bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of dental implant spacing on peri‐implant bone using the rabbit (oryctolagus cuniculus) tibia model
Authors: Hatley C. Lee , Cameron Stephen M. , Cuenin Michael F. , Parker M. Harry , Thompson Stevan H. , Harvey Stephen B. 
Published: August 2004

Purpose This study investigated the effects of implant proximity on inter‐implant bone height, density, and osseointegration using digital radiography and histology.Materials and Methods After a feasibility study, a total of 80 endosteal implants were placed in 20 New Zealand White Rabbit tibias. With the aid of a surgical jig, four 8.5‐mm implants were placed in the medial aspect of the tibial crest at inter‐implant distances of approximately 1, 1.5, and 3 mm. Standardized digital radiographs using a paralleling device were made immediately after placement of implants. Implants were allowed to osseointegrate for 90 days. After this healing period, the animals were sacrificed, and the standardized radiographs were repeated. The tibias were harvested, processed, and invested in epoxy. Sagittal sections were made from each specimen for histologic evaluation. The initial and postmortem digital radiographs were evaluated for inter‐implant distances, vertical bone height changes over time and between implant pairs, and bone density changes over time and between implant pairs using a computer image analysis program and computer statistics program.Results The actual inter‐implant distances were consistent in a range of 0.2 mm. Bone height increased significantly from presurgical levels at all 3 locations (p < .0005). Repeated measures analysis of variance comparing change in bone height at the 3 implant pair distances showed significant differences among the 3 (p= .002). Paired t tests showed that the amount of bone growth at the 1‐mm separation site was significantly greater than the 1.5‐mm site (p= .026) and the 3‐mm site (p= .001), whereas bone growth at the 1.5‐ and 3‐mm sites did not show significant differences (p= .162). A repeated measures analysis of variance comparing change in bone density showed no significant differences (p > .05) among the 3 inter‐implant distances for either the 8‐mm position (approximately crestal bone height) or the 6‐mm position (approximately 2 mm subcrestal).Conclusions Within the limits of this study, it seems placing implants closely together does not adversely affect bone height or density. Conversely, it seems that placing implants closer together may increase bone growth.
Effect of package weight on the total amount of die stone used annually in a dental school
Authors: Price Richard B. , Gerrow Jack D. , Bannerman Ronald A. 
Published: August 2004

Purpose This study compared the total amount of Type IV dental stone (die stone) used annually by dental students when they were supplied with either 70‐g or 140‐g preweighed packages of die stone.Materials and Methods In September 1994, all the bulk containers of die stone were removed from the student dental clinic and laboratories and replaced by 70‐g preweighed packages of die stone (Silky‐Rock; Whip Mix, Louisville, KY). At the end of August 1998, all 70‐g packages of die stone were removed from the student dental clinic and laboratories. The average annual number of 70‐g packages of preweighed die stone used by the students from 1994 to 1998 was calculated. From September 1998 to the end of August 1999, only 140‐g preweighed packages of die stone (Silky‐Rock) were supplied to the students. The number of the 140‐g packages of preweighed die stone and total weight used by students during this period were calculated and compared with the average annual number of 70‐g preweighed packages of die stone used during the 1994–1998 period.Results From September 1994 to August 1998, the students used an annual average of 4060 ± SD 250 of the 70‐g packages (284.2 ± 17.5 kg per annum). From September 1998 to August 1999, the students used 3360 of the 140‐g packages (470.4 kg).Conclusions Although the students used in total 700 fewer of the 140‐g die stone packages per annum than the annual average number of 70‐g packages, they used 186.2 kg (65.5%) more die stone when supplied with the 140‐g packages.
The dental student as a technician: Preclinical and clinical laboratory programs in fixed prosthodontics
Authors: Petropoulos Vicki C. , Weintraub Annette , Weintraub Gerald S. 
Published: August 2004

