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Biomedical subjects

W K Engel

Publications and source records attributed to W K Engel.

At least 127 records · Page 7Linked to original sources
PubMed1985

Autosomal dominant syndrome of lipid neuromyopathy with normal carnitine: successful treatment with long-chain fatty-acid-free diet.

A family (mother and two sons) have had lifelong muscle weakness and intolerance to fatty food. Histochemistry of muscle biopsies of all three patients demonstrated increased lipids in type I muscle fibers and type II muscle fiber atrophy and paucity. Electronmicroscopy of muscle revealed increased lipids, abnormal mitochondria, and increased lipofuscin granules. Electronmicroscopy of sural nerve showed inclusions in most of the Schwann cell cytoplasm, with lipid droplets, zebra bodies, lipofuscin granules, and abnormal mitochondria. Carnitine and CPT I and II levels were normal in serum and muscle. Treatment with long-chain fatty-acid-free diet resulted in remarkable clinical improvement and in decrease of lipid droplets in the muscle. This dietary program may be useful in other forms of lipid myopathy.

Adolescent↗
PubMed1984

Tremor as a feature of chronic relapsing and dysgammaglobulinemic polyneuropathies. Incidence and management.

Seven patients with chronic relapsing polyneuropathy and four patients with dysgammaglobulinemic polyneuropathy had tremor during the course of their illness. The tremor was coarse, irregular, and unrelated to proprioception loss, muscle weakness, or fatigue; it appeared to represent disease activity or an early sign of a new relapse. None of these patients had clinical signs of CNS disease or family history of essential tremor. The tremor in all seven patients with relapsing neuropathy and in one of the three treated patients with dysgammaglobulinemia responded to immunosuppressive drugs that controlled the underlying immune mechanism(s) of the disease. In two patients with dysgammaglobulinemic polyneuropathy, the tremor improved with propranolol hydrochloride.

Adolescent↗
PubMed1984

Abnormality of cultured muscle and Schwann's cells in familial lipid neuromyopathy. Muscle corrected by neural influence.

Muscle and Schwann's cell cultures were established from a family (mother and two sons) with non-carnitine deficient neuromyopathy. Electron microscopy of noninnervated cultured muscle showed poorly matured muscle fibers containing large "mushy" mitochondria, lipid droplets, abundant multilaminated inclusions, and dense-core dark osmiophilic bodies. Parallel innervated muscle fibers (cocultured with normal-rat motor neurons for two to three weeks) were well cross-striated, had well-developed T tubules and sarcoplasmic reticulum, and none of the abnormalities of aneural muscle cultures. Cultured Schwann's cells were normal by light microscopy, but had ultrastructurally abnormal mitochondria, lipid droplets, dark osmiophilic granular inclusions, and numerous "foamy" vacuoles. Those studies demonstrated (1) intrinsic muscle and Schwann's cell defects because of reproduction of abnormalities in culture, (2) normal muscle cell responsiveness to innervation reflected by development of contractions and longer survival in culture, and (3) beneficial influence of a neural factor(s) on the endogenous muscle cell abnormality.

Adolescent↗
PubMed1984

Adult-onset acid maltase deficiency. Electrophysiological properties of aneurally cultured muscle.

Electrophysiological studies were performed on aneurally cultured muscle cells from one patient with adult-onset acid maltase deficiency (AAMD) and from controls. The cells from the patient with AAMD had a higher mean resting membrane potential, a lower input resistance, and a higher incidence of action potentials at resting membrane potential than the control cells. Therefore, sarcolemma maturation was not adversely affected. The AAMD cells had membrane thresholds and action potential amplitudes similar to those of the control cells, and rarely produced repetitive action potentials. Therefore, the membrane instability noted in adult muscle fibers from the patient with AAMD was not present in cultured cells. This study does not support the suggestion that the biochemical and morphological abnormalities present in muscle fibers of patients with AAMD are sufficient to cause the electrical abnormalities.

Action Potentials↗
PubMed1984

Thyrotropin-releasing hormone enhances choline acetyltransferase and creatine kinase in cultured spinal ventral horn neurons.

The effect of 0.1 mM thyrotropin-releasing hormone (TRH) on ventral horn neurons was investigated in eight experimental sets of tissue cultures established from ventral and dorsal portions of spinal cords of 13-15-day rat embryos. Cultures were treated with TRH from day 1 for 2-5 weeks. TRH-treated ventral spinal cord cultures (VSCC), compared with control VSCC, had more numerous and more healthy-appearing neurons and thicker bundles of long cell processes. In TRH-treated VSCC, choline acetyltransferase (ChAT) activity was greater than 16 times (p less than 0.005) and creatine kinase greater than 3 times (p less than 0.005) that of control VSCC. Morphologic and biochemical parameters of dorsal spinal cord cultures remained unchanged by TRH treatment. Since lower motor neurons are numerous in the ventral spinal cord (and not present in the dorsal cord) and since lower motor neurons are the major ChAT-containing spinal cord cells, our data demonstrating a beneficial effect of TRH on VSCC suggest a tropic effect of TRH on lower motor neurons.

