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The aim of this study was to assess the efficacy of 21 decontamination procedures, for the removal of a multispecies biofilm. Experiments were performed on five-day-old biofilms grown inside silicone tubing, using a reactor system that mimics a dialysis machine. The treatments were tested on 5 cm tubing samples. Effects of treatment were measured using direct microscopy following staining. Bacterial viability and endotoxin removal were determined using conventional microbiological methods following biofilm detachment by scraping. The 21 procedures were classified into four groups based on the amount of biofilm removed. The most effective treatment was an acid pre-treatment, followed by use of a concentrated bleach solution. Acid pre-treatment removes calcium and magnesium carbonate crystals that are always found in dialysis biofilms. Treatments performed at high temperature did not increase the efficacy of biofilm removal. Most treatments caused at least a 10(5)-fold reduction in bacterial viability with a few resulting in complete kill. Autoclaved and bleach-treated samples gave the best results for viability reduction, with both treatments providing an equally effective and complete kill. In addition, autoclaving led to a significant decrease in endotoxin level (removal of 99.99%).

Background Endoscopic dacryocystorhinostomy (DCR) is an effective surgical procedure to treat saccal and postsaccal stenosis or nasolacrimal duct obstruction. The use of silicone tube after endoscopic DCR is still controversial. A prospective randomized study was conducted to compare the success rate between the use of silicone stent and no use of silicone stent in endoscopic DCR. Methods A prospective randomized study was conducted at Aseer Central Hospital and Abha Private Hospital, Abha, Kingdom of Saudi Arabia, on all patients undergoing endoscopic DCR between July 1, 2006 and 30 June 30, 2010. Patients were allocated randomly for endoscopic DCR with or without stent. The data collection included age, sex, diagnosis, method, and duration of surgery. Patients were followed up postoperatively at 1 week, 1 month, and then every 3 months for 1 year. Results During the period of the study a total of 173 cases of postsaccal stenosis underwent endoscopic DCR (67 male and 106 female subjects). The mean age was 51.8 years (range, 18–72 years). A stent was used in 92 patients (53.2%) and not used in 81 patients (46.8%). With silicone tubing the success rate was 96%, and without silicone tubing it was 91%, an overall success rate of 94%. The odds ratio of failure without a silicone tube was 3.25 but confidence interval was from 0.84 to 12.60 and the difference between these two groups was statistically not significant (p = 0.117). Conclusion In this study, there was no statistically significant advantage of using endoscopic DCR with stent over the endoscopic DCR without stent.

Endonasal endoscopic laser-assisted dacryocystorhinostomy has many advantages over conventional external dacryocystorhinostomy. This technique avoids a cutaneous scar and causes less surgical trauma and bleeding than that seen in conventional lacrimal surgery. A total of 20 endoscopic laser-assisted dacryocystorhinostomy in 16 patients were performed between 1998 and 1999. the procedure was successful in 90% of cases, with no major complications. This success rate is comparable with external dacryocystorhinostomy. Silicone tubing was applied in 11 cases. The difference of success rates between the two groups (with and without silicone tubing) was not significant. It seems that creading a patent rhinostomy plays a more important role to achieve desirable results. Endonasal endoscopic laser-assisted dacryocystor-hinostomy provides a simple, bloodless, and incisionless alternative to external dacryocytorhinostomy in the majority of the patients suffering from symptoms of lacrimal obstruction.

Object The authors conducted a study to develop a safe and effective intracranial venous sinus reconstruction for extensive clinical use. Methods After resecting the superior sagittal sinus (SSS), it was reconstructed in eight dogs by performing either a tube-insertion technique or end-to-end anastomosis procedure, in both of which a thin-walled silicone tube was used for repair. The patency of the SSS reconstruction was observed on digital subtraction angiography and transcranial Doppler ultrasonography, preoperatively and at 1, 2, 4, and 8 weeks postoperatively. Histological and ultrastructural changes were observed using light and electron microscopy. In five dogs the reconstructed SSS was patent, in one it was narrowed, in one it was completely occluded at the proximal site of the anastomosis, and one dog escaped from the laboratory 1 week postoperatively. The authors found no evidence of any additional neurological deficits, signs of toxicity, or side effects. Histological and ultrastructural studies generally showed vascular endothelial proliferation. No thrombosis occurred in the inner surface, at the site of anastomosis, or in the lumen of silicone tube nor in the sagittal sinus at up to 8 weeks postoperatively. Conclusions The use of a thin-walled silicone tube as an artificial substitute for intracranial dural venous sinus reconstruction seems to be a valuable technique. The silicone tubes were found to have good biological compatibility, nonthrombogenic effects, and a high patency rate. The method was found to be simple and effective as well as practicable in the clinic for the short term (8 weeks). The authors emphasize that Phase I clinical trials involving silicone tube–assisted SSS reconstruction require further research.

Propofol is an intravenous anesthetic. Currently, it is not possible to routinely measure blood concentration of the drug in real time. However, multi-capillary column ion-mobility spectrometry of exhaled gas can estimate blood propofol concentration. Unfortunately, adhesion of volatile propofol on plastic materials complicates measurements. Therefore, it is necessary to consider the extent to which volatile propofol adheres to various plastics used in sampling tubing. Perfluoralkoxy (PFA), polytetrafluorethylene (PTFE), polyurethane (PUR), silicone, and Tygon tubing were investigated in an experimental setting using a calibration gas generator (HovaCAL). Propofol gas was measured for one hour at 26 °C, 50 °C, and 90 °C tubing temperature. Test tubing segments were then flushed with N2 to quantify desorption. PUR and Tygon sample tubing absorbed all volatile propofol. The silicone tubing reached the maximum propofol concentration after 119 min which was 29 min after propofol gas exposure stopped. The use of PFA or PTFE tubing produced comparable and reasonably accurate propofol measurements. The desaturation time for the PFA was 10 min shorter at 26 °C than for PTFE. PFA tubing thus seems most suitable for measurement of volatile propofol, with PTFE as an alternative.

