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Decrement
Kinds of Decrement Selected AbstractsDecrement in area of muscle responses to repetitive nerve stimulationMUSCLE AND NERVE, Issue 4 2003Y.L. Lo MD Abstract Measurement of the decremental muscle response to repetitive nerve stimulation (RNS) has low yields for the diagnosis of neuromuscular transmission defects compared with single fiber electromyography (SFEMG). We compared area and amplitude of muscle responses to RNS in 87 patients and 30 controls, using SFEMG as the reference standard. Decrement of response area provided additional diagnostic yields of 5.3% to 30% depending on the muscle examined and disease severity, and is recommended as a diagnostic adjunct to measurement of amplitude decrement during RNS. Muscle Nerve 27: 494,496, 2003 [source] ORIGINAL RESEARCH,BASIC SCIENCE: Fluoxetine-Induced Decrements in Sexual Responses of Female Rats and Hamsters Are Reversed by 3,,5,-THPTHE JOURNAL OF SEXUAL MEDICINE, Issue 8 2010Cheryl A. Frye PhD ABSTRACT Introduction., Sexual dysfunction, as a result of selective-serotonin reuptake inhibitor (SSRI) treatment among women, is relatively common and is a factor in medication compliance. The mechanisms that underlie these side-effects of SSRIs are not well-understood. SSRIs can alter activity of catabolic enzymes that are involved in progesterone's conversion to 5,-pregnan-3,-ol-20-one (3,,5,-THP). 3,,5,-THP plays a key role in female reproductive physiology and behavior. Aims., This study aimed to determine whether 3,,5,-THP, in the midbrain ventral tegmental area (VTA) may be a potential mechanism for fluoxetine's reduction in sexual responding of female rodents. We hypothesized that if fluoxetine induces decrements in sexual responding in part through actions of 3,,5,-THP, then fluoxetine will inhibit sexual receptivity concomitant with reducing 3,,5,-THP levels, effects which can be reversed by 3,,5,-THP administration. Methods., Experiment 1 investigated effects of acute systemic fluoxetine [20 mg/kg intraperitoneal (IP)] and/or 3,,5,-THP [500 µg, subcutaneous (SC)] administration on sexual responding of ovariectomized, hormone-primed rats. Experiment 2 examined effects of 3,,5,-THP administration to the midbrain VTA (100 ng) on fluoxetine-induced decrements in lordosis of ovariectomized, hormone-primed rats and hamsters. Main Outcome Measures., Sexual responding was determined in rats and hamsters. For rats, the percentage of times that the lordosis response occurred following mounting by a sexually-vigorous male (lordosis quotients) was utilized. For hamsters, lateral displacement, the pelvic movement that females will make to facilitate intromissions by a male hamster, was utilized. Results., Fluoxetine significantly reduced lordosis, and this was reversed SC 3,,5,-THP. Intra-VTA 3,,5,-THP attenuated fluoxetine's detrimental effects on lordosis quotients and lateral displacement of rats and hamsters, respectively. Conclusions., Thus, fluoxetine's effects to disrupt female sexual responses may involve its effects on progestogens in the midbrain VTA. Frye CA, and Rhodes ME. Fluoxetine-induced decrements in sexual responses of female rats and hamsters are reversed by 3,,5,-THP. J Sex Med 2010;7:2670,2680. [source] Prospective comparison of course of disability in antipsychotic-treated and untreated schizophrenia patientsACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2009J. Thirthalli Objective:, To compare the course of disability in schizophrenia patients receiving antipsychotics and those remaining untreated in a rural community. Method:, Of 215 schizophrenia patients identified in a rural south Indian community, 58% were not receiving antipsychotics. Trained raters assessed the disability in 190 of these at baseline and after 1 year. The course of disability in those who remained untreated was compared with that in those who received antipsychotics. Results:, Mean disability scores remained virtually unchanged in those who remained untreated, but showed a significant decline (indicating decrement in disability) in those who continued to receive antipsychotics and in those in whom antipsychotic treatment was initiated (P < 0.001; group × occasion effect). The proportion of patients classified as ,disabled' declined significantly in the treated group (P < 0.01), but remained the same in the untreated group. Conclusion:, Disability in untreated schizophrenia patients remains unchanged over time. Treatment with antipsychotics in the community results in a considerable reduction in disability. [source] The association between depression and health-related quality of life in people with type 2 diabetes: a systematic literature reviewDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2010Saima Ali Abstract The relationships between co-morbid depression in people with diabetes and adverse outcomes including poor HbA1c control, adherence to medication and mortality have been examined and confirmed. However, as the awareness of the decrement to health-related quality of life (HRQOL) in people with diabetes and its clinical consequences grows, investigators have become increasingly interested in measuring HRQOL in clinical trials. Given that the psychological factors such as depression may contribute to diminished HRQOL, the present review sought to summarize the association between these variables in people with type 2 diabetes. Articles for a systematic review were obtained via a search performed using MEDLINE, EMBASE and PsycINFO (1980,2007). Fourteen articles fulfilled the inclusion criteria. Studies indicated that self-reported depressive symptoms markedly impaired HRQOL on several domains. However, depression was not related to all sub-domains of HRQOL in all studies, suggesting that the effects of depression on certain aspects of HRQOL may vary between clinical and demographic subgroups. Although a number of shortcomings identified in the current literature should be taken into account for future research, the importance of this review lies in the possibility it raises that the improvements in HRQOL and clinical practice may potentially be achieved by placing greater attention on the identification and management of depression. Copyright © 2010 John Wiley & Sons, Ltd. [source] Auditory temporal processing deficits in