bluuebunny/crossref_metadata_2025 huggingface dataset:
Mesencephalotomy for Intractable Pain due to Malignant Disease
Authors: Whisler W.W. , Voris H.C.
Published: May 2007

40 mesencephalotomies were carried out on 38 patients with intractable pain secondary to malignant disease. In 2 patients with bilateral pain, a bilateral mesencephalotomy was required. Most of the patients had pain in the head, neck or upper trunk secondary to carcinoma of the nasopharynx, jaw, tongue, or neck.
Electrical Spinal Cord Stimulation for Spastic Movement Disorders
Authors: Siegfried J. , Krainick J.-U. , Haas H. , Adorjani C. , Meyer M. , Thoden U.
Published: May 2007

Spinal cord stimulation seems today a promising method to improve spasticity. The experiences of two different clinics (Zürich and Freiburg i.Br.) are reported with long-term assessment up to 28 months. The objective data with measurement of stretch and H reflexes support the clinical results. An experimental study on animals does not permit a definitive explanation, but some hypotheses can be suggested.
A New Apparatus to Avoid Certain Complications in Stereotactic Operations at the Upper Cervical Spinal Cord
Authors: Nittner K. , Scholl H.
Published: May 2007

An electronic apparatus was developed which measures the effective current flow of the monophasic stimulation pulses while the tip of the electrode is passing through the tissue. This current flow can be observed as a function of time on the screen of a cathode ray tube.
Computerized Graphic Display of Physiological Data Collected during Human Stereotactic Surgery
Authors: Tasker R.R. , Hawrylyshyn P. , Organ L.W.
Published: May 2007

An on-line computerized graphic display has been developed for use during stereotactic operations. This depicts in the form of figurine charts and alphanumeric symbols, appropriately oriented on sagittal brain diagrams, the results of serial threshold stimulation of the brain. The display facilitates choice of target sites and the data can be stored in a tape library from which search-and-plot programs can be activated for any type or combination of types of response.
Arrest Reaction in Man
Authors: Kwak Ryungchan , Okudaira Yoshinobu , Sakamoto Tetsuya , Otabe Kazunori , Ohi Takatsugu , Niizuma Hiroshi , Suzuki Jiro , Saso Shun-ichi
Published: May 2007

In spite of many reports of arrest reaction in animals, there are very few reports in man. During a therapeutic stereotactic operation we observed peculiar phenomena caused by electrical stimulation to the deep structure of the cerebrum. This phenomenon is quite similar to that reported by Van Buren, but there are a few differences between them. Arrest reaction was observed in 14 of 23 cases, 17 of 28 tracks. Stimuli which caused the arrest reaction were 60–100 Hz square waves of 1 msec duration and 5–15 V. The electrical stimulation caused an interruption of counting and other motor actions, which could be resumed following release of stimuli. Psychic confusion or memory disturbances were not observed with the exception of a few cases. The arrest reaction that we observed is thought to be due to a direct effect on the head of the caudate nucleus, not due to secondary effects on the internal capsule and the motor fiber in the vicinity of the caudate nucleus. However, the possibility that the current spread to the motor fiber cannot be definitely ruled out.
Inversion or Pronation of the Foot following Thalamotomy for Parkinson's Disease
Authors: Zoll John G.
Published: May 2007

The author has observed inward turning of the foot of 2 parkinsonian patients following thalamotomy on the contralateral side. In one instance, the surgery was unilateral and in the other bilateral. The anatomical position of the involved lesions was in the region of the complex of the ventrocaudal nuclei (ventralis postero-lateralis). It appears that three elements are present whenever such pronation of the foot occurs, namely, paresis, hypertonicity, and impairment of sensory modalities such as localization, two-point discrimination and vibration.
Instrumentation, Working Hypotheses, and Clinical Aspects of Neurostimulation
Authors: Delgado José M.R.
Published: May 2007

The paper describes instrumentation developed in our laboratory for the therapy of neurological disorders, including (a) hybrid stimulator for chronic use which retains constant current characteristics, providing a low resistance path during the quiescent phase between pulses to minimize the postpulse charge; (b) brain radio stimulators, crystal controlled, with digital logic section and an optoelectric sensor for telemetry of the intensity used; (c) external stimoceiver for experimental and clinical use, combining multichannel stimulator and EEG telemetric instrument; (d) transdermal stimoceivers, totally implantable for two-way communication with the brain through the intact skin; and (e) implantable microprocessor for detection of EEG signals which are used to trigger contingent brain stimulation. Our working hypotheses for chronic brain stimulation include (a) electrical modification of the functional set point of specific cerebral areas; (b) feedback-controlled stimulation; and (c) establishment of artificial neuronal links with the aide of the computer. The paper concludes with a discussion of the indications for therapeutic use of brain stimulation and criteria for patient selection.
Control of Spasticity and Involuntary Movements – Cerebellar Stimulation
Authors: Davis Ross , Cullen Jr. Robert F. , Flitter Marc A. , Duenas Danilo , Engle Howard , Papazian Oscar , Weis Bonita
Published: May 2007

By stimulating the medial aspect of the superior surface of the cerebellum with relatively short, low current stimulating pulses, spasticity and some involuntary movements have been reduced. Voluntary movements, as a result, are able to come through better; however, if the child has little voluntary ability, he is at least more relaxed, thus allowing the parents to care for him more easily. The children and adults with cerebral palsy have not been transformed from their previous status, although CCS has allowed them to become more independent, more ambulatory, and more communicative.
Safety and Clinical Efficacy of Implanted Neuroaugmentive Spinal Devices for the Relief of Pain
Authors: Burton Charles V.
Published: May 2007

