bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction of a new tumour necrosis factor fusion‐protein expression vector for high‐level expression of heterologous genes in Escherichia coli
Authors: Han Wei , Zhang Yingqi , Yan Zhen , Shi Jihong
Published: October 2003

We report the construction and application of a new fusion‐protein expression plasmid (TNFHis) for Escherichia coli . The plasmid contains both PR and PL promoters and is optimized to allow a higher level of expression of mature coding sequences. It also contains a six‐histidine tag for convenient purification as well as thrombin and hydroxylamine recognition sites for cleaving heterologous protein. The potential use of this expression vector is demonstrated by comparing the expression levels of human tumour necrosis factor (TNF), interferon, interleukin 11, colony‐forming factor, osteoprotegrin and interleukin 2 in E. coli . Furthermore, all expressed TNF fusion proteins can be detected by anti‐TNFα antibody or by specific antibodies and purified by Ni2+‐nitrilotriacetate beads. The expressed TNF fusion proteins can be cleaved by hydroxylamine.
Clostridium perfringensα ‐N ‐acetylgalactosaminidase blood group A2‐degrading activity
Authors: Hsieh Hsin‐Yeh , Smith Daniel
Published: October 2003

Enzymic modification of type A2 erythrocyte membranes with Clostridium perfringens α ‐N ‐acetylgalactosaminidase was investigated. An ELISA demonstrated hydrolysis of type A2 epitopes under conditions of red‐blood‐cell collection and storage. The enzyme hydrolysed the terminal N ‐acetyl‐α ‐d‐galactosamine from the blood type A2 antigen, producing H antigen, blood group O, which is universally compatible in the ABO system. The enzyme was active in common red‐cell preservative solutions at pH 6.4–7.0, at 4 °C, at ionic strengths found in stored red cell units and in the presence of type A plasma. These data imply that the C. perfringens α ‐N ‐acetylgalactosaminidase might be added directly to packed A2 red‐blood‐cell units for enzymic conversion to blood type O. Further studies are warranted.
A simplified method for identification of human cardiac myosin heavy‐chain isoforms
Authors: Piao Shengfu , Yu Fushun , Mihm Michael J. , Reiser Peter J. , McCarthy Patrick M. , Van Wagoner David R. , Bauer John Anthony
Published: October 2003

Cardiac myosin is a central participant in the cross‐bridge cycling that mediates myocyte contraction and consists of multiple subunits that mediate both hydrolysis of ATP and mechanical production of contractile force Two isoforms of myosin heavy chain (MHC‐α and MHC‐β) are known to exist in mammalian cardiac tissue, and it is within this myosin subunit that ATPase activity resides. These isoforms differ by less than 0.2% in total molecular mass and amino acid sequence, but, strikingly, influence the rate and efficiency of energy utilization for generation of contractile force. Changes in the MHC‐α/MHC‐β ratio has been classically viewed as an adaptation of a failing myocyte in both animal models and humans; however, their measurement has traditionally required specialized preparations and materials for sufficient resolution. Here we describe a greatly simplified method for routine assessments of myosin isoform composition in human cardiac tissues. The primary advantages of our approach include higher throughput and reduced supply costs with no apparent loss of statistical power, reproducibility or achieved results. Use of this more convenient method may provide enhanced access to an otherwise specialized technique and could provide additional opportunity for investigation of cardiac myocyte adaptive changes.
Regulatory effects of alanine‐group amino acids on serine alkaline protease production by recombinant Bacillus licheniformis
Authors: Alık Pınar , Bayram Arzu , Özdamar Tunçer H.
Published: October 2003

Influences of the concentration and addition time of alanine‐group amino acids, i.e. alanine, leucine and valine, on serine alkaline protease (SAP) synthesis were investigated by Bacillus licheniformis (DSM 1969) carrying pHV1431::sub C in a defined medium to identfy the amino acids creating intracellular reaction‐rate limitation in SAP production. While the precursors of alanine‐group amino acids, pyruvate and alanine, did not affect SAP production considerably within the range 0–15 mM, the addition of leucine decreased both SAP production and cell formation, because of the inhibition of valine synthesis. Although valine inhibits reactions starting with pyruvate towards 2‐oxo‐isovalerate, due to conversion of valine into 2‐oxo‐isovalerate and from 2‐oxo‐isovalerate to leucine, valine did not inhibit leucine synthesis. Val (7.5 mM) supply at t =0 h increased SAP activity to an activity of 1070 units·cm−3 which was 1.3‐fold higher than that of the reference production medium. The highest cell growth yield on substrate (Y X/S) was obtained as 0.24 g·g−1 with the supply of alanine; and the highest product formation yield on substrate was obtained as 0.134 units·g−1 with the supply of valine. By using the results obtained, strategies for increasing SAP production and complex medium design were also discussed.
Phytoremediation of 2,4‐dichlorophenol by Brassica napus hairy root cultures
Authors: Agostini Elizabeth , Coniglio María S. , Milrad Silvia R. , Tigier Horacio A. , Giulietti Ana M.
Published: October 2003

