bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study on Control of Accumulators in Web Processing Lines
Authors: Pagilla Prabhakar R. , Singh Inderpal , Dwivedula Ramamurthy V.
Published: December 2004

Design of a stable controller and observer for web tension regulation in an accumulator, in web processing lines, is considered in this paper. A simplified average dynamic model that includes accumulator carriage dynamics, average web tension dynamics in accumulator web spans, and the process and exit side driven roller dynamics is considered in the study. A feedback controller together with an observer for average web tension is proposed. It is shown that the proposed feedback controller and observer results in a stable closed-loop system. Simulation results on an industrial continuous web processing line are given and discussed for the proposed controller/observer and compared with a currently used industrial controller. Applications of this research can be found in web process lines where accumulators are used to store/release material to ensure continuous operation.
Pseudo-Inverse Based Iterative Learning Control for Linear Nonminimum Phase Plants with Unmodeled Dynamics*
Authors: Ghosh Jayati , Paden Brad
Published: December 2004

Learning control is a very effective approach for tracking repetitive processes. In this paper, the stable-inversion based learning controller as presented in (Ghosh, J. and Paden, B., 1999, “Iterative Learning Control for Nonlinear Nonminimum Phase Plants with Input Disturbances,” in Proc. of American Control Conference; Ghosh, J. and Paden, B., 1999, “A pseudo-inverse based Iterative Learning Control for Nonlinear Plants with Disturbances,” in Proc. of 38th Conference on Decision and Control.) is modified to accommodate linear nonminimum phase plants with uncertainties. The design of the learning controller is based on the computation of an approximate inverse of the nominal model of the linear plant, rather than its exact inverse. The advantages of this approach are that the output of the plant need not be differentiated and also the plant model need not be exact. A low pass zero-phase filter is used in the iteration loop to achieve robustness to plant uncertainty. The structure of the controller is such that the low frequency components of the trajectory converge faster than the high frequency components.
Perfectly Matched Feedback Control and Its Integrated Design for Multiaxis Motion Systems
Authors: Yeh Syh-Shiuh , Hsu Pau-Lo
Published: December 2004

For motion systems with multiple axes, the approach of matched direct current gains has been generally adopted to improve contouring accuracy under low-speed operations. To achieve high-speed and high-precision motion in modern manufacturing, a perfectly matched feedback control (PMFBC) design for multiaxis motion systems is proposed in this paper. By applying stable pole-zero cancellation and including complementary zeros for uncancelled zeros for all axes, matched dynamic responses across the whole frequency range for all axes are achieved. Thus, contouring accuracy for multiaxis systems is guaranteed for the basic feedback loops. In real applications, the modeling error is unavoidable and the degradation and limitations of the model-based PMFBC exist. Therefore, a newly designed digital disturbance observer is proposed to be included in the proposed PMFBC structure for each axis to compensate for undesirable nonlinearity and disturbances to maintain the matched dynamics among all axes for the PMFBC design. Furthermore, the feedforward control loops zero phase error tracking controller are employed to reduce tracking errors. Experimental results on a three-axis CNC machining center indicate that both contouring accuracy and tracking accuracy are achieved by applying the present PMFBC design.
Construction of a Set of Nonovershooting Tracking Controllers
Authors: Bement Matt , Jayasuriya Suhada
Published: December 2004

The problem of tracking a known reference without overshooting is of great practical importance in a number of applications. However, nonminimum phase systems and systems with reference inputs other than steps have received very little attention. This paper proposes two different techniques for obtaining a continuous time, nonovershooting, feedback controller for a wide variety of linear single input, single output (SISO) systems, including nonminimum phase systems and systems whose reference input is something other than a step function. These techniques are then used to generate an initial nonovershooting controller from which a set of nonovershooting controllers is obtained. Examples are given to demonstrate all key concepts.
Experimental Study of the Robust Tracking Control of a Shape Memory Alloy Wire Actuator
Authors: Song G. , Quinn D. D.
Published: December 2004

This paper presents an experimental study of a tracking control of a shape memory alloy (SMA) wire actuator using a nonlinear robust compensator. The control design uses the sliding-mode approach and requires no detailed information about the SMA model. To test the effectiveness of the proposed controller, experiments of the tracking control of an SMA wire actuator are conducted. Experimental results show that the SMA wire actuator under the robust control can precisely follow a sinusoidal path, and the effectiveness of the proposed control strategy is thus demonstrated.
Healthcare reforms: implications for the education and training of acute and critical care nurses
Authors: Glen S
Published: December 2004

This paper offers a wide ranging analysis of the drivers that resulted in scrutiny of medical, nursing, and healthcare professional roles. It suggests that what is needed is a coherent vision of the future shape of the health workforce. This requires moving beyond the presumption that reforming working practices primarily involves “delegating doctors” responsibilities to nurses. The paper argues that it is self evident that the implications of changes in healthcare roles and the ability of existing professionals to function effectively in the future will require education, training, and human resource investment supportive of the changes. It suggests a clear definition of competence and a national standard to practice is essential for nurses working in acute and acute critical settings. There should therefore be a correlation between levels of practice, levels of education, and remuneration. Furthermore, education programmes for senior nurses should sit coherently alongside the education programmes required by Modernising Medical Careers. Finally, the realisation of the government’s service and modernisation agenda will require a culture change within higher education institutions, postgraduate deaneries, professional organisations, workforce development confederations, and NHS trusts.
Heart and mind: (1) relationship between cardiovascular and psychiatric conditions
Authors: Shah S U , White A , White S , Littler W A
Published: December 2004

