Epidemiology of chronic obstructive arterial disease of the lower limbs and diabetic patients at the University Hospital of Cotonou (Benin)

The aims of this study were to determine the prevalence of chronic obstructive arterial disease of the lower limbs and to identify the factors which contribute to its occurrence in a population of adult African francophone diabetics. This was a prospective study which included all consenting diabetics systematically over a 6 month period at the out patient clinic or during hospital admission. Patients with incomplete data were excluded. An ankle systolic pressure index of less than 0.9 was required for the diagnosis of obstructive arterial disease. Demographic parameters, the characteristics of the diabetes, the quality of blood sugar control, the presence of classical cardiovascular risk factors and the results of their treatment, the nature and distribution of the arterial lesions on ultrasonography were all studied. A univariate analysis and a multivariate analysis of their correspondences were undertaken to determine the correlation coefficients. The prevalence of arterial disease of the lower limbs in the 102 diabetics retained for the study (average age 53 years) was 33.3%. The arterial disease was distal in 47% of cases and diffuse in 26.5% of cases. The arterial wall was calcified in 19.6% of cases. In univariate analysis only age was correlated with arterial disease (p = 0.04), the duration of diabetes tended to be related (p = 0.07). In multi-factorial analysis of Correspondences with other factors, hypertension, hyperlipidaemia and multiple cardiovascular risk factors seemed to be correlated with arterial disease of the lower limbs. Therefore, arterial disease of the lower limbs is very common and an early complication of diabetic patients in Benin. Predisposing factors were age and, probably, duration of diabetes, hypertension, hyperlipidaemia and multiple cardiovascular risk factors.     

Development and evaluation of iodinated tracers targeting amyloid plaques for SPECT imaging

Successful development of iodinated ligands for various neurotransmitter receptors prompted us to explore the feasability of having iodinated ligands to target amyloid plaques of Alzheimer’s disease. Several potential iodinated tracers based on various chemical backbone structures have been successfully prepared and evaluated toward this purpose. High binding affinities for Aβ aggregates were consistently observed for those ligands. However, the desirable in vivo properties were generally missing in the majority of those iodinated ligands. Only ligands with the promising in vitro and in vivo characteristics such as IMPY will likely warrant their success to be potential imaging agents mapping amyloid plaques in living human brain.     

Group B vitamins protect murine cerebellar granule cells from glutamate/NMDA toxicity

The role of B group vitamins in preventing neuronal death against excitotoxicity was investigated. Neuronal death of cultured mouse cerebellar granule neurons (CGNs) caused by glutamate (50 microM) or NMDA (200 microM) was delayed in CGNs that had been treated with riboflavin (B2), folic acid (B9) or cynocobalamin (B12) for 18 h. Such neuroprotection by B2, B9 and B12 was in a dose- and time-dependent manner. In contrast, application of thiamin (B1), nicotinamide (B3), d-pantothenic acid (B5), pyridoxine (B6) or carnitine (BT) did not ameliorate glutamate or NMDA-mediated excitotoxicity to CGCs. These results are the first indication that certain B group vitamins are not only required for the normal brain function, but can also play a protective role against excitotoxicity to the brain.     

Neuroprotective effect of inosine on axotomized retinal ganglion cells in adult rats

PURPOSE: To explore the potential survival-promoting effect of inosine on axotomized retinal ganglion cells (RGCs) of adult rats in vivo. METHODS: The left optic nerves (ON) in the subject rats were transected at 1.5 mm from the optic disc. Repeated intraperitoneal injections or single intraocular injection of inosine were administered. The RGCs were retrogradely labeled with a gold fluorescent dye and the density of surviving RGCs in number per square millimeter of retina was calculated in wholemounted retinas. The functional integrity of the blood-retinal barrier (BRB) after ON transection was evaluated with an intravenous injection of Evans blue. RESULTS: In control animals, the mean density of surviving RGCs (number per square millimeter) of the whole retina was 2007 +/- 68 at 2 days (taken as the normal value), 927 +/- 156 at 7 days, and 384 +/- 33 at 14 days after surgery. Repeated intraperitoneal injections (75 mg/kg for each injection) of inosine significantly enhanced RGC survival at 14 days after ON transection (500 +/- 38), whereas no significant difference in the densities was detected at 7 days (974 +/- 101), even when the dosage of inosine was doubled (1039 +/- 61). At this time point, however, a single intraocular injection of inosine significantly increased the density of surviving RGCs (1184 +/- 156). Moreover, more RGCs around the optic disc were rescued when inosine, administered either intraperitoneally or intraocularly, showed a beneficial effect on RGC survival. No breakdown of the BRB after ON transection was detected with the method used in the study. CONCLUSIONS: These findings demonstrate that inosine could protect axotomized RGCs in vivo after ON transection.     

