bluuebunny/crossref_metadata_2025 huggingface dataset:
Fibrillar prion peptide (106–126) and scrapie prion protein hamper phagocytosis in microglia
Authors: Ciesielski‐Treska Jaroslava , Grant Nancy J. , Ulrich Gabrielle , Corrotte Matthias , Bailly Yannick , Haeberle Anne‐Marie , Chasserot‐Golaz Sylvette , Bader Marie‐France
Published: March 2004

The inflammatory response in prion diseases is dominated by microglial activation. As macrophages of the central nervous system, the phagocytic capacity of microglia is well recognized, and it is possible that microglia are involved in the removal and processing of amyloid fibrils, thus preventing their harmful effect. We have analyzed the effects of a synthetic peptide of the human prion protein, PrP(106–126), which can form fibrils, and the pathogenic form of prion protein, PrPsc, on phagocytosis in microglia isolated from neonatal rat brain cultures. To some extent, fibrillar PrP(106–126) is internalized and processed. However, both synthetic prion peptide PrP(106–126) in a fibrillar form and pathogenic prion protein PrPsc severely hamper the phagocytic activity as measured by the uptake of beads by microglia. At a concentration that does not induce microglial death, PrP(106–126) reduced the number of beads internalized and altered their cytoplasmic distribution. This effect was not due to decreased binding of beads to the cell surface, nor restricted to specific classes of receptors. Although the PrP(106–126) did not prevent F‐actin and Rac1 accumulation at sites of particle engulfment, it appeared to interfere with a later step of the internalization process. © 2004 Wiley‐Liss, Inc.
Glutamine‐induced free radical production in cultured astrocytes
Authors: Jayakumar Arumugam R. , Rama Rao K.V. , Schousboe Arne , Norenberg Michael D.
Published: March 2004

Ammonia is a neurotoxin implicated in the pathogenesis of hepatic encephalopathy, Reye's syndrome, inborn errors of the urea cycle, glutaric aciduria, and other metabolic encephalopathies. Brain ammonia is predominantly metabolized to glutamine in astrocytes by glutamine synthetase. While the synthesis of glutamine has generally been viewed as the principal means of ammonia detoxification, this presumed beneficial effect has been questioned as growing evidence suggest that some of the deleterious effects of ammonia may be mediated by glutamine rather than ammonia per se. Since ammonia is known to induce the production of free radicals in cultured astrocytes, we investigated whether such production might be mediated by glutamine. Treatment of astrocytes with glutamine (4.5 mM) increased free radical production at 2–3 min (95%;P< 0.05), as well as at 1 and 3 h (42% and 49%, respectively;P< 0.05). Similarly treated cultured neurons failed to generate free radicals. Free radical production by glutamine was blocked by the antioxidants deferoxamine (40 μM) and α‐phenyl‐N‐tert‐butyl‐nitrone (250 μM), as well as by the nitric oxide synthase inhibitor Nω‐nitro‐L‐arginine methyl ester (500 μM). Free radical production was also blocked by 6‐diazo‐5‐oxo‐L‐norleucine (1 mM), an inhibitor of glutaminase, suggesting that ammonia released by glutamine hydrolysis may be responsible for the generation of free radicals. Additionally, the mitochondrial permeability transition inhibitor, cyclosporin A, blocked free radical production by glutamine. The results indicate that astrocytes, but not neurons, generate free radicals following glutamine exposure. Glutamine‐induced oxidative and/or nitrosative stress may represent a key mechanism in ammonia neurotoxicity. © 2004 Wiley‐Liss, Inc.
Internal architecture, origin‐insertion site, and mass of jaw muscles in Old World hamsters
Authors: Satoh Kazuhiko , Iwaku Fumihiko
Published: March 2004

The jaw muscle (i.e., masticatory, suprahyoid, and extrinsic tongue) anatomy and mass were examined in four genera of Old World hamsters (cricetine murids), Mesocricetus, Cricetulus, Tscherskia, and Phodopus. The masseter was the largest and most complicated of the muscles examined. In the superficial layer, a few ventral fibers form a small medially turned portion with an insertion site more similar to those of sciurids than of other murids. In Mesocricetus, the superficial layer has a discrete anteroventral portion that has not been reported for other murid rodents. Examination of the fiber attachment sites indicated that the deep layer contains four parts and the medial layer contains three parts. The deep layer originates from two aponeuroses that are firmly connected to each other at their anterior ends and lie along the zygomatic arch. The aponeurosis of insertion for the deep layer is situated along the masseteric ridge and the dorsal border of the angular process, but is absent in its middle part, consistent with reports in two relatives, sigmodontine and arvicoline murids. In cricetine murids, unlike in other rodents, fibers insert on the dorsal narrow strip of the posterior mandibular aponeurosis, not on its broad medial aspect. The relative mass of some masticatory and suprahyoid muscles is related to body mass. Small species (Cricetulus and Phodopus) have relatively larger masseter and mylohyoid muscles and smaller temporalis and geniohyoid muscles than large species (Mesocricetus and Tscherskia). J. Morphol. 260:101–116, 2004. © 2004 Wiley‐Liss, Inc.
Mechanical functions of setae from the mouth apparatus of seven species of decapod crustaceans
Authors: Garm Anders
Published: March 2004

