Mapping of a distal form of spinal muscular atrophy with upper limb predominance to chromosome 7p

An autosomal dominant distal form of spinal muscular atrophy mainly affecting the upper limbs with a mean age of onset of 17 years has been identified in a large Bulgarian family. Linkage of the above family to the spinal muscular atrophy type I, II and III locus on chromosome 5 has been excluded. In an attempt to map this disease gene we have analysed individuals of this family, with more than 140 microsatellite polymorphic markers of the human genome. A maximum lod score of 5.99 at theta = 0.007 has been obtained with locus D7S795. We have thus mapped the gene for this hereditary form of distal spinal muscular atrophy to chromosome 7p.     

A case of juvenile muscular atrophy of the upper limb with intraspinal cavity formation

The patient was a 23-year-old man. He had no history of trauma in the head and neck. When he was 20 years old (in 1992), he noticed muscle atrophy and weakness in the right hand. In a hospital, he had cervical MRI study and other examinations. The diagnosis was juvenile muscular atrophy of the upper limb (Hirayama's disease). After that the symptoms became worse in the bilateral forearms and hands. The neurological examination showed severe atrophy in bilateral C7 to Th1 innervated muscles, right pyramidal sign, mild superficial and deep sensory disturbance in the dermatome of C7-Th1, and right Horner's sign. Cervical MRI and myelography revealed the atrophy of cervical cord and intraspinal cavity formations from C5 to Th1. We concluded that chronic and intermittent compression to cervical cord with flexion position made the cavities during the clinical course because these cavities were not found in the MRI taken in 1992.     

Work capacity of the upper limbs after mastectomy

A 59-year-old man presented with neck pain and limb numbness. He also had bilateral symmetrical joint deformities of his hands and wrists. Cervical spine radiographs showed C 1/2 instability and features of rheumatoid arthritis. Magnetic resonance imaging demonstrated erosion ofthe odontoid peg by pannus. C 1/2 surgical fusion was performed. The role of imaging in cervical spine involvement by rheumatoid arthritis is reviewed.     

A case of early-onset cortical cerebellar atrophy with rhythmic skeletal myoclonus in the left upper limb

A 19-year-old man developed progressive unsteady gait and speech disturbance two years ago. He recently noticed muscle twitches in the left limb. Neurological examination revealed scanning speech, saccadic ocular movement, ataxia of trunk and limbs predominant on the left side. Rhythmic myoclonus was present at rest around the left shoulder and arm, and amplified by raising the left arm. There was no myoclonus in the soft palate. MRI revealed only a cerebellar atrophy. This patient was diagnosed as having cortical cerebellar atrophy with rhythmic skeletal myoclonus (RSM). Tc-99m ECD SPECT showed a decrease in the blood flow of the right thalamus when the myoclonus was enhanced by raising the left upper limb, which suggests that the cerebello-thalamo-cortical system as well as Guillain-McIlaret triangle is involved in the development of RSM.     

Contractility and electrophysiological parameters of cremaster muscles of boys with a hernia or undescended testis

BACKGROUND/PURPOSE: The cremaster muscle (CM) has been considered to participate in regulation of blood flow and temperature of the testis. Its contribution to testicular descent has been suggested. However, there is limited information about the CM in physiological and pathological states. Therefore, an experimental study has been conducted to evaluate and compare the contractile and electrophysiological properties of CM in boys with descended or undescended testes. METHODS: Identical CM strips were obtained from eight boys who underwent orchidopexy with a mean age of 3+/-2.2 years and from eight boys who underwent herniorrhaphy with a mean age of 4+/-1.3 years. Muscle strips of 3 x 8 mm were vertically attached to an isometric force displacement transducer, and direct muscle contractions were elicited by rectangular electrical pulses. Direct isometric muscle contractions were recorded in an organ bath containing mammalian Ringer's solution. In electrophysiological experiments, conventional microelectrode techniques were used. RESULTS: Direct electrical stimulation of CM strips obtained from patients with descended and undescended testes elicited muscle twitches and frequency-dependent contractile responses. Tetanic contractions of undescended testes at 100 Hz were 67% greater in amplitude than that of descended testes (P< .002). Muscle strips of both groups exhibited increased twitch amplitudes by 105%+/-37% when the temperature of the bathing solution was increased from 22 degrees to 37 degrees C (P< .001). The electrophysiological findings were similar. CONCLUSIONS: Contrary to other striated muscles, elevated temperature increases the contractility of CM. If the increased contractility by an increase in temperature is a property unique for CM, it should reflect the attempts at regulating testicular blood flow or temperature. The increased amplitude of contractions encountered among the CM of boys with undescended testis suggests the CM to have a role on the location of the testis.     

