bluuebunny/crossref_metadata_2025 huggingface dataset:
Unveiling the molecular basis of intrinsic skin aging1
Authors: Holtkötter O. , Schlotmann K. , Hofheinz H. , Olbrisch R. R. , Petersohn D.
Published: September 2005

Synopsis

The process of skin aging is a combination of an extrinsic and intrinsic aspect, and knowing the molecular changes underlying both is a prerequisite to being able to effectively counter it. However, despite its importance for a deeper understanding of skin aging as a whole, the process of intrinsic skin aging in particular has barely been investigated. In this study, the molecular changes of intrinsic skin aging were analyzed by applying ‘Serial Analysis of Gene Expression’ (SAGETM) to skin biopsies of young and aged donors. The analysis resulted in several hundred differentially expressed genes with varying statistical significance. Of these, several genes were identified that either have never been described in skin aging before (e.g. APP) or have no identified function, e.g. EST sequences. This is the first time that intrinsic skin aging has been analyzed in such a comprehensive manner, offering a new and partially unexpected set of target genes that have to be analyzed in more detail in terms of their contribution to the skin aging process.
Racial Perceptions and Evaluative Responses to Welfare: Does Education Attenuate Race‐of‐Target Effects?
Authors: Federico Christopher M.
Published: September 2005

A growing body of research indicates that welfare attitudes may be strongly shaped by negative perceptions of Blacks. This raises questions about what might inhibit the racialization of welfare attitudes. In this vein, a long line of work indicating that education leads to increased tolerance suggests that the relationship between negative racial perceptions and welfare attitudes may be weaker among the highly educated. However, recent studies suggest that the role of education may be more complex: While negative racial perceptions may be less prevalent among the highly educated, the relationship between these perceptions and policy attitudes appears to be stronger among highly educated individuals. The present study attempts to extend this finding by examining the hypothesis that the presence of a racial cue would be more (rather than less) likely to strengthen the relationship between negative racial perceptions and evaluative responses to welfare among college‐educated Whites. Data from a survey‐based experiment included in the 1991 National Race and Politics Study provided a clear pattern of support for this hypothesis.
African‐American Partisanship and the Legacy of the Civil Rights Movement: Generational, Regional, and Economic Influences on Democratic Identification, 1973–1994
Authors: Luks Samantha , Elms Laurel
Published: September 2005

We explore the importance of generational effects and the changing economic circumstances of Blacks to explain variations over time in the partisan attachments of African Americans. More specifically, we explore whether generational differences have caused the cohorts that came of political age following the Civil Rights movement to be less Democratic than generations that lived through the Civil Rights movement and its aftermath. We find that while life‐cycle effects explain a portion of the movement away from the two major parties, generational effects account for the small but significant increase in Republican party identification in the youngest generation. Additionally, living in the South accounts for the steepest gains in political independence. Finally, changing economic influences over time appear to have led poorer Blacks to change from the most likely to the least likely to identify with a major party.
Indira Gandhi: The Relationship between Personality Profile and Leadership Style
Authors: Steinberg Blema S.
Published: September 2005

This article explores the relationship between Indira Gandhi's personality profile in the period before she became Prime Minister and her leadership style during the time she was Prime Minister. The instrument for assessing the personality profile was compiled and adapted from criteria for normal personality types and pathological variants. Gandhi emerges as a multifaceted individual with four of her personality scales—the Ambitious, the Reticent, the Contentious, and the Dominating—approaching the level of mildly dysfunctional. A psychodynamic explanation for these patterns was then offered. This study also developed an instrument for evaluating leadership styles in a cabinet system of government and postulated the theoretical links between personality patterns and leadership style profiles. Gandhi's leadership style was then examined and links between personality profile and leadership style explored: In eight of the 10 leadership categories, Indira Gandhi's leadership behavior matched our expectations for the Ambitious, Dominant, and Contentious personality profiles but not the Reticent one. Further discussion focused on the two areas in which personality patterns fell short of predicting leadership style and the possible explanations for this result.
Economic performance of ‘weak’ governments and their interaction with central banks and labour: Deficits, economic growth, unemployment and inflation, 1961–1998
Authors: SAKAMOTO TAKAYUKI
Published: September 2005

Abstract.  Comparative political economists have conventionally claimed that the strength and stability of governments affect policy making and performance, and that what they call ‘weak governments’– multiparty, minority and short‐lived governments – show poorer economic performance. This article tests this and related hypotheses on deficits, economic growth, unemployment and inflation by examining data from 17 OECD countries. I find that there is generally little evidence to indicate that so‐called ‘weak governments’, when considered independently, produce poorer performance than strong ones. However, the effects of different government types are partly contingent on central bank independence and labour organization. When central banks are independent, coalition governments exhibit better inflation and economic growth performance than one‐party governments, but the opposite happens when central banks are dependent. I attempt an explanation for these relationships. I also find that independent central banks, under certain conditions, lead to lower growth and higher inflation. Thus, some of the benefits of central bank independence are context‐specific, depending on other political‐economic factors.
The Impact of Allergy and Pulmonary Specialist Care on Emergency Asthma Utilization in a Large Managed Care Organization
Authors: Erickson Sara , Tolstykh Irina , Selby Joe V. , Mendoza Guillermo , Iribarren Carlos , Eisner Mark D.
Published: September 2005

Objective. To evaluate the longitudinal impact of asthma specialist care on the risk of emergency department (ED) visits and hospitalization for asthma.

Data Sources/Study Setting. A prospective cohort study using both telephone survey and computerized utilization data.