In this chapter, we describe the specific complications relating to the neurosurgeon’s choice of any given shunt system used in different clinical conditions and age groups. Most neurosurgeons have a particular favourite CSF shunt system and burr-hole site that they use for the majority of their patients, but in hydrocephalus management there is no perfect shunt for all occasions and each type of shunt system has its own peculiar strengths and weaknesses. Certain design features such as valve profile, size of valve components, presence of barium, distal slits or springs in the silicone tubing, number of connection points within the system and impregnation with antibiotics will all influence the risk of shunt complications, as well as the more obvious features such as pressure and flow characteristics.

Atomic force microscopy (AFM) is a powerful instrument for researching biological phenomenon at the nanoscale. A fluid cell can be used to hold the bacteria and fluid. As many biological processes occur in fluid environments, need to be kept hydrated for proper analysis, yet commercially produced fluid cells involve complex set up procedures and are expensive. As an integral part of a Research Experience for Teachers (NSF RET) summer program, we created an inexpensive fluid cell molded from polydimethylsiloxane (PDMS) with embedded silicone tubing and an attached glass cover slip at the bottom. The device was designed and assembled within 6 weeks with several revisions occurring in the following weeks. The objective of this work was to design an AFM fluid cell that allows for the exchange of fluid, is inexpensive to produce and reproduce, is sterilizable and is easy to set up and use. After multiple design iterations and testing of prototypes, we validated the device by examining peptide-membrane interactions using an AFM equipped with the fluid cell. This device will aid researchers by providing an inexpensive, simple means of investigating and analyzing various biological samples in an AFM.

Catheters designed for intermittent urological catheterization should possess appropriate lubricity and mechanical properties to ensure optimal clinical performance. However, the lack of a reproducible in vitro method that simulates clinical use makes it difficult to evaluate the lubricity of urinary catheters and other devices for urethral insertion. Therefore, this study describes a suitable method based on use of a Texture Analyzer to characterize the lubricity of such devices. The novel method was susequently applied to the evaluation of commercially-available intermittent urinary catheters. In addition, other important physicochemical properties of these catheters were examined, namely Young's modulus, degree of hydration and morphology. Catheter lubricity was quantified, using a Texture Analyzer, by measurement of the forces required for insertion and removal of the device from two model substrates, agar and mucin-coated silicone tubing. Significant differences in lubricity were identified between the commercially-available catheters, with Aquacath and Lofric exhibiting the lowest forces of insertion and removal. There were no significant differences between the extent of hydration between the catheters, with the exception of Uro-flo which exhibited the lowest hydration. Therefore, the differences in lubricity were not directly related to the extent of hydration. The forces required for insertion/removal of all catheters were markedly greater in the simulated mucin model than in the agar substrate and the former, simulated urethra model, was accepted to mimic more accurately, the in vivo situation. Significant differences were observed between the Young's Moduli of the catheter biomaterials, with Aquacath possessing the largest value. In conclusion, this study has described the use of a texture analyzer and polymeric substrates for the evaluation of biomaterial lubricity. Using these methods, Aquacath and Lofric catheters exhibited greatest lubricity. However, following additional consideration of the mechanical properties of these biomaterials, Aquacath possessed the most appropriate physicochemical properties for use in intermittent catheterization.

A Silicone-Tubing-Probe measuring system with SnO2 sensor, based on the permeation of volatile organic compounds from a water sample to the gas phase through a dimethylsilicone membrane, was used for in-situ analysis of VOCs. The SnO2 sensor was used for the continuous determination of the sum of organic compounds liberated from the water sample. On-line combination of the measuring system with capillary gas chromatography enabled the determination of individual compounds and the study of the analyte permeation processes. The system was tested by using selected aromatic hydrocarbons, oxygenated and chlorinated compounds in water as simulated samples. The compounds were isolated from the water matrix and analyzed in the 10 μ/1 — 400 mg/1 concentration range. The combined Silicone-Tubing-Probe system can be used for monitoring volatile organic compounds in water samples.

Background Endoscopic dacryocystorhinostomy (EN-DCR) is increasing in popularity as a treatment of nasolacrimal obstructions because it has proven to be an effective and safe procedure. In this study the success of EN-DCR combined with or without bicanalicular silicone stents was evaluated in patients with nasolacrimal obstructions. Methods Forty-two consecutive EN-DCR procedures were performed in 36 patients during 2000–2004. The surgery was primary in 23 cases and revision in 19 cases. Bicanalicular silicone stents were inserted in 18 cases and in 24 cases stenting was avoided. Results The overall success rate after EN-DCR was 81%. The success rate of EN-DCR was 89% with silicone tubing and 75% without silicone tubing. The mean duration of postoperative follow-up was 4 months. Conclusion In our retrospective study no significant statistical differences were seen between the patients with stenting compared with patients without stenting. However, prospective, randomized studies are clearly needed to answer the question of whether the use of stents is advisable.

