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PubMed2004

Parameters influencing AIS 1 neck injury outcome in frontal impacts.

In order to gain more knowledge of the neck injury scenario in frontal impacts, a statistical study of parameters influencing incidences of AIS 1 neck injuries was performed. The data set consisted of 616 occupants in Volvo cars. Information regarding the crash, the safety systems, occupant characteristics (including prior neck problems), behavior and sitting posture at the time of impact, and neck symptoms (including duration) was collected and analyzed. Occupant characteristics (mainly gender, weight, and age), kinematics (head impacts) and behavior at the time of impact were identified as the most prominent parameter areas with regard to AIS 1 neck injury outcome. Specifically, women had a significantly higher AIS 1 neck injury rate as compared to men, occupants under the age of 50 had a significantly higher AIS 1 neck injury rate as compared to those above 50 and occupants weighing less than 65 kg have a significantly higher AIS 1 neck injury rate than heavier occupants. Drivers stating that they impacted their head against a frontal interior structure had a significantly higher AIS 1 neck injury rate than those without head impact. Also, occupants who stated they had tensed their neck muscles at the time of impact, had a significantly higher AIS 1 neck injury rate as compared to occupants who did not. Occupant activities, such as tightly gripping the steering wheel or straightening their arms showed a significantly increased AIS 1 neck injury rate, indicating that occupant behavior at time of impact could be influential with respect to AIS 1 neck injury outcome. Also, occupants reporting prior neck problems had a higher rate of persistent symptoms (>1 year) but no difference with respect to passing symptoms (<3 months) as compared to those without prior neck problems. Additionally, there was no distinct pattern for the duration of neck symptoms.

Abbreviated Injury Scale↗
PubMed1999

The timing and nature of neovascularization of jejunal free flaps: an experimental study in a large animal model.

The present study was designed (1) to determine whether a free jejunal transfer in a large animal model can develop collateral circulation that is adequate to maintain viability after division of the pedicle and (2) to determine the earliest time pedicle ligation is safe after transplantation. A 15-cm jejunal segment was transferred to the necks of 18 dogs weighing 25 to 35 kg. The bowel segment was inset longitudinally under the skin on one side of the neck, partially covered by the neck muscles, and the mesenteric vessels were anastomosed to recipient vessels in the neck. The proximal and distal bowel stomas were exteriorized through skin openings 12 cm apart and matured. The dogs were subjected to ligation of the vascular pedicle at different intervals: postoperative day 7 (group I, n = 3), day 14 (group II, n = 5), day 21 (group III, n = 5), and day 28 (group IV, n = 5). Blood perfusion was measured in the proximal and distal bowel stomas before pedicle division (control) and 24 hours later using hydrogen gas clearance and fluorescein dye. Bowel necrosis was analyzed using planimetry. The bowel was also stained with hematoxylin and eosin and factor VIII, and new blood vessels were counted. Mean values (+/- standard deviation) were compared with control values for each test and with normal values in the intact bowel using analysis of variance with Neumann-Keuls post-hoc test for multiple comparisons. No jejunal free flaps survived when the vascular pedicle was divided 1 week postoperatively. Bowel survival was 60 percent at 2 weeks, 83 percent at 3 weeks, and 100 percent at 4 weeks. Hydrogen gas clearance values (ml/min/100 g) were 49.6 +/- 8.7 in the mucosa of the intraabdominal jejunum and 37.9 +/- 9.4 in the jejunum that was transferred to the neck before division of the pedicle. Twenty-four hours after pedicle division, hydrogen gas clearance values were 2.8 +/- 6.4 in group I (p < 0.05), 22.4 +/- 12.4 in group II, 23.9 +/- 9.3 in group III, and 34.2 +/- 7.5 in group IV. FluoroScan readings in the transferred jejunum were 201 +/- 7.2 in the control group, 9.3 +/- 2.8 in group I (p < 0.05), 79.1 +/- 10.6 in group II, 66.2 +/- 7.3 in group III, and 164 +/- 11.9 in group IV. New vessel formation as identified by factor VIII staining correlated with increasing bowel perfusion and flap survival rate. Bowel neovascularization, perfusion, and survival increased progressively 1 week after transfer. Significant portions of the transferred bowel will neovascularize and survive as early as 2 weeks postoperatively. However, a minimum of 4 weeks before ligation of the pedicle is necessary to maximize flap perfusion and guarantee survival.

