bluuebunny/crossref_metadata_2025 huggingface dataset:
Developmental and environmental regulation of chloride cells in young American shad, Alosa sapidissima
Authors: Zydlewski Joseph , McCormick Stephen D.
Published: August 2002

Location, abundance, and morphology of gill chloride cells were quantified during changes in osmoregulatory physiology accompanying early development in American shad, Alosa sapidissima. During the larval‐juvenile transition of shad, gill chloride cells increased 3.5‐fold in abundance coincident with gill formation, increased seawater tolerance, and increased Na+,K+‐ATPase activity. Chloride cells were found on both the primary filament and secondary lamellae in pre‐migratory juveniles. Chloride cells on both the primary filament and secondary lamellae increased in abundance (1.5‐ to 2‐fold) and size (2‐ to 2.5‐fold) in juveniles held in fresh water from August 31 to December 1 (the period of downstream migration) under declining temperature. This proliferation of chloride cells was correlated with physiological changes associated with migration (decreased hyperosmoregulatory ability and increased gill Na+,K+‐ATPase activity). Increases in chloride cell size and number of fish in fresh water were delayed and of a lower magnitude when shad were maintained at constant temperature (24°C). When juveniles were acclimated to seawater, chloride cell abundance on the primary filament did not (though size increased 1.5‐ to 2‐fold), but cells on the secondary lamellae disappeared. Na+,K+‐ATPase was immunolocalized to chloride cells in both fresh water and seawater acclimated fish. The disappearance of chloride cells on the secondary lamellae upon seawater acclimation is evidence that their role is confined to fresh water. The proliferation of chloride cells in fresh water during the migratory‐associated loss of hyperosmoregulatory ability is likely to be a compensatory mechanism for increasing ion uptake. J. Exp. Zool. 290:73–87, 2001. © 2001 Wiley‐Liss, Inc.
EM studies of female meiosis in wood lemmings with different sex chromosome constitutions
Authors: Akhverdyan Mikhayil , Fredga Karl
Published: August 2002

The chromosomes were studied throughout meiotic prophase by electron microscopy of surface‐spread oocytes from one XX, four X*X, and three X*Y female wood lemmings, Myopus schisticolor. The X* chromosome had originated from X by a deletion and an inversion in the short arm. The deletion was confirmed in pachytene cells from X*X females; a D‐loop was present in the sex bivalent in 16.8% of the cells, and asynapsis of unequal ends was seen in 9.1% of other cells. At late pachytene the D‐loop underwent synaptic adjustment. The breakpoints of the deletion are in G‐light bands. No inversion loop was seen, which also is in agreement with Ashley’s (’88) hypothesis; at least one of the presumed breakpoints of the inversion is in G‐dark chromatin. Various types of synaptic abnormalities, such as nonhomologous pairing (triple pairing, interchange, self‐synapsis), univalents, foldbacks, and broken lateral elements, were encountered in all types of female. X*Y females showed a high frequency of abnormal oocytes (70.7%), which significantly exceeded that of X*X (23.1%) and XX (8.1%). Univalents were particularly common in the X*Y females. J. Exp. Zool. 290:504–516, 2001. © 2001 Wiley‐Liss, Inc.
Effects of some steroids and other compounds on ovarian growth of the red swamp crayfish, Procambarus clarkii, during early vitellogenesis
Authors: Rodríguez Enrique M. , Medesani Daniel A. , Greco Laura S. López , Fingerman Milton
Published: August 2002

The effects of spiperone, a dopaminergic receptor blocker, the terpenoid JHIII, and the steroids 17α‐hydroxyprogesterone and 17β‐estradiol (10–7 mol/crayfish) were assayed in vivo on females of the red swamp crayfish, Procambarus clarkii, during early vitellogenesis. All these compounds were injected twice a week for 3 weeks. The rate of molting in response to these compounds was also determined. At the end of the experiment the ovaries were dissected out, in order to determine the gonadosomatic indexes and oocyte diameters. Spiperone, 17α‐hydroxyprogesterone, and 17β‐estradiol produced a significant increase in the gonadosomatic index, while only the first two compounds were able to significantly increase the oocyte diameter; therefore, the effect of 17β‐estradiol the on gonadosomatic index could be merely due to increased water uptake by the ovary. Spiperone could be causing a decrease in secretion of the gonad and/or mandibular inhibiting hormones from the eyestalks, and 17α‐hydroxyprogesterone could be having a direct stimulatory effect on vitellogenin production. Concerning molting, of the compound tested, only JHIII had a significant (P < 0.05) stimulatory effect, producing a 100% molting rate versus 66.7% among the controls. J. Exp. Zool. 292:82–87, 2002. © 2002 Wiley‐Liss, Inc.
Convex‐round graphs are circular‐perfect
Authors: Bang‐Jensen Jørgen , Huang Jing
Published: August 2002

We show a connection between two concepts that have hitherto been investigated separately, namely convex‐round graphs and circular cliques. The connections are twofold. We prove that the circular cliques are precisely the cores of convex‐round graphs; this implies that convex‐round graphs are circular‐perfect, a concept introduced recently by Zhu [10]. Secondly, we characterize maximal Kr‐free convex‐round graphs and show that they can be obtained from certain circular cliques in a simple fashion. Our proofs rely on several structural properties of convex‐round graphs. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 182–194, 2002
The World Development Report: concepts, content and a Chapter 12*
Authors: Chambers Robert
Published: August 2002

The World Development Report (WDR) process set new standards for openness and consultation. Its concepts and content are a major advance on its 1990 predecessor. The intention that its concepts and content should be influenced by voices of the poor was partly fulfilled. Conceptually, the VOP findings support the multidimensional view of poverty as ‘pronounced deprivation of wellbeing’, and the use of income‐poverty to describe what is only one dimension of poverty (though this welcome usage is not consistent throughout in the WDR). Two concepts or analytical orientations were not adopted: powerlessness and disadvantage seen as a multidimensional interlinked web; and livelihoods. On content, three areas where the influence fell short were: how the police persecute and impoverish poor people; the diversity of the poorest people; and the significance of the body as the main but vulnerable and indivisible asset of many poor people.

