Inhibition of zinc absorption by iron depends on their ratio.

Previous studies upon zinc-iron interactions gave conflicting results that could come from differences in protocol design or in trace element status of subjects. The present work assessed the influence of zinc : iron ratio and iron deficiency upon zinc absorption. The digestive absorption of zinc sulphate (100 micromol Zn/l) in presence of iron gluconate was studied in perfused jejunal loops (n = 6/group) of normal rats (range 0-1000 micromol Fe/l) and iron deficient rats (200-750 micromol Fe/l). In normal rats no significant iron inhibition on zinc absorption occurred at Fe:Zn ratio below 2:1. At higher ratios zinc uptake and net absorption decreased significantly (p<0.05). Between 2:1 and 5:1 a dose dependent inhibition of zinc absorption occurred and reached a plateau beyond this ratio. In iron deficient animals no changes in zinc uptake, mucosal retention and absorption compared to normal animals occurred at ratio 2:1. At higher ratios differences were observed at every zinc absorption step except for mucosal retention at 7.5:1 ratio. Iron-zinc interactions depend on their ratio and on previous trace elements status of subjects. Due to the wide and unknown variations that were likely to occur between the subjects of previous human and experimental studies, these results could explain some of the discrepancies between their results.

Mechanisms of absorption of caseinophosphopeptide bound iron.

Binding iron (Fe) to the 1-25 caseinophosphopeptide obtained from enzyme hydrolysis of beta casein (beta CPP) improves Fe bioavailability in the rat. To assess the mechanisms involved in its absorption, a perfused, vascularized duodenal rat loop model was used in controls and in Fe-deficient (bleeding of 25% blood volume) rats. Inhibitors of oxidative phosphorylation [2-4 dinitrophenol (DNP)] and/or of endocytosis [phenylarsine oxide (PAO)] were added to the perfusion solution containing 50 microM Fe as beta CPP bound Fe (Fe-beta CPP) or gluconate (Fe Gluc). Fe-beta CPP enhanced Fe uptake, reduced mucosal storage, and improved net absorption both in controls and in deficient animals. DNP reduced uptake, mucosal storage, and net absorption by the same percentage in Fe-beta CPP and Fe Gluc perfused rats in both control and Fe-deficient animals. PAO decreased uptake, mucosal storage, and net absorption of Fe-beta CPP but not of Fe Gluc. At the end of the experiment Fe serum levels were increased only in Fe Gluc animals. These results confirm the improved bioavailability of beta CPP bound Fe. They suggest that at least part of its absorption can occur by a different pathway than usual Fe salts. Fe-beta CPP can be taken up by endocytosis and absorbed bound to amino acids or peptides.

Improvement of zinc intestinal absorption and reduction of zinc/iron interaction using metal bound to the caseinophosphopeptide 1-25 of beta-casein.

Binding zinc (Zn) to soluble caseinophosphopeptides (CN), produced by the hydrolysis of caseins, improves its absorption and could prevent inhibition by other nutrients such as iron (Fe). The absorption of Zn (100 mumol/L) bound to the 1-25 CN (beta-CN(1-25)) of beta-casein, or as ZnSO4 was studied using the isolated, perfused rat intestinal loop system. Fe (Fe-CN or Fe gluconate (Fe Gluc)) was added at Zn/Fe ratios of 2:1, 1:5 and 1:10. Disappearance from the lumen (Q1) and net absorption (ZnAbs) of Zn-CN were statistically greater than for ZnSO4; Zn retention by the mucosa (Q2) did not significantly differ. Fe Gluc reduced Q1, Q2 and ZnAbs for ZnSO4 at ratios of 1:5 and 1:10 and for Zn-CN at a ratio of 1:10. Fe-CN reduced Q1 and ZnAbs of both forms of Zn at a ratio of 1:10; Q2 remained unchanged. Binding Zn to beta-CN(1-25) improved Zn absorption and prevented Fe from inhibiting its absorption.

The quadrifoliate flap: a combination of scapular, parascapular, latissimus dorsi and scapula bone flaps.

A short arm stump was lengthened with a composite flap with four different tissue units based on the subscapular artery.

[Osteocartilaginous reconstruction, research and clinical application]. / Reconstruction ostéocartilagineuse, recherche et application clinique.

Facing the problem set by losses of osteo-cartilagenous substances around the little bones, the finger- and toe-joints for example, the authors scanned a way different from that of amputation or arthrodesis: the functional rebuilding with the help of substitution grafts. An exploratory research conducted on 21 rabbits in Bordeaux in 1990 allowed to test the coupling of two bio-materials used in surgery here and now, a coupling which has not shown any side-effect and whose benefit is to obtain a non-deformable mass, colonizable by osteoblastic cells. The loss of articular substance suffered by a patient in his fingers in 1992 profited by this bone-rebuilding technique. The use of an external articulated stabilizer was an important provisional support during the colonization of the grafts by the osteoblasts. The difference of time in the osseus rebuilding between the rabbits on the one hand, and the human being on the other, is recorded.

[Replantation of the hand and fingers]. / Replantation de la main et des doigts.