When applied under the circumstances of minimal patient risk, as documented in this paper, implanted neuroaugmentive spinal devices are a reasonable means of therapy for selected severe pain problems. With presently developed screening techniques, a 50% good-to-excellent result was obtained in 198 patients predominently consisting of ‘failed back surgery syndrome’ (94%). These figures represent a very significant improvement in success of treatment for this group of patients when compared to other present modes of therapy. With continued optimization of the use of spinal neuroaugmentive devices, it is likely that future clinical success can be significantly improved.
Instrumentation Problems with Implanted Neuroaugmentive Devices
Authors: Smith Crompton
Published: May 2007

An analysis of the technical problems encountered in the implantation of 218 neurostimulation systems during the period 1971–1977 is reviewed. Multiple transmitter and antenna failures were seen. The most significant failures involved lead conductors and/or insulation in the internal portion of the system. The failures seen often required surgical revision. The observed incidence of lead wire failure appears to increase in relation to age of the devices. This survey indicates that significant material and design changes in the neuroaugmentive devices surveyed are necessary.
Alterations of Immunoreactive beta-Endorphin in the Third Ventricular Fluid in Response to Electrical Stimulation of the Human Periaqueductal Gray Matter
Authors: Amano Keiichi , Kitamura Koiti , Kawamura Hirotsune , Tanikawa Tatsuya , Kawabatake Hiroko , Notani Masao , Iseki Hiroshi , Shiwaku Tetsusi , Suda Toshihiro , Demura Hiroshi
Published: May 2007

Immunoreactive beta-endorphin in the third ventricular fluid was measured in response to electrical stimulation of the periaqueductal gray matter in 8 patients with intractable pain during rostral mesencephalic reticulotomy for pain relief. In all patients, marked increase of immunoreactive beta-endorphin was observed. On the other hand, in cases of electrical stimulation of the zona incerta performed during stereoencephalotomy, in 5 patients with involuntary movement, immunoreactive beta-endorphin in the third ventricular fluid did not show any significant change. The authors conclude that the increase of immunoreactive beta-endorphin on electrical stimulation of the periaqueductal gray matter is not a nonspecific response to brain stimulation but a specific response in regard to cerebral localization of endorphins. Direct correlation between pain relief and periaqueductal gray stimulation is also questioned.
Enhanced Capillary Formation Stimulated by a Chimeric Vascular Endothelial Growth Factor/Vascular Endothelial Growth Factor-C Silk Domain Fusion Protein
Authors: Keskitalo Salla , Tammela Tuomas , Lyytikka Johannes , Karpanen Terhi , Jeltsch Michael , Markkanen Johanna , Yla-Herttuala Seppo , Alitalo Kari
Published: May 2007

Vascular endothelial growth factor (VEGF)-C and VEGF-D require proteolytic cleavage of the carboxy terminal silk-homology domain for activation. To study the functions of the VEGF-C propeptides, we engineered a chimeric growth factor protein, VEGF-CAC, composed of the amino- and carboxy-terminal propeptides of VEGF-C fused to the receptor-activating core domain of VEGF. Like VEGF-C, VEGF-CAC underwent proteolytic cleavage, and like VEGF, it bound to and activated VEGF receptor-1 and VEGF receptor-2, but not the VEGF-C receptor VEGF receptor-3. VEGF-CAC also bound to neuropilins in a heparin-dependent manner. Strikingly, when VEGF-CAC was expressed via an adenovirus vector in the ear skin of immunodeficient mice, it proved to be a more potent inducer of capillary angiogenesis than VEGF. The VEGF-CAC–induced vessels differed greatly from those induced by VEGF, as they formed a very dense and fine network of pericyte and basement membrane–covered capillaries that were functional, as shown by lectin perfusion experiments. VEGF-CAC could prove useful in proangiogenic therapies in patients experiencing tissue ischemia.
Generation of Functional Cardiomyocytes From Adult Mouse Spermatogonial Stem Cells
Authors: Guan Kaomei , Wagner Stefan , Unsöld Bernhard , Maier Lars S. , Kaiser Diana , Hemmerlein Bernhard , Nayernia Karim , Engel Wolfgang , Hasenfuss Gerd
Published: May 2007