Purpose A 2‐part survey of United States dental schools was conducted. The first part of the survey was published in 1998 and determined the curricular structure, techniques taught, and materials used in predoctoral fixed prosthodontics courses. The purpose of the second part of the survey was to ascertain the delegation of laboratory procedures in preclinical and clinical fixed prosthodontic programs.Materials and Methods The survey was mailed to the course directors of predoctoral fixed prosthodontic programs at 53 US dental schools. Of these, 42 schools returned the completed survey, resulting in a response rate of 79%.Results Results from this survey show that certain laboratory procedures in preclinical and clinical fixed prosthodontics are completed by dental laboratories (either in‐house or commercially available laboratories).Conclusions For the preclinical programs of fixed prosthodontics, there is more student involvement in the completion of laboratory procedures in the dental schools surveyed. In clinical fixed prosthodontic programs, there is a high emphasis on patient care and less on laboratory techniques that can be delegated to laboratory technicians.
Atherosclerotic Occlusive Extracranial Vertebral Artery Disease:
Authors: WEHMAN J. CHRISTOPHER , HANEL RICARDO A. , GUIDOT CHARLES A. , GUTERMAN LEE R. , HOPKINS L. NELSON 
Published: August 2004

Background: Atherosclerotic occlusive disease of the vertebral artery (VA) affects a significant proportion of patients with cerebrovascular disease and can cause significant morbidity and mortality despite maximal medical therapy. Careful selection of both symptomatic and asymptomatic patients for intervention based on neurological symptoms, as well as anatomical and hemodynamic considerations, is essential.
Methods: To achieve proper results with angioplasty and stenting, standard endovascular techniques are modified for the unique anatomical considerations of the VA. Several technical nuances are described here to aid in the endoluminal revascularization of the VA.
Results: Technical success (<50% residual diameter stenosis) rates ranging from 94 to 98% and low rates of periprocedural complications have been achieved with VA angioplasty and stenting in select series with angiographic follow‐up. The long‐term success in those series is limited by the high (10–43%) rate of recurrent stenosis. Proper placement of the stent can reduce the risk of periprocedural complications and restenosis. In‐stent stenosis appears most commonly during the first 6–12 months after stent placement, but does not appear to correlate with return of neurological symptoms. We believe the high rate of recurrent stenosis makes follow‐up angiography essential, especially in the first 12 months after the procedure.
Conclusion: Endovascular VA angioplasty with stent placement provides an innovative approach to treat a difficult clinical entity. Evolving therapies, including drug‐eluting stents or bioresorbable stents, may prove to provide better long‐term results.
Lingering Terminal Illness and the Family: Insights From Literature
Authors: BERTMAN SANDRA L. 
Published: August 2004

Literature invites us to enter into the human dilemma in a manner that is different from but no less penetrating than clinical observation. The writer's craft uncovers realities other than the statistically measurable and objective. In languages far from the strictly literal and closer to indirection, symbolism, and aesthetics, the literary artist probes imagination and consciousness. He presents us with transcripts of conversations replete with intonations, and we thereby become privy to motivations and inner thoughts. The artistry of a piece of fiction, autobiographical essay, poem, or drama propels us into empathetic relationships. We feel with the emotions of the involved dramatis personae; we witness their interactions; we experience their points of view. And by such participation, we, the readers, come to perceive and even refine our own.Themes of chronic illness, dying, and bereavement are certainly not alien to literature. This paper explores several literary moments that may help the professional who is working with these issues to have a broader appreciation of the subtleties of these human experiences.
Immobilized Cobalt Affinity Chromatography Provides a Novel, Efficient Method for Herpes Simplex Virus Type 1 Gene Vector Purification
Authors: Jiang Canping , Wechuck James B. , Goins William F. , Krisky David M. , Wolfe Darren , Ataai Mohammad M. , Glorioso Joseph C. 
Published: August 2004

ABSTRACT

Herpes simplex virus type 1 (HSV-1) is a promising vector for gene therapy applications, particularly at peripheral nerves, the natural site of virus latency. Many gene vectors require large particle numbers for even early-phase clinical trials, emphasizing the need for high-yield, scalable manufacturing processes that result in virus preparations that are nearly free of cellular DNA and protein contaminants. HSV-1 is an enveloped virus that requires the development of gentle purification methods. Ideally, such methods should avoid centrifugation and may employ selective purification processes that rely on the recognition of a unique envelope surface chemistry. Here we describe a novel method that fulfills these criteria. An immobilized metal affinity chromatography (IMAC) method was developed for the selective purification of vectors engineered to display a high-affinity binding peptide. Feasibility studies involving various transition metal ions (Cu
2+
, Zn
2+
, Ni
2+
, and Co
2+
) showed that cobalt had the most desirable features, which include a low level of interaction with either the normal virus envelope or contaminating DNA and proteins. The introduction of a cobalt-specific recognition element into the virus envelope may provide a suitable target for cobalt-dependent purification. To test this possibility, we engineered a peptide with affinity for immobilized cobalt in frame in the heparan sulfate binding domain of HSV-1 glycoprotein B, which is known to be exposed on the surface of the virion particle and recombined into the viral genome. By optimizing the IMAC loading conditions and reducing cobalt ion leakage, we recovered 78% of the tagged HSV-1 recombinant virus, with a >96% reduction in contaminating proteins and DNA.
Retroviral Vectors Pseudotyped with Severe Acute Respiratory Syndrome Coronavirus S Protein
Authors: Giroglou Tsanan , Cinatl Jindrich , Rabenau Holger , Drosten Christian , Schwalbe Harald , Doerr Hans Wilhelm , von Laer Dorothee 
Published: August 2004

