Depletion of essential fatty acids in muscle is associated with shorter survival of cancer patients undergoing surgery-preliminary report.

Emerging studies are reporting associations between skeletal muscle abnormalities and survival in cancer patients. Cancer prognosis is associated with depletion of essential fatty acids in erythrocytes and plasma in humans. However the relationship between skeletal muscle membrane fatty acid composition and survival is unknown. This study investigates the relationship between fatty acid content of phospholipids in skeletal muscle and survival in cancer patients. Rectus abdominis biopsies were collected during cancer surgery from 35 patients diagnosed with cancer. Thin-layer and gas chromatography were used for quantification of phospholipid fatty acids. Cutpoints for survival were defined using optimal stratification. Median survival was between 450 and 500 days when patients had arachidonic acid (AA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in muscle phospholipid below the cut-point compared to 720-800 days for patients above. Cox regression analysis revealed that low amounts of AA, EPA and DHA are risk factors for death. The risk of death remained significant for AA [HR 3.5 (1.11-10.87), p = 0.03], EPA [HR 3.92 (1.1-14.0), p = 0.04] and DHA [HR 4.08 (1.1-14.6), p = 0.03] when adjusted for sex. Lower amounts of essential fatty acids in skeletal muscle membrane is a predictor of survival in cancer patients. These results warrant investigation to restore bioactive fatty acids in people with cancer.

Overnight Steady-State Infusions of Parenteral Nutrition on Myosin Heavy Chain Transcripts in Rectus Abdominis Muscle Related to Amino Acid Transporters, Insulin-like Growth Factor 1, and Blood Amino Acids in Patients Aimed at Major Surgery.

BACKGROUND: Evaluation of improvements by nutrition support to severely ill patients requires sensitive methods to demonstrate activation of protein synthesis in various tissues from groups with a limited number of patients to be statistically efficient. This study examines effects of standard parenteral nutrition (PN) on abdominal muscle transcripts of amino acid (AA) transporters, myosin heavy chains (MHCs), and the insulin-like growth factor 1 and its receptor (IGF-1/IGF-1R) in patients aimed at major surgery. METHODS: Twenty-two randomized patients received steady-state PN (0.16 gN/kg/d, 30 kcal/kg/d) or saline infusions for 12 hours before operation. Blood samples and muscle biopsies were obtained at operation start. Muscle messenger RNA (mRNA) levels of AA transporters (solute carrier family members SNAT2, LAT1, LAT3, LAT4, TAUT, PAT1, CD98), IGF-1, IGF-1R, MHC isoforms (MHC1, MHC2A, MHC2X), and LAT3 protein were quantified and related to concentrations of AA, IGF-1, insulin, and metabolic substrates in blood. RESULTS: Muscle mRNA LAT3, LAT4, IGF-1R, and MHC2A increased by PN infusion, with correlations to specific AA transporters and MHC isoforms (P < .01-.05). TAUT and LAT3 correlated to slow (MHC1) and fast (MHC2A, MHC2X) isoforms (P < .001-.02). Muscle IGF-1 mRNA correlated to plasma essential AAs, whereas IGF-1R mRNA was related to LAT3, MHC2A, and serum IGF-1 (P < .001-.03). CONCLUSIONS: The results confirm that short-term preoperative PN activates transcription of AA transporters and myosin isoforms. Thus, combinations of methods on gene transcription and translation of muscle proteins can be applied to define efficient combinations of nutrition and hormones to catabolic patients in preoperative and postoperative settings.

Glucose level evaluation in monopedicled rectus abdominis myocutaneous flap after venous occlusion: experimental study in rats.

OBJECTIVE: to validate an experimental model for the measurement of glycemic levels in surgical flaps with the use of common glucometers, and to analyze the diagnostic criteria for hypoperfusion of such flaps. METHODS: we performed vertical myocutaneous rectus abdominis flaps with upper pedicles bilaterally in 20 male Wistar rats, divided into two groups: with and without venous occlusion of the pedicle. We measured glucose levels in the flaps and in the systemic circulation with standard glucometers. We tested the accuracy of alternative diagnostic criteria for the detection of hypoperfusion. RESULTS: from 15 minutes of venous occlusion on, there was a significant reduction in glucose levels measured in the congested flap (p<0.001). Using a minimum difference of 20mg/dl in the glycemic levels between the flap and systemic blood, 30 minutes after occlusion, as a diagnostic criterion, the sensitivity was 100% (95% CI 83.99-100%) and specificity of 90% (95% CI 69.90-97.21%) for the diagnosis of flap congestion. CONCLUSION: It is possible to measure glucose levels in vertical myocutaneous rectus abdominis flaps of Wistar rats, perfused or congested, using a common glucometer. The diagnostic criteria that compare the glucose levels in the flaps with the systemic ones were more accurate in the evaluation of tissue perfusion.

