Analyse des courbes de survie de nématodes phytoparasites selon le modèle de Teissier

Four survival curves of plant parasitic nematodes are analysed with Teissier's model. The model is based upon the assumption of an exponential decrease with time of the life expectancy, E(t) = E₀ exp(−αt), with E₀ the life expectancy at time 0 and α a decay coefficient. By integrating this formula we obtain an expression for the number of survivors at time t, S(t), as a function of the time, t, and S₀, the number of individuals at time 0, and the parameters E₀ and α: S(t) = S₀exp[αt −(exp(αt) −1)/αE₀. S₀ is a scaling parameter, related to the initial number of individuals in the population, thus the form of the curve depends only on the parameters E₀ and α, which are readily understandable in a biological model. These parameters E₀ and α are estimated by fitting the model to experimental data using a non-linear regression based on a least squares procedure. The results show a highly significant fit of the model to the data indicating the ability of the model to describe the plant parasitic nematodes survival curve. Results are discussed and the hypothesis of Teissier is compared with other related hypotheses.     

Recherche de facteurs de risque de la thrombopénie induite par le 177Lu-DOTATATE dans le bilan de suivi standard

PurposeThe thrombocytopenia induced by the ¹⁷⁷Lu-DOTATATE is one of its frequent, adverse effects. Its persistence causing problems in the subsequent management of patients, especially when the disease progression occurs, predicting it is a major issue. Due to the lack of knowledge about this subject, we searched to determine the existence of predisposing factors concerning the platelet toxicity in the standard follow-up.Material and methodsThis monocentric retrospective study included 20 patients with gastroenteropancreatic neuroendocrine tumors. Various parameters were analyzed, including: the standard blood analysis, the osteomedullary invasion factor, the spleen's volume and the estimated activity in the bone marrow or the spleen 24 hours post-injection.ResultsFour patients had a persistent grade 2 thrombocytopenia, one year after the last treatment. A decrease in platelet count after the first treatment above 30% and an osteomedullary invasion factor above 30% were highlighted as risk factors odds-ratio = ∞ (P = 0.0379) and odds-ratio = ∞ (P = 0.003) respectively. The initial platelet count, splenic length and estimated activity in the spleen after 24 h were correlated with platelet nadir value r = 0.5459 (P = 0.0128); r = − 0,8105 (P < 0,0001) and r = − 0.467; (P < 0.0001) respectively.ConclusionThis study has shown that the decrease of platelet's count after the first round of treatment and the scale of osteomedullary invasion are risk factors for thrombocytopenia and has brought to light that the spleen acts as a factor impacting the severity of this thrombocytopenia.     

Place de l’embolisation percutanée de la varicocèle dans le traitement de l’infertilité

Objectives

To describe percutaneous embolization of varicocele and to evaluate the effect on fertility disorders.

Materials and methods

One hundred nineteen patients, aged 11 to 48 years, underwent percutaneous embolization for varicocele indicated by a fertility disorder in 23% of cases. Correction of the varicocele and resolution of associated pain, improvement of testicular trophicity and the effect on fertility were studied and a review of the literature was performed.

Results

Percutaneous embolization was performed using neuroleptanalgesia on an outpatient basis. The technique combined venous sclerotherapy and placement of coils in the gonadal vein. The technique was successful in 95% of cases and one complication was observed. At 3 months, the varicocele and related pain had resolved in 98% of treated patients. According to previous reports in the literature, the relations between varicocele and fertility disorders are still unclear, but improvement of fertility (semen quality and conception rates) after varicocele repair has been established.

Conclusion

Although the consequences of varicocele on fertility have not been fully elucidated, treatment of varicocele appears to be beneficial. Percutaneous embolization of varicocele is a safe and effective alternative to surgery. This technique, based on a urological and radiological consensus, is the first-line treatment for varicocele in our institution.     

Deux siècles de stratigraphie dans le bassin de Paris

Stratigraphy is the book of Earth history. This book has been read for a long time, and each reader tries to improve its general understanding. Since the introduction of the concept of stratotypes by d’Orbigny, nearly two centuries ago, the point of view has evolved and shifted from a one-dimension perception, the vertical one, the time one, to a four-dimension comprehension, the time–space one. The Paris Basin illustrates the evolution of the main concepts that prevailed in stratigraphy.     

Comment identifier le spermatozoïde vivant?

