[A left paraduodenal hernia--a case report]

The left paraduodenal hernia obtains when the small intestine goes through the left paraduodenal fosset. It (the hernia) develops on the left, at the back of the descending mesocolon. The present authors study one case looking at its pathogeny and the clinical and therapeutic problems posed by such a variety of congenital internal hernia. The authors emphasize, in particular, its morbid associations with the volvulus of the pelvic colon. Finally they highlight the importance of a through and careful exploration of the abdominal cavity during any laparatomy following an occlusive syndrome.

[Well water pollution in the Khombole district: research on the contamination by organochlorine pesticide residues and organic substances (feces)]

The study realized in the district of Khombole (SENEGAL) has permit to estimate the contamination levels of wells waters used by the populations. The research and the dosage of the organichlorine pesticide residues, nitrites and nitrates and microbiologic analysis have been done on 19 wells chosen after a drawning of lots. The organochlorine pesticide residues which have been found prove that the wells are permanently exposed to these chemical substances which don't constitute nevertheless a major risk for the populations health. The results of our research proved also that there is a real risk of intoxication with the nitrogen oxides. In effects more than 50% of the wells have revealed nitrates contents up to the indicative value (25 mg/l). As for the nitrates, with a few exceptions (5/18), the contents are superior to the authorized norm (0.1 mg/l). By another way the bacteriologic analysis has revealed in the one hand a DBT (Total Bacterian Count) up to 10,000 germs/l for all the wells, and in the other hand the presence of Escherichia coli, Enterococcus faecalis that confirm a faecal contamination.

[Lumbar hernia through the Jean Louis Petit triangle: anatomic and clinical aspects]

Lumbar hernia through Jean Louis Petit Triangles is rare. Usually asymptomatic, it is sometime revealed by lumbar mass or a complication. Surgical treatment consists on parietal repair. This could be done by direct suture, muscular plasty or prothetic material. We hereby, report three cases of lumbar hernia. We get the opportunity to make an update in the anatomical, clinical and therapeutical point to view.

[Zoophagia and alternative host selection of the marlaia vectors in Senegal]

Blood-engorged females of An. gambiae s.l., An. funestus, An. pharoensis and An. rufipes caught resting indoors were tested (precipitin or enzyme-linked immunosorbent assay) to determine the source of bloodmeal. The species of the An. gambiae complex fed mainly on human hosts in all prospected areas, except in those of the mid Senegal river valley where an important zoophily was observed within and near the irrigation zone. Among 4,597 blood-engorged females of An. gambiae s.l., 29% fed on cattle with 7.5% of mixed boodmeals, mainly human-bovine or human-equine. The presence of cattle, culicid population densities and individual mosquito safety devices were the most determinant factors of animal deviation. Blood of most domestic animals was found in the stomach of collected females, but according to areas, bovines and equines were the main hosts for zoophilic females of An. gambiae s.l. Females of An. funestus collected in the middle-west were more anthropophilic than those collected in south-eastern areas. An. pharoensis was most prevalent in the Senegal river delta where it was found to be very anthropophilic. An. rufipes was strongly endophilic but exclusively zoophilic in all prospected areas.

[Impact of the use of permethrin pre-impregnated mosquito nets on malaria transmission in a hyperendemic village of Senegal]

The efficacy of permethrin-treated bednets was evaluated in Wassadou, a hyperendemic village located in the Sudanese grasslands of southeast Senegal. Pretreatment data were collected between 1992 and 1993. Bednets were distributed to the whole population in June 1995 and impact of their use on vector populations and malaria transmission was evaluated until November 1995. This period corresponds to the rainy season during which malaria transmission is highest. Data were compared with a control village in which bednets were not distributed. Findings showed that use of bednets led to a sharp decrease in the density of the vector population and malaria transmission. The number of bites by Anopheles gambiae s.1. decreased 69%. The density of blood-laden and pregnant females inside dwellings decreased 91% and 96% respectively. The sporozoite index of females captured on the skin decreased 76% and the daily rate of entomological inoculation decreased 88%. This impact was not great enough to eliminate the risk of infection. Prolonged study over a period of 4 to 5 years is needed to evaluate the impact of long-term use of insecticide-treated bednets on vector population and malaria transmission.