Glucose level evaluation in monopedicled rectus abdominis myocutaneous flap after venous occlusion: experimental study in rats / Avaliação do nível glicêmico em retalho miocutâneo do reto abdominal monopediculado após oclusão venosa: estudo experimental em ratos

ABSTRACT Objective: to validate an experimental model for the measurement of glycemic levels in surgical flaps with the use of common glucometers, and to analyze the diagnostic criteria for hypoperfusion of such flaps. Methods: we performed vertical myocutaneous rectus abdominis flaps with upper pedicles bilaterally in 20 male Wistar rats, divided into two groups: with and without venous occlusion of the pedicle. We measured glucose levels in the flaps and in the systemic circulation with standard glucometers. We tested the accuracy of alternative diagnostic criteria for the detection of hypoperfusion. Results: from 15 minutes of venous occlusion on, there was a significant reduction in glucose levels measured in the congested flap (p<0.001). Using a minimum difference of 20mg/dl in the glycemic levels between the flap and systemic blood, 30 minutes after occlusion, as a diagnostic criterion, the sensitivity was 100% (95% CI 83.99-100%) and specificity of 90% (95% CI 69.90-97.21%) for the diagnosis of flap congestion. Conclusion: It is possible to measure glucose levels in vertical myocutaneous rectus abdominis flaps of Wistar rats, perfused or congested, using a common glucometer. The diagnostic criteria that compare the glucose levels in the flaps with the systemic ones were more accurate in the evaluation of tissue perfusion.

RESUMO Objetivo: validar um modelo experimental para mensuração de níveis glicêmicos em retalhos cirúrgicos com a utilização de glicosímetros comuns, e analisar os critérios diagnósticos para hipoperfusão destes retalhos. Métodos: foram realizados retalhos miocutâneos verticais de reto abdominal com pedículos superiores, bilateralmente, em 20 ratos Wistar machos, divididos em dois grupos: com e sem oclusão venosa do pedículo. Os níveis de glicose foram mensurados nos retalhos e na circulação sistêmica com glicosímetros comuns. A acurácia de critérios diagnósticos alternativos foi testada para a detecção de hipoperfusão. Resultados: a partir de 15 minutos de oclusão venosa, houve uma redução significativa dos níveis de glicose medidos no retalho congesto (p<0,001). Utilizando como critério diagnóstico uma diferença mínima de 20mg/dl nos níveis glicêmicos do retalho e do sangue sistêmico, 30 minutos após a oclusão, a sensibilidade foi de 100% (intervalo de confiança de 95% - 83,99 a 100%) e especificidade de 90% (intervalo de confiança de 95% - 69,90 a 97,21%) para o diagnóstico de congestão do retalho. Conclusão: os resultados demonstraram que é possível medir níveis de glicose em retalhos miocutâneos verticais de reto abdominal de ratos Wistar, perfundidos ou congestos, utilizando um glicosímetro comum. Os critérios diagnósticos que comparam os níveis de glicose nos retalhos com os níveis sistêmicos foram mais precisos na avaliação da perfusão tecidual.

Associations among Protein Biomarkers and pH and Color Traits in Longissimus thoracis and Rectus abdominis Muscles in Protected Designation of Origin Maine-Anjou Cull Cows.

