bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural comparison of dissolution and apatite precipitation on hydroxyapatite and silicon‐substituted hydroxyapatite in vitro and in vivo
Authors: Porter Alexandra E. , Botelho Claudia M. , Lopes Maria A. , Santos José D. , Best Serena M. , Bonfield William 
Published: April 2004

AbstractRecent histological studies have demonstrated that the substitution of silicate ions into hydroxyapatite (HA) significantly increases the rate of bone apposition to HA implants. The enhanced bioactivity of silicon‐substituted HA (Si‐HA) over pure HA has been attributed to the effect of silicate ions in accelerating dissolution. In the present study, high‐resolution transmission electron microscopy (HR‐TEM) was employed to compare dissolution of HA and Si‐HA in an acellular simulated body fluid (SBF) to dissolution in an in vivo model. HR‐TEM observations confirmed a difference in morphology of apatite precipitates in vivo and in SBF: apatite deposits were platelike in vivo and nodular in SBF. Compositional mapping suggested that preferential dissolution of silicon from the implant promotes the nucleation of carbonate apatite around the implant. The in vivo findings illustrated an absence of dissolution at the bone–HA or Si–HA interface, whereas dissolution was extensive from within the implant. The amount of dissolution in acellular SBF was similar to dissolution from within the implant, although the site at which the dissolution nucleates was different: dissolution predominates at the crystallite surfaces in SBF, whereas grain boundary dissolution predominates in vivo. These findings suggest that proteins in the in vivo milieu modify the processes of dissolution from the implant. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 670–679, 2004
The role of implant alignment on stability and particles on periprosthetic osteolysis—A rabbit model of implant failure
Authors: Fornasier V. L. , Goodman S. B. , Protzner K. , Kamel M. , Song Y. , Shojaci A. 
Published: April 2004

AbstractThe study objective was to determine the tissue response to polyethylene and/or titanium particles and the role that these play in peri‐prosthetic osteolysis in a rabbit model of implant failure. Twenty‐two mature rabbits were used. Unilateral tibial arthroplasty was performed on all of them. The test animals received implants that were intentionally rotationally unstable with reference to the host tibia in order to create a model of failure. The test rabbits were divided into three groups. Group 1 consisted of seven rabbits in which only the carrier was implanted. Group 2 consisted of seven rabbits that received only polyethylene particles suspended in the carrier. Group 3 consisted of eight rabbits that received a mixture of polyethylene and titanium alloy particles suspended in the carrier. The rabbits were sacrificed at 6 months post surgery. The entire knee, together with the immediately surrounding soft tissue, was retrieved. The position of the implant in each rabbit was assessed with reference to its alignment to the tibia. The number of inflammatory, foreign‐body reactive cells, the presence of neovascularization, edema, and necrosis in the periprosthetic zones were recorded and assessed in a qualitative and semiquantitative manner. Quantitative histomorphometry was used to determine the proportion of implant surface that interfaced with osseous or fibrous tissue. Also assessed was the thickness and maturity of the fibrous tissue and the endosteal remodeling activity in the peri‐implant bone counting both osteoclastic and osteoblastic activity. The results showed that implanted particles and misalignment of the implants combined to produce peri‐prosthetic bone resorption. Bone resorption was found to be proportional to the degree of misalignment. The animals that received combined polyethylene/titanium particles had a greater degree of foreign‐body and inflammatory response with osteolysis than the other groups. The combination of bio‐material particles (polyethylene and titanium alloy) produced a greater degree of bone resorption than the single biomaterial particles (polyethylene). The amount of bone resorption surrounding the implant was directly proportional to the degree of misalignment of the implant. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 179–186, 2004
Macrocyclic vs. dendrimeric effect. A DFT study
Authors: Soto‐Castro Delia , Guadarrama Patricia 
Published: April 2004

