SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The principles of reconstructive operations successfully performed with the pectoralis major or myocutaneous flap in the oral cavity, pharynx and trachea are reviewed. The author's modification is demonstrated on one case of each group.
The expression of mRNAs for transforming growth factors (TGF-beta2, myostatin, activin-B, and follistatin), insulin-like growth factors (IGF-I and -II), and fibroblast growth factor (basic, bFGF) was investigated in satellite cells derived from chicken pectoralis major (PM) and biceps femoris (BF) muscles in the stages from initiation of proliferation to fusion. These growth factor gene cDNAs were synthesized by reverse transcriptase polymerase chain reaction (RT-PCR). No myostatin, activin-B, follistatin or bFGF expression was detected in either cell culture at 0 h. TGF-beta2 mRNA level increased at 48 h (P < 0.01) and remained constant through 144 h in both PM and BF satellite cell cultures. The ontogeny of myostatin gene expression with the exception of a sharp increase in BF culture at 72 h (P < 0.01), was nearly identical in both cell cultures. Activin-B mRNA level in PM satellite cells was higher than that in BF satellite cells at 72 h and 120 h (P < 0.01). Follistatin mRNA in PM satellite cells was higher than that in BF satellite cells at 24, 96, and 120 h culture (P < 0.01). No IGF-I gene expression was detected in cell cultures at any time point. IGF-II gene expression in BF satellite cells declined at 96 h (P < 0.01) and remained reduced until 144 h. bFGF mRNA in both satellite cell cultures increased at 24 h (P < 0.05) and remained at this level in BF satellite cells through 144 h.
Capillarity, fibre types, fibre area and enzyme activities of different skeletal muscles (pectoralis, extensor digitorum longus), tibialis anterior, plantaris and the myocardium) were compared in Andean coot (Fulica americana peruviana) native to high altitude (Junín, Perú, 4200 m) and the same species nesting at sea level. Numbers of capillaries per square millimeter were higher in all high-altitude muscles when compared with sea-level muscles (P < 0.0001). Moreover, values for capillaries per fibre and capillaries in contact with each fibre were higher in digitorum and tibialis high-altitude muscles. Muscle fibres were classified as Type I, Type IIA or Type IIB on the basis of their myofibrillar ATPase pH lability. Pectoralis muscle of high-altitude and sea-level coots presented only fibres of Type IIA. In contrast, all the leg muscles studied showed a mosaic pattern of the three fibre types. Fibre areas were determined using a Leitz Texture Analysis System. Significant differences in fibre area were observed (P < 0.01) between high-altitude and sea-level muscles. Mean muscle fibre diameters were also lower in the high-altitude group than in the sea-level group. The enzyme activities studied were hexokinase, lactate dehydrogenase, citrate synthase and 3-hydroxyacyl-CoA-dehydrogenase. The oxidative capacity, as reflected by citrate synthetase and hydroxyacyl-CoA-dehydrogenase activities, was greater for myocardial and pectoralis than for leg muscles. However, analysis of maximal enzyme activities showed that there were no significant differences between the glycolytic and oxidative enzyme activities of high-altitude and sea-level coots.(ABSTRACT TRUNCATED AT 250 WORDS)
The degree of histological deterioration of the original explant and the extent of cell spreading was evaluated in cultures of pectoralis muscle from 11-day chicks. Although the frequencies of these two parameters varied with the amounts of horse serum and embryo extract added to the medium, cultures from dystrophic chicks, in comparison to those from either normal or heterozygous animals, consistently showed the largest number of explants with the most extreme forms of histological deterioration and cell spreading. At 20 per cent horse serum the cultures from heterozygous chicks showed greater frequencies of the more extensive forms of deterioration and spreading than the normal muscle explants, but at 5 per cent horse serum these two groups appeared similar. Regardless of genetic background, cultures of the pectoralis muscle from 18-day embryos and of the latissimus dorsi muscle from 11-day chicks exhibited comparable high frequencies for the maximal degrees of deterioration and spreading.
