PubMed Health⌕ Search

Biomedical subjects

Yori Gidron

Publications and source records attributed to Yori Gidron.

At least 19 recordsLinked to original sources
PubMed2006

Vagus-brain communication in atherosclerosis-related inflammation: a neuroimmunomodulation perspective of CAD.

The current understanding of the pathophysiology of atherosclerosis leading to coronary artery disease (CAD) emphasizes the role of inflammatory mediators. Given the bidirectional communication between the immune and central nervous systems, an important question is whether the brain can be "informed" about and modulate CAD-related inflammation. A candidate communicator and modulator is the vagus nerve. Until now, the vagus nerve has received attention in cardiology mainly due to its role in the parasympathetic cardiovascular response. However, the vagus nerve can also "inform" the brain about peripheral inflammation since its paraganglia have receptors for interleukin-1. Furthermore, its efferent branch has a local anti-inflammatory effect. These effects have not been considered in research on the vagus nerve in CAD or in vagus nerve stimulation trials in CAD. In addition, various behavioural interventions, including relaxation, may influence CAD prognosis by affecting vagal activity. Based on this converging evidence, we propose a neuroimmunomodulation approach to atherogenesis. In this model, the vagus nerve "informs" the brain about CAD-related cytokines; in turn, activation of the vagus (via vagus nerve stimulation, vagomimetic drugs or relaxation) induces an anti-inflammatory response that can slow down the chronic process of atherogenesis.

Animals↗
PubMed2006

Neural-endocrine-immune complex in the central modulation of tumorigenesis: facts, assumptions, and hypotheses.

For the precise coordination of systemic functions, the nervous system uses a variety of peripherally and centrally localized receptors, which transmit information from internal and external environments to the central nervous system. Tight interconnections between the immune, nervous, and endocrine systems provide a base for monitoring and consequent modulation of immune system functions by the brain and vice versa. The immune system plays an important role in tumorigenesis. On the basis of rich interconnections between the immune, nervous and endocrine systems, the possibility that the brain may be informed about tumorigenesis is discussed in this review article. Moreover, the eventual modulation of tumorigenesis by central nervous system is also considered. Prospective consequences of the interactions between tumor and brain for diagnosis and therapy of cancer are emphasized.

Animals↗
PubMed2006

Blunted HPA axis response to stress influences susceptibility to posttraumatic stress response in rats.

BACKGROUND: Posttraumatic stress disorder (PTSD) is associated with low levels of circulating cortisol, and recent studies suggest that cortisol administration may reduce PTSD symptoms. This study investigated the role of cortisol in the manifestation of anxiety- and fear-like symptoms in an animal model of PTSD. METHOD: Magnitude of changes in prevalence of anxiety-like behaviors on the elevated plus-maze and nonhabituated exaggerated startle reaction were compared in three strains of rats exposed to predator stress, with and without prior corticosterone treatment. Extreme behavioral changes in both paradigms implied an extreme behavioral response (EBR), representing PTSD-like symptoms. RESULTS: Lewis rats exhibited greater baseline anxiety-like behaviors and greater stress-induced increases in anxiety-like behaviors than Fischer F344 or Sprague-Dawley rats, with only minor corticosterone increases following stress. Prevalence of EBR was 50% among Lewis rats compared with 10% of Fischer F344 and 25% of Sprague-Dawley rats. Administering corticosterone 1 hour before stress exposure reduced the prevalence of EBR from 50% to 8% in the Lewis rats. CONCLUSIONS: These results suggest that a blunted HPA response to stress may play a causal role in this model of PTSD and that this susceptibility may be prevented by administration of cortisol before stress exposure.

Analysis of Variance↗
PubMed2006

The relation between psychological factors and DNA-damage: a critical review.

Investigating relations between psychological factors and DNA-damage can contribute to understanding how psychological factors affect the etiology and prognosis of relevant diseases (e.g., cancer, heart disease) at the fundamental level of mutated cells. This article critically reviews 21 studies in animals and humans testing relations between psychological factors and DNA-damage. After providing a biological background, we critically review each study. The findings in humans are mapped onto a model of stress, coping and health. These studies demonstrate causal relations between acute stressors and DNA-damage in animals and significant correlations between psychological factors (e.g., depression, coping) and DNA-damage in humans, which are moderated by gender. Possible mechanisms for these relations, limitations of studies, clinical implications and suggestions for future research are provided.

Adaptation, Psychological↗
PubMed2006

Maladaptation to mental stress mitigated by the adaptive immune system via depletion of naturally occurring regulatory CD4+CD25+ cells.