Using microsurgical techniques to replant an amputated hand or digit is one of the most important progress in the field of hand surgery during the last three decades. The result of a replantation depends on: the mechanism and the level of amputation, the length and the type of ischaemia of the amputated segment, the surgical techniques, the postoperative care, the rehabilitation and so on. Although the success of a replantation is first judged on the survival of the replanted segment, it nevertheless should be assessed on the function achieved. Thanks to the 30-year clinical experience, the final functional result of a replantation can now be anticipated at initial examination; thus indications can be better established by patient selection criteria. The replantation of the hand and the digits is henceforth reasonable only if there is a possibility of a useful functional result.

[The "extreme" brachial flap: a distal pedicled use of an external brachial flap. Preliminary report]. / Le lambeau brachial "extrême": une utilisation pédiculée très distale du lambeau brachial externe. Rapport préliminaire.

The authors present a new application of the procedure they called the "reverse flow YV pedicle extension" which allows a very distal pedicled mobilisation of the lateral arm flap. Until now, only the distally based lateral arm flap and the ulnar recurrent fascicutaneous island flap could to be transferred distally but reached only the proximal third of the forearm. In our experience these flaps did not seem to be very reliable. Lengthening of the lateral arm flap pedicle using the lateral triceps artery (branch arising from the profunda brachii artery) allows the lateral arm flap to be transferred beyond the distal third of the forearm. This so-called "extreme" lateral arm flap has advantages and disadvantages which are discussed in this paper. We consider cutaneous or osteocutaneous reconstructions of the forearm to be the best indication for this flap. Our first clinical case is reported.

[Transsexualism: surgical aspects. An experience of the plastic surgical unit's in Bordeaux]. / Le transsexualisme: aspects chirurgicaux. Expérience du service de chirurgie plastique de Bordeaux.

After briefly reviewing the history of transsexual surgery, the authors explain their technical choices and present their experience based on a series of 19 patients, 11 male transsexuals and 8 female transsexuals. The results are analysed. The potential complications of surgery in female transsexuals are those of microsurgical techniques aggravated by treatment with testosterone, as well as urethral fistulae and strictures. In addition to prevention of thromboses, the authors palliate these complications by ulnar elongation of the radial forearm flap in order to minimise the factors responsible for urethral fistulae, combined with enlargement of this flap to decrease the risk of stricture. The complications in male transsexuals essentially consist of rectoneovaginal fistulae. Problems of the depth of the neovagina are also important. Two rectoneovaginal fistulae were observed in this series of 11 patients, both treated medically. The unit's experience in this field will be continued in order to further improve the results.

[Humeral lengthening after replantation of the upper limb]. / Allongement de l'humérus après réimplantation du membre supérieur.

INTRODUCTION: The authors have applied the method of progressive lengthening to correct upper limb discrepancy resulting from arm reimplantation in a young female adult. MATERIAL: Following a motor vehicle accident, a twenty one years old female had her right arm sectioned. Four hours after the accident, the limb was reimplanted with 10 cm shortening of the humeral shaft, to allow direct nerve suture. Sixteen months later, she had excellent functional recovery, but was annoyed by the aesthetic appearance of her short arm. Humeral lengthening was undertaken. METHOD: The authors used a special external fixation device Orthofix (Verona, Italy) and a proximal corticotomy was performed. RESULT: Progressive callus distraction allowed 10 cm lengthening without any loss of function in 10 months; aesthetic appearance was greatly improved. DISCUSSION: Limb reimplantation necessitates substantial bone shortening to protect soft tissue sutures. Functional recovery and aesthetic tolerance are classically good but in this case, aesthetic tolerance was poor. The progressive humeral lengthening was uneventful and allowed excellent outcome, in this young girl, despite distraction of the sutured nerve. CONCLUSION: This technique should be used prudently.

[Internal plantar flap on external plantar pedicle: a technique for the coverage of the whole surface of the foot. Initial report]. / Le lambeau plantaire interne sur pédicule plantaire externe: un moyen de couverture utilisable sur toute la surface du pied. Rapport préliminaire.

The authors present a new type of the classical medial plantar flap which derives its main blood supply from the medial plantar artery, a terminal branch of the posterior tibial artery. Our approach concerning flap dissection has not been modified, but the vascular supply of the flap has been shifted and a reverse blood flow coming from the lateral plantar artery is created after dividing the posterior tibial artery just proximal to its distal bifurcation. The reverse flow medial plantar artery island flap survival is ensured by rich anastomoses that usually occur between the dorsalis pedis and lateral plantar arteries. However, the venous return is also ensured by a reverse flow as in the case of lateral plantar artery. In addition, this flap presents a wide arc of rotation that is suitable for a variety of local defects, allowing cover of the foot. This new technique mainly provides a perfect indication for cover of distal weight bearing area defects of the foot when the distally based plantar flap is not possible for anatomical aberrations and/or in the presence of an unreliable blood supply of the flap itself. Moreover, it deserves a general description of a new type of flap pedicle design that we denote by the term "reverse flow Y-V extended flap pedicle". We intend to provide the readers with more details concerning clinical applications of this new surgical procedure.

[The toxicity of different crude oils on mussel larva]. / Mise en évidence de la toxicité de divers pétroles bruts vis-à-vis des larves de Moule

Five natural oils of varied origins, mixed with sea water by stirring, have been shown to be toxic for mussel larvae, which have been contaminated during one hour. This toxicity, expressed by the mortality percentage and the growth rate after contamination, was dependent on the type and the concentration of oil. The tests were carried out on 20 h old and 5 days old larvae, and were similar and complementary.