children with reading disabilitiesDYSLEXIA, Issue 3 2007Ravit Cohen-Mimran Abstract The role of central auditory processing in reading skill development and reading disorders is unclear. The purpose of this study was to examine whether individuals with specific reading disabilities (SRD) have deficits in processing rapidly presented, serially ordered non-speech auditory signals. To this end, we compared 12 children with SRD and 12 children without SRD on their ability to detect differences and similarities in pure tones of 1000 and 2000 Hz when these signals were presented in pairs (same or different tones, randomly ordered) with short (50 ms) versus long (500 ms) inter stimulous intervals (ISI). Results showed that the children with SRD had significant difficulty in discriminating between pure tones with short, but not long ISI, whereas the controls performed well with both short and long ISI. The two groups did not differ significantly on measures of attention (d2) and performance IQ, and there were no significant correlations between these measures and ISI performance. There were significant correlations between the short ISI performance and phonologic awareness test results when the two groups were combined. These findings support the specific rapid auditory processing deficit hypothesis of SRD. Examination of intra-subject variability in performance indicated that children from the SRD group showed both decrement in performance with time on task and high overall variability in performance as compared to the controls. These findings underpin the importance of using time-series analyses of performance. Copyright © 2006 John Wiley & Sons, Ltd. [source] Color M-Mode Flow Propagation Velocity: Is It Really Preload Independent?ECHOCARDIOGRAPHY, Issue 8 2005Shih-Kai Lin M.D. Objective: This study investigates the change in flow propagation velocity (FPV) in uremic patients who undergo regular hemodialysis (H/D). Materials and Methods: We studied 93 uremic patients (44 men and 49 women; 59 ± 14-years-old) receiving regular hemodialysis. Patients were separated by baseline left ventricular ejection fraction (LVEF): 71 patients with LVEF > 50% (group 1), 13 patients with LVEF 35,50% (group 2), 7 patients with LVEF < 35% (group 3). All patients were in sinus rhythm before H/D. They received complete transthoracic echocardiographic examinations. Flow propagation velocity was measured by color M-mode echocardiography in apical four chambers view. All these parameters were obtained before and after H/D. Paired data were compared. According to different H/D amounts, we viewed the FPV response after H/D in variant baseline LVEF groups. Result: The baseline FPV became lower in patients with low LVEF. After H/D, obvious decrement of FPV occurred in group 1, but there were no obvious changes in groups 2 and 3. In fact, a slight increment of FPV was found in group 3. In patients with baseline LVEF > 50%, FPV after H/D was almost always lower, regardless of H/D amount. But there was different response in patients with baseline LVEF < 50%. Conclusion: Flow propagation velocity is preload independent in patients with LVEF < 50%, but it is preload-dependent in patients with LVEF > 50%. [source] The Effects of Adjunctive Topiramate on Cognitive Function in Patients with EpilepsyEPILEPSIA, Issue 3 2003Suzee Lee Summary: ,Purpose: We investigated possible cognitive effects of topiramate (TPM) in polypharmacy on patients with intractable epilepsy. Methods: Study 1 evaluated 22 consecutively admitted patients whose antiepileptic drugs (AEDs) on admission to the Montreal Neurological Hospital included TPM. Performance on neuropsychological tests administered on and subsequently off TPM was analyzed. Four patients also were tested before taking TPM, allowing comparisons off, then on, and then off the drug again. Measures included intellectual function, verbal and nonverbal memory, language, word and design fluency, somatosensory sensitivity, and motor skills. In Study 2, 16 patients at the Minnesota Epilepsy Group were tested first off, then on TPM with nine cognitive tasks that measured concentration, verbal fluency, language, and psychomotor speed. Results: In Study 1, significant (p , 0.01) improvements were observed off TPM on 13 measures including verbal and nonverbal fluency and certain verbal and perceptual tasks. Notably, verbal learning and memory were unaffected; a limited effect was observed on nonverbal memory. Patients tested 3 times scored better in both tests off TPM compared with on this drug. In Study 2, declines on TPM were observed on all measures, significantly (p , 0.05) for tests of fluency, sustained concentration, and visual motor processing speed. Conclusions: TPM was associated with declines in fluency, attention/concentration, processing speed, language skills, and perception; working memory but not retention was affected. As the two studies used an opposite order of testing on versus off TPM, our results clearly show a performance decrement while patients are taking TPM, without respect to which condition is tested first. [source] REPRODUCTIVE BURDEN, LOCOMOTOR PERFORMANCE, AND THE COST OF REPRODUCTION IN FREE RANGING LIZARDSEVOLUTION, Issue 4 2000Donald B. Miles Abstract. A reduction in the locomotor capacity of gravid females is considered to be a cost of reproduction if it leads to an increased risk of mortality. In this study, we measured the change in endurance between gravid and postgravid female side-blotched lizards (Uta stansburiana) as a test of the cost of reproduction. We also altered reproductive investment in some females by direct ovarian manipulation (yolkectomy), which decreased reproductive burden by 30%. Regardless of experimental treatment, all females had lower endurance when gravid. Endurance was 28% lower in gravid females from the yolkectomy treatment and 31% lower in the unmanipulated females relative to postoviposition females. The experimental reduction in clutch mass resulted in a 21% increase in endurance of gravid yolkectomy females relative to control females. Postovipositional endurance was significantly higher in the yolkectomized females than unmanipulated females, which suggests that the cost of reproduction carries over to postoviposition performance. Unmanipulated females exhibited a significant