A weakness of the WDR is its lack of critical self‐awareness. Chapter 11 is self‐serving for the International Financial Institutions: it lumps loans with grants as concessional finance; it makes liberal use of the term donor, but never lender; and it does not consider debt avoidance as a strategy. The Report ends abruptly, a body without a head. Its multidimensional view of poverty is not matched by a multidimensional view of power and responsibility. A Chapter 12 is crying out to be written. This would confront issues of professional, institutional and personal commitment and change. It would stress critical reflection as a professional norm, disempowerment for democratic diversity as institutional practice, and personal values, attitudes and courageous behaviour as primary and crucial if development is to be change that is good for poor people. A new conclusion is suggested for the WDR, and a title for the World Development Report 2010. Copyright © 2001 John Wiley & Sons, Ltd.
The dorsal compartment locomotory control system in amphioxus larvae
Authors: Lacalli Thurston C.
Published: August 2002

Amphioxus myotomes consist of separate sets of superficial and deep muscle fibers, each with its own innervation, that are thought to be responsible for slow swimming and escape behavior, respectively. Tracings from serial EM sections of the anterior nerve cord in the larva show that the motoneurons and premotor interneurons controlling the superficial fibers (the dorsal compartment, or DC pathway) are linked by specialized junctions of a previously undescribed type, referred to here as juxta‐reticular (JR) junctions for the characteristic presence of a cisterna of endoplasmic reticulum on each side. JR junctions link the DC motoneurons with each other, with the largest of the anterior paired neurons (LPN3s) and with one class of ipsilateral projection neurons (IPNs), but occur nowhere else. Because of the paucity of synaptic input to the DC system, larval behavior can only be explained if the JR junctions act as functional links between cells. An analysis of the pattern of cell contacts also suggests that the LPN3s are probably pacemakers for both slow and fast locomotion, but act through junctions in the former case and conventional synapses in the latter. The only major synaptic input to the DC system identified in somites 1 and 2 was from four neurons located in the cerebral vesicle, referred to here as Type 2 preinfundibular projection neurons (PPN2s). They have unusually large varicosities, arranged in series, that make periodic contacts with the DC motoneurons. More caudally, the DC motoneurons receive additional input via similar large varicosities from the receptor cells of the first dorsal ocellus, located in somite 5. The overall circuitry of the locomotory control system suggests that the PPN2s may be instrumental in sustaining slow swimming, whereas mechanical stimulation, especially of the rostrum, preferentially activates the fast mode. J. Morphol. 252:227–237, 2002. © 2002 Wiley‐Liss, Inc.
Binding of synthetic peptides by a human monoclonal IgM with an unusual combining site structure
Authors: Edmundson Allen B. , Tribbick Gordon , Plompen Sonja , Geysen H. Mario , Yuriev Elizabeth , Ramsland Paul A.
Published: August 2002

Using X‐ray crystallography, a human monoclonal IgM cryoglobulin (Mez) was found to have an unusual combining site topography. Analysis of the unliganded Fv at 2.6 Å resolution revealed that the HCDR3 had partitioned the active site into two compartments [Ramsland PA et al. 2000. Mol. Immunol. 37: 295–310]. The two cavities had dimensions and chemical properties that were compatible with the binding of peptides. In this study, libraries of peptides were prepared using solid‐phase synthesis. Binding of the intact Mez IgM to these peptides was tested by enzyme‐linked immunoassays. Screening of 400 dipeptides revealed that binding was markedly skewed toward amino acids with aromatic side‐chains (Phe and Trp), especially when located in the second position. Preferential recognition of aromatic side‐chains by Mez IgM was confirmed with larger peptides of three to five residues, but C‐terminal positioning was not favored in these peptides. Mez IgM also showed binding propensities for acidic residues (Asp and Glu) as well as several other side‐chains with different chemical properties, including His, Pro, Asn and Gln. Mez IgM recognized sets of overlapping octapeptides representing the sequences of the constant domains of human IgG1 heavy chains. These peptides represented similar stretches of polypeptide on the three‐dimensional structures of all three constant domains (CH1, CH2 and CH3). Thus, Mez IgM may recognize structurally homologous regions of immunoglobulin domains, which were conserved during the evolution of the immune system. Copyright © 2001 John Wiley & Sons, Ltd.
Functional mapping of conserved, surface‐exposed charges of antibody variable domains
Authors: Weidenhaupt Marianne , Khalifa Myriam Ben , Hugo Nicolas , Choulier Laurence , Altschuh Danièle , Vernet Thierry
Published: August 2002