AbstractMacrocycles up to 15 members with different heteroatoms (N, O, and S) and dendrimeric functionalized branches were assembled, resulting in unique “collective” supramolecular hosts with several active sites for transition metal ions complexation. The nature of the interactions between these kinds of systems and metal ions of the first transition series (Fe, Ni, Cu, Zn) was evaluated by calculations of the binding energies at the B3LYP/LACVP* level of theory, resulting in a preference of metal ions for macrocyclic cavity in terms of complexation; however, there is a favorable contribution in energy due to the cooperative effect of dendrimeric branches (DBs) in the inclusion process by means of long‐range interactions between metal ions and the heteroatoms present in DBs. According to calculated binding energies, even when the complexation in the middle of DBs appears as a less favored situation, still competes with the complexation occurred in several known macrocycles traditionally used in the formation of inclusion complexes. The capability of macrocycles as host entities is related to some criteria like: (1) the compatibility in orbital symmetry between host and guest molecules; (2) the cavity dimensions and the negative charge inside; and (3) the hardness–softness affinity between host and guest molecules. When DBs are included in host systems, their flexibility seems to be very important, in addition to localized negative charge, which permits the occurrence of long‐range interactions. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1215–1226, 2004
Hepatocyte‐specific gene expression from integrated lentiviral vectors
Authors: Nash Kathryn L. , Jamil Bushra , Maguire Alison J. , Alexander Graeme J. M. , Lever Andrew M. L. 
Published: April 2004

AbstractBackgroundFor many applications, efficient gene therapy will require long‐term, organ‐specific therapeutic gene expression. Lentiviral vectors based on HIV‐1 are promising gene delivery vehicles due to their ability to integrate transgenes into non‐dividing cells. Many experimental vectors express transgenes under the control of the cytomegalovirus (CMV) immediate‐early gene promoter. Although this promoter directs strong gene expression in vitro, it may be shut off rapidly in vivo. This study explores the potential of HIV‐1‐based vectors to transduce hepatocytes and compares gene expression from different promoters in integrated vectors.MethodsHIV‐1‐based vector plasmids expressing the green fluorescent protein (GFP) under the control of the CMV promoter, the alpha‐1 antitrypsin gene promoter or promoters derived from the hepatitis B virus (HBV) genome were used to compare expression in transfected and transduced cell lines.ResultsHepatocyte cell lines differed strikingly in their transfectability. Transduction with replication‐deficient HIV‐1‐based vector particles incorporating the different promoter elements was uniformly effective in hepatocyte and non‐hepatocyte lines. However, in hepatocytes, only the CMV, alpha‐1 antitrypsin and HBV core but not HBV surface promoters were able to produce GFP expression. Addition of the HBV enhancer 2 element improved the transducing ability of the HBV surface promoter and suppressed expression in non‐hepatocytes increasing specificity for hepatocytes.ConclusionsIntegrated lentiviral vectors can be used to direct transgene expression in liver cells both promiscuously and specifically. Promoters derived from the alpha‐1 antitrypsin gene or HBV are alternatives to the CMV promoter. Inclusion of the HBV enhancer 2 permits strong liver‐specific gene expression in vitro. Copyright © 2004 John Wiley & Sons, Ltd.
The influence of prior offender/victim relationship on offender stalking behavior
Authors: Groves Renee M. , Salfati C. Gabrielle , Elliot Deborah 
Published: April 2004

AbstractThe present study examined the influence of prior offender/victim relationship on offender stalking behavior. The actions that were present within the stalking offences were recorded using content analysis of victim and witness statements, and all other relevant material within the police files of 50 stalking cases. The sample was analyzed using a non‐metric multidimensional scaling procedure known as Smallest Space Analysis. The results suggested that when a prior sexual relationship existed between the offender and the victim the offender was more likely to engage in a majority of controlling style actions. However, an offender who did not have a prior sexual relationship with the victim was more likely to engage in a majority of infatuation style actions. Therefore, the study lends support to the influence of prior relationship on the actions that offenders engage in over the stalking period. Implications of the study and future research ideas are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Molecular epidemiology of HIV in Ghana: Dominance of CRF02_AG
Authors: Fischetti Lucia , Opare‐Sem Ohene , Candotti Daniel , Sarkodie Francis , Lee Helen , Allain Jean Pierre 
Published: April 2004

AbstractRecent studies showed the importance of CRF02_AG in West Africa, although the clinical relevance of these recombinant forms of HIV remains unknown. The present study aimed at determining the molecular diversity of HIV in Ghana and investigating the possible epidemiologic advantage of recombinant HIV‐1. Plasma samples collected in 1999–2002 from two populations of HIV infected individuals (144 asymptomatic candidate blood donors and 169 AIDS patients) were studied and 249 of them were molecularly characterised in gag, pol, and env regions. Five molecular groups were identified: strains clustering with CRF02_AG in all regions (147/249 or 59%), recombinant strains clustering with CRF02_AG in one or two regions (50/249 or 20%), other subtypes, pure or recombinant, but not involving CRF02_AG (37/249 or 15%), HIV‐2 (11/249 or 4.5%), and double infections (4/249 or 1.5%). There was no significant difference in the distribution of HIV‐1 recombinant strains according to clinical presentation. No evidence of a significant increase in CRF02_AG prevalence between 1999 and 2002 was found. Irrespective of clinical condition, CRF02_AG is the predominant molecular form of HIV‐1 in Kumasi, Ghana. J. Med. Virol. 73:158–166, 2004. © 2004 Wiley‐Liss, Inc.
Measurement of HIV RNA in patients infected by subtype C by assays optimized for subtype B results in an underestimation of the viral load
Authors: Gottesman Bat‐Sheva , Grosman Zehava , Lorber Margalit , Levi Itzchak , Shitrit Pnina , Mileguir Fernando , Gottesman Giora , Chowers Michal Y. 
Published: April 2004