The handling of grids and trans-ferring them individually between drops on a sheet of Parafilm with forceps is often cumbersome. Inserting grids into small slits of a piece of silicone tubing for staining has been described previ-ously (1). Here we present a novel device for the easy handling of grids attached to a piece of silicon tubing, allowing both chemical staining and immunoreactions.The base of the device is made of a Teflon

Aim of the present study was to determine the efficacy of intranasal endoscopic silicone intubation to treat congenital nasolacrimal duct obstruction in children who failed conventional lacrimal system probing. Silicone intubation with intranasal endoscopic visualization was performed in 18 eyes of 16 patients with an age range of 18–48 months (mean, 25 months) to treat congenital nasolacrimal duct obstruction. Out of 16 patients, ten had already undergone previous probings with failure, the other six were primary intubation cases without any previous probings. The tubes were left in place an average of 6 months. Follow-up ranged from 4 months to 2 years (mean, 12 months) following removal of the silicone tubing. Intranasal endoscopic silicone intubation is effective in the treatment of congenital nasolacrimal duct obstruction as a primary procedure in children over 18 months of age and, it is also recommended as the next step in the management of epiphora which fails to resolve after probing.

A silicone tubing sensor controlled a constant methanol concentration in a fermenter up to 72 hours without the need for on-line gas chromatography or complex feeding schemes based on dissolved oxygen spikes. Methanol concentration was controlled up to 1.0% (v/v) with control around a given set point of ± 0.24%. The length of tubing, airflow through the tubing, pump speed and medium formulation had no effect on the control of methanol concentration.

Although a number of techniques have been developed for sampling gaseous compounds in the soil atmosphere, their performance in saturated soil environments is usually less than satisfactory. We have evaluated the use of silicone tubing materials to sample nitrous oxide (N 2 O), an important component of anoxic soil atmospheres. Sections of regular (wall thickness, 2.4 mm) and reinforced (wall thickness, 4.8 mm) silicone tubing were placed into Mason jars and exposed to three concentrations of N 2 O (30, 45 and 60 μl l −1 ) at three different temperatures (4, 22 and 30°C). The transfer of N 2 O from the jar headspace into the silicone tubing was monitored over 2 to 3 h. The transfer of N 2 O was described by both a polynomial equation and by a first order diffusion model. The regular silicone tubing is more permeable than the reinforced silicone tubing due probably to thickness difference as well as to differences in manufacturing and composition. At 22°C, it was estimated, using a first order model, that N 2 O concentrations inside the regular silicone tubing and the jar headspace would come to equilibrium within 4.4 h contrasting with the 8.2 h needed with the reinforced silicone tubing. The performance of the soil atmosphere samplers made of regular silicone tubing was tested in alternatively saturated and unsaturated soil columns. Results obtained confirmed the suitability of silicone tubing for soil N 2 O sampling and other similar applications.

We describe the use of pieces of silicone tubing to analyse the mandibular gland components of queen and worker honeybees and show that these compounds can be efficiently trapped on bis(trimethylsilyl)trifluoroacetamide (BSTFA) treated pieces of tubing. The use of this technique rather than that of solid phase microextraction (SPME) techniques with commercially available fibres that have been shown to be efficient at sampling secretions from the cuticle of insects, is necessitated by a requirement for collection of large sample numbers in a short space of time or for sampling in the field. The technique may be generalised for use with semiochemicals of low volatility in other insect communciation systems.

The authors report 20 cases of endonasal dacryocystorhinostomy using standard otolaryngological surgical instruments. The technique used was, briefly: An osteomucous window was opened just anterior to the medial turbinate, starting superiorly to the inferior turbinate. The lacrimal sac was visualized and its medial wall excised. The lacrimal apparatus was canalized using silicone tubing.

The EMS Swiss LithoBreaker is a new, portable, electrokinetic lithotripter. We compared its tip velocity and displacement characteristics with a handheld, pneumatic lithotripter LMA StoneBreaker.™ We also evaluated fragmentation efficiency using in vitro models of percutaneous and ureteroscopic stone fragmentation.Displacement and velocity profiles were measured for 1-mm and 2-mm probes using a laser beam aimed at a photo detector. For the percutaneous model, 2-mm probes fragmented 10-mm spherical BegoStone phantoms until the fragments passed through a 4-mm mesh sieve. The ureteroscopic model used 1-mm probes and compared the pneumatic and electrokinetic devices to a 200-μm holmium laser fiber. Cylindrical (4-mm diameter, 4-mm length) BegoStone phantoms were placed into silicone tubing to simulate the ureter; fragmented stones passed through a narrowing in the tubing.For both 1-mm and 2-mm probes, the electrokinetic device had significantly higher tip displacement and slower tip velocity, P0.01. In the percutaneous model, the electrokinetic device needed an average of 484 impulses over 430 seconds to fragment one BegoStone, while the pneumatic device needed 29 impulses over 122 seconds to fragment one stone. Both clearance times and number of impulses needed for percutaneous stone clearance were significantly different at P0.01. Ureteroscopically, the mean clearance time was 97 seconds for the electrokinetic lithotripter, 145 seconds for the pneumatic lithotripter, and 304 seconds for the laser. Comparing the pneumatic device with the electrokinetic device ureteroscopically, there was no significant difference in clearance time, P=0.55. Both the pneumatic and electrokinetic lithotripters, however, demonstrated decreased clearance times compared with the laser, P=0.027.The portable electrokinetic lithotripter may be better suited for ureteroscopy instead of percutaneous nephrolithotomy. It appears to be comparable to the portable pneumatic device in the ureter. Further clinical studies are needed to confirm these findings in vivo.

