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E Stern

Publications and source records attributed to E Stern.

At least 37 records · Page 2Linked to original sources
PubMed2000

The neural correlates of 'deaf-hearing' in man: conscious sensory awareness enabled by attentional modulation.

Attentional modulation of normal sensory processing has a two-fold impact on human brain activity: activation of a network of localized brain regions is associated with paying attention, and activation of specific sensory regions is enhanced relative to passive stimulation. The mechanisms underlying attentional modulation of perception in patients with lesions of sensory cortices are less well understood. Here we report a unique patient suffering from extensive bilateral destruction of the auditory cortices (including the primary auditory fields) who demonstrated conscious perception of the onset and offset of sounds only when selectively attending to the auditory modality. This is the first description of such an attentively modulated 'deaf-hearing' phenomenon and its neural correlates, using H(2)(15)O-PET. Increases in cerebral blood flow associated with conscious awareness of sound that was achieved by listening attentively (compared with identical auditory stimulation presented when the patient was inattentive) were found bilaterally in the lateral (pre)frontal cortices, the spared middle temporal cortices and the cerebellar hemispheres. We conclude that conscious awareness of sounds may be achieved in the absence of the primary auditory cortex, and that selective, 'top-down' attention, associated with prefrontal systems, exerts a crucial modulatory effect on auditory perception within the remaining auditory system.

Acoustic Stimulation↗
PubMed2000

Cushing's syndrome presenting as a schizophrenia-like psychotic state.

Neuropsychiatric abnormalities, of which depression is the most common, are frequently associated with Cushing's syndrome. The following paper describes a 58-year-old woman in whom a prolonged psychotic state--schizophrenia-like--was the presenting sign of Cushing's syndrome. The psychiatric symptoms disappeared shortly after the cortisol level has been normalized. Due to the variety of symptoms, both organic and psychiatric, which may occur with Cushing's syndrome, a high suspicion index is advisable. Suspect clinical findings should always prompt the appropriate endocrine work-up.

Cushing Syndrome↗
PubMed1999

Linguistic threat activates the human amygdala.

Studies in animals demonstrate a crucial role for the amygdala in emotional and social behavior, especially as related to fear and aggression. Whereas lesion and functional-imaging studies in humans indicate the amygdala's participation in assessing the significance of nonverbal as well as paralinguistic cues, direct evidence for its role in the emotional processing of linguistic cues is lacking. In this study, we use a modified Stroop task along with a high-sensitivity neuroimaging technique to target the neural substrate engaged specifically when processing linguistic threat. Healthy volunteer subjects were instructed to name the color of words of either threat or neutral valence, presented in different color fonts, while neural activity was measured by using H(2)(15)O positron-emission tomography. Bilateral amygdalar activation was significantly greater during color naming of threat words than during color naming of neutral words. Associated activations were also noted in sensory-evaluative and motor-planning areas of the brain. Thus, our results demonstrate the amygdala's role in the processing of danger elicited by language. In addition, the results reinforce the amygdala's role in the modulation of the perception of, and response to, emotionally salient stimuli. The current study further suggests conservation of phylogenetically older mechanisms of emotional evaluation in the context of more recently evolved linguistic function.

Adult↗
PubMed1999

Mesolimbic activity associated with psychosis in schizophrenia. Symptom-specific PET studies.

Hallucinations and paranoid delusions are prominent among the positive symptoms of schizophrenia. Such psychotic symptoms are notable for their aberrant representations of, and relation to, the external world and for the emotional/motivational valence associated with the representations. As mesolimbic structures, including the amygdala and ventral striatum, are thought to play a significant role in imparting emotional valence to external stimuli, we here examine the mesolimbic findings of H215O PET studies designed to probe the functional neuroanatomy of psychosis. Patients with schizophrenia (including those with active hallucinations, those with active paranoid delusions, and those without active positive symptoms at the time of scanning) and healthy control subjects were studied. An event-related PET paradigm was used to identify the neural correlates of hallucinations, and a modified emotional stroop paradigm (with threat versus neutral words) was used to test the hypothesis that paranoid patients would have increased mesolimbic activity in response to threat, and even in response to neutral stimuli. The findings suggest that the positive psychotic symptoms of hallucinations and delusions share similar functional neuroanatomical features of increased mesotemporal and ventral striatal activity in the setting of decreased prefrontal activity. The pattern is evident even in a neutral context, unlike the case for normal subjects, who show such features only in response to threat. The implications of these findings for a pathophysiology of psychosis will be discussed in the context of the behavioral neuroanatomical literature in animals and humans.