This study investigated the relationships among a list of 23 protein biomarkers with CIE-L*a*b* meat color traits and ultimate pH on Longissimus thoracis (LT) and Rectus abdominis (RA) muscles of 48 protected designation of origin Maine-Anjou cows. The technological parameters were correlated with several biomarkers and were in some cases muscle-dependent. More biomarkers were related to pHu in LT than in RA muscle. Some consistencies were found, by the common correlation of pHu with MyHC-IIa and MyHC-IIx. The pHu of the LT muscle was also correlated with other cytoskeletal entities and proteins belonging to metabolism and cellular stress. In contrast to the relationships found between biomarkers and LT pHu, more proteins were related to the instrumental color coordinates in RA than in LT muscle. The regression equations were parameter- and muscle-dependent. Certain of the retained proteins explained more than one color coordinate. Hsp70-Grp75 was positive in the models of L*, a*, b*, and C* of LT and of b* in the RA muscle. Further heat shock proteins were strongly related with the meat color coordinates in both muscles. The involvement of metabolic enzymes and myofibrillar proteins in the meat color development was also verified in this experiment. This study confirmed once again the importance of numerous biological pathways in beef color.

Collagen fibers in the rectus abdominis muscle of cadavers of different age.

PURPOSE: To assess collagen content and types in the rectus abdominis muscle of cadavers of different ages. METHODS: Forty fresh adult male cadavers within 24 h of death were obtained from an Institute of Legal Medicine and divided by age at death into Group 1 (mean age, 23.3 years; range, 18-30 years; n = 20) and Group 2 (mean age, 46.2 years; range, 31-60 years; n = 20). From each cadaver, samples of the rectus abdominis muscle measuring 1 cm(2) were collected 3 cm superiorly and 2 cm inferiorly to the umbilicus. Histological sections were prepared and stained with picrosirius red and Masson's trichrome stain for visualization of total collagen fibers, and immunohistochemical analysis was performed to distinguish types I, II, III, IV and V collagen. RESULTS: No significant differences in total collagen were found between groups by Masson's trichrome staining. However, picrosirius red staining revealed a significantly greater amount and higher concentration of total collagen and types I and III collagen in Group 1 than in Group 2 (P < 0.05). All but type II collagen were detected by immunohistochemistry in both groups. No significant difference in type IV collagen was found between groups. Type V collagen was detected by immunohistochemistry in both groups, but quantification was not possible due to background staining. CONCLUSION: The amounts of types I and III collagen in the rectus abdominis muscle were significantly smaller in older subjects.

Effects of sample size on differential gene expression, rank order and prediction accuracy of a gene signature.

Top differentially expressed gene lists are often inconsistent between studies and it has been suggested that small sample sizes contribute to lack of reproducibility and poor prediction accuracy in discriminative models. We considered sex differences (69♂, 65 ♀) in 134 human skeletal muscle biopsies using DNA microarray. The full dataset and subsamples (n = 10 (5 ♂, 5 ♀) to n = 120 (60 ♂, 60 ♀)) thereof were used to assess the effect of sample size on the differential expression of single genes, gene rank order and prediction accuracy. Using our full dataset (n = 134), we identified 717 differentially expressed transcripts (p<0.0001) and we were able predict sex with ~90% accuracy, both within our dataset and on external datasets. Both p-values and rank order of top differentially expressed genes became more variable using smaller subsamples. For example, at n = 10 (5 ♂, 5 ♀), no gene was considered differentially expressed at p<0.0001 and prediction accuracy was ~50% (no better than chance). We found that sample size clearly affects microarray analysis results; small sample sizes result in unstable gene lists and poor prediction accuracy. We anticipate this will apply to other phenotypes, in addition to sex.

Histologic and immunohistochemical studies of rectus sheath in obese patients.

BACKGROUND: Obesity is a well-established risk factor for incisional hernia development. The exact causative factors have not been clearly defined, and development may result from structural disruptions in the connective tissue of the fasciae. The goal of this study was to compare the content of elastin in the rectus muscle sheath of obese patients and nonobese controls. MATERIALS AND METHODS: The study group consisted of 20 patients with body mass index over 35 kg/m(2) and the control group included 19 patients with normal-range body mass index. The biopsy specimens harvested during surgery were subjected to histologic evaluation, an immunohistochemical reaction with monoclonal anti-elastin antibodies, and the DAB chromatic reaction. The photomicrographs were evaluated using ImageJ software and the percentage of the area affected by the color reaction was assessed. A statistical evaluation was performed. RESULTS: The specimens harvested from persons in the control group showed in hematoxylin-eosin staining a high density of fibrous elements, arranged in regular bundles. In specimens obtained from the morbidly obese, the density of the fibers was lower and their architecture was disrupted; the bundles were thinner and less regularly arranged. Most photographs show adipose tissue infiltrating the structure of the fascia. Statistical analysis of the percentage of the area occupied by elastin showed a statistically significant difference in favor of the controls. CONCLUSIONS: The quantitative and qualitative changes in the elastin content of rectus abdominis muscle sheath fascia in the obese population may indicate a possible local mechanism influencing the development of incisional hernias.

