bluuebunny/crossref_metadata_2025_split huggingface dataset:
Side‐chain control of folding of the homologous α‐, β‐, and γ‐peptides into “mixed” helices (β‐helices)
Authors: Baldauf Carsten , Günther Robert , Hofmann Hans‐Jörg 
Published: February 2005

AbstractA systematic analysis of the substituent influence on the formation of the unique secondary structure type of “mixed” helices in the homologous α‐, β‐, and γ‐peptides was performed on the basis of ab initio molecular orbital theory. Contrary to the common periodic peptide helices, mixed helices have an alternating periodicity and their hydrogen‐bonding pattern is similar to those of β‐sheets. They belong, therefore, to the family of β‐helices. It is shown that folding of peptide sequences into mixed helices is energetically preferred over folding into their periodic counterparts in numerous cases. The influence of entropy and solvents on the formation of the various competitive mixed and periodic helix types is discussed. Among the oligomers of the various homologous amino acids, β‐peptides show the highest tendency to form β‐helices. The rules of substituent influence derived from the analysis of a wide variety of backbone substitution patterns might be helpful for a rational design of mixed helix structures, which could be important for mimicking membrane channels. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 80: 675–687, 2005This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Estrogen modulates the sexually dimorphic synaptic connectivity of the ventromedial nucleus
Authors: Sá Susana I. , Madeira M. Dulce 
Published: February 2005

AbstractNeurons in the ventrolateral division of the hypothalamic ventromedial nucleus (VMNvl) display a remarkable estrogen‐dependent functional and structural plasticity, which is likely to be mediated, in part at least, by neuronal afferents. The present study was designed to determine whether the number of synapses per neuron and the size of individual synapses in the VMNvl vary across the estrus cycle and, also, whether they differ between the sexes. To accomplish this, the VMNvl of adult female rats at proestrus or diestrus day 1 and of age‐matched male rats was analyzed using electron microscopy. We found that a single VMNvl neuron receives around 7,000 synapses during diestrus and ∼10,000 during proestrus. This estrus cycle‐related variation is accounted for by increases in the number of all types of synapses. In males, the number of synapses received by each VMNvl neuron is similar to that of diestrus rats (∼7,500). However, in males the number of axodendritic and axospinous synapses is smaller than in proestrus rats, whereas the number of axosomatic synapses is higher than in diestrus rats. In addition, we found that the size of the postsynaptic densities of axospinous and axosomatic synapses is consistently larger in males than in females. Our results show that the synaptic organization of the VMNvl is sexually dimorphic, with females having more dendritic synapses and males more somatic synapses. They also show that the synaptic plasticity induced by estrogen in the VMNvl is characterized by changes in the number, but not the size, of the synapses. J. Comp. Neurol. 484:68–79, 2005. © 2005 Wiley‐Liss, Inc.
Localization of the Na+‐activated K+ channel Slick in the rat central nervous system
Authors: Bhattacharjee Arin , von Hehn Christian A.A. , Mei Xiaofeng , Kaczmarek Leonard K. 
Published: February 2005

AbstractNa+‐activated K+ currents (KNa) have been reported in multiple neuronal nuclei and the properties of KNa vary in different cell types. We have described previously the distribution of Slack, a Na+‐activated K+ channel subunit. Another recently cloned Na+‐activated K+ channel is Slick, which differs from Slack in its rapid activation and its sensitivity to intracellular ATP levels. We now report the localization of Slick in the rat central nervous system using in situ and immunohistochemical techniques. As for Slack, we find that Slick is widely distributed in the brain. Specifically, strong hybridization signals and immunoreactivity were found in the brainstem, including auditory neurons such as the medial nucleus of the trapezoid body. As has also been shown for Slack, Slick is expressed in the olfactory bulb, red nucleus, facial nucleus, pontine nucleus, oculomotor nucleus, substantia nigra, deep cerebellar nuclei, vestibular nucleus, and the thalamus. Slick mRNA and protein, however, also are found in certain neurons that do not express Slack. These neurons include those of the hippocampal CA1, CA2, and CA3 regions, the dentate gyrus, supraoptic nucleus, hypothalamus, and cortical layers II, III, and V. These data suggest that Slick may function independently of Slack in these regions. Computer simulations indicate that Slick currents can cause adaptation during prolonged stimuli. Such adaptation allows a neuron to respond to high‐frequency stimulation with lower‐frequency firing that remains temporally locked to individual stimuli, a property seen in many auditory neurons. Although it is not yet known if Slick and Slack subunits heteromultimerize, the existence of two genes that encode KNa, that are widely expressed in the nervous system, with both overlapping and nonoverlapping distributions, provides the basis for the reported heterogeneity in the properties of KNa from various neurons. J. Comp. Neurol. 484:80–92, 2005. © 2005 Wiley‐Liss, Inc.
Anatomical basis of glial cell line‐derived neurotrophic factor expression in the striatum and related basal ganglia during postnatal development of the rat
Authors: Oo Tinmarla Frances , Ries Vincent , Cho Jinwhan , Kholodilov Nikolai , Burke Robert E. 
Published: February 2005

