Polylactic acid vs. polyacrylamide hydrogel for treatment of facial lipoatrophy: a randomized controlled trial [Agence Nationale de Recherches sur le SIDA et les Hépatites Virales (ANRS) 132 SMILE].

OBJECTIVES: The aim of the study was to demonstrate the noninferiority of polyacrylamide hydrogel (PH) vs. polylactic acid (PLA) for the treatment of facial lipoatrophy in HIV-infected adults. METHODS: A randomized, blinded, multicentre, noninferiority 96-week study was carried out. Patients with facial lipoatrophy were randomly assigned to receive intradermal injections with PH or PLA, and were blinded to the filler. The primary efficacy endpoint was patient satisfaction at week 48 assessed using a visual analogue scale score (VAS). Secondary efficacy end-points included cheek thickness and skin-fold, lipoatrophy grading and quality of life. Safety was assessed by the reporting of adverse events. RESULTS: A total of 148 patients were included in the study; 93% were men, the median age was 47 years, the median CD4 count was 528 cells/µL, and the median duration of antiretroviral therapy was 12 years. Mean VAS increased from 2.8 at baseline to 7.1 and 7.5 in the PLA and PH arms, respectively, at week 48 (P=0.0002 for noninferiority) and was sustained at week 96 (6.7 and 7.9 in the PLA and PH arms, respectively; P=0.003 for noninferiority). Cheek thickness and skin-fold increases and lipoatrophy improvement were similar in the two arms. Quality of life remained unchanged or improved depending on the questionnaire used. In injected patients, subcutaneous nodules emerged in 28 (41%) and 26 (37%) patients in the PLA and PH arms, respectively (P=0.73). Four patients in the PH arm developed severe inflammatory nodules, a median of 17 months after the last injection. CONCLUSIONS: PH and PLA have similar efficacies in the treatment of facial lipoatrophy, but PH may be associated with more delayed inflammatory nodules.

The effect of deprivation of glucose on the ultrastructure and function of the superior cervical ganglion of the rat in vitro.

The superior cervical sympathetic ganglion of the rat kept in vitro in a bicarbonate-buffered Krebs' solution retains its capacity for synaptic transmission and axonal conduction during more than 36 hr. After glucose withdrawal, synaptic transmission is lost in 2(1/2) hr and this loss is irreversible; on the other hand, axonal conduction can still be measured on the postganglionic nerve for more than 24 hr after glucose deprivation. Electrophysiological measurements as well as electron microscope studies revealed specific changes at the level of the presynaptic terminal processes, while the ganglion cells and the satellite cells remained relatively unaltered. The presynaptic lesion due to lack of glucose can be prevented by keeping the preparation in vitro at 6 degrees C. This strongly suggests that this lesion results from a major disturbance of the metabolism of the presynaptic fibers.

Neuronal and transneuronal tracing in the trigeminal system of the rat using the herpes virus suis.

The herpes virus suis has been used as a tracer for the pathways in the central nervous system of the rat. The viruses have been inoculated in various peripheral structures innervated by the trigeminal nerve, namely in the cornea by instillation or scarification, in the anterior chamber of the eye by injection and also by subconjunctival injection, nasal instillation and injection in the masseter muscle. The herpes virus suis is easy to detect by immunofluorescence or electron microscopy, the tracing is precise because it does not diffuse, as some other tracers. The virus is replicated at the site of inoculation and at each neuronal relay, thus 'fresh' tracer is continuously brought into the system. The herpes virus suis is transported by retrograde axonal flow. It has been observed in the motor sensory, sympathetic and parasympathetic pathways up to the central nuclei, which demonstrates transneuronal transport. The selectivity of this tracer, applied to the trigeminal pathways, has allowed us to understand the function of the 3 types of neurons present in the trigeminal ganglion, namely to confirm their somatotopy and establish their central projections in the trigeminal system.

Alteration of the electrophysiological activity in sympathetic ganglia infected with a neurotropic virus. I. Presynaptic origin of the spontaneous bioelectric activity.

