kg(-1) of body weight.day(-1))]. Saline-infused patients served as controls. Rectus abdominis muscle biopsies were taken at the time of the operation. The phosphorylation state of the proteins for initiation of translation was quantified. Plasma glucose, and serum insulin, glycerol, triacylglycerols (triglycerides) and NEFAs (non-esterified fatty acids; 'free fatty acids') were not significantly altered during TPN infusion, whereas total plasma amino acids increased, as shown by increases in methionine, phenylalanine, threonine, alanine, arginine, aspartic acid, glycine and histidine (P<0.05). Overnight TPN increased the formation of active eIF4G-eIF4E (where eIF is eukaryotic-initiation factor) complexes (P<0.05), whereas the inhibitory complex 4E-BP1 (eIF4E-binding protein)-eIF4E was moderately decreased (P<0.06). TPN increased the amount of the most phosphorylated form of 4E-BP1 (P<0.05), and increased the amount (P<0.04) and phosphorylation (P<0.01) of p70(S6K) (70 kDa ribosomal protein S6 kinase). In conclusion, an overnight pre-operative constant infusion of standard TPN altered initiation factor complexes, indicating activation of the initiation of protein translation in rectus abdominis muscle in the presence of increased plasma amino acid levels, but without a concomitant increase in energy substrates and insulin. In contrast with our results from previous studies, the methodology used in the present study appears to be more sensitive in reflecting directional changes in human muscle protein synthesis compared with traditional methods, particularly based on measurements of amino acid flux.

Increased Methylene Diphosphonate Uptake in the Rectus Abdominis After Strenuous Exercise.

A 28-year-old man with papillary thyroid cancer underwent bone scintigraphy to assess possible osseous metastasis. He had vigorous workouts 5 days prior, which involved pectorals, rectus abdominis, quadriceps, and glutei. However, the images only showed increased activity in the rectus abdominis, whereas other involved muscles had no obvious uptake. No lesion in the bone was identified.

The relationship between muscle protein content and CT-derived muscle radio-density in patients with upper GI cancer.

INTRODUCTION: Cancer cachexia is a multifactorial syndrome characterized by skeletal muscle loss. Cross-sectional analysis of CT scans is a recognized research method for assessing skeletal muscle volume. However, little is known about the relationship between CT-derived estimates of muscle radio-density (SMD) and muscle protein content. We assessed the relationship between CT-derived body composition variables and the protein content of muscle biopsies from cancer patients. METHODS: Rectus abdominis biopsies from cancer patients (n = 32) were analysed for protein content and correlated with phenotypic data gathered using CT body composition software. RESULTS: Skeletal muscle protein content varied widely between patients (median µg/mg wet weight = 89.3, range 70-141). There was a weak positive correlation between muscle protein content and SMD (r = 0.406, p = 0.021), and a weak positive correlation between protein content and percentage weight change (r = 0.416, p = 0.018). CONCLUSION: The protein content of skeletal muscle varies widely in cancer patients and cannot be accurately predicted by CT-derived muscle radio-density.

Deep sedation with dexmedetomidine in a porcine model does not compromise the viability of free microvascular flap as depicted by microdialysis and tissue oxygen tension.

BACKGROUND: Deep sedation is often necessary after major reconstructive plastic surgery in the face and neck regions to prevent sudden spontaneous movements capable of inflicting mechanical injury to the transplanted musculocutaneous flap(s). An adequate positioning may help to optimize oxygenation and perfusion of the transplanted tissues. We hypothesized that dexmedetomidine, a central alpha2-agonist and otherwise potentially ideal postoperative sedative drug, may induce vasoconstriction in denervated flaps, and thus increase the risk of tissue deterioration. METHODS: Two symmetrical myocutaneous flaps were raised on each side of the upper abdomen in 12 anesthetized pigs. The sympathetic nerve fibers were stripped from the arteries in one of the flaps (denervated flap), while nerve fibers were kept untouched in the other (innervated flap). After simulation of ischemia and reperfusion periods, the animals were randomized to deep postoperative sedation with either propofol (n = 6) or dexmedetomidine (n = 6). Flap tissue metabolism was monitored by microdialysis and tissue-oxygen partial pressure. Glucose, lactate, and pyruvate concentrations were analyzed from the dialysate every 30 min for 4 h. RESULTS: Mean arterial blood pressure was higher in the dexmedetomidine group (P = 0.036). Flap tissue metabolism remained stable throughout the experiment as measured by lactate-pyruvate and lactate-glucose ratios (median ranges 14.3-24.5 for lactate-pyruvate and 0.3-0.6 for lactate-glucose) and by tissue-oxygen partial pressure, and no differences were found between groups. CONCLUSIONS: Our data suggest that dexmedetomidine, even if used for deep sedation, does not have deleterious effects on local perfusion or tissue metabolism in denervated musculocutaneous flaps.

