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Abnormal Response (abnormal + response)

Distribution by Scientific Domains

Medical Sciences	84%
Life Sciences	15%

Selected Abstracts

Abnormal cardiovascular responses to carotid sinus massage also occur in vasovagal syncope , implications for diagnosis and treatment

EUROPEAN JOURNAL OF NEUROLOGY, Issue 8 2010
A. M. Humm
Background and purpose:, Carotid sinus massage (CSM) is commonly used to identify carotid sinus hypersensitivity (CSH) as a possible cause for syncope, especially in older patients. However, CSM itself could provoke classical vasovagal syncope (VVS) in pre disposed subjects. Methods:, Retrospective analysis of CSM, cardiovascular autonomic function tests (including tilt table testing) and medical history in 388 patients with recurrent syncope to identify and characterize patients in whom an abnormal response to CSM was more likely to reflect VVS than CSH. Results:, CSM was abnormal in 79 patients. In 53 patients (77.2 ± 8.7 years), CSH was the likely cause of syncope. VVS was the more likely diagnosis in 26 younger patients (59.7 ± 12.6 years) with longstanding syncope from youth, in whom fear or pain was as a trigger; 7/26 suffered from intense chronic or intermittent neck pain and one exacerbation of syncopal attacks followed a physical and emotional trauma to the neck. In VVS, 4/26 had spontaneous VVS during head-up tilt, another six after venepuncture (performed in 17/26). In 6/26, the abnormal response to CSM was delayed, occurring 62.8 ± 28.4 s after completion of CSM. The response to CSM was predominantly of the mixed type (20/26) and abnormal on both sides in 14/26. Conclusions:, An abnormal response to CSM may not indicate syncope caused by CSH and needs to be considered in the light of the patient's age, duration of syncopal episodes and detailed history of provocative stimuli. Differentiating CSH from VVS with an abnormal response to CSM has various implications from advice on driving to treatment strategies. [source]

Sensitive skin: mechanisms and diagnosis

INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2005
G. Primavera
Synopsis Sensitive skin is a condition of subjective cutaneous hyperreactivity to environmental factors. Subjects experiencing this condition report exaggerated reactions when their skin is in contact with cosmetics, soaps and sunscreens, and they often report worsening after exposure to dry and cold climate. Although no sign of irritation is commonly detected, itching, burning, stinging and a tight sensation are constantly present. Generally substances that are not commonly considered irritants are involved in this abnormal response. They include many ingredients of cosmetics such as: dimethyl sulfoxide, benzoyl peroxide preparations, salicylic acid, propylene glycol, amyldimethylaminobenzoic acid and 2-ethoxyethyl methoxycinnamate. Sensitive skin and subjective irritation are widespread but still far from being completely defined and understood. The aim of this paper is to summarize the relevant literature in order to elucidate the underlying mechanisms of sensitive skin and the best testing methodologies for investigation of sensitive skin. Résumé La peau sensible est la traduction d'une hyperréactivité cutanée subjective provoquée par les facteurs environnementaux. Les sujets qui en souffrent rapportent des réactions exagérées quand leur peau est au contact de cosmétiques, de savons, de produits solaires, phénomènes souvent aggravés après exposition à un climat froid et sec. Bien qu'aucun signe d'irritation ne soit généralement perçu, démangeaisons, brûlurepicotement et sensation de tiraillement sont constamment présents. En général des substances qui ne sont pas considérées comme des agents irritants sont impliquées dans ces réactions anormales. Elles incluent de nombreux ingrédients présents dans les produits cosmétiques comme le diméthyl sulfoxyde, les préparations aux peroxyde de benzoïle, l'acide salicylique, le propylène glycol, l'acide amyldiméthylaminobenzoïque et le 2-éthoxyéthylméthoxycinnamate. La peau sensible et l'irritation subjective sont des troubles répandus mais très loin d'être correctement définis et compris. L'objet de cet article est de résumer la littérature pertinente dans ces domaines afin d'élucider les mècanismes sous jacents à la peau sensible et d'appréhender les meilleures méthodologies de tests pour l'étudier. [source]

Up-Regulation and Functional Effect of Cardiac ,3 -Adrenoreceptors in Alcoholic Monkeys