The relationship of our emotions and psyche to heart disease is intriguing. In this article we have reviewed the evidence linking cardiovascular and neuropsychiatric disorders and the possible mechanisms and pathophysiology of this association. This review is derived from Medline searches (1966–2002) using the relevant search terms (psychiatric disease, cardiovascular disease, depression, anxiety, and pathophysiology). Finally, the possible role of using mood enhancing therapies (mainly antidepressants) and their safety in patients with cardiovascular disorders is briefly discussed. In a companion paper, the therapeutic aspects of these two conditions is highlighted.
Transfer of hospitals and “additional premises” to the state: questionable morality in the implementation of the National Health Service Act (1946)
Authors: Cook G C
Published: December 2004

The National Health Service Act of 1946, pioneered by Aneurin Bevan, came into being on the “appointed day”, 5 July 1948. Hospitals with their “additional premises” throughout Britain were “seized” by the state and incorporated into this vast socialist enterprise. While the majority of the population welcomed this new initiative in the creation of a welfare state, associated with medical care from cradle to grave, not all (especially members of various Hospital Boards of Management) were so enthusiastic. The hospitals for “incurables” (long stay patients) were unhappy and lost a vast proportion of their income owing to a great deal of procrastination; but most of them ultimately managed to escape nationalisation after a prolonged period of negotiation, by a claim that they were “homes” rather than “hospitals”. The confiscation of property which had been built as a result of voluntary subscription was another huge and highly contentious matter, which has been highlighted in recent years. The future of the Seamen’s Hospital Society’s properties represents a good example of this.
FOCK REPRESENTATIONS AND QUANTUM MATRICES
Authors: SHKLYAROV D. , SINEL'SHCHIKOV S. , VAKSMAN L.
Published: December 2004

In this paper we study the Fock representation of a certain *-algebra which appears naturally in the framework of quantum group theory. It is also a generalization of the twisted CCR-algebra introduced by Pusz and Woronowicz. We prove that the Fock representation is a faithful irreducible representation of the algebra by bounded operators in a Hilbert space, and, moreover, it is the only (up to unitary equivalence) representation possessing these properties.
MORPHISMS OF SIMPLE TRACIALLY AF ALGEBRAS
Authors: DADARLAT MARIUS
Published: December 2004

Let A, B be separable simple unital tracially AF C*-algebras. Assuming that A is exact and satisfies the Universal Coefficient Theorem (UCT) in KK-theory, we prove the existence, and uniqueness modulo approximately inner automorphisms, of nuclear *-homomorphisms from A to B with prescribed K-theory data. This implies the AF-embeddability of separable exact residually finite-dimensional C*-algebras satisfying the UCT and reproves Huaxin Lin's theorem on the classification of nuclear tracially AF C*-algebras.
SOCIAL CHOICE FOR DATA FUSION
Authors: ZHU SHANFENG , FANG QIZHI , ZHENG WEIMIN
Published: December 2004

Social choice theory is the study of decision theory on how to aggregate separate preferences into group's rational preference. It has wide applications, especially on the design of voting rules, and brings far-reaching influence on the development of modern political science and welfare economics. With the advent of the information age, social choice theory finds its up-to-date application on designing effective Metasearch engines. Metasearch engines provide effective searching by combining the results of multiple source search engines that make use of diverse models and techniques. In this work, we analyze social choice algorithms in a graph-theoretic approach. In addition to classical social choice algorithms, such as Borda and Condorcet, we study one special type of social choice algorithms, elimination voting, to tackle Metasearch problem. Some new algorithms are proposed and examined in the fusion experiment on TREC data. It shows that these elimination voting algorithms achieve satisfied performance when compared with Borda algorithm.
THE DESIGN AND IMPLEMENTATION OF A WEB-BASED TEACHING ASSISTANT SYSTEM
Authors: CHIM H. , CHEN L.
Published: December 2004

When distance learning becomes more and more popular, prodding the students into high and constant motivation has been an interesting research issue these years. In this paper, we introduce a Web-based learning system which provides a dynamic interaction environment for the students to share their information with each other. The system aims to make the distance learning program a fascinating game allowing students to get their scores and ranking interactively.
IMPROVED PARAMETER ESTIMATION FOR VARIANCE-STABILIZING TRANSFORMATION OF GENE-EXPRESSION MICROARRAY DATA
Authors: INOUE MASATO , NISHIMURA SHIN-ICHI , HORI GEN , NAKAHARA HIROYUKI , SAITO MICHIKO , YOSHIHARA YOSHIHIRO , AMARI SHUN-ICHI
Published: December 2004

A gene-expression microarray datum is modeled as an exponential expression signal (log-normal distribution) and additive noise. Variance-stabilizing transformation based on this model is useful for improving the uniformity of variance, which is often assumed for conventional statistical analysis methods. However, the existing method of estimating transformation parameters may not be perfect because of poor management of outliers. By employing an information normalization technique, we have developed an improved parameter estimation method, which enables statistically more straightforward outlier exclusion and works well even in the case of small sample size. Validation of this method with experimental data has suggested that it is superior to the conventional method.
HISTOGRAM-BASED SCORING SCHEMES FOR PROTEIN NMR RESONANCE ASSIGNMENT
Authors: WAN XIANG , TEGOS THEODORE , LIN GUOHUI
Published: December 2004