[Interbody arthrodesis using a plasmapore titanium block. Mechanical and histological experimental study in sheep]

A Plasmapore-coated titanium alloy block was implanted in ewes for the purpose of providing interbody fusion. Four blocks were implanted in each ewe: one uncoated block (without Plasmapore) serving as a reference specimen and three blocks coated with Plasmapore. Mechanical testing and histological study were performed on five ewes.

OBJECTIVES

Determination of the quality of the mechanical and histological anchorage of the Plasmapore implanted in the interbody space in the same animal living under conditions of physical strain exerted on the spine.

METHODS

Four months after surgical implantation of the block, the ewes were sacrificed: the removed spines were frozen for subsequent mechanical analysis and preserved in a solution of 40 degrees alcohol for subsequent histological analysis. X-rays were taken to evaluate the positioning of the implant. The mechanical analysis included extraction tests, measuring the maximum extraction force and evaluating the stiffness of the system, being indicative of the mechanical fixation quality. The histological study included both qualitative and quantitative analysis, together with an evaluation of the osteointegration of the blocks coated with Plasmapore.

RESULTS

After 4 months of implantation, a mean extraction force of 990 N was necessary for the blocks coated with Plasmapore, and of 1.338 N for the blocks coated with Plasmapore with additional osteosynthesis, whereas a mean extraction force of 332 N was necessary for the uncoated blocks. Anchorage and resistance against uprooting of the blocks coated with Plasmapore were significantly more efficient. The histological study revealed the presence of bone neoformation adhering to the implant. Quantification of this bone formation covering nearly 45% of the implant perimeter, confirmed both osteointegration of the implant perimeter, confirmed both osteointegration of the implant surfaces being in contact with the vertebral endplates and osteoconduction along the lateral surfaces.

CONCLUSION

The titanium Plasmapore block enables interbody fusion due to an osteointegration of the vertebral endplates by Plasmapore coating, which was proved by the results of extraction testing and histological study. It should be taken into account that no additional bone grafts have been used and that the implant had not been forced into the spongiosa.

[Establishing a strain of Anopheles arabiensis (Diptera:Culicidae) in an insectarium]

For the first time in Dakar (Senegal), we managed to establish a local colony of Anopheles arabiensis (Diptera: Culicidae) in insectarium. The observations on the productivity of the colony showed a gradual adaptation of the preimaginal stages to insectarium conditions. The estimated duration of the development of the various preimaginal stages showed an interval of 24 hours for egg hatching, 48 h for stage I, 24 h for stage II, 24 h for stage III and 36 h for the pupal stage. Stage IV which makes the difference in the duration of the adult-egg cycle, varied from 1 to 13 days. Pupal moulting occurred mainly between 11 h and 19 h, with a peak between 14 h and 15 h. The duration of the preimaginal cycle in insectarium was from 8 to 11 days. This fits with the duration shown in natural breeding places during the rainy season (the best period for the development) which was from 9.5 to 13.3 days. Emergence, faster in males, occurred in the evening around 6.30-7 p.m. The emergence rate was higher in insectarium (92.9%) compared with that shown in the field (6 to 20%) (the natural breeding places are subject to biological and biochemical variations and to predators's action). The sex-ratio is equal to 1. The studies in insectarium showed that the gonotrophic cycle is 3 days in neonate blood fed after day 2 and also in parous ones. This cycle is 5 days in nulliparous with pregravid stage. The average longevity is 16 days with a maximum of 26 days in females and 43 days in males.

[Evaluation of parasitic risks for the population bordering on the Mbeubeuss public waste disposal, Dakar]

The authors carried out a parasitologic survey on 367 inhabitants of Malika, a village located in the immediate surroundings of M'Beubeuss disposal, as well as on 433 other residents of Keur Massar, a location 2 km farther, in order to assess parasitic hazards encountered by people neighbouring this disposal. As far as intestinal parasitosis are concerned, the prevalence rate was significantly higher in Malika (61.3%) than in Keur Massar (48.5%) The sex, social and economic status, level of education as well as the time of dwelling in the neighbouring area were identified as the risk factors of intestinal parasitism. Only the last one can be considered as significantly and independently related to a risk of intestinal parasitism. As for malaria, the plasmodial index in Malika was 6% versus 7.6% in Keur Massar (no significant difference). Thus, if it does exist for neighbouring people, an infestation risk by intestinal parasites related to exposure duration, contrarily, it does not exist for malaria. Appropriate steps should be taken to prevent the hazards encountered by inhabitants of surrounding villages.