negative association between endurance and size-specific burden. Endurance was not correlated with clutch size or size-specific burden in the yolkectomy females. Survivorship to the second clutch was higher in the yolkectomy females. The results from a logistic regression showed the probability of survival to the second clutch was significantly and positively associated with endurance after controlling for the effects of treatment. Our analyses demonstrated that the decrement in performance associated with current reproductive investment represents a cost of reproduction expressed as diminished locomotor performance and lowered survivorship to the next clutch. [source] Carrying capacity and survival strategy for the Pacific bluefin tuna, Thunnus orientalis, in the Western PacificFISHERIES OCEANOGRAPHY, Issue 2 2006YASUO MATSUKAWA Abstract The carrying capacity for the Pacific bluefin tuna at each life stage is estimated and its survival strategy is examined numerically, using a new method to define the hypothetical capacity, the standard population, and the search volumes that are necessary and are feasible for the tuna. The carrying capacity for the adult is estimated at 1,2 × 106 individuals, which corresponds with 5,10% of the hypothetical capacity and is comparable with the maximum levels of the southern and the Atlantic bluefin tuna populations. It is hypothesized semiquantitatively that the migration at each life stage and the remarkable decrement of growth at 120 days and about 40 cm occur as an evolutionary response to population excess over the carrying capacity. It is also hypothesized semiquantitatively that the early larvae have minimal food available in the Subtropical Water and develop the predatory morphology, high growth rate, and high mobility, however, at the expense of a high mortality as an evolutionary response to the tuna spawning in the Subtropical Water. This method may be an available tool to not only investigate the carrying capacity and survival strategy of a specific fish species, but also predict when and in how much abundance the fish species occurs in a specific area of its habitat. [source] Bilateral medial temporal lobe damage does not affect lexical or grammatical processing: Evidence from amnesic patient H.M.HIPPOCAMPUS, Issue 4 2001Elizabeth A. Kensinger Abstract In the most extensive investigation to date of language in global amnesia, we acquired data from experimental measures and examined longitudinal data from standardized tests, to determine whether language function was preserved in the amnesic patient H.M. The experimental measures indicated that H.M. performed normally on tests of lexical memory and grammatical function, relative to age- and education-matched control participants. Longitudinal data from four Wechsler subtests (Information, Comprehension, Similarities, and Vocabulary), that H.M. had taken 20 times between 1953 (preoperatively) and 2000, indicated consistent performance across time, and provided no evidence of a lexical memory decrement. We conclude that medial temporal lobe structures are not critical for retention and use of already acquired lexical information or for grammatical processing. They are, however, required for acquisition of lexical information, as evidenced in previous studies revealing H.M.'s profound impairment at learning new words. Hippocampus 2001;11:347,360. © 2001 Wiley-Liss, Inc. [source] Auditory and visual distractor decrement in older worker manual assembly task learning: Impact of spatial reasoning, field independence, and level of education,HUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 4 2009S. F. Wiker This study examined the impact of age on manual assembly task learning in the presence of visual and auditory distracters. Manual assembly task learning (e.g., number of learning trials needed to obtain consistently accurate assembly and near asymptote performance times) was studied in men and women between 18 and 65 years of age. Higher spatial reasoning capabilities were associated with fewer trials to reach the learning criterion, faster manual assembly times, and material prophylaxis for the type of distractors addressed in this study that are likely to be encountered in the workplace. Years of formal education and field independence showed no impact on distractor-based decrements in task learning. For the oldest group of subjects (>50 years), concomitant presentation of visual and auditory distractors that are commonly encountered in industry were associated with a greater number of learning trials that were needed to achieve asymptotic manual assembly task learning. Spatial reasoning and field independence measures were lower in the older than in the younger age groups (p < 0.05). When spatial reasoning was treated as a covariate, however, nearly all age differences found in learning performance in the face of distractors were removed. The findings suggest that selection of workers based on spatial reasoning ability, rather than age, would yield better manual task learning in the face of visual and auditory distraction. © 2009 Wiley Periodicals, Inc. [source] Effects of virtual lighting on visual performance and eye fatigueHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 2 2002Vincent G. Duffy This study is designed to determine whether differences in eye fatigue and visual performance can be shown under varying virtual industrial lighting conditions. It is based on the results of studies of more traditional video display terminal (VDT) tasks reported in the literature. One experiment was designed to determine if the effects of virtual lighting on eye fatigue and visual performance in a simulated virtual industrial environment are similar to some other VDT tasks with varying luminance contrast. Results of a test of 20 participants in a vigilance task show that there is a significant difference in performance and eye fatigue in the virtual environment with varying virtual light conditions. These results may help designers see that performance in some virtual "lighting" conditions, for some tasks, is consistent with that in the real. However, due to the difficulties of determining the appropriate virtual objects to be considered for the luminance measures, additional research is needed to be able to generalize the results to other