Why semantic dementia drives you to the dogs (but not to the horses): A theoretical account

This paper describes a patient (IH) with semantic dementia and severe impairment in all semantic categories except for numerical knowledge, which was preserved. IH showed a severe deficit in reading and writing non-number words (e.g., candle, juice) and nonwords, and preservation of reading and writing number words (e.g., one, forty) and numerals (e.g., 1, 40). IH's pattern of performance can be explained by the combination of a selective sparing of one semantic category--i.e., numbers--with a total deficit of nonsemantic processes for mapping letters and sounds. As number was the only spared semantic category in the presence of these other nonsemantic deficits, it follows that the semantic route is sufficient for accurate reading and spelling. Our data clarify the nature of reading and writing processes and support the functional and neuroanatomical independence of the number domain.     

Everything you always wanted to know about HPV (but could not ask your doctor)

Objective To investigate specific information needs of people who search for information about the human papillomavirus (HPV) on the Internet.Methods We performed a qualitative analysis of the e-mail questions asked by the visitors of a website with evidence-based information about HPV. The website, hosted by Antwerp University, provided basic information on epidemiology and natural history of HPV in women and men, diagnostic and treatment options, screening, and vaccination. If visitors did not find an answer to their questions, they could mail their question to an e-mail address associated with the website.Results We received 713 questions posed by 527 e-mail correspondents. The following themes emerged as most important: transmission of HPV, the HPV vaccine, the natural history of the virus, the vicious circle (re-infection between partners), HPV detection in men and women, treatment of men and women, incubation time, pregnancy/fertility, genital warts (in)fidelity, and symptoms of HPV infection.Conclusion Both men and women are seeking health information on HPV on the Internet, often after being counseled by a health care provider.Practice implications Practitioners should be prepared for questions on the themes that concern people most. Practitioners may play a role in guidance towards reliable sources of information.     

Failing to get the gist: reduced false recognition of semantic associates in semantic dementia

In 2 experiments involving patients with semantic dementia, the authors investigated the impact of semantic memory loss on both true and false recognition. Experiment 1 involved recognition memory for categories of everyday objects that shared a predominantly semantic relationship. The patients showed preserved item-specific recollection for the pictorial stimuli but, compared with control participants, exhibited significantly reduced utilization of gist information regarding the categories of objects. The latter result is consistent with the patients' degraded semantic knowledge. Experiment 2 involved categories of abstract objects that were related to one another perceptually rather than semantically. Patients with semantic dementia obtained item-specific recollection and gist memory scores that were indistinguishable from those of control participants. These results suggest that the reduction in gist memory in semantic dementia is largely specific to semantic representations and cannot be attributed to general difficulty with abstracting and/or utilizing gistlike commonalities between stimuli.     

A PCR study of piroplasms in 166 dogs and 111 horses in France (March 2006 to March 2008)

Positive PCR results for piroplasms were obtained on EDTA blood samples from 166 dogs and 111 horses between March 2006 and March 2008. The organisms were initially identified using common primers, followed by restriction enzyme profiles to determine the species and types of Babesia/Theileria. In 27 dogs and eight horses with positive results, the size of the specimen was insufficient to separate species/types. We identified Babesia canis canis in 105 of the 166 dogs (63%) and Theileria equi in 89 of the 111 horses (80%). Babesia caballi was also present, but rare, in only two Babesia/Theileria of the 111 horses (1.2%). Unexpected findings were the identification of T. equi in 31 of the 166 dogs (19%), of B. caballi in one of the 166 dogs (0.6%), of B. canis canis in 11 of 111 horses (10%), as well as of Babesia canis rossi in one of 111 horses (0.9%). A positive result for B. canis rossi was also obtained in one of the 166 dogs (0.6%). A single case of the California type of “Babesia gibsoni” (presumably Babesia conradae) was found in a dog. We did not detect Babesia canis vogeli, possibly because of the geographic distribution of our clients. The unusual results were confirmed by DNA sequencing in several cases for B. canis canis and B. canis rossi in horses, as well as T. equi in dogs. Such infections might explain the difficulties met in some unsuccessfully treated animals using the standard dosage of imidocarb dipropionate at 3 mg/kg in dogs.     

