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Biomedical subjects

W K Engel

Publications and source records attributed to W K Engel.

At least 199 records · Page 11Linked to original sources
PubMed1978

The effects of single-dose alternate-day prednisone therapy on the immunological status of patients with neuromuscular diseases.

Several immunological variables were examined in patients receiving high-single-dose, alternate-day prednisone therapy for neuromuscular diseases. Dose-dependent leukocytosis, lymphopenia, and monocytopenia occurred which were maximal 6 hours after prednisone administration but returned to control levels by the 24-hour point. The lymphopenia involved T-cells, B-cells, and null cells, with the T-cells most affected. Plasma cortisol levels and lymphocyte transformation in response to mitogens were also transiently and reversibly suppressed. There was a persistent decrease in serum IgG. Lymphocyte transformation was also suppressed when normal lymphocytes were incubated with treated patient sera or when treated patient lymphocytes were incubated in autologous pretreatment sera. The suppression factor was not removed from the lymphocytes by extensive washing. Patients whose disease responded to the high-single-dose, alternate-day prednisone regiment were indistinguishable from nonresponders by the immunological responses measured.

Adolescent↗
PubMed1978

Effects of acetazolamide on myotonia.

Myotonia can occur in the periodic paralyses, particularly the hyperkalemic form. The beneficial response to acetazolamide in hypokalemic and hyperkalemic periodic paralysis has led us to study the effect of acetazolamide in 9 patients with disorders having myotonia as the major problem, 7 with myotonia congenita and 2 with paramyotonia congenita. Patients were studied before acetazolamide administration with glucose and potassium loading tests. All patients had an increase in myotonia with potassium, but no weakness occurred with either test. Acetazolamide treatment decreased myotonia in all patients and in 3 proved the most satisfactory therapy. Side-effects during acetazolamide therapy included paresthesias in 5 patients and renal calculus in 1. Flaccid weakness occurred in a patient with paramyotonia congenita. Acetazolamide treatment was associated in all patients with partially compensated metabolic acidosis and lowering of serum potassium within the normal range. Kaliuresis was also noted during introduction of therapy. Acetazolamide appears to be an acceptable treatment for occasional patients with myotonia who are unresponsive to or intolerant of other therapies.

Acetazolamide↗
PubMed1978

Cardiac manifestations in polymyositis.

Twenty-one patients with polymyositis were prospectively examined with echocardiography, phonocardiography and electrocardiography. Cardiac performance, estimated with echocardiography, was enhanced as shown by a significant (P less than 0.01) increase in ejection phase indexes of left ventricular function compared with values in a matched control group. Known causes of the high output state, such as anemia or thyrotoxicosis, were not clinically evident. There was no evidence of left ventricular enlargement, left ventricular wall hypertrophy, or left atrial enlargement in the echocardiogram or chest X-ray film. The echocardiogram showed systolic mitral valve prolapse in 11 of 17 patients (65 percent) with an adequately imaged mitral valve; midsystolic clicks were present in 7 of these. One patient, who did not have prolapse, had echocardiographic evidence of a small pericardial effusion. Electrocardiographic abnormalities were present in 11 of 21 patients (52 percent) and included evidence of atrioventricular conduction disturbances, atrial and ventricular arrhythmias and left atrial abnormality. The pathophysiology of mitral valve prolapse and increased systolic left ventricular function in polymyositis remains uncertain; however, the spectrum of cardiac abnormalities, detected noninvasively in 16 of 21 of our patients (76 percent) may represent a high frequency rate of cardiac involvement in this disease.

Adult↗
PubMed1978

Histochemistry of rat intrafusal muscle fibers and their motor innervation.

Muscle spindles were followed in serial transverse sections of freshly frozen rat soleus muscles. Adenosine triphosphatase (ATPase) histochemical staining reaction was used to identify nuclear bag1, nuclear bag2 and nuclear chain intrafusal muscle fibers. Regional differences in ATPase staining occurred along bag1 and bag2 fibers but not along chain fibers. Bag1 fibers displayed ultrastructural heterogenity when their intra- and extracapsular regions were compared. Simple "diffuse" and more elaborate "plate" motor nerve terminals were demonstrated histochemically along the poles of bag1 and bag2 fibers by staining for cholinesterase. One motor terminal of the "plate" appearance was present on a chain fiber pole. There was no consistent spatial correlation between the intensity of regional ATPase staining along the nuclear bag fibers and the location, number and type of motor endings. Other factors, such as intrafusal fiber sensory innervation and regional differences in active and passive functional recruitment of nuclear bag fibers during muscle activity, may contribute to the ATPase staining variability along the intrafusal fibers.

