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Semantic dementia (SD) is a syndrome of progressive loss of semantic knowledge for objects and people. International criteria propose that SD be included in the frontotemporal lobar degeneration syndromes, with progressive non-fluent aphasia and frontotemporal dementia (FTD). However, several related syndromes have been defined that clinically and conceptually share both similarities and differences with SD: fluent progressive aphasia, progressive prosopagnosia, temporal variant of FTD. In order to establish a French consensus for the diagnosis and modalities of evaluation and follow-up of SD, a working group, composed of neurologists, neuropsychologists and speech-therapists, was established by the Groupe de reflexion sur les evaluations cognitives (GRECO). New criteria were elaborated, based on clinical, neuropsychological, and imaging data. They define typical and atypical forms of SD. A diagnosis of typical SD relies on an isolated and progressive loss of semantic knowledge, attested by a deficit of word comprehension and a deficit of objects and/or people identification, with imaging showing temporal atrophy and/or hypometabolism. SD is atypical if the deficit of semantic knowledge is present only within a single modality (verbal versus visual), or if non-semantic deficits (mild and not present at onset) and/or neurological signs, are associated with the semantic loss.

We report a case of massive associative visual agnosia. In the light of current theories of identification and semantic knowledge organization, a deficit involving both levels of structural description system and visual semantics must be assumed to explain the case. We suggest, in line with a previous case study [1], an alternative account in the framework of (non abstractive) episodic models of memory [4].

We report the case of a 71 year-old female patient (DC) with a left parietal lesion resulting in a peripheral dysgraphia essentially characterized by difficulties in letter sequences writing. The aim of our experiments was to analyze the influence of motor difficulties on the visual perception of both writing and reaching movements. Results showed a strong link between motor and perceptual performance. For reaching movements, performances in both production and perception tasks conform to the motor principles identified in healthy subjects (Fitts' law and motor anticipation). By contrast, for handwriting movements, DC's productions do not follow the motor principles usually observed in normal subjects (isochrony principle, motor anticipation) and in perception the same results were observed. The motor references used by DC in the visual perception of writing movement were not the laws of movement but rather her own way of writing. Taken together these data strongly suggest that motor competences is involved in the visual perception of human movements. They are discussed in the general framework of the simulation theory.

The present study describes two Frenchteenagers with developmental reading andwriting impairments whose performance wascompared to that of chronological age andreading age matched non-dyslexic participants.Laurent conforms to the pattern of phonologicaldyslexia: he exhibits a poor performance inpseudo-word reading and spelling, producesphonologically inaccurate misspellings butreads most exception words accurately. Nicolas,in contrast, is poor in reading and spelling ofexception words but is quite good atpseudo-word spelling, suggesting that hesuffers from surface dyslexia and dysgraphia.The two participants were submitted to anextensive battery of metaphonological tasks andto two visual attentional tasks. Laurentdemonstrated poor phonemic awareness skills butgood visual processing abilities, while Nicolasshowed the reverse pattern with severedifficulties in the visual attentional tasksbut good phonemic awareness. The presentresults suggest that a visual attentionaldisorder might be found to be associated withthe pattern of developmental surface dyslexia.The present findings further show thatphonological and visual processing deficits candissociate in developmental dyslexia.

Patients with Alzheimer's disease (AD) produce a high rate of semantic errors when naming to confrontation. This is considered to be one of the many consequences of their semantic memory deficit. However, it has been shown, in aphasic patients with focal lesions, that semantic errors could arise from impairment to any one of the levels in the naming process. To check this hypothesis in AD, we assessed in 15 patients the capacity to name and access semantic knowledge (by multiple-choice probe questions) about 14 objects presented successively in the visual, tactile, auditory, and verbal modalities. In the visual naming task, 33 errors were recorded: 26 (78.8%) were semantic and 7 (21.2%) were unrelated errors. Of the 26 semantic errors, 8 were related to a deficit of the semantic knowledge related to the item and 17 to a deficit in the retrieval of the phonological form of the word. One was associated with a deficit of access to semantic knowledge in the visual modality. The 7 unrelated errors were associated with a loss of semantic knowledge for 4 and deficit of access to the phonological form for 3. In conclusion, this study shows that semantic errors do not systematically reflect a deficit of semantic knowledge in Alzheimer's disease. It also seems that unrelated errors are more frequently related to semantic deficits than semantic errors in this population.