Early neutrophil but not eosinophil or platelet recruitment to the lungs of allergic horses following antigen exposure

Previous studies have shown that bronchoalveolar lavage fluid from horses with allergic respiratory disease and showing clinical symptoms contains increased numbers of neutrophils. In some cases, the eosinophil count is also increased. In this study the time course of changes in lung function and the accumulation of radiolabelled leucocytes and platelets in the lungs of allergic and normal horses has been examined during a 7 hr allergen exposure. Antigen challenge had no effect on pleural pressure or the distribution of radiolabelled neutrophils, eosinophils or platelets in normal horses. In contrast, in 6/8 allergic horses, there was an increase in pleural pressure and neutrophil accumulation in the lungs, both of which were evident after 4-5 hr. However, during the 7 hr challenge period radiolabelled eosinophils were detected in the lungs of only 1/6 horses exhibiting an increase in pleural pressure and in 1/7 horses that failed to show a change in airway function despite a clinical history of allergic respiratory disease. Antigen challenge did not alter the distribution of radiolabelled platelets in the five allergic horses tested. These results demonstrate that increased pleural pressure is not accompanied by eosinophil or platelet accumulation in the lungs of horses with allergic respiratory disease following exposure to antigen. However, changes in airway function can be associated with neutrophil accumulation but can also take place in the absence of this cell recruitment. This raises the possibility that the presence of neutrophils in the lung is not a prerequisite for changes in lung function.     

They know the words, but not the music: affective and semantic priming in individuals with psychopathy

Previous work has indicated dysfunctional affect-language interactions in individuals with psychopathy through use of the lexical decision task. However, it has been uncertain as to whether these deficits actually reflect impaired affect-language interactions or a more fundamental deficit in general semantic processing. In this study, we examined affective priming and semantic priming (dependent measures were reaction times and error rates) in individuals with psychopathy and comparison individuals, classified according to the psychopathy checklist revised (PCL-R) [Hare, R.D., 1991. The Hare Psychopathy Checklist-Revised. Multi-Health Systems, Toronto, Ont] Individuals with psychopathy showed significantly less affective priming relative to comparison individuals. In contrast, the two groups showed comparable levels of semantic priming. The results are discussed with reference to current models of psychopathy.     

The differentiation of semantic dementia and frontal lobe dementia (temporal and frontal variants of frontotemporal dementia) from early Alzheimer's disease: a comparative neuropsychological study

The authors compared age-matched groups of patients with the frontal and temporal lobe variants of frontotemporal dementia (FTD; dementia of frontal type [DFT] and semantic dementia), early Alzheimer's disease (AD), and normal controls (n = 9 per group) on a comprehensive neuropsychological battery. A distinct profile emerged for each group: Those with AD showed a severe deficit in episodic memory with more subtle, but significant, impairments in semantic memory and visuospatial skills; patients with semantic dementia showed the previously documented picture of isolated, but profound, semantic memory breakdown with anomia and surface dyslexia but were indistinguishable from the AD group on a test of story recall; and the DFT group were the least impaired and showed mild deficits in episodic memory and verbal fluency but normal semantic memory. The frontal and temporal presentations of FTD are clearly separable from each other and from early AD.     

I hear you knockin' (but you can't come in): potent new HIV therapies are shutting out opportunistic infections

Highly active antiretroviral therapy (HAART) has positively impacted the epidemiology of opportunistic infections in HIV- infected patients. The following opportunistic infections and their responses to HAART and prophylaxis recommendations are examined: pneumocystis carinii pneumonia (PCP), cytomegalovirus (CMV) disease, mycobacterium avium complex (MAC) disease, and fungal diseases. The question of whether opportunistic infection prophylaxis should be continued in persons who respond to HAART is discussed. A table provides recommendations for opportunistic illness prophylaxis, listing the primary choice of therapy for each illness followed by alternative choices of therapy for each illness.     