ALCOHOLISM, Issue 7 2010
Heng-Jie Cheng
Background:, Recent studies link altered cardiac ,-adrenergic receptor (AR) signaling to the pathology of alcoholic cardiomyopathy (ACM). However, the alteration and functional effect of ,3 -AR activation in ACM are unknown. We tested the hypothesis that chronic alcohol intake causes an up-regulation of cardiac ,3 -AR, which exacerbates myocyte dysfunction and impairs calcium regulation, thereby directly contributing to the progression of ACM. Methods:, We compared myocyte ,3 - and ,1 -AR expression and myocyte contractile ([Ca2+]i), transient ([Ca2+]iT), and Ca2+ current (ICa,L) responses to ,- and ,3 -AR stimulation in myocytes obtained from left ventricle (LV) tissue samples obtained from 10 normal control (C) and 16 monkeys with self-administered alcohol for 12 months prior to necropsy: 6 moderate (M) and 10 heavy (H) drinkers with group average alcohol intakes of 1.5 ± 0.2 and 3.3 ± 0.2 g/kg/d, respectively. Results:, Compared with control myocytes (C), in alcoholic cardiomyocytes, basal cell contraction (dL/dtmax, ,39%, H: 69.8 vs. C: 114.6 ,m/s), relaxation (dR/dtmax, ,37%, 58.2 vs. 92.9 ,m/s), [Ca2+]iT (,34%, 0.23 vs. 0.35), and ICa,L (,25%, 4.8 vs. 6.4pA/pF) were all significantly reduced. Compared with controls, in moderate and heavy drinkers, ,1 -AR protein levels decreased by 23% and 42%, but ,3 -AR protein increased by 46% and 85%, respectively. These changes were associated with altered myocyte functional responses to ,-AR agonist, isoproterenol (ISO), and ,3 -AR agonist, BRL-37344 (BRL). Compared with controls, in alcoholic myocytes, ISO (10,8 M) produced significantly smaller increases in dL/dtmax (H: 40% vs. C: 71%), dR/dtmax (37% vs. 52%), [Ca2+]iT (17% vs. 37%), and ICa,L (17% vs. 27%), but BRL (10,8 M) produced a significantly greater decrease in dL/dtmax (H: ,23% vs. C: ,11%), [Ca2+]iT (,30% vs. ,11%), and ICa,L (,28% vs. ,17%). Conclusions:, Chronic alcohol consumption down-regulates cardiac ,1 - and up-regulates ,3 -ARs, contributing to the abnormal response to catecholamines in ACM. The up-regulation of cardiac ,3 -AR signaling enhances inhibition of LV myocyte contraction and relaxation and exacerbates the dysfunctional [Ca2+]i regulation and, thus, may precede the development of ACM. [source]

Ultrasonography and Cystic Hyperplasia,Pyometra Complex in the Bitch

REPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2004
E Bigliardi
Contents Cystic endometrial hyperplasia,pyometra complex is the most frequent and important endometrial disorder encountered in bitches. The pathogenesis of the disease is related to the activity of progesterone [Feldman and Nelson, Canine and Feline Endocrinology and Reproduction (1996) W.B. Saunders, Philadelphia]. Cystic endometrial hyperplasia (CEH) is an abnormal response of the bitch's uterus to ovarian hormones [De Bosschere et al. Theriogenology (2001) 55, 1509]. CEH is considered by many authors to be an exaggerated response of the uterus to chronic progestational stimulation during the luteal phase of the oestrous cycle, causing an abnormal accumulation of fluid within the endometrial glands and uterine lumen (De Bosschere et al. 2001). The resulting lesions of pyometra are due to the interaction between bacteria and hormones. The aim of this study was to evaluate if transabdominal uterine ultrasonography can be a useful and reliable diagnostic method to confirm Dow's [Veterinary Record (1958) 70, 1102] and De Bosschere's histopathological classification of CEH,pyometra complex. The study was carried out on 45 bitches with pyometra, 10 purebreeds and 35 crossbreeds, 1,15 years old, 20% of which had whelped at least once. None of these animals had received exogenous oestrogen or progesterone treatment. On admission the 45 animals were in the luteal phase of the oestrus cycle. Clinical signs, blood parameters, uterine ultrasonography, bacterial swabs and uterine histopalogical results were recorded. Results suggest that ultrasonographic examination is a useful and reliable tool for the diagnosis of cystic endometrial hyperplasia. [source]

Decreased TCR , -chain expression in T cells from patients with acquired aplastic anaemia

BRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2007
Elena E. Solomou
Summary In aplastic anaemia, T cells have a central role in the pathophysiology of bone marrow destruction. This study showed that T cells from patients with aplastic anaemia expressed decreased T-cell receptor (TCR) , -chain protein and mRNA levels compared to healthy controls. Patients with decreased TCR , -chain showed an abnormal response in intracellular calcium following stimulation through the TCR. We also observed an altered pattern of the transcription factors CREM, and Elf-1 that are implicated in , -chain transcription. We concluded that TCR , -chain expression was decreased in the majority of patients with aplastic anaemia, regardless of disease activity or treatment status. [source]