Peripheral cellular immunity was recently shown to play a critical role in brain plasticity and performance. The antigenic specificity of the participating T cells, however, was not investigated, and nor was their relevance to psychological stress. Here we show, using a mouse model, that adaptive immunity mitigates maladaptation to the acute psychological stress known to trigger abnormal behaviors reminiscent of human post-traumatic stress disorder. Assessment of behavioral adaptation (measured by the acoustic startle response and avoidance behavior) in mice after their exposure to predator odor revealed that maladaptation was several times more prevalent in T cell-deficient mice than in their wild-type counterparts. A single population of T cells reactive to central nervous system (CNS)-associated self-protein was sufficient to endow immune-deficient mice with the ability to withstand the psychological stress. Naturally occurring CD4+CD25+ regulatory T cells were found to suppress this endogenous anti-stress attribute. These findings suggest that T cells specific to abundantly expressed CNS antigens are responsible for brain tissue homeostasis and help the individual to cope with stressful life episodes. They might also point the way to development of immune-based therapies for mental disorders, based either on up-regulation of T cells that partially cross-react with self-antigens or on weakening of the activity of regulatory T cells.

Adaptation, Physiological↗
PubMed2005

Physicians' attitudes toward preventive therapy for coronary artery disease: is there a gender bias?

BACKGROUND: While much of the gender difference in the treatment of coronary artery disease (CAD) results from the fact that the women being treated are older and have more comorbidities, it remains to be established whether a true gender bias exists. We compared physicians' attitudes and practice toward preventive therapy in men and women with CAD. HYPOTHESIS: Physicians perceive the prevention of CAD in men as more important than in women. METHODS: In the "attitude study," we obtained data on the attitudes of 172 physicians toward treatment, using hypothetical case histories of 58-year-old male and postmenopausal female patients with identical clinical and laboratory data and mild coronary atherosclerosis on angiography. In the "actual practice study," we evaluated the lipoprotein levels and prescription of lipid-lowering medications from medical records of 344 male and female patients with angiographic evidence of CAD. RESULTS: In the hypothetical case histories, physicians in general considered the male patient to be at higher risk and prescribed aspirin (91 vs. 77%, p < 0.01) and lipid-lowering medications (67 vs. 54%, p < 0.07) more often for the male patient. Evaluation of medical charts of patients with CAD revealed that in patients with baseline low-density lipoprotein cholesterol > 110 mg/dl, 77% of the males received a lipid-lowering medication, compared with only 47% of the female patients (p < 0.001). CONCLUSIONS: We found evidence for a gender bias in the attitude as well as in actual practice of secondary prevention toward patients with CAD. While the proportion of male patients receiving lipid-lowering medications appears appropriate, the proportion of women receiving such treatment remains undesirable.

Adult↗
PubMed2005

Memory performance in late pregnancy and erythrocyte indices.

OBJECTIVE: A previous study in elderly people observed an association between chronologically younger erythrocyte population and memory impairment. The aim of this study was to assess whether a similar shift in erythrocyte population in pregnant women in late pregnancy is associated with changes in memory performance in healthy pregnant women. METHODS: Thirty healthy pregnant women were included in a prospective cross-sectional study. Explicit memory and autobiographic memory tests were performed in the late third trimester and 4 months postpartum. Mean corpuscular volume (MCV) was considered the primary predictor variable. RESULTS: The mean explicit memory recall scores were significantly higher at post-delivery compared to pre-delivery: 8.3 +/- 1.7 and 7.4 +/- 1.4, respectively (P = .015). The difference in mean autobiographic memory test score pre- and post-delivery did not reach statistical significance. A positive correlation between post-delivery explicit memory recall scores and the difference between pre- and post-delivery MCV was detected (r = 0.458, P = .01). The correlation between delta MCV and delta explicit memory recall scores was r = 0.2, P =.311. Pre-delivery autobiographic memory test scores were positively correlated with MCV (r = 0.50, P = .006), mean corpuscular hemoglobin (r = 0.57, P = .001), and mean corpuscular hemoglobin concentration (r = 0.46, P = .013). CONCLUSION: The change in erythrocyte population that is present in late pregnancy predicted explicit memory performance after delivery, when it was improved. The younger erythrocyte population that exists in late pregnancy is associated with a better autobiographic memory.

Adolescent↗
PubMed2005

Does the vagus nerve inform the brain about preclinical tumours and modulate them?

The inflammatory microenvironment is thought to play a pivotal part in tumorigenesis. But, can the brain be informed about peripheral preclinical cancer cells? Can it modulate tumour development? One of the key routes for information to reach the brain from visceral regions is through the vagus nerve. Yet, patients with ulcers who have had a vagotomy have been shown to die from cancer more frequently than do those who have not had this procedure, and surgical and chemical vagotomy attenuates tumour-induced anorexia and leads to enhanced tumour progression. We therefore postulate that the vagus nerve participates in informing the brain about tumorigenesis by transmiting information to the brain about tumour-associated proinflammatory cytokines. Furthermore, activation of the vagus could slow tumorigenesis by suppression of peripheral proinflammatory cytokines.

