The Fast and One-Step Growth of ZnO Nanorods on Cellulose Nanofibers for Highly Sensitive Photosensors

Cellulose is the most abundant organic material on our planet which has a key role in our daily life (e.g., paper, packaging). In recent years, the need for replacing fossil-based materials has expanded the application of cellulose and cellulose derivatives including into electronics and sensing. The combination of nanostructures with cellulose nanofibers (CNFs) is expected to create new opportunities for the development of innovative electronic devices. In this paper, we report on a single-step process for the low temperature (<100 °C), environmentally friendly, and fully scalable CNF-templated highly dense growth of zinc oxide (ZnO) nanorods (NRs). More specifically, the effect of the degree of substitution of the CNF (enzymatic CNFs and carboxymethylated CNFs with two different substitution levels) on the ZnO growth and the application of the developed ZnO NRs/CNF nanocomposites in the development of UV sensors is reported herein. The results of this investigation show that the growth and nature of ZnO NRs are strongly dependent on the charge of the CNFs; high charge promotes nanorod growth whereas with low charge, ZnO isotropic microstructures are created that are not attached to the CNFs. Devices manufactured via screen printing/drop-casting of the ZnO NRs/CNF nanocomposites demonstrate a good photo-sensing response with a very stable UV-induced photocurrent of 25.84 µA. This also exhibits excellent long-term stability with fast ON/OFF switching performance under the irradiance of a UV lamp (15 W).

An innovative strategy for personalised medicine in a CFSPID case that evolved with time

We present a challenging case that illustrates how the clinical manifestations in children with CFTR mutations of uncertain significance may change over time. This case highlights the evolution of confirming a diagnosis of CF and emphasises the importance of regular review and monitoring of this patient cohort.

Cross-Sections of Nanocellulose from Wood Analyzed by Quantized Polydispersity of Elementary Microfibrils

Bio-based nanocellulose has been shown to possess impressive mechanical properties and simplicity for chemical modifications. The chemical properties are largely influenced by the surface area and functionality of the nanoscale materials. However, finding the typical cross-sections of nanocellulose, such as cellulose nanofibers (CNFs), has been a long-standing puzzle, where subtle changes in extraction methods seem to yield different shapes and dimensions. Here, we extracted CNFs from wood with two different oxidation methods and variations in degree of oxidation and high-pressure homogenization. The cross-sections of CNFs were characterized by small-angle X-ray scattering and wide-angle X-ray diffraction in dispersed and freeze-dried states, respectively, where the results were analyzed by assuming that the cross-sectional distribution was quantized with an 18-chain elementary microfibril, the building block of the cell wall. We find that the results agree well with a pseudosquare unit having a size of about 2.4 nm regardless of sample, while the aggregate level strongly depends on the extraction conditions. Furthermore, we find that aggregates have a preferred cohesion of phase boundaries parallel to the (110)-plane of the cellulose fibril, leading to a ribbon shape on average.

Highly Conducting Nanographite-Filled Paper Fabricated via Standard Papermaking Techniques

Eco-friendly and cost-effective materials and processes to manufacture functional substrates are crucial to further advance the area of printed electronics. One potential key component in the printed electronics platform is an electrically functionalized paper, produced by simply mixing common cellulosic pulp fibers with high-performance electroactive materials. Herein, an electronic paper including nanographite has been prepared using a standardized and scalable papermaking technique. No retention aid was needed to achieve a conducting nanographite loading as high as 50 wt %. The spontaneous retention that provides the integrity and stability of the nanographite paper, likely originates partially from an observed water-stable adhesion of nanographite flakes onto the fiber surfaces. The resulting paper exhibits excellent electrical characteristics, such as an in-plane conductivity of 107 S/cm and an areal capacitance of 9.2 mF/cm², and was explored as the back-electrode in printed electrochromic displays.

Inducing nematic ordering of cellulose nanofibers using osmotic dehydration

The formation of nematically-ordered cellulose nanofiber (CNF) suspensions with an order parameter f_max≈ 0.8 is studied by polarized optical microscopy, small-angle X-ray scattering (SAXS), and rheological measurements as a function of CNF concentration. The wide range of CNF concentrations, from 0.5 wt% to 4.9 wt%, is obtained using osmotic dehydration. The rheological measurements show a strong entangled network over all the concentration range whereas SAXS measurements indicate that at concentrations >1.05 wt% the CNF suspension crosses an isotropic-anisotropic transition that is accompanied by a dramatic increase of the optical birefringence. The resulting nanostructures are modelled as mass fractal structures that converge into co-existing nematically-ordered regions and network-like regions where the correlation distances decrease with concentration. The use of rapid, upscalable osmotic dehydration is an effective method to increase the concentration of CNF suspensions while partly circumventing the gel/glass formation. The facile formation of highly ordered fibers can result in materials with interesting macroscopic properties.

