Benign reversible muscle cytochrome c oxidase deficiency: a second case

A 6-week-old boy had generalized weakness, requiring assisted ventilation, and lactic acidosis. At 6 months, the lactic acidosis resolved, and the patient started to improve; assisted ventilation was discontinued at 15 months. Muscle biopsies at 4 and 11 months showed accumulation of mitochondria, lipid, and glycogen; cytochrome c oxidase (COX) activity was 11% of the lowest control in the first biopsy and 57% in the second. Immunocytochemistry and immunotitration showed presence of immunologically reactive enzyme protein in both biopsies. This case confirms a previous report of benign infantile myopathy due to reversible COX deficiency. The severe fibrosis in the second biopsy may explain the slower rate of clinical recovery in this child.     

Widespread tissue distribution of mitochondrial DNA deletions in Kearns-Sayre syndrome

We performed Southern analysis of mitochondrial DNA (mtDNA) in 6 tissues from a patient with Kearns-Sayre syndrome and found a single deletion of 4.9 kb in all tissues. The percentage of deleted mtDNAs varied widely between tissues, from only 4% in smooth muscle to approximately 50% in skeletal muscle. Samples of DNA obtained from 3 different skeletal muscles and from separate areas of individual tissues showed little variation in percentage of deleted mtDNA. Biochemical analysis showed no clear correlation between mitochondrial enzyme activity and deleted mtDNAs.     

Neglected traumatic posterior dislocations of the shoulder: controversies on indications for treatment and new CT scan findings

We report seven missed traumatic posterior dislocations of the shoulder in six patients. In all seven shoulders, anteroposterior radiographs did not provide the diagnosis in the emergency room after the trauma (epileptic seizure in four patients) and diagnosis was delayed for at least 24 h. The final diagnosis was reached by clinical suspicion and computed tomography (CT) scan of the seven shoulders. Two shoulders were treated by closed reduction and three were treated by closed reduction and percutaneous pinning, although four of these five shoulders presented a defect in the humeral head involving 20%–25% of the articular surface. Two shoulders dislocated for more than 6 months were treated according to Mc Laughlin's technique modified by Hawkins instead of an arthroplasty. At a minimum follow-up of 2 years and 2 months, the functional results according to Hawkins were good in all seven shoulders. There was no recurrence of the dislocation in any patient. Radiographs showed mild degenerative changes. The establishment of indications for treatment, based on the proportion of articular surface of the humeral head involved and the time of evolution of the dislocation, needs more clinical or experimental evidence. In epileptic patients, strict control of medication is of the utmost importance. Received for publication on Jan. 7, 1999; accepted on June 23, 1999     

Partial dystrophin deficiency in monozygous twin carriers of the Duchenne gene discordant for clinical myopathy

We studied monozygous twin women, age 63. One, asymptomatic, had a serum creatine kinase (CK) level of 191 units (normal, 1 to 50); her son died of typical Duchenne muscular dystrophy (DMD) at age 18. Her twin sister had symptomatic limb weakness from about age 40. Her serum CK was 495 units. EMG and muscle biopsy were compatible with myopathy. In the asymptomatic twin, the peripheral blood lymphocyte karyotype was 46,XX. In the affected twin, 18% of cells were 45,X, and the others 46,XX, without X/autosome translocation. DNA analysis did not reveal a deletion at the DMD locus. Immunologic studies of dystrophin showed a partial deficiency of the protein that was more severe in the symptomatic twin. The clinical discordance and the different severity of dystrophin deficiency may have resulted from the effects of lyonization.     

Mitochondrial encephalomyopathies

The mitochondrial diseases present with great heterogeneity. They are often multisystemic and vary considerably in age at onset, distribution of weakness, severity, and course. Only nonthyroidal hypermetabolism has a distinctive clinical presentation. Therefore, attempts at classification have generated some controversy. This article discusses the general classification that takes into account genetic and biochemical features, which has resulted from the fast pace of biochemical and molecular genetic investigations.     

A multimodal approach prevents instability after total hip arthroplasty: A 1 year follow-up prospective study

Introduction

Joint dislocation is one of the most frequent complications after hip arthroplasty. Multiple strategies have demonstrated ability to prevent instability when used in isolation, but the effect when more than one intervention is implemented has not been measured. The purpose of this study is to assess the rate of dislocation after implementation of a protocol of combined strategies for prevention of instability.

Phase I study of granulocyte colony-stimulating factor in patients with transitional cell carcinoma of the urothelium.

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) was administered at a dose of 1-60 micrograms/kg of body weight to 22 patients with transitional cell carcinoma before chemotherapy as part of a Phase I/II study. In all patients, a specific dose-dependent increase in the absolute neutrophil count (ANC) of 1.8-12 fold was seen. In addition, this augmentation in the ANC was accompanied by an increase in leukocyte alkaline phosphatase, a marker of secondary granule formation. In six of eight patients analyzed, an increase in bone marrow myeloid to erythroid cell ratio was seen. Day 14 peripheral blood cell derived colony forming unit granulocyte macrophage were also increased by day 6 of rhG-CSF treatment. Circulating levels of eosinophils and basophils were unchanged; however, a 10-fold increase in monocytes was observed in patients treated at the highest doses. There was also a small increase in CD3+ lymphocytes that was not dose dependent. Hemoglobin, hematocrit, and platelet count remained near baseline throughout the period of rhG-CSF administration. These findings demonstrate that rhG-CSF is a potent stimulus for normal neutrophil proliferation and maturation.