Morphological variability of the pectoralis major muscle in human fetuses.

BACKGROUND: The pectoralis major muscle is located in the anterior chest wall. In most cases, it is divided into clavicular, sternal (sternocostal) and abdominal heads. The aim of this study is to demonstrate and classify the morphological variability of the pectoralis major muscles in human fetuses. MATERIAL AND METHODS: Classical anatomical dissection was performed on 35 human fetuses aged 18-38 weeks of gestation at death were examined. (17 female, and 18 male, 70 sides; fixed in 10% formalin solution). The fetuses were obtained from spontaneous abortion after informed consent of both parents and through deliberate donation to the Medical University anatomy program. Upon dissection, the following morphological features were assessed: the morphology of the pectoralis major, the possible occurrence of accessory heads, the possible absence of some head, and morphometric measurements of each head of the pectoralis major muscle. RESULTS: Five types of morphology (based on number of bellies) were observed in the fetuses. Type I was characterized by a single claviculosternal belly (10% of all samples). Type II comprised the clavicular and sternal heads (37.1%). Type III comprised three clavicular, sternal and abdominal heads (31.4%). Type IV (17.2%) was characterized by four muscle bellies and was divided into four subtypes. Type V (4.3%), was represented by five parts, and was divided into two subtypes. CONCLUSIONS: Due to its embryological development, the PM demonstrates great variability in the numbers of its parts. The most common type was the PM with two bellies, in line with previous studies which also distinguished only clavicular and sternal heads.

Muscle Injury Around the Shoulder.

Acute shoulder tendon and intra-articular injuries are common and their imaging well described. However, a subset of patients present with more unusual acute shoulder muscle injury. Of these, pectoralis major muscle injuries are encountered the most often and are increasingly prevalent due to a focus on personal fitness, particularly bench-press exercises. Other muscle injuries around the shoulder are rare. This article reviews the anatomy, mechanism of injury, and the imaging findings in relation to injuries of these muscles around the shoulder. We focus on pectoralis major injury but also review proximal triceps, latissimus dorsi, teres major, and deltoid muscle injuries, providing imaging examples.

The proximal humeral locking plate positioning to the pectoralis major tendon in achieving the proper calcar screw location: a cadaveric study.

BACKGROUND: Proximal humeral fracture is the third most common of osteoporotic fracture. Most surgical cases were treated by fixation with anatomical locking plate system. The calcar screw plays a role in medial support and improving varus stability. Proximal humerus fracture in elderly patients are commonly seen with greater tuberosity (GT) fracture. The GT fragment is sometimes difficult to use as an anatomic landmark for proper plate and screw position. Therefore, the insertion of pectoralis major tendon (PMT) may be used as an alternative landmark for appropriate plate and calcar screw position. The purpose of study is going to identify the vertical distance from PMT to a definite point on the position of locking plate. METHODS: 30 cadaveric shoulders at the department of clinical anatomy were performed. Shoulders with osteoarthritic change (n = 5) were excluded. Finally, 25 soft cadaveric shoulders were recruited in this study. The PHILOS™ plate was placed 2 mm posterior to the bicipital groove. A humeral head (HH) was cut in the coronal plane at the level of the anterior border of the PHILOS plate with a saw. A calcar screw was inserted close to the inferior cortex of HH. Distance from the upper border of elongated combi-hole (UB-ECH) to the upper border of pectoralis major tendon (UB-PMT) was measured. The plate was then moved superiorly until the calcar screw was 12 mm superior to the inferior border of HH and the distance was repeatedly measured. RESULTS: The range of distance from UB-PMT to the UB-ECH was from - 4.50 ± 7.95 mm to 6.62 ± 7.53 mm, when calcar screw was close to inferior border of HH and when the calcar screw was 12 mm superior to the inferior border of HH, respectively. The highest probability of calcar screw in proper location was 72% when UB-ECH was 3 mm above UB-PMT. DISCUSSION AND CONCLUSION: The GT fragment is sometimes difficult to use as an anatomic landmark for proper plate and screw position. PMT can be used as an alternative anatomic reference. UB-PMT can serve as a guide for proper calcar screw insertion. UB-ECH should be 3 mm above UB-PMT and three-fourths of cases achieved proper calcar screw location.