Assembly of cellulose nanocrystals in a levitating drop probed by time-resolved small angle X-ray scattering

Assembly of bio-based nano-sized particles into complex architectures and morphologies is an area of fundamental interest and technical importance. We have investigated the assembly of sulfonated cellulose nanocrystals (CNC) dispersed in a shrinking levitating aqueous drop using time-resolved small angle X-ray scattering (SAXS). Analysis of the scaling of the particle separation distance (d) with particle concentration (c) was used to follow the transition of CNC dispersions from an isotropic state at 1-2 vol% to a compressed nematic state at particle concentrations above 30 vol%. Comparison with SAXS measurements on CNC dispersions at near equilibrium conditions shows that evaporation-induced assembly of CNC in large levitating drops is comparable to bulk systems. Colloidal states with d vs. c scalings intermediate between isotropic dispersions and unidirectional compression of the nematic structure could be related to the biphasic region and gelation of CNC. Nanoscale structural information of CNC assembly up to very high particle concentrations can help to fabricate nanocellulose-based materials by evaporative methods.

Active learning improves on-task behaviors in 4th grade children

While increased opportunities for physical activity (PA) are a critical, public health need for children, school-based interventions often place teachers in the position to choose between PA and time spent on academic lessons. Active learning is designed to overcome this by combining PA with academic material. Moreover, teachers are likely to be more responsive to change in academic-related outcomes than in PA. This study utilizes a large, cluster randomized control trial in which student attention, or time on task (TOT) and accelerometer-based PA is assessed in conjunction with active learning. Participants were 2716 children (46% male, 46% white) from 28 elementary schools in Central Texas that were assigned to either: 1) active learning (math n = 10; spelling n = 9); or 2) traditional, sedentary academic lessons (n = 9). PA was measured with accelerometers. TOT was measured through a momentary time sampling protocol. A series of three-level (student, classroom, school) regression models estimated the effect of the intervention. The intervention lead to significantly increased TOT. Moreover, the dose of PA (steps) during the intervention was positively associated with the increase in TOT. In contrast, a greater dose of PA was associated with reduced TOT for students in control schools. Race, gender, and SES did not moderate these effects. Planned PA - as a part of an active, academic lesson - positively impacted TOT. In contrast, a traditional, sedentary lesson was associated with lower TOT. This differential impact offers intriguing possibilities to better understand the relationship between PA and academic performance.

Formation of Colloidal Nanocellulose Glasses and Gels

Nanocellulose (NC) suspensions can form rigid volume-spanning arrested states (VASs) at very low volume fractions. The transition from a free-flowing dispersion to a VAS can be the result of either an increase in particle concentration or a reduction in interparticle repulsion. In this work, the concentration-induced transition has been studied with a special focus on the influence of the particle aspect ratio and surface charge density, and an attempt is made to classify these VASs. The results show that for these types of systems two general states can be identified: glasses and gels. These NC suspensions had threshold concentrations inversely proportional to the particle aspect ratio. This dependence indicates that the main reason for the transition is a mobility constraint that, together with the reversibility of the transition, classifies the VASs as colloidal glasses. If the interparticle repulsion is reduced, then the glasses can transform into gels. Thus, depending on the preparation route, either soft and reversible glasses or stiff and irreversible gels can be formed.

Optimal strengthening of particle-loaded liquid foams

Foams made of complex fluids such as particle suspensions have a great potential for the development of advanced aerated materials. In this paper, we study the rheological behavior of liquid foams loaded with granular suspensions. We focus on the effect of small particles, i.e., particle-to-bubble size ratio smaller than 0.1, and we measure the complex modulus as a function of particle size and particle volume fraction. With respect to previous work, the results highlight a new elastic regime characterized by unequaled modulus values as well as independence of size ratio. A careful investigation of the material microstructure reveals that particles organize through the network between the gas bubbles and form a granular skeleton structure with tightly packed particles. The latter is proven to be responsible for the reported new elastic regime. Rheological probing performed by strain sweep reveals a two-step yielding of the material: The first one occurs at small strain and is clearly attributed to yielding of the granular skeleton; the second one corresponds to the yielding of the bubble assembly, as observed for particle-free foams. Moreover, the elastic modulus measured at small strain is quantitatively described by models for solid foams in assuming that the granular skeleton possesses a bulk elastic modulus of order 100 kPa. Additional rheology experiments performed on the bulk granular material indicate that this surprisingly high value can be understood as soon as the magnitude of the confinement pressure exerted by foam bubbles on packed grains is considered.

[Profil course of SC sickle-cell patients in Dakar: a case-control study with SS sickle cell form]

AIMS

The study aim to describe the epidemiological, clinico-biological and evolutionary aspects of SC sickle cell patients compared to SS sickle cell disease.