Este trabalho teve por objetivo avaliar a regeneração do nervo ulnar de equinos, submetidos à neurotomia, tubulização com tubo de silicone e terapia celular com fração de células mononucleares da medula óssea (FCM) ou células-tronco mesenquimais do tecido adiposo (ADSC). Foram utilizados 15 equinos adultos alocados em três grupos, com cinco animais em cada: grupo controle (GC) com utilização de soro fisiológico; grupo com deposição de FCM; e grupo com deposição de ADSC. Foi realizado o mesmo procedimento cirúrgico em todos os grupos, utilizando-se os dois nervos de cada animal (direito e esquerdo), e estabelecido dois momentos de biopsia: na 13ª semana com biopsia no membro direiro (GC1, FCM1 e ADSC1) e na 26ª semana com biopsia no membro esquerdo (GC2, FCM2 e ADSC2). A FCM e a ADSC foram obtidas respectivamente, da medula óssea e tecido adiposo de cada aninal, ambos utilizados como implantes autólogos. Após 13 e 26 semanas, realizaram-se as biopsias de todos os grupos e imediatamente, faziam-se imprints dos fragmentos para visualização do marcador fluorescente nanocristal. Os fragmentos foram fixados em formol tamponado a 10%, para análise histológica, com as coloraçãoes de HE, luxol fast blue, tricrômio de Masson e imuno-histoquímica com os anticorpos neurofilamento (NF), S-100, FGF-2 e GDNF. Microscopicamente avaliou-se a presença de proliferação axonal, tecido conjuntivo, infiltrado inflamatório, células de Schwann, fatores de crescimento neurais, bainha de mielina, e degeneração walleriana. Para a análise histológica estabeleceram-se escores qualitativos e para a imuno-histoquímica realizou-se análise quantitativa com o programa Image J. Foi observada diminuição da degeneração walleriana, melhor reorganização fascicular, aumento do colágeno novo, início de formação de bainha de mielina, além de maior marcação do anticorpo NF nos grupos experimentais em relação ao GC. O grupo ADSC apresentou melhores resultados em relação aos demais, enfatizando a eficiência das ADSCs em relação à FCM e ao GC para a regeneração nervosa periférica. Porém, há a necessidade de um tempo maior para ocorrer completa regeneração do tecido nervoso periférico após lesão. The aim of this work was to evaluate the regeneration of equine ulnar nerves submitted to neurotomy, silicone tubing and cell therapy with bone marrow mononuclear cells fraction (MCF) or adipose derived mesenchymal stem cells (ADSC). Fifteen adult horses were divided into three groups with five animals each: control group (CG) with the use of saline solution, group with FCM deposition and group with ADSC deposition. The same surgical procedure was performed in all groups, using both nerves of each animal (right and left), establishing two moments of biopsy: on the 13th week on the right limb (CG1, MCF1 and ADSC1) and on the 26th week on the left limb (CG2, MCF2 and ADSC2). The MCF and ADSC were obtained respectively, from bone marrow and adipose tissue from each animal, both used as an authologous implant. After 13 and 26 weeks, biopsies were performed in all groups and immediately it was made some fragments slide imprints for viewing the nanocrystal fluorescent label. The fragments were fixed in 10% buffered formalin for histological analysis, with HE, luxol fast blue, Masson's trichrome, immunohistochemistry against the antibodies neurofilament (NF), S-100, FGF-2 and GDNF. Microscopically it was observed the presence of axonal growth, connective tissue, inflammatory infiltrate, Schwann cells, neural growth factors, myelin sheath and wallerian degeneration. For histologic analysis, it was established qualitative scores and for immunohistochemistry it was performed quantitative analysis with Image J program. It was observed wallerian degeneration reduction, better fascicular reorganization, new collagen increased, myelin sheath early formation, and NF antibody stronger staining in the experimental groups compared to CG. The ADSC group presented the best results than the other groups, showing ADSCs efficiency compared to MCF and CG for peripheral nerve regeneration. However, it was proved a longer time necessity to occur complete regeneration of peripheral nerve after injury.

The mean forces required to dislodge two types of endoscopic ligation clips from both porcine cystic ducts and silicone tubing were quantitated. The two types of endoscopic clips were EndoClip II and Ligaclip ERCA. Following application of the clips, the force required to dislodge the clips in both a perpendicular direction and a longitudinal direction was determined. The mean levels of force required to dislodge the EndoClip II clips in both directions were significantly (p ≤ 0.01) greater than those required to dislodge the Ligaclip ERCA clips.

The author reports a new bicanalicular intubation method using a Nunchaku-style silicone tubing (n-st) which consists of three pieces. One piece is the thinner central segment, and the other two are thicker bilateral segments. In the new method, there is no difficult procedure of retrieving the tip of a metal probe from the nasal cavity. The n-st requires no suture to secure it in position. The author believes the n-st makes bicanalicular intubation easier and leads to more frequent use, and results in a reduced number of major surgical interventions.