Take-off in birds at high speeds and steep angles of elevation requires a high burst power output. The mean power output of the pectoralis muscle of blue-breasted quail (Coturnix chinensis) during take-off is approximately 400 W kg(-1) muscle, as determined using two independent methods. This burst power output is much higher than has been measured in any other cyclically contracting muscle. The power output of muscle is determined by the interactions between the physiological properties of the muscle, the stimulation regime imposed by the central nervous system and the details of the strain cycle, which are determined by the reciprocal interaction between the muscle properties and the environmental load. The physiological adaptations that enable a high power output to be achieved are those that allow the muscle to develop high stresses whilst shortening rapidly. These characteristics include a high myofibrillar density, rapid twitch contraction kinetics and a high maximum intrinsic velocity of shortening. In addition, several features of the strain cycle increase the power output of the quail pectoralis muscle. First, the muscle operates at a mean length shorter than the plateau of the length/force relationship. Second, the muscle length trajectory is asymmetrical, with 70 % of the cycle spent shortening. The asymmetrical cycle is expected to increase the power output substantially. Third, subtle deviations in the velocity profile improve power output compared with a simple asymmetrical cycle with constant lengthening and shortening rates. The high burst power outputs found in the flight muscles of quail and similar birds are limited to very brief efforts before fatigue occurs. This strong but short flight performance is well-suited to the rapid-response anti-predation strategy of these birds that involves a short flight coupled with a subsequent sustained escape by running. These considerations serve as a reminder that the maximum power-producing capacities of muscles need to be considered in the context of the in vivo situation within which the muscles operate.
We evaluated the effects of genotype (Muscovy, Pekin and their crossbreed hinny and mule ducks) and feeding levels (overfeeding between 12 and 14 weeks of age vs ad libitum feeding) on energy metabolism and lipid deposition in breast muscle of ducks. Samples of breast muscle (Pectoralis major) were collected at 14 weeks of age from 8 birds per group. Overfeeding induced an accumulation of lipids in breast muscle (1.5- to 1.7-fold, depending on genotype) mainly induced by triglyceride deposition. It also induced a considerable increase in the amounts (expressed as g/100 g of tissue) of saturated and mono-unsaturated fatty acids (SFA, MUFA), while the amounts of poly-unsaturated fatty acids (PUFA) remained unchanged in hinny and Muscovy ducks or slightly increased in Pekin and mule ducks. In breast muscle, overfeeding decreased the activity of the main enzymes involved in lipogenesis from glucose (glucose-6-phosphate dehydrogenase, G6PDH, malic enzyme, ME, acetyl CoA carboxylase, ACX). Lipoprotein lipase (LPL) activity in Pectoralis major muscle was also significantly decreased (-21%). The ability of muscle tissues to catabolize long-chain fatty acids, as assessed by beta-hydroxyacyl CoA dehydrogenase (HAD) activity, was increased in Pectoralis major muscle, as was cytochrome-c oxidase (COX) activity. Hybrid and Pekin ducks exhibited higher levels of ACX and LPL activity in Pectoralis major muscle than Muscovy ducks, suggesting a greater ability to synthesise lipids in situ, and to take up circulating lipids. Total lipid content in breast muscle of hybrid and Pekin ducks was higher than in that of Muscovy ducks. In hybrid and Pekin ducks, lipid composition of breast muscle was characterized by higher amounts of triglycerides, SFA and MUFA than in Muscovy ducks. Finally, oxidative metabolism was greater in Pectoralis major muscles of hybrid and Pekin ducks than in Muscovy ducks, suggesting an adaptative strategy of muscle energy metabolism according to lipid level.
The ontogenetic trends in the expression of 25 isozymes in liver, gizzard, heart, and pectoralis muscle of White Leghorn chickens were examined using starch gel electrophoresis. Little change in expression during development was evident in liver S-AAT-A, GPI-A, S-ICDH-A, S-MDH-A and M-MDH-A, in gizzard S-ACON-A, ADH-A, GPI-A, HK-1, HK-3, ME-A PEP-1, and PGM-A, in heart ADH-A, HK-1, HK-3, ME-A, PEP-2, PGM-A, and LDH-A, in pectoralis M-ACON-A, S-ACON-A, ADH-A, HK-1, HK-3, ME-A, PEP-2, and PGM-A, and in liver, gizzard, and heart M-ACON-A, ALD-A, CK-A, G3PDH-A, HK-1, and PGDH-A. Increasing levels of activity were demonstrated in liver ADH-A, ME-A, and PEP-2, in heart M-MDH-A, S-ICDH-A, M-ICDH, and M-AAT-A, and in pectoralis LDH-A, LDH-B, G3PDH-3, ALD-A, CK-A, HK-2, and PGM-B. There was a decrease in the activity of HK-1 in liver and in PEP-1 and PGDH-A in pectoralis muscle throughout development. While CK-C is active in the embryonic pectoralis, CK-A is restricted to later developmental stages. Isozyme expressions in regions of the pectoralis containing fast and slow muscle fibers in 7-month-posthatch individuals were noted and found to be identical. The results underscore the need to use similar developmental stages and tissue samples in comparative electrophoretic studies of birds.
Peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha), a transcriptional coactivator, plays a role in mitochondrial biogenesis, muscle fiber specialization, and adaptive thermogenesis. Because of an absence of brown adipose tissue, the skeletal muscle tissue in chickens serves as an important source of thermogenesis to counter the cold. The present experiments were conducted (i) to clone the cDNA of PGC-1alpha homologs from chicken skeletal muscle and to examine alterations to PGC-1alpha mRNA expression in the skeletal muscles of cold-exposed chickens, (ii) to study the effect of cold-acclimation on the metabolic fiber phenotype of typically fast-glycolytic (type IIB) pectoralis muscles, and (iii) to compare avANT and avUCP mRNA expression in control and cold-exposed chickens. Results show that the cloned avPGC-1alpha cDNA encodes a 796 amino-acid protein (GenBank Accession No. AB170013) showing 84% identity with rodent PGC-1alpha cDNA. Exposure of chickens to a cold environment resulted in the prompt upregulation of avPGC-1alpha expression, which preceded increments in avUCP and avANT expression in skeletal muscle mitochondria. Consistent with the morphological appearance of muscles, an increase in the number of fast-oxidative-glycolytic (type IIA) fibers in the pectoralis muscle, which contains exclusively type IIB fibers in control chickens, was observed in cold-acclimated chickens. These findings provide novel information about possible regulatory pathways in avian skeletal muscle during thermogenesis.
OBJECTIVES: We sought to evaluate the cause for catheter loops of central venous ports. MATERIAL AND METHODS: A total of 241 patients who received a central venous port via subclavian vein access were included in this retrospective study. Eighty of these patients had undergone a computed tomography of the chest, allowing retrospective evaluation of the course of central venous catheters. Complications were evaluated by review of the clinical data charts. RESULTS: In 49 patients, the catheter penetrated only the major pectoralis muscle. Only one of these patients (2.0%) showed a loop. In 31 cases, the catheter went through both the major and minor pectoralis muscle, and in 26 of these patients (83.9%), a loop was seen. Complications after port implantation were catheter occlusion (n = 2), pneumothorax (n = 2), thrombosis (n = 2), infection (n = 1), and catheter dislocation (n = 1). CONCLUSIONS: The loop of catheter of central venous ports is caused by catheter penetration through pectoralis major and minor.
AIM: The syndrome was first described by Poland in 1841. It classically consists of unilateral muscular and osseous anomalies of the thorax and upper limb with defects of the ipsilateral breast and nipple. We report the value of panoramic-sonography in the diagnosis of this rare condition in three patients. METHOD: The three girls, all born in 1990, were independently introduced to our unit of children and adolescent gynaecology because of unilateral "developmental defects" of the breasts at the beginning of puberty. To discriminate a Poland-Syndrome from unilateral accentuation of thelarche standardized clinical and sonographical examinations were performed. RESULTS: In 2 cases we found unilateral aplasia of the glandular tissue of the breast with different distinction of mamilla and pectoralis muscle. The 3 (rd) case showed a hypoplastic breast development with osseous defects of the chest wall, aplasia of the pectoralis muscle and brachydaktylia. CONCLUSION: The standardized panoramic sonography allowed an immediate and safe diagnosis without hazardous radiation exposure.
Myosins from the following sources were purified by diethylaminoethyl-Sephadex chromatography: moytubes grown in vitro for 7-8 days, prepared from pectoralis muscles of 10-day old embryos, and breast and leg muscles from 16-day old embryos. The adenosine triphosphatase activities of these myosins were close to that of adult m. pectoralis myosin. The light chains of the embryonic myosins had the same mobilities in sodium dodecyl sulfate electrophoresis as those in adult pectoralis muscle myosin and were clearly distinguishable from those in myosin from tonic muscle m. latissimus dorsi anterior. The fastest light chain in embryonic muscle myosin-apparent mol wt 16,000-was present in smaller amounts than in adult myosin. The negative staining pattern of paracrystals of embryonic light meromyosin (LMM) was indistinguishable from that of adult fast muscle LMM. The significance of these results for differentiation of various muscle types has been discussed.
