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At least 91 records · Page 5Linked to original sources
PubMed2003

A quantitative analysis of valgus torque on the ACL: a human cadaveric study.

The loads needed to elicit a positive pivot shift test in a knee with an anterior cruciate ligament (ACL) rupture have not been quantified. The coupled anterior tibial translation (ATT), coupled internal tibial rotation (ITR), and the in situ force in the ACL in response to a valgus torque, an inherent component of the pivot shift test, were measured in 10 human cadaveric knee specimens. Using a robotic/universal force-moment sensor testing system, valgus torques ranging from 0.0 to 10.0 Nm were applied in nine increments on the intact and ACL-deficient knee in flexion ranging from 0 degrees to 90 degrees. At 15 degrees of knee flexion, the coupled ATT and ITR were significantly increased in the ACL-deficient knee when compared to the intact knee. Coupled ATT increased a maximum of 291% (6.7 mm, p<0.05), while coupled ITR increased a maximum of 85% (5.1 degrees, p<0.05). At 30 degrees, the increases in coupled ATT and ITR were significant at valgus loads of 3.3 Nm and greater with a maximum increase in coupled ATT of 137% (6.3 mm, p<0.05) and a maximum increase in coupled ITR of 38% (3.6 degrees, p<0.05). At 45 degrees, coupled ATT increased significantly (maximum of 69%, 4.4 mm, p<0.05), but only at torques > or =6.7 Nm. The in situ force in the ACL was less than 20 N for all flexion angles when a torque between 3.3 and 5.0 Nm was applied. Low valgus torque elicited tibial subluxation in the ACL-deficient knee with low in situ ACL forces, similar to a positive pivot shift test. Thus, application of a valgus torque may be suitable to evaluate ACL-deficient and ACL-reconstructed knees, since subluxation can be achieved with minimal harm to the ACL graft. This work is important in understanding one load component needed for the pivot shift examination; further studies quantifying other load components are essential for better comprehension of the in vivo pivot shift examination.

Adult↗
PubMed2003

Free DNA ends are essential for concatemerization of synthetic double-stranded adeno-associated virus vector genomes transfected into mouse hepatocytes in vivo.

Recombinant adeno-associated virus (rAAV) vectors stably transduce hepatocytes in vivo. In hepatocyte nuclei, the incoming single-stranded (ss) vector genomes are converted into various forms of double-stranded (ds) genomes including extrachromosomal linear and circular monomers and concatemers, and a small portion of the vector genomes integrate into chromosomes. The mechanism of genome conversion is not well understood. In the present study, we analyzed the role of inverted terminal repeat (ITR) sequences of ds circular or linear rAAV vector intermediates in concatemerization. We synthesized supercoiled ds circular monomers with a double-D ITR (DDITR) (C+), and ds linear monomers with an ITR at each end (L+), and their control molecules, C- and L-, which lack the ITR-derived sequences, and transfected mouse hepatocytes with these molecules in vivo to assess their capacity for concatemerization. The transfected L+ or L-, but not C+ or C- molecules, concatemerized in vivo irrespective of the presence or absence of the ITRs. In addition, our results suggested that transfected C+ or C- species were not efficient substrates for integration. Based on these observations, we propose a model whereby ds linear molecules with free DNA ends, but not circular molecules, play an important role in rAAV vector genome concatemerization.

Animals↗
PubMed2007

Hybrid adeno-associated virus bearing nonhomologous inverted terminal repeats enhances dual-vector reconstruction of minigenes in vivo.

