Double Syringe Research Articles

Platelet-rich Plasma for Skin Rejuvenation and Treatment of Actinic Elastosis in the Lower Eyelid Area.

BackgroundTreatment of the lower eyelid region to rejuvenate the skin or treat actinic elastosis often proves difficult. Established treatment options, such as hyaluronic acid injections, botulinum toxin injections, microneedling, skin resurfacing (microdermabrasion, chemical peel (exfoliation), laser treatment), as well as blepharoplasties and autologous fat transfers, can be associated with significant risks and increased patient burden. Furthermore, they may not be effective for treating the signs of skin aging or actinic elastosis, including dark rings under the eyes, a lack of volume and cutis laxa. A minimally invasive treatment approach which visibly improves the above-mentioned conditions and which involves minimal risk and patient burden would be a desirable alternative.Materials & methodsTwenty patients were treated a total of three times at monthly intervals with PRP (platelet-rich plasma). The patients were examined on the days of treatment and one month after the third injection. The PRP was obtained directly prior to treatment using the Arthrex ACP double syringe at the point of care. The injections (2 ml PRP per side) were administered laterally using 27 G 38 mm cannulas. Accurate photographic documentation and skin elasticity measurements using a cutometer were performed to objectify the subjective assessments from the patient and practitioner questionnaires.ResultsA progressive improvement in the esthetic outcome and a high level of patient satisfaction were determined. The cutometer measurements showed a statistically significant higher level of skin firmness (due to increased collagen production) and a statistically significant increase in skin elasticity (thanks to increased elastin production). Other than the anticipated visible swelling directly after the PRP injection, no other undesirable side effects or complications occurred. The typical burning sensation during the injection had not been reported.ConclusionThe results indicate that a series of PRP injections in the lower eyelid region is a safe, efficient, virtually pain-free, simple and rapid treatment option for an area with otherwise limited treatment alternatives.

All-in-One Flow Injection Spectrophotometric System for Field Testing

To date one of the most significant innovative trends in chemical analysis is to develop analytical instruments that have processed to analyze on-site. Such an apparatus should minimize problems related to sample transports, sample handlings and sample storages. Currently, a traditional wet analysis in laboratories has been replaced with a portable device designed to minimize problems from sending samples to the lab. One of the practical chemical methods which can be developed as the mobile device is flow injection analysis (FIA) because the scaled-down FIA manifolds have been already presented. Regarding the detection, the rapid progress in material science and electronic technology consents the construction of portable detection devices, particularly light-emitting-diodes (LEDs) based-spectrometers. In this work, the FIA analyzer integrated with a built-in detector was designed for on-site chemical testing. A double syringes pump was assembled for transporting of the reagent carrier which were merged at the first mixing coil. A plug of a sample solution was inserted automatically by using a six-port-valve and was mixed with the carrier stream at the second mixing coil before directed to the detector. The heart of the developed analyzer is the built-in spectrophotometric sensor, made of the LEDs as a light source and a photodiode as a detector. The continuous stream of the final product was pushed into a quartz flow-through cuvette and then was exposed to the LED light. Finally, the absorbance of the product solution was calculated according to the Beer-Lambert law.

PG - 85: An Experimental Study to assess the Effectiveness of Double Syringe Method Vs Rubber Band Method on Successful Breast Feeding Among Primi Para Mothers with Flat And Inverted Nipple at Mgmcri, Puducherry

PG - 85: An Experimental Study to assess the Effectiveness of Double Syringe Method Vs Rubber Band Method on Successful Breast Feeding Among Primi Para Mothers with Flat And Inverted Nipple at Mgmcri, Puducherry

Leukocyte-reduced platelet-rich plasma increases proliferation of tenocytes treated with prednisolone: a cell cycle analysis.