Two main hypotheses have been proposed regarding the role of phonology in written word production. According to the phonological mediation hypothesis, the retrieval of the lexical phonological representation of a word is an obligatory prerequisite to the retrieval of its spelling. Therefore, deficits to the phonological lexicon should affect both spoken and written picture naming. In contrast, the orthographic autonomy hypothesis posits that the lexical orthographic representations of words can be accessed without any necessary phonological mediation. In support of this view, cases of preserved written naming despite impaired lexical phonology have been reported following brain damage. In this report, we replicate this basic pattern of performance in case YP, a 60-year-old woman with a pattern of frontotemporal dementia. As her disease progressed, YP's ability to write down the names of pictures remained very good despite a severe decline in oral naming. Further testing indicated that this deficit was not primarily due to an articulatory or post-lexical phonological deficit. YP's case provides strong additional support for the orthographic autonomy hypothesis. The significance of this case with respect to the characterization of dementia syndromes is discussed.

Following cerebral anoxia, EC, a 55-year-old patient, exhibited a severe and clear-cut pattern of semantic impairments without general intellectual deficit or perceptual difficulty. EC demonstrated a complex neuropsychological picture including a massive visual agnosia and a complete lack of imagery, both of which involved all categories of objects (living and non living) and a category-specific word comprehension deficit limited to animal names. Findings are discussed in the light of the theoretical frameworks currently available in the area of neuropsychology. It is argued that neither the single nor the multiple view of semantics fully succeed in providing a satisfactory account of the data and a tentative interpretation of the whole pattern of impairment is proposed in the general framework of non abstractive conceptions of meaning.

A double-blind, placebo-controlled, parallel-group, multicentre study was conducted to evaluate the efficacy of pentoxifylline (Trental) in patients with multi-infarct dementia (MID) according to DSM-III-R criteria. Men and women aged 45 years or older, with a Hachinski Ischemia Scale scoreor = 7 and a Mini Mental State Examination (MMSE) score of 10-25 at entry, and computed tomographic evidence of vascular disease were enrolled. A total of 289 patients were randomised to receive either oral pentoxifylline 400 mg t.i.d. or placebo for 9 months, and efficacy was assessed every 3 months. The primary outcome variable was the difference in scores between the two treatment groups, as measured on the Gottfries, Bråne, Steen (GBS) scale. Secondary outcome variables included the scores achieved on the Sandoz Clinical Assessment Geriatric (SCAG) scale and MMSE, and a battery of psychological and other tests. The intention-to-treat analysis for patients completing the study (n = 239) showed a statistically significant difference in the total GBS score in favour of pentoxifylline (improvement of 3.5 points, p = 0.028). A significant difference in the total GBS score in favour of pentoxifylline was even almost achieved in the intention-to-treat analysis for all evaluable patients (n = 269, improvement of 2.1 points, p = 0.065). It is concluded that treatment with pentoxifylline is beneficial for patients with MID, the global results of the GBS and SCAG scales being reinforced by significant improvements in those subscales specific for intellectual and cognitive function.

A case study is presented of a patient, EA, who demonstrated all the defining features of deep dysphasia. His repetition disorder was associated with surface dyslexia and deep dysgraphia. EA also showed a severely restricted phonological STM. His performance in both picture confrontation naming and writing-to-dictation paralleled his performance in repetition, whereas reading aloud and oral lexical decision were not influenced by the imageability of the word input. Further testing indicated that EA did not have difficulty in either perceiving or semantically processing spoken words. An exhaustive investigation of EA's cognitive functioning was first conducted by reference to Patterson and Shewell's model (1987). Such a triple-route model can account for EA's overall performance by postulating multiple functional lesions. We alternatively show that EA's language profile could be accounted for within a highly interactive model of language processing incorporating most basic principles of connection...