Presence of incomplete superficial axillary arch and pectoralis quartus muscle in one male body / Presencia en un individuo de un arco axilar superficial incompleto y de un músculo pectoral cuarto

SUMMARY: The anatomical variations of the pectoralis major muscle (PMM) and latissimus dorsi muscle (LDM) range from agenesis to the presence of supernumerary fascicles with a variety of insertions and relationships with the muscles, fascia, vessels, nerves and skeletal components of the shoulder girdle and the axilla. Many of these variations are clinically irrelevant, but extremely interesting and revealing from the perspective of comparative anatomy, ontogeny, and phylogeny. In this report, we present two different supernumerary muscles in the chest of one adult male body, identified during dissection practice of undergraduate medical students at Universidad Surcolombiana. These supernumerary fascicles in the axillary region were caudal to the lower edge of the PMM on the right side of the chest, and in contact with the anterior edge of the LDM on the left side of the chest; each fascicle was inserted in the ipsilateral coracoid process. These observations are congruent with the pectoralis quartus muscle and an incomplete and superficial axillary arch, respectively.

RESUMEN: Las variaciones anatómicas del músculo pectoral mayor (MPM) y del músculo latísimo del dorso (MLD) van desde la agenesia hasta la presencia de fascículos supernumerarios con una variedad de inserciones y relaciones con los músculos, fascias, vasos, nervios y componentes esqueléticos de la cintura escapular y la axila. Clínicamente, muchas de las variaciones son irrelevantes, pero extremadamente interesantes y reveladoras desde la perspectiva de la anatomía comparada, la ontogenia y la filogenia. En este estudio, presentamos dos músculos supernumerarios diferentes en la pared torácica de un hombre adulto, identificados durante la práctica de disección de estudiantes de medicina de la Universidad Surcolombiana. Estos fascículos supernumerarios en la región axilar estaban caudales al margen inferior del MPM en el lado derecho del tórax y en contacto con el margen anterior del MLD en el lado izquierdo del tórax; cada fascículo se insertaba en el proceso coracoides ipsilateral. Estas observaciones son congruentes con el músculo pectoral cuarto y un arco axilar incompleto y superficial, respectivamente.

The clinical anatomy of variations of the pectoralis minor.

Shoulder pathology is a very common medical presentation and can be due to anatomical variations. Therefore, knowledge of variants is important for the clinician treating patients with such complaints so that misdiagnosis is minimized and iatrogenic injury prevented. A review of the literature was performed of the variant anatomy of the pectoralis minor muscle. The aim of this review is to better inform clinicians who might treat patients with shoulder pathology so that if identified, variants of the pectoralis minor muscle are better appreciated.

Effects of marketable ages on meat quality through fiber characteristics in the goose.

Goose meat is increasingly popular among consumers because of its good quality. The fiber characteristics have been well demonstrated to be key contributing factors of meat quality, and the marketable ages are also closely related to meat quality. However, little is known about the effect of different marketable ages on the quality of goose meat through its fiber characteristics. Here, fiber characteristics of Yangzhou geese of different marketable ages (70, 90, and 120 d) and their effect on meat quality were investigated. The results showed that only fast-twitch fibers were present in breast muscle, irrespective of age, and that few slow-twitch fibers could be identified in leg muscle, especially in gastrocnemius and extensor digitorum longus. Fiber diameter in breast muscle increased rapidly from age 70 d to 90 d, from 19.88 to 26.27 µm, and remained stable for 90 d thereafter. The diameter and cross-sectional area of muscle fiber continue to grow with day increasing in leg muscle. In addition, we measured the proximate composition and physical properties at different ages. Among the 3 marketable ages investigated, the 120-day-old geese had higher intramuscular fat and protein content, as well as lower moisture content, both in breast and leg meat. Greater lightness and pressing loss, with lower redness and shear force, were observed in the breast and leg meat of 70-day-old geese when compared with 90- or 120-day-old geese. Taken together, although older marketable age hardly affected muscle fiber type in geese, it would contribute to larger muscle fiber area, higher intramuscular fat and protein content, as well as redder and chewier meat. As a result, the reasonable marketable age should be taken into account to improve quality in goose meat production, and the marketable age of 90 or 120 d was recommended and it could potentially improve meat quality in goose meat production.