Repeatability of the low-dose ACTH test in asthmatic children on inhaled corticosteroids

ACTA PAEDIATRICA, Issue 12 2009
Atul Gupta
Abstract Aim:, To assess the repeatability of low-dose Synacthen test (LDST) in asthmatic children receiving high-dose fluticasone propionate (FP). Methods:, Low-dose Synacthen test was performed on 18 children with stable chronic asthma treated with FP at a constant daily dose of ,500 ,g and repeated 1 month later. Repeatability was assessed using the Kappa statistic for categorical variables. Results:, Fifteen patients had consistent results (either two normal or two abnormal responses) and three patients had inconsistent results (one normal and one abnormal response). The Kappa statistic was 0.56 indicating fair to good agreement between the tests. Conclusion:, The results of adrenal function testing in patients on inhaled steroids can have major implications for patient management, making it important to use a test with excellent repeatability. The LDST conducted using our protocol does not fulfil this criterion. [source]

Quantitative study on cerebral blood volume determined by a near-infrared spectroscopy during postural change in children

ACTA PAEDIATRICA, Issue 3 2009
Yasuko Taeja Kim
Abstract Aim: To investigate changes in cerebral blood volume during standing in healthy children with or without abnormal cardiovascular responses. Methods: We studied 53 children (age, 10,15 years). Cerebral oxygenated haemoglobin (oxy-Hb) and deoxygenated Hb (deoxy-Hb) were non-invasively and continuously measured using near-infrared spectroscopy (NIRS) (NIRO 300, Hamamatsu Photomedics, Shizuoka, Japan) during active standing. Beat-to-beat arterial pressure was monitored by Portapres. Results: Of 49 children with complete data acquisition, 33 had a normal cardiovascular response to the test (Group I) and 16 showed an abnormal response (Group II); nine with instantaneous orthostatic hypotension, three with postural tachycardia syndrome, three with neutrally mediated syncope and one with delayed orthostatic hypotension. At the onset of standing, Group II showed a significantly larger fall of oxy-Hb than Group I did (,2.9 ± 2.8 ,mol/L vs. ,6.4 ± 7.2 ,mol/L, respectively, p < 0.05). During min 1 to 7 of standing, with one exception, changes in oxy-Hb were normally distributed over the level of ,4 ,mol/L in Group I. Group II also showed a significantly marked decrease in oxy-Hb compared to Group I. Decreases in oxy-Hb were not correlated with blood pressure changes. Conclusion: This study shows that precise change in cerebral blood volume caused by orthostatic stress can be determined by NIRS in children in a quantitative manner of NIRS. Children with abnormal circulatory responses to standing showed a significant reduction of oxy-Hb compared with normal counterparts, suggesting impairment of cerebral autoregulation in these children. [source]

Is osseous dysplasia a primary feature of neurofibromatosis 1 (NF1)?

CLINICAL GENETICS, Issue 5 2005
S Alwan
Characteristic skeletal lesions are a cardinal feature of the autosomal dominant condition, neurofibromatosis 1 (NF1). The most frequently involved skeletal sites are the sphenoid wing, vertebrae, and tibia. Osseous lesions may range in severity in NF1 but are often progressive. They may lead to serious clinical consequences and be resistant to treatment. The skeletal lesions of NF1 are usually considered to be ,dysplasias', i.e. primary defects of bone, although there is no direct evidence supporting this interpretation. Moreover, it is difficult to understand why a generalized dysplasia of bone would produce focal lesions that show such a striking predisposition to only a few bones. We review the clinical and pathological features of NF1 skeletal lesions and propose that they result from an abnormal response of NF1 halpoinsufficient bone to abnormal mechanical forces rather than from a primary osseous dysplasia. [source]

Ret deficiency in mice impairs the development of A5 and A6 neurons and the functional maturation of the respiratory rhythm

