Exercise-induced cramp, myoglobinuria, and tubular aggregates in phosphoglycerate mutase deficiency

We report two patients in whom phosphoglycerate mutase (PGAM) deficiency was associated with the triad of exercise-induced cramps, recurrent myoglobinuria, and tubular aggregates in the muscle biopsy. Serum creatine kinase (CK) levels were elevated between attacks of myoglobinuria. Forearm ischemic exercise tests produced subnormal increases of venous lactate. Muscle biopsies showed subsarcolemmal tubular aggregates in type 2 fibers. Muscle PGAM activities were markedly decreased (3% of the normal mean) and molecular genetic studies showed that both patients were homozygous for a described missense mutation (W78X). A review of 15 cases with tubular aggregates in the muscle biopsies from our laboratory and 15 cases with PGAM deficiency described in the literature showed that this clinicopathological triad is highly suggestive of PGAM deficiency.

Plasma antioxidants in subjects before hematopoietic stem cell transplantation

Chemo-irradiation induced oxidative damage to vascular endothelium may contribute to pulmonary complications of hematopoietic stem cell transplantation (HSCT). We measured antioxidants, markers of oxidative stress and plasma antioxidant capacity in plasma or serum from 24 subjects at day 7 before HSCT and 20 control subjects. The plasma concentration of extracellular glutathione peroxidase (GPX-3) was significantly reduced in the HSCT subjects compared with controls (HSCT: 98+/-42 microg/ml, control: 169+/-56 microg/ml, P<0.0001). The concentration of gamma-tocopherol was significantly higher in the HSCT subjects compared with controls (HSCT: 207+/-103 microg/dl;

CONTROL

98+/-52 microg/dl; P=0.0002). The plasma concentrations of protein carbonyl, nitrotyrosine, malondialdehyde, alpha-tocopherol, vitamin A, homocysteine, cysteine and cysteinylglycine did not differ between HSCT and control subjects. Plasma from HSCT subjects was as effective as control plasma in quenching menadione-induced intracellular reactive oxygen species production in human microvascular endothelial cells. In summary, subjects before HSCT have significantly reduced plasma concentrations of GPX-3, elevated plasma gamma-tocopherol yet retains the ability to quench an acute oxidative stress. These changes may play a role in chronic oxidative stress in the HSCT population.

Electrophysiological diagnostic criteria of Lambert-Eaton myasthenic syndrome

Various parameters of the repetitive nerve stimulation (RNS) test of the abductor digiti quinti muscle were analyzed statistically in 34 patients with Lambert-Eaton myasthenic syndrome (LEMS). The sensitivity and specificity of the increments after exercise and after 50-HZ stimulation for the diagnosis of LEMS were compared with reference values in 40 normal subjects and data from 538 tests in patients with myasthenia gravis (MG). When we used a 100% increment (the "gold standard") as the normal limit for the postexercise facilitation (PEF) or the high-rate stimulation (HRS) test, the diagnosis of LEMS was confirmed in 29 (85%) cases. When a 60% increment was used as the normal limit, the diagnosis of LEMS was made in 97% of cases. In MG, a 60% increment was observed in only 4 of 538 cases by HRS and in none by the exercise test. Thus, the use of a 60% increment showed a sensitivity of 97% for the diagnosis of LEMS and a specificity of 99% in excluding MG. A 60% increment in either the PEF or HRS test for the diagnosis of LEMS is a desirable alternative to the 100% increment previously considered to be the gold standard for this diagnosis.

Sensory neuropathy in vasculitis: a clinical, pathologic, and electrophysiologic study

BACKGROUND

Vasculitis is not usually considered as a cause of symmetric sensory neuropathy.

OBJECTIVE AND METHODS

To present the clinical, pathologic, and electrophysiologic features of 17 (16%) cases of sensory neuropathy in vasculitis (SNV) among 106 cases with histologically proven vasculitic neuropathy that were collected over the last 30 years.

RESULTS

In 41% of cases, SNV was found as systemic vasculitic neuropathy in association with primary vasculitic disease. The most common clinical presentation was symmetric polyneuropathy, seen in 53% of cases. The most common nerve conduction pattern was diffuse neuropathy pattern of axonal degeneration. Sural nerve biopsy was diagnostic in 88% of cases. In two cases, muscle biopsy was necessary for the definite diagnosis of vasculitis. Non-systemic SNV is usually benign. Of 11 patients followed for longer than 2 years, none developed motor weakness due to neuropathy.

CONCLUSION

Sensory neuropathy, regardless of symmetry, can be due to vasculitis.

