bluuebunny/crossref_metadata_2025_split huggingface dataset:
Encapsulation and osteoinduction of human periodontal ligament fibroblasts in chitosan–hydroxyapatite microspheres
Authors: Inanç Bülend , Eser Elçin A. , Koç Aysel , Baloş Köksal , Parlar Ateş , Murat Elçin Y. 
Published: March 2007

AbstractPeriodontal ligament cells play a crucial role in the regeneration of periodontal tissues and an undifferentiated mesenchymal cell subset is thought to exist within this population. The aim of this study was to assess the osteogenic differentiation potential of human periodontal ligament fibroblasts (hPDLFs) in three dimensional (3D)‐osteogenic culture environment following encapsulation in chitosan–hydroxyapatite (C/HA) microspheres with the size range of 350–450 μm. Human PDLF cultures were established and three experimental groups were formed: (i) two‐dimensional (2D)‐culture as single cell monolayer, (ii) 3D‐static culture of C/HA encapsulated hPDLFs, and (iii) 3D‐dynamic culture of C/HA encapsulated hPDLFs in a rotating wall vessel bioreactor. The cells were cultured in standard culture medium supplemented with β‐glycerophosphate, dexamethasone, and ascorbic acid. After 21 days, immunohistochemistry was performed using antibodies against osteonectin, osteopontin, bone‐sialoprotein, and osteocalcin as osteogenic differentiation markers. Phase‐contrast and scanning electron microscopy observations were used for histological and morphological evaluation. The combined effects of osteoinductive medium and HA‐containing composite microsphere material on encapsulated hPDLFs resulted in the transformation of a considerable portion of the cells into osteoblastic lineage at the end of the experiments. Results demonstrate the ability of hPDLFs to undergo osteogenic differentiation upon induction in vitro, both under 2D and 3D culture conditions. C/HA microspheres in microgravity bioreactor may serve as a suitable 3D environment to support the osteogenic differentiation of human PDLFs, in vitro. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Comparison between sol‐gel‐derived anatase‐ and rutile‐structured TiO2 coatings in soft‐tissue environment
Authors: Rossi S. , Moritz N. , Tirri T. , Peltola T. , Areva S. , Jokinen M. , Happonen R.‐P. , Närhi T. 
Published: March 2007

AbstractThe bioactivity of the surface reactive TiO2 coatings for medical implants can be locally modified by CO2 laser processing to match with the properties of surrounding tissues. The TiO2 coatings heat‐treated at 500°C exhibit in vitro bioactivity. With further CO2 laser treatment they exhibit enhanced in vitro bioactivity. The aim of this in vivo study was to compare the performance of heat‐treated anatase‐structured TiO2 coatings with preheat‐treated and CO2 laser‐treated rutile‐structured coatings in terms of their ability to attach soft connective tissues. The coatings were characterized with TF‐XRD and AFM. TiO2‐coated discs were implanted in rats. The samples were analyzed with routine histology, SEM‐EDS, and TEM. In both groups, already at 3 days, soft connective tissues were in immediate contact with the surface. No thick crystalline CaP layer was detected by SEM‐EDS, but a thin amorphous CaP layer was detected by XPS. No gap between the cell membrane and the coating could be observed in TEM pictures. No differences were observed between the anatase‐ and rutile‐structured coatings in terms of tissue responses. Further studies are needed to verify if the tissues are adherent to the surface of the implant. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Biochemical composition of the superficial layer of articular cartilage
Authors: Crockett R. , Grubelnik A. , Roos S. , Dora C. , Born W. , Troxler H. 
Published: March 2007