Testicular sperm extraction (TESE) has been used to retrieve spermatozoa in patients with secretory azoospermia for intracytoplasmic sperm injection (ICSI). However, testicular spermatozoa have poor motility that significantly decreases after cryopreservation and thawing. The major difficulty with testicular spermatozoa is to distinguish between living and dead spermatozoa, as most spermatozoa are immotile. The aim of this study was firstly to report the various methods used to explore spermatozoa vitality. Most tests assess the functional and structural integrity of the sperm membrane, such as staining methods and hypo-osmotic swelling test (HOS-test). We then evaluates the potential of pentoxifylline (PTX), a phosphodiesterase inhibitor of the methylxanthine group, to improve the distinction between living and dead immotile testicular spermatozoa by increasing the number of post-thawed motile spermatozoa. We also analysed the results of 100 ICSI cycles performed with frozen-thawed testicular (n=72) and epididymal (n=28) spermatozoa treated with 3.5 mM PTX. To test the effect of PTX on motility, 14 samples of frozen-thawed testicular spermatozoa from eight patients with secretory azoospermia and six patients with excretory azoospermia were divided into three equal samples: one sample treated with 3.5 mM PTX, one sample initially migrated on two-layer Percoll gradient and then divided into two aliquots (one treated with 3.5 mM PTX, one without treatment), and the last sample without migration and without PTX treatment. The number of motile spermatozoa was evaluated in 10 μL of each sample with an inverted microscope at 15, 30, 60, 120 minutes and 24 hours. We also compared the outcome of ICSI in 100 cycles using frozen-thawed epididymal or testicular spermatozoa between secretory and excretory patients. PTX significantly increased the number of motile frozen-thawed testicular spermatozoa in secretory and excretory azoospermia. In excretory azoospermia, the number of motile spermatozoa was further increased when PTX was associated with migration on Percoll gradient, while PTX alone gave the best results in secretory azoospermia. Fertilization and pregnancy rates as well as embryo quality and division stages were comparable in the two groups. By increasing the number of motile frozen-thawed testicular spermatozoa, PTX improves the selection of living spermatozoa.     

Apport de l’iode 131 dans le traitement de la maladie de Basedow dans le service de médecine nucléaire de l’hôpital Ibn Sina de Rabat

One hundred and twenty-nine Grave's Basedow diseases in any gender and variable age patients, coming from several cities of Morocco, were randomized in a study of radio-iodine treatment who took place at the nuclear medicine department of Ibn Sina Hospital (Rabat, Morocco) during the period (from January 2001 to December 2008). The radio-iodine treatment was a first, second or third option and radio-iodine activities delivered varied (from 222 to 555 MBq 6 to 15 mCi) according to the age, the thyroid volume, the degree of hyperthyroidism and socio-economical situation. The high amounts of ¹³¹I were reserved especially to the patients who live far and whose socio-economic level is low with an aim of quickly obtaining an easily controllable state of hypothyroidism by a substitute treatment. The results showed that: (1) 57.36% of patients reverted to euthyroïdism (n = 74) with a patient having received two ¹³¹I cures. The second cure was justified by recurrence of hyperthyroidism after the first cure; (2) 34.88% passed in hypothyroidism (n = 45) with three patients having received two cures of ¹³¹I, the second cure was justified by recurrence of hyperthyroidism after the first cure in two patients and by the persistence of the hyperthyroidism after the first cure for the third patient. The average time of passage in hypothyroidism was 4.5 months; (3) 7.76% had remained in hyperthyroidism after the radioactive iodine treatment. Finally, 92.24% of our patients treated by radioactive iodine had passed in euthyroïdism or hypothyroidism against 7.76% whose hyperthyroidism had persisted or occurred.     

Intérêt de l’utilisation de la scintigraphie osseuse dans le diagnostic et le suivi de l’ostéochondrite primitive de la hanche

Osteochondritis, or Legg-Calvé-Perthes disease (LCP), is a necrosis of the proximal femoral epiphysis. This vascular accident entails on the complex phenomenon of growth of the child's hip and can result in deformations or even a strict destruction of the proximal femoral epiphysis. The aim of this article is to show the interest of the bone scintigraphy (BS) in precocious diagnosis and follow-up of LCP disease. In this aim, we introduced a clinical case of LCP disease where BS allowed a precocious diagnosis and a strigent monitoring. Discussion of case includes a systematic review of literature.     

Hyperparathyroïdie par autonomisation d’une autogreffe de parathyroïde dans l’avant-bras : le rôle de la scintigraphie

We report the case of a 36-year old patient, referred for parathyroid imaging in a context of hyperparathyroidism. He had a history of congenital bilateral renal hypoplasia treated by four successive transplantations, the last one in July 2011. In 1990, a total parathyroidectomy with autologous parathyroid tissue graft in the right forearm has been performed for secondary hyperparathyroidism. However, hypocalcaemia persisted (2.78 mmol/L), associated with high levels of PTH (1329 pg/mL), even after the last renal transplantation. Neck ultrasound and parathyroid scintigraphy images did not show any cervical or thoracic ectopic parathyroid tissue, while right forearm incidences revealed a high uptake focus corresponding to the autonomisation of the parathyroid transplanted tissue. A brief review of the literature evaluating the benefits of this type of intervention is presented.     