Afferent Pathways↗
PubMed2005

Development and validation of a new measure of student attitudes and knowledge of international health and medicine.

There is increasing awareness of the importance of international health and medicine (IHM) but there is a paucity of data regarding medical students' attitudes towards and knowledge of the subject. To the best of our knowledge there is currently no validated measure to assess this. The aim of the present study was to develop a validated measure of medical students' attitudes and knowledge of IHM and examine its correlates. A panel experienced in IHM formulated attitude and general knowledge items and clinical cases based on personal experience, literature review and texts. The survey was piloted and then administered to 82 students of the Ben Gurion University-Columbia University MD program in IHM, and 59 students from programs without specific IHM focus. Cronbach's a was 0.87. Test-retest reliability of attitudes was r=0.87. Correlation of openness to experience with attitudes was r=0.376, showing construct validity. Third-year IHM students scored higher than incoming students on IHM knowledge and clinical cases, demonstrating sensitivity. General IHM knowledge was positively correlated to clinical IHM knowledge r=0.36, but not attitude or openness to experience. Those with previous IHM work experience showed greater openness and positive attitude. Women showed more positive attitudes towards IHM than men. Attitude was negatively correlated with number of languages spoken r=-0.198. The survey may be a reliable and valid tool to assess and compare medical students' knowledge and attitude toward international health. This survey can be used to evaluate curricular innovations in the field.

Adult↗
PubMed2005

Interleukin-1 may link helplessness-hopelessness with cancer progression: a proposed model.

A model of the relations between psychological factors and cancer progression should include brain and systemic components and their link with critical cellular stages in cancer progression. We present a psychoneuroimmunological (PNI) model that links helplessness-hopelessness (HH) with cancer progression via interleukin-1beta (IL-1beta). IL-1beta was elevated in the brain following exposure to inescapable shock, and HH was minimized by antagonizing cerebral IL-1beta. Elevated cerebral IL-1beta increased cancer metastasis in animals. Inescapable shock was associated with systemic elevations of IL-1beta and peripheral IL-1beta was associated with escape from apoptosis, angiogenesis, and metastasis. Involvement of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis are discussed. Future studies need to identify the role of additional factors in this PNI pathway.

Apoptosis↗
PubMed2005

Do psychological factors predict occurrence of influenza-like symptoms in vaccinated elderly residents of a sheltered home?

OBJECTIVES: A previously shown relation between psychological factors and the occurrence of flu has not been tested in elderly people, who are at the greatest risk of mortality from flu complications. This study examined whether psychological factors predict the occurrence of influenza-like symptoms (ILS) in elderly residents. DESIGN: A prospective correlation design was used. METHOD: Our sample included 70 elderly residents of a sheltered home (mean age 83.0 years) who were vaccinated against influenza and assessed for background, biomedical factors (e.g. number of illnesses) and psychological factors (e.g. hostility, depression, life-events, and social support). The occurrence of ILS during 2 subsequent winter months was evaluated by a nurse blind to patients' psychological data, according to explicit valid criteria and physicians' notes. RESULTS: Seventeen patients (24.3%) developed ILS. Number of medications, little physical activity, hostility, depression, and little social support significantly predicted ILS. In a multivariate analysis, only number of drugs (relative risk, RR: 1.54; 95% confidence interval, CI: 1.06-2.22) and hostility (RR = 1.18; 95% CI: 1.00-1.38) significantly and independently predicted occurrence of ILS. CONCLUSIONS: Psychological factors (particularly hostility) predict occurrence of ILS in an elderly sample. Possible behavioural and immunological mechanisms linking hostility to development of ILS are discussed. These findings add to the literature on psychological factors and flu, and may have implications for the prediction and prevention of flu in elderly people.

Aged↗
PubMed2005

Psychological correlates of idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension, also known as pseudotumor cerebri, is a relatively rare disorder of increased intracranial pressure >250 mm water, with a normal neuroimaging and normal cerebrospinal fluid content. OBJECTIVES: To examine whether hostility, anxiety and autobiographical memory (a correlate of depression) are associated with IIH. METHODS: Using a case-control cross sectional design, 20 patients with IIH were compared with 9 healthy controls of similar age, weight and height, and 11 headache controls. Patients were assessed for hostility and anxiety. The Autobiographical Memory Test was used to assess episodic memories. RESULTS: The IIH group reported significantly more anxiety and more general episodic memories than the healthy controls, but not the headache control group. The headache control patients reported more general memories than did the healthy controls. CONCLUSIONS: Patients with headaches, whether of general origin or related to IIH, have a poor psychosocial profile. While the study design does not permit any conclusions regarding causality, our results support the need to consider psychological factors in evaluating and treating IIH and headache patients.

Adult↗
PubMed2004

Preventive therapy in patients with insignificantly narrowed coronary arteries: evaluation of physician attitude and practice.

