How can the diagnostic value of head and neck biopsies be increased in Wegener's granulomatosis: a clinicopathologic study of 49 biopsies in 21 patients

Head and neck biopsies usually have a low diagnostic value in Wegener's granulomatosis (WG). On the basis of 49 biopsies obtained from 21 WG patients at diagnosis from various sites, i.e. nose (29), paranasal sinus (7), oral cavity (4), larynx (4), conjunctiva (3) and external ear (2), we described the suggestive histological features and studied the diagnostic potential of the biopsy size, anaesthesia method (general (GA) or local (LA)), anatomic region of the biopsy, number of sections, and presenting macroscopic manifestations. Associated granulomatous inflammation (scattered giant cells, 28.5% of biopsies; poorly-formed granulomas, 28.5%), necrosis (neutrophilic microabscesses, 16.3%; geographic necrosis, 18.3%), angiitis (leukocytoclastic, 10%; necrotizing, 12%; and granulomatous, 6%) which confirmed the diagnosis were only present in 18.3% of the biopsies (28.5% of the patients). We think it is possible to propose a "WG-compatible" diagnosis when at least one of these histological features is present (24.5% of biopsies, 26% of patients in our study). We found that it was always better to perform biopsies targeted on macroscopic lesions. When there was no lesion, samples from paranasal sinuses obtained under GA had the highest diagnostic value in the head and neck region, whereas 90% of nasal systematic biopsies performed under LA were nonspecific. Moreover, we demonstrated that performing two further sections increased the sensitivity of histological examination by 7%.     

Postnatal development of alkaline phosphatase activity correlates with the maturation of neurotransmission in the cerebral cortex

We have shown previously that the tissue nonspecific alkaline phosphatase (TNAP) is selectively expressed in the synaptic cleft of sensory cortical areas in adult mammals and, by using sensory deprivation, that TNAP activity depends on thalamocortical activity. We further analyzed this structural functional relationship by comparing the developmental pattern of TNAP activity to the maturation of the thalamocortical afferents in the primate brain (Callithrix jacchus). Cortical expression of alkaline phosphatase (AP) activity reflects the sequential maturation of the modality-specific sensory areas. Within the visual cortex, the regional and laminar distribution of AP correlates with the differential maturation of the magno- and parvocellular streams. AP activity, which is transiently expressed in the white matter, exhibits a complementary distributional pattern with myelin staining. Ultrastructural analysis revealed that AP activity is localized exclusively to the myelin-free axonal segments, including the node of Ranvier. It was also found that AP activity is gradually expressed in parallel with the maturation of synaptic contacts in the neuropile. These data suggest the involvement of AP, in addition to neurotransmitter synthesis previously suggested in the adult, in synaptic stabilization and in myelin pattern formation and put forward a role of AP in cortical plasticity and brain disorders.     

Gene expression profiling in chronic inflammatory demyelinating polyneuropathy

Gene expression in archived frozen sural nerve biopsies of patients with chronic inflammatory demyelinating polyneuropathy (CIDP) was compared to that in vasculitic nerve biopsies (VAS) and to normal nerve (NN) by DNA microarray technology. Hierarchical clustering analysis demonstrated distinct gene expression patterns distinguishing these disease groups. Of particular interest were: (1) Tachykinin precursor 1, which may be involved in pain mediation; (2) Stearoyl-CoA-desaturase, which may be a marker for remyelination and (3) the Allograft Inflammatory Factor 1 (AIF-1), a modulator of immune response during macrophage activation. Differential gene expression may help distinguish between CIDP, VAS and NN in sural nerve biopsies and identify genes that may be involved in disease pathogenesis.     

Dopamine D3 modulation of locomotor activity and sleep in the nucleus accumbens and in lobules 9 and 10 of the cerebellum in the rat

Dopamine D3 receptors are present in the nucleus accumbens and in lobules 9 and 10 of the cerebellum. Their function is not fully understood. In the present study, the involvement of D3 receptors in locomotor activity and sleep in the two structures was investigated. The method used was the measure of locomotor activity in an open field and the measure of sleep and sleep/waking stages by electroencephalographic recordings in the rat. Dopamine receptor agonists (7-OH-DPAT, quinelorane and SKF38393) and antagonists (amisulpride, nafadotride and haloperidol) were microinjected into the two structures. Concerning locomotor activity, the results show that D3 receptor stimulation, as well as concomitant stimulation of D1 and D3 receptors, have opposite effects in the cerebellum and in the core of nucleus accumbens, with an inhibition of locomotion in the cerebellum and a stimulation of locomotion in the nucleus accumbens. D1 and D3 stimulation have mutual potentiating locomotor effects. The results also show that in the cerebellum, the effects are selective to lobules 9 and 10, and are not observed with microinjections into lobule 8. Concerning sleep, the effects of agonists and antagonists show a similar tendency in the cerebellum and nucleus accumbens, with a somnogenic effect of D2 blockage, an awakening effect of at least one of the D2/D3 agonists, and a dose-dependent awakening effect of the D2/D3 antagonists. In conclusion, this study suggests that dopamine D3 receptors in the cerebellum and nucleus accumbens are involved in several aspects of the regulation of locomotor activity and sleep.     