Contrôle neurologique de l’éjaculation

The brain control of the genital tract and sexual behaviour remains poorly understood. Clinical results and basic research indicate that the neural control of ejaculation depends on three levels of organization. The first level consists of peripheral autonomic and somatic nerves. Leaving the spinal cord, these nerves control the motility, secretions and blood supply of the genital tract, and contractions of perineal striated muscles. Their path in the abdominal cavity and the effects of their neuro-transmitters on peripheral tissues have been established. These nerves also convey sensory information from the genital tract to the spinal cord. The second level is represented by the spinal cord. The thoracolumbar (sympathetic), and sacral (parasympathetic and pudendal) segments of the cord contain the somata of autonomic and somatic motoneurons, whose axons run in the above nerves. These motoneurons are part of a spinal network that likely organizes the activity of the whole genital tract in a given context such as copulation. The role of the different spinal cord segments in the control of ejaculation is mainly inferred from observations of the deleterious effects of spinal cord injury in human patients. A small population of galaninergic positive neurons has recently been identified in the lumbar segments of the rat spinal cord that plays a major role in ejaculation (Truitt and Coolen, 2003). Selective lesion of this population abolishes in copula ejaculations, but spares erection. Finally, the third level of organization is represented by supraspinal nervous structures. The spinal cord receives direct excitatory and inhibitory information from the brainstem, pons and hypothalamus. In turn, these structures receive sensory information from the genital tract. However, their role in the control of ejaculation remains poorly investigated. Again, it is mainly inferred from the observation of the deleterious effects of pharmacological treatments on brain neurotransmission. Positron emission tomography has recently been used to observe brain areas whose activity is enhanced during ejaculation in humans (Holstege et al., 2003). In this study, several areas of the right side of the cortex and the cerebellum were activated. The targets of future clinical and basic research include: the neural basis of the required coordination between spinal autonomic and somatic nuclei that innervate the genital tract, the role of sensory information from the genital tract in the recruitment and coordination of spinal and supraspinal nuclei, and finally the integration of descending excitatory and inhibitory influences onto the spinal cord. Both the organization during development and the activation at puberty of the spinal neural network that controls the genital tract are dependent on androgens. Future research should identify the regulatory factors that, in response to the action of androgens, provide neurons with the possibility of building their connexions and selecting their neurotransmitters and receptors.     

Rôle du sens de l’effort dans le syndrome d’influence

Centrally generated signals from premotor areas play a key role in voluntary muscle force perception. Indeed, sensations of effort, rather than sensations of intramuscular tension, make it possible to evaluate the intensity of willed muscle forces. We suggest that the sense of effort is involved in agency, the cognitive process by which one is aware of one’s actions. We argue that effort awareness accompanies each action and is the key component of the feeling of will. In delusions of alien control, patients with schizophrenia do not recognize some of their acts as their own and are convinced that they are under the control of someone else. Some experimental data suggest that delusions of control are related to an altered awareness of effort and an exaggerated awareness of afferent neural information, caused by neurological disorders in the frontal and parietal lobes. This impairment could lead to the inability to identify the author of an action. In this pathological condition, the cerebral state coding for “I intend to act” might move toward the state coding for “someone else intends to act”, even in the absence of another agent.     

Le contrôle de qualité externe en Biologie de la Reproduction de 1992 à 1996

Clinical efficiency of laboratory results in spermiology needs to have reliable data, and a quality assurance in their determinations. This could be done by creating an External Quality Control, each laboratory analyzing the same specimens. We transferred in spermiology methodologies currently used in Quality Control in Biochemistry and results presented here referred to the 1992–1996 period. Volountary participation of 37 laboratories who recieved two slides issuing from the same ejaculate. Coloration was made with that used in their own laboratory. Two parameters were specially studied: the total normal sperm count and the degree of teratospermia by evaluation of the Multiple Abnormalities Index (MAI). An area around the target value of 15% is actually retained and results in terms of precision and accuracy are interpreted with the Youden’s diagram. For the total normal sperm count, the disperson remains important during the 4 years (about 30 and 40%) with a poor percentage of laboratories in the area of accuracy. For the MAI, results are better as soon as the dispersion falls from 25 to 15% during the same time and the percentage of laboratories in the accuracy area rises from 10% to 68%. After four years of external quality control, such a protocol is very useful. But the quality results of some parameters must be more extensively explored to reduce interlaboratory dispersion and to improve the clinical efficiency of laboratory data in the spermiology approach.     