Surface‐exposed charges can affect protein structure, stability and solubility as well as the kinetics of both the folding process and interaction with binding partners. We have investigated the influence on kinetic interaction parameters of 14 conserved, surface‐exposed charges located away from the paratope in the variable domains of two antibodies of different specificity. We found that conserved, surface‐exposed, charged framework residues are asymmetrically distributed on opposite faces of both VH and VL domains. Some of the charges play a critical role in protein folding and stability. While electrostatic forces within or close to the binding interface can be used to optimize the association rate, we confirmed the predicted minor effects of charge modifications remote from the binding site. They had no effect on the dissociation rate parameter. Our study demonstrates the role of residues remote from the interaction site in the recognition function as well as the limited effect of surface charge modifications in antibody fragments on kinetic interaction parameters. Copyright © 2002 John Wiley & Sons, Ltd.
A computational analysis of substrate binding strength by phosphorylase kinase and protein kinase A
Authors: Brinkworth Ross I. , Horne James , Kobe Bostjan
Published: August 2002

Protein kinases exhibit various degrees of substrate specificity. The large number of different protein kinases in the eukaryotic proteomes makes it impractical to determine the specificity of each enzyme experimentally. To test if it were possible to discriminate potential substrates from non‐substrates by simple computational techniques, we analysed the binding enthalpies of modelled enzyme–substrate complexes and attempted to correlate it with experimental enzyme kinetics measurements. The crystal structures of phosphorylase kinase and cAMP‐dependent protein kinase were used to generate models of the enzyme with a series of known peptide substrates and non‐substrates, and the approximate enthalpy of binding assessed following energy minimization. We show that the computed enthalpies do not correlate closely with kinetic measurements, but the method can distinguish good substrates from weak substrates and non‐substrates. Copyright © 2002 John Wiley & Sons, Ltd.
Lack of mutagenic and co‐mutagenic effects of magnetic fields during magnetic resonance imaging
Authors: Schreiber Wolfgang G. , Teichmann Elke M. , Schiffer Ilka , Hast Jochem , Akbari Wahida , Georgi Hildegart , Graf Robert , Hehn Michael , Spieβ Hans W. , Thelen Manfred , Oesch Franz , Hengstler Jan G.
Published: August 2002

Mutagenic and co‐mutagenic effects of static, pulsed bipolar gradient, and high‐frequency magnetic fields, as well as combinations of them, were examined using the Ames test. The Ames test using Salmonella typhimurium bacteria, wild‐type strain RTA, preincubation assay, without metabolic activation, was performed. All combinations of magnetic fields were tested with and without co‐exposure to N‐methyl‐N′‐nitro‐N‐nitrosoguanidine and benzo[a]pyrene‐4,5‐oxide, ethylene oxide, carboplatin, or cisplatin. As expected, chemical mutagens caused a clear‐cut increase of the revertants in the Ames test. However, neither the static fields nor a combination of a static magnetic field with the time‐varying bipolar gradient field or a pulsed high‐frequency magnetic field caused an alteration in the number of revertants in the Ames test. No co‐mutagenic effect of any magnetic field combination was observed. In conclusion, magnetic fields used during clinical magnetic resonance imaging (MRI) were neither mutagenic nor co‐mutagenic. J. Magn. Reson. Imaging 2001;14:779–788. © 2001 Wiley‐Liss, Inc.
In vivo investigation of hepatic iron overload in rats using T2 maps: Quantification at high intensity field (4.7‐T)
Authors: Fenzi A. , Bortolazzi M. , Marzola P. , Colombari R.
Published: August 2002

In vivo quantitation of hepatic iron content is useful in diagnosis and staging of several iron related diseases. We used an experimental model of hepatic iron overload to determine the correlation between iron content and T2 relaxation time in rat liver. Experiments were carried out at 4.7T for high signal‐to‐noise ratio (SNR) using a spin‐echo multiecho sequence with six echoes and minimum echo‐time of 5.5 msec. The liver iron content was determined ex vivo by atomic absorption spectrophotometry (AAS). T2 maps were calculated in order to evaluate the space distribution of the iron content. We found good linear correlation between the in vivo liver transversal relaxation rate and the iron content within the range explored (106–4538 μg Fe/g liver wet wt.). T2 maps revealed that the decrease in T2 is not homogeneous through the liver parenchyma. This finding represents a physiological limitation to obtaining better correlation between T2 and iron content. J. Magn. Reson. Imaging 2001;13:392–396. © 2001 Wiley‐Liss, Inc.
Virtual endoscopy of the labyrinth, using a 3D‐FastASE sequence
Authors: Naganawa Shinji , Iwayama Eriko , Koshikawa Tokiko , Fukatsu Hiroshi , Ishigaki Takeo , Ninomiya Ayako , Aoki Ikuo
Published: August 2002

Virtual endoscopy (VE) of the labyrinth was performed using three‐dimensional (3D)‐fast asymmetric spin‐echo MR imaging. The spatial resolution requirements and the usefulness of zero‐fill interpolation (ZIP) were evaluated, and VE was used to examine three patients. The (0.6‐mm) voxel data with ZIP satisfies the minimum requirements for VE for evaluation of the complex 3D anatomy and pathology of the labyrinth. J. Magn. Reson. Imaging 2001;13:792–796. © 2001 Wiley‐Liss, Inc.
Simulation of tagged MR images with linear tetrahedral solid elements
Authors: Truscott Kent J. , Buonocore Michael H.
Published: August 2002

Computer simulation of tagged magnetic resonance (MR) images is presented using signals derived from connected solid triangular or tetrahedral elements. Simulation provides precisely‐known deformations for validating tag quantification algorithms. MR imaging signal is derived by Fourier‐transforming over a standard element, then mapping to actual elements via transformations. Linear intensity variations over the element are interpolated from vertex intensities determined by tag calculations. J. Magn. Reson. Imaging 2001;14:336–340. © 2001 Wiley‐Liss, Inc.
Metastable ion study of organosilicon compounds. Part XIV—trimethylsilylacetic acid, (CH3)3SiCH2COOH, and its methyl ester, (CH3)3SiCH2COOCH3
Authors: Tajima Susumu , Watanabe Daisuke , Nakajima Satoshi , Sekiguchi Osamu , Nibbering Nico M. M.
Published: August 2002