Study Design. We recruited a prospective cohort of 4,742 adult members of a closed panel managed care organization who were hospitalized for asthma (the “baseline hospitalization”).

Data Collection/Extraction Methods. Visits to asthma specialists were ascertained from computerized utilization databases. Specialist visits after baseline hospitalization were defined as time‐dependent covariates. An alternative analysis defined specialist visits during the year preceding baseline hospitalization. A subcohort of 596 subjects completed telephone interviews.

Principal Findings. Compared with subjects who received no specialist visits after baseline hospitalization, treatment by allergists (hazard ratio (HR) 1.04; 95 percent confidence interval (CI) 0.87–1.26) or pulmonologists (HR 0.92; 95 percent CI 0.71–1.19) was not associated with a reduction in the risk of future ED visits for asthma in the entire cohort, controlling for age, sex, race, recent asthma medication dispensing, and pharmacy benefits status. There was also no association between allergist visits and the risk of subsequent hospitalizations for asthma (HR 0.93; 95 percent CI 0.75–1.14). In contrast, visits to pulmonologists (HR 0.74; 95 percent CI 0.55–0.99) were related to a reduced risk of rehospitalization.

Conclusions. Pulmonary specialist visits appeared to reduce the risk of hospitalization for asthma, whereas asthma specialist visits did not reduce the risk of ED visits. In the context of comprehensive prepaid health care, the benefit of specialist care was modest.
Impact of Generalist Care Managers on Patients with Diabetes
Authors: Dorr David A. , Wilcox Adam , Donnelly Steven M. , Burns Laurie , Clayton Paul D.
Published: September 2005

Objective. To determine how the addition of generalist care managers and collaborative information technology to an ambulatory team affects the care of patients with diabetes.

Study Setting. Multiple ambulatory clinics within Intermountain Health Care (IHC), a large integrated delivery network.

Study Design. A retrospective cohort study comparing diabetic patients treated by generalist care managers with matched controls was completed. Exposure patients had one or more contacts with a care manager; controls were matched on utilization, demographics, testing, and baseline glucose control. Using role‐specific information technology to support their efforts, care managers assessed patients' readiness for change, followed guidelines, and educated and motivated patients.

Data Collection. Patient data collected as part of an electronic patient record were combined with care manager‐created databases to assess timely testing of glycosylated hemoglobin (HbA1c) and low‐density lipoprotein (LDL) levels and changes in LDL and HbA1c levels.

Principal Findings. In a multivariable model, the odds of being overdue for testing for HbA1c decreased by 21 percent in the exposure group (n=1,185) versus the control group (n=4,740). The odds of being tested when overdue for HbA1c or LDL increased by 49 and 26 percent, respectively, and the odds of HbA1c <7.0 percent also increased by 19 percent in the exposure group. The average HbA1c levels decreased more in the exposure group than in the controls. The effect on LDL was not significant.

Conclusions. Generalist care managers using computer‐supported diabetes management helped increase adherence to guidelines for testing and control of HbA1c levels, leading to improved health status of patients with diabetes.
Are Primary Care Services a Substitute or Complement for Specialty and Inpatient Services?
Authors: Fortney John C. , Steffick Diane E. , Burgess James F. , Maciejewski Matt L. , Petersen Laura A.
Published: September 2005

Objective. To determine whether strategies designed to increase members' use of primary care services result in decreases (substitution) or increases (complementation) in the use and cost of other types of health services.

Study Setting. Encounter and cost data were extracted from the Department of Veterans Affairs (VA) administrative data sources for the period 1995–1999. This timeframe captures the VA's natural experiment of increasing geographic access to primary care by establishing new satellite primary care clinics, known as Community‐Based Outpatient Clinics (CBOCs).

Study Design. We exploited this natural experiment to estimate the substitutability of primary care for other health services and its impact on cost. Hypotheses were tested using ordinary least squares (OLS) regression, which was potentially subject to endogeneity bias. Endogeneity bias was assessed using a Hausman test. Endogeneity bias was accounted for by using instrumental variables analysis, which capitalized on the establishment of CBOCs to provide an exogenous identifier (change in travel distance to primary care).

Data Collection. Demographic, encounter, and cost data were collected for all veterans using VA health services who resided in the catchment areas of new CBOCs and for a matched group of veterans residing outside CBOC catchment areas.

Principal Findings. Change in distance to primary care was a significant and substantial predictor of change in primary care visits. OLS analyses indicated that an increase in primary care service use was associated with increases in the use of all specialty outpatient services and inpatient services, as well as increases in inpatient and outpatient costs. Hausman tests confirmed that OLS results for specialty mental health encounters and mental health admissions were unbiased, but that results for specialty medical encounters, physical health admissions, and outpatient costs were biased. Instrumental variables analyses indicated that an increase in primary care encounters was associated with a decrease in specialty medical encounters and was not associated with an increase in physical health admissions, or outpatient costs.

Conclusions. Results provide evidence that health systems can implement strategies to encourage their members to use more primary care services without driving up physical health costs.
Medicare Beneficiaries and the Impact of Gaining Prescription Drug Coverage on Inpatient and Physician Spending
Authors: Briesacher Becky A. , Stuart Bruce , Ren Xiaoqang , Doshi Jalpa A. , Wrobel Marian V.
Published: September 2005

Objective. To assess whether gaining prescription drug coverage produces cost offsets in Medicare spending on inpatient and physician services.

Data Source. Two‐year panels constructed from 1995 to 2000 Medicare Current Beneficiary Survey, a dataset of Medicare claims and health care surveys from the Medicare population.