The mouthpart setae of seven species of decapods were examined with macro‐video recordings and scanning electron microscopy. The general mechanical (nonsensory) functions of the different mouthparts are described and an account of their setation is given. This offers the possibility to determine the mechanical functions of the different types of setae. Pappose setae do not participate in food handling but in general make setal barriers. Plumose setae likewise do not contact food objects but assist in current generation. Papposerrate setae are rare but they were seen to assist in pushing food particles into the mouth. Serrulate setae are very common and mainly participate in gentle food handling and grooming. Serrate setae are used for more rough food manipulation and grooming. The roughest shredding, tearing, and manipulation of prey items are handled by the cuspidate setae. Simple setae seem to be divided into two populations with very different functions. On the maxillipeds of Panulirus argus they are used for shredding, tearing, and holding the food objects, but on the basis of maxilla 2 of three other species they appear to have very little mechanical influence and only when handling small prey items. The functional scheme seems to be consistent within the Decapoda. J. Morphol. 260:85–100, 2004. © 2004 Wiley‐Liss, Inc.
Chemokine receptors are expressed widely by embryonic and adult neural progenitor cells
Authors: Tran Phuong B. , Ren Dongjun , Veldhouse Thomas J. , Miller Richard J.
Published: March 2004

We investigated the expression and functions of chemokine receptors in neural progenitor cells isolated from embryonic and adult mice. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis demonstrated mRNA expression for most known chemokine receptors in neural progenitor cells grown as neurospheres from embryonic (E17) and adult (4‐week‐old) mice. The expression of CXCR4 receptors was demonstrated further in E17 neurospheres using immunohistochemistry, in situ hybridization, Northern blot analysis and fura‐2‐based Ca2+ imaging. Most neurospheres grown from E17 mice responded to stromal cell‐derived factor‐1 (SDF‐1/CXCL12) in Ca2+ imaging studies. In addition, immunohistochemical studies demonstrated that these neurospheres consisted of dividing cells that uniformly colocalized nestin and CXCR4 receptors. Differentiation of E17 neurospheres yielded astrocytes and neurons exhibiting several different phenotypes, including expression of calbindin, calretinin, gamma‐aminobutyric acid (GABA), and glutamate, and many also coexpressed CXCR4 receptors. In addition, neurospheres grown from the subventricular zone (SVZ) of 4‐week‐old mice exhibited large increases in Ca2+ in response to CXCL12 and several other chemokines. In comparison, neurospheres prepared from olfactory bulb of adult mice exhibited only small Ca2+ responses to CXCL12, whereas neurospheres prepared from hippocampus were insensitive to CXCL12, although they did respond to other chemokines. Investigations designed to investigate whether CXCL12 can act as a chemoattractant demonstrated that cells dissociated from E17 or adult SVZ neurospheres migrated toward an CXCL12 gradient and this was blocked by the CXCR4 antagonist AMD3100. These results illustrate widespread chemokine sensitivity of embryonic and adult neural progenitor cells and support the view that chemokines may be of general importance in control of progenitor cell migration in embryonic and adult brain. © 2004 Wiley‐Liss, Inc.
Patterning of spinal cord oligodendrocyte development by dorsally derived BMP4
Authors: Miller Robert H. , Dinsio Kyl , Wang Rae , Geertman Robert , Maier Charles E. , Hall Alison K.
Published: March 2004

Oligodendrocyte precursors (OPCs) initially arise in the motor neuron domain of the ventral ventricular zone of the developing spinal cord. After dispersal throughout gray and white matter, OPCs differentiate in a characteristic ventral to dorsal sequence. The spatial localization of OPC induction is in part a result of both positive local sonic hedgehog signaling and dorsally derived inhibitory cues. One component of dorsal inhibitory signals seems to be members of the transforming growth factor β (TGFβ) superfamily such as the bone morphogenetic proteins (BMPs). We show that during the initial appearance and subsequent maturation of OPCs, BMP4 was expressed specifically in the dorsal midline and its expression was correlated spatially and temporally with phospho‐Smad 1+, BMP4‐responsive cells. Implantation of sonic hedgehog (Shh)‐coated beads adjacent to dorsal spinal cord in Xenopus embryos induced ectopic dorsal OPCs whereas BMP4‐coated beads inhibited OPC appearance. More importantly, blocking endogenous dorsal BMP4 with anti‐BMP4‐coated beads locally induced ectopic OPCs. Similar results were obtained using soluble ligands on slice preparations of rodent spinal cord in vitro. In dissociated cell cultures of embryonic rat spinal cord, Shh and BMP4 had antagonistic effects on OPC development and the sensitivity of oligodendrocyte lineage cells to BMP4 increased with maturation. These data suggest that BMP4 contributes to the pattern of spinal cord oligodendrogenesis by regulating both induction and maturation of spinal cord OPCs. © 2004 Wiley‐Liss, Inc.
Oxidative stress inhibits ionomycin‐mediated cell death in cortical neurons
Authors: McCollum Adrian T. , Jafarifar Faegheh , Chan Roy , Guttmann Rodney P.
Published: March 2004