We have previously demonstrated that hybrid adeno-associated viral (AAV) vectors bearing nonhomologous inverted terminal repeats (ITRs) enhance directional intermolecular recombination and the efficiency of dual-AAV vector trans-splicing in cultured cells. Using hybrid-ITR vectors carrying two exons of a lacZ minigene, we demonstrate that this dual-vector approach also mediates higher levels (3- to 6-fold) of gene reconstitution in mouse skeletal muscle, liver, and heart. Inhibition of the proteasome by systemic administration of Doxil (Food and Drug Administration-approved lipid-formulated doxorubicin) further enhanced dual-vector trans-splicing 6- to 12-fold in two mouse strains. Hence, using hybrid-ITR AAV vectors in combination with proteasome modulation enhanced dual-vector delivery of a transgene approximately 36-fold over the current dual-vector trans-splicing approaches. These data provide in vivo evidence that ITR sequence-dependent homologous recombination, rather than nonhomologous end joining, is the predominant mechanism for AAV genome heterodimerization. Hence, enhanced directional recombination provided by hybrid-ITR vectors may be a useful in vivo strategy for improving dual-vector delivery of transgenes larger than the AAV packaging limit.

Animals↗
PubMed2004

Pontine intertrigeminal region attenuates sleep apneas in rats.

STUDY OBJECTIVES: To determine whether the pontine intertrigeminal region (ITR), with recently described anatomic connections and an effect on vagally induced reflex apnea, has an impact on spontaneous sleep apneas in rats. DESIGN: Respiration, electroencephalogram (EEG), and electromyogram (EMG) were recorded in rats with lesions of the pontine ITR and in control animals. PARTICIPANTS: 9 adult male Sprague-Dawley rats. INTERVENTIONS: Rats were implanted with EEG and EMG electrodes and were polygraphically recorded for 6 hours, and their respiration was monitored by placing each animal inside a single-chamber plethysmograph. Subsequently, a respiratory-related intertrigeminal site was identified by probing on dorsoventral tracks with 2 to 5 nL glutamate (10 nL, 10 mmol) injections from a multibarrel glass pipette. This site was then lesioned by injecting ibotenic acid (10 nL, 50 mmol) from a second pipette barrel. Animals were again recorded for 6 hours on days 2, 7, and 14 after the lesion. MEASUREMENTS AND RESULTS: ITR lesions exerted no impact on mean respiratory pattern during any sleep-wake state, compared to baseline recordings. In contrast, apnea frequency during non-rapid eye movement sleep increased following ITR lesion, more than doubling by day 14. CONCLUSIONS: This study demonstrates that a small and well-localized unilateral lesion of the ITR region in the lateral pons can increase sleep apnea expression in freely moving rats over a 2-week period. The present findings are in agreement with the general modulatory role of pontine structures in activities including respiration, heart rate, and regulation of blood pressure.

Animals↗
PubMed1999

A state trauma registry as a tool for occupational injury surveillance.

The goal of occupational surveillance is to identify and determine the magnitude of work-related disease and injury and workplace hazards for the purposes of focusing prevention programs and tracking their effectiveness. There are a number of databases that collect information on pieces of the puzzle of workplace exposure and adverse health outcomes. Other than that for the fatalities, none of these datasets specifically describes the most severe occupational injuries or their attendant disability. The goal of this study was to evaluate the usefulness of the Illinois Trauma Registry (ITR) in the surveillance of occupational injuries. The entire dataset of the ITR was obtained from the Illinois Department of Public Health for the years 1993 and 1994. The occupational injuries were extracted and frequency distributions were determined for all demographic and health variables. Background population, employment, and death-rate data were obtained for the purpose of rate calculation and for comparison of raw data. Mean costs for acute occupational injuries were calculated. There were 5844 occupational cases, comprising 6.7% of the total group. The majority of injuries had occurred in males (86%), in urban settings (81%), and were of the "blunt" injury type. External cause (coded according to the International Classification of Diseases, 9th Revision, External Injury) categories for work-related injuries were "Cut/Struck," 39%; "Falls," 36%; "Transportation," 12%; "Environmental," 6%; "Violence," 3%; and the remainder, 5%. By definition, all cases were admitted to the hospital, with 62% classified as "minor," 28% "moderate," and the remaining 11% "severe" to "life threatening." Surgery was performed in 54%, and admission to a monitored bed or the intensive care unit occurred in 15%. Although 93% were discharged home, only 54% ambulated independently. Seven percent were not independent with regard to self-feeding status. The mean hospital charge was $10,802 (standard deviation, $31,438). A pyramidal model of the place of ITR cases in the universe of occupational injuries is presented. The ITR contains a unique set of variables that broaden our understanding of serious work-related injuries. It is recommended that these variables--"occupation," "type of industry," and "nature of injury"--be added to the ITR so that it may be linked with other databases to check its validity and completeness and to enhance its value in occupational surveillance.