Study Design. We estimated a series of fixed‐effects panel models to calculate adjusted changes in Medicare spending as drug coverage was acquired (Gainers) relative to the spending of beneficiaries who never had drug coverage (Nevers). Explanatory variables in the model include age, calendar year, income, and health status.

Principal Findings. Assessments of inpatient and physician services spending provided no evidence of overt selection behavior prior to the acquisition of drug coverage (i.e., there were no preswitch spikes in Medicare spending for Gainers). After enrollment, the medical spending of Gainers resembled those of beneficiaries who never had drug coverage. Overall, the multivariate models showed no systematic postenrollment changes in either inpatient or physician spending that could be attributed to the acquisition of drug coverage.

Conclusions. We found no consistent evidence that drug coverage either increases or reduces spending for hospital and physician services. This does not necessarily mean that drug therapy does not substitute for or complement other medical treatments, but rather that neither effect predominates across the Medicare population as a whole.
Dividend Taxes and Implied Cost of Equity Capital
Authors: DHALIWAL DAN , KRULL LINDA , LI OLIVER ZHEN , MOSER WILLIAM
Published: September 2005

We estimate firm‐level implied cost of equity capital based on recent advances in accounting and finance research and examine the effect of dividend taxes on the cost of equity capital. We investigate whether dividend taxes affect firms' cost of capital by testing the relation between the implied cost of equity capital and a measure of the tax‐penalized portion of dividend yield, which we define as the product of dividend yield and the dividend tax penalty. The results generally support the dividend tax capitalization hypothesis. We find a positive relation between the implied cost of equity capital and the tax‐penalized portion of dividend yield that is decreasing in aggregate institutional ownership, our proxy for tax‐advantaged investors. The evidence in this study adds to the understanding of the effect of investor‐level taxes on equity value.
Budesonide in previously untreated autoimmune hepatitis
Authors: Wiegand Johannes , Schüler Andreas , Kanzler Stephan , Lohse Ansgar , Beuers Ulrich , Kreisel Wolfgang , Spengler Ulrich , Koletzko Sibylle , Jansen Peter L. M. , Hochhaus Günther , Möllmann Helmut W. , Pröls Markus , Manns Michael P.
Published: September 2005

Abstract: Background: Autoimmune hepatitis (AIH) is a chronic liver disease that is effectively treated with immunosuppressive therapy. Predniso(lo)ne, often in combination with azathioprine, is the basic therapeutic option to induce remission. However, this regimen can cause numerous side effects. The aim of the present study was to evaluate budesonide as a treatment option in the induction of remission in patients with previously untreated AIH.

Methods: Between October 1998 and August 1999, 12 patients were treated with 3 mg budesonide thrice daily for 3 months in this open one‐arm multicenter phase IIa study. Primary end point was induction of remission indicated by a drop of aspartate aminotransferase and alanine aminotransferase levels below two times the upper limit of normal.

Results: Seven of the 12 patients (58%) reached complete remission, three patients (25%) had a partial response. Thus, 10/12 individuals (83.3%) responded to therapy. Therapy was tolerated well in 10/12 cases (83.3%).

Conclusions: Budesonide monotherapy was effective in the induction of remission and well tolerated in treatment naïve patients with AIH. It should be further evaluated in prospective controlled trials and should be compared to predniso(lo)ne both in monotherapy and in combination with azathioprine.
Undetectable phospho‐STAT1 in peripheral blood mononuclear cells from patients with chronic hepatitis C who do not respond to interferon‐α therapy
Authors: Aceti Antonio , Zechini Barbara , Griggi Tamara , Marangi Massimo , Pasquazzi Caterina , Quaranta Giorgio , Sorice Maurizio
Published: September 2005

Abstract: Background: Recent studies have suggested that phosphorylated signal transducers and activators of transcription 1 (STAT1) plays an important role in interferon (IFN)‐mediated biological functions, including antiviral activity. Moreover, it has been demonstrated that suppressors of the cytokine signal 1 (SOCS1) negatively regulates IFN activities.

Aims: To investigate the involvement of phospho‐STAT1 in the response to IFN‐α therapy in patients with chronic hepatitis C and to evaluate the negative regulatory effect of SOCS1 on STAT1 activation.

Methods: Sixty‐five patients with chronic hepatitis C and 25 healthy subjects were enrolled. Twenty‐five of the patients had never been treated with IFN‐α therapy (naive), while the remaining 40 patients had. The IFN‐treated patients were divided into sustained responders (SRs) or non‐responders (NRs) on the basis of their response to the antiviral therapy. Peripheral blood mononuclear cells (PBMCs) were obtained from each patient and control, and were either stimulated with IFN‐α or left unstimulated. Total STAT1, phospho‐STAT1 and SOCS1 were revealed by means of Western blot.

Results: Total STAT1 was equally expressed in unstimulated and stimulated PBMCs from all patients and controls. One hundred percent of the stimulated PBMCs from healthy controls and SRs, 96% from naive subjects, and 30% from NRs showed detectable phospho‐STAT1. By contrast, 70% of the stimulated PBMCs from NRs showed undetectable phospho‐STAT1.