Summary Biochemical and immunological studies of the membrane cytoskeleton were carried out using the entodiniomorphid ciliated protozoa: Entodinium bursa, Eudiplodinium maggii, Epidinium caudatum and Polyplastron multivesiculatum. Immunological cross-reactions within the four ciliates show significant labelling of proteins with the same or different molecular weights among species. Antigenic homologies among cytoskeletal proteins with variable MW suggest that Ophryoscolecidae have maintained both a similar architectural organization and a cytoskeletal function while diversifying the MW of many cytoskeletal proteins. A comparative study of the antigenic relationships points away from an evolutionary lineage from simplest (the ancestral Entodinium) to more complex (the intermediate Eudiplodinium and the more advanced Epidinium and then Polyplastron), and also the linear evolution based on the increasing complexity of the cytoalimentary system. It suggests a bushy evolution by radiation from unknown ancestral forms. This is supported by sequencing of the different entodiniomorphid ribosomal RNAs.

Summary We have previously reported biochemical evidence suggesting that a 58 Kd protein (p 58) is a major constituent of the membrane skeleton of the ciliated protozoan Entodinium bursa . In this study, monoclonal antibodies were produced in order to determine the distribution of p 58 in the four entodiniomorphids Entodinium bursa, Eudiplodinium maggii, Epidinium caudatum and Polyplastron multivesiculatum . Two clones, 78-116-4 and 76-12-7, were selected from a set of hybridomas obtained using either p 58 or whole proteins from cytoskeletal preparations of Eudiplodinium maggii as immunogens. Specificity tests by Western blot analysis indicate that MABs 78-116-4 and 76-12-7 both recognize p 58 in Entodinium bursa and protein ranging from 59 to 62 Kd in the three other species examined. Immunocytochemical evidence is presented which confirms that 78-116-4 and 76-12-7 antigens are located in the membrane skeleton. This suggests that the latter may represent homologous proteins implicated in the maintenance of a consistent pattern of cortical organization in the entodiniomorphid ciliates.

Aphasia is common in elderly patients in the context of vascular or neurodegenerative disorders. In some cases, aphasia is an isolated symptom, occurring suddenly after a stroke, or developing progressively as a primary progressive aphasia. The diagnosis and treatment are then very similar in older and younger patients. Therapy may be more complicated because of the high prevalence, in older patients, of associated non linguistic symptoms (attentional and dysexecutive symptoms, behavioral and psychological symptoms or sensorial deficits), fatigability, and comprehension deficits. It may then become very difficult to recognize aphasia among all these disorders and to appreciate the physiopathology. A complete evaluation of language, cognitive functions, psychopathology, and behavior is very helpful, as are neuroimaging techniques (MRI is the most relevant). A good knowledge of classical aphasic pictures associated with stroke, Alzheimer disease or related disorders, is highly recommended. Rehabilitation must be proposed even for older patients, so far as aphasia alters the communication abilities. It must be kept in mind that associated symptoms may limit considerably the therapy.

Primary progressive aphasia (PPA), initially described by Mesulam, is a syndrome of progressive deterioration of language, occurring in the presenium. Several classifications have been proposed, but the most useful one distinguishes non fluent and fluent forms of PPA. Both begin by anomia. In non fluent PPA, there is a progressive reduction of language, sometimes with aggramatism and articulatory impairment, but without impairment of comprehension. Fluent PPA is characterized by preserved fluency with severe impairment of single word comprehension. It is frequently confounded with semantic dementia (SD), but some observations can be differentiated from SD. After several years, all patients become mute, and most of them develop dementia, usually of frontal lobe type. The syndrome of PPA is due to neurodegenerative brain pathology affecting mostly the perisylvian regions of the left hemisphere. In most cases, no Alzheimer type pathology was found in the brain, but tauopathy (mainly in non fluent PPA) or motor neuron disease type pathology - tau negative ubiquitin inclusions (mainly in fluent PPA). However, Alzheimer type pathology was found in a substantial number of cases.