Corpus Striatum↗
PubMed1999

Role of ERAB/L-3-hydroxyacyl-coenzyme A dehydrogenase type II activity in Abeta-induced cytotoxicity.

Endoplasmic reticulum-associated amyloid beta-peptide (Abeta)-binding protein (ERAB)/L-3-hydroxyacyl-CoA dehydrogenase type II (HADH II) is expressed at high levels in Alzheimer's disease (AD)-affected brain, binds Abeta, and contributes to Abeta-induced cytotoxicity. Purified recombinant ERAB/HADH II catalyzed the NADH-dependent reduction of S-acetoacetyl-CoA with a Km of approximately 68 microM and a Vmax of approximately 430 micromol/min/mg. The contribution of ERAB/HADH II enzymatic activity to Abeta-mediated cellular dysfunction was studied by site-directed mutagenesis in the catalytic domain (Y168G/K172G). Although COS cells cotransfected to overexpress wild-type ERAB/HADH II and variant beta-amyloid precursor protein (betaAPP(V717G)) showed DNA fragmentation, cotransfection with Y168G/K172G-altered ERAB and betaAPP(V717G) was without effect. We thus asked whether the enzyme might recognize alcohol substrates of which the aldehyde products could be cytotoxic; ERAB/HADH II catalyzed oxidation of a variety of simple alcohols (C2-C10) to their respective aldehydes in the presence of NAD+ and NAD-dependent oxidation of 17beta-estradiol. Addition of micromolar levels of synthetic Abeta(1-40) to purified ERAB/HADH II inhibited, in parallel, reduction of S-acetoacetyl-CoA (Ki approximately 1.6 microM), as well as oxidation of 17beta-estradiol (Ki approximately 3.2 microM) and (-)-2-octanol (Ki approximately 2.6 microM). Because micromolar levels of Abeta were required to inhibit ERAB/HADH II activity, whereas Abeta binding to ERAB/HADH II occurred at much lower concentrations (Km approximately 40-70 nM), the latter more closely simulating Abeta levels within cells, Abeta perturbation of ERAB/HADH II was likely to result from mechanisms other than the direct modulation of enzymatic activity. Cells cotransfected to overexpress ERAB/HADH II and betaAPP(V717G) generated malondialdehyde-protein and 4-hydroxynonenal-protein epitopes, which were detectable only at the lowest levels in cells overexpressing either ERAB/HADH II or betaAPP(V717G) alone. Generation of such toxic aldehydes was not observed in cells contransfected to overexpress Y168G/K172G-altered ERAB and betaAPP(V717G). We conclude that the generalized alcohol dehydrogenase activity of ERAB/HADH II is central to the cytotoxicity observed in an Abeta-rich environment.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1999

Prevalence of diabetes mellitus among workers in Israel: a nation-wide study.

The prevalence of diabetes mellitus in Israel has been described in various populations and ranges from 4.1% to 8.9%. However, the large immigration wave in the late 1980s and early 1990s could have affected the previous estimates. Moreover, data from the United states and other countries report a significant proportion of undiagnosed diabetes. The main purpose of this study was to estimate the prevalence and the ratio of undiagnosed/diagnosed diabetes in a large sample of workers. The study involved interviews, anthropometric measurements at the work site, and blood glucose determinations (casual capillary, fasting, and when necessary, 2 h after a 75-gram oral glucose load). Diabetes and impaired glucose tolerance (IGT) were diagnosed according to WHO criteria. Five thousand four hundred sixteen workers participated in the study. Three hundred ten reported to be known diabetics (5.7%), 35 (0.7%) were diagnosed as diabetic during the survey, and an additional 93 (1.8%) were classified as IGT. The ratio undiagnosed/diagnosed diabetes was therefore 1:10. Extrapolation of these results produced an estimate of diabetes prevalence in Israel of 10% among people over age 40 years. It seems that in the Israeli health care system, based on universal health insurance and easy access to primary care, the proportion of undiagnosed diabetes is lower than that described in other countries.

