Science.gov

Sample records for intravitreal injection analysis

  1. Antibioprophylaxis in Prevention of Endophthalmitis in Intravitreal Injection: A Systematic Review and Meta-Analysis.

    PubMed

    Benoist d'Azy, Cédric; Pereira, Bruno; Naughton, Geraldine; Chiambaretta, Frédéric; Dutheil, Frédéric

    2016-01-01

    Despite endophthalmitis being the most feared complication, antibioprophylaxis remains controversial in intravitreal injections. Therefore, we conducted a systematic review and meta-analysis on the effects of antibioprophylaxis in intravitreal injections in the prevention of endophthalmitis. The PubMed, Cochrane Library, Embase and Science Direct databases were searched for studies comparing groups with and without antibiotics in intravitreal injection, with the use of the following keywords: "antibiotic*", "endophthalmitis" and "intravitreal injection*". To be included, studies needed to specify number of participants and number of endophthalmitis within each group (with and without antibiotics). We conducted meta-analysis on the prevalence of clinical endophthalmitis including both culture-proven and culture negative samples. Nine studies were included. A total of 88 incidences of endophthalmitis were reported from 174,159 injections (0.051% i.e., one incidence of endophthalmitis for 1979 injections). Specifically, 59 incidences of endophthalmitis were reported from 113,530 injections in the group with antibiotics (0.052% or one incidence of endophthalmitis for 1924 injections) and 29 incidences of endophthalmitis from 60,633 injections in the group without antibiotics (0.048% or one endophthalmitis for 2091 injections). Our meta-analysis did not report a significant difference in the prevalence of clinical endophthalimitis between the two groups with and without topical antibiotics: the odds ratio of clinical endophthalimitis was 0.804 (CI95% 0.384-1.682, p = 0.56) for the antibiotic group compared with the group without antibiotics. In conclusion, we performed the first large meta-analysis demonstrating that antibioprophylaxis is not required in intravitreal injections. Strict rules of asepsis remain the only evidence-based prophylaxis of endophthalmitis. The results support initiatives to reduce the global threat of resistance to antibiotics.

  2. Antibioprophylaxis in Prevention of Endophthalmitis in Intravitreal Injection: A Systematic Review and Meta-Analysis

    PubMed Central

    Benoist d’Azy, Cédric; Pereira, Bruno; Naughton, Geraldine; Chiambaretta, Frédéric; Dutheil, Frédéric

    2016-01-01

    Despite endophthalmitis being the most feared complication, antibioprophylaxis remains controversial in intravitreal injections. Therefore, we conducted a systematic review and meta-analysis on the effects of antibioprophylaxis in intravitreal injections in the prevention of endophthalmitis. The PubMed, Cochrane Library, Embase and Science Direct databases were searched for studies comparing groups with and without antibiotics in intravitreal injection, with the use of the following keywords: "antibiotic*", "endophthalmitis" and “intravitreal injection*”. To be included, studies needed to specify number of participants and number of endophthalmitis within each group (with and without antibiotics). We conducted meta-analysis on the prevalence of clinical endophthalmitis including both culture-proven and culture negative samples. Nine studies were included. A total of 88 incidences of endophthalmitis were reported from 174,159 injections (0.051% i.e., one incidence of endophthalmitis for 1979 injections). Specifically, 59 incidences of endophthalmitis were reported from 113,530 injections in the group with antibiotics (0.052% or one incidence of endophthalmitis for 1924 injections) and 29 incidences of endophthalmitis from 60,633 injections in the group without antibiotics (0.048% or one endophthalmitis for 2091 injections). Our meta-analysis did not report a significant difference in the prevalence of clinical endophthalimitis between the two groups with and without topical antibiotics: the odds ratio of clinical endophthalimitis was 0.804 (CI95% 0.384–1.682, p = 0.56) for the antibiotic group compared with the group without antibiotics. In conclusion, we performed the first large meta-analysis demonstrating that antibioprophylaxis is not required in intravitreal injections. Strict rules of asepsis remain the only evidence-based prophylaxis of endophthalmitis. The results support initiatives to reduce the global threat of resistance to antibiotics. PMID

  3. Pharmacokinetic analysis of topotecan after intra-vitreal injection. Implications for retinoblastoma treatment.

    PubMed

    Buitrago, Emiliano; Höcht, Christian; Chantada, Guillermo; Fandiño, Adriana; Navo, Elliot; Abramson, David H; Schaiquevich, Paula; Bramuglia, Guillermo F

    2010-07-01

    Topotecan is a promising drug with activity against retinoblastoma, however, attaining therapeutic concentrations in the vitreous humor is still a challenge for the treatment of vitreous seeds in retinoblastoma. Our aim was to characterize topotecan pharmacokinetics in vitreous and aqueous humor, and to assess the systemic exposure after intra-vitreal injection in rabbits as an alternative route for maximizing local drug exposure. Anesthetized rabbits were administered intra-vitreal injections of 5 microg of topotecan. Vitreous, aqueous, and blood samples were collected at pre-defined time points. A validated high-performance liquid chromatography assay was used to quantitate topotecan (lactone and carboxylate) concentrations. Topotecan pharmacokinetic parameters were determined in vitreous, aqueous and plasma using a compartmental analysis. Topotecan lactone concentrations in the vitreous of the injected eye were about 8 ng/mL 48 h after drug administration. The median maximum vitreous, aqueous and plasma total topotecan concentrations (C(max)) were 5.3, 0.68 and 0.21 microg/mL, respectively. The C(max) vitreous/aqueous of treated eyes and the C(max) vitreous/plasma were approximately 8 and 254, respectively. Total topotecan exposure (AUC) in the vitreous of the injected eye was 50 times greater than the total systemic exposure. These findings suggest that intra-vitreal administration of only 5 microg of topotecan reaches significant local levels over an extended period of time while minimizing systemic exposure in the rabbit. Intra-vitreal topotecan administration offers a promising alternative route for enhanced drug exposure in the vitreous humor with potential application for treatment of vitreal seeds in retinoblastoma while avoiding systemic toxicities.

  4. Ocular toxicity after intravitreal injection of terconazole.

    PubMed

    Schulman, J A; Peyman, G A; Dietlein, J; Fiscella, R; Colantino, B

    1989-09-01

    Terconazole, a new triazole antifungal agent, was injected intravitreally in doses ranging from 10 to 100 micrograms dissolved in dimethyl sulfoxide (DMSO) 60% into the eyes of New Zealand rabbits. Three control eyes received only DMSO. The eyes were evaluated with biomicroscopy, indirect ophthalmoscopy, electroretinography, and histopathologic examination. From these data, it was determined that an intravitreal injection containing a concentration of 10 micrograms/0.1 mL of terconazole is not toxic to the rabbit eye.

  5. Assistive Device for Efficient Intravitreal Injections.

    PubMed

    Ullrich, Franziska; Michels, Stephan; Lehmann, Daniel; Pieters, Roel S; Becker, Matthias; Nelson, Bradley J

    2016-08-01

    Intravitreal therapy is the most common treatment for many chronic ophthalmic diseases, such as age-related macular degeneration. Due to the increasing worldwide demand for intravitreal injections, there exists a need to render this medical procedure more time- and cost-efficient while increasing patient safety. The authors propose a medical assistive device that injects medication intravitreally. Compared to the manual intravitreal injection procedure, an automated device has the potential to increase safety for patients, decrease procedure times, allow for integrated data storage and documentation, and reduce costs for medical staff and expensive operating rooms. This work demonstrates the development of an assistive injection system that is coarsely positioned over the patient's head by the human operator, followed by automatic fine positioning and intravitreal injection through the pars plana. Several safety features, such as continuous eye tracking and iris recognition, have been implemented. The functioning system is demonstrated through ex vivo experiments with porcine eyes. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:752-762.].

  6. Adverse skin reactions following intravitreal bevacizumab injection

    PubMed Central

    Ameen, S; Entabi, M; Lee, N; Stavrakoglou, A

    2011-01-01

    The authors describe two separate cases of skin eruption following intravitreal bevacizumab injection with evidence to suggest that these were adverse drug reactions to bevacizumab. The authors also discuss how each case was treated and report on the final outcome. PMID:22715260

  7. [Viral retinitis following intravitreal triamcinolone injection].

    PubMed

    Zghal, I; Malek, I; Amel, C; Soumaya, O; Bouguila, H; Nacef, L

    2013-09-01

    Necrotizing viral retinitis is associated with infection by the Herpes family of viruses, especially herpes simplex virus (HSV), varicella zoster virus (VZV) and occasionally cytomegalovirus (CMV). When the diagnosis is suspected clinically, antiviral therapy must be instituted immediately. We report the case of a patient presenting with necrotizing viral retinitis 3 months following intravitreal injection of triamcinolone acetonide for diabetic macular edema. Fluorescein angiography demonstrated a superior temporal occlusive vasculitis. A diagnostic anterior chamber paracentesis was performed to obtain deoxyribo-nucleic acid (DNA) for a polymerase chain reaction (PCR) test for viral retinitis. PCR was positive for CMV. The patient was placed on intravenous ganciclovir. CMV retinitis is exceedingly rare in immunocompetent patients; however, it remains the most common cause of posterior uveitis in immunocompromised patients. The incidence of this entity remains unknown. Local immunosuppression, the dose and the frequency of injections may explain the occurrence of this severe retinitis.

  8. Experience of intravitreal injections in a tertiary Hospital in Oman

    PubMed Central

    Al-Hinai, Ahmed S.

    2015-01-01

    Aim: To find out statistical data regarding intravitreal injections in an outpatient department setup at a tertiary center in Oman. Design: Retrospective chart review. Methods: Data collection of patients who underwent intravitreal injections from November 2009 to May 2013 at Sultan Qaboos University Hospital. Results: Throughout a period of 42 months, a total of 711 intravitreal injections were performed. That included 214 patients (275 eyes). Around one-third of the eyes received two injections or more. The injected agents were bevacizumab (59.8%), ranibizumab (32.3%), triamcinolone (7.5%), and very few patients with endophthalmitis received intravitreal antibiotics and antifungal agents. The three most common indications for the injection therapy were diabetic macular edema (50.9%), choroidal neovascularization (24.3%), and retinal vein occlusive diseases (11.5%). Serious adverse events were rare, and they occurred as ocular (0.9% per patient) and systemic (3.3% per patient). There were 42 eyes received intravitreal triamcinolone, and 24% of them developed intraocular hypertension that required only medical treatment. Conclusion: Different intravitreal agents are currently used to treat many ocular diseases. Currently, therapy with intravitreal agents is very popular, and it carries a promising outcome with more efficiency and safety. PMID:26903722

  9. Visual perceptions induced by intravitreous injections of therapeutic agents

    PubMed Central

    Charalampidou, S; Nolan, J; Ormonde, G O; Beatty, S

    2011-01-01

    Purpose The purpose of this study was to conduct a questionnaire-based survey of subjective visual perceptions induced by intravitreous (IVT) injections of therapeutic agents. Patients and methods Patients undergoing an IVT injection of ranibizumab, pegaptanib sodium, or triamcinolone acetonide were administered a questionnaire in the immediate post-injection period and at 2 weeks of follow-up. Results In the immediate post-injection period (75 IVT injections, 75 eyes, 75 patients), lights and floaters were reported after 20 (27%) and 24 (32%) IVT injections, respectively. In comparison, at the 2-week follow-up, the incidence of reported lights (11; 15%) was similar (P>0.05), but the incidence of reported floaters was higher (48; 64% P=0.00). Subgroup analysis for various injection subgroups (no previous injection vsprevious injection(s) in the study eye; injections in study eyes with good VA (logarithm of minimal angle of resolution [logMAR] ≤0.3) vsmoderate VA (0.7 0.3) vspoor VA (logMAR ≥0.7); injections according to pharmacological agent (ranibizumab vspegaptanib vstriamcinolone acetonide); injections in study eyes with choroidal neovascularization (of various causes) vsstudy eyes with macular edema (of various causes); and injections in phakic vspseudophakic eyes) did not reveal any statistically significant associations. Visual perceptions experienced following 15% of IVT injections gave cause for concern to the patient (mean visual analog scale score (±SD): 4.5 (±1.7)), and in 64% of cases, the patients believed that preoperative counseling would have averted the concern. Conclusions Lights and floaters are frequent visual perceptions following IVT injections of therapeutic agents. They can give rise to concern that could be alleviated with preinjection counseling. PMID:21274011

  10. Air entry into the anterior chamber post intravitreal injection of Eylea.

    PubMed

    Lim, Wei Sing; Sikandar, Munir; Jackson, Heather

    2016-07-20

    An 84-year-old man had air entry into the anterior chamber following intravitreal injection. The air bubble was reabsorbed over time without any complications. No further problems occurred with subsequent intravitreal injections.

  11. Tower microneedle minimizes vitreal reflux in intravitreal injection.

    PubMed

    Lee, Chang Yeol; You, Yong Sung; Lee, Sung Ho; Jung, Hyungil

    2013-10-01

    Intravitreal injection is widely used for easy control of drug levels in posterior segment of the eye by injecting the drug directly with hypodermic needles. Patients, however, often experience complications from intravitreal injection due to repeated injections, increased intraocular pressure, and infection. In addition, injected drug reflux after intravitreal injection makes it challenging to maintain predetermined drug dose due to the drug loss through backward effusions. Here, we described that the Tower Microneedle can reduce initial reflux and bleb formation due to its smaller outer diameter compared to a traditional hypodermic needle. Furthermore, we use phenylephrine hydrochloride for pupil expansion and demonstrated that Tower Microneedle induced similar pupil expansions using only half the drug volume, in the same period of time, compared to the 31 Gauge hypodermic needle. Consequently, Tower Microneedle achieves the same therapeutic effect in the vitreous body using fewer drugs than a traditional hypodermic needle due to the decreased backward drug effusion. Tower Microneedle described herein holds great promise for intravitreal injection with less reflux and lower drug dosage.

  12. Intravitreal injection of Bevacizumab in diabetic macular edema

    PubMed Central

    Ateeq, Asim; Tahir, Muhammad Ali; Cheema, Alyscia; Dahri, Arif; Tareen, Saifullah

    2014-01-01

    Objective: To assess the effectiveness of intravitreal injection of Bevacizumab in the treatment of diabetic macular edema. Methods: This case series was conducted at Department of Ophthalmology, Jinnah Post Graduate Medical Centre (JPMC), Karachi. The duration of study was six months from May 26, 2011 to November 25, 2011. The study group comprised of 54 patients of the Diabetic Macular Edema (DME). Intravitreal injection of 1.25 mg of bevacizumab (Avastin) was injected 3.5 mm from the limbus under topical anaesthetic drops. Post procedure follow up was scheduled on 1st post procedure day and after one month. Post procedure Optical Coherence tomography (OCT) was performed in all patients 1 week before and 1st month after 1st injection. The results were statistically analyzed through SPSS 17. Results: Out of the 54 Eyes of 54 Patients who were given the Intravitreal injection of Avastin (Bevacizumab), 43 Eyes (79.6%) showed more than ten percent decrease in macular thickness from pre-injection thickness, 10 Eyes (18.5%) showed less than ten percent decrease and 1 Eye (1.9%) showed increase in macular thickness post operatively after one month. Conclusions: Intravitreal injection of Bevacizumab (Avastin) is effective in the treatment of diabetic macular edema. PMID:25674143

  13. Intravitreal injections: a review of the evidence for best practice.

    PubMed

    Fagan, Xavier J; Al-Qureshi, Salmaan

    2013-07-01

    Intravitreal injection is a common procedure performed by ophthalmologists. It is a quick and targeted treatment for a number of ophthalmic conditions. Despite this, the potential to cause serious complications and patient discomfort cannot be ignored. This article presents the level of evidence in the scientific literature supporting common practices such as location of the procedure, anaesthetic choice, sterile procedure techniques, comparison of some common pharmaceutical agents and the use of antibiotics.

  14. Topical azithromycin or ofloxacin for endophthalmitis prophylaxis after intravitreal injection

    PubMed Central

    Romero-Aroca, Pedro; Sararols, Laura; Arias, Lluis; Casaroli-Marano, Ricardo P; Bassaganyas, Francisca

    2012-01-01

    Background The number of patients who have undergone intravitreal injections has increased enormously in recent years, but a consensus is still lacking on prophylaxis for endophthalmitis. The aim of this prospective, observational study was to evaluate the prophylactic effect of azithromycin eye drops versus ofloxacin eye drops. Methods The study was conducted in five hospitals in Spain and included all patients undergoing intravitreal injections of triamcinolone, bevacizumab, ranibizumab, or pegaptanib over one year. Patients received azithromycin 15 mg/g eye drops (twice daily on the day prior to injection and for another 2 days) or ofloxacin 3 mg/g eye drops (every 6 hours on the day prior to injection and for another 7 days). Results In the azithromycin group, there were 4045 injections in 972 eyes of 701 patients. In the ofloxacin group, there were 4151 injections in 944 eyes of 682 patients. There were two cases of endophthalmitis (0.049%) in the azithromycin group and five (0.12%) in the ofloxacin group. The odds ratio of presenting with endophthalmitis in the ofloxacin group compared with the azithromycin group was 2.37 (95% confidence interval [CI] 1.32–3.72, P < 0.001). There were two cases of noninfectious uveitis after triamcinolone injection in the azithromycin group (0.049%) and two (0.048%) in the ofloxacin group; no significant differences were observed (odds ratio 0.902, 95% CI 0.622–1.407, P = 0.407). Conjunctival hyperemia was observed in 12 cases in the azithromycin group and none in the ofloxacin group. Conclusion The risk of endophthalmitis was significantly greater with ofloxacin than with azithromycin. These findings provide a valuable addition to the ever-increasing pool of information on endophthalmitis prophylaxis after intravitreal injection, although further large-scale studies are required to provide definitive conclusions. PMID:23109798

  15. Establishment of a novel retinoblastoma (Rb) nude mouse model by intravitreal injection of human Rb Y79 cells - comparison of in vivo analysis versus histological follow up.

    PubMed

    Tschulakow, Alexander V; Schraermeyer, Ulrich; Rodemann, H Peter; Julien-Schraermeyer, Sylvie

    2016-11-15

    Retinoblastoma (Rb) is the most frequent primary intraocular tumour in children and, if left untreated, can cause death. Preclinical animal models that mimic molecular, genetic, and cellular features of cancers are essential for studying cancer and searching for promising diagnosis and treatment modalities. There are several models described for Rb, but none of them fully meet our requirements. The aim of this study was to create a novel xenograft-nude mouse-model with broad application possibilities, which closely resembles the clinical observations of Rb patients and which could be used to investigate the development and spread of the tumour by using scanning laser ophthalmoscopy/optical coherence tomography (SLO/OCT) as well as histology methods. We injected human retinoblastoma Y79 cells intravitreally in both eyes of immune-deficient nude mice. The incidences of retinoblastoma as well as growth velocity were analysed 3, 6, 9 and 12 weeks after cell injection in vivo by SLO/OCT as well as ex vivo by electron microscopy (EM) and hematoxylin/eosin (HE) staining. Moreover, internal organs were histologically screened for potentially occurring metastases. Three weeks post-injection, animals developed a retinoblastoma, and after five weeks tumour growth resulted in swelling of the eyes in individual animals, showing a similar phenotype to that of untreated Rb patients at advanced stages of tumour-development. After 12 weeks, 67.5% of all analysed eyes (29 of 42) contained a retinoblastoma. At early stages of Rb development, the SLO/OCT analysis correlated with the histology results. If the tumours were too large, only histological investigations were feasible. The ultrastructural characteristics of the xenograft-tumours were very similar to those described for patient's tumours. In one mouse, brain metastases were observed. Our retinoblastoma mouse model closely resembles the human disease. SLO/OCT can be used for the detection of Rb at early stages of

  16. Pharmacokinetics of Intravitreally Injected Bevacizumab in Vitrectomized Eyes

    PubMed Central

    Ahn, Jeeyun; Kim, Hyuncheol; Park, Ji Hyun; Park, Sunyoung; Hwang, Duck Jin; Park, Kyu Hyung

    2013-01-01

    Abstract Purpose To compare the pharmacokinetics (PKs) of intravitreally injected bevacizumab in vitrectomized versus nonvitrectomized control rabbit eyes. Methods Twenty-five-gauge pars plana vitrectomy without lensectomy was performed in 17 right rabbit eyes (V) and 18 nonvitrectomized right rabbit eyes served as controls (C). After 1.25 mg/0.05 mL intravitreal bevacizumab (IVB) injections, eyes were enucleated at 1 h, 1, 2, 5, 14, and 30 days after the injection and immediately frozen at −80°C. Bevacizumab concentrations were determined after separation of frozen vitreous and aqueous humor (AH) compartments using indirect enzyme-linked immunosorbent assay. Bevacizumab concentration–time data were analyzed to obtain PK data. Results Vitreous clearance of IVB consisted of 2 phases, the first fast distribution and second slow elimination phase. Clearance of IVB was accelerated in V eyes only during the first phase and not in the second phase. The vitreous concentration percent ratios between V and C eyes were 94.7% (1 h), 70.5% (1 day), 89.2% (2 days), 94.2% (5 days), 99.2% (14 days), and 79.1% (30 days). Overall vitreous half-lives were 6.99 and 7.06 days for V and C eyes, respectively (1.6-h difference). Conclusion Overall IVB PKs in rabbit eyes after vitrectomy without lensectomy are not substantially different from nonvitrectomized control eyes. PMID:23735192

  17. Establishment of a novel retinoblastoma (Rb) nude mouse model by intravitreal injection of human Rb Y79 cells – comparison of in vivo analysis versus histological follow up

    PubMed Central

    Tschulakow, Alexander V.; Schraermeyer, Ulrich; Rodemann, H. Peter

    2016-01-01

    ABSTRACT Retinoblastoma (Rb) is the most frequent primary intraocular tumour in children and, if left untreated, can cause death. Preclinical animal models that mimic molecular, genetic, and cellular features of cancers are essential for studying cancer and searching for promising diagnosis and treatment modalities. There are several models described for Rb, but none of them fully meet our requirements. The aim of this study was to create a novel xenograft-nude mouse-model with broad application possibilities, which closely resembles the clinical observations of Rb patients and which could be used to investigate the development and spread of the tumour by using scanning laser ophthalmoscopy/optical coherence tomography (SLO/OCT) as well as histology methods. We injected human retinoblastoma Y79 cells intravitreally in both eyes of immune-deficient nude mice. The incidences of retinoblastoma as well as growth velocity were analysed 3, 6, 9 and 12 weeks after cell injection in vivo by SLO/OCT as well as ex vivo by electron microscopy (EM) and hematoxylin/eosin (HE) staining. Moreover, internal organs were histologically screened for potentially occurring metastases. Three weeks post-injection, animals developed a retinoblastoma, and after five weeks tumour growth resulted in swelling of the eyes in individual animals, showing a similar phenotype to that of untreated Rb patients at advanced stages of tumour-development. After 12 weeks, 67.5% of all analysed eyes (29 of 42) contained a retinoblastoma. At early stages of Rb development, the SLO/OCT analysis correlated with the histology results. If the tumours were too large, only histological investigations were feasible. The ultrastructural characteristics of the xenograft-tumours were very similar to those described for patient's tumours. In one mouse, brain metastases were observed. Our retinoblastoma mouse model closely resembles the human disease. SLO/OCT can be used for the detection of Rb at early stages of

  18. Patients’ tolerance of bimanual lid retraction versus a metal speculum for intravitreal injections

    PubMed Central

    Alattas, Khadijah

    2016-01-01

    Objective To compare patients’ acceptance of and correlate their pain level for bimanual versus metal speculum fixation in intravitreal injections. Design Prospective analysis. Participants Seventy-three eyes of 56 patients. Methods A questionnaire indicating patients’ discomfort and pain grading immediately after intravitreal injections using either bimanual fixation or metal speculum fixation (Barraquer Wire Speculum). Results Fifty-six patients who underwent intravitreal injections were enrolled in this study for various conditions. Patients’ overall pain and discomfort were as follows, right eye – bimanual was 0.3 on our grading scale with a standard deviation of 0.54, right eye – metal was 1.6 on our grading scale with a standard deviation of 1.5, left eye – bimanual was 0.41 on our grading scale with a standard deviation of 0.87, and left eye – metal was 1.91 on our grading scale with a standard deviation of 1.14 (P=0.003). Conclusion Patients who underwent bimanual fixation had a much more comfortable experience with less pain in comparison to patients who underwent metal speculum fixation. PMID:27660408

  19. Sterile Inflammation after Intravitreal Injection of Aflibercept in a Korean Population

    PubMed Central

    Kim, Ju Young; You, Yong Sung; Kwon, Oh Woong

    2015-01-01

    Purpose To report the frequency and clinical features of sterile inflammation after intravitreal aflibercept injection in a Korean population. Methods A single-center, retrospective study was performed in patients who received intravitreal aflibercept from July 2013 through January 2015. Results A total of four cases of post-injection sterile inflammation were identified from 723 aflibercept injections in 233 patients. Patients presented 1 to 13 days after intravitreal aflibercept injection (mean, 5 days). The mean baseline visual acuity was 20 / 60, which decreased to 20 / 112 at diagnosis but ultimately recovered to 20 / 60. Three cases had inflammatory cells in the anterior chamber (mean, 2.25+; range, 0 to 4+), and all cases had vitritis (mean, 3+; range, 2+ to 4+). No patients had pain. Only one patient underwent anterior chamber sampling (culture negative) and injection of antibiotics. Three of four patients were treated with a topical steroid, and all experienced improvement in their symptoms and signs of inflammation. Conclusions The overall incidence of sterile inflammation after intravitreal aflibercept injection in a Korean population was 4 of 723 injections (0.55%), or 4 of 233 patients (1.79%). Sterile inflammation after intravitreal aflibercept injection typically presents without pain, and the visual outcomes are generally favorable. PMID:26457038

  20. Macular Hole Formation After Intravitreal Ranibizumab Injection in Wet Age-Related Macular Degeneration

    PubMed Central

    Mukherjee, Chandoshi; Mitra, Arijit; Kumar, N. Ajith; Elsherbiny, Samer; Lip, Peck Lin

    2015-01-01

    Ranibizumab is a monoclonal antibody fragment that inhibits angiogenesis by inhibiting vascular endothelial growth factor A, used as a treatment for patients with wet aged-related macular degeneration (ARMD). Adverse effects from intravitreal Ranibizumab injections are well recognised. Macular hole formation following Ranibizumab injection is a complication that has been recently reported in few case reports. We present a larger case series of five patients, who developed full thickness macular holes (FTMH) after intravitreal Ranibizumab injections for treatment of wet ARMD that we were aware of between 2009 and 2013. PMID:26962382

  1. Characteristics of Macular Edema in Behcet Disease after Intravitreal Bevacizumab Injection

    PubMed Central

    Ghassemi, Fariba; Mirak, Sohrab Afshari; Chams, Hormoz; Sabour, Siamak; Ahmadabadi, Mehdi Nilli; Davatchi, Fereidoun; Shahram, Farhad

    2017-01-01

    Purpose: To investigate the effect of intravitreal bevacizumab (IVB) injection on macular edema (ME) secondary to Behcet's disease. Methods: This prospective case series included 15 patients with bilateral ME due to Behcet's disease. Intravitreal bevacizumab was injected into the more severely involved eye; the contralateral eye was evaluated as the control. Patients were followed up with comprehensive ocular examination, optical coherence tomography, and fluorescein angiography (FA) for a minimum of 6 months by a single ophthalmologist. Results: Patients with a mean age of 30.6 ± 7.4 years received a mean number of 3.3 IVB injections during the 6 months. The mean preinjection vision was 0.6 ± 0.3 and 0.4 ± 0.4 LogMAR in the case and control groups, respectively, with no significant improvement at 6 months. Mean central foveal thickness was 375.3 ± 132.1 and 307.2 ± 84.5 μm in the case and control groups, respectively, and these changed to 401 ± 199.9 (P = 0.65) and 307.7 ± 82.8 μm (P = 0.73) at month 6, respectively. A statistically nonsignificant improvement in ME was observed during the first 3 months in the case group. However, it did not persist up to month 6 on an as-needed basis. IVB injections caused a disproportionate decrease in the thickness of macular subfields. A reduction in disc leakage was observed on FA (P = 0.058). Logistic regression analysis revealed no statistically significant predictive factor for an improvement in visual acuity (VA) and a reduction in foveal thickness. Conclusion: During a 6-month period, IVB injections based on an as-needed protocol provided no statistically significant improvement in VA and ME. PMID:28299006

  2. [The results of wet AMD treatment by intravitreal injections--preliminary report].

    PubMed

    Okruszko, Anna; Borucka, Anna I; Ulińska, Magdalena; Szaflik, Jerzy

    2007-01-01

    Age-related macular degeneration (AMD) is the leading cause of irreversible, severe loss of vision in the developed countries. One of the modern methods of treatment in neovascular form of AMD are repeated intravitreal injections of ranibizumab (Lucentis). Ranibizumab is a recombinant, humanized, monoclonal antibody that neutralizes all biologically active forms of vascular endothelial growth factor A (VEGF-A). The aim of the study was to analyze the results of intravitreal ranibizumab injections in wet AMD patients. There were 57 patients enrolled in the study. 87% of them avoided any loss of visual acuity and 47.3% gained at least one line at visual acuity chart. Authors conclude that treatment with repeated intravitreal injections of ranibizumab is effective in neovascular form of AMD.

  3. Safety evaluation of poly(lactic-co-glycolic acid)/poly(lactic-acid) microspheres through intravitreal injection in rabbits.

    PubMed

    Rong, Xianfang; Yuan, Weien; Lu, Yi; Mo, Xiaofen

    2014-01-01

    Poly(lactic-co-glycolic acid) (PLGA) and/or poly(lactic-acid) (PLA) microspheres are important drug delivery systems. This study investigated eye biocompatibility and safety of PLGA/PLA microspheres through intravitreal injection in rabbits. Normal New Zealand rabbits were randomly selected and received intravitreal administration of different doses (low, medium, or high) of PLGA/PLA microspheres and erythropoietin-loaded PLGA/PLA microspheres. The animals were clinically examined and sacrificed at 1, 2, 4, 8, and 12 weeks postadministration, and retinal tissues were prepared for analysis. Retinal reactions to the microspheres were evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end staining and glial fibrillary acidic protein immunohistochemistry. Retinal structure changes were assessed by hematoxylin and eosin staining and transmission electron microscopy. Finally, retinal function influences were explored by the electroretinography test. Terminal deoxynucleotidyl transferase-mediated dUTP nick end staining revealed no apoptotic cells in the injected retinas; immunohistochemistry did not detect any increased glial fibrillary acidic protein expression. Hematoxylin and eosin staining and transmission electron microscopy revealed no micro- or ultrastructure changes in the retinas at different time points postintravitreal injection. The electroretinography test showed no significant influence of scotopic or photopic amplitudes. The results demonstrated that PLGA/PLA microspheres did not cause retinal histological changes or functional damage and were biocompatible and safe enough for intravitreal injection in rabbits for controlled drug delivery.

  4. Comparison of In Vivo Gene Expression Profiling of RPE/Choroid following Intravitreal Injection of Dexamethasone and Triamcinolone Acetonide

    PubMed Central

    Smit-McBride, Zeljka; Moisseiev, Elad; Modjtahedi, Sara P.; Telander, David G.; Hjelmeland, Leonard M.; Morse, Lawrence S.

    2016-01-01

    Purpose. To identify retinal pigment epithelium (RPE)/choroid genes and their relevant expression pathways affected by intravitreal injections of dexamethasone and triamcinolone acetonide in mice at clinically relevant time points for patient care. Methods. Differential gene expression of over 34,000 well-characterized mouse genes in the RPE/choroid of 6-week-old C57BL/6J mice was analyzed after intravitreal steroid injections at 1 week and 1 month postinjection, using Affymetrix Mouse Genome 430 2.0 microarrays. The data were analyzed using GeneSpring GX 12.5 and Ingenuity Pathway Analysis (IPA) microarray analysis software for biologically relevant changes. Results. Both triamcinolone and dexamethasone caused differential activation of genes involved in “Circadian Rhythm Signaling” pathway at both time points tested. Triamcinolone (TAA) uniquely induced significant changes in gene expression in “Calcium Signaling” (1 week) and “Glutamate Receptor Signaling” pathways (1 month). In contrast, dexamethasone (Dex) affected the “GABA Receptor Signaling” (1 week) and “Serotonin Receptor Signaling” (1 month) pathways. Understanding how intraocular steroids affect the gene expression of RPE/choroid is clinically relevant. Conclusions. This in vivo study has elucidated several genes and pathways that are potentially altering the circadian rhythms and several other neurotransmitter pathways in RPE/choroid during intravitreal steroid injections, which likely has consequences in the dysregulation of RPE function and neurodegeneration of the retina. PMID:27429799

  5. Intravitreal Anti-VEGF Injections in Pregnancy: Case Series and Review of Literature.

    PubMed

    Polizzi, Silvio; Mahajan, Vinit B

    2015-12-01

    The use of intravitreal antivascular endothelial growth factor (anti-VEGF) injection is gaining wide acceptance as an off-label therapy for diseases that may affect pregnant women. However, these drugs may cause systemic side effects in the mother and fetal harm. This could lead specialists to not administer the drug or women to abort the fetus or to refuse treatment during pregnancy. We report the course of pregnancy in 3 women treated with intravitreal bevacizumab and provide a review of the literature on the use of intravitreal anti-VEGF in pregnancy. Our patients did not have any drug-related adverse event and delivered healthy full-term infants, although one of the women had risk factors for miscarriage. Infants reached all developmental milestones appropriately during infancy. A literature search on the use of intravitreal anti-VEGF injection in pregnancy was undertaken. Data for this review were identified by searches of PubMed and references from relevant articles using the search terms "pegaptanib," "bevacizumab," "ranibizumab," "aflibercept," "anti-VEGF," "intravitreal injection," "pregnant," "pregnancy," "abortion," "miscarriage," "preeclampsia," "embryo-fetal toxicity," "fetal malformations," "teratogenesis," "adverse events," and "maternofetal complications" in multiple combinations. We believe that intravitreal anti-VEGF can be given during pregnancy only when potential benefit to the woman justifies the potential risks to the fetus. When making a decision about whether to give drugs during pregnancy, it is important to consider the timing of exposure and its relationship to windows of developmental sensitivity. We believe that this review will be useful to specialists to inform and possibly treat their pregnant patients.

  6. Intravitreal Anti-VEGF Injections in Pregnancy: Case Series and Review of Literature

    PubMed Central

    Mahajan, Vinit B.

    2015-01-01

    Abstract The use of intravitreal antivascular endothelial growth factor (anti-VEGF) injection is gaining wide acceptance as an off-label therapy for diseases that may affect pregnant women. However, these drugs may cause systemic side effects in the mother and fetal harm. This could lead specialists to not administer the drug or women to abort the fetus or to refuse treatment during pregnancy. We report the course of pregnancy in 3 women treated with intravitreal bevacizumab and provide a review of the literature on the use of intravitreal anti-VEGF in pregnancy. Our patients did not have any drug-related adverse event and delivered healthy full-term infants, although one of the women had risk factors for miscarriage. Infants reached all developmental milestones appropriately during infancy. A literature search on the use of intravitreal anti-VEGF injection in pregnancy was undertaken. Data for this review were identified by searches of PubMed and references from relevant articles using the search terms “pegaptanib,” “bevacizumab,” “ranibizumab,” “aflibercept,” “anti-VEGF,” “intravitreal injection,” “pregnant,” “pregnancy,” “abortion,” “miscarriage,” “preeclampsia,” “embryo–fetal toxicity,” “fetal malformations,” “teratogenesis,” “adverse events,” and “maternofetal complications” in multiple combinations. We believe that intravitreal anti-VEGF can be given during pregnancy only when potential benefit to the woman justifies the potential risks to the fetus. When making a decision about whether to give drugs during pregnancy, it is important to consider the timing of exposure and its relationship to windows of developmental sensitivity. We believe that this review will be useful to specialists to inform and possibly treat their pregnant patients. PMID:26302032

  7. Dramatic resolution of vitreous hemorrhage after an intravitreal injection of dobesilate.

    PubMed

    Cuevas, Pedro; Outeiriño, Luis Antonio; Azanza, Carlos; Angulo, Javier; Giménez-Gallego, Guillermo

    2015-01-01

    Vitreous hemorrhages are important clinical manifestations of proliferative diabetic retinopathy. Non-cleared vitreous hemorrhages could lead to hemosiderosis bulbi and glaucoma. Here, we describe the case of a type 2 diabetic patient presenting anterior segment and vitreous hemorrhages that resolved three days after treatment with a single intravitreal injection of dobesilate.

  8. Pharmacokinetics, Electrophysiological, and Morphological Effects of the Intravitreal Injection of Mycophenolic Acid in Rabbits

    PubMed Central

    Gasparin, Fabio; Aguiar, Renata Genaro; Ioshimoto, Gabriela Lourençon; Silva-Cunha, Armando; Fialho, Silvia Ligório; Liber, André Mauricio; Nagy, Balázs Vince; Oiwa, Nestor Norio; Costa, Marcelo Fernandes; Joselevitch, Christina; Ventura, Dora Fix

    2014-01-01

    Abstract Purpose: To determine the half-life of mycophenolic acid (MPA) in the vitreous of New Zealand albino rabbits after intravitreal injection and the retinal toxicity of different doses of MPA. Methods: Ten micrograms of MPA (Roche Bioscience, Palo Alto, CA) was injected in the vitreous of 16 rabbits, animals were sacrificed at different time-points, and vitreous samples underwent high-performance liquid chromatography. For functional and morphological studies, 5 doses of MPA (0.05, 0.5, 2, 10, and 100 μg) were injected in the vitreous of 20 rabbits. As control, contralateral eyes were injected with aqueous vehicle. Electroretinograms (ERGs) were recorded before injection and at days 7, 15, and 30. Animals were sacrificed on day 30 and retinas were analyzed under light microscopy. Results: MPA half-life in the vitreous was 5.0±0.3 days. ERG revealed photoreceptor functional impairment in eyes injected with 0.5 μg and higher on day 30, while eyes injected with 100 μg presented the same changes already from day 15. No morphological change was found. Conclusions: MPA vitreous half-life is 5.0 days. Intravitreal injection of 0.5 μg MPA and higher causes dose- and time-related photoreceptor sensitivity decrease in rabbits. The MPA dose of 0.05 μg may be safe for intravitreal use in rabbits. PMID:24828287

  9. Pharmacokinetics and distributions of bevacizumab by intravitreal injection of bevacizumab-PLGA microspheres in rabbits

    PubMed Central

    Ye, Zhuo; Ji, Yan-Li; Ma, Xiang; Wen, Jian-Guo; Wei, Wei; Huang, Shu-Man

    2015-01-01

    AIM To investigate the pharmacokinetics and distributions of bevacizumab by intravitreal injection of prepared bevacizumab-poly (L-lactic-co-glycolic acid) (PLGA) microspheres in rabbits, to provide evidence for clinical application of this kind of bevacizumab sustained release dosage form. METHODS Bevacizumab was encapsulated into PLGA microsphere via the solid-in-oil-in-hydrophilic oil (S/O/hO) method. Fifteen healthy New Zealand albino-rabbits were used in experiments. The eyes of each rabbit received an intravitreal injection. The left eyes were injected with prepared bevacizumab-PLGA microspheres and the right eyes were injected with bevacizumab solution. After intravitreal injection, rabbits were randomly selected at days 3, 7, 14, 28 and 42 respectively, three animals each day. Then we used immunofluorescence staining to observe the distribution and duration of bevacizumab in rabbit eye tissues, and used the sandwich ELISA to quantify the concentration of free bevacizumab from the rabbit aqueous humor and vitreous after intravitreal injection. RESULTS The results show that the concentration of bevacizumab in vitreous and aqueous humor after administration of PLGA formulation was higher than that of bevacizumab solution. The T1/2 of intravitreal injection of bevacizumab-PLGA microspheres is 9.6d in vitreous and 10.2d in aqueous humor, and the T1/2 of intravitreal injection of soluble bevacizumab is 3.91d in vitreous and 4.1d in aqueous humor. There were statistical significant difference for comparison the results of the bevacizumab in vitreous and aqueous humor between the left and right eyes (P<0.05). The AUC0-t of the sustained release dosage form was 1-fold higher than that of the soluble form. The relative bioavailability was raised significantly. The immunofluorescence staining of PLGA-encapsulated bevacizumab (b-PLGA) in rabbit eye tissues was still observed up to 42d. It was longer than that of the soluble form. CONCLUSION The result of this study

  10. Epiretinal deposit of triamcinolone acetonide at the posterior pole after intravitreal injection.

    PubMed

    Jaissle, Gesine B; Szurman, Peter; Völker, Michael; Bartz-Schmidt, Karl Ulrich

    2007-01-01

    The authors investigated possible toxic side effects of epiretinal triamcinolone acetonide deposits at the posterior pole after an intravitreal injection in both a vitrectomized and a non-vitrectomized eye. The vitrectomized eye developed massive epiretinal triamcinolone acetonide deposits at the posterior pole that were less pronounced in the non-vitrectomized eye. After resolution of the deposits, no morphologic signs of retinal toxicity were apparent. Mild scattered visual field defects did not correlate with the localization of the triamcinolone acetonide deposits. However, because recent in vitro studies indicate potential cytotoxicity, patients should be instructed to keep their heads in an upright position after intravitreal triamcinolone acetonide injection to avoid deposits at the posterior pole.

  11. Ocular silicon distribution and clearance following intravitreal injection of porous silicon microparticles.

    PubMed

    Nieto, Alejandra; Hou, Huiyuan; Sailor, Michael J; Freeman, William R; Cheng, Lingyun

    2013-11-01

    Porous silicon (pSi) microparticles have been investigated for intravitreal drug delivery and demonstrated good biocompatibility. With the appropriate surface chemistry, pSi can reside in vitreous for months or longer. However, ocular distribution and clearance pathway of its degradation product, silicic acid, are not well understood. In the current study, rabbit ocular tissue was collected at different time point following fresh pSi (day 1, 5, 9, 16, and 21) or oxidized pSi (day 3, 7, 14, 21, and 35) intravitreal injection. In addition, dual-probe simultaneous microdialysis of aqueous and vitreous humor was performed following a bolus intravitreal injection of 0.25 mL silicic acid (150 μg/mL) and six consecutive microdialysates were collected every 20 min. Silicon was quantified from the samples using inductively coupled plasma-optical emission spectroscopy. The study showed that following the intravitreal injection of oxidized pSi, free silicon was consistently higher in the aqueous than in the retina (8.1 ± 6.5 vs. 3.4 ± 3.9 μg/mL, p = 0.0031). The area under the concentration-time curve (AUC) of the retina was only about 24% that of the aqueous. The mean residence time was 16 days for aqueous, 13 days for vitreous, 6 days for retina, and 18 days for plasma. Similarly, following intravitreal fresh pSi, free silicon was also found higher in aqueous than in retina (7 ± 4.7 vs. 3.4 ± 4.1 μg/mL, p = 0.014). The AUC for the retina was about 50% of the AUC for the aqueous. The microdialysis revealed the terminal half-life of free silicon in the aqueous was 30 min and 92 min in the vitreous; the AUC for aqueous accounted for 38% of the AUC for vitreous. Our studies indicate that aqueous humor is a significant pathway for silicon egress from the eye following intravitreal injection of pSi crystals.

  12. Ocular silicon distribution and clearance following intravitreal injection of porous silicon microparticles

    PubMed Central

    Nieto, Alejandra; Hou, Huiyuan; Sailor, Michael J.; Freeman, William R.; Cheng, Lingyun

    2013-01-01

    Porous silicon (pSi) microparticles have been investigated for intravitreal drug delivery and demonstrated good biocompatibility. With the appropriate surface chemistry, pSi can reside in vitreous for months or longer. However, ocular distribution and clearance pathway of its degradation product, silicic acid, are not well understood. In the current study, rabbit ocular tissue was collected at different time point following fresh pSi (day 1, 5, 9, 16, and 21) or oxidized pSi (day 3, 7, 14, 21, and 35) intravitreal injection. In addition, dual-probe simultaneous microdialysis of aqueous and vitreous humor was performed following a bolus intravitreal injection of 0.25 mL silicic acid (150 μg/mL) and six consecutive microdialysates were collected every 20 min. Silicon was quantified from the samples using inductively coupled plasma-optical emission spectroscopy. The study showed that following the intravitreal injection of oxidized pSi, free silicon was consistently higher in the aqueous than in the retina (8.1 ± 6.5 vs. 3.4 ± 3.9 μg/mL, p = 0.0031). The area under the concentration-time curve (AUC) of the retina was only about 24% that of the aqueous. The mean residence time was 16 days for aqueous, 13 days for vitreous, 6 days for retina, and 18 days for plasma. Similarly, following intravitreal fresh pSi, free silicon was also found higher in aqueous than in retina (7 ± 4.7 vs. 3.4 ± 4.1 μg/mL, p = 0.014). The AUC for the retina was about 50% of the AUC for the aqueous. The microdialysis revealed the terminal half-life of free silicon in the aqueous was 30 min and 92 min in the vitreous; the AUC for aqueous accounted for 38% of the AUC for vitreous. Our studies indicate that aqueous humor is a significant pathway for silicon egress from the eye following intravitreal injection of pSi crystals. PMID:24036388

  13. [Time course of changes in aqueous flare following intravitreous gas injection in rabbits].

    PubMed

    Yamamoto, K

    1991-06-01

    The quantitative changes of the aqueous flare following intravitreous gas injection were determined by laser flare-cell metry in rabbits. A volume of 0.4 ml of air, 100% sulfur hexafluoride (SF6), or 100% perfluoropropane (C3F8), was injected separately into the vitreous of pigmented rabbits. The normal range of the aqueous flare was 7.8 +/- 3.0 (photon counts/msec). Each model showed an increase of aqueous flare on the first day (air: 18.9 +/- 9.1, SF6: 19.5 +/- 11.5, C3F8: 40.8 +/- 22.8). Subsequently, the aqueous flare of air-injected eyes gradually decreased, while that of SF6-injected eyes increased on the 4th day, and then gradually decreased. Also that of C3F8-injected eyes increased on the 4th day, and the 7th day, then decreased on the 14th day, but it was still higher than normal. Cataracts developed in two of the five eyes injected with SF6 and all of the four eyes injected with C3F8. These findings revealed that following intravitreous gas injection, disruption of the blood-ocular barrier depended on the expansibility of the gas and the length of time it remained in the vitreous cavity.

  14. Ocular disposition and tolerance of ganciclovir-loaded albumin nanoparticles after intravitreal injection in rats.

    PubMed

    Merodio, Marta; Irache, Juan Manuel; Valamanesh, Fatemeh; Mirshahi, Massoud

    2002-04-01

    Cytomegalovirus (CMV) infection mainly affects endothelial cells of ocular vessels, optic nerve and the retina, resulting in direct or autoimmune damages, uveoretinitis and disturbed vision. The use of colloidal carriers for the intravitreal delivery of ganciclovir may prolong its residence in the eye, minimizing the opacification observed for macroscopic implants. The aim of this work was to evaluate the ocular toxicity induced by the prolonged presence of ganciclovir-loaded bovine serum albumin nanoparticles after their intravitreal injection. The intraocular disposition of these carriers was also studied by immunochemistry. Two weeks post-injection, a significant amount of nanoparticles remained in the vitreous cavity, mainly in a thin layer overlying the retina and in the area close to the blood aqueoUs barrier. Their prolonged residence in the eve seemed to be well tolerated and the histological evaluation of the retina, mainly the photoreceptor layer, and adjacent tissues revealed the absence of inflammatory reactions or alterations in the tissue architecture (i.e. cellular infiltrations or vascular inflammation). In addition, nanoparticles neither alter the expression and distribution of arrestin and rhodopsin autoantigens nor the mineralocorticoid receptor. In summary, the vision was not affected by autoimmune phenomena or alterations in the behavior of ophthalmic cells due to the intravitreal injection of these nanoparticles.