AbstractQuantitation assays of HIV‐1 RNA used currently were designed and optimized for subtype B viruses. However, infection with non‐B HIV viruses has become more common worldwide. Unfortunately, little information is available regarding the suitability of these assays for measurement of viral load in specific non‐B subtypes. The performance of two commercial HIV‐1 RNA quantitation assays was evaluated in 82 HIV subtype C‐infected patients and in 43 HIV‐1 subtype B‐infected patients. Blood samples were tested by the Amplicor HIV‐1 Monitor Assay, Version 1.5, and by the nucleic acid sequence‐based amplification HIV‐1 assay (NucliSens). The results were compared by using a paired, two‐tailed Student's t‐test; the difference between the assays was found to be significant only for subtype C. Discordant results (>0.5 log difference) between the two assays were detected in 39% of subtype C samples, compared to 23.2% of subtype B samples. In all cases in which a discordant result was detected, the lower results were obtained by the NucliSens assay. Discordant results between CD4 and viral load (CD4 < 200 cells/ml with a viral load <5,000 copies/ml) were observed in eight of the subtype C‐infected patients when a viral load was measured by NucliSens (9.7%), compared to three patients (3.6%) when measured by the Amplicor assay. In conclusion, in patients with HIV subtype C infection, measurement of HIV RNA by the NucliSens assay resulted in a significant underestimation of the viral load as compared to the Amplicor assay. As a consequence, such an underestimation may result in sub‐optimal care of patients infected with HIV subtype C. J. Med. Virol. 73:167–171, 2004. © 2004 Wiley‐Liss, Inc.
Transgenic tobacco cells producing the human monoclonal antibody to hepatitis B virus surface antigen
Authors: Yano Akira , Maeda Fumiko , Takekoshi Masataka 
Published: April 2004

AbstractThe recombinant human monoclonal antibody (MAb) against hepatitis B virus (HBV) surface antigen (HBsAg) was expressed in tobacco suspension cultures. The parental CL4MAb was produced by the Epstein–Barr virus (EBV) transformed human cell line TAPC301‐CL4. The CL4MAb cDNA was introduced into tobacco suspension cells by Agrobacterium mediated transformation. The monoclonal antibodies (MAbs), B294 and B303, which were derived from CL4 and subsequently produced in plant cells were selected for study. After purification on Protein A columns, B294 and B303 MAbs had anti‐HBs relative affinity constants similar to the parental CL4MAb. B303 MAb interacted with cell surface HBsAgs and showed complement‐dependent cytotoxicity in a manner that was similar to anti‐HBs human immunoglobulins (HBIg) that are used clinically. The results of this study point to the feasibility of producing MAbs to HBsAg in plants as an alternative to HBIg. J. Med. Virol. 73:208–215, 2004. © 2004 Wiley‐Liss, Inc.
Human astrovirus, norovirus (GI, GII), and sapovirus infections in Pakistani children with diarrhea
Authors: Phan Tung Gia , Okame Michio , Nguyen Tuan Anh , Maneekarn Niwat , Nishio Osamu , Okitsu Shoko , Ushijima Hiroshi 
Published: April 2004

AbstractFecal specimens from 517 infants and young children admitted to the Civil Karachi Hospital, Dow Medical College, Karachi city, Pakistan with acute gastroenteritis from 1990 to 1994 were collected and screened by RT‐PCR for human astrovirus (AstV), norovirus (NV), and sapovirus (SV). The specific epidemiological data for illness caused by these viruses in Pakistan are not available. AstV, NV, and SV were detected in 58, 51, and 17 of 517 fecal specimens, and this represented 11.2, 9.9, and 3.2%, respectively. An outbreak of gastroenteritis attributable to AstV serotype 1 was identified during September and October 1990. Moreover, one specimen with a triple mixed infection between AstV (serotypes 1 and 3) and NV GII was found. NV and SV were subjected to molecular analysis by sequencing. One of the sequenced specimens positive for SV turned out to be similar to a strain tentatively called a genogroup IV. The result underscores the importance of these viruses in association with acute gastroenteritis in Karachi city, Pakistan. J. Med. Virol. 73:256–261, 2004. © 2004 Wiley‐Liss, Inc.
Age related differences in humoral immune response to respiratory syncytial virus infection in adults
Authors: Walsh Edward E. , Falsey Ann R. 
Published: April 2004

