bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time‐course changes in the expression of Na, K‐ATPase and the morphometry of mitochondrion‐rich cells in gills of euryhaline tilapia (Oreochromis mossambicus) during freshwater acclimation
Authors: Lin Chia‐Hao , Huang Chao‐Lu , Yang Chi‐Hwa , Lee Tsung‐Han , Hwang Pung‐Pung 
Published: December 2003

AbstractChanges in expression of Na, K‐ATPase (NKA) and morphometry of mitochondrion‐rich (MR) cells in gills of tilapia were investigated on a 96–hr time course following transfer from seawater (SW) to fresh water (FW). A transient decline in plasma osmolality and Na+, Cl− concentrations occurred from 3 hrs onward. Gills responded to FW transfer by decreasing NKA activity as early as 3 hrs from transfer. This response was followed by a significant decrease in the NKA isoform α1–mRNA abundance, which was detected by real‐time PCR at 6 hrs post transfer. Next, a decrease of α1–protein amounts were observed from 6 hrs until 24 hrs post transfer. Additionally, during the time course of FW transfer, modifications in number and size of subtypes of gill MR cells were observed although no significant difference was found in densities of all subtypes of MR cells. These modifications were found as early as 3 hrs, evident at 6 hrs (exhibition of 3 subtypes of MR cells), and mostly completed by 24 hrs post transfer. Such rapid responses (in 3 hrs) as concurrent changes in branchial NKA expression and modifications of MR cell subtypes are thought to improve the osmoregulatory capacity of tilapia in acclimation from hypertonic SW to hypotonic FW. J. Exp. Zool. 301A:85–96, 2004. © 2004 Wiley‐Liss, Inc.
Modulation of gill Na+,K+‐ATPase activity by ammonium ions: Putative coupling of nitrogen excretion and ion uptake in the freshwater shrimp Macrobrachium olfersii
Authors: Furriel Rosa Prazeres Melo , Masui Douglas Chodi , Mcnamara John Campbell , Leone Francisco Assis 
Published: December 2003

AbstractThe effect of NH4+ ions on (Na+ ,K+)‐ATPase hydrolytic activity was examined in a gill microsomal fraction from M. olfersii. In the absence of NH4+ ions, K+ ions stimulated ATP hydrolysis, exhibiting cooperative kinetics (nH=0.8), to a maximal specific activity of V=556.1±22.2 nmol.min−1.mg−1 with K0.5=2.4±0.1 mmol.L−1. No further stimulation by K+ ions was observed in the presence of 50 mmol.L−1 NH4+ ions. ATP hydrolysis was also stimulated by NH4+ ions obeying Michaelian kinetics to a maximal specific activity of V=744.8±22.3 nmol.min−1.mg−1 and KM=8.4±0.2 mmol.L−1. In the presence of 10 mmol.L−1 K+ ions, ATP hydrolysis was synergistically stimulated by NH4+ ions to V=689.8±13.8 nmol.min−1.mg−1 and K0.5=6.6±0.1 mmol.L−1, suggesting that NH4+ ions bind to different sites than K+ ions. PNPP hydrolysis was also stimulated cooperatively by K+ or NH4+ ions to maximal values of V= 235.5±11.8 nmol.min−1.mg−1 and V=234.8±7.0 nmol.min−1.mg−1, respectively. In contrast to ATP hydrolysis, K+ ‐phosphatase activity was not synergistically stimulated by NH4+ and K+ ions. These data suggest that at high NH4+ ion concentrations, the (Na+, K+)‐ATPase exposes a new site; the subsequent binding of NH4+ ions stimulates ATP hydrolysis to rates higher than those for K+ ions alone. This is the first demonstration that (Na+, K+)‐ATPase activity in a freshwater shrimp gill is modulated by ammonium ions, independently of K+ ions, an effect that may constitute a fine‐tuning mechanism of physiological relevance to osmoregulatory and excretory processes in palaemonid shrimps. J. Exp. Zool. 301A: 63–74, 2004. © 2004 Wiley‐Liss, Inc.
A firm level analysis of trade, technology and employment in South Africa
Authors: Edwards Lawrence 
Published: December 2003