Adenosine Triphosphatases↗
PubMed1978

Histochemistry and acetylcholine receptor distribution in normal and denervated monkey extraocular muscles.

In monkey extraocular muscles (EOM), a battery of histochemical reactions delineates three muscle fiber types, coarse, fine, and granular. Normal EOM are compared with EOM denervated by intracranial oculomotor nerve section. The experimentally denervated EOM fibers did not show the constellation of histologic responses typical of denervated limb muscle, making a diagnosis of a denervation process in EOM muscle very difficult. Although the denervated fine and granular fibers (but not the coarse fibers) develop diffuse extrajunctional acetylcholine receptors (AChR) following experimental denervation, this is not a reliable criterion of denervation because not all of those fibers developed it and they did not show it beyond a 12-week period following nerve section; moreover, myopathic mechanisms have previously been shown capable of provoking diffuse extrajunctional AChR in limb-muscle fibers.

Acetylcholine↗
PubMed1977

Focal lesions of muscle in peripheral vascular disease.

Lesions in skeletal muscle resulting from ischemia caused by peripheral vascular disease in two patients were essentially identical to the early muscle lesions of Duchenne muscular dystrophy (DMD) patients and carriers of that disease, as well as to the early muscle lesions of experimental animals with aorta ligations plus a small dose of 5-hydroxytryptamine (serotonin). The one similarity is harmonious with, although does not necessarily advance, the ischemia hypothesis of DMD, and the other supports the ischemia mechanism proposed in the animal model.

Adult↗
PubMed1977

Amyloidosis with plasma cell dyscrasia. An overlooked caused of adult onset sensorimotor neuropathy.

In ten previously undiagnosed patients, we have found erstwhile-"primary" nonhereditary amyloidosis as an overlooked cause of a predominately sensory, painful, and hyperesthetic distal neuropathy occurring in middle-age and older patients. These symptoms, associated with orthostatic hypotension, diarrhea or constipation, cardiac abnormality, and male impotence are virtually diagnostic (in the absence of diabetes mellitus). Tissue diagnosis is quickly made by crystal-violet metachromasia of amyloid in fresh-frozen sections of a muscle biopsy specimen. Immunoglobulin and bone marrow evidence of plasma cell dyscrasia in eight of the ten patients suggests that the neuropathy in this form of amyloidosis is actually secondary to a plasma-cell-originating dysproteinemia. Therapy with melphalan and prednisone was not of benefit.

Adult↗
PubMed1977

Blood-to-cerebrospinal fluid barrier for cyclic adenosine monophosphate in man.

A definite blood to lumbar CSF barrier for cyclic adenosine monophosphate (cAMP) exists in man under physiologic conditions. Lumbar CSF cAMP level remained unchanged, while the CSF glucose level rose significantly after a glucagon hydrochloride infusion that caused a 40-fold increase in the plasma cAMP level.

Blood-Brain Barrier↗
PubMed1977

Muscle-type phosphorylase activity present in muscle cells cultured from three patients with myophosphorylase deficiency.

Skeletal muscle fibers cultured from three patients whose mature fibers are deficient in glycogen myophosphorylase (EC 2.4.1.1) were shown to become rather mature, to have no excessive glycogen accumulation, and to develop signifcant myophosphorylase activity. That activity was characterized electrophoretically and immunologically and shown to be muscle phosphorylase rather than a genetically different type, thereby demonstrating true "rejuvenation" in culture of an enzyme genetically programmed ultimately to be deficient.

Adult↗
PubMed1977

Neuromuscular blockade with anti-axoplasmic antibodies.

In the process of developing an immunopharmacologic method for identifying a "trophic" protein released from motor nerve terminals, a soluble fraction of peripheral nerve axoplasm was prepared. An attempt was made to eliminate contaminating myelin and basic protein. Antibodies were produced to soluble nerve proteins in all sheep immunized. On boosting, after a 6-week interval, the animals became weak, and some could not stand on the fifth day after injection. A distinct component of neuromuscular blockade was demonstrated electrically and in response to edrophonium. Because this syndrome was (1) in the broadest sense, an experimental allergic neuropathy but produced by a distinctly different antigen than has been utilized previously (the soluble nerve proteins represented the axoplasmic compartment) and (2) a clinical condition associated with a defect in neuromuscular transmission, this may represent a new and potentially important model in the study of neuromuscular and other neurologic diseases.