Heart Failure Severity Stratification Beyond INTERMACS Profiles: A Step Toward Optimal Left Ventricular Assist Device Timing.

The purpose of this analysis is to determine whether pectoralis muscle measures quantified on pre left ventricular assist device (LVAD) computerized tomography (CT) scans can identify subgroups of patients with differential disease severity within each Interagency Registry for Mechanical Circulatory Support (INTERMACS) profile. Patients with chest CTs performed ≤3 months before LVAD implantation at University of Minnesota (n = 143) and Houston Methodist Hospital (n = 133) were identified from the larger LVAD cohorts (University of Minnesota n = 353, Houston Methodist =278). Unilateral Pectoralis muscle mass indexed to body surface area and pectoralis muscle attenuation were measured on preoperative chest CT scans. Patients within each INTERMACS profile were separated into HIGH and LOW PEC muscle groups. Kaplan-Meier and multivariable cox regression analyses were performed to compare mortality among INTERMACS profiles by HIGH and LOW PEC muscle groups. INTERMACS 3 and 4 patients in the HIGH PEC groups had the highest survival on LVAD support (1 year survival 85% vs. 68%, log rank P = 0.0001). Being in this group was associated with a 60% reduction in the hazards rate (HR) of death after LVAD (adjusted HR 0.40, 95% confidence interval 0.25-0.62). Additionally, renal function deterioration in the year before LVAD was associated with lower INTERMACS profiles and lower measured pectoralis muscle tissue attenuation at the time of LVAD implantation. INTERMACS 3 and 4 patients with the highest pectoralis muscle measures had the best survival after LVAD. The association between renal function deterioration and sarcopenia suggests these muscle changes are progressive. Computerized tomography quantification of sarcopenia may help identify optimal LVAD implantation timing.

The Shoulder Trans-pectoralis Arthroscopic Portal Is a Safe Approach to the Arthroscopic Latarjet Procedure: A Cadaveric Analysis.

PURPOSE: To assess the proximity of neurovascular structures in a layered approach during medial portal placement and determine standardized measurements for establishing a portal medial to the coracoid used in arthroscopic Latarjet-type procedures. METHODS: Twelve shoulders (6 right and 6 left) in 6 fresh frozen cadaveric torsos were mounted in the modified beach-chair position. A standard posterior portal and 3 anterior portals-central, lateral, and medial-were used. A long spinal needle was placed along the path of the medial portal to the lateral tip of the coracoid, superficial to the conjoined tendon and pectoralis minor. A second long spinal needle was directed toward the medial base of the coracoid, penetrating the pectoralis minor. Superficial and deep plane dissections were performed, and distances to surrounding neurovascular structures were recorded. RESULTS: In the superficial plane, the cephalic vein and lateral pectoral nerve were located a mean distance (± standard deviation) of 4.6 ± 1.9 mm and 9.4 ± 2.6 mm from the spinal needle, respectively. In the deep plane, the axillary nerve was 24.9 ± 7.4 mm from the needle; the lateral cord of the brachial plexus, 25.5 ± 8.1 mm; the axillary artery, 34.1 ± 6.0 mm; and the musculocutaneous nerve, 42.2 ± 9.2 mm. The portal was consistently established 45.0 to 50.0 mm distal and 30.0 to 35.0 mm medial to the coracoid, which was a minimum distance of 10 mm to the lateral pectoral nerve. CONCLUSIONS: In a cadaveric model, the creation of a medial trans-pectoralis major portal used in the arthroscopic Bankart-Bristow-Latarjet procedure can avoid compromise of vital neurovascular structures, alleviating concerns of creating a portal medial to the coracoid. Portal placement 45.0 to 50.0 mm distal and 30.0 to 35.0 mm medial to the palpable tip of the coracoid process may be a safe approach to perform the arthroscopic Bankart-Bristow-Latarjet procedure. CLINICAL RELEVANCE: Creation of a portal medial to the level of the coracoid may pose a risk to neurovascular structures. This cadaveric study establishes a working zone for medial trans-pectoralis portal placement, which avoids vital neurovascular structures, and provides standardized measurements for establishing this portal for use in the arthroscopic Bankart-Bristow-Latarjet procedure.

Large-Scale Whole Genome Sequencing Study Reveals Genetic Architecture and Key Variants for Breast Muscle Weight in Native Chickens.