ABSTRACT
The worldwide outbreak of severe acute respiratory syndrome (SARS) was shown to be associated with a novel coronavirus (CoV) now called SARS CoV. We report here the generation of SARS CoV S protein-pseudotyped murine leukemia virus (MLV) vector particles. The wild-type S protein pseudotyped MLV vectors, although at a low efficiency. Partial deletion of the cytoplasmic tail of S dramatically increased infectivity of pseudotypes, with titers only two- to threefold lower than those of pseudotypes generated in parallel with the vesicular stomatitis virus G protein. S-pseudotyped MLV particles were used to analyze viral tropism. MLV(SARS) pseudotypes and wild-type SARS CoV displayed similar cell types and tissue and host restrictions, indicating that the expression of a functional receptor is the major restraint in permissiveness to SARS CoV infection. Efficient gene transfer could be detected in Vero and CaCo2 cells, whereas the level of gene marking of 293T, HeLa, and HepG2 cells was only slightly above background levels. A cat cell line and a dog cell line were not susceptible. Interestingly, PK-15, a porcine kidney cell line, and primary porcine kidney cells were also highly permissive for SARS S pseudotypes and wild-type SARS CoV. This finding suggests that swine may be susceptible to SARS infection and may be a source for infection of humans. Taken together, these results indicate that MLV(SARS) pseudotypes are highly valuable for functional studies of viral tropism and entry and, in addition, can be a powerful tool for the development of therapeutic entry inhibitors without posing a biohazard to human beings.
The N-Terminal Region of the Murine Coronavirus Spike Glycoprotein Is Associated with the Extended Host Range of Viruses from Persistently Infected Murine Cells
Authors: Schickli Jeanne H. , Thackray Larissa B. , Sawicki Stanley G. , Holmes Kathryn V. 
Published: August 2004

ABSTRACT

Although murine coronaviruses naturally infect only mice, several virus variants derived from persistently infected murine cell cultures have an extended host range. The mouse hepatitis virus (MHV) variant MHV/BHK can infect hamster, rat, cat, dog, monkey, and human cell lines but not the swine testis (ST) porcine cell line (J. H. Schickli, B. D. Zelus, D. E. Wentworth, S. G. Sawicki, and K. V. Holmes, J. Virol.
71:
9499-9507, 1997). The spike (S) gene of MHV/BHK had 63 point mutations and a 21-bp insert that encoded 56 amino acid substitutions and a 7-amino-acid insert compared to the parental MHV strain A59. Recombinant viruses between MHV-A59 and MHV/BHK were selected in hamster cells. All of the recombinants retained 21 amino acid substitutions and a 7-amino-acid insert found in the N-terminal region of S of MHV/BHK, suggesting that these residues were responsible for the extended host range of MHV/BHK. Flow cytometry showed that MHV-A59 bound only to cells that expressed the murine glycoprotein receptor CEACAM1a. In contrast, MHV/BHK and a recombinant virus, k6c, with the 21 amino acid substitutions and 7-amino-acid insert in S bound to hamster (BHK) and ST cells as well as murine cells. Thus, 21 amino acid substitutions and a 7-amino-acid insert in the N-terminal region of the S glycoprotein of MHV/BHK confer the ability to bind and in some cases infect cells of nonmurine species.
Specific Residues in the Connector Loop of the Human Cytomegalovirus DNA Polymerase Accessory Protein UL44 Are Crucial for Interaction with the UL54 Catalytic Subunit
Authors: Loregian Arianna , Appleton Brent A. , Hogle James M. , Coen Donald M. 
Published: August 2004