Thiol‐proteases play important roles in many cellular processes, including maintenance of protein homeostasis and execution of cell death. Therefore, determining how this family of enzymes is regulated is critical for our understanding of both physiological and pathological conditions. Because these proteases require a reduced cysteine residue for activity, the cellular redox state plays a crucial role in regulating the activity of thiol proteases. Importantly, increased oxidative stress can result in the direct modification of the active site cysteine, leading to enzyme inactivation. This would suggest that oxidative stress that occurs during pathological insults could prolong cell survival by preventing the execution of thiol‐protease‐dependent cell death pathways. To test this hypothesis, cultured rat cortical neurons were treated with the oxidizing agent diamide or doxorubicin in the presence or absence of the calcium ionophore ionomycin. Under normoxic conditions, ionomycin treatment resulted in ∼70% cell death, which was prevented by addition of the calpain‐selective inhibitor benyzloxycarbonyl‐Leu‐Leu‐Tyr fluoromethylketone. Similarly, pretreatment of neurons with either oxidant was also protective. Protection resulting from oxidative stress was not due to new protein synthesis, insofar as cycloheximide did not affect oxidant‐mediated protection. Interestingly, treatment with the antioxidant Trolox to reverse or prevent oxidative stress blocked the protective effects of both oxidants against ionomycin‐induced cell death. We interpret these findings to suggest that, in diseases or conditions in which oxidative stress is increased, the ability of thiol‐proteases to execute cell death pathways fully is decreased and may prolong cell survival. © 2004 Wiley‐Liss, Inc.
Ca2+‐dependent glutamate release involves two classes of endoplasmic reticulum Ca2+ stores in astrocytes
Authors: Hua Xue , Malarkey Erik B. , Sunjara Vice , Rosenwald Steven E. , Li Wen‐hong , Parpura Vladimir
Published: March 2004

Astrocytes can modulate synaptic transmission by releasing glutamate in a Ca2+‐dependent manner. Although the internal Ca2+ stores have been implicated as the predominant source of Ca2+ necessary for this glutamate release, the contribution of different classes of these stores is still not well defined. To address this issue, we cultured purified solitary cortical astrocytes and monitored changes in their internal Ca2+ levels and glutamate release into the extracellular space. Ca2+ levels were monitored by using the Ca2+ indicator fluo‐3 and quantitative fluorescence microscopy. Glutamate release was monitored by an L‐glutamate dehydrogenase‐linked detection system. Astrocytes were mechanically stimulated with a glass pipette, which reliably caused an increase in internal Ca2+ levels and glutamate release into the extracellular space. Although we find that the presence of extracellular Cd2+, a Ca2+ channel blocker, significantly reduces mechanically induced glutamate release from astrocytes, we confirm that internal Ca2+ stores are the predominant source of Ca2+ necessary for this glutamate release. To test the involvement of different classes of internal Ca2+ stores, we used a pharmacological approach. We found that diphenylboric acid 2‐aminoethyl ester, a cell‐permeable inositol 1,4,5‐trisphosphate (IP3) receptor antagonist, greatly reduced mechanically induced glutamate release. Additionally, the preincubation of astrocytes with caffeine or ryanodine also reduced glutamate release. Taken together, our data are consistent with dual IP3‐ and caffeine/ryanodine‐sensitive Ca2+ stores functioning in the control of glutamate release from astrocytes. © 2004 Wiley‐Liss, Inc.
Evolution of missing colorectal liver metastases following inductive chemotherapy and hepatectomy
Authors: Elias Dominique , Youssef Omar , Sideris Lucas , Dromain Clarisse , Baton Olivier , Boige Valérie , Ducreux Michel
Published: March 2004

Background

A dramatic response to chemotherapy in some patients with multiple bilateral and initially unresectable liver metastases (LM) from colorectal cancer sometimes leads to their disappearance from imaging studies. Our study was aimed at assessing the evolution of these metastases when they were also not found during liver surgery.

Patients

Among 104 hepatectomized patients for colorectal LM in 4 years, 15 patients were retrospectively eligible. Eligibility criteria were: initially unresectable LM; a dramatic response to chemotherapy; and the complete disappearance of at least one LM on imaging studies (ultrasonography (US), computed tomography, and magnetic resonance) during more than 3 months. In four patients (27%), the disappeared LM could be found and treated at laparotomy. The main selection criterion for the 11 studied patients of this series was the impossibility of finding and treating the disappeared LM sited in the remaining liver after hepatectomy, resulting in “missing LM.”

Results

After a median follow‐up of 31 months (range: 18–55) for the series, eight patients among the eleven (73%) did not present any recurrence of the missing LM. The median follow‐up was 31.3 months for these eight patients. The three recurrences occurred respectively at 5, 5, and 8 months after surgery.