Animals↗
PubMed1993

The comparison of patients suffering from temporomandibular disorders and a general headache population.

The purpose of this study was to examine the possible association of signs and symptoms of temporomandibular disorders relative to headache. Fifty-six sequential patients referred to the Headache Institute of Minnesota for evaluation and treatment of migraine and tension headaches were examined for signs and symptoms of temporomandibular disorders. The results of the examination of headache patients were compared to patients suffering from myofascial pain dysfunction and/or TMJ internal derangements from the TMJ and Craniofacial Pain Clinic at the University of Minnesota. Finally the migraine and tension headache patients were compared to each other and an asymptomatic population. Results indicate that patients with temporomandibular disorders exhibit significantly more jaw dysfunction and pericranial muscle tenderness than migraine and tension headache patients. Migraine and tension headache patients were found to have similar amounts of pericranial muscle tenderness. Migraine and tension headache patients exhibited significantly more pericranial and neck muscle tenderness than a general population.

Analysis of Variance↗
PubMed1986

Discharge patterns of reticulospinal and other reticular neurons in chronic, unrestrained cats walking on a treadmill.

Recordings were made from single units in the medullary reticular formation (MRF) between AP-4.2 and AP-12.9 and from the midline to 3.7 mm lateral in chronically prepared, unrestrained cats walking on a treadmill. Recordings were made with rigid microelectrodes held in a microdrive, and reticulospinal neurons were identified by antidromic stimulation of their axons through microwires chronically implanted into the spinal cord at the L2 level. Electromyograms (EMGs) were recorded from flexor and extensor muscles of the fore- and hindlimbs as well as from back and neck muscles. In total, 295 cells were recorded from 40 penetrations in 4 cats; 252 of these cells were recorded from the more medial regions of the reticular formation encompassing the gigantocellular, magnocellular, and lateral tegmental fields; 38.5% of these (97/252) were antidromically identified from the spinal cord. The remaining 43 neurons (43/295) were recorded from a more lateral and ventral position. These medial and ventrolateral groups of neurons differed not only in position but also in aspects of their discharge during locomotion. Rank-ordered raster displays, triggered from the onset of each recorded muscle, were used to correlate neuronal and muscular activity. The discharge rate of 31% of the reticulospinal neurons (30/97) was modulated once or twice in each step cycle and was strictly related to one or more of the recorded EMGs (EMG-related neurons) on the basis of the pattern of discharge. The discharge of 33/97 (34%) of the neurons was modulated at the periodicity of the locomotor rhythm but could not be correlated with any of the recorded EMGs (locomotor-related cells), whereas the remaining 34/97 neurons (35%) were either silent, fired tonically, or were not related to the locomotor pattern (unrelated cells). Of the EMG-related neurons 27% were related to flexor muscles and the remaining 63% to extensor muscle activity. The discharge pattern of all except two of the flexor-related neurons was correlated with hindlimb muscle activity, whereas that of the extensor-related neurons was correlated almost equally with fore- and hindlimb muscles. Correlations were found with muscles lying both ipsilaterally and contralaterally to the site of the recordings. Although the locomotor-related neurons showed no preferential relation with any of the recorded EMGs, a comparison of the depth of modulation of their discharge measured from postevent histograms suggested that more of these cells were related to the forelimb than to the hindlimb.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1982

Regional topography of spinal cord neurons innervating pelvic floor muscles and bladder neck in the dog: a study by combined horseradish peroxidase histochemistry and autoradiography.