In NMR protein structure determination, after the resonance peaks have been identified and chemical shifts from peaks across multiple spectra have been grouped into spin systems, associating these spin systems to their host residues is the key toward the success of structural information extraction and thus the key to the success of the structure calculation. To achieve accurate enough structure calculation, a near complete and accurate assignment is a prerequisite. There are two pieces of information that can be used into the assignment, one of which is the adjacency information among the spin systems and the other is the signature information of the spin systems. The signature information reflects the fact that, generally speaking, for one type of amino acid residing in a specific local structural environment, the chemical shifts for the atoms inside the amino acid fall into some very narrow distinct ranges. In most of the existing work, normal distributions are assumed with means and standard deviations statistically collected from the available data. In this paper, we followed a simple yet effective histogram-based way to estimate for every spin system the probability that its host is a certain type of amino acid residing in a certain type of secondary structure. We used two combinations of chemical shifts to demonstrate the effectiveness of this type of histogram-based scoring schemes.
How Well Can Simulation Predict Protein Folding Kinetics and Thermodynamics?
Authors: Snow Christopher D. , Sorin Eric J. , Rhee Young Min , Pande Vijay S.
Published: December 2004

▪ Abstract  Simulation of protein folding has come a long way in five years. Notably, new quantitative comparisons with experiments for small, rapidly folding proteins have become possible. As the only way to validate simulation methodology, this achievement marks a significant advance. Here, we detail these recent achievements and ask whether simulations have indeed rendered quantitative predictions in several areas, including protein folding kinetics, thermodynamics, and physics-based methods for structure prediction. We conclude by looking to the future of such comparisons between simulations and experiments.
HCO3−secretion in the esophageal submucosal glands
Authors: Abdulnour-Nakhoul Solange , Nakhoul Nazih L. , Wheeler Scott A. , Wang Paul , Swenson Eric R. , Orlando Roy C.
Published: December 2004

The mammalian esophagus has the capacity to secrete a HCO3−and mucin-rich fluid in the esophageal lumen. These secretions originate from the submucosal glands (SMG) and can contribute to esophageal protection against refluxed gastric acid. The cellular mechanisms by which glandular cells achieve these secretions are largely unknown. To study this phenomenon, we used the pH-stat technique to measure luminal alkali secretion in an isolated, perfused pig esophagus preparation. Immunohistochemistry was used to localize receptors and transporters involved in HCO3−transport. The SMG-bearing esophagus was found to have significant basal alkali secretion, predominantly HCO3−, which averaged 0.21 ± 0.04 μeq·h−1·cm−2. This basal secretion was doubled when stimulated by carbachol but abolished by HCO3−or Cl−removal. Basal- and carbachol-stimulated secretions were also blocked by serosal application of atropine, pirenzipine, DIDS, methazolamide, and ethoxzolamide. The membrane-impermeable carbonic anhydrase inhibitor benzolamide, applied to the serosal bath, partially inhibited basal HCO3−secretion and blocked the stimulation by carbachol. Immunohistochemistry using antibodies to M1cholinergic receptor or carbonic anhydrase-II enzyme showed intense labeling of duct cells and serous demilunes but no labeling of mucous cells. Labeling with an antibody to Na+-(HCO3−)n(rat kidney NBC) was positive in ducts and serous cells, whereas labeling for Cl−/HCO3−exchanger (AE2) was positive in duct cells but less pronounced in serous cells. These data indicate that duct cells and serous demilunes of SMG play a role in HCO3−secretion, a process that involves M1cholinergic receptor stimulation. HCO3−transport in these cells is dependent on cytosolic and serosal membrane-bound carbonic anhydrase. HCO3−secretion is also dependent on serosal Cl−and is mediated by DIDS-sensitive transporters, possibly NBC and AE2.
Effects of cortisol on cardiac myocytes and on expression of cardiac genes in fetal sheep
Authors: Lumbers E. R. , Boyce A. C. , Joulianos G. , Kumarasamy V. , Barner E. , Segar J. L. , Burrell J. H.
Published: December 2004

In 17 fetal sheep aged 129 days, the effects of large-dose infusions of cortisol (72.1 mg/day for 2–3 days) on proliferation, binucleation, and hypertrophy of cardiac myocytes, cardiac expression of angiotensinogen, angiotensin receptor subtypes 1 and 2, Glut-1, glucocorticoid and mineralocorticoid receptors, proteins of the MAPK pathways and calcineurin were studied. Cortisol levels were 8.7 ± 2.3 nM (SE) in 8 control and 1,028 ± 189 nM in 9 treated fetuses ( P < 0.001). Cortisol had no effect on myocyte binucleation. Left ventricular free wall (LVFW) uni- and binucleated myocytes were larger in cortisol-treated fetuses ( P < 0.001, P < 0.05). Cortisol-treated fetuses had higher right ventricular free wall (RVFW) and LVFW angiotensinogen (Aogen) mRNA levels (treated: 2.30 ± 0.37, n = 8 and 2.05 ± 0.45, n = 7 vs. control: 0.94 ± 0.12, n = 8 and 0.67 ± 0.09, n = 7, P < 0.02). Levels of the glucose transporter Glut-1 mRNA were lower in the LVFW of treated fetuses (0.83 ± 0.23 vs. 1.47 ± 0.30 in control, P < 0.05, n = 7, 8). The higher the cortisol level, the greater the Aogen mRNA level (RVFW, r = 0.61, P < 0.01, n = 16; LVFW, r = 0.83, P < 0.0003, n = 14). There were no other changes in mRNA levels nor in levels of extracellular kinase, JNK, p38, their phosphorylated forms, and calcineurin. Thus high levels of cortisol such as occur after birth do not affect fetal cardiac myocyte binucleation or number but are associated with higher levels of ventricular Aogen mRNA, lower levels of Glut-1 mRNA, and hypertrophy of LVFW myocytes. These effects could impact on postnatal cardiac development.
Energetics of high-speed running: integrating classical theory and contemporary observations
Authors: Weyand Peter G. , Bundle Matthew W.
Published: December 2004