Animals↗
PubMed1984

Nature of amyloid deposits in hypernephroma. Immunocytochemical studies in 2 cases associated with amyloid polyneuropathy.

Two patients who presented with amyloid polyneuropathy were found to have an amyloid-positive hypernephroma. The amyloid extracted from the tumor of one patient was purified by gel filtration and found to immunoreact by immunodiffusion, only with antiserum against denatured lambda-type amyloid protein but not with antisera against denatured kappa amyloid, AA, or prealbumin. With the unlabeled immunoperoxidase method or immunofluorescence in combination with these specific antisera, it was shown that in both patients the amyloid deposits in the tumor, kidney, lymph node, muscle, and nerve had lambda-type amyloid antigenic fibril determinants. Some regions, amyloid-negative by congo red, immunoreacted with anti-lambda antiserum and were shown to represent amyloid fibrils electron microscopically. Several plasma cells found in the tumor and lymph node immunoreacted specifically with the anti-amyloid lambda antiserum. The findings provide the first observation that the amyloid in hypernephroma can be of immunocytic origin, even in the absence of overt signs of plasma cell dyscrasia, and suggest that amyloid polyneuropathy could be the presenting sign of hypernephroma.

Adenocarcinoma↗
PubMed1983

Effect on weakness and spasticity in amyotrophic lateral sclerosis of thyrotropin-releasing hormone.

Very high intravenous doses (2-19 mg/min) of thyrotropin-releasing hormone (TRH, L-pyroglutamyl-L-histidyl-L-prolinamide) given to 12 patients with amyotrophic lateral sclerosis (ALS) produced a moderate to marked improvement of functions caused by deficiency of lower motor neurons (weakness) and upper motor neurons (spasticity). The improvement was sustained throughout the infusion and for about 1 h thereafter; sometimes a slight improvement was evident 20 h after infusion. At a given dose benefits and side-effects were more evident in men than in women. Whether TRH is replacing an ALS-associated deficiency or is simply a symptomatic treatment is unknown. The results of this study raise the possibility of a treatment for ALS, and may provide new insight into its pathogenesis. The potential response to TRH of spasticity and/or lower motor neuron involvement of other causes is proposed.

Adult↗
PubMed1983

Intravenous treatment of hypokalemic periodic paralysis.

Acute attacks of weakness in patients with hypokalemic periodic paralysis can usually be treated with oral potassium preparations. Occasional patients, however, require intravenous (IV) potassium administration. We studied a patient with hypokalemic periodic paralysis to determine the effect of using 5% glucose as a diluent for potassium administration during acute attacks of weakness. Administration of IV potassium chloride in 5% glucose (50 mEq/L) was associated with a worsening of strength and no rise in potassium level. Intravenous potassium in 5% mannitol was associated with a rise in potassium and improvement in strength. This study confirms the hazard of using glucose-containing solutions for correction of hypokalemia.

Adult↗
PubMed1983

Treatment of polyneuropathy in Waldenström's macroglobulinemia: role of paraproteinemia and immunologic studies.

A patient with polyneuropathy due to Waldenström's macroglobulinemia (WM) was treated successfully with chlorambucil and prednisone. Before therapy, 60% of peripheral lymphocytes were B cells, the nerve had IgM-bearing B-cell infiltrates, and the circulating IgM had antibody-binding activity to autologous and homologous nerves. Neurologic improvement, sustained for 4 years, began 3 months after therapy and coincided with the return to normal of bone marrow and circulating B cells. Binding of IgM to autologous and homologous nerves persisted after therapy, suggesting that not the IgM alone but other B-cell factors, possibly complexed to IgM, may have been responsible for the nerve damage.

B-Lymphocytes↗
PubMed1983

Nearly fatal muscle carnitine deficiency with full recovery after replacement therapy.

A 23-year-old woman became quadriplegic and respirator-dependent after 18 years of weakness and rhabdomyolysis. Her muscle tissue and that of a deceased sister contained lipid-laden fibers. Treatment with D,L-carnitine 4 grams per day was followed by a dramatic improvement within 10 days. Muscle function was normal at 8 months and has remained so during 3 subsequent years of L-carnitine 3 grams per day. Pretreatment muscle biopsy had documented low levels of free carnitine and short-chain acylcarnitine compounds. Carnitine palmityltransferase was slightly elevated. The asymptomatic parents had low-normal muscle carnitine levels, slight increase in muscle fiber lipid droplets, osmiophilic lipid-laden Schwann's cell vacuoles, and myelin lamellae with different periodicities.

Adult↗
PubMed1983

Increased circulation of T lymphocytes bearing surface thymosin alpha 1 in patients with myasthenia gravis: effect of thymectomy.

