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At least 937 records · Page 52Linked to original sources
PubMed1985

Pharyngoesophageal reconstruction. Is a skin-lined pharynx necessary?

Current methods of pharyngoesophageal reconstruction have in common the creation of an epithelial lined pharynx. We performed eight cases of pharyngoesophageal reconstruction with a pectoralis major muscle flap. In the first six cases, split-thickness skin was quilted onto the muscle. In the last two cases, pectoralis major muscle alone was used, allowing epithelialization to occur from adjacent mucosa. The results with this simplified technique have been as good as when a skin-grafted muscle flap was used. We prefer a pectoralis major muscle flap, with or without split-thickness skin, to a pectoralis myocutaneous flap. There is no hair growth, it is easy to tube, and a thin-walled pharynx is produced. This is an advantage for the development of an esophageal voice, and tracheoesophageal puncture can be easily performed if no voice is achieved. All of our patients received full-dose, preoperative radiotherapy. One patient developed a fistula that closed spontaneously. There have been no strictures at the pharyngoesophageal junction. All patients quickly established a good oral intake.

Aged↗
PubMed1979

Loss of thick filaments from fast-twitch glucolytic muscle fibers of the pigeon pectoralis after chronic administration of dantrolene sodium.

Adult pigeons received dantrolene sodium, a skeletal muscle relaxant which blocks the release of calcium during excitation-contraction coupling, for 12 to 16 weeks. The pectoralis muscles of these birds were analyzed for changes occurring in the various fiber types of the muscle. Both histochemistry (ATPase and SDH activity) and electron microscopy (mitochondrial and lipid volume percentages) differentiated two fiber types. The two fiber-types consisted of fast-twitch glycolytic fibers (FG) and fast-twitch oxidative-glycolytic (FOG) fibers. After dantrolene treatment some FG fibers showed little or no ATPase activity. Dantrolene treatment also produced a disappearance of thick filaments in some FG fibers. We infer that the fibers without thick filaments are the ones lacking ATPase activity. The FOG fibers were nearly normal. Since drug-fed birds lose weight, a few birds were starved to determine whether the filament loss was related solely to the bird's loss in weight. No fibers in starved birds showed reduced ATPase activity or loss of thick filaments. In fibers that showed thick filament disappearance, the I-bands remained organized and intact, suggesting that the I-band maintains its integrity without interaction with the thick filaments. Changes in activity patterns may cause loss of thick filaments by inhibiting either their synthesis or assembly.

Adenosine Triphosphatases↗
PubMed1991

Histopathological and ultrastructural alterations of turkey skeletal muscle.

The pectoralis thoracicus and biceps femoris muscles were obtained from 30 18-wk-old Large White turkey males at the time of slaughter. The birds had no observable mobility or postural problems, and the meat appeared normal. Samples were processed for histology, histochemistry, and electron microscopy. Degenerative features were found in muscle from 10 of the 30 birds. Four of the 10 had alterations in both muscles. The degenerative changes included scattered focal necrosis, hypercontraction of muscle fibers, infiltration by mononuclear cells, formation of fibrous tissue scars, and Z-band streaming. These structural alterations appear to be related to muscle ischemia.

Abattoirs↗
PubMed1991

The extended pectoralis major myocutaneous flap: uses and indications.

The vascular territory of the pectoralis major muscle and overlying skin was studied by selective intraarterial dye injections in fresh cadavers. The area of skin overlying the anterior chest and abdominal wall beyond the limits of the pectoralis major muscle that can be elevated as an extended myocutaneous flap was determined. The cadaver injections were evaluated to determine the size and shape of the skin island used to reconstruct defects of the head, neck, and upper trunk with an extended skin paddle off the pectoralis major muscle. Pectoralis muscle flaps with variously shaped skin paddles, some extending beyond the limits of the muscle, were used in 27 patients to cover large soft-tissue defects of the upper thorax, face, and floor of the mouth and as a skin tube to reconstruct the cervical esophagus. The size of the skin paddle ranged from 5 x 7 cm to 26 x 16 cm. All flaps survived completely, and there were no major donor-site complications.

Adult↗
PubMed1987

The anatomy of the pectoral nerves and its significance to the general and plastic surgeon.

It has previously been shown that in 62% of patients the medial pectoral nerve courses through the pectoralis minor muscle to innervate the lower half or two thirds of the pectoralis major muscle. In the other 38% of patients, the medial pectoral nerve exits around the lateral aspect of the pectoralis minor muscle. The lateral pectoral nerve courses on the undersurface of the pectoralis major muscle, innervating the proximal one third or more of the muscle. Consequently, when the pectoralis minor muscle is removed in a modified radical mastectomy, or dissection between the two muscles is performed, there is partial deinnervation of the pectoralis major muscle with partial atrophy and a decrease in size. Further, if the lateral pectoral nerve also is injured or removed, it can result in total deinnervation of the pectoralis major muscle with more severe atrophy and fibrosis of the muscle. In cosmetic augmentations, when the breast implant is placed behind the pectoralis major muscle, that muscle is partially deinnervated. In this clinical situation, this is believed to be advantageous because it allows the breast to project better. This paper details the anatomy of the pectoral nerves and discusses the clinical implications of surgery in this region as it relates to the size and function of the pectoral muscles.