The bioelectric activity of the rat superior cervical ganglion (SCG) infected with pseudorabies virus (PRV) was examined in vitro 30-38 h after inoculation. Simultaneous intra- and extracellular recordings on the internal (ICN) and external carotid nerves (ECN) revealed a synchronized spontaneous activity. This synchronization can be ascribed either to the functional organization of the ganglion or to the mechanism of initiation itself. In the infected ganglia two categories of cells were observed: cells displaying abnormal spontaneous discharges, and silent cells whose electrophysiological behavior was similar to control cells. Spontaneously active cells showed intermittent spiking and bursting activity. The discharge pattern was associated with the firing rate of the emitting cell: sporadically active cells emitted single spikes whereas highly active cells fired bursts of action potentials (APs). Long lasting intracellular recordings demonstrated that the cells undergo gradual changes evolving from sporadic on to high activity. Spontaneous APs usually rode on prepotentials similar to the excitatory postsynaptic potentials (EPSPs). A comparative study of spontaneous prepotentials and orthodromically evoked EPSPs in the same cell demonstrated that the spontaneous prepotentials are real synaptic potentials. No pace-maker potentials were observed. The passive and active electrical membrane properties of spontaneously active neurons were not different from those of silent cells or control cells impaled in uninfected ganglia. D-Tubocurarine abolished the spontaneous activity in the whole ganglion. Ortho- and antidromic electrical stimulations of suprathreshold intensity elicited an evoked response in neurons displaying spontaneous activity, followed by a delayed burst whose shape was similar to the spontaneous burst of the cell. Stimuli of subthreshold intensities induced this delayed burst independently from the evoked response. We conclude that the spontaneous bioelectrical activity is of presynaptic, but not necessarily of preganglionic origin. The possible existence of a cholinergic intraganglionic pathway revealed by the viral infection is discussed.

Ultrastructure and function in sympathetic ganglia isolated from rats infected with pseudorabies virus.

(1) After inoculation of the pseudorabies virus in the anterior chamber of the eye of the rat, virions can be found only in the neurons of the superior cervical sympathetic ganglion and in the sensory ganglion of the fifth nerve on the inoculated side. Other nervous structures--central or peripheral--are not infected. (2) It is shown that the retrograde axonal flow carries the virus from the eye to the sympathetic neurons. (3) The ultrastructure of the infected neuron has been studied at various intervals after inoculation and at different stages of the viral replication. (4) Excised infected ganglia in vitro show a spontaneous electrophysiological activity that can be recorded on both the post- and preganglionic nerve. Such an activity has never been seen in normal excised ganglion of rat. (5) The shape and frequency of the electrophysiological discharges recorded on the postganglionic nerve have been analyzed at various intervals after inoculation. (6) Correlations established between the ultrastructure, the effect of various drugs and the electrophysiological activity permit the proposal of various hypothesis about the abnormal activity of the infected neurons.

Neuronal organization of the stapedius reflex pathways in the rat: a retrograde HRP and viral transneuronal tracing study.

The location of stapedius motoneurons in the rat was determined with horseradish peroxidase (HRP) retrograde tracing techniques. After injection of free HRP or wheat germ agglutinin-horseradish peroxidase (WGA-HRP) in the stapedius muscle on one side, labeled neurons were seen ipsilaterally in a region ventromedial to the rostral half of the facial motor nucleus (VII), extending rostrally to the caudal part of the superior olivary complex (SOC). These labeled neurons, located outside the SOC and facial motor nuclei themselves, constitute the pool of stapedius motoneurons, in agreement with previous descriptions for other species. In order to identify the origin of some inputs to the stapedius motoneurons, injections of herpes virus suis were performed in the stapedius muscle. After replication in the motoneurons, the viruses are transported transneuronally to some premotor neurons, as previously reported in other systems. The presence of the virus was detected by immunofluorescence in neurons corresponding to the stapedius motoneurons labeled with HRP or WGA-HRP. In addition, infected neurons were seen bilaterally at the level of the SOC, in the mediotrapezoid region, where no labeled cells were observed following HRP or WGA-HRP injections in the stapedius muscle. These neurons were considered as infected transneuronally and therefore providing inputs to the pool of stapedius motoneurons. No virus could be detected in cochlear nucleus neurons. These data are consistent with previous observations in the rabbit based on lesion experiments, suggesting that neurons at the level of the SOC are involved in the reflex arc of middle ear muscles.

Paralytic tremor (pt) rabbit: a sex-linked mutation affecting proteolipid protein-gene expression.

Paralytic tremor (pt) is a neurological sex-linked recessive mutation in rabbits which is characterized by a coarse body tremor and limb paresis. Morphological studies showed that this mutation affects CNS myelination. Although the number of oligodendrocytes is not reduced, myelination is slower, irregular and defective. We have made a biochemical and molecular analysis of 4-wk-old mutant and normal rabbits. The amount of myelin in the mutant represents only approximately 25% of the normal level. Radioimmunoassay for myelin basic protein showed a reduction to approximately 40% in pt whole-brain homogenate but the difference was not significant in purified myelin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of brain homogenates followed by immunoblotting showed that all major myelin proteins are affected by the pt mutation, although to different degrees. While most of the myelin proteins are reduced to approximately 60-80% of the normal level, an important reduction to approximately 30%, was measured for the proteolipid protein (PLP). In purified myelin, the difference in PLP concentration was significant while the other specific proteins were less affected. A similar reduction in myelin-protein gene expression was detected at the mRNA level. Sex-linked transmission, low concentrations of PLP and its specific mRNA in the CNS indicate that the pt mutation primarily affects the expression of the Plp gene.