Conclusions

The disappearance of LM after chemotherapy on high‐quality imaging studies and after intra‐operative liver exploration resulted in their definitive cure in approximately 70% of cases. The current dogma stipulating an obligatory resection of the initially affected part of the liver is no longer acceptable. J. Surg. Oncol. 2004;86:4–9. © 2004 Wiley‐Liss, Inc.
A pharmacodynamic investigation of tacrolimus in pediatric liver transplantation
Authors: Staatz Christine E. , Taylor Paul J. , Lynch Stephen V. , Tett Susan E.
Published: March 2004

Although monitoring of tacrolimus blood concentrations is standard clinical practice following liver transplantation, a greater understanding of the relationship between trough concentrations and clinical outcome is required. The aim of this study was to perform a pharmacodynamic investigation of tacrolimus in pediatric liver transplant recipients. A retrospective analysis was performed on 35 pediatric liver recipients who received oral tacrolimus as the primary immunosuppressant. Outcome data were recorded corresponding to the times that tacrolimus trough concentrations had been determined (using a validated high-performance liquid chromatography-tandem mass spectrometry assay). A Mann-Whitney rank sum test was used to investigate differences between median concentrations at which drug toxicity, infection, and organ rejection did and did not occur. Outcome data and trough concentrations were recorded from the immediate post-transplant time to over 3 years (656 concentration-effect measures). Seventy one percent of data was obtained after the first 90 days post-transplant. Patients were identified as having experienced hypomagnesemia (20), hypertension (14), hyperkalemia (12), infection (11), nephrotoxicity (8), diarrhea (6), hyperglycemia (3), neurotoxicity(3), and rejection (3) during retrospective follow-up. Median trough concentrations were significantly higher (P < .05) at times patients experienced tacrolimus toxicity compared to no toxicity for nephrotoxicity (11.8 vs. 6.1 ng/mL) and neurotoxicity (15.1 vs. 6.2 ng/mL) and at times when patients suffered from diarrhea (8.9 vs. 6.0 ng/mL). No significant difference could be found between median trough concentrations at which hypertension, hyperkalemia, hyperglycemia, infection and organ rejection did and did not occur. A statistically significant relationship exists between some tacrolimus toxicities and tacrolimus trough concentrations. To minimize toxicity in the later post-transplant period, we propose a target trough tacrolimus concentration of 6 ng/mL. (Liver Transpl 2004;10:506-512.)
Arteriopathy in chronic allograft rejection in liver transplantation
Authors: Miyagawa-Hayashino Aya , Tsuruyama Tatsuaki , Haga Hironori , Oike Fimitaka , Il-Deok Kim , Egawa Hiroto , Hiai Hiroshi , Tanaka Koichi , Manabe Toshiaki
Published: March 2004

Chronic rejection is an important cause of liver allograft failures. The allograft undergoing chronic rejection shows affected large- and medium-sized muscular arteries with homing of foamy macrophages and enlargement of the intimal area. The objective of this study was to elucidate the pathogenesis of the intimal lesion that causes obliterative arteriopathy by identifying the origin of the foamy macrophages and mesenchymal cells present in the intimal area. Nine allografted livers (6 male and 3 female patients) from sex-mismatched donors undergoing chronic rejection were studied by combined staining of the macrophages or the mesenchymal cells in the intimal area with immunohistochemistry and in situ hybridization using a probe for the human Y chromosome. By using the specimens from female donor allografts transplanted to male recipients, it was found that 62 ± 11% of CD68+ foamy macrophages and 71 ± 4% of smooth muscle actin-positive mesenchymal cells in the intimal lesions and a few interstitial myofibroblasts were positive for the Y chromosome probe. This indicated that they were derived from the recipients. In conclusion, the thickening intimal lesion seen in obliterative vasculopathy in liver allografts consists of the foamy macrophages and mesenchymal cells of recipient origin. These circulating recipient cells migrated to the areas in advance of remodeling arteries. (Liver Transpl 2004;10:513-519.)
Immunosuppression affects the rate of recurrent primary biliary cirrhosis after liver transplantation
Authors: Neuberger James , Gunson Bridget , Hubscher Stefan , Nightingale Peter
Published: March 2004

Identifying the risk factors associated with recurrence of primary biliary cirrhosis after liver transplantation may affect immunosuppression and increase understanding of the pathogenesis. Four hundred eighty-five patients with PBC were followed for a median of 79 months after transplantation; histological evidence of recurrence was found in 23%. On multivariate analysis, the only risk factor identified with recurrence was the type of calcineurin inhibitor used. The odds ratio for recurrence on tacrolimus was 2.73 (95% confidence interval: 1.84-4.10) compared with cyclosporine. For those receiving cyclosporine, the median time to recurrence was 123 months and for those on tacrolimus 62 months (P < .001). Reasons for this difference between the 2 calcineurin inhibitors are not clear. (Liver Transpl 2004;10:488-491.)
Monitoring mycophenolate in liver transplant recipients: Toward a therapeutic range
Authors: Tredger John Michael , Brown Nigel William , Adams Jemimah , Gonde Chris Elton , Dhawan Anil , Rela Mohamed , Heaton Nigel
Published: March 2004

