32G Needle Research Articles

The interaction between water droplets and superhydrophobic holes: Detachment and penetration

Water droplets of varying volumes exhibit distinct behaviors at the tip of a needle under the influence of gravitational force: larger droplets fall from the needle tip, while smaller droplets adhere to the needle tip. By integrating a superhydrophobic hole, which allows the needle to pass through but hinders droplets' passage, a method to allow smaller droplets to fall from the needle was evaluated. The interaction between water droplets and a superhydrophobic hole was studied experimentally, and two phenomena were observed: either the droplet detached from the needle tip or the needle pulled it through the superhydrophobic hole. A critical detachment volume Vcrid0,D, dependent on the needle diameter d0 and the superhydrophobic hole diameter D, determines droplet behavior. When the volume of the droplet Vdroplet>Vcrid0,D, the droplet detaches from the needle tip. When the Vdroplet<Vcrid0,D, the droplet penetrates through the superhydrophobic hole. The results show that the critical detachment volume Vcrid0,D increases with an increase in d0 for a given superhydrophobic hole and with an increase in D for a given needle. To enable a 0.25 μl droplet to fall from a 32G needle, a superhydrophobic hole of 0.48 mm diameter was employed. Furthermore, a mechanical model based on force equilibrium was developed to describe the interaction between water droplets and a superhydrophobic hole.

Injectable Hyaluronan-Based Thermoresponsive Hydrogels for Dermatological Applications.

Most marketed HA-based dermal fillers use chemical cross-linking to improve mechanical properties and extend their lifetime in vivo; however, stiffer products with higher elasticity require an increased extrusion force for injection in clinical practice. To balance longevity and injectability, we propose a thermosensitive dermal filler, injectable as a low viscosity fluid that undergoes gelation in situ upon injection. To this end, HA was conjugated via a linker to poly(N-isopropylacrylamide) (pNIPAM), a thermosensitive polymer using "green chemistry", with water as the solvent. HA-L-pNIPAM hydrogels showed a comparatively low viscosity (G' was 105.1 and 233 for Candidate1 and Belotero Volume®, respectively) at room temperature and spontaneously formed a stiffer gel with submicron structure at body temperature. Hydrogel formulations exhibited superior resistance against enzymatic and oxidative degradation and could be administered using a comparatively lower injection force (49 N and >100 N for Candidate 1 and Belotero Volume®, respectively) with a 32G needle. Formulations were biocompatible (viability of L929 mouse fibroblasts was >100% and ~85% for HA-L-pNIPAM hydrogel aqueous extract and their degradation product, respectively), and offered an extended residence time (up to 72 h) at the injection site. This property could potentially be exploited to develop sustained release drug delivery systems for the management of dermatologic and systemic disorders.

The Current Art Combination of Platelet-Rich Plasma and Poly-D,L-Lactic Acid For Improvement of Deep Nasolabial Folds: A Case Report

Background: Platelet-rich plasma (PRP) is blood plasma containing an above baseline level of platelets and growth factors. Recently, Platelet-rich plasma (PRP) has come to the attention of aesthetic surgeons, with burgeoning new applications ranging from hair restoration to soft tissue augmentation. Injectable Poly-D,L-Lactic Acid (PDLLA) is a biostimulator rather than a traditional filler, which provides immediate volumetric improvement. Injectable PLA can produce a result comparable with Hyaluronic Acid fillers for the correction of wrinkles such as nasolabial folds, and can be a good choice for such a treatment. Methods: A Female 45 years Old with deep smile lines and fine wrinkles on cheeks. The patient was treated with injected of Poly(D,L Lactic Acid) and Platelet Rich Plasma. Poly-D,L-Lactic Acid was injected subdermal with retrograde linear thread technique and used 24-G cannula needle. After 3 weeks PDLLA Injection, PRP was injected intradermal into the whole face especially along the smile lines using a 32-G Needle at a dose of 0.05 ml at each injection site with a distance of about 0.5-1.0 cm. PRP was injected every 2 weeks for 3 months. Results: Wrinkle Severity Rating Scale was downgrading and skin quality like skin tone looks more brightening and fading hyperpigmentation. Conclusion: The combination of Poly-D,L-Lactic Acid and Platelet-Rich Plasma is effective for facial rejuvenation.