Stem cell–based therapy is a promising approach for the treatment of heart failure. Adult stem cells with the pluripotency of embryonic stem cells (ESCs) would be an ideal cell source. Recently, we reported the successful establishment of multipotent adult germline stem cells (maGSCs) from mouse testis. These cultured maGSCs show phenotypic characteristics similar to ESCs and can spontaneously differentiate into cells from all 3 germ layers. In the present study, we used the hanging drop method to differentiate maGSCs into cardiomyocytes and analyzed their functional properties. Differentiation efficiency of beating cardiomyocytes from maGSCs was similar to that from ESCs. The maGSC-derived cardiomyocytes expressed cardiac-specific L-type Ca
2+
channels and responded to Ca
2+
channel–modulating drugs. Cx43 was expressed at cell-to-cell contacts in cardiac clusters, and fluorescence recovery after photobleaching assay showed the presence of functional gap junctions among cardiomyocytes. Action potential analyses demonstrated the presence of pacemaker-, ventricle-, atrial-, and Purkinje-like cardiomyocytes. Stimulation with isoproterenol resulted in a significant increase in beating frequency, whereas the addition of cadmium chloride abolished spontaneous electrical activity. Confocal microscopy analysis of intracellular Ca
2+
in maGSC-derived cardiomyocytes showed that calcium increased periodically throughout the cell in a homogenous fashion, pointing to a fine regulated Ca
2+
release from intracellular Ca
2+
stores. By using line-scan mode, we found rhythmic Ca
2+
transients. Furthermore, we transplanted maGSCs into normal hearts of mice and found that maGSCs were able to proliferate and differentiate. No tumor formation was found up to 1 month after cell transplantation. Taken together, we believe that maGSCs provide a new source of distinct types of cardiomyocytes for basic research and potential therapeutic application.
Direct Evidence of Endothelial Oxidative Stress With Aging in Humans
Authors: Donato Anthony J. , Eskurza Iratxe , Silver Annemarie E. , Levy Adam S. , Pierce Gary L. , Gates Phillip E. , Seals Douglas R.
Published: May 2007

Aging is associated with impaired vascular endothelial function, as indicated in part by reduced endothelium-dependent dilation (EDD). Decreased EDD with aging is thought to be related to vascular endothelial cell oxidative stress, but direct evidence is lacking. We studied 95 healthy men: 51 young (23±1 years) and 44 older (63±1 years). EDD (brachial artery flow-mediated dilation) was ≈50% lower in older versus young men (3.9±0.3% versus 7.6±0.3%,
P
<0.01; n=42 older/n=51 young). Abundance of nitrotyrosine (quantitative immunofluorescence), an oxidatively modified amino acid and marker of oxidative stress, was higher in endothelial cells (ECs) obtained from the brachial artery (1.25±0.12 versus 0.61±0.11 nitrotyrosine intensity/human umbilical vein EC [HUVEC] intensity,
P
=0.01; n=11 older/n=11 young) and antecubital veins (0.55±0.04 versus 0.34±0.03,
P
<0.05; n=19 older/n=17 young) of older men. Flow-mediated dilation was inversely related to arterial EC nitrotyrosine expression (
r
=−0.62,
P
=0.01; n=22). In venous samples, EC expression of the oxidant enzyme NAD(P)H oxidase-p47
phox
was higher in older men (0.71±0.05 versus 0.57±0.05 NAD[P]H oxidase-p47
phox
intensity/HUVEC intensity,
P
<0.05; n=19 older/n=18 young), whereas xanthine oxidase and the antioxidant enzymes cytosolic and mitochondrial superoxide dismutase and catalase were not different between groups. Nuclear factor-κB p65, a component of the redox-sensitive nuclear transcription factor nuclear factor-κB, was elevated in both arterial (0.73±0.07 versus 0.53±0.05 NF-κB p65 intensity/HUVEC intensity,
P
<0.05; n=9 older/n=12 young) and venous (0.65±0.07 versus 0.34±0.05,
P
<0.01; n=13 older/n=15 young) EC samples of older men and correlated with nitrotyrosine expression (
r
=0.51,
P
<0.05 n=16). These results provide direct support for the hypothesis that endothelial oxidative stress develops with aging in healthy men and is related to reductions in EDD. Increased expression of NAD(P)H oxidase and nuclear factor-κB may contribute to endothelial oxidative stress with aging in humans.
Histamine Upregulates the Expression of Inducible Nitric Oxide Synthase in Human Intimal Smooth Muscle Cells via Histamine H1 Receptor and NF-κB Signaling Pathway
Authors: Tanimoto Akihide , Wang Ke-Yong , Murata Yoshitaka , Kimura Satoshi , Nomaguchi Masako , Nakata Sei , Tsutsui Masato , Sasaguri Yasuyuki
Published: May 2007

Objective—

Histamine increases endothelial nitric oxide (NO) production as an endothelium-dependent vasodilator, which acts as a vasoconstrictor in atherosclerotic coronary arteries. To investigate the relation between histamine and NO production in intimal smooth muscle cells (SMCs), we studied the effect of histamine on inducible NO synthase (iNOS) expression in the SMCs.

Methods and Results—

In cultured human intimal SMCs, histamine increased NO production, iNOS expression, and NF-κB nuclear translocation, which were inhibited by histamine H1 blocker and NF-κB inhibitor. Luciferase assay using −8.3 kb upstream of human iNOS promoter region and electrophoretic mobility shift assay suggested that a NF-κB motif located at −3922 to −3914 would be necessary for histamine-inducible promoter activity. In addition, H1 blocker, NF-κB inhibitor, and dominant negative IκBα or IκB kinase β downregulated the histamine-induced iNOS promoter activity. In the human aorta, histamine content was estimated to be 310±66 pmol/mg protein in the atherosclerotic intima, while that was to be 43±22 pmol/mg protein in the media (
P
<0.001).

Conclusions—

Histamine stimulates intimal SMCs to increase iNOS expression via H1 receptors and NF-κB signaling pathway. Histamine could be one of NO-regulating factors, by inducing iNOS expression in intimal SMCs, and may be related to atherogenesis.
ABCA1-Induced Cell Surface Binding Sites for ApoA-I
Authors: Vedhachalam Charulatha , Ghering Amy B. , Davidson W. Sean , Lund-Katz Sissel , Rothblat George H. , Phillips Michael C.
Published: May 2007

Objective—

The purpose of this study was to understand the interactions of apoA-I with cells expressing ABCA1.