Congenital talipes equinovarus (clubfoot): a disorder of the foot but not the hand

Idiopathic (non-syndromic) congenital talipes equinovarus, or clubfoot, is a poorly understood but common developmental disorder of the lower limb, which affects at least 2 per 1000 Scottish births (ISD data). It is defined as a fixation of the foot in a hand-like orientation--in adduction, supination and varus--with concomitant soft tissue abnormalities. Despite advances in treatment, disability often persists. The aetiology of the condition has been little studied and is poorly understood. Neurological, muscular, bony, connective tissue and vascular mechanisms have been proposed, but the only firm evidence is that the mildest cases appear to be associated with intra-uterine posture. There is evidence for a genetic contribution to congenital talipes equinovarus aetiology. Its incidence varies with ethnic group, and we found that a family history is present in 24-50% of cases, depending on the population studied. Complex segregation analysis suggests that the most likely inheritance pattern is a single gene of major effect operating against a polygenic background. Possible mechanisms for congenital talipes equinovarus are discussed.     

A monoclonal antibody against the human IL-2 receptor binds to paraformaldehyde-fixed but not viable frog (Xenopus) splenocytes

Others have reported that a monoclonal anti-human IL-2 receptor antibody (anti-CD25) specifically binds a membrane receptor on Xenopus laevis PHA-induced and paraformaldehyde-fixed splenic blasts. In this paper, we present evidence suggesting that this binding is an artifact of membrane damage. Specifically, significant binding of anti-CD25 could only be achieved if the lymphoblasts were acid-washed and/or paraformaldehyde-fixed prior to being incubated with the fluoresceinated antibody. For example, in a representative experiment 95% of paraformaldehyde-fixed blasts, about 19% of acid-washed but not fixed blasts, but fewer than 2% of viable (untreated) blasts were positive for the CD25 epitope. Paraformaldehyde is known to alter membrane permeability. The DNA dye propidium iodide (PI) was used to demonstrate that the acid washing procedure also causes membranes to become permeable. Flow cytometric analyses of acid-washed PHA-induced splenic blasts doubly stained with the anti-CD25 antibody and PI showed that only 1.5% of the cells that were positive for CD25 did not stain with PI. Additionally, the anti-CD25 antibody, which immunoprecipitated a molecule from human lymphoblasts of between 50 and 60 kDa, did not immunoprecipitate any surface molecules from 125I-labeled Xenopus splenic blasts. Since binding of anti-CD25 to Xenopus splenic blasts appears to occur only after membrane damage, the antibody may be recognizing a cross-reactive internal epitope that is not involved in ligand binding on the cell surface.     

Memory reconsolidation hypothesis revived but restrained: theoretical comment on Biedenkapp and Rudy (2004)

J. C. Biedenkapp and J. W. Rudy (2004) reported that the protein synthesis inhibitor anisomycin administered into the hippocampus after context preexposure or contextual fear conditioning impaired subsequent retention performance. In contrast, anisomycin administered after context memory retrieval did not impair subsequent contextual fear conditioning. Their findings challenge the hypothesis that memory retrieval induces memory reconsolidation and suggest that the hypothesis needs to be constrained to account for negative findings. However, their evidence does not suggest compelling clues to how the hypothesis might be constrained to accommodate the findings. Thus, it is not yet clear whether their findings can be explained by a revised reconsolidation hypothesis, or whether some other hypothesis is required to account for postretrieval memory impairment, when it is observed.     