Development of a Unique Mouse Intervertebral Disc Degeneration Model Using a Simple Novel Tool.

Study DesignAnimal case control study.PurposeTo create a simple, reproducible disc degeneration model for mouse coccygeal vertebrae.Overview of LiteratureBack pain due to disc degeneration is probably the most common problem encountered in neurosurgical practice. An easily reproducible animal model for disc degeneration will help in understanding its pathophysiology, and serve as a platform for examining various therapeutic options.MethodsA total of 18 mice were divided into injured (n=12) and non-injured (n=6) groups. The disc height index (DHI%) at coccygeal 4–5 level was measured by computed tomography (CT) scan for all mice. Coccygeal 4–5 discs of the injury group were injured using a 32G needle fixed to a novel tool and confirmed by CT. The non-injury group underwent no procedure. DHI% was measured by CT at 2-, 4-, and 6-week post-injury, and all mice tails were sectioned for histopathology grading of disc degeneration at the respective time intervals.ResultsThe injured group showed significant variation in DHI% at 2, 4, and 6 weeks, whereas there was no change in the non-injured group. Histopathologic evaluation with Safranin O stain showed a worsening of the disc degeneration score at 2, 4, and 6 weeks in the injured group, but in the non-injured group there was no change. Percutaneous needle injury technique with our novel tool provided 100% accuracy and uniform degeneration.ConclusionsA simple, easily reproducible mouse model for disc degeneration was created using a simple, cost-effective, novel tool and technique, its advantage being high precision and user friendly.

Efficacy, safety and acceptability of the new pen needle 34G × 3.5 mm: a crossover randomized non-inferiority trial; AGO 02 study

Objective: Insulin injection aspects, such as fear of injection and pain, directly affect glycemic control, patient adherence and quality of life. Use of thinner and shorter needles could increase acceptance of injections. The aim of the study is to evaluate the non-inferiority of the new 34G × 3.5 mm needle compared to a 32G × 4 mm in patients with diabetes treated with insulin.Methods: This is an open, randomized, two-period crossover, non-inferiority trial. Every treatment period lasted 3 weeks. Patients with type 1 or type 2 diabetes, treated with multiple daily insulin injections, were randomly assigned to receive a 34G × 3.5 mm or a 32G × 4 mm pen needle. The primary endpoint was the non-inferiority of the 34G × 3.5 mm in comparison with the 32G × 4 mm pen needle in terms of percentage absolute change of blood fructosamine (% |ΔFru|), using a non-inferiority margin of 20%.Results: Overall 77 patients were randomized and 73 completed the study. Patients characteristics were: 52% male, 80.5% affected by type 1 diabetes, mean age 52 years (±14.6), mean BMI 24.5 kg/m2 (±5.6), HbA1c 8% (±1.1) and baseline fructosamine level 350 µmol/l (±84). Mean fructosamine levels increased by 0.56 µmol/l with the 34G needle, while a reduction of 7.29 μmol/l was documented with the 32G needle. The difference between the two groups (7.84 μmol/l) was not statistically significant (p = .27). The % |ΔFru| between the two groups was 7.55% (95% CI 5.67–9.44), meeting the non-inferiority criterion. Glycemic variability, expressed as standard deviation of fasting blood glucose and post-prandial glucose, was not different between the two treatment groups (p = .63 and p = .77, respectively).Conclusions: The 34G × 3.5 mm needle was non-inferior to the 32G × 4 mm needle regarding fructosamine levels and glycemic variability supporting the suitability of the 34G × 3.5 mm needle for insulin injection in patients with diabetes.Clinical trial registration: NCT02690467