The purpose of this study was to evaluate the effect of allogenic leukocyte-reduced platelet-rich plasma on human tenocytes after treatment with prednisolone and to develop a standardization of its application for clinical practice. A leukocyte-reduced PRP was produced using the Arthrex Double Syringe (Arthrex, Inc., Naples, FL, USA), in a modified single-spin separation method. Human tenocytes were isolated from discarded rotator cuff segments. Tenocytes were cultured in the presence of PRP and prednisolone, both alone and in combination. Control samples were treated in media containing 2% FCS for 72h. After 72h of incubation, cell cycle kinetics of tenocytes were analyzed to assess proliferation. Incubation of the tenocytes with PRP alone for 48h led to high proliferation rate (10% PRP, 28.0±10.5%; 20% PRP, 40.9±3.3%). Incubation in the presence of prednisolone led to a significant decrease of the proliferation rate (5.2±3.1%; p<0.05). Treatment with PRP for 48h significantly increased the proliferation of tenocytes in a dose-dependent manner (10% PRP, 28.0±10.5%; 20% PRP, 40.9±3.3%; p<0.05). The presence of prednisolone resulted in a decreased tenocyte proliferation (5.2±3.1%; p<0.05), whereas addition of PRP for 24 and 48h after prednisolone exposure did not show any compensating effect independent of PRPs concentration (10% PRP, 3.7±3.0%; 20% PRP, 2.5±2.5%). However, a significantly increased cell proliferation of tenocytes was evident when PRP was applied 24 h after prednisolone incubation for 48h (31.0±3.4 and 34.3±4.7%). The use of leukocyte-reduced PRP stimulates the proliferation of tenocytes and antagonizes the negative effect of prednisolone 24h after treatment. Addition of PRP 48h after treatment with prednisolone has no positive effect on the proliferation rate of tenocytes.

The Influence of Trocar Fenestration and Volume on Connective Tissue Progenitor Cells (Stem Cells) in Arthroscopic Bone Marrow Aspiration From the Proximal Humerus

To evaluate the number of connective tissue progenitor cells (CTPs) and nucleated cells obtained during bone marrow aspiration (BMA) from the proximal humerus using either a fenestrated or a nonfenestrated trocar and determine differences in varying amounts of aspiration volume. The first hypothesis was that the number of CTPs extracted with the fenestrated trocar would be greater due to its potential to extract more cells through its fenestrations. The second hypothesis was that using consecutive aspirations with either trocar would provide a consistent number of CTPs and nucleated cells throughout the aspiration with no significant decrease of cells at the end. Patients were eligible for inclusion if they underwent primary or revision arthroscopic rotator cuff surgery, were between 18 and 75years of age, and signed the informed consent. Between January 2011 and September 2013, 24 patients underwent BMA from the proximal humerus during arthroscopic surgery. They were grouped according to which of 3 different trocars were used for aspiration: (1) nonfenestrated, (2) fenestrated trocar A, and (3) fenestrated trocar H. Four consecutive 12mL double syringes were used for each aspiration: 1 (0-12mL), 2 (12-24mL), 3 (24-36mL), and 4 (36-48mL). One milliliter was removed from each syringe (nonconcentrated BMA). The remainder of the BMA was then spun using a centrifuge. BMA and concentrated BMA were brought to the laboratory, counted for nucleated cells (million cells/mL BMA) and cultured for 7days to obtain colony-forming units (CTPs/million cells). No significant differences were observed in tubes 1 to 4 in the number of nucleated cells in the nonconcentrated and concentrated BMA using the nonfenestrated trocar compared with the fenestrated trocars A and H (all P > .05), except for concentrated BMA tube 3 (P= .014) and tube 4 (P= .003). Nonconcentrated and concentrated BMA from tubes 1 to 4 had a significantly higher CTP prevalence using the nonfenestrated trocar compared with the fenestrated trocars A and H (all P < .05). Most of the times the first tube of each aspiration showed a significantly greater amount of cells and a greater CTP prevalence compared with tubes 2, 3, and4. Aspiration from the proximal humerus with the nonfenestrated trocar during BMA was associated with higher prevalence of CTPs, suggesting that more CTPs can be obtained using a nonfenestrated trocar. Furthermore, CTPs can be obtained through all consecutive aspirations with a greater amount in the first tubes. Level II, prospective comparative study.

Novel developments in foam sclerotherapy: Focus on Varithena® (polidocanol endovenous microfoam) in the management of varicose veins.