The unimolecular metastable decompositions of trimethylsilylacetic acid, (CH3)3SiCH2COOH (1), and its methyl ester, (CH3)3SiCH2COOCH3 (2), were investigated by mass‐analyzed ion kinetic energy (MIKE) spectrometry in conjunction with thermochemical data. The abundance of the molecular ions of both compounds, generated by electron ionization, is extremely low. However, the abundance of the ions generated by the loss of .CH3 and observed at m/z 117 and 131 is moderate. These fragment ions further decompose to form the most abundant m/z 75 and 89 ions, respectively, by the loss of CH2CO through a (CH3)2Si group migration. The loss of CH2CO is also observed to occur from 2+. and its fragment ion at m/z 115 generated by the loss of .OCH3. The former reaction is proposed to occur via an ion–radical complex. Copyright © 2002 John Wiley & Sons, Ltd.
Nevirapine quantification in human plasma by high‐performance liquid chromatography coupled to electrospray tandem mass spectrometry. Application to bioequivalence study
Authors: Laurito Tiago L. , Santagada Vincenzo , Caliendo Giuseppe , Oliveira Celso H. , Barrientos‐Astigarraga Rafael E. , De Nucci Gilberto
Published: August 2002

A rapid, sensitive and specific method to quantify nevirapine in human plasma using dibenzepine as the internal standard (IS) was developed and validated. The method employed a liquid–liquid extraction. The analyte and the IS were chromatographed on a C18 analytical column, (150 × 4.6 mm i.d. 4 µm) and analyzed by tandem mass spectrometry in the multiple reaction monitoring mode. The method had a chromatographic run time of 5.0 min and a linear calibration curve over the range 10–5000 ng ml−1 (r2 > 0.9970). The between‐run precision, based on the relative standard deviation for replicate quality controls was 1.3% (30 ng ml−1), 2.8% (300 ng ml−1) and 3.6% (3000 ng ml−1). The between‐run accuracy was 4.0, 7.0 and 6.2% for the above‐mentioned concentrations, respectively. This method was employed in a bioequivalence study of two nevirapine tablet formulations (Nevirapina from Far‐Manguinhos, Brazil, as a test formulation, and Viramune from Boehringer Ingelheim do Brasil Química e Farmacêutica, as a reference formulation) in 25 healthy volunteers of both sexes who received a single 200 mg dose of each formulation. The study was conducted using an open, randomized, two‐period crossover design with a 3 week washout interval. The 90% confidence interval (CI) of the individual ratio geometric mean for Nevirapina/Viramune was 96.4–104.5% for AUC(0–last), 91.4–105.1% for AUC(0–∞) and 95.3–111.6% for Cmax (AUC = area under the curve; Cmax = peak plasma concentration). Since both 90% CI for AUC(0–last) and AUC(0–∞) and Cmax were included in the 80–125% interval proposed by the US Food and Drug Administration, Nevirapina was considered bioequivalent to Viramune according to both the rate and extent of absorption. Copyright © 2002 John Wiley & Sons, Ltd.
Low‐abundance plasma and urinary [15N]urea enrichments analyzed by gas chromatography/combustion/isotope ratio mass spectrometry
Authors: Metges Cornelia C. , Daenzer Maren , Petzke Klaus J. , Elsner Angelika
Published: August 2002

We report a method for determining plasma und urinary [15N]urea enrichments in an abundance range between 0.37 and 0.52 15N atom% (0–0.15 atom% excess (APE) 15N) using a dimethylaminomethylene derivative. Compared with conventional off‐line preparation and 15N analysis of urea, this method requires only small sample volumes (0.5 ml of plasma and 25 µl of urine). The 15N/14N ratio of urea derivatives was measured by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). Two peaks were separated; one was identified by gas chromatography/mass spectrometry (GC/MS) as the complete derivatized urea. Calibration of the complete urea derivative was performed by linear regression of enrichment values of known standard mixtures. Replicate standard (6–465‰ δ15N) derivatizations showed a relative standard deviation ranging from 0.1 to 7%. In order to test the feasibility of the method, human subjects and rats ingested a single meal containing either 200 mg of [15N]glycine (95 AP 15N) or 0.4 mg of [15N]‐α‐lysine (95 AP 15N), respectively. Urine and plasma were collected at hourly intervals over 7 h after the meal intake. After 15N glycine intake, maximum urinary urea 15N enrichments were 330 and 430‰ δ15N (0.12 and 0.16 APE 15N) measured by GC/C/IRMS, whereas plasma [15N]glycine enrichments were 2.5 and 3.3 APE 15N in the two human subjects 2 h after the meal. 15N enrichments of total urine and urine samples devoid of ammonia were higher enriched than urinary [15N]urea measured by GC/C/IRMS, reflecting the presence of other urinary N‐containing substances (e.g. creatinine). In rats plasma urea 15N enrichments were 15–20 times higher than those in urinary urea (10–20‰ δ15N). The different [15N]urea enrichments observed after ingestion of [15N]‐labeled glycine and lysine confirm known differences in the metabolism of these amino acids. Copyright © 2002 John Wiley & Sons, Ltd.
Longitudinal analysis of human cytomegalovirus glycoprotein B (gB)‐specific and neutralizing antibodies in AIDS patients either with or without cytomegalovirus end‐organ disease
Authors: Alberola Juan , Tamarit Amparo , Cardeñoso Laura , Estellés Francisco , Igual Rafael , Navarro David
Published: August 2002