[Cervical teratomas in the child (apropos of 8 cases)]

Eight cases of cervical teratomas in children are reported including 4 boys and 4 girls. Six patients presented within the first 10 days of life. The tumor was congenital in 7 cases. In 3 neonates it produced severe respiratory distress. Neural and chondral tissues were predominant but all three germ layers were represented. All patients were operated upon, with a 2/8 mortality. The main clinical and histopathological features of these rare tumors are reviewed. Early total surgical removal is the cornerstone of treatment.

[Gastric volvulus in the infant. Clinical and radiological diagnosis]

The authors reported two cases of gastric volvulus in female and male babies respectively 5 and 3 months old. Patients presented functional symptoms as vomiting, regurgitation. Baryum meal X ray allows to make diagnosis in meso-axial and organoxial varieties. They showed the interest to evocate this diagnosis related to an infant vomiting's diagnosis and discussed about therapeutic modality.

[Total vaginal hysterectomy for genital prolapse apropos of 10 cases]

There are many variants in vaginal hysterectomy procedures owing to precises indications. We have performed a total vaginal hysterectomy procedure which technique is described herein. Our procedure was using the preexisting anatomic structures. It allows a solid cure adapted to each compound of the genital prolapse. Among a series of 10 cases, we report few complications. An important peroperative bleeding occurred in one case. The postoperative morbidity included 1 case of genital infection and 1 case of urinary fistula. One patient died from a cause not reliable to the procedure. The mean duration of the hospital stay was 10 days. After 2 years follow up, 9 of our patients have good anatomical and functional results. The shortness of this series does not allow us to concluded definitively. However, our results are comparable with those reported in the literature.

Characterization of the mechanical behaviour parameters of the costo-vertebral joint

This in vitro study introduces a new method to determine quantitative parameters characterizing the mechanical behaviour of the costo-vertebral joint. These parameters are useful in building numerical models of the thoracic spine, taking into account the thoracic cage. Nine thoracic cages were isolated from fresh human cadavers. From each cage, three functional units were tested: T1-T2, T5-T6, T9-T10. Loads were applied according to the joint local coordinate system. Every functional unit was tested first intact and again after section of successive costo-transverse ligaments. We used an opto-electronic system to follow the three-dimensional motion of the joint, and obtained non-linear load/displacement curves according to the primary rotation axis. A statistical analysis of these curves allowed the calculation of parameters describing the joint mechanical behaviour: total range of motion, motion in the low-stiffness zone, and flexibilities in the positive and negative quasi-linear zones. These values can be used as a database for mechanical modeling of the spine.

Crimean-Congo hemorrhagic fever in ticks (Acari: Ixodidae) and ruminants: field observations of an epizootic in Bandia, Senegal (1989-1992)

From 1989 to 1992, a longitudinal study of the relationships between different tick species and domestic ungulates in the transmission and amplification of Crimean-Congo hemorrhagic fever (CCHF) virus was undertaken in the Bandia area in Senegal where the presence of the virus had been reported previously. An epizootic occurred in 1991-1992 and 22 strains of CCHF virus were isolated from Hyalomma marginatum rufipes Koch, Amblyomma variegatum (F.), Rhipicephalus guilhoni Morel & Vassiliades, and R. evertsi evertsi Neumann ticks collected from cattle and goats. No human cases were reported. Transmission of CCHF virus in the area involves a complicated pattern including many tick species and hosts. Amplicons of the S fragment (536 bp) of the CCHF genome of 12 isolates from the study were obtained by polymerase chain reaction and analyzed by restriction-length fragment polymorphism. Three different genotypes of CCHF virus were identified and present during the epizootic. One genotype was recovered from A. variegatum, R. guilhoni, and R. e. evertsi and 2 genotypes were isolated from H. m. rufipes.