Conclusions: We have demonstrated that phospho‐STAT1 proteins in 70% of patients with chronic hepatitis C who do not respond to IFN treatment are undetectable, which suggests that this protein may be involved in the mediation of IFN sensitivity. The down‐regulation of the Jak‐STAT pathway because of SOCS1 expression may be one of the possible underlying mechanisms involved in resistance to IFN.
Effects of plasma from patients with fulminant hepatic failure on function of primary rat hepatocytes in three‐dimensional culture
Authors: Nagaki Masahito , Naito Tomoo , Ohnishi Hiroo , Akaike Toshihiro , Muto Yasutoshi , Moriwaki Hisataka
Published: September 2005

Abstract: Background/Aim: As biotechnology continues to advance, a bioartificial liver is expected to be developed for the treatment of patients with fulminant hepatic failure (FHF) whose liver dysfunction is potentially reversible or for providing liver support as a bridge to liver transplantation. While monolayer‐cultured hepatocytes rapidly lose their capacity to express many liver‐specific functions over time when cultured, spherical‐shaped hepatocytes in three‐dimensional culture with the use of extracellular matrix components sustain long‐term survival by maintaining differentiated hepatocyte functions. The aim of this study was to investigate whether sufficient functions of viable spherical‐shaped hepatocytes could be maintained in plasma of patients with FHF in order to use these cells in an extracorporeal system. Methods: Hepatocyte functions were evaluated under monolayer or three‐dimensional culture in FHF plasma. Results: Primary rat hepatocytes on poly‐N‐p‐vinylbenzyl‐d‐lactonamide (PVLA) formed spheroids even in FHF plasma and maintained their spherical shapes in FHF plasma as long as in medium. Spherical‐shaped hepatocytes on PVLA cultured in FHF plasma showed higher activity in albumin secretion, urea formation, and gluconeogenesis than those in normal human plasma or medium. As being cultured in medium, hepatocytes on PVLA cultured in plasma were also superior to cells on collagen in regard to albumin secretion, amino acid metabolism, and gluconeogenesis. Conclusions: These findings demonstrated that FHF plasma is not toxic to rat hepatocyte spheroids and that hepatocyte spheroids have potential use in the development of a bioartificial liver.
Contrast‐enhanced gray‐scale harmonic ultrasound in the efficacy assessment of ablation treatments for hepatocellular carcinoma
Authors: Pompili Maurizio , Riccardi Laura , Covino Marcello , Barbaro Brunella , Di Stasi Carmine , Orefice Ruggero , Gasbarrini Giovanni , Rapaccini Gian Ludovico
Published: September 2005

Abstract: Background. The aim of this study was to compare contrast‐enhanced gray‐scale harmonic ultrasound with multiphasic spiral computed tomography in the assessment of treatment efficacy of non‐surgically treated HCC.

Methods. We studied 56 HCCs treated by percutaneous ethanol injection (31 cases), radiofrequency ablation (three cases), trans‐arterial chemoembolization (12 cases), and combined treatment (10 cases). The efficacy of therapies was blindly assessed by multiphasic computed tomography and gray‐scale harmonic ultrasound with a second‐generation contrast agent (sulfur hexafluoride).

Results. On computed tomography 30 tumors (53.6%) showed complete necrosis, while 26 lesions (45.4%) were still viable. On contrast‐enhanced ultrasound examination 33/56 nodules (58.9%) had no contrast enhancement in the arterial phase, while 23/56 lesions (41.1%) were still vascularized. All the nodules assessed as completely necrotic on computed tomography did not show arterial enhancement on contrast‐enhanced ultrasound and diagnostic agreement was found in 53/56 cases (94.6%) (P<0.001). Contrast‐enhanced ultrasound demonstrated relative sensitivity and specificity of 87.0% and 98.4%.

Conclusions. Contrast‐enhanced harmonic ultrasound is promising in the efficacy evaluation of ablation treatments for HCC. Nodules vascularized in the arterial phase on contrast harmonic ultrasound should be considered still viable and addressed to additional treatment without further evaluation.
P‐selectin mediates leukocyte rolling in concanavalin‐A‐induced hepatitis
Authors: March Sandra , Garcia‐Pagán Joan‐Carles , Massaguer Anna , Pizcueta Pilar , Panés Juliàn , Engel Pablo , Bosch Jaume
Published: September 2005

Abstract: Concanavalin‐ A (Con‐A)‐induced hepatitis is an experimental model of human autoimmune hepatitis characterized by leukocyte activation and infiltration of the liver. The aim of the present study was to evaluate the role of P‐selectin on leukocyte–endothelial interactions within the hepatic microvasculature in response to Con‐A.

Methods: The study was performed in P‐selectin‐deficient mice and wild‐type mice pretreated with anti‐P‐selectin blocking monoclonal antibody (mAb) or vehicle. After 2 h of Con‐A (20 mg/kg i.v.) or PBS administration, leukocyte rolling and adhesion and the index of sinusoidal perfusion were evaluated using the intravital microscopy technique in the liver. Apoptosis was determined by flow cytometry analysis of caspase‐3 activity assayed on freshly isolated hepatocytes.

Results: Con‐A induced a significant increase in leukocyte rolling, mainly located at the central venule (2.1±0.4 vs 0.6±0.2 cells/min in wild‐type mice treated with vehicle) and less marked, but still significant, in portal venules. This was associated with a significant increase in leukocyte adhesion. In P‐selectin‐deficient mice treated with Con‐A, leukocyte rolling in portal and central venules was markedly reduced. However, leukocyte adhesion was only partially attenuated. A few sinusoids were perfused in wild‐type mice treated with Con‐A (26%). The percentage of perfused sinusoids was significantly higher in P‐selectin‐deficient mice (45%; P<0.05 vs wild‐type). Similar effects were noted after the simultaneous injection of Con‐A and anti‐P‐selecting mAb in wild‐type mice. After Con‐A treatment, apoptosis was markedly reduced in isolated hepatocytes of P‐selectin‐deficent mice (37±7% vs 75±5% in wild type).