Isolation and partial characterization of rat CNS axolemma enriched fractions.

Axolemma-enriched fractions were prepared from rat brain by osmotic shock of a purified preparation of myelinated axons and subsequent separation of myelin, two axolemma-enriched fractions and myelin-free axons by density gradient centrifugation. Compared with the starting whole homogenate, the fractions were enriched in specific activity of Na+K+ ATPase, acetylcholinesterase, 5'nucleotidase as well as 2',3'-cyclic nucleotide 3'phosphohydrolase. Compared with myelin, the axolemmal fractions are greatly enriched in high molecular weight proteins. The 1.0/1.2 fraction has a predominant peak of fucose-labeled glycoprotein with a molecular weight between that of the myelin associated glycoprotein and the Wolfgram protein which is absent from the myelin glycoprotein profile. Polyacrylamide gel electrophoresis showed that the protein profile of myelin isolated by this procedure was similar to that of myelin isolated by other procedures and that the myelin specific basic and proteolipid proteins were virtually absent in the axolemma-enriched fractions. Both axolemma fractions were enriched in higher MW proteins, some of which resembled proteins in the myelin protein profile. Both axolemma-enriched fractions specifically bind between 2 and 3 pmoles of [3H]tetrodotoxin per mg protein. The axolemma-enriched fractions incorporated [3H]leucine and [14C]fucose exclusively into high molecular weight proteins and glycoproteins. In contrast myelin concomitantly isolated with the axolemma-enriched fractions had a significant amount of [3H]leucine labeled protein in myelin proteolipid and basic proteins. In addition to the myelin associated g-ycoprotein the [14C]fucose labeled a glycoprotein of slightly larger apparent molecular weight than proteolipid protein was found in the myelin fraction while the comparable labeled glycoprotein was absent in the axolemma-enriched fractions. The possible extent of contamination of these fractions by myelin or myelin subfractions and relationship of these axolemma-enriched fractions to other axolemma preparations are discussed.

Tensor tympani reflex pathways studied with retrograde horseradish peroxidase and transneuronal viral tracing techniques.

The neural pathway involved in activation of the tensor tympani (TT) muscle was studied in the rat using retrograde HRP and transneuronal viral tracing techniques. The pool of TT motoneurons labeled with HRP was located ipsilaterally under the anterior third of the trigeminal motor nucleus and extended rostrally towards the lateral lemniscus. The origin of the inputs to these motoneurons was then determined using transneuronal viral transport: presumably transneuronally infected neurons appeared bilaterally in the vicinity of the superior olivary complex, mainly in between the two nuclei of the trapezoid body. The present data are consistent with previous conclusions based on lesion experiments that the TT reflex loop is made up of a chain of 4 neurons.

Neurohypophysial peptides depress cholinergic transmission in a mammalian sympathetic ganglion.

The actions of arginine-vasopressin (AVP) and oxytocin (OXT) were investigated in the rat superior cervical ganglion (SCG). At micromolar concentrations AVP decreased the amplitude of fast excitatory postsynaptic potentials (f-EPSPs) evoked by preganglionic stimulation and in many cells depolarized the postsynaptic membrane. Both effects were reversibly abolished by a potent vasopressor antagonist. The peptide decreased the frequency of spontaneous miniature EPSPs and the quantal content of the f-EPSPs without affecting the sensitivity of the ganglion cells to acetylcholine. OXT exerted the same effects as AVP but was less powerful. It was concluded that neurohypophysial peptides exert a dual pre- and post-synaptic action mediated by specific receptors.

Characterization of two subcellular fractions isolated from myelinated axons.

Myelin and a heavy membrane fraction (1.0/1.2 fraction) were isolated from rabbit white matter by a slight modification of the procedure for bovine CNS. The specific activities of acetylcholinesterase and Na+, K+-ATPase were higher in the 1.0/1.2 fraction than in myelin. In contrast, the cerebroside content and 2'3'-cyclic nucleotide 3'-phosphohydrolase activity in the 1.0/1.2 fraction were 4.5 and 3.4 times lower than in myelin. Total lipids accounted for only 30% of the 1.0/1.2 fracton's dry weight; for myelin, they represented 70%. Polacrylamide gel electrophoresis showed the presence of many high molecular weight proteins and glycoproteins in the 1.0/1.2 fraction but myelin components were practically missing. Cytochrome c oxidase and NADPH-cytochrome c reductase activities suggested about 15% contamination in the 1.0/1.2 fraction but less than 5% for myelin. In electron micrographs of the 1.0/1.2 fraction, there were many membraneous profiles that varied in size, some mitochondrial fragments, and only a few lamellar whorls of compact myelin. The results suggest that the 1.0/1.2 fraction is different from other myelin-related fractions and is probably enriched in axolemma.

