The Experts below are selected from a list of 8517 Experts worldwide ranked by ideXlab platform
Viren Mishra - One of the best experts on this subject based on the ideXlab platform.
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surgical repair of symptomatic chronic achilles tendon rupture using Synthetic Graft augmentation
Foot and Ankle Surgery, 2016Co-Authors: Ahmed Shoaib, Viren MishraAbstract:Abstract Background Surgical repair of symptomatic chronic Achilles tendon (TA) rupture is a challenging problem due to the presence of a large defect between tendon edges. We report the results of surgical repair of symptomatic chronic TA rupture by Synthetic Graft augmentation. Methods Seven consecutive patients with a symptomatic chronic TA rupture underwent surgical repair by VY plasty and augmentation with bio-absorbable Synthetic Graft (Artelon ® ). In all patients, the intraoperative tendon gap after debridement was more than 5cm (Myerson Grade 3). The total duration of plaster immobilization was 10 weeks. The complications were recorded prospectively and functional outcome was assessed by AOFAS score and Achilles tendon Total Rupture Score (ATRS). Results At a mean follow up of 29 months there was no re-rupture or deep infection. All patients reported good functional outcome as shown by AOFAS and ATRS scores. There were no Graft related complications. At final follow up, six patients were able to do single stance heel raise however, calf wasting was noted in all patients. Conclusions Tendon repair augmented by absorbable Synthetic Graft is an acceptable technique in Myerson Grade 3 chronic symptomatic TA ruptures. Level of evidence Level IV, Case series.
Ralph Weissleder - One of the best experts on this subject based on the ideXlab platform.
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size optimization of Synthetic Graft copolymers for in vivo angiogenesis imaging
Bioconjugate Chemistry, 2001Co-Authors: Ralph Weissleder, Alexei A Bogdanov, And Chinghsuan Tung, Hannsjoachim WeinmannAbstract:Angiogenesis is a critical step in tumor development and more than 25 angiogenesis inhibitors are currently in clinical trials. Noninvasive in vivo imaging of angiogenesis represents a unique opportunity of repeatedly quantitating microvascular parameters prior to and during anti-angiogenic treatments. While several imaging tracers have been proposed for MR and nuclear imaging, there does not exist any consensus of what constitutes an ideal size of an imaging agent. A series of Synthetic pegylated DOTA derivatized Graft copolymers (30, 60, 120 kDa) were synthesized and their in vivo behavior tested in two breast cancer models differing in vascular endothelial growth factor (VEGF) expression. Polymers were labeled with different lanthanides (Eu, Gd, Dy) and absolute blood and tumor concentrations were determined by ICP-AES measurements. DOTA and the 30 kDa polymers underwent renal clearance resulting in low plasma levels. Slow leakage across neovasculature into tumor interstitium was clearly dependent on t...
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preparation of a cathepsin d sensitive near infrared fluorescence probe for imaging
Bioconjugate Chemistry, 1999Co-Authors: Chinghsuan Tung, Umar Mahmood, Sebastian Bredow, Ralph WeisslederAbstract:A variety of proteases are overexpressed or activated during pathogenesis and represent important targets for therapeutic drugs. We have previously shown that optical imaging probes sensitive in the near-infrared fluorescence (NIRF) spectrum can be used for in vivo imaging of enzyme activity. In the current study, we show that these probes can be designed with specificity for specific enzymes, for example, cathepsin D which is known to be overexpressed in many tumors. A NIR cyanine fluorochrome served as the optical reporter and was attached to the amino terminal of an 11 amino acid peptide sequence with specificity for cathepsin D. The peptides were subsequently attached to a Synthetic Graft copolymer for efficient tumoral delivery. The close spatial proximity of the multiple fluorochromes resulted in quenching of fluorescence in the bound state. A 350-fold signal amplification was observed post cleavage during in vitro testing. Cell culture experiments using a rodent tumor cell line stably transfected w...