Breast muscle weight (BrW) is one of the most important economic traits in chicken, and directional breeding for that results in both phenotypic and genetic changes. The Jingxing yellow chicken, including an original (without human-driven selection) line and a selected line (based on selection for increased intramuscular fat content), were used to dissect the genetic architecture and key variants associated with BrW. We detected 1069 high-impact single nucleotide polymorphisms (SNPs) with high conserved score and significant frequency difference between two lines. Based on the annotation result, the ECM-receptor interaction and fatty acid biosynthesis were enriched, and muscle-related genes, including MYOD1, were detected. By performing genome-wide association study for the BrW trait, we defined a major haplotype and two conserved SNPs that affected BrW. By integrated genomic and transcriptomic analysis, IGF2BP1 was identified as the crucial gene associated with BrW. In conclusion, these results offer a new insight into chicken directional selection and provide target genetic markers by which to improve chicken BrW.

The Effects of Resistance Exercise Selection on Muscle Size and Strength in Trained Women.

The study compared the effects of resistance training programs composed by multi-joint (MJ), single-joint (SJ) and the combination of multi- and single-joint (MJ+SJ) exercises on muscle strength and hypertrophy in trained women. Thirty participants were divided into groups that performed only MJ exercises, SJ exercises and MJ+SJ exercises for six months. Participants were tested for 1-repetition maximum (RM) and muscle thickness (MT) before and after the intervention. All groups showed significant gains on 1RM tests from pre- to post-training (P<0.01). However, MJ and MJ+SJ groups obtained greater gains in 1RM for the MJ exercises in comparison with the SJ group. Increases in 1RM for the SJ exercises were similar among groups, with the exception of leg curl, where the SJ group obtained greater gains than MJ and MJ+SJ. All groups obtained significant increases in MT from pre- to post-training for all muscle groups. However, MJ and MJ+SJ groups presented greater increases in gluteus maximus, quadriceps femoris and pectoralis major in comparison with the SJ group. Therefore, our results suggest that, in general, performing MJ exercises seems to be necessary to obtain optimal results from a resistance training program; however SJ might be necessary to provide optimal strength gains in knee flexion.

Predictors of throwing performance in amateur male cricketers: A musculoskeletal approach.

Optimal throwing speed and accuracy is built on a complex interaction of multiple variables. Although strength and power has been associated with throwing speed in cricketers, the individual muscles that contribute to optimal function of the shoulder-complex has not been adequately explored in connection with throwing performance. Consequently, this study aimed to investigate the correlation between musculoskeletal variables and overhead throwing performance in cricketers. Thirty-two amateur male cricketers were tested using a battery of 16 tests (strength, flexibility, scapula positioning) as well as a throwing speed (TS) and a novel accuracy test (TA). Only two of the sixteen tests were correlated with throwing performance in the multiple regression analysis. Non-dominant hip abduction strength correlated positively with TS (p < 0.05): on average, a strength increase of 10 newtons (N) was associated with an increase in TS of 0.60 km/h (95% CI: 0.12-1.08). Non-dominant pectoralis minor length correlated positively with TA (p < 0.01): on average, a one-centimetre increase in the length correlated to an increase, of 0.633 points (95% CI: 0.225-1.041). This cross-sectional study demonstrated that from an array of musculoskeletal variables, only non-dominant hip abduction strength correlated with TS, while only non-dominant pectoralis minor length correlated with TA in amateur cricketers.

Variation of insertion of the pectoralis major in a cadaveric study: A case report.

RATIONALE: Typically, the tendon of the pectoralis major inserts into the crest of the greater tubercle of the humerus. However, anomalous insertion sites of the pectoralis major tendons have been noted. PATIENT CONCERNS: The cadaver of a 95-year-old Japanese man was selected from the bodies used for gross anatomy practice at the Tokai University School of Medicine in 2018. DIAGNOSIS: In this cadaver, the left side of the pectoralis major tendon appeared to insert at the crest of the greater tubercle and lesser tubercle of the humerus, forming a tunnel measuring 2.5 cm in total length. INTERVENTION: We removed the fat and skin around the shoulder joint and upper extremity for observational purposes and carefully examined the structures during gross anatomy. OUTCOMES: The medial side of the insertion of the pectoralis major tendon was not into the humerus but had combined with the tendon of the latissimus dorsi, which then loosely inserted into the humerus. As the roof and both walls comprised the tendon of the pectoralis major and the floor was formed by the tendon of the latissimus dorsi and humerus, the structure formed a tunnel. LESSONS: This study is important for orthopedic and rehabilitation physicians in treating diseases of the long head of the biceps brachii tendon. As part of management, the condition of the tendon of the pectoralis major should be confirmed using magnetic resonance imaging or echocardiography.