Animals↗
PubMed1977

Acetylcholine receptors of aneurally cultured human and animal muscle.

We describe the diffuse nonjunctional distribution of AChR molecules of aneurally cultured human and animal muscle and the influence of sera from myasthenia grivis patients and rabbits with experimental autoimmune myasthenia gravis on binding of alphaBT to diffuse nonjunctional AChR. One-hour incubation of myasthenia gravis seria resulted in blocking of the alphaBT-immunoperoxidase staining of their AChRs, while incubation in normal sera did not. Aneurally cultured muscle can aid studies of regenerating fibers in normal muscle compared with those of muscles in neuromuscular diseases, and also act as an environmentally controlled test object for demonstrating the effect of circulating pathogenic factors.

Animals↗
PubMed1977

Erythrocyte survival in Duchenne muscular dystrophy.

Hemolysis was investigated in seven patients with Duchenne dystrophy. No increase in red-cell turnover was detected by indirect measurement (hemoglobin, reticulocyte count, plasma hemoglobin, serum haptoglobin) or by turnover of 51Cr-labeled erythrocytes. Our findings fail to support the likelihood of a significant erythrocyte membrane defect.

Adolescent↗
PubMed1977

Adrenomyeloneuropathy: a probable variant of adrenoleukodystrophy. I. Clinical and endocrinologic aspects.

We have studied four unrelated males with a heritable disorder that we term adrenomyeloneuropathy; limited clinical information is available on a fifth case. All had adrenal insufficiency beginning in childhood and developed progressive spastic paraparesis in the third decade. Hypogonadism of variable severity was present in all four cases appropriately examined. Neurologic features included peripheral neuropathy, impotence, and sphincter disturbances. Late manifestations were cerebellar dysfunction in one case and dementia and hemiparesis in another. A family history of adrenal disease or spastic paraparesis was present in two cases and absent in one; in the other two, no family history was available. Although males are predominantly affected, the mode of inheritance is uncertain. Adrenomyeloneuropathy probably represents a clinically and genetically distinct variant of childhood adrenoleukodystrophy.

Addison Disease↗
PubMed1977

Morphologic and immunologic studies in experimental autoimmune myasthenia gravis and myasthenia gravis.

An indirect immunoperoxidase technique was used to study by light microscopy the binding of serum from experimental autoimmune myasthenia gravis (EAMG) rabbits to junctionally and extrajunctionally located acetylcholine receptors (AChRs) in human and rat muscles. Binding was restricted to junctional AChR. Alpha bungarotoxin (a-BGT) partially blocked the binding of EAMG serum, while myasthenia gravis serum, carbamylcholine, decamethonium, and tubocurarine did not. A radioimmunoassay showed significant binding of antibodies in EAMG sera to 125l AChR. This binding was not inhibited by a-BGT, nor by carbamylcholine, decamethonium, or tubocurarine. Sera from 10 myasthenia gravis patients did not contain antibodies binding to the 125l AChR. We suggest that EAMG in rabbits induced by Torpedo AChR differs serologically from myasthenia gravis in patients, probably owing to antigenic differences between Torpedo and human AChR, and that antigenic differences also exist between junctional and extrajunctional receptors.

Acetylcholine↗
PubMed1977

Localization of technetium-99m diphosphonate in acutely injured muscle. Relationship to muscle calcium deposition.

In rats with experimental ischemic myopathy, there was a significant correlation (r = 0.778, p less than 0.001) between muscle uptake of technetium-99m (99mTc) diphosphonate and tissue calcium concentration. In addition, the accumulation of both calcium and 99mTc-diphosphonate in acutely injured muscles was further increased in rats with vitamin D-induced hypercalcemia. Histologic studies demonstrated staining of damaged muscle fibers with alizarin red, indicating the presence of microcrystalline or ultramicrocrystalline calcium salts. Staining of muscle fibers was most intense in the outer marginal zones of individual microscopic infarcts. Our results suggest that the uptake of 99mTc-diphosphonate in acutely damaged skeletal muscle is directly related to the deposition of calcium salts within the injured muscle fibers.

Acute Disease↗