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preparation of a cathepsin d sensitive near infrared fluorescence probe for imaging
Bioconjugate Chemistry, 1999Co-Authors: Chinghsuan Tung, Umar Mahmood, Sebastian Bredow, Ralph WeisslederAbstract:A variety of proteases are overexpressed or activated during pathogenesis and represent important targets for therapeutic drugs. We have previously shown that optical imaging probes sensitive in the near-infrared fluorescence (NIRF) spectrum can be used for in vivo imaging of enzyme activity. In the current study, we show that these probes can be designed with specificity for specific enzymes, for example, cathepsin D which is known to be overexpressed in many tumors. A NIR cyanine fluorochrome served as the optical reporter and was attached to the amino terminal of an 11 amino acid peptide sequence with specificity for cathepsin D. The peptides were subsequently attached to a Synthetic Graft copolymer for efficient tumoral delivery. The close spatial proximity of the multiple fluorochromes resulted in quenching of fluorescence in the bound state. A 350-fold signal amplification was observed post cleavage during in vitro testing. Cell culture experiments using a rodent tumor cell line stably transfected with human cathepsin D confirmed enzyme specific activation within cells. This sequence but not a scrambled control sequence showed enzyme specificity in vitro. We conclude that activatable NIRF optical probes can be synthesized to potentially probe for specific enzymes in living organisms.
Ahmed Shoaib - One of the best experts on this subject based on the ideXlab platform.
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surgical repair of symptomatic chronic achilles tendon rupture using Synthetic Graft augmentation
Foot and Ankle Surgery, 2016Co-Authors: Ahmed Shoaib, Viren MishraAbstract:Abstract Background Surgical repair of symptomatic chronic Achilles tendon (TA) rupture is a challenging problem due to the presence of a large defect between tendon edges. We report the results of surgical repair of symptomatic chronic TA rupture by Synthetic Graft augmentation. Methods Seven consecutive patients with a symptomatic chronic TA rupture underwent surgical repair by VY plasty and augmentation with bio-absorbable Synthetic Graft (Artelon ® ). In all patients, the intraoperative tendon gap after debridement was more than 5cm (Myerson Grade 3). The total duration of plaster immobilization was 10 weeks. The complications were recorded prospectively and functional outcome was assessed by AOFAS score and Achilles tendon Total Rupture Score (ATRS). Results At a mean follow up of 29 months there was no re-rupture or deep infection. All patients reported good functional outcome as shown by AOFAS and ATRS scores. There were no Graft related complications. At final follow up, six patients were able to do single stance heel raise however, calf wasting was noted in all patients. Conclusions Tendon repair augmented by absorbable Synthetic Graft is an acceptable technique in Myerson Grade 3 chronic symptomatic TA ruptures. Level of evidence Level IV, Case series.
Jeffrey H Lawson - One of the best experts on this subject based on the ideXlab platform.
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multicenter evaluation of the bovine mesenteric vein bioprostheses for hemodialysis access in patients with an earlier failed prosthetic Graft
Journal of The American College of Surgeons, 2005Co-Authors: Howard E Katzman, Marc H Glickman, Frederick A Schild, Roy M Fujitani, Jeffrey H LawsonAbstract:Background The number of patients requiring hemodialysis increases each year, with a large cohort of patients still requiring prosthetic Grafts for hemodialysis. All available prosthetic vascular access Grafts have predictable failure rates, leading to a large group of patients with multiple failed access Grafts. This report evaluates use of mesenteric vein bioprosthesis (MVB) as a conduit for patients who have failed at least one earlier Synthetic vascular access Graft. Study design Two-hundred seventy-six access Grafts were implanted in patients who had at least one earlier failed Synthetic Graft. Of these Grafts, 183 were MVB and 93 were Synthetic. Graft histories were obtained from 128 of the 183 patients who received the MVB, representing a nonrandomized historic data set of previously failed Grafts as an internal control group (INT). Patency was determined by Kaplan-Meier analysis, and the Cox proportional hazards model was used for multivariate analysis of factors predictive of effect. Results Primary patency at 12 months was 35.6% MVB versus 28.4% Synthetic Grafts. At 24 months, secondary patency was 60.3% MVB, 42.9% Synthetic, and 18.0% INT (p Conclusions MVB provided superior secondary Graft patency compared with both historic Graft data or newly implanted nonrandomized Synthetic implants. A considerable reduction in thrombosis, infection, and interventions was observed with the MVB Graft. These results suggest that MVB offers a safe alternative to patients who have a history of failing Synthetic access Grafts and may represent an option for extending vascular access to this patient population.