BACKGROUND: Although the outcome of patients with angiographically insignificantly narrowed coronary arteries (INCA) is not clearly defined, such lesions can progress or rupture, thus causing cardiovascular morbidity. Preventive therapy with aspirin and lipid-lowering drugs therefore seems warranted in these patients. HYPOTHESIS: The study was undertaken to evaluate the attitude and practice of physicians toward the provision of preventive treatment to patients with INCA. METHODS: The attitude of physicians was evaluated using written case histories of three patients with identical clinical features but different angiographic diagnoses. We then examined randomly chosen files of 130 patients with angiographically normal coronary arteries, 130 patients with INCA, and 130 patients with significant coronary artery disease, in relation to the use of lipid-lowering medications and achieved lipoprotein levels. RESULTS: For the hypothetical patients, more physicians prescribed statins (78 vs. 47%, p<0.0001) and aspirin (89 vs. 74%, p<0.003) for patients with significant disease than they did for those with INCA. A target low-density lipoprotein (LDL) cholesterol of < 100 mg/dl was considered appropriate for significant disease by 85% of physicians compared with 40% for INCA (p<0.0001). In the real patients, more of those with significant disease received lipid-lowering drugs and achieved the LDL target level than did those with INCA. CONCLUSIONS: Many physicians regard the need to prescribe preventive treatment as less important for patients with INCA than for patients with significant coronary disease. Additional long-term studies are warranted to elucidate the prognostic significance of INCA and the efficacy of preventive therapy in these patients.

Adult↗
PubMed2004

The relationship between tourists' agreeableness and openness to experience with coronary heart disease mortality.

OBJECTIVE: This study examined relationships between tourists' agreeableness and openness to experience (AOE) and rates of coronary heart disease (CHD) mortality in an international context. METHODS: AOE was obtained from the "Expedia Tourist Survey" (2002), which asked tourist office staff in 17 places around the world to nominate the two countries with the "best" and two with the "worst" tourists. AOE reflected tourists' behaviour, politeness, interest in other countries' language and foods, and spending money. Rates of CHD mortality were obtained for 22 of the countries, from published epidemiological studies. RESULTS: Controlling for alcohol consumption and national health budget, countries with low AOE had higher rates of CHD mortality than countries with high AOE. This was found in both men and women. CONCLUSIONS: AOE may be a risk factor of CHD mortality, a concept that is the antonym of hostility. If replicated with standardized AOE measures, these findings may have relevance to preventing CHD mortality.

Adult↗
PubMed2004

Evaluation of student attitudes and knowledge in a new program in international health and medicine.

Ben-Gurion University (BGU) in collaboration with Columbia University inaugurated a medical school in 1998, with the expressed purpose of training physicians in International Health and Medicine (IHM). The Beer-Sheva Survey of Attitudes and Knowledge in International Health and Medicine was given to the first graduating class and three control groups. The graduates of the new program retained their positive attitudes toward IHM and increased their knowledge of the subject. Further studies are necessary to document the effect of the program on the clinical practice of its graduates.

Academic Medical Centers↗
PubMed2004

Prevalence and moderators of terror-related post-traumatic stress disorder symptoms in Israeli citizens.

BACKGROUND: A major psychological sequel of terrorist attacks is post-traumatic stress disorder. The relation between certain psychological factors specific to terrorist attacks (e.g., perceived control attributed to oneself/to the military, anticipated duration of terrorism) and PTSD symptoms have not been examined. OBJECTIVE: To examine the prevalence, correlates and moderators of PTSD-like symptoms following terrorist attacks in Israel. METHODS: Soon after a long wave of terrorist attacks in Israel in 2002, a convenience sample of 149 Israelis from five cities was assessed for terrorist attack exposure, perceived control, control attributed to the govemment/military, anticipated duration of the terrorism wave (predictability), and frequency of listening to the news. PTSD-like symptoms were assessed with a brief self-report scale. RESULTS: We found that 15.4% of the sample was directly exposed to a terrorist attack and 36.5% knew someone dose who had been exposed to an attack. "Clinically significant" PTSD-like symptoms were reported by 10.1% of the sample. Correlates of PTSD-like symptoms were: perceived control in men, government control, and education in women (all inversely correlated to PTSD symptoms), and news-listening frequency in women (positively correlated to PTSD symptoms). PTSD-like symptoms were attenuated by the ability to predict the duration of the terrorism wave only in citizens exposed to an attack, and by perceived government control only among citizens listening infrequently to the news. CONCLUSIONS: This study revealed that approximately 10% of Israelis in our sample had relatively frequent PTSD-like symptoms. Correlates of PTSD-like symptoms differed between men and women, and moderator effects were found. These findings reveal additional moderators that may have implications for treating PTSD following terrorist attacks.

Adult↗