Multiple system atrophy: clinical presentation and diagnosis

Multiple system atrophy (MSA) describes a relatively uncommon, debilitating disorder that is frequently misdiagnosed as Parkinson's disease. Patients with MSA show various combinations of parkinsonism, cerebellar ataxia, pyramidal signs and progressive autonomic failure, especially cardiovascular and urologic autonomic dysfunction. Few treatment options exist. Although some patients initially respond well to dopaminergic treatment for their parkinsonian symptoms, striatal degeneration occurs, and levodopa often becomes ineffective. Thus, physicians may provide only symptomatic treatment and support for patients with MSA. In this paper, we present a case study of a 68-year-old woman who came to the Vanderbilt Movement Disorders Clinic with severe autonomic dysfunction and parkinsonism, previously diagnosed as Parkinson's disease. Following autonomic function tests as well as clinical evaluation, she was diagnosed with MSA and began treatment for orthostatic hypotension and micturition dysfunction.     

Pre-clinical and clinical electrophysiological studies for the prediction of iatrogenic proarrhythmic effect (torsade de pointes)

Two new research approaches in combustion toxicology are: 1. the prediction of smoke toxicity from mathematical equations, which are empirically derived from, experiments on the toxicological interactions of complex fire gas mixtures and 2. the use of toxicant suppressants in materials or products to prevent the formation of toxic combustion products. The predictive approach consists of burning materials using a bench-scale method that simulates realistic fire conditions, measuring the concentrations of the primary fire gases--CO, CO2, low O2, HCN, HCl, HBr, and NO2--and predicting the toxicity of the smoke using either the 6- or 7-gas N-Gas Model. These models are based on the results of toxicological studies of these primary gases as individual gases and as complex mixtures. The predicted toxic potency is checked with a small number of animal (Fischer 344 male rats) tests to assure that an unanticipated toxic gas is not generated or an unexpected synergistic or antagonistic effect has not occurred. The results indicate if the smoke from a material or product is extremely toxic (based on mass consumed at the predicted toxic level) or unusually toxic (based on the gases deemed responsible). The predictions based on bench-scale laboratory tests have been validated with full-scale room burns of a limited number of materials of widely differing characteristics chosen to challenge the system. The advantages of this new approach are 1. the number of test animals is minimized by predicting the toxic potency from the chemical analysis of the smoke, 2. smoke may be produced under conditions that simulate the fire scenario of concern, 3. fewer tests are needed, thereby reducing the overall cost of the testing and 4, information is obtained on both the toxic potency of the smoke and the responsible gases. The N-Gas Models have been developed into the N-Gas Method (described in this paper) and these results have been used in computations of fire hazard. The 6-Gas Model is now part of the international standard ISO 13344 approved by 16 member countries of the International Standards Organization (ISO) and is also included in the U.S. national standard ASTM E1678 approved by the American Society for Testing and Materials (ASTM). In addition, the 6-Gas Model is used in the American National Standard--NFPA 269--approved by the National Fire Protection Association (Quincy, MA). The second new research approach, toxicant suppressants, examines the potential of chemical compounds, which when added to a material, to inhibit or reduce the concentration of a specific toxic gas normally generated during the material's thermal decomposition. The effectiveness of this approach was demonstrated at the National Institute of Standards and Technology (NIST) when HCN generation was reduced by 90% and the resultant toxicity of the combustion products was lowered by 50% when a flexible polyurethane foam (FPU) was treated with 0.1% (by weight) cuprous oxide (Cu2O). Copper and cupric oxide (CuO) also reduced the HCN generation but were not as efficient as Cu2O. Although melamine-treated FPU foams are being promoted as more fire safe than standard foams, a melamine-treated foam generated 10 times more HCN than a foam without melamine. The addition of Cu2O to this melamine foam also reduced the HCN generation by 90%.     

A comparison of the electrophysiological effects of two organophosphates, mipafox and ecothiopate, on mouse limb muscles