Conclusion: The results of this intravital microscopy study clearly demonstrate that P‐selectin is involved in the initial leukocyte rolling that leads to the development of Con‐A‐induced liver injury.
Prediction of the ablated area by the spread of microbubbles during radiofrequency ablation of hepatocellular carcinoma
Authors: Nouso Kazuhiro , Shiraga Kunihiro , Uematsu Shuji , Okamoto Ryoichi , Harada Ryo , Takayama Shoko , Kawai Wakako , Kimura Shigeru , Ueki Toru , Okano Nobuaki , Nakagawa Masahiko , Mizuno Motowo , Araki Yasuyuki , Shiratori Yasushi
Published: September 2005

Abstract: Background/Aim: Radiofrequency ablation (RFA) is effective for the treatment of hepatocellular carcinoma (HCC). To prevent the ablation of adjacent organs and vessels, the spread of microbubbles generated by heating during RFA was observed by ultrasonography (US) and used to predict the ablated area; however, several reports documented that discrepancies existed between the spread of microbubbles and the ablated area.

Patients and Methods: The spread of microbubbles during RFA was observed by US in 24 patients with HCC and the areas were compared with the defect of enhancement in contrast enhanced (CE)‐US, using Levovist in the same plane.

Results: During the ablation, the posterior margin was obscure but the border could be visualized 5 min after the ablation. The size of the area of hyperechogenicity 5 min after ablation and that of the defect observed by CE‐US was found to correlate (r2=0.91, P<0.0001). The shape of the hyperechogenicity corresponded well to the defect area, even in cases showing irregular spread of the microbubbles.

Conclusion: The observation of microbubbles during RFA can predict the ablated area and might be useful to prevent the unfavorable ablation of adjacent organs and vessels.
Study of portal vein thrombosis in patients with idiopathic portal hypertension in Japan
Authors: Matsutani Shoichi , Maruyama Hitoshi , Akiike Taro , Kobayashi Satoshi , Yoshizumi Hiroaki , Okugawa Hidehiro , Fukuzawa Takeshi , Kimura Kunio , Saisho Hiromitsu
Published: September 2005

Abstract: Background/Aims: The aim of this study was to elucidate the incidence and clinical manifestations of portal vein thrombosis (PVT) in patients with idiopathic portal hypertension (IPH) in Japan during long‐term follow‐up.

Patients and Methods: Twenty‐two patients with IPH were examined for PVT by sonography during a follow‐up of 12±6 years. Clinical manifestations and patient outcome related to PVT were studied. Seventy patients with liver cirrhosis were examined by sonography as an incidence control of thrombosis.

Results: Nine IPH patients had portal thrombosis (9/22, 41%), a higher incidence than in liver cirrhosis patients (7/70, 10%). Those with thrombosis showed ascites, marked hypersplenism, and low serum albumin. Four patients with thrombosis died. Patients without thrombosis showed less clinical problems after long‐term follow‐up. Plasma antithrombin III and protein C activity decreased in almost half of the patients. However, there were no differences in these parameters between patients with and without thrombosis.

Conclusions: In Japan, IPH patients had a high incidence of portal thrombosis, a significant factor for poor prognosis. Whether the management of PVT contributes to an improvement of a clinical course of IPH or not should be clarified in further study.
Different growth capacity between infant and adult mouse hepatocytes in vitro correlates to the cyclin D1 level without relation to oxidative DNA damage
Authors: Imamura Emi , Yamamoto Masahiro , Miyakoshi Masaaki , Honmo Satoshi , Ozaki Atsuko , Yoshie Masumi , Tamakawa Susumu , Yaginuma Yuji , Kasai Shinichi , Ogawa Katsuhiro
Published: September 2005

Abstract: Background: Proliferating capacity of hepatocytes is rapidly decreased during growth into maturity, but its exact reason(s) are not well known.

Methods: Hepatocytes isolated from infant (10–14 days old) and adult (10–13 months old) B6C3F1 mice were cultivated in the medium containing epidermal growth factor and insulin. Proliferative capacity, apoptosis, morphological changes, cell cycle proteins and 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) were compared between the two hepatocyte populations.

Results: Although adult hepatocytes rapidly underwent cellular crisis characterized by extended morphology and multiple nuclei without proliferation, infant hepatocytes could proliferate with less crisis. Cyclin D1 was much more abundant in the infant than adult cells, but there was no difference according to the expression of cdk4, cdk2, cyclin E and cdk inhibitors (p16Ink4 (p16), p21Cip1/Waf1 (p21) and p27Kip1 (p27)). 8‐OHdG became high soon after cultivation, while it rapidly went down after day 2 both in the infant and adult cells.

