Pure Muscle Research Articles

Pure Muscle Transfers Can Be Monitored by Use of Microdialysis

Most of the methods available for postoperative monitoring of free transfers depend on an accessible skin island. Monitoring of muscle transfers without skin islands represents a challenge. The aim of this study was to describe the experiences after clinical monitoring of free muscle transfers by the use of microdialysis. The charts of 75 free muscle transfers monitored with microdialysis were evaluated with special emphasis on whether or not complications were predicted by the monitoring system. In 16 of the 75 cases, an ischemic trend was seen. In five of these cases, the ischemic trend was reversed without surgical revascularization. In the remaining 11 cases (14.7%), further ischemic trends were seen, and surgical revision with revascularization was needed for transfer salvage. Six of the 11 transfers were subsequently saved. None of the remaining five transfers were lost due to neglected ischemia. The microdialysis system did not exhibit any negative or positive false alarms. No damage to the muscle flap was experienced while performing the monitoring procedures. Microdialysis is a reliable and safe monitoring method for surveillance of free muscle transfers.

Effect of acidification on elemental and isotopic compositions of sediment organic matter and macro‐invertebrate muscle tissues in food web research

Stable isotope techniques in food web studies often focus on organic carbon in food sources which are subsequently assimilated in the tissue of consumer organisms through diet. The presence of non-dietary carbonates in bulk samples can affect their δ(13)C values, altering how their results are interpreted. Acidification of samples is a common practice to eliminate any inorganic carbon present prior to analysis. We examined the effects of pre-analysis acidification on two size fractions of sediment organic matter (SOM) from marine and freshwater wetlands and pure muscle tissue of a common freshwater invertebrate (Cherax destructor). The elemental content and isotopic ratios of carbon and nitrogen were compared between paired samples of acidified and control treatments. Our results showed that acidification does not affect the elemental or isotopic values of freshwater SOM. In the marine environment acidification depleted the δ(13)C and δ(15)N values of the fine fraction of saltmarsh and δ(15)N values of mangrove fine SOM. Whilst acidification did not change the elemental content of invertebrate muscle tissue, the δ(13)C and δ(15)N values were affected. We recommend to researchers considering using acidification techniques on material prepared for stable isotope analysis that a formal assessment of the effect of acidification on their particular sample type should be undertaken. Further detailed investigation to understand the impact of acidification on elemental and isotopic values of organic matter and muscular tissues is required.

Plasmapheresis is useful in phenprobamate overdose

Although previous scientific articles claim that morbidity and mortality are low in pure skeletal muscle relaxant ingestion, this is the 10th leading cause of death recently; however, this represents only a 2.1% ratio in adult toxic exposures in the United States. We report the case of a patient with phenprobamate overdose whose neurologic and psychiatric symptoms were the dominant findings. We were unable to perform hemoperfusion because of insufficient equipment. Thus, the patient was taken to for hemodialysis for 3 hours. However, the clinical response was inadequate. Furthermore, plasmapheresis was applied using 12 U of fresh frozen plasma for the consecutive 2 days. This caused resolution of neurologic and psychiatric symptoms. The patient was released with no residual complication on the fifth day of admission. We conclude that in phenprobamate intoxication, if hemoperfusion is impossible, plasmapheresis seems to be the best modality.

Exercise-induced expression of angiogenic growth factors in skeletal muscle and in capillaries of healthy and diabetic mice