We hypothesized that the anaerobic power and aerobic power outputs during all-out runs of any common duration between 10 and 150 s would be proportional to the maximum anaerobic (Ėan-max) and aerobic powers (Ėaer-max) available to the individual runner. Seventeen runners who differed in Ėan-max and Ėaer-max (5 sprinters, 5 middle-distance runners, and 7 long distance runners) were tested during treadmill running on a 4.6° incline. Ėan-max was estimated from the fastest treadmill speed subjects could attain for eight steps. Ėaer-max was determined from a progressive, discontinuous, treadmill test to failure. Oxygen deficits and rates of uptake were measured to assess the respective anaerobic and aerobic power outputs during 11–16 all-out treadmill runs that elicited failure between 10 and 220 s. We found that, during all-out runs of any common duration, the relative anaerobic and aerobic powers utilized were largely the same for sprint, middle-distance, and long-distance subjects. The similar fractional utilization of the Ėan-max and Ėaer-max available during high-speed running 1) provides empirical values that modify and advance classic theory, 2) allows rates of anaerobic and aerobic energy release to be quantified from individual maxima and run durations, and 3) explains why the high-speed running performances of different event specialists can be accurately predicted ( R2 = 0.97; n = 254) from two direct measurements and the same exponential time constant.
Intermedin/adrenomedullin-2 acts within central nervous system to elevate blood pressure and inhibit food and water intake
Authors: Taylor Meghan M. , Bagley Sara L. , Samson Willis K.
Published: December 2004

Intermedin (IMD)/adrenomedullin-2 (AM2) is a novel peptide that was independently discovered by two groups. The 47-amino acid peptide is homologous to adrenomedullin (AM) and can activate both the AM and calcitonin gene-related peptide (CGRP) receptors. IMD should therefore have actions similar to those of AM and CGRP. Indeed, like AM and CGRP, intravenous administration of IMD decreased blood pressure in rats and mice. We demonstrate here that immunoreactive IMD is present in plasma as well as heart, lung, stomach, kidney, pituitary, and brain. Because IMD is present in brain and both AM and CGRP have potent central nervous system (CNS) effects, we examined the ability of IMD within brain to regulate blood pressure and ingestive behaviors. Administration of IMD into the lateral cerebroventricle of rats caused significant, long-lasting elevations in mean arterial pressure and heart rate. These elevations are similar to the effects of CGRP and significantly greater than the effects of AM. IMD-induced elevations in mean arterial pressure were inhibited by intravenous administration of phentolamine, indicating that IMD activates the sympathetic nervous system. Intracerebroventricular administration of IMD also inhibited food and water intake in sated and in food- and water-restricted animals. The effects on feeding are likely related to activation of the CGRP receptor and are independent of the effects on water intake, which are likely through the AM receptor. Our data indicate that IMD has potent actions within the CNS that may be a result of the combined activation of both AM and CGRP receptors.
Hepatitis B Genotypes in Chronic Hepatitis B and Lamivudine Therapy
Authors: Yuen Man-Fung , Tanaka Yasuhito , Lai Ching-Lung
Published: December 2004

The influence of hepatitis B virus (HBV) genotypes on the natural history and the response to treatment of patients with chronic hepatitis B are of potential interest. Compared to the patients with HBV genotype C, those with genotype B were of a younger age and had a higher cumulative rate of hepatitis B e antigen (HBeAg) seroconversion during the initial 6 years of follow-up. The earlier HBeAg seroconversion in the patients with genotype B, however, did not provide them with a benefit in terms of a reduced risk of developing long-term complications. The response to lamivudine therapy was evaluated in 21 patients infected with HBV genotype B (all of subtype Ba) and 61 with genotype C. There were no differences in the virological response to lamivudine therapy, based on the reduction in median logarithmic HBV DNA titer as well as alanine aminotransferase (ALT) levels, normalization of ALT and the rate of HBeAg seroconversion between the patients with genotypes B and C. No differences were noted either, in the frequency of YMDD mutants at week 52 or the cumulative risk of HBV DNA breakthroughs with YMDD mutations during long-term lamivudine therapy (median 37.5 months). In conclusion, there is no influence of HBV genotypes on the development of long-term complications and lamivudine therapy in Hong Kong.
Interferon Therapy for 2 Years or Longer Reduces the Incidence of Hepatocarcinogenesis in Patients with Chronic Hepatitis C Viral Infection
Authors: Arase Yasuji , Ikeda Kenji , Tsubota Akihito , Suzuki Fumitaka , Suzuki Yoshiyuki , Saitoh Satoshi , Kobayashi Masahiro , Akuta Norio , Someya Takashi , Hosaka Tetsuya , Sezaki Hitomi , Kobayashi Mariko , Kumada Hiromitsu
Published: December 2004

