Semiconductor gel in shark sense organs?

Sharks can sense bioelectric fields of prey and other animals in seawater using an extraordinary system of sense organs (ampullae of Lorenzini) [R.D. Fields, The shark's electric sense. Sci. Am. 297 (2007) 74-81]. A recent study reported that these sense organs also enable sharks to locate prey-rich thermal fronts using a novel mode of temperature reception without ion channels. The study reported that gel extracted from the organs operates as a thermoelectric semiconductor, generating electricity when it is heated or cooled [B.R. Brown, Neurophysiology: sensing temperature without ion channels, Nature 421 (2003) 495]. Here we report biophysical studies that call into question this mechanism of sensory transduction. Our experiments indicate that the material exhibits no unusual thermoelectric or electromechanical properties, and that the thermoelectric response is an artifact caused by temperature effects on the measurement electrodes. No response is seen when non-metallic electrodes (carbon or salt bridges) are used, and ordinary seawater produces the same effect as shark organ gel when silver wire electrodes are used. These data are consistent with the voltages arising from electrochemical electrode potentials rather generated intrinsically within the sample. This new evidence, together with the anatomy of the organs and behavioral studies in the literature, best support the conclusion that the biological function of these sense organs is to detect electric fields.     

Disparities in sense of community: true race differences or differential item functioning?

The sense of community index (SCI) has been widely used to measure psychological sense of community (SOC). Furthermore, SOC has been found to differ among racial groups. Because different ethnic groups have different cultural and historical experiences that may lead to different interpretations of measurement items, it is important to know whether the instrument used to measure the construct of interest has equivalency in measurement across groups or if the instrument exhibits differential item functioning (DIF). Examining DIF in the SCI helps assure that subgroup comparisons identify true differences in SOC between Blacks and Whites. Although we did not find DIF between races, we did find that the SCI question, “I feel at home in my neighborhood,” was a more reliable measure of SOC for Whites than for Blacks. In other words, this item has less measurement error for Whites than for Blacks. Therefore, differences on the SCI may be attributable to true differences in SOC between races rather than DIF. © 2009 Wiley Periodicals, Inc.     

Awareness of breathing as a way to enhance the sense of coherence: Patients’ experiences in psychomotor physiotherapy

Aims: The intention of this study was to clarify former patients’ experience while undergoing therapeutic treatment in Norwegian Psychomotor Physiotherapy (NPMP).

Subjects and methods: A qualitative approach based on 10 in-depth interviews was adopted. The data were analysed with the aid of grounded theory.

Results: Three categories were identified from the patients' experiences: (1) the realisation that their health was at stake, (2) the therapeutic process, and (3) increased self-awareness. During NPMP they realised that when the therapists brought their attention to autonomic reactions, such as changes in their breathing rhythm, they came to a better understanding of what these reactions could mean, thereby increasing their self-understanding.

Discussion and conclusion: Focused attention on autonomic reactions, mainly breathing, increased the patients’ self-understanding and their sense of coherence (Antonovsky, 1987 Antonovsky, A. 1987. Unraveling the mystery of health. How people manage stress and stay well, San Francisco/London: Jossey-Bass.  [Google Scholar], 1996).     

Antonovsky's sense of coherence: trait or state?

BACKGROUND: The aim of this study was first to analyze the stability of Antonovsky's Sense of Coherence (SOC) as a measure of a person's world view over time; secondly, to investigate its relationship with depression and anxiety. METHODS: Data from two longitudinal studies were used: a study of severely injured accident victims (n = 96), and a study of patients suffering from rheumatoid arthritis (RA, n = 60). The 13 items short version of the SOC scale and measures of depression and anxiety (Symptom Checklist, Hospital Anxiety and Depression Scale) were administered repeatedly over 6-12 months in both studies. RESULTS: In the sample of accident victims, a significant decrease in the SOC mean score was observed during the first half year after the accident. During the same time period, symptoms of anxiety and depression decreased significantly. In the second half year after the accident, SOC as well as measures of psychopathology remained stable. RA patients showed high stability of SOC and measures of anxiety and depression over time. In both samples, between-time correlations of SOC scores were high (r > or = 0. 70, p<0.01), indicating a high test-retest stability of SOC. Furthermore, in both samples, significant negative correlations of a moderate to high degree (r = -0.28 to -0.73, p<0.01) were found between SOC and measures of anxiety and depression. CONCLUSIONS: SOC can be seen as a relatively stable (trait) measure. However, traumatic events such as life-threatening accidents may change a person's world view and thus their SOC, even if psychiatric symptoms abate. This suggests that SOC is not merely a proxy measure of psychopathology, but rather a partially independent, general measure of a person's world view.     