To identify the spinal origin of the innervation of the bladder neck and pelvic floor muscles retrograde axonal transport of horseradish peroxidase and tritiated horseradish peroxidase was used in a technique combining histochemistry and autoradiography. This technique proved to be suitable for differential labeling of spinal cord neurons innervating two different targets, thus extension as well as overlap of different nuclei could be judged. The parasympathetic outflow was concentrated in the intermediolateral and intermediomedial gray matter of S2, the somatic innervation was derived mostly from Onuf's motor nucleus in S1 and S2. Onuf's nucleus proved to be the main somatic motonucleus for pelvic floor muscles; there was no evidence of an autonomic share. The innervation of the striated urethral sphincter also originated in this nucleus; there was no basic difference when it was compared to the innervation of other pelvic floor muscles.

Animals↗
PubMed1997

[Clinical characteristics and muscle histopathology in polymyositis positive anti-hepatitis with C virus antibody].

In 14 patients with polymyositis (PM), 5 patients (2 males and 3 females) were positive for anti-hepatitis C virus (HCV) antibody measured by a second generation assay. We analysed the clinical characteristics and histopathological findings of the biopsied muscles from those 5 patients. They aged from 42 to 65 years averaging 53.6 years. Two asymptomatic patients visited our hospital due to elevated muscle enzyme levels, who had slight weakness in their orbicularis oculi and neck muscles on physical examination. The other 3 patients had moderate weakness of the proximal muscles. Anti-nuclear antibody was positive in 2 of the 5 patients and anti-Jo 1 antibody was negative in all patients. The serum enzymes elevated were creatine kinase (215-2, 207 (IU/l)) and glutamate oxaloacetate transaminase (40-119 (KU)). HCV-RNA was positive in the sera of 4 patients examined. All muscle biopsy specimens revealed variation in fiber size with inflammatory cellular infiltration and observed degenerating and regenerating fibers. The scant infiltration type was observed in 2 asymptomatic patients in whom the infiltrated cells were CD4 positive. The endomysial infiltration type was observed in 3 symptomatic patients; CD8 positive cells were found focally to diffusely in 2 patients examined. The expression of class 1 molecules from the major histocompatibility complex was detected mainly in infiltrated fibers to variable degrees. All of the patients showed a good response to the initial steroid therapy. The present study suggests that autoimmune reaction related to HCV infection causes myositis, therefore anti-HCV antibody should be checked in cases of PM.

Adult↗
PubMed2003

Muscle spindles in the deep muscles of the human neck: a morphological and immunocytochemical study.

Muscle spindle density is extremely high in the deep muscles of the human neck. However, there is a paucity of information regarding the morphology and immunoreactivity of these muscle spindles. The objective of this study was to investigate the intrafusal fiber content and to assess the myosin heavy chain (MyHC) composition of muscle spindles from human deep neck muscles. In addition to the conventional spindles containing bag(1), bag(2), and chain fibers (b(1)b(2)c spindle), we observed a number of spindles lacking bag(1) (b(2)c spindle) or bag(2) (b(1)c spindle) fibers. Both bag(1) and bag(2) fibers contained slow tonic MyHCs along their entire fiber length and MyHCI, MyHCIIa, embryonic, and alpha-cardiac MyHC isoforms along a variable length of the fibers. Fetal MyHC was present in bag(2) fibers but not in bag(1) fibers. Nuclear chain fibers contained MyHCIIa, embryonic, and fetal isoforms with regional variations. We also compared the present data with our previous results obtained from muscle spindles in human biceps brachii and the first lumbrical muscles. The allotment of numbers of intrafusal fibers and the MyHC composition showed some muscle-related differences, suggesting functional specialization in the control of movement among different human muscles.

Adenosine Triphosphatases↗
PubMed2004

Influence of muscle contraction on whiplash kinematics.