BackgroundDiabetes has negative, and exercise training positive, effects on the skeletal muscle vasculature, but the mechanisms are not yet fully understood. In the present experiment the effects of running exercise on the mRNA expression of pro- and antiangiogenic factors were studied in healthy and diabetic skeletal muscle. The responses in capillaries and muscle fibers, collected from the muscle with laser capture microdissection, were also studied separately.MethodsHealthy and streptozotocin-induced diabetic mice were divided into sedentary and exercise groups. Exercise was a single bout of 1 h running on a treadmill. Gastrocnemius muscles were harvested 3 h and 6 h post exercise, and angiogenesis-related gene expressions were analyzed with real-time PCR. In addition to muscle homogenates, capillaries and muscle fibers were collected from the muscle with laser capture microdissection method and analyzed for vascular endothelial growth factor-A (VEGF-A) and thrombospondin-1 (TSP-1) mRNA expression.ResultsOf the proangiogenic factors, VEGF-A and VEGF receptor-2 (VEGFR-2) mRNA expression increased significantly (P < 0.05) in healthy skeletal muscle 6 h post exercise. VEGF-B also showed a similar trend (P = 0.08). No significant change was observed post exercise in diabetic muscles in the expression of VEGF-A, VEGFR-2 or VEGF-B. The expression of angiogenesis inhibitor TSP-1 and angiogenic extracellular matrix protein Cyr61 were significantly increased in diabetic muscles (P < 0.05–0.01). Capillary mRNA expression resembled that in the muscle homogenates, however, the responses were greater in capillaries compared to muscle homogenates and pure muscle fibers.ConclusionThe present study is the first to report the effects of a single bout of exercise on the expression of pro- and antiangiogenic factors in diabetic skeletal muscle, and it provides novel data about the separate responses in capillaries and muscle fibers to exercise and diabetes. Diabetic mice seem to have lower angiogenic responses to exercise compared to healthy mice, and they show markedly increased expression of angiogenesis inhibitor TSP-1. Furthermore, exercise-induced VEGF-A expression was shown to be greater in capillaries than in muscle fibers.

Versatile Use of the Pedicled Latissimus Dorsi Flap as a Salvage Procedure in Reconstruction of Complex Injuries of the Upper Extremity

Complex injuries of the upper limb are usually associated with massive soft tissue necrosis, infection, and exposure of the vital structures. Management is fairly problematic, requiring multiple operations and prolonged hospitalization. We herein present a versatile use of the pedicled latissimus dorsi flap as a salvage procedure, and its advantages. In 6 patients with such injuries, all known variations of the flap have been successfully used as a musculocutaneous, pure muscle, and pure skin (thoracodorsal artery perforator) flap. The mean follow-up time was 11.8 months. All flaps survived completely. The donor sites were closed primarily, with acceptable linear scars in all cases. Variants of the pedicled latissimus dorsi flap may be suitable to address complex defects of the upper extremity, including forearm and hand, which have little chance for free flap. Content of the flap to be used should be determined depending on requirements in the recipient site.

Asymmetric Atrophy of Multifidus Muscle in Patients With Unilateral Lumbosacral Radiculopathy

Prospective case-control study of multifidus muscle atrophy in 39 patients with unilateral lumbosacral radiculopathy and lumbosacral disc herniation and 20 controls. To evaluate quantitatively the asymmetry of multifidus muscles in unilateral lumbosacral radiculopathy with disc herniation (herniated intervertebral disc; HIVD) by using magnetic resonance imaging (MRI). Histologic and morphologic changes of multifidus muscles have been reported in lumbosacral disc herniation, but there are few imaging studies on the changes of multifidus muscles in unilateral radiculopathy. Bilateral multifidus muscles in L3-L4, L4-L5, and L5-S1 levels were detected in fast spin-echo T1 axial MRI images. The total cross-sectional area (CSA) of multifidus muscles (TMA) and the density of pure muscle CSA (PMA) were measured by a computerized analysis program, and the ratios of PMA to TMA (PMA/TMA) and the PMA ratios of involved to uninvolved sides (IMA/UMA) were calculated. The patients were divided into 2 groups according to the electrodiagnosis results: a radiculopathy (RAD) group and an HIVD group without definite radiculopathy. Fourteen patients had lumbosacral radiculopathies (RAD group) while 25 had no radiculopathy (HIVD group). No significant difference was found between the RAD and HIVD groups in TMA, PMA, and PMA/TMA. In terms of the criteria for the upper limit of IMA/UMA, 78.6% in the RAD group had an abnormal IMA/UMA ratio in at least 1 level, compared with 24% in the HIVD group and 10% in the control group. Thus, more cases with less muscle volume in the involved side were seen in the RAD group than in the HIVD and control groups. Asymmetry of the multifidus muscles as seen in MRI was a useful finding to assess patients who had unilateral lumbosacral radiculopathy with HIVD. This may reflect the denervation of multifidus muscles in lumbosacral radiculopathy.