The human costal cartilage: Anatomical and radiological study of macro-vascularization and micro-vascularization and its clinical relevance regarding vascularized chondrocostal free flap surgery.

INTRODUCTION: Cartilage repair usually involves in non-vascularized osteochondral or chondral grafts with some drawbacks potentially linked to the lack of vascular supply in those grafts. The aim of this study was to describe a surgical approach for harvesting a vascularized chondrocostal graft, to study the vascular supply to the perichondrium and finally to describe the perichondrium micro-vascularization in order to know how such grafts could be used in cartilage repair surgery. MATERIALS AND METHODS: We harvested and studied 18 costal cartilages harvested from 12 fresh anatomical subjects. The anatomic pieces were injected with a radio-opaque tracer, analyzed macroscopically, then a plain X-rays and CT scan analysis with three-dimensional rendering was performed in order to evaluate the characteristics of the different patterns of their vascularization. RESULTS: The surgical approach to harvest a vascularized 5th chondrocostal graft is explained in detail. All of the cartilages were vascularized by the internal thoracic artery and harvested with a pedicle of an average length of 34mm and diameter of 2.14mm. In all specimens, perichondrium vascularization arises from both superior and inferior intercostal branches. Anastomoses between inferior and superior intercostal branches are always found in all specimens at the level of the epichondrium. CONCLUSIONS: The anatomic approach for harvesting a vascularized chondrocostal graft is simple and only slightly differs from the approach described for harvesting a non-vascularized chondrocostal graft. The vascular supply to the perichondrium of such a vascularized chondrocostal graft is sustained by the internal thoracic vessels which have a sufficient diameter and length to allow easy micro-anastomosis. The organization of the micro-vasculature within the perichondrium allows the graft to be tailored to a large cartilage defects and also to small bipolar cartilage defects.

Seasonal variation in body composition in an Afrotropical passerine bird: increases in pectoral muscle mass are, unexpectedly, associated with lower thermogenic capacity.

Phenotypic flexibility in avian metabolic rates and body composition have been well-studied in high-latitude species, which typically increase basal metabolic rate (BMR) and summit metabolism (Msum) when acclimatized to winter conditions. Patterns of seasonal metabolic acclimatization are more variable in lower-latitude birds that experience milder winters, with fewer studies investigating adjustments in avian organ and muscle masses in the context of metabolic flexibility in these regions. We quantified seasonal variation (summer vs winter) in the masses of organs and muscles frequently associated with changes in BMR (gizzard, intestines and liver) and Msum (heart and pectoral muscles), in white-browed sparrow-weavers (Plocepasser mahali). We also measured pectoral muscle thickness using a portable ultrasound system to determine whether we could non-lethally estimate muscle size. A concurrent study measured seasonal changes in BMR and Msum in the same population of sparrow-weavers, but different individuals. There was no seasonal variation in the dry masses of the gizzard, intestines or liver of sparrow-weavers, and during the same period, BMR did not vary seasonally. We found significantly higher heart (~ 18% higher) and pectoral muscle (~ 9% higher) dry mass during winter, although ultrasound measurements did not detect seasonal changes in pectoral muscle size. Despite winter increases in pectoral muscle mass, Msum was ~ 26% lower in winter compared to summer. To the best of our knowledge, this is the first study to report an increase in avian pectoral muscle mass but a concomitant decrease in thermogenic capacity.

Water-spraying forced ventilation during holding improves the water holding capacity, impedance, and microstructure of breast meat from summer-transported broiler chickens.