EXPERIMENTAL VISUALIZATION AND QUANTIFICATION OF VITREOUS CONTAMINATION FOLLOWING INTRAVITREAL INJECTIONS

To detect and quantify vitreous contamination after intravitreal injection using an experimental vitreous contamination model. Enucleated porcine eyes served as a Type 1 experimental vitreous contamination model with fluoresbrite carboxylate microspheres applied to the conjunctival surface. Saline solution (0.05 mL) was injected using a 27-, 30-, or 32-gauge (G) needle. Injection procedures were monitored using an intraocular fiber catheter. Condensed microspheres were applied to an excised sheet of porcine sclera (Type 2 experimental vitreous contamination model). Saline solution (0.05 mL) was injected from the top of an applied condensed microsphere through the sclera using a needle of one of the aforementioned gauges, and samples were then collected. The fluorescence strength of samples was measured using fluorophotometry. We visually detected fluorescent microspheres in 10/10, 9/10, and 9/10 eyes injected with 27-G, 30-G, and 32-G needles, respectively. In the experimental quantification study, values at all needle gauges were significantly higher than those of controls (P < 0.01). Fluorescence strength was significantly higher in the 27-G group than in the 30- (P < 0.01) and 32-G (P < 0.01) groups. Intravitreal injection carries the risk of introducing contamination directly into the eyes even when a 32-G needle is used. Furthermore, the 27-G needle carries the highest contamination risk.

Injection Technique and Pen Needle Design Affect Leakage From Skin After Subcutaneous Injections.

After a subcutaneous injection fluid might leak out of the skin, commonly referred to as leakage or backflow. The objective was to examine the influence of needle design and injection technique on leakage after injections in the subcutaneous tissue of humans and pigs. Leakage data were obtained from a post hoc analysis of clinical trial data and from a pig study. Data from the clinical study were used to determine leakage as a function of injection volume, speed and region. Data from the pig study were used to determine leakage as a function of needle wall thickness, needle taper, injection angle, and wait time from end of injection to withdrawal of needle from skin. Leakage volume was positively related to injection volume. Injections in the abdomen caused less leakage than thigh injections. A 32G needle caused less leakage than a 31G and a 32G tip (tapered) needle, and a "straight in" 90° needle insertion angle caused less leakage than an angled (~45°) insertion. Wait times of minimum 3 seconds caused less leakage than immediate withdrawal of the needle after injection. Needle wall thickness and injection speed did not influence leakage. Leakage will be minimized using a thin needle, using 90° needle insertion in the abdomen, injecting maximum 800 µL at a time, and waiting at least 3 seconds after the injection until the needle is withdrawn from the skin.

Microbotox of the Lower Face and Neck: Evolution of a Personal Technique and Its Clinical Effects.

Microbotox is the injection of multiple microdroplets of diluted onabotulinumtoxinA into the dermis or the interface between the dermis and the superficial layer of facial muscles. The intention is to decrease sweat and sebaceous gland activity to improve skin texture and sheen and to target the superficial layer of muscles that find attachment to the undersurface of the dermis causing visible rhytides. For treatment of the lower face and neck, hundreds of microdroplets of diluted Botox are injected into the dermis or immediate subdermal plane to improve skin texture, smoothen horizontal creases, and decrease vertical banding of the neck, as well as to achieve better apposition of the platysma to the jawline and neck, improving contouring of the cervicomental angle. The Microbotox solution is mixed in the syringe by adding a small volume of lidocaine to the calculated dose of onabotulinumtoxinA drawn from a standard bottle of Botox prepared with 2.5 mL saline. Each 1 mL syringe of Microbotox solution contains 20-28 units of onabotulinumtoxinA per mL of solution and is used to deliver 100-120 injections. The lower face and neck will usually require 1 mL per side. The injections are delivered intradermally using a 30- or 32-G needle raising a tiny blanched weal at each point. The author has over 1867 documented cases of Microbotox in various parts of the face (forehead, glabellar, crow's-feet, infraorbital, and cheeks) and neck, the majority of these patients being treated in forehead or the lower face and neck as described in this article.

A modified bilateral carotid artery stenosis procedure to develop a chronic cerebral hypoperfusion rat model with an increased survival rate