We have obtained hairy root cultures of Brassica napus with high biomass and genetic stability which produce peroxidases, enzymes involved in biodegradation processes. In this work, these hairy root cultures were used to study the removal of 2,4‐dichlorophenol (2,4‐DCP), a common contaminant in industrial effluents that is highly toxic for human and aquatic life. The optimum conditions to obtain high efficiency in the removal process were established. Roots were able to remove 2,4‐DCP from aqueous solutions containing 100–1000 mg/l, in the presence of H2O2 concentrations ranging from 5 to 10 mM. After a short period of incubation (15 min), high removal efficiencies were achieved (91–94%) and maximal removal, of approx. 97–98%, was obtained with 1 h of reaction. High removal efficiencies (93–95%) were observed in a broad pH range (pH 3–9), reaching 98–99% in the range pH 4–8. Moreover, roots could be re‐used, almost for six consecutive cycles, to remove 2,4‐DCP. The oxidation catalysed by peroxidases would be the main mechanism involved in this process. The results suggest that these cultures could be useful tools for phytoremediation.
Low‐molecular‐mass thiol compounds from a free‐living highly pathogenic amoeba,Naegleria fowleri
Authors: Ondarza Raúl N. , Iturbe Angélica , Hernández Eva , Hurtado Gerardo
Published: October 2003

Acid extracts labelled with the fluorescent reagent monobromobimane and separated by HPLC have enabled the detection of low‐molecular‐mass thiol compounds inNaegleria fowlerifor the first time. The amounts detected are expressed in nmol/1×106trophozoites cultivated at various stages of growth in the appropriate culture medium.N. fowleriis a highly pathogenic free‐living amoeba, in which we found important thiol compounds, some of them in their reduced and oxidized forms. Unlike cysteine and glutathione, a number of these are not represented in normal human lymphocytes. Some of these thiol compounds fromNaegleriamust have their respective disulphide reductases, although the presence of thiol‐disulphide exchange reactions must be considered. Ovothiol A, with antioxidant properties, is an example of a compound that is kept reduced by trypanothione in trypanosomatids, although no disulphide reductase for ovothiol A has yet been discovered. In our case we were unable to detect this biothiol inNaegleria. The presence of thiol compounds that seem to be particular to this pathogen and which are not present in human lymphocytes opens the possibility of searching for disulphide‐reducing enzymes that can serve as drug targets.
An improved methodology to produce Flavobacterium heparinum chondroitinases, important instruments for diagnosis of diseases
Authors: Aguiar Jair A. K. , Lima Cilene R. , Berto Alessandra G. A. , Michelacci Yara M.
Published: October 2003

Chondroitinases are very important tools for the identification and structural analysis of proteoglycans. Enzymic analysis with Flavobacterium heparinum chondroitinases has shown that chondroitin sulphate and dermatan sulphate structures are modified in many human diseases, suggesting a diagnostic value for these enzymes. Furthermore, it was recently shown that F. heparinum chondroitinases AC and B inhibit tumoural cell growth, invasion and angiogenesis. Due to the increasing importance of F. heparinum chondroitinases, we investigated optimized conditions for preparation and assay of chondroitinases AC, B and C. The Dimethylmethylene Blue assay was modified and fully developed to measure the chondroitinase activities of crude extracts of F. heparinum . This method estimates chondroitin sulphate or dermatan sulphate depolymerization upon the digestion of chondroitinase, and was compared with A 232, which measures the unsaturated products formed. Trypticase was the best culture medium, both for bacterial growth and enzyme induction. The chondroitinases were solubilized by ultrasound under conditions that do not completely disrupt the cells, suggesting that they are located at the periplasmic space. Maximum chondroitinase induction occurred in the presence of 0.2–1.0 g/l chondroitin sulphate. Chondroitin sulphate‐degradation products were also inducers, but heparin and heparan sulphate were not. Chondroitinases AC, B and C were separated from each other by hydrophobic‐interaction chromatography on Phenyl‐Sepharose HP. When contaminant proteins were first removed from crude extract by Q‐Sepharose, the chondroitinases could be purified to homogeneity in this phenyl‐Sepharose chromatographic step.
Effects of fermentation strategy on the characteristics of plasmid DNA production
Authors: O'Kennedy Ronan D. , Ward John M. , Keshavarz‐Moore Eli
Published: October 2003

The synthesis of supercoiled plasmid DNA (SC‐pDNA) for therapeutic use will involve large‐scale production in bioreactors. The success of these fermentations will be dependent on the interactions between the host organism, the recombinant plasmid vector and the growth environment. In the present study, the recombinant host, Escherichia coli DH5α bearing the recombinant plasmid pSVβ, was grown in shake flasks, batch and exponentially fed‐batch bioreactors. Specific and volumetric pDNA yields were increased 8‐ and 25‐fold respectively using exponentially fed‐batch cultures in comparison with shake‐flask cultures. The percentage of SC‐pDNA as a proportion of total plasmid DNA decreased over time in batch cultures, but remained relatively constant during fed‐batch cultures. The relative merits of different modes of fermentation and their effects on the quality of alkaline lysate extracts of pDNA with respect to genomic contamination and the percentage of SC‐pDNA are discussed.
Elicitation of plants and microbial cell systems
Authors: Radman Romeo , Saez Teresa , Bucke Christopher , Keshavarz Tajalli
Published: October 2003