Does proprioception contribute to the sense of verticality?

The representation of the vertical can be assessed by measuring the visual, tactile or perception of the postural vertical (PV). It is well accepted that visceral graviceptors and Golgi tendon receptors contribute to perception of the PV, whereas the role of muscular proprioception (Ia muscle spindles) remains to be clarified. The objective of this study was to analyze whether or not muscular proprioception contributes to the representation of verticality. We hypothesized that the modulation of proprioception by appropriate tendinomuscular vibration may tilt the PV. We present two experiments that explore this hypothesis. PV was firstly measured in the pitch plane in twelve healthy subjects in two conditions: baseline and vibration of both Achilles tendons during six minutes, according to a counterbalanced presentation. PV orientation (mean) and dispersion (standard deviation) were calculated on the six measurements per condition. Vibration of the Achilles tendons induced a systematic backward tilt of PV (2.7° ± 0.8° on average; P < 10⁻³), and no significant changes regarding PV dispersion. A clear post-effect was found for PV orientation in subjects who started the experiment with the condition vibration on. The possibility that PV could also be modulated by a much shorter duration of vibration (less than 8 s of vibration) was analyzed in a second experiment using a similar general procedure but a simplified experimental plane in other subjects. Again a backward PV tilt was induced by the vibration, but with a magnitude lower than that found in the first experiment, and with no post-effect. Since body geometry was unchanged, these two studies mean that proprioception contributes to the representation of the vertical. In conclusion, this study brings new insights to our understanding of the sense of verticality and contributes to the interpretation of backward falls induced by vibration. The induced backward fall is partly due to alignment of the erect posture with a backward-tilted referential of verticality.     

Commentary: a sense of story, or why teach reflective writing?

Reflective writing is being introduced in many medical schools in the United States and abroad for a variety of reasons and with a variety of goals in mind. As Wald and colleagues write, multiple methods, including the rubric introduced in their study, have been proposed for rating or grading this writing to quantify the gains obtained. The authors of this commentary detail the assumptions both about reflection and about writing implied in Wald and colleagues' work. They then describe a reciprocal model of writing as discovery, suggesting that the writing itself is what teaches the skills of reflection. Equipping medical students with a sense of story may well be the active ingredient in whatever gains are observed in teaching reflective writing.     

The choice is yours? How women with ovarian cancer make sense of treatment choices

OBJECTIVE: Much has been made of the need for cancer patients to be involved in choices about their treatments. We explore the different approaches to involvement described by women with ovarian cancer and consider why being invited to make a choice can sometimes seem inappropriate and untimely. METHOD: Qualitative interviews were conducted in the UK with women with ovarian cancer. Interviews were audio tape recorded and transcribed for qualitative analysis. The interviews were collected as part of a broader study of experiences of ovarian cancer as part of the DIPEx (personal experiences of health and illness) project which runs a website featuring further analyses and video and audio clips from the interviews. RESULTS: Women did not always recall being involved in decisions -some felt there had been no 'real' decisions to make or said they preferred their medical team to decide on their behalf. Other women described asking questions and seeking second opinions but still 'going along with' their doctor's recommendation. A few women (including some of those who had felt unable to participate in decisions soon after their diagnosis) said that they had learnt enough to take control or make at least some of their own treatment decisions. The manner in which options were offered to women sometimes led to confusion and concern, especially if women felt the doctor was unwilling to express his or her own preference. Some worried that not accepting the doctor's advice would prejudice their future care. CONCLUSION: Patients and doctors are often uncertain how best to share in decisions about treatments. Being asked about their preferences can surprise or shock women. Clinicians need to explain about clinical uncertainty and how individual values and preferences may relate to treatment decisions. Presenting the rationale for choice can be difficult and even when well presented, women can be left feeling ill prepared, panicky and trying to second guess what they think the doctor 'really' wanted them to do. PRACTICE IMPLICATIONS: When patients are invited to make choices their clinicians need to explain about clinical uncertainty and how individual values and preferences may relate to treatment decisions. The options should be communicated in a clear manner, differences in opinion should be acknowledged and the doctor's own preference stated. Patients need to be encouraged and supported to make their decision-whether or not it reflects their doctor's preference. Patients should also be reassured that whichever decision they make their subsequent care and relationship with their medical team will not be adversely affected.     