  15. Vitreous pharmacokinetics and electroretinographic findings after intravitreal injection of acyclovir in rabbits

    PubMed Central

    Damico, Francisco Max; Scolari, Mariana Ramos; Ioshimoto, Gabriela Lourençon; Takahashi, Beatriz Sayuri; da Silva Cunha, Armando; Fialho, Sílvia Ligório; Bonci, Daniela Maria; Gasparin, Fabio; Ventura, Dora Fix

    2012-01-01

    OBJECTIVES: Acute retinal necrosis is a rapidly progressive and devastating viral retinitis caused by the herpesvirus family. Systemic acyclovir is the treatment of choice; however, the progression of retinal lesions ceases approximately 2 days after treatment initiation. An intravitreal injection of acyclovir may be used an adjuvant therapy during the first 2 days of treatment when systemically administered acyclovir has not reached therapeutic levels in the retina. The aims of this study were to determine the pharmacokinetic profile of acyclovir in the rabbit vitreous after intravitreal injection and the functional effects of acyclovir in the rabbit retina. METHODS: Acyclovir (Acyclovir; Bedford Laboratories, Bedford, OH, USA) 1 mg in 0.1 mL was injected into the right eye vitreous of 32 New Zealand white rabbits, and 0.1 mL sterile saline solution was injected into the left eye as a control. The animals were sacrificed after 2, 9, 14, or 28 days. The eyes were enucleated, and the vitreous was removed. The half-life of acyclovir was determined using high-performance liquid chromatography. Electroretinograms were recorded on days 2, 9, 14, and 28 in the eight animals that were sacrificed 28 days after injection according to a modified protocol of the International Society for Clinical Electrophysiology of Vision. RESULTS: Acyclovir rapidly decayed in the vitreous within the first two days after treatment and remained at low levels from day 9 onward. The eyes that were injected with acyclovir did not present any electroretinographic changes compared with the control eyes. CONCLUSIONS: The vitreous half-life of acyclovir is short, and the electrophysiological findings suggest that the intravitreal delivery of 1 mg acyclovir is safe and well tolerated by the rabbit retina. PMID:22948462

  16. Intravitreal Injection of Bone Marrow Mesenchymal Stem Cells in Patients with Advanced Retinitis Pigmentosa; a Safety Study

    PubMed Central

    Satarian, Leila; Nourinia, Ramin; Safi, Sare; Kanavi, Mozhgan Rezaei; Jarughi, Neda; Daftarian, Narsis; Arab, Leila; Aghdami, Nasser; Ahmadieh, Hamid; Baharvand, Hossein

    2017-01-01

    Purpose: To examine the safety of a single intravitreal injection of autologous bone Marrow Mesenchymal stem cells (MSCs) in patients with advanced retinitis pigmentosa (RP). Methods: A prospective, phase I, nonrandomized, open-label study was conducted on 3 eyes of 3 volunteers with advanced RP. Visual acuity, slit-lamp examination, fundus examination, optical coherence tomography, fundus auto-fluorescence, fluorescein angiography and multifocal electroretinography were performed before and after an intravitreal injection of approximately one-million MSCs. The patients were followed for one year. Further evaluation of MSCs was performed by injection of these cells into the mouse vitreous cavity. Results: No, adverse events were observed in eyes of 2 out of 3 patients after transplantation of MSCs. These patients reported improvements in perception of the light after two weeks, which lasted for 3 months. However, severe fibrous tissue proliferation was observed in the vitreous cavity and retrolental space of the third patient's eye, which led to tractional retinal detachment (TRD), iris neovascularization and formation of mature cataract. Injection of this patient's MSCs into the vitreous cavity of mice also resulted in fibrosis; however, intravitreal injections of the two other patients' cells into the mouse vitreous did not generate any fibrous tissue. Conclusion: Intravitreal injection of autologous bone marrow MSCs into patients' eyes with advanced RP does not meet safety standards. Major side effects of this therapy can include fibrosis and TRD. We propose thorough evaluation of MSCs prior to transplantation by intravitreal injection in the laboratory animals.\\ PMID:28299008

  17. Ocular Decompression with Cotton Swabs Lowers Intraocular Pressure Elevation Following Intravitreal Injection

    PubMed Central

    Gregori, Ninel Z.; Weiss, Matthew J.; Goldhardt, Raquel; Schiffman, Joyce C.; Vega, Edgardo; Mattis, Cherrie-Ann; Shi, Wei; Kelley, Linda; Hernandez, Vilma; Feuer, William J.

    2013-01-01

    Objective To determine the effect of pre-injection ocular decompression by cotton swabs on the immediate rise in intraocular pressure (IOP) after intravitreal injections. Methods Forty-eight patients receiving 0.05-ml ranibizumab injections in a retina clinic were randomized to two anesthetic methods in each eye on the same day (if bilateral disease) or on consecutive visits (if unilateral disease). One method utilized cotton swabs soaked in 4% lidocaine applied to the globe with moderate pressure and the other 3.5% lidocaine gel applied without pressure. IOPs were recorded at baseline (before injection) and at 0, 5, 10, and 15 minutes after the injection until the IOP was ≤30 mmHg. The IOP elevations from baseline were compared after the two anesthetic methods. Results The pre-injection mean IOP (SD, mmHg) was 15.5 (3.3) before the cotton swabs and 15.9 (3.0) before the gel (p=0.28). Mean IOP (SD, mmHg) change immediately after injection was 25.7 (9.2) after the cotton swabs and 30.9 (9.9) after the gel (P=0.001). Thirty-five percent of gel eyes had IOP ≥50 mmHg compared to only 10% of cotton swab eyes immediately after the injection (P<0.001). Conclusion Decompressing the eye with cotton swabs during anesthetic preparation prior to an intravitreal injection produces a significantly lower IOP spike after the injection. PMID:23632408

  18. A Single Intravitreal Injection of Ranibizumab Provides No Neuroprotection in a Nonhuman Primate Model of Moderate-to-Severe Nonarteritic Anterior Ischemic Optic Neuropathy

    PubMed Central

    Miller, Neil R.; Johnson, Mary A.; Nolan, Theresa; Guo, Yan; Bernstein, Steven L.

    2015-01-01

    Purpose Ranibizumab, a vascular endothelial growth factor-antagonist, is said to be neuroprotective when injected intravitreally in patients with nonarteritic anterior ischemic optic neuropathy (NAION). We evaluated the efficacy of a single intravitreal (IVT) injection of ranibizumab in a nonhuman primate model of NAION (pNAION). Methods We induced pNAION in one eye of four adult male rhesus monkeys using a laser-activated rose Bengal induction method. We then immediately injected the eye with either ranibizumab or normal saline (NS) intravitreally. We performed a clinical assessment, optical coherence tomography, electrophysiological testing, fundus photography, and fluorescein angiography in three of the animals (one animal developed significant retinal hemorrhages and, therefore, could not be analyzed completely) prior to induction, 1 day and 1, 2, and 4 weeks thereafter. Following the 4-week analysis of the first eye, we induced pNAION in the contralateral eye and then injected either ranibizumab or NS, whichever substance had not been injected in the first eye. We euthanized all animals 5 to 12 weeks after the final assessment of the second eye and performed both immunohistochemical and light and electron microscopic analyses of the retina and optic nerves of both eyes. Results A single IVT dose of ranibizumab administered immediately after induction of pNAION resulted in no significant reduction of clinical, electrophysiological, or histologic damage compared with vehicle-injected eyes. Conclusions A single IVT dose of ranibizumab is not neuroprotective when administered immediately after induction of pNAION. PMID:26624498

  19. Intravitreal Injection of Splice-switching Oligonucleotides to Manipulate Splicing in Retinal Cells.

    PubMed

    Gérard, Xavier; Perrault, Isabelle; Munnich, Arnold; Kaplan, Josseline; Rozet, Jean-Michel

    2015-09-01

    Leber congenital amaurosis is a severe hereditary retinal dystrophy responsible for neonatal blindness. The most common disease-causing mutation (c.2991+1655A>G; 10-15%) creates a strong splice donor site that leads to insertion of a cryptic exon encoding a premature stop codon. Recently, we reported that splice-switching oligonucleotides (SSO) allow skipping of the mutant cryptic exon and the restoration of ciliation in fibroblasts of affected patients, supporting the feasibility of a SSO-mediated exon skipping strategy to correct the aberrant splicing. Here, we present data in the wild-type mouse, which demonstrate that intravitreal administration of 2'-OMePS-SSO allows selective alteration of Cep290 splicing in retinal cells, including photoreceptors as shown by successful alteration of Abca4 splicing using the same approach. We show that both SSOs and Cep290 skipped mRNA were detectable for at least 1 month and that intravitreal administration of oligonucleotides did not provoke any serious adverse event. These data suggest that intravitreal injections of SSO should be considered to bypass protein truncation resulting from the c.2991+1655A>G mutation as well as other truncating mutations in genes which like CEP290 or ABCA4 have a mRNA size that exceed cargo capacities of US Food and Drug Administration (FDA)-approved adeno-associated virus (AAV)-vectors, thus hampering gene augmentation therapy.

  20. Progression to macula-off tractional retinal detachment after a contralateral intraoperative intravitreal bevacizumab injection for proliferative diabetic retinopathy.

    PubMed

    Zlotcavitch, Leonid; Flynn, Harry W; Avery, Robert L; Rachitskaya, Aleksandra

    2015-01-01

    We report a patient with progression to a macula-off tractional retinal detachment in a fellow eye after a contralateral intraoperative intravitreal bevacizumab injection. A 32-year-old diabetic man noted decreased vision in his left eye 1 week following 25 gauge pars plana vitrectomy, gas tamponade, and intraoperative injection of bevacizumab in his right eye. Left eye visual acuity decreased from 20/80 to 20/200, and macula-off tractional retinal detachment was seen on clinical exam and imaging. Progression of tractional retinal detachment associated with proliferative diabetic retinopathy in a fellow eye after a contralateral intraoperative intravitreal bevacizumab injection may occur.

  1. Effect of intravitreal injection of bevacizumab-chitosan nanoparticles on retina of diabetic rats

    PubMed Central

    Lu, Yan; Zhou, Nan; Huang, Xiao; Cheng, Jin-Wei; Li, Feng-Qian; Wei, Rui-Li; Cai, Ji-Ping

    2014-01-01

    AIM To investigate the effects of intravitreal injection of bevacizumab-chitosan nanoparticles on pathological morphology of retina and the expression of vascular endothelial growth factor (VEGF) protein and VEGF mRNA in the retina of diabetic rats. METHODS Seventy-two 3-month aged diabetic rats were randomly divided into 3 groups, each containing 24 animals and 48 eyes. Both eyes of the rats in group A were injected into the vitreous at the pars plana with 3µL of physiological saline, while in groups B and C were injected with 3µL (75µg) of bevacizumab and 3µL of bevacizumab-chitosan nanoparticles (containing 75µg of bevacizumab), respectively. Immunohistochemistry was used to assess retinal angiogenesis, real-time PCR assay was used to analyse the expression of VEGF mRNA, and light microscopy was used to evaluate the morphology of retinal capillaries. RESULTS Real-time PCR assay revealed that the VEGF mRNA expression in the retina before injection was similar to 1 week after injection in group A (P>0.05), while the VEGF mRNA expression before injection significantly differed from those 4 and 8 weeks after injection (P<0.05). Retinal expression of VEGF protein and VEGF mRNA was inhibited 1 week and 4 weeks after injection (P<0.05) in group B, and the expression of VEGF protein and VEGF mRNA was obviously inhibited until 8 weeks after injection (P<0.05) in group C. Using multiple comparisons among group A, group B, and group C, the VEGF expression before injection was higher than at 1, 4 and 8 weeks after injection (P<0.05). The amount of VEGF expression was higher 8 weeks after injection than 1 week or 4 weeks after injection, and also higher 1 week after injection compared with 4 weeks after injection (P<0.05). No toxic effect on SD rats was observed with bevacizumab-chitosan nanoparticles injection alone. CONCLUSION The results offer a new approach for inhibiting angiogenesis of diabetic retinopathy and indicate that the intravitreal injection of

  2. Streptococcus Endophthalmitis Outbreak after Intravitreal Injection of Bevacizumab: One-year Outcomes and Investigative Results

    PubMed Central

    Goldberg, Roger A.; Flynn, Harry W.; Miller, Darlene; Gonzalez, Serafin; Isom, Ryan F.

    2013-01-01

    Purpose To report the one-year clinical outcomes of an outbreak of Streptococcus endophthalmitis after intravitreal injection of bevacizumab, including visual acuity outcomes, microbiological testing and compound pharmacy investigations by the Food and Drug Administration (FDA). Design Retrospective consecutive case series. Participants 12 eyes of 12 patients who developed endophthalmitis after receiving intravitreal bevacizumab prepared by a single compounding pharmacy. Methods Medical records of patients were reviewed; phenotypic and DNA analyses were performed on microbes cultured from patients and from unused syringes. An inspection report by the FDA based on site-visits to the pharmacy that prepared the bevacizumab syringes was summarized. Main Outcome Measures Visual acuity, interventions received, time-to-intervention; microbiological consistency; FDA inspection findings. Results Between July 5 and July 8, 2011, 12 patients developed endophthalmitis after intravitreal bevacizumab from syringes prepared by a single compounding pharmacy. All patients received initial vitreous tap and injection, and eight (67%) subsequently underwent pars plana vitrectomy (PPV). After twelve months follow-up, outcomes have been poor: 7 patients (58%) required evisceration or enucleation, and only one patient regained pre-injection visual acuity. Molecular testing using real time polymerase chain reaction, partial sequencing of the groEL gene, and multilocus sequencing of 7 housekeeping genes confirmed the presence of a common strain of Streptococcus mitis/oralis in vitreous specimens and seven unused syringes prepared by the compounding pharmacy at the same time. An FDA investigation of the compounding pharmacy noted deviations from standard sterile technique, inconsistent documentation, and inadequate testing of equipment required for safe preparation of medications. Conclusions In this outbreak of endophthalmitis, outcomes have been generally poor and PPV did not improve

  3. Evaluation of triamcinolone acetonide following intravitreal injection in New Zealand white rabbits.

    PubMed

    McGee, David H; Dembinska, Olga; Gruebbel, Margarita M

    2005-01-01

    The safety of intravitreally injected triamcinolone acetonide suspension (TA) was evaluated in rabbits. Each animal received 0.1 ml (1) balanced salt solution (BSS) vehicle, (2) formulation vehicle, (3) 4% TA (4-mg dose), (4) 16% TrAc (16-mg dose) or (5) 25% TA (25-mg dose) as a single intravitreal injection into the right eye. The left eyes served as untreated controls. All animals were observed for 1 month following treatment. In-life evaluations included clinical signs, body weights, slit-lamp biomicroscopic and indirect ophthalmoscopic examinations, intraocular pressure and corneal thickness measurements, and electroretinograms (ERGs). Ocular tissues were harvested following a 1-month post-treatment observation period, fixed, processed, and evaluated by light microscopy. No significant or treatment-related clinical signs were observed for any animals during the study. The opaque white test article was clearly visible in the eye for all TrAc-treated groups, and remained so throughout the study. No statistically significant differences in mean body weights were present between the control and treatment groups, though changes in body weight varied. Corneal thickness was slightly reduced for some treated groups. Intraocular pressures were not statistically significantly different from controls for any treatment group. No significant changes in ERG were evident between treatment groups or from baseline readings. Microscopically, basophilic material (presumed to be drug) was seen in the vitreous of all or most treated eyes, with accumulations in the vitreous or in clumps adjacent to the retinal surface. No pathological changes were observed in the retina or other ocular structures. Triamcinolone acetonide suspension was safe and well tolerated following intravitreal injection in New Zealand white rabbits.

  4. Peristence of triamcinolone crystals after intra-vitreal injection: Benign crystalline hyaloidopathy

    PubMed Central

    Zarifa, Rafik; Shaikh, Saad; Kester, Elizabeth

    2013-01-01

    We report a case of unusually long persistence of triamcinolone crystals after intra-vitreal injection. Crystals were noted on fundus examination predominantly confined to the posterior pole. Optical coherence tomography localized the crystals to the posterior hyaloidal surface. Over 6 years of follow-up the patient has retained good visual acuity and no observable changes in the retina. As the condition clinically resembles both crystalline maculopathy and asteroid hyalosis, we suggest the term ‘drug-induced benign crystalline hyaloidopathy’. PMID:23685493

  5. Safety of bilateral same-day intravitreal injections of anti-vascular endothelial growth factor agents

    PubMed Central

    Ruão, Miguel; Andreu-Fenoll, María; Dolz-Marco, Rosa; Gallego-Pinazo, Roberto

    2017-01-01

    Purpose The aim was to evaluate the safety of bilateral same-day injections with intravitreal antiangiogenic drugs for macular diseases. Methods Cross-sectional retrospective review of unilateral and bilateral same-day antiangiogenic injections was conducted between January 2011 and March 2016 in the Unit of Macula, University and Polytechnic Hospital La Fe (Valencia, Spain). A total of 8,172 injections were administered, among which 6,560 were unilateral and 1,612 were bilateral injections. Patients were included in the study regardless of the diagnosis. Ranibizumab and aflibercept were the antiangiogenic drugs used. The presence of endophthalmitis or retinal detachment was evaluated. Results A total of 1 (0.012%) culture-proven endophthalmitis and 19 (0.233%) acute intraocular inflammations were registered. In the unilateral injections group, there were 18 (0.274%) acute intraocular inflammations and 1 (0.015%) culture-proven endophthalmitis. One (0.062%) of the 1,612 bilateral same-day injections had a unilateral acute intraocular inflammation, and there were no culture-proven endophthalmitis in this group. Conclusion Bilateral same-day injections are more convenient for patients and their caregivers than the unilateral injections administered on different days. In our study, the prevalence of culture-proven endophthalmitis and acute intraocular inflammation was lower in the bilateral injections than in the unilateral group. These data support the idea that bilateral same-day injections are a safe and valid treatment to use in our clinical practice. PMID:28203056

  6. Apoptosis and electroretinogram after intravitreal injection of methotrexate in an experimental rabbit model.

    PubMed

    Aly, Eman; Ebrahim, Amal

    2016-04-01

    The aim of this study was to explore the changes in electroretinogram of rabbit retina and apoptosis in methotrexate-induced toxicity. Rabbits were divided into 5 groups. Group I served as control in which saline solutions was injected intravitreally. Methotrexate (800 μg, 1.76 μmol) was injected into the vitreous of both eyes of rabbits groups II, III, IV and V by an insulin injector with a 26 gauge needle under general anesthesia. Retinal function was assessed by electroretinogram (ERG) after 2, 4, 10 days and one month then animals were decapitated. The eyes were enucleated and processed for DNA fragmentation studies by gel electrophoresis to retinae and measurement of caspase-3 activities. The results indicated a significant reduction (p ˂ 0.05) in a- and b-wave, a time-dependent appearance of the typical ladder pattern of internucleosomal fragmentation, a characteristic of apoptosis and increase of relative caspase-3 activity after methotrexate intravitreal injection. Methotrexate lead to apoptosis, increase of caspase-3 and affect retinal function.

  7. Retinal reperfusion in diabetic retinopathy following treatment with anti-VEGF intravitreal injections

    PubMed Central

    Levin, Ariana M; Rusu, Irene; Orlin, Anton; Gupta, Mrinali P; Coombs, Peter; D’Amico, Donald J; Kiss, Szilárd

    2017-01-01

    Purpose The aim of this study is to report peripheral reperfusion of ischemic areas of the retina on ultra-widefield fluorescein angiography (UWFA) following anti-vascular endothelial growth factor (VEGF) intravitreal injections in patients treated for diabetic retinopathy. Methods This study is a retrospective review of 16 eyes of 15 patients with diabetic retinopathy, who received anti-VEGF intravitreal injections and underwent pre- and postinjection UWFA. The main outcome measured was the presence of reperfusion in postinjection UWFA images in areas of the retina that demonstrated nonperfusion in preinjection images. Images were analyzed for reperfusion qualitatively and quantitatively by two graders. Results Twelve of 16 eyes (75%) or 11 of 15 patients (73.3%) demonstrated reperfusion following anti-VEGF injection. On UWFA, reperfusion was detected both within the field of 7-standard field (7SF) fluorescein angiography and in the periphery outside the 7SF. Four of 16 eyes or 4 of 15 patients did not demonstrate reperfusion, one of which had extensive scarring from prior panretinal photocoagulation. Conclusion In patients with diabetic retinopathy, treatment with anti-VEGF agents can be associated with reperfusion of areas of nonperfusion, as demonstrated by UWFA. PMID:28176934

  8. Thermo-responsive hydrogels for intravitreal injection and biomolecule release

    NASA Astrophysics Data System (ADS)

    Drapala, Pawel

    In this dissertation, we develop an injectable polymer system to enable localized and prolonged release of therapeutic biomolecules for improved treatment of Age-Related Macular Degeneration (AMD). Thermo-responsive hydrogels derived from N-isopropylacrylamide (NIPAAm) and cross-linked with poly(ethylene glycol) (PEG) poly(L-Lactic acid) (PLLA) copolymer were synthesized via free-radical polymerization. These materials were investigated for (a) phase change behavior, (b) in-vitro degradation, (c) capacity for controlled drug delivery, and (d) biocompatibility. The volume-phase transition temperature (VPTT) of the PNIPAAm- co-PEG-b-PLLA hydrogels was adjusted using hydrophilic and hydrophobic moieties so that it is ca. 33°C. These hydrogels did not initially show evidence of degradation at 37°C due to physical cross-links of collapsed PNIPAAm. Only after addition of glutathione chain transfer agents (CTA)s to the precursor did the collapsed hydrogels become fully soluble at 37°C. CTAs significantly affected the release kinetics of biomolecules; addition of 1.0 mg/mL glutathione to 3 mM cross-linker accelerated hydrogel degradation, resulting in 100% release in less than 2 days. This work also explored the effect of PEGylation in order to tether biomolecules to the polymer matrix. It was demonstrated that non-site-specific PEGylation can postpone the burst release of solutes (up to 10 days in hydrogels with 0.5 mg/mL glutathione). Cell viability assays showed that at least two 20-minute buffer extraction steps were needed to remove cytotoxic elements from the hydrogels. Clinically-used therapeutic biomolecules LucentisRTM and AvastinRTM were demonstrated to be both stable and bioactive after release form PNIPAAm-co-PEG-b-PLLA hydrogels. The thermo-responsive hydrogels presented here offer a promising platform for the localized delivery of proteins such as recombinant antibodies.

  9. Experiences of patients undergoing repeated intravitreal anti-vascular endothelial growth factor injections for neovascular age-related macular degeneration.

    PubMed

    Boyle, Jessica; Vukicevic, Meri; Koklanis, Konstandina; Itsiopoulos, Catherine; Rees, Gwyneth

    2017-01-09

    Current therapy to slow disease progression in patients with neovascular age-related macular degeneration (AMD) entails regular intravitreal anti-vascular endothelial growth factor (VEGF) injections, often indefinitely. Little is known about the burden imposed on patients by this repetitive treatment schedule and how this can be best managed. The aim of this study was to explore the psychosocial impact of repeated intravitreal injections on patients with neovascular AMD. Forty patients (16 males, 24 females) with neovascular AMD undergoing anti-VEGF treatment were recruited using purposive sampling from a private ophthalmology practice and public hospital in Melbourne. Patients were surveyed using the Macular Disease Treatment Satisfaction Questionnaire (MacTSQ; Bradley, Health Psychology Research Unit, Surrey, England) and underwent semi-structured, one-on-one interviews. Interview topics were: treatment burden and satisfaction; tolerability; barriers to adherence; treatment motivation; and patient education. Interviews were audio recorded and thematic analysis performed using NVivo 10 (QSR International, Doncaster, Australia). Patients recognised the importance of treatment to preserve eyesight, yet experienced significant psychosocial and practical burden from the treatment schedule. Important issues included treatment-related anxiety, financial considerations and transport burden placed on relatives or carers. Many patients were restricted to sedentary activities post-injection owing to treatment side effects. Patients prioritised treatment, often sacrificing family, travel and social commitments owing to a fear of losing eyesight if treatment was not received. Whilst anti-VEGF injections represent the current mainstay of treatment for neovascular AMD, the ongoing treatment protocol imposes significant burden on patients. An understanding of the factors that contribute to the burden of treatment may help inform strategies to lessen its impact and assist

  10. Incidence of endophthalmitis following intravitreal Bevacizumab injection at a tertiary care hospital in Eastern Province of Saudi Arabia

    PubMed Central

    Cheema, Rizwan A.; Alshihry, Ahmad M.; Cheema, Haider R.

    2014-01-01

    The aim of this communication is to report the incidence of endophthalmitis following the use of intravitreal Bevacizumab (IVB) at a tertiary care hospital in the Eastern province of Saudi Arabia. A total of 2769 intravitreal Bevacizumab injections were carried out between January 2009 and April 2014. During this period, one case of endophthalmitis following IVB injection occurred. The overall incidence of clinical endophthalmitis was 0.036% (1/2769; 95% confidence interval: 0.0001–0.002%). This compares favorably with studies reported from other parts of the world. PMID:25892933

  11. Intravitreal bevacizumab injections for diabetic macular edema – predictors of response: a retrospective study

    PubMed Central

    Joshi, Lavnish; Bar, Asaf; Tomkins-Netzer, Oren; Yaganti, Satish; Morarji, Jiten; Vouzounis, Panayiotis; Seguin-Greenstein, Sophie; Taylor, Simon R; Lightman, Sue

    2016-01-01

    Background Outcomes of intravitreal antivascular endothelial growth factor injections are variable among patients with diabetic macular edema (DME). The aim of this study was to determine the ocular and systemic predictors of DME response to intravitreal bevacizumab (IVB). Methods Retrospective review over 2 years of 78 eyes from 54 patients. An anatomical response to IVB was defined as a 20% reduction in central macula thickness after the first course (three injections) of IVB. Results Twenty-eight percent of patients had an anatomical response after the first course of IVB. Systemic hypertension (odds ratio, 95% confidence interval: 12.1, 0.7–21) was a statistically significant predictor (P=0.025) of a good response to IVB, whereas previous macular laser was a statistically significant (P=0.0005) predictor of a poor response (0.07, 0.01–0.32). Sixty-eight percent of eyes underwent subsequent treatment for DME after the first course of IVB. The visual acuity gain at 24 months in hypertensive (0.7±3.6 letters) and nonhypertensive (5.2±3.7 letters) patients was not significantly different (P=0.41). Conclusion Hypertension and previous macular laser were positive and negative predictors of response to IVB, respectively. However, long-term visual acuity changes were not significantly different between eyes with and without systemic hypertension. PMID:27799737

  12. Role of Intravitreal Antivascular Endothelial Growth Factor Injections for Choroidal Neovascularization due to Choroidal Osteoma

    PubMed Central

    Mansour, Ahmad M.; Al Kahtani, Eman; Zegarra, Hernando; Anand, Rajiv; Ahmadieh, Hamid; Sisk, Robert A.; Mirza, Salman; Tuncer, Samuray; Navea Tejerina, Amparo; Mataix, Jorge; Ascaso, Francisco J.; Pulido, Jose S.; Guthoff, Rainer; Goebel, Winfried; Roh, Young Jung; Banker, Alay S.; Gentile, Ronald C.; Martinez, Isabel Alonso; Morris, Rodney; Panday, Neeraj; Min, Park Jung; Mercé, Emilie; Lai, Timothy Y. Y.; Massoud, Vicky; Ghazi, Nicola G.

    2014-01-01

    We treated 26 eyes of 25 young patients having a mean age of 30 years with intravitreal vascular endothelial growth factor (VEGF) inhibitor for choroidal new vessel (CNV) formation overlying choroidal osteoma over a mean follow-up of 26 months. Mean number of injections was 2.4 at 6 months, 3.2 at 12 months, and 5.5 at 24 months. CNV was subfoveal in 14 eyes, juxtafoveal in 5, extrafoveal in 5, and peripapillary in 2. By paired comparison, mean decrease from baseline was 119.7 microns at 6 months (n = 15; P = 0.001), 105.3 microns at 1 year (n = 10; P = 0.03), and 157.6 microns at 2 years (n = 7; P = 0.08). BCVA improved by 3.3 lines at 6 months after therapy (n = 26; P < 0.001), 2.8 lines (n = 20; P = 0.01) at 1 year, and 3.1 lines (n = 13; P = 0.049) at 2 years. We conclude that intravitreal anti-VEGF injections improve vision in majority of eyes with CNV from choroidal osteoma. PMID:25147732

  13. Role of Intravitreal Antivascular Endothelial Growth Factor Injections for Choroidal Neovascularization due to Choroidal Osteoma.

    PubMed

    Mansour, Ahmad M; Arevalo, J Fernando; Al Kahtani, Eman; Zegarra, Hernando; Abboud, Emad; Anand, Rajiv; Ahmadieh, Hamid; Sisk, Robert A; Mirza, Salman; Tuncer, Samuray; Navea Tejerina, Amparo; Mataix, Jorge; Ascaso, Francisco J; Pulido, Jose S; Guthoff, Rainer; Goebel, Winfried; Roh, Young Jung; Banker, Alay S; Gentile, Ronald C; Martinez, Isabel Alonso; Morris, Rodney; Panday, Neeraj; Min, Park Jung; Mercé, Emilie; Lai, Timothy Y Y; Massoud, Vicky; Ghazi, Nicola G

    2014-01-01

    We treated 26 eyes of 25 young patients having a mean age of 30 years with intravitreal vascular endothelial growth factor (VEGF) inhibitor for choroidal new vessel (CNV) formation overlying choroidal osteoma over a mean follow-up of 26 months. Mean number of injections was 2.4 at 6 months, 3.2 at 12 months, and 5.5 at 24 months. CNV was subfoveal in 14 eyes, juxtafoveal in 5, extrafoveal in 5, and peripapillary in 2. By paired comparison, mean decrease from baseline was 119.7 microns at 6 months (n = 15; P = 0.001), 105.3 microns at 1 year (n = 10; P = 0.03), and 157.6 microns at 2 years (n = 7; P = 0.08). BCVA improved by 3.3 lines at 6 months after therapy (n = 26; P < 0.001), 2.8 lines (n = 20; P = 0.01) at 1 year, and 3.1 lines (n = 13; P = 0.049) at 2 years. We conclude that intravitreal anti-VEGF injections improve vision in majority of eyes with CNV from choroidal osteoma.

  14. Viral Retinitis Following Intravitreal Triamcinolone Injection in Patients with Predisposing Medical Comorbidities

    PubMed Central

    Shah, Ankur M.; Oster, Stephen F.; Freeman, William R.

    2009-01-01

    Purpose To review the cases of viral retinitis following intravitreal steroid administration at a single center, to estimate the incidence, and to propose risk factors for its occurrence. Design Retrospective, observational case series Methods 736 intravitreal triamcinolone (IVTA) injections were given in the clinic and operating room by three retina specialists at a single academic medical center, between September 2002 to November 2008. Inclusion criteria were simply a history of one or more IVTA injections during the period. The overall incidence of viral retinitis following IVTA was calculated. Subsequently, a chart audit was performed to estimate the number of patients with immune-altering conditions who had received IVTA during the time period, and the incidence within this subgroup was calculated. Results Viral retinitis developed following IVTA injection in three patients, yielding an overall incidence of 3/736 or 0.41%. An estimated 334 injections were given to patients with an immune-altering condition, including diabetes. All three of the patients who developed viral retinitis following IVTA possessed abnormal immune systems, yielding an incidence rate of 3/334 or 0.90% within this subgroup. Conclusions Our high reported incidence for this potentially devastating complication can be attributed to multiple factors, including coexisting medical immunocompromising comorbidities, a higher dose with a longer duration of local immunosuppression in the vitreous, multiple injections, as well as previous viral retinitis. Caution with a high index of clinical suspicion and frequent follow-up is advised in patients receiving IVTA with potentially immune-altering conditions, even after apparent immune recovery. PMID:20172069

  15. Intravitreal injection

    MedlinePlus

    ... disorder that slowly destroys sharp, central vision Macular edema: Swelling or thickening of the macula, the part ... 29, 2013. Mitchell P, Wong TY, Diabetic Macular Edema Treatment Guideline Working Group. Management paradigms for diabetic ...

  16. Lowered intraocular pressure in a glaucoma patient after intravitreal injection of ocriplasmin

    PubMed Central

    McClintock, Michael; MacCumber, Mathew W

    2015-01-01

    We report the case of a glaucoma patient who received a single intravitreal injection of 125 µg ocriplasmin for vitreomacular traction in the right eye. The patient had bilateral advanced glaucoma and had previously undergone an implantation of an Ahmed glaucoma valve in the right eye and trabeculectomy in both eyes. The patient was using three topical ophthalmic intraocular pressure (IOP)-lowering medications on the day of injection. Baseline uncorrected Snellen visual acuity was 20/80-1 and IOP was 19 mmHg. Resolution of vitreomacular traction was achieved 1 week after injection. IOP was transiently decreased, reaching a maximum reduction of 12 mmHg below baseline at 1 month after injection, when serous choroidal effusion was also present. IOP returned to baseline levels and choroidal effusion resolved at 2 months after injection of IOP-lowering medication. Vitrectomy with epiretinal membrane and internal limiting membrane peeling, endolaser photocoagulation, and fluid–gas exchange were performed in the right eye ~3.5 months after injection to treat persistent epiretinal membrane, and presumed tractional retinal detachment. Final visual acuity was 20/50+ and IOP was 18 mmHg at 16 weeks after surgery. To our knowledge, this is the first report of IOP reduction and serous choroidal effusion after ocriplasmin injection. PMID:26604668

  17. Practice patterns of ophthalmologists administering intravitreal injections in Europe: a longitudinal survey

    PubMed Central

    Huang, Kui; Sultan, Marla B; Zhou, Duo; Tressler, Charles S; Mo, Jingping

    2016-01-01

    Purpose This study was performed to understand the practice patterns of ophthalmologists administering intravitreal (IVT) injections in Europe after the procedure became routine. Methods As part of a prospective, multinational, non-interventional cohort study in 13 countries in Europe between 2006 and 2012, ophthalmologists completed the Baseline Questionnaire and the Follow-up Questionnaire 1 year after baseline. Results and discussion Of the 125 ophthalmologists who participated in the study, 113 (90.4%) completed the Baseline Questionnaire. Most of these ophthalmologists were medical retina specialists (43.0%). The median number of IVT injections that the ophthalmologists performed per month during the year prior to completing the Baseline Questionnaire was 20.0. The majority of the ophthalmologists had performed their last IVT injection prior to completing the questionnaire in an operating room or theater (68.4%). When performing IVT injections, a majority of the ophthalmologists reported applying povidone–iodine (90.4%) before IVT injections and topical antibiotics right after IVT injections (89.5%). In addition, 81.6% of the ophthalmologists reported using a sterile adhesive eye drape and 80.7% reported using an eyelid speculum. In all, 95 ophthalmologists (76%) completed the Follow-up Questionnaire. The median number of IVT injections performed per month during the year prior to completing the Follow-up Questionnaire by these ophthalmologists was increased to 35. The results of the Follow-up Questionnaire on administering IVT injections were similar to those of the Baseline Questionnaire. A majority of the ophthalmologists reported applying povidone–iodine (87.4%) before IVT injections, topical antibiotics right after IVT injections (89.5%), and an eyelid speculum (85.3%). Conclusion The results of this study indicated a good adherence to all aspects of the guidelines on IVT injections. It seemed that ophthalmologists were more experienced in IVT

  18. Poly(ortho ester) nanoparticles targeted for chronic intraocular diseases: ocular safety and localization after intravitreal injection.

    PubMed

    Li, Huiling; Palamoor, Mallika; Jablonski, Monica M

    2016-10-01

    Treatment of posterior eye diseases is more challenging than the anterior segment ailments due to a series of anatomical barriers and physiological constraints confronted by drug delivery to the back of the eye. In recent years, concerted efforts in drug delivery have been made to prolong the residence time of drugs injected in the vitreous humor of the eye. Our previous studies demonstrated that poly(ortho ester) (POE) nanoparticles were biodegradable/biocompatible and were capable of long-term sustained release. The objective of the present study was to investigate the safety and localization of POE nanoparticles in New Zealand white rabbits and C57BL/6 mice after intravitreal administration for the treatment of chronic posterior ocular diseases. Two concentration levels of POE nanoparticles solution were chosen for intravitreal injection: 1.5 mg/ml and 10 mg/ml. Our results demonstrate that POE nanoparticles were distributed throughout the vitreous cavity by optical coherence tomography (OCT) examination 14 days post-intravitreal injection. Intraocular pressure was not changed from baseline. Inflammatory or adverse effects were undetectable by slit lamp biomicroscopy. Furthermore, we demonstrate that POE nanoparticles have negligible toxicity assessed at the cellular level evidenced by a lack of glia activation or apoptosis estimation after intravitreal injection. Collectively, POE nanoparticles are a novel and nontoxic as an ocular drug delivery system for the treatment of posterior ocular diseases.

  19. Dual Intravitreal Injections With Foscarnet and Ganciclovir for Ganciclovir-Resistant Recurrent Cytomegalovirus Retinitis in a Congenitally Infected Infant.

    PubMed

    Boss, Joseph D; Rosenberg, Kevin; Shah, Rajiv

    2016-10-22

    Resistant strains of cytomegalovirus can be difficult to treat in cases of congenital cytomegalovirus retinitis. The authors describe a case of recurrent bilateral congenital cytomegalovirus retinitis in an immunocompetent newborn with ganciclovir resistance successfully treated uniquely with dual therapy of intravenous ganciclovir and foscarnet and dual intravitreal injections with ganciclovir and foscarnet. [J Pediatr Ophthalmol Strabismus. 2016;53:e58-e60.].

  20. Routes for Drug Delivery to the Eye and Retina: Intravitreal Injections.

    PubMed

    Meyer, Carsten H; Krohne, Tim U; Charbel Issa, Peter; Liu, Zengping; Holz, Frank G

    2016-01-01

    The advantage of intravitreal injections is an immediate and increased therapeutic effect in the intended retinal tissue. The accuracy, precision and reproducibility of the delivered volume depend on the size of the syringe and the physician's manual experience. The eyelids and eyelashes are usually disinfected using a povidone-iodine solution (10%); a sterile speculum is placed and drops of povidone-iodine (5%) are applied. The use of adequate anesthetic topical lidocaine 2% is required. The injection site should be located 3.5-4 mm posterior to the limbus. The angle of the incision through the sclera may be directed in an oblique fashion of 30°. The diameter of the needle should be smaller than 25 G, and the injected volume should be limited to 0.15 ml without a routine paracentesis. The incidence of lens injury is 0.006% (2/32,318) and 0.013% (5/35,942) for rhegmatogenous retinal detachments. The rate of suspected endophthalmitis is 0.018% after bevacizumab and 0.027% after ranibizumab injections. Sterile inflammations have been observed after Avastin injections. The concentrations of vascular endothelial growth factor inhibitors decline in a monoexponential fashion. The half-life of unbound bevacizumab is 9.82 days and that of ranibizumab 7.19 days.

  1. Exosome-associated AAV2 vector mediates robust gene delivery into the murine retina upon intravitreal injection.

    PubMed

    Wassmer, Sarah J; Carvalho, Livia S; György, Bence; Vandenberghe, Luk H; Maguire, Casey A

    2017-03-31

    Widespread gene transfer to the retina is challenging as it requires vector systems to overcome physical and biochemical barriers to enter and diffuse throughout retinal tissue. We investigated whether exosome-associated adeno-associated virus, (exo-AAV) enabled broad retinal targeting following intravitreal (IVT) injection, as exosomes have been shown to traverse biological barriers and mediate widespread distribution upon systemic injection. We packaged an AAV genome encoding green fluorescent protein (GFP) into conventional AAV2 and exo-AAV2 vectors. Vectors were IVT injected into the eyes of adult mice. GFP expression was noninvasively monitored by fundus imaging and retinal expression was analyzed 4 weeks post-injection by qRT-PCR and histology. Exo-AAV2 outperformed conventional AAV2 in GFP expression based on fundus image analysis and qRT-PCR. Exo-AAV2 demonstrated deeper penetration in the retina, efficiently reaching the inner nuclear and outer plexiform, and to a lesser extent the outer nuclear layer. Cell targets were ganglion cells, bipolar cells, Müller cells, and photoreceptors. Exo-AAV2 serves as a robust gene delivery tool for murine retina, and the simplicity of production and isolation should make it widely applicable to basic research of the eye.

  2. Exosome-associated AAV2 vector mediates robust gene delivery into the murine retina upon intravitreal injection

    PubMed Central

    Wassmer, Sarah J.; Carvalho, Livia S.; György, Bence; Vandenberghe, Luk H.; Maguire, Casey A.

    2017-01-01

    Widespread gene transfer to the retina is challenging as it requires vector systems to overcome physical and biochemical barriers to enter and diffuse throughout retinal tissue. We investigated whether exosome-associated adeno-associated virus, (exo-AAV) enabled broad retinal targeting following intravitreal (IVT) injection, as exosomes have been shown to traverse biological barriers and mediate widespread distribution upon systemic injection. We packaged an AAV genome encoding green fluorescent protein (GFP) into conventional AAV2 and exo-AAV2 vectors. Vectors were IVT injected into the eyes of adult mice. GFP expression was noninvasively monitored by fundus imaging and retinal expression was analyzed 4 weeks post-injection by qRT-PCR and histology. Exo-AAV2 outperformed conventional AAV2 in GFP expression based on fundus image analysis and qRT-PCR. Exo-AAV2 demonstrated deeper penetration in the retina, efficiently reaching the inner nuclear and outer plexiform, and to a lesser extent the outer nuclear layer. Cell targets were ganglion cells, bipolar cells, Müller cells, and photoreceptors. Exo-AAV2 serves as a robust gene delivery tool for murine retina, and the simplicity of production and isolation should make it widely applicable to basic research of the eye. PMID:28361998

  3. Six month delivery of GDNF from PLGA/vitamin E biodegradable microspheres after intravitreal injection in rabbits.

    PubMed

    García-Caballero, Cristina; Prieto-Calvo, Esther; Checa-Casalengua, Patricia; García-Martín, Elena; Polo-Llorens, Vicente; García-Feijoo, Julián; Molina-Martínez, Irene Teresa; Bravo-Osuna, Irene; Herrero-Vanrell, Rocío

    2017-03-01

    Local long-term delivery of glial cell line derived neurotrophic factor (GDNF) from vitamin E/poly-lactic-co-glycolic acid microspheres (MSs) protects retinal ganglion cells in an animal model of glaucoma for up to 11weeks. However, the pharmacokinetics of GDNF after intravitreal injection of MSs is not known. We evaluated the GDNF levels after a single intravitreal injection of GDNF/VitE MSs. Biodegradable MSs were prepared by the solid-oil-in-water emulsion-solvent evaporation technique and characterized. Rabbits received a single intravitreal injection (50μL) of GDNF/VitE MSs (4%w/v; 24 right eyes; 74.85ng GDNF), blank MSs (4%w/v; 24 left eyes), and balanced salt solution (4 eyes). Two controls eyes received no injections. At 24h, 1, 4, 6, 8, 12, 18, and 24weeks after injection, the eyes were enucleated, and the intravitreal GDNF levels were quantified. Pharmacokinetic data were analysed according to non-compartmental model. Intraocular GDNF levels of 717.1±145.1pg/mL were observed at 24h for GDNF-loaded MSs, followed by a plateau (745.3±25.5pg/mL) until day 28. After that, a second plateau (17.4±3.7pg/mL) occurred from 8 to 24weeks post-injection, significantly higher than the basal levels. Eyes injected with GDNF/vitE and Blank-MSs did not show any abnormalities during the six-months follow up after administration. The single injection of GDNF/VitE MSs provided a sustained controlled release of the neurotrophic factor in a controlled fashion for up to six months.

  4. Electroretinographic evaluations of retinal function before, just after, and after intravitreal injections

    PubMed Central

    Yagura, Kazuma; Shinoda, Kei; Matsumoto, Soiti; Terauchi, Gaku; Kawashima, Makoto; Watanabe, Emiko; Matsumoto, Harue; Iwata, Takeshi; Mizota, Atsushi; Miyake, Yozo

    2016-01-01

    Intravitreal injections (IVI) have become a part of daily practice for a growing number of procedures. We evaluated the retinal function by recording intraoperative photopic electroretinograms (ERGs) before an injection (T1), just after the injection (T2), and after the aspiration of the anterior chamber fluid (T3) of 19 eyes of 19 patients (mean age 70.6 years; men = 11) who received an IVI of an anti-vascular endothelial growth factor. The mean amplitudes of the b-wave, photopic negative responses (PhNR), and oscillatory potentials (OPs) 1 and 2 at T2 were significantly smaller than that at T1, but no significant difference was observed between T3 and T1. The mean implicit times of the a-wave and OP1, 2, and 3 at T2 and the a-wave and the OP2 at T3 were significantly longer than that at T1. The mean intraocular pressure (IOP) at T2 (49.32 mm Hg) was significantly higher and the IOP at T3 (8.74 mm Hg) was significantly lower than that at T1 (21.05 mm Hg). The retinal function was reduced and the IOP elevated just after the IVI. The response of each ERG component was different suggesting a different sensitivity of each type of retinal neuron to IVI. PMID:27492923

  5. Effects of moxifloxacin exposure on the conjunctival flora and antibiotic resistance profile following repeated intravitreal injections

    PubMed Central

    Ataş, Mustafa; Başkan, Burhan; Özköse, Ayşe; Mutlu Sarıgüzel, Fatma; Demircan, Süleyman; Pangal, Emine

    2014-01-01

    AIM To evaluate the effects of moxifloxacin exposure on the conjunctival flora and antibiotic resistance profile following repeated intravitreal injections. METHODS Seventy-two eyes of 36 patients [36 eyes in control group, 36 eyes in intravitreal injection (IVI) group] were enrolled in the study. All the eyes had at least one IVI and had diabetic macular edema (DME) or age-related macular degeneration (ARMD). Moxifloxacin was prescribed to all the patients four times a day for five days following injection. Conjunctival cultures were obtained from the lower fornix via standardized technique with every possible effort made to minimize contamination from the lids, lashes, or skin. Before the application of any ophthalmic medication, conjunctival cultures were obtained from both eyes using sterile cotton culture. An automated microbiology system was used to identify the growing bacteria and determine antibiotic sensitivity. RESULTS The bacterial cultures were isolated from 72 eyes of 36 patients, sixteen of whom patients (44.4%) were male and twenty (55.6%) were female. Average age was 68.4±9.0 (range 50-86). The average number of injections before taking cultures was 3.1+1.0. Forty-eight (66.7%) of 72 eyes had at least one significant organism. There was no bacterial growth in 8 (20.5%) of IVI eyes and in 16 (44.4%) of control eyes (P=0.03). Of the bacteria isolated from culture, 53.8% of coagulase negative staphylococci (CoNS) in IVI eyes and 47.2% CoNS in control eyes. This difference between IVI eyes and control eyes about bacteria isolated from culture was not statistically significant (P=0.2). Eleven of 25 bacteria (44.0%) isolated from IVI eyes and 11 (57.9%) of 19 bacteria isolated from control eyes were resistant to oxacillin. The difference in frequency of moxifloxacine resistance between two groups was not statistically significant (12.0% in IVI eyes and 21.1% in control eyes) (P=0.44). There were no cases of resistance to vancomycin, teicoplanin and

  6. Intravitreal tPA Injection and Pneumatic Displacement for Submacular Hemorrhage in a 10-Year-Old Child

    PubMed Central

    Hirose, Hiroshi; Hattori, Tomohiro

    2016-01-01

    Background. Submacular hemorrhage can occur after blunt trauma to the eye. Intravitreal tissue plasminogen activator (tPA) and gas injection are often used for treatment and are effective for submacular hemorrhage caused by age-related macular degeneration. This report describes the clinical outcome in a child with submacular hemorrhage caused by traumatic choroidal rupture who underwent successful intravitreal tPA injection and pneumatic displacement. Case Presentation. A 10-year-old boy developed sudden decrease of vision and a central scotoma in his right eye after trauma. Submacular hemorrhage was found in the eye. Visual acuity was 20/70 OD. Tissue plasminogen activator (12.5 μg in 0.05 mL) and 0.3 mL of pure sulfur hexafluoride were injected into the vitreous cavity under general anesthesia. After surgery, the patient was instructed to maintain a prone position. Displacement of the submacular hemorrhage from the fovea revealed a choroidal rupture, presumed to be the cause of the hemorrhage. After 4 months of follow-up, visual acuity was restored and final visual acuity is 20/16. Conclusion. Intravitreal tPA and gas injection can be an effective treatment for children with submacular hemorrhage. PMID:27722001

  7. Restoration of foveal photoreceptors after intravitreal ranibizumab injections for diabetic macular edema

    PubMed Central

    Mori, Yuki; Suzuma, Kiyoshi; Uji, Akihito; Ishihara, Kenji; Yoshitake, Shin; Fujimoto, Masahiro; Dodo, Yoko; Yoshitake, Tatsuya; Miwa, Yuko; Murakami, Tomoaki

    2016-01-01

    Anti-vascular endothelial growth factor drugs are the first-line treatment for diabetic macular edema (DME), although the mechanism of the visual acuity (VA) improvement remains largely unknown. The association between photoreceptor damage and visual impairment encouraged us to retrospectively investigate the changes in the foveal photoreceptors in the external limiting membrane (ELM) and ellipsoid zone (EZ) on spectral-domain optical coherence tomography (SD-OCT) images in 62 eyes with DME treated with intravitreal ranibizumab (IVR) injections. The transverse lengths of the disrupted EZ and ELM were shortened significantly (P < 0.001 and P = 0.044, respectively) at 12 months. The qualitative investigation also showed restoration of the EZ and ELM lines on SD-OCT images. The EZ at 12 months lengthened in 34 of 38 eyes with discontinuous EZ and was preserved in 16 of 21 eyes with complete EZ at baseline. VA improvement was positively correlated with shortening of the disrupted EZ at 12 months (ρ = 0.463, P < 0.001), whereas the decrease in central subfield thickness was associated with neither VA improvement nor changes in EZ status (ρ = 0.215, P = 0.093 and (ρ = 0.209, P = 0.103, respectively). These data suggested that photoreceptor restoration contributes to VA improvement after pro re nata treatment with IVR injections for DME independent of resolved retinal thickening. PMID:27966644

  8. Mobile ultra-clean unidirectional airflow screen reduces air contamination in a simulated setting for intra-vitreal injection.