Predose plasma mycophenolic acid (MPA) concentrations measured with a semi-automated enzyme-multiplied immunoassay were related to adverse events (e.g., rejection, leukopenia, infection), drug dose, and clinical status in 147 adult and 63 pediatric liver allograft recipients receiving adjunctive immunosuppression with mycophenolate mofetil (MMF). In 12 of 13 acute rejection episodes, predose MPA levels were below the 1 mg/L cut-off defined using receiver operating characteristic (ROC) curve analysis. The relative risk of developing infection or leukopenia increased more than 3-fold above predose MPA levels of 3 to 4 mg/L. Plasma MPA levels correlated weakly (r2 = 0.081) with MMF dose and the dose / level relationship was variably influenced by age, the indication for MMF, concentrations of serum albumin and creatinine, and comedication with tacrolimus or cyclosporine. The median mycophenolate dose required per unit mycophenolate level was 50% lower in children than in adults. Comparable drug requirements were also decreased by renal dysfunction (by 40 and 43% in adults and children, respectively), and in patients prescribed MMF alone rather than with tacrolimus or cyclosporine. However, in patients with serum albumin less than 35g/L, MMF dose requirements were higher than in those with normal albumin levels (by 2.1- and 2.6-fold in adults and children, respectively). In adults, 44.7% achieved clinically acceptable therapeutic MPA concentrations at a dose less than 1 g MMF twice daily and only 6.3% required 1.5 g twice daily as suggested by the manufacturer. The immunoassay was a rapid, reliable, and acceptably precise technique in which only 10.8% of measurements were unproductive. In conclusion, our data suggests that MPA predose level monitoring is both clinically- and cost-effective and that a therapeutic range of 1 to 3.5mg/L (by immunoassay) is applicable in liver allograft recipients given adjunctive MMF. (Liver Transpl 2004;10:492-502.)
Feasibility of auxiliary partial orthotopic liver transplantation from living donors for patients with adult-onset type II citrullinemia
Authors: Yazaki Masahide , Hashikura Yasuhiko , Takei Yo-ichi , Ikegami Toshihiko , Miyagawa Shin-ichi , Yamamoto Kanji , Tokuda Takahiko , Kobayashi Keiko , Saheki Takeyori , Ikeda Shu-ichi
Published: March 2004

More than 20 patients with adult-onset type II citrullinemia have undergone liver transplantation, showing dramatic therapeutic effects. In Japan, living donor liver transplantation is the standard technique of liver transplantation because of the rare availability of cadaveric donors. The feasibility of auxiliary partial orthotopic liver transplantation (APOLT) for adult-onset type II citrullinemia to overcome the problem of a small-for-size graft in living donor liver transplantation has not been defined. We recently performed APOLT for patients with type II citrullinemia. Here, we present 2 patients: patient 1 was a 32-year-old man and patient 2 was a 43-year-old woman. Both patients suffered from hepatic encephalopathy, and laboratory data showed highly elevated plasma levels of ammonia and citrulline. In patient 1, the liver graft was obtained from a patient with familial amyloid polyneuropathy as a domino liver transplant. In patient 2, APOLT was performed after graft donation from her husband. The postoperative clinical courses of both patients were uneventful, and the neurological symptoms were completely resolved. The plasma concentrations of ammonia and citrulline normalized rapidly in both patients. APOLT can provide an adequate hepatocyte mass to correct the underlying enzyme deficiency in adult patients with type II citrullinemia. In addition, APOLT can be carried out safely to overcome the limitation of graft volume in living donor liver transplantation. (Liver Transpl 2004;10:550-554.)
Fibrosing cholestatic hepatitis secondary to precore/core promoter hepatitis B variant with lamivudine resistance: Successful retransplantation with combination adefovir dipivoxil and hepatitis B immunoglobulin
Authors: Lo Chung-Mau , Cheung Siu-Tim , Ng Irene Oi-Lin , Liu Chi-Leung , Lai Ching-Lung , Fan Sheung-Tat
Published: March 2004

Fibrosing cholestatic hepatitis (FCH) is a peculiar variant of hepatitis B virus (HBV) infection in immunocompromised patients characterized by rapid viral replication. Posttransplant patients receiving lamivudine for prophylaxis or treatment of HBV infection may develop drug resistance due to viral mutants, but FCH is rare because escape mutants are usually replication deficient. We report the development of FCH due to lamivudine-resistant HBV mutants in 2 patients at 12 and 13 months after liver transplantation. Rapidly progressive graft failure, accompanied by an escalating HBV DNA level, developed within weeks of onset. Analysis of gene sequence variation by polymerase chain reaction (PCR) and direct sequencing showed that both had a core promoter variant A1762T/G1764A and 1 had a concomitant precore stop codon G1896A variant in prelamivudine and postrecurrence serum samples. Comparison of the HBV polymerase gene in the 2 serum samples revealed a single mutation with methionine-to-isoleucine substitution at codon 552 (M552I) in both patients. “Add-in” treatment with adefovir dipivoxil resulted in a more than 2 to 3 log10 reduction in HBV DNA level within 2 weeks and retransplantation was performed with adefovir dipivoxil and hepatitis B immunoglobulin (HBIG) prophylaxis. Both patients were alive at 15 months and 48 months after retransplantation, with normal graft function and serum negative for HBsAg and HBV DNA by quantitative PCR (< 200 copies/mL). The current report demonstrates that recurrent graft infection by precore/core promoter variant with lamivudine-resistant escape mutation may result in FCH. With combination of adefovir and high-dose HBIG, however, long-term survival can be achieved after retransplantation. (Liver Transpl 2004;10:557-563.)
Two-stage total hepatectomy and liver transplantation for acute deterioration of chronic liver disease: A new bridge to transplantation
Authors: Guirl Michael J. , Weinstein Jeffrey S. , Goldstein Robert M. , Levy Marlon F. , Klintmalm Goran B.
Published: March 2004