Conclusions: The high growth capacity of infant hepatocytes in vitro was dependent on the cyclin D1 level, but there was no relation to 8‐OHdG.
PHOTOSYNTHETIC ADAPTATION OF A BLOOM‐FORMING CYANOBACTERIUM MICROCYSTIS AERUGINOSA (CYANOPHYCEAE) TO PROLONGED UV‐B EXPOSURE1
Authors: Jiang Haibo , Qiu Baosheng
Published: September 2005

The bloom‐forming cyanobacterium Microcystis aeruginosa Kütz 854 was cultured with 1.05 W·m−2 UV‐B for 3 h every day, and its growth, pigments, and photosynthesis were investigated. The specific growth rates represented by chl a concentration and OD750 were inhibited 8% and 9% by UV‐B exposure, respectively. Six days of UV‐B treatment significantly reduced cellular contents of phycocyanin and allophycocyanin by 32% and 62%, respectively, and markedly increased the carotenoid content by 27%, but had little effect on the chl a content. The initial values of optimal photosynthetic efficiency for UV‐B treated samples were, respectively, 52%, 87%, and 93% of controls on days 4, 7, and 10 of growth. The light‐saturated photosynthetic rates at day 6 were significantly lower than controls grown without UV‐B. The probability of electron transfer beyond QA decreased during UV‐B exposure, and this indicated that the acceptor side of PSII was one of main damage sites. The adaptation of M. aeruginosa 854 to UV‐B radiation could be observed from light‐saturated photosynthetic rates on day 13 and diurnal changes of chl fluorescence during the late growth phase. When both exposed to higher UV‐B, samples cultured under 1.05 W·m−2 UV‐B for 9 days recovered faster than controls. It is suggested that M. aeruginosa 854 had at least three adaptive strategies to cope with the enhanced UV‐B: increasing the synthesis of carotenoids to counteract reactive oxidants caused by UV‐B exposure, degrading phycocyanin and allophycocyanin to avoid further damage to DNA and reaction centers, and enhancing the repair of UV‐B induced damage to the photosynthetic apparatus.
PHYLOGENY OF THE HYDRODICTYACEAE (CHLOROPHYCEAE): INFERENCES FROM rDNA DATA1
Authors: Buchheim Mark , Buchheim Julie , Carlson Tracy , Braband Anke , Hepperle Dominik , Krienitz Lothar , Wolf Matthias , Hegewald Eberhard
Published: September 2005

The hydrodictyacean green algal lineage has been the focus of much research due to the fossil record of at least some members, their ornamented cell walls, and their distinctive reproductive strategies. The phylogeny of the family was, until recently, exclusively morphology based. This investigation examines hydrodictyacean isolates from several culture collections, focusing on sequences from ribosomal data: 18S rDNA, 26S rDNA (partial), and internal transcribed spacer (ITS)‐2 data. Results from phylogenetic analyses of independent and combined data matrices support the Hydrodictyaceae as a monophyletic lineage that includes isolates of Chlorotetraedron, Hydrodictyon, Pediastrum, Sorastrum, and Tetraedron. Phylogenetic analyses of rDNA data indicate that the three‐dimensional coenobium of Hydrodictyon is evolutionarily distinct from the three‐dimensional coenobium of Sorastrum. The more robust aspects of the ITS‐2 data corroborate the 18S+26S rDNA topology and provide a structural autapomorphy for the Hydrodictyaceae and Neochloridaceae, that is, an abridgment of helix IV in the secondary structure. The rDNA data do not support monophyly of Pediastrum but rather suggest the existence of four additional hydrodictyacean genera: Monactinus, Parapediastrum, Pseudopediastrum, and Stauridium.
Psychotropic Effects of Antiepileptic Drugs
Authors: Nadkarni Siddhartha , Devinsky Orrin
Published: September 2005

Antiepileptic drugs are important psychotropic agents that are commonly used to treat psychiatric disorders. The behavioral effects of antiepileptic drugs may differ between epilepsy and psychiatric patient populations. Randomized, double-blind, controlled data on the psychotropic efficacy of antiepileptic drugs are limited mainly to bipolar disorder.
Seizure Exacerbation by Antiepileptic Drugs
Authors: French Jacqueline A.
Published: September 2005

Worsening of Seizures by Oxcarbazepine in Juvenile Idiopathic Generalized Epilepsies

Gelisse P, Genton P, Kuate C, Pesenti A, Baldy-Moulinier M, Crespel A

Epilepsia 2004;45:1282–1286

Purpose

Several studies have shown that carbamazepine (CBZ) may aggravate idiopathic generalized epilepsy (IGE). Oxcarbazepine (OXC) is a new drug chemically related to CBZ. We report six cases of juvenile IGE with a clear aggravation by OXC.

Methods

We retrospectively studied all patients with IGE first referred to our epilepsy department between January 2001 and June 2003 and treated with OXC.

Results

During this period, six patients were identified. All had an aggravation of their epilepsy in both clinical and EEG activities. OXC had been used because of an incorrect diagnosis of focal epilepsy or generalized tonic–clonic seizures (GTCSs) of undetermined origin (no syndromic classification of the epilepsy). Before OXC, only one patient had experienced a worsening of seizures with an inadequate drug (carbamazepine; CBZ). Four had juvenile myoclonic epilepsy, one had juvenile absence epilepsy, and one had IGE that could not be classified into a precise syndrome. OXC (dosage range, 300–1,200 mg/day) was used in monotherapy in all of them except for one patient. Aggravation consisted of a clear aggravation of myoclonic jerks (five cases) or de novo myoclonic jerks (one case). Three patients had exacerbation of absence seizures. One patient had worsened dramatically and had absence status, and one had de novo absences after OXC treatment. The effects of OXC on GTCSs were less dramatic, with no worsening in frequency in three and a slight increase in three.