AbstractThis paper uses two firm level surveys, the National Enterprise (NE) survey and the Greater Johannesburg Metropolitan Area (GJMA) survey, to explore the implications of globalization for employment in South Africa. These relationships are explored using cross‐tabulations and estimated labour demand functions. The paper finds that rising import penetration negatively affected employment in large firms, but not small firms. Relatively large declines in employment also occurred within export firms, despite improvements in export competitiveness and export growth through trade liberalization. Finally, the study finds that skill‐biased and trade‐induced technological change, as reflected in increased use of computers, foreign investment and the importation of raw material inputs, have raised the skill intensity of production. Copyright © 2004 John Wiley & Sons, Ltd.
The impact of European market changes on employment in the Kenyan horticulture sector
Authors: Humphrey John , McCulloch Neil , Ota Masako 
Published: December 2003

AbstractIn Kenya, exports of fresh vegetables have grown rapidly in the past decade, but the employment impact of this business has been changing as a result of market conditions in the major export destination, the United Kingdom. Continued rapid growth in overall exports, an increase in post‐harvest processing, a switch from smallholder production to exporters' own plantations, and price shocks such as tariff changes and shifts in transport costs. A simulation exercise demonstrates that the positive impact on employment of continued export growth and increased post‐harvest processing is much greater than any likely reduction in employment resulting from the shift away from smallholder production. Copyright © 2004 John Wiley & Sons, Ltd.
Squaring the circle: global production and the informalization of work in South African fruit exports
Authors: Barrientos Stephanie , Kritzinger Andrienetta 
Published: December 2003

AbstractSouth African fruit growers simultaneously face rising standards imposed within supermarket global value chains, falling market prices internationally, and increasing government legislation. These pressures are leading to falling permanent employment and increasing use of contract labour on fruit farms, tempered by the need to employ skilled workers to meet quality and labour standards. Informal contract employment provides some (male) workers with regular work at relatively good pay, but others (particularly women) work for short periods at low pay. None enjoy work security or employment benefits. The informality of work intensifies their risks and vulnerability to poverty. Copyright © 2004 John Wiley & Sons, Ltd.
Vietnam in the global garment and textile value chain: impacts on firms and workers
Authors: Nadvi Khalid , Thoburn John T. , Thang Bui Tat , Ha Nguyen Thi Thanh , Hoa Nguyen Thi , Le Dao Hong , Armas Enrique Blanco De 
Published: December 2003

AbstractOver the course of little more than a decade, Vietnam has become a significant exporter of garments to the EU and Japan, and now to the US too. Based on interviews with firms and buyers, and analysis of trade data, this paper traces how Vietnamese garment and textile firms are inserted into global garment and textile value chains. It considers ties between the Vietnamese garment and textiles industries. And, it reflects on how the nature of insertion into global value chains leads to differentiated gains for state owned and private enterprises, and for textile and garment workers. Copyright © 2004 John Wiley & Sons, Ltd.
Globalization and the South African textiles industry: impacts on firms and workers
Authors: Roberts Simon , Thoburn John T. 
Published: December 2003

AbstractSouth Africa has been integrating into the global economy since the early 1990s through a rapid programme of trade liberalization. Its textile industry—an activity important in manufacturing value‐added in most developing countries—illustrates the effects of this policy on firms and their employment and wage payments, which are among the most important channels through which trade shocks affect poverty in an economy. Exporting has been driven by trade liberalization, but the restructuring of firms has involved substantial falls in total textile employment, while production has stagnated. Labour productivity has increased and average real wage payments have risen. Copyright © 2004 John Wiley & Sons, Ltd.
Prevalence of human T‐cell leukemia virus types I and II in Switzerland
Authors: Böni Jürg , Bisset Leslie R. , Burckhardt Johann J. , Joller‐Jemelka Helen I. , Bürgisser Philippe , Perrin Luc , Gorgievski Meri , Erb Peter , Fierz Walter , Piffaretti Jean‐Claude , Schüpbach Jörg 
Published: December 2003