Two-stage total hepatectomy and liver transplantation has been reported for acute liver disease such as fulminant hepatic failure, primary graft failure, severe hepatic trauma, and spontaneous hepatic rupture secondary to hemolysis, elevated liver function tests, low platelets syndrome, and preeclampsia. This is the first report of patients with cirrhosis to undergo a 2-stage total hepatectomy and liver transplantation. From 1984 to 2002, our institution performed 2008 orthotopic liver transplantations. We identified 4 patients with chronic liver disease who underwent a 2-stage hepatectomy and liver transplantation. This is a retrospective review of these 4 patients and a review of the literature on this procedure. All 4 patients were young men with an age range of 29-31 years and had underlying cirrhosis as well as a previous transjugular intrahepatic portosystemic shunt (TIPS)procedure. Acute decompensation fulfilling Ringes’ criteria for toxic liver syndrome secondary to an upper gastrointestinal bleed occurred in all patients. The approximate average time between hepatectomy and liver transplantation was 20 hours (range: 8-42 hours). In all cases, the explanted liver showed histological changes of acute hepatic necrosis within the background of cirrhosis. After hepatectomy, vasopressor requirements were well documented in 2 patients. For 1 patient, there was a clear improvement in their hemodynamic status. The mean hospital stay of the 4 patients was 63 days. All patients were discharged from the hospital and are alive and well with adequate liver function at 6 to 37 months follow-up. Two-stage total hepatectomy and liver transplantation may be a life-saving procedure in highly selected cirrhotic patients with acute hepatic decompensation and multiorgan dysfunction. (Liver Transpl 2004;10:564-570.)
Tolerance for immunosuppression in organ transplantation†
Authors: Stegall Mark D. , Platt Jeffrey L.
Published: March 2004

Background

Insight into the mechanisms of organ engraftment and acquired tolerance has made it possible to facilitate these mechanisms, by tailoring the timing and dosage of immunosuppression in accordance with two therapeutic principles: recipient pretreatment and minimum use of posttransplant immunosuppression. We aimed to apply these principles in recipients of renal and extrarenal organ transplants.

Methods

82 patients awaiting kidney, liver, pancreas, or intestinal transplantation were pretreated with about 5 mg/kg of a broadly reacting rabbit antithymocyte globulin during several hours. Posttransplant immunosuppression was restricted to tacrolimus unless additional drugs were needed to treat breakthrough rejection. After 4 months, patients on tacrolimus monotherapy were considered for dose-spacing to every other day or longer intervals.

Findings

We frequently saw evidence of immune activation in graft biopsy samples, but unless this was associated with graft dysfunction or serious immune destruction, treatment usually was not intensified. Immunosuppression-related morbidity was virtually eliminated. 78 (95%) of 82 patients survived at 1 year and at 13-18 months. Graft survival was 73 (89%) of 82 at 1 year and 72 (88%) of 82 at 13-18 months. Of the 72 recipients with surviving grafts, 43 are on spaced doses of tacrolimus monotherapy: every other day (n = 6), three times per week (11), twice per week (15), or once per week (11).

Interpretation

The striking ability to wean immunosuppression in these recipients indicates variable induction of tolerance. The simple therapeutic principles are neither drug-specific nor organ-specific. Systematic application of these principles should allow improvements in quality of life and long-term survival after organ transplantation. (Lancet 2003;361:1502-1510)
A microstrip filter utilized in ultra‐wideband antennas
Authors: Wang Chien‐Jen , Lin Chia‐Horng , Wu Jin‐Wei
Published: March 2004

In this paper, a microstrip filter has been designed, fabricated, and measured for application in ultra‐wideband antennas. By using the combination of a band‐stop filter and a low‐pass filter, the band‐selective characteristics can be demonstrated. In order to enhance the suppression of the out‐of‐band signals, a defected ground structure (DGS) with stopband performance is used. The passband responses of the filter, which range below 2.8 GHz and from 5.0 to 6.0 GHz, cover most commercial wireless communication systems. The LC‐lumped equivalent circuit of the filter has been extracted and simulated by using transmission‐line analysis. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 248–251, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20107
An efficient and fast approach for surface‐wave pole extraction in two‐layered microstrip geometry
Authors: Wang Y. , Ooi B. L. , Leong M. S.
Published: March 2004

An efficient approach for fast evaluation of the poles' locations in two‐layered microstrip geometry has been presented. For the first time, good initial values and functional expressions with quadratic convergence for two‐layered pole extraction have been derived. Numerical comparison with available methods of extraction shows that our proposed method is very accurate and extremely fast in convergence. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 253–258, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20109
A thin wideband microstrip patch antenna with two adjacent slots
Authors: Yang G. , Ali M. , Dougal R.
Published: March 2004