industrial training scenarios. A second experiment was intended to test for the luminance decrement in a VDT that was shown in recent literature. The results would have potential implications for the experiment that included a vigilance task. However, the results showed that the luminance decrement demonstrated in recent literature did not occur. These results suggest that the equipment used in the present experiments should not cause difficulty in interpreting the results of the vigilance task. © 2002 Wiley Periodicals, Inc. [source] Modeling Infant Speech Sound Discrimination Using Simple Associative NetworksINFANCY, Issue 1 2001Graham Schafer Infants' responses in speech sound discrimination tasks can be nonmonotonic over time. Stager and Werker (1997) reported such data in a bimodal habituation task. In this task, 8-month-old infants were capable of discriminations that involved minimal contrast pairs, whereas 14-month-old infants were not It was argued that the older infants' attenuated performance was linked to their processing of the stimuli for meaning. The authors suggested that these data are diagnostic of a qualitative shift in infant cognition. We describe an associative connectionist model showing a similar decrement in discrimination without any qualitative shift in processing. The model suggests that responses to phonemic contrasts may be a nonmonotonic function of experience with language. The implications of this idea are discussed. The model also provides a formal framework fer studying habituation-dishabituation behaviors in infancy. [source] Achieving performance enhancement in IEEE 802.11 WLANs by using the DIDD backoff mechanismINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 1 2007P. Chatzimisios Abstract Wireless local area networks (WLANs) based on the IEEE 802.11 standards have been widely implemented mainly because of their easy deployment and low cost. The IEEE 802.11 collision avoidance procedures utilize the binary exponential backoff (BEB) scheme that reduces the collision probability by doubling the contention window after a packet collision. In this paper, we propose an easy-to-implement and effective contention window-resetting scheme, called double increment double decrement (DIDD), in order to enhance the performance of IEEE 802.11 WLANs. DIDD is simple, fully compatible with IEEE 802.11 and does not require any estimation of the number of contending wireless stations. We develop an alternative mathematical analysis for the proposed DIDD scheme that is based on elementary conditional probability arguments rather than bi-dimensional Markov chains that have been extensively utilized in the literature. We carry out a detailed performance study and we identify the improvement of DIDD comparing to the legacy BEB for both basic access and request-to-send/clear-to-send (RTS/CTS) medium access mechanisms. Copyright © 2006 John Wiley & Sons, Ltd. [source] Susceptibility of spatial and verbal working memory to demands of the central executive1JAPANESE PSYCHOLOGICAL RESEARCH, Issue 2 2004HIROHITO KONDO Abstract:, We used a dual-task paradigm to examine the degree to which domain-specific spatial and verbal subsystems depend on the domain-general central executive. Forty participants were asked to retain spatial or verbal information while performing a concurrent secondary task related to simple arithmetic. The secondary tasks consisted of three cognitive processes: single-digit addition, a digit-carrying operation, and digit reading. The single-digit addition and carry operation include central executive functioning, while digit reading relies solely on the phonological loop. The single-digit addition caused a performance decrement on the spatial working memory task, while the digit reading impaired performance on the verbal working memory task. The carry operation interfered with recall accuracy on both working memory tasks. The spatial working memory task was significantly correlated with the verbal working memory task only when the secondary task was more demanding on the central executive. Our results suggest that spatial working memory rather than verbal working memory is susceptible to failure of central executive functioning and that the central executive plays an important role in regulating the cognitive demands of different domains. [source] Fabrication and characterization of solution cast MWNTs/PEI nanocompositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2009Lu Shao Abstract Under mild conditions with the aid of ultrasonic, multi-walled carbon nanotubes (MWNTs) have been functionalized by mixed acid treatment which was proved by FTIR and XPS. According to SEM, acid treatment on MWNTs decreased the thickness of the membrane. However, no devastating damage and fracture happened on MWNTs after acid treatment under mild conditions. Precipitation observation illustrated that the enhanced solubility of MWNTs in water, ethanol, and dimethylformaide (DMF). Further, MWNTs/polyetherimide (PEI) nanocomposite films have been prepared by the simple solution casting method. The dispersion of MWNTs in polyetherimide (PEI) matrix was observed by Atomic Force Microscopy (AFM) which illustrated the improved dispersion for acid treated MWNTs in PEI. The adding of MWNTs in PEI decreased the dispersive component of surface energy and increased the polar component of surface energy, which resulted in the decrement of film surface energy. Differential scanning calorimetry showed that the glass transition temperature of PEI increased by about 4°C after the introduction of MWNTs. This improvement was related to the better affinity between MWNTs and PEI matrix, which also resulted in the improvement of mechanical strength in MWNTs/PEI nanocomposites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Conduction Characteristics at the Crista Terminalis During Onset of Pulmonary Vein Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2004SIMON P. FYNN M.D. Introduction: Focal atrial fibrillation (AF) may initiate with an irregular rapid burst of atrial ectopic (AE) activity from a pulmonary vein (PV) focus, but how AF is maintained it is not known. The crista terminalis (CT) is an important line of block in atrial flutter (AFL), but its role in AF has not been determined. The aim of this study was to examine the conduction