Adult male albino mice were given single subcutaneous injections of either mipafox (110 mumol/kg) or ecothiopate (0.5 mumol/kg), two organophosphorus compounds (OPs). Acetylcholinesterase activity was measured in the soleus (slow-twitch) and extensor digitorum longus (EDL; fast-twitch) muscles. At 7 and 28 days after dosing, in vitro electrophysiological measurements were carried out in the soleus and EDL. Action potentials and end-plate potentials were evoked at 30 Hz and recorded intracellularly from single muscle fibers. The amplitudes, time course, and latencies of these potentials were measured and the variability (jitter) of latencies was calculated. Recordings after mipafox were also made with 3-Hz stimulation. Acetylcholinesterase activity was inhibited by mipafox (65% in the soleus; 76% in the EDL) and ecothiopate (59% in the soleus; 42% in the EDL). Mipafox and ecothiopate both increased postjunctional (muscle action potential) jitter in the soleus and EDL at 7 days after dosing. Organophosphates caused an increase in end-plate potential amplitudes in the soleus. Mipafox caused an increase in prejunctional (end-plate potential) jitter at 28 days after dosing in both muscles. A single dose of ecothiopate also caused an increase in prejunctional jitter at 28 days in the soleus. The OP-induced increase in jitter was different at different frequencies of stimulation. The results show that there are electrophysiological changes in both muscles after administration of organophosphorus compounds. The slow-twitch soleus appears more sensitive to prejunctional changes caused by OPs than the fast-twitch EDL.     

Postnatal development of the rat neostriatum: electrophysiological, light- and electron-microscopic studies

The postnatal development of the electrophysiological properties and morphology of rat neostriatum was studied using in vivo and in vitro intracellular recording and biocytin staining and light and electron microscopy. The principal neurons, the medium spiny neurons, were found to undergo a protracted postnatal development of their electrophysiological and morphological characteristics. Most of the intrinsic membrane properties of medium spiny neurons came to resemble those in the adult by the end of the 3rd postnatal week. Synaptic responses and spontaneous activity patterns in medium spiny neurons were dependent on the arrival and functional maturation of excitatory afferents from cortex and thalamus and did not become adult-like until the end of the 1st postnatal month.     

Study on musculoskeletal complaints involving the back, neck and upper limbs

OBJECTIVE & METHODS: A mail questionnaire survey was conducted among designated factory doctors (DFDs) to determine the nature and extent of musculoskeletal aches/pains in patients attending their clinics over one working week. Information was recorded for all patients aged 15 years and above presenting with aches or pains in the back, neck or upper limbs, as the main complaint or as one of the presenting symptoms. RESULTS: For the 155 doctors participating in the survey, the total attendance of patients aged 15 years and above during the study period was 35,010. Of these, 3.9% presented with the symptoms studied and 1.8% had work-related complaints. The commonest site affected was the back (55.7%), followed by the neck (21.4%) and shoulders (19.2%). A higher proportion of males than females had back complaints with the reverse for complaints involving hands/wrists and arms/forearms. 82.3% of the affected were employed, 60.3% being production workers, compared to 33.3% professional/office workers and 6.4% service workers. Of the patients who were working, 51.3% had work-related symptoms and 54.4% were given medical leave. Production workers had the highest proportion with work-related symptoms while service workers had the highest proportion given medical leave. The "medical certificate rate" was highest for back symptoms -57.6%, while work-related symptoms was highest for complaints involving hands/wrists. CONCLUSION: The study findings are consistent with those of a 1993 morbidity survey of outpatients in Singapore and indicate that the prevalence of work-related musculoskeletal aches/pains is not high.     

Hereditary motor and sensory neuropathy with spastic paraplegia and optic atrophy: report on a family

To determine the effect of RGP contact lens solution on corneal epithelial wound healing, the following solutions including Soaclens, Contopharma GPHCL-S, Boston condition, Bausch & Lomb condition and Duracare were applied on corneal epithelial wounds of enucleated pig eyes to evaluate possible cytotoxicity of RGP solutions. The wounds, created by excimer laser, were 1.5mm in diameter with 70 microns in depth. The eyeballs were maintained in an incubator using a perfusion system. After twenty-four hours, a score from 3 to 0 was given depending on the size of defect from absence of healing to completely healing. The average scores of the epithelial defect in each group are: Soaclens: 0.38 +/- 0.74; GPHCL-S: 0.63 +/- 0.52; Boston condition: 0.38 +/- 0.52; Bausch & Lomb condition: 0.25 +/- 0.46 and Duracare: 2.38 +/- 0.52. Most of the epithelial wounds healed with one exception, the eyeballs which received Duracare still had large defects. The difference of scores between Duracare and other groups are statistically significant. Duracare, which contains benzalkonium chloride, may be responsible for retarded wound healing.     