Comparison of behavior and vector efficiency of Anopheles gambiae and An. arabiensis (Diptera:Culicidae) in Barkedji, a Sahelian area of Senegal

The ecology, population dynamics, and malaria vector efficiency of Anopheles gambiae and An. arabiensis were studied for 2 yr in a Sahelian village of Senegal. Anophelines were captured at human bait and resting indoors by pyrethrum spray. Mosquitoes belonging to the An. gambiae complex were identified by polymerase chain reaction. Of 26,973 females, An. arabiensis represented 79% of the mosquitoes captured and remained in the study area longer than An. gambiae after the rains terminated. There were no differences in nocturnal biting cycles or endophagous rates between An. gambiae and An. arabiensis. Based on an enzyme-linked immunosorbent assay test of bloodmeals, the anthropophilic rate of these 2 vectors were both approximately 60%, when comparisons were made during the same period. Overall, 18% of the resting females had patent mixed bloodmeals, mainly human-bovine. The parity rates of An. gambiae and An. arabiensis varied temporally. Despite similar behavior, the Plasmodium falciparum circumsporozoite protein (CSP) rates were different between An. gambiae (4.1%) and An. arabiensis (1.3%). P. malariae and P. ovale only represented 4% of the total Plasmodium identified in mosquitoes. Transmission was seasonal, occurring mainly during 4 mo. The CSP entomological inoculation rates were 128 bites per human per year for the 1st yr and 100 for the 2nd yr. Because of the combination of a high human biting rate and a low CSP rate, An. arabiensis accounted for 63% of transmission. Possible origin of differences in CSP rate between An. gambiae and An. arabiensis is discussed in relation to the parity rate, blood feeding frequency, and the hypothesis of genetic factors.

Intervertebral disc prosthesis. Results and prospects for the year 2000

Presently, the kinematic disc prosthesis model (SB Charité) is the best disc replacement compromise, and is the basis of the evolution of the prosthetic concept at the dawning of the year 2000. Clinical results of a homogeneous series of 105 cases with a mean followup of 51 months show 79% of the patients had an excellent result and 87% returned to work, radiologically, these results correlated with restoration of a well balanced lordosis and with segmental mobility. Factors leading to failure are posterior facet arthritis, osteoporosis, structural deformities, and secondary facet pain. Two- and 3-dimensional numeric modeling enables one to study the total facet joint loading and the maximal local loading on the facet. Dissociation of the stiffness in pure rotation and stiffness in translation of the disc are the bases of the technologic improvement.

Biomechanical study of screws in the lateral masses: variables affecting pull-out resistance

The purpose of this study was to investigate the effects of the design of the screw, the depth of insertion, the vertebral level, and the quality of the host bone on the pull-out resistance of screws used in the lateral masses. The study included twelve fresh cervical spines from human cadavera. Radiographs were made of each specimen to ensure the absence of defects, and then the cancellous-bone density of the vertebral bodies was measured at each level with quantitative computed tomography scanning. Six commercially available screws of various diameters and thread configurations (2.7, 3.2, 3.5, and 4.5-millimeter cortical-bone screws; a 3.5-millimeter cancellous-bone screw; and a 3.5-millimeter self-tapping screw) that are currently used for fixation of the cervical lateral masses were tested for axial load to failure. A twelve-by-twelve Latin square design was used to randomize the screws with regard to level (second through seventh cervical vertebrae), side (right and left), and depth of insertion (unicortical or bicortical purchase). Each screw was then subjected to uniaxial load to failure. The data were analyzed to determine if the diameter of the screw, the thread configuration, the number of cortices engaged, the cervical level, or the bone density was associated with the load to failure. Three major subgroups (greatest, intermediate, and lowest pull-out resistance) were identified. The subgroup with the greatest pull-out resistance included only screws with bicortical purchase; the 3.2, 3.5, and 4.5-millimeter cortical-bone screws and the 3.5-millimeter cancellous-bone screw were in this subgroup. Regardless of the thread configuration, no screw with unicortical purchase was in the group with the greatest pull-out resistance. Two of the three values in the subgroup with the lowest pull-out resistance were for the 3.5-millimeter self-tapping screw (with unicortical or bicortical purchase). The cancellous-bone density of the vertebral body was not associated with pull-out resistance and it did not vary significantly according to the cervical level, with the numbers available. However, the pull-out resistance of the screws varied significantly (p = 0.004) by level: it was the greatest at the fourth cervical level, decreasing cephalad and caudad to that level.