Plants show physiological and morphological responses to a range of physical and chemical factors known as ‘elicitors’. These responses have been considered as defence reactions ‘elicited’ by the plants’ biochemical factory to ensure their survival, persistence and competitiveness. Recently examples have been cited of elicitation in some fungal and bacterial cultures. Through a chronological survey, this Review considers examples of elicitors and elicitation and describes suggested mechanisms of elicitation in plants and microbial cell cultures. The majority of research in this field has been carried out on the plant systems using complex (undefined) biotic elicitors. Carbohydrates are the main class of compounds used as defined elicitors. This Review focuses on carbohydrates as compounds initiating a defence response in cell cultures. Physiological changes brought about on the plant and microbial cultures include expression of novel metabolites and overproduction of already known products. Recent reports confirming elicitation in microbial cultures are of potential importance, as the relative ease of fermentation and scale‐up could open an opportunity for the introduction of useful novel metabolites as well as enhancement of commercially useful bioproducts. In this context, a sound knowledge of the elicitor molecules’ structure–function relationships and mechanisms of elicitation is essential.
The sickest first? Disparities with model for end-stage liver disease-based organ allocation: One region’s experience
Authors: Schaffer Randolph L. , Kulkarni Sanjay , Harper Ann , Millis Michael J. , Cronin David C.
Published: October 2003

February 27, 2002, allocation of cadaver livers for transplantation changed from a waiting-time-based system to an evidence-based system referred to as the Model for End-Stage Liver Disease (MELD). We reviewed data from 1 of the 11 United Network for Organ Sharing regions to determine the impact of the MELD on the allocation of cadaver livers for transplantation in that region. The region of interest (study region) consists of three distinct geographic areas (referred to as Transplant Service Areas [TSAs]). Based on information obtained from the Organ Procurement and Transplantation Network for the United States and for the study region, the following observations were made: (1) study region patients who received a cadaver liver had higher mean and median MELD scores than cadaver liver recipients in the United States (study region mean score, 25.1; median, 26.0; US mean score, 23.9; median, 24.0); (2) within the study region, TSAs with competing liver transplant programs performed transplantation on patients at a significantly higher mean MELD score than TSAs dominated by a single center (TSA-1 mean score, 27.3; TSA-2 mean score, 26.6; TSA-3 mean score, 21.3); this disparity persisted when transplantations for hepatocellular carcinoma (HCC) were excluded; and (3) study region patients removed from the waiting list because of death or being too sick for transplantation have higher MELD scores than the national average (study region mean score, 25.4; US mean score, 23.8). Overall, implementation of the MELD resulted in a substantial increase in the number of transplantations performed for HCC, and MELD exceptions for all reasons were more common in TSAs that have multiple centers. Despite the MELD, there remains disparity in organ allocation within the study region. The MELD may accurately predict pretransplantation mortality, but it does not ensure equitable organ distribution. We propose that intraregional sharing of cadaver livers based on the MELD may help limit disparities in organ allocation.
Bile secretory function after warm hepatic ischemia-reperfusion injury in the rat
Authors: Accatino Luigi , Pizarro Margarita , Solís Nancy , Arrese Marco , Koenig Cecilia S.
Published: October 2003

Hepatic ischemia-reperfusion (I-R) injury frequently is associated with cholestasis. However, the underlying mechanisms are not fully understood. The aim of the study is to assess bile secretory function in vivo in rats subjected to warm lobar hepatic ischemia at different times during reperfusion. A model of lobar 70% warm hepatic ischemia for 30 minutes was used with studies conducted at 1 and 6 hours and 1, 3, and 7 days after reperfusion. Bile secretory function was assessed after selective cannulation of bile ducts of ischemic (ILs) and nonischemic lobes (NILs). Serum activity of hepatic alanine and aspartate aminotransferase was slightly increased in rats subjected to I-R, whereas serum bile salt levels increased early during reperfusion, returning to control values after 7 days. ILs showed mild reversible leukocyte infiltration and no significant necrosis. Bile flow and bile salt excretion were significantly decreased in ILs during the first 24-hour reperfusion period compared with sham-operated rats and NILs. A marked reduction in glutathione (GSH) excretion occurred at 1 and 6 hours and 1 and 3 days, which returned to control values after 7 days. Total GSH and both reduced and oxidized GSH levels in liver homogenate and arterial blood GSH levels were unchanged at all times. Protein mass of multidrug resistance protein 2 and its function, assessed by the hepatic maximum secretory rate of ceftriaxone, did not show significant changes in ILs or NILs compared with sham-operated rats. Liver tissue γ-glutamyl transpeptidase (GGT) and γ-glutamylcysteine synthetase activities remained unchanged, whereas biliary GGT and cysteine secretory rates were significantly increased in ILs and NILs. Administration of acivicin, a GGT inhibitor, resulted in decreased secretion of this enzyme into bile and a parallel marked increase in biliary GSH secretion compared with untreated ischemic rats. In conclusion, warm hepatic I-R induces reversible cholestatic changes in ILs. GSH secretory rates from both ILs and NILs were markedly decreased during reperfusion. The reversibility of this effect after GGT inhibition, as well as increased release of active GGT into bile and cysteine biliary secretory rates, suggest increased GSH degradation in bile. These findings might be relevant for the I-R-induced clinical cholestasis, as well as cholangiocyte injury, seen after hepatic ischemia.
Long-term survival of recipients of liver grafts from donors older than 80 years: Is it achievable?
Authors: Cescon Matteo , Grazi Gian Luca , Ercolani Giorgio , Nardo Bruno , Ravaioli Matteo , Gardini Andrea , Cavallari Antonino
Published: October 2003