properties of the CT during onset of AF. Methods and Results: In 10 patients (mean age 38 ± 8 years), we analyzed conduction across the CT during onset of focal AF from an arrhythmogenic PV and during pacing from the same PV at cycle lengths of 700 and 300 ms. A 20-pole catheter was positioned on the CT using intracardiac echocardiography. In 10 control patients with no history of AF, we analyzed conduction across the CT during pacing from the distal coronary sinus at 700 and 300 ms. In all 10 AF patients, AF was initiated with 1 to 9 AE beats (median 5) from a PV. During sinus rhythm, there were no split components (SC) recorded on the CT. During PV AE activity, discrete SC were recorded on the CT in all patients over 6.3 ± 0.9 bipoles (3.7 ± 0.3 cm). Maximal splitting of SC was 66 ± 31 ms (37,139). There was an inverse relationship between AE coupling intervals and the degree of splitting between SC in all patients. Degeneration to AF was preceded by progressive decrement across the CT. SC were recorded during PV pacing at 700 and 300 ms (maximal distance between SC of 24 ± 3 ms and 43 ± 5 ms, respectively, P < 0.001). Maximum SC at CT in controls was 13 ± 8 ms at 700 ms (P = 0.06 vs AF patients) and 16 ± 9 ms at 300 ms (P < 0.01 vs AF patients). Conclusion: (1) These observations provide evidence of anisotropic, decremental conduction across the CT during onset of focal AF and during pacing from the same PV. A line of functional conduction block develops along this anatomic structure (CT). Whether this line of block acts as an initiator of AF or simply contributes passively to nonuniform fibrillatory conduction is unknown. (2) In some patients with focal AF, development of conduction block along the CT may provide a substrate for typical AFL. [source] Prenatal testosterone treatment potentiates the aggression-inhibiting effect of the neurosteroid dehydroepiandrosterone in female miceAGGRESSIVE BEHAVIOR, Issue 2 2001Fabrice Perché Abstract The neurosteroid dehydroepiandrosterone (DHEA) is a powerful inhibitor of aggression in murine models when given for 15 days and potentially may be useful in the management of inappropriate human aggression. Although the biosynthesis and metabolism of DHEA have been described, little is known about the potential effect of the steroidal environment during sexual differentiation on the subsequent response to DHEA. Whether prenatal androgen exposure influences the subsequent response to DHEA was assessed by comparing the effect of DHEA (80 ,g/d) on aggression in female offspring where dams were treated with 1, 10, or 100 ,g of testosterone (T) on days 15 to 18 of gestation (Experiment I) or that developed in different uterine positions (Experiment II). The results showed that DHEA decreased attack behavior in general and that the 100-,g prenatal T treatments enhanced the antiaggressive effect of this neurosteroid. Neither the lower doses of exogenously administered T nor the uterine position led to an enhanced response to DHEA. In addition, whether DHEA produced changes in social and nonsocial activities was examined. In the 100-,g T females, DHEA increased the duration of the former and decreased the frequency and duration of the latter, indicating that it was not a general decrement in behavioral expression that mediated the enhanced response to the antiaggressive effect of DHEA. In the second experiment, DHEA treatment led to increased frequencies of social nonaggressive and nonsocial activities. However, the uterine positions × treatment interactions were not significant, demonstrating that contiguity to male fetuses did not differentially affect the response to DHEA. Aggr. Behav. 27:130,138, 2001. © 2001 Wiley-Liss, Inc. [source] Mitochondrial function and apoptotic susceptibility in aging skeletal muscleAGING CELL, Issue 1 2008Béatrice Chabi Summary During aging, skeletal muscle undergoes sarcopenia, a condition characterized by a loss of muscle cell mass and alterations in contractile function. The origin of these decrements is unknown, but evidence suggests that they can be partly attributed to mitochondrial dysfunction. To characterize the nature of this dysfunction, we investigated skeletal muscle contractile properties, subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondrial biogenesis and function, as well as apoptotic susceptibility in young (6 months old) and senescent (36 months old) Fischer 344 Brown Norway rats. Muscle mass and maximal force production were significantly lower in the 36-month group, which is indicative of a sarcopenic phenotype. Furthermore, contractile activity in situ revealed greater fatigability in the 36-month compared to the 6-month animals. This decrement could be partially accounted for by a 30% lower mitochondrial content in fast-twitch muscle from 36-month animals, as well as lower protein levels of the transcriptional coactivator peroxisome proliferator-activated receptor , coactivator-1,. Enzyme activities and glutamate-induced oxygen consumption rates in isolated SS and IMF mitochondria were similar between age groups. However, mitochondrial reactive oxygen species (ROS) production during state 3 respiration was ~1.7-fold greater in mitochondria isolated from 36-month compared to 6-month animals, and was accompanied by a 1.8-fold increase in the DNA repair enzyme 8-oxoguanine glycosylase 1 in fast-twitch muscle. Basal rates of release of cytochrome c and endonuclease G in SS mitochondria were 3.5- to 7-fold higher from senescent animals. These data suggest that the age-related sarcopenia and muscle fatigability are associated with enhanced ROS production, increased mitochondrial apoptotic susceptibility and reduced transcriptional drive for mitochondrial biogenesis. [source] EFFECTS OF EXTRUSION CONDITIONS ON PHYSICOCHEMICAL PROPERTIES OF A MUTANT RICE CULTIVAR, GOAMI2 , HIGH IN NONDIGESTIBLE CARBOHYDRATESJOURNAL OF FOOD QUALITY, Issue 5 2008I. CHOI ABSTRACT A mutant rice Goami2, a cultivar high in nondigestible carbohydrates (NDCs), was extrusion-cooked at feed moisture (20, 25%), screw speed (200, 300 rpm) and barrel temperature (110, 120 and 130C). Effects of extrusion conditions on the physical and functional properties were investigated. NDCs were determined by total dietary fiber (TDF) and resistant starch (RS) contents. Increasing moisture