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multicenter evaluation of the bovine mesenteric vein bioprostheses for hemodialysis access in patients with an earlier failed prosthetic Graft
Annual Symposium on Vascular Surgery, 2005Co-Authors: Howard E Katzman, Marc H Glickman, Frederick A Schild, Roy M Fujitani, Jeffrey H LawsonAbstract:BACKGROUND: The number of patients requiring hemodialysis increases each year, with a large cohort of patients still requiring prosthetic Grafts for hemodialysis. All available prosthetic vascular access Grafts have predictable failure rates, leading to a large group of patients with multiple failed access Grafts. This report evaluates use of mesenteric vein bioprosthesis (MVB) as a conduit for patients who have failed at least one earlier Synthetic vascular access Graft. STUDY DESIGN: Two-hundred seventy-six access Grafts were implanted in patients who had at least one earlier failed Synthetic Graft. Of these Grafts, 183 were MVB and 93 were Synthetic. Graft histories were obtained from 128 of the 183 patients who received the MVB, representing a nonrandomized historic data set of previously failed Grafts as an internal control group (INT). Patency was determined by Kaplan-Meier analysis, and the Cox proportional hazards model was used for multivariate analysis of factors predictive of effect. RESULTS: Primary patency at 12 months was 35.6% MVB versus 28.4% Synthetic Grafts. At 24 months, secondary patency was 60.3% MVB, 42.9% Synthetic, and 18.0% INT (p < 0.0001, log-rank). Complication rates, including dilation, seroma, infection, and thrombosis, were all notably lower for the MVB compared with Synthetic Grafts by Cox regression (p < 0.001). Intervention rate per patient year was lower in the MVB group (0.97 versus 1.37) compared with Synthetic Grafts (p = 0.003). CONCLUSIONS: MVB provided superior secondary Graft patency compared with both historic Graft data or newly implanted nonrandomized Synthetic implants. A considerable reduction in thrombosis, infection, and interventions was observed with the MVB Graft. These results suggest that MVB offers a safe alternative to patients who have a history of failing Synthetic access Grafts and may represent an option for extending vascular access to this patient population.
Nicola Maffulli - One of the best experts on this subject based on the ideXlab platform.
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failed Synthetic Graft after acute achilles tendon repair
Muscles ligaments and tendons journal, 2017Co-Authors: Asmaa Mohamed, Francesco Oliva, Stefano Nardoni, Nicola MaffulliAbstract:Background The present case report aimed to determine the results of Flexor Hallucis Longus (FHL) transfer as a second surgery after Synthetic tissue reinforcement Graft (Artelon®) implanted to a primary repaired Achilles tendon (AT), that was undertaken by another orthopedic. One year post-operative the patient was referred to us with retrocalcaneal pain and difficulty in walking, associated with stiffness and significant impairment of daily living activities. Methods MRI and full clinical examination were the outcome measures applied before and 1 year after surgery. Removal of the Synthetic Graft and subsequent FHL autologous transfer was undertaken and the Graft was sent for histology examination. After removing the below knee leg cast, patient started rehabilitation program supervised by a trained physiotherapist. Results The patient was allowed to return to his normal activities at the sixth post-operative month, 1 year post-surgery MRI showed correct position of the autoGraft in the calcaneous bone and in the centre of the native AT plus reduced oedema of the AT body, with clinical improvement of the patient who reported no pain and was able to walk on tiptoes. Conclusion Synthetic patch augmentation to enhance tendon healing should be subjected to proper investigation before using it in routine parctice, as it may act as a barrier against proper tendon healing. Level of evidence V.