Control of Actin Assembly Dynamics in Cell Motility

Control of Actin Assembly Dynamics in Cell Motility

Proteomic analysis of fast and slow muscles from normal and kyphoscoliotic mice using protein arrays, 2-DE and MS

A proteomic strategy based upon the integrated use of SELDI-TOF/MS, 2-DE and MALDI-TOF/MS has been used to identify a panel of fast muscle protein markers: MLC1F, MLC3F, fast troponin C (STNC) and slow muscle markers: MLC1SB and MLC2v. MLC3F, MLC1F and STNC were virtually absent in the physiologically pure slow soleus muscle of kyphoscoliotic mutant mice compared to control BDmice, whereas MLC2v increased threefold. A SELDI-TOF/MS peak at 18,012 Da in spectra from strong anionic exchange protein array fractions of fast vastus muscle was confirmed as STNC by its specific depletion from crude extracts of vastus muscle using an anti-TNC mAb. SELDI-TOF/MS also identified MLC2F phosphorylation in crude muscle extracts after treatment with alkaline phosphatase. High probability protein identifications were achieved by SELDI-TOF/MS PMF based upon the resolution of large peptides formed by partial cleavage and high peptide coverage. When the pI from 2-D gels and molecular weight estimations from SELDI-TOF/MS were entered into the TagIdent algorithm, high probability protein identity predictions were obtained that were confirmed later by PMF. We confirm that SELDI-TOF/MS can be integrated with other proteomics techniques for the efficient analysis of protein expression changes and PTMs associated with physiological changes in skeletal muscle.

Beauty of skin-grafted free muscle flaps in head and neck reconstruction

In the era of perforator flaps, muscle flaps might seem "out of fashion" for use in microvascular reconstructions. In this presentation, the advantages of pure muscle flaps covered with full-thickness (FTSG) or split-thickness (STSG) skin grafts employed in certain head and neck reconstructions shall be demonstrated. The free vastus lateralis muscle flap (n = 13) and latissimus dorsi flap (n = 1), covered with either FTSG (n = 8) or STSG (n = 6), were used for major head and neck reconstructions in a total of 13 patients. There was no revision, no partial flap necrosis, and no flap loss. All skin grafts healed in. After initial swelling, all flaps developed an adequate form according to the respective skin level, with adequate texture and color match. This was especially the case when FTSG was used. No cosmetic corrections were necessary. Donor-site morbidity was negligible. In conclusion, a free muscle flap covered with FTSG is a safe and fast reconstruction that provides good cosmetic and functional results, combined with negligible donor-site morbidity.

Impaired energy metabolism and abnormal muscle histology in mut – methylmalonic aciduria

The authors report a 27-year-old man with B12-responsive mut- methylmalonic aciduria associated with pure muscle symptoms. Two mutations were found in the methylmalonyl-CoA mutase gene. An exercise test showed a reduced maximal workload and reduced oxygen uptake, and a muscle biopsy showed subsarcolemmal accumulation of mitochondria and normal respiratory chain enzyme activities. These findings may be caused by inhibition of mitochondrial energy metabolism by methylmalonate or its metabolites.

