Association of neonatal myasthenia gravis with antibodies against the fetal acetylcholine receptor.

The specificities of autoantibodies directed against the acetylcholine receptor (AChR) for embryonic and adult muscle AChR were studied in 22 mothers with myasthenia gravis (MG) and in their newborns using human fetus and normal adult muscle AChR preparations. 12 mothers had transmitted MG to their neonates with, in three cases, antenatal injury. A clear correlation was found between occurrence of neonatal MG (NMG) and the high overall level of anti-AChR antibodies (embryonic or adult muscle AChR). However, a strong correlation was also found between occurrence of NMG and the ratio of anti-embryonic AChR to anti-adult muscle (Te/Ta) AChR antibodies (P < 0.0002). Taken together, these data suggest that autoantibodies directed against the embryonic form of the AChR could play a predominant role in the pathogenesis of NMG. Paradoxically, the three cases with antenatal injury presumably the most severe form of NMG, were not associated with high Te/Ta. At the clinical level, these observations could prove helpful in the prediction of transmission of NMG.

The fetal/adult acetylcholine receptor antibody ratio in mothers with myasthenia gravis as a marker for transfer of the disease to the newborn.

High anti-fetal/anti-adult muscle anti-acetylcholine receptor (AChR) antibody (Ab) titer ratio is predictive of the occurrence of neonatal myasthenia gravis in a first child. The aim of the present study was to determine whether the ratio between the levels of antibodies is an intrinsic property of the mother's sera or varies with physiologic status such as pregnancy. We performed a longitudinal study of the levels of Ab directed against both fetal and adult AChRs and the ratio between them in 11 mothers with myasthenia gravis (MG). Sera were taken during, before, and after pregnancy. Absolute levels of Ab varied considerably during the time of observation as indicated by analyzing the maximum change between any two sample times during the study (adult mean percentage change 45.9 +/- 26.4; fetal 42.51 +/- 22.05). In contrast to this, the anti-fetal/anti-adult muscle AChR Ab titer ratio was much less variable (mean percentage change 16.66 +/- 10.11; p < 0.0033). The levels of the two Ab types yielded a correlation of 0.918, consistent with the stability of the ratio between them. This stability of ratio has practical value in the management of pregnancy and infant care in mothers with MG because the ratio at any time, before or during pregnancy, will predict whether the child will contract neonatal MG. We determined this for the first child, but further studies are necessary to establish if this remains true for subsequent pregnancies.

[A comparative mechanical study of types of external fixator (author's transl)]. / Etude mécanique comparative de fixateurs externes. Le modèle du Service de Santé des Armées.

The authors have designed and original type of external fixator which can be used in the forces in case of armed conflict. Study has been directed towards a simple, strong and inexpensive apparatus which can be applied in emergency circumstances. Secondarily it can be replaced by another apparatus to allow compression, distraction or better reduction of a fracture without removal of the pins. The fixator should be applied as close as possible to bone and there should be three pins in each fragment, one close to the fracture, one distant and one intermediate. The best methods for the insertion of the pins have been tested.

[Gas gangrene: an extreme surgico-medical rather than medico-surgical emergency]. / La gangrène gazeuse: une extrême urgence "chirurgico-médicale" et non pas médico-chirurgicale.

A diabetic woman developed spontaneous gas gangrene of upper limb extending into trunk and due to clostridium septicum. Recovery was obtained after major surgery involving disarticulation of upper limb and excision of soft tissues of left hemithorax, and a difficult intensive care programme (hyperbaric oxygen therapy, assisted ventilation). The presence of this gas gangrene revealed a bipolar colon cancer treated in parallel. The conventional therapeutic hierarchy is discussed: surgery should be carried out as an extreme emergency and should not be delayed to allow transfer to a center equipped with a hyperbaric oxygen therapy apparatus.

[Reconstruction of post-traumatic diaphyseal bone loss by segmental bone transfer]. / Comblement des pertes de substance osseuse post-traumatiques diaphysaires par transport osseux segmentaire.

Until the beginning of the 1980s, reconstruction of major post-traumatic diaphyseal bone loss as an alternative to amputation was possible only by massive autologous bone grafts. Such a technique was limited by the amount of available bone required for grafting. Ilizarov explained the distraction osteogenesis principle and designed a circular external fixation material that was suitable for compression-extension. He described the concept of segmental bone transfer, which allows bone regeneration to take place within the actual injured limb. Our present experience is based on the literature and the study of 12 cases. All patients presented with significant post-traumatic tibial bone loss ranging from 45 to 145 mm. In this article, we discuss the indications, benefits and risks of such a technique compared to classic methods. Mainly indicated in patients who have sustained significant bone loss, bone transfer is the method of choice for preserving bone stock and correcting limb discrepancy, although it does not reduce consolidation time. Moreover, circular external fixations are often poorly tolerated and may be replaced by unilateral devices that are easier to install.

[Posterolateral sural fasciocutaneous island flap with proximal aponeurotic pedicle. Anatomical study and use for cutaneous cover of the knee. Apropos of 9 clinical cases]. / Le lambeau sural postéro-latéral en îlot fascio-cutané à pédicule aponévrotique proximal. Etude anatomique et application à la couverture cutanée du genou. A propos de neuf cas cliniques.

The authors propose an elaborate variant of the classical saphenous or lateral leg fascio-cutaneous flap with a proximal pedicle for the cover of post-traumatic skin defects of the knee. The original feature of this flap resides in the purely aponeurotic or adipo-fascial pedicle which increases the arc of rotation, while minimizing cutaneous sequelae of the donor site. Twenty four injected cadaveric dissections were used to define the neurovascular content of the lateral sural fascia: the lateral and medial superficial sural arteries and their territory of perfusion, accompanying veins and the short saphenous vein, as well as the lateral and medial sural cutaneous nerves. The technique of harvesting of the island flap is described. Nine patients were operated between 1991 and 1994, with an uncomplicated postoperative course in terms of flap vitality and donor site. The skin cover of the knee was considered to be of excellent quality, stable and sensitive, with a follow-up ranging from 6 months to 3 years four months.

[The folded fibula flap: anatomical study and clinical application to septic post-traumatic femoral reconstruction. A propos of 6 cases]. / Le lambeau dédoublé de fibula: étude anatomique et application clinique a la reconstruction fémorale post-traumatique septique. A propos de six cas.

The reconstruction of extensive femoral defects, particularly septic, by revascularized free fibula flap has become part of routine practice for many years. Following the demonstration of secondary stress fractures, splitting of the fibula into two vascularized barrels was proposed in 1987 to avoid this complication. The authors conducted an anatomical study on 100 dry bones in order to define the situation of the fibular foramen which is usually found at about 1.45 cm from the midpoint of the fibula. This foramen must be spared during the intermediate splitting osteotomy in order to obtain two bone barrels: one with a double centromedullary and periosteal blood supply which will be used like a contromedullary pin, and the other with only a periosteal blood supply, which will be used as a medial or lateral splint. The deductions concerning the preoperative strategy and splitting technique are explained as a function of the length of the defect. From 1989 to 1993, 6 male patients underwent extensive femoral reconstruction (average length of 9.8 cm). Four free revascularized transfers were performed, including one osteocutaneous flap. In two cases, the osteocutaneous transfer was a proximally based island pedicle flap. Apart from one patient who was subsequently amputated, five patients underwent a secondary autologous bone graft after an average of three months. Consolidation was achieved after a mean of 12.6 months. A secondary stress fracture was observed in one case. With a minimum follow-up of two years, all patients are able to walk with a mean shortening of 2 cm of the reconstructed limb and without any donor site sequelae.