PATIENTS AND METHODS

We realized a case-control study of 12 months duration including 98 major sickle cell patients (49 SC and 49 SS sickle cell patients). SS sickle cell patients were randomly selected according to age and sex. Socio-demographic, clinico-biological and evolutionary data were noted for each patient.

RESULTS

Mean age was 24.7 years (5 - 53). Sex ratio was 0.8. Mean number of transfusions was 0.06 of SC patients and 0.34 for SS patients (p=0.0008). Mean number of vaso-occlusive crisis per year was 2.24 of SC patients and 2.37 of SS patients (p=0.3). Mean basic hemoglobin level was 10.8 of SC patients and 7.8 of SS patients (p=0.0000). Priapism was found in 2.04% of SC patients and 4.04% of SS patients (p=0.3) and acute anemia in 2.04% of SC and 24.48% of SS patients (p=0.003); 26.53% of SC patients had a chronic complication compared to 18.36% of SS patients (p=0.0001).

CONCLUSION

This study shows that SC sickle cell patients are less symptomatology compared to SS patients, however they would develop more chronic complications from where the utility for regular follow-up.

Two-Dimensional Aggregation and Semidilute Ordering in Cellulose Nanocrystals

The structural properties and aggregation behavior of carboxymethylated cellulose nanocrystals (CNC-COOH) were analyzed with small angle neutron scattering (SANS), transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic light scattering (DLS) and compared to sulfuric acid hydrolyzed cellulose nanocrystals (CNC-SO3H). The CNC-COOH system, prepared from single carboxymethylated cellulose nanofibrils, was shown to laterally aggregate into 2D-stacks that were stable both in bulk solution and when adsorbed to surfaces. CNC-SO3H also showed a 2D aggregate structure with similar cross sectional dimensions (a width to height ratio of 8) as CNC-COOH, but a factor of 2 shorter length. SANS and DLS revealed a reversible ordering of the 2D aggregates under semidilute conditions, and a structure peak was observed for both systems. This indicates an early stage of liquid crystalline arrangement of the crystal aggregates, at concentrations below those assessed using birefringence or polarized optical microscopy.

Exposition par réalité virtuelle : une approche plus sereine pour nos patients ?

Depuis une vingtaine d’années, on assiste au développement de la réalité virtuelle dans le domaine de la psychopathologie. Elle se définit comme une application permettant à un utilisateur de naviguer et d’interagir en temps réel avec un environnement en trois dimensions généré par un ordinateur [1]. Grâce à cette technologie, les difficultés rencontrées dans les techniques d’exposition de TCC habituelles peuvent être contrées. L’environnement virtuel permet, par exemple, de contrôler les imprévus, d’être exposé à certaines peurs pouvant être difficiles à reproduire en situation réelle, et garantit une meilleure confidentialité [2]. Nous avons acquis, il y a peu un logiciel de thérapie par réalité virtuelle pour les troubles anxieux. Le patient est plongé dans un environnement virtuel relativement proche des situations anxiogènes réelles. Il est progressivement désensibilisé par une exposition virtuelle répétée, prolongée et complète. De nombreuses études ont déjà prouvé l’efficacité de ce genre d’exposition [3]. Nous pensons que cet outil permettrait aux patients d’aborder de manière plus sereine les séances d’exposition. Notre projet d’étude est de présenter à des anxieux sociaux deux techniques d’exposition : in vivo et in virtuo. Dans les deux situations, les sujets sont amenés à faire face à un groupe de personnes : « réelles » (groupe thérapeutique dans la clinique où a lieu l’étude) ou « virtuelle » (salle de classe avec des étudiants, dans l’environnement virtuel). Leur niveau d’anxiété avant chaque séance est évalué grâce à l’inventaire d’anxiété état-trait de Spielberger. Ce poster présente les premiers résultats de l’étude, qui est en cours.

Macroscopic discontinuous shear thickening versus local shear jamming in cornstarch

We study the emergence of discontinuous shear thickening (DST) in cornstarch by combining macroscopic rheometry with local magnetic resonance imaging measurements. We bring evidence that macroscopic DST is observed only when the flow separates into a low-density flowing and a high-density jammed region. In the shear-thickened steady state, the local rheology in the flowing region is not DST but, strikingly, is often shear thinning. Our data thus show that the stress jump measured during DST, in cornstarch, does not capture a secondary, high-viscosity branch of the local steady rheology but results from the existence of a shear jamming limit at volume fractions quite significantly below random close packing.