AbstractThe retroviruses human immunodeficiency virus (HIV)‐1/2 and human T‐cell leukemia virus (HTLV)‐I/II share modes of transmission, suggesting that efforts to monitor the current HIV‐1 epidemic in Switzerland should be complemented by assessment of HTLV‐I/II prevalence. This study presents an updated evaluation of HTLV‐I/II infection among groups within the Swiss population polarized towards either low or increased risk of infection. Archived serum and peripheral blood mononuclear cell (PBMC) samples were examined for evidence of HTLV‐I/II infection by enzyme‐linked immunosorbant assay (ELISA), type‐specific Western blot, type‐specific polymerase chain reaction (PCR), DNA sequence analysis, and virus culture. Among blood donations obtained from low‐risk Swiss donors, we report a complete lack of HTLV‐II infection and the occurrence of HTLV‐I infection limited to a prevalence of 0.079 per 100,000 (1/1,266,466). Among high‐risk HIV‐positive persons and HIV‐negative persons at increased risk of HIV‐infection, we report a focus of HTLV‐I and HTLV‐II infection at prevalence rates of 62 per 100,000 (1/1,620) and 309 per 100,000 (5/1,620), respectively. The finding of low HTLV‐I/II prevalence among Swiss blood donors and containment of HTLV‐I/II infection within known risk‐groups does not support initiation of HTLV‐I/II screening for Swiss blood, tissue, and organ donations. J. Med. Virol. 72:328–337, 2004. © 2004 Wiley‐Liss, Inc.
Intrahepatic CD8 T‐lymphocytes and HBV core expression in relation to response to antiviral therapy for chronic hepatitis B patients
Authors: Tang Thjon J. , de Man Robert A. , Kusters Johannes G. , Kwekkeboom Jaap , Hop Wim C.J. , van der Molen Renate G. , Schalm Solko W. , Janssen Harry L.A. 
Published: December 2003

AbstractRecognition of HBV‐infected hepatocytes by CD8 T‐lymphocytes is important for viral clearance. Expression of hepatitis B core antigen (HBcAg) in HBV‐infected hepatocytes can trigger this antiviral T‐cell response. The intrahepatic CD8 T‐lymphocytes and HBcAg expression were investigated in relation to response to antiviral therapy. Forty chronic HBeAg‐positive patients treated with either lamivudine (n = 20) or interferon‐alpha (n = 20) were investigated. Ten patients from each treatment group exhibited a response. Liver biopsies were carried out before and after therapy. CD8 T‐lymphocytes and HBcAg expression were detected by immunohistochemistry. The number of pretreatment intrahepatic CD8 T‐lymphocytes was significantly higher in responders (P = 0.008). In responders baseline nuclear HBcAg expression tended to be lower (P = 0.09). Cytoplasmic expression was not significantly different between responders and non‐responders (P = 0.46). The number of CD8 T‐lymphocytes correlated with cytoplasmic HBcAg (rs = 0.31; P = 0.04); CD8 T‐lymphocytes were situated in clusters of hepatocytes with cytoplasmic HBcAg. Longitudinal analysis showed a significant reduction of CD8 T‐lymphocytes after treatment in responders (P < 0.001). Multivariate analysis revealed pretreatment CD8 T‐lymphocytes and age as independent prognostic factors for response (n = 40). The number of pretreatment CD8 T‐lymphocytes was the only independent prognostic indicator for response to interferon‐alpha (P = 0.03); it was of borderline significance for lamivudine therapy (P = 0.06). It is concluded that the number of pretreatment intrahepatic CD8 T‐lymphocytes is an important predictor of response to HBV therapy with either interferon‐alpha or lamivudine. Response to therapy led to a significant reduction of intrahepatic CD8 T‐lymphocytes. Co‐localisation of CD8 T‐lymphocytes and HBcAg‐positive hepatocytes suggests antiviral activity predominantly at the site of maximum HBV replication. J. Med. Virol. 72:215–222, 2004. © 2004 Wiley‐Liss, Inc.
Virological significance of low‐level hepatitis B virus infection in patients with hepatitis C virus associated liver disease
Authors: Tanaka Takeshi , Inoue Kazuaki , Hayashi Yukiko , Abe Aki , Tsukiyama‐Kohara Kyoko , Nuriya Hideko , Aoki Yoshikazu , Kawaguchi Ryuji , Kubota Kiichi , Yoshiba Makoto , Koike Morio , Tanaka Satoshi , Kohara Michinori 
Published: December 2003