    PubMed

    Lapid-Gortzak, Ruth; Traversari, Roberto; van der Linden, Jan Willem; Lesnik Oberstein, Sarit Y; Lapid, Oren; Schlingemann, Reinier O

    2017-02-01

    The aim of this study is to determine whether the use of a mobile ultra-clean laminar airflow screen reduces the air-borne particle counts in the setting of a simulated procedure of an intra-vitreal injection. A mobile ultra-clean unidirectional airflow (UDF) screen was tested in a simulated procedure for intra-vitreal injections in a treatment room without mechanical ventilation. One UDF was passed over the instrument tray and the surgical area. The concentration of particles was measured in the background, over the instrument table, and next to the ocular area. The degree of protection was calculated at the instrument table and at the surgical site. Use of the UDF mobile screen reduced the mean particle concentration (particles > 0.3 microns) on the instrument table by a factor of at least 100.000 (p < 0.05), and over the patient's eye by at least a factor of 436 (p < 0.05), which in clinical practice translates into significantly reduced air contamination. Mobile UDF screen reduces the mean particle concentration substantially. The mobile UDF screen may therefore allow for a safer procedural environment for ambulatory care procedures such as intra-vitreal injections in treatment rooms.

  9. Assessment of Corneal Sensation, Innervation and Retinal Nerve Fiber Layer in Patients Treated with Multiple Intravitreal Ranibizumab Injections

    PubMed Central

    Belviranli, Selman; Malik, Rayaz A.; Kerimoglu, Hurkan; Satirtav, Gunhal; Zengin, Nazmi

    2017-01-01

    Purpose To evaluate the effects of repeated intravitreal ranibizumab injections on corneal sensitivity, corneal sub-basal nerve plexus (SBNP) and peripapillary retinal nerve fiber layer (RNFL) thickness in patients with neovascular age-related macular degeneration (AMD). Methods Sixty-six eyes of 33 patients who had received unilateral repeated intravitreal ranibizumab injections (0.5 mg/0.05 ml) for the treatment of AMD and 25 eyes of 25 healthy subjects were included in the study. Central corneal sensation was measured using the contact Cochet-Bonnet esthesiometer. The laser scanning in vivo corneal confocal microscope was used to determine corneal SBNP parameters. The peripapillary RNFL thickness was assessed with spectral-domain optical coherence tomography. Data obtained from the ranibizumab-injected eyes were compared with those of the fellow non-treated eyes and the eyes of the healthy control subjects. Results The mean number of ranibizumab injections per eye was 8.9±5.0 (range 3–20). There were no statistically significant differences in the central corneal sensitivity threshold and corneal SBNP parameters between the ranibizumab-injected eyes and the fellow untreated eyes or between those with neovascular AMD and the healthy control group (P>0.05 for all). The average peripapillary RNFL thickness of the treated eyes did not differ significantly to the fellow eyes (P = 0.237), and the eyes of healthy control subjects (P = 0.918). There were no significant correlations between the number of ranibizumab injections and any of the study parameters. Conclusions Multiple intravitreal injections of ranibizumab seem to have no harmful effects on corneal sensitivity, innervation and peripapillary RNFL thickness in patients with AMD. PMID:28085965

  10. Intravitreal Injection of Bevacizumab for Retinopathy of Prematurity in an Infant with Peters Anomaly

    PubMed Central

    Minami, Tsuyoshi; Kuniyoshi, Kazuki; Kusaka, Shunji; Sugioka, Koji; Sakuramoto, Hiroyuki; Sakamoto, Masuo; Izu, Akane; Wada, Norihisa; Shimomura, Yoshikazu

    2014-01-01

    Purpose To report our findings in an infant with Peters anomaly type II whose retinopathy of prematurity (ROP) was treated with an anti-VEGF agent and surgeries. Case Report A male infant weighing 548 g was born prematurely at 23 weeks and 1 day with corneal opacity and shallow anterior chambers in both eyes. At the postmenstrual age of 35 weeks and 3 days, the infant was tentatively diagnosed with stage 3 ROP because of a dilated tunica vasculosa lentis and ultrasonographic findings. The boy was treated with bilateral intravitreal injections of bevacizumab (IVB) because laser photocoagulation of the retina could not be performed due to the corneal opacity. The retina in the right eye detached 3 times, namely 5 days, 16 days, and 7 months after the IVB; encircling the scleral buckle and a vitrectomy with endolaser photocoagulation were therefore required. In his left eye, the retina was reattached after the initial IVB, and no additional treatment was required. ROP was not reactivated in both eyes until the last examination at the age of 2 years and 6 months. Conclusions Our results showed that IVB is a useful treatment for ROP in patients with Peters anomaly. However, a retinal detachment can be a complication after IVB. The optimal timing of IVB for ROP in infants with hazy media needs to be determined. PMID:25408672

  11. Catalytic Nanoceria Are Preferentially Retained in the Rat Retina and Are Not Cytotoxic after Intravitreal Injection

    PubMed Central

    Wong, Lily L.; Hirst, Suzanne M.; Pye, Quentin N.; Reilly, Christopher M.; Seal, Sudipta; McGinnis, James F.

    2013-01-01

    Cerium oxide nanoparticles (nanoceria) possess catalytic and regenerative radical scavenging activities. The ability of nanoceria to maintain cellular redox balance makes them ideal candidates for treatment of retinal diseases whose development is tightly associated with oxidative damage. We have demonstrated that our stable water-dispersed nanoceria delay photoreceptor cell degeneration in rodent models and prevent pathological retinal neovascularization in vldlr mutant mice. The objectives of the current study were to determine the temporal and spatial distributions of nanoceria after a single intravitreal injection, and to determine if nanoceria had any toxic effects in healthy rat retinas. Using inductively-coupled plasma mass spectrometry (ICP-MS), we discovered that nanoceria were rapidly taken up by the retina and were preferentially retained in this tissue even after 120 days. We also did not observe any acute or long-term negative effects of nanoceria on retinal function or cytoarchitecture even after this long-term exposure. Because nanoceria are effective at low dosages, nontoxic and are retained in the retina for extended periods, we conclude that nanoceria are promising ophthalmic therapeutics for treating retinal diseases known to involve oxidative stress in their pathogeneses. PMID:23536794

  12. Multiple Intravitreal Ranibizumab Injections for Persistant Choroidal Neovascularization Associated with Presumed Ocular Histoplasmosis Syndrome

    PubMed Central

    Yılmaz, Turgut; Dikci, Seyhan; Genç, Oğuzhan; Mutlu, Kayhan

    2017-01-01

    Presumed ocular histoplasmosis syndrome (POHS) is a clinical entity that is characterized by small, round, discrete, macular or mid peripheral atrophic (punched out) chorioretinal lesions (histo spots), peripapillary scarring, choroidal neovascularization (CNV), and the absence of anterior uveitis and vitritis. Diagnosis of this disorder is based upon characteristic clinical findings and a positive histoplasmin skin test or residence in an endemic region for Histoplasma capsulatum. There is no active systemic disease during diagnosis of POHS. Disciform scarring and macular CNV secondary to POHS is a well-known complication which leads to loss of visual acuity or visual disturbance. Without therapy, the visual prognosis in these patients is unfavorable. Submacular surgery, radiation, steroids, photodynamic therapy, and most recently anti-vascular endothelial growth factor therapy are current therapeutic options for this condition. We report a case with persistent CNV secondary to POHS in a middle-aged woman with moderate myopia and the clinical course of treatment with multiple intravitreal ranibizumab (Lucentis®, Novartis) injections.

  13. Effectiveness of Intravitreal Injection of Ranibizumab for Neovascular Age-Related Macular Degeneration with Serous Pigment Epithelial Detachment

    PubMed Central

    Zhao, Chun; Zhang, Zhen; Chen, Lei; Wang, Fang; Xu, Ding

    2016-01-01

    Background We sought to observe the effectiveness of intravitreal injection of ranibizumab in treating neovascular age-related macular degeneration (nAMD) with serous pigment epithelial detachment (sPED). Material/Methods A retrospective, noncomparative case series was performed. Twenty-3 eyes of 23 patients with sPED secondary to nAMD who had received intravitreal injections of ranibizumab were included in this study. All patients underwent best-corrected visual acuity (BCVA), synchronous fluorescein fundus angiography (FFA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT) examinations. All patients were treated with pro re nata intravitreal injections after 3 loading doses of ranibizumab and were followed up for 12 months. The differences in the BCVAs, maximum PED heights, PED volumes and CFTs of the affected eyes were compared between the baseline and last visit. Results Twelve months after the first injection, improved visual acuity was observed in 16 of the 23 eyes. 4 eyes exhibited stable visual acuity, and 3 eyes exhibited impaired visual acuity. The mean post-injection logMAR BCVA was 0.58±0.05, which was much better than that at baseline (0.76±0.08; t=1.751, P=0.0869). The mean maximum PED height at baseline was 350.17±35.73μm and it was decreased to 238.87±36.87μm (t=2.192, P=0.0337) at the last visit. The mean PED volume after injection was 0.34±0.1 mm3, which was significantly decreased compared with that at baseline (0.81±0.21 mm3; t=2.021, P=0.0494).The mean CFT decreased, but this difference was not statistically significant (t=1.003, P=0.3211). None of the patients exhibited endophthalmitis, uveitis or RPE tears. Conclusions Intravitreal injection of ranibizumab for the treatment of neovascular age-related macular degeneration with serous pigment epithelial detachment safely and effectively improved the patients’ visual acuities and decreased their PED heights volumes. PMID:26972376

  14. Acute Hemorrhagic Retinopathy following Intravitreal Melphalan Injection for Retinoblastoma: A Report of Two Cases and Technical Modifications to Enhance the Prevention of Retinal Toxicity

    PubMed Central

    Aziz, Hassan A.; Kim, Jonathan W.; Munier, Francis L.; Berry, Jesse L.

    2017-01-01

    Aims To report the occurrence of acute hemorrhagic retinopathy following intravitreal melphalan injection for retinoblastoma. Methods This is a retrospective case series of 2 patients with retinoblastoma treated with intravitreal melphalan for vitreous seeding who developed acute hemorrhagic retinopathy. Results Patient 1 is a 6-month-old female with bilateral retinoblastoma (Group D right eye and Group B left eye) treated with 4 cycles of systemic chemotherapy and 2 intravitreal melphalan injections in each eye. Patient 2 is a 10-month-old male with unilateral Group D retinoblastoma treated with 6 cycles of systemic chemotherapy and 2 injections of intravitreal melphalan. At the 1-week follow-up after the second injection, both patients had an acute hemorrhagic retinopathy that resulted in chorioretinal toxicity with a sharp demarcation line between the normal and abnormal retina. At the last follow-up (22 and 12 months, respectively), there was total tumor control and resolution of vitreous seeding in both patients. Conclusions Although intravitreal melphalan injection is effective for vitreous seeding in eyes with retinoblastoma, acute hemorrhagic retinopathy and diffuse chorioretinal atrophy is a possible complication of this treatment modality. Given the clinical findings observed in these patients, the development of this retinal toxicity most likely results from a retrohyaloid overdose. Consequently we suggest preventive measures aimed at limiting the risk of retrohyaloid injection.

  15. The effect of intravitreal injection of vehicle solutions on form deprivation myopia in tree shrews.

    PubMed

    Ward, Alexander H; Siegwart, John T; Frost, Michael R; Norton, Thomas T

    2016-04-01

    lntravitreal injection of substances dissolved in a vehicle solution is a common tool used to assess retinal function. We examined the effect of injection procedures (three groups) and vehicle solutions (four groups) on the development of form deprivation myopia (FDM) in juvenile tree shrews, mammals closely related to primates, starting at 24 days of visual experience (about 45 days of age). In seven groups (n = 7 per group), the myopia produced by monocular form deprivation (FD) was measured daily for 12 days during an 11-day treatment period. The FD eye was randomly selected; the contralateral eye served as an untreated control. The refractive state of both eyes was measured daily, starting just before FD began (day 1); axial component dimensions were measured on day 1 and after eleven days of treatment (day 12). Procedure groups: the myopia (treated eye - control eye refraction) in the FD group was the reference. The sham group only underwent brief daily anesthesia and opening of the conjunctiva to expose the sclera. The puncture group, in addition, had a pipette inserted daily into the vitreous. In four vehicle groups, 5 μL of vehicle was injected daily. The NaCl group received 0.85% NaCl. In the NaCl + ascorbic acid group, 1 mg/mL of ascorbic acid was added. The water group received sterile water. The water + ascorbic acid group received water with ascorbic acid (1 mg/mL). We found that the procedures associated with intravitreal injections (anesthesia, opening of the conjunctiva, and puncture of the sclera) did not significantly affect the development of FDM. However, injecting 5 μL of any of the four vehicle solutions slowed the development of FDM. NaCl had a small effect; myopia development in the last 6 days (-0.15 ± 0.08 D/day) was significantly less than in the FD group (-0.55 ± 0.06 D/day). NaCl + Ascorbic acid further slowed the development of FDM on several treatment days. H2O (-0.09 ± 0.05 D/day) and H2O + ascorbic acid

  16. Management of Acute Submacular Hemorrhage with Intravitreal Injection of Tenecteplase, Anti-vascular Endothelial Growth Factor and Gas

    PubMed Central

    Lee, Jung Pil; Park, Jun Sang; Kwon, Oh Woong; You, Yong Sung

    2016-01-01

    Purpose To evaluate the visual and anatomical outcomes for neovascular age-related macular degeneration with submacular hemorrhage after intravitreal injections of tenecteplase (TNK), anti-vascular endothelial growth factor (VEGF) and expansile gas. Methods This study was a retrospective clinical case series following 25 eyes of 25 patients. All patients received a triple injection using 0.05 mL TNK (50 µg), 0.05 mL anti-VEGF and 0.3 mL of perfluoropropane gas. Retreatment with anti-VEGF was performed as needed. Preoperative and postoperative best-corrected visual acuity and central retinal thickness were analyzed. Results The mean logarithm of the minimum angle of resolution of best-corrected visual acuity improved significantly from 1.09 ± 0.77 at baseline to 0.52 ± 0.60 at 12 months (p < 0.001). The mean central retinal thickness also improved significantly from 545 ± 156 at baseline to 266 ± 107 at 12 months (p < 0.001). A visual improvement of 0.3 logarithm of the minimum angle of resolution unit or more was achieved in 15 eyes (60%). During the 12 postoperative months, an average of 4.04 intravitreal anti-VEGF injections was applied. Conclusions A triple injection of TNK, anti-VEGF, and a gas appears to be safe and effective for the treatment of submacular hemorrhage secondary to neovascular age-related macular degeneration. PMID:27247518

  17. A cluster of presumed, noninfectious endophthalmitis after intravitreal injection of bevacizumab: long-term follow-up

    PubMed Central

    Ricci, Federico; Calabrese, Antonio; De Felici, Cecilia; Missiroli, Filippo; Pileri, Marco; Regine, Federico

    2016-01-01

    Purpose To report the outcome of 5 consecutive cases of presumed, noninfectious endopththalmitis following intravitreal injection of bevacizumab (IVB). Methods Ten pre-loaded syringes of bevacizumab (1.25 mg/50 µL) furnished by a compounding pharmacy were injected intravitreally. Treatments were performed in the operating room by the same surgeon on 2 consecutive days. Results Of 10 eyes, 5 showed moderate to severe ocular inflammation within a few days of injection. All patients were treated in the same surgical session. Vitreous tap performed in the patient presenting with the most severe grade of inflammation was negative for bacteria and fungi. At the time of the vitreous biopsy, this patient was injected with vancomycin 1 mg/100 µL in the vitreous cavity. Other eyes with moderate inflammation received topical and systemic antibiotics and topical steroid treatment. Visual acuity returned to pre-endophthalmitis or better levels in all eyes within 1 month. The other 5 patients treated with IVB from the same batch in the other surgical session did not develop inflammation. Conclusions IVB can induce noninfectious endophthalmitis. The use of compounded syringes can explain clustering of the inflammation. We were unable to identify the reasons for the variable grade of inflammation we observed in our patients. PMID:27582674

  18. Clinical effects and safety of treating diabetic macular edema with intravitreal injection of ranibizumab combined with retinal photocoagulation

    PubMed Central

    Yan, Panshi; Qian, Cheng; Wang, Wenzhan; Dong, Yi; Wan, Guangming; Chen, Yue

    2016-01-01

    Background This study was designed to examine the clinical effects of treating diabetic macular edema with an intravitreal injection of ranibizumab in combination with retinal photocoagulation. Methods Sixty-two cases (75 eyes) with confirmed severe proliferative diabetic retinopathy or proliferative diabetic retinopathy in combination with macular edema were randomly divided into the observation group (37 eyes were given an intravitreal injection of ranibizumab combined with retinal photocoagulation) and the control group (38 eyes received retinal photocoagulation only). Vision, fundus condition, central macular thickness, and the macular leakage area were recorded before and after treatment. Results The best-corrected visual acuity and macular leakage area were similar between the observation and control groups (P>0.05). The best-corrected visual acuity in the observation group was higher than that in the control group 3 and 6 months after treatment (P<0.05) and showed a rising tendency. The macular leakage area in the observation group was significantly lower than that in the control group 1 and 3 months after treatment (P<0.05). However, the macular leakage area was similar 6 months after treatment (P>0.05). The central macular thickness of the observation group was lower than that in the control group 1, 3, and 6 months after treatment (P<0.05). The laser energy used in the observation group was also smaller than that in the control group (P<0.05). The intraocular pressure was not significantly different between the groups (P<0.05). No patients in the two groups developed eye or systemic complications, such as glaucoma, cataract, or vitreous hemorrhage during treatment. Conclusion Intravitreal injection of ranibizumab combined with retinal photocoagulation was proven to be effective in treating diabetic macular edema as it improved vision and resulted in fewer complications. PMID:27103811

  19. Anterior segment changes following intravitreal bevacizumab injection for treatment of neovascular glaucoma

    PubMed Central

    Canut, MI; Alvarez, A; Nadal, J; Abreu, R; Abreu, JA; Pulido, JS

    2011-01-01

    Background: The purpose of this study was to describe anterior segment changes in a prospective, interventional, noncomparative case series of patients with neovascular glaucoma secondary to proliferative diabetic retinopathy treated with intravitreal bevacizumab. Methods: Five consecutive patients with neovascular glaucoma and a refractory, symptomatic elevation of intraocular pressure and pronounced anterior segment congestion received intravitreal bevacizumab 1.25 mg/0.05 mL. Follow-up examinations were performed at 4–16 weeks by the same specialists, with testing performed at hour 48, week 1, and months 1, 3, and 6 after intravitreal bevacizumab. Results: We observed a significant difference (P = 0.021) between initial and mean neovascularization at three months in all the quadrants. At three months, median intraocular pressure was 19 ± 5.38 (range 12–26) mmHg. In three of the five cases, diode laser cyclophotocoagulation was required, and in one case a trabeculectomy was performed. One patient showed complete synechial angle closure 48 hours after treatment which required cyclodestructive procedures to normalize intraocular pressure. Conclusion: Intravitreal bevacizumab achieves complete regression of neovascularization in neovascular glaucoma secondary to proliferative diabetic retinopathy, and this regression is stable when associated with treatment of the underlying disease and should be investigated more thoroughly as an adjunct in the management of neovascular glaucoma. PMID:21629579

  20. Visual tracing of diffusion and biodistribution for amphiphilic cationic nanoparticles using photoacoustic imaging after ex vivo intravitreal injections.

    PubMed

    Xu, Xu; Xu, Zhaokang; Liu, Junyi; Zhang, Zhaoliang; Chen, Hao; Li, Xingyi; Shi, Shuai

    To visually trace the diffusion and biodistribution of amphiphilic cation micelles after vitreous injection, various triblock copolymers of monomethoxy poly(ethylene glycol)-poly(ε-caprolactone)-polyethylenimine were synthesized with different structures of hydrophilic and hydrophobic segments, followed by labeling with near-infrared fluorescent dye Cyanine5 or Cyanine7. The micellar size, polydispersity index, and surface charge were measured by dynamic light scattering. The diffusion was monitored using photoacoustic imaging in real time after intravitreal injections. Moreover, the labeled nanoparticle distribution in the posterior segment of the eye was imaged histologically by confocal microscopy. The results showed that the hydrophilic segment increased vitreous diffusion, while a positive charge on the particle surface hindered diffusion. In addition, the particles diffused through the retinal layers and were enriched in the retinal pigment epithelial layer. This work tried to study the diffusion rate via a simple method by using visible images, and then provided basic data for the development of intraocular drug carriers.

  1. Durable recovery of the macular architecture and functionality of a diagnosed age-related macular degeneration 1 year after a single intravitreal injection of dobesilate.

    PubMed

    Cuevas, P; Outeiriño, L A; Azanza, C; Giménez-Gallego, G

    2013-11-13

    Among the age-related diseases that affect vision, age-related macular degeneration is the most frequent cause of blindness in patients older than 60 years. In this communication, we report the full anatomical and functional recovery of a patient diagnosed with wet age-related macular degeneration 1 year after a single intravitreal injection of dobesilate.

  2. Durable recovery of the macular architecture and functionality of a diagnosed age-related macular degeneration 1 year after a single intravitreal injection of dobesilate

    PubMed Central

    Cuevas, P; Outeiriño, L A; Azanza, C; Giménez-Gallego, G

    2013-01-01

    Among the age-related diseases that affect vision, age-related macular degeneration is the most frequent cause of blindness in patients older than 60 years. In this communication, we report the full anatomical and functional recovery of a patient diagnosed with wet age-related macular degeneration 1 year after a single intravitreal injection of dobesilate. PMID:24225910

  3. Vitrectomy Before Intravitreal Injection of AAV2/2 Vector Promotes Efficient Transduction of Retinal Ganglion Cells in Dogs and Nonhuman Primates.

    PubMed

    Tshilenge, Kizito-Tshitoko; Ameline, Baptiste; Weber, Michel; Mendes-Madeira, Alexandra; Nedellec, Steven; Biget, Marine; Provost, Nathalie; Libeau, Lyse; Blouin, Véronique; Deschamps, Jack-Yves; Le Meur, Guylène; Colle, Marie-Anne; Moullier, Philippe; Pichard, Virginie; Rolling, Fabienne

    2016-06-01

    Recombinant adeno-associated virus (AAV) has emerged as a promising vector for retinal gene delivery to restore visual function in certain forms of inherited retinal dystrophies. Several studies in rodent models have shown that intravitreal injection of the AAV2/2 vector is the optimal route for efficient retinal ganglion cell (RGC) transduction. However, translation of these findings to larger species, including humans, is complicated by anatomical differences in the eye, a key difference being the comparatively smaller volume of the vitreous chamber in rodents. Here, we address the role of the vitreous body as a potential barrier to AAV2/2 diffusion and transduction in the RGCs of dogs and macaques, two of the most relevant preclinical models. We intravitreally administered the AAV2/2 vector carrying the CMV-eGFP reporter cassette in dog and macaque eyes, either directly into the vitreous chamber or after complete vitrectomy, a surgical procedure that removes the vitreous body. Our findings suggest that the vitreous body appears to trap the injected vector, thus impairing the diffusion and transduction of AAV2/2 to inner retinal neurons. We show that vitrectomy before intravitreal vector injection is an effective means of overcoming this physical barrier, improving the transduction of RGCs in dog and macaque retinas. These findings support the use of vitrectomy in clinical trials of intravitreal gene transfer techniques targeting inner retinal neurons.

  4. Intravitreal injection of forskolin, homotaurine, and L-carnosine affords neuroprotection to retinal ganglion cells following retinal ischemic injury

    PubMed Central

    Adornetto, Annagrazia; Cavaliere, Federica; Varano, Giuseppe Pasquale; Rusciano, Dario; Morrone, Luigi Antonio; Corasaniti, Maria Tiziana; Bagetta, Giacinto; Nucci, Carlo

    2015-01-01

    Purpose Retinal ganglion cell (RGC) death is the final event leading to visual impairment in glaucoma; therefore, identification of neuroprotective strategies able to slow down or prevent the process is one of the main challenges for glaucoma research. The purpose of this study was to evaluate the neuroprotective potential of RGC death induced by the in vivo transient increase in intraocular pressure (IOP) of a combined treatment with forskolin, homotaurine, and L-carnosine. Forskolin (7beta-acetoxy-8, 13-epoxy-1a, 6β, 9a-trihydroxy-labd-14-en-11-one) is an activator of adenylate cyclase that decreases IOP by reducing aqueous humor production and functions as a neuroprotector due to its neurotrophin-stimulating activity. Homotaurine is a natural aminosulfonate compound endowed with neuromodulatory effects, while the dipeptide L-carnosine is known for its antioxidant properties. Methods Retinal ischemia was induced in the right eye of adult male Wistar rats by acutely increasing the IOP. Forskolin, homotaurine, and L-carnosine were intravitreally injected and RGC survival evaluated following retrograde labeling with FluoroGold. Total and phosphorylated Akt and glycogen synthase kinase-3β (GSK-3β) protein levels, as well as calpain activity, were analyzed with western blot. Protein kinase A (PKA) was inhibited by intravitreal injection of H89. Results A synergic neuroprotective effect on RGC survival was observed following the combined treatment with forskolin, homotaurine, and L-carnosine compared to forskolin alone. The observed neuroprotection was associated with reduced calpain activity, upregulation of phosphoinositide 3-kinase (PI3K)/Akt pathway, and inhibition of GSK-3β but was independent from PKA activation and distinct from the hypotensive effects of forskolin. Conclusions A multidrug/multitarget approach, by interfering with several pathways involved in RGC degeneration, may be promising to achieve glaucoma neuroprotection. PMID:26167113

  5. Biochemical changes induced by intravitreally-injected doxorubicin in the iris-ciliary body and lens of the rabbit eye.

    PubMed

    Phylactos, A C; Unger, W G

    1998-01-01

    The aim of this study was to examine the chronic effects and mode of action of doxorubicin in ocular tissues. A dose of 10 microg (17.24 nanomoles) of doxorubicin hydrochloride in 20 microl sterile saline were intravitreally injected, under local anaesthesia, in one eye of 13 rabbits and 50 microg (86.20 nanomoles) were similarly injected in one eye of 3 rabbits. The contralateral eye received 20 microl of saline only. The dose of 50 microg induced initially mild uveal inflammation which became chronic and turned into circular iritis. Both doses of the drug induced cataract of the lens and clouding of the cornea within 2-3 months. The activity of superoxide dismutase, in iris-ciliary bodies and lenses treated with either 10 or 50 microg of the compound, was significantly lower relative to that in respective control tissues. In contrast to superoxide dismutase, catalase showed an increased activity in experimental tissues relative to control. The lysosomal hydrolases acid phosphatase, N-acetyl-B-D-glucosaminidase, aryl sulphatase and acid cathepsin, all showed significantly elevated activities in iris-ciliary body tissues one year after injection with the 50 microg doxorubicin. The reduction in superoxide dismutase activity may render ocular tissues susceptible to peroxidative attack and the increased activities of lysosomal hydrolases may contribute to chronic cell injury and inflammation.

  6. Visual tracing of diffusion and biodistribution for amphiphilic cationic nanoparticles using photoacoustic imaging after ex vivo intravitreal injections

    PubMed Central

    Xu, Xu; Xu, Zhaokang; Liu, Junyi; Zhang, Zhaoliang; Chen, Hao; Li, Xingyi; Shi, Shuai

    2016-01-01

    To visually trace the diffusion and biodistribution of amphiphilic cation micelles after vitreous injection, various triblock copolymers of monomethoxy poly(ethylene glycol)–poly(ε-caprolactone)–polyethylenimine were synthesized with different structures of hydrophilic and hydrophobic segments, followed by labeling with near-infrared fluorescent dye Cyanine5 or Cyanine7. The micellar size, polydispersity index, and surface charge were measured by dynamic light scattering. The diffusion was monitored using photoacoustic imaging in real time after intravitreal injections. Moreover, the labeled nanoparticle distribution in the posterior segment of the eye was imaged histologically by confocal microscopy. The results showed that the hydrophilic segment increased vitreous diffusion, while a positive charge on the particle surface hindered diffusion. In addition, the particles diffused through the retinal layers and were enriched in the retinal pigment epithelial layer. This work tried to study the diffusion rate via a simple method by using visible images, and then provided basic data for the development of intraocular drug carriers. PMID:27785015

  7. Effective Intravitreal Injections of Bevacizumab in a Case of Serous Macular Detachment from the Superior Border of the Posterior Staphyloma

    PubMed Central

    Tsubota, Yukiko; Takahashi, Hidenori; Sugisaki, Kenji; Tanabe, Tatsuro; Fujino, Yujiro

    2017-01-01

    Purpose We present an atypical case of submacular fluid leading to serous macular detachment. Method/Patient A 69-year-old man was evaluated for metamorphopsia in the left eye. Results Best-corrected visual acuity was 20/25 in both eyes. He had undergone cataract surgeries in both eyes 12 years ago. The axial length was 25.93 mm (OD) and 24.12 mm (OS). Optical coherence tomography showed posterior staphylomas and subretinal fluid on the superior border of the staphylomas in both eyes; in the left eye, submacular fluid was noted extending up to the macula. Fundus fluorescein angiography revealed leakage from the superior border of the staphylomas in both eyes. The fluid persisted for 4 months. Four consecutive, monthly injections of bevacizumab (1.25 mg/0.05 mL) were administered in the left eye; subsequently, the subretinal fluid gradually dissipated from the macula and became localized at the superior border of the staphyloma. This localization persisted for 12 months. Conclusions We have detailed a case of submacular fluid that spread from the superior border of the posterior staphyloma in a patient with macular detachment, in whom intravitreal injections of bevacizumab were highly effective in eliminating the fluid. PMID:28203196

  8. The combination of phacoemulsification surgery and intravitreal triamcinolone injection in patients with cataract and diabetic macular edema

    PubMed Central

    Ozgur, Ozlen Rodop; Ozkurt, Yelda; Kulekci, Zeynep; Evciman, Tufan

    2015-01-01

    Purpose To assess the safety and efficiency of combined phacoemulsification (PHACO) surgery and intravitreal triamcinolone (IVTA) injection with or without macular grid laser photocoagulation in patients with cataract and diabetic macular edema. Material and methods This prospective study included 41 eyes of 36 diabetic patients with cataract and coexisting clinically significant macular edema (CSME). After PHACO and IVTA injection eyes were divided into two groups: the laser and IVTA group (Group 1) and only IVTA group (Group 2). Preoperative and postoperative best corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP) were recorded. Paired sample t-test was used to compare data in the groups and C square test for qualitative variables. Results Postoperative BCVA was significantly higher than the initial BCVA during the follow-up period in both groups (p < 0.01). The BCVA 6 months after surgery was significantly higher in group 1 than in group 2 (p < 0.01). There was no statistically significant difference in IOP between two groups preoperatively and postoperatively during the follow-up period (p > 0.05). There was no statistically significant difference between both groups in mean CMT preoperatively and 2nd week, 2nd month and 3rd month after surgery (p > 0.05). The mean CMT 6 months after surgery was statistically significantly lower in group 1 than in group 2 (p < 0.01). Conclusions PHACO surgery combined with IVTA injection improves BCVA and provides a decrease in CMT in diabetic patients with CSME. Additional macular grid laser photocoagulation after surgery helps to preserve this improvement in BCVA and decrease in CMT. PMID:26949356

  9. Combination of Intravitreal Injection of Ranibizumab and Photocoagulation for the Treatment of Aggressive Posterior Retinopathy of Prematurity with Vitreous Hemorrhage

    PubMed Central

    Huang, Qiujing; Lv, Jiao

    2016-01-01

    To investigate the efficacy of intravitreal ranibizumab (IVR) combined with laser photocoagulation for aggressive posterior retinopathy of prematurity (AP-ROP) patients with vitreous hemorrhage, we conducted a retrospective observational case series study. A total of 37 eyes of 20 patients' medical records were reviewed. Patients first received IVR (0.25 mg/0.025 mL) and later photocoagulation. The mean postconceptual age of injection was 34.6 ± 1.4 weeks, and the mean follow-up period was 39.3 ± 8.3 weeks. During the follow-up, 96.6% eyes had various degree of rapid absorption of vitreous hemorrhage after IVR. The mean time of received first photocoagulation after IVR was 4.8 ± 2.9 weeks. Ten (27.0%) eyes received second laser therapy and the mean time of second laser therapy after IVR was 3.2 ± 0.8 weeks. All eyes exhibited adequate regression of ROP and were stable with attached retina. Fibrosis membrane was observed in seven eyes (18.9%) and three of them demonstrated mild ectopic macula. No significant side effects related to IVR were observed. So IVR could be conducted as primary treatment of AP-ROP associated with vitreous hemorrhage, which can improve the fundus visibility, followed by conventional photocoagulation. Further randomized controlled trials are necessary to compare the clinical efficacy and safety with conventional interventions. PMID:28070414

  10. Management of recurrent inflammatory choroidal neovascular membrane secondary to Vogt-Koyanagi-Harada syndrome, using combined intravitreal injection of bevacizumab and triamcinolone acetate

    PubMed Central

    Pai, Sivakami A; Hebri, Sudhira P; Lootah, Afra M

    2012-01-01

    The purpose of this report is to evaluate the efficacy and safety of combined intravitreal injection of bevacizumab and intravitreal triamcinolone acetonide (IVTA) for recurrent inflammatory choroidal neovascular membrane (CNVM). It was a prospective interventional study of a young female, who was a known case of Vogt-Koyanagi-Harada syndrome. She presented with an inflammatory choroidal neovascualar membrane and signs of panuveitis in the right eye. She underwent a complete ophthalmic examination. She was given intravitreal injection of bevacizumab and IVTA at different sites. There was complete regression of CNVM and ocular inflammation within a week. After six months, she had recurrence of CNVM in the same eye, which was treated similarly. There was a complete resolution of CNVM and ocular inflammation after the combination therapy and systemic steroids, until one year of follow-up. No serious systemic or ocular adverse events were noted. Combination therapy appears to be an effective and safe method in the management of recurrent inflammatory CNVM. PMID:23202396

  11. [Intravitreous injection of bevacizumab and C3F8 gas for the treatment of submacular hemorrhage due to age-related macular degeneration: case reports].

    PubMed

    Ferraz, Daniel Araújo; Bressanim, Gláucio Luciano; Morita, Celso; Takahashi, Walter Yukihiko

    2010-01-01

    The purpose of this case series is to describe if the intravitreal use of bevacizumab and perfluoropropane gas (C3F8) would be beneficial to the displacement of subretinal hemorrhage in patients with age-related macular degeneration (AMD). A retrospective study of 5 eyes that received concurrent intravitreal injection of bevacizumab and C3F8 was performed. The results were graded according to blood displacement under the fovea, best final visual acuity and intraoperative complications. At the initial presentation, mean age of patients was 72.6 +/- 8.9 years-old and duration of symptoms was 13 +/- 9.7 days. From the 5 patients, 3 (60%) were male and 2 (40%) female. The success of submacular hemorrhage full displacement was achieved in 4 patients. The mean preoperative visual acuity (VA) was 1.12 +/- 0.34 logMAR and the mean postoperative VA was 0.92 +/- 0.4 logMAR. No cases of retinal detachment, endophthalmitis, vitreous hemorrhage, uveitis, cataracts and increased intraocular pressure were noted during the follow-up period. Intravitreal bevacizumab and C3F8 injection, associated to prone position can be a valuable therapeutic option for eyes with neovascular age-related macular degeneration and subretinal hemorrhage to the blood displacement out of the foveal area.

  12. Distribution of Triamcinolone Acetonide after Intravitreal Injection into Silicone Oil-Filled Eye.

    PubMed

    Da, Ma; Li, Kenneth K W; Chan, Kevin C; Wu, Ed X; Wong, David S H

    2016-01-01

    There is increasing use of the vitreous cavity as a reservoir for drug delivery. We study the intraocular migration and distribution of triamcinolone acetonide (TA) after injection into silicone oil tamponade agent during and after vitrectomy surgery ex vivo (pig eye) and in vitro (glass bottle). For ex vivo assessment, intraocular migration of TA was imaged using real-time FLASH MRI scans and high-resolution T2W imaging and the in vitro model was monitored continuously with a video camera. Results of the ex vivo experiment showed that the TA droplet sank to the interface of silicone oil and aqueous almost immediately after injection and remained inside the silicone oil bubble for as long as 16 minutes. The in vitro results showed that, after the shrinkage of the droplet, TA gradually precipitated leaving only a lump of whitish crystalline residue inside the droplet for about 100 minutes. TA then quickly broke the interface and dispersed into the underlying aqueous within 15 seconds, which may result in a momentary increase of local TA concentration in the aqueous portion and potentially toxic to the retina. Our study suggests that silicone oil may not be a good candidate as a drug reservoir for drugs like TA.

  13. Distribution of Triamcinolone Acetonide after Intravitreal Injection into Silicone Oil-Filled Eye

    PubMed Central

    Wu, Ed X.; Wong, David S. H.

    2016-01-01

    There is increasing use of the vitreous cavity as a reservoir for drug delivery. We study the intraocular migration and distribution of triamcinolone acetonide (TA) after injection into silicone oil tamponade agent during and after vitrectomy surgery ex vivo (pig eye) and in vitro (glass bottle). For ex vivo assessment, intraocular migration of TA was imaged using real-time FLASH MRI scans and high-resolution T2W imaging and the in vitro model was monitored continuously with a video camera. Results of the ex vivo experiment showed that the TA droplet sank to the interface of silicone oil and aqueous almost immediately after injection and remained inside the silicone oil bubble for as long as 16 minutes. The in vitro results showed that, after the shrinkage of the droplet, TA gradually precipitated leaving only a lump of whitish crystalline residue inside the droplet for about 100 minutes. TA then quickly broke the interface and dispersed into the underlying aqueous within 15 seconds, which may result in a momentary increase of local TA concentration in the aqueous portion and potentially toxic to the retina. Our study suggests that silicone oil may not be a good candidate as a drug reservoir for drugs like TA. PMID:27493959

  14. Determination of triamcinolone acetonide in silicone oil and aqueous humor of vitrectomized rabbits' eyes: Application for a pharmacokinetic study with intravitreal triamcinolone acetonide injections (Kenalog® 40).

    PubMed

    Fernandes-Cunha, Gabriella M; Saliba, Juliana B; Siqueira, Rubens C; Jorge, Rodrigo; Silva-Cunha, Armando

    2014-02-01

    A simple and accurate method including liquid-liquid extraction and protein precipitation procedures from silicone oil and aqueous humor samples followed by high-performance liquid chromatography (HPLC-UV) was developed and validated to determine the pharmacokinetic profile of triamcinolone acetonide in silicone oil and aqueous humor of rabbits' eyes submitted to the pars plana vitrectomy surgery. The method was successfully applied to quantify the drug remaining in silicone oil and aqueous humor (LOQ range of 1μg/mL). The triamcinolone acetonide remained in silicone oil and aqueous humor of vitrectomized rabbits' eyes for four weeks after the intravitreal injections.

  15. [Choroidal metastasis from a lung adenocarcinoma treated by intravitreal injection of anti-VEGF and external beam radiotherapy: A case report].

    PubMed

    Menoux, I; Guihard, S; Antoni, D; Bijon, J-C; Noël, G

    2017-03-23

    Choroidal metastases of lung cancer are very uncommon. This localization should be suspected on blurred vision and confirmed with an ophthalmological examination. Its treatment is not entirely codified. We report a case of blurred vision secondary to bilateral choroidal metastasis in a patient with choroidal metastases from a lung adenocarcinoma, treated by intravitreal anti-vascular endothelial growth factor (VEGF) injection and external beam radiotherapy. According to a literature review, we analyzed the place of the targeted treatments used alone or combined with the radiotherapy.

  16. DAPI diffusion after intravitreal injection of mesenchymal stem cells in the injured retina of rats.

    PubMed

    Castanheira, Paula; Torquetti, Leonardo Torquetti; Magalhãs, Débora Rodrigues Soares; Nehemy, Marcio B; Goes, Alfredo M

    2009-01-01

    To evaluate DAPI (4',6-diamidino-2-phenylindole) as a nuclear tracer of stem cell migration and incorporation it was observed the pattern of retinal integration and differentiation of mesenchymal stem cells (MSCs) injected into the vitreous cavity of rat eyes with retinal injury. For this purpose adult rat retinas were submitted to laser damage followed by transplantation of DAPI-labeled BM-MSCs grafts and double-labeled DAPI and quantum dot-labeled BM-MSCs. To assess a possible DAPI diffusion as well as the integration and differentiation of DAPI-labeled BM-MSCs in laser-injured retina, host retinas were evaluated 8 weeks after injury/transplantation. It was demonstrated that, 8 weeks after the transplant, most of the retinal cells in all neural retinal presented nuclear DAPI labeling, specifically in the outer nuclear layer (ONL), inner nuclear layer (INL), and ganglion cell layer (GCL). Meanwhile, at this point, most of the double-labeled BM-MSCs (DAPI and quantum dot) remained in the vitreous cavity and no retinal cells presented the quantum dot marker. Based on these evidences we concluded that DAPI diffused to adjacent retinal cells while the nanocrystals remained labeling only the transplanted BM-MSCs. Therefore, DAPI is not a useful marker for stem cells in vivo tracing experiments because the DAPI released from dying cells in moment of the transplant are taken up by host cells in the tissue.

  17. Intravitreal Injection of Ozurdex® Implant in Patients with Persistent Diabetic Macular Edema, with Six-Month Follow-Up

    PubMed Central

    Pacella, Fernanda; Ferraresi, Adriana Francesca; Turchetti, Paolo; Lenzi, Tommaso; Giustolisi, Rosalia; Bottone, Andrea; Fameli, Valeria; Romano, Maria Rosaria; Pacella, Elena

    2016-01-01

    AIM To evaluate the efficacy of intravitreal dexamethasone injections in diabetic macular edema (DME). METHODS A 700 μg slow-release intravitreal dexamethasone implant (Ozurdex®) was placed in the vitreal cavity of 17 patients (19 eyes) affected with persistent DME. Best corrected visual acuity (BCVA) was assessed through Early Treatment Diabetic Retinopathy Study (ETDRS). Central macular thickness (CMT) was measured by spectral-domain optical coherence tomography. BCVA and CMT examinations were carried out at baseline (T0) and repeated after three days, one month (T1), three months (T3), four months (T4), and six months (T6) post injection. RESULTS Dexamethasone implant induced an improvement in ETDRS at T1, T3, T4, and T6 post injection. CMT was reduced at T1, T3, and T4, while at T6, CMT values were not statistically different from baseline. No complications were observed during the follow-up. CONCLUSION Our data suggest that dexamethasone implant is effective in reducing DME symptoms within a six-month frame. PMID:27147895

  18. Effect of prophylactic intraocular pressure-lowering medication (brinzolamide) on intraocular pressure after ranibizumab intravitreal injection: A case–control study

    PubMed Central

    Song, Shuang; Yu, Xiao-bing; Dai, Hong

    2016-01-01

    Purpose: To observe the effect of prophylactic intraocular pressure (IOP)-lowering medication (brinzolamide) on IOP after ranibizumab intravitreal injections (IVIs). Materials and Methods: This prospective case–control study included 352 eyes from 352 patients (1 eye per patient) who were treated with ranibizumab intravitreal injection and divided randomly into two groups. Two hundred and three patients in control group only received the ranibizumab IVI, but 149 patients in case group received one drop of prophylactic intraocular brinzolamide preinjection. The IOP was measured by noncontact tonometer before injection, at 10, 30, 120 min and 1 day after injection in a sitting position. Results: The mean IOP measured before injection, at 10, 30, 120 min and 1 day after injection individually were 15.79 ± 2.21 mmHg, 19.33 ± 4.86 mmHg, 16.64 ± 2.93 mmHg, 16.17 ± 3.13 mmHg, and 15.07 ± 2.55 mmHg in case group and were 15.82 ± 2.57 mmHg, 21.34 ± 5.88 mmHg, 18.17 ± 4.06 mmHg, 17.59 ± 4.42 mmHg, and15.48 ± 2.92 mmHg in control group. Comparing two groups, the mean increase on IOP was statistically significant at 10, 30, 120 min postinjection (P < 0.05). Conclusions: IVI of ranibizumab causes a considerable short-term transient rise on IOP in most patients. The effect of prophylactic IOP-lowering medication on IOP after IVIs can be statistically significant from 10 min to 2 h after IVIs. PMID:27905340

  19. Effect of prophylactic timolol 0.1% gel on intraocular pressure after an intravitreal injection of ranibizumab: a randomized study

    PubMed Central

    Pece, Alfredo; Allegrini, Davide; Montesano, Giovanni; Dimastrogiovanni, Andrea Fabio

    2016-01-01

    Purpose The purpose of this study is to make a prospective evaluation of the effect of timolol 0.1% eye gel on short-term intraocular pressure (IOP) after an intravitreal injection (IVI) of ranibizumab. Participants and methods One hundred and fifty eyes of 150 IVI-naïve patients with macular edema caused by various pathological conditions (age-related macular degeneration, central or branch retinal vein occlusion, and diabetic retinopathy) were scheduled to undergo an IVI of ranibizumab (0.5 mg/0.05 cc). The patients were randomly divided into three groups: 50 were not treated with timolol before the IVI (group 1); 50 received an instillation of timolol 0.1% eye gel the evening before the IVI (group 2); and 50 received an instillation of timolol 0.1% eye gel 2 hours before the IVI (group 3). The incidence of clinically significant intraocular hypertensive spikes (>25 mmHg and >40 mmHg) was then assessed. Results Our findings showed that mean IOP at baseline was significantly higher than at both 5 and 60 minutes after IVI (P<0.01). Spikes of >25 mmHg were recorded at either time in 27 patients (54%) in group 1, 23 patients (44%) in group 2, and 24 patients (48%) in group 3. None of the between-group differences were significant. Spikes of >40 mmHg (which were only detected 5 minutes after IVI) were recorded in nine (18%), eight (16%), and one patient (2%) in groups 1, 2, and 3, respectively. The only significant difference was between the control and group 3 (P=0.012). Conclusion An increase in IOP after antivascular endothelial growth factor IVI is a frequent complication. The prophylactic use of timolol 0.1% gel effectively reduced the mean IOP when administered 2 hours before IVI and was also effective in preventing dangerous IOP spikes of >40 mmHg. It is therefore recommended before IVIs as a means of preventing emergency procedures and preserving the health of the optic nerve. PMID:27382246

  20. Intravitreal Dexamethasone Implant (Ozurdex) in Coats’ Disease

    PubMed Central

    Saatci, Ali Osman; Doruk, Hasan Can; Yaman, Aylin

    2013-01-01

    We injected an intravitreal dexamethasone implant in two eyes of 2 pediatric patients with Coats’ disease in addition to other treatment modalities, such as intravitreal ranibizumab injection and indirect laser photocoagulation. In both eyes, intraocular pressure moderately rose in a temporary fashion. The dexamethasone implant seems to be a valuable addition to the armamentarium of treatment options for Coats’ disease as it necessitates fewer injections than anti-VEGF injections and thereby fewer sessions of general anesthesia in the pediatric population. PMID:24163679

  1. Effects of Intravitreal Ranibizumab Injection on Chinese Patients with Wet Age-Related Macular Degeneration: 5-Year Follow-Up Results

    PubMed Central

    Lu, Yingyi; Huang, Jianfeng; Zhao, Jing; Long, Li

    2016-01-01

    Purpose. To observe the effect of intravitreal ranibizumab injection on wet age-related macular degeneration (wAMD) over 5 years in Chinese patients. Methods. Thirty-seven patients who were diagnosed with wAMD in our hospital from June 2007 to June 2014 were retrospectively reviewed. The PRN regimen and the treatment and extend regimen were applied. Best corrected visual acuity (BCVA), number of ranibizumab injections, and changes in the choroidal neovascularization (CNV) lesion over 5 years were analyzed. Results. The mean BCVA measured by the ETDRS chart at baseline was 47.4 and 5 years after the treatment it was 34.89 letters, which was significantly different (p = 0.013). Fourteen eyes (37.8%) had improved visual acuity after 5 years. The number of injections in 5 years was 11.53, and most of the injections were in the first two years. Seventeen (45.9%) cases developed fibrous lesions, and 2 (5.4%) cases had atrophic lesions after 5 years. The fibrosis/atrophy was significantly correlated with the injection numbers (Pearson, r = 0.663, and p = 0.000). Conclusion. Most of the patients can maintain visual acuity treated by ranibizumab in the first 3 years. After 5 years, some patients can still improve or maintain visual acuity. Fibrous scarring of the lesion is the main reason for a decrease in vision of wAMD patients. PMID:27885338

  2. Intravitreal Injection of Bevacizumab in Primary Vitrectomy to Decrease the Rate of Retinal Redetachment: A Randomized Pilot Study

    PubMed Central

    Tousi, Adib; Hasanpour, Hossein; Soheilian, Masoud

    2016-01-01

    Purpose: To evaluate the effect of intravitreal bevacizumab (IVB) as a surgical adjunct in prevention of proliferative vitreoretinopathy (PVR) after retinal detachment surgery. Methods: In this controlled, randomized pilot study, 27 patients with primary retinal detachment undergoing pars plana deep vitrectomy were included. Of these, 12 received IVB at the end of procedure. The anatomic success and best corrected visual acuity (BCVA) were compared to the control group at months 3 and 6 postoperatively. Results: At three month follow-up, 3 of 11 eyes (27.3%) had detached retinas in the IVB group versus 6 of 12 (50.0%) in the control group (P = 0.40). At six-month follow-up, 3 of 10 eyes (30%) had detached retinas in the IVB group versus 3 in 8 (37.5%) in the control group (P > 0.99). Mean logMAR BCVA improved significantly in both groups relative to baseline, but did not show a significant difference at three-and six-month follow-ups between the two groups. Conclusion: Our preliminary results show neither a benefit nor any harm from intervention in both anatomic and visual outcomes. Our results support conducting additional studies to evaluate the effect of intravitreal bevacizumab on postoperative PVR. PMID:27621784

  3. Sustained Elevation of Intraocular Pressure Associated with Intravitreal Administration of Anti-vascular Endothelial Growth Factor: A Systematic Review and Meta-Analysis

    PubMed Central

    Zhou, Yandan; Zhou, Minwen; Xia, Shigang; Jing, Qiancheng; Gao, Ling

    2016-01-01

    This study aimed to assess whether repetitive intravitreal injections (IVI) of anti-vascular endothelial growth factor (anti-VEGF) cause sustained elevation of intraocular pressure (SE-IOP). We conducted a systematic review and meta-analysis based on five randomized controlled trials (RCTs) assessing 1428 subjects and 17 non-RCTs evaluating 8358 cases. In the RCTs, an increased risk of SE-IOP was found in the anti-VEGF group (summary risk ratio [RR] = 3.00, 95% confidence interval [CI]: 1.63–5.53) compared with the sham injection or laser group. The increased risk of SE-IOP was correlated with follow-up duration (RR = 2.14, 95% CI 0.69–6.57 at 6 months; RR = 3.15, 95% CI 0.99–10.09 at 12 months; RR = 3.48, 95% CI 1.38–8.78 at 23 months). The risk of SE-IOP after non-exclusion of pre-existing glaucoma patients (RR = 3.48, 95% CI 1.38–8.78) was higher than that obtained after excluding pre-existing glaucoma patients (RR = 2.6, 95% CI 1.16–5.81). In non-RCTs, the pooled prevalence of SE-IOP was 4.7% (95% CI 3.7–5.8) regardless of diagnosis criteria. In conclusion, repeated intravitreal injections of anti-VEGF agents cause a 2-fold elevation in SE-IOP risk. PMID:28000707

  4. Intravitreal injection of ciliary neurotrophic factor (CNTF) causes peripheral remodeling and does not prevent photoreceptor loss in canine RPGR mutant retina.