Heat stress is a broiler welfare issue and economic deficit to the broiler industry. Water atomizing with three-dimensional forced ventilation, a holding treatment after summer transport for broiler, has been proved to significantly improve water holding capacity of fresh meat. However, effectiveness of this treatment on water retention after freeze-thaw needs to be conducted. Therefore, the objective of this study was to assess whether water atomizing with forced ventilation could increase freeze-thaw meat quality after birds slaughtering. Arbor Acres broiler (n = 105), undergoing 32°C ambient temperature transport, was randomly categorized into 3 treatments: 1) T group, which underwent 45-min transport without rest; 2) TR group, which underwent 45-min transport with 1-h rest; and the 3) TWFR group, which underwent 45-min transport followed by 15-min water atomizing with three-dimensional forced ventilation and 45-min rest. All birds were hot-deboned within 30-min postmortem. A total of 105 breast fillets were collected and split into halves, which left part fillets were kept in 4°C and for meat analysis, the other part fillets, marked with T-F, TR-F, and TWFR-F, were frozen (-18°C) for 1 mo and then thawed overnight for meat quality analysis. Regardless of fresh or frozen treatment among 3 groups, TWFR has the highest pH which was more than 6.01 (P < 0.05). The L* value, drip loss, and cooking loss of TWFR were significantly lower compared to T and TR groups in both fresh and frozen breast fillets (P < 0.05). Compared with the T group, the TWFR meat shows closely microscopic structure which means less water loss channel. The impedance amplitude of the fresh meat was significantly higher than that of the frozen-thawing meat (P < 0.05). TWFR-treated meat has significantly higher impedance module than T and TR meat at 50 Hz frequency region, for both fresh or thawed meat. Among 6 treatments, TWFR fresh meat has significantly highest Q (modulus change ratio) value (P < 0.05). These results indicate that TWFR treatment for 15 min after transport can improve meat quality, which may be due to the improved welfare of broilers transported in hot summer months.

Pectoralis major tendon and enthesis: anatomic, magnetic resonance imaging, ultrasonographic, and histologic investigation.

BACKGROUND: This study evaluates the pectoralis major (PM) tendon humeral insertion, using imaging and histologic assessment in cadaveric specimens. Current descriptions of the pectoralis major tendon depict a bilaminar enthesis, and clarification of the anatomy is important for diagnostic and surgical considerations. MATERIALS AND METHODS: Fourteen fresh-frozen whole upper extremity specimens were used in this study. Magnetic resonance (MRI) and ultrasonographic (US) imaging of the PM muscles, tendons, and entheses were performed, followed by anatomic dissection and inspection. Morphology of the lateral tendon and entheses were evaluated, focused on the presence of layers. In 11 specimens, the lateral 3 cm of the PM tendon was carefully dissected from the footprint, whereas in 3 specimens, the tendon and humeral insertion were preserved and removed en bloc. Histology was performed in axial slabs along the medial-lateral length of the tendon and also evaluated for the presence of layers. RESULTS: The superior-inferior and medial-lateral lengths of the PM footprint were 75 ± 9 mm and 7 ± 1 mm respectively. In all specimens, the clavicular and sternal head muscles and tendons were identified, with the clavicular head tendon generally being shorter. The medial-lateral length of the clavicular head tendon measured 19 ± 8 mm superiorly and 9 ± 3 mm inferiorly. The medial-lateral length of the sternal head tendon measured 38 ± 8 superiorly and 41 ± 18 mm inferiorly. All specimens demonstrated a unilaminar, not bilaminar, enthesis with abundant fibrocartilage on histology. Three specimens demonstrated interspersed entheseal fat and loose connective tissue at the enthesis on MRI and histology. CONCLUSION: The PM tendon humeral insertion consists of a unilaminar fibrocartilaginous enthesis. US, MRI, and histology failed to identify true tendon layers at the enthesis. Delaminating injuries reported in the literature may originate from a location other than the enthesis.

Dynamic accumulation of fatty acids in duck (Anas platyrhynchos) breast muscle and its correlations with gene expression.