AbstractThe humoral immune response to Respiratory Syncytial Virus (RSV) was investigated in old and young adults. RSV was identified by culture and/or reverse transcription polymerase chain reaction (RT‐PCR) in 52 elderly (mean age 74 years) and 15 young adults (mean age 33 years) with respiratory illness. Preinfection serum neutralizing and binding antibody levels were similar in the two age groups, although older persons had significantly greater serum neutralizing responses to group A RSV (log2 2.8 increase vs. 1.7, P = 0.001) and group B RSV (log2 2.8 vs. 1.3, P = 0.0008). Older persons also had significantly increased responses to the RSV F (log2 2.9 vs. 1.1, P < 0.0001), Ga (log2 2.1 vs. 1.3, P = 0.0007), and Gb proteins (log2 2.7 vs. 1.4, P = 0.0004). The exuberant antibody response seen in older adults may be a reflection of greater viral load and antigenic stimulation and/or a shift from Th1 to Th2 dominant immune response with aging. The relationship of immune response to disease pathogenesis in older persons deserves further study. J. Med. Virol. 73:295–299, 2004. © 2004 Wiley‐Liss, Inc.
Epidemiology of rotavirus diarrhoea in Iranian children
Authors: Khalili B. , Cuevas L.E. , Reisi N. , Dove W. , Cunliffe N.A. , Hart C.A. 
Published: April 2004

AbstractHuman rotavirus is the most important cause of severe diarrhoea in infants and young children worldwide. We describe the aetiology of viral diarrhoea and the characteristics of rotavirus infection in Shahrekord, Iran. Two hundred and fifty nine children <5 years old admitted to Hajar Hospital, 245 children with acute diarrhoea attending primary health centres in Shahrekord, and 114 children hospitalised for elective surgery were selected from October 2001 to August 2002. Stool samples were screened for enteric viruses using EM. Rotaviruses were characterised using ELISA, reverse transcription‐polymerase chain reaction (RT‐PCR), and electropherotyping. One hundred and eighty six viruses were identified, of which 146 (78%) were rotavirus. The second most frequent virus was coronavirus, followed by calicivirus. Rotaviruses exhibited a marked seasonal variation, being most frequently isolated from November to February (50% of rotavirus recovered) and affected mostly children <2 years old. The RT‐PCR successfully typed 139 of the 146 (95%) rotavirus G types and 124 (85%) P types. The most frequent P type was, P[8] in 108 (74%), P[4] in 16 (11%), and was P non‐typeable in 22 (15%). Among the G types, G1 was identified in 120 (82%), G2 in 19 (13%), and was G‐non‐typeable in 7 (5%). Our results are the first report of rotavirus genotypes affecting Iranian children. The most frequent G and P types (G1, G2, P[8], and P[4]) are similar to those reported from around the world and will be covered by existing rotavirus vaccines targeting G types G1–G4. J. Med. Virol. 73:309–312, 2004. © 2004 Wiley‐Liss, Inc.
Effects of neonatal capsaicin deafferentation on neuromuscular adjustments, performance, and afferent activities from adult tibialis anterior muscle during exercise
Authors: Dousset Erick , Marqueste Tanguy , Decherchi Patrick , Jammes Yves , Grelot Laurent 
Published: April 2004