Scope Varithena® is a recently approved commercially available drug/delivery unit that produces foam using 1% polidocanol for the management of varicose veins. The purpose of this review is to examine the benefits of foam sclerotherapy, features of the ideal foam sclerosant and the strengths and limitations of Varithena® in the context of current foam sclerotherapy practices. Method Electronic databases including PubMed, Medline (Ovid) SP as well as trial registries and product information sheets were searched using the keywords, 'Varithena', 'Varisolve', 'polidocanol endovenous microfoam', 'polidocanol' and/or 'foam sclerotherapy/sclerosant'. Articles published prior to 20 September 2016 were identified. Results Foam sclerosants have effectively replaced liquid agents due to their physiochemical properties resulting in better clinical outcomes. Medical practitioners commonly prepare sclerosant foam at the bedside by agitating liquid sclerosant with a gas such as room air, using techniques as described by Tessari or the double syringe method. Such physician-compounded foams are highly operator dependent producing inconsistent foams of different gas/liquid compositions, bubble size, foam behaviour and varied safety profiles. Varithena® overcomes the variability and inconsistencies of physician-compounded foam. However, Varithena® has limited applications due to its fixed sclerosant type and concentration, cost and lack of worldwide availability. Clinical trials of Varithena® have demonstrated efficacy and safety outcomes equivalent or better than physician-compounded foam but only in comparison to placebo alone. Conclusion Varithena® is a promising step towards the creation of an ideal sclerosant foam. Further assessment in independent randomised controlled clinical trials is required to establish the advantages of Varithena® over and above the current best practice physician-compounded foam.

Dual-component collagenous peptide/reactive oligomer hydrogels as potential nerve guidance materials - from characterization to functionalization.

Toward a new generation of improved nerve guidance conduits (NGCs), novel biomaterials are required to address pressing clinical shortcomings in peripheral nerve regeneration (PNR) and to promote biological performance. A dual-component hydrogel system formed by cross-linking reaction between maleic anhydride groups in an oligomeric building block for cross-linking of free amine functionalities in partially hydrolyzed collagen is formulated for continuous processing and NGC fabrication. The influence of the gelation base is optimized for processing from a double syringe delivery system with a static mixer. A hydrophilic low-concentrated base was introduced to control network formation and to utilize highly reactive macromers for gelation. Cross-linking extent and building block conversion were improved and homogenous monoliths were fabricated. Chemically derivatized hydrogels were obtained by conversion of a fraction of anhydride groups in the oligomeric precursor with monovalent primary amine-containing grafting molecules prior to gelation. Network stability in functionalized hydrogels was maintained and cationic moieties were implement to the gel that promoted in vitro cell attachment and spreading irrespective of mechanical stiffness. A molding strategy was introduced that allowed for fabrication of flexible tubular conduits in tunable dimensions and with chemically patterned structures. These hydrogel-based conduits hold promise for the next generation NGCs with integrated chemical cues for PNR.

The effect of plasma preparation rich in growth factors on patellar stability after medial patellofemoral ligament reefing

Introduction: Although more than 100 operative procedures have been described for the treat- ment of patellar instability, there is no single univer- sally successful procedure. For the most patients with lateral patellar instability medial patellofemoral liga- ment (MPFL) reefing is recommended. When we per- form MPFL reefing we are not aware of the quality and strength of the MPFL tissue. In the presence of recur- rent patellar instability, the quality and strength of MPFL tissue is often compromised and it disturbs pa- tellar stability after MPFL reefing. Biomedicine devel- opment, recognizing the ligament healing process show us that autologous blood products, particularly PRP can enhance healing in soft tissue injuries. Purpose: The purpose of this study was to deter- mine the potential effect of Plasma preparation rich in growth factors on patellar stability after MPFL reefing. Material and methods: Plasma preparation rich in growth factors was produced from a unit of autolo- gous whole blood using Arthrex ACP double syringe system.Platelet gel was prepared by adding bovine thrombin and 10% solution of calcium chloride.The platelet gel was applied locally into the place where su- turing of the MPFL was performed. In this prospective, randomized and double blind study12 patients were in- cluded:6 patients in the PG group who received plate- let gel and 6 patients in the control group who were not treated with platelet gel. Patellar stability was evalua- ted before surgery and 3 months after surgery with Ax- ial stress radiographs. Results: The calculated 3 month improvement was 12.67 ± 2.51 in the control group and 17.33 ± 1.52 in the PG group, (p = 0.064). Although there was greater improvement in patellar stability in PG group compar- ing to the control group, the difference was not statisti- cally significant (p > 0.05). The main reason for this was probably the small number of patients included in the study. Conclusion: Results showed that growth factors from the plasma preparation rich in growth factors ha- ve positive effect on patellar stability after MPFL reef- ing.We believe that they stimulate and accelerate phys- iological healing and reparative tissue processes in li- gament healing. More studies should be made, including more patients, if we want to get more relevant results.

