Myasthenia gravis

Oesophageal atresia (OA) encompasses a group of congenital anomalies comprising of an interruption of the continuity of the oesophagus with or without a persistent communication with the trachea. In 86% of cases there is a distal tracheooesophageal fistula, in 7% there is no fistulous connection, while in 4% there is a tracheooesophageal fistula without atresia. OA occurs in 1 in 2500 live births. Infants with OA are unable to swallow saliva and are noted to have excessive salivation requiring repeated suctioning. Associated anomalies occur in 50% of cases, the majority involving one or more of the VACTERL association (vertebral, anorectal, cardiac, tracheooesophageal, renal and limb defects). The aetiology is largely unknown and is likely to be multifactorial, however, various clues have been uncovered in animal experiments particularly defects in the expression of the gene Sonic hedgehog (Shh). The vast majority of cases are sporadic and the recurrence risk for siblings is 1%. The diagnosis may be suspected prenatally by a small or absent stomach bubble on antenatal ultrasound scan at around 18 weeks gestation. The likelihood of an atresia is increased by the presence of polyhydramnios. A nasogastric tube should be passed at birth in all infants born to a mother with polyhydramnios as well as to infants who are excessively mucusy soon after delivery to establish or refute the diagnosis. In OA the tube will not progress beyond 10 cm from the mouth (confirmation is by plain X-ray of the chest and abdomen). Definitive management comprises disconnection of the tracheooesophageal fistula, closure of the tracheal defect and primary anastomosis of the oesophagus. Where there is a "long gap" between the ends of the oesophagus, delayed primary repair should be attempted. Only very rarely will an oesophageal replacement be required. Survival is directly related to birth weight and to the presence of a major cardiac defect. Infants weighing over 1500 g and having no major cardiac problem should have a near 100% survival, while the presence of one of the risk factors reduces survival to 80% and further to 30–50% in the presence of both risk factors.     

Myasthenia gravis and the thymus gland.

Six skin cancer detection clinics were held at a county fair booth in Turlock, California during August, 1973. Examination of sun-exposed skin areas in 605 people showed potential skin cancer in 28.6 percent of people 25 years of age or older. Of the people examined, 135 were referred to their own physicians for follow-up diagnosis and treatment of skin lesions.     

The proliferative capacity of pure red cell aplasia bone marrow cells.

Pure red cell aplasia (PRCA) is a heterogeneous disorder. Immunologic abnormalities have recently been uncovered suggesting that both cell-mediated and humoral immune mechanisms may be of etiological importance in PRCA. Utilizing a technique for the cloning of bone marrow erythroid precursors, we determined the in vitro proliferative capacity of erythroid cells obtained from 21 patients with PRCA. Bone marrow cells from one group of patients produced normal or increased numbers of erythroid colonies while the in vitro proliferative capacity of bone marrow cells from a second group was characterized by subnormal erythroid colony formation. Sera obtained from the former group was frequently associated with demonstrable serum inhibitors of erythropoiesis, while PRCA in the latter group was probably the consequence of intrinsic erythroid stem cell defects or pathologic cellular interactions with nonerythroid regulatory cells. This survey of a relatively large population of patients with PRCA provides evidence for the multiple causative mechanisms that can be operative in the production of PRCA.     

Myasthenia gravis associated with penicillamine treatment for rheumatoid arthritis.

Four patients with rheumatoid arthritis (R.A.) developed myasthenia gravis after taking penicillamine. In one patient withdrawal of the drug was followed by spontaneous remission of the myasthenia, and in two the dose of anticholinesterase was subsequently reduced. In the fourth patient continuing penicillamine treatment was associated with increasingly severe myasthenic features, but on withdrawal of the drug these resolved. As myasthenia gravis rarely complicates R.A. its onset in these patients shortly after the start of penicillamine treatment suggested that penicillamine may have precipitated this condition.     

Pure red cell aplasia: review of treatment and proposal for a treatment strategy.

The management of pure red cell aplasia (PRCA) continues to challenge clinical investigators because the pathophysiology is heterogeneous and poorly understood. There are five treatment regimens that have established efficacy for patients with chronic PRCA. In patients with congenital hypoplastic anemia the best results have been reported using corticosteroids. Cyclosporine A is recommended as the treatment of choice in acquired PRCA. High-dose intravenous immunoglobulin therapy is highly effective in PRCA associated with parvovirus B19 infections and impaired IgG-antibody response. Treatment failures may be successfully managed with horse anti-human thymocyte globulin or cyclophosphamide plus corticosteroids. The potential of hematopoietic growth factors in the treatment of PRCA awaits further studies.