AbstractTo investigate the role played by muscle afferents in the sensorimotor loops, we measured the effects of capsaicin injection in newborns on the mechano‐ and metabosensitive discharges and the running performance at adulthood. Female Sprague Dawley rats received a subcutaneous injection of either 50 mg/kg capsaicin or solvent (10% ethanol, 10% Tween 80 in 0.9% saline) during their second day of life. These two groups were compared with a control, untreated group. Four months later, treadmill running performance and muscle afferent (mechanosensitive and metabosensitive) activities from the tibialis anterior muscle were measured. The capsaicin‐treated group demonstrated a reduced maximal exercise capacity (time to exhaustion) and a reduced response of muscle metabosensitive fibers (group III and IV nerve endings) to the examined stimuli (arterial KCl and lactic acid injections, electrically induced fatigue) compared with the sham‐injected solvent and control groups. Group IV afferent responses were absent in the compound nerve action potentials evoked by peripheral nerve stimulation. The response to mechanosensitive fibers to tendon vibration was also affected in the capsaicin group compared with the control and sham‐injected groups, which presented a bimodal response corresponding to the activation of muscle spindles and Golgi tendon organs. Finally, measurements of the force developed by the tibialis anterior muscle from the beginning to the end of a 3‐min muscle stimulation revealed a more significant fall in the capsaicin group compared with the others. The present experiments reveal that the pharmacological alteration of muscular metabosensitive afferent resulted in drastic changes in the neuromuscular sensory encoding and in the central neural network that could accelerate failure of the task during fatigue. © 2004 Wiley‐Liss, Inc.
AMPA receptor subunit expression in chick vestibular nucleus neurons
Authors: Popratiloff Anastas , Wang Ya‐Xian , Narvid Jared , Petralia Ronald S. , Giaume Christian , Peusner Kenna D. 
Published: April 2004

AbstractThe principal cells of the chick tangential nucleus are vestibular nucleus neurons whose responses on vestibular nerve stimulation are abolished by glutamate receptor antagonists. Using confocal microscopy, we quantified immunolabeling for AMPA receptor subunits GluR1, GluR2, GluR2/3, and GluR4 in principal cells that were identified by the neuronal marker, microtubule‐associated protein 2 (MAP2). This work was focused primarily on 9 days after hatching (H9) when the principal cells have acquired some important mature electrophysiologic properties. At H9, the principal cell bodies stained strongly with GluR2/3 and GluR4, whereas GluR1 and GluR2 produced weak signals. Moreover, GluR2/3 and GluR4 receptor subunit clusters in principal cell bodies and dendrites were localized at sites contacted by biocytin‐labeled vestibular nerve terminals and synaptotagmin‐labeled terminals. Developmental expression of AMPA receptor immunolabeling was studied in the principal cell bodies at embryonic day 16 (E16) and hatching (H1). At E16, labeling for GluR4 was already strong, and continued to increase at H1 and H9. In contrast, GluR2/3 labeling was weak at E16, but increased significantly at H1, and more so by H9. GluR1 and GluR2 were present at low levels at E16 and H1. From E16 to H9, overall AMPA receptor subunit expression increased steadily, with H9 showing the strongest labeling. Ultrastructural observations at E16 and H3 confirmed the presence of immunogold labeling for AMPA receptor subunits at the vestibular nerve and non‐vestibular nerve synapses on the principal cell bodies. In summary, these results indicate that GluR3 and GluR4 are the major AMPA receptor subunits involved in excitatory synaptic transmission in principal cells during the perinatal period. © 2004 Wiley‐Liss, Inc.
Triblock Copolymers Based on 1,3‐Trimethylene Carbonate and Lactide as Biodegradable Thermoplastic Elastomers
Authors: Zhang Zheng , Grijpma Dirk W. , Feijen Jan 
Published: April 2004

AbstractSummary: Biodegradable triblock copolymers based on 1,3‐trimethylene carbonate (TMC) and different lactides (i.e. D,L‐lactide(DLLA), L‐lactide (LLA), D‐lactide (DLA)) designated as poly(DLLA‐TMC‐DLLA), poly(LLA‐TMC‐LLA) and poly(DLA‐TMC‐DLA) were prepared and their mechanical and thermal properties were compared with those of high molecular weight poly(TMC) and poly(TMC‐co‐DLLA) statistical copolymers. Triblock copolymers containing crystallizable LLA or DLA segments perform as thermoplastic elastomers (TPEs) when the poly(lactide) blocks are long enough to crystallize. In blends of poly(LLA‐TMC‐LLA) and poly(DLA‐TMC‐DLA) triblock copolymers, stereo‐complex formation between the enantiomeric poly(lactide) segments occurs as demonstrated by differential scanning calorimetry and light microscopy. These blends have good tensile properties and excellent resistance to creep under static and dynamic loading conditions.Permanent deformation (after 2 h recovery) of compression‐molded poly(TMC) and solvent‐cast poly(LLA‐TMC‐LLA) and poly(ST‐TMC‐ST) films.imagePermanent deformation (after 2 h recovery) of compression‐molded poly(TMC) and solvent‐cast poly(LLA‐TMC‐LLA) and poly(ST‐TMC‐ST) films.