Leukocyte-Reduced Platelet-Rich Plasma Normalizes Matrix Metabolism in Torn Human Rotator Cuff Tendons

Background: The optimal platelet-rich plasma (PRP) for treatment of supraspinatus tendinopathy has not been determined. Purpose: To evaluate the effect of low- versus high-leukocyte concentrated PRP products on catabolic and anabolic mediators of matrix metabolism in diseased rotator cuff tendons. Study Design: Controlled laboratory study. Methods: Diseased supraspinatus tendons were treated with PRP made by use of 2 commercial systems: Arthrex Autologous Conditioned Plasma Double Syringe System (Llo PRP) and Biomet GPS III Mini Platelet Concentrate System (Lhi PRP). Tendon explants were placed in 6-well plates and cultured in Llo PRP, Lhi PRP, or control media (Dulbecco’s Modified Eagle Medium + 10% fetal bovine serum) for 96 hours. Tendons were processed for hematoxylin-eosin histologic results and were scored with the modified Bonar scale. Group 1 tendons were defined as moderate tendinopathy (Bonar score <3); group 2 tendons were assessed as severely affected (Bonar score = 3). Transforming growth factor β–1 (TGFβ-1), interleukin-1β (IL-1β), interleukin-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6), interleukin-8 (IL-8), and matrix metalloproteinase–9 (MMP-9) concentrations in PRP media were measured by use of enzyme-linked immunosorbent assay after 96 hours of culture with diseased tendon. Tendon messenger RNA expression of collagen type I (COL1A1), collagen type III (COL3A1), cartilage oligomeric matrix protein (COMP), MMP-9, MMP-13, and IL-1β was measured with real-time quantitative polymerase chain reaction. Results: Leukocytes and platelets were significantly more concentrated in Lhi PRP compared with Llo PRP. Increased IL-1β was present in Lhi PRP after culture with group 1 tendons. IL-6 was increased in Lhi PRP after culture with group 2 tendons. Both TGFβ-1 and MMP-9 were increased in Lhi PRP after culture with either tendon group. In Llo PRP cultures, IL-1Ra:IL-1β in PRP used as media and COL1A1:COL3A1 gene expression were increased for group 1 tendon cultures. Gene expression of MMP-9 and IL-1β was increased in group 2 tendons cultured in Llo PRP. There was no significant difference in the expression of MMP-13 or COMP in either group of tendons cultured in Llo PRP or Lhi PRP. Conclusion: Llo PRP promotes normal collagen matrix synthesis and decreases cytokines associated with matrix degradation and inflammation to a greater extent than does Lhi PRP in moderately degenerative tendons. In severely degenerative tendons, neither PRP preparation enhanced matrix synthesis. Clinical Relevance: Llo PRP may promote healing in moderately degenerative rotator cuff tendons.

The role of clinically-relevant parameters on the cohesiveness of sclerosing foams in a biomimetic vein model.