Isolated cases or small series of orthotopic liver transplantation (OLT) with grafts from donors older than 80 years have been reported, but the long-term outcome of patients receiving livers from extremely old donors is unknown. From 1998 to 2003, we performed 17 OLTs with donors older than 80 years (median, 82 years; range, 80 to 87 years). No deaths occurred in the early postoperative period. We analyzed the outcome in 12 patients with a follow-up longer than 1 year. Hepatic insufficiency was caused by hepatitis C virus (HCV)-related cirrhosis in five cases (42%) and non-HCV-related diseases in seven cases (58%). All donors had normal liver function, hemodynamic stability, and no parenchymal alterations. OLT was uneventful in all cases. Median follow-up was 30.3 months (range, 17 to 42 months). No late vascular complications occurred. One patient (8.3%) died 3 years after OLT for causes unrelated to hepatic dysfunction. Two- and 3-year actuarial survival rates were 100% and 75%, respectively. All HCV-positive (HCV+) patients developed hepatitis recurrence (after 2, 3, 4, 5, and 22 months) requiring antiviral treatment in 3 patients and leading to graft cirrhosis in 1 patient. Non-HCV+ patients had well-preserved liver function throughout the observation period. At the end of follow-up, we observed no clinical hepatic decompensation in the entire group and biochemical signs of recurrent disease in 3 patients. Use of grafts for OLT from donors older than 80 years is safe because of their potentially normal functional recovery. A selection among available organs is mandatory to minimize other risk factors for poor outcome. Long-term patient and graft survival seem to be achievable, but the high rate and rapidity of HCV reinfection remain a major concern for HCV+ patients.
Live donor liver transplantation for fulminant hepatic failure in children
Authors: Liu Chi-Leung , Fan Sheung-Tat , Lo Chung-Mau , Tam Paul Kwong-Hang , Saing Htut , Wei William Ignace , Yong Boon-Hun , Tsoi Nai-Shun , Wong John
Published: October 2003

The mortality rate among children with fulminant hepatic failure (FHF) on the waiting list for cadaveric donor liver transplantation (CDLT) is high. Results of emergency CDLT in this situation often are unsatisfactory, and a long-term survival rate less than 30% has been reported. Live donor liver transplantation (LDLT) for FHF in children has been advocated, but is reported rarely. We present our experience with LDLT in children with FHF. Between September 1993 and December 2002, primary LDLT was performed for 26 children; 8 of these children had FHF. Patient demographics, clinical and laboratory data, surgical details, complications, and graft and patient survival are reviewed. Four boys and four girls received left-lateral segment (n = 7) and full left-lobe (n = 1) grafts. Mean age was 2.9 ± 1.2 years (range, 3 months to 11 years). Causes of FHF were drug induced in 2 patients and idiopathic in 6 patients. One child received a blood group-incompatible graft. Two patients died; 1 patient of cytomegalovirus infection at 8.6 months and 1 patient of recurrent hepatitis of unknown cause at 2.8 months after LDLT. The child who received a mismatched graft had refractory rejection and underwent a second LDLT with a blood group-compatible graft 19 days afterward. He eventually died of lymphoproliferative disease. Another patient developed graft failure related to venous outflow obstruction and survived after retransplantation with a cadaveric graft. With a median follow-up of 13.2 months (range, 2.8 to 60.3 months), actuarial graft and patient survival rates were 50% and 62.5%, respectively. Survival results appear inferior compared with those of 18 children who underwent LDLT for elective conditions during the same study period (graft survival, 89%; P = .051; patient survival, 89%; P = .281). Although survival outcomes are inferior to those in elective situations, LDLT is a timely and lifesaving procedure for children with FHF.
Liver transplantation for growing teratoma syndrome: Report of a case
Authors: Eghtesad Bijan , Marsh Wallis J. , Cacciarelli Thomas , Geller David , Reyes Jorge , Jain Ashok , Fontes Paulo , DeVera Michael , Fung John
Published: October 2003

Liver transplantation is a well-established treatment for liver failure and for a selected group of patients with hepatic tumors. The growing teratoma syndrome refers to the phenomenon whereby germ cell tumors enlarge after chemotherapy despite complete eradication of malignant cells and normalization of serum tumor markers. We present the case of a young patient with rapidly growing teratomatous masses in his liver who was treated with liver transplantation from a live donor. We discuss his postoperative management, follow-up, and briefly review literature on the subject.
Cognitive dysfunction and health-related quality of life in long-term liver transplant survivors
Authors: Lewis Mark B. , Howdle Peter D.
Published: October 2003