ABSTRACT

The human cytomegalovirus DNA polymerase includes an accessory protein, UL44, which has been proposed to act as a processivity factor for the catalytic subunit, UL54. How UL44 interacts with UL54 has not yet been elucidated. The crystal structure of UL44 revealed the presence of a connector loop analogous to that of the processivity subunit of herpes simplex virus DNA polymerase, UL42, which is crucial for interaction with its cognate catalytic subunit, UL30. To investigate the role of the UL44 connector loop, we replaced each of its amino acids (amino acids 129 to 140) with alanine. We then tested the effect of each substitution on the UL44-UL54 interaction by glutathione
S
-transferase pulldown and isothermal titration calorimetry assays, on the stimulation of UL54-mediated long-chain DNA synthesis by UL44, and on the binding of UL44 to DNA-cellulose columns. Substitutions that affected residues 133 to 136 of the connector loop measurably impaired the UL44-UL54 interaction without altering the ability of UL44 to bind DNA. One substitution, I135A, completely disrupted the binding of UL44 to UL54 and inhibited the ability of UL44 to stimulate long-chain DNA synthesis by UL54. Thus, similar to the herpes simplex virus UL30-UL42 interaction, a residue of the connector loop of the accessory subunit is crucial for UL54-UL44 interaction. However, while alteration of a polar residue of the UL42 connector loop only partially reduced binding to UL30, substitution of a hydrophobic residue of UL44 completely disrupted the UL54-UL44 interaction. This information may aid the discovery of small-molecule inhibitors of the UL44-UL54 interaction.
Factors That Increase the Effective Concentration of CXCR4 Dictate Feline Immunodeficiency Virus Tropism and Kinetics of Replication
Authors: de Parseval Aymeric , Ngo Stacie , Sun Peiqing , Elder John H. 
Published: August 2004

ABSTRACT
The surface glycoprotein (gp95) of the feline immunodeficiency virus (FIV) binds in a strain-specific manner to several cell surface molecules, including CXCR4, heparan sulfate proteoglycans (HSPGs), DC-SIGN, and a 43-kDa cell surface receptor on T cells recently identified as CD134 by M. Shimojima et al. (Science 303:1192-1195, 2004). CXCR4 is the entry receptor in all known cases, and the other molecules act as binding receptors to help facilitate infection. In this report, we confirm and extend the findings regarding CD134 as a primary receptor for FIV. In addition, we show that temperature critically influences the binding properties of FIV gp95 to CXCR4 and HSPGs. The data show that gp95 of the field strain FIV-PPR bound to CXCR4 at 22°C, whereas binding was not detected at 4°C. In contrast, binding of the laboratory adapted FIV-34TF10 gp95 was observed at either 4°C or 22°C, albeit at increased levels at the higher temperature. The level of CXCR4 increased after the temperature was switched from 4 to 22°C, whereas the level of HSPGs decreased, resulting in higher binding of gp95 from both strains to CXCR4 and lower binding of gp95 of FIV-34TF10 to HSPGs (FIV-PPR gp95 does not bind to these molecules). The findings also show that HSPGs facilitate the CXCR4-mediated infectivity of CrFK and G355-5 cells by FIV-34TF10. These two nonlymphoid cell lines express very low levels of CXCR4 and are permissive to FIV-34TF10 but not to productive infection by FIV-PPR. However, overexpression of human CXCR4 in CrFK or G-355-5 cells resulted in extensive cell fusion and infection by FIV-PPR. Taken together, these findings indicate that factors that increase the effective concentration of CXCR4 enhance FIV infectivity and may involve (i) temperature or ligand-induced conformational changes in CXCR4 that enhance SU binding, (ii) coreceptor interactions with gp95 that either alter gp95 conformation to enhance CXCR4 binding and/or raise the localized concentration of receptor or ligand, or (iii) direct increase in CXCR4 concentration via overexpression.
Human Cytomegalovirus UL84 Oligomerization and Heterodimerization Domains Act as Transdominant Inhibitors of
ori
Lyt-Dependent DNA Replication: Evidence that IE2-UL84 and UL84-UL84 Interactions Are Required for Lytic DNA Replication
Authors: Colletti Kelly S. , Xu Yiyang , Cei Sylvia A. , Tarrant Margaret , Pari Gregory S. 
Published: August 2004