resulted in an increment of density, water absorption index (WAI) and hardness, and a decrement in expansion and water solubility index (WSI). A higher barrel temperature decreased the hardness and increased the WSI probably due to a higher proportion of gelatinized starch. Extrusion caused a reduction in TDF in the extrudates, as well as a significant decrease in RS contents. However, extrudates processed at moisture (%), screw speed (rpm) and barrel temperature (C) combinations of 25/200/110 and 25/200/120 showed no significant difference in TDF contents compared with its raw rice. Multiple regression models showed that feed moisture had the most pronounced effect on extrudate qualities, followed by barrel temperature and screw speed. PRACTICAL APPLICATIONS Rice, being one of the primary dietary sources of carbohydrates worldwide, is the major energy and nutritional sources. In recent years, demands have been increasing for rice with a wide range of value-added properties, such as enhanced nutrient, aroma, color and rice kernel shape, including functional properties. Goami2 is a mutant rice of Ilpumbyeo, a high japonica rice cultivar, and has been revealed to have higher nondigestible fractions. However, Goami2 rice has unsuitable properties for traditional cooking because of the difficulty of gelatinization, which might result in a hard texture of cooked rice compared with that of ordinary rice. On the basis of its nutritional and functional benefits, exploiting the possible utilization of Goami2 for processed food products would increase the potential consumption of Goami2 for various food products. [source] Cimetidine inhibits epidermal growth factor-induced cell signalingJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 3 2007Tatsuya Fujikawa Abstract Background:, Cimetidine, a histamine-2 (H2) receptor antagonist, has been demonstrated to have anticancer effects on colorectal cancer, melanoma and renal cell carcinoma. In the current study, we clarified that cimetidine inhibits both epidermal growth factor (EGF)-induced cell proliferation and migration in hepatocellular carcinoma (HCC) cell lines. Method:, HCC cell lines (Hep3B, HLF, SK-Hep-1, JHH-2, PLC/PRF/5 and HLE) were used and cell proliferation was assessed by [3H]-thymidine incorporation assay. Cell migration was measured by in vitro cell migration assay. Biological effects of cimetidine were assessed with human EGF receptor (EGFR)-expressing mouse fibroblast cells (NR6-WT). The autophosphorylation of EGFR and the activation of other downstream effectors were analyzed by immunoprecipitation and immunoblotting. The concentration of intracellular cyclic AMP (cAMP) was measured by competitive enzyme immunoassay. Results:, Cimetidine inhibited both EGF-induced cell proliferation and migration in Hep3B, HLF, SK-Hep-1 and JHH-2, while cimetidine did not affect EGF-induced cell proliferation and migration in PLC/PRF/5 and HLE. Cimetidine was revealed to disrupt the EGF-induced autophosphorylation of EGFR and its downstream effectors, mitogen activated protein kinases and phospholipase C-,. To define the molecular basis of this negative regulation, we identified that cimetidine significantly decreased intracellular cAMP levels and that decrement of cAMP inhibited autophosphorylation of EGFR. The cell permeable cAMP analog, CPT-cAMPS reversed the cimetidine-induced inhibition of EGF-induced cell proliferation and cell migration by restoring autophosphorylation of EGFR. Conclusion:, Cimetidine inhibited EGF-induced cell proliferation and migration in HCC cell lines by decreasing the concentration of intracellular cAMP levels. Cimetidine may be a candidate chemopreventive agent for HCC. [source] Mathematical modeling of solid oxide fuel cells at high fuel utilization based on diffusion equivalent circuit modelAICHE JOURNAL, Issue 5 2010Cheng Bao Abstract Mass transfer and electrochemical phenomena in the membrane electrode assembly (MEA) are the core components for modeling of solid-oxide fuel cell (SOFC). The general MEA model is simply governed with the Stefan-Maxwell equation for multicomponent gas diffusion, Ohm's law for the charge transfer and the current-overpotential equation for the polarization calculation. However, it has obvious discrepancy at high-fuel utilization or high-current density. An advanced MEA model is introduced based on the diffusion equivalent circuit model. The main purpose is to correct the real-gas concentrations at the triple-phase boundary by assuming that the resistance of surface diffusion is in series with that of the gaseous bulk diffusion. Thus, it can obtain good prediction of cell performance in a wide range by avoiding the decrement of effective gas diffusivity via unreasonable increment of the electrode tortuosity in the general MEA model. The mathematical model has been validated in the cases of H2H2O, COCO2 and H2CO fuel system. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] A non-invasive method for studying an index of pupil diameter and visual performance in the rhesus monkeyJOURNAL OF MEDICAL PRIMATOLOGY, Issue 2 2006Sarah J. Fairhall Abstract Background, A non-invasive model has been developed to estimate gaze direction and relative pupil diameter, in minimally restrained rhesus monkeys, to investigate the effects of low doses of ocularly administered cholinergic compounds on visual performance. Methods, Animals were trained to co-operate with a novel device, which enabled eye movements to be recorded using modified human eye-tracking equipment, and to perform a task which determined visual threshold contrast. Responses were made by gaze transfer under twilight conditions. 