GC-MS detection of central nervous tissues as TSE risk material in meat products: analytical quality and strategy

The detection of central nervous system (CNS) tissue (i.e. brain and spinal cord) by the use of GC-MS and certain fatty acids (FAs) as their methyl esters (FAMEs) was previously shown to be a very promising approach towards identification of CNS tissue as a specified risk material (SRM) in meat products, contrasting available immunochemical methods. This GC-MS method promised to allow quantification of CNS material as low as 0.01%. Here, we show that the CNS-relevant FAMEs C22:6, C24:1omega9, C24:1omega7, C24:0 and C24-OH are present in pure muscle and adipose tissue samples in detectable amounts. Thus, limits of detection are not feasible as quality parameters in this analytical GC-MS approach. Instead, cut-off values have to be applied as calculated from the baseline content of the respective FAME in CNS-free samples and its variation for a given statistical security. Furthermore, the FAs used for quantification of the CNS showed distinct differences depending on species and age. This finding is in accordance with previous studies where it had been concluded that species and age differentiation of CNS might be possible with GC-MS. However, it was not taken into account that it also necessitates a strict analytical strategy for quantification of the CNS content: identification of the presence of CNS (step 1); identification of species and age (step 2); and quantification by use of a species- and age-specific CNS calibration (step 3). Differences between the FA content of the CNS used for calibrating and the CNS in the sample will cause up to fivefold deviation from the true CNS content. Our results show that the FA best suited for identification (step 1) and quantification (step 3) purposes is cerebronic acid C24-OH after silylation. Further in-depth studies are needed in order to elucidate variability of brain FA content and to determine analytical limits. However, the present GC-MS approach is already a highly promising supplement to existing immunochemical methods for the detection of traces of CNS material in meat products.

Muscle CT in peripheral neuropathies.

We studied retrospectively the muscle CT scans of 60 acquired and 40 congenital motor peripheral neuropathies in order to define the diagnostic usefulness of muscle CT in these disorders. Fifty-five percent of the acquired and 72% of the congenital forms showed muscle CT pathological changes correlated to the clinical severity. The typical finding was pure muscle atrophy but several patients also revealed areas of hypodensity. In most of the acquired forms, muscle changes affected both the thighs and legs with a prevalent involvement of the posterior muscles. The congenital forms showed early involvement of the anterior leg muscles. Our study suggests that a CT scan might be useful in evaluating the severity of muscular atrophy, its evolution in time and the prognosis of motor function, in confirming the diagnosis of acquired or congenital neuropathies, and in some cases in defining the phenotypes of congenital forms.

Evidence for three fast myosin heavy chain isoforms in type II skeletal muscle fibers in the adult llama (Lama glama).

Skeletal muscle fiber types classified on the basis of their content of different myosin heavy chain (MHC) isoforms were analyzed in samples from hindlimb muscles of adult sedentary llamas (Lama glama) by correlating immunohistochemistry with specific anti-MHC monoclonal antibodies, myofibrillar ATPase (mATPase) histochemistry, and quantitative histochemistry of fiber metabolic and size properties. The immunohistochemical technique allowed the separation of four pure (i.e., expressing a unique MHC isoform) muscle fiber types: one slow-twitch (Type I) and three fast-twitch (Type II) phenotypes. The same four major fiber types could be objectively discriminated with two serial sections stained for mATPase after acid (pH 4.5) and alkaline (pH 10.5) preincubations. The three fast-twitch fiber types were tentatively designated as IIA, IIX, and IIB on the basis of the homologies of their immunoreactivities, acid denaturation of their mATPase activity, size, and metabolic properties expressed at the cellular level with the corresponding isoforms of rat and horse muscles. Acid stability of their mATPase activity increased in the rank order IIA>IIX>IIB. The same was true for size and glycolytic capacity, whereas oxidative capacity decreased in the same rank order IIA>IIX>IIB. In addition to these four pure fibers (I, IIA, IIX, and IIB), four other fiber types with hybrid phenotypes containing two (I+IIA, IIAX, and IIXB) or three (IIAXB) MHCs were immunohistochemically delineated. These frequent phenotypes (40% of the semitendinosus muscle fiber composition) had overlapped mATPase staining intensities with their corresponding pure fiber types, so they could not be delineated by mATPase histochemistry. Expression of the three fast adult MHC isoforms was spatially regulated around islets of Type I fibers, with concentric circles of fibers expressing MHC-IIA, then MHC-IIX, and peripherally MHC-IIB. This study demonstrates that three adult fast Type II MHC isoproteins are expressed in skeletal muscle fibers of the llama. The general assumption that the very fast MHC-IIB isoform is expressed only in small mammals can be rejected.