It is unclear whether reflexive muscle contraction in unaware occupants can alter spinal kinematics to mitigate injury in the unaware occupant subjected to whiplash loading. Whiplash injury likely occurs during the non-physiologic S-curvature phase of spinal kinematics, present during the first 100 msec after the initiation of T1 acceleration. Experimental investigations using human volunteers have reported 45 to 60 msec delays prior to electrical activity of the sternocleidomastoid. The effects of reflexive contraction of the neck muscles were investigated using a validated head-neck computational model consisting of head, cervical spine, and first thoracic vertebra. Intervertebral discs. spinal ligaments, and facet joints were modeled using discrete elements. Passive and active musculature were incorporated using the Hill-type muscle model. The computational model was subjected to 2.6 m/sec rear impact velocity, applied to T1. Reflexive muscle contraction in the unaware occupant model was incorporated using a 54-msec muscle delay, 13-msec electromechanical delay, and an 81-msec muscle rise time. Results of the unaware occupant model were compared to the model exercised without muscle contraction. Reflexive muscle contraction altered segmental angulations by less than 10% and facet joint capsular ligament distractions by less than 16% during the time of maximum S-curvature. At the C5-C6 and C6-C7 levels, muscle contraction increased capsular ligament distractions. Due to the nominal affect of reflexive muscle contraction on segmental angulations and facet joint capsular ligament distractions during S-curvature, it is unlikely that this contraction can alter the cervical kinematics responsible for whiplash injury.

Acceleration↗
PubMed1983

Push-pull perfusion of pentylenetetrazol in the brain stem of 'encéphale isolé' cats.

Nine 'encéphale isolé' cats had 'push-pull' perfusions of pentylenetetrazol (PTZ) in various loci of the brain stem, while the EEG from the right and left motor cortices, EMG from neck muscles, ocular movements and clinical changes were recorded. Perfusions in the rostral MRF induced bilateral rhythmic paroxysmal EEG discharges and myoclonic twitching of neck and head, more prominent in the muscles contralateral to the perfused side. PTZ in the caudal MRF induced tonic-clonic paroxysmal EEG discharges and EMG seizures, similar to those seen when PTZ is injected systemically. Perfusion in the PRF induced EEG spindle bursts, muscular hypotonia and myosis. When perfusion in the MRF inducing rhythmic paroxysmal EEG discharges and myoclonic twitching was followed by perfusion in the PRF, the EEG discharges were not modified, but the myoclonic movements were abolished. Perfusions outside the MRF and PRF did not produce obvious changes other than tonic gaze deviation to the contralateral side or nystagmus. The results suggest that PTZ has a differential effect in various structures of the CNS, producing primary generalized convulsive seizures when acting directly on the MRF.

Animals↗
PubMed2004

Current approaches and future directions to understanding control of head movement.

This chapter reviews four key issues that must be addressed to advance our knowledge of control of head movement by the central nervous system (CNS). (1) Researchers must consider how the CNS utilizes the multiple muscle patterns that can produce the same head movement in carrying out tasks in an optimal way. (2) More attention must be paid to the dynamics of neck muscle activation that are required to implement head movements and show they are produced by CNS circuits. (3) Research is required to determine how the multiple pathways that impinge upon neck motor centers are utilized in a variety of tasks including eye-head gaze shifts, smooth head tracking, head stabilization and manipulating objects with the head. These pathways include corticospinal, vestibulospinal, reticulospinal (three subdivisions), fastigiospinal, tectospinal and interstitiospinal tracts. (4) Further analysis is needed to understand how vestibular signals are modulated during each of the above-mentioned tasks. This ambitious agenda is justified by the fact that the head-neck motor system is an ideal model for understanding issues of complex motor control.

Animals↗
PubMed1978

Hereditary "draft lamb" disease of Border Leicester sheep: the ultrastructural pathology of the skeletal muscles.