Introduction La demence semantique se definit comme une perte progressive des connaissances semantiques, responsable d’une difficulte a identifier les objets (et/ou personnes) a partir de leur image et/ou de leur nom. La memoire au jour le jour est normale et les aspects non semantiques du langage sont theoriquement preserves. Cependant, les travaux qui ont evalue chez les patients DS l’integrite des representations lexicales pre-semantiques au moyen de la tâche de decision lexicale donnent lieu a des resultats divergents, allant d’une preservation totale a un deficit severe. L’hypothese la plus couramment avancee consiste a mettre en relation la degradation des performances en decision lexicale avec la severite des troubles semantiques. Afin de tester cette hypothese, nous avons evalue de facon systematique les performances dans cette tâche de 6 patients DS. Methode 6 patients presentant une DS selon les criteres de Neary et al (1998) ont participe a l’etude. 2 patients presentent une forme verbale pure de DS et 4 presentent une forme multimodale associant des troubles du langage a des deficits de l’identification visuelle des objets et des personnes. La severite des troubles semantiques etait attestee par la performance au Pyramid et Palm Trees test, dans sa forme verbale. La tâche de decision lexicale comportait des mots de haute et basse frequence et des non mots legaux, apparies en longueur et frequence des graphemes, presentes oralement. Resultats Les performances en decision lexicale sont variables et vont d’une preservation totale a des performances tres deficitaires. Il n’existe aucune correlation avec la severite des troubles semantiques mesures par la performance au PPTT verbal. En revanche, la performance est correlee avec le profil des troubles : la decision lexicale est tres deficitaire chez les 2 patients presentant une forme atypique (verbale pure) selon les criteres de Moreaud et al (2008), alors qu’elle est preservee dans les DS typiques (multimodales), qui presentent pourtant des deficits semantiques plus severes. Conclusion Ce resultat suggere que la forme verbale pure et la forme multimodale de demence semantique pourraient representer deux entites cliniques distinctes sous-tendues par des deficits fonctionnels differents.

The microsporidian Encephalitozoon cuniculi is an obligate intracellular parasite that can cause opportunistic infections in AIDS patients. Spore invasion of host cells involves extrusion of a polar tube. After immunocytochemical identification of several polar tube proteins (PTPs) in E. cuniculi, a major PTP was isolated from two-dimensional gels and two peptide fragments were sequenced. The complete nucleotide sequence of the corresponding gene was obtained using a combination of PCR amplification and cloning techniques. The gene exists as a single copy per haploid genome and encodes an acidic proline-rich protein, with a deduced molecular mass of 37 kDa, that contains four tandemly arranged 26-amino-acid repeats. An N-terminal region of 22 residues represents a cleaved signal peptide, probably involved in the targeting of the PTP. No similarity with known proteins has been found. The protein was expressed in Escherichia coli, purified and injected into mice. The antisera reacted specifically with the polar tube in indirect immunofluorescence assays and electron microscope immunocytochemistry. Further identification of conserved and variable PTP structural motifs should be useful for diagnostic purposes and new therapeutic strategies.

Chick and Quail eggs were treated for 30 seconds, before incubation, with diluted aqueous suspension of commercial DDT. During the early stages of development, the germ cell population of treated embryos increases progressively and is only slightly lower than the control one. For each stage, the difference between the number of germ cells in controls and embryos contaminated by DDT, is not statistically significant. To exert its sterilizing effect on the germ cells, DDT must be administered before the beginning of incubation. At a later stage, when the gonocytes have colonized the gonads, the germ deficit becomes significant.

1) An ultrastructural and optical examination of the "in utero" development of the stomach in Rabbit embryos, demonstrates that the epithelium increases by"vacuolisation". The intraepithelial vacuoles, formed by a secretory process, secondarily open into the gastric cavity, whence the constitution of primary villi. Then the mesenchyme buds chorionic evaginations under the epithelial crests and transforms the primary into secondary villi. As the villi grow longer the epithelium loses its pseudostratified structure in order to become simply unistratified. At the same time, the four types of gastric cells progressively accomplish their differentiation into parietal, mucous, peptic cells and surface epithelium. 2) The presumptive gastric area of a ten-day-old Rabbit embryo corresponds to the lower third of the entomesoblastic part of the embryonic pharynx, posteriorly amputated at the umbilical edge. This presumptive area, grafted in the Chick embryo, differentiates into characteristic gastric tissue. Finally the stomach is explanted ("in vitro" and"in ovo") at different stages of ontogenesis. Up to the thirteenth day it degenerates in culture but grows and accomplishes its morphogenesis as a graft. From the fifteenth day, the cultured and grafted stomach differentiates on both morphogenetic and cytochemical planes.