Methods and Results—

The binding of wild-type (WT) and mutant forms of human apoA-I to mouse J774 macrophages was examined. Analysis of total binding at 37°C of
125
I-WT apoA-I to the cells and specifically to ABCA1, as determined by covalent cross-linking, revealed saturable high affinity binding in both cases. Determination of the level of cell-surface expression of ABCA1 showed that only about 10% of the apoA-I associated with the cell surface was bound directly to ABCA1. Furthermore, when
125
I -apoA-I was cross-linked to ABCA1-upregulated cells and examined by SDS-PAGE, the major (≈90%) band migrated as monomeric apoA-I. In contrast to WT apoA-I, the C-terminal deletion mutants Δ190 to 243 and Δ223 to 243 that have reduced lipid affinity, exhibited marked reductions (50 and 70%, respectively) in their abilities to bind to the surface of ABCA1-upregulated cells. However, these C-terminal deletion mutants cross-linked to ABCA1 as effectively as WT apoA-I.

Conclusions—

This study demonstrates that ABCA1 activity creates 2 types of high affinity apoA-I binding sites at the cell surface. The low capacity site formed by direct apoA-I/ABCA1 interaction functions in a regulatory role, whereas the much higher capacity site generated by apoA-I/lipid interactions functions in the assembly of nascent HDL particles.
MicroRNA Expression Signature and Antisense-Mediated Depletion Reveal an Essential Role of MicroRNA in Vascular Neointimal Lesion Formation
Authors: Ji Ruirui , Cheng Yunhui , Yue Junming , Yang Jian , Liu Xiaojun , Chen He , Dean David B. , Zhang Chunxiang
Published: May 2007

MicroRNAs (miRNAs) are a recently discovered class of endogenous, small, noncoding RNAs that regulate about 30% of the encoding genes of the human genome. However, the role of miRNAs in vascular disease is currently completely unknown. Using microarray analysis, we demonstrated for the first time that miRNAs are aberrantly expressed in the vascular walls after balloon injury. The aberrantly expressed miRNAs were further confirmed by Northern blot and quantitative real-time polymerase chain reaction. Modulating an aberrantly overexpressed miRNA, miR-21, via antisense-mediated depletion (knock-down) had a significant negative effect on neointimal lesion formation. In vitro, the expression level of miR-21 in dedifferentiated vascular smooth muscle cells was significantly higher than that in fresh isolated differentiated cells. Depletion of miR-21 resulted in decreased cell proliferation and increased cell apoptosis in a dose-dependent manner. MiR-21–mediated cellular effects were further confirmed in vivo in balloon-injured rat carotid arteries. Western blot analysis demonstrated that PTEN and Bcl-2 were involved in miR-21–mediated cellular effects. The results suggest that miRNAs are novel regulatory RNAs for neointimal lesion formation. MiRNAs may be a new therapeutic target for proliferative vascular diseases such as atherosclerosis, postangioplasty restenosis, transplantation arteriopathy, and stroke.
Effect of K+ATPChannel and Adenosine Receptor Blockade During Rest and Exercise in Congestive Heart Failure
Authors: Traverse Jay H. , Chen YingJie , Hou MingXiao , Li Yunfang , Bache Robert J.
Published: May 2007

K+ATPchannels are important metabolic regulators of coronary blood flow (CBF) that are activated in the setting of reduced levels of ATP or perfusion pressure. In the normal heart, blockade of K+ATPchannels results in a ≈20% reduction in resting CBF but does not impair the increase in CBF that occurs during exercise. In contrast, adenosine receptor blockade fails to alter CBF or myocardial oxygen consumption (MVO2) in the normal heart but contributes to the increase in CBF during exercise when vascular K+ATPchannels are blocked. Congestive heart failure (CHF) is associated with a decrease in CBF that is matched to a decrease in MVO2suggesting downregulation of myocardial energy utilization. Because myocardial ATP levels and coronary perfusion pressure are reduced in CHF, this study was undertaken to examine the role of K+ATPchannels and adenosine in dogs with pacing-induced CHF. Myocardial blood flow (MBF) and MVO2were measured during rest and treadmill exercise before and after K+ATPchannel blockade with glibenclamide (50 μg/kg/min ic) or adenosine receptor blockade with 8-phenyltheophylline (8-PT; 5 mg/kg iv). Inhibition of K+ATPchannels resulted in a decrease in CBF and MVO2at rest and during exercise without a change in the relationship between CBF and MVO2. In contrast, adenosine receptor blockade caused a significant increase in CBF that occurred secondary to an increase of MVO2. These findings demonstrate that coronary K+ATPchannel activity contribute to the regulation of resting MBF in CHF, and that endogenous adenosine may act to inhibit MVO2in the failing heart.
An Example of US Food and Drug Administration Device Regulation
Authors: Peña Carlos , Li Khan , Felten Richard , Ogden Neil , Melkerson Mark
Published: May 2007