4% w/v pilocarpine nitrate was studied to demonstrate the suitability of the model. Results, Pilocarpine induced marked miosis for >3 h which was accompanied by a decrement in task performance. Conclusions, The method obviates the need for invasive surgery and, as the position of point of gaze can be approximately defined, the approach may have utility in other areas of research involving non-human primates. [source] Effect of hypoxia on the auditory system of goat fetuses during extrauterine incubationJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2003Nobuko Nishioka Abstract Aim:, To investigate the effect of hypoxia on the auditory system in fetuses, we attempted to analyze the auditory brainstem response, the middle latency response, and changes of several physiological parameters of goat fetuses during extrauterine incubation. Methods:, We conducted extrauterine incubation of five goat fetuses at around 127 days of gestation (term = 148 days). Their physiological parameters, such as fetal heart rate, mean blood pressure, flow rate of carotid artery, as well as the auditory brainstem response and middle latency response, were recorded prior to and during hypoxia, and the two sets of data were compared with each other. Results:, In all five cases, the fetal heart rate decreased from 178 ± 12.2 b.p.m. to 144 ± 15.2 b.p.m. during hypoxia, while mean blood pressure and flow rate of carotid artery increased from 37.3 ± 3.7 mmHg to 43.2 ± 5.1 mmHg, and from 38.5 ± 5.5 mL/min to 47.0 ± 5.1 mL/min, respectively. The latency of the auditory brainstem response's wave V and of the middle latency response's Pa wave elongated from 5.24 ± 0.24 ms to 5.69 ± 0.20 ms, and from 19.2 ± 1.6 ms to 20.9 ± 1.4 ms, respectively. Conclusions:, Although fetal compensatory reactions, such as increases in mean blood pressure and flow rate of carotid artery during hypoxia were recognized, elongation of latency, and decrement of amplitude were observed in the auditory brainstem response and middle latency response. These results suggest that hypoxia itself influences the auditory system of the fetus. [source] Pharmacologic Dissociation Between Impulsivity and Alcohol Drinking in High Alcohol Preferring MiceALCOHOLISM, Issue 8 2010Brandon G. Oberlin Background:, Impulsivity is genetically correlated with, and precedes, addictive behaviors and alcoholism. If impulsivity or attention is causally related to addiction, certain pharmacological manipulations of impulsivity and/or attention may affect alcohol drinking, and vice versa. The current studies were designed to explore the relationship among impulsivity, drinking, and vigilance in selectively bred High Alcohol Preferring (HAP) mice, a line that has previously demonstrated both high impulsivity and high alcohol consumption. Amphetamine, naltrexone, and memantine were tested in a delay discounting (DD) task for their effects on impulsivity and vigilance. The same drugs and doses were also assessed for effects on alcohol drinking in a 2-bottle choice test. Methods:, HAP mice were subjected to a modified version of adjusting amount DD using 0.5-second and 10-second delays to detect decreases and increases, respectively, in impulsive responding. In 2 experiments, mice were given amphetamine (0.4, 0.8, or 1.2 mg/kg), naltrexone (3 and 10 mg/kg), and memantine (1 and 5 mg/kg) before DD testing. Another pair of studies used scheduled access, 2-bottle choice drinking to assess effects of amphetamine (0.4, 1.2, or 3.0 mg/kg), naltrexone (3 and 10 mg/kg), and memantine (1 and 5 mg/kg) on alcohol consumption. Results:, Amphetamine dose-dependently reduced impulsivity and vigilance decrement in DD, but similar doses left alcohol drinking unaffected. Naltrexone and memantine decreased alcohol intake at doses that did not affect water drinking but had no effects on impulsivity or vigilance decrement in the DD task. Conclusions:, Contrary to our hypothesis, none of the drugs tested here, while effective on either alcohol drinking or impulsivity, decreased both behaviors. These findings suggest that the genetic association between drinking and impulsivity observed in this population is mediated by mechanisms other than those targeted by the drugs tested in these studies. [source] Persistent Deficits in Heart Rate Response Habituation Following Neonatal Binge Ethanol ExposureALCOHOLISM, Issue 9 2009Katherine C. Morasch Background:, We have previously shown that the rate of habituation of the heart rate orienting response to a novel odor in rats is negatively affected by neonatal ethanol exposure. Thus far, however, only young rats (16 days of age) have been tested. Given the persistence of attention and memory problems evident in humans exposed to ethanol in utero, the purpose of this experiment was to examine the longer-term consequences of ethanol exposure on response habituation. Methods:, Ethanol (5.25 g/kg/d) was administered intragastrically to male and female Sprague-Dawley rats on postnatal days (PD) 4 to 9, and controls were given sham intubations. Animals were tested for heart rate orienting and response habituation to a novel olfactory stimulus (amyl acetate) on PD 16, 23, or 30. Results:, Animals tested on PD 16 or 23 showed normal heart rate deceleration to the novel odor, a measure of the orienting response. However, ethanol-treated subjects showed impaired response habituation compared with sham controls. While controls exhibited complete habituation within 4 to 5 trials, ethanol-treated animals continued to respond throughout the testing session, with little decrement in heart rate response magnitude across 10 stimulus presentations. A different pattern of responding was observed in animals tested during adolescence (PD 30). Control animals failed to show the typical heart rate decrease indicative of orienting, and instead showed a tendency toward tachycardia. In contrast, ethanol-treated animals tested on PD 30 showed orienting bradycardia that persisted for several trials. Conclusions:, These data suggest that there are relatively long-term consequences of neonatal ethanol exposure on nonassociative memory. This impairment in habituation may be relevant to the distractibility and poor focused attention that is pervasive among humans diagnosed with fetal alcohol spectrum disorders. [source] Spousal Concordance for Alcohol Dependence: Evidence for Assortative Mating or Spousal Interaction Effects?ALCOHOLISM, Issue 5 2007Julia D. Grant Background: Alcohol dependence (AD) is among the most common psychiatric disorders, and impacts the health and well-being of problem drinkers, their family members, and society as a whole. Although previous research has consistently indicated that genetic factors contribute to variance in risk for AD, little attention has been paid to nonrandom mating for AD. When assortative mating occurs for a heritable trait, spouses are genetically correlated and offspring are at increased risk of receiving high-risk genes from both parents. The