Sur le déterminisme de la formation de la grappe chez les abeilles

Conclusion Il existe une interattraction vraie chez les ouvrières d'Apis mellifica. Cette interattraction a pour point de dépárt un stimulus complexe pour une part de nature vibratoire et pour l'autre de nature olfactive.Le point de départ du stimulus olfactif se situe dans l'abdomen. Enfin pour que le stimulus soit perçu d'une manière efficace par l'abeille il faut que celle-çi soit intégrée à un groupe suffisamment nombreux.     

Problematique de réalisation des projets de biométhanisation dans le secteur agro-industriel: cas de l'abattoir de Dakar

Résumé Chaque jour 130 m³ d'eaux résiduaires de l'abattoir de Dakar sont évacués à la mer. Ces eaux contiennent les matières stercoraires des animaux abattus (9.5 tonne/jour), les eaux de lavage et les graisses. Les besoins en énergie de l'abattoir sont de deux types: électricité et eau chaude. L'électricité alimente les chambres frigorifiques à raison de 90% et représente une facture annuelle de 50 millions de francs CFA. L'eau chaude est utilisée pour l'échaudage de porcs: 3 m³ à 60°C sont produits par jour par cuisson sur feu de bois. La facture qui en résulte est de 450 000 francs CFA.

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Summary Every day more than 130 m³ of wastewaters from the Dakar municipal slaughterhouse are disposed off in the ocean. These waters comprise mainly stercoral matters, washing waters and greases. The energy requirements in the slaughterhouse are mainly of two types: electricity and heated water. Electricity is used to operate the refrigerating rooms, which corresponds to a total cost per year of 50 million CFA. Heated water is used for the pigs scalding with a bare 3 m³ of water used per day, at a temperature 60°C, obtained with fuel wood, the annual costs of which amounts to 450 000 CFA.

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Resumen Cada día más de 130 cm³ de aguas residuales del matadero municipal de Dakar se vierten al oceano. Estas aguas consisten principalmente en estiércoles, aguas de lavado y grasas. Los requerimientos energéticos del matadero son principalmente de dos tipos: electricidad y agua caliente. La electricidad se usa para las cámaras frigoríficas con un coste total de 50 millones de CFA anuales. El agua caliente se utiliza para escaldar cerdos con una media de 3 m³ de agua por día a una temperatura de 60°C, se calienta mediante carburante vegetal, con un coste anual de 450000 CFA.

     

Apport de l’embolisation de la varicocèle chez 51 patients infertiles

This study evaluated the changes induced on the parameters of the sperm count four months after sclero-embolization of varicocele. From February 1993 to February 2000, 51 infertile patients with testicular hypotrophy or oligospermia were treated by percutaneous sclero-embolization of varicocele. All patients underwent preoperative diagnostic evaluation by semen analysis, Doppler flowmetry or color Doppler ultrasound and venography. Scrotal ultrasound was performed to evaluate the echogenicity of the testes, their volume and funicular vein enlargement during Valsalva manoeuvre. Patients were reviewed four months after sclero-embolization with semen analysis. Clinical follow-up showed complete resolution of the varicocele in 94% of cases (47 patients), while the varicocele persisted in two cases. In 2% of cases (1 patient), selective catheterization of the internal spermatic vein was impossible. Four months later, analysis of semen parameters showed an increased number of spermatozoa. In 69.4% of oligospermic cases, the sperm count was at least tripled. The time-course of the sperm count (average) was as follows: in a total of 50 patients with pre- and post-embolization evaluation, sperm count increased from 19.6 106/ml to 26.7 106/ml. In the population of 36 patients with a sperm count <20 106/ml (i.e. with oligospermia or azoospermia), the sperm count increased from 3 106/ml to 14.6 106/ml. In the subgroup of patients with oligospermia (1–20.106/ml), the sperm count increased (p<0.01) from 5.32 106/ml to 22.32 106/ml; in the subgroup of patients with severe oligospermia (0–1 106/ml), the sperm count increased (p<0.01) from 0.188 106/ml to 3.5 106/ml. Semen analysis was improved in 1 of the 4 patients with azoospermia. In conclusion, sclero-embolization improved sperm count in this population of infertile patients with varicocele and testicular hypotrophy. In vitro fertilization or intra-uterine insemination can therefore be considered in the place of ICSI.