The Food and Drug Administration has established requirements for protecting the public health by assuring the safety and effectiveness of a variety of medical products including drugs, devices, and biological products, and for promoting public health by expediting the approval of treatments that are safe and effective. The Center for Devices and Radiological Health is the center within the agency that is responsible for pre- and postmarket regulation of medical devices. In this article, we review current regulation of medical devices, research and development programs, pre- and postmarket perspectives, and future considerations of medical devices, particularly as they relate to devices targeting acute ischemic stroke as an example of the process. We also review the Center for Devices and Radiological Health’s historical perspective of acute ischemic stroke trials and clinical trial design considerations used in prior studies that have led to US market clearance as they are related to currently marketed devices indicated for acute ischemic stroke.
Life After Cerovive
Authors: Ginsberg Myron D.
Published: May 2007

The SAINT II Trial, a large randomized multicenter clinical trial of the putative neuroprotectant, NXY-059, failed to demonstrate a treatment benefit in acute ischemic stroke. The further development of this agent was suspended. The implications of this outcome are considered from several perspectives, including: (1) the marginally positive antecedent trial, SAINT I, and the critical commentary stimulated by it, which called attention to its interpretively challenging primary outcome measure—a shift in the full-scale modified Rankin scale score—and to other statistical shortcomings; (2) the cogency of the STAIR recommendations, to which the development of NXY-059 closely adhered; and (3) the inherent physiochemical shortcomings of NXY-059 as a neuroprotective agent—its polar, nonlipophilic nature, poor blood–brain barrier penetrability, nonphysiological oxidation potential, and low potency. Caution is urged, however, regarding the unwarranted adoption of a nihilistic view toward neuroprotection on the part of the stroke community in view of the abundant preclinical evidence demonstrating proof-of-principle of the feasibility of neuroprotection, as well as the multiplicity of biochemical and molecular neuroprotective targets. The author offers the personal example of a translational journey in which a promising neuroprotectant agent targeting multiple injury mechanisms, high-dose albumin therapy, has proceeded successfully from preclinical studies that established efficacy through a pilot clinical trial that demonstrated safety and offered strong suggestions of clinical efficacy, leading to a large multicenter clinical trial currently in progress.
Estimated Cost Savings of Increased Use of Intravenous Tissue Plasminogen Activator for Acute Ischemic Stroke in Canada
Authors: Yip Todd R. , Demaerschalk Bart M.
Published: May 2007

Background and Purpose—

Intravenous tissue plasminogen activator (tPA) is an economically worthwhile but underused treatment option for acute ischemic stroke. We sought to identify the extent of tPA use in Canadian medical centers and the potential savings associated with increased use nationally and by province.

Methods—

We determined the nationwide annual incidence of ischemic stroke from the Canadian Institute of Health Information. The proportion of all ischemic stroke patients who received tPA was derived from published data. Economic analyses that report the expected annual cost savings of tPA were consulted. The analysis was conducted from the perspective of a universal health care system during 1 year. We estimated cost-savings with incrementally (eg, 2%, 4%, 6%, 8%, 10%, 15%, and 20%) increased use of tPA for acute ischemic stroke nationally and provincially.

Results—

The current average national tPA utilization is 1.4%. For every increase of 2 percentage points in utilization, $757 204 (Canadian) could possibly be saved annually (95% CI maximum loss of $3 823 992 to a maximum savings of $2 201 252). With a 20% rate, >$7.5 million (Canadian) could be saved nationwide the first year.

Conclusions—

We estimate that even small increases in the proportion of all Canadian ischemic stroke patients receiving tPA could result in substantial realized savings for Canada’s health care system.
The Role of Expectancies in Accepting Task-Related Diversity: Do Disappointment and Lack of Commitment Stem From Actual Differences or Violated Expectations?
Authors: Rink Floor , Ellemers Naomi
Published: May 2007

Two studies show that initial expectancies influence the way people respond toward task-related differences (i.e., in work goals or work styles) between the self and a collaboration partner. When no advance information is available, participants expect their partner to be similar to themselves in task-related aspects. However, when people expect their partner to have a different work goal (Study 1) or work style (Study 2), and this actually is the case, disappointment is reduced and commitment toward future collaboration is increased. Initial expectations are important because these help people develop a clear picture of their partner. When initial expectations are violated, people conceive the other less clearly and this is part of the reason they report lower levels of commitment.
An Expansion and Practical Evaluation of Expected Classification Accuracy
Authors: Martineau Joseph A.
Published: May 2007

Rudner (2001, 2005) described an expected classification accuracy index for determining the asymptotic expectation of accuracy of classifications of examinees into score categories. This article expands on that exposition by evaluating the index as it is likely to be used in practice (as a point estimate of classification accuracy), provides a related index of expected proportion in each score category, derives a measurement error—based standard error of expected proportion in each category, applies the methods to a large-scale state assessment database, and analyzes the benefits and limitations of the methodology. This study demonstrates that Rudner's index as a point estimate is slightly positively biased but nevertheless useful for groups with reasonably large numbers of examinees. It also reinforces the inappropriateness of estimating proportions in score categories for many small groups.
Ramsay Curve IRT for Likert-Type Data
Authors: Woods Carol M.
Published: May 2007

Ramsay curve item response theory (RC-IRT) was recently developed to detect and correct for nonnormal latent variables when unidimensional IRT models are fitted to data using maximum marginal likelihood estimation. The purpose of this research is to evaluate the performance of RC-IRT for Likert-type item responses with varying test lengths, sample sizes, and latent variable distributions. Also, RC-IRT is compared to a related procedure implemented in the PARSCALE program. Results indicated that for nonnormal latent variables, item parameters and scores from RC-IRT can be more accurate than those obtained from the normal model, as long as there is enough information in the data (i.e., enough items and people). The procedure in PARSCALE tended to give better answers than the normal model but was generally not as accurate as RC-IRT.
Standardized Conditional SEM: A Case for Conditional Reliability
Authors: Raju Nambury S. , Price Larry R. , Oshima T.C. , Nering Michael L.
Published: May 2007