Adolescent↗
PubMed2006

E1A promoter of bovine adenovirus type 3.

Conserved motifs of eukaryotic gene promoters, such as TATA box and CAAT box sequences, of E1A of human adenoviruses (e.g human adenovirus 5) lie between the left inverted terminal repeat (ITR) and the ATG of E1A. However, analysis of the left end of the bovine adenovirus 3 (BAdV-3) genome revealed that the conserved sequences of the E1A promoter are present only in the ITR. As such, the promoter activity of ITR was tested in the context of a BAdV-3 vector or a plasmid-based system. Different regions of the left end of the BAdV-3 genome initiated transcription of the red fluorescent protein gene in a plasmid-based system. Moreover, BAdV-3 mutants in which the open reading frame of E1A was placed immediately downstream of the ITR produced E1A transcript and could be propagated in non-E1A-complementing Madin-Darby bovine kidney cells. These results suggest that the left ITR contains the sole BAdV-3 E1A promoter.

5' Flanking Region↗
PubMed1997

Adeno-associated virus Rep78 protein and terminal repeats enhance integration of DNA sequences into the cellular genome.

Two adeno-associated virus (AAV) elements are necessary for the integration of the AAV genome: Rep78/68 proteins and inverted terminal repeats (ITRs). To study the contribution of the Rep proteins and the ITRs in the process of integration, we have compared the integration efficiencies of three different plasmids containing a green fluorescent protein (GFP) expression cassette. In one plasmid, no viral sequences were present; a second plasmid contained AAV ITRs flanking the reporter gene (integration cassette), and a third plasmid consisted of an integration cassette plus a Rep78 expression cassette. One day after transfection of 293 cells, fluorescent cells were sorted by flow cytometry and plated at 1 cell per well. Two weeks after sorting, colonies were monitored for stable expression of GFP. Transfection with the GFP plasmid containing no viral sequences resulted in no stable fluorescent colonies. Transfection with the plasmid containing the integration cassette alone (GFP flanked by ITRs) produced stable fluorescent colonies at a frequency of 5.3% +/- 1.0% whereas transfection with the plasmid containing both the integration cassette and Rep78 expression cassette produced stable fluorescent colonies at a frequency of 47% +/- 7.5%. Southern blot analysis indicated that in the presence of Rep78, integration is targeted to the AAVSI site in more than 50% of the clones analyzed. Some clones also showed tandem arrays of the integrated GFP cassette. Both head-to-head and head-to-tail orientations were detected. These findings indicate that the presence of AAV ITRs and the Rep78 protein enhance the integration of DNA sequences into the cellular genome and that the integration cassette is targeted to AAVS1 in the presence of Rep78.

Cell Line, Transformed↗
PubMed1999

Integrating adenovirus-adeno-associated virus hybrid vectors devoid of all viral genes.

Recently, we demonstrated that inverted repeat sequences inserted into first-generation adenovirus (Ad) vector genomes mediate precise genomic rearrangements resulting in vector genomes devoid of all viral genes that are efficiently packaged into functional Ad capsids. As a specific application of this finding, we generated adenovirus-adeno-associated virus (AAV) hybrid vectors, first-generation Ad vectors containing AAV inverted terminal repeat sequences (ITRs) flanking a reporter gene cassette inserted into the E1 region. We hypothesized that the AAV ITRs present within the hybrid vector genome could mediate the formation of rearranged vector genomes (DeltaAd.AAV) and stimulate transgene integration. We demonstrate here that DeltaAd.AAV vectors are efficiently generated as by-products of first-generation adenovirus-AAV vector amplification. DeltaAd.AAV genomes contain only the transgene flanked by AAV ITRs, Ad packaging signals, and Ad ITRs. DeltaAd.AAV vectors can be produced at a high titer and purity. In vitro transduction properties of these deleted hybrid vectors were evaluated in direct comparison with first-generation Ad and recombinant AAV vectors (rAAVs). The DeltaAd.AAV hybrid vector stably transduced cultured cells with efficiencies comparable to rAAV. Since cells transduced with DeltaAd.AAV did not express cytotoxic viral proteins, hybrid viruses could be applied at very high multiplicities of infection to increase transduction rates. Southern analysis and pulsed-field gel electrophoresis suggested that DeltaAd.AAV integrated randomly as head-to-tail tandems into the host cell genome. The presence of two intact AAV ITRs was crucial for the production of hybrid vectors and for transgene integration. DeltaAd.AAV vectors, which are straightforward in their production, represent a promising tool for stable gene transfer in vitro and in vivo.