    PubMed

    Beltran, William A; Wen, Rong; Acland, Gregory M; Aguirre, Gustavo D

    2007-04-01

    Ciliary neurotrophic factor (CNTF) rescues photoreceptors in several animal models of retinal degeneration and is currently being evaluated as a potential treatment for retinitis pigmentosa in humans. This study was conducted to test whether CNTF prevents photoreceptor cell loss in XLPRA2, an early onset canine model of X-linked retinitis pigmentosa caused by a frameshift mutation in RPGR exon ORF15. Four different treatment regimens of CNTF were tested in XLPRA2 dogs. Under anesthesia, the animals received at different ages an intravitreal injection of 12 microg of CNTF in the left eye. The right eye served as a control and was injected with a similar volume of phosphate buffered saline (PBS). Ocular examinations were performed regularly during the treatment periods. At termination, the dogs were euthanatized, eyes collected and the retinas were processed for embedding in optimal cutting temperature (OCT) medium. The outer nuclear layer (ONL) thickness was evaluated on H&E sections and values in both CNTF- and PBS-treated eyes were compared. Morphologic alterations in the peripheral retina were characterized by immunohistochemistry using cell-specific markers. Cell proliferation in the retinas was examined on semi-thin plastic sections, and by BrdU pulse-labeling and Ki67 immunohistochemistry on cryosections. All CNTF-treated eyes showed early clinical signs of corneal epitheliopathy, subcapsular cataracts and uveitis. No statistically significant difference in ONL thickness was seen between the CNTF- and PBS-injected eyes. Prominent retinal remodeling that consisted in an abnormal increase in the number of rods, and in misplacement of some rods, cones, bipolar and Müller cells, was observed in the peripheral retina of CNTF-treated eyes. This was only seen when CNTF was in injected before the age at which the canine retina reaches full maturation. In XLPRA2 dogs, intravitreal injections of CNTF failed to prevent photoreceptors from undergoing cell death in the

  5. Intravitreal injection of ciliary neurotrophic factor (CNTF) causes peripheral remodeling and does not prevent photoreceptor loss in canine RPGR mutant retina

    PubMed Central

    Beltran, William A.; Wen, Rong; Acland, Gregory M.; Aguirre, Gustavo D.

    2009-01-01

    Ciliary neurotrophic factor (CNTF) rescues photoreceptors in several animal models of retinal degeneration and is currently being evaluated as a potential treatment for retinitis pigmentosa in humans. This study was conducted to test whether CNTF prevents photoreceptor cell loss in XLPRA2, an early onset canine model of X-linked retinitis pigmentosa caused by a frameshift mutation in RPGR exon ORF15. Four different treatment regimens of CNTF were tested in XLPRA2 dogs. Under anesthesia, the animals received at different ages an intravitreal injection of 12 μg of CNTF in the left eye. The right eye served as a control and was injected with a similar volume of phosphate buffered saline (PBS). Ocular examinations were performed regularly during the treatment periods. At termination, the dogs were euthanatized, eyes collected and the retinas were processed for embedding in optimal cutting temperature (OCT) medium. The outer nuclear layer (ONL) thickness was evaluated on H&E sections and values in both CNTF- and PBS-treated eyes were compared. Morphologic alterations in the peripheral retina were characterized by immunohistochemistry using cell-specific markers. Cell proliferation in the retinas was examined on semi-thin plastic sections, and by BrdU pulse-labeling and Ki67 immunohistochemistry on cryosections. All CNTF-treated eyes showed early clinical signs of corneal epitheliopathy, subcapsular cataracts and uveitis. No statistically significant difference in ONL thickness was seen between the CNTF- and PBS-injected eyes. Prominent retinal remodeling that consisted in an abnormal increase in the number of rods, and in misplacement of some rods, cones, bipolar and Müller cells, was observed in the peripheral retina of CNTF-treated eyes. This was only seen when CNTF was in injected before the age at which the canine retina reaches full maturation. In XLPRA2 dogs, intravitreal injections of CNTF failed to prevent photoreceptors from undergoing cell death in the

  6. Local and systemic responses following intravitreous injection of AAV2-encoded modified Volvox channelrhodopsin-1 in a genetically blind rat model.

    PubMed

    Sugano, E; Tabata, K; Takahashi, M; Nishiyama, F; Shimizu, H; Sato, M; Tamai, M; Tomita, H

    2016-02-01

    We previously designed a modified channelrhodopsin-1 (mVChR1) protein chimera with a broader action than that of Chlamydomonas channelrhodopsin-2 and reported that its transduction into retinal ganglion cells can restore visual function in genetically blind, dystrophic Royal College of Surgeons (RCS) rats, with photostimuli ranging from 486 to 640 nm. In the current study, we sought to investigate the safety and influence of mVChR1 transgene expression. Adeno-associated virus type 2 encoding mVChR1 was administered by intravitreous injection into dystrophic RCS rats. Reverse-transcription PCR was used to monitor virus and transgene dissemination and the results demonstrated that their expression was restricted specifically within the eye tissues, and not in non-target organs. Moreover, examination of the blood, plasma and serum revealed that no excess immunoreactivity was present, as determined using standard clinical hematological parameters. Serum antibodies targeting the recombinant adeno-associated virus (rAAV) capsid increased after the injection; however, no increase in mVChR1 antibody was detected during the observation period. In addition, retinal histological examination showed no signs of inflammation in rAAV-injected rats. In conclusion, our results demonstrate that mVChR1 can be exogenously expressed without harmful immunological reactions in vivo. These findings will aid in studies of AAV gene transfer to restore vision in late-stage retinitis pigmentosa.

  7. Rabbit as an animal model for intravitreal pharmacokinetics: Clinical predictability and quality of the published data.

    PubMed

    Del Amo, Eva M; Urtti, Arto

    2015-08-01

    Intravitreal administration is the method of choice in drug delivery to the retina and/or choroid. Rabbit is the most commonly used animal species in intravitreal pharmacokinetics, but it has been criticized as being a poor model of human eye. The critique is based on some anatomical differences, properties of the vitreous humor, and observed differences in drug concentrations in the anterior chamber after intravitreal injections. We have systematically analyzed all published information on intravitreal pharmacokinetics in the rabbit and human eye. The analysis revealed major problems in the design of the pharmacokinetic studies. In this review we provide advice for study design. Overall, the pharmacokinetic parameters (clearance, volume of distribution, half-life) in the human and rabbit eye have good correlation and comparable absolute values. Therefore, reliable rabbit-to-man translation of intravitreal pharmacokinetics should be feasible. The relevant anatomical and physiological parameters in rabbit and man show only small differences. Furthermore, the claimed discrepancy between drug concentrations in the human and rabbit aqueous humor is not supported by the data analysis. Based on the available and properly conducted pharmacokinetic studies, the differences in the vitreous structure in rabbits and human patients do not lead to significant pharmacokinetic differences. This review is the first step towards inter-species translation of intravitreal pharmacokinetics. More information is still needed to dissect the roles of drug delivery systems, disease states, age and ocular manipulation on the intravitreal pharmacokinetics in rabbit and man. Anyway, the published data and the derived pharmacokinetic parameters indicate that the rabbit is a useful animal model in intravitreal pharmacokinetics.

  8. The effect of laser pan-retinal photocoagulation with or without intravitreal bevacizumab injections on the OCT-measured macular choroidal thickness of eyes with proliferative diabetic retinopathy

    PubMed Central

    Preti, Rony C; Mutti, Anibal; Ferraz, Daniel A; Zacharias, Leandro C; Nakashima, Yoshitaka; Takahashi, Walter Y; Monteiro, Mario L R

    2017-01-01

    OBJECTIVES: To investigate the effect of laser pan-retinal photocoagulation with or without intravitreal bevacizumab injections on macular choroidal thickness parameters in eyes with high-risk proliferative diabetic retinopathy. METHODS: High-risk proliferative diabetic retinopathy patients undergoing laser treatment were prospectively enrolled in this study. One eye was randomly selected for laser treatment combined with bevacizumab injections, study group, whereas the corresponding eye was subjected to laser treatment alone, control group. Spectral-domain optical coherence tomography with enhanced depth imaging was used to measure the macular choroidal thickness prior to and 1 month after treatment. Measurements in both groups were compared. Clinicaltrials.gov: NCT01389505. RESULTS: Nineteen patients (38 eyes) with a mean±standard deviation age of 53.4±9.3 years were evaluated, and choroidal thickness measurements for 15 patients were used for comparison. The greatest measurement before treatment was the subfoveal choroidal thickness (341.68±67.66 μm and 345.79±83.66 μm for the study and control groups, respectively). No significant difference between groups was found in terms of macular choroidal thickness measurements at baseline or after treatment. However, within-group comparisons revealed a significant increase in choroidal thickness parameters in 10 measurements in the study group and in only 5 temporal measurements in the control group when 1-month follow-up measurements were compared to baseline values. CONCLUSIONS: The macular choroidal thickness does not appear to be significantly influenced by laser treatment alone but increases significantly when associated with bevacizumab injections in patients with proliferative diabetic retinopathy and macular edema. Because bevacizumab injections reduce short-term laser pan-retinal photocoagulation-induced macular edema, our findings suggest that the choroid participates in its pathogenesis. PMID:28273240

  9. Neuroprotective and antiapoptotic activity of lineage-negative bone marrow cells after intravitreal injection in a mouse model of acute retinal injury.

    PubMed

    Machalińska, Anna; Rogińska, Dorota; Pius-Sadowska, Ewa; Kawa, Miłosz P; Paczkowska, Edyta; Rudnicki, Michał; Lejkowska, Renata; Baumert, Bartłomiej; Wiszniewska, Barbara; Machaliński, Bogusław

    2015-01-01

    We investigated effects of bone marrow-derived, lineage-negative cell (Lin(-)BMC) transplantation in acute retinal injury. Lin(-)BMCs were intravitreally injected into murine eyes at 24 h after NaIO3-induced injury. Morphology, function, and expression of apoptosis-related genes, including brain-derived neurotrophic factor (BDNF) and its receptor, were assessed in retinas at 7 days, 28 days, and 3 months after transplantation. Moreover, global gene expression at day 7 was analyzed by RNA arrays. We observed that Lin(-)BMCs integrated into outer retinal layers improving morphological retinal structure and induced molecular changes such as downregulation of proapoptotic caspase-3 gene, a decrease in BAX/BCL-2 gene ratio, and significant elevation of BDNF expression. Furthermore, transplanted Lin(-)BMCs differentiated locally into cells with a macrophage-like phenotype. Finally, Lin(-)BMCs treatment was associated with generation of two distinct transcriptomic patterns. The first relates to downregulated genes associated with regulation of neuron cell death and apoptosis, response to oxidative stress/hypoxia and external stimuli, and negative regulation of cell proliferation. The second relates to upregulated genes associated with neurological system processes and sensory perception. Collectively, our data demonstrate that transplanted Lin(-)BMCs exert neuroprotective function against acute retinal injury and this effect may be associated with their antiapoptotic properties and ability to express neurotrophic factors.

  10. Bilateral Severe Sterile Inflammation with Hypopyon after Simultaneous Intravitreal Triamcinolone Acetonide and Aflibercept Injection in a Patient with Bilateral Marked Rubeosis Associated with Ocular Ischemic Syndrome

    PubMed Central

    Durmaz Engin, Ceren; Ayhan, Ziya; Men, Süleyman

    2017-01-01

    We report the clinical course of a diabetic patient with bilateral cataract and rubeosis in association with ocular ischemic syndrome and initially treated him with simultaneous intravitreal 2 mg aflibercept and 2 mg triamcinolone acetonide injection at the same setting prior to planned cataract surgery and further photocoagulation. However, sterile anterior segment inflammation characterized by hypopyon occurred four days apart in OU. Right eye developed the sterile inflammation at the third postinjection day and the left eye developed the sterile inflammation at the seventh postinjection day (two days after the uneventful cataract surgery with intraocular lens implantation) without any pain or significant redness. Vitreous biopsy taken during the right phacovitrectomy was negative for any microbial contamination. Both eyes were treated successfully with intensive topical prednisolone acetate with a relatively good visual outcome. It is likely that underlying ocular ischemic syndrome might have facilitated the formation of sterile inflammation as blood-aqueous barrier disruption and flare have already been present. PMID:28386497

  11. Neuroprotective and Antiapoptotic Activity of Lineage-Negative Bone Marrow Cells after Intravitreal Injection in a Mouse Model of Acute Retinal Injury

    PubMed Central

    Machalińska, Anna; Pius-Sadowska, Ewa; Kawa, Miłosz P.; Paczkowska, Edyta; Rudnicki, Michał; Lejkowska, Renata; Baumert, Bartłomiej; Wiszniewska, Barbara; Machaliński, Bogusław

    2015-01-01

    We investigated effects of bone marrow-derived, lineage-negative cell (Lin−BMC) transplantation in acute retinal injury. Lin−BMCs were intravitreally injected into murine eyes at 24 h after NaIO3-induced injury. Morphology, function, and expression of apoptosis-related genes, including brain-derived neurotrophic factor (BDNF) and its receptor, were assessed in retinas at 7 days, 28 days, and 3 months after transplantation. Moreover, global gene expression at day 7 was analyzed by RNA arrays. We observed that Lin−BMCs integrated into outer retinal layers improving morphological retinal structure and induced molecular changes such as downregulation of proapoptotic caspase-3 gene, a decrease in BAX/BCL-2 gene ratio, and significant elevation of BDNF expression. Furthermore, transplanted Lin−BMCs differentiated locally into cells with a macrophage-like phenotype. Finally, Lin−BMCs treatment was associated with generation of two distinct transcriptomic patterns. The first relates to downregulated genes associated with regulation of neuron cell death and apoptosis, response to oxidative stress/hypoxia and external stimuli, and negative regulation of cell proliferation. The second relates to upregulated genes associated with neurological system processes and sensory perception. Collectively, our data demonstrate that transplanted Lin−BMCs exert neuroprotective function against acute retinal injury and this effect may be associated with their antiapoptotic properties and ability to express neurotrophic factors. PMID:25810725

  12. Detection of aqueous VEGF concentrations before and after intravitreal injection of anti-VEGF antibody using low-volume sampling paper-based ELISA.

    PubMed

    Hsu, Min-Yen; Hung, Yu-Chien; Hwang, De-Kuang; Lin, Shang-Chi; Lin, Keng-Hung; Wang, Chun-Yuan; Choi, Hin-Yeung; Wang, Yu-Ping; Cheng, Chao-Min

    2016-10-11

    Intraocular vascular endothelial growth factor (VEGF) levels play an important role in the pathogenesis of blindness-related diseases, such as age-related macular degeneration (AMD). Here, we aimed to develop a paper-based enzyme-linked immunosorbent assay (P-ELISA) to analyze the suppression of aqueous VEGF concentrations following intravitreal injection (IVI) of anti-VEGF antibody (bevacizumab or ranibizumab). A total of 25 eyes with wet AMD, one with myopic neovascularization, and one with polypoidal choroidal vasculopathy were enrolled in this study. The limit of detection using P-ELISA was 0.03 pg/mL. Forty-six consecutive samples of aqueous humor were acquired. From all samples, 66.67% (10/15) achieved complete VEGF suppression (below the detection limit) within 5 weeks of receiving IVI of anti-VEGF antibody. Only 13.33% of samples (2/15) achieved complete VEGF suppression 5 weeks after receiving treatment. In some patients, elevated VEGF was still detected 5 weeks after receipt of anti-VEGF antibody, and all samples (10/10) were found to have elevated VEGF levels 49 days after treatment. Thus, we suggest that monthly IVI of anti-VEGF antibody may be required to ensure durable VEGF inhibition. Ultrasensitive P-ELISA can detect elevated VEGF at an earlier time point and may facilitate decision-making regarding appropriate treatment strategies.

  13. Detection of aqueous VEGF concentrations before and after intravitreal injection of anti-VEGF antibody using low-volume sampling paper-based ELISA

    PubMed Central

    Hsu, Min-Yen; Hung, Yu-Chien; Hwang, De-Kuang; Lin, Shang-Chi; Lin, Keng-Hung; Wang, Chun-Yuan; Choi, Hin-Yeung; Wang, Yu-Ping; Cheng, Chao-Min

    2016-01-01

    Intraocular vascular endothelial growth factor (VEGF) levels play an important role in the pathogenesis of blindness-related diseases, such as age-related macular degeneration (AMD). Here, we aimed to develop a paper-based enzyme-linked immunosorbent assay (P-ELISA) to analyze the suppression of aqueous VEGF concentrations following intravitreal injection (IVI) of anti-VEGF antibody (bevacizumab or ranibizumab). A total of 25 eyes with wet AMD, one with myopic neovascularization, and one with polypoidal choroidal vasculopathy were enrolled in this study. The limit of detection using P-ELISA was 0.03 pg/mL. Forty-six consecutive samples of aqueous humor were acquired. From all samples, 66.67% (10/15) achieved complete VEGF suppression (below the detection limit) within 5 weeks of receiving IVI of anti-VEGF antibody. Only 13.33% of samples (2/15) achieved complete VEGF suppression 5 weeks after receiving treatment. In some patients, elevated VEGF was still detected 5 weeks after receipt of anti-VEGF antibody, and all samples (10/10) were found to have elevated VEGF levels 49 days after treatment. Thus, we suggest that monthly IVI of anti-VEGF antibody may be required to ensure durable VEGF inhibition. Ultrasensitive P-ELISA can detect elevated VEGF at an earlier time point and may facilitate decision-making regarding appropriate treatment strategies. PMID:27725716

  14. Location of a Dexamethasone Implant at the Macula after Intravitreal Injection in a Silicone Oil-Filled Eye

    PubMed Central

    Esenulku, Cenap Mahmut

    2016-01-01

    Here, we report a case with cystoid macular edema (CME) due to central retinal vein occlusion (CRVO) presented with a dexamethasone implant (Ozurdex) trapped at the macula in her silicone oil- (SO-) filled eye after injection. No additional complications such as intraocular pressure (IOP) rise or retinal damage were observed. The CME was resolved during the follow-up period. At the last visit, 3 months following the injection, Ozurdex implant was found to be mostly dissolved without any additional ocular complications. PMID:27999699

  15. Short-term efficacy of intravitreal dobesilate in central serous chorioretinopathy

    PubMed Central

    2012-01-01

    Purpose To report the anatomic and functional outcome of intravitreal dobesilate to treat recurrent central serous chorioretinopathy (CSC). Methods This is an interventional case report in which dobesilate was intravitreally injected in a case of recurrent CSC. Main measures included fundoscopy, Snellen visual acuity (VA) testing, fluorescein angiography and optical coherence tomography (OCT). Results We present anatomical and functional evidences, obtained as early as eleven days after the treatment, of the efficacy of intravitreal dobesilate, in the treatment of chronic CSC condition. The effect after intravitreal dobesilate injection for CSC might be related to the normalization of retinal architecture. Conclusions Intravitreal dobesilate may be an effective treatment option for recurrent CSC. PMID:22788836

  16. Retinal pseudoangiitis after intravitreal triamcinolone

    PubMed Central

    García-Campos, Jose Manuel; García-Basterra, Ignacio; Kamal-Salah, Radua; Baquero-Aranda, Isabel

    2015-01-01

    We present a case of a 40-year-old woman with a fundus image similar to frosted retinal angiitis after undergoing pars plana vitrectomy and intravitreal triamcinolone injection. The patient with diabetic retinopathy was referred to our hospital with vision loss in her right eye secondary to vitreous haemorrhage. After pars plana vitrectomy and injection of triamcinolone acetonide a funduscopy examination revealed deposits of triamcinolone along the retinal vessels simulating a frosted retinal angiitis. Triamcinolone deposits along blood vessels could be the result of the reabsorption process of these crystals by the perivascular macrophages. Further studies are needed. PMID:25678611

  17. Pharmacokinetics and safety of intravitreal caspofungin.

    PubMed

    Shen, Ying-Cheng; Liang, Chiao-Ying; Wang, Chun-Yuan; Lin, Keng-Hung; Hsu, Min-Yen; Yuen, Hon-Leung; Wei, Li-Chen

    2014-12-01

    Caspofungin exhibits potent antifungal activities against Candida and Aspergillus species. The elimination rate and retinal toxicity of caspofungin were determined in this study to assess its pharmacokinetics and safety in the treatment of fungal endophthalmitis. Intravitreal injections of 50 μg/0.1 ml of caspofungin were administered to rabbits. Levels of caspofungin in the vitreous and aqueous humors were determined using high-performance liquid chromatography (HPLC) at selected time intervals (10 min and 1, 2, 4, 8, 16, 24, and 48 h), and the half-lives were calculated. Eyes were intravitreally injected with caspofungin to obtain concentrations of 10 μg/ml, 50 μg/ml, 100 μg/ml, and 200 μg/ml. Electroretinograms were recorded 4 weeks after injections, and the injected eyes were examined histologically. The concentrations of intravitreal caspofungin at various time points exhibited an exponential decay with a half-life of 6.28 h. The mean vitreous concentration was 6.06 ± 1.76 μg/ml 1 h after intravitreal injection, and this declined to 0.47 ± 0.15 μg/ml at 24 h. The mean aqueous concentration showed undetectable levels at all time points. There were no statistical differences in scotopic a-wave and b-wave responses between control eyes and caspofungin-injected eyes. No focal necrosis or other abnormality in retinal histology was observed. Intravitreal caspofungin injection may be considered to be an alternative treatment for fungal endophthalmitis based on its antifungal activity, lower retinal toxicity, and lower elimination rate in the vitreous. More clinical data are needed to determine its potential role as primary therapy for fungal endophthalmitis.

  18. Successful treatment of pseudophakic cystoid macular edema with intravitreal bevacizumab.

    PubMed

    Barone, Antonio; Prascina, Francesco; Russo, Vincenzo; Iaculli, Cristiana; Primavera, Vito; Querques, Giuseppe; Stella, Andrea; Delle Noci, Nicola

    2008-07-01

    A 67-year-old woman developed refractory pseudophakic cystoid macular edema (CME) after uneventful phacoemulsification. Three months after an intravitreal injection of bevacizumab (1.25 mg), the CME was completely resolved, with resultant improvement in visual acuity.

  19. Rescue of retinal degeneration by intravitreally injected adult bone marrow–derived lineage-negative hematopoietic stem cells

    PubMed Central

    Otani, Atsushi; Dorrell, Michael Ian; Kinder, Karen; Moreno, Stacey K.; Nusinowitz, Steven; Banin, Eyal; Heckenlively, John; Friedlander, Martin

    2004-01-01

    Inherited retinal degenerations afflict 1 in 3,500 individuals and are a heterogeneous group of diseases that result in profound vision loss, usually the result of retinal neuronal apoptosis. Atrophic changes in the retinal vasculature are also observed in many of these degenerations. While it is thought that this atrophy is secondary to diminished metabolic demand in the face of retinal degeneration, the precise relationship between the retinal neuronal and vascular degeneration is not clear. In this study we demonstrate that whenever a fraction of mouse or human adult bone marrow–derived stem cells (lineage-negative hematopoietic stem cells [Lin– HSCs]) containing endothelial precursors stabilizes and rescues retinal blood vessels that would ordinarily completely degenerate, a dramatic neurotrophic rescue effect is also observed. Retinal nuclear layers are preserved in 2 mouse models of retinal degeneration, rd1 and rd10, and detectable, albeit severely abnormal, electroretinogram recordings are observed in rescued mice at times when they are never observed in control-treated or untreated eyes. The normal mouse retina consists predominantly of rods, but the rescued cells after treatment with Lin– HSCs are nearly all cones. Microarray analysis of rescued retinas demonstrates significant upregulation of many antiapoptotic genes, including small heat shock proteins and transcription factors. These results suggest a new paradigm for thinking about the relationship between vasculature and associated retinal neuronal tissue as well as a potential treatment for delaying the progression of vision loss associated with retinal degeneration regardless of the underlying genetic defect. PMID:15372100

  20. Macular ischemia after intravitreal amikacin on patient with intraocular foreign body.

    PubMed

    Kartasasmita, Arief; Mona, Susi; Iskandar, Erwin; Sovani, Iwan; Panggabean, Djonggi

    2017-01-01

    Background: Although still used in third world countries, amikacin has a harmful effect to be used intravitreally. Purpose: To report macular ischemia after an intravitreal injection of amikacin Methods: A case report regarding a traumatized eye of a 26-year-old man that was injected intravitreally with amikacin due to intraocular foreign body endophthalmitis Results: Angiography and OCT show macular ischemia due to amikacin toxicity. Conclusion: The case reported here is to alert about the potential harmful effect of intravitreally injected amikacin despite its role as an accepted regimen for endohthalmitis cases.

  1. Macular ischemia after intravitreal amikacin on patient with intraocular foreign body

    PubMed Central

    Kartasasmita, Arief; Mona, Susi; Iskandar, Erwin; Sovani, Iwan; Panggabean, Djonggi

    2017-01-01

    Background: Although still used in third world countries, amikacin has a harmful effect to be used intravitreally. Purpose: To report macular ischemia after an intravitreal injection of amikacin Methods: A case report regarding a traumatized eye of a 26-year-old man that was injected intravitreally with amikacin due to intraocular foreign body endophthalmitis Results: Angiography and OCT show macular ischemia due to amikacin toxicity. Conclusion: The case reported here is to alert about the potential harmful effect of intravitreally injected amikacin despite its role as an accepted regimen for endohthalmitis cases.

  2. Diabetic papillopathy treated with intravitreal ranibizumab

    PubMed Central

    Yildirim, Mine; Kilic, Deniz; Dursun, Mehmet Emin; Dursun, Birgul

    2017-01-01

    In this report, we present a case of diabetic papillopathy that resolved after a single dose of intravitreal ranibizumab injection. A 50-year-old male presented with painless visual loss in his right eye. His visual acuity was 1/10 in the right eye and 10/10 in the left eye. Anterior segment examination of both eyes was unremarkable. Posterior segment of the right eye showed nonproliferative diabetic retinopathy with a swollen optic disc. Fluorescein angiography and optical coherence tomography were performed. There was dye leakage from the right optic disc. Optical coherence tomography revealed a significant increase in retinal nerve fiber layer thickness. Magnetic resonance imaging of the brain and orbit were normal. The patient received a single intravitreal ranibizumab (0.5 mg) injection. Two weeks after the injection, there was a marked regression of the disc swelling. Three months after the injection the optic disc was pallor and visual acuity was 6/10. PMID:28356776

  3. Gene therapy following subretinal AAV5 vector delivery is not affected by a previous intravitreal AAV5 vector administration in the partner eye

    PubMed Central

    Li, Wensheng; Kong, Fansheng; Li, Xia; Dai, Xufeng; Liu, Xiaoqiang; Zheng, Qinxiang; Wu, Ronghan; Zhou, Xiangtian; Lü, Fan; Chang, Bo; Li, Qiuhong; Hauswirth, William W.; Pang, Ji-jing

    2009-01-01

    Purpose In an earlier study we found normal adeno-associated viral vector type 2 (AAV2)-mediated GFP expression after intravitreal injection to one eye of normal C57BL/6J mice. However, GFP expression was very poor in the partner eye of the same mouse if this eye received an intravitreal injection of the same vector one month after the initial intravitreal injection. We also found both injections worked well if they were subretinal. In this study, we tested whether the efficiency of subretinal AAV vector transduction is altered by a previous intravitreal injection in the partner eye and more importantly whether therapeutic efficiency is altered in the rd12 mouse (with a recessive RPE65 mutation) after the same injection series. Methods One μl of scAAV5-smCBA-GFP (1x1013 genome containing viral particles per ml) was intravitreally injected into the right eyes of four-week-old C57BL/6J mice and 1 μl of scAAV5-smCBA-hRPE65 (1x1013 genome containing viral particles per ml) was intravitreally injected into the right eyes of four-week-old rd12 mice Four weeks later, the same vectors were subretinally injected into the left eyes of the same C57BL/6J and rd12 mice. Left eyes of another cohort of eight-week-old rd12 mice received a single subretinal injection of the same scAAV5-smCBA-hRPE65 vector as the positive control. Dark-adapted electroretinograms (ERGs) were recorded five months after the subretinal injections. AAV-mediated GFP expression in C57BL/6J mice and RPE65 expression and ERG restoration in rd12 mice were evaluated five months after the second subretinal injection. Frozen section analysis was performed for GFP fluorescence in C57BL/6J mice and immunostaining for RPE65 in rd12 eyes. Results In rd12 mice, dark-adapted ERGs were minimal following the first intravitreal injection of scAAV5-smCBA-RPE65. Following subsequent subretinal injection in the partner eye, dramatic ERG restoration was recorded in that eye. In fact, ERG b-wave amplitudes were

  4. Tower microneedle via reverse drawing lithography for innocuous intravitreal drug delivery.

    PubMed

    Lee, Chang Yeol; Lee, Kwang; You, Yong Sung; Lee, Sung Ho; Jung, Hyungil

    2013-06-01

    The "tower microneedle" (TM) via reverse drawing lithography for intravitreal injection by fabricating a long hollow microneedle on the blunt hypodermic needle: The hollow hole between the microneedle and hypodermic needle is aligned concentrically, and fifteen degree bevel angle is introduced to TM by laser cutting to achieve intravitreal injection with minimal damage to eye tissue.

  5. A randomised, double-masked phase III/IV study of the efficacy and safety of Avastin® (Bevacizumab) intravitreal injections compared to standard therapy in subjects with choroidal neovascularisation secondary to age-related macular degeneration: clinical trial design

    PubMed Central

    Patel, Praveen J; Bunce, Catey; Tufail, Adnan

    2008-01-01

    Background The management of neovascular age-related macular degeneration (nAMD) has been transformed by the introduction of agents delivered by intravitreal injection which block the action of vascular endothelial growth factor-A (anti-VEGF agents). One such agent in widespread use is bevacizumab which was initially developed for use in oncology. Most of the evidence supporting the use of bevacizumab for nAMD has come from interventional case series and this clinical trial was initiated because of the increasing and widespread use of this agent in the treatment of nAMD (an off-label indication) despite a lack of definitive unbiased safety and efficacy data. Methods and design The Avastin® (bevacizumab) for choroidal neovascularisation (ABC) trial is a double-masked randomised controlled trial comparing intravitreal bevacizumab injections to standard therapy in the treatment of nAMD. Patients are randomised to intravitreal bevacizumab or standard therapy available at the time of trial initiation (verteporfin photodynamic therapy, intravitreal pegaptanib or sham treatment). Ranibizumab treatment was not included in the control arm as it had not been licensed for use at the start of recruitment for this trial. The primary outcome is the proportion of patients gaining ≥ 15 letters of visual acuity at 1 year and secondary outcomes include the proportion of patients with stable vision and mean visual acuity change. Discussion The ABC Trial is the first double-masked randomised control trial to investigate the efficacy and safety of intravitreal bevacizumab in the treatment of nAMD. This trial fully recruited in November 2007 and results should be available in early 2009. Important design issues for this clinical trial include (a) defining the control group (b) use of gain in vision as primary efficacy end-point and (c) use of pro re nata treatment using intravitreal bevacizumab rather than continuous therapy. Trial registration Current controlled trials ISRCTN

  6. A Phase 2 Randomized Clinical Trial of Intravitreal Bevacizumab for Diabetic Macular Edema

    PubMed Central

    2008-01-01

    Objective To provide data on the short-term effect of intravitreal bevacizumab for diabetic macular edema (DME). Design Randomized phase 2 clinical trial. Participants 121 eyes of 121 subjects (109 eligible for analysis) with DME and Snellen acuity equivalent ranging from 20/32-20/320. Interventions Random assignment to one of five groups: focal photocoagulation at baseline (N=19, Group A), intravitreal injection of 1.25mg bevacizumab at baseline and 6 weeks (N=22, Group B), intravitreal injection of 2.5mg bevacizumab at baseline and 6 weeks (N=24, Group C), intravitreal injection of 1.25mg bevacizumab at baseline and sham injection at 6 weeks (N=22, Group D), or intravitreal injection of 1.25mg bevacizumab at baseline and 6 weeks with photocoagulation at 3 weeks (N=22, Group E). Main Outcome Measures Central subfield thickness (CST) on optical coherence tomography and best-corrected visual acuity (VA) were measured at baseline and after 3, 6, 9, 12, 18, and 24 weeks. Results At baseline, median CST was 411 microns and median Snellen VA equivalent was 20/50. Compared with Group A, Groups B and C had a greater reduction in CST at 3 weeks and about one line better median visual acuity over 12 weeks. There were no meaningful differences between Groups B and C in CST reduction or VA improvement. A CST reduction >11% (the reliability limit) was present at 3 weeks in 36/84 (43%) bevacizumab-treated eyes and in 5/18 (28%) eyes treated with laser alone, and at 6 weeks in 31/84 (37%) and 9/18 (50%) eyes, respectively. Combining focal photocoagulation with bevacizumab resulted in no apparent short-term benefit or adverse outcomes. Endophthalmitis developed in one eye. The following events occurred during the first 24 weeks in subjects treated with bevacizumab without attributing cause to the drug: myocardial infarction (N=2), congestive heart failure (N=1), elevated blood pressure (N=3), and worsened renal function (N=3). Conclusion These results demonstrate that

  7. Clinical outcomes of primary intraocular lymphoma patients treated with front-line systemic high-dose methotrexate and intravitreal methotrexate injection.

    PubMed

    Ma, Wei-Li; Hou, Hsin-An; Hsu, Ya-Jui; Chen, Yin-Kai; Tang, Jih-Luh; Tsay, Woei; Yeh, Po-Ting; Yang, Chung-May; Lin, Chang-Ping; Tien, Hwei-Fang

    2016-03-01

    A standard treatment for patients with primary intraocular lymphoma (PIOL) remains unclear. This study retrospectively analyzed the clinical features and outcomes of 19 patients with PIOL who were treated with a first-line therapy comprising combined intravenous high-dose methotrexate and intravitreal methotrexate between January 2003 and December 2013. Thirteen (68.4 %) patients were female, and the median age at diagnosis was 57 (39-77 years). Diagnoses were based on the identification of abnormal lymphoid cells in vitreous fluid. Ten (52.6 %) patients had bilateral eye involvement, and six had concurrent central nervous system (CNS) involvement. All 19 patients achieved complete remission (CR) as confirmed by cytological examination of vitreous and cerebrospinal fluid and brain imaging if CNS was involved. Patients with concurrent brain involvement required a longer time to achieve CR. However, the duration of complete remission did not differ between patients with and without CNS involvement. The 5-year overall survival rate was 55.8 % for the total cohort and was higher (68.8 %) in patients with isolated PIOL than in those with concurrent CNS involvement. In all patients, methotrexate treatment was well tolerated, with manageable side effects. We conclude that combined intravitreal methotrexate and systemic high-dose methotrexate treatment is effective in patients with PIOL.

  8. Miniaturized flow injection analysis system

    DOEpatents

    Folta, J.A.

    1997-07-01

    A chemical analysis technique known as flow injection analysis is described, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38{times}25{times}3 mm, but can be designed for gas analysis and be substantially smaller in construction. 9 figs.

  9. Miniaturized flow injection analysis system

    DOEpatents

    Folta, James A.

    1997-01-01

    A chemical analysis technique known as flow injection analysis, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38.times.25.times.3 mm, but can be designed for gas analysis and be substantially smaller in construction.

  10. Ex vivo investigation of ocular tissue distribution following intravitreal administration of connexin43 mimetic peptide using the microdialysis technique and LC-MS/MS.

    PubMed

    Bisht, Rohit; Mandal, Abhirup; Rupenthal, Ilva D; Mitra, Ashim K

    2016-12-01

    This study aimed to develop and evaluate an ex vivo eye model for intravitreal drug sampling and tissue distribution of connexin43 mimetic peptide (Cx43MP) following intravitreal injection using the microdialysis technique and LC-MS/MS. An LC-MS/MS method was developed, validated, and applied for quantification of Cx43MP in ocular tissues. Microdialysis probes were calibrated for in vitro recovery studies. Bovine eyes were fixed in a customized eye holder and after intravitreal injection of Cx43MP, microdialysis probes were implanted in the vitreous body. Vitreous samples were collected at particular time intervals over 24 h. Moreover, 24 and 48 h after intravitreal injection ocular tissues were collected, processed, and analyzed for Cx43MP concentrations using LC-MS/MS. The LC-MS/MS method showed good linearity (r (2) = 0.9991). The mean percent recovery for lower (LQC), medium (MQC), and higher quality control (HQC) (0.244, 3.906, and 125 μg/mL) was found to be 83.83, 84.92, and 94.52, respectively, with accuracy ranges between 96 and 99 % and limits of detection (LOD) and quantification (LOQ) of 0.122 and 0.412 μg/mL. The in vitro recovery of the probes was found to be over 80 %. As per microdialysis sample analysis, the Cx43MP concentration was found to increase slowly in the vitreous body up to 16 h and thereafter declined. After 48 h, the Cx43MP concentration was higher in vitreous, cornea, and retina compared to lens, iris, and aqueous humor. This ex vivo model may therefore be a useful tool to investigate intravitreal kinetics and ocular disposition of therapeutic molecules after intravitreal injection.

  11. Retinal Electrophysiological Effects of Intravitreal Bone Marrow Derived Mesenchymal Stem Cells in Streptozotocin Induced Diabetic Rats

    PubMed Central

    Akkoç, Tolga; Eraslan, Muhsin; Şahin, Özlem; Özkara, Selvinaz; Vardar Aker, Fugen; Subaşı, Cansu; Karaöz, Erdal; Akkoç, Tunç

    2016-01-01

    Diabetic retinopathy is the most common cause of legal blindness in developed countries at middle age adults. In this study diabetes was induced by streptozotocin (STZ) in male Wistar albino rats. After 3 months of diabetes, rights eye were injected intravitreally with green fluorescein protein (GFP) labelled bone marrow derived stem cells (BMSC) and left eyes with balanced salt solution (Sham). Animals were grouped as Baseline (n = 51), Diabetic (n = 45), Diabetic+BMSC (n = 45 eyes), Diabetic+Sham (n = 45 eyes), Healthy+BMSC (n = 6 eyes), Healthy+Sham (n = 6 eyes). Immunohistology analysis showed an increased retinal gliosis in the Diabetic group, compared to Baseline group, which was assessed with GFAP and vimentin expression. In the immunofluorescence analysis BMSC were observed to integrate mostly into the inner retina and expressing GFP. Diabetic group had prominently lower oscillatory potential wave amplitudes than the Baseline group. Three weeks after intravitreal injection Diabetic+BMSC group had significantly better amplitudes than the Diabetic+Sham group. Taken together intravitreal BMSC were thought to improve visual function. PMID:27300133

  12. Dexamethasone intravitreal implant in the treatment of diabetic macular edema

    PubMed Central

    Dugel, Pravin U; Bandello, Francesco; Loewenstein, Anat

    2015-01-01

    Diabetic macular edema (DME) resembles a chronic, low-grade inflammatory reaction, and is characterized by blood–retinal barrier (BRB) breakdown and retinal capillary leakage. Corticosteroids are of therapeutic benefit because of their anti-inflammatory, antiangiogenic, and BRB-stabilizing properties. Delivery modes include periocular and intravitreal (via pars plana) injection. To offset the short intravitreal half-life of corticosteroid solutions (~3 hours) and the need for frequent intravitreal injections, sustained-release intravitreal corticosteroid implants have been developed. Dexamethasone intravitreal implant provides retinal drug delivery for ≤6 months and recently has been approved for use in the treatment of DME. Pooled findings (n=1,048) from two large-scale, randomized Phase III trials indicated that dexamethasone intravitreal implant (0.35 mg and 0.7 mg) administered at ≥6-month intervals produced sustained improvements in best-corrected visual acuity (BCVA) and macular edema. Significantly more patients showed a ≥15-letter gain in BCVA at 3 years with dexamethasone intravitreal implant 0.35 mg and 0.7 mg than with sham injection (18.4% and 22.2% vs 12.0%). Anatomical assessments showed rapid and sustained reductions in macular edema and slowing of retinopathy progression. Phase II study findings suggest that dexamethasone intravitreal implant is effective in focal, cystoid, and diffuse DME, in vitrectomized eyes, and in combination with laser therapy. Ocular complications of dexamethasone intravitreal implant in Phase III trials included cataract-related events (66.0% in phakic patients), intraocular pressure elevation ≥25 mmHg (29.7%), conjunctival hemorrhage (23.5%), vitreous hemorrhage (10.0%), macular fibrosis (8.3%), conjunctival hyperemia (7.2%), eye pain (6.1%), vitreous detachment (5.8%), and dry eye (5.8%); injection-related complications (eg, retinal tear/detachment, vitreous loss, endophthalmitis) were infrequent (<2

  13. Intravitreal Melphalan for Vitreous Seeds: Initial Experience in China

    PubMed Central

    Ji, Xunda; Hua, Peiyan; Li, Jing; Li, Jiakai; Zhao, Junyang; Zhao, Peiquan

    2016-01-01

    Purpose. To evaluate the efficacy of intravitreal melphalan for vitreous seeds from retinoblastoma in Chinese patients. Methods. This is a retrospective review of 17 consecutive Chinese patients (19 eyes) with viable vitreous seeds from retinoblastoma. The patients received multiple intravitreal injections of 20 ug melphalan. Results. The International Classification of Retinoblastoma groups were B in 1 eye, C in 5 eyes, D in 11 eyes, and E in 2 eyes. On average, 6 injections (range: 1–15) were given to each eye at the interval of 2–4 weeks. Successful control of vitreous seeds was achieved in 16 of 19 eyes (84.21%). Globe retention was achieved in 73.68% (14/19) eyes. The patients were followed up for 27 months on average (median: 26; range: 17–42 months). There is a significant difference in response to intravitreal melphalan for cloud, spheres, and dust seeds with a median number of injections of 9, 6, and 3, respectively (P = 0.003). Complications related to intravitreal melphalan included vitreous hemorrhage, cataract, salt-and-pepper retinopathy, and pupil posterior synechia. There was no case of epibulbar extension or systemic metastasis within the period of follow-up. Conclusion. Intravitreal melphalan achieved a high local control rate for vitreous seeds without extraocular extension and with acceptable toxicity in Chinese retinoblastoma patients. PMID:26977313

  14. Intravitreal infusion: A novel approach for intraocular drug delivery

    PubMed Central

    Tian, Jiao; Liu, Jia; Liu, Xiao; Xiao, Yangyan; Tang, Luosheng

    2016-01-01

    Intraocular injection has become an increasingly important intervention in the treatment of posterior segment diseases. However, an acute intraocular pressure (IOP) elevation after intravitreal injection is a common concern. This study aimed to evaluate the efficacy of intravitreal infusion in maintaining stable IOP in a rabbit model. Trypan blue (TB) 0.06% with an external pump was used to evaluate intravitreal infusion in rabbit eyes. Groups A (50 μL), B (100 μL), C (150 μL), and D (200 μL) were slowly infused over 30 minutes with TB. As a control, Group E underwent conventional intravitreal injection of 100 μL of TB. Group F received a bolus infusion of 100 μL of TB within 1 minute. The mean increases in IOP during infusion for each group were: Group A (7.93 ± 3.80 mmHg), B (13.97 ± 3.17 mmHg), C (19.91 ± 6.06 mmHg) and D (29.38 ± 8.97 mmHg). Immediately post-injection in group E the mean increase in IOP amounted to 34.33 ± 6.57 mmHg. The mean increase in IOP of group F after bolus infusion was 49.89 ± 1.71 mmHg. Intravitreal infusion maintains a stable IOP and provides a controlled infusion speed compared with intravitreal injection. PMID:27886224

  15. Antibody neutralization poses a barrier to intravitreal adeno-associated viral vector gene delivery to non-human primates.

    PubMed

    Kotterman, M A; Yin, L; Strazzeri, J M; Flannery, J G; Merigan, W H; Schaffer, D V

    2015-02-01

    Gene delivery vectors based on adeno-associated viruses (AAV) have exhibited promise in both preclinical disease models and human clinical trials for numerous disease targets, including the retinal degenerative disorders Leber's congenital amaurosis and choroideremia. One general challenge for AAV is that preexisting immunity, as well as subsequent development of immunity following vector administration, can severely inhibit systemic AAV vector gene delivery. However, the role of neutralizing antibodies (NABs) in AAV transduction of tissues considered to be immune privileged, such as the eye, is unclear in large animals. Intravitreal AAV administration allows for broad retinal delivery, but is more susceptible to interactions with the immune system than subretinal administration. To assess the effects of systemic anti-AAV antibody levels on intravitreal gene delivery, we quantified the anti-AAV antibodies present in sera from non-human primates before and after intravitreal injections with various AAV capsids. Analysis showed that intravitreal administration resulted in an increase in anti-AAV antibodies regardless of the capsid serotype, transgene or dosage of virus injected. For monkeys injected with wild-type AAV2 and/or an AAV2 mutant, the variable that most significantly affected the production of anti-AAV2 antibodies was the amount of virus delivered. In addition, post-injection antibody titers were highest against the serotype administered, but the antibodies were also cross-reactive against other AAV serotypes. Furthermore, NAB levels in serum correlated with those in vitreal fluid, demonstrating both that this route of administration exposes AAV capsid epitopes to the adaptive immune system and that serum measurements are predictive of vitreous fluid NAB titers. Moreover, the presence of preexisting NAB titers in the serum of monkeys correlated strongly (R=0.76) with weak, decaying or no transgene expression following intravitreal administration of AAV

  16. Management of macular epiretinal membrane by vitrectomy and intravitreal triamcinolone.

    PubMed

    Shukla, Dhananjay

    2014-04-01

    A patient underwent successful vitrectomy for macular epiretinal membrane with anatomical and functional improvement. 10 weeks later, there was a recurrence of macular edema with corresponding visual decline. An intravitreal injection of triamcinolone acetonide not only restored the macular anatomy but also improved the visual outcome beyond that achieved after surgery.