An experimental model for the study of collagen fibers in skeletal muscle.

PURPOSE: To examine histological and histomorphometric techniques for measuring collagen in skeletal muscle. METHODS: The following staining methods were used in the study: hematoxylin and eosin, Masson's trichrome, reticulin, and picrosirius red, and immunostaining for collagen types I, II, III, IV, and V. Histomorphometric measurements were performed using Corel PhotoPaint and UTHSCSA Image Tool 3.0 software. RESULTS: Both the Masson's trichrome and picrosirius red staining provided the best visualization for the measurement of collagen content. CONCLUSION: This methodology is important for the identification and quantification of the different types of collagen in muscles and can be used in the investigation of the qualitative and quantitative influence of collagen on physical activities, aging, and diseases.

An experimental model for the study of collagen fibers in skeletal muscle / Modelo experimental para o estudo de fibras de colágeno no músculo esquelético

PURPOSE: To examine histological and histomorphometric techniques for measuring collagen in skeletal muscle. METHODS: The following staining methods were used in the study: hematoxylin and eosin, Masson's trichrome, reticulin, and picrosirius red, and immunostaining for collagen types I, II, III, IV, and V. Histomorphometric measurements were performed using Corel PhotoPaint and UTHSCSA Image Tool 3.0 software. RESULTS: Both the Masson's trichrome and picrosirius red staining provided the best visualization for the measurement of collagen content. CONCLUSION: This methodology is important for the identification and quantification of the different types of collagen in muscles and can be used in the investigation of the qualitative and quantitative influence of collagen on physical activities, aging, and diseases.

OBJETIVO: Examinar os procedimentos empregados na quantificação do colágeno por métodos histológicos e histomorfométricos. MÉTODOS: Foram utilizadas colorações histológicas por HE, Tricrômico de Masson, Reticulina, Picrossírius e reação imuno-histoquímica para colágeno I, II, III, IV e V. A quantificação histomorfométrica foi realizada utilizando-se os programas Corel PhotoPaint e Image Tool versão 3.0. RESULTADOS: Os métodos histológicos de Masson e Picrossírius apresentaram uma maior facilidade na quantificação do colágeno. CONCLUSÃO: Este modelo é importante para que possa ser identificado e quantificado os diferentes tipos de colágenos nos músculos e relacionar com a atividade física, envelhecimento e doenças.

Immunohistochemical analysis of collagen content and types in the rectus abdominis muscle of cadavers of different ages.

PURPOSE: To assess the collagen content and types in the rectus abdominis muscle of cadavers of different ages. METHODS: Forty fresh adult male cadavers, at room temperature, were obtained from the Institute of Legal Medicine of Franca and dissected within 24 hours of death. The cadavers were divided into two groups: Group A (n=20), 18 to 30 years of age, and Group B (n=20), 31 to 60 years of age. Bilateral incisions were made in the middle portion of anterior rectus sheath 3 cm superiorly and 2 cm inferiorly to the umbilicus and four fragments of the rectus abdominis muscle were dissected. The samples were fixed in 10% buffered formalin and sent for immunohistochemical analysis to determine collagen content and types. RESULTS: Immunohistochemical results revealed higher amounts of type I and type III collagen in Group A. However, no difference in the amount of type IV collagen was found between the groups. CONCLUSION: The amount of type I and type III collagen was higher in group A.

Biochemical study of dermatan sulfate glycosaminoglycan in adult male patients with Nyhus type II inguinal hernia.

OBJECTIVE: To compare the amount of the dermatan sulfate glycosaminoglycan between male patients with Nyhus type II inguinal hernias and subjects without inguinal hernia, aged between 20 and 40 years. METHODS: Two groups were formed: One with 15 male patients with Nyhus type II inguinal hernia and aged between 20 and 40 years with ASA risk I and II, and a control group of ten individuals, also males between 20 and 40, who had died up to 24 h before. We excluded female patients, diabetic patients with connective tissue disease, smokers and surgical risk ASA III and IV. We resected a sample of 1 cm² of the transversalis fascia in the middle of the inguinal trigone, and 1 cm² of the anterior sheath of the rectus abdominis muscle in the groin for the quantification of dermatan sulfate glycosaminoglycans by densitometry after agarose gel electrophoresis. RESULTS: The amount of dermatan sulfate showed no statistically significant difference between patients with inguinal hernia and individuals without inguinal hernia in both the transverse fascia (p = 0.108) and anterior sheath of the rectus abdominis muscle (p = 0.292). CONCLUSION: There was no difference in the amount of the dermatan sulfate glycosaminoglycan among patients with Nyhus type II inguinal hernias and subjects without inguinal hernia in adult males.