Adenoviridae↗
PubMed2002

Herpes simplex virus type 1/adeno-associated virus hybrid vectors mediate site-specific integration at the adeno-associated virus preintegration site, AAVS1, on human chromosome 19.

Herpes simplex virus type 1 (HSV-1)-based amplicon vectors have a large transgene capacity and can efficiently infect many different cell types. One disadvantage of HSV-1 vectors is their instability of transgene expression. By contrast, vectors based on adeno-associated virus (AAV) can either persist in an episomal form or integrate into the host cell genome, thereby supporting long-term gene expression. AAV expresses four rep genes, rep68, -78, -40, and -52. Of those, rep68 or rep78 are sufficient to mediate site-specific integration of the AAV DNA into the host cell genome. The major disadvantage of AAV vectors is the small transgene capacity ( approximately 4.6 kb). In this study, we constructed HSV/AAV hybrid vectors that contained, in addition to the standard HSV-1 amplicon elements, AAV rep68, rep78, both rep68 and -78, or all four rep genes and a reporter gene that was flanked by the AAV inverted terminal repeats (ITRs). Southern blots of Hirt DNA from cells transfected with the hybrid vectors and HSV-1 helper DNA demonstrated that both the AAV elements and the HSV-1 elements were functional in the context of the hybrid vector. All hybrid vectors could be packaged into HSV-1 virions, although those containing rep sequences had lower titers than vectors that did not. Site-specific integration at AAVS1 on human chromosome 19 was directly demonstrated by PCR and sequence analysis of ITR-AAVS1 junctions in hybrid vector-transduced 293 cells. Cell clones that stably expressed the transgene for at least 12 months could easily be isolated without chemical selection. In the majority of these clones, the transgene cassette was integrated at AAVS1, and no sequences outside the ITR cassette, rep in particular, were present as determined by PCR, ITR rescue/replication assays, and Southern analysis. Some of the clones contained random integrations of the transgene cassette alone or together with sequences outside the ITR cassette. These data indicate that the long-term transgene expression observed following transduction with HSV/AAV hybrid vectors is, at least in part, supported by chromosomal integration of the transgene cassette, both randomly and site specifically.

Animals↗
PubMed2003

Inhibition of experimental intimal thickening in mice lacking a novel G-protein-coupled receptor.

BACKGROUND: Vascular restenosis attributable to intimal thickening remains a major problem after percutaneous transluminal coronary angioplasty (PTCA). METHODS AND RESULTS: Through differential-display analysis, we have identified a novel gene whose expression was increased after catheter injury of rabbit aorta. The gene that is expressed predominantly in vascular smooth muscle cells encodes a novel protein with 7 transmembrane domains, and we termed it ITR (intimal thickness-related receptor). The ITR sequence contains a motif common to the Rhodopsin-like GPCR (G-protein-coupled receptor) superfamily. In vivo analyses of this gene revealed that expression of ITR protein increased with intimal thickening induced by cuff placement around murine femoral artery. Furthermore, ITR-knockout mice were found to be resistant to this experimental intimal thickening. CONCLUSIONS: ITR thus seems to be a novel receptor that may play a role in vascular remodeling and that may represent a good target for development of drugs in the prevention of vascular restenosis.

