Surface tension of cavitation bubbles.

We have studied homogeneous cavitation in liquid nitrogen and normal liquid helium. We monitor the fluid content in a large number of independent mesopores with an ink-bottle shape, either when the fluid in the pores is quenched to a constant pressure or submitted to a pressure decreasing at a controlled rate. For both fluids, we show that, close enough to their critical point, the cavitation pressure threshold is in good agreement with the Classical Nucleation Theory (CNT). In contrast, at lower temperatures, deviations are observed, consistent with a reduction of the surface tension for bubbles smaller than two nanometers in radius. For nitrogen, we could accurately measure the nucleation rate as a function of the liquid pressure down to the triple point, where the critical bubble radius is about one nanometer. We find that CNT still holds, provided that the curvature dependence of the surface tension is taken into account. Furthermore, we evaluate the first- and second-order corrections in curvature, which are in reasonable agreement with recent calculations for a Lennard-Jones fluid.

[Flexor digitorum superficialis tendon transfer for intrinsic paralysis in leprosy]. / Transfert tendineux palliatif utilisant le Flexor Superficialis Digitorum dans les paralysies intrinsèques d'origine lépreuse.

A follow up study was performed in the rehabilitation centre for patients with leprosy in Hôchiminhville - Vietnam. All patients had claw-hand deformity due to ulnar and median nerve intrinsic paralysis. Thirty-two affected hands (128 long fingers) were included in the study. A Bunnel-Littler tendon transfer procedure was performed using a four-tailed graft of the flexor digitorum superficialis of the third finger. Clinical evaluation included anatomical measurements of interphalangeal and metacarpal joints in complete extension and in the intrinsic position. In the open hand assessment, 48.5% reported good results, 14.8% medium results and 36.7% poor results. With the hand in the intrinsic position, 53.9% achieved good results, while 33.6% achieved medium results and poor in 12.5%. Poor functional outcome is related to a failure of this procedure and seems to be due to extensor tendon laxity, with or without stiffness of the interphalangeal joints. There were many anatomical deformities (27.3%) found at the time of follow up, notably boutonniere (51.4%) and mallet finger deformities (31.4%) The fourth and fifth fingers had the worst results. We have therefore decided to change our protocol for claw-hand correction and use the Bouvier test in deciding on our surgical indications. Preoperative physiotherapy is absolutely necessary to reduce stiffness of the interphalangeal joints.

Transfert tendineux palliatif utilisant le Flexor Superficialis Digitorium dans les paralysies intrinseques dorigine lepreuse / Flexor digitorum superficialis tendon transfer for intrinsic paralysis in leprosy

A follow up study was performed in the rehabilitation centre for patients with leprosy in Hôchiminhville - Vietnam. All patients had claw-hand deformity due to ulnar and median nerve intrinsic paralysis. Thirty-two affected hands (128 long fingers) were included in the study. A Bunnel-Littler tendon transfer procedure was performed using a four-tailed graft of the flexor digitorum superficialis of the third finger. Clinical evaluation included anatomical measurements of interphalangeal and metacarpal joints in complete extension and in the intrinsic position. In the open hand assessment, 48.5% reported good results, 14.8% medium results and 36.7% poor results. With the hand in the intrinsic position, 53.9% achieved good results, while 33.6% achieved medium results and poor in 12.5%. Poor functional outcome is related to a failure of this procedure and seems to be due to extensor tendon laxity, with or without stiffness of the interphalangeal joints. There were many anatomical deformities (27.3%) found at the time of follow up, notably boutonniere (51.4%) and mallet finger deformities (31.4%) The fourth and fifth fingers had the worst results. We have therefore decided to change our protocol for claw-hand correction and use the Bouvier test in deciding on our surgical indications. Preoperative physiotherapy is absolutely necessary to reduce stiffness of the interphalangeal joints.

Universality of small scale turbulence.