BACKGROUND: Fatty acid composition contributes greatly to the quality and nutritional value of meat. However, the molecular regulatory mechanisms underlying fatty acid accumulation in poultry have not yet been cleared. The aims of this study were to characterize the dynamics of fatty acid accumulation in duck breast muscle and investigate its correlations with gene expression. RESULTS: Here, we analyzed the fatty acid profile and transcriptome of breast muscle derived from Pekin ducks and mallards at the ages of 2 weeks, 4 weeks, 6 weeks and 8 weeks. Twenty fatty acids were detected in duck breast muscle, with palmitic acid (C16:0, 16.6%~ 21.1%), stearic acid (C18:0, 9.8%~ 17.7%), oleic acid (C18:1n-9, 15.7%~ 33.8%), linoleic acid (C18:2n-6, 10.8%~ 18.9%) and arachidonic acid (C20:4n-6, 11.7%~ 28.9%) as the major fatty acids. Our results showed that fatty acid composition was similar between the two breeds before 6 weeks, but the compositions diverged greatly after this point, mainly due to the stronger capacity for C16:0 and C18:1n-9 deposition in Pekin ducks. By comparing the multistage transcriptomes of Pekin ducks and mallards, we identified 2025 differentially expressed genes (DEGs). Cluster analysis of these DEGs revealed that the genes involved in oxidative phosphorylation, fatty acid degradation and the PPAR signaling pathway were upregulated in mallard at 8 weeks. Moreover, correlation analysis of the DEGs and fatty acid composition traits suggested that the DEGs involved in lipogenesis, lipolysis and fatty acid ß-oxidation may interact to influence the deposition of fatty acids in duck breast muscle. CONCLUSIONS: We reported the temporal progression of fatty acid accumulation and the dynamics of the transcriptome in breast muscle of Pekin ducks and mallards. Our results provide insights into the transcriptome regulation of fatty acid accumulation in duck breast muscle, and will facilitate improvements of fatty acid composition in duck breeding.

Comparison of Myofascial Release Techniques on Pectoralis Minor Length, Glenohumeral Total Arc of Motion, and Skin Temperature: A Pilot Study.

CONTEXT: The pectoralis minor (PM) is an important postural muscle that may benefit from myofascial techniques, such as Graston Technique® (GT) and self-myofascial release (SMR). OBJECTIVE: To examine the effects of GT and SMR on PM length, glenohumeral total arc of motion (TAM), and skin temperature. DESIGN: Cohort. SETTING: Laboratory. PARTICIPANTS: Twenty-six healthy participants (19 females and 7 males; age = 20.9 [2.24] y, height = 170.52 [8.66] cm, and weight = 72.45 [12.32] kg) with PM length restriction participated. INTERVENTIONS: Participants were randomized to the intervention groups (GT = 12 and SMR = 14). GT and SMR interventions were both applied for a total of 5 minutes during each of the 3 treatment sessions. MAIN OUTCOME MEASURES: PM length, TAM, and skin temperature were collected before and after each intervention session (Pre1, Post1, Pre2, Post2, Pre3, and Post3) and at 1-week follow-up (follow-up). Separate intervention by time analyses of variance examined differences for each outcomes measure. Bonferroni post hoc analyses were completed when indicated. Significance was set a priori at P ≤ .05. RESULTS: No significant intervention by time interactions were identified for PM length, TAM, or temperature (P > .05). No significant intervention main effects were identified for PM length (P > .05), TAM (P > .05), or temperature (P > .05) between the GT or SMR technique groups. Overall, time main effects were found for PM length (P = .02) and temperature (P < .001). Post hoc analysis showed a significant increase in PM length for both intervention groups at follow-up (P = .03) compared with Post2. Furthermore, there were significant increases in temperature at Post1 (P < .001), Post2 (P = .01), and Post3 (P < .001) compared with Pre1; Post2 was increased compared with Pre2 (P = .003), Pre3 (P < .001), and follow-up (P = .01); Post3 increased compared with Pre3 (P = .01) and follow-up (P = .01). CONCLUSION: Serial application of GT and SMR to the PM did not result in increases in PM length or TAM. Regardless of intervention, skin temperature increased following each intervention.

Perforator Flaps Based on the Terminal Perforators of the Pectoral Branch of Thoracoacromial Vessels Axis: A Viable Option in the Head and Neck Reconstructions.