  17. Pharmacokinetics and retinal toxicity of various doses of intravitreal triamcinolone acetonide in rabbits

    PubMed Central

    Ye, You-Fan; Gao, Yong-Feng; Xie, Hua-Tao

    2014-01-01

    Purpose To compare the pharmacokinetics and retinal toxicity of various doses of intravitreal triamcinolone acetonide (TA) in rabbits. Methods The rabbits received intravitreal injections of 4 mg and 8 mg TA. The drug concentrations were determined with high-performance liquid chromatography after extraction from the vitreous at various time points. The main pharmacokinetics parameters were calculated with 3p97 pharmacokinetics software. The intraocular pressure, electroretinography, and pathological examinations were evaluated before and after intravitreal injection of different doses of TA. Results The half-life of intravitreal injection of 4 mg and 8 mg TA was 24 days and 34 days, respectively. No significant differences were found in intraocular pressure (p>0.05) and the electroretinography b-wave amplitudes (p>0.05) among the rabbits before and after intravitreal injection of 4 mg and 8 mg TA. Light and electron microscopy did not show any retinal damage in any group. Conclusions Intravitreal injection of 4 mg and 8 mg TA are safe for the rabbit retina. The injection of 8 mg TA produced a longer vitreous half-life and had a prolonged effect on the retina. This conclusion may be referenced in the clinical application of TA in retinal diseases. PMID:24868137

  18. Intravitreal injection or topical eye-drop application of a μ-calpain C2L domain peptide protects against photoreceptor cell death in Royal College of Surgeons' rats, a model of retinitis pigmentosa.

    PubMed

    Ozaki, Taku; Nakazawa, Mitsuru; Yamashita, Tetsuro; Sorimachi, Hiroyuki; Hata, Shoji; Tomita, Hiroshi; Isago, Hitomi; Baba, Ayaka; Ishiguro, Sei-Ichi

    2012-11-01

    Mitochondrial μ-calpain initiates apoptosis-inducing factor (AIF)-dependent apoptosis in retinal photoreceptor degeneration. Mitochondrial μ-calpain inhibitors may represent therapeutic targets for the disease. Therefore, we sought to identify inhibitors of mitochondrial calpains and determine their effects in Royal College of Surgeons' (RCS) rats, an animal model of retinitis pigmentosa (RP). We synthesized 20-mer peptides of the C2-like (C2L) domain of μ-calpain. Two μ-calpain peptides N2 and N9 inhibited mitochondrial μ-calpain activity (IC(50); 892 and 498nM, respectively), but not other proteases. Western blotting showed that 50μM of both μ-calpain peptides caused specific degradation of mitochondrial μ-calpain. Three-dimensional structure of calpains suggested that the peptides N2 and N9 corresponded to the regions forming salt bridges between the protease core domain 2 and the C2L domain. We determined the inhibitory regions of μ-calpain peptides N2 and N9 using 10-mers, and one peptide, N2-10-2, inhibited the activity of mitochondrial μ-calpain (IC(50); 112nM). We next conjugated the peptide N2-10-2 to the C-terminal of HIV-1 tat (HIV), a cell-penetrating peptide. Using isolated rat liver mitochondria, 50μM HIV-conjugated μ-calpain N2-10-2 peptide (HIV-Nμ, IC(50); 285nM) significantly inhibited AIF truncation. The intravitreal injection of 20mM HIV-Nμ also prevented retinal photoreceptor apoptosis determined by TUNEL staining, and preserved retinal function assessed by electroretinography in RCS rats. Topical application of 40mM HIV-Nμ also prevented apoptosis of retinal photoreceptors in RCS rats. Our results demonstrate that HIV-Nμ, a peptide inhibitor of mitochondrial μ-calpain, offers a new modality for treating RP.

  19. Acute sterile endophthalmitis following intravitreal bevacizumab: case series

    PubMed Central

    Orozco-Hernández, Axel; Ortega-Larrocea, Ximena; Sánchez-Bermúdez, Gustavo; García-Aguirre, Gerardo; Cantón, Virgilio Morales; Velez-Montoya, Raul

    2014-01-01

    Background Since the ophthalmological community adopted the use of intravitreal bevacizumab as an accepted off-label treatment for neovascular diseases, the amount of knowledge regarding its effects and properties has been increasing continually. In the last few years, there have been an increasing number of reports about sterile intraocular inflammation and intraocular pressure elevations after intravitreal bevacizumab. In the following case series, we describe the clinical presentation and outcomes of ten consecutive cases of patients developing mild-to-severe sterile intraocular inflammation after intravitreal bevacizumab and their management. Methods This report presents a retrospective case series. We reviewed the medical records of ten consecutive patients from a group of 46, in whom repackaged bevacizumab in individual aliquots from two vials from the same batch were used. All surgical procedures were performed using standard sterile techniques in the operating room. At each follow-up visit, patients underwent a complete ophthalmological examination including visual acuity assessment, intraocular pressure, biomicroscopy, and posterior fundus examination. Results Ten patients presented sterile endophthalmitis with an onset time of 3.5±1.95 days. The clinical characteristics were mild pain, slight visual loss, conjunctival hyperemia, and various degrees of intraocular inflammation with microhypopyon. All cultures were negative. All patients were managed with topical steroids and antibiotics, except two, in whom, due to severe vitreous cells, intravitreal antibiotics were used. Three patients showed a transient elevation of intraocular pressure. Only 50% of the patients regained a visual acuity equal or better to the baseline visual acuity on file. Conclusion The increasing number of intravitreal injections of bevacizumab applied every day, due to its widespread acceptance, might be one reason why the number of cases of sterile endophthalmitis is rising. Fast

  20. Intravitreal controlled release of dexamethasone from engineered microparticles of porous silicon dioxide.

    PubMed

    Wang, Chengyun; Hou, Huiyuan; Nan, Kaihui; Sailor, Michael J; Freeman, William R; Cheng, Lingyun

    2014-12-01

    Dexamethasone is a glucocorticoid that is widely used in the ophthalmic arena. The recent FDA approved dexamethasone implant can provide a three month efficacy but with high rate of drug related cataract and high intraocular pressure (IOP). It seems that higher steroid in aqueous humor and around lens may be associated with these complications based on clinical fact that higher IOP was observed with intravitreal triamcinolone acetonide (TA) than with subtenon TA. We hypothesize that placing a sustained dexamethasone release system near back of the eye through a fine needle can maximize efficacy while mitigate higher rate of IOP rise and cataract. To develop a sustained intravitreal dexamethasone delivery system, porous silicon dioxide (pSiO2) microparticles were fabricated and functionalized with amines as well as carboxyl groups. Dexamethasone was conjugated to pSiO2 through the Steglich Esterification Reaction between hydroxyl of dexamethasone and carboxyl groups on the pSiO2. The drug loading was confirmed by Fourier transform infrared spectroscopy (FTIR) and loading efficiency was quantitated using thermogravimetric analysis (TGA). In vitro release was conducted for three months and dexamethasone was confirmed in the released samples using liquid chromatography-tandem mass spectrometry (LC/MS/MS). A pilot ocular safety and determination of vitreous drug level was performed in rabbit eyes. The drug loading study demonstrated that loading efficiency was from 5.96% to 10.77% depending on the loading reaction time, being higher with longer loading reaction time before reaching saturation around 7 days. In vitro drug release study revealed that dexamethasone release from pSiO2 particles was sustainable for over 90 days and was 80 days longer than free dexamethasone or infiltration-loaded pSiO2 particle formulation in the same setting. Pilot in vivo study demonstrated no sign of ocular adverse reaction in rabbit eyes following a single 3 mg intravitreal injection and

  1. Intravitreal Controlled Release of Dexamethasone from Engineered Microparticles of Porous Silicon Dioxide

    PubMed Central

    Wang, Chengyun; Hou, Huiyuan; Nan, Kaihui; Sailor, Michael J; Freeman, William R.; Cheng, Lingyun

    2014-01-01

    Dexamethasone is a glucocorticoid that is widely used in the ophthalmic arena. The recent FDA approved dexamethasone implant can provide a three month efficacy but with high rate of drug related cataract and high intraocular pressure (IOP). It seems that higher steroid in aqueous humor and around lens may be associated with these complications based on clinical fact that higher IOP was observed with intravitreal triamcinolone acetonide (TA) than with subtenon TA. We hypothesize that placing a sustained dexamethasone release system near back of the eye through a fine needle can maximize efficacy while mitigate higher rate of IOP rise and cataract. To develop a sustained intravitreal dexamethasone delivery system, porous silicon dioxide (pSiO2) microparticles were fabricated and functionalized with amines as well as carboxyl groups. Dexamethasone was conjugated to pSiO2 through the Steglich Esterificaion Reaction between hydroxyl of dexamethasone and carboxyl groups on the pSiO2. The drug loading was confirmed by Fourier transform infrared spectroscopy (FTIR) and loading efficiency was quantitated using thermogravimetric analysis (TGA). In vitro release was conducted for three months and dexamethasone was confirmed in the released samples using liquid chromatography-tandem mass spectrometry (LC/MS/MS). A pilot ocular safety and determination of vitreous drug level was performed in rabbit eyes. The drug loading study demonstrated that loading efficiency was from 5.96% to 10.77% depending on the loading reaction time, being higher with longer loading reaction time before reaching saturation around 7 days. In vitro drug release study revealed that dexamethasone release from pSiO2 particles was sustainable for over 90 days and was 80 days longer than free dexamethasone or infiltration-loaded pSiO2 particle formulation in the same setting. Pilot in vivo study demonstrated no sign of ocular adverse reaction in rabbit eyes following a single 3 mg intravitreal injection and

  2. Intravitreal properties of porous silicon photonic crystals

    PubMed Central

    Cheng, L; Anglin, E; Cunin, F; Kim, D; Sailor, M J; Falkenstein, I; Tammewar, A; Freeman, W R

    2009-01-01

    Aim To determine the suitability of porous silicon photonic crystals for intraocular drug-delivery. Methods A rugate structure was electrochemically etched into a highly doped p-type silicon substrate to create a porous silicon film that was subsequently removed and ultrasonically fractured into particles. To stabilise the particles in aqueous media, the silicon particles were modified by surface alkylation (using thermal hydrosilylation) or by thermal oxidation. Unmodified particles, hydrosilylated particles and oxidised particles were injected into rabbit vitreous. The stability and toxicity of each type of particle were studied by indirect ophthalmoscopy, biomicroscopy, tonometry, electroretinography (ERG) and histology. Results No toxicity was observed with any type of the particles during a period of >4 months. Surface alkylation led to dramatically increased intravitreal stability and slow degradation. The estimated vitreous half-life increased from 1 week (fresh particles) to 5 weeks (oxidised particles) and to 16 weeks (hydrosilylated particles). Conclusion The porous silicon photonic crystals showed good biocompatibility and may be used as an intraocular drug-delivery system. The intravitreal injectable porous silicon photonic crystals may be engineered to host a variety of therapeutics and achieve controlled drug release over long periods of time to treat chronic vitreoretinal diseases. PMID:18441177

  3. Self-assembled phenylalanine-α,β-dehydrophenylalanine nanotubes for sustained intravitreal delivery of a multi-targeted tyrosine kinase inhibitor.

    PubMed

    Panda, Jiban J; Yandrapu, Sarath; Kadam, Rajendra S; Chauhan, Virander S; Kompella, Uday B

    2013-12-28

    Current standard of care for sustained back of the eye drug delivery is surgical placement or injection of large, slow release implants using a relatively large 22 gauge needle. We designed novel dipeptide (phenylalanine-α,β-dehydrophenylalanine; Phe-∆Phe) based nanotubes with a diameter of ~15-30 nm and a length of ~1500 nm that could be injected with a 33 gauge needle for sustained intravitreal delivery of pazopanib, a multi-targeted tyrosine kinase inhibitor. The drug could be loaded during nanotube assembly or post-loaded after nanotube formation, with the former being more efficient at 25% w/w pazopanib loading and ~55% loading efficiency. Plain and peptide loaded nanotube were non-cytotoxic to retinal pigment epithelial cells even at a concentration of 200 μg/ml. Following intravitreal injection of fluorescently labeled nanotubes using a 33 gauge needle in a rat model, the nanotube persistence and drug delivery were monitored using noninvasive fluorophotometry, electron microscopy and mass spectrometry analysis. Nanotubes persisted in the vitreous humor during the 15 days study and pazopanib levels in the vitreous humor, retina, and choroid-RPE at the end of the study were 4.5, 5, and 2.5-folds higher, respectively, compared to the plain drug. Thus, Phe-∆Phe nanotubes allow intravitreal injections with a small gauge needle and sustain drug delivery.

  4. Injection Locking Techniques for Spectrum Analysis

    NASA Astrophysics Data System (ADS)

    Gathma, Timothy D.; Buckwalter, James F.

    2011-04-01

    Wideband spectrum analysis supports future communication systems that reconfigure and adapt to the capacity of the spectral environment. While test equipment manufacturers offer wideband spectrum analyzers with excellent sensitivity and resolution, these spectrum analyzers typically cannot offer acceptable size, weight, and power (SWAP). CMOS integrated circuits offer the potential to fully integrate spectrum analysis capability with analog front-end circuitry and digital signal processing on a single chip. Unfortunately, CMOS lacks high-Q passives and wideband resonator tunability that is necessary for heterodyne implementations of spectrum analyzers. As an alternative to the heterodyne receiver architectures, two nonlinear methods for performing wideband, low-power spectrum analysis are presented. The first method involves injecting the spectrum of interest into an array of injection-locked oscillators. The second method employs the closed loop dynamics of both injection locking and phase locking to independently estimate the injected frequency and power.

  5. Injection Locking Techniques for Spectrum Analysis

    SciTech Connect

    Gathma, Timothy D.; Buckwalter, James F.

    2011-04-19

    Wideband spectrum analysis supports future communication systems that reconfigure and adapt to the capacity of the spectral environment. While test equipment manufacturers offer wideband spectrum analyzers with excellent sensitivity and resolution, these spectrum analyzers typically cannot offer acceptable size, weight, and power (SWAP). CMOS integrated circuits offer the potential to fully integrate spectrum analysis capability with analog front-end circuitry and digital signal processing on a single chip. Unfortunately, CMOS lacks high-Q passives and wideband resonator tunability that is necessary for heterodyne implementations of spectrum analyzers. As an alternative to the heterodyne receiver architectures, two nonlinear methods for performing wideband, low-power spectrum analysis are presented. The first method involves injecting the spectrum of interest into an array of injection-locked oscillators. The second method employs the closed loop dynamics of both injection locking and phase locking to independently estimate the injected frequency and power.

  6. Treatment of noninfectious posterior uveitis with dexamethasone intravitreal implant

    PubMed Central

    Myung, Jane S; Aaker, Grant D; Kiss, Szilárd

    2010-01-01

    Purpose To report our experience with dexamethasone 0.7 mg sustained-release intravitreal implant (Ozurdex®; Allergan, Inc, Irvine, CA) in noninfectious posterior uveitis. Methods A retrospective chart review of patients with noninfectious uveitis treated with sustained-release dexamethasone 0.7 mg intravitreal implant was performed. Complete ophthalmic examination including signs of inflammatory activity, visual acuity, fundus photography, fluorescein angiography, optical coherence tomography, and tolerability of the implant were assessed. Results Six eyes of 4 consecutive patients treated with a total of 8 dexamethasone 0.7 mg sustained-release intravitreal implants for posterior noninfectious uveitis were included. Two patients presented with unilateral idiopathic posterior uveitis; 2 patients had bilateral posterior uveitis, one secondary to sarcoidosis and the other to Vogt-Koyanagi-Harada syndrome. All eyes showed clinical and angiographic evidence of decreased inflammation following implant placement. Mean follow-up time post-injection was 5.25 months. Four eyes received 1 and 2 eyes received 2 Ozurdex implants during the follow-up period. The duration of effect of the implant was 3 to 4 months. No serious ocular or systemic adverse events were noted during the follow-up period. Conclusions In patients with noninfectious posterior uveitis, sustained-release dexamethasone 0.7 mg intravitreal implant may be an effective treatment option for controlling intraocular inflammation. PMID:21188153

  7. Successful Resolution of Preretinal Haemorrhage with Intravitreal Ranibizumab

    PubMed Central

    Noorlaila, Baharuddin; Raja-Azmi, Mohd-Noor

    2016-01-01

    We would like to report two cases of preretinal haemorrhage from two different aetiology courses of bleeding being treated with intravitreal ranibizumab and its outcome. Our first case was a 39-year-old man with a diagnosis of severe aplastic anaemia that presented with bilateral premacular haemorrhages in both eyes. His right eye vision was 6/45 and it was counting finger in the left eye. He was treated with intravitreal ranibizumab once to the right eye and twice to the left eye. Right eye showed complete resolution of premacular haemorrhage and minimal residual premacular haemorrhage in the left eye at 3 months after initial presentation. Our second case was a 32-year-old healthy teacher that presented with preretinal haemorrhage at superotemporal region extending to macular area in left eye secondary to valsalva retinopathy. Her left vision was counting finger. She was treated with single intravitreal ranibizumab to the left eye. There was significant reduction of premacular haemorrhage and her left eye vision improved to 6/6 at 10 weeks after injection. Both cases had favourable outcome with intravitreal ranibizumab and can be considered as nonsurgical treatment option in treating premacular haemorrhage. PMID:27800200

  8. Intravitreal diclofenac versus intravitreal bevacizumab in naive diabetic macular edema: a randomized double-masked clinical trial.

    PubMed

    Soheilian, Masoud; Karimi, Saeed; Ramezani, Alireza; Montahai, Talieh; Yaseri, Mehdi; Soheilian, Roham; Peyman, Gholam A

    2015-06-01

    The purpose of the study is to compare single injection of intravitreal diclofenac (IVD) with intravitreal bevacizumab (IVB) in the treatment of eyes with naïve diabetic macular edema (DME). In this randomized clinical trial, 57 eyes of 57 patients were randomly assigned to IVD group (30 eyes), cases who received a single intravitreal injection of diclofenac (500 μg/0.1 ml), and IVB group (27 eyes), cases who received a single intravitreal injection of bevacizumab (1.25 mg). Change in best-corrected visual acuity in logMAR at week 12 was the primary outcome measure. Secondary outcomes included changes in central macular thickness, macular leakage, and potential injection-related complications. Best-corrected visual acuity improved significantly more in the IVD group than in the IVB group (P = 0.033), from 0.57 ± 0.25 to 0.49 ± 0.31 versus 0.55 ± 0.24-0.59 ± 0.27 logMAR at 12 weeks, respectively. However, the difference of macular thickness changes was in favor of IVB, but not to a significant level. The amount of change in leakage was not significantly different between the groups either. None of the eyes, in either group, developed ocular hypertension (≥23 mmHg) or cataract progression. No important injection-related complication was observed during the study period. This study demonstrated the superiority of IVD over IVB in the treatment of naïve DME regarding functional, but not anatomical outcomes. Therefore, using IVD as an adjunct or even alternative to other treatments might enhance the functional outcomes in such cases. Further studies are warranted to confirm potential benefit of IVD observed in this study.

  9. Automated Protein Assay Using Flow Injection Analysis

    NASA Astrophysics Data System (ADS)

    Wolfe, Carrie A. C.; Oates, Matthew R.; Hage, David S.

    1998-08-01

    The technique of flow injection analysis (FIA) is a common instrumental method used in detecting a variety of chemical and biological agents. This paper describes an undergraduate laboratory that uses FIA to perform a bicinchoninic acid (BCA) colorimetric assay for quantitating protein samples. The method requires less than 2 min per sample injection and gives a response over a broad range of protein concentrations. This method can be used in instrumental analysis labs to illustrate the principles and use of FIA, or as a means for introducing students to common methods employed in the analysis of biological agents.

  10. Safety of intravitreal quinupristin/dalfopristin in an animal model

    PubMed Central

    Giordano, Veronica E.; Hernandez-Da Mota, Sergio E.; Adabache-Guel, Tania N.; Castillejos-Chevez, Armando; Corredor-Casas, Sonia; Salinas-Longoria, Samantha M.; Romero-Vera, Rafael; Jimenez-Sierra, Juan M.; Guerrero-Naranjo, Jose L.; Morales-Canton, Virgilio

    2016-01-01

    AIM To determine whether different intravitreal doses of quinupristin/dalfopristin lead to electroretinographic or histological changes in the rabbit retina over one month period after injection. METHODS Eighteen New Zealand white rabbits were divided into three treatment groups (groups 1 to 3) and different intravitreal doses of quinupristin/dalfopristin were tested in each group. The right eye was injected with the drug and the left eye received intravitreal injection of 5% dextrose water and served as control eye. The doses delivered to each group were 0.1 mg/0.1 mL, 1 mg/0.1 mL and 10 mg/0.1 mL. Simultaneous, bilateral, dark-adapted electroretinography and clinical images of both eyes were obtained in all groups before injection (baseline) and after 7, 14, 21 and 28d, followed by enucleation for histological examination. RESULTS Subjects in the group 1 showed no signs of toxicity in the electroretinogram when compared with groups 2 and 3 (Kruskall-Wallis test, P=0.000). By day 7, no electrical response to light stimuli was recorded in the treated eyes in groups 2 and 3, consistent with severe damage due to retinal toxicity. Light microscopy revealed no significant histopathological changes in the group 1, while rabbits in groups 2 and 3 had signs of granulomatous inflammation in most cases. CONCLUSION Intravitreal 0.1 mg/0.1 mL doses of quinupristin/dalfopristin do not lead to electroretinographic or histological signs of retinal toxicity compared with 1 mg/0.1 mL and 10 mg/0.1 mL in this rabbit model. PMID:27158605

  11. Intravitreal aflibercept versus intravitreal ranibizumab for the treatment of diabetic macular edema

    PubMed Central

    Fouda, Sameh Mosaad; Bahgat, Ahmed M

    2017-01-01

    Purpose The purpose of this study was to compare the efficacy of intravitreal aflibercept and ranibizumab in the treatment of diabetic macular edema (DME) in eyes with moderate visual loss. Patients and methods This study is a randomized prospective study. Seventy eyes with DME were divided into two groups (each containing 35 eyes). Eyes in group I were treated with intravitreal injection of 2 mg/0.05 mL aflibercept and eyes in group II were treated with intravitreal injection of 0.5 mg/0.1 mL ranibizumab. All the eyes had three successive injections as a loading dose (with 1 month interval), and then the patients were followed up monthly for 12 months. The outcomes of the study were visual acuity, central macular thickness (CMT), and the number of re-injections of the drug. Results Mean age of the patients in group I was 55.05±4.7 years and in group II was 56.64±5.8 years (P=0.17). The mean baseline best corrected visual acuity (BCVA) of eyes treated with aflibercept was 0.17±0.05 and with ranibizumab was 0.18±0.04 (P=0.9). BCVA was improved in both the groups at the end of the follow-up period and was found to be 0.42±0.28 and 0.37±0.23, respectively (P=0.27). The mean baseline CMT of eyes in group I was 465.29±33.7 µm and in group II was 471.5±34.4 µm (P=0.65). CMT decreased in both the groups to 360.8±85.7 µm and 387.3±87.8 µm, respectively (P=0.2). The mean number of drug re-injection was 2.62±0.68 and 3.03±0.95 in both the groups, respectively (P=0.02). Conclusion Aflibercept and ranibizumab have the same efficacy in the treatment of DME in eyes with moderate visual loss but with less number of drug re-injection and less treatment burden with aflibercept (2.62±0.68 versus 3.03±0.95). PMID:28356711

  12. Intravitreal Bevacizumab (Avastin) for Diabetic Retinopathy: The 2010 GLADAOF Lecture

    PubMed Central

    Arevalo, J. Fernando; Sanchez, Juan G.; Lasave, Andres F.; Wu, Lihteh; Maia, Mauricio; Bonafonte, Sergio; Brito, Miguel; Alezzandrini, Arturo A.; Restrepo, Natalia; Berrocal, Maria H.; Saravia, Mario; Farah, Michel Eid; Fromow-Guerra, Jans; Morales-Canton, Virgilio

    2011-01-01

    This paper demonstrates multiple benefits of intravitreal bevacizumab (IVB) on diabetic retinopathy (DR) including diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) at 24 months of followup. This is a retrospective multicenter interventional comparative case series of intravitreal injections of 1.25 or 2.5 mg of bevacizumab for DME, PDR without tractional retinal detachment (TRD), and patients who experienced the development or progression of TRD after an intravitreal injection of 1.25 or 2.5 mg of bevacizumab before vitrectomy for the management of PDR. The results indicate that IVB injections may have a beneficial effect on macular thickness and visual acuity (VA) in diffuse DME. Therefore, in the future this new therapy could complement focal/grid laser photocoagulation in DME. In PDR, this new option could be an adjuvant agent to panretina photocoagulation so that more selective therapy may be applied. Finally, TRD in PDR may occur or progress after IVB used as an adjuvant to vitrectomy. Surgery should be performed 4 days after IVB. Most patients had poorly controlled diabetes mellitus associated with elevated HbA1c, insulin administration, PDR refractory to panretinal photocoagulation, and longer time between IVB and vitrectomy. PMID:21584260

  13. Analysis of rocket engine injection combustion processes

    NASA Technical Reports Server (NTRS)

    Salmon, J. W.

    1976-01-01

    A critique is given of the JANNAF sub-critical propellant injection/combustion process analysis computer models and application of the models to correlation of well documented hot fire engine data bases. These programs are the distributed energy release (DER) model for conventional liquid propellants injectors and the coaxial injection combustion model (CICM) for gaseous annulus/liquid core coaxial injectors. The critique identifies model inconsistencies while the computer analyses provide quantitative data on predictive accuracy. The program is comprised of three tasks: (1) computer program review and operations; (2) analysis and data correlations; and (3) documentation.

  14. Intravitreal aflibercept treatment in eyes with exudative age-related macular degeneration following prior treatment with intravitreal ranibizumab

    PubMed Central

    Narayan, Daniel Sanju; Muecke, James

    2015-01-01

    Background: To investigate visual and anatomical outcomes in eyes with exudative age-related macular degeneration treated with intravitreal aflibercept following prior treatment with intravitreal ranibizumab. Materials and Methods: Retrospective, single-center study of 192 eyes treated with 0.5 mg intravitreal ranibizumab every 4 weeks for three consecutive doses followed by a variable dose schedule. After more than 12 months of ranibizumab treatment, eyes that required ranibizumab injections at 4-week or 6-week intervals were switched to aflibercept therapy. Results: After 12–69 months (42 months ± 18 months, mean ± standard deviation [SD]) of treatment with intravitreal ranibizumab, 80 eyes were changed to 2 mg intravitreal aflibercept treatment with follow-up after 12–18 months (16 months ± 1 month, mean ± SD). Thirty-nine eyes had persistent macular fluid after treatment with ranibizumab. Mean logMAR visual acuity (VA) in eyes treated with ranibizumab changed by − 0.089 ± 0.310 (mean ± SD; P = 0.0003), which correlates to an approximate gain of 4.5 letters. The number of eyes with macular fluid decreased from 39 to 23 after aflibercept treatment. Mean logMAR VA in eyes with intraretinal macular fluid treated with aflibercept changed by −0.079 ± 0.134 (mean ± SD; P = 0.006), which correlates to an approximate gain of 4 letters. Mean logMAR VA in eyes with submacular fluid was not significantly different after aflibercept treatment. Conclusion: Eyes with persistent intraretinal macular fluid had visual and anatomic response after changing from ranibizumab to aflibercept treatment. PMID:26669334

  15. Dosage dependency of intravitreal triamcinolone acetonide as treatment for diabetic macular oedema

    PubMed Central

    Spandau, U H M; Derse, M; Schmitz-Valckenberg, P; Papoulis, C; Jonas, J B

    2005-01-01

    Aim: To evaluate the effect of different doses of intravitreal triamcinolone acetonide on diffuse diabetic macular oedema. Methods: The prospective, randomised, double masked, clinical interventional study included 27 eyes (27 patients) with diffuse diabetic macular oedema. They were randomly divided into three study groups receiving an intravitreal injection of filtered triamcinolone acetonide of about 2 mg (n = 8 eyes), 5 mg (n = 10), or 13 mg (n = 9), respectively. Dosage measurement was performed before filtration. Mean follow up was 6.6 (SD 2.4) months (3–12 months). Main outcome measures were visual acuity and intraocular pressure. Results: Maximal increase in visual acuity was significantly (p = 0.046; 95% CI: 0.032 to 2.99; r = 0.38) correlated with the dosage of intravitreal triamcinolone acetonide. Additionally, the duration of the effect of intravitreal triamcinolone acetonide increased significantly with the dosage of intravitreal triamcinolone acetonide (r = 0.45; p = 0.014). Increase in intraocular pressure during follow up was statistically not significantly associated with the dosage used (p = 0.77). Conclusions: In patients with diffuse diabetic macular oedema receiving intravitreal triamcinolone acetonide, treatment response may last longer and be more pronounced with a dosage of 13 mg than in lower doses of 5 mg or 2 mg. Triamcinolone acetonide induced increase in intraocular pressure may not be markedly associated with the dosage used. PMID:16024853

  16. Intravitreal Dexamethasone Implant (Ozurdex) for Refractory Macular Edema Secondary to Retinitis Pigmentosa

    PubMed Central

    Örnek, Nurgül; Örnek, Kemal; Erbahçeci, İnci Elif

    2016-01-01

    Macular edema (ME) in retinitis pigmentosa (RP) often impairs central vision dramatically. A 41-year-old woman diagnosed with RP was referred to our outpatient clinic due to severe visual deterioration in both eyes. The patient was treated with topical carbonic anhydrase inhibitors, topical corticosteroids and intravitreal triamcinolone acetonide injections, but her ME recurred. Intravitreal 0.7 mg dexamethasone implant (Ozurdex, Allergan) was administered into both eyes without complications. On the fourth day after both injections, visual acuity improved and ME almost totally resolved. No recurrence was observed at follow-up six months later. PMID:28058154

  17. Solenoid pumps for flow injection analysis.

    PubMed

    Weeks, D A; Johnson, K S

    1996-08-01

    Methods employing flow injection analysis (FIA), particularly for in situ seawater techniques, would benefit from reduction in pump size and power requirement, longer maintenance intervals, and the ability to incorporate microprocessor control of each reagent and sample flow stream. In this work, the peristaltic pump of a conventional FIA system was replaced by three solenoid-driven diaphragm pumps with integral Viton check valves, and the system was tested by performing the simple nitrite analysis, which has well-defined FIA performance characteristics. Sixty injections per hour were possible with flow rates of 0.5 mL/min for reagents and sample. The coefficient of variation was 1% for 10 μM NO(2)(-) concentrations, and the detection limit was less than 0.1 μM NO(2)(-). These values match the reported performance for this method using peristaltic pumps.

  18. Residual ozone determination by flow injection analysis

    SciTech Connect

    Straka, M.R.; Pacey, G.E.; Gordon, G.

    1984-09-01

    It has been proposed that ozone be used to replace free chlorine for the disinfection of drinking water and waste water. For the use of ozone in this capacity, it would be necessary to have a fast accurate and precise method to analyze for the presence of residuals. An automated method for ozone determination based on the indigo reagent method is presented. This method is based on the advantages of flow injection analysis (FIA) techniques. 19 references, 3 tables, 2 figures.

  19. Retinal toxicity of intravitreal tenecteplase in the rabbit

    PubMed Central

    Rowley, S A; Vijayasekaran, S; Yu, P K; McAllister, I L; Yu, D-Yi

    2004-01-01

    Aim: To investigate the retinal toxicity of intravitreal injection of a novel fibrinolytic tenecteplase in rabbit eyes. Methods: Tenecteplase (25–350 μg in 0.1 ml BSS) was injected into the vitreous cavity of normal rabbit eyes. Control (fellow) eyes received 0.1 ml of BSS. One day, 1 week, and 2 months post-injection, the eyes were examined by slit lamp biomicroscopy, indirect ophthalmoscopy, and electroretinography, and then harvested for histopathological examination. Results: No evidence of retinal toxicity was seen with tenecteplase doses up to and including 50 μg. At a dose of 150 μg ophthalmoscopy was normal, but histology showed mild retinal damage in the inner nuclear layer and electroretinography showed a temporary reduction in B-wave amplitude. At doses of 200 μg and above, there was evidence of retinal toxicity on electroretinography, ophthalmoscopy, and histology. Ophthalmoscopic findings included vitreal fibrosis, retinal necrosis and tractional retinal detachment and light microscopy revealed necrosis of retinal pigment epithelium and other retinal layers. Damage was centred around the injection site but was more widespread with the higher doses. Conclusion: A dose of 50 μg tenecteplase appears safe for intravitreal injection in the rabbit. Tenecteplase could have potential applications in the treatment of submacular haemorrhage and retinal vein occlusion. PMID:15031179

  20. Visualization of residual perfluorocarbon liquid using intravitreal triamcinolone acetonide.

    PubMed

    Hirata, Fumisato; Tamura, Hironori; Ogura, Yuichiro

    2005-01-01

    The visualization of transparent perfluorocarbon liquid (PFCL) using triamcinolone acetonide is described. Intravitreal injection of triamcinolone acetonide enabled visualization of residual PFCL intraoperatively. In addition, it was shown that triamcinolone acetonide could visualize PFCL in an in vitro preparation of balanced salt solution. This in vitro experiment confirmed that triamcinolone acetonide also could be adsorbed by PFCL outside the vitreous. Triamcinolone acetonide was helpful to visualize transparent PFCL both in vivo and in vitro, and may be useful at the end of vitrectomy to completely remove residual PFCL from the eye.

  1. Successful use of intravitreal bevacizumab and pascal laser photocoagulation in the management of adult Coats' disease.

    PubMed

    Raoof, Naz; Quhill, Fahd

    2013-01-01

    Traditional methods of managing exudative retinal detachment secondary to Coats' disease have been associated with varying degrees of success. We describe a case of a 34 year-old male who presented with a sub-total exudative retinal detachment of the right eye that encroached upon the macula, associated with a vasoproliferative tumor secondary to Coats' disease. The patient under-went successful treatment with two intravitreal injections of bevacizumab (Avastin, Genetech Inc., San Francisco, CA, USA) combined with targeted laser photocoagulation with a 532 nm Pascal laser (Topcon Corp., Tokyo, Japan). The visual acuity improved 5 days after the second intravitreal injection from 6/18 to 6/5, with no residual macular edema and complete regression of the vasoproliferative tumor. The improvement in visual acuity was maintained at 12 months post-treatment. We believe this is the first case report describing the successful use of Pascal laser photocoagulation with intravitreal bevacizumab in the treatment of Coats' disease. Our aim was to defer laser treatment until 'near total' retinal reattachment and regression of the vasoproliferative tumor was achieved. There are, however, reports of vitreous fibrosis in patients with Coats' disease treated with intravitreal bevacizumab. This suggests further long-term follow-up studies are required in patients treated with this approach.

  2. Ocular and systemic toxicity of intravitreal topotecan in rabbits for potential treatment of retinoblastoma.

    PubMed

    Buitrago, Emiliano; Del Sole, María José; Torbidoni, Ana; Fandino, Adriana; Asprea, Marcelo; Croxatto, J O; Chantada, Guillermo L; Bramuglia, Guillermo F; Schaiquevich, Paula

    2013-03-01

    Treatment of intraocular retinoblastoma with vitreous seeding is a challenge. Different routes of chemotherapy administration have been explored in order to attaining pharmacological concentrations into the posterior chamber. Intravitreal drug injection is a promissing route for maximum bioavailability to the vitreous but it requires a well defined dose for achieving tumor control while limited toxicity to the retina. Topotecan proved to be a promising agent for retinoblastoma treatment due to its pharmacological activity and limited toxicity. High and prolonged concentrations were achieved in the rabbit vitreous after 5 μg of intravitreal topotecan. However, whether a lower dose could achieve potentially therapeutic levels remained to be determined. Thus, we here study the pharmacokinetics of topotecan after 0.5 μg and the toxicity profile of intravitreal topotecan in the rabbit eye as a potential treatment of retinoblastoma. A cohort of rabbits was used to study topotecan disposition in the vitreous after a single dose of 0.5 μg of intravitreal topotecan. In addition, an independent cohort of non-tumor bearing rabbits was employed to evaluate the clinical and retinal toxicity after four weekly injections of two different doses of intravitreal topotecan (Group A, 5 μg/dose; Group B, 0.5 μg/dose) to the right eye of each animal. The same volume (0.1 ml) of normal saline was administered to the left eye as control. A third group of rabbits (Group C) served as double control (both eyes injected with normal saline). Animals were weekly evaluated for clinical and hematologic values and ocular evaluations were performed with an inverse ophthalmoscope to establish potential topotecan toxicity. Weekly controls included topotecan quantitation in plasma of all rabbits. Electroretinograms (ERGs) were recorded before and after topotecan doses. One week after the last injection, topotecan concentrations were measured in vitreous of all eyes and samples for retinal

  3. Pharmacokinetics of intravitreal bevacizumab (Avastin®) in rabbits

    PubMed Central

    Sinapis, Christos I; Routsias, John G; Sinapis, Angelos I; Sinapis, Dimitrios I; Agrogiannis, George D; Pantopoulou, Alkistis; Theocharis, Stamatis E; Baltatzis, Stefanos; Patsouris, Efstratios; Perrea, Despoina

    2011-01-01

    Purpose: To describe the pharmacokinetics of intravitreal bevacizumab (Avastin®) in rabbits. Methods: The right eye of 20 rabbits was injected intravitreally with 1.25 mg/0.05 mL bevacizumab. Both eyes of four rabbits each time were enucleated at days 1, 3, 8, 15, and 29. Bevacizumab concentrations were measured in serum, aqueous humor, and vitreous. Results: Maximum vitreous (406.25 μg/mL) and aqueous humor (5.83 μg/mL) concentrations of bevacizumab in the right eye were measured at day 1. Serum bevacizumab concentration peaked at day 8 (0.413 μg/mL) and declined to 0.032 μg/mL at 4 weeks. Half-life values in right vitreous, right aqueous humor, and serum were 6.61, 6.51, and 5.87 days, respectively. Concentration of bevacizumab in the vitreous of the noninjected eye peaked at day 8 (0.335 ng/mL) and declined to 0.218 ng/mL at 4 weeks. In the aqueous humor of the noninjected eye, maximum concentration of bevacizumab was achieved at day 8 (1.6125 ng/mL) and declined (to 0.11 ng/mL) at 4 weeks. Conclusion: The vitreous half-life of 1.25 mg/0.05 mL intravitreal bevacizumab was 6.61 days in this rabbit model. Maximum concentrations of bevacizumab were reached at day 1 in both vitreous and aqueous humor of the right eye and at day 8 in the serum. Very low concentrations of bevacizumab were measured in the fellow noninjected eye. PMID:21629577

  4. Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration

    PubMed Central

    Reis, Gustavo MSM; Grigg, John; Chua, Brian; Lee, Anne; Lim, Ridia; Higgins, Ralph; Martins, Alessandra; Goldberg, Ivan

    2017-01-01

    ABSTRACT Aim The aim of this article is to evaluate the rate of patients developing sustained elevated intraocular pressure (IOP) after ranibizumab (Lucentis) intravitreal (IVT) injections. Design This is a retrospective study. Participants Charts of 192 consecutive patients receiving Lucentis for age-related macular degeneration (AMD) were retrospectively reviewed. Materials and methods We enrolled patients with at least two IOP measurements between injections. Elevated IOP was defined as >21 mm Hg with an increase of at least 20% from baseline. Noninjected contralateral eyes of the same patient cohort were used as control. Main outcome measures Primary outcome was defined as elevated IOP. Secondary outcomes were presence and type of glaucoma, number of injections, and time to IOP elevation. Results Elevated IOP occurred at a significantly higher rate in eyes receiving IVT ranibizumab (7.47%; n = 9) compared with control (0.93%; n = 1). Patients with preexisting glaucoma or ocular hypertension (OHT) were more likely to develop elevated IOP after IVT ranibizumab injection. Conclusion Intravitreal ranibizumab injections are associated with sustained IOP elevation in some eyes. How to cite this article Reis GMSM, Grigg J, Chua B, Lee A, Lim R, Higgins R, Martins A, Goldberg I, Clement CI. The Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration. J Curr Glaucoma Pract 2017;11(1):3-7. PMID:28138211

  5. Combined therapy (intravitreal bevacizumab plus verteporfin photodynamic therapy) versus intravitreal bevacizumab monotherapy for choroidal neovascularization due to age-related macular degeneration: a 1-year follow-up study

    PubMed Central

    Saviano, Sandro; Leon, Pia Easter; Mangogna, Alessandro; Tognetto, Daniele

    2016-01-01

    Purpose To assess the efficacy and safety of combined intravitreal bevacizumab and low-fluency-rate photodynamic therapy (PDT) in the treatment of choroidal neovascularization (CNV) associated with age-related macular degeneration (AMD) and to compare it with intravitreal bevacizumab monotherapy. Methods A total of 62 eyes of 62 patients with angiographic evidence of CNV were divided into 2 groups: the eyes of one group were treated with a combined therapy of 1 intravitreal bevacizumab injection (1.25 mg) and PDT within 7 days; the eyes of the other group received intravitreal bevacizumab monotherapy. Clinical evidence of complications, best-corrected visual acuity (BVCA) and fluorescein leakage were evaluated. Best-corrected visual acuity and optical coherence tomography (OCT) were tested monthly and followed for 12 months. Results In the combined group the mean BCVA increased from 0.61 logMAR before the treatment to 0.54 logMAR at 12 months’ follow-up. In the monotherapy group the mean BCVA increased from 0.65 logMAR to 0.60 logMAR at 12 months’ follow-up. There was no significant difference in visual acuity outcomes between groups (P > 0.05). In the combined group the mean number of treatments was 1.19 per patient; in the monotherapy group, 5.31 per patient (P < 0.01). Conclusions Combined therapy appears to be an effective option for CNV associated with AMD treatment allowing a significant reduction of intravitreal injections. PMID:27582675

  6. Efficient vitreolysis by combining plasmin and sulfur hexafluoride injection in a preclinical study in rabbit eyes

    PubMed Central

    Wu, Wei-Chi; Liu, Chi-Hsien; Chen, Chih-Chun; Wang, Nan-Kai; Chen, Kwan-Jen; Chen, Tun-Lu; Hwang, Yih-Shiou; Li, Lien-Min

    2012-01-01

    Purpose To investigate the efficacy of plasmin and sulfur hexafluoride (SF6) on the vitreoretinal junction, as well as the long-term safety in the eye and effect on the recipient’s general health after application in the eye. Methods The study design included four groups of rabbits with three animals in each group. Group 1 received an intravitreal injection (IVI) of plasmin and SF6 in the right eye; group 2 received an IVI of plasmin in the right eye; group 3 received an IVI of SF6 in the right eye; and group 4 received an IVI of balanced salt solution in the right eye, which served as a normal control. Long-term safety (up to approximately three months) after plasmin and/or SF6 injection was evaluated morphologically by clinical examination, histology, and immunohistochemistry, and functionally by electroretinograms (ERGs). General health evaluations after intravitreal injection included the assessment of weight gain, food intake, body temperature, and complete blood count analysis. Results Plasmin plus SF6 injection resulted in complete posterior vitreous detachment (PVD), whereas plasmin or SF6 injection alone resulted in only partial PVD. Balanced salt solution did not induce PVD. Eighty days after intravitreal injection, there were no major differences among the eyes of the three groups of animals compared with the normal control animals upon clinical evaluation, or regarding retinal morphology and ERGs. The lenses examined remained clear for up to 80 days following the intravitreal injection of plasmin plus SF6, except one eye in the plasmin-treated group. ERGs decreased transiently one week after intravitreal injection in groups 1 through 3, but animals recovered fully to normal status afterward. General health was not affected after the injection of plasmin plus SF6. Conclusions Efficient vitreoretinal separation could be achieved, and an acceptable long-term safety profile was noted after plasmin plus SF6 injection in the eye. No major ocular toxicity or

  7. Alternated intra-arterial and intravitreal chemotherapy for advanced intraocular retinoblastoma: preliminary successful results without systemic chemotherapy.

    PubMed

    De Francesco, Sonia; Galluzzi, Paolo; Bracco, Sandra; Menicacci, Felice; Motolese, Edoardo; Hadjistilianou, Theodora

    2015-12-01

    To describe the efficacy of intravitreal chemotherapy (IViC) preceded by intra-arterial chemotherapy (IAC) for the treatment of advanced stage retinoblastoma. This non-comparative interventional case series retrospectively reviewed the medical records of six patients who presented within months of each other with unilateral retinoblastoma, Reese-Ellsworth stage Vb/D of ABC classification in the affected eye. After clinical and ophthalmoscopic evaluation, they underwent MRI to exclude local and CNS dissemination. The IAC was given to treat retinal masses and intravitreal injections to treat vitreous seeding. Patients had received two cycles (six infusions) of IAC, and from six up to ten melphalan injections into the vitreous, with an interval of 7-10 days between them. From one to four intravitreal injections were performed for partial remission or consolidation. No permanent complications of procedures have been reported. All patients underwent to bimonthly MRI examination, during treatment and every 3 months for 1 year after last injection, to exclude orbital dissemination. Successful control (100 %) of tumor masses and vitreous seeds was achieved in all cases at 12 months follow-up. Complications were posterior lens opacity, acute ischemic papillitis, partial CVR thrombosis, hypotonia (case 1), partial vitreous hemorrhage (case 4). No complications appeared in cases 2, 3, 5, and 6. No intraocular or orbital tumor recurrence or retinoblastoma metastases (follow-up range, 12-33 months) were observed. Sequential IAC and intravitreal melphalan for advanced retinoblastoma allowed to provide retinal and vitreous seed control.

  8. Transscleral iontophoretic and intravitreal delivery of a macromolecule: Study of ocular distribution in vivo and postmortem with MRI

    PubMed Central

    Molokhia, Sarah A.; Jeong, Eun-Kee; Higuchi, William I.; Li, S. Kevin

    2008-01-01

    The distribution and clearance of macromolecules in ocular delivery are not well understood. It has been hypothesized that iontophoresis can enhance transscleral delivery of macromolecules. The objective of this study was to investigate the ocular distribution of a macromolecule after transscleral iontophoretic delivery and intravitreal injection in vivo using nuclear magnetic resonance imaging (MRI) and to compare these results. Experiments of constant current transscleral iontophoresis of 4 mA or intravitreal injection were performed on New Zealand white rabbits in vivo. Iontophoresis experiments were also performed on rabbits postmortem. Galbumin™ (Gd-labeled albumin) was the model permeant surrogate to clinical therapeutic agents. MRI was used to monitor the distribution of the molecule in the eye after ocular iontophoresis and intravitreal injection. In addition, the conjunctiva, sclera, choroid, and retina were extracted in the transscleral iontophoresis study to determine the amounts of Galbumin™ in these tissues using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The results show that iontophoresis enhanced the ocular delivery of Galbumin™. The macromolecule was mainly delivered into the conjunctiva and sclera in microgram quantities and then diffused towards the posterior section in the upper hemisphere of the eye in vivo. Both in vivo and postmortem studies show that the iontophoretic delivery of Galbumin™ into the vitreous was below the detection limit. In the intravitreal injection study, the diffusion coefficient of Galbumin™ in the vitreous humor was estimated to be close to that of free aqueous diffusion. PMID:19000673

  9. Steam-injected gas turbine analysis: steam rates

    NASA Astrophysics Data System (ADS)

    Rice, I. G.

    1995-04-01

    This paper presents an analysis of steam rates in steam-injected gas turbines (simple and reheat). In considering a gas turbine of this type, the steam-injection flow is separated from the main gas stream for analysis. Dalton's and Avogadro's laws of partial pressure and gas mixtures are applied. Results obtained provide for the accurate determination of heat input, gas expansion based on partial pressures, and heat-rejection steam-enthalpy points.

  10. Steam-injected gas turbine analysis: Steam rates

    SciTech Connect

    Rice, I.G.

    1995-04-01

    This paper presents an analysis of steam rates in steam-injected gas turbines (simple and reheat). In considering a gas turbine of this type, the steam-injection flow is separated from the main gas stream for analysis. Dalton`s and Avogadro`s laws of partial pressure and gas mixtures are applied. Results obtained provide for the accurate determination of heat input, gas expansion based on partial pressures, and heat-rejection steam-enthalpy points.

  11. Immobilized Bioluminescent Reagents in Flow Injection Analysis.

    NASA Astrophysics Data System (ADS)

    Nabi, Abdul

    Available from UMI in association with The British Library. Bioluminescent reactions exhibits two important characteristics from an analytical viewpoint; they are selective and highly sensitive. Furthermore, bioluminescent emissions are easily measured with a simple flow-through detector based on a photomultiplier tube and the rapid and reproducible mixing of sample and expensive reagent is best achieved by a flow injection manifold. The two most important bioluminescent systems are the enzyme (luciferase)/substrate (luciferin) combinations extracted from fireflies (Photinus pyralis) and marine bacteria (Virio harveyi) which requires ATP and NAD(P)H respectively as cofactors. Reactions that generate or consume these cofactors can also be coupled to the bioluminescent reaction to provide assays for a wide range of clinically important species. A flow injection manifold for the study of bioluminescent reactions is described, as are procedures for the extraction, purification and immobilization of firefly and bacterial luciferase and oxidoreductase. Results are presented for the determination of ATP using firefly system and the determination of other enzymes and substrates participating in ATP-converting reactions e.g. creatine kinase, ATP-sulphurylase, pyruvate kinase, creatine phosphate, pyrophosphate and phophoenolypyruvate. Similarly results are presented for the determination of NAD(P)H, FMN, FMNH_2 and several dehydrogenases which produce NAD(P)H and their substrates, e.g. alcohol, L-lactate, L-malate, L-glutamate, Glucose-6-phosphate and primary bile acid.