AbstractThere is increasing evidence that glial cell line‐derived neurotrophic factor (GDNF) plays a role as a limiting, striatal target‐derived neurotrophic factor for dopamine neurons of the substantia nigra pars compacta (SNpc) by regulating the magnitude of the first phase of postnatal natural cell death which occurs in these neurons. While it has been shown that GDNF mRNA is relatively abundant in postnatal striatum, the cellular basis of its expression has been unknown. We therefore used nonradioactive in situ hybridization and immunohistochemistry to examine the cellular basis of GDNF mRNA and protein expression, respectively, in postnatal striatum and related structures. We found that GDNF mRNA is expressed within medium‐sized striatal neurons. Expression in glia was not observed. At the protein level, regionally, GDNF expression in striatum was observed in striosomal patches, as previously described. At a cellular level a few neurons were observed, but they do not account for the striosomal pattern. This pattern is predominantly due to GDNF‐positive neuropil. Some of this neuropil arises from tyrosine hydroxylase‐positive nigro‐striatal dopaminergic afferents. Astrocytic processes do not appear to contribute to the striosomal pattern. GDNF‐positive fibers are identified not only within intrinsic striatal neuropil, but also in fibers within the major striatal efferent targets: the globus pallidus, the entopeduncular nucleus, and the SN pars reticulata. We conclude that during normal postnatal development, medium‐sized neurons are the principal source of GDNF within the striatum. J. Comp. Neurol. 484:57–67, 2005. © 2005 Wiley‐Liss, Inc.
Comorbidity of depression and anxiety in nursing home patients
Authors: Smalbrugge Martin , Jongenelis Lineke , Pot Anne Margriet , Beekman Aartjan T. F. , Eefsting Jan A. 
Published: February 2005

AbstractObjectivesTo assess the occurrence and risk indicators of depression, anxiety, and comorbid anxiety and depression among nursing home patients and to determine whether depression and anxiety are best described in a dimensional or in a categorical classification system.MethodsDSM and subthreshold anxiety disorders, anxiety symptoms, major and minor depression and depressive symptoms were assessed in 333 nursing home patients of somatic wards of 14 nursing homes in the north west of the Netherlands with the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) and the Geriatric Depression Scale (GDS). Comorbidity was studied along a severity gradient. Logistic regression analyses were carried out to identify demographic, health‐related, psychosocial and care‐related correlates of anxiety and depression.ResultsThe prevalence of pure depression (PD) was 17.1%, of pure anxiety (PA) 4.8%, and of comorbid anxiety and depression (CAD) 5.1%. Comorbidity increased dependent on severity of both anxiety and depression. Different patterns of risk indicators were demonstrated for PA, PD and CAD for the investigated baseline characteristics.ConclusionsComorbidity of anxiety and depression is most prevalent in the more severe depressive and anxious nursing home patients. The gradual increase of comorbidity of anxiety and depression dependent on the levels of severity of depression and anxiety suggests that for nursing home patients a dimensional classification of depression and anxiety is more appropriate than a categorical one. The observed differences in patterns of risk indicators for PA, PD and CAD support a distinguishing of anxiety and depression. Future studies are needed to assess the effect of treatment of PA, PD and CAD in nursing home patients. Copyright © 2005 John Wiley & Sons, Ltd.
Quality of life in dementia—a one‐year follow‐up study
Authors: Selwood Amber , Thorgrimsen Lene , Orrell Martin 
Published: February 2005