Although several studies have investigated short-term effects of liver transplantation on cognitive function and health-related quality of life, there have been no studies looking at long-term effects. Patients who received a single liver transplant at St James’s University Hospital (Leeds, UK) before October 1, 1991, were invited to participate in this cross-sectional study. Cognitive function was assessed using the Mini-Mental State Examination, the Rey Auditory Verbal Learning Test, trail-making tests, the Stroop test, and the Benton Visual Retention Test. Anxiety and depression were documented using the Hospital Anxiety and Depression Scale. Health-related quality of life was assessed using the EuroQol. Twenty-five healthy volunteers acted as controls. Thirty-six patients had undergone transplantation before October 1, 1991. Thirteen patients (36%) had died, 6 patients had received more than one transplant, 2 patients did not speak English, and 3 patients did not want to participate, leaving 12 patients included in the study. Patients scored significantly lower on measures of health-related quality of life than healthy controls, but there were no differences in levels of anxiety or depression. Patients scored significantly lower than controls across a wide range of cognitive functions, suggesting global cognitive impairment. We show that patients who survive for more than 10 years after liver transplantation have significant cognitive dysfunction and poor health-related quality of life. Whether these patients never return to normal after transplantation or whether they experience an increased rate of decline in cognitive function and health-related quality of life is uncertain and requires further study.
Oxygen availability during orthotopic liver transplantation
Authors: Kostopanagiotou Georgia , Smyrniotis Vassilios , Theodoraki Kassiani , Skalkidis Yannis , Heaton Nigel , Potter Dennis
Published: October 2003

Studies have stressed the role of adequate tissue oxygenation in the light of an optimal patient outcome and allograft viability in liver transplantation. The practice of monitoring conventional hemodynamic parameters during liver transplantation could be complemented by parameters assessing real oxygen availability. In the present prospective study, real arterial available oxygen content (CavlO2) and its extraction ratio (O2ERavl) were calculated. These parameters include the effect of changes in oxyhemoglobin dissociation curve (ODC; expressed by P50) on oxygen availability, under the different circumstances occurring during liver transplantation. Sixteen adult cirrhotic patients were studied during orthotopic liver transplantation with the use of venovenous bypass. Classic hemodynamic measurements using a Swan-Ganz thermodilution catheter and arterial and mixed venous blood gas analysis were performed, and P50, oxygen delivery index (DO2 ind), oxygen consumption index (VO2 ind), oxygen extraction ratio (O2ER), CavlO2, and O2ERavl were calculated. Statistical analysis was performed using ANOVA for repeated measures and Spearman correlation coefficient matrix among the six variables (DO2 ind, VO2 ind, O2ER, P50, CavlO2, and O2ERavl) taken two at a time at every phase. Parameter P50 changed from 25.98 ± 1.10 to 23.15 ± 2.24 (at the end of operation). A leftward shift of the ODC was observed. The results showed positive association between P50 and CavlO2 after the removal of the native liver, and a weak and inconsistent relation of DO2 ind with any of the other study variables. The intraoperative changes in P50 values, which represent a shift of the ODC to the left, may reflect a more accurate estimation of O2 release to the tissues, than the hemoglobin, Pao
2 and Sao
2 alone. Besides conventional hemodynamic parameters, P50, which includes the effect of alterations in ODC on oxygen availability, could be of value in monitoring the systemic oxygenation during liver transplantation.
Host and donor risk factors before and after liver transplantation that impact HCV recurrence
Authors: Berenguer Marina
Published: October 2003

Key points

1. The natural history of hepatitis C after liver transplantation is variable. Several factors, including those related to the virus, the host, the environment and the donor, are probably implicated in the outcome.

2. The immune status per se likely represents the main significant variable in influencing disease severity in hepatitis C virus-infected patients. Findings that support this statement include the higher aggressivity of hepatitis C in immunocompromised liver transplant recipients as compared with that observed in immunocompetent patients, both before and after the development of compensated cirrhosis, and the significant association described between the degree of immunosuppression and disease severity.

3. Similar to that observed in the immunocompetent population, the age at the time of infection (age of the donor) strongly affects posttransplantation hepatitis C virus-related disease progression.

4. Hepatitis C-related disease progression is faster in patients who underwent transplantation in recent years as compared with those who underwent transplantation in earlier cohorts. The increasing age of the donor and the use of stronger immunosuppression may, in part, explain the worse outcomes seen in recent years.

5. Additional host-related variables predictive of outcome include the immunogenetic background, the timing of recurrence, and the early histologic findings.
Liver biopsy, viral kinetics, and the impact of viremia on severity of hepatitis C virus recurrence
Authors: Charlton Michael
Published: October 2003

Key points

1. Nearly all recipients who are chronically infected with hepatitis C virus (HCV) at the time of liver transplantation will have HCV RNA detectable postoperatively.

2. HCV replication can begin as early as the first postoperative week.

3. HCV levels fall significantly during the anhepatic phase of liver transplantation and continue to fall during the first 12-24 hours posttransplantation.

4. Serum HCV RNA levels typically increase rapidly from the second week posttransplantation and peak by the fourth postoperative month. HCV RNA levels at one year posttransplantation are 10-20 fold greater than pretransplant levels.