Estudo bioquímico do glicosaminoglicano dermatam sulfato em homens adultos portadores de hérnia inguinal tipo II de Nyhus / Biochemical study of dermatan sulfate glycosaminoglycan in adult male patients with Nyhus type II inguinal hernia

OBJETIVO: Comparar a quantidade do glicosaminoglicano dermatam sulfato entre pacientes homens, portadores de hérnia inguinal tipo II de Nyhus e, indivíduos sem hérnia inguinal, com idade entre 20 e 40 anos. MÉTODOS: Foram constituídos dois grupos. Um de 15 pacientes do sexo masculino com hérnia inguinal tipo II de Nyhus e idade entre 20 e 40 anos, com risco ASA I e II, e um grupo controle com dez indivíduos, também do sexo masculino entre 20 e 40 anos, que morreram em período de até 24 h. Foram excluídos os pacientes do sexo feminino, diabéticos, portadores de doença do tecido conjuntivo, tabagistas e com risco cirúrgico ASA III e IV. Foi retirada uma amostra de 1cm² da fáscia transversal na parte intermediária do trígono inguinal, e 1cm² na bainha anterior do músculo reto abdominal na região inguinal correspondente e quantificados os glicosaminoglicanos dermatam sulfato por densitometria, após eletroforese em gel de agarose. RESULTADOS: A quantidade de dermatam sulfato não apresentou diferença estatisticamente significante entre os pacientes com hérnia inguinal e os indivíduos sem hérnia inguinal, tanto na fáscia transversal (p=0,108) quanto na bainha anterior do músculo reto abdominal (p=0,292). CONCLUSÃO: Não se encontrou diferença na quantidade do glicosaminoglicano dermatam sulfato entre os pacientes portadores de hérnia inguinal tipo II de Nyhus e indivíduos sem hérnia inguinal em homens adultos.

OBJECTIVE: To compare the amount of the dermatan sulfate glycosaminoglycan between male patients with Nyhus type II inguinal hernias and subjects without inguinal hernia, aged between 20 and 40 years. METHODS: Two groups were formed: One with 15 male patients with Nyhus type II inguinal hernia and aged between 20 and 40 years with ASA risk I and II, and a control group of ten individuals, also males between 20 and 40, who had died up to 24 h before. We excluded female patients, diabetic patients with connective tissue disease, smokers and surgical risk ASA III and IV. We resected a sample of 1 cm² of the transversalis fascia in the middle of the inguinal trigone, and 1 cm² of the anterior sheath of the rectus abdominis muscle in the groin for the quantification of dermatan sulfate glycosaminoglycans by densitometry after agarose gel electrophoresis. RESULTS: The amount of dermatan sulfate showed no statistically significant difference between patients with inguinal hernia and individuals without inguinal hernia in both the transverse fascia (p = 0.108) and anterior sheath of the rectus abdominis muscle (p = 0.292). CONCLUSION: There was no difference in the amount of the dermatan sulfate glycosaminoglycan among patients with Nyhus type II inguinal hernias and subjects without inguinal hernia in adult males.

Apoptosis and myostatin mRNA are upregulated in the skeletal muscle of patients with chronic kidney disease.