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2005
J. C. Viemari
Abstract Although a normal respiratory rhythm is vital at birth, little is known about the genetic factors controlling the prenatal maturation of the respiratory network in mammals. In Phox2a mutant mice, which do not express A6 neurons, we previously hypothesized that the release of endogenous norepinephrine by A6 neurons is required for a normal respiratory rhythm to occur at birth. Here we investigated the role of the Ret gene, which encodes a transmembrane tyrosine kinase receptor, in the maturation of norepinephrine and respiratory systems. As Ret -null mutants (Ret,/,) did not survive after birth, our experiments were performed in wild-type (wt) and Ret,/, fetuses exteriorized from pregnant heterozygous mice at gestational day 18. First, in wt fetuses, quantitative in situ hybridization revealed high levels of Ret transcripts in the pontine A5 and A6 areas. Second, in Ret,/, fetuses, high-pressure liquid chromatography showed significantly reduced norepinephrine contents in the pons but not the medulla. Third, tyrosine hydroxylase immunocytochemistry revealed a significantly reduced number of pontine A5 and A6 neurons but not medullary norepinephrine neurons in Ret,/, fetuses. Finally, electrophysiological and pharmacological experiments performed on brainstem ,en bloc' preparations demonstrated impaired resting respiratory activity and abnormal responses to central hypoxia and norepinephrine application in Ret,/, fetuses. To conclude, our results show that Ret gene contributes to the prenatal maturation of A6 and A5 neurons and respiratory system. They support the hypothesis that the normal maturation of the respiratory network requires afferent activity corresponding to the A6 excitatory and A5 inhibitory input balance. [source]

Diagnostic utility of light transmission platelet aggregometry: results from a prospective study of individuals referred for bleeding disorder assessments

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2009
C. P. M. HAYWARD
Summary.,Background: Light transmission aggregometry (LTA) is commonly performed to assess individuals for bleeding disorders. Objectives: The goal was to evaluate the incidence and spectrum of platelet function abnormalities in a prospective cohort of individuals referred for bleeding disorder assessments after exclusion of thrombocytopenia and von Willebrand disease. Patients/methods: Subjects were healthy controls and patients from a prospective cohort of individuals referred for bleeding disorder assessments after exclusion of thrombocytopenia and von Willebrand disease. LTA was performed by standardized methods using platelet-rich plasma adjusted to 250 × 109 platelets L,1. Maximal aggregation data were analyzed to determine the likelihood of detecting a platelet function disorder by LTA, and the sensitivity and specificity of LTA for platelet disorders. Results: The incidence of false positive LTA among subjects excluded of having bleeding disorders was similar to healthy controls. Abnormal LTA was more common in subjects with bleeding disorders and the likelihood of a bleeding disorder was significantly increased (odds ratio 32) when maximal aggregation was reduced with two or more agonists. Receiver operator curve analyses indicated that LTA had high specificity and moderate sensitivity for detecting inherited defects in platelet function and that the LTA agonists 1.25 ,g mL,1 collagen, 6 ,M epinephrine, 1.6 mM arachidonic acid and 1.0 ,M thromboxane analogue U44619 detected most inherited disorders with abnormal LTA. Conclusions: LTA is valuable for detecting platelet function abnormalities among individuals referred for bleeding problems, particularly when the test indicates abnormal responses to multiple agonists. [source]

Postural responses to continuous unilateral neck muscle vibration in standing patients with cervical dystonia

MOVEMENT DISORDERS, Issue 4 2007
Marco Bove MD
Abstract Several observations support the notion that integration of neck proprioceptive input is impaired in cervical dystonia (CD). An example is the inconsistent or opposite to normal effect of lateral neck muscle vibration on body rotation during stepping. We hypothesized that lateral neck vibration produces abnormal responses also in a static task. Normal subjects and patients with CD stood quietly with eyes closed, without or with vibration applied to the sternocleidomastoid muscle, and center of foot pressure and body sway were recorded by a dynamometric platform. Patients had a larger than normal sway under control condition. They showed little or no postural responses to vibration. When body tilt occurred, it was rarely in the frontal plane as in normal subjects, but in the sagittal plane. No relationship existed between vibration-induced tilt during stance and body rotation during stepping. Therefore, in CD, proprioceptive neck input is less used for the construction of the postural vertical during quiet stance than it is used for the definition of the subjective straight ahead during a dynamic task. © 2007 Movement Disorder Society [source]

Abnormal vestibular responses to vertical head motion in cerebellar ataxia

ANNALS OF NEUROLOGY, Issue 2 2008
Ke Liao MS
Falls pose an important problem to neurologists caring for patients with cerebellar disorders. Normal human gait is characterized by prominent up-and-down linear head movements (vertical translations). Thus, we asked whether patients with cerebellar gait ataxia showed abnormal responses of otolithic vestibuloocular reflexes to this motion. Compared with healthy subjects, all cerebellar patients showed impaired otolith-ocular responses. Neurologists often test the rotational vestibuloocular reflexes in cerebellar patients, but our results indicate that vestibular responses to vertical linear motion are severely affected. Impairment of the corresponding otolith-spinal reflexes may contribute substantially to falls. Ann Neurol 2008 [source]