BackgroundBilateral carotid artery occlusion (2-vessel occlusion, 2VO) in rats is a classic and frequently used approach to develop an animal model of chronic cerebral hypoperfusion. However, this method results in substantial mortality in rats. New methodWe investigated whether a modified 2VO procedure, which induces bilateral carotid artery stenosis via ligation of each bilateral common carotid artery (CCA) with a 32 gauge (G) needle followed by needle removal, could produce a chronic cerebral hypoperfusion rat model with an increased survival rate. Sprague-Dawley (SD) rats were treated with the standard or modified 2VO procedure, and changes in cerebral blood flow (CBF) and survival rates were determined. On day 28, cognitive function was assessed with the Morris Water Maze (MWM) test, and neuronal survival and degeneration within the hippocampal CA1 area were measured. Damage to the white matter (WM) within the corpus striatum was assessed via Luxol fast blue (LFB) staining and analyses analyzing the levels of the myelin basic protein (MBP) protein levels. ResultsThe modified 2VO procedure induced similar cognitive impairments, hippocampal lesions and WM damage compared with the standard 2VO procedure in rats; however, it had an increased survival rate.Comparison with existing methods This novel method can be used to quickly and effectively establish a chronic cerebral hypoperfusion rat model with common materials and an improved survival rate. ConclusionBilateral carotid artery stenosis using a 32G needle is a useful and reliable method to develop a rat model of chronic cerebral hypoperfusion with increased survival.

Efficacy, safety and acceptability of the new pen needle 33G × 4 mm. AGO 01 study

Objectives:Adherence to insulin therapy can be threatened by pain and needle fear. This cross-over randomized non-inferiority trial evaluated a new Pic Insupen 33G × 4 mm needle vs. a 32G × 4 mm needle in terms of metabolic control, safety and acceptability in patients with diabetes treated with insulin.Research design and methods:We used a centralized, permuted block randomization, stratified by center and maximum insulin dose per single injection. Subjects used the two needles in two 3 week treatment periods. The primary endpoint was the absolute percentage variation of the blood fructosamine between the two treatments (% |ΔFru|). Additional endpoints were: glycemic variability, total insulin doses, body weight, severe hypoglycemic episodes, leakage at injection sites and pain measured by visual analogue scale. Equivalent glycemic control was defined a priori as % |ΔFru| (including 95% CI) within 20%.Results:Of 87 subjects randomized, 77 completed the study (median age 53.1 [IR 42.3–61.2], median BMI 24.3 Kg/m2 [IR 21.3–28.5], median duration of insulin therapy [in months] 141.4 (IR 56.3–256.9), median baseline HbA1c 7.9% [IR 7.2–8.8]). The % |ΔFru| was 7.93% (95% CI 6.23–9.63), meeting the non-inferiority criterion. The fasting blood glucose standard deviation was 46.2 (mean 154.6) with the 33G needle and 42.8 (mean 157.3) with the 32G needle (p = 0.42). Insulin daily dose and patients’ weight did not show any statistically significant variation. We observed 95 episodes of symptomatic hypoglycemia with the 33G needle and 96 with the 32G needle. One episode of severe hypoglycemia was documented in the latter group. As for insulin leakage we observed 37.55 episodes per 100 patient-days with the 33G needle and 32.21 episodes per 100 patient-days with the 32G needle (p = 0.31). Patients reported less pain with the 33G × 4 mm needle (p = 0.05).Study limitations:Study sample was mainly composed of adults with type 1 diabetes and study was not blinded.Conclusions:The 33G needle is not inferior to the 32G needle in terms of efficacy and safety, with reduced pain and no difference in insulin leakage.Clinical trial registration:NCT01745549.

Regression of melasma with platelet-rich plasma treatment.