Adult↗
PubMed1999

Efficacy of inhaled steroids (beclomethasone dipropionate) for treatment of mild to moderately severe asthma in the emergency department: a randomized clinical trial.

STUDY OBJECTIVE: To examine the efficacy of an inhaled steroid, when added to a standard regimen of beta-agonist therapy, in the treatment of patients with mild to moderately severe asthma in the emergency department. METHODS: A convenience sample of adult patients with asthma (FEV1 % predicted 40% to 69%) presenting to the ED was randomly assigned in a double-blind fashion into 2 treatment groups. The first group received 2.5 mg nebulized salbutamol plus 1 mg (4 puffs) of beclomethasone dipropionate (BDP) at baseline, 30 minutes, and at 1, 2, and 4 hours, delivered by a metered-dose inhaler (MDI) attached to a spacer device (Vent-AH-aler, Glaxo). The second group was given the same salbutamol regimen plus MDI placebo through the Vent-AH-aler. The primary endpoint was improvement in FEV1 %predicted at 6 hours. RESULTS: Of 54 patients enrolled, 28 were assigned to the BDP group and 26 to the placebo group. Spirometry improved significantly in both groups over the 6 hours compared with baseline (ANOVA, P <.001). At 6 hours, the mean absolute improvement in FEV1 % predicted for BDP was 18% versus 17% for placebo (95% confidence interval for the absolute difference of 1% [-8% to 10%]). The proportion of patients in the BDP group who were hospitalized was 7% compared with 19% for patients in the placebo group (95% confidence interval for the difference of 12% [-6%, 30%]). CONCLUSION: In this group of patients with mild to moderately severe asthma, 5 mg BDP delivered by MDI during the initial 4 hours of an emergency visit was of no added benefit over standard therapy, as measured by improvement in FEV1 % predicted at 6 hours. However, a trend toward a difference in admission favoring BDP was observed. [Afilalo M, Guttman A, Colacone A, Dankoff J, Tselios C, Stern E, Wolkove N, Kreisman H: Efficacy of inhaled steroids (beclomethasone dipropionate) for treatment of mild to moderately severe asthma in the emergency department: A randomized clinical trial.

Administration, Inhalation↗
PubMed1999

Rostral and orbital prefrontal cortex dysfunction in the manic state of bipolar disorder.

OBJECTIVE: This study investigated prefrontal cortex function in the manic state of bipolar disorder. METHOD: High-sensitivity [15O]H2O positron emission tomography and a word generation activation paradigm were used to study regional cerebral blood flow in five manic and six euthymic individuals with bipolar disorder and in five healthy individuals. RESULTS: Decreased right rostral and orbital prefrontal cortex activation during word generation and decreased orbitofrontal activity during rest were associated with mania. CONCLUSIONS: The data support the presence of rostral and orbital prefrontal dysfunction in primary mania. These findings, when seen in the context of the human brain lesion and the behavioral neuroanatomic literatures, may help to explain some of the neurobehavioral abnormalities characteristic of the manic state.

Adult↗
PubMed1998

Towards a functional neuroanatomy of conscious perception and its modulation by volition: implications of human auditory neuroimaging studies.

Conscious sensory perception and its modulation by volition are integral to human mental life. Functional neuroimaging techniques provide a direct means of identifying and characterizing in vivo the systems-level patterns of brain activity associated with such mental functions. In a series of positron emission tomography activation experiments, we and our colleagues have examined a range of normal and abnormal auditory states that, when contrasted, provide dissociations relevant to the question of the neural substrates of sensory awareness. These dissociations include sensory awareness in the presence and absence of external sensory stimuli, the transition from sensory unawareness to awareness (or vice versa) in the presence of sensory stimuli, and sensory awareness with and without volition. The auditory states studied include hallucinations, mental imagery, cortical deafness modulated by attention, and hearing modulated by sedation. The results of these studies highlight the distributed nature of the functional neuroanatomy that is sufficient, if not necessary, for sensory awareness. The probable roles of unimodal association (as compared with primary) cortices, heteromodal cortices, limbic/paralimbic regions and subcortical structures (such as the thalamus) are discussed. In addition, interactions between pre- and post-rolandic regions are examined in the context of top-down, volitional modulation of sensory awareness.