Objective: The purpose of this clinical study was to determine the effect of long-term interferon (IFN) administration on the incidence of hepatocellular carcinomas (HCC) in chronic hepatitis C patients, without eradication of hepatitis C virus (HCV) by IFN therapy. Methods: The number of patients with biopsy-proven chronic hepatitis with moderate or severe staging, HCV genotype 1b, a high viral load exceeding 1 MEq/ml (mega equivalents per milliliter), who received 6 MU of natural IFN-α daily for 2–8 weeks, followed by three times/week for 16–22 weeks, as initial IFN therapy, and positivity for HCV RNA during IFN administration was 131. 47 of the 131 patients continued to be treated with IFN (long-term IFN group, dose 3 or 6 MU twice or three times weekly for 1.5–10.5 years, median 4.0 years) after initial IFN therapy, while 84 patients did not receive any IFN therapy apart from the initial 6-month course (no-add-IFN group). The patients were prospectively monitored, and the cumulative incidence of HCC and risk factors for HCC were examined. Results: The 5- and 10-year cumulative rates of HCC were 1.9 and 6.4% and 1.9 and 26.8% for long-term IFN and no-add-IFN groups, respectively. Cox regression analysis indicated that the relative risk of HCC in the patients of the no-add-IFN group was 8.72 times of that in patients of the long-term IFN group. Conclusion: Long-term IFN therapy in patients with chronic HCV infection is effective in preventing hepatocarcinogenesis.
Adefovir Dipivoxil for Treatment of Breakthrough Hepatitis Caused by Lamivudine-Resistant Mutants of Hepatitis B Virus
Authors: Hosaka Tetsuya , Suzuki Fumitaka , Suzuki Yoshiyuki , Saitoh Satoshi , Kobayashi Masahiro , Someya Takashi , Sezaki Hitomi , Akuta Norio , Tsubota Akihito , Arase Yasuji , Ikeda Kenji , Kumada Hiromitsu
Published: December 2004

Objective: Adefovir dipivoxil (ADV) is a nucleoside analogue that inhibits wild-type hepatitis B virus (HBV) and lamivudine-resistant HBV mutants in vitro and in vivo. The aim of this study was to evaluate the efficacy of ADV against lamivudine-resistant mutants and of adefovir and interferon (IFN) add-on to lamivudine for patients with severe acute exacerbation of hepatitis caused by lamivudine-resistant mutants. Methods: Fourteen patients with breakthrough hepatitis were treated with ADV. Four of the 14 patients also received IFN as combined treatment for severe acute exacerbation of hepatitis. Results: At week 24, serum HBV DNA levels had significantly decreased by a median of over 4.8 log copies/ml in the ADV group and over 5.9 log copies/ml in the ADV + IFN group compared to baseline. The median decrease in alanine aminotransferase (ALT) levels from baseline to week 24 was –1.05 times the upper limit of normal (ULN) in the ADV group [significant at week 24 compared with baseline (p = 0.012)] and –22.3 times the ULN in the ADV + IFN group. Conclusions: Administration of ADV add-on to lamivudine for patients with breakthrough hepatitis reduced HBV DNA and ALT levels. ADV and IFN add-on to lamivudine could prevent a fatal course in patients with severe acute exacerbation of hepatitis.
Prevalence of Hepatitis B and Hepatitis CViral Infections in Indian Patients with Chronic Renal Failure
Authors: Chandra Madhavi , Khaja Mohammad Nanne , Hussain Mohammad Mehaboob , Poduri Chetan Datta , Farees Nafeesa , Habeeb Mohammad Aejaz , Krishnan Srinivasan , Ramareddy Guntaka Venkata , Habibullah Chittoor Mohammad
Published: December 2004

The present study reports prevalence of posttransplant hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in 256 patients with chronic renal failure (CRF) and with a history of either renal transplant or hemodialysis. Out of 256 patients 138 had renal transplant and 118 were on maintenance hemodialysis. Among the patients screened, 7% had HBV infection alone, 46% were infected with HCV alone, while 37.10% were found to have co-infection of both the viruses. Our findings implicate these viruses as the major cause of posttransplant hepatitis in Indian patients with CRF and indicate implementation of stringent screening procedures for these two viral infections.
Immunomodulatory Therapy in Ophthalmology – Is There a Place for Topical Application?
Authors: Bertelmann Eckart , Pleyer Uwe
Published: December 2004

Topical corticosteroids, although effective in the treatment of ocular immune-mediated diseases, are well known for their ocular side-effects. Not surprisingly, a variety of alternative immunomodulatory agents have been tested for topical use including cyclosporin A (CsA), mycophenolate mofetil (MMF), tacrolimus (FK506), rapamycin (sirolimus) and leflunomide. Local application bears the possibility to avoid the severe side-effects of systemic therapy. The effect of topical therapy is naturally restricted to local immune response mechanisms, such as antigen presentation by Langerhans and dendritic cells. Moreover, many immunomodulatory agents (e.g. CsA) are lipophilic and thus have low water solubility and penetrate insufficiently intra-ocularly, often being stored in the lipophilic corneal epithelial barrier. Therefore, the therapeutical success is limited for intra-ocular immune-mediated diseases like anterior uveitis. However, a multitude of strategies have been introduced to circumvent these problems including complexing substances such as cyclodextrins (CDs) and liposomes. In the prevention and treatment of transplant rejection after keratoplasty, many attempts to introduce topical immunomodulatory therapy have failed; on the other hand, further therapeutic options not primarily expected are being evaluated today such as treatment of severe keratoconjunctivitis sicca. In our own studies, we investigated the pharmacokinetics of topical treatment with different agents including MMF and evaluated the efficacy of topical treatment in animal models for uveitis and keratoplasty. Taken together, topical immunomodulatory therapy will not replace systemic therapy but further treatment options can be expected.
Retinal Peripapillary Blood Flow before and after Topical Brinzolamide
Authors: Iester Michele , Altieri Michele , Michelson Georg , Vittone Paolo , Traverso Carlo E. , Calabria Giovanni
Published: December 2004