O2 arterial desaturation in endurance athletes increases muscle deoxygenation

PURPOSE: The aim of this study was to compare the muscle deoxygenation measured by near infrared spectroscopy in endurance athletes who presented or not with exercise-induced hypoxemia (EIH) during a maximal incremental test in normoxic conditions. METHODS: Nineteen male endurance sportsmen performed an incremental test on a cycle ergometer to determine maximal oxygen consumption (VO2max) and the corresponding power output (P(max)). Arterial O2 saturation (SaO2) was measured noninvasively with a pulse oxymeter at the earlobe to detect EIH, which was defined as a drop in SaO2 > 4% between rest and the end of the exercise. Muscle deoxygenation of the right vastus lateralis was monitored by near infrared spectroscopy and was expressed in percentage according to the ischemia-hyperemia scale. RESULTS: Ten athletes exhibited arterial hypoxemia (EIH group) and the nine others were nonhypoxemic (NEIH group). Training volume, competition level, VO2max, Pmax, and lactate concentration were similar in the two groups. Nevertheless, muscle deoxygenation at the end of the exercise was significantly greater in the EIH group (P < 0.05). CONCLUSION: Greater muscle deoxygenation at maximal exercise in hypoxemic athletes seems to be due, at least in part, to reduced oxygen delivery--that is, exercise-induced hypoxemia--to working muscle added to the metabolic demand. In addition, our finding is also consistent with the hypothesis of greater muscle oxygen extraction in order to counteract reduced O2 availability.     

Mercury concentrations in king penguin (Aptenodytes patagonicus) feathers at Crozet Islands (sub-Antarctic): temporal trend between 1966--1974 and 2000--2001

Remote sub-Antarctic islands and their wildlife may be contaminated by mercury via atmospheric and oceanic currents. Because of mercury's high toxicity and its capacity to be biomagnified in marine food chains, top predators like seabirds may be threatened by secondary poisoning. The present study provides data regarding mercury concentrations in breast feathers sampled in 2000 and 2001 on king penguins (Aptenodytes patagonicus) living at Crozet Islands. These contemporary concentrations were compared to those measured in feathers of king penguins sampled in the same colony between 1966 and 1974 and preserved in a museum (1970s sample). The average concentration of the contemporary sample is 1.98 microg g(-1) (dry mass) and is significantly different than the concentrations reported in some other penguin species. The concentration of the contemporary sample is significantly lower than the concentration of the 1970s sample (2.66 microg g(-1)). This suggests that mercury concentrations in southern hemisphere seabirds do not increase, which conflicts with the trends observed in the northern hemisphere. This difference in temporal trends between the northern and southern hemispheres usually is attributed mainly to a higher degree of pollutant emission in the northern hemisphere. Parameters that may explain the interspecies differences in mercury concentrations are discussed. These first results may constitute a basis for further ecotoxicological and/or biomonitoring studies of king penguins in these remote ecosystems.     

Rift Valley fever in small ruminants, Senegal, 2003

During the 2003 rainy season, the clinical and serologic incidence of Rift Valley fever was assessed in small ruminant herds living around temporary ponds located in the semi-arid region of the Ferlo, Senegal. No outbreak was detected by the surveillance system. Serologic incidence was estimated at 2.9% (95% confidence interval 1.0-8.7) and occurred in 5 of 7 ponds with large variations in the observed incidence rate (0%-20.3%). The location of ponds in the Ferlo Valley and small ponds were correlated with higher serologic incidence (p = 0.0005 and p = 0.005, respectively). Rift Valley fever surveillance should be improved to allow early detection of virus activity. Ruminant vaccination programs should be prepared to confront the foreseeable higher risks for future epidemics of this disease.     

Infant feeding practices before implementing alternatives to prolonged breastfeeding to reduce HIV transmission through breastmilk in Abidjan, Cote d'Ivoire

The aim of this study was to describe baseline infant feeding practices in women of unknown HIV status in Abidjan, C?te d'Ivoire, before the implementation of infant feeding interventions aimed at the prevention of mother-to-child transmission of HIV through breastmilk. We conducted a cross-sectional survey in March 2000 among 225 mothers attending community-run health facilities with their own child for either immunization or weighting. All but two children had ever been breastfed, of whom 94 per cent were still being breastfed at 6 months of age. Exclusive breastfeeding was not practiced in this population since all women had given water to their child, starting in median one day after birth. Moreover, 20 per cent of the mothers had introduced infant formula in median three weeks after delivery. This study provides useful information for planning purposes in this urban African population, where exclusive breastfeeding is rare and the use of infant formula relatively common.