AbstractBackgroundQuality of life (QoL) is becoming an increasingly used outcome measure in both clinical practice and research but little is known about QoL in dementia and how it may change over time.ObjectiveTo study longitudinal change in quality of life over a period of one year in 60 people with dementia aged 65 years or over.MethodsThe original sample was selected from inpatient, day hospital, nursing home and residential home settings within a London Mental Health Trust. The QoL‐AD, DQoL and EQ‐5D were assessed at baseline and repeated one‐year later. At follow‐up the CSDD, MMSE and RAID were also completed.ResultsFifty‐eight people were traced and of these 40 (69%) were alive at follow up. There was no mean change in quality of life over the one‐year period, however around half of the people had increases or decreases in their quality of life. The only significant predictor of quality of life at follow‐up was initial quality of life (p < 0.0005). Quality of life at follow‐up correlated significantly with depression (p < 0.0005) and anxiety (p < 0.01) but not with cognition.ConclusionThe main finding of this study is that people with dementia do not perceive that their quality of life declined over a period of one‐year. More people were able to complete the QoL‐AD than the DQoL or EQ‐5D at follow‐up and it seemed easier to use for people with severe dementia. Future research should investigate how quality of life changes over longer time periods with larger samples and in relation to specific interventions. Copyright © 2005 John Wiley & Sons, Ltd.
Mortality from dementia in a community‐dwelling Brazilian population
Authors: Nitrini Ricardo , Caramelli Paulo , Herrera Emílio , de Castro Isac , Bahia Valéria S. , Anghinah Renato , Caixeta Leonardo F. , Radanovic Márcia , Charchat‐Fichman Helenice , Porto Cláudia S. , Teresa Carthery Maria , Hartmann Ana Paula J. , Huang Nancy , Smid Jerusa , Lima Edison P. , Takahashi Daniel Yasumasa , Takada Leonel Tadao 
Published: February 2005

AbstractBackgroundThe influence of dementia on mortality has not yet been reported for a Latin American country.ObjectivesTo evaluate the influence of dementia on mortality of a community‐dwelling elderly population in Brazil, and to verify the extent to which the diagnosis of dementia is reported on death certificates.MethodsA cohort of 1,656 individuals, aged 65 and over, was screened for dementia at their domiciles, in 1997. The same population was re‐evaluated in 2000, and information on deaths was obtained from relatives and from the municipal obituary service. Kaplan‐Meier curves were used for the survival analysis, and the mortality risk ratio (MMR) was calculated using Cox proportional hazards models.ResultsWe obtained data from 1,393 subjects, corresponding to 84.1% of the target population. The number of deaths was 58 (51.3%) among the patients with dementia and 163 (12.7%) among those without dementia in 1997 (p < 0.0001). Dementia and Alzheimer's disease (AD) decreased survival, with hazards ratios of 5.16 [95% Confidence Interval (CI): 3.74–7.12] for dementia and 4.76 (95% CI: 3.16–7.18) for AD. The Cox proportional hazards model identified dementia (MMR = 3.92, 95% CI: 2.80–5.48) as the most significant predictor of death, followed by age, history of stroke, complaints of visual impairment and heart failure and by severe arterial hypertension in the baseline evaluation. Dementia and/or AD were mentioned in only 12.5% of the death certificates of individuals with dementia.ConclusionsDementia causes a significant decrease in survival, and the diagnosis of dementia is rarely reported on death certificates in Brazil. Copyright © 2005 John Wiley & Sons, Ltd.
Psychological wellbeing in later life: the longitudinal effects of marriage, widowhood and marital status change
Authors: Bennett Kate M. 
Published: February 2005

AbstractAimThe study examined cross‐sectionally and longitudinally psychological wellbeing in the context of marital status, gender, and age.MethodMeasures were taken eight years apart for three groups: married at both interviews; widowed at both interviews; and married at first interview but widowed at third. Data were analysed using multiple regression models: dependent variables were morale and social engagement; independent variables were marital status, gender and age.ResultsCross‐sectionally significant differences were found for marital status and age for both morale and social engagement. Both widowed and newly widowed participants reported lower morale and social engagement than their married counterparts. In the longitudinal model, when prior levels of morale were taken into account, only age and being newly widowed contributed significantly to the variance (R2). The same pattern of results was found for social engagement. Gender was never significant.ConclusionThe results illustrate the value of modelling both cross‐sectional and longitudinal data. The latter demonstrated that the size of the effect differed between those who had recently widowed and those who had been widowed for longer. The study shows that age needs to be taken into account when examining widowhood. Copyright © 2005 John Wiley & Sons, Ltd.
Surface modification of poly(ether urethane urea) with modified dehydroepiandrosterone for improved in vivo biostability
Authors: Christenson Elizabeth M. , Wiggins Michael J. , Anderson James M. , Hiltner Anne 
Published: February 2005