[The primary pulmonary MALT lymphoma: a rare lung tumor]

The primary pulmonary lymphoma is a rare disease, representing 0.5 to 1% of the malignant lung tumors. In our countries, in spite of the increasing prevalence of the pulmonary tumors, aggravated by smoking and environmental factors, any case report of the primary pulmonary lymphoma is notified. We report a confirmed case of MALT lung lymphoma that is managed in our hospital. Mr. S.B., 68-year-old man, not smoking, without particular professional exhibition, is admitted for a chronic cough with blood-streaked sputum, dyspnea, chest pain and loss of weight. His symptomatology is evolving for 4months. In the examination, the general health was passable and he presented a pulmonary condensation syndrome at right. The physical examination of others systems was normal. There was a biological inflammatory syndrome. The bacteriological examinations of the bronchial expectorations were negative. The chest CT showed bilateral alveolar opacities at the upper, with attraction of the fissures, without nodes. The bronchoscopy showed anomalies of the bronchial mucous membrane in 2 superior lobes. The perendoscopiques biopsies confirmed a MALT lung lymphoma. We did not find other localizations. Chemotherapy was proposed to our patient with favorable evolution. The MALT primary lung lymphoma must not be underestimated. Clinical manifestations and radiological characteristics are no specific and it's necessary to eliminate a lung cancer or tuberculosis in our countries. The difficulties of their diagnostic are intensified by the not availability of an adequate technical tray.

Sliding friction on wet and dry sand

We show experimentally that the sliding friction on sand is greatly reduced by the addition of some-but not too much-water. The formation of capillary water bridges increases the shear modulus of the sand, which facilitates the sliding. Too much water, on the other hand, makes the capillary bridges coalesce, resulting in a decrease of the modulus; in this case, we observe that the friction coefficient increases again. Our results, therefore, show that the friction coefficient is directly related to the shear modulus; this has important repercussions for the transport of granular materials. In addition, the polydispersity of the sand is shown to also have a large effect on the friction coefficient.

Closed loop obstruction: pictorial essay

Closed loop obstruction occurs when a segment of bowel is incarcerated at two contiguous points. The diagnosis is based on multiple transitional zones. The incarcerated loops appear in U or C form or present a radial layout around the location of the obstruction. It's very important to specify the type of obstruction because, in patients with simple bowel obstruction, a conservative approach is often advised. On the other hand, a closed loop obstruction immediately requires a surgical approach because of its high morbidity and the risk of death in case of a late diagnosis.

Dissipation in quasistatically sheared wet and dry sand under confinement

We investigated the stress-strain behavior of sand with and without small amounts of liquid under steady and oscillatory shear. Since dry sand has a lower shear modulus, one would expect it to deform more easily. Using a new technique to quasistatically push the sand through a tube with an enforced parabolic (Poiseuille-like) profile, we minimize the effect of avalanches and shear localization. We observe that the resistance against deformation of the wet (partially saturated) sand is much smaller than that of the dry sand, and that the latter dissipates more energy under flow. This is also observed in large-amplitude oscillatory shear measurements using a rotational rheometer, showing that the effect is robust and holds for different types of flow.

[Assisted reproductive technoloy: indications and perceptions among couples presenting for infertility at Dakar University Hospital]

AIMS

To identify, among the cases of sterility, the indications for assisted reproductive technology to analyze the knowledge, attitudes and perceptions regarding ART among patients consulted for infertility

PATIENTS AND METHODS

A retrospective analysis of 1718 files of infertile patients, selecting the cases likely to recover from ART completed by an individual and anonymous survey assessing knowledge regarding ART techniques among 209 patients seeking infertility consultation.

RESULTS

Among women, cervico-vaginal (26.7%) and tubal (20.9%) etiological factors were the predominating causes of infertility. Among men, azoospermatozoa was the predominant cause of infertility (24.5%). The indications for ART were estimated at 98.8% of cases: 3.14% indicated for artificial insemination, 95.7% for in-vitro fertilization. Around 18.21% of couples could have conceived with the assistance of these methods, compared to 3.8% of pregnancies obtained without ART. Among interviewed couples, a favorabl, perception of ART was found: although the majority of patients (78.9%) were ready to resort to ART, only 24.9% of interviewed women were in a position to mobilize required resources.

CONCLUSION

Advocacy for the feasibility of ART in the public hospital setting should be supported by the potential indications of modern technology demonstrated in this study.

Procalcitonin for early prediction of survival outcome in postoperative critically ill patients with severe sepsis

BACKGROUND

Identification of postoperative patients at high risk of dying early after intensive care unit (ICU) admission through a fast and readily available parameter may help in determining therapeutic interventions or further diagnostic procedures that could have an impact on patients' outcome. The aim of our study was to assess the utility of procalcitonin (PCT) and other readily available parameters, as useful early (days 1-3) predictors of mortality in postoperative patients diagnosed with severe sepsis within 24 h preceding their operation.

METHODS

More than a period of 2 yr, subsets of 69 postoperative patients admitted with severe sepsis and 890 non-septic ICU patients were investigated. PCT, C-reactive protein (CRP) and sequential organ failure assessment (SOFA) score were recorded over the duration of ICU stay.