Purpose: To study the effect of topical brinzolamide on retinal capillary blood flow by the Heidelberg Retina Flowmeter (HRF) in patients with glaucoma. Methods: Twenty patients with glaucoma were consecutively recruited. One eye for each patient was randomly selected. Patients were classified as glaucomatous if they had an abnormal visual field and/or an abnormal optic nerve head with an intraocular pressure (IOP) greater than 21 mm Hg without any treatment. After an eye examination, baseline retinal blood flow measurements were made with confocal scanning laser Doppler flowmetry. Blood flow and IOP measurements were then repeated after 1 month of treatment. Blood flow measurements were analyzed by using an automatic full-field perfusion image analysis (AFFPIA) program. The blood flow was calculated in the superior and inferior part of the optic disk. In each area, the blood flow was calculated as temporal area, the nasal area and the rim area as for software AFFPIA. Results: The mean age of the patients was 56 ± 7 (mean ± standard deviation) years. The mean IOP before treatment was 23.7 ± 1.5 mm Hg while the mean IOP after 4 weeks of treatment was 19.1 ± 2.2 mm Hg. This difference was statistically significant (p < 0.01). Significant (p < 0.05) increases in retinal blood flow were found for the temporal and nasal areas between baseline and 1 month after the treatment. No difference was found between superior and inferior sectors. Conclusion: Topical brinzolamide reduced the IOP significantly and apparently improved retinal blood flow as measured by the HRF.
Visual Acuity in Premature Infants
Authors: Spierer Abraham , Royzman Zana , Kuint Jacob
Published: December 2004

Purpose: To measure grating visual acuity in premature infants and compare it with that in full-term infants. Methods: The visual acuity of 73 premature and 73 full-term infants was tested at 6 months of age by the Teller Acuity Card procedure. All premature infants had undergone indirect funduscopy for the detection of retinopathy of prematurity (ROP). Seven infants had developed ROP. The mean gestational age of the premature infants was 33 ± 1.4 weeks as compared with 39.9 ± 0.9 weeks in the full-term infants. The mean birth weights of the 2 groups were 1,906 ± 412 and 3,244 ± 420 g, respectively. Results: Impaired binocular visual acuity was found in 53.4% of the premature infants, but in only 11% of the full-term infants (p < 0.0001). Impaired monocular visual acuity was found in 13.7% of the premature infants as compared with 2.7% of the full-term infants. Within the premature infant group, monocular visual acuity was impaired in 42.9% of those with ROP and in 10.6% of those without ROP (p = 0.0497). Pathological refraction was found in 33.3% of the prematures without ROP and in 14.3% of the prematures with ROP. This difference was not statistically significant. Visual acuity of preterm infants was not different from full-term infants when examined at 6 months of postconceptual age. Conclusions: Both monocular and binocular visual acuities as measured by the Teller Acuity Cards are worse in premature infants than in full-term infants at the same chronological age. Poor visual acuity in premature infants can be attributed mainly to immaturity of the visual system.
The Medial Horn and Capsulopalpebral Fascia in the Medial Canthus Are Significant Antagonists of the Orbicularis Oculi Muscle for Lacrimal Drainage
Authors: Kakizaki Hirohiko , Zako Masahiro , Nakano Takashi , Asamoto Ken , Iwaki Masayoshi
Published: December 2004

Purpose: The anatomical relationship indicates that the medial horn of the levator aponeurosis (MH) and the capsulopalpebral fascia (CPF) are the potential candidates for antagonists of the orbicularis oculi muscle (OOM). This study sought to disclose the relationships among the MH, CPF and OOM, and to discuss their roles in the lacrimal drainage system. Methods: Twelve medial canthuses of 6 cadavers were studied. After peeling eyelid skin from the OOM, we carefully observed the MH, CPF and OOM in the medial canthus. Results: The MH attached to the superior aspect of the medial canthal tendon. The CPF, which attached to the lower tarsal margin, traveled just under Horner’s muscle in the medial canthus and dispersed from a lateral aspect of the lacrimal sac to the posterior lacrimal crest. Conclusions: As the movement of a muscle can be determined by its origin and insertion, the MH and the CPF are considered to be the antagonists of the OOM, and as such must be taken into consideration for an understanding of the lacrimal drainage system.
Systemic Melanoma Metastatic to the Retina and Vitreous
Authors: Zografos Leonidas , Mirimanoff René-Olivier , Angeletti Carlo Alberto , Frosini Riccardo , Beati Donata , Schalenbourg Ann , Chamot Line
Published: December 2004