Amino Acid Sequence↗
PubMed2003

Implicit theories of relationships: orientations toward evaluation and cultivation.

Implicit theories of relationships (ITRs) influence goals, motivations, attributions, and behavior in romantic relationships. We developed a model of ITRs that draws from social cognition, motivation, and achievement literatures, and derived conceptual parallels and hypotheses with regard to relationships. It is proposed that ITRs reflect the belief component of a larger system of motivations and goals that can influence the degree to which people are oriented toward the evaluation and cultivation of relationships. Research on ITRs is reviewed with regard to how they moderate well-documented associations between relationship perceptions and outcomes. Differences between ITRs and implicit theories in other domains are also discussed.

Attitude↗
PubMed1997

Changes of intertrial response rate with elapse of time after two-way avoidance trial in rats.

The changes of intertrial response (ITR) rate along the intertrial interval duration were examined in 30 rats trained in two-way avoidance. The lowest ITR rate was observed just after a cross-through response terminating a trial. Rats trained with a warning signal of darkness showed over-all higher ITR rates and shorter periods of post-trial reduction of ITR rate than rats trained with a more salient noise warning signal. The period of post-trial low ITR rate lengthened in consecutive sessions indicating the gradual development of a safety state.

Animals↗
PubMed2003

[Application of a new vascular injection technique in the study of the infratemporal region].

The infra-temporal region (ITR) is an anatomically rich region thanks to its arterial and venous divisions and large nerve crossroads. It is also, as described by Robert et al". in a publication about the ITR, (22) "the hidden face of the manductory apparatus. The ITR is therefore a passageway for a large number of anatomical elements and its complexity makes it a particularly delicate region for daily surgical practice. For these many reasons the anatomical study of the ITR, which has already been the origin of a number of works, seemed interesting to us, and more particularly combined with the use of an original injection material, Odongel. The injection of this material, in the arterial as well as the venous system, enabled us to improve our dissections thanks to its flexibility, elasticity, its case-of-use and its speed of preparation. The complexity and richness of the region meant that in order to study it anatomically we had to focus on a specific anatomical element for each dissection session, especially at the beginning. After having used traditional products such as resins (methyl methacrylate), latex and even the too rigid silicon elastomers, Odongel seemed interesting to us because it is very easier to use it. The purpose of this study was to prove that Odongel is an efficient material, working equally well for both the arterial and venous systems irrespective of the diameter of the vessels concerned. It can become an alternative to the other injection products in some situations. Finally, in the case of the ITR, an extension of the existing techniques used in anatomical studies coupled with an increase in anatomical precision could improve our knowledge of this zone and eventually facilitate certain surgical interventions.

Aged↗
PubMed1990

Chagas' disease. Immunotoxin inhibition of Trypanosoma cruzi release from infected host cells in vitro.

Virulent tissue culture-derived Trypanosoma cruzi trypomastigotes were readily killed by immune IgG-ricin A chain conjugates (ITR) in vitro. Forty micrograms of ITR immobilized 10(6) trypomastigotes after 48 hours of incubation at 37 degrees C. ITR showed antibody specificity and 125I-labeled anti-T. cruzi IgG bound to parasitized host cells 9-fold more than to nonparasitized host cells. The degree of specificity was evaluated further in experiments in which 10 micrograms of ITR showed 78% inhibition of [3H]thymidine incorporation by T. cruzi. In contrast, nonimmune IgG-ricin A chain conjugate neither immobilized nor inhibited [3H]thymidine incorporation by the parasite. Furthermore, 20 micrograms of ITR significantly inhibited T. cruzi trypomastigote release from infected host cells and thus prevented reinfection of other cells in vitro.

Animals↗
PubMed1989

Effect of immunotoxins against Trypanosoma cruzi.