RESULTS

PCT area under receiver operating characteristic (ROC) curve was 0.78 on day 3 and was highly predictive of fatal outcome (0.90) at day 6. Area under ROC curve of SOFA score was 0.85 on day 3 and remained in this range until day 6. Area under ROC curves on day 3 of CRP (0.61) was non-predictive and remained non-predictive over the duration of ICU stay.

CONCLUSIONS

PCT exhibited no discriminative power early after ICU admission for prediction of mortality in critically ill patients with severe sepsis, compared with a high predictive power of SOFA score on day 3. However, using PCT could still serve as a useful complementary comparator for prediction of survival outcome using the SOFA score.

Public-health impact of accelerated measles control in the WHO African Region 2000-03

BACKGROUND

In 2000, the WHO African Region adopted a plan to accelerate efforts to lower measles mortality with the goal of decreasing the number of measles deaths to near zero. By June, 2003, 19 African countries had completed measles supplemental immunisation activities (SIA) in children aged 9 months to 14 years as part of a comprehensive measles-control strategy. We assessed the public-health impact of these control measures by use of available surveillance data.

METHODS

We calculated percentage decline in reported measles cases during 1-2 years after SIA, compared with 6 years before SIA. On the basis of data from 13 of the 19 countries, we assumed that the percentage decline in measles deaths equalled that in measles cases. We also examined data on routine and SIA measles vaccine coverage, measles case-based surveillance, and suspected measles outbreaks.

FINDINGS

Between 2000 and June, 2003, 82.1 million children were targeted for vaccination during initial SIA in 12 countries and follow-up SIA in seven countries. The average decline in the number of reported measles cases was 91%. In 17 of the 19 countries, measles case-based surveillance confirmed that transmission of measles virus, and therefore measles deaths, had been reduced to low or very low rates. The total estimated number of deaths averted in the year 2003 was 90,043. Between 2000 and 2003 in the African Region as a whole, we estimated that the percentage decline in annual measles deaths was around 20% (90,043 of 454,000).

INTERPRETATION

The burden of measles in sub-Saharan Africa can be reduced to very low levels by means of appropriate strategies, resources, and personnel.

[Effects of Ramadan fast on weight, performance and glycemia during training for resistance]

INTRODUCTION

Pysical activity and sports training can be proved exhausted for the organism during normal alimentation period. These sensations may go on more pronounced during Ramadan, period of complete fast marked by an absence of energetic and hydroelectrolytic supply. Our propose was to evaluate the impact of Ramadan on weight, performance and glycaemia during a training for resistance.

MATERIALS AND METHODS

Ten Senegalese males 200 and 400 meters runners aged 24.4 +/- 6 years old had two training sessions, one during the Ramadan and the other during normal non fast time. The 200 meters runners had executed each one two series of 3 x 150 m, and the 400 meters runners executed one serie of 3 x 250 m. These parameters have been measured respectively by a SECA scales, a PC 70 A chronometer, and a capillary glycaemia reader.

RESULTS

During Ramadan the weights a nd performances of our athletes decreased significantly (0.01 > p > 0.001) with race intensities equal to or slightly higher than those of competition, requiring anaerobic glycolysis. We found severe hypoglycaemia mainly before the training session, 10 hours after the last meal. We found no severe hypoglycaemia in normal non-fast time. Therefore all differences in average glycaemia rates in each testing case (except between the morning and after training in time of complete fast) a nd between them, a re significant. The performance fall is the conjugation of the blood sugar rate collapse a nd recovery.

CONCLUSION

A balance diet with high content of carbon hydrates is a dvisable to prevent h ypoglycaemia that c an a dversely affect the health of fasting sportsman training for resistance.

EphA/ephrin-A interactions during optic nerve regeneration: restoration of topography and regulation of ephrin-A2 expression

During visual system development, interactions between Eph tyrosine kinase receptors and their ligands, the ephrins, guide retinal ganglion cell (RGC) axons to their topographic targets in the optic tectum. Here we show that Eph/ephrin interactions are also involved in restoring topography during RGC axon regeneration in goldfish. Following optic nerve crush, EphA/ephrin-A interactions were blocked by intracranial injections of recombinant Eph receptor (EphA3-AP) or phospho-inositol phospholipase-C. Topographic errors with multiple inputs to some tectal loci were detected electrophysiologically and increased projections to caudal tectum demonstrated by RT-97 immunohistochemistry. In EphA3-AP-injected fish, ephrin-A2-expressing cells in the retino-recipient tectal layers were reduced in number compared to controls and their distribution was no longer graded. The findings, supported by in vitro studies, implicate EphA/ephrin-A interactions in restoring precise topography and in regulating ephrin-A2 expression during regeneration.