Presynaptic regulation of spinal cord tachykinin signaling via GABA(B) but not GABA(A) receptor activation

Internalization of spinal cord neurokinin-1 receptors following noxious stimulation provides a reliable measure of tachykinin signaling. In the present study, we examined the contribution of GABAergic mechanisms to the control of nociceptor processing involving tachykinins. Spinal administration of the GABA(B) receptor agonist R(+)-baclofen in the rat, at antinociceptive doses, significantly reduced the magnitude of neurokinin-1 receptor internalization in neurons of lamina I in response to acute noxious mechanical or thermal stimulation. By contrast, administration of even high doses of the GABA(A) receptor agonists, muscimol or isoguvacine, were without effect. CGP55845, a selective GABA(B) receptor antagonist, completely blocked the effects of baclofen, but failed to increase the incidence of internalization when administered alone. These results provide evidence for a presynaptic control of nociceptive primary afferent neurons by GABA(B) but not GABA(A) receptors in the superficial laminae of the spinal cord, limiting tachykinin release. Because CGP5584 alone did not increase the magnitude of neurokinin-1 receptor internalization observed following noxious stimulation, there appears to be little endogenous activation of GABA(B) receptors on tachykinin-releasing nociceptors under acute stimulus conditions. The contribution of pre- and postsynaptic regulatory mechanisms to GABA(B) receptor-mediated antinociception was also investigated by comparing the effect of baclofen on Fos expression evoked by noxious stimulation to that induced by intrathecal injection of substance P. In both instances, baclofen reduced Fos expression not only in neurons that express the neurokinin-1 receptor, but also in neurons that do not.We conclude that baclofen acts at presynaptic sites to reduce transmitter release from small-diameter nociceptive afferents. Presynaptic actions on non-tachykinin-containing nociceptors could similarly account for the reduction by baclofen of noxious stimulus-induced Fos expression in neurokinin-1 receptor-negative neurons. However, the inhibition of Fos expression induced by exogenous substance P indicates that actions at sites postsynaptic to tachykinin- and/or non-tachykinin-containing primary afferent terminals must also contribute to the antinociceptive actions of GABA(B) receptor agonists.     

Conceptual priming in semantic dementia: A window into the cognitive and neural basis of conceptual implicit memory

The present study examined the impact of impairment in semantic memory on conceptual repetition priming by means of the longitudinal study of a patient with semantic dementia. ST was tested in four consecutive years, during which his semantic memory progressively deteriorated. On each occasion, he performed an abstract/concrete verification task and a verb generation task. In both of these tasks, performance during a test phase was compared for stimuli previously processed in a study phase and stimuli first seen in the test phase. Control subjects showed priming, as indicated by faster responses to studied than to baseline stimuli. ST showed intact priming that was of normal magnitude in the first two years of testing, but failed to show priming in the subsequent two years of testing. This pattern of results is interpreted with reference to the differential decline of item-specific and superordinate knowledge. The implications of these findings for the neural basis of conceptual priming are also discussed.     

Conceptual priming in semantic dementia: A window into the cognitive and neural basis of conceptual implicit memory

The present study examined the impact of impairment in semantic memory on conceptual repetition priming by means of the longitudinal study of a patient with semantic dementia. ST was tested in four consecutive years, during which his semantic memory progressively deteriorated. On each occasion, he performed an abstract/concrete verification task and a verb generation task. In both of these tasks, performance during a test phase was compared for stimuli previously processed in a study phase and stimuli first seen in the test phase. Control subjects showed priming, as indicated by faster responses to studied than to baseline stimuli. ST showed intact priming that was of normal magnitude in the first two years of testing, but failed to show priming in the subsequent two years of testing. This pattern of results is interpreted with reference to the differential decline of item-specific and superordinate knowledge. The implications of these findings for the neural basis of conceptual priming are also discussed.     