primary goal of the present analyses is to test hypotheses about the source(s) and magnitude of spousal associations for AD using a twin-spouse design. Methods: DSM-IV AD (without the clustering criterion) was assessed via telephone interview for 5,974 twin members of an older cohort of the Australian Twin Register (born 1902,1964) and 3,814 spouses of the twins. Quantitative genetic modeling was used to determine the extent to which variability in risk for AD was influenced by genetic factors, the extent of spousal association for AD, and whether the association was attributable to assortative mating, reciprocal spousal interaction, or both processes. Results: Genetic factors explained 49% of the variance in risk for AD. There was no evidence of gender differences in the spousal interaction effect, the degree of rater bias, or the association between the twin's report of spouse AD and the spouse's AD phenotype. Either the assortative mating parameter or the spousal interaction parameter could be removed from the model without a significant decrement in fit, but both could not be dropped simultaneously, suggesting a lack of power to differentiate between these 2 causes of spousal correlation. When both effects were included in the model, the spousal correlation was 0.29, the assortative mating coefficient was 0.45 (i.e., "like marries like"), and the reciprocal spousal interaction coefficient was ,0.10 (i.e., after controlling for assortative mating, the additional impact of spousal interactions is slightly protective). Conclusions: These analyses provide evidence of significant spousal associations for AD, with assortative mating increasing spouse similarity and spousal interaction effects decreasing it after controlling for assortative mating. Although the genetic impact is modest, assortative mating results in an increased proportion of offspring exposed to 2 alcoholic parents and the associated detrimental environmental sequelae, and increases the likelihood of offspring inheriting high-risk genes from both parents. [source] Symptoms and quality of life in obese children and adolescents with non-alcoholic fatty liver diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2010K. D. KISTLER Aliment Pharmacol Ther,31, 396,406 Summary Background, Data on the quality of life (QOL) of children with non-alcoholic fatty liver disease (NAFLD) are needed to estimate the true burden of illness in children with NAFLD. Aim, To characterize QOL and symptoms of children with NAFLD and to compare QOL in children with NAFLD with that in a sample of healthy children. Methods, Quality of life and symptoms were assessed in children with biopsy-proven NAFLD enrolled in the NASH Clinical Research Network. PedsQL scores were compared with scores from healthy children. For children with NAFLD, between-group comparisons were made to test associations of demography, histological severity, symptoms and QOL. Results, A total of 239 children (mean age 12.6 years) were studied. Children with NAFLD had worse total (72.8 vs. 83.8, P < 0.01), physical (77.2 vs. 87.5, P < 0.01) and psychosocial health (70.4 vs. 81.9, P < 0.01) scores compared with healthy children. QOL scores did not significantly differ by histological severity of NAFLD. Fatigue, trouble sleeping and sadness accounted for almost half of the variance in QOL scores. Impaired QOL was present in 39% of children with NAFLD. Conclusions, Children with NAFLD have a decrement in QOL. Symptoms were a major determinant of this impairment. Interventions are needed to restore and optimize QOL in children with NAFLD. [source] A population-based epidemiologic study of irritable bowel syndrome in South China: stratified randomized study by cluster samplingALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 11 2004L. S. Xiong Summary Background :,The detailed population-based data on irritable bowel syndrome in South China are lacking. Aims :,To assess the prevalence of irritable bowel syndrome in South China and its impact on health-related quality of life. Subjects and methods :,A face-to-face interview was carried out in South China to assess the prevalence of irritable bowel syndrome. Random clustered sampling of permanent inhabitants aged 18,80 years was carried out under stratification of urban and suburban areas. The impact of irritable bowel syndrome on health-related quality of life was evaluated using the Chinese version of SF-36. Results :,A total of 4178 subjects (1907 male and 2271 female) were interviewed. The adjusted prevalence of irritable bowel syndrome in South China is 11.50% according to the Manning criteria and 5.67% according to the Rome II criteria. Factors including history of analgesic use such as non-steroidal anti-inflammatory drug (odds ratio 3.83), history of food allergies (odds ratio 2.68), psychological distress (odds ratio 2.18), life events (odds ratio 1.89), history of dysentery (odds ratio 1.63) and negative coping style (odds ratio 1.28) were significantly associated with the presence of irritable bowel syndrome (P < 0.05). Irritable bowel syndrome was significantly associated with a decrement in health-related quality of life score. Conclusion :,Irritable bowel syndrome is a common disorder in South China and has a negative impact on health-related quality of life. [source] Ultrasensitive assay of clindamycin in medicine and bio-fluids with chemiluminescence detectionLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 6 2007Gaili Wei Abstract A simple chemiluminescence (CL) method using flow injection has been developed for the determination of clindamycin, based on the inhibitory effect of clindamycin on the CL generated from the luminol,K3Fe(CN)6 system in alkaline medium. It was found that the decrement of CL intensity was linear with the logarithm of clindamycin concentration over the range 0.7,1000 ng/mL. The detection limit was 0.2 ng/mL with a relative standard deviation (RSD) of <5.0% (n = 7). At a flow rate of 3.0 mL/min, a complete analytical process could be performed within 0.5 min, including sampling and washing. The proposed procedure was applied successfully to the determination of clindamycin in pharmaceutical preparations and human urine without pretreatment. Copyright © 2007 John Wiley & Sons, Ltd. 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