Breast↗
PubMed1989

A new method of modified radical mastectomy for breast cancer.

We have developed a new type of modified radical mastectomy, the method and clinical results of which are reported herein. In this operation, axillary dissection is performed by the following two approaches. Firstly, the axillary contents are dissected from the highest possible subclavicular point to the pectoralis minor muscle, after partially cutting the sternocostal origin of the pectoralis major muscle. The second approach is from the posterior aspect of the pectoralis minor muscle to the lateral portion of the latissimus dorsi muscle. Parasternal dissection can also be performed for stage II and IIIa cancers with a central or medial tumor. After lymph node dissection, the detached edge of the sternocostal origin of the pectoralis major muscle is resutured to cover the parasternal region. Thus, complete dissection of the axillary nodes is performed whilst preserving the pectoralis major and pectoralis minor muscles. Good clinical results were achieved with respect to radicality, cosmetic effects and function in 28 patients with stage I, II, and IIIa breast cancers who were followed up for between 5 to 8 years. This new operation may therefore be adopted for the majority of patients with Stage I, II, or IIIa cancers, unless massive infiltration into the pectoralis major muscle has occurred. Preservation of both the pectoralis major and pectoralis minor muscles results in a good cosmetic appearance, good functioning of the arm and easy reconstruction of the breast following mastectomy.

Adult↗
PubMedDate not supplied

Participation of the deltoid (anterior portion) and pectoralis major (clavicular portion) muscles in different modalities of supine and frontal elevation exercises with different grips.

The muscles deltoid-anterior portion (DA) and pectoralis major-clavicular portion (PMC) were analysed to establish the muscular behavior and intensity patterns, as well to evaluate the connected participation of these muscles during supine and frontal elevation exercises. Twenty-four male volunteers were examined using a 2-channel TECA TE4 electromyograph and Hewlett Packard surface electrodes. Our results showed low levels of activity to PMC in frontal elevation exercises, whereas to DA the levels were very high. In the supine exercise, the action potential levels developed by the PMC were always lower than those presented by DA, however, with action simultaneity. Some suggestions to the use of the tested exercises are presented.

Action Potentials↗
PubMed2005

Effect of post-tetanic potentiation of pectoralis and triceps brachii muscles on bench press performance.

The effect of post-tetanic potentiation (PTP) induced in the pectoralis and triceps brachii muscles by high-frequency submaximal percutaneous electrical stimulation (PES) on average and maximal power attained in bench press throwing was measured in 12 healthy men. Three PES regimens were used: (a) a 7-second and (b) a 10-second trial at 100 Hz, and (c) an intermittent trial with 8 1-second tetanic trains at 100 Hz with rest periods of 20 seconds. Only nonsignificant (p > 0.05) increase was observed in average power at 8 minutes and in maximal power at 5, 8, and 11 minutes after tetanus after 7-second trial, and in maximal power at 5 and 8 minutes after tetanus after an intermittent trial. These data indicate that PES application was a noneffective stimulus for increased bench press performance. A great interindividual variability response was observed and, therefore, PTP induction for improving upper-body muscle performance needs further experiments.

Adult↗
PubMed2006

An unusual innervation of pectoralis minor and major muscles from a branch of the intercostobrachial nerve.

Variations of the branching pattern of the intercostobrachial nerve have been known to complicate dissection during mastectomy and other procedures involving the axilla. We present a unilateral case of a 73-year-old Caucasian female, in which the intercostobrachial nerve gives rise to an additional medial pectoral branch, which partially innervates the pectoralis minor muscle, as well as the abdominal head of pectoralis major muscle. Clinical consequences of such a variation may include motor losses, in addition to the commonly reported sensory losses, resulting from accidental or intentional dissection of the intercostobranchial nerve.

Aged↗
PubMed2004

Growth changes of the collagen content and architecture in the pectoralis and iliotibialis lateralis muscles of cockerels.