Human water contacts patterns in Schistosoma mansoni epidemic foci in northern Senegal change according to age, sex and place of residence, but are not related to intensity of infection

In an epidemic focus in northern Senegal, adults had lower intensities of infection than adolescents, a phenomenon that could not be attributed to immunity acquired over the previous 10-15 years of exposure to the parasite because all age groups had had the same number of years' experience of the worm. This article considers whether this pattern could have been because of higher levels of exposure to the parasite in younger age groups. Personal contact with infected water was recorded using a questionnaire in Schistosoma mansoni foci not more than 3 years old and in another, 10-year-old focus. Many aspects of contact (e.g. frequency, duration or time of day of contact) may contribute to the number of encounters with infective cercariae (true exposure), so various assumptions regarding the relationship between water contact and true exposure were tested resulting in a range of exposure indices. People reported a mean of 4.4 separate contacts, and spent a median of 57 min per day in water. Patterns of water contact differed depending on the exposure index used, e.g. considering duration, males spent a longer time in water than females (P < 0.001). But using frequency, females had more contacts with water than males in most villages (P < 0.001). Generally, exposure levels dropped as people become aged (P < 0.001) and residents of the older focus were more exposed than residents of other foci (P < 0.002). Intensity of (re)infection was not related to exposure either alone or in models incorporating age, sex and/or village irrespective of the index used. There is therefore evidence that age, sex and place of residence determine exposure but none to suggest that exposure had an influence on the relationship between these factors and intensity of infection. We propose therefore that in this population other factors have principal importance in determining intensity of infection.

[Complicated parathyroïd adenoma. A case report]

Parathyroid adenoma is the first etiology of primary hyperparathyroidism althrough the majority of patients with primary hyperparathyroidism have a relatively asymptomatic benign disorder. There are patients who have a more aggressive disorder. We report a case of 41 years old man whose primary hyperparathyroidism was discovered through exploration of recurrent ureteral stone associated with severe hypertension. The diagnosis was set up on high level serum calcium and low serum phosphorus with very elevated level of parathyroid hormone. Adenome was localised by ultrasound examination. The patient underwent successfully surgery and the pathological study confirm the diagnosis. This case illustrate the importance of investing earlier ureteral recurrent stone to prevent severe complications of primary hyperparathyroidism.

[Bicycle test: measure of anaerobic power, heart rate and blood lactic acid]

Seven sportsmen, 100 meters and 400 meters runners are submitted to an effort test of 30 seconds. The subjects are on average 23.7 +/-2 years old. The purpose of our work is to study on the one hand the evlution of the anaerobic power. the heart rate and the lactic acid in blood during and after a bicycle test. and their relation, and on the other hand. to know the suitable pratical importance of the heart rate and the lactic acid in blood in connection with the intermittent efforts recovery aiming the anaerobic power developpement. These physiological parameters have been measured by a Monark bicycle 864, a sport-tester PE 3000 and a spectrophotometer JASCO 7800 UV/VIS. The power and the heart rate increase quickly in the 5 first seconds. Our subjects reach their average maximal anaerobic power at the 10th second, and then this power decreases progressively, while the heart rate continues to increase, without being maximal at the end of te test. Five minutes later it decreases in a half, while the lactic acid level calculated at the 30th second is continuing significantly. We have not found a significant relation between the measured parameters at the test stopping and during the recovery period (except between the lactic acid and the recovery index of the heart rate at the 25th minute). The lactic acid in blood would inform better about a good recovery during an interval training effort.

Single-tube and nested reverse transcriptase-polymerase chain reaction for detection of Rift Valley fever virus in human and animal sera

Rift Valley fever (RVF) is an anthropozoonosis caused by a Phlebovirus (Bunyaviridae family) that has re-emerged recently in East and West Africa in 1997-1998. This emphasizes the need for early and rapid detection of the virus and an efficient surveillance system. To this goal, a single tube or a nested reverse transcriptase-polymerase chain reaction (RT-PCR) method focusing on the NSs coding region of the S segment was developed and used to detect the RVF virus (RVFV) genome, resulting respectively in the synthesis of 810 and 662 bp DNA amplimers. The assay was specific for RVFV and did not amplify any other phleboviruses known to circulate in sub-Saharan Africa. When serial dilutions of RVFV were artificially mixed with human normal serum, the minimal detection limits were 50 and 0.5 plaque forming units respectively using the simple and the nested RT-PCR. The RT-PCR method was efficient for the detection of RVFV RNA in the blood from experimentally RVFV-infected mice and lamb and the nested RT-PCR was found more sensitive than the virus isolation method. Additionally, this detection method was applied successfully for the diagnosis of human cases during the 1998 Mauritanian outbreak.