A hereditary and congenital disease of Border Leicester lambs clinically indistinguishable from the "draft lambs" of Innes et al. (1949) but with no cerebellar lesion, is defined in terms of the ultrastructural pathology of the muscle, intramuscular nerves and neuromuscular junctions. The pathognomonic feature of these congenitally affected lambs was the occurrence of large intrafascicular muscle cells. On the basis of the mitochondrial content and Z disc thickness these were considered to be one of two subtypes of type I cell. There was evidence of muscle cell growth in all cell types between birth and 3 mth of age, particularly in the form of myofibrillar splitting. The myofibrils of the large cells were very large and incompletely split. The mitochondria in these cells were of two kinds, roughly rounded and tubular. The latter showed conspicuous branching. A few muscle cells appeared immature but no significant degenerative changes were detected. In some neck muscles intramuscular nerves were seen and in 28 per cent. of the axons lamellated electron-dense bodies occurred. The periodicity of the lamellations was 40--60 nm. No other defects were observed in their vicinity but some axon terminals contained distended mitochondria which themselves contained membranous bodies. The axon terminals also contained morphologically normal synaptic vesicles and there was evidence that these were transmitting their transmitter substance. The lesions in hereditary "draft" lamb disease of Border Leicester sheep may result from functional defects of the nervous system which have a delaying effect on the development of some muscle cells, whilst others capable of normal growth hypertrophy. Alternatively, there may be a primary defect in the muscle cells themselves either alone or together with an unrelated neuropathy.

Animals↗
PubMed2002

Inflammatory myopathies.

Inflammatory myopathies are the result of infiltration of inflammatory cells into striated muscle, with or without an association with an underlying cause. Two broad classifications are IIMs and secondary inflammatory myopathies associated with other diseases. Standard diagnostic criteria for inflammatory myopathy include the presence of weakness or loss of specific muscle group function, an increase in CK, EMG changes associated with muscle membrane instability, and histologic evidence of inflammation. Not all these criteria, however, must be present. Fresh-frozen biopsy from two proximal muscles is recommended for biopsy confirmation. IIM can either focally affect head or neck muscles or be more diffuse. MMM is an immune-mediated disease characterized by a humoral antibody produced against the unique type IIM and type I variant mvofibers of masticatory muscles of dogs, which causes inflammation and loss of function of the muscles of mastication. Idiopathic polymyositis can affect focal muscle groups (extraocular, laryngeal) or present as multifocal or diffuse involvement of skeletal muscle in the cat and dog. Familial canine DM is an inflammatory disease of the striated muscle, skin, and vasculature in young Collies, Shetland Sheepdogs (Shelties), and, rarely, Collie-crossbred dogs. Immunosuppressive therapy is the key to successful treatment. Protozoal parasitic myopathies are the most common cause of clinically relevant secondary inflammatory myopathies. The degree of systemic involvement is often the limiting factor to successful treatment. Early recognition of the clinical signs for proper diagnostic testing and institution of appropriate therapy can result in a rewarding outcome in treating inflammatory myopathies in the cat and dog.

Animals↗
PubMed1993

Use of chuck muscles and their acceptability in restructured beef/surimi steaks.

Ten major muscles along with any unidentifiable lean, were carefully excised from 16 Choice square-cut chucks Yield Grade 2, and placed according to previously determined tenderness rankings, into one of three muscle groups. Group 1 was composed of the most tender muscles, and contained the infraspinatus, longissimus, and triceps brachii. Group 2 contained intermediate tenderness muscles and was composed of the serratus ventralis, deep pectoral, and complexus. Group 3 contained the least tender muscles and was composed of the biceps brachii, supraspinatus, rhomboideus, trapezius, deltoids, and neck muscles. Each group was restructured into beef/surimi steaks and was evaluated. Total muscle yield before trimming accounted for 66.2% of the chuck. Careful fat trimming, desinewing, and internal seam cutting on individual muscles resulted in 34.7% lean available for the restructuring of steaks. The triceps brachii, longissimus, supraspinatus, and infraspinatus required the least trimming and were easiest to excise. These muscles made up 49% of the trimmed meat and 13.7% of the total chuck. Steaks were evaluated by a consumer sensory panel for tenderness, flavor, overall preference, and intent to purchase. There were no differences detected by consumers among the muscle groups for the sensory traits studied. Tenderness and flavor were rated equal to intact steaks for all muscle groups studied. The consumer sensory panel indicated that Groups 1 and 2 would be purchased twice a month and Group 3 once a month.