Dear Editor: Platelet-rich plasma (PRP) treatment is performed via the autologous injection of high concentration of platelets in a small volume of plasma1. A 27-year-old woman presented at our dermato-cosmetology department for skin rejuvenation, as she had epidermal hyperpigmentation over the cheeks, perioral region, and forehead for about 5 years. PRP treatment was initiated and her face was injected with autologous PRP prepared by using RegenKit® (Regen Lab., Le Montsur-Lausanne, Switzerland). Before the treatment sessions, 8 ml of blood was collected from the patient into a special tube containing a separation gel and an anticoagulant. The tube was then centrifuged for 8 minutes at 3,500 rpm, and PRP was obtained from the upper part of the buffy coat. A 32-G needle was used for superficial microinjections via the mesotherapy technique, and the injections were administered in to the papillary dermis (1.5~2.0 mm deep). Approximately 1.5 ml of PRP was injected in to the dermis of the face at each session with 15-day intervals. At the end of the third session of PRP treatment, >80% reduction in epidermal hyperpigmentation was observed (Fig. 1, ​,2).2). We did not provide any other treatment or post treatment care besides prescribing the use of a sun-screen product. There has been no recurrence of melasma for 6 months now. Fig. 1 Hyperpigmentation over the cheeks, perioral region, and forehead. Fig. 2 Significant regression in epidermal hyperpigmentation. PRP is commonly used in dermatology and plastic surgery, especially for treating chronic wounds, ulcers, and burns. In recent years, PRP has also started to be used in the field of cosmetology1. Volumetric filling, skin rejuvenation, acne scars, and alopecia are the main targets of PRP application in cosmetology1. The most important contents of platelets are contained in the α-granules. There are >30 bioactive substances in these granules2. Some of the bioactive substances present in the α-granules include platelet-derived growth factor (PDGF), transforming growth factor (TGF)-β1, 2, epidermal growth factor, and mitogenic growth factors such as platelet-derived angiogenesis factor and fibrinogen3. To our knowledge, only TGF-β1 has been investigated about its relation with melanogenesis. Kim et al.4 investigated the effects of TGF-β1 on melanogenesis by using a spontaneously immortalized mouse melanocyte cell line, and asserted that TGF-β1 significantly inhibits melanin synthesis in a concentration-dependent manner. They declared that TGF-β1 decreases melanogenesis via delayed extracellular signal-regulated kinase activation. The pigmentary improvement that occurs with PRP treatment may be associated with the increase in skin volume. PDGF has a significant role in blood vessel formation and in the synthesis of collagen and components of the extracellular matrix, including hyaluronic acid. Hyaluronic acid has been shown to increase skin tone and volume, resulting in providing a more 'glowing skin'5. Although, it is not possible to reach a definitive conclusion, we consider the regression of melasma after PRP treatment as an interesting finding. Controlled clinical trials are needed to confirm this preliminary observation.

Influence of hypodermic needle dimensions on subcutaneous injection delivery – a pig study of injection deposition evaluated by CT scanning, histology, and backflow

Thinner and shorter needles for subcutaneous administration are continuously developed. Previous studies have shown that a thinner needle causes fewer occurrences of painful needle insertions and that a shorter needle decreases the occurrence of painful intramuscular injections. However, little is known about local drug delivery in relation to needle length and thickness. This study aimed to compare deposition depth and backflow from three hypodermic needles of 3 mm 34G (0.19 mm), 5 mm 32G (0.23 mm), and 8 mm 30G (0.30 mm) in length and thickness. Ex vivo experiments were carried out on pigs, in neck tissue comparable to human skin at typical injection sites. Six pigs were included and a total of 72 randomized injections were given, i.e. 24 subcutaneous injections given with each needle type. Accordingly, 400 μL was injected including 70% NovoRapid(®) (Novo Nordisk A/S, Bagsvμrd, Denmark) and 30% Xenetix(®) (Guerbet, Villepinte, France) contrast including 1 mg/mL Alcian blue. Surgical biopsies of injection sites were sampled and computer topographic (CT)-scanned in 3D to assess deposition and local distribution. Biopsies were prepared and stained to evaluate deposition in comparison to the CT-scanning findings. The backflow of each injection was collected with filter paper. The blue stains of filter paper were digitized and volume estimated by software calculation vs. control staining. CT-scanning (n = 57) and histology (n = 10) showed that, regardless of injection depth, the bulk of the injection was in the subcutaneous tissue and did not propagate from subcutis into dermis. With the 8 mm 30G needle all injections apart from one intramuscular injection were located in the subcutaneous layer. The volume depositions peaked in 4-5 mm depth for the 3 mm 34G needle, in 5-6 mm depth for the 5 mm 32G needle, and in 9-10 mm depth for the 8 mm 30G needle. In general, injection depositions evaluated by histology and CT-scans compared well for the individual biopsies. The amount of backflow (n = 69) from the 3 mm 34G needle was smaller (P < 0.05) as compared to the 5 mm 32G and the 8 mm 30G needles. Analysis showed a correlation between backflow and the needle's outer dimension with the needle diameter being the pivotal parameter. Furthermore, CT-scanning and histology confirmed that local propagation of the injection and final distribution followed a route of less mechanical resistance as determined by connective tissue barriers preset in the site of injection. Needles as short as 3 mm efficiently delivered injections into the subcutaneous target. The amount of backflow was smaller with thinner needles. Local distribution was variable and determined by mechanical barriers preset in the tissue. CT-scans and histology were concordant.