BACKGROUND: The purpose of this article is to develop a new method for elevating the pedicled terminal pectoral perforator flaps (PTPPFs) and to resolve the difficulties and controversies that shroud the anatomy of terminal pectoral perforators from the pectoral branch of the thoracoacromial axis. AIM: Anatomical study was conducted to assess the feasibility of perforator flaps based on the terminal perforators of the pectoral branch of the thoracoacromial vessel axis. The knowledge that gleaned from this anatomical study was applied in the clinical scenario. A clinical retrospective study was conducted to evaluate the outcome of PTPPFs for the reconstruction of postexcisional head and neck defects. MATERIALS AND METHODS: Thirty cadaveric specimens were examined for the anatomy of the terminal musculocutaneous pectoral branch perforators. Thirty-two cases (22 males, 10 females) of various head and neck postexcision defects were reconstructed with the PTPPFs in a single-stage manner. Pectoralis major muscle with its innervation was spared in all cases. All the secondary defects were closed primarily. RESULTS: The maximum cutaneous paddle size was 156 cm harvested on a single best terminal pectoral branch perforator. The average size of the cutaneous paddle harvested was 73.47 cm. The flap complications noted (9.3%) were trivial, and all the flaps survived well. The average institutional computed score for esthetic and functional recovery at the donor and reconstructed site done by 2 independent observers were 4.56 and 3.78, respectively. CONCLUSIONS: The recruitment of the chest skin on the terminal pectoral branch perforators resulted in a long pedicle flap with adequate qualities like color match, texture match, and pliability. This flap shall serve as a primary option for pedicle and free flap head and neck reconstructions.

Expresión morfológica del músculo axilopectoral: un estudio anatómico directo en una muestra de población colombiana / Morphological expression of the axillary pectoral muscle: a direct anatomical study in a sample of Colombian population

El músculo axilopectoral (MAP) es una estructura fibromuscular accesoria de la región axilar, que se relaciona con el plexo braquial, vasos y linfonodos axilares, y es reportado en los diferentes grupos poblacionales con incidencia variable. Se evaluaron un total de 106 axilas correspondientes a 53 cadáveres frescos que fueron sometidos a autopsia. El MAP se presentó en 5 regiones axilares (4,7 %), con tres casos unilaterales (2,8 %) y uno bilateral (0,9 %). La longitud total del MAP estuvo en un rango de 81,6-119,7 mm, mientras que su segmento tendinoso midió 13,3-28,1 mm. El espesor de su vientre muscular fue de 7,1-52 mm y del tendinoso 6,920,1 mm. En todos los casos, el MAP se originó del músculo latísimo del dorso y se insertó en el labio lateral del surco intertubercular del húmero, adyacente a la inserción del músculo pectoral mayor. Los MAP evaluados fueron inervados por el nervio toracodorsal. En dos casos, el vientre muscular del MAP cursó con trayectoria antero medial a las fibras infraclaviculares del plexo braquial, mientras que en los tres restantes, los segmentos fibrosos de inserción del MAP estuvieron relacionados con el plexo. La incidencia del MAP encontrada en el presente estudio es similar a los reportes previos realizados en cadáveres y considerablemente mayor a los reportes anatomoquirúrgicos. La importancia del MAP radica en su implicación con el síndrome de salida torácica, trombosis profunda del miembro superior y en las complicaciones en la linfadenectomía axilar.

The axillary pectoral muscle (APM) is an accessory fibromuscular structure of the axillary region. It is related to the brachial plexus, axillary vessels and lymph nodes, and is reported with variable incidence in different population groups. A total of 106 axilla were evaluated corresponding to 53 fresh cadavers. The APM was presented in 5 axillary regions (4.7 %), with three unilateral cases (2.8 %) and one bilateral (0.9 %). The total length of the APM ranged from 81.6-119.7 mm, while its tendinous segment measured 13.3-28.1 mm. Muscular belly thickness was 7.1-52 mm and the tendinous segment measured 6.9-20.1 mm. In all cases, the APM originated from the latissimus dorsi muscle and inserted into the lateral lip of humerus intertubercular sulcus, adjacent to the pectoralis major muscle insertion. The evaluated APMs were innervated by the thoracodorsal nerve. In two cases, the APM muscular belly had an anterior medial trajectory to brachial plexus fibers, while in the remaining samples, long fibrous segments of APM insertion were related to the plexus. The incidence of the APM found in the present study is similar to previous reports carried out in cadavers; it was considerably higher than previous anatomy-surgical reports. The importance of APM relies on its involvement with thoracic outlet syndrome, deep thrombosis of the upper limb and complications in axillary lymphadenectomy.