Screening of male patients with autosomal recessive Duchenne dystrophy through dystrophin and DNA studies

Previously we estimated that about 2.5-4% of isolated male patients diagnosed as Duchenne dystrophy (DMD) may have the autosomal recessive form (AR-DMD). Such cases can be distinguished from X-linked DMD through the analysis of dystrophin. Fifty DMD patients from 47 families were investigated for dystrophin and DNA deletions. Based on our results, we estimate that the frequency of AR-DMD may be about 8-12% among male patients diagnosed as DMD in whom X-linked inheritance could not be confirmed through pedigree data, serum enzymes in female relatives or DNA studies. Such an estimate must be confirmed in a larger sample; however, it shows the importance of assessing dystrophin in all patients diagnosed as DMD in whom X-linked inheritance cannot be proved, since the distinction between these 2 forms has implications for genetic counseling.     

Shoulder instability: impact of glenohumeral arthrotomography on treatment

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.     

Rupture of the posterior tibial tendon: CT and surgical findings

Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture.     

MM-CK subtypes diagnose reperfusion early after myocardial infarction

Isoelectric focusing (IEF) was used to analyze the serum MM-CK isoenzyme subtypes in 16 patients receiving streptokinase (SK) for attempted coronary thrombolysis early after acute myocardial infarction. Twelve patients had revascularization documented by serial coronary angiograms (Group I); in four patients, angiography documented no such reperfusion (Group II). The data also were compared with a previously reported group of 8 patients who did not receive streptokinase (Group III). Total and MB-CK activity, as well as the MM-CK isoenzyme subtypes MM3-CK, MM2-CK, and MM1-CK tended to rise earlier and peak earlier in Group I compared with Group II; serum MM3-CK, the predominant subtype in myocardium, however, definitely peaked earlier in Group I (8.65 +/- 2.07 hr) compared with Group II (18.50 +/- 6.67 hr) (p less than 0.001). Soon after its release from myocardium, MM3-CK is converted in the serum to MM2-CK and eventually to MM1-CK; thus, the MM3-CK:MM1-CK ratio amplifies the time course of subtype conversion. The MM3-CK:MM1-CK activity ratio peaked earlier in Group I (5.51 +/- 0.97 H) compared to Group II (10.74 +/- 3.28 hr) (p less than 0.01), and peaked even earlier than MM3-CK (p less than 0.007) in both Groups I and II. Thus, the time course of the MM3-CK:MM1-CK ratio separates those patients who reperfuse when early SK is used after acute myocardial infarction from those who do not, and does it significantly earlier than the other enzymatic parameters of cellular necrosis, total CK, and MB-CK.