Apoptosis and myostatin are major mediators of muscle atrophy and might therefore be involved in the wasting of uremia. To examine whether they are expressed in the skeletal muscle of patients with chronic kidney disease (CKD), we measured muscle apoptosis and myostatin mRNA and their related intracellular signal pathways in rectus abdominis biopsies obtained from 22 consecutive patients with stage 5 CKD scheduled for peritoneal dialysis. Apoptotic loss of myonuclei, determined by anti-single-stranded DNA antibody and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays, was significantly increased three to fivefold, respectively. Additionally, myostatin and interleukin (IL)-6 gene expressions were significantly upregulated, whereas insulin-like growth factor-I mRNA was significantly lower than in controls. Phosphorylated JNK (c-Jun amino-terminal kinase) and its downstream effector, phospho-c-Jun, were significantly upregulated, whereas phospho-Akt was markedly downregulated. Multivariate analysis models showed that phospho-Akt and IL-6 contributed individually and significantly to the prediction of apoptosis and myostatin gene expression, respectively. Thus, our study found activation of multiple pathways that promote muscle atrophy in the skeletal muscle of patients with CKD. These pathways appear to be associated with different intracellular signals, and are likely differently regulated in patients with CKD.

Immunohistochemical analysis of collagen content and types in the rectus abdominis muscle of cadavers of different ages / Imunohistoquímica do colágeno no músculo reto do abdome de cadáveres de diferentes grupos etários

PURPOSE: To assess the collagen content and types in the rectus abdominis muscle of cadavers of different ages. METHODS: Forty fresh adult male cadavers, at room temperature, were obtained from the Institute of Legal Medicine of Franca and dissected within 24 hours of death. The cadavers were divided into two groups: Group A (n=20), 18 to 30 years of age, and Group B (n=20), 31 to 60 years of age. Bilateral incisions were made in the middle portion of anterior rectus sheath 3 cm superiorly and 2 cm inferiorly to the umbilicus and four fragments of the rectus abdominis muscle were dissected. The samples were fixed in 10 percent buffered formalin and sent for immunohistochemical analysis to determine collagen content and types. RESULTS: Immunohistochemical results revealed higher amounts of type I and type III collagen in Group A. However, no difference in the amount of type IV collagen was found between the groups. CONCLUSION: The amount of type I and type III collagen was higher in group A.

OBJETIVO: Avaliar o colágeno no músculo reto do abdome em cadáveres de diferentes faixas etárias. MÉTODOS: Foram dissecados 40 cadáveres adultos masculinos, não fixados, com tempo de óbito de até 24 horas, em temperatura ambiente, provenientes do Instituto Médico-Legal de Franca (SP - Brasil). Os cadáveres foram distribuídos em dois grupos: GRUPO A (n=20) - 18 a 30 anos e GRUPO B (n=20) -31 a 60 anos. Realizou-se incisão na porção mediana da lâmina anterior da bainha do músculo reto a 3 cm superiormente e 2 cm inferiormente ao umbigo em ambos os lados, sendo retirados quatro fragmentos de músculo reto do abdome. Esse material foi conservado em formalina tamponado a 10 por cento e enviado para imuno-histoquímica para determinação do tipo de colágeno. RESULTADOS: Na Imunihistoquímica os colágenos I e III foram estatisticamente maiores no grupo A, porém não houve diferença entre os grupos em relação ao colágeno IV. CONCLUSÃO: A quantidade de colágeno tipo I e III foi maior no grupo A.

Skeletal muscle of gastric cancer patients expresses genes involved in muscle regeneration.

Experimental studies have suggested that defective skeletal muscle regeneration could contribute to muscle wasting in cancer patients. However, data in humans are still lacking. In this study we aimed to assess the expression of the genes involved in muscle regeneration in gastric cancer patients. The RNA expression of the genes involved in muscle regeneration was assessed in the rectus abdominis muscle of patients with gastric cancer (n=30) and in age-matched control subjects (n=8). The Pax7 expression was significantly increased in the muscle of gastric cancer patients, either in the first stages of the disease or in stages IIIA and B. The increased expression was present both in stages IA and B and in stages II and III. The MyoD espression was also higher in the cancer patients than in the controls. However, the increased MyoD expression was present only in stages IA and B and not in the more advanced stages of the disease. The Myf5 expression, as well as that of the neonatal isoform of Myosin Heavy Chain (nMHC) did not differ significantly between the cancer patients and the controls. The necdin expression was negligible in healthy adult muscles and was significantly up-regulated in the muscle of gastric cancer patients. Its expression was highly increased in stages IA and B while it was similar to the control in stages II and III. The results of the present study show that in the skeletal muscle of gastric cancer patients, the expression of the genes involved in muscle regeneration is increased with respect to the controls.

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.

Gene expression in the rectus abdominus muscle of patients with and without pelvic organ prolapse.