Conclusions

OXC can be added to the list of antiepileptic drugs that can exacerbate myoclonic and absence seizures in IGE.
COLOR DOPPLER ULTRASONOGRAPHY IN PREDICTION OF THE REDUCIBILITY OF INTUSSUSCEPTED BOWEL IN 15 YOUNG DOGS
Authors: Patsikas Michail N. , Papazoglou Lysimachos G. , Jakovljevic Samuel , Dessiris Aggelos K.
Published: September 2005

Color Doppler ultrasonography was performed in 15 young dogs with intestinal intussusception to test the hypothesis that color Doppler findings can be used as a predictor of the manual reducibility of the intussusception at celiotomy. Color flow Doppler ultrasonography indicated blood flow within mesentery of the intussuscepted bowel in 12 of 15 dogs and reduction was achieved in nine of these 12 dogs (75%). In the remaining three dogs and in three dogs where no color Doppler signal were observed, an irreducible intussusception was confirmed at celiotomy. Color Doppler ultrasonography is a useful method for predicting the reducibility of intussusception in dogs.
99MTC‐CIPROFLOXACIN IN IMAGING OF CLINICAL INFECTIONS IN CAMELIDS AND A GOAT
Authors: Alexander Kate , Drost Wm Tod , Mattoon John S. , Anderson David E.
Published: September 2005

99mTc‐ciprofloxacin was used to image five adult camelids and a juvenile goat with clinical and/or radiographic signs of infection. 99mTc‐ciprofloxacin (range 10–33 MBq/kg) was injected intravenously and a series of 2‐min static images were acquired at 1‐ and 4‐h postinjection. At 24‐h postinjection, 5‐min static images were acquired. Only the skull or abdomen was imaged in the adults; the whole body was imaged in the goat. The quality of the 1‐, 4‐, and 24‐h studies was evaluated subjectively. Normal and abnormal areas of 99mTc‐ciprofloxacin uptake were recorded and subjectively graded as mild, moderate or intense. Image quality was best 4‐h postinjection. Twenty‐four‐hour images were poor because of insufficient radioactivity. 99mTc‐ciprofloxacin imaging resulted in true positive or true negative scans in four of six animals. Two false‐negative studies occurred. Intense 99mTc‐ciprofloxacin activity was seen in the lungs and urinary bladder, moderate/intense activity in the kidneys, and mild activity in the physes/epiphyses, liver and intermittently in the gastrointestinal tract. The normal distribution of 99mTc‐ciprofloxacin in camelids/small ruminants differed from people. Further studies to determine the sensitivity and specificity of infection detection using 99mTc‐ciprofloxacin in animals are warranted.
Mitochondrial biogenesis in mtDNA‐depleted cells involves a Ca2+‐dependent pathway and a reduced mitochondrial protein import
Authors: Mercy Ludovic , Pauw Aurélia de , Payen Laetitia , Tejerina Silvia , Houbion Andrée , Demazy Catherine , Raes Martine , Renard Patricia , Arnould Thierry
Published: September 2005

Alterations in mitochondrial activity resulting from defects in mitochondrial DNA (mtDNA) can modulate the biogenesis of mitochondria by mechanisms that are still poorly understood. In order to study mitochondrial biogenesis in cells with impaired mitochondrial activity, we used rho‐L929 and rho0143 B cells (partially and totally depleted of mtDNA, respectively), that maintain and even up‐regulate mitochondrial population, to characterize the activity of major transcriptional regulators (Sp1, YY1, MEF2, PPARgamma, NRF‐1, NRF‐2, CREB and PGC‐1α) known to control the expression of numerous nuclear genes encoding mitochondrial proteins. Among these regulators, cyclic AMP‐responsive element binding protein (CREB) activity was the only one to be increased in mtDNA‐depleted cells. CREB activation mediated by a calcium‐dependent pathway in these cells also regulates the expression of cytochrome c and the abundance of mitochondrial population as both are decreased in mtDNA‐depleted cells that over‐express CREB dominant negative mutants. Mitochondrial biogenesis in mtDNA‐depleted cells is also dependent on intracellular calcium as its chelation reduces mitochondrial mass. Despite a slight increase in mitochondrial mass in mtDNA‐depleted cells, the mitochondrial protein import activity was reduced as shown by a decrease in the import of radiolabeled matrix‐targeted recombinant proteins into isolated mitochondria and by the reduced mitochondrial localization of ectopically expressed HA‐apoaequorin targeted to the mitochondria. Decrease in ATP content, in mitochondrial membrane potential as well as reduction in mitochondrial Tim44 abundance could explain the lower mitochondrial protein import in mtDNA‐depleted cells. Taken together, these results suggest that mitochondrial biogenesis is stimulated in mtDNA‐depleted cells and involves a calcium‐CREB signalling pathway but is associated with a reduced mitochondrial import for matrix proteins.
Modules, multidomain proteins and organismic complexity
Authors: Tordai Hedvig , Nagy Alinda , Farkas Krisztina , Bányai László , Patthy László
Published: September 2005

Originally the term ‘protein module’ was coined to distinguish mobile domains that frequently occur as building blocks of diverse multidomain proteins from ‘static’ domains that usually exist only as stand‐alone units of single‐domain proteins. Despite the widespread use of the term ‘mobile domain’, the distinction between static and mobile domains is rather vague as it is not easy to quantify the mobility of domains. In the present work we show that the most appropriate measure of the mobility of domains is the number of types of local environments in which a given domain is present. Ranking of domains with respect to this parameter in different evolutionary lineages highlighted marked differences in the propensity of domains to form multidomain proteins. Our analyses have also shown that there is a correlation between domain size and domain mobility: smaller domains are more likely to be used in the construction of multidomain proteins, whereas larger domains are more likely to be static, stand‐alone domains. It is also shown that shuffling of a limited set of modules was facilitated by intronic recombination in the metazoan lineage and this has contributed significantly to the emergence of novel complex multidomain proteins, novel functions and increased organismic complexity of metazoa.
Electron Diffraction at Multiple Slits
Authors: Jönsson Claus
Published: September 2005

