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Biomedical subjects

A J Waclawik

Publications and source records attributed to A J Waclawik.

13 recordsLinked to original sources
PubMed1999

Iliac artery pseudoaneurysm following renal transplantation presenting as lumbosacral plexopathy.

A renal transplant patient developed chronic and progressive back and lower extremity pain followed by foot weakness. The correct diagnosis of lumbosacral plexopathy was made after electromyography and nerve conduction studies and the etiology of radiculopathy due to nerve root compression was excluded. This prompted further investigations that led to the discovery of a large internal iliac artery pseudoaneurysm. We emphasize the use of electrodiagnostic studies to investigate patients with back and limb pain for correctly localizing responsible pathology. In this case a potentially lethal situation was correctly identified in a transplant patient.

Aneurysm, False↗
PubMed1999

Infantile botulism: pitfalls in electrodiagnosis.

Botulism in infants, unless recognized early, is associated with high mortality and morbidity. The diagnosis is suspected when infants present with sudden onset of weakness, respiratory failure, and constipation and is confirmed by demonstration of botulinum toxin in stool several weeks later. Electrodiagnosis allows quick and reliable confirmation of botulism. Low-amplitude compound muscle action potentials, tetanic or post-tetanic facilitation, and the absence of post-tetanic exhaustion support the diagnosis. Two infants with confirmed botulism did not exhibit the characteristic electrodiagnostic features, demonstrating the pitfalls in electrodiagnosis of infantile botulism.

Biopsy↗
PubMed1999

Zidovudine [AZT] myotoxicity: quantitative separation of AZT effects on proliferation and differentiation of muscle cells in vitro. Lack of myotoxicity potentiation by retrovirus.

We compared quantitatively the myotoxicity of 3'-azido-2',3'-dideoxythymidine (AZT) against uninfected and ts1 retrovirus infected mouse skeletal muscle (ATCC CRL 1772) cells at different stages of maturation in vitro. The AZT half inhibitory concentration (IC50) for myoblast proliferation was determined for uninfected myoblasts and parallel cultures infected with ts1 virus. The AZT IC50 for muscle cell differentiation was determined in cultures where myoblasts were grown to confluence and then changed to the fusion medium to which AZT was added at increasing concentrations. Creatine kinase activity was used as a marker of muscle cell differentiation and was determined in homogenates after 7 days. Total cellular mitochondrial DNA was analyzed by Southern blotting. The estimated AZT IC50 for muscle cell proliferation (2-5 microM) was significantly less than the AZT IC50 for muscle cell differentiation (100 microM). Infection with ts1 retrovirus did not significantly shift the IC50 for either proliferation or differentiation of muscle cells. Toxic concentrations of AZT did not cause selective depletion of mitochondrial DNA. The myotoxic effects of AZT on myoblast proliferation and muscle cell differentiation in vitro were quantitatively different and were not changed by productive ts1 retrovirus infection of muscle cells. These results suggest that AZT may impair muscle fiber regeneration in the course of retrovirus associated myopathy. The mechanism of AZT myotoxicity was not explained by alterations in total mitochondrial DNA content.

Animals↗
PubMed1997

Muscle pathology and clinical features of the sarcolemmopathies.

We report the clinical features and the muscle pathology in 2 patients with congenital muscular dystrophy (CMD) secondary to merosin deficiency and in 2 patients with sarcoglycan (adhalin) deficiency. Electron microscopic examination revealed sarcolemmal defects in non-necrotic muscle fibers in all cases. These pathological findings are indistinguishable from those of Duchenne/Becker muscular dystrophy. We suggest that the similarities in histological findings reflect a common pathogenetic mechanism, i.e., a structural weakening of the sarcolemma with an increased susceptibility to rupture under mechanical stress. We propose the term sarcolemmopathy as an all-encompassing rubric for these disorders.

Adolescent↗
PubMed1996

Myofibrillar myopathy with abnormal foci of desmin positivity. I. Light and electron microscopy analysis of 10 cases.

A number of myopathies whose common denominator is abnormal foci of desmin positivity have been described under the rubrics of spheroid body myopathy, cytoplasmic body myopathy, Mallory body myopathy, myopathy with granulofilamentous inclusions, desmin storage myopathy, and intermediate filament myopathy. In this study we reevaluate the light microscopic and ultrastructural features of the myopathy with abnormal foci of desmin positivity. In 10 cases of the disease, ultrastructural analysis reveals 2 major types of lesions: (a) foci of myofibrillar destruction and (b) hyaline structures that appear as spheroidal bodies on electron microscopy. The foci of myofibrillar destruction consist of fiber areas containing disrupted myofilaments, Z-disk-derived bodies, dappled dense structures of Z-disk origin, and streaming Z-disks that are sometimes adjacent to lakes of dense material. The spheroid bodies are composed of compacted and degraded myofibrillar elements. Membrane-bound vacuoles harboring degenerating membranous organelles are a less frequent and probably secondary abnormality. None of the lesions in muscle comprise 8 to 10 nm intermediate filaments. The findings imply that spheroid body myopathy, cytoplasmic body myopathy, Mallory body myopathy, and myopathy with granulofilamentous inclusions are consequences of a single or closely related pathologic processes. Because the common denominator appears to be focal dissolution of the myofibrils followed by accumulation of the products of the degradative process, we propose the term myofibrillar myopathy to cover the observed spectrum of pathologic changes.