AbstractIn this study, a fatty acid urethane derivative of dehydroepiandrosterone (DHEA) was synthesized and evaluated as a polyurethane additive to increase long‐term biostability. The modification was hypothesized to reduce the water solubility of the DHEA and physically anchor the additive in the polyurethane during implantation. Polyurethane film weight loss in water as a function of time was studied to determine the polymer retention of the modified DHEA. The polyurethane film with unmodified DHEA had significant weight loss in the first day (10%) that was previously correlated to rapid leaching of the additive. The polyurethane film with modified DHEA had significantly less weight loss at all time points indicating improved polymer retention. The effect of the modified DHEA additive on the biostability of a poly(ether urethane urea) was examined after 5 weeks of subcutaneous implantation in Sprague‐Dawley rats. Optical micrographs and infrared analysis of the specimens indicated that the modified DHEA bloomed to the surface of the film forming a crystalline surface layer approximately 10–15 microns thick. After explantation, this surface layer was intact without measurable differences in surface chemistry as monitored by attenuated total reflectance‐Fourier transform infrared spectroscopy. There was no evidence of degradation of the polyurethane underneath the modified DHEA surface layer as compared with the polyurethane control. We have concluded that the modified DHEA self‐assembled into a protective surface coating that inhibited degradation of the polyurethane. The roughness of the modified DHEA surface layer prevented adherent cell analysis to determine if the additive retained the ability to down‐regulate macrophage activity. Subsequent studies will investigate the ability of surface‐modifying additives to modulate cellular respiratory bursts in addition to the formation of an impermeable barrier. This bimodal approach to improving biostability holds great promise in the field of polyurethane biomaterials. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 73A: 108–115, 2005
Role of interleukin‐6 in cardiomyocyte/cardiac fibroblast interactions during myocyte hypertrophy and fibroblast proliferation
Authors: Fredj Sandra , Bescond Jocelyn , Louault Claire , Delwail Adriana , Lecron Jean‐claude , Potreau Daniel 
Published: February 2005

AbstractThe process of cardiac hypertrophy is considered to involve two components: that of cardiac myocyte (CM) enlargement and cardiac fibroblast (CF) proliferation. The interleukin‐6 (IL‐6) family cytokines have been implicated in a variety of cellular and molecular interactions between myocytes and non‐myocytes (NCMs), which in turn have important roles in the development of cardiac hypertrophy. In the study of these interactions, we previously detected very high levels of IL‐6 in supernatants of a “dedifferentiated model” of adult ventricular CMs cultured with CFs. In the present study, we have used this in vitro coculture system to examine how IL‐6 is involved in the interactions between CMs and CFs during CM hypertrophy and CF proliferation. IL‐6 and its signal transducer, 130‐kDa glycoprotein (gp130), were detected by immunostaining cultured CMs and CFs with anti‐IL‐6 or anti‐gp130 antibodies. Addition of anti‐IL‐6 or anti‐gp130 antagonist antibodies into CM/CF cocultures induced a significant decrease in expression of atrial natriuretic peptide (ANP) and β‐myosin heavy chain (β‐MHC) in CMs. The presence of IL‐6 antagonist also resulted in a decrease in the surface area of 12‐day‐old CMs cultured with CFs or in the presence of fibroblast conditioned medium (FCM), and decreased fibroblast proliferation in CM/CF cocultures, particularly in the presence of a gp130 antagonist. The results also show that angiotensin II (AngII) is mainly secreted by CFs and induces IL‐6 secretion in CMs cultured with CFs or with FCM. In addition, the effects of IL‐6 on cardiomyocyte hypertrophy and fibroblast proliferation were inhibited by addition of the AT‐1 receptor antagonist, losartan. These results suggest that IL‐6 contributes significantly to CM hypertrophy by an autocrine pathway and to fibroblast proliferation by a paracrine pathway and that these effects could be mediated by AngII. © 2005 Wiley‐Liss, Inc.
Deep desulfurization of hydrodesulfurized diesel oil by Pseudomonas delafieldii R‐8
Authors: Guobin Shan , Jianmin Xing , Huaiying Zhang , Huizhou Liu 
Published: February 2005