[Phenotypic differences of nosocomial bacterial strains isolated in the obstetric-gynecology service of the University Hospital Center of Dakar]

A study on nosocomial infections was conducted in the Laboratory of Bacteriology-Virology of Aristide Le Dantec's Hospital, in collaboration with the Gynecology Obstetrics clinic located both in the same Dakar's hospital, during May 1995. The aim of the study was to define the phenotypical characteristics of various bacterial strains isolated from the atmosphere health care staff's hands, medical equipment (material, antiseptics) and patients (hospitalized pregnant and newborns in day Nursery). A total of 133 strains were collected and the most frequent isolates were Staphylococcus aureus (27 strains) and Klebsiella pneumoniae (10 strains) encountered mainly in the atmosphere. Otherwise, Escherichia coli (11 strains) and Enterococcus faecalis (11 strains) were more present in hospitalized patients. Results obtained after antimicrobial agents susceptibility (Antibiotics and Heavy metal salts) by Antibiogramm and Minimal inhibitory concentrations (MIC) and also data from biotyping of Klebsiella strains have allowed us to say there's a probable contamination of hospitalized patients by the bacteria from the atmosphere but manuportage too.

Growth of tracheal sutures with absorbable sutures in primates

Postoperative wound healing is studied after tracheal suturing in 5 primates operated on in two stages. First by double level hemisection comparing continuous and interrupted sutures with polydioxanone. In a second stage: comparison of continuous sutures after tracheal segmental resection. The tracheas were harvested sequentially to study the evolution of the sutured zone by measuring its diameter and by histopathologic examination. The reduction of the tracheal diameter observed was not statistically significant after hemisection using continuous (p = 0.7) or interrupted sutures (p = 0.6). But after tracheal resection the stenosis was significant with continuous sutures (p < 0.05). Histologic study revealed that polydioxanone is well tolerated and is absorbed within 26 weeks. The authors recommend the use of continuous sutures to repair simple wounds and of interrupted sutures after tracheal resection anastomosis.

[Multi-segment ventral stabilization of the lumbar spine: a comparative biomechanical study]

The stability provided by three anterior spinal fixation devices (VDS, TSRH, CDH) designed for multisegmental instrumentation have been studied in an in-vitro model using L1-L5 sections of six human cadaveric spines for each instrumentation. Three-dimensional measurement of rotation and translation for the intact and instrumented spine under physiological loads in flexion/extension, lateral bending, and axial rotation were determined. After measuring the intact spine the destabilization was performed by complete intersection of the intervertebral disc, all spines were instrumented for 3 segments. TSRH was found to be significantly (p < 0.05) higher in stiffness in flexion/extension and torsion than VDS. In bending there was no statistical difference. In all tests CDH was significantly more stable than VDS. In flexion/extension it proved higher in stiffness than TSRH, no statistical difference was observed in bending and rotation.

Automatic in vivo NMR data processing based on an enhancement procedure and linear prediction method

A new data processing method for in vivo NMR data quantitation is presented. This method (EPLPSVD) is based on the enhancement procedure (EP) proposed by J. A. Cadzow (IEEE Trans. Acoust. Speech Signal Process. 36, 49, 1988) followed by the usual linear prediction method using the singular value decomposition (LPSVD). The evaluation of this protocol is performed using synthesized 31P signals with different signal-to-noise ratios. A Monte-Carlo simulation as a function of signal-to-noise ratio (SNR) has proved that EPLPSVD leads to unbiased estimated values of parameters. Then the Cramer-Rao method yields reliable confidence intervals for the estimated parameters. The estimates of NMR parameters using EPLPSVD are reliable and accurate for SNR > or = 1.2 while the LPSVD method failed for SNR < or = 4. This protocol is applied to analyze automatically a series of 31P free induction decays obtained from the human gastrocnemius muscle during exercise. Spectral parameters with their confidence intervals, curves of relative intensity variations in phosphocreatine and inorganic phosphate, and pH curves are automatically provided.

Improving data acquisition parameters of 31P in vivo spectra for signal analysis in the time domain

To obtain reliable NMR quantitation, experimental cautions concerning data acquisition must be taken when using automatic predictive calculations. For this study, 2000 31P in vitro and in vivo spectra were processed, using the enhancement procedure with linear prediction using singular value decomposition (EPLPSVD) method, and analyzed. The effects of quadrature detection modes (simultaneous or sequential), of the number of time-domain samples used are investigated and experimental conditions such as sample motions and spectral width are discussed.