AbstractTo gain more information on the mechanism of lubrication in articular joints, the superficial layer of bovine articular cartilage was mechanically removed in a sheet of ice that formed on freezing the cartilage. Freeze‐dried samples contained low concentrations of chondroitin sulphate and protein. Analysis of the protein by SDS PAGE showed that the composition of the sample was comparable to that of synovial fluid (SF). Attenuated total reflection infrared (ATR‐IR) spectroscopy of the dried residue indicated that the sample contained mostly hyaluronan. Moreover, ATR‐IR spectroscopy of the upper layer of the superficial layer, adsorbed onto silicon, showed the presence of phospholipids. A gel could be formed by mixing hyaluronan and phosphatidylcholine in water with mechanical properties similar to those of the superficial layer on cartilage. Much like the superficial layer of natural cartilage, the surface of this gel became hydrophobic on drying out. Thus, it is proposed that the superficial layer forms from hyaluronan and phospholipids, which associate by hydrophobic interactions between the alkyl chains of the phospholipids and the hydrophobic faces of the disaccharide units in hyaluronan. This layer is permeable to material from the SF and the cartilage, as shown by the presence of SF proteins and chondroitin sulphate. As the cartilage dries out after removal from the joint, the phospholipids migrate towards the surface of the superficial layer to reduce the surface tension. It is also proposed that the highly efficient lubrication in articular joints can, at least in part, be attributed to the ability of the superficial layer to adsorb and hold water on the cartilage surface, thus creating a highly viscous boundary protection. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Superparamagnetic iron oxide (SPIO)‐enhanced liver MRI with ferucarbotran: Efficacy for characterization of focal liver lesions
Authors: Namkung Sook , Zech Christoph J. , Helmberger Thomas , Reiser Maximilian F. , Schoenberg Stefan O. 
Published: March 2007

AbstractPurposeTo evaluate the efficacy of ferucarbotran in T2‐weighted (T2W) fast spin‐echo (FSE) and T2*W gradient‐echo (GRE) sequences for characterizing focal liver lesions.Materials and MethodsIn 68 patients, 46 malignant and 22 benign focal liver lesions were evaluated. Precontrast (NCE) T2W FSE images and contrast‐enhanced (CE) T2W FSE and T2*W GRE images were obtained on a 1.5T MR system. Based on signal intensity (SI) measurements in focal lesions and liver parenchyma, the signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) were calculated for all sequences. The percentage of SI loss (PSIL) in focal lesions after contrast agent (CA) application was calculated for the T2W FSE sequence. Qualitative analyses were performed to assess image quality and lesion conspicuity obtained with the CE‐T2W FSE and CE‐T2*W GRE sequences.ResultsThe mean PSIL was higher in solid benign lesions than in malignant lesions (39.6% vs. 3.2%, P < 0.05). With a threshold PSIL of 25%, the sensitivity and specificity for characterizing malignant lesions were 97.8% and 92.9%, respectively. The mean CNR of the malignant lesions was higher in the CE‐T2*W sequence than in the CE‐ and NCE‐T2W FSE sequences (29.9 vs. 22.7 (P < 0.01) vs. 12.8 (P < 0.01)). CE‐T2*W images showed a superior image quality and lesion conspicuity (P < 0.05) compared to the CE‐T2W FSE sequence.ConclusionThe PSIL can be an accurate tool for characterizing benign and malignant lesions. The addition of a CE‐T2*W GRE sequence is helpful for the detection and characterization of malignant lesions. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
3D excretory MR urography: Improved image quality with intravenous saline and diuretic administration
Authors: Ergen F. Bilge , Hussain Hero K. , Carlos Ruth C. , Johnson Timothy D. , Adusumilli Saroja , Weadock William J. , Korobkin Melvyn , Francis Isaac R. 
Published: March 2007

AbstractPurposeTo assess the effect of diuretic administration on the image quality of excretory magnetic resonance urography (MRU) obtained following intravenous hydration, and to determine whether intravenous hydration alone is sufficient to produce diagnostic quality studies of nondilated upper tracts.Materials and MethodsA total of 22 patients with nondilated upper tracts were evaluated with contrast‐enhanced MRU. All patients received 250 mL of saline intravenously immediately prior to the examination. A total of 11 patients received 10–20 mg furosemide in addition to saline. Imaging was performed with a three‐dimensional (3D) and two‐dimensional (2D) breathhold spoiled gradient‐echo sequences. Excretory MRU images were acquired five minutes after the administration of 0.1 mmol/kg gadolinium and were independently reviewed by two radiologists, who were blinded to the MRU technique. Readers evaluated the calyces, renal pelvis, and ureters qualitatively for degree of opacification, distention, and artifacts on a four‐point scale. Statistical analysis was performed using a permutation test.ResultsThere was no significant disagreement between the two readers (P = 0.14). Furosemide resulted in significant improvement in calyceal and renal pelvis distention (P < 0.005), and significant artifact reduction in all upper tract segments (P < 0.001) compared to the effect of saline alone.ConclusionIntravenous furosemide significantly improves the image quality of excretory MRU studies obtained following intravenous hydration. Intravenous saline alone is insufficient to produce diagnostic quality studies of the non‐dilated upper tracts. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Primary human herpesvirus‐6 infection is frequently overlooked as a cause of febrile fits in young children
Authors: Ward K. N. , Gray J. J. 
Published: March 2007