Cryptosporidium spp. in domestic dogs: the "dog" genotype

Genetic and phylogenetic characterization of Cryptosporidium isolates at two loci (18S rRNA gene and heat shock gene) from both Australian and United States dogs demonstrated that dog-derived Cryptosporidium isolates had a distinct genotype which is conserved across geographic areas. Phylogenetic analysis provided support for the idea that the "dog" genotype is, in fact, a valid species.

Investigation of the child with interstitial lung disease

Many disorders can affect the pulmonary interstitium in children. Although individual interstitial lung diseases are rare, the range of conditions encountered is wide. Interstitial disease is also seen increasingly as a consequence of the treatment of children having other primary problems including cancer, immunodeficiency and haemotological diseases, as well as in recipients of solid organ and bone marrow transplants. The management and prognosis of individual conditions is highly variable, thus it is essential to search for a precise diagnosis in every patient. High resolution computerised tomography (HRCT) and other less invasive investigations may be helpful in the management of patients. However, it is unusual to be able to make a firm diagnosis without a lung biopsy.

Tsetse challenge, trypanosome and helminth infection in relation to productivity of village Ndama cattle in Senegal

Data on tsetse fly, and on village Ndama cattle collected over a 4-year period in southern Senegal, were analysed. A total of 431 Ndama cattle in four herds of three villages in the Upper Casamance area of southern Senegal were monitored monthly. Glossina morsitans submorsitans and Glossina palpalis gambiensis are present in the study area. Mean tsetse apparent density was 5.4 flies/trap/day. Trypanosome (Trypanosoma congonlense and Trypanosoma vivax) infection rate in flies was 2.4 (s.e. 0.37)%. Tsetse challenge index was 17.3 (s.e. 4.18). Mean monthly trypanosome prevalence in cattle was 2.5 (s.e. 0.51)%. Highest trypanosome prevalence occurred during the dry season, and animals less than 1-year old were more frequently infected than older animals. The linear relationship between the log10+1 tsetse challenge and the arcsine of the trypanosome prevalence was significant only when mean monthly values of these variables over the 4-year period were used with tsetse challenge preceding infection rate by 3 months. Mean monthly prevalence of strongyle, Strongyloides spp., Toxocara spp. and coccidia were 34.4 (s.e. 0.60), 2.1 (s.e. 0.18), 1.2 (s.e. 0.45) and 15.6 (s.e. 0.47)%, respectively. Calf mortality rate at 1,6 and 12 months of age was 2.1 (s.e. 2.1), 5.2 (s.e. 2.8) and 12.2 (s.e. 3.3)%, respectively. Calving interval (584 s.e. 58 days) was not influenced by trypanosome status of the cow during lactation. Calving interval was shorter by 167 days when the calf died before 1 year of age in comparison to calving intervals for which the calf survived beyond one year. Live weight at birth, 6 and 12 months of age were 15.8 (s.e. 0.54), 48.1 (s.e. 2.56) and 71.1 (s.e. 5.44) kg, respectively. Mean lactation length, total and daily milk offtake were 389 (s.e. 16) days, 231 (s.e. 15) litres and 0.69 (s.e. 0.037) litres, respectively. Trypanosome infection during lactation did not have a significant effect on the amount of milk extracted for human consumption nor did trypanosome status affect calf growth.

[Epididymal manifestations of urogenital tuberculosis]

The morbidity of tuberculous epididymitis is due to the risk of male infertility secondary to vasal or epididymal obstruction or testicular necrosis. The aim of this study was to emphasize the epidemiological, clinical and therapeutical aspects of tuberculous epididymitis in adult. About eleven cases of epididymal localisation of urogenital tuberculosis, it appears that the diagnosis of the condition is rather difficult and often necessitate pathological exam of a specimen of epididymectomy. In other aspects, if antituberculous drugs are always effective in initial stages, surgery is usually radical, and rarely conservative. The latter procedures are vasovasostomy or vasoepididymostomy whose results are very hazardous.

Yellow fever outbreak in Kaffrine, Senegal 1996: epidemiological and entomological findings

In November 1996 a yellow fever (YF) outbreak occurred near Kaffrine in the central part of Senegal. Thirty-six deaths were notified, all children under 15 years of age. The YF diagnosis was confirmed by MAC-ELISA or by virus isolation. The immune status against YF virus of a sample population of 449 individuals was determined, and 31 confirmed cases and 69 asymptomatic cases were reported. Distribution of YF cases and incidence rate decreased with age, while the attack rate was stable in all age groups. Larva indices were high and Aedes aegypti was common in all villages, causing man-to-man transmission. The greatest risk of YF disease was lack of immunity, especially in individuals <20 years of age. The outbreak was rapidly controlled by an emergency immunization campaign. YF epidemics occurred in Senegal over two consecutive years. The last outbreak reached the main road to Dakar and the risk of spread to urban areas has increased.