OBJECTIVE: The objective of the study was to compare gene expression in a group of actin and myosin-related proteins in the rectus muscle of 15 patients with pelvic organ prolapse and 13 controls. STUDY DESIGN: Six genes previously identified by microarray GeneChip analysis were examined using real-time quantitative reverse transcriptase-polymerase chain reaction analysis, including 2 genes showing differential expression in pubococcygeus muscle. Samples and controls were run in triplicate in multiplexed wells, and levels of gene expression were analyzed using the comparative critical threshold method. RESULTS: One gene, MYH3, was 3.2 times overexpressed in patients with prolapse (P = .032), but no significant differences in expression were seen for the other genes examined. An age-matched subset of 9 patients and controls showed that MYH3 gene expression was no longer significantly different (P = .058). CONCLUSION: Differential messenger ribonucleic acid levels of actin and myosin-related genes in patients with pelvic organ prolapse and controls may be limited to skeletal muscle from the pelvic floor.

Restoration of sterol-regulatory-element-binding protein-1c gene expression in HepG2 cells by peroxisome-proliferator-activated receptor-gamma co-activator-1alpha.

The expression of SREBP-1 (sterol-regulatory-element-binding protein-1) isoforms differs between tissues and cultured cell lines in that SREBP-1a is the major isoform in established cell lines, whereas SREBP-1c predominates in liver and most other human tissues. SREBP-1c is transcriptionally less active than SREBP-1a, but is a main mediator of hepatic insulin action and is selectively up-regulated by LXR (liver X receptor) agonists. LXR-mediated transactivation is co-activated by PGC-1alpha (peroxisome-proliferator-activated receptor-gamma co-activator-1alpha), which displays deficient expression in skeletal-muscle-derived cell lines. In the present paper, we show that PGC-1alpha expression is also deficient in HepG2 cells and in a human brown adipocyte cell line (PAZ6). In transient transfection studies, PGC-1alpha selectively amplified the LXR-mediated transcription from the human SREBP-1c promoter in HepG2 and PAZ6 cells via two LXR-response elements with extensive similarity to the respective murine sequence. Mutational analysis showed that the human LXR-response element-1 (hLXRE-1) was essential for co-activation of LXR-mediated SREBP-1c gene transcription by PGC-1alpha. Ectopic overexpression of PGC-1alpha in HepG2 cells enhanced basal SREBP-1c and, to a lesser extent, -1a mRNA expression, but only SREBP-1c expression was augmented further in an LXR/RXR (retinoic X receptor)-dependent fashion, thereby inducing mRNA abundance levels of SREBP-1c target genes, fatty acid synthase and acetyl-CoA carboxylase. These results indicate that PGC-1alpha contributes to the regulation of SREBP-1 gene expression, and can restore the SREBP-1 isoform expression pattern of HepG2 cells to that of human liver.

Immunohistochemical analysis of bFGF, TGF-beta1 and catalase in rectus abdominis muscle from cattle foetuses at 180 and 260 days post-conception.

The potential for muscle growth depends on myoblast proliferation, which occurs essentially during the first two thirds of the foetal period in cattle. Thereafter, myofibres acquire their contractile and metabolic properties. Proliferation is regulated by molecular growth factors and by the tissue oxidative activity. The aim of this study was the quantification by immunochemistry of basic fibroblast growth factor (bFGF) and transforming growth factor beta 1 (TGF-beta1) and also of enzyme catalase (CAT) activity in rectus abdominis muscle. Samples were collected from cattle foetuses of different growth potential at 180 and 260 days post-conception (dpc). One major conclusion from this work is that protein contents of the muscle tissue bFGF and, to a lower extent, CAT activity decreased with increasing age during the foetal life. No differences were found between the different genotypes of cattle. However, the CAT to bFGF ratio tended to be lower in fast-growing cattle and increased with foetal age. TGF-beta1 did not change with age and was localised mostly at the vascular bed. CAT was detected in smooth and rough reticulum in striated muscles at 180dpc, and additionally in mitochondria at 260dpc. In conclusion, the balance between intracellular growth factors (bFGF and TGF-beta1) and the activity of antioxidant enzyme CAT may participate in the regulation of the transition from myoblast proliferation to differentiation. Thus, increased ratio of CAT to bFGF might be a good index indicating initiation of muscle maturation in cattle foetus prior to birth.