Metabolic rates of animal tissues typically increase with increasing temperature and thermoregulatory control in an animal is a regional or whole body process. Here we report that metabolic rates of isolated leatherback turtle (Dermochelys coriacea) pectoralis muscle are independent of temperature from 5-38 degrees C (Q10 = 1). Conversely, metabolic rates of green turtle (Chelonia mydas) pectoralis muscle exhibit a typical vertebrate response and increase with increasing temperature (Q10 = 1.3-3.0). Leatherbacks traverse oceanic waters with dramatic temperature differences during their migrations from sub-polar to equatorial regions. The metabolic stability of leatherback muscle effectively uncouples resting muscle metabolism from thermal constraints typical of other vertebrate tissues. Unique muscle physiology of leatherbacks has important implications for understanding vertebrate muscle function, and is another strong argument for preservation of this endangered species.
Twiddler's syndrome is a rare complication in patients with pacemakers. We report this very rare syndrome in a patient with pectoral implanted unipolar cardioverter defibrillator. This syndrome was detected because the patient presented in the 3 month routine visit an exitblock with an increased pacing impedance. The defibrillation threshold remained unchanged. The chest x-ray revealed an inferolaterally migrated generator with a multiply rotated lead. The intraoperative exploration showed a generator which was rotated nine-fold around its longitudinal axis with a multiple twisted unipolar lead. The lead was substituted and the aggregate fixed with a suture to the underlying muscle fascia. An atrophy of the pectoralis muscle was found in this patient which previously resulted from a long hospital stay. This atrophy was identified as a possible risk factor for the development of Twiddler's syndrome. This report illustrates that Twiddler's syndrome, a rare complication in patients with pectoral ICD, may become a significant problem in these patients as it is for pacemaker patients but with more serious possible consequences.
The effect of flying activity on capillary density and geometry was investigated in pectoralis muscle of 4 wild-caught (W) pigeons (BW 233-348 g) perfusion-fixed in situ and processed for electron microscopy. Morphometric analysis revealed both differences and similarities with similar sampling sites (superficial and deep in central area of right or left pectoralis major muscle, approximately midway along cranio-caudal and lateral axis) in sedentary (S) pigeons. Differences were the greater fractional cross-sectional area of aerobic fibers (W, 82 +/- 2%; S, 63 +/- 6%; p = 0.006) and the greater volume density of mitochondria per volume of fiber (W, 22.0 +/- 1.3%; S, 15.7 +/- 1.7%; p = 0.011) in wild-caught pigeons. While glycolytic fibers were significantly narrower in W, the size of the majority of fibers comprising the muscles, i.e. aerobic fibers, was similar in the two groups. Other similarities were found in capillary-to-fiber ratio (W, 2.0 +/- 0.2; S, 2.1 +/- 0.2) and in the degree of orientation of capillaries in the two groups. In addition, both capillary density at a given fractional cross-sectional area of aerobic fibers and capillary length per fiber volume at a given mitochondrial volume density were similar in the two groups, indicating a proportional increase in capillarity and muscle aerobic capacity in W compared with S. Comparison of capillary numbers around aerobic fibers at a given mitochondrial volume per microns length of fiber showed no difference between W and S groups nor with previous data in muscles with wide differences in fiber size and mitochondrial density such as rat soleus, bat muscles and hummingbird flight muscles. This supported the notion of a tight correlation between capillary numbers around individual fibers and mitochondrial volume per unit length of fiber in aerobic muscles. It also supported the idea that it is the number of capillaries around the fibers rather than diffusion distance which determines O2 flux rates in highly aerobic muscles.
Nuclear magnetic resonance (NMR) imaging and spectroscopy were used to assess body composition of the chicken and turkey poult. The NMR imaging was performed using a clinical, whole-body imaging system operating at 1.5 tesla (T; 63 MHz). Three-dimensional reconstruction of cross-sectional images made along the transaxial plane was used to estimate mass of the Pectoralis muscle of chickens ranging in weight from 140 to 2,760 g. Results indicate that NMR imaging can be used to determine size of the Pectoralis muscle (R2 = .99) in the bird, thus permitting repetitive measurements during the growth and development of the bird. The NMR spectroscopy was performed using an imaging spectrometer operating at 4.7 T (200 MHz). Integral areas of the water and lipid proton peaks of the spectra were compared with the water and lipid content of the whole body as determined by chemical analysis. Regression analysis of measurements made on turkey poults, ranging in weight from 115 to 630 g (n = 6), resulted in R2 values of .94 for NMR water proton peak area and total body water, .93 for NMR lipid proton peak area and total body lipid, and .96 for NMR water proton peak area and total body protein. From NMR spectroscopy of chickens weighing 528 +/- 18 g (n = 6), the relative area of the lipid peak correlated with whole-body lipid (R2 = .97). Thus, whole-body spectroscopy of smaller birds can be used to measure total body water, protein, and lipid content.