  12. Photodynamic Therapy and Intravitreal Bevacizumab with Versus without Triamcinolone for Neovascular Age-related Macular Degeneration; a Randomized Clinical Trial

    PubMed Central

    Piri, Niloofar; Ahmadieh, Hamid; Taei, Ramin; Soheilian, Masoud; Karkhaneh, Reza; Lashay, Alireza; Golbafian, Faegheh; Yaseri, Mehdi; Riazi-Esfahani, Mohammad

    2014-01-01

    Purpose: To compare the outcomes of photodynamic therapy (PDT) combined with intravitreal bevacizumab (IVB) with versus without intravitreal triamcinolone (IVT) in neovascular age-related macular degeneration (AMD). Methods: Eighty-four eyes with active CNV secondary to AMD with no prior treatment were enrolled and followed for 1-year. Eligible eyes were randomly assigned to either PDT/IVB or PDT/IVB/IVT. The main outcome measure was change in best-corrected visual acuity (BCVA). Results: Mean patient age was 71 ± 9 years. BCVA changes from baseline were statistically significant in both study arms at all follow-up intervals, however no significant difference was observed between the two groups regarding BCVA changes at week 12 (95% CI:-0.11–0.12 LogMAR) and other time points (all P > 0.6). Mixed model analysis revealed a significant effect from age (P < 0.001), pigment epithelial detachment (P = 0.009) and baseline BCVA (P < 0.001) on visual improvement. Significant central macular thickness (CMT) reduction occurred at all-time points as compared to baseline in both groups which was comparable between the study arms. There was no significant difference between the study arms in terms of retreatment rate (P = 0.1) and survival to the first repeat IVB injection (P = 0.065). Conclusion: Additional low-dose IVT to a PDT/IVB regimen for neovascular AMD provided no beneficial effects in terms BCVA or CMT, yet demonstrated a trend toward extending the injection-free period. PMID:25709773

  13. Intravitreal bevacizumab for persistent macular edema with proliferative diabetic retinopathy.

    PubMed

    Gulkilik, Gokhan; Taskapili, Muhittin; Kocabora, Selim; Muftuoglu, Gulipek; Demirci, Goktug

    2010-12-01

    To evaluate the effectiveness of an intravitreal bevacizumab injection on retinal neovascularization and diabetic macular edema (DME) refractory to laser photocoagulation therapy. Thirty-four eyes of 22 patients with proliferative diabetic retinopathy and DME refractory to laser photocoagulation therapy received an intravitreal injection of 1.25 mg/0.05 ml of bevazicumab. Changes in mean best-corrected visual acuity (BCVA), central macular thickness (CMT), regression of neovascularization over time, and correlation between BCVA and CMT were evaluated. Follow-up visits were at weeks 1, 2 and 4 and months 3 and 6. Mean BCVA was significantly better than baseline only at week 2 (P = 0.036). Mean CMT decreased significantly from baseline at weeks 1, 2, and 4 (P = 0.001). At months 3 and 6, mean CMT increased, albeit insignificantly (P = 0.804 and P = 1.0). The decrease in fluorescein leakage was moderate in all eyes at the end of week 1. At week 2, there was total resolution of fluorescein leakage in 24 (70.5%) eyes and moderate resolution in 10 (29.5%) eyes. At the end of month 3, the fluorescein leakage was fully resolved in 5 (14.7%) eyes, moderately resolved in 24 (70.5%) eyes, and was similar to baseline in 5 (14.7%) eyes. At month 6, the fluorescein leakage was fully resolved in 3 (8.8%) eyes, moderately resolved in 20 (58.8%) eyes, and was similar to baseline in 11 (32.4%) eyes. A moderate but insignificant negative correlation was found between visual acuity and CMT (P > 0.05). Persistence or recurrence of neovascular tissue after panretinal photocoagulation may be attributed to the production of vascular endothelial growth factor by the residual ischemic retina, which also results in persistent or recurrent DME despite macular grid photocoagulation.

  14. Intravitreal Topotecan Inhibits Laser-induced Choroidal Neovascularization in a Rat Model

    PubMed Central

    Gholipour, Mohammad Ali; Kanavi, Mozhgan Rezaei; Ahmadieh, Hamid; Aldavood, Seyed Javid; Nourinia, Ramin; Hosseini, Seyed Bagher; Daftarian, Narsis; Nashtaei, Ebrahim Mohammad; Tousi, Adib; Safi, Sare

    2015-01-01

    Purpose: A two-phase preclinical study was designed to determine the safe dose of intravitreal topotecan and its inhibitory effect on experimental choroidal neovascularization (CNV) in a rat model. Methods: In phase I, 42 rats were categorized into 6 groups, 5 of which received intravitreal topotecan injections of 0.125 μg, 0.25 μg, 0.5 μg, 0.75 μg, and 1.0 μg/5 μl, respectively; the control group received an injection of normal saline. Ophthalmic examination and electroretinography (ERG) were performed on days 7 and 28, and enucleated globes were processed for histopathology and immunostaining for glial fibrillary acidic protein. In phase II, CNV was induced via laser burns in 20 rats and the animals were divided into 2 groups. One group received topotecan and the other received normal saline intravitreally. Four weeks later, mean scores of fluorescein leakage on fluorescein angiography as well as mean CNV areas on histology sections were compared. Results: In phase I, clinical, ERG and histopathologic results were unremarkable in terms of retinal toxicity in all groups. Based on the results of phase I, a dose of 1 μg/5 μl topotecan was chosen for phase II. Leakage scores obtained from late-phase fluorescein angiography were significantly lower in topotecan-treated than control eyes (P < 0.01) four weeks after induction of CNV. Compared to control eyes, topotecan-treated eyes showed a significantly lower incidence of fibrovascular proliferation (8.7% vs. 96.2%) and significantly smaller areas of CNV (P < 0.01). Conclusion: Intravitreal injection of topotecan at a dose of 1 μg/5 μl is safe and may be a promising treatment for CNV. PMID:26730316

  15. Intravitreal aflibercept for the treatment of choroidal neovascularization associated with pathologic myopia: a pilot study

    PubMed Central

    Korol, Andrii R; Zadorozhnyy, Oleg S; Naumenko, Volodymyr O; Kustryn, Taras B; Pasyechnikova, Nataliya V

    2016-01-01

    Purpose To determine the efficacy of intravitreal aflibercept injections for the treatment of patients with choroidal neovascularization (CNV) associated with pathologic myopia. Methods In this uncontrolled, prospective cohort study, 31 eyes of 30 consecutive patients affected by CNV associated with pathologic myopia were treated with intravitreal aflibercept (2 mg) as needed following two initial monthly doses and observed over a 12-month follow-up period. The primary endpoint was change in best-corrected visual acuity (BCVA) at month 12, while central retinal thickness (CRT) on optical coherence tomography (OCT), neovascularization activity on fluorescein angiography, the number of aflibercept injections administered, and safety were examined as secondary endpoints. Results Patients received a mean of 2.6 intravitreal aflibercept injections over the 12-month study period. Compared with baseline, BCVA improved significantly at all time points (P<0.05). Mean (standard deviation [SD]) decimal BCVA was 0.2 (0.1) at baseline and 0.35 (0.16) at month 12. The greatest improvement in BCVA was seen within the first 2 months (P=0.01). Mean (SD) CRT on OCT decreased from 285 (62) µm at baseline to 227 (42) µm (P=0.01) at month 12. There was a continuous decrease in mean CRT on OCT over time. No cases of endophthalmitis, uveitis, stroke, or retinal detachment were noted. No patient demonstrated an intraocular pressure >20 mmHg during any study visit. Conclusion The 12-month results of intravitreal aflibercept for myopic CNV using an as-needed regimen were positive, showing benefits in visual and anatomic outcomes and an acceptable tolerability profile. PMID:27853350

  16. Comparison of the efficacy of anti-VEGF monotherapy versus PDT and intravitreal anti-VEGF combination treatment in AMD: a Meta-analysis and systematic review

    PubMed Central

    Tong, Yao; Zhao, Ke-Ke; Feng, Dong; Biswal, Manas; Zhao, Pei-Quan; Wang, Zhao-Yang; Zhang, Yun

    2016-01-01

    AIM To compare the effect of anti-vascular endothelial growth factor (VEGF) monotherapy versus photodynamic therapy (PDT) and anti-VEGF combination treatment in age-related macular degeneration (AMD). METHODS A computerized online search was performed using PubMed, Web of Science and the Cochrane Library. Studies that compared anti-VEGF monotherapy with PDT and anti-VEGF combination treatment of AMD and were designed as randomized controlled trials were included. The means and standard deviations of the best-corrected visual acuity (BCVA), central retinal thickness (CRT), number of treatments and proportions of patients who gained BCVA ≥15, 10, 5, or 0 letters at 12th month were extracted. A systematic review and Meta-analysis of the comparison of the two approaches was conducted using Review Manager 5.2. Subgroup. A sensitivity analysis was also performed. RESULTS Eight studies were included. When the subgroup and sensitivity analysis was conducted, the results indicated that in the findings that included the monotherapy group and PDT (standard fluence, SF) group of Kaiser's study, the patients in the monotherapy group had a better BCVA compared with the combination group at 12th month in the PDT (SF) subgroup [weighted mean difference (WMD): 3.54; 95%CI: 0.36 to 6.73; P=0.03], and there were more patients who gained ≥15 letters of BCVA in the monotherapy group compared with the combination group in the total result [odds ratio (OR): 1.41; 95%CI: 1.02 to 1.95; P=0.04]. The same conclusion was obtained in the total result that included the monotherapy group and PDT (reduced fluence, RF) group of Kaiser's study (OR: 1.56; 95%CI: 1.13 to 2.15; P=0.007). However, there were no significant differences in the other indexes between the two therapies. CONCLUSION We found that anti-VEGF monotherapy is more effective on the recovery of visual acuity than combination therapy and more researches with lager sample size should be performed to study on the effect of the two

  17. Effects of intravitreal ranibizumab on the untreated eye and systemic gene expression profile in age-related macular degeneration.

    PubMed

    Michalska-Małecka, Katarzyna; Kabiesz, Adam; Kimsa, Malgorzata W; Strzałka-Mrozik, Barbara; Formińska-Kapuścik, Maria; Nita, Malgorzata; Mazurek, Urszula

    2016-01-01

    The purpose of this study was to evaluate the systemic effects of intravitreal ranibizumab (Lucentis) treatment in patients with neovascular age-related macular degeneration (AMD). The impact of intravitreal ranibizumab injections on central retinal thickness (CRT) of treated and contralateral untreated eyes, and differences in gene expression patterns in the peripheral blood mononuclear cells were analyzed. The study included 29 patients aged 50 years old and over with diagnosed neovascular AMD. The treatment was defined as 0.5 mg of ranibizumab injected intravitreally in the form of one injection every month during the period of 3 months. CRT was measured by optical coherence tomography. The gene expression profile was assigned using oligonucleotide microarrays of Affymetrix HG-U133A. Studies have shown that there was a change of CRT between treated and untreated eyes, and there were differences in CRT at baseline and after 1, 2, and 3 months of ranibizumab treatment. Three months after intravitreal injection, mean CRT was reduced in the treated eyes from 331.97±123.62 to 254.31±58.75 μm, while mean CRT in the untreated fellow eyes reduced from 251.07±40.29 to 235.45±36.21 μm at the same time. Furthermore, the research has shown that among all transcripts, 3,097 expresses change after the ranibizumab treatment in relation to controls. Among these transcripts, 1,339 were up-regulated, whereas 1,758 were down-regulated. Our results show the potential systemic effects of anti-VEGF therapy for AMD. Moreover, our study indicated different gene expression in peripheral blood mononuclear cells before and after intravitreal ranibizumab treatment.

  18. Effects of intravitreal ranibizumab on the untreated eye and systemic gene expression profile in age-related macular degeneration

    PubMed Central

    Michalska-Małecka, Katarzyna; Kabiesz, Adam; Kimsa, Malgorzata W; Strzałka-Mrozik, Barbara; Formińska-Kapuścik, Maria; Nita, Malgorzata; Mazurek, Urszula

    2016-01-01

    The purpose of this study was to evaluate the systemic effects of intravitreal ranibizumab (Lucentis) treatment in patients with neovascular age-related macular degeneration (AMD). The impact of intravitreal ranibizumab injections on central retinal thickness (CRT) of treated and contralateral untreated eyes, and differences in gene expression patterns in the peripheral blood mononuclear cells were analyzed. The study included 29 patients aged 50 years old and over with diagnosed neovascular AMD. The treatment was defined as 0.5 mg of ranibizumab injected intravitreally in the form of one injection every month during the period of 3 months. CRT was measured by optical coherence tomography. The gene expression profile was assigned using oligonucleotide microarrays of Affymetrix HG-U133A. Studies have shown that there was a change of CRT between treated and untreated eyes, and there were differences in CRT at baseline and after 1, 2, and 3 months of ranibizumab treatment. Three months after intravitreal injection, mean CRT was reduced in the treated eyes from 331.97±123.62 to 254.31±58.75 μm, while mean CRT in the untreated fellow eyes reduced from 251.07±40.29 to 235.45±36.21 μm at the same time. Furthermore, the research has shown that among all transcripts, 3,097 expresses change after the ranibizumab treatment in relation to controls. Among these transcripts, 1,339 were up-regulated, whereas 1,758 were down-regulated. Our results show the potential systemic effects of anti-VEGF therapy for AMD. Moreover, our study indicated different gene expression in peripheral blood mononuclear cells before and after intravitreal ranibizumab treatment. PMID:27069359

  19. Visual performance in patients with neovascular age-related macular degeneration undergoing treatment with intravitreal ranibizumab.

    PubMed

    Sabour-Pickett, Sarah; Loughman, James; Nolan, John M; Stack, Jim; Pesudovs, Konrad; Meagher, Katherine A; Beatty, Stephen

    2013-01-01

    Purpose. To assess visual function and its response to serial intravitreal ranibizumab (Lucentis, Genentech) in patients with neovascular age-related macular degeneration (nv-AMD). Methods. Forty-seven eyes of 47 patients with nv-AMD, and corrected distance visual acuity (CDVA) logMAR 0.7 or better, undergoing intravitreal injections of ranibizumab, were enrolled into this prospective study. Visual function was assessed using a range of psychophysical tests, while mean foveal thickness (MFT) was determined by optical coherence tomography (OCT). Results. Group mean (±sd) MFT reduced significantly from baseline (233 (±59)) to exit (205 (±40)) (P = 0.001). CDVA exhibited no change between baseline and exit visits (P = 0.48 and P = 0.31, resp.). Measures of visual function that did exhibit statistically significant improvements (P < 0.05 for all) included reading acuity, reading speed, mesopic and photopic contrast sensitivity (CS), mesopic and photopic glare disability (GD), and retinotopic ocular sensitivity (ROS) at all eccentricities. Conclusion. Eyes with nv-AMD undergoing intravitreal ranibizumab injections exhibit improvements in many parameters of visual function. Outcome measures other than CDVA, such as CS, GD, and ROS, should not only be considered in the design of studies investigating nv-AMD, but also in treatment and retreatment strategies for patients with the condition.

  20. Visual Performance in Patients with Neovascular Age-Related Macular Degeneration Undergoing Treatment with Intravitreal Ranibizumab

    PubMed Central

    Loughman, James; Nolan, John M.; Stack, Jim; Pesudovs, Konrad; Meagher, Katherine A.; Beatty, Stephen

    2013-01-01

    Purpose. To assess visual function and its response to serial intravitreal ranibizumab (Lucentis, Genentech) in patients with neovascular age-related macular degeneration (nv-AMD). Methods. Forty-seven eyes of 47 patients with nv-AMD, and corrected distance visual acuity (CDVA) logMAR 0.7 or better, undergoing intravitreal injections of ranibizumab, were enrolled into this prospective study. Visual function was assessed using a range of psychophysical tests, while mean foveal thickness (MFT) was determined by optical coherence tomography (OCT). Results. Group mean (±sd) MFT reduced significantly from baseline (233 (±59)) to exit (205 (±40)) (P = 0.001). CDVA exhibited no change between baseline and exit visits (P = 0.48 and P = 0.31, resp.). Measures of visual function that did exhibit statistically significant improvements (P < 0.05 for all) included reading acuity, reading speed, mesopic and photopic contrast sensitivity (CS), mesopic and photopic glare disability (GD), and retinotopic ocular sensitivity (ROS) at all eccentricities. Conclusion. Eyes with nv-AMD undergoing intravitreal ranibizumab injections exhibit improvements in many parameters of visual function. Outcome measures other than CDVA, such as CS, GD, and ROS, should not only be considered in the design of studies investigating nv-AMD, but also in treatment and retreatment strategies for patients with the condition. PMID:23533703

  1. Treatment of recent onset central retinal vein occlusion with intravitreal tissue plasminogen activator: a pilot study

    PubMed Central

    Glacet-Bernard, A.; Kuhn, D.; Vine, A.; Oubraham, H.; Coscas, G.; Soubrane, G.

    2000-01-01

    AIMS—To study the effects of intravitreal tissue plasminogen activator (tPA) in recent onset central retinal vein occlusion (CRVO).
METHODS—15 patients with recent onset CRVO (from 1-21 days' duration, mean 8 days) were given 75-100 µg of tPA intravitreally associate with low dose low molecular weight heparin. CRVO was perfused in nine patients and with mild ischaemia not exceeding 100 disc diameters in six patients. Follow up ranged from 5 to 21 months for 14 patients (mean 8 months). Visual acuity measurement, macular threshold (Humphrey perimeter), fluorescein angiography with the scanning laser ophthalmoscope with special emphasis on retinal circulation times, and retinal perfusion were performed at days 0, 1, and 8 and months 1, 3, and 6.
RESULTS—Visual acuity was significantly improved on the first day after treatment in only one eye, and decreased transiently in six eyes (40%). Retinal blood velocity was not significantly modified by tPA injection. Retinal ischaemia developed in six eyes (43%), leading to panretinal photocoagulation in five eyes including one with rubeosis iridis. At the end of follow up, visual acuity had improved to 20/30 or better in five eyes (36%), including two with complete recovery; visual acuity was worse than 20/200 in three eyes (28%). No complication of tPA injection was observed.
CONCLUSION—Intravitreal tPA treatment for CRVO appears to be simple and safe, but did not significantly modify the course of the occlusion in our patients immediately after treatment. Final visual outcome did not differ significantly from that observed in the natural course of the disease, but final visual acuity seemed to be slightly better. A randomised study is required to determine if intravitreal tPA actually improves visual outcome in CRVO.

 PMID:10837386

  2. In vitro benzyl alcohol cytotoxicity: implications for intravitreal use of triamcinolone acetonide.

    PubMed

    Chang, Yi-Sheng; Wu, Chao-Liang; Tseng, Sung-Huei; Kuo, Pao-Ying; Tseng, Shih-Ya

    2008-06-01

    The aim of the study was to investigate the toxicity of benzyl alcohol (BA), the preservative in commercial triamcinolone acetonide (TA) suspensions, on retinal pigment epithelial (RPE) cells. Cultured RPE cells from a human cell line (ARPE-19) and from rabbits were exposed to the balanced salt solution (control) or BA (0.0225, 0.225, 0.9, 3 or 9mg/mL) for 5, 30, 60, or 120min. Morphological changes of RPE cells were evaluated by the trypan blue in situ staining. The proportions of dead cells were quantitatively measured by the trypan blue exclusion assay, and those of functional cells were assessed by a mitochondrial dehydrogenase assay. The mechanism of cytotoxicity was determined by the acridine orange/ethidium bromide staining and DNA laddering technique. Furthermore, ultrastructural changes were observed by transmission electron microscopy. The results showed that RPE cell damage was dose- and time-dependent. BA 0.225mg/mL, the clinically relevant concentration in TA following intravitreal injection, caused ultrastructural damage and impaired human RPE cell function at 2h; but BA 0.0225mg/mL did not. BA 9.0mg/mL, the concentration in commercial TA suspensions, was toxic within 5min on each assay for both human and rabbit RPE cells. The major mechanism of cell death was necrosis. In conclusion, BA in commercial TA suspensions injected intravitreally (0.225-9mg/mL) can damage RPE cells. Our in vitro study on benzyl alcohol cytotoxicity has significant clinical implications for intravitreal use of TA. We suggest that, before a commercial TA solution is used intravitreally, the vehicle should be removed to prevent damaging the RPE layer, particularly during macular hole surgery. Commercial development of a preservative-free TA suspension for intraocular use is urged.

  3. INTRAVITREAL CORTICOSTEROIDS IN DIABETIC MACULAR EDEMA

    PubMed Central

    Bailey, Clare; Loewenstein, Anat; Massin, Pascale

    2015-01-01

    Purpose: To review the relationship between kinetics, efficacy, and safety of several corticosteroid formulations for the treatment of diabetic macular edema. Methods: Reports of corticosteroid use for the treatment of diabetic macular edema were identified by a literature search, which focused on the pharmacokinetics, efficacy, and safety of these agents in preclinical animal models and clinical trials. Results: Available corticosteroids for diabetic macular edema treatment include intravitreal triamcinolone acetonide, dexamethasone, and fluocinolone acetonide. Because of differences in solubility and bioavailability, various delivery mechanisms are used. Bioerodible delivery systems achieve higher maximum concentrations than nonbioerodible formulations. There is a relationship between visual gains and drug persistence in the intravitreal compartment. Safety effects were more complex; level of intravitreal triamcinolone acetonide exposure is related to development of elevated intraocular pressure and cataract; this does not seem to be the case for dexamethasone, where two different doses showed similar mean intraocular pressure and incidence of cataract surgery. With fluocinolone acetonide, rates of intraocular pressure elevations requiring surgery seem to be dose related; rates of cataract extraction were similar regardless of dose. Conclusion: Available corticosteroids for diabetic macular edema exhibit different pharmacokinetic profiles that impact efficacy and adverse events and should be taken into account when developing individualized treatment plans. PMID:26352555

  4. Determination of Reaction Stoichiometries by Flow Injection Analysis.

    ERIC Educational Resources Information Center

    Rios, Angel; And Others

    1986-01-01

    Describes a method of flow injection analysis intended for calculation of complex-formation and redox reaction stoichiometries based on a closed-loop configuration. The technique is suitable for use in undergraduate laboratories. Information is provided for equipment, materials, procedures, and sample results. (JM)

  5. Posterior Vitreous Detachment With Microplasmin Alters the Retinal Penetration of Intravitreal Bevacizumab (Avastin) in Rabbit Eyes

    PubMed Central

    Goldenberg, David T.; Giblin, Frank J.; Cheng, Mei; Chintala, Shravan K.; Trese, Michael T.; Drenser, Kimberly A.; Ruby, Alan J.

    2010-01-01

    Purpose Intravitreal bevacizumab (Avastin) is frequently used for the treatment of age-related macular degeneration. Previous studies have demonstrated full thickness retinal penetration. Intravitreal recombinant microplasmin (MP) has been shown to successfully induce a posterior vitreous detachment (PVD) and vitreous liquefaction in animals. It has been suggested that a PVD may alter the retinal penetration of molecules in the vitreous cavity. The aim of this study was to compare bevacizumab (BV) retinal penetration in rabbit eyes with and without a MP-induced PVD. Methods Twelve adult rabbits were injected with 0.1 ml (0.4 mg) of MP into the vitreous cavity of one eye. One week later, the rabbits were injected with 0.05 ml (1.25 mg) of BV into both eyes. Both eyes of three rabbits each were harvested at 6, 12, 24, and 72 hours after the BV injection. Frozen retinal cross sections were prepared, and BV retinal penetration was evaluated with immunohistochemistry using a fluorescence-labeled antibody against BV. Two eyes from one rabbit were not injected with either agent and used as controls to compare the background autofluorescence. Peripapillary retinal sections were recorded with a digital camera, and intra-retinal BV fluorescence-labeled antibody was measured by qualitative photographic interpretation. Two additional rabbits received an intravitreal injection of 0.1 ml of MP in one eye. One week later, both eyes from each rabbit were enucleated and frozen retinal sections were prepared and analyzed with light microscopy to evaluate for histologic damage. Results Full thickness BV retinal penetration was observed throughout the retina in both eyes of each rabbit. All of the MP-injected eyes exhibited increased antibody labeling in retinas evaluated 6, 12, and 24 hours after BV injection when compared with the contralateral non-MP-injected eyes. By three days after BV injection, all eyes demonstrated decreased antibody labeling compared to earlier time periods

  6. Panretinal photocoagulation versus panretinal photocoagulation plus intravitreal bevacizumab for high-risk proliferative diabetic retinopathy

    PubMed Central

    Zhou, Ai-Yi; Zhou, Chen-Jing; Yao, Jing; Quan, Yan-Long; Ren, Bai-Chao; Wang, Jian-Ming

    2016-01-01

    AIM To evaluate the effects of panretinal photocoagulation (PRP) compared with PRP plus intravitreal bevacizumab (IVB) in patients with high-risk proliferative diabetic retinopathy (PDR) according to the Early Treatment Diabetic Retinopathy Study criteria. METHODS The data were collected retrospectively from the eyes of high-risk PDR patients, which were divided into two groups. After treated with standard PRP, the eyes were randomly assigned to receive only PRP (PRP group) or PRP plus intravitreal injection of 1.25 mg of bevacizumab (PRP-Plus group). Patients underwent complete ophthalmic evaluation, including best corrected visual acuity (BCVA), intraocular pressure (IOP), and new vessel size in fluorescein angiography (FA) and optical coherence tomography for the assessment of central subfield macular thickness (CSMT) at baseline and at weeks 12 (±2), 16 (±2), 24 (±2) and 48 (±2). Main outcome measures also included vitreous clear-up time and neovascularization on the disc (NVD) regression time. Adverse events associated with intravitreal injection were investigated. RESULTS Thirty consecutive patients (n=36 eyes) completed the 48-week follow-up. There was no significant difference between the PRP and PRP-Plus groups with respect to age, gender, type or duration of diabetes, area of fluorescein leakage from active neovascularizations (NVs), BCVA or CSMT at baseline. The mean vitreous clear-up time was 12.1±3.4wk after PRP and 8.4±3.5wk after PRP combined with IVB. The mean time interval from treatment to complete NVD regression on FA examination was 15.2±3.5wk in PRP group and 12.5±3.1wk in PRP-Plus group. No significant difference in CSMT was observed between the groups throughout the study period. However, the total area of actively leaking NVs was significantly reduced in the PRP-Plus group compared with the PRP group (P<0.05). Patients received an average of 1.3 injections (range: 1-2). Ten eyes (27.8%) underwent 2 injections. Two eyes had ocular

  7. Comprehensive Quantitative Analysis of SQ Injection Using Multiple Chromatographic Technologies.

    PubMed

    Chau, Siu-Leung; Huang, Zhi-Bing; Song, Yan-Gang; Yue, Rui-Qi; Ho, Alan; Lin, Chao-Zhan; Huang, Wen-Hua; Han, Quan-Bin

    2016-08-19

    Quality control of Chinese medicine injections remains a challenge due to our poor knowledge of their complex chemical profile. This study aims to investigate the chemical composition of one of the best-selling injections, Shenqi Fuzheng (SQ) injection (SQI), via a full component quantitative analysis. A total of 15 representative small molecular components of SQI were simultaneously determined using ultra-high performance liquid chromatography (UHPLC) coupled with quadrupole tandem time-of-flight mass spectrometry (Q-TOF-MS); saccharide composition of SQI was also quantitatively determined by high performance liquid chromatography (HPLC) with evaporative light scattering detector (ELSD) on an amino column before and after acid hydrolysis. The existence of polysaccharides was also examined on a gel permeation chromatography column. The method was well validated in terms of linearity, sensitivity, precision, accuracy and stability, and was successfully applied to analyze 13 SQI samples. The results demonstrate that up to 94.69% (w/w) of this injection product are quantitatively determined, in which small molecules and monosaccharide/sucrose account for 0.18%-0.21%, and 53.49%-58.2%, respectively. The quantitative information contributes to accumulating scientific evidence to better understand the therapy efficacy and safety of complex Chinese medicine injections.

  8. Post-intravitreal anti-VEGF endophthalmitis in the United Kingdom: incidence, features, risk factors, and outcomes

    PubMed Central

    Lyall, D A M; Tey, A; Foot, B; Roxburgh, S T D; Virdi, M; Robertson, C; MacEwen, C J

    2012-01-01

    Purpose To describe the incidence, features, management, and risk factors of post-intravitreal anti-VEGF endophthalmitis (PIAE) in patients undergoing treatment for exudative age-related macular degeneration in the United Kingdom. Methods Prospective observational case control study. Forty-seven cases of PIAE were identified through the British Ophthalmological Surveillance Unit from January 2009 to March 2010. Data collected at diagnosis and at 6 months follow-up included patient demographics, intravitreal injection details, pre- and post-injection management, visual acuity, clinical features and management of PIAE, causative organisms, and clinical outcomes. Details were compared with 200 control cases from 10 control centres to identify potential risk factors. Results Estimated PIAE was 0.025%. Culture-positive PIAE incidence was 0.015%. Mean age of presentation was 78 years. Mean number of intravitreal injections before PIAE was 5. Mean days to presentation was 5 (range 1–39). Positive microbiology culture was found in 59.6%. The majority of causative organisms were Gram positive (92.8%). Significant risk factors were failure to administer topical antibiotics immediately after the injection (P=0.001), blepharitis (P=0.006), subconjunctival anaesthesia (P=0.021), patient squeezing during the injection (P=0.021), and failure to administer topical antibiotics before anti-VEGF injection (P=0.05). Discussion The incidence of PIAE in the United Kingdom is comparable to other studies at a rate of 0.025%. The most common causative organisms were Gram positive. Measures to minimise the risk of PIAE include treatment of blepharitis before injection, avoidance of subconjunctival anaesthesia, topical antibiotic administration immediately after injection with consideration to administering topical antibiotics before injection. PMID:23060022

  9. Intravitreal ziv-aflibercept for macular edema following retinal vein occlusion

    PubMed Central

    Paulose, Remya; Chhablani, Jay; Dedhia, Chintan J; Stewart, Michael W; Mansour, Ahmad M

    2016-01-01

    Aim To report the efficacy of intravitreal ziv-aflibercept injections in eyes with macular edema due to retinal vein occlusions (RVOs). Methods Consecutive patients with persistent or recurrent macular edema (central macula thickness >250 μm) due to RVO were enrolled in this prospective study. Study eyes received intravitreal injections of ziv-aflibercept (1.25 mg/0.05 mL) at baseline. Patients were reassessed monthly for 4 months and given additional injections pro re nata for worsening best-corrected visual acuity (BCVA), intraretinal edema or subretinal fluid seen on spectral domain optical coherence tomography, or central macular thickness (CMT) measurements >250 μm. The primary endpoint was improvement in mean CMT at 4 months. Secondary endpoints included improvement in mean BCVA, and ocular and systemic safety signals. Results Nine eyes (five central and four branch RVOs) of nine patients were enrolled. The mean ± standard deviation CMT decreased from 604±199 μm at baseline to 319±115 μm (P=0.001) at 1 month and to 351±205 μm (P=0.026) at 4 months. The mean BCVA did not improve significantly from baseline (1.00 LogMAR) to the 1-month (0.74 LogMAR; P=0.2) and 4-month (0.71 LogMAR; P=0.13) visits. No safety signals were noted. Conclusion In this small prospective study, intravitreal ziv-aflibercept significantly improved mean CMT in eyes with persistent or recurrent macular edema due to RVOs. Prospective, randomized trials comparing ziv-aflibercept with standard pharmacotherapy are needed to better define efficacy and safety. PMID:27703326

  10. Predictive Factors in OCT Analysis for Visual Outcome in Exudative AMD.

    PubMed

    Gamulescu, Maria-Andreea; Panagakis, Georgios; Theek, Carmen; Helbig, Horst

    2012-01-01

    Background. Reliable predictive factors for therapy outcome may enable treating physicians to counsel their patients more efficiently concerning probability of improvement or time point of discontinuation of a certain therapy. Methods. This is a retrospective analysis of 87 patients with exudative age-related macular degeneration who received three monthly intravitreal ranibizumab injections. Visual acuity before initiation of intravitreal therapy and 4-6 weeks after last intravitreal injection was compared and related to the preoperative visualisation of continuity of the outer retinal layers as assessed by OCT: external limiting membrane (ELM), inner photoreceptor segments (IPS), junction between inner and outer segments (IS/OS), and outer photoreceptor segments (OPS). Results. Visual acuity increased in 40 of 87 (46.0%) patients, it remained stable in 25 (28.7%), and 22 (25.3%) patients had decreased visual acuity four to six weeks after triple intravitreal ranibizumab injections. No statistically significant predictive value could be demonstrated for grade of continuity of outer retinal layers concerning visual acuity development. Conclusions. In our series of AMD patients, grade of continuity of outer retinal layers was not a significant predictive value for visual acuity development after triple ranibizumab injections.

  11. The remote effects of intravitreal anti-VEGF therapy

    PubMed Central

    Balta, F; Merticariu, M; Taban, C; Neculau, G; Merticariu, A; Muresanu, D; Badescu, D; Jinga, V

    2016-01-01

    Objective: To study the effects of intravitreal anti-Vascular Endothelial Growth Factor (VEGF) therapy with Avastin for wet Age-Related Macular Degeneration (AMD) on Benign Prostatic Hyperplasia (BPH)-related symptoms. Methods: An exploratory trial was conducted from August 1, 2013 to February 1, 2014, that included 14 male patients previously diagnosed with BPH, who were aged between 59 and 69 years. The trial was performed in Bucharest and involved two medical institutions: the Clinical Hospital of Eye Emergencies and the “Prof. Dr. Theodor Burghele” Hospital. This prospective study utilized both objective and subjective indicators to analyze the link between intravitreal anti-VEGF therapy for wet AMD and BPH. The evaluations consisted of uroflowmetry and International Prostate Symptom Score (I-PSS) assessments. Results: The maximum flow rate (Qmax) improved by an average of 5.05 ml/ sec in 9 patients, whereas the remaining 5 patients showed a slight decrease in Qmax (mean 1.6 ml/ sec). The I-PSS score improved, with an overall decrease of 1.18 points at follow-up compared to the initial score (mean initial score = 2.42; mean follow-up score = 1.24). Conclusion: The analysis revealed that anti-VEGF therapy for wet AMD had a significant positive effect on all BPH-related symptoms; patients reported improved urinary streams and decreased nocturia. Abbreviations: BPH = benign prostatic hyperplasia, AMD = age-related macular degeneration, VEGF = vascular endothelial growth factor, I-PSS = international prostate symptom score, Qmax = maximum flow rate, TSP-1 = thrombospondin-1, FGF-2 = fibroblast growth factor, mRNA = precursor messenger ribonucleic acid, PSA = prostate-specific antigen, DRE = digital rectal examination, AUR = acute urinary retention, COX2 = cyclooxygenase 2, QoL = quality of life PMID:27928444

  12. The remote effects of intravitreal anti-VEGF therapy.

    PubMed

    Balta, F; Merticariu, M; Taban, C; Neculau, G; Merticariu, A; Muresanu, D; Badescu, D; Jinga, V

    2016-01-01

    Objective: To study the effects of intravitreal anti-Vascular Endothelial Growth Factor (VEGF) therapy with Avastin for wet Age-Related Macular Degeneration (AMD) on Benign Prostatic Hyperplasia (BPH)-related symptoms. Methods: An exploratory trial was conducted from August 1, 2013 to February 1, 2014, that included 14 male patients previously diagnosed with BPH, who were aged between 59 and 69 years. The trial was performed in Bucharest and involved two medical institutions: the Clinical Hospital of Eye Emergencies and the "Prof. Dr. Theodor Burghele" Hospital. This prospective study utilized both objective and subjective indicators to analyze the link between intravitreal anti-VEGF therapy for wet AMD and BPH. The evaluations consisted of uroflowmetry and International Prostate Symptom Score (I-PSS) assessments. Results: The maximum flow rate (Qmax) improved by an average of 5.05 ml/ sec in 9 patients, whereas the remaining 5 patients showed a slight decrease in Qmax (mean 1.6 ml/ sec). The I-PSS score improved, with an overall decrease of 1.18 points at follow-up compared to the initial score (mean initial score = 2.42; mean follow-up score = 1.24). Conclusion: The analysis revealed that anti-VEGF therapy for wet AMD had a significant positive effect on all BPH-related symptoms; patients reported improved urinary streams and decreased nocturia. Abbreviations: BPH = benign prostatic hyperplasia, AMD = age-related macular degeneration, VEGF = vascular endothelial growth factor, I-PSS = international prostate symptom score, Qmax = maximum flow rate, TSP-1 = thrombospondin-1, FGF-2 = fibroblast growth factor, mRNA = precursor messenger ribonucleic acid, PSA = prostate-specific antigen, DRE = digital rectal examination, AUR = acute urinary retention, COX2 = cyclooxygenase 2, QoL = quality of life.

  13. The role of intravitreal chemotherapy for retinoblastoma

    PubMed Central

    Manjandavida, Fairooz P; Shields, Carol L

    2015-01-01

    Targeted therapy in retinoblastoma (RB) is widely accepted as the current management tool with an aim of increasing drug availability at the tumor location. Inevitably the effect is several times higher compared to systemic delivery of chemotherapeutic drugs and carries less systemic toxicity. Despite tremendous advancement in saving life, eye salvage in advanced RB especially with active vitreous seeds remains a challenge. The hypoxic environment of the vitreous and reduced vitreous concentration of the drugs delivered makes these tumor seeds resistant to chemotherapy. Direct delivery of chemotherapeutic drugs into the vitreous cavity aids to overcome these challenges and is progressively being accepted worldwide. However, intraocular procedure in RB was abandoned due to high risk of extraocular tumor dissemination. Recently, the forbidden therapeutic technique was re-explored and modified for safe use. Although eye salvage rate has tremendously improved after intravitreal chemotherapy (IVitC), retinal toxicity, and vision salvage are yet to be validated. In our preliminary report of intravitreal melphalan in 11 eyes, we reported 100% eye salvage and 0% recurrence with an extended 15 months mean follow-up. In this review, we analyzed published reports on IVitC in RB via PubMed, Medline, and conference proceedings citation index, electronic database search, without language restriction that included case series and reports of humans and experimental animal eyes with RB receiving IVitC. PMID:25827545

  14. [A technique of rhesus monkey neural progenitor cells intravitreal transplant to rats].

    PubMed

    Bian, Hui; Fan, Yao-Dong; Guo, Li-Yun; Yu, Hua-Lin

    2012-02-01

    To investigate a simple and effective intraocular xenotransplant technique of rhesus monkey neural progenitor cells to rats, mechanical injury was induced in the rat's right retina. And the GFP-labeled rhesus monkey neural progenitor cells suspension was slowly injected into the vitreous space of the right injured and left control eye. Confocal image suggested that the xenografted cells survived in both the injured and control eye, meanwhile the cells integrated in the injured right retina. The results demonstrated that intravitreal xenotransplant could be adopted as a simple and reliable method.

  15. Posterior capsule opacification and neovascularization treated with intravitreal bevacizumab and Nd:YAG capsulotomy

    PubMed Central

    Sánchez-Castro, Grimelda Yuriana; Hitos-Fájer, Alejandra; Mendoza-Schuster, Erick; Velez-Montoya, Raul; Velasco-Barona, Cecilio Francisco

    2008-01-01

    We reported a 75-year-old diabetic man, who developed opacification and neovascularization of the posterior capsule after extracapsular cataract extraction and posterior chamber intraocular lens implantation. The patient was treated with two injections of 2.5 mg of intravitreal bevacizumab. The treatment produced an important regression of the posterior capsular new vessels, allowing us to perform a successful Nd:YAG capsulotomy, clearing the visual axis and improving the visualization of the posterior pole. Even though, best corrected visual acuity was 20/200 due to diabetic macular edema. PMID:19668770

  16. Neuroprotective effects of BDNF and GDNF in intravitreally transplanted mesenchymal stem cells after optic nerve crush in mice

    PubMed Central

    Hu, Zong-Li; Li, Ni; Wei, Xin; Tang, Li; Wang, Ting-Hua; Chen, Xiao-Ming

    2017-01-01

    AIM To assess the neuro-protective effect of bone marrow mesenchymal stem cells (BMSCs) on retinal ganglion cells (RGCs) following optic nerve crush in mice. METHODS C56BL/6J mice were treated with intravitreal injection of PBS, BMSCs, BDNF-interference BMSCs (BIM), and GDNF-interference BMSCs (GIM) following optic nerve crush, respectively. The number of surviving RGCs was determined by whole-mount retinas and frozen sections, while certain mRNA or protein was detected by q-PCR or ELISA, respectively. RESULTS The density (cell number/mm2) of RGCs was 410.77±56.70 in the retina 21d after optic nerve crush without any treatment, compared to 1351.39±195.97 in the normal control (P<0.05). RGCs in BMSCs treated eyes was 625.07±89.64/mm2, significantly higher than that of no or PBS treatment (P<0.05). While RGCs was even less in the retina with intravitreal injection of BIM (354.07+39.77) and GIM (326.67+33.37) than that without treatment (P<0.05). BMSCs injection improved the internal BDNF expression in retinas. CONCLUSION Optic nerve crush caused rust loss of RGCs and intravitreally transplanted BMSCs at some extent protected RGCs from death. The effect of BMSCs and level of BDNF in retinas are both related to BDNF and GDNF expression in BMSCs. PMID:28149774

  17. Automated correlation dimension analysis of optically injected solid state lasers.

    PubMed

    Toomey, J P; Kane, D M; Valling, S; Lindberg, A M

    2009-04-27

    Nonlinear lasers are excellent systems from which to obtain high signal-to-noise experimental data of nonlinear dynamical variables to be used to develop and demonstrate robust nonlinear dynamics analysis techniques. Here we investigate the dynamical complexity of such a system: an optically injected Nd:YVO(4) solid state laser. We show that a map of the correlation dimension as a function of the injection strength and frequency detuning, extracted from the laser output power time-series data, is an excellent mirror of the dynamics map generated from a theoretical model of the system. An automated computational protocol has been designed and implemented to achieve this. The correlation dimension map is also contrasted with prior research that mapped the peak intensity of the output power as an experimentally accessible measurand reflecting the dynamical state of the system [Valling et al., Phys. Rev. A 72, 033810 (2005)].

  18. Simultaneous Therapy with Intravitreal Dexamethasone Implant and Bevacizumab for the Treatment of Macular Edema

    PubMed Central

    de ANDRADE, Felipe L.; LOPES, Flavio S.; de ANDRADE, Gabriel C.; PRATA, Tiago S.; MAIA, André

    2016-01-01

    To investigate the safety profile and benefits of a short-term simultaneous treatment regimen combining two drugs—an intravitreal implant of dexamethasone with an intravitreal injection of bevacizumab—in patients with macular edema. This was a retrospective, non-randomized, open-label case series study. Patients were treated between April 2014 and July 2015 and were diagnosed with recurrent macular edema secondary to diabetic retinopathy and retinal vein occlusion. They underwent simultaneous treatment with an intravitreal injection of bevacizumab (1.25 mg) and an intravitreal implant of dexamethasone (0.7 mg). Patients were evaluated at baseline and at each subsequent visit with a complete ophthalmological examination and spectral-domain optical coherence tomography (OCT) scans. They were examined 24 hours after the treatment, and then followed up after 30 days and 60 days. Twenty patients (representing 20 eyes) were included in the study. At the time of injection (i.e., baseline), the best-corrected visual acuity (BCVA) was 0.758 ± 0.42 logarithm of the minimum angle of resolution (logMAR). It improved significantly to 0.51 ± 0.33 logMAR at 1 month and to 0.5 ± 0.34 logMAR at 2 months (P ≤ 0.03). The median baseline central macular thickness (CMT) was 542 µm (interquartile range, 466 – 751 µm). The median CMT decreased significantly to 321 µm (interquartile range, 288–381 µm) at 1 month and 310 µm (interquartile range, 286 – 354 µm) at 2 months (P ≤ 0.0002). The mean intraocular pressure (IOP) increased from 14.9 ± 2.29 mmHg (at baseline) to 16.5 ± 2.99 mmHg (P = 0.04) after 2 months. Two (10%) eyes showed cataract progression. There were no other ocular or systemic complications for the duration of this study. Simultaneous therapy combining a dexamethasone implant plus bevacizumab for macular edema may be an attractive treatment regimen with an acceptable safety profile. PMID:28289686

  19. Evaluation of Intravitreal Ranibizumab on the Surgical Outcome for Diabetic Retinopathy With Tractional Retinal Detachment

    PubMed Central

    Dong, Feng; Yu, Chenying; Ding, Haiyuan; Shen, Liping; Lou, Dinghua

    2016-01-01

    Abstract This study aims to investigate intravitreal injection of Ranibizumab on the surgical outcome for diabetic patients who had tractional retinal detachment but did not receive any preoperative retinal photocoagulation. Ninety-seven patients (97 eyes) who had diabetic retinopathy with tractional retinal detachment were enrolled to receive 23-G pars plana vitrectomy (PPV). They were assigned to an experimental group (Group I, n = 47 eyes) and a control group (Group II, n = 50 eyes). The patients in Group I were given 1 injection of intravitreal Ranibizumab (Lucentis 0.5 mg/0.05 mL) 1 week before surgery, whereas those in Group II went down to surgery directly. Follow-ups were performed for 6 months to 3 years (16 ± 6 months), and indicators observed included postoperative best-corrected visual acuity, complications, and retinal thickness in the macula measured by optical coherence tomography. In Group I, BCVA improved from logMAR 1.92 ± 0.49 to logMAR 0.81 ± 0.39 following surgery, whereas in Group II, BCVA improved from logMAR 1.91 ± 0.49 to logMAR 0.85 ± 0.41. There was significant postoperative gain in vision, but there was no significant difference between the 2 groups at postoperative follow-up visits. The mean duration of vitrectomy in Group I and Group II was (40 ± 7) minutes and (53 ± 9) minutes, respectively, with significant difference. Iatrogenic breaks were noted in 5 eyes (11%) in the experimental group and 17 eyes (34%) in the control group; the difference was significant. The retinal thickness in the macula measured by OCT was (256 ± 44) μm and (299 ± 84) μm in Group I and Group II respectively with significant difference. Besides, there were significantly more eyes in Group II that required silicone oil tamponade and postoperative retinal photocoagulation. 23-G PPV combined with intravitreal tamponade and panretinal photocoagulation still remains an effective regimen for the

  20. Intravitreal aflibercept in neovascular age-related macular degeneration previously treated with ranibizumab

    PubMed Central

    Lim, Rachel Hui Fen; Gupta, Bhaskar; Simcock, Peter

    2017-01-01

    AIM To report the change in visual acuity and central macular thickness (CMT) following treatment with intravitreal aflibercept injections in patients with neovascular age-related macular degeneration (nAMD) with suboptimum response to ranibizumab. METHODS This was a retrospective study. The inclusion criteria were patients with nAMD who responded poorly to ranibizumab. Patients then received either 3 consecutive aflibercept injections followed by pro re nata (PRN) treatment or PRN alone. Primary endpoints were mean change in best-corrected visual acuity (BCVA) and CMT at 12mo. Secondary endpoints were number of injections and adverse events. RESULTS Forty-nine eyes from 49 patients met the inclusion criteria and completed 12-month follow up on aflibercept. Thirty-eight eyes received 3 consecutive aflibercept injections followed by PRN treatment and 11 eyes received PRN injections alone. At 12mo, mean BCVA improved by one letters (logMAR 0.56±0.31 to 0.54±0.34) and mean CMT decreased from 303.9±82.1 to 259.2±108.3 µm. Four percent of eyes gained 15 letters or more, 6% lost more than 15 letters and the remaining 90% had stable BCVA. The mean number of aflibercept injections was 6. There was one case of infectious endophthalmitis. CONCLUSION Intravitreal aflibercept in patients with nAMD with a previous suboptimal response to ranibizumab resulted in an anatomical improvement in macular appearance at 12mo without a corresponding improvement in visual acuity. PMID:28393034

  1. Contralateral eye-to-eye comparison of intravitreal ranibizumab and a sustained-release dexamethasone intravitreal implant in recalcitrant diabetic macular edema

    PubMed Central

    Thomas, Benjamin J; Yonekawa, Yoshihiro; Wolfe, Jeremy D; Hassan, Tarek S

    2016-01-01

    Objective To compare the effects of intravitreal ranibizumab (RZB) or dexamethasone (DEX) intravitreal implant in cases of recalcitrant diabetic macular edema (DME). Methods Retrospective, interventional study examining patients with symmetric bilateral, center-involved DME recalcitrant to treatment with RZB, who received DEX in one eye while the contralateral eye continued to receive RZB every 4–5 weeks for a study period of 3 months. Results Eleven patients (22 eyes) were included: mean logarithm of the minimal angle of resolution (logMAR) visual acuity (VA) for the DEX arm improved from 0.415 (standard deviation [SD] ±0.16) to 0.261 (SD ±0.18) at final evaluation, and mean central macular thickness (CMT) improved from 461 µm (SD ±156) to 356 µm (SD ±110; net decrease: 105 µm, P=0.01). Mean logMAR VA for the RZB arm improved from 0.394 (SD ±0.31) to 0.269 (SD ±0.19) at final evaluation. Mean CMT improved from 421 µm (SD ±147) to 373 µm (SD ±129; net decrease: 48 µm, P=0.26). Conclusion A subset of recalcitrant DME patients demonstrated significant CMT reduction and VA improvement after a single DEX injection. PMID:27621587

  2. Neuroprotective effect of systemic and/or intravitreal rosuvastatin administration in rat glaucoma model

    PubMed Central

    Unlu, Metin; Aktas, Zeynep; Gocun, Pinar Uyar; Ilhan, Sevil Ozger; Hasanreisoglu, Murat; Hasanreisoglu, Berati

    2016-01-01

    AIM To evaluate the neuroprotective effect of rosuvastatin, in a rat experimental glaucoma model. METHODS Ocular hypertension was induced in right eyes of Long-Evans rats (n=30) by cauterization of three episcleral veins. Left eyes were defined as controls. Rats were divided into five groups: oral rosuvastatin, intravitreal rosuvastatin, oral+intravitreal rosuvastatin, intravitreal sham and glaucoma without intervention. Rats were sacrificed at day 14. Retinal ganglion cell (RGC) number was assessed by histopathological analysis. Terminal deoxynucleotidyl transferase-mediated dUTP-nick end-labeling (TUNEL) staining and the expression of glial fibrillary acidic protein (GFAP) in RGC layer was also examined. RESULTS A significant intraocular pressure (IOP) elevation was seen (P=0.002). Elevated IOP resulted in a significant decrease in number of RGCs in group 5 (70.33±8.2 cells/mm2) when compared with controls (92.50±13.72 cells/mm2; P=0.03). The RGC number in group 1 (92.4±7.3 cells/mm2) was significantly higher than group 5 (P=0.03). The numbers of RGC in groups 2, 3 (57.3±8.2 cells/mm2, 60.5±12.9 cells/mm2) were comparable with that of group 5 (P=0.18 and P=0.31). The apoptosis rates with TUNEL staining were also parallel to RGC number. Animals with experimentally induced glaucoma showed an increase in retinal GFAP immunoreactivity. CONCLUSION Decrease in RGC loss and apoptosis suggest the neuroprotective potential of oral rosuvastatin treatment in a rat model of ocular hypertension. However intravitreal rosuvastatin showed a contrary effect and further studies are required. PMID:27158600

  3. Flow injection analysis of MWC fly ash leaching characteristics

    SciTech Connect

    Willemin, J.A.; Nesbitt, C.C.; Dewey, G.R.; Sandall, J.F.; Sutter, L.L.