We have recently reported on the development of a biomimetic vein model to measure the performance of sclerosing foams. In this study we employed the model to compare the commercially-available Varithena® (polidocanol injectable foam) 1 % varicose vein treatment (referred to as polidocanol endovenous microfoam, or PEM) with physician compounded foams (PCFs) made using different foam generation methods (Double Syringe System and Tessari methods) and different foam formulations [liquid to gas ratios of 1:3 or 1:7; gas mixtures composed of 100 % CO2, various CO2:O2 mixtures and room air (RA)]. PCFs produced using the DSS method had longer dwell times (DTs) (range 0.54–2.21 s/cm in the 4 mm diameter vein model) than those of the corresponding PCFs produced by the Tessari technique (range 0.29–0.94 s/cm). PEM had the longest DT indicating the best cohesive stability of any of the foams produced (2.92 s/cm). Other biomimetic model variables investigated included effect of vessel size, delayed injection and rate of plug formation (injection speed). When comparing the 4 and 10 mm vessel diameters, the DTs seen in the 10 mm vessel were higher than those observed for the 4 mm vessel, as the vein angle had been reduced to 5° to allow for foam plug formation. PCF foam performance was in the order RA > CO2:O2 (35:65) ≅ CO2:O2 (65:35) > CO2; PEM had a longer DT than all PCFs (22.10 s/cm) except that for RA made by DSS which was similar but more variable. The effect of delayed injection was also investigated and the DT for PEM remained the longest of all foams with the lowest percentage deviation with respect to the mean values, indicating a consistent foam performance. When considering rate of plug formation, PEM consistently produced the longest DTs and this was possible even at low plug expansion rates (mean 29.5 mm/s, minimum 20.9 mm/s). The developed vein model has therefore demonstrated that PEM consistently displays higher foam stability and cohesiveness when compared to PCFs, over a range of clinically-relevant operational variables.Electronic supplementary materialThe online version of this article (doi:10.1007/s10856-015-5587-z) contains supplementary material, which is available to authorized users.

An in vitro evaluation of infusion methods using a syringe pump to improve noradrenaline administration.

International guidelines recommend noradrenaline (NA) as the vasopressor of choice to treat septic shock. The aim of this study was to determine the best way to infuse patients with NA. The in vitro study was designed to measure NA concentration at the end of each studied assembly line. Three infusion systems used the double pump method and three single pumps, which differed as regards NA concentrations (0,2 - 0,5 - 1 mg/h), dead space volume of the devices and the use of saline. Infusion systems were compared according to the time necessary to reach an NA mass flow rate steady-state plateau after the onset of infusion or after a flow change. Times were significantly different between the six methods for infusing NA. The system using the double syringe method with a standard extension set was the longest to reach the steady state after the onset of infusion [40.00 min (19.57 - 49.22)]. The steady-state plateau was obtained most rapidly with the double-syringe pump systems using very low dead-space volume extension sets and single-syringe pump systems containing diluted noradrenaline at the beginning of NA infusion. A combination of a low dead-space volume extension set and a double pump method with a constant saline flow rate at 5 ml/h might be the solution to provide the most reliable NA infusion delivery.

Properties of polidocanol foam in view of its use in sclerotherapy

Foam sclerotherapy is a widely used method to treat varicose veins disease. It is easy to use and apply, affordable, and has high efficiency that depends on foam stability upon injection. Since sclerotherapy is usually applied in a medical doctor’s office, one of the most employed methods to generate foam is based on the Tessari technique which uses pumping cycles of liquid and air in-and-out of a double syringe system. Finally, the produced foam exits through a small orifice (∼2mm) at the output of a three-way valve. The present work shows results regarding the factors that may influence foam stability (liquid to air ratio, type of connector, syringe diameter, number of pumping cycles, etc.) of a commonly used sclerosing agent (polidocanol). Furthermore, an effort is made to evaluate the effect of adding different substances on the stability of polidocanol foams (0.5% w/w) by altering the surface tension or/and the bulk and interfacial rheological properties of the fluids. It is shown that adding small concentrations of nonionic surfactants can increase foam stability with just a very small variation of the mean bubbles size.

Matrix Metalloproteinase Content and Activity in Low-Platelet, Low-Leukocyte and High-Platelet, High-Leukocyte Platelet Rich Plasma (PRP) and the Biologic Response to PRP by Human Ligament Fibroblasts