Granular cell tumors of the abdominal wall.

Granular cell tumors (GCT) are found in virtually any body site, including the tongue, skin, subcutaneous tissue, breast, rectum and vulva. However, they are rarely seen in the abdominal wall. We report here on a rare case of GCT in the rectus muscle of the abdominal wall. A 44-year-old woman presented with a non-tender, hard mass in the right lower abdominal wall. Upon microscopic examination, the tumor was found to comprise of large polygonal cells with an abundant eosinophilic granular cytoplasm and round to oval nuclei. Upon immunohistochemical staining, the large cells showed S-100 and CD68 positive granular aggregates in the cytoplasm. Many lysosomes of variable size were observed in the cytoplasm.

Toll-like receptor 4 signalling mediates inflammation in skeletal muscle of patients with chronic kidney disease.

BACKGROUND: Inflammation in skeletal muscle is implicated in the pathogenesis of insulin resistance and cachexia but why uremia up-regulates pro-inflammatory cytokines is unknown. Toll-like receptors (TLRs) regulate locally the innate immune responses, but it is unknown whether in chronic kidney disease (CKD) TLR4 muscle signalling is altered. The aim of the study is to investigate whether in CKD muscle, TLRs had abnormal function and may be involved in transcription of pro-inflammatory cytokine. METHODS: TLR4, phospho-p65, phospho-ikBα, tumour necrosis factor (TNF)-α, phospho p38, Murf 1, and atrogin were studied in skeletal muscle from nondiabetic CKD stage 5 patients (n = 29) and controls (n = 14) by immunohistochemistry, western blot, and RT-PCR. Muscle cell cultures (C2C12) exposed to uremic serum were employed to study TLR4 expression (western blot and RT-PCR) and TLR-driven signalling. TLR4 signalling was abrogated by a small molecule chemical inhibitor or TLR4 siRNA. Phospho AKT and phospho p38 were evaluated by western blot. RESULTS: CKD subjects had elevated TLR4 gene and protein expression. Also expression of NFkB, p38 MAPK and the NFkB-regulated gene TNF-α was increased. At multivariate analysis, TLR4 protein content was predicted by eGFR and Subjective Global Assessment, suggesting that the progressive decline in renal function and wasting mediate TLR4 activation. In C2C12, uremic serum increased TLR4 as well as TNF-α and down-regulated pAkt. These effects were prevented by blockade of TLR4. CONCLUSIONS: CKD promotes muscle inflammation through an up-regulation of TLR4, which may activate downward inflammatory signals such as TNF-α and NFkB-regulated genes.

Premorbid obesity, but not nutrition, prevents critical illness-induced muscle wasting and weakness.

BACKGROUND: The 'obesity paradox' of critical illness refers to better survival with a higher body mass index. We hypothesized that fat mobilized from excess adipose tissue during critical illness provides energy more efficiently than exogenous macronutrients and could prevent lean tissue wasting. METHODS: In lean and premorbidly obese mice, the effect of 5 days of sepsis-induced critical illness on body weight and composition, muscle wasting, and weakness was assessed, each with fasting and parenteral feeding. Also, in lean and overweight/obese prolonged critically ill patients, markers of muscle wasting and weakness were compared. RESULTS: In mice, sepsis reduced body weight similarly in the lean and obese, but in the obese with more fat loss and less loss of muscle mass, better preservation of myofibre size and muscle force, and less loss of ectopic lipids, irrespective of administered feeding. These differences between lean and obese septic mice coincided with signs of more effective hepatic fatty acid and glycerol metabolism, and ketogenesis in the obese. Also in humans, better preservation of myofibre size and muscle strength was observed in overweight/obese compared with lean prolonged critically ill patients. CONCLUSIONS: During critical illness premorbid obesity, but not nutrition, optimized utilization of stored lipids and attenuated muscle wasting and weakness.