1. Growth changes of the collagen content and architecture in the pectoralis (PT) and iliotibialis lateralis (ITL) muscles were examined using cockerels from 1 to 14 weeks of age. 2. Total collagen content in PT muscle showed little change, but in ITL muscle reached a maximum at 5 weeks and thereafter decreased slightly until 14 weeks. The collagen content was markedly larger in ITL muscle after 5 weeks. Pyridinoline content of collagen increased abruptly from 5 to 14 weeks in both muscles, but no difference between muscle types was detected. 3. The cell size of the endomysial honeycombs increased with the development of myofibres, and the mesh size of the perimysium around the honeycombs enlarged. 4. In both muscles endomysia were an incomplete network of collagen fibrils with many foramina at one week, became a very thin membrane of felt-like fabric in 2 to 5 weeks and thereafter increased in thickness until 11 to 14 weeks. 5. Perimysial width around the secondary fasciculus differed between the muscle types after 5 weeks. In the wider perimysium of ITL muscle, the collagen fibres increased in number and size to make a stack of collagen bands around the fasciculus. In the narrower perimysium of PT muscle, a few platelets of collagen fibres also developed. 6. The perimysial collagen fibre at 1 to 2 weeks had a smooth surface and appeared to be composed of fine collagen fibrils. The fibre at 11 to 14 weeks showed a rugged surface and was composed of coarser collagen bundles that combined with each other into a net-like configuration with very slim meshes. 7. Our results showed that the collagenous components of chicken intramuscular connective tissue changed markedly during the early period of muscle growth in distribution, architecture and quality but with little difference in quantity.

Animals↗
PubMed1981

In vivo effects of protease inhibitors on chickens with hereditary muscular dystrophy.

Beginning on day 4 ex ovo, and every 3 d thereafter, genetically dystrophic Line 413 chickens were given intraperitoneal injections (4 mg/kg body wt) of a protease inhibitor, leupeptin, pepstatin, or antipain. Experimental chickens received protease inhibitors dissolved in a water:ethanol:dimethyl sulfoxide solution (50:40:10, vol:vol:vol). Control untreated animals received diluent injections. Untreated dystrophic chickens typically reach around day 30 ex ovo a maximum ability to right from the supine position in a standardized functional test for muscle weakness. After day 30 ex ovo, the dystrophic chickens are found to decline progressively in their ability to right, compared with normal, nondystrophic controls, which have an unimpaired ability to right. Concomitantly, dystrophic chickens exhibit characteristically high levels of plasma creatine phosphokinase enzyme activity. In addition, an increased frequency of degenerating, regenerating, and vacuolated myofibers, and inflammatory cells appear in the affected pectoralis major muscles from the dystrophic chicken. Throughout the duration of the trial, there was no major enhancement in the functional righting ability of dystrophic chickens receiving any one of the protease inhibitors tested. However, there was a significant reduction in the abnormally high levels of plasma creatine phosphokinase in the treated chickens. Also, there was an apparent reduction in the mean number of vacuolated fibers in the pectoralis muscle from the protease inhibitor-treated birds. No significant reductions were observed in the relative frequency of degenerating and regenerating myofibers or inflammatory cells. In addition to the plasma creatine phosphokinase decrease, however, therapeutic benefit was seen in 31.0, 30.5, and 14.8% increases in the wet weight (and total noncollagen protein) of pectoralis muscle from dystrophic chickens receiving leupeptin, pepstatin or antipain, respectively.

Animals↗
PubMed1977

Enzymatic activities of muscle fibres differentiated, in vitro, from pectoralis major (white) and adductor magnus (red) muscles of chick embryos.

Specific activities of NADP isocitrate dehydrogenase and acetylcholinesterase were significantly higher in muscle fibres differentiated, in vitro, from myoblasts of adductor magnus (red) than pectoralis major (white) muscles 10-day-old chick embryos. This is evidence, as far as enzyme activities are concerned, that myoblasts from different types of skeletal muscles are able to give, in tissue culture, muscle fibres of different properties, even in the absence of nerve supply.

Acetylcholinesterase↗
PubMed1998

Breast and pectoralis musculo-aponeurotic fibromatosis: two independent lesions occurring in the same patient. A case report.

We report the first case of primitive breast fibromatosis associated with a synchronous independent musculo-aponeurotic fibromatosis of the omolateral pectoralis major muscle in an otherwise healthy 29-year-old woman without clinical evidence of any genetic syndrome. The primary occurrence of the two lesions was supported by the absence of any macroscopic and microscopic connection. The present case suggests that a pre- or intraoperative frozen section diagnosis of breast fibromatosis should lead the surgeon and pathologist to exclude an independent fibromatosis of the underlying musculo-aponeurotic fascia.

Actins↗
PubMed1955

Phase and electron microscope studies of the interrelationship of cytochondria and myofibrils in pigeon breast muscle.

MITOCHONDRIA IN PIGEON BREAST MUSCLE ARE COMPOSED OF TWO PROTEIN GELS: a fibrous gel, in the form of a folded ribbon, enclosed within a non-fibrous matrix. An external limiting "membrane" is not demonstrated, and there is poor demarcation between the mitochondria and adjacent structures or sarcoplasm. No internal structure has been determined for sarcosomes. These structures, however, are symplasmic with mitochondria and usually are located within mitochondrial depressions. They apparently have a high lipid content. The myofibrils also have no external limiting "membranes" and the mitochondria and sarcosomes are symplasmic with them. The mitochondria normally lie in the intermyofibrillar sarcoplasm oriented with their longitudinal axes parallel to the myofibrils. Cross-sections show that the myofilaments are oriented into well defined sheets.

Animals↗