The proposed universality of small scale turbulence is investigated for a set of measurements in a cryogenic free jet with a variation of the Reynolds number (Re) from 8500 to 10(6) (max(R(lambda) approximately 1200). The traditional analysis of the statistics of velocity increments by means of structure functions or probability density functions is replaced by a new method which is based on the theory of Markov processes. It gives access to a more complete characterization by means of joint probabilities of finding velocity increments at several scales. Based on this more comprehensive method, our results are very far from a possible universal state, even for R(lambda) above 1000.

Observation of the 1/2 power law in Rayleigh-Bénard convection.

The 1/2 power law is reported in a Rayleigh-Bénard experiment: Nu approximately Ra(1/2), where Ra and Nu are the Rayleigh and Nusselt numbers. This observation is coherent with the predictions of the ultimate convection regime, characterized by fully turbulent heat transfers. Ordered rough boundaries are used to cancel the correction due to the thickness variation of the viscous sublayer, and the observation of the asymptotic regime is therefore possible. This result supports the interpretation of a laminar-turbulent boundary-layer transition to account for the observation of Chavanne et al. of a new regime [X. Chavanne et al., Phys. Rev. Lett. 79, 3648 (1997)].

[Arthroscopy of the wrist]. / Arthroscopie du poignet.

Wrist arthroscopy may add specific datas to that provided by standard or motion view radiographs, arthrography, bone scan, TDM or RMN. Eight portals allow direct visualization of articular surfaces of radio-carpal and medio-carpal joints, triangular fibrocartilage, spaces between the carpal bones, interosseous and extrinsic ligaments. Wrist arthroscopy may be useful to evaluate lesions involving ligaments or cartilages, in degenerative or post-traumatic conditions. Arthroscopy may help to the decision in treatment of carpal instabilities, scaphoid pseudarthrosis, or Kienbock disease. Operative arthroscopy may allow shaving of damaged cartilage or fibrocartilage, bone resection or triangular fibrocartilage reinsertion.

[Arthroscopy of the ankle: a new of postero-internal point of entry]. / Arthroscopie de la cheville: un nouveau point d'entrée postéro-interne.

INTRODUCTION: The development of the indications in the arthroscopic surgery of the ankle and the narrowness of this joint impose perfectly adapted portals. Several posterior portals which allow to access to the postero medial corner of the joint have been already described, but are not satisfying. We describe, here, a new postero-medial portal which allows a safe and easy access to the posterior part of the joint. METHODS: The arthroscopy is performed with a standard arthroscope (30 degrees, 4.5 mm in diameter) and a lateral ankle distractor. The landmark for this portal is the posterior crest of the medial malleolus. Above the posterior tip of the medial malleolus, this crest is directed up and back, then its direction becomes strictly vertical. The new portal is situated there, 5 millimeters behind the crest (generally 2 centimeters above the posterior tip of the medial malleolus). A needle visualized by the anterior portal is helpful to show the right direction for the portal. After skin incision, a forceps is used to widen the portal. Then the instruments or the arthroscope can be introduced. Posterior tibial artery and nerve are protected by the tendons of tibialis posterior and flexor digitorum longus. MATERIAL: We have used this portal (instrumentation and arthroscope) in four patients (3 osteochondritis dissecans of the medial part of the talus, 1 loose body) without problem. RESULTS: This portal is safe; it does not intersect the direction of posterior tibial artery and nerve as in the postero-medial portal described by Parisien and avoids in most cases the approach described by Guhl. DISCUSSION: Because the medial malleolus is more anterior than the lateral malleolus, it allows a larger approach to the posterior part of the joint than the postero-lateral portal. We recommend it for the arthroscopic treatment of all the lesions of the postero-medial part of the joint.

[An original experience through the creation of a new functional rehabilitation center for Vietnamese lepers]. / Une expérience originale à travers la création d'un nouveau centre de réhabilitation fonctionnelle pour les lépreux vietnamiens.