Background: Recent work has shown the presence of catabolic cytokines in platelet-rich plasma (PRP), but little is known about endogenous catabolic proteases such as matrix metalloproteinases (MMPs). Hypothesis/Purpose: To quantify MMP content in 2 commercially available PRP preparation systems: Arthrex Double Syringe System autologous conditioned plasma (ACP) and Biomet GPS (GPS). The hypothesis was that MMPs are actively secreted from PRP immediately after preparation. Study Design: Controlled laboratory study. Methods: PRP was prepared using either ACP (low platelet, low leukocyte) or GPS (high platelet, high leukocyte). MMP-2, MMP-3, and MMP-9 concentrations were measured using multiplex enzyme-linked immunosorbent assays for up to 6 days in 2 donors, and MMP activity was measured in 3 donors using kinetic activity kits able to detect the enzymatic cleavage of a fluorogenic peptide. Human ligament fibroblasts were cultured and exposed to both ACP and GPS from 1 donor each. MMP-2, -3, and -9 concentrations were assayed in culture media at 24 and 48 hours after exposure. Results: GPS exhibited higher total MMP-2, -3, and -9 concentrations for up to 144 hours of release, while ACP had higher platelet-normalized MMP-2 and MMP-3 concentrations. GPS had significantly higher total and endogenous MMP-2 activity (P = .004 and .014, respectively), MMP-3 activity (P = .020 and .015, respectively), and MMP-9 activity (P = .004 and .002, respectively) compared with ACP. Once normalized to platelet count, differences in MMP activity were not significant between ACP and GPS. Compared with controls, cells stimulated with interleukin-1 beta (IL-1β) and treated with ACP showed significantly higher fold changes of MMP-2 (P = .001) and MMP-3 (P = .003) concentrations at 24 hours than did cells treated with GPS. Total MMP-9 content was higher in the media of GPS-treated, IL-1β–stimulated cells compared with ACP-treated cells (P = .001). At 48 hours, IL-1β–stimulated cells treated with GPS exhibited higher fold changes of MMP-2 concentration (P = .002) compared with controls, but no difference in MMP-3 concentration was found. At 48 hours, there was a significantly higher concentration of MMP-9 in the cell culture media of ACP-treated cells compared with GPS-treated cells (P = .003). Conclusion: PRP prepared as both ACP and GPS contains MMP-2, -3, and -9, which is released over a period of at least 6 days. Furthermore, a large proportion of these MMPs are in their active form, and MMP activity is dependent on platelet count within the PRP preparation. Once exposed to ligament fibroblasts, both ACP and GPS cause the fibroblasts to release MMPs, most notably 24 hours after PRP exposure, and this release is dependent on prior IL-1β stimulation. Clinical Relevance: The results of this study demonstrate that PRP therapy delivers ng/mL-range concentrations of catabolic proteases, which could perpetuate inflammation and inhibit tissue healing.

Moderately stable emulsions produced by a double syringe method

Different emulsification techniques lead to emulsions with different targeted properties specific to their intended use. In this study, emulsions are generated using several emulsification techniques. They are compared as regards the component droplet size distribution and their stability in time. A particular technique based on the “Tessari” (known as double syringe system – DSS, as well) method – used originally for foam generation – is evaluated for emulsion production. Results show that DSS method leads to emulsions with mean droplet size about two orders of magnitude larger than in the case of emulsions obtained by conventional high speed and high pressure homogenizers (HPH). However, DSS emulsions have comparable viscosity behavior with the emulsions obtained by conventional methods and are stable for time intervals of a couple of hours which is convenient for specific medical applications. Furthermore, this study evaluates the effect of small quantities of some emulsion stabilizers on the mean droplet size distribution of emulsions. In the examined narrow range of values no significant modifications of the mean droplet size distribution was observed.

Impact of noradrenaline infusion set on mean arterial pressure: A retrospective clinical study

ObjectivesNoradrenaline (NA) can be infused through various systems including single or double syringe pumps. The aim of this study was to define the best and most efficient infusion system in an emergency context. Study designThis was a retrospective clinical study based on the analysis of patients’ hemodynamic data. Patients and methodThree infusion lines used presently in our postoperative ICU were compared through a retrospective clinical study: an NA syringe pump at 2mL/h and a saline carrier solution syringe pump at 8mL/h (infusion system 1- IS1) or 5mL/h (IS2), both connected to a very low dead-space volume set (V=0.046mL); IS3 with the same NA syringe at 2mL/h directly connected to the central venous catheter. Mean arterial pressure (MAP) was obtained from retrospective data analysis of ICU patients with postoperative septic shock criteria. Infusion systems were compared according to the time required to reach an MAP greater than 65mmHg after the onset of infusion. ResultsData from 37 patients was analysed. The MAP objective was attained in 14:00minutes (9:20 – 26:10, n=15) with IS1, in 19:10minutes (12:20 – 27:20, n=13) with IS2 and in 34:10minutes (23:10 – 62:30, n=9) with IS3 (P=0.00032). ConclusionThe use of a double syringe pump system associated with a very low dead-space volume infusion set appears to be the most appropriate system for NA infusion.