Abstract A20: Development and pharmacological assessment of new models of orthotopic primary human uveal melanoma and retinoblastoma xenografts.

Abstract Background: The treatment of both uveal melanoma and retinoblastoma could require enucleation in unfavorable prognostic disease. In order to allow pharmacological assessment of innovative intraocular treatments in more relevant and predictive models, we have developed preclinical orthotopic xenografts of both primary human uveal melanoma (UM) and retinoblastoma (Rb) into immunodeficient mice. Materials and methods: Orthotopic models of human UM and Rb have been developed from two panels of subcutaneous xenografts previously established and characterized in the laboratory (Némati et al 2010; Aerts et al 2010), i.e. 6 UM models (MP34, MP41, MP42, MP55, MP65, and MM26) and 3 Rb models (RB102, RB111, and RB200). Mice bearing xenografts were sacrificed and tumors were dissected to obtain a suspension of fresh tumor cells at a concentration of 8000 cells/l in DMEM serum-free medium. Under intraperitoneal anesthesia, 2 l of cell suspension was injected into the subretinal space of the right eye for 3 groups of mice using a 32G needle via a Hamilton syringe. Each group was constituted by 3 to 6 SCID mice. After sub-retinal injection, ophthalmic examination of the mice was performed weekly. When tumor cells invaded vitreal cavity and anterior chamber, the mice were sacrificed for ophthalmological pathological analyzes. Finally, using the RB200 model, we have then evaluated the efficacy of 2 μl intraocular administration of bevacizumab (25 mg/kg/week for 4 weeks), melphalan (500 μg/kg/week for 4 weeks), and carboplatin (100 μg/kg/week for 4 weeks). Results: The 6 UM cells developed in all injected eyes, 6 to 10 weeks after orthotopic transplantation. Pathological analyzes confirmed UM diagnosis and conservation of histological sub-type, i.e. epithelioid and/or spindle cell, than in corresponding patient's tumors and subcutaneous xenografts. Liver tissues examination is on-going. Rb tumor cells developed in all injected eyes 4 to 6 weeks after orthotopic transplantation for RB102 and RB200. In contrast, no tumor growth was observed in injected eyes of the RB111 model. Pathological examination of the injected eyes confirmed the presence of a massive infiltration of the retina, vitreous and anterior chamber by retinoblastoma cells. Finally, we have observed a high efficacy of intraocular administration of carboplatin (17% of intraocular tumors), but not bevacizumab (100%) nor melphalan (67%), in the RB200 model than in the control group. Conclusions: We have developed relevant and available preclinical models of human UM and Rb that allow pharmacological assessment of intraocular standard therapies. We will now evaluate innovative therapeutic approaches in such a tumor situation. Némati et al. Clin Cancer Res 2010;16:2352–2362. Aerts et al. Photodiagnosis Photodyn Ther 2010;7:275–283. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A20.

Development of new models of orthotopic primary human retinoblastoma xenografts

AbstractPurpose To develop preclinical orthotopic models of primary human retinoblastomaMethods Orthotopic models of human retinoblastoma have been developed from three subcutaneous xenografted models that have previously been established and characterized in our laboratory, i.e. RB102‐FER, RB111‐MIL, and RB200‐GS that have been maintained in nude mice. Mice bearing xenografts were sacrificed and tumors were dissected to obtain a suspension of fresh tumor cells at a concentration of 8000 cells/l in DMEM serum‐free medium. Under intraperitoneal anesthesia, 2l of cell suspension was injected into the subretinal space of the right eye for 3 groups of mice using a 32G needle via a Hamilton syringe. Each group was constituted by 2 female SQUID mice and 3 male nude mice. After subretinal injection, ophthalmic examination of the mice was done every 15 days with binocular microscope. When tumor cells invaded vitreal cavity and anterior chamber, the mice were sacrificed for ophthalomological pathological analyses.Results Tumor cells developed in all injected eyes, whatever the mouse categories used, 4 weeks after orthotopic transplantation for RB102‐FER and 6 weeks after for RB200‐GS. In contrast, no tumor growth was observed in injected eyes of the RB111‐MIL model. In the 2 first xenografts, the proliferation started with a white hemorrhagic retinal mass; three weeks later, the vitreous was invaded by tumor cells that extended to the anterior chamber. Pathological examination of the injected eyes confirmed the presence of a massive infiltration of the retina, vitreous and anterior chamber by retinoblastoma cells.Conclusion We have then developed two new models of orthotopic primary human retinoblastoma that well reproduce the patient’s tumors.