AbstractBiodesulfurization is a promising technology for deep desulfurization. The remaining alkylated DBTs (dibenzothiophenes) in the HDS‐treated (hydrodesulfurized‐treated) diesel oil could be selectively and efficiently desulfurized by resting cells of Pseudomonas delafieldii R‐8, a Gram‐negative bacterium. The desulfurization activities of resting cells were greatly affected by W/O ratio (the volume ratio of aqueous phase to oil phase) and cell concentration. The desulfurization activity increased with the increase in the W/O ratio. When the W/O ratio and cell concentration were 2 and 25 mg cm−3, the desulfurization activity was as high as 0.41 mg(total sulfur) g−1(dry cell weight, DCW) h−1, ie higher than that reported previously. GC‐AED (gas chromatography with an atomic emission detector) analysis showed that the total reductions for all the C1DBTs and C2DBTs were approximately 100%, 94.63% for C3DBT, and 97.09% for C4DBT (designated CxDBT, where x is the number of alkyl groups attached). The rates of biodesulfurization relate to the number and position of alkyl groups attached to the DBT. Copyright © 2005 Society of Chemical Industry
Estimating the selectivity of ozone in the removal of polyphenols from vinasse
Authors: Martín Santos MA , Bonilla Venceslada JL , Martín Martín A , García García I 
Published: February 2005

AbstractThe detoxification of some types of wastewater such as vinasse requires the combined use of chemical and biological treatments. The chemical treatment (eg chemical oxidation) tries to remove resistant compounds in order to make the waste more biodegradable. For economic and environmental reasons, the oxidant should be as selective as possible. Ozone in an acid medium can be an appropriate choice for this purpose. In this work, a straightforward method for estimating the oxidative selectivity of ozone against the rest of the organic load of the waste is developed. Though the kinetic constants found for the reactions of ozone with phenolic compounds are between 20 and 4 times higher than the reaction of ozone with the rest of the whole organic charge, the high organic load (COD) of vinasse yields low values for the selectivity of the reaction of interest, in any case, the selectivity increases with the increasing concentration of phenols. For the highest phenols concentration relative to the whole organic load (ie 0.6%) a selectivity of approximately 12% is obtained. Copyright © 2005 Society of Chemical Industry
Effective poxvirus removal by sterile filtration during manufacture of plasma derivatives
Authors: Berting A. , Goerner W. , Spruth M. , Kistner O. , Kreil T.R. 
Published: February 2005

AbstractAs a consequence of the September 2001 terrorist events, programs to protect against further such acts including potentially the use of biological warfare agents have been launched in the USA and elsewhere. As part of these initiatives, Vaccinia virus was procured for the pre‐emptive vaccination of key personnel against smallpox as well as population‐wide protection after an eventual exposure. The introduction of this live virus into a population at a relatively large scale represents a theoretical challenge for the safety of the blood supply, and potentially for plasma for fractionation. To strengthen further the demonstration of safety margins for plasma derived products against Vaccinia virus, the capacity of sterile filtration procedures to remove the virus was investigated. An infectivity assay for the Vaccinia virus strain which represents the majority of smallpox vaccine stocks available currently was used to investigate the potential removal of this virus by sterile filtration processes during the manufacture of plasma derivatives. Vaccinia virus behaves as predicted based on its size, i.e., an artificially added virus load is removed about 10,000‐fold by the sterile filtration procedures tested. As the current investigation covered a range of different protein concentrations, filter materials and filters from different manufacturers, the results obtained are considered to be widely applicable. The current investigation supports further the high safety margins of plasma derivatives against any potential Vaccinia virus content of plasma for fractionation. As the large size is a general feature of Orthopox viruses, the results would also provide assurance against poxviruses identified more recently, for example, Monkeypox virus. J. Med. Virol. 75:603–607, 2005. © 2005 Wiley‐Liss, Inc.