Since 1990, the creation of a Rehabilitation Center for Vietnamese leprosy patients under the aegis of "Oeuvres Hospitalières Françaises de l'Ordre de Malte" is the result of emphasized collaboration between governmental and non-governmental organizations, and between medical and paramedical specialists. This humanitarian action is not "a present home delivery". The end of this action is to set progressively a realist enterprise that depends on preliminary epidemiologic investigations on the spot to analyse means and necessities. Frequency of disabilities (49.6%) and predominance of grades 1 and 2 (83.5%) require aids. The realisation of technology transfer at all medical care levels is necessary. But at the same time, it is essential to build surroundings adapted infrastructure, to equip with effective material giving comfort and security for patients, and even to supply with pharmaceutic drugs in order to continue rehabilitation's activities. In short range, patient's selection and regular control give first objective results.

[Surgical applications of anatomical variations of the median nerve at the wrist]. / Applications chirurgicales des variations anatomiques du nerf médian au poignet.

After a brief report of median nerve anatomy at wrist, authors describe terminal variations of its distribution. Classic description of five terminal sensitive and motor median nerve branches is not constant. Many anatomic variations have been reported and so many, classifications proposed. Lantz' classification is useful, it may be divided in four groups. Other anatomic variations concern cutaneous palmar nerve branch and different nervous anastomosis. Advantage of this anatomic study is incidence of variations on surgical access of carpal tunnel. Those nervous variations of median nerve at wrist are frequent, unknown and wrong indexed and may be so many "anatomic traps" for surgeon.

[The "lethality" of attempted suicide]. / La "léthalité" des tentatives de suicide.

It is possible to quantify medical severity of a suicide attempt ("lethality") and its relationships with other components of the suicidal gesture have to be analysed. Our study about 758 suicide attempts aims to define psychiatric and psychological factors which are linked to "lethality" as measured by Weisman and Worden scale. Results of factorial analysis show a strong relation between "lethality" and some variables proving the intensity of psychological difficulties. Those results suggest the existence of relationship between "high lethality" on one hand, and diagnosis of psychosis, depressive symptomatology, high suicidal intent, some conceptions of death, on the other hand. A "low lethality" is associated with hedonistic conception of death, lack of positive signs of depression, existence of impulsiveness, psychopathic behaviors or lack of established mental disorder. These results reinforce the hypothesis of a relation between severity of patients psychological difficulties and medical severity of suicide attempt.

The use of mebendazole in the treatment of filariases due to Loa loa and Mansonella perstans.

Patients harbouring Loa loa and/or Mansonella perstans infections, or presenting typical filarial symptomatology, were treated with mebendazole, a drug shown to be efficient in other parasitoses. Of the patients who took the drug during 21 days and provided regular blood samples, 84% showed a significant decrease in their L. loa microfilaraemia and 100% in their M. perstans microfilaraemia, with a concomitant improvement in the clinical manifestations and no side reaction to drug administration. Additionally, the long-lasting effect of the drug (up to day 200 in some cases) may suggest a positive action on the adult worm. Mebendazole may consequently be regarded as a safer alternative to diethylcarbamazine for the treatment of these two parasitoses.

Filariasis due to Loa loa and Mansonella perstans: distribution in the region of Okondja, Haut-Ogooué Province, Gabon, with parasitological and serological follow-up over one year.

The prevalence of Loa loa and Mansonella perstans filariasis has been determined in 6 rural villages in eastern Gabon. Between 18.9 and 27.2% of people carry L. loa microfilariae with an overall microfilarial rate of 25.1%. The microfilarial rate for M. perstans was more variable, between 33.3 and 62.2% (average 49.1%). No significant difference was seen in the microfilarial rate with age over 15 years for either parasite, but men were infected more frequently than women. Anti-L. loa antibody titres were measured, using a homologous microfilarial antigen in ELISA. Taking the parasitological and immunological evaluations together, only 10% of the sample population appear to be free of these filarial infections. L. loa and M. perstans microfilaraemia and corresponding serology were also investigated twice in 150 people at a one-year interval. 99.1% of the cases who had no circulating L. loa microfilaria in March 1984 still did not show any 12 months later. Similarly, 97.1% of the untreated, microfilaraemic cases still harboured this parasite a year later. The same was not observed for M. perstans, since microfilariae appeared or disappeared in 26.7% of the cases. This suggests different dynamics for the two filarial infections. Variation in individual anti-L. loa antibody titres was low. The possibility of a genetic influence on the expression of loiasis is discussed.