Purpose: Report of a case of retinal and vitreous metastases of a systemic melanoma, possibly arising in the lung, that responded favourably to radiotherapy. Case Report: Retinal and vitreous metastases were demonstrated in a 57-year-old woman during routine follow-up after surgical resection of a melanoma presumed to be a primary pulmonary melanoma. After a 7-week observation period, which confirmed the progressive nature of the intra-ocular lesions, the patient was treated by external beam radiotherapy at a dose of 35 Gy delivered in 14 fractions of 2.5 Gy. Complete disappearance of the vitreous invasion and progressive elimination of the retinal invasion were observed over a period of 9 months. Final visual function was 20/25. Review of Published Cases: A review of the literature identified 28 cases of melanoma with metastases to the retina and vitreous. In almost all of these cases, the primary tumour was a cutaneous melanoma and the mean patient survival following the diagnosis of intra-ocular metastases was 22 months. Retinal metastases, as in the case reported here, present a vascular tropism and tend to develop around veins. These metastases are generally unilateral and may be either solitary or multiple. Tumour invasion of the vitreous occurred by means of isolated cells forming a suspension of aggregates or spherules. Vitreous haemorrhage and irreducible neovascular glaucoma leading to functional impairment, which requires enucleation, were both the most frequent and the most serious complications of these metastases. Treatment is always palliative and is effective in cases with limited retinal and vitreous invasion, as in the case reported here. Conclusions: Metastatic melanoma in the retina and vitreous is a rare entity and can lead to functional impairment and enucleation because of neovascular glaucoma. As treatment is only effective in cases with limited invasion, systematic screening is recommended in all patients with a metastatic cutaneous melanoma presenting with suggestive ocular symptoms.
Cellular Reactions of Osteoblasts to Micron- and Submicron-Scale Porous Structures of Titanium Surfaces
Authors: Zhu Xiaolong , Chen Jun , Scheideler Lutz , Altebaeumer Thomas , Geis-Gerstorfer Juergen , Kern Dieter
Published: December 2004

Osteoblast reactions to topographic structures of titanium play a key role in host tissue responses and the final osseointegration. Since it is difficult to fabricate micro- and nano-scale structures on titanium surfaces, little is known about the mechanism whereby the topography of titanium surfaces exerts its effects on cell behavior at the cellular level. In the present study, the titanium surface was structured in micron- and submicron-scale ranges by anodic oxidation in either 0.2 M H3PO4 or 0.03 M calcium glycerophosphate with 0.15 calcium acetate. The average dimensions of pores in the structured surface were about 0.5 and 2 µm in diameter, with roughness averaging at 0.2 and 0.4 µm, respectively. Enhanced attachment of cells (SaOS-2) was shown on micron- and submicron-scale structures. Initial cell reactions to different titanium surfaces, e.g. the development of the actin-containing structures, are determined by the different morphology of the surfaces. It is demonstrated that on either micron- or submicron-structured surfaces, many well-developed filopodia were observed to be primary adhesion structures in cell-substrate interactions, and some of them entered pores using their distinct tips or points along their length for initial attachment. Therefore, porous structures at either micro- or submicrometre scale supply positive guidance cues for anchorage-dependent cells to attach, leading to enhanced cell attachment. In contrast, the cells attached to a smooth titanium surface by focal contacts around their periphery as predominant adhesion structures, since repulsive signals from the environment led to retraction of the filopodia back to the cell bodies. These cells showed well-organized stress fibres, which exert tension across the cell body, resulting in flattened cells.
Purinergic Signalling to Rat Ovarian Smooth Muscle: Changes in P2X Receptor Expression during Pregnancy
Authors: Katugampola Harshini , Burnstock Geoffrey
Published: December 2004

The expression of P2X and P2Y receptor subtypes in the smooth muscle of the rat ovary during the oestrus cycle and pregnancy was examined using immunohistochemistry. RT-PCR studies of P2X receptor mRNA were also carried out. In the non-pregnant rats, P2X2 receptor protein was dominant in the smooth muscle of perifollicular rings and blood vessels. P2X1 protein expression was seen on vascular smooth muscle too, but little, if any, was present on perifollicular smooth muscle. No changes in P2X1 or P2X2 receptor expression were seen during the oestrous cycle. During early and mid-late pregnancy, there was a switch from P2X2 to P2X1 receptor protein expression in the smooth muscle of the perifollicular ring; P2X1 receptors were also more prominently expressed than P2X2 receptors on ovarian vascular smooth muscle in non-pregnant animals, but during late pregnancy the expression of P2X2 receptors was found to equal that of the P2X1 receptors. There was a return to non-pregnant P2 receptor subtype distribution 2 days after birth. Ovarian vascular and perifollicular smooth muscle showed immunoreactivity for P2Y1, but not for P2X3–7, P2Y2 or P2Y4 receptors. P2Y1 receptor expression in ovarian smooth muscle of both blood vessels and follicular rings did not show significant changes during the oestrus cycle or pregnancy. RT-PCR studies indicated that P2X1 and P2X2 receptor mRNA was present in the ovary during pregnant and non-pregnant conditions. P2X4–6 receptor mRNA was also present in all stages studied, however no immunostaining showing receptor protein for these subtypes was seen on the ovarian sections examined. In summary, purinergic signalling to ovarian perifollicular smooth muscle changed from P2X2 to P2X1 receptors during pregnancy, while there was an increase in P2X2 receptor expression on vascular smooth muscle.
Transglottic Acinic Cell Carcinoma
Authors: Boscolo-Rizzo Paolo , da Mosto Maria Cristina , Marchiori Carlo , Boccato Paolo
Published: December 2004

Acinic cell carcinoma (ACC) is a rare tumor generally involving the parotid gland and infrequently the minor salivary glands with the potential for both local recurrence and metastatic spread when tracked for decades. The biological behavior of ACC cannot be predicted on the basis of histological features, and surgical stage is still the best predictor of clinical outcome. Only 5 cases of ACC of the larynx have been reported in the English literature. The authors present a case of a rare transglottic ACC in a 74-year-old woman. At admission, a submucosal mass involving the left arytenoid and adjacent aryepiglottic fold was noted. A CT scan of the head and neck region showed a mass of the left hemilarynx involving the paraglottic space and extending from the aryepiglottic fold to the sinus piriformis. Definitive histopathological examination showed an ACC with a large amount of clear cells. The patient was treated by radiotherapy alone (66 Gy in 7 weeks) with complete remission.
Investigation of the Use of Positron Emission Tomography for Neuroreceptor Imaging in Rabbit Eyes
Authors: Wang Wei-Fang , Ishiwata Kiichi , Kiyosawa Motohiro , Kawamura Kazunori , Oda Keiichi , Matsuno Kiyoshi , Kobayashi Tadayuki , Mochizuki Manabu
Published: December 2004