5. Corticosteroid treatment for acute cellular rejection is associated with large increases in HCV RNA levels.

6. HCV RNA levels do not appear to vary with choice of calcineurin inhibitor.

7. Early HCV RNA levels are predictive of subsequent histological severity of recurrence.

8. A correlation between early levels of viremia and subsequent allograft injury suggests that initiation of antiviral therapy early in the posttransplant course might be desirable.
Treatment of patients with hepatitis C virus on the waiting list
Authors: Everson Gregory T.
Published: October 2003

Key points

1. Over 90% of patients with hepatitis C on the waiting list might be candidates for therapy with interferon plus ribavirin.

2. One must exercise caution in the treatment of these patients. Those with Child-Turcotte-Pugh score >11 or Model for End-Stage Liver Disease score >25 should be excluded from treatment.

3. Sustained virologic response (hepatitis C virus RNA-negative) is mainly dependent on viral genotype, with 50% of genotype 2 and 3 patients achieving sustained virologic response.

4. The ability to achieve sustained virologic response in genotype 1 patients is dependent on dose and duration of treatment.

5. Patients rendered hepatitis C virus RNA-negative pretransplantation may not experience posttransplantation recurrence.
The natural history and outcome of liver transplantation in hepatitis C virus-infected recipients
Authors: Gane Edward
Published: October 2003

Key points

1. Recurrence of hepatitis C infection is universal and immediate after liver transplantation.

2. Graft and patient survival is reduced in liver transplantation recipients with recurrent hepatitis C virus infection compared with hepatitis C virus-negative recipients.

3. The natural history of chronic hepatitis C is accelerated after liver transplantation compared with nontransplantation chronic hepatitis C; 20% to 40% of patients progress to allograft cirrhosis within 5 years, compared with less than 5% of nontransplantation patients.

4. The rate of fibrosis progression is not uniform and may change over time.

5. The rate of progression from cirrhosis to decompensation is accelerated after liver transplantation. The rate of decompensation is >40% at 1 year and >60% at 3 years, compared with <5% and <10%, respectively, in immunocompetent patients.

6. The rate of progression from decompensation to death is also accelerated after liver transplantation. The 3-year survival is <10% after the onset of hepatitis C virus-related allograft failure, compared with 60% after decompensation in immunocompetent patients.
The use of hepatitis C-infected grafts in liver transplantation
Authors: Arenas Juan I. , Vargas Hugo E. , Rakela Jorge
Published: October 2003

Key points

1. Liver grafts from hepatitis C virus (HCV)-infected deceased donors can be used safely in HCV-infected recipients.

2. Histological assessment of the graft before orthotopic liver transplantation (OLT) is advised.

3. Recipients of these grafts should give consent accordingly.

4. The course of HCV disease after OLT parallels that in patients who received noninfected organs.
Hepatitis C pathogenesis: Mechanisms of viral clearance and liver injury
Authors: Rosen Hugo R.
Published: October 2003

Key points

1. The development of hepatitis C virus (HCV) quasispecies has a number of biological consequences, including the development of escape mutants to humoral or cellular immunity, the generation of “defective” viral particles, variable cell tropism, and the development of drug resistance.

2. Accumulating evidence shows that HCV affects the early innate immune response mediated by natural killer and dendritic cells.

3. Recent data suggest that clearance of HCV bestows antibody to HCV immunity that affords partial protection against persistent infection. However, after spontaneous recovery from HCV infection, titers of HCV-specific antibodies decline and disappear in a subset of patients, whereas viral-specific CD4+ and CD8+ T-cell responses persist for decades.

4. HCV-specific CD8+ T-cell responses are phenotypically and functionally diverse and may be associated with either viral eradication or chronic hepatic immunopathologic states.

5. Novel HCV genome-wide screening approaches have shown that the breadth of the immune response is considerably greater than was initially appreciated using more conventional assays, but why the majority of patients remain chronically infected despite the presence of viral-specific immune responses remains undefined
Natural history and risk factors for progression of hepatitis C virus disease and development of hepatocellular cancer before liver transplantation
Authors: Shiffman Mitchell L.
Published: October 2003

Key points

1. Chronic infection with hepatitis C virus (HCV) is the leading cause of cirrhosis and the most common indication for liver transplantation in many countries throughout the world.

2. The most significant factors leading to fibrosis progression in patients with chronic HCV infection include the degree of inflammation present on liver biopsy and ongoing alcohol use.

3. Patients with cirrhosis secondary to chronic HCV infection are at increased risk for developing hepatocellular carcinoma (HCC).

4. Achieving a sustained virological response after treatment with interferon, with or without ribavirin, is associated with a reduced risk for the development of cirrhosis and HCC and prolonged survival.
Prophylactic and preemptive therapies for hepatitis C virus-infected patients undergoing liver transplantation
Authors: Terrault Norah A.
Published: October 2003

Key points

1. Preclinical data from chimpanzees and studies in hepatitis B virus/hepatitis C virus (HCV) coinfected transplant recipients suggest prophylactic HCV antibody therapy may have a role in the prevention of HCV recurrence.

2. There are insufficient data available to evaluate the efficacy of this therapeutic approach. A small study found no benefit. Other ongoing studies using alternative antibody preparations and more intensive dosing schedules are underway.

3. Preemptive antiviral therapy, started within the first 4 weeks posttransplantation and prior to the onset of clinical signs and symptoms, is effective in some patients (5-33%) and is not associated with an increased risk of acute rejection. Tolerability of antiviral agents in the early posttransplantation period may be a factor limiting treatment efficacy.