P.1.g.027 Correlation among neurocognitive performance, social cognition and functionality in euthymic bipolar patients

Bilateral carotid artery occlusion (2-vessel occlusion, 2VO) in rats is a classic and frequently used approach to develop an animal model of chronic cerebral hypoperfusion. However, this method results in substantial mortality in rats.We investigated whether a modified 2VO procedure, which induces bilateral carotid artery stenosis via ligation of each bilateral common carotid artery (CCA) with a 32 gauge (G) needle followed by needle removal, could produce a chronic cerebral hypoperfusion rat model with an increased survival rate. Sprague-Dawley (SD) rats were treated with the standard or modified 2VO procedure, and changes in cerebral blood flow (CBF) and survival rates were determined. On day 28, cognitive function was assessed with the Morris Water Maze (MWM) test, and neuronal survival and degeneration within the hippocampal CA1 area were measured. Damage to the white matter (WM) within the corpus striatum was assessed via Luxol fast blue (LFB) staining and analyses analyzing the levels of the myelin basic protein (MBP) protein levels.The modified 2VO procedure induced similar cognitive impairments, hippocampal lesions and WM damage compared with the standard 2VO procedure in rats; however, it had an increased survival rate.Comparison with existing methods This novel method can be used to quickly and effectively establish a chronic cerebral hypoperfusion rat model with common materials and an improved survival rate.Bilateral carotid artery stenosis using a 32G needle is a useful and reliable method to develop a rat model of chronic cerebral hypoperfusion with increased survival.

Pain following controlled cutaneous insertion of needles with different diameters

Background and aim. Needle injections are used daily by millions of people around the world for the administration of various drugs (e.g., insulin), venepuncture, and some neurophysiological procedures. The aim of this paper was to study the influence of the outer needle diameter on the pain evoked by controlled needle insertion.Methods. An automated needle injection system was used to perform a series of insertions where velocity, angle of insertion, and depth of injection were controlled. The frequency of pain following needle insertions (23G, 27G, 30G, 32G) was recorded together with the pain intensity (measured using the visual analogue scale—VAS) and the occurrence of bleeding.Results. The outer needle diameter was positively and significantly correlated to the frequency of the insertion pain; for example, 63% of insertions with 23G needles caused pain, 53% of insertions with 27G and 31% of insertions with the thinnest (32G) needle (p < 0.0001) caused pain. The thickest needle caused most insertions ...

Pain following controlled cutaneous insertion of needles with different diameters

Background and aim. Needle injections are used daily by millions of people around the world for the administration of various drugs (e.g., insulin), venepuncture, and some neurophysiological procedures. The aim of this paper was to study the influence of the outer needle diameter on the pain evoked by controlled needle insertion.Methods. An automated needle injection system was used to perform a series of insertions where velocity, angle of insertion, and depth of injection were controlled. The frequency of pain following needle insertions (23G, 27G, 30G, 32G) was recorded together with the pain intensity (measured using the visual analogue scale—VAS) and the occurrence of bleeding.Results. The outer needle diameter was positively and significantly correlated to the frequency of the insertion pain; for example, 63% of insertions with 23G needles caused pain, 53% of insertions with 27G and 31% of insertions with the thinnest (32G) needle (p < 0.0001) caused pain. The thickest needle caused most insertions associated with bleeding. Bleeding insertions were approximately 1.3 times more painful (as indicated by VAS scores) than insertions without concomitant bleedings (p = 0.004).Conclusion. By decreasing the outer diameter of a needle, the frequency of insertion pain can be reduced and may encourage patients to adhere to demanding injection regimens such as recurrent insulin administration.