    1995-11-01

    A completely mixed batch reactor leaching method utilizing flow injection analysis (the CMBR-FIA method) was developed to study the lead leaching characteristics of municipal waste combustor fly ash. Flow injection analysis (FIA) coupled with atomic absorption spectrophotometry enabled the determination of lead concentrations at one minute intervals. The pH and oxidation-reduction potential of the solution were continuously monitored to characterize the leaching conditions. Automatic titration was used to alter the solution pH to defined endpoints. The CMBR-FIA method offers the ability to immediately observe alterations to the leaching solution, and grants the freedom to study a number of parameters concurrently. The CMBR-FIA method is a rapid and reliable means to investigate leaching characteristics. This paper describes the method and demonstrates its use to monitor the leaching of lead from municipal solid waste combustor fly ash as a function of pH. Soluble lead concentrations are shown to increase quickly with decreasing pH. A maximum of 50% of the total lead concentration was available in solution at pH 2. This value gradually decreased with time to over 35% of the total. 16 refs., 6 figs.

  4. Modified electrokinetic sample injection method in chromatography and electrophoresis analysis

    DOEpatents

    Davidson, J. Courtney; Balch, Joseph W.

    2001-01-01

    A sample injection method for horizontal configured multiple chromatography or electrophoresis units, each containing a number of separation/analysis channels, that enables efficient introduction of analyte samples. This method for loading when taken in conjunction with horizontal microchannels allows much reduced sample volumes and a means of sample stacking to greatly reduce the concentration of the sample. This reduction in the amount of sample can lead to great cost savings in sample preparation, particularly in massively parallel applications such as DNA sequencing. The essence of this method is in preparation of the input of the separation channel, the physical sample introduction, and subsequent removal of excess material. By this method, sample volumes of 100 nanoliter to 2 microliters have been used successfully, compared to the typical 5 microliters of sample required by the prior separation/analysis method.

  5. Retinal safety of intravitreal rtPA in healthy rats and under excitotoxic conditions

    PubMed Central

    Daruich, Alejandra; Parcq, Jérôme; Delaunay, Kimberley; Naud, Marie-Christine; Le Rouzic, Quentin; Picard, Emilie; Crisanti, Patricia; Vivien, Denis; Berdugo, Marianne

    2016-01-01

    Purpose Intravitreal recombinant tissue plasminogen activator (rtPA) is used off-label for the surgical management of submacular hemorrhage, a severe complication of neovascular age-related macular degeneration. rtPA is approved for coronary and cerebral thrombolysis. However, in ischemic stroke rtPA is known to increase excitotoxic neural cell death by interacting with the N-methyl-D-aspartate (NMDA) receptor. We therefore investigated the retinal toxicity of rtPA in healthy rats and in a model of NMDA-induced retinal excitotoxicity. Methods First, rtPA at three different doses (2.16 µg/5 µl, 0.54 µg/5 µl, and 0.27 µg/5 µl) or vehicle (NaCl 0.9%) was injected intravitreally in healthy rat eyes. Electroretinograms (ERGs) were performed at 24 h or 7 days. Annexin V-fluorescein isothiocyanate (FITC)-labeled apoptotic retinal ganglion cells (RGCs) were counted on flatmounted retinas at 24 h or 7 days. Next, NMDA + vehicle or NMDA + rtPA (0.27 µg/5 µl) was injected intravitreally to generate excitotoxic conditions. Apoptotic annexin V-FITC-labeled RGCs and surviving Brn3a-labeled RGCs were quantified on flatmounted retinas and radial sections, 18 h after treatment. Results In healthy rat eyes, the number of apoptotic RGCs was statistically significantly increased 24 h after the administration of rtPA at the highest dose (2.16 µg/5 µl; p = 0.0250) but not at the lower doses of 0.54 and 0.27 µg/5 µl (p = 0.36 and p = 0.20), compared to vehicle. At day 7, there was no difference in the apoptotic RGC count between the rtPA- and vehicle-injected eyes (p = 0.70, p = 0.52, p = 0.11). ERG amplitudes and implicit times were not modified at 24 h or 7 days after injection of any tested rtPA doses, compared to the baseline. Intravitreal administration of NMDA induced RGC death, but under these excitotoxic conditions, coadministration of rtPA did not increase the number of dead RGCs (p = 0.70). Similarly, the number of surviving RGCs on the flatmounted retinas and

  6. Controlled Release of Dexamethasone From an Intravitreal Delivery System Using Porous Silicon Dioxide

    PubMed Central

    Hou, Huiyuan; Wang, Chengyun; Nan, Kaihui; Freeman, William R.; Sailor, Michael J.; Cheng, Lingyun

    2016-01-01

    Purpose The current study aims to evaluate a porous silicon-based drug delivery system meant for sustained delivery of dexamethasone (Dex) to the vitreous and retina. Methods Dexamethasone was grafted covalently into the pore walls of fully oxidized porous silicon particles (pSiO2-COO-Dex), which then was evaluated for the pharmacological effect of the payload on cultured ARPE19 cells before intravitreal injection. The Dex release profile was investigated in a custom designed dynamic dissolution chamber to mimic the turnover of vitreous fluid in rabbit eyes. Ocular safety, in vivo release, and pharmacodynamics were evaluated in rabbit eyes, and the human VEGF-induced rabbit retinal vascular permeability model. Results Loading efficiency of Dex was 69 ± 9 μg per 1 mg of the pSiO2-COO-Dex particles. Dynamic in vitro release demonstrated a sustained mode when compared to free Dex, with the drug half-life extended by 5 times. The released Dex was unaltered and biologically active. In vivo drug release in rabbit eyes revealed a mode similar to the release seen in vitro, with a vitreous half-life of 11 days. At 2 and 4 weeks after a single intravitreal injection of pSiO2-COO-Dex particles (mean 2.71 ± 0.47 mg), intravitreal 500 ng of VEGF did not induce significant retinal vessel dilation or fluorescein leakage, while these events were observed in the eyes injected with empty pSiO2 particles or with free Dex. The retinal vessel score from fluorescein angiography for the control eyes was double the score for the eyes injected with pSiO2-COO-Dex. No adverse reaction was observed for the eyes injected with drug-loaded pSi particles during the course of the study. Conclusions The porous silicon-based Dex delivery system (pSiO2-COO-Dex) can be administered safely into vitreous without toxicity. Dex release from the porous silicon particles was sustained for 2 months and was effective against VEGF-induced retinal vessel reaction. PMID:26882530

  7. Simple and clean determination of tetracyclines by flow injection analysis

    NASA Astrophysics Data System (ADS)

    Rodríguez, Michael Pérez; Pezza, Helena Redigolo; Pezza, Leonardo

    2016-01-01

    An environmentally reliable analytical methodology was developed for direct quantification of tetracycline (TC) and oxytetracycline (OTC) using continuous flow injection analysis with spectrophotometric detection. The method is based on the diazo coupling reaction between the tetracyclines and diazotized sulfanilic acid in a basic medium, resulting in the formation of an intense orange azo compound that presents maximum absorption at 434 nm. Experimental design was used to optimize the analytical conditions. The proposed technique was validated over the concentration range of 1 to 40 μg mL- 1, and was successfully applied to samples of commercial veterinary pharmaceuticals. The detection (LOD) and quantification (LOQ) limits were 0.40 and 1.35 μg mL- 1, respectively. The samples were also analyzed by an HPLC method, and the results showed agreement with the proposed technique. The new flow injection method can be immediately used for quality control purposes in the pharmaceutical industry, facilitating monitoring in real time during the production processes of tetracycline formulations for veterinary use.

  8. Randomized Clinical Trial Evaluating Intravitreal Ranibizumab or Saline for Vitreous Hemorrhage from Proliferative Diabetic Retinopathy

    PubMed Central

    Bhavsar, Abdhish R.; Torres, Karisse; Beck, Roy W.; Bressler, Neil M.; Ferris, Frederick L.; Friedman, Scott M.; Glassman, Adam R.; Maturi, Raj K.; Melia, Michele; Singer, Michael A.; Stockdale, Cynthia R.

    2014-01-01

    Objective To evaluate intravitreal ranibizumab compared with intravitreal saline injections on vitrectomy rates for vitreous hemorrhage (VH) from proliferative diabetic retinopathy (PDR). Main Outcome Cumulative probability of vitrectomy within 16 weeks. Methods Study eyes had VH from PDR precluding panretinal photocoagulation (PRP) completion. Eyes were randomly assigned to 0.5-mg ranibizumab (N = 125) or saline (N = 136) at baseline, 4, and 8 weeks. Results Cumulative probability of vitrectomy by 16 weeks was 12% with ranibizumab versus 17% with saline (difference 4%, 95% confidence interval −4%–13%) and of complete PRP without vitrectomy by 16-weeks was 44% and 31% respectively (P = 0.05). The mean (±SD) visual acuity improvement from baseline to 12 weeks was 22±23 letters and 16±31 letters respectively (P = 0.04). Recurrent VH occurred within 16 weeks in 6% and 17% respectively (P = 0.01). One eye developed endophthalmitis after saline. Conclusions Overall the 16 week vitrectomy rates were lower than expected in both groups. This study suggests little likelihood of a clinically important difference between ranibizumab and saline on the rate of vitrectomy by 16 weeks in eyes with VH from PDR. Short term secondary outcomes including visual acuity improvement, increased PRP completion rates, and reduced recurrent VH rates suggest biologic activity of ranibizumab. Long term benefits remain unknown. Whether vitrectomy rates after saline or ranibizumab are different than observation alone cannot be determined from this study. Application to Clinical Practice Intravitreal ranibizumab does not appear to reduce vitrectomy rates compared with saline for VH from PDR. PMID:23370902

  9. Steerable intravitreal inserts for drug delivery: in vitro and ex vivo mobility experiments.

    PubMed

    Bergeles, Christos; Kummer, Michael P; Kratochvil, Bradley E; Framme, Carsten; Nelson, Bradley J

    2011-01-01

    The progress of wet age-related macular degeneration can now be controlled by intravitreal drug injection. This approach requires repeated injections, which could be avoided by delivering the drug to the retina. Intraocular implants are a promising solution for drug delivery near the retina. Currently, their accurate placement is challenging, and they can only be removed after a vitrectomy. In this paper, we introduce an approach for minimally invasive retinal drug delivery using magnetic intraocular inserts. We briefly discuss the electromagnetic-control system for magnetic implants and then focus on evaluating their ability to move in the vitreous humor. The mobility of magnetic intraocular implants is estimated in vitro with synthesized vitreous humors, and ex vivo with experiments on cadaver porcine eyes. Preliminary results show that with such magnetic implants a vitrectomy can be avoided.

  10. Equivalent circuit analysis of the RHIC injection kicker

    SciTech Connect

    Hahn, H.; Ratti, A.

    1997-07-01

    The RHIC injection kicker is built as a traveling wave structure in order to assure the required 95 nsec risetime in the deflection strength. The kicker is constructed from 14 cells, each 7.5 cm long, with alternating ferrite and high-permittivity dielectric sections. The cell structure permits an analysis of the electrical properties of the kicker using lumped L, C, and R circuit elements. Their values are obtained directly from impedance measurements of the full-length kicker, the inductance and shunt capacitance values by measuring the input impedance at 1 MHz with the output shorted and open, respectively. A lossy series resonance circuit in each cell is found to reproduce the measured input impedance of the terminated kicker up to {approximately}100 MHz. The validity of the equivalent circuit was confirmed by comparing the measured output current pulse shape time with that computed by the P-Spice program.

  11. Sustained-release dexamethasone intravitreal implant in juvenile idiopathic arthritis-related uveitis.

    PubMed

    Pichi, Francesco; Nucci, Paolo; Baynes, Kimberly; Lowder, Careen Y; Srivastava, Sunil K

    2017-02-01

    The purpose of this study is to review the results of treatment of juvenile idiopathic arthritis-related uveitis with the use of intravitreal dexamethasone implant. Sixteen eyes with Juvenile idiopathic arthritis (JIA)-associated uveitis received intravitreal dexamethasone implant to treat recalcitrant anterior segment inflammation (43.7 %), chronic macular edema (6.2 %), or a combination of both (50 %). One month after injection, mean visual acuity had improvement to 39.6 ± 11 ETDRS letters (p < 0.001). Mean AC cells measure at 1 month was 0.79 and 0.75 at 3 months. One month after injection, there was a significant reduction of central retinal thickness (CRT) to 342.4 ± 79.3 µm (p < 0.01). One month after the second implant, 11 eyes (91.6 %) achieved improved activity of the anterior uveitis, and mean best-corrected visual acuity improved to 44.6 ± 8.1 ETDRS letters (p < 0.01). At 1 month after the second injection, 4/5 eyes had resolution of macular edema with CRT of 250.4 ± 13.7 µm (p < 0.01). Of the 16 eyes, 12 eyes received a second injection at mean of 7.5 ± 3.1 months after the first treatment, and 5 eyes received a third Ozurdex injection on average 7 ± 4.6 months after the second injection. Of the 16 eyes, five eyes were pseudophakic prior to injection. Of the remaining 11 eyes, 8 (73 %) developed worsening posterior subcapsular cataract at a mean of 7.3 ± 1.2 months after the first injection. After the first injection, only one eye required topical antiglaucoma therapy with maximum pressure of 25 mmHg. In patients with recalcitrant JIA-associated active uveitis, injection of sustained-release dexamethasone can achieve control of anterior inflammation and resolution of macular edema.

  12. Intraocular pharmacokinetics of intravitreal vascular endothelial growth factor-Trap in a rabbit model

    PubMed Central

    Park, S J; Oh, J; Kim, Y-K; Park, J H; Park, J Y; Hong, H K; Park, K H; Lee, J-E; Kim, H M; Chung, J Y; Woo, S J

    2015-01-01

    Purpose To determine intraocular pharmacokinetic properties of intravitreally injected vascular endothelial growth factor (VEGF)-Trap in a rabbit model. Methods VEGF-Trap was intravitreally injected in 18 rabbit eyes. Eyes were enucleated 1 h and 1, 2, 5, 14, and 30 days after injections and immediately frozen at −80 °C. Concentration of VEGF-Trap in vitreous, aqueous humor, and retina/choroid was determined using an indirect enzyme-linked immunosorbent assay and analyzed to obtain pharmacokinetic properties. Results Maximum concentration of VEGF-Trap was achieved at 1 h in all three tissues. A one-compartment model of distribution was selected as the final model for all tissues studied. Estimated half-life of VEGF-Trap in vitreous, aqueous humor, and retinal/choroid was 87.1, 36.8, and 35.0 h, respectively, and estimated mean residence time was 125.7, 53.1, and 50.5 h, respectively. Area under the curve from time 0 to the end point was 10009.8, 3945.1, and 1189.3, respectively. Total exposure of the aqueous humor and retina/choroid to VEGF-Trap was 39.4% and 11.9% of vitreous exposure, respectively. Conclusion The vitreous half-life of VEGF-Trap is 3.63 days. This is shorter than that of bevacizumab (6.99 days) and longer than that of ranibizumab (2.51 days), as shown in studies using the same experimental settings. The concentration of VEGF-Trap peaked at 1 h after injections in all eye tissues studied. PMID:25592118

  13. Intravitreal methotrexate infusion for proliferative vitreoretinopathy

    PubMed Central

    Sadaka, Ama; Sisk, Robert A; Osher, James M; Toygar, Okan; Duncan, Melinda K; Riemann, Christopher D

    2016-01-01

    Purpose The purpose of this study was to evaluate intravitreal methotrexate infusion (IMI) during pars plana vitrectomy (PPV) for retinal detachment in patients with high risk for the development of proliferative vitreoretinopathy (PVR). Methods Patients presenting with severe recurrent PVR with tractional retinal detachment and/or a history of severe ocular inflammation were treated with IMI. Clinical outcomes were determined from a retrospective medical chart review. Results Twenty-nine eyes presenting with either tractional retinal detachment and recurrent PVR (n=22) or a history of severe inflammation associated with high PVR risk (n=7) received IMI during PPV. Best-corrected visual acuity at 6 months was ≥20/200 in 19 of 29 eyes (66%) and remained stable or improved compared with initial presentation in 24 of 29 eyes (83%). At the last follow-up examination, the retinas of 26 of 29 eyes (90%) remained attached after IMI while three eyes required another reattachment procedure. Three additional eyes (10%) developed recurrent limited PVR without recurrent RD and were observed. No complications attributable to IMI occurred during a mean follow-up of 27 months. Conclusion Eyes at high risk for PVR development due to a history of prior PVR or intraocular inflammation had a low incidence of PVR following IMI at the time of PPV for RD repair. No significant safety issues from IMI were observed in this series. PMID:27698550

  14. Screening of conditions controlling spectrophotometric sequential injection analysis

    PubMed Central

    2011-01-01

    Background Despite its potential benefits over univariate, chemometrics is rarely utilized for optimizing sequential injection analysis (SIA) methods. Specifically, in previous vis-spectrophotometric SIA methods, chemometrically optimized conditions were confined within flow rate and reagent concentrations while other conditions were ignored. Results The current manuscript reports, for the first time, a comprehensive screening of conditions controlling vis-spectrophotometric SIA. A new diclofenac assay method was adopted. The method was based on oxidizing diclofenac by permanganate (a major reagent) with sulfuric acid (a minor reagent). The reaction produced a spectrophotometrically detectable diclofenac form. The 26 full-factorial design was utilized to study the effect of volumes of reagents and sample, in addition to flow rate and concentrations of reagents. The main effects and all interaction order effects on method performance, i.e. namely sensitivity, rapidity and reagent consumption, were determined. The method was validated and applied to pharmaceutical formulations (tablets, injection and gel). Conclusions Despite 64 experiments those conducted in the current study were cumbersome, the results obtained would reduce effort and time when developing similar SIA methods in the future. It is recommended to critically optimize effective and interacting conditions using other such optimization tools as fractional-factorial design, response surface and simplex, rather than full-factorial design that used at an initial optimization stage. In vis-spectrophotometric SIA methods those involve developing reactions with two reagents (major and minor), conditions affecting method performance are in the following order: sample volume > flow rate ≈ major reagent concentration >> major reagent volume ≈ minor reagent concentration >> minor reagent volume. PMID:21333024

  15. Protocol: Effect of intravitreal bevacizumab (avastin) in the treatment of macular edema: A systematic review of randomized controlled trials

    PubMed Central

    Qazi, Hammad A.

    2012-01-01

    Cystoid macular edema (CME) is a relatively common painless condition usually accompanied by blurred vision. The prevalence of CME varied from 5% to 47% depending on cause of pathology. There are several treatments available for ME including intravitreal use of bevacizumab that has been used in different doses in few studies. However, there is still scarcity of data available on the use of bevacizumab for the treatment of ME. A systematic review is needed to provide a foundational base to discuss and synthesize the available information on the effectiveness and safety of intravitreal bevacizumab in macular edema, so that recommendations and policies can be built regarding controversial use of bevacizumab in macular edema. We have planned to perform a systematic review with an objective to compare the effects of a single injection of 1.25 mg intravitreal bevacizumab (avastin) in the improvement of visual acuity, macular edema, and thickness with other interventions/controls for the treatment of macular edema at 3 and 6 months interval using randomized controlled trials. This is only a protocol of the review and we will be conducting a full length review, addressing the issue in future. PMID:23853638

  16. Dendrimer-based targeted intravitreal therapy for sustained attenuation of neuroinflammation in retinal degeneration.

    PubMed

    Iezzi, Raymond; Guru, Bharath R; Glybina, Inna V; Mishra, Manoj K; Kennedy, Alexander; Kannan, Rangaramanujam M

    2012-01-01

    Retinal neuroinflammation, mediated by activated microglia, plays a key role in the pathogenesis of photoreceptor and retinal pigment epithelial cell loss in age-related macular degeneration and retinitis pigmentosa. Targeted drug therapy for attenuation of neuroinflammation in the retina was explored using hydroxyl-terminated polyamidoamine (PAMAM) dendrimer-drug conjugate nanodevices. We show that, upon intravitreal administration, PAMAM dendrimers selectively localize within activated outer retinal microglia in two rat models of retinal degeneration, but not in the retina of healthy controls. This pathology-dependent biodistribution was exploited for drug delivery, by covalently conjugating fluocinolone acetonide to the dendrimer. The conjugate released the drug in a sustained manner over 90 days. In vivo efficacy was assessed using the Royal College of Surgeons (RCS) rat retinal degeneration model over a four-week period when peak retinal degeneration occurs. One intravitreal injection of 1 μg of FA conjugated to 7 μg of the dendrimer was able to arrest retinal degeneration, preserve photoreceptor outer nuclear cell counts, and attenuate activated microglia, for an entire month. These studies suggest that PAMAM dendrimers (with no targeting ligands) have an intrinsic ability to selectively localize in activated microglia, and can deliver drugs inside these cells for a sustained period for the treatment of retinal neuroinflammation.

  17. Intravitreal Kinetics of Hesperidin, Hesperetin and Hesperidin G: Effect of Dose and Physicochemical Properties

    PubMed Central

    Srirangam, Ramesh; Hippalgaonkar, Ketan; Majumdar, Soumyajit

    2014-01-01

    Hesperidin, a flavanone glycoside, and its aglycone hesperetin, are potential candidates for the treatment of diabetic retinopathy and macular edema. The objective of this study was to delineate the vitreal pharmacokinetics of hesperidin and hesperetin and the hydrophilic derivative hesperidin G (glucosyl hesperedin), following intravitreal administration in anaesthetized rabbits. Concentration changes in the vitreous humor were monitored using microdialysis sampling procedure. All three molecules were administered intravitreally at three dose levels (50 μl injection volume containing 1.5, 4.5 and 15 µg of the drug, resulting in a final vitreal concentration of 1, 3 and 10 μg/mL). Vitreal microdialysis samples were collected every 20 minutes over a period of 10 h. All three molecules exhibited linear pharmacokinetics, within the dose range tested, since AUC and Cmax increased linearly with increasing dose and a significant difference in the elimination parameters, like clearance or half-life, was not observed. The vitreal elimination half-life of these three compounds was observed to correlate with the molecular weight and lipophilicity of the molecules. The findings from this study provide practical information that will be useful in the future design of ocular drug delivery strategies for the bioflavonoids. PMID:22228207

  18. Management of noninfectious posterior uveitis with intravitreal drug therapy

    PubMed Central

    Tan, Hui Yi; Agarwal, Aniruddha; Lee, Cecilia S; Chhablani, Jay; Gupta, Vishali; Khatri, Manoj; Nirmal, Jayabalan; Pavesio, Carlos; Agrawal, Rupesh

    2016-01-01

    Uveitis is an important cause of vision loss worldwide due to its sight-threatening complications, especially cystoid macular edema, as well as choroidal neovascularization, macular ischemia, cataract, and glaucoma. Systemic corticosteroids are the mainstay of therapy for noninfectious posterior uveitis; however, various systemic side effects can occur. Intravitreal medication achieves a therapeutic level in the vitreous while minimizing systemic complications and is thus used as an exciting alternative. Corticosteroids, antivascular endothelial growth factors, immunomodulators such as methotrexate and sirolimus, and nonsteroidal anti-inflammatory drugs are currently available for intravitreal therapy. This article reviews the existing literature for efficacy and safety of these various options for intravitreal drug therapy for the management of noninfectious uveitis (mainly intermediate, posterior, and panuveitis). PMID:27789936

  19. Natural Short-term Course of Recurrent Macular Edema Following Intravitreal Bevacizumab Therapy in Branch Retinal Vein Occlusion

    PubMed Central

    Yoo, Su Jin; Lee, Tae Gon; Kim, Jong Woo; Cho, Sung Won; Han, Jung Il

    2017-01-01

    Purpose To evaluate the 3-month natural course of recurrent macular edema secondary to branch retinal vein occlusion (BRVO) treated with intravitreal bevacizumab. Methods This retrospective, observational study included 36 eyes with macular edema secondary to BRVO. All patients were initially treated with intravitreal bevacizumab for macular edema. Recurrence of macular edema was either not treated (untreated group) or treated with a single intravitreal bevacizumab injection (treated group). Central foveal thickness (CFT) and best-corrected visual acuity (BCVA) were compared at the time of recurrence and 3 months later. Results At the time of recurrence, the mean CFT and logarithm of the minimum angle of resolution BCVA were 484.9 ± 124.1 µm and 0.58 ± 0.26 in the untreated group (n = 19) and 456.3 ± 126.8 µm and 0.51 ± 0.21 in the treated group (n = 17), respectively. Three months later, the mean CFT and BCVA had changed to 493.7 ± 123.9 µm and 0.62 ± 0.29 in the untreated group and 294.7 ± 104.4 µm and 0.40 ± 0.24 in the treated group, respectively. The differences in CFT and BCVA between the two time points were not significant in the untreated group (p = 0.106 and p = 0.687, respectively), whereas statistically significant differences were noted in the treated group (p = 0.002 and p < 0.001, respectively). Conclusions Unlike the first episode of macular edema following BRVO, recurrent macular edema following intravitreal bevacizumab therapy did not spontaneously resolve, suggesting the potential benefit of prompt treatment. PMID:28367036

  20. Development of devices for self-injection: using tribological analysis to optimize injection force

    PubMed Central

    Lange, Jakob; Urbanek, Leos; Burren, Stefan

    2016-01-01

    This article describes the use of analytical models and physical measurements to characterize and optimize the tribological behavior of pen injectors for self-administration of biopharmaceuticals. One of the main performance attributes of this kind of device is its efficiency in transmitting the external force applied by the user on to the cartridge inside the pen in order to effectuate an injection. This injection force characteristic is heavily influenced by the frictional properties of the polymeric materials employed in the mechanism. Standard friction tests are available for characterizing candidate materials, but they use geometries and conditions far removed from the actual situation inside a pen injector and thus do not always generate relevant data. A new test procedure, allowing the direct measurement of the coefficient of friction between two key parts of a pen injector mechanism using real parts under simulated use conditions, is presented. In addition to the absolute level of friction, the test method provides information on expected evolution of friction over lifetime as well as on expected consistency between individual devices. Paired with an analytical model of the pen mechanism, the frictional data allow the expected overall injection system force efficiency to be estimated. The test method and analytical model are applied to a range of polymer combinations with different kinds of lubrication. It is found that material combinations used without lubrication generally have unsatisfactory performance, that the use of silicone-based internal lubricating additives improves performance, and that the best results can be achieved with external silicone-based lubricants. Polytetrafluoroethylene-based internal lubrication and external lubrication are also evaluated but found to provide only limited benefits unless used in combination with silicone. PMID:27274319

  1. Subhyaloid hemorrhage treated with SF6 gas injection.

    PubMed

    Park, Sang-Woo; Seo, Man-Seong

    2004-01-01

    A 72-year old woman with a premacular subhyaloid hemorrhage could not be treated by laser photodisruption due to a thick posterior cortical vitreous. Pure sulfur hexafluoride (SF6, 0.3 mL) gas was injected intravitreally without recombinant tissue plasminogen activator, and facedown positioning was recommended for 5 days. Posterior vitreous detachment was induced and the hemorrhage dispersed into the vitreous cavity. Eight weeks later, her visual acuity had recovered from hand motions to 20/40. Fluorescein angiography revealed an arterial macroaneurysm in the inferotemporal retina. Intravitreal SF6 gas injection without recombinant tissue plasminogen activator may be an alternative method for treating a relatively new subhyaloid hemorrhage.

  2. Remote calorimetric detection of urea via flow injection analysis.

    PubMed

    Gaddes, David E; Demirel, Melik C; Reeves, W Brian; Tadigadapa, Srinivas

    2015-12-07

    The design and development of a calorimetric biosensing system enabling relatively high throughput sample analysis are reported. The calorimetric biosensor system consists of a thin (∼20 μm) micromachined Y-cut quartz crystal resonator (QCR) as a temperature sensor placed in close proximity to a fluidic chamber packed with an immobilized enzyme. Layer by layer enzyme immobilization of urease is demonstrated and its activity as a function of the number of layers, pH, and time has been evaluated. This configuration enables a sensing system where a transducer element is physically separated from the analyte solution of interest and is thereby free from fouling effects typically associated with biochemical reactions occuring on the sensor surface. The performance of this biosensing system is demonstrated by detection of 1-200 mM urea in phosphate buffer via a flow injection analysis (FIA) technique. Miniaturized fluidic systems were used to provide continuous flow through a reaction column. Under this configuration the biosensor has an ultimate resolution of less than 1 mM urea and showed a linear response between 0-50 mM. This work demonstrates a sensing modality in which the sensor itself is not fouled or contaminated by the solution of interest and the enzyme immobilized Kapton® fluidic reaction column can be used as a disposable cartridge. Such a system enables reuse and reliability for long term sampling measurements. Based on this concept a biosensing system is envisioned which can perform rapid measurements to detect biomarkers such as glucose, creatinine, cholesterol, urea and lactate in urine and blood continuously over extended periods of time.

  3. The effect of intravitreal vascular endothelial growth factor on inner retinal oxygen delivery and metabolism in rats.

    PubMed

    Blair, Norman P; Wanek, Justin; Teng, Pang-yu; Shahidi, Mahnaz

    2016-02-01

    Vascular endothelial growth factor (VEGF) is stimulated by hypoxia and plays an important role in pathologic vascular leakage and neovascularization. Increased VEGF may affect inner retinal oxygen delivery (DO2) and oxygen metabolism (MO2), however, quantitative information is lacking. We tested the hypotheses that VEGF increases DO2, but does not alter MO2. In 10 rats, VEGF was injected intravitreally into one eye, whereas balanced salt solution (BSS) was injected into the fellow eye, 24 h prior to imaging. Vessel diameters and blood velocities were determined by red-free and fluorescent microsphere imaging, respectively. Vascular PO2 values were derived by phosphorescence lifetime imaging of an intravascular oxyphor. Retinal blood flow, vascular oxygen content, DO2 and MO2 were calculated. Retinal arterial and venous diameters were larger in VEGF-injected eyes compared to control eyes (P < 0.03), however no significant difference was observed in blood velocity (P = 0.21). Thus, retinal blood flow was greater in VEGF-injected eyes (P = 0.007). Retinal vascular PO2 and oxygen content were similar between control and VEGF-injected eyes (P > 0.11), while the arteriovenous oxygen content difference was marginally lower in VEGF-injected eyes (P = 0.05). DO2 was 950 ± 340 and 1380 ± 650 nL O2/min in control and VEGF-injected eyes, respectively (P = 0.005). MO2 was 440 ± 150 and 490 ± 190 nL O2/min in control and VEGF-injected eyes, respectively (P = 0.31). Intravitreally administered VEGF did not alter MO2 but increased DO2, suggesting VEGF may play an offsetting role in conditions characterized by retinal hypoxia.

  4. Effects of intravitreal insulin and insulin signaling cascade inhibitors on emmetropization in the chick

    PubMed Central

    Penha, Alexandra Marcha; Burkhardt, Eva; Schaeffel, Frank

    2012-01-01

    Purpose Intravitreal insulin has been shown to be a powerful stimulator of myopia in chickens, in particular if the retinal image is degraded or defocused. In most tissues, the insulin receptor activates two main signaling pathways: a) the mitogen-activated protein kinase (MAPK) cascade (e.g., mitogen-activated protein kinasem kinase [MEK] and extracellular regulated kinase [ERK]) and b) the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway. In the current study, insulin was injected, and these pathways were separately inhibited to determine which is activated when the retinal image is defocused by spectacle lenses. Methods Chicks were treated with either +7 D, −7 D, or no lenses. They were intravitreally injected with insulin, the MEK inhibitor U0126, the PI3K inhibitor Ly294002, or a combination of insulin and one of the inhibitors. Refractions and ocular dimension were measured at the beginning and after four days of treatment. The retinal proteins of the chicks were measured with western blots after 2 h and four days of treatment. Incubation occurred with anti-Akt1, anti-Erk1/2, anti-phospho-AktThr308, and anti-phospho-Erk1/2(Thr202/Tyr204) antibodies, and the ratio between the relative intensity of the phospho-form and the total-form was calculated. Results Chicks wearing positive lenses and injected with saline and with PI3K inhibitor compensated for the imposed defocus and became hyperopic. Insulin injections and insulin plus PI3K inhibitor injections prevented lens-induced hyperopia, whereas the MEK inhibitor alone and insulin plus MEK inhibitor had no effect. Obviously, the MEK inhibitor suppressed the effect of insulin on eye growth in the plus lens–treated animals. Chicks treated with negative lenses and injected with insulin, or with insulin plus MEK inhibitor, overcompensated for the imposed defocus. This effect of insulin was not detected in eyes injected with PI3K inhibitor plus insulin, suggesting that the PI3K inhibitor

  5. Intravitreal Phacoemulsification Using Torsional Handpiece for Retained Lens Fragments

    PubMed Central

    Kumar, Vinod; Takkar, Brijesh

    2016-01-01

    Purpose: To evaluate the results of intravitreal phacoemulsification with torsional hand piece in eyes with posteriorly dislocated lens fragments. Methods: In this prospective, interventional case series, 15 eyes with retained lens fragments following phacoemulsification were included. All patients underwent standard three-port pars plana vitrectomy and intravitreal phacoemulsification using sleeveless, torsional hand piece (OZiL™, Alcon's Infiniti Vision System). Patients were followed up for a minimum of six months to evaluate the visual outcomes and complications. Results: The preoperative best-corrected visual acuity (BCVA) ranged from light perception to 0.3. No complications such as thermal burns of the scleral wound, retinal damage due to flying lens fragments, or difficult lens aspiration occurred during intravitreal phacoemulsification. Mean post-operative BCVA at the final follow-up was 0.5. Two eyes developed cystoid macular edema, which was managed medically. No retinal detachment was noted. Conclusion: Intravitreal phacoemulsification using torsional hand piece is a safe and effective alternative to conventional longitudinal phacofragmentation. PMID:27621783

  6. Improved Intravitreal AAV-Mediated Inner Retinal Gene Transduction after Surgical Internal Limiting Membrane Peeling in Cynomolgus Monkeys.

    PubMed

    Takahashi, Kazuhisa; Igarashi, Tsutomu; Miyake, Koichi; Kobayashi, Maika; Yaguchi, Chiemi; Iijima, Osamu; Yamazaki, Yoshiyuki; Katakai, Yuko; Miyake, Noriko; Kameya, Shuhei; Shimada, Takashi; Takahashi, Hiroshi; Okada, Takashi

    2017-01-04

    The retina is an ideal target for gene therapy because of its easy accessibility and limited immunological response. We previously reported that intravitreally injected adeno-associated virus (AAV) vector transduced the inner retina with high efficiency in a rodent model. In large animals, however, the efficiency of retinal transduction was low, because the vitreous and internal limiting membrane (ILM) acted as barriers to transduction. To overcome these barriers in cynomolgus monkeys, we performed vitrectomy (VIT) and ILM peeling before AAV vector injection. Following intravitreal injection of 50 μL triple-mutated self-complementary AAV serotype 2 vector encoding EGFP, transduction efficiency was analyzed. Little expression of GFP was detected in the control and VIT groups, but in the VIT+ILM group, strong GFP expression was detected within the peeled ILM area. To detect potential adverse effects, we monitored the retinas using color fundus photography, optical coherence tomography, and electroretinography. No serious side effects associated with the pretreatment were observed. These results indicate that surgical ILM peeling before AAV vector administration would be safe and useful for efficient transduction of the nonhuman primate retina and provide therapeutic benefits for the treatment of retinal diseases.

  7. Tevatron anti-proton injection kicker waveform analysis

    SciTech Connect

    Hanna, B.; Finley, D.; /Fermilab

    1996-08-01

    This note describes the measurements of the waveform of the Tevatron antiproton injection kicker using the 150 Gev proton beam. This new horizontal kicker was installed at D48 during the summer of 1995 shutdown. These measurements were taken in two sessions [1] starting on October 10 and October 18, 1995. The measurements use the Tevatron BPM and flying wire systems. This note is a companion to the Tevatron proton injection kicker note published recently [2]. The design specifications for the kicker are given in Dinkel et al. [3].

  8. Solid Lipid Nanoparticles Improve the Diclofenac Availability in Vitreous after Intraocular Injection

    PubMed Central

    Abrishami, Majid; Vakili Ahrari Roodi, Mohammad

    2016-01-01

    Purpose. In order to improve the drug availability after intravitreal administration, solid lipid nanoparticles (SLNs) containing diclofenac were prepared. Methods. In this experimental study, 18 albino rabbits were included. In right and left eyes of all rabbits, SLNs containing diclofenac and commercial form of diclofenac (0.3 mg drug) were intravitreally injected, respectively. One, four, twelve, twenty-four, and forty-eight hours after injection, vitreous and aqueous humor samples were obtained in all cases. Then, the concentration of diclofenac sodium was evaluated in all samples. Results. Size of nanoparticles was around 170 nm after preparation. Drug concentration in eyes injected with SLNs was significantly higher than left eyes injected with commercial formulation up to 4 hours after intravitreal injection (p < 0.05). Diclofenac was quantified in samples up to 48 hours after intraocular injection. Four hours after intravitreal injection, the concentration of diclofenac in vitreous and aqueous humor of eyes receiving SLNs was, respectively, 2.5 and 6.5 times higher than eyes injected with commercial form of drug. Conclusions. Here, we demonstrate the potential of SLNs as a carrier of diclofenac for intraocular injection in order to prevent the systemic effects of the drug, increase the injection intervals, and improve the patient compliance. PMID:27803815

  9. Resin Flow Analysis in the Injection Cycle of a Resin Transfer Molded Radome

    NASA Astrophysics Data System (ADS)

    Golestanian, Hossein; Poursina, Mehrdad

    2007-04-01

    Resin flow analysis in the injection cycle of an RTM process was investigated. Fiberglass and carbon fiber mats were used as reinforcements with EPON 826 epoxy resin. Numerical models were developed in ANSYS finite element software to simulate resin flow behavior into a mold of conical shape. Resin flow into the woven fiber mats is modeled as flow through porous media. The injection time for fiberglass/epoxy composite is found to be 4407 seconds. Required injection time for the carbon/epoxy composite is 27022 seconds. Higher injection time for carbon/epoxy part is due to lower permeability value of the carbon fibers compared to glass fiber mat.

  10. Antigen profiling analysis of vaccinia virus injected canine tumors

    PubMed Central

    Cecil, Alexander; Gentschev, Ivaylo; Adelfinger, Marion; Nolte, Ingo; Dandekar, Thomas; Szalay, Aladar A

    2014-01-01

    Virotherapy on the basis of oncolytic vaccinia virus (VACV) strains is a novel approach for cancer therapy. In this study we describe for the first time the use of dynamic boolean modeling for tumor growth prediction of vaccinia virus GLV-1h68-injected canine tumors including canine mammary adenoma (ZMTH3), canine mammary carcinoma (MTH52c), canine prostate carcinoma (CT1258), and canine soft tissue sarcoma (STSA-1). Additionally, the STSA-1 xenografted mice were injected with either LIVP 1.1.1 or LIVP 5.1.1 vaccinia virus strains.   Antigen profiling data of the four different vaccinia virus-injected canine tumors were obtained, analyzed and used to calculate differences in the tumor growth signaling network by type and tumor type. Our model combines networks for apoptosis, MAPK, p53, WNT, Hedgehog, TK cell, Interferon, and Interleukin signaling networks. The in silico findings conform with in vivo findings of tumor growth. Boolean modeling describes tumor growth and remission semi-quantitatively with a good fit to the data obtained for all cancer type variants. At the same time it monitors all signaling activities as a basis for treatment planning according to antigen levels. Mitigation and elimination of VACV- susceptible tumor types as well as effects on the non-susceptible type CT1258 are predicted correctly. Thus the combination of Antigen profiling and semi-quantitative modeling optimizes the therapy already before its start. PMID:25482233

  11. Analysis and characterization of the injection efficiency tuning IGBT

    NASA Astrophysics Data System (ADS)

    Zhang, Fei; Shi, Lina; Zhang, Liang; Li, Chengfang; Wang, Wei; Yu, Wen; Sun, Xiaowei

    2006-05-01

    For the first time, an insulated gate bipolar transistor with a novel buffer, called injection efficiency tuning IGBT (IET-IGBT), is proposed and verified by two-dimensional (2D) mixed device-circuit simulations. The structure of the proposed device is almost identical with that of the conventional IGBT, except for the buffer layer which is formed by employing a very highly doped stripped n+ and a weakly doped n- structure. Compared with the conventional PT-IGBT and recent FS-IGBT, the proposed device exhibits a better trade-off relation between the conduction and switching losses. An interesting feature of the IET-IGBT is that its on-resistance can be largely decreased at the expenditure of a moderate and neglectable increase in the turn-off time. The weakly doped n- buffer region leads to a high injection efficiency anode providing an optimum level of conductivity modulation required for a given on-state voltage drop in the n-drift region, while the very highly doped n+ buffer region results in a low injection anode accelerating the device turn-off. Detailed physical mechanisms are given.

  12. Pneumatic Displacement with Perfluoropropane Gas and Intravitreal Tissue Plasminogen Activator for Subretinal Subfoveal Hemorrhage after Focal Laser Photocoagulation in Central Serous Chorioretinopathy

    PubMed Central

    Espinoza, Juan V.; Lasave, Andres F.; Savino-Zari, Dario; Arevalo, Fernando A.

    2014-01-01

    Objective. To report the visual and anatomic outcomes of pneumatic displacement with perfluoropropane (C3F8) gas and intravitreal tissue plasminogen activator (IVTPA) for subretinal subfoveal hemorrhage after focal laser photocoagulation in central serous chorioretinopathy (CSCR). Method. Interventional, retrospective case report of one eye (one patient). Outcome measures included visual acuity (VA), central macular thickness (CMT), and size of the lesion at two weeks of followup. Fluorescein angiography (FA) and optical coherent tomography (OCT) were used to measure anatomic outcomes. Results. A 35-year-old man with history of chronic CSCR received focal laser photocoagulation in the right eye two days before presentation. At initial examination, VA was 20/200 (ETDRS chart), CMT was 398 μ, and a subretinal subfoveal hemorrhage was seen. Tissue plasminogen activator (tPA) at a dose of 25 µg/0.1 mL was injected intravitreally before intravitreal C3F8 injection, and prone positioning was indicated postoperatively. At 24 hours, the hemorrhage had been displaced inferiorly and VA improved to 20/100. Two weeks later, VA improved to 20/80, CMT decreased to 225 μ, and the hemorrhage decreased without foveal involvement. Conclusions. The technique seems safe and effective in treating visually significant subretinal subfoveal hemorrhage. PMID:25485161

  13. Pneumatic displacement with perfluoropropane gas and intravitreal tissue plasminogen activator for subretinal subfoveal hemorrhage after focal laser photocoagulation in central serous chorioretinopathy.

    PubMed

    Al Rubaie, Khalid; Espinoza, Juan V; Lasave, Andres F; Savino-Zari, Dario; Arevalo, Fernando A; Arevalo, J Fernando

    2014-01-01

    Objective. To report the visual and anatomic outcomes of pneumatic displacement with perfluoropropane (C3F8) gas and intravitreal tissue plasminogen activator (IVTPA) for subretinal subfoveal hemorrhage after focal laser photocoagulation in central serous chorioretinopathy (CSCR). Method. Interventional, retrospective case report of one eye (one patient). Outcome measures included visual acuity (VA), central macular thickness (CMT), and size of the lesion at two weeks of followup. Fluorescein angiography (FA) and optical coherent tomography (OCT) were used to measure anatomic outcomes. Results. A 35-year-old man with history of chronic CSCR received focal laser photocoagulation in the right eye two days before presentation. At initial examination, VA was 20/200 (ETDRS chart), CMT was 398 μ, and a subretinal subfoveal hemorrhage was seen. Tissue plasminogen activator (tPA) at a dose of 25 µg/0.1 mL was injected intravitreally before intravitreal C3F8 injection, and prone positioning was indicated postoperatively. At 24 hours, the hemorrhage had been displaced inferiorly and VA improved to 20/100. Two weeks later, VA improved to 20/80, CMT decreased to 225 μ, and the hemorrhage decreased without foveal involvement. Conclusions. The technique seems safe and effective in treating visually significant subretinal subfoveal hemorrhage.