Serum neutralizing and glycoprotein B (gB)‐specific antibody levels were monitored prospectively in AIDS patients who either did or did not develop human cytomegalovirus (HCMV) end‐organ disease, to delineate further the role of antibodies in protecting against HCMV disease. Antibody levels declined substantially (at least 4‐fold) only in patients who developed HCMV disease; this decline in turn occurred concurrently with antigenemia. Nevertheless, AIDS patients who remained free of HCMV disease and did not become antigenemic during the follow‐up period maintained stable levels of serum antibodies, with only minor fluctuations. The impact of HAART on the levels of functional anti‐HCMV antibodies was investigated in a number of AIDS patients. Serum levels and kinetics of gB and neutralizing antibodies did not differ significantly between patients who responded biologically and virologically to therapy and those who failed to respond. In addition, CD4 + cell counts and HIV viral RNA levels did not correlate with anti‐HCMV antibody titers. J. Med. Virol. 64:35–41, 2001. © 2001 Wiley‐Liss, Inc.
Novel PCR assay for differential detection and screening of erythrovirus B19 and erythrovirus V9
Authors: Heegaard Erik D. , Jensen Inge Panum , Christensen Jesper
Published: August 2002

Diagnosis of erythrovirus B19 relies on serology and the detection of viral DNA. These techniques were believed to detect all field isolates because erythrovirus B19 has been known to undergo little genetic variation (1–2%). Recently, a distinct erythrovirus isolate termed V9, markedly different from erythrovirus B19 (>11% nucleotide disparity), was isolated from a child in France suffering from transient aplastic anemia. Standard PCR assays and serological tests failed to demonstrate an acute erythrovirus B19 infection. Subsequent sequencing of the erythrovirus V9 genome shows that the nucleotide discrepancies encompass the entire genome, indicating that standard erythrovirus B19 PCR assays will not reliably detect erythrovirus V9 DNA. As a tool for studying the epidemiological role and medical importance of this erythrovirus variant, a PCR assay is described that allows simultaneous detection of, and distinction between, erythrovirus B19 and the V9 isolate. Examination of 100 erythrovirus B19 IgM positive samples as well as plasma pools representing 100,000 Danish blood donor units for the presence of B19 and V9 DNA was performed. Despite the apparent absence of erythrovirus V9 in the clinical samples at present, the DNA sequence variability demonstrates that the erythrovirus group may be more divergent than thought previously and the child harboring this isolate may herald erythrovirus V9 as a possible emerging virus. J. Med. Virol. 65:362–367, 2001. © 2001 Wiley‐Liss, Inc.
Prevalence of the mutational pattern E44D/A and/or V118I in the reverse transcriptase (RT) gene of HIV‐1 in relation to treatment with nucleoside analogue RT inhibitors
Authors: Montes Brigitte , Segondy Michel
Published: August 2002

It has been reported that a new pattern of mutations, E44D/A and/or V118I, in the reverse transcriptase (RT) gene of HIV‐1 confers a moderate level of resistance to lamivudine in the absence of the M184V mutation. The prevalence of this mutational pattern was studied in HIV‐1 isolates obtained from 280 patients. These mutations were not identified in the RT sequences from 23 antiretroviral‐naive patients but were detected in 82 (31.9%) of the 257 RT sequences obtained from nucleoside reverse transcriptase inhibitors (NRTI)‐experienced patients. Mutation at codon 44 was identified in 41 patients (7 mutations E44A and 34 mutations E44D), mutation V118I was identified in 73 patients and a combination of mutations at codons 44 and 118 was found in 32 patients. Multivariate analysis showed an association between the E44D/A and/or V118I mutational pattern and the RT mutations D67N, T69D, L210W, and T215Y/F. No relationship was observed between this mutational pattern and the lamivudine‐specific resistance mutation M184V. The prevalence of these mutations increased significantly with the number of drug regimens experienced and a prevalence of 42.4% was observed in patients who had received ≥ 4 antiretroviral regimens. A relationship was found between the E44D/A and/or V118I mutational pattern and experience with didanosine or stavudine but not with lamivudine. The results suggest that the development of the E44D/A and/or V118I mutational pattern is frequent in patients treated with NRTIs. Thymidine analogues and didanosine, but not lamivudine, could promote the development of these mutations. J. Med. Virol. 66:299‐303, 2002. © 2002 Wiley‐Liss, Inc.
Basal replication of hepatitis C virus in nude mice harboring human tumor
Authors: Labonté Patrick , Morin Nicolas , Bowlin Terry , Mounir Samir
Published: August 2002

Hepatitis C virus (HCV) can infect and propagate in humans and chimpanzees. Whereas the chimpanzee has been used as an animal model for infection, ethical considerations, conservation, and the prohibitively high cost preclude progress for experimental research on the biology of the virus. The development of a small animal model for HCV infection is thus desirable to facilitate studies on the infectious cycle of the virus and for the evaluation of drugs for the treatment of HCV infections in humans. As an alternative to the chimpanzee model, we have established a model based on ex vivo infection of orthotopically‐implanted human hepatocellular carcinoma cells (HCC) in athymic nude mice. The results show that up to 42 days post‐infection, HCV RNA was present in the tumor cells as well as in the liver and serum of infected mice. Furthermore, a direct correlation between size of the tumor and the presence of HCV RNA in the liver was observed, which is concordant with the finding that HCV RNA was detectable only in mice harboring human tumor. Immunohistochemistry analysis of infected liver specimens showed cells expressing the HCV encoded NS5B protein. A few mice developed a humoral response against the nonstructural viral proteins, providing further evidence for expression of these proteins during viral infection. In summary, these results suggest that mice harboring orthotopic tumors support a basal level of HCV replication in vivo. J. Med. Virol. 66:312‐319, 2002. © 2002 Wiley‐Liss, Inc.
Co‐delivery of GM‐CSF gene enhances the immune responses of hepatitis C viral core protein‐expressing DNA vaccine: Role of dendritic cells
Authors: Ou‐Yang Pu , Hwang Lih‐Hwa , Tao Mi‐Hua , Chiang Bor‐Luen , Chen Ding‐Shinn
Published: August 2002