AbstractSera from 248 children aged 30–179 weeks were tested retrospectively for human herpesvirus‐6 (HHV‐6) IgG antibody avidity. Twenty‐five children presented with febrile fits, in one case with a rash, exanthem subitum resulting from primary HHV‐6 infection was diagnosed at the time, but in the others HHV‐6 was not considered in the differential diagnosis even though two patients had a rash. In fact, five of the 25 patients experienced primary infection as shown by low avidity HHV‐6 antibody. Although nine other of these patients were seronegative in the acute phase of the illness, and unfortunately convalescent sera were not available to confirm primary HHV‐6 infection, seronegativity was clearly a risk factor for febrile fits (P = 0.03, odds ratio 3.14 for all children; P = 0.002, odds ratio 7.20 for children aged 70–179 weeks), and primary HHV‐6 infection was a very likely diagnosis. The remaining 11 children had high avidity antibody, so HHV‐6 was excluded as a cause of their febrile fits. HHV‐6 may frequently be a cause of febrile fits, often without the typical rash of exanthem subitum, and this diagnosis is often overlooked by clinicians.
Detection by PCR of human polyomaviruses BK and JC in immunocompromised individuals and partial sequencing of control regions
Authors: Schäutzl H. M. , Sieger E. , Jäuger G. , Nitschko H. , Bader L. , Ruckdeschel G. , Jäuger G. 
Published: March 2007

AbstractImmunocompromised individuals were tested for the presence of the human polyomaviruses JC (JCV) and BK (BKV) by the polymerase chain reaction (PCR). The use of appropriate primers in a nested PCR allowed the detection of both viruses simultaneously. Viruses were differentiated by restriction fragment length analysis of amplified DNA fragments. Both BKV and JCV DNA were detected in the urine of an AIDS patient with progressive multifocal leukencepha‐lopathy. In autopsy materials from this patient, JCV‐ but not BKV‐DNA was found in brain and kidney tissue, whereas lung tissue was negative for both virus DNAs. To evaluate the methology further, hybridization‐positive urines from three recipients of bone marrow transplants and a positive urine of an acute myeloid leukemia patient were analyzed by this PCR method. One case was positive both for BKV and JCV, two cases were positive only for BKV, and one was negative for both.Parts of the control regions of JCV and BKV were sequenced directly from PCR‐derived fragments. The JCV sequence from urine of the AIDS patient compared to sequences from a bone marrow transplant recipient and to archetypical reference strains showed two nucleotide (nt) exchanges out of 250 nt. The BKV sequences from the AML and the AIDS patients showed five nt exchanges out of 265 nt in the control region and were identified as BKV WW or WWT3 strains. In the agnogene region five exchanges were detected, two of them resulting in non‐conservative amino acid exchanges.The possibility of testing clinical specimens of different origins by this PCR method is important for elucidating often unclear clinical courses in immunocompromised patients. Furthermore, our results show the versatility of PCR for diagnosis and for molecular characterization of human polyomaviruses.
Prevalence of antibodies to hepatitis C virus among patients with leprosy in several African countries and the Yemen
Authors: Denis F. , Aussel L. , Ranger S. , Martin P. , Itoua‐N'Gaporo A. , Frommel D. , Teckle‐Haimanot R. T. , Sangare A. , M'Boup S. , Millan J. , Al Qubati Y. 
Published: March 2007

AbstractThe prevalence of anti‐HCV was determined in 1,309 leprosy patients and a control group of 1,469 subjects from 6 sub‐Saharan African countries and the Yemen. Sera found positive by an initial second generation ELISA were subjected to 3 additional confirmatory tests. The anti‐HCV prevalence in leprosy patients (7.1%) was significantly higher than in the control group (2.6%). HCV seroprevalence increased with age in both the control and leprosy groups. No statistically significant difference could be found between anti‐HCV prevalence and the several clinical forms of leprosy among patients. The results of this study indicate a high degree of exposure or chronic carriage of hepatitis C among leprosy patients. © 1994 Wiley‐Liss, Inc.
Development of a rapid quantitative assay for HIV‐1 plasma infectious viraemia‐culture‐PCR (CPID)
Authors: Ariyoshi Koya , Bloor Stuart , Bieniasz Paul D. , Bourrelly Michel , Foxall Russell , Weber Jonathan N. 
Published: March 2007