4. It is unclear whether the preemptive antiviral treatment is superior to delaying treatment until recurrent disease is present and controlled trials addressing this issue are needed.
Retransplantation for recurrent hepatitis C: The argument against
Authors: Wall William J. , Khakhar Anand
Published: October 2003

Key points

1. Cirrhosis from chronic hepatitis C is the most common indication for liver grafting today. The course of hepatitis C is accelerated after liver transplantation, and no current therapy reliably prevents or arrests it.

2. It is anticipated that 20% or more of hepatitis C virus-positive transplant recipients will develop allograft cirrhosis, and the only solution will be retransplantation.

3. Results of retransplantation are inferior to primary transplantation.

4. Recipient risk factors that adversely affect mortality after repeated liver grafting include age older than 50 years, renal insufficiency, and severity of hyperbilirubinemia. When present, they reduce survival after retransplantation to approximately 40% or less.

5. Retransplantation on a large scale for recurrent hepatitis C is problematic from the perspectives of outcome, resource utilization, and fairness to candidates awaiting primary grafts.
The role of immunosuppression in recurrence of hepatitis C
Authors: Lake John R.
Published: October 2003

Key points

1. Recurrent hepatitis C is an increasing problem posttransplantation.

2. It is difficult to determine histologically if alloimmunity, i.e., rejection, is also plays a role in posttransplantation hepatitis C.

3. Change in the degree of immunosuppression, rather than the absolute amount of immunosuppression, is bad for HCV-infected recipients.

4. Corticosteroid boluses are bad for HCV-infected recipients.
Impact of immunosuppression on immunopathogenesis of liver damage in hepatitis C virus-infected recipients following liver transplantation
Authors: McCaughan Geoffrey W. , Zekry Amany
Published: October 2003

Key points

1. Hepatitis C virus (HCV) infection in the allograft occurs in the setting of greater viral burdens than in patients pretransplantation.

2. Viral burden is increased by such immunosuppressive therapies as corticosteroids and interleukin-2 receptor antibodies.

3. Cholestatic HCV infection occurs in the setting of very high viral load and is almost certainly induced by overimmunosuppression. It is managed best by rapid reduction in levels of immunosuppression.

4. The more common chronic hepatitic HCV disease seems to behave at the molecular/cellular level in a fashion similar to the nontransplantation setting with activation of T helper subtype 1 inflammatory, profibrotic, and proapoptotic pathways. The role of immunosuppression in the acceleration of this disease is unclear, and rapid reduction in immunosuppressive doses may be detrimental.

5. Changes to definitions of types of HCV disease recurrence, disease severity, and acute allograft rejection in the presence of HCV infection are required to improve understanding of the pathogenesis.
An integrated system to measure the effective charge of fusion plasmas in the ASDEX Upgrade tokamak
Authors: Meister H. , Dux R. , Horton L. D. , Kurzan B. , Zohm H. ,   the ASDEX Upgrade Team, McCarthy P. J.
Published: October 2003

At the ASDEX Upgrade tokamak a new approach has been developed to determine the profiles of the effective charge (Zeff) from bremsstrahlung emission in hot fusion plasmas. The signals of all diagnostics measuring bremsstrahlung have been incorporated into one evaluation algorithm, resulting in the possibility to check whether or not signals are disturbed during each discharge. Especially helpful to this aim is a recently installed diagnostic measuring the bremsstrahlung spectrally resolved by using a spectrometer and a charge-coupled-device (CCD) camera as a detector. The experimental results are verified qualitatively and quantitatively using a discharge with silicon laser blow-off. Modeling of the bremsstrahlung as measured with the CCD camera using the routines and data of the ADAS package reveals that the background of the spectra is dominated by bremsstrahlung for most sight lines. Only those passing mainly outside the last closed flux surface measure a considerable amount of line and molecular band radiation. This edge emission can be considered as a radiative mantle. Subtracting it from all other signals results in reduced statistical errors of the deduced Zeff profiles while not changing the profile shape inside a normalized minor radius of 0.8.
Interchangeability of genotypes and growth locations for high-quality, high-protein wheat production in Australia
Authors: Skerritt J. H. , Heywood R. H. , Ellison F. , Kammholz S. J. , Allen H. M.
Published: October 2003

The aim of this study was to assess whether the recent finding that 4 Prime Hard wheat varieties grown at southern sites provided flour of comparable quality with that from northern sites is likely to be generally applicable to other varieties, as this is especially important as new varieties are developed. The grain, dough processing, and baking properties of samples from 4 sets of lines, each grown over 2 seasons at 2 northern and 2 southern sites, was assessed. The samples included 2 sets of doubled haploid lines (one derived from Hartog × Klasic, differing only at Glu-A3, and the other Hartog × CD-87, differing at 5 glutenin loci), and 2 sets of F8 crossbred lines (from Janz/Hartog and Janz*2/Dollarbird, permitting an additional comparison of effects of allelic variation at the Glu-D1 locus). Approximately similar grain protein contents were obtained at one pair of northern and southern sites (respectively Narrabri and Ariah Park, 12–14%) and a second pair of northern and southern sites (respectively Roma and Walpeup, 14–17%, although the latter was consistently higher). The results demonstrated that the grain, dough, and baking properties of the lines were broadly similar at each protein content, and that in general, grain from the southern sites had comparable quality characteristics with that from the northern sites. However, in 1997, the Walpeup southern site suffered very dry conditions late in grain filling, and several of the grain samples were of low size and poor flour milling extraction rate and colour. In 1998, wet conditions late in the season meant that the grain at Ariah Park was lower in protein content and doughs were of lower extensibility and produced depressed loaf volumes. The variation in glutenin subunit composition also permitted the conduct of a detailed comparison of allelic influences on flour processing and baking properties at 4 sites and in 4 backgrounds. This revealed significant effects of allelic variation at Glu-B1, Glu-D1, and Glu-B3 on dough properties, with the effect of Glu-B1 differing between sets of lines.
Organic acid exudation associated with aluminium stress tolerance in triticale and wheat
Authors: Zhang X. G. , Jessop R. S. , Alter D.
Published: October 2003