Adult↗
PubMed1996

CD8 and CD4 T cell-mediated polymyositis complicating the HTLV-1 associated myelopathy. Quantitative evaluation of corticosteroid treatment.

INTRODUCTION: Inflammatory myopathy is a treatable cause of worsening in the spectrum of neurological conditions that may develop during the course of HTLV-1 infection. MATERIAL AND METHODS: To investigate the cause of subacute worsening in the strength of a 46-y-old black male with HTLV-1 associated myelopathy we performed electrodiagnostic examination and a muscle biopsy which was studied with histochemistry, immunocytochemistry and electron microscopy. Serial measurements of isometric muscle strength were performed during the course of corticosteroid treatment. RESULTS: The muscle biopsy showed evidence of denervation atrophy and prominent inflammatory changes with autoaggressive features. Lymphocyte typing showed a predominance of CD8+ T cells. The patient had sustained, marked improvement in strength, especially of the upper extremities, with oral, high single-dose, alternate-day prednisone therapy. CONCLUSION: A muscle biopsy should be considered in all patients with HTLV-1 associated weakness, especially when electromyography indicates possible coexisting primary muscle involvement and/or serum creatine kinase levels are elevated. HTLV-1-associated polymyositis can be successfully treated with corticosteroids.

Anti-Inflammatory Agents↗
PubMed1995

Congenital myopathy with ringlike distribution of myonuclei and mitochondria and accumulation of nemaline rods. A variant of centronuclear myopathy?

Histopathologic and ultrastructural findings in a muscle biopsy performed on an 11-year old boy with congenital hypotonia, weakness, respiratory insufficiency requiring chronic ventilatory support, and a probable X-linked inheritance are presented. The muscle biopsy disclosed a peculiar, ringlike arrangement of mitochondria and myonuclei in most muscle fibers. Accumulations of nemaline rods were present in approximately 10-15% of fibers. We believe that our patient represents a variant of myotubular/centronuclear myopathy. The histochemical findings suggest disturbance in developmental migration of nuclei and mitochondria probably due to impaired function of the cytoskeleton.

Biopsy↗
PubMed1993

Experimental lovastatin myopathy.

Lovastatin (LS) is a potent HMG-CoA inhibitor used in the treatment of hypercholesterolemia. In humans it can cause a severe, necrotizing myopathy with myoglobinuria and renal failure. To investigate the pathogenesis of LS-induced myopathy we studied the effects of LS on rat skeletal muscle. Lewis rats were gavage-fed 1 mg/g body weight/day of LS. Control rats received carboxymethylcellulose-based suspension by gavage. Gastrocnemius and soleus, fast and slow twitch muscles respectively, were studied by light and electron microscopy. By day 10 LS-treated rats became severely weak. Gastrocnemius was severely affected with degeneration of membranous organelles and microvacuole formation, but soleus was spared. Eventually, 20-50% of the gastrocnemius but none of the soleus fibers became necrotic. Non-necrotic fibers showed no increases of acid phosphatase, indicating that autophagy was not excited. We conclude that LS causes muscle injury by inducing degeneration of membranous organelles, and fast twitch muscle fibers are selectively vulnerable to LS myopathy.

Acid Phosphatase↗
PubMed1992

Acute myopathy with selective degeneration of myosin filaments following status asthmaticus treated with methylprednisolone and vecuronium.

We report two cases of severe, acute myopathy with selective degeneration of myosin filaments in asthmatics who developed respiratory failure with hypercapnia and acidosis requiring endotracheal intubation, administration of vecuronium and prolonged ventilatory support. Hypoxia was documented in one case and probably present in the other. Both patients received prolonged treatment with high doses of intravenous methylprednisolone. Flaccid quadriparesis was noted after discontinuation of vecuronium. Muscle biopsy showed nonspecific myopathic changes on light microscopy. Electron microscopy revealed selective loss of myosin filaments in many fibers. Recovery occurred within 2 months with supportive treatment. This entity is probably related to a combination of high doses of corticosteroids, vecuronium administration and metabolic abnormalities associated with respiratory failure.

Acute Disease↗
PubMedDate not supplied

Sarcoidosis of the spinal cord with extensive vertebral involvement: a case report.

We report on a patient with systemic sarcoidosis who was presented with myelopathy and backache. Plain spinal films were normal, CT scan showed sclerotic lesions within the vertebrae. MRI showed more extensive involvement of the spine with multiple vertebral lesions which were hypointense on both T1W1 and T2W1 and did not enhance with gadolinium. MRI also showed high signal lesions within the cervical and lumbar spinal cord on T2-weighted images (T2W1) which were isointense on T1-weighted images (T1W1) and did not enhance. Vertebral biopsy results were consistent with the diagnosis of sarcoidosis. MRI is very sensitive in detecting sarcoidosis of bone but non-specific and other types of sclerotic or lytic bone lesions (notably metastases) need to be excluded.

Adult↗