To determine whether positron emission tomography (PET) can be used for imaging of neuroreceptors in eyes of rabbits. PET imaging of dopamine D2 receptor, dopamine transporter, serotonin1A receptor and sigma1 receptor in the eyes and brain was performed using corresponding positron-emitting ligands in baseline, pretreatment and displacement conditions. The 4 radioligands outlined the eyes and brain in the baseline. Pretreatment resulted in a slight reduction (26–28%) in the uptake in the anterior segments of eyes. The binding of each radioligand in the iris-ciliary body and retina was confirmed by ex vivo autoradiography. However, the PET signal in the eyes was unexpectedly higher than the autoradiography signal. The identification of radioligand-neuroreceptor binding by PET in the rabbit eyes is not specific enough.
Corneal Cell Density Measurement in vivo by Scanning Slit Confocal Microscopy: Method and Validation
Authors: Popper Mónika , Morgado António Miguel , Quadrado Maria João , van Best Jaap A.
Published: December 2004

Purpose: Method and validation of a technique to quantify cell density in vivo in 6 corneal layers with a scanning slit confocal microscope (SSCM). Method: A confocal image of a small volume in a corneal layer is registered on videotape. Cells or nuclei according to a layer classification are counted manually using an unbiased frame. Surface cell density is calculated from an image on the screen, and volumetric density is obtained using stereological methods. Results: Image distortion on the screen is less than 3%. The classification of a cell layer is verified by determining the position of the measurement volume in the cornea. Validation of density measurements is performed by comparing confocal results with those obtained by histology. The difference between the two methods varies from –24.1% (posterior stroma) to +16.4% (basal layer). Intersession and intrasession repeatability are 8.3 and 5.8%, respectively. The cell density (mean ± SD) in 20 healthy controls in the superficial, basal and endothelial layers was 759 ± 162, 5,817 ± 632 and 2,743 ± 285 cells·mm–2 (surface), and in the anterior, mid and posterior stroma 28,616 ± 3,081, 19,578 ± 4,421 and 26,073 ± 5,962 cells·mm–3 (volumetric). These results are in accordance with those of other investigators. Conclusions: The SSCM can produce repeatable quantitative measurements of corneal cell density in conscious humans.
Cyclosporin A-Associated Changes in Red Blood Cell Membrane Composition, Deformability, Blood and Plasma Viscosity in Rats
Authors: Ademoglu Evin , Tamer Sule , Albeniz Isil , Gokkusu Cahide , Tanrikulu Sevda
Published: December 2004

Most of the studies concerning the effects of cyclosporin A (Cs A) on red blood cell (RBC) rheology were carried out in human transplant recipients who may still have residual insufficiency and concomitant administration of other immunosuppressive and antihypertensive drugs. The aim of this study is to evaluate the effects of Cs A on red cell rheology and membrane composition in nontransplant healthy rats. Female Wistar albino rats were divided into two groups of 10 animals each. Rats received 10 mg/kg Cs A, i.p. or saline for 4 weeks. Cs A administration significantly increased the RBC deformability, and plasma and blood viscosity (p < 0.001, p < 0.01 and p < 0.01, respectively). Cs A administration to the rats increased RBC membrane cholesterol (CHO) levels and the CHO/phospholipid (PL) ratio significantly (p < 0.01 and p < 0.05, respectively) but did not change RBC membrane proteins and membrane PL levels. These results suggest that Cs A changes the rheological functions of RBC and lipid content of RBC membrane in healthy rats and thereby it may play an important role in the regulation of microcirculation.
Predictors of Delayed Therapy after Expectant Management for Localized Prostate Cancer in the Era of Prostate-Specific Antigen
Authors: Panagiotou Irene , Beer Tomasz M. , Hsieh Yi-Ching , Mori Motomi , Peters Laura , Klein Thomas , Garzotto Mark
Published: December 2004

Objective: To identify risk factors for delayed cancer-directed intervention in modern era prostate cancer patients who initially elect expectant management. Materials and Methods: An observational, cohort study of expectantly managed patients, diagnosed with clinical T1–4NxM₀ prostate cancer between 1993 and 2000 was carried out. Data including TNM stage, age, serum prostate-specific antigen (PSA), prostate gland volume by transrectal ultrasound, Gleason score, percent biopsies positive for cancer, imaging results, initial treatment selection, and outcome data were collected on all patients. Results: 192 of 561 patients (34.3%) elected expectant management, and follow-up data were available for 187 (97.4%) patients. With a median follow-up of 3.6 years, 90 (48.1%) patients had a cancer-directed intervention. Gleason score (p = 0.0097) and percent of positive biopsy cores (p = 0.03) were independent predictors of time to intervention. As expected, PSA doubling time became the most significant predictor of intervention (p = 0.0057) when added to the model. These independent covariates are able to characterize low-, intermediate- and high-risk groups for cancer-directed intervention. Conclusions: Cancer-directed intervention is common in patients who choose expectant management in the PSA era. Gleason score and percent of positive biopsy cores predict cancer-directed interventions, thus, these patients may be least suitable for expectant management.