Hepatitis C virus (HCV) infection has become a critical public health problem worldwide. In Taiwan, it has been estimated that more than 300,000 people, 2% of the general population, have HCV infection. It has been well documented that direct delivery of gene intramuscularly can generate both humoral and cellular immunity, which more closely simulates the conditions of infection. In this study, female Balb/c mice immunized with HCV core plasmid DNA with or without adjuvant GM‐CSF cytokine gene could induce both cellular immune response and HCV core‐specific antibody titers after injection. Furthermore, the mice immunized with HCV core plus GM‐CSF genes showed higher antibody titer and cytotoxic T cell activity compared to those of mice immunized with HCV core gene only (P < 0.05). To explore the effect of GM‐CSF gene, the mice were immunized with reporter gene and cytokine gene plasmid. Increased levels of reporter protein and infiltrating cells around muscle tissue were noted. Moreover, the protein could be detected in inguinal node 24 hr after injection, especially in mice immunized with HCV/core plasmid plus GM‐CSF gene. It was also observed that reporter protein expressing CD11c+ dendritic cells could be seen in the inguinal node. These data suggest that the GM‐CSF gene did enhance HCV core specific immune response when co‐immunized with HCV core DNA plasmid. Although more studies are needed, dendritic cells that appeared around the naked DNA injection area and that local lymph nodes might play a critical role in the immune response induced by naked DNA immunization. J. Med. Virol. 66:320‐328, 2002. © 2002 Wiley‐Liss, Inc.
GABAB receptor gene expression is not altered in cocaine‐sensitized rats
Authors: Li Jinyuan , Olinger Anthony B. , Dassow Michael S. , Abel Marc S.
Published: August 2002

Recent behavioral and neurobiological data indicate that GABAB receptor transmission is involved in cocaine‐induced hyperactivity and reinforcement. GABAB receptor gene expression in cocaine‐sensitized rats was examined in this study. Rats were injected with cocaine (15 mg/kg, daily, i.p.) or saline for 5 consecutive days, and challenged with the same dose of cocaine after a 1‐, or 20‐day hiatus. The locomotor activities of rats were recorded after challenge, and the rats were killed 24 hr later. GABABR1a, 1b, and GABABR2 mRNA in discrete brain regions was detected by RPA and In Situ Hybridization; GABABR1a protein was measured by Western blotting. Rats pretreated with cocaine developed a hyperactivity to the cocaine challenge after a 1‐day or 20‐day hiatus, but GABABR subunit mRNA and GABABR1a protein densities in the targeted regions showed no significant difference compared to those in control rats. These data indicate that GABAB receptor gene expression is not necessarily relevant to the behavioral sensitization of cocaine. © 2002 Wiley‐Liss, Inc.
Effect of exogenous lactate on rat glioma metabolism
Authors: Bouzier‐Sore Anne‐Karine , Canioni Paul , Merle Michel
Published: August 2002

Glioma‐bearing rats were infused intravenously with a solution containing either [3‐13C]lactate or both glucose and [3‐13C]lactate for 20 min or 1 hr. Perchloric acid extracts of healthy and tumoral brain tissues were prepared and analyzed by 13C‐ and 1H‐observed 13C‐edited nuclear magnetic resonance (NMR) spectroscopy to determine 13C‐label incorporation into brain tissue and glioma metabolites. Moreover, 13C enrichments in blood lactate and glucose were determined from 1H‐NMR spectra. In the nontumoral tissue, 13C labeling of amino acids indicated that [3‐13C]lactate entered the brain and was metabolized. There was no labeling difference between the contralateral and the ipsilateral hemispheres. Lactate metabolism appeared more specifically neuronal, in agreement with our previous results obtained with normal rat brain (Bouzier et al. [2000] J. Neurochem. 75:480–486). In the glioma tissue, comparison of Ala C3, Glu C4, and Gln C4 labeling indicated that the contributions of blood glutamine and tricarboxylic acid (TCA) cycle to glutamate labeling were about 80% and 20%, respectively, after 1 hr of [3‐13C]lactate infusion. In contrast, these contributions were about 10% and 90%, respectively, when [1‐13C]glucose was infused in the absence of lactate. This indicated a major effect of the exogenous lactate on glioma metabolism, which may be due to the following process: The high blood lactate level might hinder the drain of glycolytic lactate produced inside the glioma and thus generate a change in redox potential such that the tumor cells are unable to restore it with oxidative phosphorylation. Thereafter, the high NADH level might inhibit glycolysis and the TCA cycle, and glutamine could become the major carbon source for glutamate labeling. J. Neurosci. Res. 65:543–548, 2001. © 2001 Wiley‐Liss, Inc.
Validation of ECMWF (re)analysis surface climate data, 1979–1998, for Greenland and implications for mass balance modelling of the ice sheet
Authors: Hanna Edward , Valdes Paul
Published: August 2002