AbstractThe clinical and virological significance of low‐level viremia by hepatitis B virus (HBV) in hepatitis C virus (HCV)‐infected patients remains unclear. HBV‐DNA and HCV‐RNA were, therefore, quantitatively analyzed in livers and sera from co‐infected patients. HBV‐DNA and HCV‐RNA were quantitated using real‐time detection of polymerase chain reaction (RTD‐PCR), based on Taq‐Man chemistry, in 220 non‐HCV‐infected healthy volunteers and 93 HCV‐infected patients without detectable HBsAg. Serum HBV‐DNA was detected in 4 (1.8%) of 220 non‐HCV‐infected healthy volunteers and 32 (34.4%) of 93 HCV‐infected patients without detectable HBsAg. HCV‐infected patients displayed higher frequency of HBV infection than healthy volunteers (P < 0.0001). Hepatocellular carcinoma (HCC) was more frequent among co‐infected patients than among HCV mono‐infected patients (P < 0.001). However, quantities of HBV‐DNA in sera from co‐infected patients were very low (8–19,000 copies/ml). HBV‐DNA was detected in liver tissue from co‐infected patients at 2–20 copies per 100 hepatocytes, accounting for 1/1,000 to 1/10,000 of HBsAg positive patients. In livers of patients with HCC and HCV or HBV mono‐infection, the viruses existed predominantly in non‐cancerous tissue, with levels 10‐ to 1,000‐fold and 1‐ to 100‐fold higher than in cancerous tissue, respectively. In contrast, patients co‐infected with HCV and HBV displayed decreased HBV levels in non‐cancerous tissue, but no change in cancerous tissue. These results indicate that low‐level HBV infection exists in HCV‐infected patients. HCC was more common among HCV/HBV co‐infected patients than among HCV mono‐infected patients. HCV might initiate hepatocarcinogenesis, but does not necessarily determine progression to HCC. J. Med. Virol. 72:223–229, 2004. © 2004 Wiley‐Liss, Inc.
Increased prooxidant production and enhanced susceptibility to glutathione depletion in HepG2 cells co‐expressing HCV core protein and CYP2E1
Authors: Wen Feng , Abdalla Maher Y. , Aloman Costica , Xiang Jinhua , Ahmad Iman M. , Walewski Jose , McCormick Michael L. , Brown Kyle E. , Branch Andrea D. , Spitz Douglas R. , Britigan Bradley E. , Schmidt Warren N. 
Published: December 2003