Cyclic mechanical loading improves strength and extracellular matrix (ECM) synthesis in tissue engineered blood vessels (TEBV). The goal of this project was to design a device to impart cyclic circumferential stretch on cell-derived TEBV rings cultured on flexible silicone tubing. During static inflation tests, the tubing diameter increased by 10±1.6%. Our device cyclically displaces water (75 µl volume) to inflate tubing at a frequency of 1 Hz. TEBV rings were loaded onto silicone tubing and subjected to mechanical conditioning for 3–7 days. Structural analysis of conditioned TEBV ring samples (compared to statically cultured control rings) is in progress.

Purpose To report a series of lacrimal complications associated with a specific type of lacrimal plug (Herrick Lacrimal Plug; Lacrimedics Incorporated, Rialto, CA.) Design Retrospective, noncomparative case series and survey. Methods Members of the American Society of Ophthalmic Plastic and Reconstructive Surgery were asked to submit personally treated cases of patients referred for treatment of complications after placement of a Herrick Lacrimal Plug. Main outcome measures Failure of the device to be removed by simple lacrimal irrigation. Results The clinical courses of 41 patients were analyzed. Patients ranged in age from 19 to 81 years, and all had symptomatic epiphora related to the presence of the lacrimal plug. Several interventions were used to treat lacrimal obstruction. Nasolacrimal duct probing with irrigation was used in 15 lacrimal systems, whereas six systems were probed and subsequently stented with silicone tubing. Eyelid margin cutdown was used in eight cases. Balloon dacryoplasty was performed in three systems, dacryocystorhinostomy in 18 instances, and conjunctivodacryocystorhinostomy in two patients. Conclusions The Herrick lacrimal occlusion device sometimes cannot be removed by simple irrigation and is capable of inducing permanent, irreversible, symptomatic lacrimal drainage system obstruction.

Purpose: To evaluate the success rate of dacryocystorhinostomy (DCR) for epiphora in patients with a clinically patent lacrimal drainage system. Methods: A series of 51 patients, 12 men and 39 women, who underwent DCR surgery for epiphora with a clinically patent lacrimal drainage system in the background of normal eyelid examination, were evaluated. All patients underwent fluorescein dye disappearance testing and Jones 1 and 2 testing with dacryocystograms in borderline cases. A standard DCR was performed with bicanalicular silicone tubing inserted in all cases. The average time for the removal of the silicone tubes was 9.6 weeks. Results: In 48 cases (94%) there was improvement in symptoms with minimal or no significant epiphora postoperatively. Conclusions: Epiphora with a patent lacrimal drainage system obstruction can be successfully treated by DCR based on fluorescein dye disappearance tests and Jones 1 and 2 tests, with dacryocystography in borderline cases.

The rotation of rollers in cardiopulmonary bypass pumps propels the blood through various devices to reach the patient. Very occlusive settings may squeeze red blood cells, whereas a nonocclusive setting may result in retrograde flow. Occlusion of roller pumps may be regulated either by measuring the drop rate or by dynamic calibration. This study evaluated the influence of silicone tubing residual stress found on pump regulation. Silicone tubes obtained from two different suppliers were used in 6-inch DeBakey roller pumps. The variations occurring over time in the measurements of drop rate, dynamic calibration, and tube residual stress were analyzed. Covariance analysis of the four linear regressions has shown a progressive and accentuated reduction in drop rate (p0.002). It is noticeable that the angular coefficients of the drop rate measurements of the four silicone tubes are the same (p0.56). This reduction in drop rate measurements may affect the regulation of the pumps before surgical procedures. One probable cause for this reduction is the residual stress found in the silicone tubes. Settings based on the dynamic calibration process tended to be repeated over time. Simple linear regression test (angular coefficient equals zero) has shown a p0.79 showing no interference of the silicone tubes residual stress on dynamic calibration, suggesting that one should use this method to calibrate roller pumps.

Silicone tubes are widely used in lacrimal system surgery. A common complication associated with the use of silicone tubes is lateral migration or displacement of the tubes. In some cases, the distal part of the silicone tube passes through the rhinostomy area, where it may become embedded in the lacrimal sac. The silicone tubes could not be seen in the nose endoscopically. The distal part of the silicon tube could not be seen in the rhinostomy area, so it was removed using a new method.

The purpose of the study was to compare angiogenic response of isolated saphenous and epigastric arteriovenous bundles in avascular environment, in an in-vivo model. Saphenous and epigastric bundles of 20 rats were dissected and ligated distally. The bundles were implanted into silicone tubing to create a biologically neutral environment. Gross and histologic examination was performed at different intervals. No thrombus was detected in any of bundles prior to 24 hours. An adherent thrombus was seen at 24 hours in all ligated saphenous bundles; it persisted at three weeks with no evidence of neovascular sprouting. The ligated epigastric bundles remained patent with evidence of neovascular sprouting. The saphenous vessels are more likely to thrombose and do not show vascular proliferation when placed in an isolated environment, whereas the epigastric vessels are likely to remain patent and show vascular proliferation.

Two procedures were used to modify gauze bandages, polyester sutures, silicone tubing, and polyvinyl chloride tubing. In one procedure, the materials were first modified by in situ precipitation of metallic hydroxides and then used to adsorb silver ions. In the second procedure, the materials were soaked in sodium pyrophosphate or sodium chloride, dried, and then soaked in silver nitrate. These procedures produced materials with silver deposited on the surface of the tubing and sutures and both on the surface and within the gauze fibers. The modified materials inhibited the growth of Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus in vitro. Key words: tubing, sutures, bandages, antibacterial.