Three triticale cultivars differing in aluminium (Al) stress response, together with 1 Al-tolerant wheat cultivar (Carazinho) and 1 Al-tolerant wheat line (ET3), were used to investigate the root exudation of organic acids during Al stress. The likely relationship of organic acid exudation with Al tolerance, as assessed by root regrowth in nutrient solutions, was also examined. An enzymatic assay was used to detect malate release from both root tips and the whole root system; high performance liquid chromatography (HPLC) was also used to measure the exudation of organic acids from Al-stressed root tips. The enzymatic assay revealed some associations between Al tolerance and malate efflux from Al-stressed wheat or triticale roots, although Al-tolerant triticale cvv. Tahara and 19th ITSN 70-4 released less malate than the Al-tolerant wheat. HPLC analysis indicated that malate and citrate were not the main exudates related to the different levels of Al tolerance in these triticale cultivars. A yet to be identified organic acid in 19th ITSN 70-4 showed significant concentration differences from 2 other cultivars tested. This study highlighted the importance and necessity of elucidating the biochemical mechanisms involved in Al stress tolerance in triticale and other crops.
Effects of combined Actinobacillus pleuropneumoniae challenge and change in environmental temperature on production, plasma insulin-like growth factor I (IGF-I), and cortisol parameters in growing pigs
Authors: Kerr C. A. , Eamens G. J. , Briegel J. , Sheehy P. A. , Giles L. R. , Jones M. R.
Published: October 2003

There is limited information on the combined effects of stress factors on physiological and endocrinological parameters in growing pigs. This study measured the effects of pleuropneumonia and changes in environmental temperature singularly and in combination. Forty entire male pigs (liveweight 33 ± 5 kg) were allocated to 1 of 4 treatments: control (22�C room temperature), Actinobacillus pleuropneumoniae challenge (Day�1), temperature stress (15�C for 8 h on Days 0, 1, and 2, and 30�C for 24 h on Day 6), or combined A.�pleuropneumoniae challenge and temperature stress. Control pigs had an average daily gain of 1.15 ± 0.12 kg/day and an average daily feed intake of 2.29 ± 0.06 kg/day over 8 days. Challenge with A. pleuropneumoniae caused a reduction (P < 0.001) in feed intake, weight gain, and plasma insulin-like growth factor I (IGF-I) concentration and an increase (P < 0.001) in plasma cortisol concentration. There was no significant effect of the temperature stress on circulating cortisol and IGF-I concentrations or liveweight gain. Thus, the treatment effects did not appear to be additive and the effects of the A. pleuropneumoniae challenge were more profound than changes in ambient air temperature.
Rice F1 hybrids: the breeding goal or a costly solution?
Authors: Ntanos D. A. , Roupakias D. G.
Published: October 2003

Whether to develop inbred cultivars or F1 hybrids is a dilemma faced by many rice (Oryza sativa L.) breeders. This could be partially answered if one could select superior recombinant inbred lines with an equal yielding ability and good quality traits from commercial F1 hybrids. Thus, it was attempted in this study to select superior inbred lines from 2 commercial F1 hybrids after application of honeycomb selection and panicle-to-row selection. The 2 F2 populations were advanced to F6 generation by both methods and, finally, 5 F5:6 lines with high yield potential and good grain quality were selected from each population and selection method and were tested in a randomised complete block design for 2 years in Kalochori, Thessaloniki, Greece. In each case the respective F1 hybrid and the check cultivar Strymonas were used as checks. Fourteen of the 20 lines selected by honeycomb selection and panicle-to-row selection from both populations exhibited a yielding ability that was not significantly different from the yield of the F1 hybrids in both years. Three of them, however, in 1 of the 2 years, had a significantly higher grain yield than the corresponding F1 hybrid. In addition, 6 of the above lines exhibited significantly higher values for more than 1 of the 4 quality traits (total milling yield, grain vitreosity, grain length, and grain length/width ratio) and they were not inferior for the remaining ones. It was concluded that application of combined selection for yield and quality could lead to the isolation of recombinant inbred lines with equal yielding ability and quality equal to or higher than the F1 hybrids. This, together with the higher cost associated with hybrid technology, indicates that the long-term goal of a rice-breeding program should be the production of superior inbred lines, unless hybrid production cost is low and quality is not critical for the particular market.