The resection of gastrocnemius muscles in aesthetically disturbing calf hypertrophy.

In some patients, oversized calves lead to mental distress and avoidance of certain social activities. They hide their legs in pants and seek medical advice. If the thickness of the subcutaneous fat is normal and cannot be diminished by liposuction, the oversized calves are caused by pure muscle hypertrophy. Using the gastrocnemius for muscle flaps in covering knee defects does not impair the function of the patient's leg; therefore, resection of the total gastrocnemius muscle for aesthetic calf reduction was performed in 15 consecutive patients without any lasting impairment with stability or sports activities. The patient was placed in a prone position, and the muscles were bluntly freed and pulled through two incisions of 5-cm length in the hollow of the knee and above the Achilles tendon. The resected muscles weighed between 410 and 810 g each. In two patients, the sural nerve was stretched or cut during the operation. The consequent numbness of the lateral ankle and sole persisted for 9 and 13 months, respectively. All 15 patients were satisfied with the results; none complained of lack of stability or insecurity in walking; and all became active in sports or changed their dress habits.

Indications for the vastus lateralis flap in oral and maxillofacial surgery

Objective: To find out the applications, usefulness and advantages of the microsurgically anastomosed vastus lateralis flap. We evaluated the results of 60 consecutive oral and maxillofacial reconstructions and established typical indications for use of this flap. Design: The transplant was applied as a pure muscle flap in 17 cases, four of those being a split-skin flap for coverage of defects on the scalp. Further reconstructions were done with myocutaneous flaps for the tongue ( n = 13), floor of the mouth ( n = 16) and external skin defects ( n = 6) as well as to close perforating defects ( n = 8). Results: The long and high-calibre vascular pedicle, the unvarying anatomy, and the time-saving possibility of simultaneously resecting the tumour and raising the flap in the head and neck region proved to be particularly advantageous during flap transfer. The best results were obtained in extensive, deep, or perforating defects and in tongue reconstruction; neuromuscular connection of the transplant is possible. Pure muscle transplants have only a few indications for application in the oral cavity because of their tendency to shrink. Donor site morbidity was generally low; the flap was lost in 5 cases. Conclusion: This hitherto rarely used transplant is well-suited for maxillofacial reconstructions if the correct indications apply.

Motoneuronal projection pattern of single C3–C4 propriospinal neurones

The pattern of motoneuronal projection and termination of single C3-C4 propriospinal neurones in the forelimb segments C6-T1 of the cat was investigated by intra-axonal injection of horseradish peroxidase into stem axons. Twelve well-stained axons were used for analysis. Termination was observed in the estimated location of motor nuclei innervating pure shoulder muscles in 10 cases. Among motoneurones innervating shoulder, elbow, wrist, and digit muscles, projection and termination were observed in motor nuclei controlling muscles of two or three joints in the following combinations: shoulder + elbow, shoulder + wrist, shoulder + elbow + wrist, shoulder + elbow + digit, and elbow + wrist + digit. In one case it was difficult to exclude the possibility of projection and termination in motor nuclei controlling muscles at all four joints. These patterns of motoneuronal projection from C3-C4 propriospinal neurones are compatible with their function in mediating the descending command for visually guided target reaching movements with the forelimb. In addition, it was found that the C3-C4 propriospinal neurones project and terminate in the region of ventral and ventromedial motor nuclei, which innervate axial muscles acting on the trunk. This was confirmed by intracellular recording from presumed ventromedial motoneurones in the C6-C7 segments. It is postulated that the C3-C4 propriospinal neurones, in addition to their control of forelimb movements, provide for conjoint control of axial muscles to stabilize the trunk during target reaching.