We studied the interaction of the thymic hormone thymosin alpha 1 with peripheral blood B and T lymphocytes in patients with myasthenia gravis (MG), using antibodies against thymosin alpha 1 in an immunofluorescence technique. Eleven of 16 patients with symptomatic MG had an increased number of T lymphocytes bearing surface thymosin alpha 1 (T alpha 1); 5 patients with asymptomatic disease had normal levels of T alpha 1. In six young adults with symptomatic MG who subsequently responded to thymectomy, the number of T alpha 1 cells returned to normal 1 month after thymectomy. Because levels of T alpha 1 correlated with symptoms and thymosin alpha 1 specifically recruits helper T cells, our findings suggest that T alpha 1 may play an immunoregulatory role in the pathogenesis of MG. Determination of T alpha 1 levels may prove to be helpful in assessing residual thymic activity after thymectomy.

Fluorescent Antibody Technique↗
PubMed1983

Electrophysiologic properties of aneurally cultured muscle from patients with myotonic muscular atrophy.

Electrophysiologic studies were performed on aneurally cultured human muscle cells from seven patients with myotonic muscular atrophy and seven controls. There was no significant difference in resting membrane potential. When the cells were hyperpolarized to -80 mV, there was no significant difference in effective membrane resistance, effective membrane capacitance, normalized membrane conductance, membrane threshold, action potential amplitude, or maximum rate of rise of the action potential. Repetitive discharges were elicited by anodal-break excitation in a few cells from each group. We found no evidence that cultured myotonic atrophy muscle cells are electrically different from control cells.

Action Potentials↗
PubMed1983

Laser Doppler blood flow studies during open muscle biopsy in patients with neuromuscular diseases.

Laser Doppler measurements of skeletal muscle blood flow were performed in 12 patients with neuromuscular disorders and 6 controls. The mean resting blood flows and postocclusive reactive hyperemias were similar for the patients with neuropathic disorders and for controls. The patients with myopathic disorders had higher resting muscle blood flows and reactive hyperemias. Correlation of blood flow results and muscle biopsy characteristics suggested that muscle type grouping was not associated with a change in skeletal muscle blood flow, whereas muscle fiber degeneration was associated with an increased blood flow.

Adult↗
PubMed1983

Muscle carnitine deficiency: fatty acid metabolism in cultured fibroblasts and muscle cells.

L-carnitine, as little as 25nM, greatly increased oxidation of palmitate by carnitine-depleted cultured human skin fibroblasts from normal subjects, and from two patients with muscle carnitine deficiency. Carnitine stimulated oxidation of labeled palmitate by cultured muscle cells from rat, normal humans, or patients with muscle carnitine deficiency. Carnitine reduced incorporation of palmitate into glycerides in normal fibroblasts, and it may thereby counteract cellular accumulation of glycerides in cells. Fibroblasts from patients with muscle carnitine deficiency took up labeled carnitine at a normal rate. Dexamethasone increased palmitate oxidation by normal human fibroblasts and muscle cells of rat, and normal and muscle carnitine-deficient humans. The results parallel the reported effectiveness of carnitine, glucocorticoids, or medium-chain triglycerides in treatment of these patients.

Adolescent↗
PubMed1983

Hemopexin metabolism in patients with altered serum levels.

The rates of synthesis and degradation of hemopexin (Hx) were studied in vivo to determine the cause of altered serum levels of this protein as seen in hemolytic anemias, chronic neuromuscular diseases, and acute intermittent porphyria. The synthetic and fractional catabolic rates of Hx were measured in patients exhibiting low, normal, or elevated serum Hx levels. It was found that the elevated levels were mainly due to increased synthesis rather than decreased catabolism of Hx. In patients with elevated serum Hx levels, the mean synthetic rate of Hx (13 +/- 1.0 mg/kg/day) was twice that of the patients with normal Hx levels (6.6 +/- 0.3), whereas the fractional catabolic rate was 35.3 +/- 7.1% of the i.v. pool per day vs. 26.5 +/- 0.8 for controls. The low serum Hx levels observed in patients with sickle cell anemia appeared to be due to increased Hx catabolism (36.0 and 40.0% of the i.v. pool per day vs. 26.5 +/- 0.8 for controls) with no compensatory increase in synthesis. This latter finding is in agreement with a study in rhesus monkeys in which repeated administration of a large dose of heme caused an increase in the catabolism of hemopexin without a concurrent increase in its synthesis (J LAB CLIN MED 100:451, 1982). Our results indicate that although both synthesis and catabolism are increased in patients with elevated Hx levels, only catabolism is increased in patients with sickle cell anemia.

Adolescent↗
PubMed1983

Families with myotonic dystrophy with and without cardiac involvement.

Study of 30 patients with myotonic dystrophy and 17 unaffected family members in a total of 18 families by echocardiography and ECG, including noninvasive His-bundle recording, appeared to show two phenotypes of myotonic dystrophy: those with and those without substantial cardiac involvement. Besides the 29% incidence of asymptomatic mitral valve prolapse common to many neuromuscular diseases, 20% of families had progressive involvement of the cardiac conduction system. It is important to recognize these families in order to treat patients with cardiac pacemakers who are rapidly progressive or symptomatic. If one patient with myotonic dystrophy is found to have myotonic heart disease with cardiac block or arrhythmia, it should be expected in other family members with myotonic dystrophy.

Arrhythmias, Cardiac↗
PubMed1982

Abolish boxing.

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Athletic Injuries↗