Growth Factor and Catabolic Cytokine Concentrations Are Influenced by the Cellular Composition of Platelet-Rich Plasma

Background: Previous studies of bioactive molecules in platelet-rich plasma (PRP) have documented growth factor concentrations that promote tissue healing. However, the effects of leukocytes and inflammatory molecules in PRP have not been defined. Hypothesis: The hypothesis for this study was that the concentration of growth factors and catabolic cytokines would be dependent on the cellular composition of PRP. Study Design: Controlled laboratory study. Methods: Platelet-rich plasma was made from 11 human volunteers using 2 commercial systems: Arthrex ACP (Autologous Conditioned Plasma) Double Syringe System (PRP-1), which concentrates platelets and minimizes leukocytes, and Biomet GPS III Mini Platelet Concentrate System (PRP-2), which concentrates both platelets and leukocytes. Transforming growth factor-β1 (TGF-β1), platelet-derived growth factor–AB (PDGF-AB), matrix metalloproteinase-9 (MMP-9), and interleukin-1β (IL-1β) were measured with enzyme-linked immunosorbent assay (ELISA). Results: The PRP-1 system consisted of concentrated platelets (1.99×) and diminished leukocytes (0.13×) compared with blood, while PRP-2 contained concentrated platelets (4.69×) and leukocytes (4.26×) compared with blood. Growth factors were significantly increased in PRP-2 compared with PRP-1 (TGF-β1: PRP-2 = 89 ng/mL, PRP-1 = 20 ng/mL, P < .05; PDGF-AB: PRP-2 = 22 ng/mL, PRP-1 = 6.4 ng/mL, P < .05). The PRP-1 system did not have a higher concentration of PDGF-AB compared with whole blood. Catabolic cytokines were significantly increased in PRP-2 compared with PRP-1 (MMP-9: PRP-2 = 222 ng/mL, PRP-1 = 40 ng/mL, P < .05; IL-1β: PRP-2 = 3.67 pg/mL, PRP-1 = 0.31 pg/mL, P < .05). Significant, positive correlations were found between TGF-β1 and platelets (r2 = .75, P < .001), PDGF-AB and platelets (r2 = .60, P < .001), MMP-9 and neutrophils (r2 = .37, P < .001), IL-1β and neutrophils (r2 = .73, P < .001), and IL-1β and monocytes (r2 = .75, P < .001). Conclusion: Growth factor and catabolic cytokine concentrations were influenced by the cellular composition of PRP. Platelets increased anabolic signaling and, in contrast, leukocytes increased catabolic signaling molecules. Platelet-rich plasma products should be analyzed for content of platelets and leukocytes as both can influence the biologic effects of PRP. Clinical Relevance: Depending on the clinical application, preparations of PRP should be considered based on their ability to concentrate platelets and leukocytes with sensitivity to pathologic conditions that will benefit most from increased platelet or reduced leukocyte concentration.

Chitosan in situ gelation for improved drug loading and retention in poloxamer 407 gels

A method for the in situ gelation of poloxamers and the mucoadhesive polymer chitosan has been developed by exploiting the tendency of poloxamer solution to form gel at physiological temperatures and of chitosan (CT) to form ionotropic gel structures in the presence of sodium tripolyphosphate (TPP). Novel poloxamer gels containing CT–TPP complex formed in situ during the administration were prepared by mixing poloxamer–CT and poloxamer–TPP solutions in double syringes. The micellization and gelation of poloxamer 407 in the presence of chitosan and/or TPP were studied using differential scanning calorimetry and tube inversion; both additives were found to reduce the critical micellization temperature and critical gelation temperature of poloxamer aqueous solution. The poloxamer gels containing CT–TPP complex formed in situ were found to exhibit reduced dissolution rate and superior release characteristics with three different drugs – metoprolol, doxycycline and flufenamic acid. Furthermore, by varying the compositions of the two solutions independently, it is possible to control the pH in a way to suit the solubilization of a drug as well as the specific environment of a particular application site. By varying the concentrations of chitosan, TPP and poloxamer, the delivery system can be fine-tuned to afford gels with specific properties, ranging from nanoparticle suspensions to semisolid gels. These in situ gels have the potential to increase the utility of thermo-reversible poloxamers in drug delivery.