Auditory Perception↗
PubMed1998

Production of digoxigenin-labelled RNA probes and the detection of cytokine mRNA in rat spleen and brain by in situ hybridization.

Non-radioactive in situ hybridization is a sensitive method for determining the site of production for secretory molecules such as cytokines. We report here on the central and peripheral induction of proinflammatory cytokines by endotoxin, and outline procedures for the generation and application of rat-specific digoxigenin (Dig)-labelled RNA probes for the localization of mRNA by in situ hybridization. Rats were injected either intravenously (i.v.) or intracerebroventricularly (i.c.v.) with vehicle or lipopolysaccharide (LPS) and sacrificed at various time intervals post-injection. Rats were then perfused with 4% paraformaldehyde and the spleens and brains were removed and cryoprotected in 30% sucrose. Dig-labelled, rat-specific, antisense and sense RNA probes were generated by in vitro transcription from PCR-derived templates. Positive staining with all the antisense probes was cytoplasmic, whereas the sense probes showed no staining. Numerous tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) mRNA positive cells were observed in the marginal zone and in the red pulp of the spleen after iv LPS injections, whereas sections from saline-treated animals showed minimal cytokine mRNA expression. Cells positive for TNF-alpha and IL-1beta mRNA were detectable in the brain after i.c.v. injections of LPS, but not after icv injection of vehicle. An antisense probe for c-fos was utilized in these studies as a positive control for our procedure due to its anatomically specific expression in the rat brain after LPS. In conclusion we have demonstrated that in situ hybridization with Dig-labelled RNA probes is an efficient, sensitive and reliable tool to localize cytokine mRNA production in rat tissue.

Actins↗
PubMed1998

Conscious and unconscious strategy discoveries: a microgenetic analysis.

We examined second graders' strategy discoveries on a task that could be solved either by arithmetic computation or by a simple insight. Strategy use was assessed on each trial through both an implicit measure and an explicit one. The results provided unambiguous evidence that strategies can be discovered without conscious awareness. Almost 90% of children showed the insight at an implicit, unreportable level before they showed it at an explicit, reportable one. When children received the relevant problems on each trial, 80% reported the insight within 5 trials of when their solution times indicated that they first generated it. Implications for understanding the relation between unconscious and conscious discoveries and for the role of competing activations in strategy discovery are discussed.

Awareness↗
PubMed1997

An intracellular protein that binds amyloid-beta peptide and mediates neurotoxicity in Alzheimer's disease.

Amyloid-beta is a neurotoxic peptide which is implicated in the pathogenesis of Alzheimer's disease. It binds an intracellular polypeptide known as ERAB, thought to be a hydroxysteroid dehydrogenase enzyme, which is expressed in normal tissues, but is overexpressed in neurons affected in Alzheimer's disease. ERAB immunoprecipitates with amyloid-beta, and when cell cultures are exposed to amyloid-beta, ERAB inside the cell is rapidly redistributed to the plasma membrane. The toxic effect of amyloid-beta on these cells is prevented by blocking ERAB and is enhanced by overexpression of ERAB. By interacting with intracellular amyloid-beta, ERAB may therefore contribute to the neuronal dysfunction associated with Alzheimer's disease.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1997

Cholecystokinin modulates mucosal immunoglobulin A function.

