Solubility parameter of poly(1,3-dioxepane)

Intrinsic viscosity measurements and turbidimetric titrations were made on poly(1,3-dioxepane) in a series of solvents to determine the solubility parameter δ. The Flory-Huggins interaction parameter was also used for the same purpose. A value of δ = 9,2 cal^1/2 · cm^?3/2 was obtained and compared with that calculated from empirical methods. The three-dimensional solubility parameter approach was also applied in order to obtain informations about the effect of chemical structure on the solubility behaviour.     

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.     

Homozygous sickle cell disease in patients above 20 years of age: follow-up of 108 patients in Dakar

CONTEXT: The progress realized in the treatment of sickle cell anemia has resulted to a better and longer life for these patients in developed countries. Ongoing challenge are to manage complication and social living for these patients. The purpose of this study was to determine morbidity, mortality and socioprofessional insertion of homozygous sickle cell patients, followed up in Dakar university hospital. PATIENTS AND METHODS: We performed a longitudinal and prospective study including 108 homozygous sickle cell anemia patients, whose age were above 20 years, followed in a regular basis (at least 3 times per year), during 5 years on average (3 to 12 years). All patients had a quarterly hematological check-up and a annual statement to detect chronic complications. Clinic and paraclinical data, as information in socioprofessional insertion were noted in medical records for analysis. RESULTS: Mean age was 27 years (20-51 years). The age between 20-29 years was represented by 67.5%, 26.9% aged 30-39 years and 5.6% were above 40 years of age. Men were slightly predominant with a sex-ratio of 1.25. Concerning morbidity, 96.3% of patients had at least 1 vaso-occlusive crisis per year, 26.9% were transfused and 64.8% had been hospitalized during the follow-up. A chronic complication was found in 49% of patients (53/108). The more frequent of these complications were gall stone (10%), femoral head necrosis (9.2%), priapism (11.6% of men), chronic leg ulceration (4.6%), ophthalmic involvement (3.7%), renal and cardiac complications (2.7% for each one). The presence of complications was not significantly influenced by patient's sex. Five patients died during a mean follow-up of 5 years. Concerning school attendance, 13% reach university level whereas 47% stop their education on the secondary level and 40% on primary level. Professionally, 36.2% of patients had no exercise any activity. CONCLUSION: Our results emphasize that life expectancy can be prolonged in sickle cell anemia patients in Africa, when they have a benefit of a regular follow-up. We show also the respective frequency of chronic complications and then, the necessity of multidisciplinary teams to optimize the take care of sickle cell anemia patients in Africa.     

Influence of school bag carrying on gait kinetics

The purpose of this study was to determine the effect of different methods of backpack carrying on gait kinetics in children, using a new treadmill that allowed three-dimensional measurement of right and left leg ground reaction forces (GRFs). Forty-one healthy children, with a mean age of 12 years, participated in this study. The mean height was 152 cm and the mean weight 40 kg. The three trials consisted of walking on the treadmill at the speed of 3.5 km/h, first without a backpack and then carrying a 10 kg school bag on the right shoulder or on both shoulders. For each carrying condition GRFs were recorded, averaged, and analyzed for 30 steps. Stride, stance, double stance, thirteen specific GRF parameters and the symmetry index were measured. The right leg produced higher propulsive fore-aft forces than the left one, whatever the walking conditions. For the two maximum peaks and the average vertical force during stance, a statistical difference was found between walking without a backpack and carrying a backpack on one or two shoulders (one or two shoulder carrying > no backpack) but never between one-shoulder and two-shoulder carrying. The children increased their stance and double stance when walking with a backpack compared with walking without a pack. The symmetry index increased with one-strap carrying (compared with no backpack and two-strap carrying) for the maximum force during the breaking phase (Fy1) when it decreased for the maximum propulsive horizontal force before taking-off (Fy2). Children should be advised to carry their backpack on two shoulders rather than use a one-strap backpack.     

The excipient properties of shea butter compared with vaseline and lanolin

A shea butter ointment containing 3% aureomycin (clortetracyclin hydrocloride) was prepared and some of its macroscopic and microscopic characteristics were evaluated. Then, the release of the active ingredient was compared by UV spectrophotometry with those obtained when excipients such as petroleum jelly and lanoline were used. Results had shown that the shea butter ointment had satisfactory characteristics. In the other hand, it was found that shea butter released the aureomycin easily and at a faster rate than the other excipients.     

Emergency reimplantation of the tongue after complete traumatic amputation

Complete traumatic amputation of the tongue is very exceptional, the intra-oral position generally protecting the tongue. Most reported cases of trauma have involved partial section with satisfactory results after simple suture. Complete amputation of a portion of the tongue occurred in a 12-year-old boy during a fight. The fragment of the tongue was brought to the emergency unit. It was placed in heparinated saline solution and replanted successfully three hours after the trauma. Plastic surgery of the oral cavity was also performed to repair laceration injuries. The postoperative period was uneventful and the tongue regained vitality and normal motion. There was just a slight retraction. Replantation of the tongue after complete section may not be successful but should be attempted when possible.     

Biomechanical evaluation of different instrumentation for spinal stabilisation

The varying problems following arthrodesis of the lumbar spine with rods or plates (too much rigidity for the first and insufficient stability for the second) have led us to conceive another type of material, flexible but with enough stability, to favorise healing of bone graft, and decrease the induced pathology on adjacent levels. An experimental study of three types of material: rigid, semi-rigid and flexible was performed on eighteen fresh cadaver spinal segments without and then with discectomy and corporectomy to find out the various types of behaviour. The flexible device seems more supple than the other materials tested: more mobility, less stiffness. Rising hysteresis is explained by plastic deformation. The semi-rigid device presents strong osseous stresses on the L3 level and a large hysteresis corresponding most likely to a mobility between the screws and plates. The rigid device has less mobility, especially in torsion, ascribed to the transverse connection. The stability is high with a small hysteresis. This is of value for bone loss or instability with displacement of the vertebral body. The second study was a modeling of the flexible device validated by comparison to the experimental study. The strains in the wire were high, decreasing with increasing diameter, but is still lower than the elastic limit. The proximity of the elastic limit may allow plastic deformation of the wire. Howewer less strains were found on the screw fixation but increase with the increase diameter of the wire. The influence of the bone quality on the behavior of the device was demonstrated.