An examinee-level (or conditional) reliability is proposed for use in both classical test theory (CTT) and item response theory (IRT). The well-known group-level reliability is shown to be the average of conditional reliabilities of examinees in a group or a population. This relationship is similar to the known relationship between the square of the conditional standard error of measurement (SEM) and the square of the group-level SEM. The proposed conditional reliability is illustrated with an empirical data set in the CTT and IRT frameworks.
The “Other Hispanics”— What Are Their National Origins?
Authors: Chun Sung-Chang
Published: May 2007

This population study examines possible reasons for a severe underestimation of Latino-origin group populations in 2000 and introduces several alternative methods for estimating these Latino subgroup populations. The new simulated estimates for the Latino subgroups, based on the 2000 Public Use Microdata Sample from the 2000 U.S. Census, are presented at the national level and for selected states and cities. The figures included here represent some of the first alternative estimates for Latino-origin groups at the subnational level. Differences between official 2000 enumerations and estimated counts were larger for smaller Latino subgroups. The 2000 population of Dominicans should have been nearly 1 million rather than the approximately 799,768 the Census recorded. The estimates also gave 42.6% more Salvadorans, 47% more Central Americans, and 41.3% more South Americans.
Bilingual Computerized Speech Recognition Screening for Depression Symptoms
Authors: González Gerardo M. , Carter Colby , Blanes Erika
Published: May 2007

The Voice-Interactive Depression Assessment System (VIDAS) is a computerized speech recognition application for screening depression based on the Center for Epidemiological Studies–Depression scale in English and Spanish. Study 1 included 50 English and 47 Spanish speakers. Study 2 involved 108 English and 109 Spanish speakers. Participants completed demographic and acculturation scales, Beck Depression Inventory–II, Beck Anxiety Inventory, Composite International Diagnostic Interview–Short Form, and VIDAS (aural or visual). Both studies examined the psychometric properties and participant comfort ratings for VIDAS. Study 2 also examined psychometric sensitivity and specificity, and participant selection of digitized gender for VIDAS. Both studies found that VIDAS generally demonstrated adequate interitem reliability, convergent validity, sensitivity, and specificity. However, the aural modality displayed lower reliability and validity. Participants in both language groups rated each VIDAS modality favorably; however, the visual modality received higher positive evaluations. Participant comfort ratings of digitized gender revealed an interaction, such that the visual female and the aural male were rated more favorably.
Sharpening the Focus on Acculturative Change
Authors: Campos Belinda , Schetter Christine Dunkel , Walsh Julia A. , Schenker Marc
Published: May 2007

Acculturation is conceptualized as a multidimensional process but is typically measured as a concurrent movement away from culture of origin as a new cultural orientation is obtained. In this study, the authors examined the overall and subscale scoring systems of the ARSMA-II, the most popular acculturation measure, for its associations with stress, pregnancy anxiety, and birthweight in a large sample of pregnant, Mexican-origin women from the Study for Hispanic Acculturation, Reproduction, and the Environment. As predicted, the ARSMA-II's overall acculturation score and two orthogonal subscales, Mexican orientation and Anglo orientation, revealed differing patterns of associations with stress, pregnancy anxiety, and birthweight. Mexican orientation was negatively associated with stress, positively associated with pregnancy anxiety, and not associated with birthweight. Anglo orientation was positively associated with stress and negatively associated with birthweight. The gains to be made in understanding processes that may change with acculturation by incorporating multidimensional analyses of acculturation are discussed.
Potential risks of bone marrow cell transplantation into infarcted hearts
Authors: Breitbach Martin , Bostani Toktam , Roell Wilhelm , Xia Ying , Dewald Oliver , Nygren Jens M. , Fries Jochen W. U. , Tiemann Klaus , Bohlen Heribert , Hescheler Juergen , Welz Armin , Bloch Wilhelm , Jacobsen Sten Eirik W. , Fleischmann Bernd K.
Published: May 2007

Cellular replacement therapy has emerged as a novel strategy for the treatment of heart failure. The aim of our study was to determine the fate of injected mesenchymal stem cells (MSCs) and whole bone marrow (BM) cells in the infarcted heart. MSCs were purified from BM of transgenic mice and characterized using flow cytometry and in vitro differentiation assays. Myocardial infarctions were generated in mice and different cell populations including transgenic MSCs, unfractionated BM cells, or purified hematopoietic progenitors were injected. Encapsulated structures were found in the infarcted areas of a large fraction of hearts after injecting MSCs (22 of 43, 51.2%) and unfractionated BM cells (6 of 46, 13.0%). These formations contained calcifications and/or ossifications. In contrast, no pathological abnormalities were found after injection of purified hematopoietic progenitors (0 of 5, 0.0%), fibroblasts (0 of 5, 0.0%), vehicle only (0 of 30, 0.0%), or cytokine-induced mobilization of BM cells (0 of 35, 0.0%). We conclude that the developmental fate of BM-derived cells is not restricted by the surrounding tissue after myocardial infarction and that the MSC fraction underlies the extended bone formation in the infarcted myocardium. These findings seriously question the biologic basis and clinical safety of using whole BM and in particular MSCs to treat nonhematopoietic disorders.
Analysis of probe level patterns in Affymetrix microarray data
Authors: Cambon Alexander C , Khalyfa Abdelnaby , Cooper Nigel GF , Thompson Caryn M
Published: May 2007

Background

Microarrays have been used extensively to analyze the expression profiles for thousands of genes in parallel. Most of the widely used methods for analyzing Affymetrix Genechip microarray data, including RMA, GCRMA and Model Based Expression Index (MBEI), summarize probe signal intensity data to generate a single measure of expression for each transcript on the array. In contrast, other methods are applied directly to probe intensities, negating the need for a summarization step.