An automatic approach for estimating bolus arrival time in dynamic contrast MRI using piecewise continuous regression models

We present two regression models for the automatic estimation of bolus arrival times (BATs) in dynamic contrast MRI datasets. Results of Monte Carlo simulation experiments show that the means and standard deviations of the estimated BATs are within the sampling interval even in the presence of significant noise.     

Kinetics of picosecond laser pulse induced charge separation and proton transfer in bacteriorhodopsin

Bacteriorhodopsin (BR) films oriented by an electrophoretic method are deposited on a transparent conductive ITO glass. A counterelectrode of copper and gelose gel is used to compose a sandwich-type photodetector with the structure of ITO/BR film/gelose gel/Cu. A single 30-ps laser pulse and a mode-locked pulse train are respectively used to excite the BR photodetector. The ultrafast falling edge and the bipolar response signal are measured by the digital oscilloscope under seven different time ranges. Marquardt nonlinear least squares fitting is used to fit all the experimental data and a good fitting equation is found to describe the kinetic process of the photoelectric signal. Data fitting resolves six exponential components that can be assigned to a seven-step BR photocycle model: BR-->K-->KL-->L-->M-->N-->O-->BR. Comparing tests of the BR photodetector with a 100-ps Si PIN photodiode demonstrates that this type of BR photodetector has at least 100-ps response time and can also serve as a fast photoelectric switch.     

Cord serum ferritin concentrations and mental and psychomotor development of children at five years of age

OBJECTIVE: Our purpose was to evaluate the association between fetal iron status and mental and psychomotor development at 5 years of age. STUDY DESIGN: We evaluated the association of fetal iron status (umbilical cord serum ferritin concentrations) with test scores of mental and psychomotor development of 278 children. Six tests were given, including full-scale intelligence quotient (FSIQ), language ability, fine- and gross-motor skills, attention, and tractability. RESULTS: Compared with children with cord ferritin in the 2 median quartiles, those in the lowest quartile scored lower on every test and had significantly worse language ability, fine-motor skills, and tractability. They were also 4.8-fold more likely to score poorly in fine-motor skills and 2.7-fold more likely to have poor tractability than children in the median quartiles. FSIQ in the highest quartile was slightly, but not significantly, lower than the median quartiles, but the odds ratio for having a FSIQ score of less than 70 for children in the highest quartile was 3.3 (95% CI 1.2-9.1). CONCLUSION: Poor iron status (low ferritin) in utero appears to be associated with diminished performance in certain mental and psychomotor tests. The reason for the association between high ferritin concentrations and low FSIQ scores is unknown.     

Effects of a calcium channel blocker on electrical activity in myofascial trigger spots of rabbits

OBJECTIVE: This study investigated the effect of a calcium channel blocking agent, verapamil, on the spontaneous electrical activity (SEA) in a myofascial trigger spot of biceps femoris muscles of rabbits. DESIGN: Left and right legs of eight adult New Zealand rabbits were randomly assigned into either experimental or control groups to assess the effect of verapamil on SEA. Verapamil and normal saline were injected into the external iliac artery for experimental and control groups, respectively. The experiment was divided into two phases: Phase A investigated the immediate effect of verapamil on SEA of one active locus, and phase B studied the effect of verapamil on SEA of 25 different active loci. The average integrated value of SEA was used to statistically analyze the effect of verapamil on myofascial trigger-spot sensitivity. RESULTS: In phase A, conducted on one active locus, the regression analysis results showed that the average integrated value in the verapamil group linearly decreased with time, but the average integrated value did not significantly change with time in the control group. In phase B, which analyzed 25 different active loci, the results indicated that the mean average integrated values in the verapamil group was significantly lower than that of the control group. CONCLUSIONS: Calcium channel blockers can effectively inhibit the SEA of myofascial trigger spots.