The epithelio-mesenchymal relations during the gastric organogenesis of the rabbit foetus The experimental study of the epithelio-mesenchymal relations during the gastric organogenesis shows the following facts: Completely deprived of mesenchyme, the cultured or grafted isolated epithelium cannot develop. On the other hand the mesenchyme free of epithelium can survive and differentiate its muscular layer. Isolated after the 18th day, it possesses sufficient autonomy to form chorionic villi when covered only by vitelline membrane. The epithelium and the mesenchyme, dissociated by treatment with trypsin, then reassociated in culture (with or without subsequent grafting), develop identically to those of untreated controls. From the 19th day the mesenchyme shows a polarity and only the zone normally adjacent to the epithelium can form chorionic villi. The heterochronic associations of gastric epithelium and mesenchyme demonstrate the existence of two types of mesenchymal inductors: (a) a primary inductor, responsible for the epithelial morphogenesis, elaborated early in embryonic life (10th day); it acts till about the 21st day. (b) A secondary inductor, produced at a later time (15th day), provokes the epithelial cytodifferentiation; its activity is still strong at the 23rd day. These experiments again show the early competence of the epithelium to react to the two mesenchymal inductors. The presumptive gastric endoderm of the 10-day-old rabbit foetus has a developmental potential such that it can respond as well to the stimuli elaborated by a young mesenchyme as to those of an older mesenchyme.

Experimental associations of gastric epithelium of the Rabbit foetus with homologous or heterologous mesenchyme, separated by membrane filter or "partially" associated, permit us to prove the existence of two types of inductors.The first factor induces the epithelial morphogenesis. It is thermostable and highly diffusible.The second factor, organospecific, is more or less favorable to the differentiation of the gastric epithelium according to the nature of the mesenchyme. Lightly diffusible and thermolabile, it is elaborated in the cytoplasmic phase of the mesenchymal cells.

Chick and Quail eggs were treated for 30 seconds, before incubation, with diluted aqueous suspension of commercial DDT. During the early stages of development, the germ cell population of treated embryos increases progressively and is only slightly lower than the control one. For each stage, the difference between the number of germ cells in controls and embryos contaminated by DDT, is not statistically significant. To exert its sterilizing effect on the germ cells, DDT must be administered before the beginning of incubation. At a later stage, when the gonocytes have colonized the gonads, the germ deficit becomes significant.

Experimental associations of gastric epithelium of the Rabbit foetus with homologous or heterologous mesenchyme, separated by membrane filter or "partially" associated, permit us to prove the existence of two types of inductors.The first factor induces the epithelial morphogenesis. It is thermostable and highly diffusible.The second factor, organospecific, is more or less favorable to the differentiation of the gastric epithelium according to the nature of the mesenchyme. Lightly diffusible and thermolabile, it is elaborated in the cytoplasmic phase of the mesenchymal cells.

1) An ultrastructural and optical examination of the "in utero" development of the stomach in Rabbit embryos, demonstrates that the epithelium increases by"vacuolisation". The intraepithelial vacuoles, formed by a secretory process, secondarily open into the gastric cavity, whence the constitution of primary villi. Then the mesenchyme buds chorionic evaginations under the epithelial crests and transforms the primary into secondary villi. As the villi grow longer the epithelium loses its pseudostratified structure in order to become simply unistratified. At the same time, the four types of gastric cells progressively accomplish their differentiation into parietal, mucous, peptic cells and surface epithelium. 2) The presumptive gastric area of a ten-day-old Rabbit embryo corresponds to the lower third of the entomesoblastic part of the embryonic pharynx, posteriorly amputated at the umbilical edge. This presumptive area, grafted in the Chick embryo, differentiates into characteristic gastric tissue. Finally the stomach is explanted ("in vitro" and"in ovo") at different stages of ontogenesis. Up to the thirteenth day it degenerates in culture but grows and accomplishes its morphogenesis as a graft. From the fifteenth day, the cultured and grafted stomach differentiates on both morphogenetic and cytochemical planes.