Results

In this study, we used the Affymetrix rat genome Genechip to explore variability in probe response patterns within transcripts. We considered a number of possible sources of variability in probe sets including probe location within the transcript, middle base pair of the probe sequence, probe overlap, sequence homology and affinity. Although affinity, middle base pair and probe location effects may be seen at the gross array level, these factors only account for a small proportion of the variation observed at the gene level. A BLAST search and the presence of probe by treatment interactions for selected differentially expressed genes showed high sequence homology for many probes to non-target genes.

Conclusion

We suggest that examination and modeling of probe level intensities can be used to guide researchers in refining their conclusions regarding differentially expressed genes. We discuss implications for probe sequence selection for confirmatory analysis using real time PCR.
MRX87 family with Aristaless Xdup24bp mutation and implication for polyAlanine expansions
Authors: Laperuta Carmela , Spizzichino Letizia , D'Adamo Pio , Monfregola Jlenia , Maiorino Antonio , D'Eustacchio Angela , Ventruto Valerio , Neri Giovanni , D'Urso Michele , Chiurazzi Pietro , Ursini Matilde Valeria , Miano Maria Giuseppina
Published: May 2007

Background

Cognitive impairments are heterogeneous conditions, and it is estimated that 10% may be caused by a defect of mental function genes on the X chromosome. One of those genes is Aristaless related homeobox (ARX) encoding a polyA-rich homeobox transcription factor essential for cerebral patterning and its mutations cause different neurologic disorders. We reported on the clinical and genetic analysis of an Italian family with X-linked mental retardation (XLMR) and intra-familial heterogeneity, and provided insight into its molecular defect.

Methods

We carried out on linkage-candidate gene studies in a new MRX family (MRX87). All coding regions and exon-intron boundaries of ARX gene were analysed by direct sequencing.

Results

MRX87 patients had moderate to profound cognition impairment and a combination of minor congenital anomalies. The disease locus, MRX87, was mapped between DXS7104 and DXS1214, placing it in Xp22-p21 interval, a hot spot region for mental handicap. An in frame duplication of 24 bp (ARXdup24) in the second polyAlanine tract (polyA_II) in ARX was identified.

Conclusion

Our study underlines the role of ARXdup24 as a critical mutational site causing mental retardation linked to Xp22. Phenotypic heterogeneity of MRX87 patients represents a new observation relevant to the functional consequences of polyAlanine expansions enriching the puzzling complexity of ARXdup24-linked diseases.
The importance of a taste. A comparative study on wild food plant consumption in twenty-one local communities in Italy
Authors: Ghirardini Maria Pia , Carli Marco , del Vecchio Nicola , Rovati Ariele , Cova Ottavia , Valigi Francesco , Agnetti Gaia , Macconi Martina , Adamo Daniela , Traina Mario , Laudini Francesco , Marcheselli Ilaria , Caruso Nicolò , Gedda Tiziano , Donati Fabio , Marzadro Alessandro , Russi Paola , Spaggiari Caterina , Bianco Marcella , Binda Riccardo , Barattieri Elisa , Tognacci Alice , Girardo Martina , Vaschetti Luca , Caprino Piero , Sesti Erika , Andreozzi Giorgia , Coletto Erika , Belzer Gabriele , Pieroni Andrea
Published: May 2007

A comparative food ethnobotanical study was carried out in twenty-one local communities in Italy, fourteen of which were located in Northern Italy, one in Central Italy, one in Sardinia, and four in Southern Italy. 549 informants were asked to name and describe food uses of wild botanicals they currently gather and consume. Data showed that gathering, processing and consuming wild food plants are still important activities in all the selected areas. A few botanicals were quoted and cited in multiple areas, demonstrating that there are ethnobotanical contact points among the various Italian regions (Asparagus acutifolius, Reichardia picroides, Cichorium intybus, Foeniculum vulgare, Sambucus nigra, Silene vulgaris, Taraxacum officinale, Urtica dioica, Sonchus and Valerianella spp.). One taxon (Borago officinalis) in particular was found to be among the most quoted taxa in both the Southern and the Northern Italian sites.

However, when we took into account data regarding the fifteen most quoted taxa in each site and compared and statistically analysed these, we observed that there were a few differences in the gathering and consumption of wild food plants between Northern and Southern Italy. In the North, Rosaceae species prevailed, whereas in the South, taxa belonging to the Asteraceae, Brassicaceae, and Liliaceae s.l. families were most frequently cited. We proposed the hypothesis that these differences may be due to the likelihood that in Southern Italy the erosion of TK on wild vegetables is taking place more slowly, and also to the likelihood that Southern Italians' have a higher appreciation of wild vegetables that have a strong and bitter taste.