The history of sclerosing foams.

The use of foamed sclerosants in phlebology is undergoing a renaissance. The use of foam sclerotherapy was relaunched only a few years ago. Despite this, the early developments, pioneer findings, and improvements, especially in foaming techniques, are not widely recognized. The objective of this study was to give an overview from the very beginnings of foam sclerotherapy until the most recent and progressive techniques, as described by Tessari or the double syringe system technique. The publications found after a thorough research for literature about foam sclerotherapy allow us to examine what has been invented between Orbach's work in 1944 and now and--surprisingly--even before 1944. The contributions of greatly reputed and also of unknown colleagues, such as Orbach, Sigg, Mayer, or Flückiger, are presented, giving a historical overview from the very beginnings of foam sclerotherapy until the most recent techniques. Basically, the literature shows that remarkable work was carried out in the field of noncommercial foam sclerotherapy and that sclerosing foams have been used by numerous doctors continuously for the past six decades, especially for the treatment of varicose veins of the lower limbs. The use of foamed sclerosing agents in therapy of large or small varicose veins is not new. It started as early as 1939 and has continuously been improved in the past decades.

Improvement of parenchymal and vascular enhancement using saline flush and power injection for multiple-detector-row abdominal CT.

The aim of this study was to determine if a saline solution flush following low dose contrast material bolus improves parenchymal and vascular enhancement during abdominal multiple detector-row computed tomography (MDCT). Forty-one patients (24 men and 17 women; mean age 49 years, age range 27-86 years) underwent abdominal MDCT (collimation 4x5 mm, 15-mm table increment, reconstruction interval 5 mm, gantry rotation period 0.8 s) with a single- as well as with a double syringe power injector. Indication for examination were benign and malignant tumors and inflammatory diseases. Patients received 100 ml nonionic contrast material (300 mgI/ml) alone or pushed with 20 ml saline solution. Mean enhancement values for both protocols were measured in the liver, the spleen, the pancreas, the renal cortex, the portal vein, the inferior vena cava and the abdominal aorta. Double syringe power-injector protocol led to significantly higher parenchymal and vascular enhancement than single syringe power-injector protocol (p<0.05). The improvement in mean enhancement of the liver was 9 +/- 9 HU, of the spleen 8 +/- 10 HU, of the pancreas 7 +/- 9 HU, and of the renal cortex 8 +/- 20 HU. The improvement in mean enhancement of the portal vein was 10 +/- 17 HU of the inferior vena cava 8 +/- 13 HU and of the abdominal aorta 10 +/- 17 HU. The use of a double syringe power injector with saline flush following contrast material bolus significantly improves parenchymal and vascular enhancement during contrast-enhanced abdominal MDCT with low iodine doses.

Double syringe blistering by adding a three-way connector for grafting stable vitiligo patches

BACKGROUND/AIMS: Blistering and grafting the roof of blisters to either dermabraded or cryoblistered vitiliginous sites are techniques used to correct persistent, medically non-responsive vitiliginous patches in stable vitiligo patients or in those with other leukodermas. METHODS: We used two syringes or a syringe and a cylinder funnel connected by a three-way connector for blister induction. The needle pieces of two syringes are connected by a threeway connector. The piston of the first syringe is removed and applied from the base to the donor site. The piston of the second syringe is withdrawn for 100–200% of the volume of the first-applied syringe, which creates a negative pressure of about 260 to 380 mmHg or -380 to -510 mmHg by intermittently locking the three-way connector, removing the second syringe, pushing back its piston and reinserting it, and then withdrawing again. Finally, the three-way connector is locked and the second syringe is removed. This magnitude of negative pressure is enough for a unilocular blister to develop within 0.5–2 h. The roof of the blister is then removed and applied to dermabraded or previously cryoblistered recipient sites covered only by dry or saline-soaked sterile gauze. RESULTS: Subtotal repigmentation may be seen 10–14 days later after removing the dressing. Total repigmentation may occur 2–3 months later after receiving topical or systemic PUVA therapy. CONCLUSION: Connecting two syringes or a syringe and a cylinder bottle by a three-way connector is a simple and inexpensive device for inducing blister, harvesting epidermal sheets and grafting to the recipient stable vitiliginous patches. (J Dermatol Treat (2000) 11:43–46)