Climate (re)analysis products are potentially valuable tools, when properly verified, for helping to constrain the surface mass balance of the Greenland Ice Sheet (GIS). Monthly surface fields from European Centre for Medium‐Range Weather Forecasts (ECMWF) operational‐ and re‐analyses spanning 1979–1998 were validated using in situ data (surface air pressure and temperature, precipitation, cloud cover, short‐/all‐wave radiation, and wind speed/direction). These validation data are from coastal or near‐coastal Danish Meteorological Institute (DMI) synoptic stations, inland Greenland Climate Network (GC‐Net) and University of Wisconsin Automatic Weather Stations (AWSs), and two energy balance stations near the southern ice margin. The ECMWF analyses closely reproduce the seasonal patterns and interannual variations of much of the in situ data. Differences in the mean values of surface air pressure and temperature can mainly be ascribed to orography errors in the analyses' schemes, compared with the latest available accurate digital elevation model. Much of the GIS margin as modelled by ECMWF was too cold, on average by 4°C, and ECMWF precipitation averaged some 136% of the DMI station values. The misrepresentation of the (relatively) steep ice‐sheet margin, which tends to be broadened and systematically over‐elevated by several hundred metres, orographically reduced temperature and enhanced precipitation there in the ECMWF models. The cloud‐cover comparison revealed not dissimilar annual mean cloud covers (ECMWF −8%) but the ECMWF analyses had too little cloud and were too ‘sunny’ during the critical summer melt‐season. ECMWF‐modelled surface albedo in summer was ∼11% lower than GC‐Net values, which was mainly responsible for the disagreement of modelled surface short‐wave radiation fluxes with observations. Model albedo and cloud errors need to be rectified if the analyses are to be used effectively to drive energy balance models of Greenland snowmelt. ECMWF wind speed averaged 66% (62%) of the DMI station (AWS) values. The validation results provide useful insights into how one can best improve the ECMWF Greenland climate data for use in glaciological and climatological studies. Copyright © 2001 Royal Meteorological Society
Synthesis and properties of diads based on tetra-aryl porphyrins and ruthenium bis-terpyridine-type complexes
Authors: DIXON ISABELLE M. , COLLIN JEAN-PAUL
Published: August 2002

Four diads consisting of a free-base or zinc aryl-porphyrin associated with two ruthenium(II) bis(terdentate) complexes (non-cyclometallated Ru ( N 6) or cylometallated Ru ( N 5 C )) have been synthesized. The strong electron-withdrawing properties of the Ru ( N 6) as compared to the Ru ( N 5 C ) complex have been illustrated by their electrochemical and spectroscopic properties. Emission spectra of the diads and the reference compounds have shown that very efficient fluorescence quenching occurs, probably by energy transfer processes from the porphyrin to the 3MLCT excited state of the ruthenium unit.
Lattice dynamic investigation of Raman and infrared wavenumbers at the zone center of orthorhombic RFeO3 (R = Tb, Dy, Ho, Er, Tm) perovskites
Authors: Gupta H. C. , Kumar Singh Manoj , Tiwari L. M.
Published: August 2002

A short‐range force constant model was applied for the first time to investigate the phonons in RFeO3 (R = Tb, Dy, Ho, Er, Tm) perovskites in the orthorhombic phase. The calculations with the 12 stretching and three bending force constants provide good agreement for the observed Raman and infrared wavenumbers. The infrared wavenumbers were assigned for the first time. The variation of the force constants on going from Tb to Tm is discussed . The effect of changing the R ion from Tb to Tm in the Raman modes of RFeO3 is also discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Precision nutrition: weighing feed ingredients correctly
Authors: van Kempen Theo , Park Bill , Hannon Mike , Matzat Paul
Published: August 2002

The ability to mix a quality feed is often equated to the quality of the mixer; the ability to weigh ingredients correctly has received little attention. To assess how accurately feed mills weigh their ingredients, 14 feed mills specialising in swine diets were surveyed, which yielded 8432 data points (for 229 ingredients and 11–44 batch records per ingredient within mills). Amounts actually weighed (according to scale readings) were compared to calls, and differences were analysed statistically. Feed mills overdosed ingredients by 1.5 ± 16.3%: between mills, overdosing ranged from −0.7 to 13.0%. Within ingredients, weighing variation ranged from 0.6 to 11.1% between mills and averaged 5.2%. Some of the weighing problems observed were attributed to discrepancies between the call size and the scale resolution. For example, weighing 11.3 units (pounds) on a scale with a 2 unit resolution leads to a minimum error of 6%. Such problems occurred for 8.7% of the calls and resulted in a minimum error ranging from 0.01 to 20%, averaging 1.95%. Poor choice of scales was the major source of errors in weighing, and the relationship weighing variation = 10∧ [1.56 − 0.50 log (call/scale resolution)] explained 40% of the variation observed (p < 0.05). Weighing ingredients in the right scale would thus not only benefit feed quality but also reduce diet cost, as it would reduce the overdosing of ingredients.

