Cardiac Myoglobin in Myoglobinuria

Studies were undertaken to determine whether significant abnormalities were present in cardiac myoglobin in a case of primary paroxysmal myoglobinuria.No qualitative abnormality was found in cardiac myoglobin from a patient with myoglobinuria, compared to normal controls, using urea starch gel electrophoresis. Quantitative analysis, however, revealed depletion of cardiac myoglobin in the patient with myoglobinuria.It is considered that the basic defect in primary paroxysmal myoglobinuria is not related to myoglobin per se, and although evidence is lacking, an autoimmune process, as encountered in some of the hemolytic anemias, may be involved in this condition.     

Myoglobinuria detection by capillary electrophoresis

Capillary electrophoresis was used in this study to separate urinary myoglobin from hemoglobin based on its electrophoretic mobility. Urine was applied directly without any treatment. The separation was accomplished in less than 7 min. Myoglobin extracted from human muscle tissues was separated, in a borate buffer 150 mM, pH 8.7 containing 0.5% polyethyleneglycol at 6 kV, into two peaks (MI and MII) which were also resolved far from hemoglobin. Upon standing at room temperature, MII converted into MI. Horse myoglobin eluted close to MI.The addition of polyethyleneglycol to the buffer enhanced the separation and increased the peak height of myoglobin. Optimum conditions for the separation are discussed. The method is suitable for routine clinical analysis because of its simplicity and speed.     

Myoglobinuria in hereditary progressive muscular dystrophies

Myoglobin (Mb) levels in pooled urine samples were investigated and compared in patients with different types of hereditary progressive muscular dystrophies (MD). The samples were taken before and after physical exercise. The Mb levels in the patients were significantly higher than in controls under both resting and exercise conditions. The formation of separate clusters of Mb values enabled us to distinguish patients with different types of MD according to the clinical diagnosis. Urine protein detection with SDS-acrylamide electrophoresis showed an abnormal pattern in patients compared to healthy controls.     

Rehabilitation of Paralytic Dysphonia

Vocal rehabilitation has been successful for patients with paralytic dysphonia. At the discretion of the laryngologist, vocal rehabilitation is used alone or in combination with intracordal injection. Except for post-surgical patients, a complete diagnostic evaluation is advisable before vocal therapy is undertaken. During vocal rehabilitation, pitch, volume, quality, breath support and the vocal image are realigned to afford an optimal and efficient voice.For the 18 patients completing vocal therapy, the results were excellent in 14 and good in four. Vocal therapy was completed within six months for 11 patients; seven were treated for periods ranging from six months to a year.     

Paralytic shellfish poisoning.

Two cases of paralytic shellfish poisoning after ingestion of mussels occurred in October 1977 in Nova Scotia. The incidence of this type of poisoning is relatively high among persons living on the coast of the Bay of Fundy and the estuary of the St. Lawrence River. The causative organism, Gonyaulax tamarensis, elaborates an endotoxin, saxitoxin, that blocks neuromuscular transmission in the motor axon and muscle membrane while leaving the end-plate unaffected; it also suppresses conduction in the atrioventricular node and inhibits the respiratory centre. The clinical manifestations are unique and include numbness of the lips, tongue and fingertips within minutes of ingestion of the poisoned shellfish, then numbness of the legs, arms and neck, with general muscular incoordination, and finally respiratory distress and muscular paralysis. Treatment is symptomatic and prevention can only occur by public education.