ABSTRACT

Human cytomegalovirus (HCMV) UL84 encodes a 75-kDa protein required for
ori
Lyt-dependent DNA replication and interacts with IE2 in infected and transfected cells. UL84 localizes to the nucleus of transfected and infected cells and is found in viral replication compartments. In transient assays it was shown that UL84 can interfere with the IE2-mediated transactivation of the UL112/113 promoter of HCMV. To determine whether UL84 protein-protein interactions are necessary for lytic DNA synthesis, we purified UL84 and used this protein to generate a monoclonal antibody. Using this antibody, we now show that UL84 forms a stable interaction with itself in vivo. The point of self-interaction maps to a region of the protein between amino acids 151 and 200, a domain that contains a series of highly charged amino acid residues. Coimmunoprecipitation assays determined that UL84 interacts with a protein domain present within the first 215 amino acids of IE2. We also show that an intact leucine zipper domain of UL84 is required for a stable interaction with IE2 and UL84 leucine zipper mutants fail to complement
ori
Lyt-dependent DNA replication. UL84 leucine zipper mutants no longer interfere with IE2-mediated transactivation of the UL112/113 promoter, confirming that the leucine zipper is essential for a functional interaction with IE2. In addition, we demonstrate that both the leucine zipper and oligomerization domains of UL84 can act as transdominant-negative inhibitors of lytic replication in the transient assay, strongly suggesting that both an IE2-UL84 and a UL84-UL84 interaction are required for DNA synthesis.
Identification and Characterization of a New Cross-Reactive Human Immunodeficiency Virus Type 1-Neutralizing Human Monoclonal Antibody
Authors: Zhang Mei-Yun , Xiao Xiaodong , Sidorov Igor A. , Choudhry Vidita , Cham Fatim , Zhang Peng Fei , Bouma Peter , Zwick Michael , Choudhary Anil , Montefiori David C. , Broder Christopher C. , Burton Dennis R. , Quinnan Gerald V. , Dimitrov Dimiter S. 
Published: August 2004

ABSTRACTThe identification and characterization of new human monoclonal antibodies (hMAbs) able to neutralize primary human immunodeficiency virus type 1 (HIV-1) isolates from different subtypes may help in our understanding of the mechanisms of virus entry and neutralization and in the development of entry inhibitors and vaccines. For enhanced selection of broadly cross-reactive antibodies, soluble HIV-1 envelope glycoproteins (Envs proteins) from two isolates complexed with two-domain soluble CD4 (sCD4) were alternated during panning of a phage-displayed human antibody library; these two Env proteins (89.6 and IIIB gp140s), and one additional Env (JR-FL gp120) alone and complexed with sCD4 were used for screening. An antibody with relatively long HCDR3 (17 residues), designated m14, was identified that bound to all antigens and neutralized heterologous HIV-1 isolates in multiple assay formats. Fab m14 potently neutralized selected well-characterized subtype B isolates, including JRCSF, 89.6, IIIB, and Yu2. Immunoglobulin G1 (IgG1) m14 was more potent than Fab m14 and neutralized 7 of 10 other clade B isolates; notably, although the potency was on average significantly lower than that of IgG1 b12, IgG1 m14 neutralized two of the isolates with significantly lower 50% inhibitory concentrations than did IgG1 b12. IgG1 m14 neutralized four of four selected clade C isolates with potency higher than that of IgG1 b12. It also neutralized 7 of 17 clade C isolates from southern Africa that were difficult to neutralize with other hMAbs and sCD4. IgG1 m14 neutralized four of seven primary HIV-1 isolates from other clades (A, D, E, and F) much more efficiently than did IgG1 b12; for the other three isolates, IgG b12 was much more potent. Fab m14 bound with high (nanomolar range) affinity to gp120 and gp140 from various isolates; its binding was reduced by soluble CD4 and antibodies recognizing the CD4 binding site (CD4bs) on gp120, and its footprint as defined by alanine-scanning mutagenesis overlaps that of b12. These results suggest that m14 is a novel CD4bs cross-reactive HIV-1-neutralizing antibody that exhibits a different inhibitory profile compared to the only known potent broadly neutralizing CD4bs human antibody, b12, and may have implications for our understanding of the mechanisms of immune evasion and for the development of inhibitors and vaccines.