We describe a procedure to secure a jugular vein catheter system at the dorsal nape of the neck in the hamster. An 8-cm piece of silicone tubing is connected with a 2.6 cm L-shaped metal tubing which is embedded in prosthetic material. The prosthetic material is placed underneath the neck skin of the hamster and keeps the metal end of the catheter system in a sturdy, upright position.

BACKGROUND: Intraperitoneal local anesthetic administration has been reported to provide perioperative analgesia during laparoscopic procedures. The aim of this in vitro study was to assess the efficiency of commercially available humidification devices to deliver ropivacaine and to determine the effects of modifying the device’s position between the insufflator and the Veress needle on the amount of ropivacaine delivered. METHODS: In the first experiment, four humidification devices filled with ropivacaine (0.20% and 0.75%) were placed at the outlet of a laparoscopic insufflation system delivering a constant carbon dioxide flow. A catheter was connected to the humidifier’s outlet and the other end submerged in a calibrated vial containing 25 mL of 50% methanol in water. The concentration of ropivacaine collected in the methanol-water solution was measured using high performance liquid chromatography. In the second experiment, the clinical situation was imitated by placing 3 m of silicone tubing between the humidifier and the collection vial to evaluate its influence on the amount of ropivacaine delivered. Only one humidifier was tested in the second experiment because the other three tested humidification devices did not efficiently deliver ropivacaine. RESULTS: The evaporation-based humidifiers delivered very small or nonmeasurable quantities of ropivacaine. In contrast, the microvibration-based aerosol humidification device delivered significant amounts (89.1%–94.3%) of the drug. The insertion of silicone tubing between the humidifier and the collecting vial reduced the amount of delivered ropivacaine to 62.3%. CONCLUSIONS: The microvibration-based aerosol humidification device may be used to deliver local anesthetics during laparoscopic procedures. Further research is necessary to confirm these results in clinical practice and to provide effective humidification that does not blur the surgeon’s view. (Anesth Analg 2008;107:549‐51)

The initial rate of acetoclastic methanogenic biofilm formation was significantly higher than rates that have been reported for mixed anaerobic cultures. Biofilm development rate increased with an increase in biomass concentration and specific activity (mg substrate‐mg biomass−1‐day−1) of the mixed liquor biomass. Biofilm concentration also increased with higher specific activity. Results indicate the involvement of polysacchar‐ides in acetoclastic biofilm formation. The existence of a loosely held biofilm at flow velocities of 005 to 1–5 cm‐s−1 was observed. Flow velocity increases in that range resulted in higher attached film accumulation rates. Silicone tubing was superior to Tygon tubing in facilitating biofilm formation.

Conventional preparation of the weak aqueous eluent for reversed phase liquid chromatography by weighing, pipeting, and/or titrating materials can be time consuming, poorly reproducible, and require storage of many containers of final buffer. Stored buffers can become contaminated by vapors, container-leached materials, or microbes. This paper discribes a novel approach for preparing eluents in which LC-grade water is drawn through lengths of silicone tubing in a small “equilibration-chamber” containing gases, vapors of liquids, or salt-saturated solutions. Besides offering a broad range of pHs from 2 to 13, and saving the time and materials for eluent preparation, other advantages are described, including the possibility of preparing ultra-pure buffered eluents.

Macrophytic marine algae are a rich source of pharmacologically active compounds. Cell and tissue suspension cultures established from macrophytic marine algae have the potential to biosynthesize these compounds in a controlled environment within bioreactor systems at a scale required for further product development or commercial production. Toward this end, we recently developed a tubular recycle photobioreactor that integrates the best features of tubular, stirred-tank, and air-lift bioreactor configurations into one system. The tubular recycle photobioreactor consisted of a tubular section, stirred aeration tank, and recycle line with a peristaltic pump to move the culture between the tubular section and the aeration tank. In the tubular section, 39 m of silicone tubing of 0.8-cm inner diameter (1.9-L culture volume) was wrapped around a 30.5-cm diameter cylindrical frame. The tubular section was radially illuminated by two 20-W fluorescent lamps positioned at the center of the coil to provide an incident light intensity of 18 µE m−2s−1. The culture was pumped through the tubular section at a rate of 125 mL min−1 to provide residence times of 15 min in the tubular section and 6 min in the aeration tank. An air flow rate of 1.5 vvm in the aeration tank provided all the CO2/O2 gas exchange requirements for the culture. Air was also injected directly into the tubular section at 2 L min−1 for 90 sec every 90 min to remove cell mass attached to the tubing wall. Under these conditions, gametophyte cell suspension cultures of the macrophytic brown alga Laminaria saccharina achieved a specific growth rate of 0.1 day−1 and a maximum cell density exceeding 1000 mg DCW L−1 over a 30-day cultivation period. The efficient delivery of light to the suspension culture makes this system an attractive alternative to externally illuminated stirred-tank or air-lift bioreactors for the production of photosynthetic biomass.

Hypothesis Transdermal sustained-delivery oxygen therapy improves wound healing. Design Experimental study using a well-established rabbit ear model for acute wound healing. Setting Wound-healing research laboratory in a university center. Methods Four full-thickness 7-mm punch wounds were created on each ear of young, female New Zealand white rabbits. Treated ears received transdermal sustained delivery of oxygen via silicone tubing tunneled subcutaneously to a pocket under a semiocclusive dressing. Oxygen production (100% oxygen at 3 mL/h continuously) relied on a small, self-contained device connected to the silicone tubing and secured to the rabbit’s back for the duration of the experiment using a body harness. Ears were harvested at each of 2 time points: day 5 and day 8. Results Histologic analysis of the wounds showed significantly greater healing at both day 5 and day 8 in response to oxygen therapy. Most significantly, epithelial wound coverage was almost doubled in treated ear wounds when compared with controls. Conclusion Our results suggest that epithelial wound healing is improved by transdermal sustained-delivery treatment with 100% oxygen.