AbstractA simple and rapid assay for the quantification of infectious HIV‐1 in plasma was developed using short‐term culture and DNA PCR. This method, called culture PCR, allows detection and quantification of infectious HIV‐1 viraemia within 48 hours, and measures the number of infectious cell‐free HIV‐1 particles, expressed as culture PCR infectious doses (CPID/ml). 42 HIV infected subjects were assessed by this method. The titres obtained by CPID closely correlated with CD4+ count and clinical status. CPID titres had significant correlation with infectious virus titre determined by conventional limiting dilution tissue‐culture methods. This culture‐PCR technique permits rapid assessment of infectious plasma viraemia, and is comparable to longer culture based assay methods. © 1994 Wiley‐Liss, Inc.
Class and subclass distribution of hantavirus‐specific serum antibodies at different times after the onset of nephropathia epidemica
Authors: Groen J. , Gerding M. , Jordans J. G. M. , Clement J. P. , Osterhaus A. D. M. E. 
Published: March 2007

AbstractSera from Dutch and Belgium individuals who suffered from nephropathia epidemica (NE), a mild form of haemorrhagic fever with renal syndrome (HFRS), were tested for the distribution of classes and subclasses of Hantavirus (HV)‐specific antibodies at different times after the onset of the disease, with class‐ and subclass‐specific Ig capture enzyme‐linked immunosorbent assays (ELISAs). In the acute, early convalescent, and convalescent phases, predominantly specific IgA, IgM, and IgGS antibodies were detected. Specific IgG2 antibodies were only detected at low levels in the early convalescent and convalescent phases. In the late convalescent phase specific IgG1 and IgGS antibodies were found, whereas in the late post convalescent phase only specific IgG1 antibodies proved to be present. Specific IgG4 antibodies were not detected in any of the respective phases. These data show that the simultaneous determination of classes and subclasses of HV specific serum antibodies allows the estimation of the time elapsed after the onset of NE. © 1994 Wiley‐Liss, Inc.
Effect of age on serum immunoglobulin G subclass antibody responses to inactivated influenza virus vaccine
Authors: Powers Douglas C. 
Published: March 2007

AbstractWe previously reported an age‐associated impairment of serum immunoglobulin G (IgG) antibody responses to inactivated influenza virus vaccine. The present study extends these observations by examining the IgG subclass distribution of vaccine responses measured by enzyme linked immunosorbent assay in healthy adults aged <40 (young), 40–64 (middle‐aged), and ⩾65 (elderly) years. Serological responses in all age groups showed antibodies that were predominantly IgG1 and secondarily IgGS. Influenza antigen‐specific IgG4 titers did not change following vaccination, and antibodies of the IgG2 subclass were not detected in any serum specimens. Aging was associated with a significant impairment of IgG1, but not of IgGS, antibody production. Relative differences in the magnitude and frequency of response between IgG1 and IgGS subclasses, which were present in young and middle‐aged adults (viz., IgG1 > IgGS), were less apparent in the elderly. This observation was confirmed in a second analysis of IgG subclass‐specific responses in a separate cohort of elderly vaccinees. These results suggest that the age‐related impairment of humoral responses to inactivated influenza virus vaccine is primarily accounted for by differences in IgG1 antibody production, and that IgGS antibodies make up a larger proportion of the overall serologic response in the elderly than they do in younger persons. © 1994 Wiley‐Liss, Inc.
Evolution of the hepatitis B virus gene during chronic infection in seven patients
Authors: Uchida Toshikazu , Aye Thein Thein , Shikata Toshio , Yano Michitami , Yatsuhashi Hiroshi , Koga Michiaki , Mima Satoaki 
Published: March 2007