A correspondence analysis confirmed that the differences in the frequencies of quotation of wild plants within the Northern and the Southern Italian sites could be ascribed only partially to ethnic/cultural issues. An additional factor could be recent socio-economic shifts, which may be having a continued effort on people's knowledge of wild food plants and the way they use them.

Finally, after having compared the collected data with the most important international and national food ethnobotanical databases that focus on wild edible plants, we pointed out a few uncommon plant food uses (e.g. Celtis aetnensis fruits, Cicerbita alpine shoots, Helichrysum italicum leaves, Lonicera caprifolium fruits, Symphytum officinale leaves), which are new, or have thus far been recorded only rarely.
A search engine to identify pathway genes from expression data on multiple organisms
Authors: Chen Chunnuan , Weirauch Matthew T , Powell Corey C , Zambon Alexander C , Stuart Joshua M
Published: May 2007

Background

The completion of several genome projects showed that most genes have not yet been characterized, especially in multicellular organisms. Although most genes have unknown functions, a large collection of data is available describing their transcriptional activities under many different experimental conditions. In many cases, the coregulatation of a set of genes across a set of conditions can be used to infer roles for genes of unknown function.

Results

We developed a search engine, the Multiple-Species Gene Recommender (MSGR), which scans gene expression datasets from multiple organisms to identify genes that participate in a genetic pathway. The MSGR takes a query consisting of a list of genes that function together in a genetic pathway from one of six organisms:Homo sapiens,Drosophila melanogaster,Caenorhabditis elegans,Saccharomyces cerevisiae,Arabidopsis thaliana, andHelicobacter pylori. Using a probabilistic method to merge searches, the MSGR identifies genes that are significantly coregulated with the query genes in one or more of those organisms. The MSGR achieves its highest accuracy for many human pathways when searches are combined across species. We describe specific examples in which new genes were identified to be involved in a neuromuscular signaling pathway and a cell-adhesion pathway.

Conclusion

The search engine can scan large collections of gene expression data for new genes that are significantly coregulated with a pathway of interest. By integrating searches across organisms, the MSGR can identify pathway members whose coregulation is either ancient or newly evolved.
Enhanced Voluntary Alcohol Consumption after Estrogen Supplementation Negates Estrogen-Mediated Vascular Repair in Ovariectomized Mice
Authors: Rajasingh Johnson , Bord Evelyn , Qin Gangjian , Ii Masaaki , Silver Marcy , Hamada Hiromichi , Ahluwalia Deepali , Goukassian David , Zhu Yan , Losordo Douglas W. , Kishore Raj
Published: May 2007

Preclinical and observational studies in ovariectomized (OVX) animals and pre- and postmenopausal women, respectively, have suggested the cardioprotective effects of estrogen replacement therapy. However, randomized clinical trials have not confirmed estrogen-mediated cardioprotection. Although uncertainties about the duration and optimal type of estrogen replacement regimen might explain the disparity, other factors that may mask the protective effects of 17β-estradiol (E2) on cardiovascular outcome need scrutiny. Increased ethanol consumption may be one such factor. We examined the effect of E2 supplementation on ethanol consumption in OVX mice and the effect of ethanol consumption on E2-mediated vascular repair, in vivo. OVX mice implanted with E2 pellets consumed significantly more ethanol, compared with those receiving placebo pellets. E2-induced increase in ethanol consumption was not affected by the absence of either estrogen receptor-α or -β. Reendothelialization after carotid artery denudation was repressed, and neovascularization in ischemic hind limbs was blunted in mice consuming ethanol, despite E2 supplementation. In vitro, ethanol dose-dependently attenuated E2-induced endothelial cell (EC) proliferation and tube formation activity and enhanced EC apoptosis, suggesting that ethanol blocks E2-induced EC survival and function. Taken together our data suggest that increased ethanol consumption after E2 supplementation blunts the beneficial effects of E2 on EC function and that novel approaches to estrogen replacement for cardioprotection may benefit from the control of alcohol consumption.
Translational Fusion of Two β-Subunits of Human Chorionic Gonadotropin Results in Production of a Novel Antagonist of the Hormone
Authors: Roy Satarupa , Setlur Sunita , Gadkari Rupali A. , Krishnamurthy H. N. , Dighe Rajan R.
Published: May 2007

The strategy of translationally fusing the α- and β-subunits of human chorionic gonadotropin (hCG) into a single-chain molecule has been used to produce novel analogs of hCG. Previously we reported expression of a biologically active single-chain analog hCGαβ expressed using Pichia expression system. Using the same expression system, another analog, in which the α-subunit was replaced with the second β-subunit, was expressed (hCGββ) and purified. hCGββ could bind to LH receptor with an affinity three times lower than that of hCG but failed to elicit any response. However, it could inhibit response to the hormone in vitro in a dose-dependent manner. Furthermore, it inhibited response to hCG in vivo indicating the antagonistic nature of the analog. However, it was unable to inhibit human FSH binding or response to human FSH, indicating the specificity of the effect. Characterization of hCGαβ and hCGββ using immunological tools showed alterations in the conformation of some of the epitopes, whereas others were unaltered. Unlike hCG, hCGββ interacts with two LH receptor molecules. These studies demonstrate that the presence of the second β-subunit in the single-chain molecule generated a structure that can be recognized by the receptor. However, due to the absence of α-subunit, the molecule is unable to elicit response. The strategy of fusing two β-subunits of glycoprotein hormones can be used to produce antagonists of these hormones.