Immunotoxins were constructed with IgG antibodies against Trypanosoma cruzi surface antigens by hybridization with abrin (ITA) and ricin (ITR) A chains. The biological activity of the hybrid macromolecules was tested on the parasite forms. Motility of parasite forms was lost in vitro after incubation with ITR. In general, killing of the parasite with ITR was more efficient than with ITA. Inhibition of protein synthesis after incubation with either ITR or ITA, measured by 3H-leucine incorporation, confirmed the parasite immobilization experiments. The lethal effect was potentiated when the immunotoxins were used in the presence of 2.5 mM ammonium chloride. T. cruzi antibodies specific to cell surface antigens are excellent drug carriers that can be delivered to the target cell. However, ITR and ITA did not reduce parasitemia or increase survival of mice infected with T. cruzi.

Abrin↗
PubMed2005

Interstitial telomeric DNA sequences of Chinese hamster cells are hypersensitive to nitric oxide damage, and DNA-PKcs has a specific local role in its repair.

The DNA breakage detection-fluorescence in situ hybridization (DBD-FISH) procedure was used to analyze DNA single-strand breaks (SSBs) and alkali-labile sites induced by exposure to the nitric oxide (NO) donors sodium nitroprusside (SNP) and 3-morpholinosydnomine hydrochloride (SIN-1) in the whole genome and in long interstitial telomeric repeat sequence (ITRS) blocks from Chinese hamster cells. The relative density of DNA damage generated in the ITRS by X-rays was similar to that induced in the genome overall, whereas it was 1.7 times higher when the alkylating agent MNNG was assayed. Nevertheless, after SNP or SIN-1 treatment, ITRSs proved to be 2.8 and 2.7 times relatively more damaged, respectively, than the whole genome. When the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) was not active, as in XR-C1 mutant cells, the repair kinetics in the whole genome did not differ from that in the parental cell line with X-ray or SNP exposure. However, whereas the SSBs and alkali-labile sites induced in the ITRS by X-rays exhibited rejoining kinetics similar to that of the parental cell line, the damage induced by SNP was more slowly rejoined. This implies a role for DNA-PKcs in the repair of DNA damage induced by NO, especially in ITRSs. The results demonstrated intragenomic heterogeneity of NO-induced DNA damage and repair; there was a higher density of DNA damage in the ITRS blocks, possibly because of their guanine richness. This suggests that a parallel process may occur in the terminal telomeres, which has implications for premature aging and neoplastic development by chronic NO exposure in vivo.

Animals↗
PubMed1995

Rescue and replication signals of the adeno-associated virus 2 genome.

The adeno-associated virus 2 (AAV) genome is a single-stranded DNA which contains the inverted terminal repeats (ITRs) of 145 nucleotides. The terminal 125 nucleotides of each ITR form palindromic hairpin structures that serve as primers for AAV DNA replication. These hairpin structures also play a crucial role in the integration, as well as the rescue, of the proviral genome from latently-infected cells, or from the recombinant AAV plasmids. However, the ITRs also contain an additional domain, designated the D-sequence, a 20-nucleotide stretch that is not involved in the formation of hairpins. In order to examine the role of the D-sequence in viral DNA rescue and replication, a number of recombinant AAV plasmids were constructed which contained deletions/substitutions in different regions of the ITRs. The results presented here reveal the existence of additional sequences, other than the hairpin structures, which serve as primers for AAV DNA replication. The results also show that whereas the hairpin structures are sufficient for excision and replication of the viral DNA, the D-sequence is crucial for the high efficiency of rescue and replication of the AAV genome.

Base Sequence↗
PubMed1978

Serum activity inhibiting specific simian virus 40-induced transplantation resistance and its correlation with primary SV40 tumors appearance in hamsters.

Using the modified technique of transplantation test, ITR serum activity was found in most (14 out of 21) individual hamster sera obtained during the latent period of primary SV40 carcinogenesis (60 days after virus infection when newborn). On the other hand, as a rule, no ITR activity was observed in the sera of the same hamsters after tumor appearance and during their growth. ITR activity rapidly disappeared from sera of hamsters neonatally infected with SV40 after their successful immunization with the same virus during the latent period. There appears to be a correlation between the presence of ITR serum factor during the latent period and the subsequent primary SV40 tumor appearance in hamsters.

Animals↗