AbstractWe analyzed the evolution of the precore/core gene of hepatitis B virus (HBV) over a period of 6 to 11 years in seven patients with chronic HBV infection, who exhibited a variety of clinical features. Sequence analysis revealed the following results: (1) HBeAg to anti‐HBe seroconversion was correlated roughly with the occurrence of precore‐defective mutants, and several years appeared to be required for complete replacement of wild types by mutants; (2) core gene mutations preceded precore‐defective mutations and tended to increase with time, although not cumulatively. They occurred not only during serum alanine aminotransferase (ALT) elevations but also after ALT returned to normal; (3) ALT fluctuations appeared to subside with complete replacement of the wild type by the mutant type and/or substantial accumulation of core gene mutations; (4) unexpectedly, the anti‐HBe‐positive “healthy” carrier was found to harbor the wild type precore gene, as did the HBeAg‐positive “healthy” carrier; however, the core gene of the former evolved at a rapid rate; and (5) a partial deletion was recognized in the core gene at the onset of fatal hepatic failure in one patient. Thus, the precore/core mutation was closely related with the clinical features in the patients. © 1994 Wiley‐Liss, Inc.
High levels of viral replication during acute hepatitis B infection predict progression to chronicity
Authors: Fong Tse‐Ling , Di Bisceglie Adrian M. , Biswas Robin , Waggoner Jeanne G. , Wilson Leonard , Claggett Janet , Hoofnagle Jay H. 
Published: March 2007

AbstractTo assess the pattern of development of serologic markers during acute hepatitis B, levels of HBsAg, HBeAg, and hepatitis B virus (HBV) DNA were assayed in stored serum samples obtained sequentially from 12 subjects infected with HBV during experimental studies conducted in the 1950s. Six patients developed acute self‐limited hepatitis, three developed chronic hepatitis, and three had an asymptomatic infection without HBsAg. HBsAg was the first serologic marker detected (mean = 52 days after exposure), followed by HBeAg (62 days) and HBV DNA (72 days). Peak HBsAg levels occurred before onset of symptoms and correlated with peak titers of HBeAg and HBV DNA. Patients who developed chronic hepatitis had higher peak levels of viral markers than those with self‐limited disease: HBsAg (30 versus 5.4 μg/ml), HBeAg (1:2,000 versus 1:60 titer) and HBV DNA (3,192 versus 444 pg/ml). Thus, chronic HBV infection is characterized by high levels of viral replication appearing early during the acute phase of infection. © 1994 Wiley‐Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of America.
Benign human enterovirus becomes virulent in selenium‐deficient mice
Authors: Beck Melinda A. , Kolbeck Peter C. , Rohr Lisa H. , Shi Qing , Morris Virginia C. , Levander Orville A. 
Published: March 2007

AbstractCoxsackieviruses have been implicated as possible co‐factors in the etiology of the selenium (Se)‐responsive cardiomyopathy known as Keshan disease. Here we report that a cloned and sequenced amyocarditic coxsackievirus B3 (CVB3/0), which causes no pathology in the hearts of Se‐adequate mice, induces extensive cardiac pathology in Se‐deficient mice. CVB3/0 recovered from the hearts of Se‐deficient mice inoculated into Se‐adequate mice induced significant heart damage, suggesting mutation of the virus to a virulent genotype. We demonstrate the important role of host nutritional status in determining the severity of a viral infection. © 1994 Wiley‐Liss, Inc.
Detection of varicella‐zoster virus‐specific DNA sequences in cerebrospinal fluid from patients with acute aseptic meningitis and no cutaneous lesions
Authors: Echevarría José M. , Casas Inmaculada , Tenorio Antonio , de Ory Fernando , Martinez‐Martin Pablo 
Published: March 2007

AbstractAcute aseptic meningitis (AAM) is considered as an uncommon manifestation of varicella‐zoster virus (VZV) recrudescence and is usually regarded as a complication of the cutaneous infection in patients with impaired cellular immunity. Indirect evidence suggests, however, that VZV‐associated AAM may also respond to direct spread of the virus to the leptomeninges from the cells supporting the latency. The polymerase chain reaction (PCR) was used to amplify VZV‐specific DNA sequences in serial cerebrospinal fluid (CSF) samples from 21 patients with AAM, who presented laboratory evidence of intrathe‐cal production of VZV‐specific antibody on follow‐up. Eleven of these patients never showed cutaneous zosteriform lesions. VZV‐DNA sequences were detected in the CSF from all patients with cutaneous zoster, as well as from six patients (55%) lacking skin lesions. Viral DNA sequences were present in six cases before the rise in specific antibody was seen in CSF, disappearing during follow‐up in the seven positive cases. These results support the proposed involvement of VZV in the etiology of AAM seen among normal young adults and strongly suggest that the virus can reach directly and infect the CNS from the latently infected spinal ganglia. © 1994 Wiley‐Liss, Inc.