BACKGROUND: We have established that mucosal immunoglobulin A (IgA) production is highly dependent on cholecystokinin release and is markedly suppressed by glucocorticoids. The purpose of the present study was to examine the role of cholecystokinin on the functional responsiveness of the mucosal IgA system in glucocorticoid treated rats. METHODS: A total of 24 Fischer rats were assigned to three groups of 8 animals each. Animals were injected with vehicle (CON), dexamethasone (DEX) (0.08 mg/150 g), or DEX (0.08 mg/150 gm) and ARL1294KF (500 ng twice daily), a novel and potent long-acting cholecystokinin agonist (DEX+CCK). Animals were treated for 48 hours and killed. Duodenum was harvested, and the total mucosal concentration of cholecystokinin was measured by radioimmunoassay. Mucosal IgA was assayed by quantitation of immunoreactive cells in the ileum. Bacterial adherence was evaluated by quantitative culture of vigorously washed stripped cecal mucosa. Transepithelial electrical resistance, a measure of tight junction permeability, was assessed by mounting strips of adjacent cecal mucosa in Ussing chambers. RESULTS: Glucocorticoid administration resulted in a statistically significant (p < 0.001) decrease in duodenal cholecystokinin, decreased IgA, and impaired mucosal immunity (increased bacterial adherence and decreased tissue resistance). Cholecystokinin administration preserved mucosal immune function in DEX-treated rats. CONCLUSIONS: Cholecystokinin may play an important role in maintaining the functional responsiveness of mucosal immunity during catabolic stress.

Animals↗
PubMed1997

Two cases of hepatitis C treated with herbs and supplements.

The treatment of two cases of hepatitis C using herbal medicine and nutritional supplements is presented. The selection of medicinals was based upon both biomedical findings and traditional Chinese medical diagnosis. The text describes the course of each patient's illness documented both subjectively and objectively using blood values and traditional Chinese medicine analysis as parameters. Explanation and/or citations are given for each medicinal used. Both patients improved during the course of treatment; subjective signs and symptoms (especially fatigue) as well as liver enzyme levels demonstrated improvement.

Ascorbic Acid↗
PubMed1996

Regional metabolic correlates of surgical outcome following unilateral pallidotomy for Parkinson's disease.

Stereotaxic ventral pallidotomy has been employed in the symptomatic treatment of patients with advanced Parkinson's disease (PD). To understand the pathophysiology of clinical outcome following this procedure, we studied 10 PD patients (5 men and 5 women; mean age 60.0 +/- 6.1 years; mean Hoehn and Yahr stage 3.8 +/- 1.0) with quantitative 18F-fluorodeoxyglucose (FDG) and positron emission tomography (PET). All patients were scanned preoperatively; 8 of 10 patients were rescanned 6 to 8 months following surgery. Clinical performance was assessed off medications before and after surgery using standardized timed motor tasks. We found that preoperative lentiform metabolism correlated significantly with improvement in contralateral motor tasks at 1 week, 3 months, and 6 months following unilateral pallidotomy (p<0.03). Postoperatively, significant metabolic increases were noted in the primary motor cortex, lateral premotor cortex, and dorsolateral prefrontal cortex (p<0.01) of the hemisphere that underwent surgery. Improvement in contralateral limb motor performance correlated significantly with surgical declines in thalamic metabolism (p<0.01) and increases in lateral frontal metabolism (p<0.05). Principal components analysis disclosed a significant covariance pattern characterized by postoperative declines in ipsilateral lentiform and thalamic metabolism associated with bilateral increase in supplementary motor control metabolism. Subject scores for this pattern correlated significantly with improvements in both contralateral and ipsilateral limb performance (p<0.005). These results suggest that pallidotomy reduced the preoperative overaction of the inhibitory pallidothalamic projection. Clinical improvement may be associated with modulations in regional brain metabolism occurring remote from the lesion site.

Aged↗
PubMed1996

The development of in vivo tracer methods to obtain new information about human disease: a study of the hallucinating brain.

An outline is provided of the development of methodological strategies to address the question of focal cerebral activation during hallucinations in schizophrenic patients. In so doing, the innovation and diligence required to tailor in vivo tracer procedures to specific clinical research issues are highlighted. Attention is drawn to the complexity of methodological advances and the way in which they are based upon close scientific and technical collaboration between clinical scientists, and non-clinical scientists and research support staff.

Hallucinations↗