Muscle CT in peripheral neuropathies

We studied retrospectively the muscle CT scans of 60 acquired and 40 congenital motor peripheral neuropathies in order to define the diagnostic usefulness of muscle CT in these disorders. Fifty-five percent of the acquired and 72% of the congenital forms showed muscle CT pathological changes correlated to the clinical severity. The typical finding was pure muscle atrophy but several patients also revealed areas of hypodensity. In most of the acquired forms, muscle changes affected both the thighs and legs with a prevalent involvement of the posterior muscles. The congenital forms showed early involvement of the anterior leg muscles. Our study suggests that a CT scan might be useful in evaluating the severity of muscular atrophy, its evolution in time and the prognosis of motor function, in confirming the diagnosis of acquired or congenital neuropathies, and in some cases in defining the phenotypes of congenital forms.

A Novel Mitochondrial DNA Point Mutation in the tRNA IleGene Is Associated with Progressive External Ophtalmoplegia

We report a new mutation, a T → C transition at nt.4285 in the mitochondrial tRNA Ilegene, in a sporadic case of progressive external ophtalmoplegia (PEO) and ragged-red fibers (RRF). The mutation, involving a highly conserved base-pair in the anticodon stem, was detected in high percentages (91%) in muscle, but not in blood. It has never been reported in literature in normal subjects and it was not found in any of 80 controls studied in our laboratory. The absence of the mutation in leukocytes in this case with pure muscle involvement confirms the importance of performing mtDNA studies in PEO patients preferentially on muscle rather than blood, which could give false negative results. Other mutations in the tRNA Ilegene associated with different phenotypes have been previously reported. Thus, tRNA Ilegene is confirmed to be another “hot spot” region for mtDNA mutations.

Free Latissimus Dorsi Flap for Reconstruction of the Anterior Base of the Skull

Defects resulting after resection of malignant tumors of the paranasal sinuses involving the anterior base of the skull need an adequate closure. In addition to such avital tissue as fascia lata, fat, or ceramics, in recent years we used free muscle flaps from the latissimus dorsi for reconstruction. We performed this reconstructive method in seven patients after radical tumor ##. The operation was performed in cooperation with the neurosurgeon. In three cases a transfrontal in combination with a transfacial approach was used and in four cases only a transfacial approach was chosen. The flap was tailored as a pure muscle transplant if only the base of the skull had to be repaired and the surgical cavity had to be obhiterated. In three cases a skin paddle was left on the muscle to perform a closure of the orbit and the hard palate. In four patients we performed primary reconstruction, in three cases secondary reconstruction, which was necessary because cerebrospinal fluid (CSF) leakage occurred after primary reconstruction with avital tissue in addition to insufficient pericranial flap. None of the patients with primary reconstruction developed CSF leakage. There was no free flap failure. The aim of this reconstruction is a safe closure of skull base defects to prevent infection, meningitis, brain abscess, and brain herniation.

Repair of anterior base of skull with free latissimus dorsi flap.

After craniofacial resection for ethmoid and nasal cancer the resulting defect in the anterior base of skull often is a problem because of liquorrhoea, followed by meningitis and brain herniation. Two approaches were used for surgery of ethmoid and nasal cancer involving the anterior base of skull-the transfrontal and the transethmoidal. The neurosurgeon performs the transfrontal approach, an additional lateral rhinotomy and ethmoidectomy is made by the ENT-surgeon. Seven patients underwent radical operation with immediate repair of the skull base defect performed in four and delayed repair in three cases with a microvascular latissimus dorsi muscle flap. The flap was tailored as a pure muscle transplant if only the base of skull had to be repaired and the surgical cavity had to be obliterated. In three cases a skin paddle was left on the muscle to perform closure of the orbit and of the hard palate. The aim of reconstruction is a good functional and cosmetic result and reduction of postoperative problems-such as brain herniation, CSF-leakage and meningitis-by obliteration of surgical cavities. Furthermore crusting of large cavities and disorders of phonation are reduced. The disadvantage of limited direct postoperative tumour control by nasal endoscopy however is justified by an increase of quality of life.