© 2001 Society of Chemical Industry
Cell death in the colorectal cancer cell line HT29 in response to glucosinolate metabolites
Authors: Lund Elizabeth K , Smith Tracy K , Clarke Rosemary G , Johnson Ian T
Published: August 2002

Glucosinolate breakdown products are potential anti‐carcinogenic phytochemicals derived from cruciferous vegetables. This study compared the induction of apoptosis in colorectal adenocarcinoma cells (HT29) by four isothiocyanates (ITC) benzyl‐ITC, allyl‐ITC (AITC), phenylethyl‐ITC (PEITC) and methylsulphinylbutyl‐ITC (sulforaphane). Apoptosis was determined by analysis of DNA content, annexin V staining, gel electrophoresis, CPP32 expression/inhibition and the histological appearance of nuclei. In terms of their ability to reduce adherent cell number, the relative potency of ITCs was BITC = AITC > PEITC ≫ sulforaphane. Non‐adherent cells from test flasks showed less evidence of apoptosis than those grown under control conditions. Our results implied that ITCs first blocked cells at G2/M and subsequently caused a loss in adherence which was not reduced by caspase inhibitors or by pre‐loading the cells with an antioxidant, the GST mimic Ebselen. This suggests that the primary action of ITCs is to block rapidly proliferating cancer cells in G2/M. In this particular p53 null cell line, loss of cell adherence was not part of an apoptotic process, nor did it involve free radical signaling pathways.

© 2001 Society of Chemical Industry.
Some studies directed at increasing the potential use of palmyrah (Borassus flabellifer L) fruit pulp
Authors: Ariyasena Darshika D , Jansz E R , Abeysekera A M
Published: August 2002

Attempts have been made to predict the most feasible end‐use for palmyrah fruit pulp (PFP), which is still largely regarded as a waste product. Correlation of end‐use with flabelliferin profile is logical but practically difficult, as it has been found that the morphology of the fruit and the colour of the pulp (carotenoid content) do not correlate with each other, and that neither has predictive value for the flabelliferin profile. It appears that some varieties of palmyrah are sweet and can be used for products such as jams and cordials. A few very bitter PFPs can be de‐bittered with a cheap commercial enzyme for similar uses. The majority of available PFP appears to be best used as an alcoholic fermentation base, with the possibility of using the carotenoids (by‐product) as a food colorant.

© 2001 Society of Chemical Industry
Mutations in the von Hippel‐Lindau (VHL) gene refine differential diagnostic criteria in renal cell carcinoma
Authors: Barnabas Nandita , Amin Mitual B. , Pindolia Kirit , Nanavati Reshma , Amin Mahul B. , Worsham Maria J.
Published: August 2002

Background and Objectives

Renal cell carcinomas (RCC) with abundant granular cytoplasm include oncocytomas, eosinophillic variants of chromophobe RCC, papillary RCC, collecting duct carcinoma, and some conventional (clear cell) RCC. Tumors with predominantly clear cell cytoplasm include typical chromophobe RCC and conventional (clear cell) RCC. The objective of this study was to determine if mutations in the VHL gene can serve as auxiliary diagnostic criteria in refining histology based subtyping of renal epithelial neoplasia.

Methods

The study cohort of 67 cases included 24 conventional RCC, 14 chromophobe RCC, 14 papillary RCC, and 15 oncocytomas. Single strand conformational polymorphism (SSCP) was used as a screening procedure for mutations followed by automated sequencing to identify mutations.

Results

Thirteen of the 14 mutations identified were novel, seven of which were in the coding region. In chromophobe RCC, mutations clustered in the 5′UTR/promoter region and have not been previously reported. Exon 3 appeared to favor conventional (clear cell) RCC and correlated with a more aggressive phenotype. Mutations were absent in the papillary and oncocytoma RCC subtypes.

Conclusions

Exon 3 mutations permitted a morphological distinction between conventional (clear cell) RCC and chromophobe RCC with clear cells. Mutations in the VHL gene refine histologic diagnostic criteria in RCC serving as adjuncts to the present morphology based diagnosis of RCC. J. Surg. Oncol. 2002;80:52–60. © 2002 Wiley‐Liss, Inc.
Multinational hotel development in developing countries: an exploratory analysis of critical policy issues
Authors: Kusluvan Salih , Karamustafa Kurtulus
Published: August 2002

Multinational hotel companies, often integrated with tour operators, travel agencies and other businesses in tourist‐generating or tourist‐receiving countries, play a key role in the development and continuity of an international tourism industry in developing countries. In order to take advantage of benefits and minimise the unwanted adverse effects from multinational hotel involvement, developing countries need the planning, implementation and evaluation of carefully designed policies linked to their particular objectives. This paper reviews the potential benefits and costs of multinational hotel companies and brings together previously scattered critical policy issues in relation to them, while suggesting possible options for developing countries to follow. Seven critical policy areas are identified: establishment of the need for foreign investment; deciding on forms of involvement; deciding on the scale of hotel development; supporting sectoral linkages; supporting indigenous employment/training; monitoring business practices; and determining foreign investment incentives and regulations. It is argued that policies should be worked out in these areas and co‐ordinated in order to achieve a balance between the benefits and costs of multinational hotel involvement in developing countries. Copyright © 2001 John Wiley & Sons, Ltd.
Uncivil aviation: a review of the air rage phenomenon
Authors: Morgan Michelle , Nickson Dennis
Published: August 2002

This article examines the issue of air rage. Attempting to define and identify the extent of this phenomenon provides the context in which to review contributory factors. The analysis of violence or aggression directed at flight attendants is developed with recourse to the work of Poyner and Warne, who offer a framework for understanding violence to staff. Use of this framework suggests that air rage remains a multifaceted phenomenon, with a number of contributory factors. Identification of a variety of factors is then used to develop an analysis of possible solutions to the air rage phenomenon. These solutions are concerned with controlling the assailant and, more proactively, supporting flight attendants through initiatives such as enhanced training programmes. Finally, the article suggests a number of areas for future research that may add to an understanding of a so‐far under investigated phenomenon. Copyright © 2001 John Wiley & Sons, Ltd.