[Neurologic aspects of vesico-vaginal fistula of obstetrical origin]

OBJECTIVE

To study the electromyographic alterations of the urethral sphincter, perineal muscles and lower limbs observed in women with obstetric vesicovaginal fistula.

METHODS

We compared a group of 22 women with obstetric vesicovaginal fistula with a control group of 10 women without fistula. Each woman underwent a neurological examination of the perineum and lower limbs and electromyography of the lower limbs and urethral sphincter. According to the classification proposed by MENSAH, the fistulas were classified as simple (54.5%), complex (31.8%) and complicated (13.6%).

RESULTS

Twenty women with VVF presented a peripheral nerve lesion. Five of these patients had a clinical and electromyographic lesion; while the other fifteen patients had a subclinical lesion. 68.18% of the fistula patients presented a clinical neuropathy in the perineum. This lesion was detected on electromyography in all patients with fistula. The severity of this denervation lesion ranged from moderate (36.37%) to severe (63.63%). No neurological lesions were detected in the control group. The degree of denervation has more severe in young women (21-25 years) and in primiparous women. In contrast, the severity of denervation did not appear to be related to the history of the fistula. The risk of treatment failure increased proportionally to the severity of denervation. 73% of fistulas with severe denervation remained "unsuturable", or required multiple operations with disappointing results in the form of persistent vesicosphincteric dysfunction.

CONCLUSION

Although the psychosocial impairment and upper urinary tract repercussions have been well evaluated, the peripheral neurological lesion has always been underestimated in the management of obstetric vesicovaginal fistulas. The authors consider that the fistula is only the apparent manifestation of "neurovesical damage", which remains the decisive factor in the prognosis and which largely explains the high frequency of treatment failure.

[Malaria morbidity and therapeutic efficacy of antimalarials. Study conducted in the Dakar region]

During November and December 1992, the authors surveyed the malaria morbidity and the drugs efficiency in an urban area of Dakar region. Malaria represented 13.68% of the fevers in Dakar district and 12.4% in Pikine. The mean parasitic density was evaluated at 5000/mm3. Good efficiency of antimalarial drugs were noted but chloroquine-resistance is present with 24% of prevalence.

[Effect of water fasting on sport performances in the laboratory]

15 sport men heart rate and central temperature were measured at rest and at the end of a progressive maximal exercise. Maximum consumption of oxygen (VO2 max) was estimated after the effort. The experience began in the morning from 9 to 11 a.m. and the afternoon from 4 to 6 p.m. In the first time subjects had a normal alimentation and in the second they observed a rigorous fast. The comparison of the results doesn't show difference induced by fast on VO2 max and maximal heart rate. However heart rate at rest and capacity of work decrease during fast and permit to think that a more intensive and long exercise in more strenuous climates than this one should give significative modifications.

[Cylindroma of the epiglottis]

The observation of an exceptional laryngeal localization of an adenoid cystic carcinoma allows authors to review diagnostic, therapeutic and increasing problems of this glandular carcinoma. The reported case constitutes a histologic surprise. An economical removal has allowed to obtain a long remission without recurrence, nor metastasis; this never put back the principle of the broad surgery to institute when faced this type of cancer, but just emphasize the interest of an early treatment.

[Percutaneous transluminal balloon valvuloplasty and balloon angioplasty in congenital heart defects with left heart obstruction in childhood]

Balloon dilation was performed in 31 patients with congenital left heart obstructions. In 16 patients with aortic stenosis aged 2 days to 16.3 years (mean 10.03 +/- 4.79 years) the peak systolic gradient decreased significantly from 80 +/- 21 mmHg to 23 +/- 13 mmHg immediately after dilation, and remained low at the time of follow up (6 months to 3 years), namely 30 +/- 12 mmHg (p less than 0.0001). Mild aortic regurgitation (I degrees) was already present before the procedure in 56%, increased in 3 patients, and reached haemodynamic significance in 1 (III degrees). Half of the 14 patients with coarctation, aged 2 months to 16.75 years (mean 4.98 +/- 5.15 years), had undergone previous surgery 2 months to 7.9 years before the balloon dilation; coarctation was native in the remainder. Peak systolic gradient across the coarctation site was reduced from 46 +/- 10 mmHg to 5 +/- 5 mmHg, and was 9 +/- 7 mmHg at the time of follow up (6 months-3.6 years) (p less than 0.0001). Aneurysms were not detected. In a 6-year-old girl with congenital mitral stenosis the gradient fell from 13 mmHg to 7 mmHg immediately after the procedure. There were no serious complications. Peripheral arterial lesions required medical or surgical treatment in 16% of cases. Our report suggests that balloon valvuloplasty and angioplasty is a safe and well-tolerated procedure in childhood. It can reduce the gradient in congenital left heart obstructions with good short-term and intermediate-term results.