Six trials were conducted to determine the influence of muscle (pectoralis major and pectoralis minor) and location within the muscle on fiber type and diameter in four different age groups of chicken. Broilers obtained from a commercial processing plant, Athens Canadian Randombred chickens, roasters, and broiler breeder hens were killed via cervical dislocation. Muscle samples were removed from the anterior, middle, and posterior areas of the pectoralis major (p. major), and from the anterior and posterior areas of the pectoralis minor (p. minor). Frozen transverse muscle sections, 10 mm thick, were prepared at -20 C, stained for adenosine phosphatase activity, and photomicrographed for fiber typing and fiber diameter measurement. No differences were found in fiber types by age group, sex, or location within the muscle. The p. minor muscle had more intermediate fibers than the p. major muscle. Fiber diameters were significantly larger in the posterior portion of the p. major muscle than in the anterior or middle portions in two of the broiler trials, the female roasters, and the breeder hens. No significant differences in fiber diameter were noted for the p. minor muscle.
A 72-year-old female had undergone mastectomy at the age of 67 for right breast cancer (T2a, n1 alpha, positive for ER). In the surgery the pectoralis muscle was preserved. For adjuvant therapy, 20 mg/day of tamoxifen was orally administered for 5 years. Six years after surgery, relapse was detected in the right major pectoralis muscle. Irradiation at this site and oral administration of 120 mg/day of toremifene citrate were started. The patient had a medical history of diabetes, and the control of her blood sugar was poor. About 2 months after oral administration of toremifene citrate was started, flares with blebs and swelling were observed in the right lower leg, suggesting acute phlebothrombosis of the right lower limb. The symptoms were ameliorated by intravenous administration of heparin and an antibiotic. In administering a high dose of toremifene citrate to patients with complications, careful follow-up is needed.
Regenerating areas of adult chicken fast muscle (pectoralis major) and slow muscle (anterior latissimus dorsi) were examined in order to determine synthesis patterns of myosin light chains, heavy chains and tropomyosin. In addition, these patterns were also examined in muscle cultures derived from satellite cells of adult fast and slow muscle. One week after cold-injury the regenerating fast muscle showed a pattern of synthesis that was predominately embryonic. These muscles synthesized the embryonic myosin heavy chain, beta-tropomyosin and reduced amounts of myosin fast light chain-3 which are characteristic of embryonic fast muscle but synthesized very little myosin slow light chains. The regenerating slow muscle, however, showed a nearly complete array of embryonic peptides including embryonic myosin heavy chain, fast and slow myosin light chains and both alpha-fast and slow tropomyosins. Peptide map analysis of the embryonic myosin heavy chains synthesized by regenerating fast and slow muscles showed them to be identical. Thus, in both muscles there is a return to embryonic patterns during regeneration but this return appears to be incomplete in the pectoralis major. By 4 weeks postinjury both regenerating fast and slow muscles had stopped synthesizing embryonic isoforms of myosin and tropomyosin and had returned to a normal adult pattern of synthesis. Adult fast and slow muscles yielded a satellite cell population that formed muscle fibers in culture. Fibers derived from either population synthesized the embryonic myosin heavy chain in addition to alpha-fast and beta-tropomyosin. Thus, muscle fibers derived in culture from satellite cells of fast and slow muscles synthesized a predominately embryonic pattern of myosin heavy chains and tropomyosin. In addition, however, the satellite cell-derived myotubes from fast muscle synthesized only fast myosin light chains while the myotubes derived from slow muscle satellite cells synthesized both fast and slow myosin light chains. Thus, while both kinds of satellite cells produced embryonic type myotubes in culture the overall patterns were not identical. Satellite cells of fast and slow muscle appear therefore to have diverged from each other in their commitment during maturation in vivo.