[Progression of the rabies virus in the visual system of the rat]. / Etude de la progression du virus rabique dans le système visuel du rat.

The CVS rabies virus, inoculated in the anterior chamber of the eye, is transported from the retina to the central nervous system only along the accessory optic tract and invades transsynaptically its terminal nuclei. On the other hand the retino-geniculo-cortical system is affected much later. Thus the virus shows a special affinity for a well defined neuronal system and behaves as a precise tracer of its intracerebral connections.

Developmental expression of major myelin proteins in hypomyelinated pt mutant rabbit.

A term "paralytic tremor" (pt) is attributed to a neurological mutation of Chinchilla rabbits, affecting the development of the central nervous system (CNS). A quantification of myelin protein content indicates the strong CNS hypomyelination during the development (1-120 postnatal days). SDS-PAGE electrophoresis of total brain homogenates, followed by immunoblotting, shows a reduced concentration of major myelin-connected proteins. MBP deficiency corresponds approximately to the level of the hypomyelination, whereas PLP expression is drastically reduced.

[Double-blind study versus excipient of 0.75% metronidazole gel in the treatment of rosacea]. / Etude en double insu contre excipient du métronidazole gel à 0.75 p. 100 dans le traitement de la rosacée.

INTRODUCTION: The proven value of tetracyclines and metronidazole administered orally in the treatment of the chronic and recurrent disease that is rosacea is tempered by the important undesirable effects observed in long-term therapy. The purpose of this study was to test the effectiveness of an 0.75 p. 100 metronidazole gel in the treatment of rosacea. PATIENTS AND METHODS: The study involved two groups of patients: one received the metronidazole gel and the other the vehicle of the gel used as placebo. The multicentre randomized trial was conducted in the double-blind fashion by 18 private dermatologists working in the Paris region. Fifty one patients who, since more than 3 months, had been presenting with rosacea, defined as at least 4 papulopustules associated with erythema and/or telangiectasia, entered the trial. Topical treatments and systemic treatments which had shown some activity against rosacea had been interrupted for 15 days or 2 months respectively. The product (or the placebo) was applied a.m. and p.m. on the whole dry face. The patients were seen on days 0, 21 and 42. The evaluation was purely clinical, and the principal criterion of judgement was a change in the number of papulopustules between days 0 and 42. RESULTS: The metronidazole gel reduced the number of papulopustules between day 0 and day 42, and this reduction was significantly greater than that observed with the excipient alone. The active product began to be effective during the third week and remained so during the next three weeks. Both the metronidazole gel and its excipient seemed to be poorly tolerated, with frequent complaints of dry skin, but in 5 women of the metronidazole group this dryness was alleviated by application of moisturizers. CONCLUSION: This study has demonstrated that the 0.75 p. 100 metronidazole gel is effective in the treatment of the papulopustular component of rosacea.

Segmental pruritus and intramedullary vascular malformation.

Pruritus remains a medical mystery. Generally related with dermatological diseases, it is rarely associated with a neurological cause. We report a case of segmental pruritus (right T2 dermatome) related to an intramedullary vascular malformation. An anatomicophysiological explanation is presented. It is the first demonstration in man that pain receptors are not involved in pruritus, and suggests pruritus is under the control of descending inhibitory pathways.

Myelin proteolipid protein mutation in the rabbit: a new model of Pelizaeus-Merzbacher disease.

Proteolipid protein (PLP) is a major myelin protein of the central nervous system. Mutations of the Plp gene are responsible for a number of sex-linked disorders in humans (Pelizaeus-Merzbacher disease) and in animals. We have identified a novel mutation of the Plp gene which gives rise to the paralytic tremor (pt) phenotype in rabbit. Pt rabbits are hypomyelinated and present very low levels of PLP protein and its mRNA. Sequence analysis revealed a single nucleotide change in exon 2 which results in the substitution of a histidine by a glutamine at position 36. Histidine36 is positioned at the boundary of the first transmembrane domain. Therefore, its position can be crucial for the efficient interaction of PLP with other proteins and lipids, and for correct incorporation into the membrane.