AbstractHepatitis C virus (HCV) and HCV core protein are hypothesized to induce hepatic oxidative stress and exacerbate injury caused by other toxins such as ethanol that induce the cytochrome P450 enzyme, CYP2E1. In the current study, the effects of HCV core protein [sequence genotype 1b, (nt 342–915)] on parameters indicative of oxidative stress were evaluated in HepG2 cells stably over expressing CYP2E1 (E47), or vector controls (C34). Stable (>10 passages) expression of HCV core protein and CYP2E1 was confirmed in clonal cell lines at the level of mRNA and immunoreactive protein. Prooxidant production, as determined by cellular oxidation of dichlorodihydrofluorescin and dihydroethidium (HE), was increased by expression of HCV core protein in the presence or absence of CYP2E1. Depletion of glutathione (GSH) with buthionine sulfoximine (BSO) enhanced prooxidant production in both C34 and E47 cells. In addition, prooxidant production was greater in BSO‐treated cells expressing HCV core protein, and this effect was further enhanced in cells expressing both HCV core and CYP2E1. The CYP2E1 inhibitor, 4‐methylpyrazole, could suppress increased prooxidant production in E47 cells. Finally, cells co‐expressing both CYP2E1 and HCV core protein showed significantly decreased viability following GSH depletion. These studies show simultaneous expression of HCV core protein and CYP2E1 increases parameters indicative of oxidative stress as well as sensitization to cell injury induced by GSH depletion. These results support the hypothesis that enhanced injury in hepatocytes over expressing both HCV core protein and CYP2E1 is mediated by increases in oxidative stress. J. Med. Virol. 72:230–240, 2004. © 2004 Wiley‐Liss, Inc.
Hepatitis A vaccine: Indirect evidence of immune memory 12 years after the primary course
Authors: Van Herck Koen , Van Damme Pierre , Lievens Marc , Stoffel Michel 
Published: December 2003

AbstractVaccine‐induced hepatitis A antibodies persist up to 10 years in adults, with mathematical models estimating further persistence up to 20–25 years. Thirty‐one adults received booster inoculations 12 years after their initial vaccination (Havrix™ 720 El.U at months 0, 1, 6). At the time of booster inoculation, all still had detectable antibodies. All but one subject met pre‐defined criteria for anamnestic response 14 days after the booster, and all subjects did so after 30 days. The subjects' geometric mean titre (GMT) increased rapidly from 242 IU/L at baseline to 3,832 IU/L at day 14 and 5,282 IU/L at day 30. This study shows a substantial immune response to re‐exposure to hepatitis A antigen after 12 years, which occurs rapidly to ensure protection within the average incubation period of hepatitis A virus. J. Med. Virol. 72:194–196, 2004. © 2004 Wiley‐Liss, Inc.
Seroprevalence of hepatitis A virus antibodies in Turkish and Moroccan children in Rotterdam
Authors: Richardus J.H. , Vos D. , Veldhuijzen I.K. , Groen J. 
Published: December 2003

AbstractSeasonal fluctuations in hepatitis A have been observed in the Netherlands related to Turkish and Moroccan children after visiting their home countries. This study determined the prevalence and associated factors of hepatitis A virus (HAV) antibodies in Turkish and Moroccan children in Rotterdam. A random sample was taken of children in Rotterdam, aged 5–16 years, of Turkish and Moroccan origin, together with a random sample of native Dutch children aged 5–7 and 14–16 years. Blood was collected by finger prick on filter paper. IgG and IgM anti‐HAV was detected by an enzyme‐linked immunoassay (EIA). The 319 Turkish, 329 Moroccan, and 248 native Dutch children participated in the study. In Turkish children, IgG anti‐HAV increased from 2.2% to 22.2% over the age groups. In Moroccan children, IgG anti‐HAV increased from 10.2% to 57.7%. In native Dutch children, 0.8% had IgG anti‐HAV in the youngest and 3.1% in the oldest age group. The percentage IgG‐positive also having IgM anti‐HAV was 21% in Turkish, and 41% in Moroccan children. No IgG‐positive native Dutch children had IgM anti‐HAV. The prevalence of IgG anti‐HAV was associated with increased age, being Moroccan, longer stay in the country of origin before migrating to the Netherlands, and known contact to HAV. The majority of Turkish and Moroccan children aged 4–16 years in Rotterdam are not protected against HAV, but do have a high risk of becoming infected while visiting their native country. Active vaccination against HAV of these children is indicated, with as primary aim their own protection. Prevention of HAV‐transmission in the general community should be seen as a secondary benefit. In addition, possible Dutch contacts of nonvaccinated Turkish and Moroccan children, such as day care workers and teachers, should also be vaccinated against HAV. J. Med. Virol. 72:197–202, 2004. © 2004 Wiley‐Liss, Inc.
Predictors of sustained response to therapy resumption after treatment interruption in HIV‐infected patients failing antiretroviral therapy
Authors: Gianotti Nicola , Soria Alessandro , Galli Laura , Castagna Antonella , Cernuschi Massimo , Hasson Hamid , Lazzarin Adriano 
Published: December 2003