γδ and αβ T cell lineage choice: Resolution by a stronger sense of being

A common bipotent thymocyte precursor gives rise to both lineages of T cells, αβ and γδ. However, the cell intrinsic and extrinsic factors that influence αβ- versus γδ-lineage bifurcation remain controversial. γδ T cells play a unique and vital role in host defense, from maintaining integrity at epithelial and mucosal barriers to their newly defined role as an important innate source of interleukin-17. Although a T cell receptor (TCR)-independent fate choice may take place, emerging data supports a model in which the differential signaling capacity of αβ and γδTCRs play an instructional role in specifying lineage fate, with strength of signal measured by the amount of ERK/MAPK pathway activation. Here we discuss how the interplay between intrinsic TCR signals and cell extrinsic signals provided by Notch and TCR ligands help to assign and support a final lineage fate decision.     

Role of SIRPα in regulation of mucosal immunity in the intestine

Mononuclear phagocytes such as dendritic cells (DCs) and macrophages in the lamina propria (LP) are thought to be important for both induction of inflammatory responses and maintenance of immunologic tolerance in the mammalian intestine. The molecular mechanisms by which these cells regulate intestinal immunity have remained poorly understood, however. Signal regulatory protein α (SIRPα) is a transmembrane protein that is specifically expressed in DCs, macrophages and neutrophils. Here, we show that SIRPα is abundant in CD11c(+) CD11b(+) LP cells of the mouse intestine. Whereas SIRPα did not appear to be important for the steady-state homeostasis of mucosal immunity in the intestine, the flagellin-stimulated production of IL-17 or interferon (IFN)-γ by LP cells of SIRPα mutant (MT) mice that lack the cytoplasmic region of the protein was markedly decreased compared with that observed with wild-type cells. Moreover, the flagellin-induced production of IL-6 by LP cells from SIRPα MT mice was also greatly reduced. SIRPα MT mice were also resistant to the development of colitis induced by IL-10 deficiency. Our data thus suggest that SIRPα expressed on CD11c(+) LP cells is important for the production of IL-17 or IFN-γ in the LP as well as for the development of colitis induced by IL-10 deficiency.     

Involvement of PPARγ in the protective action of tropisetron in an experimental model of ulcerative colitis

Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal (GI) tract. Tropisetron, a selective 5-HT₃ receptor antagonist, is highly used to counteract chemotherapy-induced emesis. Previous studies revealed the anti-in?ammatory properties of this drug. The aim of this study was to evaluate the role of peroxisome proliferator-activated receptor gamma (PPARγ) receptor in the protective effect of tropisetron in an animal model of ulcerative colitis. Experimental colitis was induced by a single intra-colonic instillation of 4% (V/V) acetic acid in male rats. Tropisetron (3?mg/kg) and GW9662 (PPARγ antagonist) (5?mg/kg) were given twice daily for 2 days after colitis induction. Forty-eight hours after induction of colitis, colon was removed and macroscopic and microscopic features were given. Moreover, colonic concentrations of malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) levels, myeloperoxidase (MPO), and PPARγ activity were assessed. Both macroscopic and histopathological features of colonic injury were markedly ameliorated by tropisetron. Likewise, levels of NO, MDA, TNF-α, and IL-1β diminished significantly (p?p?相似文献   

Role of α2A-Adrenoceptors of Locus Coeruleus in Regulation of Plasma Corticosterone Content in Male Rats

Administration of specific oligonucleotide selectively inhibiting _2A-adrenoceptor gene expression into the locus coeruleus of male rats for 3 days activated the hypothalamic-pituitary-adrenal system, which was manifested in a rise of blood plasma corticosterone content in rats with normal and hypertrophied (after castration) adrenal glands. These data indicate that _2A-adrenoceptors of the locus coeruleus are involved in the regulation of basal plasma corticosterone content.     

Diversity of carbapenemases in clinical isolates of Enterobacteriaceae in Croatia—the results of a multicentre study

Since the first carbapenem-resistant Klebsiella pneumoniae strain was isolated in 2008, Enterobacteriaceae with reduced susceptibility to one or more carbapenems have emerged sporadically in different geographical regions in Croatia. These observations gave rise to a multicenter study on carbapenem resistance in Enterobacteriaceae from Croatia. Fifty-seven carbapenem-non-susceptible strains of Enterobacteriaceae were collected during 2011–2012 from four large hospital centres in Croatia. Overall, 36 strains produced VIM-1 β-lactamase, three produced NDM-1, and one produced KPC-2. A high degree of clonal relatedness was observed in Enterobacter cloacae and Citrobacter freundii strains, in contrast to K. pneumoniae strains. Bla_VIM genes were located within class1 integron which contained genes encoding resistance to aminoglycosides (aac_A4). The study found strong association between bla_VIM and qnr_B6 and between bla_NDM and qnr_A6 genes.     

Involvement of IL-1β and IL-6 in antiarrhythmic properties of atorvastatin in ouabain-induced arrhythmia in rats

Purpose: Evidence show that statins possess wide beneficial cardioprotective and anti-inflammatory effects; therefore, in the present experiment, we investigated the antiarrhythmic properties of atorvastatin in ouabain-induced arrhythmia in isolated rat atria and the role of several inflammatory cytokines in this effect.