Most currently used disinfectants for dialysis machines have a good bactericidal efficacy on biofilms but leave dead cells on the surface. This contributes to the regrowth of biofilm and the release of pyrogens. A new anti-biofilm procedure consisting of sequential treatment combining enzymes and detergents is able to detach adherent cells. The efficacy of this procedure was assessed both in vitro and in reality. For in vitro studies, a biofilm model was set up. Studies were also performed in reality in a clinically used dialysis machine. Biofilm removal was first monitored by image analysis. Then, the biomass was detached by scraping and quantified by plate counts and endotoxin level measurement. Treated samples were compared to untreated control samples. The procedure led to the complete detachment of the biomass, both in vitro and in the reality situation. The aim of thisprocedure is to replace or complete the usual disinfection methods for medical devices.

During a compatibility study between a formulation containing sulfobutylether cyclodextrin (SBECD) and silicone tubing, an extraneous peak was observed in the HPLC chromatograms. The extraneous material was identified by LC/MS, MS/MS and UV as a previously unreported tubing extractable, o-phenylphenol (o-PP). Several studies were conducted to assess the impact of formulation and process-related variables on the amount of the o-PP extracted, including contact time, sulfobutylether cyclodextrin concentration, formulation pH, and tubing sterilization and storage conditions. Results show that the concentration of the SBECD, tubing processing and storage conditions and the duration of the study influenced the levels of o-PP extracted. However, the largest contributor to the amount extracted was the lot of tubing tested. The extracted levels varied widely from lot to lot (0.007–3.89 μg/cm2 of tubing surface area). A dynamic study conducted to simulate a manufacturing process also resulted in the extraction of o-PP by the formulation.

A rigid-type of polyethylene T-cannula was fitted into the anterior ileum of six horses in order to improve the cannulation techniques. A piece of polyethylene net was fastened onto the intestinal wall around the cannula to prevent dislodgment of the cannula by promoting a secure adhesion between the ileum and the abdominal wall. The cannula barrel sheathed with silicone tubing was exteriorized through a stab incision at the lateral ventral wall on the transverse line of the second lumber vertebra, and a flange was screwed onto the barrel. The feeding regime gradually increased concentrate without roughage prevented any colic signs. The use of these techniques succeeded in the ileal cannulation with no leakage of digesta.

A comprehensive series of 16 laboratory experiments demonstrated that the presence of vinyl tubing within a recirculating pipe system was responsible for lowering zebra mussel kill following treatment with the bacterium Pseudomonas fluorescens. All vinyl tubing was replaced in all testing units with silicone tubing, and high mussel kill (>95%) was then obtained.

The authors describe the usefulness of split silicone tubing to protect the cranial nerves and arteries during microneurosurgery. The inner diameter of the tube varied from 1.0 to 3.3 mm with a thickness of 0.125 mm. Application of the tube protects the nerves and arteries from mechanical trauma, electrical injury, and dryness.

Chromium-sensitized and thulium- and holmiumdoped YAG lasers (THC:YAG laser) were used to create a nasal bony ostium in the area of the lacrimal sac fossa in four fresh frozen bisected human cadaver heads. The lasers - long pulsed (300 milliseconds), compact, self-contained, and solid state - operate in the near infrared (2.1 urn). The opening was created by passing the 320-micrometer laser fiber across the canalicular system. Pulse energies of 250 to 900 mJ were used with a repetition rate of 5 to 15 pulses per second. Energy levels ranging from 1.25 to 9 W produced a full-thickness bony ostium approximately 3 to 4 mm in diameter. Silicone tubing was then threaded through the superior and inferior canaliculus system in the standard fashion. This technique may simplify conventional dacryocystorhinostomy as well as endonasal laser dacryocystorhinostomy procedures.

Silicone tubing of the lacrimal pathway is used after lacrimal pathway injuries or canalicular stenosis. This procedure is often complicated by the so-called accordeon phenomenon. Far the last 3 years we have used a new system for lacrimal intubation: the Ritleng intubation set. It consists of a silcone tube which is connected to a polypropylene tube and a specially designed stainless probe for lacrimal insertion. Due to the smooth connection of the polypropylene tube and the silicone tube intubation can be performed easily and without the so-called accordeon phenomenon. In case of congenital or acquired lacrimal stenosis probing and silicone intubation can be performed in one step. We used this set in 19 lacrimal lacerations of the lacrimal pathway and in 7 cases of congenital and 12 cases of acquired lacrimal stenosis. With this specially designed lacrimal intubation set lacerated canaliculi can be quickly reapproximated. It allows probing of the lacrimal system and intubation in one procedure. In this report the technique and indications will be described and discussed.

A silicone tube segment was used for repairing the median and ulnar nerves in the forearm. This study includes 26 patients (20 male and six female), with a mean age of 23 years (range, 18-26). Injuries were caused by saw, knife and glass accidents, the latter being most frequent. The mean interval between the injury and repair was 101 days. Fourteen patients had median nerve injuries, eight had ulnar nerve injuries and four had both median and ulnar nerve injuries. The technique was effective in the repair of peripheral nerve injuries with gaps of up to 3 cm, with better results in the ulnar nerves than in the median nerves.