Subacute inflammatory demyelinating polyneuropathy

OBJECTIVE

To report the clinical, electrophysiologic, and histologic characteristics of subacute inflammatory demyelinating polyneuropathy (SIDP) and to present the diagnostic criteria of this disease.

METHODS

For a diagnosis of "definite SIDP," there were four mandatory criteria: 1) progressive motor and/or sensory dysfunction consistent with neuropathy in more than one limb with time to nadir between 4 and 8 weeks, 2) electrophysiologic evidence of demyelination in at least two nerves, 3) no other etiology of neuropathy, and 4) no relapse on adequate follow-up. Supportive criteria included high spinal fluid protein level (>55 mg/dL) and inflammatory cells in the nerve biopsy. A diagnosis of "probable SIDP" required progression of demyelinating neuropathy over a 4- to 8-week period.

RESULTS

Sixteen definite SIDP patients were identified among 29 probable SIDP patients. An antecedent infection was found in 38% of cases. The two most common neuropathy types were a symmetric motor-sensory neuropathy and a pure motor neuropathy. Cranial nerve deficits and respiratory failure were rare. Spinal fluid protein was high in 93% of cases. Demyelination was documented by the motor nerve conduction in 88% of cases and by the near-nerve needle sensory nerve conduction in two cases. Almost all patients were treated with prednisone and some with additional immunotherapies. Complete recovery was achieved in 69% of cases and partial recovery in others. Definite SIDP had all the characteristics of CIDP with three exceptions: a higher rate of antecedent infection, no relapse rate, and a high rate of recovery to normal.

CONCLUSION

Subacute inflammatory demyelinating polyneuropathy is a definite entity bridging the gap between Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy.

Postexercise facilitation of reflexes is not common in Lambert-Eaton myasthenic syndrome

Postexercise facilitation (PEF) with clinical reflexes, H-reflex, and T-reflexes at the ankle and knee was systematically studied in 16 patients with Lambert-Eaton myasthenic syndrome (LEMS). PEF was observed in ankle and knee deep tendon reflexes in five patients, in H-reflex in three patients, and in T-reflexes in six patients. When all reflex tests were combined, 7 (43.7%) of 16 patients showed PEF by at least one test. The authors conclude that the PEF of reflexes, the most helpful diagnostic clinical marker for LEMS, is not common.

Improved survival for patients with acute myelogenous leukemia

PURPOSE

Despite improvement in chemotherapy and supportive care over the past two decades, overall survival for patients with acute myelogenous leukemia (AML) remains poor; only 25% to 30% of individuals with this disorder will be cured. In 1987, we initiated a prospective multiinstitution study designed to improve long-term survival in adults with AML.

METHODS

We modified the usual 7-day treatment scheme of daunorubicin and cytarabine with high-dose cytarabine (HiDAC) on days 8 through 10 (3 + 7 + 3). Allogeneic or autologous bone marrow transplantation (BMT) was offered to all patients who entered complete remission (CR) to decrease the rate of leukemic relapse. Data were analyzed by intention to treat.

RESULTS

CRs were achieved in 84 of 94 patients (89%; 95% confidence interval [CI], 83 to 95). Because of the high remission rate, factors previously thought to predict outcome, such as cytogenetics, WBC count, French-American-British (FAB) classification, sex, and age, were not useful prognostic variables. The overall survival rate for the entire cohort of patients from data of diagnosis is 55% at 5 years. Sixty percent of all patients who achieved a CR underwent marrow grafting. There was no significant difference in event-free survival (EFS) at 5 years comparing patients assigned to receive allogeneic BMT with patients assigned to receive autologous BMT (56% v 45%, P = .54).

CONCLUSION

The long-term disease-free survival observed in this study is excellent compared with historical data. This improvement in survival is probably due to the high rate of remission induction, as well as to the effective nature of the consolidation therapy.

Pancreatic ascites, producing abdominal distension

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The hydrolysis of chloroform and carbon tetrachloride by anion-exchange resins

Chloroform in acetone or ethanol solvent was rapidly hydrolysed to carbon monoxide and formate by Amberlite XE-78 in the OH-form. Hydroxyl sites on the resin were converted into chloride. The apparent loss in capacity of the resin which occurs during the reaction cannot be wholly accounted for by production of formate. The most probable explanation for the phenomenon is the adsorption of carbon trichloride anions at resin sites. Carbon tetrachloride in ketonic solvents also gave carbon monoxide and formate in the presence of the OH-form of the resin, but in alcohol or ether solvent carbon dioxide and phosgene were formed.