A thin (only 5% of the operating wavelength, λ) wideband microstrip patch antenna with two closely spaced slots is introduced. When connected to each other, the two slots translate into two distinct resonant frequencies, resulting in wide impedance bandwidth (about 20% within 2:1 VSWR). Detailed design data, including resonance frequency, impedance, and bandwidth, are presented as function of the antenna and slot parameters. It is also demonstrated that such antennas can be designed at different frequency bands by appropriately adjusting the antenna and slot parameters. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 261–266, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20111
Frequency‐selective surface based bandpass filters in the near‐infrared region
Authors: Govindaswamy Srikanth , East Jack , Terry Fred , Topsakal Erdem , Volakis John L. , Haddad George I.
Published: March 2004

A spatial bandpass filter resonant at 1.5 μm and based on a frequency‐selective surface (FSS) was analyzed and fabricated. It consists of circular apertures arranged in a hexagonal lattice and was modeled using a hybrid finite‐element/boundary‐integral method, which accounted for metal thickness and conductivity. Measurements demonstrate the accuracy of the design. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 266–269, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20112
Design and fabrication of slant‐counter electrodes for optical switches
Authors: Dong Wei , Ruan Shengping , Zhang Xindong , Liu Caixia , Sun Dongming , Jia Cuiping , Pan Jianxuan , Ji Ping , Chen Weiyou
Published: March 2004

This paper describes electrostatically actuated micromechanical optical switches based on the slant‐counter electrode, and proposes an advanced method of fabricating the slant‐counter electrode. The pull‐in voltage and switching time are investigated. The slant‐counter electrode is fabricated by anisotropic wet etching of a (111) silicon wafer tilted at a 2.5° angle, which is normally tilted 2.5° off the 〈111〉 direction toward the nearest 〈110〉 direction. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 273–275, 2004; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002sol;mop.20115
Arbitrary planar microwave filter design by the EEM‐GA approach
Authors: Wang Wen , Lu Yilong , Fu Jeffrey S.
Published: March 2004

The traditional microstrip or coplanar‐waveguide filter design restricts filter structure to regular shapes so that the results may not be optimal. In this paper, we present a novel design approach that allows arbitrary planar structures. This approach combines two powerful and flexible methods: the finite‐element method (FEM) as the three‐dimensional (3D) field simulator and the genetic algorithm (GA) as the optimization engine. In order to reduce the optimization time, parallel computing is also utilized. The FEM‐GA design approach is much more flexible than traditional ones. Numerical examples are presented to show the validity and effectiveness of this approach. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 276–279, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20116
The method of lines and electromagnetic scattering for line sources
Authors: Hooshyar M. A. , Lasater Lena V.
Published: March 2004

The direct and inverse problems of electromagnetic scattering by cylindrical structures with arbitrary cross sections for E‐polarized line sources are considered. It is shown that the method of lines gives a computationally efficient and accurate procedure for calculating the scattering amplitude. The developed procedure also enables one to determine shape of cylindrical structures form scattering amplitudes. To illustrate the procedure and its computational performance, two numerical examples are presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 286–290, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20118
Transmission characteristics of a new type of closed elliptic‐groove waveguide for millimeter waves
Authors: Xu Fuyong , Shangguan Changping , Ma Hongmei
Published: March 2004

A new type of closed elliptic‐groove guide is developed. Its characteristic equation and transmission characteristics for the dominant mode have been analyzed using the mode‐matching method and discussed. The obtained results show that this new type of closed elliptic‐groove guide has low loss, low dispersion, and high‐power handling, and it can be suitably used as the single‐mode transmission in short millimeter and submillimeter waves. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 301–304, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20122
A simple and efficient approach to train artificial neural networks using a genetic algorithm to calculate the resonant frequency of an RMA on thick substrate
Authors: Khuntia Bonomali , Pattnaik Shyam S. , Panda Dhruba C. , Neog Dipak K. , Devi S. , Dutta Malay
Published: March 2004

Both genetic algorithms (GAs) and artificial neural networks (ANNs) have been used in the field of computational electromagnetics as the most powerful optimizing tools. In this paper, a simple and efficient method is presented to handle the problem of competing convention while training an ANN by using a GA. This technique is applied to calculate the resonant frequency of a thick‐substrate rectangular microstrip antenna (RMA). The training time is less than that of a normal feed‐forward backpropagation algorithm. The measured results are in very good agreement with experimental results. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 313–315, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20126
CPW EBG using butterfly‐radial slot (BRS) for low‐pass wideband filtering
Authors: Yu Jong Jen , Tan Boon Tiong , Chew Siou Teck
Published: March 2004

Uniplanar one‐dimensional EBG with a periodic butterfly‐radial slot (BRS) structure has been proposed for wide spurious filtering. An optimum design ratio and parameters have been characterized for this particular BRS‐CPW EBG configuration. Two six‐cell BRS‐CPW EBG low‐pass filters are designed and they demonstrate a wide bandwidth rejection of more than 86% up to the 3rd harmonic. The experimental and simulated results are in good agreement. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 320–323, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20130
Implementation of broadband microwave absorber using FSS screens coated with Ba(MnTi)Fe10O19 ferrite
Authors: Liu Ji‐Chyun , Liu Chin‐Yen , Wu Ching‐Yang , Hsu Hsing‐Yao
Published: March 2004