AbstractIn order to evaluate whether a sustained virologic response to therapy resumption after treatment interruption can be achieved in the setting of virologic failure, we reviewed retrospectively the data relating to 56 human immunodeficiency virus (HIV)‐infected subjects selected from 3,145 patient charts. At the time of treatment interruption (study entry), the median (interquartile range) CD4+ counts and HIV‐RNA levels were respectively 247 (127–502) × 106 cells/L and 4.24 (3.68–5.02) log10 copies/ml, and the patients had been exposed to eight (5–9) antiretroviral drugs. After treatment interruption, the patients received at least three drugs depending on their treatment history. Forty‐eight weeks after the resumption of therapy, 19 of the 56 patients (34%) had HIV‐RNA levels of <400 copies/ml and, in comparison with study entry, the difference in the median increase in CD4+ counts between the virologic responders and non‐responders (83 vs. 8.5 × 106 cells/L) was statistically significant (P = 0.02). Multivariate analysis showed that higher peak HIV‐RNA levels before treatment interruption were independently predictive of virologic failure, whereas a longer treatment interruption period independently correlated with a virologic response. Four patients with CD4+ counts of <200 × 106 cells/L at study entry developed HIV‐related clinical events. A sustained virologic response to therapy resumption after treatment interruption can be achieved in the setting of virologic failure. An evaluation of clinical history may help to identify the patients who are more likely to respond. J. Med. Virol. 72:181–186, 2004. © 2004 Wiley‐Liss, Inc.
Presence of specific viruses in the middle ear fluids and respiratory secretions of young children with acute otitis media
Authors: Nokso‐Koivisto Johanna , Räty Riitta , Blomqvist Soile , Kleemola Marjaana , Syrjänen Ritva , Pitkäranta Anne , Kilpi Terhi , Hovi Tapani 
Published: December 2003

AbstractThe purpose of the study was to investigate the presence of different viruses in middle ear fluids and nasopharyngeal aspirates in young children with acute otitis media. Two cohorts of children (N = 329 and 611) were followed from 2 to 24 months of age in Finland in two prospective studies (Finnish Otitis Media Cohort Study and Finnish Otitis Media Vaccine Trial). During the study period, nasopharyngeal and middle ear fluid specimens for each acute otitis media event were examined for eight (Cohort Study) or ten (Vaccine Trial) common respiratory viruses; adenoviruses, influenza viruses A and B, parainfluenza viruses 1, 2, and 3, respiratory syncytial virus (RSV), enteroviruses, parechoviruses, and rhinoviruses. Picornaviruses (rhinoviruses, enteroviruses, and parechoviruses) were determined by reverse transcription PCR while antigen detection was used for the other viruses. A virus was present in either nasopharyngeal or middle ear specimen in 54% of events in the first cohort and in 67% of events in the second. Rhinoviruses formed the most common virus group detected (41–32%), followed by enteroviruses (25%, sought in the second cohort only) and respiratory syncytial virus (RSV) (10%). All the other viruses represented jointly 8–10% of the events. In conclusion, using the methods described in this study, a specific virus infection was diagnosed in two thirds of all acute otitis media events in young children. Picornavirus RNA was detected in association with more than a half of all acute otitis media events. The use of PCR‐based methods for the other respiratory viruses might have increased further the overall virus detection rate in acute otitis media. J. Med. Virol. 72:241–248, 2004. © 2004 Wiley‐Liss, Inc.