Objective: The aim of this study is to present our endoscopic DCR operation method without the use of silicone tubing and our results on the patients suffering from chronic epiphora with postsaccal stenosis. Methods: Endoscopic dacryocystorhinostomy operations were performed to 21 sides of 18 patients who had chronic epiphora. No silicone tubing was used in any of the cases. In the postoperative healing period, the rhinostomy opening was maintained with frequent removal of nasal debris and using eyedrops. The patients were evaluated by fluoresceine test and endoscopic controls. Results: Symptomatic improvement was achieved in 19 out of 21 sides of the patients (90.5%) and the results were confirmed by the fluoresceine test under endoscopic control. Conclusion: Our results of 21 sides of 18 cases underwent primary DCR without stents are as successful as those reported in the literature and the technique seems to be promising.

Purpose: To report a method of identifying the lower end of the nasolacrimal duct when more usual methods have failed. Methods: A vitreoretinal fibre-optic light pipe was used to identify the lower end of the nasolacrimal duct in a child with unusual congenital nasolacrimal duct obstruction. Results: This intraluminal light source enabled easy cut down onto the ‘blind’ end of the lacrimal drainage apparatus and subsequent intubation with silicone tubing to overcome the obstruction. Conclusion: This technique may prove useful in the rare cases in which it is not possible to identify the lower end of the nasolacrimal duct with a probe and nasal endoscope alone.

Twenty-eight patients (34 eyes) with congenital nasolacrimal duct obstruction underwent silicone intubation with the Ritleng lacrimal intubation system. The technique involves introduction of a Prolene (Ethicon Inc, Somerville, NJ) monofilament guide thread, securely fastened to the silicone tubing, into a tubular metal probe that opens into the inferior meatus. The outcome was evaluated in terms of ease of intubation and objective success rate. Thirty-two (94%) of the 34 lacrimal systems were successfully intubated with the Ritleng system. Difficulty passing the Prolene thread through the probe and out the tip, necessitating conversion to a Crawford intubation system, was encountered in only 2 eyes (6%). The Prolene spontaneously emerged from the nose in 24 (75%) of 32 eyes, making retrieval simple and uncomplicated. The success rate for relieving signs and symptoms of obstruction was 97% (31/32) for the eyes with the Ritleng system and 100% (2/2) for the eyes with the Crawford system. Bicanalicular silicone intubation with the Ritleng intubation system is an easy and effective technique for treatment of congenital nasolacrimal duct obstruction.

Migration of particulate matter from plastic tubing and solid plastic implants has been documented in a number of studies, including some with the use of cardiac bypass, haemodialysis, and pump-assisted intravenous infusions. In order to ascertain whether silicone embolisation occurs when children have an Ivac 560 pump-assisted IV infusion, we passed 180 ml of pumped fluid through a microfilter and compared the scanning electron micrographs of those filters with unused filters and with others through which a similar volume had been passed without using the pump. The particles on the filters were analysed for their elemental content using energy-dispersive X-ray analysis. In addition, the appearance of the silicone tubing used in the pump over 3 and 72 h was assessed and compared to that of flow-only and unused tubing. More particles were found on the microfilter when fluid had been delivered via the pump than on those through which non-pumped fluid had passed or that were unused. Elemental silicon-containing particles were only found on the filter when a pump had been attached to the IV line. The flow-only and unused tubing were found to have adherent particles on the inner surface that were not seen once the tubing had been used for 3 h in the Ivac 560 pump. Also, after 72 h use, the silicone tubing had a deformed inner layer. The clinical significance of these findings is yet to be determined, but it does appear that silicone embolisation occurs during pump-assisted infusions in children.

We have evaluated in vitro, the security of laparoscopically applied clips, through two commercially available clip appliers: the Endo Clip II (US Surgical) and the Ligaclip (Ethicon). The clip performance was tested with respect to dislodgment and leakage. Dislodgment was attempted both transversely and at 45 degrees with respect to the main axis of the tubular structures tested. The mean maximum force (N = 24) necessary to dislodge a clip applied to silicone tubing (2.1, 2.4, 3.2 mm o.d.) and porcine vascular tissue was measured. The maximum force needed to transversely dislodge a clip applied to silicone tubing, ranged from 262 +/- 9 g (2.1 mm) to 315 +/- 11 g (3.2 mm) for the Endo Clip II applier, while the values for the Ligaclip were 220 +/- 28 g (2.1 mm) and 273 +/- 11 g (3.2 mm), respectively. To achieve dislodgment at 45 degrees pull, corresponding forces of 294 +/- 8 g (2.1 mm) and 369 +/- 14 g (3.2 mm) for the Endo Clip II, and 254 +/- 14 g (2.1 mm) and 297 +/- 13 g (3.2 mm) for the Ligaclip (N = 24) were required. Transverse dislodgment forces, for clips applied to tissue, were 556 +/- 146 g for the Endo Clip II and 356 +/- 170 for the Ligaclip (N = 6). Leakage tests were also performed under pulsatile blood circulation at mean pressure of approximately 800 mm Hg. No tested clips applied to either silicone tubing or tissue allowed for any blood leakage. The dislodgment test showed that the Endo Clip II exhibits superior performance compared to the Ligaclip, based on the fact that it requires more force for transverse and semiaxial dislodgment. In the leakage test, both clip appliers performed equivalently.