Disopyramide phosphate: electrophysiological and inotropic effects in isolated cat papillary muscles and comparison with quinidine (author's transl)

The effects of 4-diisopropylamino-2-phenyl-2-(2-pyridyl)-butyramide monophosphate (disopyramide phosphate; D; 10(-6)--10(-4) M) on transmembrane resting potential, action potential, effective refractory period and twitch tension were simultaneously studied in electrically driven (frequency 1 Hz) papillary muscles isolated from the right ventricles of cats. The experiments were performed at 35degrees C with intracellular glass microelectrodes. Quinidine sulfate (10(-6)--10(-4) M) was used for comparison. D increased the duration of the action potential during phase 3 (90% repolarization) in a concentration-dependent manner. The effective refractory period was prolonged by nearly the same extent whereas the maximal rate of rise of the action potential was reduced. The overshoot was slightly decreased only at 10(-4) M. Resting potential and plateau phase of the action potential were not affected by D. The effects of D on the electrical events were accompanied by concomitant decreases in twitch tension. The effects of quinidine were essentially similar to those obtained with D. It is concluded that the effects of D on dV/dtmax and effective refractory period observed in cat papillary muscle may account for the clinically observed efficacy of D to overcome ventricular arrhythmias. The results suggest also that the mechanism of the ventricular effects of D is similar to that of quinidine.     

EMG biofeedback with the upper extremity: A critical review of experimental foundations of clinical treatment with the disabled.

Presents a critical literature review of experimental investigations of electromyogram (EMG) biofeedback with the upper extremity with physically disabled individuals as Ss. Studies on increasing and decreasing muscle activity are examined as well as comparisons of EMG biofeedback with physical therapy and assessment. The majority of studies did not demonstrate that EMG biofeedback is a significantly valuable treatment in these cases, but the possibility of some clinical improvement is not ruled out. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Double-gracilis anorectal neosphincter: technique of reconstruction after necrosis of the distal part of the muscles

BACKGROUND: The Lichtenstein tension-free repair has become the standard method for repairing inguinal hernia in many surgical units. This study compared two methods of mesh fixation. METHODS: Fifty men undergoing unilateral primary Lichtenstein inguinal hernia repair under general anaesthesia were randomized into two groups. In the control group polypropylene mesh was secured with 2/0 polypropylene sutures and the skin closed with subcuticular 3/0 polydioxanone. In the study group polypropylene mesh was secured with skin staples and the skin was closed with staples from the same staple gun. Duration of the operation was recorded. Early follow-up was achieved by patient review at 6 weeks and postal questionnaire at 12 weeks. RESULTS: The operation was significantly shorter when staples were used (median 20 min 0 s versus 29 min 30 s, P < 0.001). There was no significant difference in the incidence of postoperative complications or pain score. The study group reported earlier return to normal activity (4 weeks 0 days versus 6 weeks 2 days, P < 0.01) although there was no difference in the time taken to return to work or driving. CONCLUSION: The use of skin staples to secure mesh in the Lichtenstein inguinal hernia repair significantly reduced the duration of the operation and was as effective as conventional mesh fixation with polypropylene in the short term.     

Visual–spatial-frequency model of cerebral asymmetry: A critical survey of behavioral and electrophysiological studies.

In this article, the authors present a review of research on the role of the 2 hemispheres in processing spatial frequencies. J. Sergent (see record 1982-25222-001) postulated that the hemispheres differ in their sensitivity to frequency characteristics of the sensory outputs on which cognitive processes are performed. Specifically, she proposed that the right hemisphere displays greater efficiency than the left hemisphere in processing low-spatial-frequency content of a visual image, whereas the left hemisphere is better equipped than the right to deal with high frequencies. The authors present an extensive review of behavioral and electrophysiological studies whose researchers tried to verify Sergent's hypothesis and offer its reformulation, taking into account the findings that have accumulated in the last 10 years. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

OCRA: a concise index for the assessment of exposure to repetitive movements of the upper limbs

In the light of data and speculation contained in the literature, and based on procedures illustrated in a previous research project in which the author described and evaluated occupational risk factors associated with work-related musculoskeletal disorders of the upper limbs (WMSDs), this paper proposes a method for calculating a concise index of exposure to repetitive movements of the upper limbs. The proposal, which still has to be substantiated and validated by further studies and applications, is conceptually based on the procedure recommended by the NIOSH for calculating the Lifting Index in manual load handling activities. The concise exposure index (OCRA index) in this case is based on the relationship between the daily number of actions actually performed by the upper limbs in repetitive tasks, and the corresponding number of recommended actions. The latter are calculated on the basis of a constant (30 actions per minute), which represents the action frequency factor; it is valid--hypothetically--under so-called optimal conditions; the constant is diminished case by case (using appropriate factors) as a function of the presence and characteristics of the other risk factors (force, posture, additional elements, recovery periods). Although still experimental, the exposure index can be used to obtain an integrated and concise assessment of the various risk factors analysed and to classify occupational scenarios featuring significant and diversified exposure to such risk factors.