A glass plate covered with an evaporated silver layer of about 200 Å thickness is irradiated by a line-shaped electron probe in a vacuum of 10−4 Torr. A layer of polymerized hydrocarbon of very low electrical conductivity is formed at places subjected to high electron current density. An electrolytically deposited copper layer leaves these places free from copper. When the copper layer is peeled away a grating with slits free of any material is obtained. Slits 50 μ long and 0.3 μ wide with a grating spacing of 1 μ are obtained. The maximum number of slits is five. The electron diffraction pattern obtained using these slits in an arrangement analogous to Young's light interference experiment in the Fraunhofer region shows effects corresponding to the well-known interference phenomena in light optics.
An Introduction to Monte Carlo Methods
Authors: Raeside D. E.
Published: September 2005

Monte Carlo methods have become well-established research tools during the past three decades. With the increasing availability of computers it is now possible to encourage a wider audience to learn about these powerful methods. This review aims to arouse interest in the Monte Carlo approach to problem solving.
Remark on the Factor 1/N! in the Partition Function
Authors: Buchdahl H. A.
Published: September 2005

In a purely classical context it is argued on the basis of considerations involving the grand canonical probability-in-phase that the internal consistency of the Gibbsianensemble formalism necessarily implies the presence of the factor 1/N! in the canonical partition function.
Simple, Spin-Echo Spectrometer
Authors: Muller B. H. , Noble J. D. , Burnett L. J. , Harmon J. F. , McKay D. R.
Published: September 2005

In an attempt to make pulsed nuclear magnetic resonance (NMR) widely available for teaching purposes, the design and construction of a simple and inexpensive pulsed NMR spectrometer are described in considerable detail. This spectrometer requires only one twelve-volt power supply. A complete procedure for tuning the spectrometer to resonance is also presented.
Optical Crystals
Authors: Bergsten Ronald
Published: September 2005

Optical crystals are one-, two-, and three-dimensional diffraction plates used to demonstrate Laue diffraction by using light rather than x rays or particles. The flexibility afforded by optical crystals makes them better suited for demonstration purposes than naturally occurring crystals. The sequence of optical crystals has been proven effective for demonstrating diffraction phenomena at the high school level and is applicable at all university levels in both classroom and laboratory situations.
Water Stream “Loop-the-Loop”
Authors: Jefimenko Oleg
Published: September 2005

A water stream is “looping-the-loop” on the inside of a vertical, circular track made from an aluminum tubing cut along its length. The apparatus demonstrates the effect of centripetal (centrifugal) forces much more dramatically than when a ball is used. Although the track is only 34-in. wide and only 38-in. deep, the water is completely confined to it even at the uppermost portion of the loop. The water inside the loop can drive a small paddle wheel, and small boats can make the loop when dropped on the water stream at the bottom of the track. The apparatus has a built-in pump for pumping the water from the reservoir in the base of the apparatus to the starting point of the track.
A 1010 MeV Cyclotron
Authors: Edge R. D.
Published: September 2005

A simple device to demonstrate the principles of acceleration and phase stability in a cyclotron is described in which a steel ball is accelerated gravitationally along a spiral groove. The principle can be extended to demonstrate acceleration in a linear accelerator.
Dynamic Force Measurement with Strain Gauges
Authors: Lee Bruce E.
Published: September 2005

An apparatus is described which permits general physics laboratory students to measure forces dynamically. The apparatus consists of four strain gauges, mounted two on each side of a flat spring, which form the arms of a Wheatstone bridge. The spring is cantilevered with the force to be analyzed applied at the free end. As the spring is flexed, resistance of the gauges change producing a voltage signal from the bridge which is observed with an oscilloscope. An experiment using the apparatus to measure centripetal force of a pendulum is also described.
Superconducting, Magnetically Levitated Merry-Go-Round
Authors: Byer R. L. , Begley R. F. , Stewart G. R.
Published: September 2005

Magnetic levitation is seriously being considered as a method of supporting high-speed guided vehicles. In this article we review the present status of magnetically levitated trains with particular emphasis on the use of superconducting magnets. We present the basic theory for the lift and drag forces of a magnetically levitated vehicle riding over a conducting sheet guideway. To obtain experimental results we have designed and constructed a superconducting magnetically levitated merry-go-round on a laboratory scale. This simple apparatus permits observation of all the principal characteristics of a much larger magnetically levitated vehicle. The “train” consists of six fixed, alternately positively and negatively oriented, superconducting solenoids held in a 2-in diam liquid helium dewar and suspended above a rotating dish track. A simple pan balance measures the levitation force which in this experimental geometry is downward. The track is driven by a small dc motor through a thin-walled stainless steel shaft and pulley. The electrical power into the dc motor gives a measurement of the drag force. The sample disk tracks are threaded onto the end of the steel shaft, allowing the quick interchange of track samples to test different track configurations. Stanford students in the Advanced Applied Physics Laboratory designed and built the apparatus for this highly successful experiment of current interest.
Wave Phenomena in an Acoustic Resonant Chamber
Authors: Smith Mary E. , Moore Thomas W. , Nicholson Howard W.
Published: September 2005

A high Q acoustical resonant chamber which can be used to investigate a wide variety of wave phenomena is described. Several short experiments are discussed and typical results are given in graphical form.