Construction of FSS screens coated with ferrite Ba(MnTi)Fe10O19 to implement broadband microwave absorbers is presented in this paper. The decrement method is used to measure the reflective response of the microwave absorber. Both reflectivity and absorption representations recognize the characterization of microwave absorbers for the X‐band. Two types of FSS screens, a square‐lattice screen and an equilateral‐triangle‐lattice screen, are introduced to obtain better bandwidth and absorption in this study. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 323–326, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20131
Model test of the relationship between self‐help‐promoting nursing interventions and self‐care and health status outcomes
Authors: Kreulen Grace J. , Braden Carrie Jo
Published: March 2004

In this study of a nursing intervention outcomes model was tested. Path analysis techniques were used to examine predicted relationships between self‐help‐promoting interventions and patient outcomes of self‐care practice and client morbidity at three times. A sample of 307 women receiving medical treatment for breast cancer provided data for the study. The average participant was White, middle‐aged, married, educated, and in stage I or stage II disease. Findings support the hypothesized model linking these nursing interventions directly to self‐care outcomes and self‐care to client morbidity outcomes. Client factors of age, social network size, disease stage, receipt of chemotherapy, resourcefulness, and uncertainty significantly influenced predicted relationships. Examination of specific patterns of relationships for the sample revealed delayed behavioral responses to the interventions, variability in predictors of each outcome at the three measurement times and a more strongly predictive model when patient outcomes were considered within the context of client factors. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:97–109, 2004
Biochemical hypoglycemia in female nurses during clinical shift work
Authors: Inoue Kayoko , Kakehashi Yuko , Oomori Suiko , Koizumi Akio
Published: March 2004

Female nurses in Japan commonly experience symptoms similar to those of hypoglycemia while working. Biochemical hypoglycemia can lead to impaired cognition; thus, it is important to know the prevalence of biochemical hypoglycemia among nurses. Five hundred and sixty‐eight female nurses (53% of the target population) in four hospitals completed questionnaires. They determined their blood glucose levels 12 times, at four points during three shifts. Fifty‐seven nurses (10%) recorded biochemical hypoglycemia (≤3.0 mM) at least once. Multivariate analysis revealed three independent risk factors for hypoglycemia: higher coefficient of variation of blood glucose level, lower body mass index, and not smoking. Subjective symptoms were not associated with hypoglycemia. More research on hypoglycemia is needed in order to improve working environment for nurses. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:87–96, 2004
The modal distribution of protein isoelectric points reflects amino acid properties rather than sequence evolution
Authors: Weiller Georg F. , Caraux Gilles , Sylvester Nicole
Published: March 2004

Two‐dimensional gel electrophoresis, a routine application in proteomics, separates proteins according to their molecular mass (Mr) and isoelectric point (pI). As the genomic sequences for more and more organisms are determined, the Mr and pI of all their proteins can be estimated computationally. The examination of several of these theoretical proteome plots has revealed a multimodal pI distribution, however, no conclusive explanation for this unusual distribution has so far been presented. We examined the pI distribution of 115 fully sequenced genomes and observed that the modal distribution does not reflect phylogeny or sequence evolution, but rather the chemical properties of amino acids. We provide a statistical explanation of why the observed distributions of pI values are multimodal.
Two‐dimensional reference map of Agrobacterium tumefaciens proteins
Authors: Rosen Ran , Sacher Ayelet , Shechter Nelia , Becher Dörte , Büttner Knut , Biran Dvora , Hecker Michael , Ron Eliora Z.
Published: March 2004

Proteomics based on two‐dimensional (2‐D) gel electrophoresis of proteins followed by spot identification with mass spectrometry is a commonly used method for physiological studies. Physiological proteomics requires 2‐D reference maps, on which most of the main proteins are identified. We present a reference map for the bacterial plant pathogen Agrobacterium tumefaciens proteins, which contains more than 300 entries with an isoelectric point (pI) between 4 and 7. The quantitative study of the proteins in the analytical window of the master gel demonstrated unique features, in comparison with other bacteria. In addition, a theoretical analysis of several protein parameters was performed and compared with the experimental results. A comparison of the theoretical molecular weight (MW) of the proteins and their theoretical pI with their vertical and horizontal migration distances, respectively, pointed out the existence of several proteins that strongly diverted from the graph trend‐line. These proteins were clearly subjected to post‐translational modifications, which changed their pI and/or MW. Additional support for post‐translational modifications comes from the identification of multiple spots of the same gene products. Post‐translational modifications appear to be more common than expected, at least for soluble proteins, as more than 10% of the proteins were associated with multiple spots.
About the mechanism of interference of silver staining with peptide mass spectrometry
Authors: Richert Sophie , Luche Sylvie , Chevallet Mireille , Van Dorsselaer Alain , Leize‐Wagner Emmanuelle , Rabilloud Thierry
Published: March 2004

The mechanism by which silver staining of proteins in polyacrylamide gels interferes with mass spectrometry of peptides produced by proteolysis has been investigated. It was demonstrated that this interference increases with time between silver staining and gel processing, although the silver image is constant. This suggested an important role of the formaldehyde used in silver staining development in this interference process. Consequently, a formaldehyde‐free staining protocol has been devised, using carbohydrazide as the developing agent. This protocol showed much increased peptide coverage and retained the sensitivity of silver staining. These results were however obtained at the expense of an increased background in the stained gels and of a reduced staining homogeneity.