Animals↗
PubMed2005

Evaluation of specific humoral immune response in pigs vaccinated intradermally with deleted Aujeszky's disease vaccine and challenged with virulent strain of Herpesvirus suis type 1.

A comparison of intradermal (ID) versus intramuscular (IM) routes of pig vaccination with deleted Aujeszky's disease (AD) vaccine on the formation of specific postvaccinal and postchallenge humoral immune response was performed. The studies were carried out on 21 eight week-old piglets, divided into three groups--two experimental and one control of 7 piglets each. Animals of first two groups were vaccinated twice in 12 and 16 week of age with deleted, live attenuated AD vaccine Porcilis Begonia (Intervet). Group I was vaccinated with a dose of 2.0 ml (10(6.0) TCID50)) intramuscularly (IM) into neck muscles, and group II received 0.2 ml (10(5.0) TCID50) intradermally (ID) in neck area using needleless apparatus SERENA model SD 1-2 (Emplast, Italy). In group K (control) 2.0 ml PBS IM was used. Seventy days after the first vaccination all pigs were intranasally infected with a dose of 10(5.5) TCID50 of virulent Northern Ireland Aujeszky-3 (NIA-3) strain of Herpesvirus suis type 1 (SHV-1) by instilling 0.5 ml of virus suspension into each nostril. Specific humoral immune response was evaluated using seroneutralization (SN) test and gE-ELISA-Pseudorabies virus gpI Antibody Test Kit (Herd Chek Anti-PRV gpI), IDEXX Lab Inc (USA). It was found that challenge caused anamnestic reaction in both groups of vaccinated pigs, but postchallenge immune response was stronger in ID-vaccinated group--on 14 day post infection (dpi) SN antibody level was considerably higher than in IM-vaccinated group. The obtained results suggest that secondary immunological response after challenge is decidedly more effective in the range of evaluated parameters in animals vaccinated by ID route, which can be linked to, perhaps underestimated yet and seldom utilized, skin immunity mechanisms in specific prophylaxis of infectious diseases. Advantages and disadvantages of SN test and ELISA are also discussed.

Animals↗
PubMed2001

Dynamic and kinematic strategies for head movement control.

This paper describes our analysis of the complex head-neck system using a combination of experimental and modeling approaches. Dynamical analysis of head movements and EMG activation elicited by perturbation of trunk position has examined functional contributions of biomechanically and neurally generated forces in lumped systems with greatly simplified kinematics. This has revealed that visual and voluntary control of neck muscles and the dynamic and static vestibulocollic and cervicocollic reflexes preferentially govern head-neck system state in different frequency domains. It also documents redundant control, which allows the system to compensate for lesions and creates a potential for substantial variability within and between subjects. Kinematic studies have indicated the existence of reciprocal and co-contraction strategies for voluntary force generation, of a vestibulocollic strategy for stabilizing the head during body perturbations and of at least two strategies for voluntary head tracking. Each strategy appears to be executed by a specific muscle synergy that is presumably optimized to efficiently meet the demands of the task.

Animals↗
PubMedDate not supplied

[Electromyographic studies of nape and temporal muscles in headaches of various etiology].

The author reports the results of electromyographic investigations of the muscles of the nape and temporal muscles in 132 patients with headaches of different aetiology (migraine, cervical migraine, vasomotor headache, symptomatic headaches) and in 51 controls who had never had headaches. In the healthy subjects no bioelectric activity was observed when the patients relaxed completely. On the other hand, in most patients with headaches continuous bioelectric activity was observed at rest in these muscles indicating their involuntary contraction. This phenomenon is called by the author "cephalalgic" spasm of head and neck muscles, which is rather characteristic of various headaches.

Electromyography↗