A duck with four legs: Investigating the structure of conceptual knowledge using picture drawing in semantic dementia

In Study 1, six patients with semantic dementia were asked to produce drawings of concrete concepts from dictation of their names. The drawings were characterised by a loss of distinctive features. In the artefact domain, this feature loss resulted in representations that were increasingly box-like. In the living domain, as well as distinctive features being lost, there was a tendency for patients to include incorrect features that resulted in more familiar and "prototypical" representations. A second study included two further conditions in the drawing assessment: immediate and delayed copying of line drawings of concrete concepts. Analysis of the drawings produced by three patients with semantic dementia confirmed that overall performance was significantly influenced by the task condition (immediate delayed) and severity of disease. The rate of intruding features, but not of omitted ones, was influenced by the domain of the item, with a greater proportion of intrusions in the living than in the nonliving domain. There was also a significant effect of feature distinctiveness on the proportions of these error types: Intruded features were most likely to come from the pool of properties that are shared across domain.     

Naked bodies,naked genomes: the special (but not exceptional) nature of genomic information

Genetic exceptionalism, the view that genomic information is different from other types of sensitive information and deserves exceptional types of protections, has been roundly criticized. However, the public still expresses special fears about the access others might have to their genomic information. In this article, it is argued that there may be a basis for the public perception that genomic information is special, even if it cannot be said that policies could or should be enacted to protect the privacy and confidentiality of genomic information that would be exceptional relative to the protections one would enact to protect other types of sensitive information. The special nature of genomic information lies in understanding that it is neither personal property nor mere information. A genome is, at one and the same time, a physical aspect of a person and information about that person. Genomic data are embodied information that partially constitutes as well as describes individuals and that connects them in physical ways to their ancestors and their relatives. All forms of privacy need to be protected, but some intimate aspects of our lives command special respect. To see a genome is more analogous to seeing a naked body than to seeing a social security number. This metaphor suggests that clinicians and investigators ought to respect the special concerns of patients regarding genomic information while not claiming that there are any exceptional measures one could take to protect genomic privacy. Suggestions are given for how this view might affect patient interactions, consent discussions, public policy, and public trust in genomic research and clinical genetics.Genet Med17 5, 331–336.     

Vagal afferents mediate the feeding response to mercaptoacetate but not to the beta (3) adrenergic receptor agonist CL 316,243

To evaluate the role of subdiaphragmatic vagal afferents in the anorectic response to peripheral administration of the highly selective beta(3)-adrenergic receptor agonist CL 316,243 (CL), we tested the ability of intraperitoneal (IP) injections of CL to inhibit feeding in rats with subdiaphragmatic vagal deafferentation (SDA, n=13) or sham surgeries (SHAM, n=13). Doses of 10, 100 and 1000 ng/kg CL significantly reduced feeding by statistically similar amounts in SHAM and SDA rats. One hour after IP injection, each dose of CL also significantly increased plasma concentrations of free fatty acids and beta-hydroxybutyrate, an indicator of hepatic fatty acid oxidation (FAO), whereas 6h after injection only the two highest CL doses increased plasma beta-hydroxybutyrate. In contrast, peripheral administration of the FAO inhibitor mercaptoacetate (MA, 45.6 mg/kg IP) stimulated feeding in SHAM but not in SDA rats, extending previous data suggesting a necessary role of vagal afferents in the feeding-stimulatory effect of FAO inhibition. We conclude that subdiaphragmatic vagal afferents are essential for the feeding-stimulatory action of MA but not for the anorectic action of peripheral CL and that CL-induced increase in hepatic FAO is not essential for its feeding-inhibitory effect.     

Ocular sensitization of mice by live (but not irradiated) Chlamydia trachomatis serovar A.

Ocular exposure of mice to live elementary bodies of Chlamydia trachomatis serovar A results in immunological sensitization of the mice. This reactivity is manifested by the development of early (5 h) and delayed-type (24 h) dermal reactivity and serovar-specific antibody formation against either live or irradiated (100 kilorads) elementary bodies. Parallel ocular exposure of mice to irradiated elementary bodies does not result in this sensitization. The early and late dermal immune responses induced by ocular exposure to live organisms can be transferred to unexposed mice by serum and lymphoid cell transfers, respectively. It appears that successful murine ocular sensitization by human C. trachomatis serovar A elementary bodies is an ability manifested by live organisms and not by inactivated but antigenic organisms.