Materials and methods: Male rats were pretreated with either of atorvastatin (10?mg/kg) or vehicle, orally once daily for 6 weeks. After induction of anesthesia, we isolated the atria and after incubation with ouabain, time of onset of arrhythmia and asystole as well as atrial beating rate and contractile force were recorded. We also measured the atrial levels of IL-1β, IL-6, and TNF-α after the injection of ouabain to animals.

Results: Pretreatment with atorvastatin significantly delayed the onset of arrhythmia and asystole compared with vehicle-treated group (p?p?p?p?>?.05). Injection of ouabain elevated the atrial levels of IL-1β, IL-6, and TNF-α, while pretreatment of animals with atorvastatin could reverse the ouabain-induced increase in atrial IL-1β and IL-6 (p?p?Conclusions: It is concluded that observed antiarrhythmic effects of atorvastatin might be attributed to modulation of some inflammatory cytokines, at least IL-1β and IL-6.     

Prevalence of HBs antigen in blood donors in the Bouaké regional centre of blood transfusion in 2001

A prospective cross-sectional study was conducted in the regional center of blood transfusion in Bouaké from December 1, 2001 to February 28, 2002. One thousand two hundred thirty one new blood donors were tested. HBs Antigen detection was made according to ELISA technique (Hepanostika HBs Ag Uni-Form II). HBs Antigen prevalence in blood donors in Bouaké was 12.5%. One hundred fifty four blood donors were tested positive and were divided into 131 males (85%) and 23 females (15%). Their average age was 27, 5 years old (18-65 years). HBs Antigen carriage rate was lower in females and students. They were mainly pupils (62%) and had risk factors of hepatitis B infection (intramuscular injection, multiple sexual partners, unsafe sex). HBs Antigen carriage rate in blood donors is high in Bouaké and justifies the systematic screening of this Antigen in any blood donor to reduce the transfusion risk. On the other hand, it is necessary to modify the blood collection strategy in order to make the most of the donation and to decrease the residual risk.     

The Role of β1,2-Adrenoceptors in the Amygdala in the Behavior of Rats with Different Levels of Freezing in Conditioned Reflex Fear

Neuroscience and Behavioral Physiology - Individual sensitivity to blockade of β1,2-adrenoceptors was studied by dividing rats into groups depending on the manifestation of conditioned reflex...     

Men without a sense of smell exhibit a strongly reduced number of sexual relationships,women exhibit reduced partnership security – A reanalysis of previously published data

Olfactory function influences social behavior. For instance, olfaction seems to play a key role in mate choice and helps detecting emotions in other people. In a previous study, we showed that people who were born without a sense of smell exhibit enhanced social insecurity. Based on the comments to this article we decided to have a closer look to whether the absence of the sense of smell affects men and women differently. Under this focus questionnaire data of 32 patients, diagnosed with isolated congenital anosmia (10 men, 22 women) and 36 age-matched healthy controls (15 men, 21 women) was reanalyzed.     

Differentiation of hMSC in Micromass Culture

1 Introduction Mesenchymal stem cells (MSCs) are multipotential stem cells which can be expanded in culture while still maintaining their undifferentiated state. They have the potential to differentiate into distinct mesenchymal tissue cells, including chondrocytes. Thus, they are an attractive cell source for cartilage tissue engineering. In vitro high density micromass culture has been widely used for chondrogenesis induction. The objective of our study was to analyze viability and differe…     

Neuroimmune Aspects of the Pathogenesis of Tourette’s Syndrome and Experience in the Use of Immunoglobulins in Children

A total of 60 patients aged 6–16 years with tics and Tourette’s syndrome were studied. Antibodies to caudate nucleus proteins were assayed by western blot hybridization. Ten patients with Tourette’s syndrome were found to have antibodies to caudate nucleus protein. Seven patients with neuroleptic-resistant types of Tourette’s syndrome received single transfusions of immunoglobulin preparations, which produced regression of vocal and motor hyperkinesias and improvement in behavior (remission for more than six months). The observation of antibodies to caudate nucleus proteins and the positive effects seen on administration of immunoglobulins to patients with Tourette’s syndrome support previous data on the possibility of using immunoglobulin therapy in the treatment of tic-type hyperkinesias and provide evidence of the involvement of autoimmune mechanisms inducing damage to the dopaminergic system of the striatum. Translated from Zhurnal Nevrologii i Psikhiatrii imeni S. S. Korsakova, Vol. 108, No. 8, pp. 10–13, August, 2008.