  14. Dexamethasone Intravitreal Implant Rescue Treatment for Bevacizumab Refractory Macular Edema Secondary to Branch Retinal Vein Occlusion

    PubMed Central

    Lee, Kyou Ho; Kang, Eui Chun

    2017-01-01

    Purpose To evaluate the prognostic factors and outcomes of dexamethasone intravitreal implant (DEX implant) for intravitreal bevacizumab refractory macular edema secondary to branch retinal vein occlusion (BRVO). Methods This was a retrospective, interventional case series. Medical records were reviewed, and a total of 38 eyes that were treated with DEX implant for macular edema secondary to BRVO that did not respond to at least two consecutive intravitreal bevacizumab injections (IBIs) were included. Best-corrected visual acuity (BCVA), central subfield macular thickness, and central subfoveal choroidal thickness were evaluated at baseline, 2 months, and 6 months after DEX implantation. Results Patients had undergone an average of 6.32 ± 4.66 prior IBI treatments. The average BCVA improved from 0.53 ± 0.26 to 0.41 ± 0.25 and 0.44 ± 0.23 logarithm of the minimal angle of resolution (logMAR) at 2 and 6 months, respectively (p < 0.001). The average central subfield macular thickness was 504.00 ± 121.54 µm at baseline and changed to 293.21 ± 74.17 µm and 427.28 ± 119.57 µm at 2 and 6 months, respectively (p < 0.001 and p = 0.002). Average central subfoveal choroidal thickness was 237.46 ± 92.21 µm at baseline and changed to 204.75 ± 74.74 µm and 226.86 ± 90.77 µm at 2 and 6 months, respectively (p < 0.001 and p = 0.455). Twenty-two eyes (58%) gained ≥0.1 logMAR at 2 months, while 16 eyes showed no improvement. Low BCVA at symptom presentation, low baseline BCVA, and shorter duration of macular edema were correlated with increased BCVA after treatment. Conclusions The DEX implant improves functional and anatomical outcomes for up to 6 months in about half of the patients treated with IBI refractory macular edema secondary to BRVO, particularly in patients with low initial and baseline BCVA. PMID:28367038

  15. DURIP: Electrokinetic Injection and Separation System for Analysis of Protein and Peptide Transport, Adsorption and Kinetics Instrumentation Proposal

    DTIC Science & Technology

    2015-03-18

    SECURITY CLASSIFICATION OF: We requested equipment necessary to build an electrokinetic injection and separation system for the analysis of protein...Jul-2014 Approved for Public Release; Distribution Unlimited Final Report: DURIP: Electrokinetic Injection and Separation System for Analysis of...Injection and Separation System for Analysis of Protein and Peptide Transport, Adsorption and Kinetics Instrumentation Proposal Report Title We requested

  16. Effect of initial retinal thickness on outcome of intravitreal bevacizumab therapy for diabetic macular edema

    PubMed Central

    Mushtaq, Bushra; Crosby, Niall J; Dimopoulos, Antonios T; Lip, Peck Lin; Stavrou, Panagiota; El-Sherbiny, Samer; Yang, Yit

    2014-01-01

    Purpose To investigate whether eyes with diabetic macular edema (DME) and central retinal thickness (CRT) >400 μm had better visual and anatomical outcomes compared to eyes with a CRT <400 μm when treated with intravitreal bevacizumab in a real-world setting. Patients and methods Patients undergoing intravitreal bevacizumab therapy for DME were identified from the departmental database of a tertiary referral unit. Following the initial injection, a retreatment was performed for any persistent macular edema, unless there had been no previous response to repeated doses. Recorded parameters included visual acuity, CRT on optical coherence tomography (spectral domain optical coherence tomography [SD-OCT]), and SD-OCT characteristics. Comparisons were made between data at baseline and 12 months after the first injection, and differences were tested for statistical significance using the Student’s t-test. Results In all, 175 eyes of 142 patients were analyzed. Patients in group 2 (CRT >400 μm) had significantly more injections than group 1 (CRT <400 μm) (4.0 versus 3.3; P=0.003). Both groups had similar numbers of eyes with preexisting epiretinal membrane and/or vitreomacular traction at baseline. The reduction in CRT was significantly greater in group 2 when compared to group 1 (P<0.0001). In terms of visual gain between baseline and month 12, each gained significantly by a mean of 0.12 logarithm of the minimum angle of resolution units (P=0.0001), but there was no difference between groups 1 and 2 (P=0.99). Conclusion These results do not support a 400 μm baseline CRT cut-off for treating DME with bevacizumab, in contrast to published data on ranibizumab. Our results also indicate that patients with a thicker CRT require more bevacizumab injections, making treatment less cost-effective for these patients. Our results could be used by practitioners to support the use of bevacizumab in DME without applying a CRT cut-off. PMID:24812486

  17. Novel approaches to analysis by flow injection gradient titration.

    PubMed

    Wójtowicz, Marzena; Kozak, Joanna; Kościelniak, Paweł

    2007-09-26

    Two novel procedures for flow injection gradient titration with the use of a single stock standard solution are proposed. In the multi-point single-line (MP-SL) method the calibration graph is constructed on the basis of a set of standard solutions, which are generated in a standard reservoir and subsequently injected into the titrant. According to the single-point multi-line (SP-ML) procedure the standard solution and a sample are injected into the titrant stream from four loops of different capacities, hence four calibration graphs are able to be constructed and the analytical result is calculated on the basis of a generalized slope of these graphs. Both approaches have been tested on the example of spectrophotometric acid-base titration of hydrochloric and acetic acids with using bromothymol blue and phenolphthalein as indicators, respectively, and sodium hydroxide as a titrant. Under optimized experimental conditions the analytical results of precision less than 1.8 and 2.5% (RSD) and of accuracy less than 3.0 and 5.4% (relative error (RE)) were obtained for MP-SL and SP-ML procedures, respectively, in ranges of 0.0031-0.0631 mol L(-1) for samples of hydrochloric acid and of 0.1680-1.7600 mol L(-1) for samples of acetic acid. The feasibility of both methods was illustrated by applying them to the total acidity determination in vinegar samples with precision lower than 0.5 and 2.9% (RSD) for MP-SL and SP-ML procedures, respectively.

  18. Analysis of cause and mechanism for injection-induced seismicityat the Geysers Geothermal Field, California

    SciTech Connect

    Rutqvist, Jonny; Oldenburg, Curtis

    2007-06-14

    We analyzed relative contributions to the cause andmechanism of injection-induced seismicity at The Geysers geothermalfield, California, using coupled thermal-hydrological-mechanicalmodeling. Our analysis shows that the most important cause forinjection-induced seismicity is injection-induced cooling and associatedthermal-elastic shrinkage that changes the stress state in such a waythat mechanical failure and seismicity can be induced. Specifically, thecooling shrinkage results in unloading and associated loss of shearstrength in critically shear-stressed fractures, which are thenreactivated. Thus, our analysis shows that cooling-induced shear slipalong fractures is the dominant mechanism of injection-induced seismicityat The Geysers.

  19. Glioprotection of Retinal Astrocytes After Intravitreal Administration of Memantine in the Mouse Optic Nerve Crush Model

    PubMed Central

    Maciulaitiene, Ruta; Pakuliene, Giedre; Kaja, Simon; Pauza, Dainius Haroldas; Kalesnykas, Giedrius; Januleviciene, Ingrida

    2017-01-01

    Background In glaucoma, non-intraocular pressure (IOP)-related risk factors can result in increased levels of extracellular glutamate, which triggers a cascade of neurodegeneration characterized by the excessive activation of N-methyl-D-aspartate (NMDA). The purpose of our study was to evaluate the glioprotective effects of memantine as a prototypic uncompetitive NMDA blocker on retinal astrocytes in the optic nerve crush (ONC) mouse model for glaucoma. Material/Methods Optic nerve crush was performed on all of the right eyes (n=8), whereas left eyes served as contralateral healthy controls (n=8) in Balb/c/Sca mice. Four randomly assigned mice received 2-μl intravitreal injections of memantine (1 mg/ml) after ONC in the experimental eye. One week after the experiment, optic nerves were dissected and stained with methylene blue. Retinae were detached from the sclera. The tissue was immunostained. Whole-mount retinae were investigated by fluorescent microscopy. Astrocyte counts for each image were performed manually. Results Histological sections of crushed optic nerves showed consistently moderate tissue damage in experimental groups. The mean number of astrocytes per image in the ONC group was significantly lower than in the healthy control group (7.13±1.5 and 10.47±1.9, respectively). Loss of astrocytes in the memantine-treated group was significantly lower (8.83±2.2) than in the ONC group. Assessment of inter-observer reliability showed excellent agreement among observations in control, ONC, and memantine groups. Conclusions The ONC is an effective method for investigation of astrocytic changes in mouse retina. Intravitreally administered memantine shows a promising glioprotective effect on mouse retinal astrocytes by preserving astrocyte count after ONC. PMID:28265105

  20. Long-term follow-up of anatomical and functional macular changes after a single intravitreal implant of dexamethasone 0.7 mg for radiation macular edema secondary to proton beam therapy for choroidal melanoma

    PubMed Central

    Stringa, Francesco; Marzi, Federico; Giannì, Laura; Imparato, Manuela; Bianchi, Alessandro; Bianchi, Paolo Emilio

    2016-01-01

    Purpose To describe the efficacy and safety of a single intravitreal implant of dexamethasone in a patient affected by radiation maculopathy due to proton beam radiotherapy for choroidal melanoma. Patient and methods Retrospective data of a 46-year-old woman treated with a single intravitreal injection of dexamethasone for radiation maculopathy due to proton beam radiotherapy were collected. The main outcome measures were best-corrected visual acuity and central retinal thickness. Intraocular pressure, anterior segment evaluation with slit lamp, macular changes depicted with spectral domain optical coherence tomography, retinal perfusion studied with fundus fluorescein angiography, and grade of macular edema using the Horgan classification were also evaluated during a 16-month follow-up. Results Macular edema occurred 25 months after radiation treatment in the left eye. The patient underwent a single intravitreal implant of dexamethasone. Preinjection visual acuity and central retinal thickness were 6/12 and 502 µm, respectively. After 8 months, visual acuity was 6/6 and remained stable until 16 months. Central retinal thickness was 269 µm at 16 months. Conclusion A single intravitreal implant of dexamethasone could effectively and stably improve visual acuity and central retinal thickness in some patients with radiation macular edema for 16 months after injection. PMID:27942234

  1. Sensitive flow-injection spectrophotometric analysis of bromopride

    NASA Astrophysics Data System (ADS)

    Lima, Liliane Spazzapam; Weinert, Patrícia Los; Pezza, Leonardo; Pezza, Helena Redigolo

    2014-12-01

    A flow injection spectrophotometric procedure employing merging zones is proposed for direct bromopride determination in pharmaceutical formulations and biological fluids. The proposed method is based on the reaction between bromopride and p-dimethylaminocinnamaldehyde (p-DAC) in acid medium, in the presence of sodium dodecyl sulfate (SDS), resulting in formation of a violet product (λmax = 565 nm). Experimental design methodologies were used to optimize the experimental conditions. The Beer-Lambert law was obeyed in a bromopride concentration range of 3.63 × 10-7 to 2.90 × 10-5 mol L-1, with a correlation coefficient (r) of 0.9999. The limits of detection and quantification were 1.07 × 10-7 and 3.57 × 10-7 mol L-1, respectively. The proposed method was successfully applied to the determination of bromopride in pharmaceuticals and human urine, and recoveries of the drug from these media were in the ranges 99.6-101.2% and 98.6-102.1%, respectively. This new flow injection procedure does not require any sample pretreatment steps.

  2. Four-wave mixing analysis on injection-locked quantum dot semiconductor lasers.

    PubMed

    Lin, Chih-Hao; Lin, Fan-Yi

    2013-09-09

    We derive a simplified rate equation model for the four-wave mixing (FWM) analysis on quantum dot (QD) semiconductor lasers subject to optical injection. The regenerative and the amplitude modulation spectra of the FWM signals with different intrinsic laser parameters and external injection conditions are investigated. By curve fitting the regenerative and the amplitude modulation spectra obtained experimentally, the intrinsic parameters of a commercial single-mode QD laser under different injection conditions are extracted. The linewidth enhancement factor α at different injection levels and detunings are shown, where a reduction of up to 39% from its free-running value is demonstrated. By increasing the injection strength, the α can be further reduced to minimized the chirp in optical communications.

  3. Integrated Simulation of an Aspheric Lens Combining Injection Moulding Analysis with Ray Tracing

    NASA Astrophysics Data System (ADS)

    Park, Keun; Joo, Wonjong

    2007-05-01

    The present study covers an integrated simulation method for injection-moulded plastic lenses by combining a ray tracing simulation with a finite element (FE) analysis of injection moulding. Traditional ray tracing methods have based on the assumption that the optical properties of a lens are homogeneous throughout the entire volume. This assumption is to a certain extent unrealistic for injection-moulded plastic lenses because material properties vary at every point due to the injection moulding effects. To take into account the effects of the inhomogeneous optical properties of the moulded lens, a new ray tracing scheme is proposed in conjunction with an FE analysis of the injection moulding. A numerical scheme is developed to estimate the distribution of refractive indices from injection moulding analysis, and to calculate ray paths on every element layer with more realistic information of the refractive indices. A fully three-dimensional FE analysis is then performed for the aspheric lens moulding process. Through the FE analysis, the distribution of the refractive indices of the lens can be obtained on every mesh point. This information is then used to calculate the ray paths based on the FE mesh of which nodal points have unique index values. The proposed tracing scheme is implemented on the tracing of an aspheric lens, and its validity is ascertained through experimental verification.

  4. Sequential injection analysis of ethanol using immobilized alcohol dehydrogenase

    SciTech Connect

    Hedenfalk, M.; Mattiasson, B.

    1996-05-01

    A Sequential Injection (SI) system was used to analyze the ethanol concentration in fermentation broth. The method is based on the use of immobilized NAD{sup +} dependent alcohol dehydrogenase. A non-linear standard curve for ethanol (range 0.25-100 mM) was used to determine the concentration in fermentation broth and the results correlated well with HPLC measurements. The assay time was 140 s, 0.5 {mu}mol of cofactor was used for each determination, and the relative standard deviation was less than 6% when analyzing fermentation samples. The assay system is very stable and makes it possible to reduce the cofactor consumption while keeping the system set up simple.

  5. Performance analysis of the BNL FACE gas injection system

    SciTech Connect

    Lipfert, F.W.; Hendrey, G.R.; Lewin, K.F.; Nagy, J.; Alexander, Y.

    1992-12-31

    As described elsewhere in this volume, the criteria for successful operation of a FACE-type crop fumigation system include the spatial uniformity of the gas injected over the crop growing area, the efficiency of gas usage, and the overall cost of the system. Efficiency of gas usage is important not only from a cost standpoint, but also to reduce the distances required to preclude interference between replicate FACE arrays or control plots. The details of the FACE design and analyses of the important fluid mechanical concepts are described below. A more detailed description of the hardware was given. Additional FACE performance and CO{sub 2} distribution data are given. 7 refs., 25 figs.

  6. A factorial design for optimizing a flow injection analysis system.

    PubMed

    Luna, J R; Ovalles, J F; León, A; Buchheister, M

    2000-05-01

    The use of a factorial design for the response exploration of a flow injection (FI) system is described and illustrated by FI spectrophotometric determination of paraquat. Variable response (absorbance) is explored as a function of the factors flow rate and length of the reaction coil. The present study was found to be useful to detect and estimate any interaction among the factors that may affect the optimal conditions for the maximal response in the optimization of the FI system, which is not possible with a univariate design. In addition, this study showed that factorial experiments enable economy of experimentation and yield results of high precision due to the use of the whole data for calculating the effects.

  7. Sequential-Injection Analysis: Principles, Instrument Construction, and Demonstration by a Simple Experiment

    ERIC Educational Resources Information Center

    Economou, A.; Tzanavaras, P. D.; Themelis, D. G.

    2005-01-01

    The sequential-injection analysis (SIA) is an approach to sample handling that enables the automation of manual wet-chemistry procedures in a rapid, precise and efficient manner. The experiments using SIA fits well in the course of Instrumental Chemical Analysis and especially in the section of Automatic Methods of analysis provided by chemistry…

  8. Efficacy of ondansetron for the prevention of propofol injection pain: a meta-analysis

    PubMed Central

    Pei, Shenglin; Zhou, Chengmao; Zhu, Yu; Huang, Bing

    2017-01-01

    Aim This review was performed to investigate the effect of ondansetron on the prevention of propofol injection pain. Methods PubMed, Cochrane Library, and China National Knowledge Infrastructure (CNKI) were searched for randomized controlled trials (RCTs) of ondansetron in preventing the pain on injection of propofol. Then, RevMan 5.2 was adopted to conduct a meta-analysis on propofol injection pain. Results Ten RCTs, totaling 782 patients, were included in this analysis. The meta-analysis showed that: 1) compared with the control group, the ondansetron group was related to a decreasing incidence of propofol injection pain, and it was statistically significant (risk ratio [RR] = 0.41, 95% confidence interval [CI, 0.34, 0.49], P < 0.00001); 2) compared with the incidence of propofol injection pain in the lidocaine group, there was no difference and no statistical significance (RR = 1.28, 95% CI [0.85, 1.93], P = 0.25); 3) no statistically significant differences were found between the ondansetron and magnesium sulfate groups in the incidence of propofol injection pain (RR = 1.20, 95% CI [0.87, 1.66], P = 0.27); and 4) the incidence of ondansetron group igniting moderate pain (RR = 0.37, 95% CI [0.26, 0.52], P < 0.00001) and severe pain (RR = 0.27, 95% CI [0.17, 0.43] P < 0.00001) was less likely to occur during the injection of propofol compared with the control group, but there was no difference between the ondansetron and control groups in the incidence of mild propofol injection pain (RR = 0.83, 95% CI [0.63, 1.10], P = 0.20). Conclusion Ondansetron can effectively prevent propofol injection pain, and the effect is similar to that of magnesium sulfate and lidocaine. PMID:28260943

  9. A new injection method for soil nutrient analysis in capillary electrophoresis

    NASA Astrophysics Data System (ADS)

    Smolka, M.; Puchberger-Enengl, D.; Bipoun, M.; Fercher, G.; Klasa, A.; Krutzler, C.; Keplinger, F.; Vellekoop, M. J.

    2013-05-01

    We present a new method for the direct injection of liquid sample into a capillary electrophoresis (CE) device. Instead of a double-T injection mechanism, a single inlet provided with a membrane filter is used. From a reservoir on top of this inlet, the liquid directly enters the separation channel through the membrane. The driving force is a short electrical pulse. This avoids an additional sample channel, so that the chip needs only three microfluidic connects and no mechanical sample pumping is demanded. The high injection reproducibility and the comparatively simple setup open up the way for mobile application of soil analysis.

  10. Implementation of terbium-sensitized luminescence in sequential-injection analysis for automatic analysis of orbifloxacin.

    PubMed

    Llorent-Martínez, E J; Ortega-Barrales, P; Molina-Díaz, A; Ruiz-Medina, A

    2008-12-01

    Orbifloxacin (ORBI) is a third-generation fluoroquinolone developed exclusively for use in veterinary medicine, mainly in companion animals. This antimicrobial agent has bactericidal activity against numerous gram-negative and gram-positive bacteria. A few chromatographic methods for its analysis have been described in the scientific literature. Here, coupling of sequential-injection analysis and solid-phase spectroscopy is described in order to develop, for the first time, a terbium-sensitized luminescent optosensor for analysis of ORBI. The cationic resin Sephadex-CM C-25 was used as solid support and measurements were made at 275/545 nm. The system had a linear dynamic range of 10-150 ng mL(-1), with a detection limit of 3.3 ng mL(-1) and an R.S.D. below 3% (n = 10). The analyte was satisfactorily determined in veterinary drugs and dog and horse urine.

  11. Clinical outcomes after injection of a compounded pharmaceutical for prophylaxis after cataract surgery: a large-scale review

    PubMed Central

    Tyson, Sydney L.; Bailey, Robert; Roman, Janika S.; Zhan, Tingting; Hark, Lisa A.; Haller, Julia A.

    2017-01-01

    Purpose of review To evaluate relevant clinical outcomes following a transzonular intravitreal injection of a compounded triamcinolone–moxifloxacin–vancomycin (TMV) formulation for postoperative prophylaxis after cataract surgery in a retrospective review of medical records from a private practice, single-specialty ambulatory center in New Jersey, USA. Recent findings The analysis included 1541 cases from 922 patients who underwent cataract surgery with an intravitreal injection of TMV from November 2013 to December 2014. Cataract surgery was performed by a standard clear corneal phacoemulsification technique. Transzonular injection was used to deliver TMV directly into the anterior vitreous after implantation of an intraocular lens. Summary There were no major intraoperative complications associated with the transzonular injection technique. There were no cases of postoperative endophthalmitis. Nearly 92% of cases (n = 1413/1541) did not require supplemental medication after surgery. The rate of breakthrough inflammation at Days 14–21 was 9.2% (n = 132/1429). The rate of visually significant postoperative cystoid macular edema was 2.0% (n = 28/1429). The rate of clinically significant postoperative intraocular pressure increase was low: 0.9% (n = 13/1425) of cases had an at least 10 mmHg increase at Days 14–21 or 90. Four of these cases had intraocular pressure at least 30 mmHg. The rates of infection and inflammation reported in this retrospective review of a transzonular injection of TMV for prophylaxis after cataract surgery appear similar to reported rates with alternative prophylactic therapies such as topical drops. The transzonular injection of TMV may have advantages in terms of patient compliance. PMID:27653606

  12. Analysis of of Injection-Velocity Effects on Rocket Motor Dynamics and Stability

    NASA Technical Reports Server (NTRS)

    Hurrell, Herbert G.

    1959-01-01

    A concept of combustion time lag that includes dependency on injection velocity is introduced. The concept is used in the formulation of chamber transfer functions and in an analysis of low-frequency combustion instability. Theoretical frequency responses and stability boundaries are compared with those obtained when the injection-velocity effect on the time lag to be an important consideration, in the theory of chamber dynamics and combustion instability

  13. Performance analysis on terahertz optical asymmetric demultiplexer with assist light injection

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Wu, Jian; Lin, Jintong

    2005-12-01

    Operating characteristics of terahertz optical asymmetric demultiplexer (TOAD), under gain and transparent region assist light injection, are investigated in theory. We have analyzed the demultiplexing performance for three OTDM systems: 10, 40, 100 Gb/s. Though the switching window is distorted, the resilience to timing jitter is improved under transparent light injection. In practical application, counter-propagating configuration should be taken. Gain region assist light should not be used in TOAD. Some key parameters are given through numerical analysis and simulations.

  14. Possible migration and histopathological analysis of injections of polymethylmethacrylate in wistar rats.

    PubMed

    Neves, Rodrigo d'Eça; Herdt, Marcello Alberton; Wohlgemuth, Felipe Barbieri; Ely, Jorge Bins; de Vasconcellos, Zulmar Antonio Accioli; Bastos, José Caldeira Ferreira; d'Acampora, Armando José

    2012-01-01

    Objective. To evaluate the possible migration of polymethylmethacrylate after injections in various corporal compartments of Wistar rats. Methods. The experimental work consisted in the injection of PMMA in corporal compartments for later histopathological analysis of the locations of implants and of distant filtering organs. The dose applied in each implant was of 0.2 mL. The animals were divided into groups according to the location of the implant realized: group GB had intradermic injections in the glabella. Group SD had subdermal injections in dorsal subcutaneous tissue cells. Group IP had intraperitoneal injections in the abdomen. Group PD had intramuscular injections in the right rear leg. The rats were sacrificed 30 days after realization of the implants and tissue samples from the lung, liver, spleen, and kidney, and locations of implantation were removed for histopathological analysis. Results. Characteristic microspheres that were compatible with the presence of PMMA in any of the histological slides analyzed were not observed. One animal had an amorphous exogenous substance, with a histiocytic reaction. Twelve of the 16 lungs analyzed had locations of intraalveolar hemorrhaging. Two animals had nonspecific spleen alterations. Conclusion. The histopathological analysis of this study found no PMMA microspheres in any of the tissues analyzed.

  15. Photoreceptor-targeted gene delivery using intravitreally administered AAV vectors in dogs

    PubMed Central

    Boyd, RF; Sledge, DG; Boye, SL; Boye, SE; Hauswirth, WW; Komáromy, AM; Petersen-Jones, SM; Bartoe, JT

    2016-01-01

    Delivery of therapeutic transgenes to retinal photoreceptors using adeno-associated virus (AAV) vectors has traditionally required subretinal injection. Recently, photoreceptor transduction efficiency following intravitreal injection (IVT) has improved in rodent models through use of capsid-mutant AAV vectors; but remains limited in large animal models. Thickness of the inner limiting membrane (ILM) in large animals is thought to impair retinal penetration by AAV. Our study compared two newly developed AAV vectors containing multiple capsid amino acid substitutions following IVT in dogs. The ability of two promoter constructs to restrict reporter transgene expression to photoreceptors was also evaluated. AAV vectors containing the interphotoreceptor-binding protein (IRBP) promoter drove expression exclusively in rod and cone photoreceptors, with transduction efficiencies of ~ 4% of cones and 2% of rods. Notably, in the central region containing the cone-rich visual streak, 15.6% of cones were transduced. Significant regional variation existed, with lower transduction efficiencies in the temporal regions of all eyes. This variation did not correlate with ILM thickness. Vectors carrying a cone-specific promoter failed to transduce a quantifiable percentage of cone photoreceptors. The newly developed AAV vectors containing the IRBP promoter were capable of producing photoreceptor-specific transgene expression following IVT in the dog. PMID:26467396

  16. Photoreceptor-targeted gene delivery using intravitreally administered AAV vectors in dogs.

    PubMed

    Boyd, R F; Sledge, D G; Boye, S L; Boye, S E; Hauswirth, W W; Komáromy, A M; Petersen-Jones, S M; Bartoe, J T

    2016-02-01

    Delivery of therapeutic transgenes to retinal photoreceptors using adeno-associated virus (AAV) vectors has traditionally required subretinal injection. Recently, photoreceptor transduction efficiency following intravitreal injection (IVT) has improved in rodent models through use of capsid-mutant AAV vectors; but remains limited in large animal models. Thickness of the inner limiting membrane (ILM) in large animals is thought to impair retinal penetration by AAV. Our study compared two newly developed AAV vectors containing multiple capsid amino acid substitutions following IVT in dogs. The ability of two promoter constructs to restrict reporter transgene expression to photoreceptors was also evaluated. AAV vectors containing the interphotoreceptor-binding protein (IRBP) promoter drove expression exclusively in rod and cone photoreceptors, with transduction efficiencies of ~4% of cones and 2% of rods. Notably, in the central region containing the cone-rich visual streak, 15.6% of cones were transduced. Significant regional variation existed, with lower transduction efficiencies in the temporal regions of all eyes. This variation did not correlate with ILM thickness. Vectors carrying a cone-specific promoter failed to transduce a quantifiable percentage of cone photoreceptors. The newly developed AAV vectors containing the IRBP promoter were capable of producing photoreceptor-specific transgene expression following IVT in the dog.

  17. Gold nanorods for surface Plasmon resonance detection of mercury (II) in flow injection analysis.

    PubMed

    Trieu, Khang; Heider, Emily C; Brooks, Scott C; Barbosa, Fernando; Campiglia, Andres D

    2014-10-01

    This article investigates the flow injection analysis of mercury (II) ions in tap water samples via surface Plasmon resonance detection. Quantitative analysis of mercury (II) is based on the chemical interaction of metallic mercury with gold nanorods immobilized on a glass substrate. A new flow cell design is presented with the ability to accommodate the detecting substrate in the sample compartment of commercial spectrometers. Two alternatives are here considered for mercury (II) detection, namely stop-flow and continuous flow injection analysis modes. The best limit of detection (2.4 ng mL(-1)) was obtained with the continuous flow injection analysis approach. The accurate determination of mercury (II) ions in samples of unknown composition is demonstrated with a fortified tap water sample.

  18. Longitudinal Analysis of the Relationship Between Perceived Norms and Sharing Injection Paraphernalia

    PubMed Central

    Latkin, Carl A.; Tobin, Karin E.

    2010-01-01

    Despite decline in needle sharing in some countries, many injectors continue to share injection paraphernalia such as cookers and cotton. While individual and structural factors are associated with injection risk behavior, little attention has been given to the influence of social network members, such as norms, on injection paraphernalia sharing. The present study is a longitudinal analysis of the association between perceived norms and sharing syringes and non-syringe injection paraphernalia. Participants were enrolled in the STEP into Action study and reported injection drug use at both baseline and follow-up assessments (n = 398). Results showed that descriptive norms, or believing that peers practiced risky injection behaviors, predicted sharing both syringes and nonsyringe paraphernalia. However, there was no association between injunctive norms (i.e., perceived peer approval) and either syringe or non-syringe paraphernalia sharing. Changing norms may lead to sustained behavior change. Accessible, norms-based interventions are needed to discourage drug injectors from sharing injection paraphernalia. PMID:19148743

  19. Twelve-Month Results of a Single or Multiple Dexamethasone Intravitreal Implant for Macular Edema following Uncomplicated Phacoemulsification

    PubMed Central

    Abdolrahimzadeh, Solmaz; Fenicia, Vito; Maurizi Enrici, Maurizio; Plateroti, Pasquale; Cianfrone, Dora; Recupero, Santi Maria

    2015-01-01

    The clinical efficacy of one or two intravitreal injections of a continued deliverance dexamethasone 700 μg implant in ten patients with persistent macular edema following uncomplicated phacoemulsification was evaluated. Complete ophthalmological examination and spectral domain optical coherence tomography were carried out. Follow-up was at day 7 and months 1, 2, 4, 6, 8, and 12. At baseline mean best corrected visual acuity was 62 Early Treatment Diabetic Retinopathy Study Chart letters, which showed statistically significant improvement at each follow-up, except at month 6, to reach 79 letters at month 12 (P = 0.018). Prior to treatment mean central foveal thickness was 622 μm, which showed statistically significant improvement at each follow-up to reach a mean value of 282 μm (P = 0.012) at month 12. Five patients received a second dexamethasone implant at month 7. Two patients were excluded from the study at months 4 and 8. Intraocular pressure remained stable during the study period with the exception of mild increase in two patients requiring topical therapy. In conclusion there was statistically significant improvement of best corrected visual acuity and mean central foveal thickness with one or two intravitreal dexamethasone implants over 12 months. PMID:26509151

  20. An Ion-Selective Electrode/Flow-Injection Analysis Experiment: Determination of Potassium in Serum.

    ERIC Educational Resources Information Center

    Meyerhoff, Mark E.; Kovach, Paul M.

    1983-01-01

    Describes a low-cost, senior-level, instrumental analysis experiment in which a home-made potassium tubular flow-through electrode is constructed and incorporated into a flow injection analysis system (FIA). Also describes experiments for evaluating the electrode's response properties, examining basic FIA concepts, and determining potassium in…

  1. Detection of Catechol by Potentiometric-Flow Injection Analysis in the Presence of Interferents

    ERIC Educational Resources Information Center

    Lunsford, Suzanne K.; Widera, Justyna; Zhang, Hong

    2007-01-01

    This article describes an undergraduate analytical chemistry experiment developed to teach instrumental lab skills while incorporating common interferents encountered in the real-world analysis of catechol. The lab technique incorporates potentiometric-flow injection analysis on a dibenzo-18-crown-6 dual platinum electrode to detect catechol in…

  2. Fundus spectroscopy and studies in retinal oximetry using intravitreal illumination

    NASA Astrophysics Data System (ADS)

    Salyer, David Alan

    This dissertation documents the development of a new illumination technique for use in the studies of retinal oximetry and fundus spectroscopy. Intravitreal illumination is a technique where the back of the eye is illuminated trans-sclerally using a scanning monochromator coupled into a fiber optic illuminator. Retinal oximetry is the process of measuring the oxygen saturation of blood contained in retinal vessels by quantitative measurement of the characteristic color shift seen as blood oxygen saturation changes from oxygenated blood (reddish) to deoxygenated blood (bluish). Retinal oximetry was first attempted in 1963 but due to a variety of problems with accuracy and difficulty of measurement, has not matured to the point of clinical acceptability or commercial viability. Accurate retinal oximetry relies in part on an adequate understanding of the spectral reflectance characteristics of the fundus. The use of intravitreal illumination allows new investigations into the spectral reflectance properties of the fundus. The results of much research in fundus reflectance and retinal oximetry is detailed in this document, providing new insight into both of these related fields of study. Intravitreal illumination has been used to study retinal vessel oximetry and fundus reflectometry resulting in several important findings that are presented in this document. Studies on enucleated swine eyes have provided new insight into the bidirectional reflectance distribution function of the fundus. Research on live swine has shown accurate measurement of retinal vessel oxygen saturation and provided the first in vivo spectral transmittance measurement of the sensory retina. A secondary discovery during this research suggests that vitrectomy alters the retinal vasculature, an finding that should spawn new research in its own right.

  3. Meta-analysis of Huangqi injection for the adjunctive therapy of aplastic anemia.

    PubMed

    Zhu, Changtai; Gao, Yulu; Jiang, Ting; Hao, Cao; Gao, Zongshuai; Sun, Yongning

    2015-01-01

    Aplastic anemia therapy remains difficult, due to lack of effective treatment regimens. In recent years, Huangqi injection for the adjunctive therapy of aplastic anemia has been reported in many clinical trials. Considering that Huangqi injection may be a novel approach to aplastic anemia treatment, we conducted a meta-analysis of clinical controlled trials to assess the clinical value of Huangqi injection in the treatment of aplastic anemia. We searched the Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Full-text Database (VIP), Wanfang Database, PubMed and EMBASE database to collect the data about the trials of Huangqi injection combined with androgens for treating aplastic anemia. A total of ten studies involving 720 patients with aplastic anemia were included in this study. The meta-analysis showed significant increases in the pool effectiveness rate, white blood cells (WBC), haematoglobin (Hb), platelets (PLT), and reticulocytes (Ret) between the experimental group versus the control group. No severe side effects were found in this study. However, the lower Jadad scores and asymmetric funnel plot degrades the validity of the meta-analysis as the clinical evidence. Therefore, Huangqi injection may significantly enhance the efficacy of androgens for aplastic anemia, suggesting that the novel approach of Chinese traditional medicine combined with Western medicine is promising. The exact outcome required confirmation with rigorously well-designed multi-center trials.

  4. Efficacy of intravitreal dexamethasone implant for prostaglandin-induced refractory pseudophakic cystoid macular edema: case report and review of the literature

    PubMed Central

    Sacchi, Matteo; Villani, Edoardo; Gilardoni, Francesca; Nucci, Paolo

    2014-01-01

    Background Macular edema is a known complication even after uneventful cataract surgery. The chronic use of prostaglandin analogs is a risk factor for the development of pseudophakic cystoid macular edema (CME). Nonsteroidal anti-inflammatory drugs (NSAIDs) are considered first-line therapy but refractory postsurgical CME represents a therapeutic challenge, as there is not an evidence-based treatment. Objective To report the use of a single implant of intravitreal dexamethasone for tafluprost-associated pseudophakic CME refractory to NSAIDs and to sub-Tenon’s corticosteroid injections. Case report A 64-year-old female with ocular hypertension treated with tafluprost experienced decreased vision (visual acuity 20/60) and metamorphopsia 2 months after uneventful cataract extraction. Spectral domain optical coherence tomography (SD-OCT) revealed CME. After 1 month of topical and oral NSAIDs, CME was still evident on SD-OCT (visual acuity 20/50). Two sub-Tenon’s betamethasone injections were performed at a 2-week interval. As CME was still present, 2 months after the diagnosis of CME (visual acuity 20/40), the patient underwent a single dexamethasone intravitreal implant. One month later, macular appearance was normal, and visual acuity increased to 20/30. This result was maintained throughout the 6 months of follow-up. Conclusion In this report, a single implant of intravitreal dexamethasone successfully treated pseudophakic CME associated with the use of prostaglandin analogs unresponsive to NSAIDs and sub-Tenon’s betamethasone. The results of this report need to be corroborated by powered, prospective, randomized trials. The need for repeated treatments as well as the retreatment interval in patients requiring more than a single injection are issues still needing further investigations. PMID:25061272

  5. High-throughput pesticide residue quantitative analysis achieved by tandem mass spectrometry with automated flow injection.

    PubMed

    Nanita, Sergio C; Pentz, Anne M; Bramble, Frederick Q

    2009-04-15

    The use of automated flow injection with MS/MS detection for fast quantitation of agrochemicals in food and water samples was demonstrated in this study. Active ingredients from the sulfonylurea herbicide and carbamate insecticide classes were selected as model systems. Samples were prepared using typical procedures from residue methods, placed in an autosampler, and injected directly into a triple quadrupole instrument without chromatographic separation. The technique allows data acquisition in 15 s per injection, with samples being injected every 65 s, representing a significant improvement from the 15-30 min needed in typical HPLC/MS/MS methods. The availability of HPLC systems is an advantage since they can be used in flow-injection mode (bypassing the column compartment). Adequate accuracy, linearity, and precision (R(2) > 0.99 and RSD < 20%) were obtained using external standards prepared in each control matrix. The limit of quantitation (LOQ) achieved for all analytes was 0.01 mg/kg in food samples and 0.1 ng/mL in water; while limits of detection (LOD) were estimated to be about 0.003 mg/kg and 0.03 ng/mL in food and water, respectively. The advantages and limitations of flow injection MS/MS for ultratrace-level quantitative analysis in complex matrixes are discussed.

  6. Macular laser photocoagulation with or without intravitreal triamcinolone pretreatment for diabetic macular edema: a result from five randomized controlled trials

    PubMed Central

    Liu, Xiang-Dong; Zhou, Xiao-Dong; Wang, Zhi; Shen, Yong-Ming

    2016-01-01

    AIM To assess possible benefits of intravitreal triamcinolone acetonide (IVTA) injection as pretreatment for macular laser photocoagulation (MLP) in patients with diabetic macular edema (DME). METHODS Published randomized controlled trials (RCTs) concerning MLP with or without IVTA pretreatment for DME were retrieved from databases CNKI, Medline, EMbase, Web of Science, and the Cochrane Library. A Meta-analysis on eligible studies was conducted using RevMan 5.0 software. Two investigators independently assessed the quality of the trials and extracted data. Main outcome measures included the change in best corrected visual acuity (BCVA), difference in central macular thickness (CMT) and adverse events reporting in particular elevated intraocular pressure within the follow-up period. The results were pooled using weight mean difference (WMD) or odds risk (OR) with their corresponding 95% confidence intervals (CI). A fixed- or random-effect model was employed depending on the heterogeneity of the inclusion trials. RESULTS Finally, five independent RCTs were identified and used for comparing MLP with IVTA pretreatment (131 eyes) with MLP alone (133 eyes, control group). The overall study quality was relatively higher according to the modified Jadad scale. The Meta-analysis showed that MLP with IVTA pretreatment significantly reduced CMT at one, three and six months (P=0.002, 0.0003 and 0.04, respectively), compared with MLP alone. The IVTA pretreatment group showed statistically significant improvements in BCVA at the one-month follow up as compared with the control group (P=0.03). At three- and six-month follow up, there was a beneficial trend towards improving visual acuity in the IVTA pretreatment group without statistical significance between groups (P=0.06 and 0.20, respectively). The incidence of elevation of intraocular pressure was significantly higher in the IVTA pretreatment group than in the control group (P<0.0001). No evidence of publication bias was

  7. Enhanced sensitivity in flow injection analysis using a long pathlength liquid waveguide capillary flow cell for spectrophotometric detection.

    PubMed

    Zhang, Jia-Zhong

    2006-01-01

    Incorporation of a liquid waveguide capillary flow cell into a flow injection instrument enhances the sensitivity of flow injection analysis with spectrophotometric detection by two orders of magnitude. Nitrite determination at nM levels has been used to demonstrate the feasibility of this novel technique for trace analysis. Combining the long pathlength spectrophotometry with flow injection analysis, this technique has advantages of low detection limit, good precision and high sample throughput.

  8. Efficacy and Safety of Intravitreal Dexamethasone Implants for Treatment of Refractory Diabetic Macular Edema

    PubMed Central

    Eltutar, Kadir; Sultan, Pınar; Erkul, Sezin Ozdogan; Osmanbasoglu, Ozen Ayranci

    2017-01-01

    Purpose To evaluate the safety and efficacy of intravitreal dexamethasone (IVD) implants in eyes with diabetic macular edema that did not respond to previous treatment. Methods We included 46 eyes of 46 patients in this retrospective study. Each month, we recorded patient visual acuity with logarithm of the minimum angle of resolution using the Early Treatment Diabetic Retinopathy Study chart, central macular thickness measurements with optical coherence tomography, intraocular pressure (IOP), and posttreatment complication occurrence. Results The mean follow-up time was 8.95 ± 1.33 months (range, 6 to 12). Best-corrected visual acuity improved significantly in the first 4 months after IVD, but no statistically significant change was observed over the following 2 months. Although a statistically significant decrease in central macular thickness was observed in the first 3 months, the change was not statistically significant in the following 3 months. There was a statistically significant increase in IOP in the first 2 months, but no statistically significant change was observed in the following months. IOP was controlled with medication in all patients with elevated IOP. Of the 26 phakic patients, two had cataracts requiring surgery. Conclusions Cases of refractory diabetic macular edema that did not respond to previous treatment, such as anti-vascular endothelial growth factor injections and laser photocoagulation, exhibited improvements in visual acuity and decreases in retinal thickness after IVD implantation. Both functional and anatomical effects were observed in the first 3 months after injection. Repeat injections and frequent examination might be required for continued improvement. Side effects, such as cataracts and elevation of IOP, may require medical or surgical treatment. PMID:28367039

  9. A Microconduit Flow Injection Analysis Demonstration Using a 35-mm Slide Projector.

    ERIC Educational Resources Information Center

    McKelvie, Ian D.; And Others

    1990-01-01

    Described is a 35mm projector demonstration which combines the advantages a highly magnified view of the sample zone as it undergoes dispersion and the ability to show more than a single-line flow injection analysis manifold. Manufacture and use of the slide for demonstration are discussed. (CW)

  10. Analysis of a laminar boundary layer flow over a flat plate with injection or suction

    NASA Astrophysics Data System (ADS)

    Sadri, S.; Babaelahi, M.

    2013-01-01

    An analysis is performed to study a laminar boundary layer flow over a porous flat plate with injection or suction imposed at the wall. The basic equations of this problem are reduced to a system of nonlinear ordinary differential equations by means of appropriate transformations. These equations are solved analytically by the optimal homotopy asymptotic method (OHAM), and the solutions are compared with the numerical solution (NS). The effect of uniform suction/injection on the heat transfer and velocity profile is discussed. A constant surface temperature in thermal boundary conditions is used for the horizontal flat plate.

  11. Fluocinolone acetonide intravitreal sustained release device – a new addition to the armamentarium of uveitic management

    PubMed Central

    Brumm, Matthew V; Nguyen, Quan Dong

    2007-01-01

    Uveitis is a potentially sight-threatening inflammatory eye disease caused by multiple infectious and non-infectious etiologies for which the standard of care involves corticosteroids or various immunomodulary therapy (IMT) drugs. These available treatments, although effective, may cause significant morbidity and sometimes mortality in uveitis patients due to their toxic side-effects and the necessity of long-term therapy to prevent recurrences. In order to avoid the systemic toxicity of corticosteroids and IMT or the repeated injections of local steroids necessary to control ocular inflammation, and to prevent development of cumulative damage resulting from recurrent episodes of inflammation, researchers have developed a number of local corticosteroid sustained-release devices that can be implanted directly into the vitreous of the eye, at the site of the inflammatory disease. Preliminary studies of such a device, the fluocinolone acetonide (Retisert™) implant, have shown significant reductions in the number of inflammatory episodes and decreased reliance on systemic corticosteroids or other IMT. This review explores the current research evaluating the fluocinolone sustained-release intravitreal implant in the treatment of posterior uveitis and the implications for its future use on a wider scale. PMID:17722513

  12. Recent Development in Optical Chemical Sensors Coupling with Flow Injection Analysis

    PubMed Central

    Ojeda, Catalina Bosch; Rojas, Fuensanta Sánchez

    2006-01-01

    Optical techniques for chemical analysis are well established and sensors based on these techniques are now attracting considerable attention because of their importance in applications such as environmental monitoring, biomedical sensing, and industrial process control. On the other hand, flow injection analysis (FIA) is advisable for the rapid analysis of microliter volume samples and can be interfaced directly to the chemical process. The FIA has become a widespread automatic analytical method for more reasons; mainly due to the simplicity and low cost of the setups, their versatility, and ease of assembling. In this paper, an overview of flow injection determinations by using optical chemical sensors is provided, and instrumentation, sensor design, and applications are discussed. This work summarizes the most relevant manuscripts from 1980 to date referred to analysis using optical chemical sensors in FIA.

  13. Coupled reservoir-geomechanical analysis of CO2 injection and ground deformations at In Salah, Algeria

    SciTech Connect

    Rutqvist, J.; Vasco, D.W.; Myer, L.

    2009-11-01

    In Salah Gas Project in Algeria has been injecting 0.5-1 million tonnes CO{sub 2} per year over the past five years into a water-filled strata at a depth of about 1,800 to 1,900 m. Unlike most CO{sub 2} storage sites, the permeability of the storage formation is relatively low and comparatively thin with a thickness of about 20 m. To ensure adequate CO{sub 2} flow-rates across the low-permeability sand-face, the In Salah Gas Project decided to use long-reach (about 1 to 1.5 km) horizontal injection wells. In an ongoing research project we use field data and coupled reservoir-geomechanical numerical modeling to assess the effectiveness of this approach and to investigate monitoring techniques to evaluate the performance of a CO{sub 2}-injection operation in relatively low permeability formations. Among the field data used are ground surface deformations evaluated from recently acquired satellite-based inferrometry (InSAR). The InSAR data shows a surface uplift on the order of 5 mm per year above active CO{sub 2} injection wells and the uplift pattern extends several km from the injection wells. In this paper we use the observed surface uplift to constrain our coupled reservoir-geomechanical model and conduct sensitivity studies to investigate potential causes and mechanisms of the observed uplift. The results of our analysis indicates that most of the observed uplift magnitude can be explained by pressure-induced, poro-elastic expansion of the 20 m thick injection zone, but there could also be a significant contribution from pressure-induced deformations within a 100 m thick zone of shaly sands immediately above the injection zone.

  14. Intravitreal Bevacizumab with or without Triamcinolone for Refractory Diabetic Macular Edema: Long-term Results of a Clinical Trial

    PubMed Central

    Shoeibi, Nasser; Ahmadieh, Hamid; Entezari, Morteza; Yaseri, Mehdi

    2013-01-01

    Purpose To report the long-term results of intravitreal bevacizumab (IVB) injection alone or combined, at the time of first IVB injection, with intravitreal triamcinolone acetonide (IVT) for treatment of refractory diabetic macular edema (DME). Methods In this randomized clinical trial, 115 eyes of 101 patients with refractory DME were enrolled and randomly assigned to one of the three study arms: the IVB group (41 eyes) received three consecutive injections of 1.25 mg IVB at 6-week intervals; the IVB/IVT group (37 eyes) additionally received 2 mg of IVT at the time of first IVB injection; and the control (sham injection) group. Patients in the IVB and IVB/IVT groups were followed for a mean of 13.3 months and received retreatment with IVB alone whenever indicated. Main outcome measures were best corrected visual acuity (BCVA) and central macular thickness (CMT). Results At the last follow up, CMT decreased significantly in the IVB group (p=0.013) but it was not significant (p=0.13) in the IVB/IVT group. Mean CMT improvement was 91 (95% CI, 20 to 161) microns and 57 (95% CI, -18 to 133) microns in the IVB and IVB/IVT groups, respectively. Mean BCVA improvement from baseline was 0.28 (95% CI, 0.18 to 0.38) logMAR (P=0.017) in the IVB group and 0.19 (95% CI, 0.08 to 0.30) logMAR (P=0.001) in the IVB/IVT group. There was no difference between the two groups in terms of visual improvment (p=0.42). In generalized linear mixed model, only the time interval between the last injection and CMT measurement was statistically significant (P=0.04). The same results were repeated for visual acuity (P=0.03). Conclusion Three loading doses of IVB (added doses if required) have long-term beneficial effects for treatment of refractory DME. Adding triamcinolone to this regimen provides no additional long-term benefit. PMID:23943683

  15. Surface Engineering of Porous Silicon Microparticles for Intravitreal Sustained Delivery of Rapamycin

    PubMed Central

    Nieto, Alejandra; Hou, Huiyuan; Moon, Sang Woong; Sailor, Michael J.; Freeman, William R.; Cheng, Lingyun

    2015-01-01

    Purpose. To understand the relationship between rapamycin loading/release and surface chemistries of porous silicon (pSi) to optimize pSi-based intravitreal delivery system. Methods. Three types of surface chemical modifications were studied: (1) pSi-COOH, containing 10-carbon aliphatic chains with terminal carboxyl groups grafted via hydrosilylation of undecylenic acid; (2) pSi-C12, containing 12-carbon aliphatic chains grafted via hydrosilylation of 1-dodecene; and (3) pSiO2-C8, prepared by mild oxidation of the pSi particles followed by grafting of 8-hydrocarbon chains to the resulting porous silica surface via a silanization. Results. The efficiency of rapamycin loading follows the order (micrograms of drug/milligrams of carrier): pSiO2-C8 (105 ± 18) > pSi-COOH (68 ± 8) > pSi-C12 (36 ± 6). Powder X-ray diffraction data showed that loaded rapamycin was amorphous and dynamic drug-release study showed that the availability of the free drug was increased by 6-fold (compared with crystalline rapamycin) by using pSiO2-C8 formulation (P = 0.0039). Of the three formulations in this study, pSiO2-C8-RAP showed optimal performance in terms of simultaneous release of the active drug and carrier degradation, and drug-loading capacity. Released rapamycin was confirmed with the fingerprints of the mass spectrometry and biologically functional as the control of commercial crystalline rapamycin. Single intravitreal injections of 2.9 ± 0.37 mg pSiO2-C8-RAP into rabbit eyes resulted in more than 8 weeks of residence in the vitreous while maintaining clear optical media and normal histology of the retina in comparison to the controls. Conclusions. Porous silicon–based rapamycin delivery system using the pSiO2-C8 formulation demonstrated good ocular compatibility and may provide sustained drug release for retina. PMID:25613937

  16. Injection blow moulding single stage process: Validation of the numerical simulation through tomography analysis

    NASA Astrophysics Data System (ADS)

    Biglione, Jordan; Béreaux, Yves; Charmeau, Jean-Yves

    2016-10-01

    The injection blow moulding single stage process has been made available on standard injection moulding machine. Both the injection moulding stage and the blow moulding stage are being taken care of in an injection mould. Thus the dimensions of this mould are those of a conventional injection moulding mould. The fact that the two stages are located in the same mould leads to a process more constrained than the conventional one. This process introduces temperature gradients, molecular orientation, high stretch rates and high cooling rates. These constraints lead to a small processing window. In practice, the preform has to remain sufficiently melted to be blown so that the process takes place between the melting temperature and the crystallization temperature. In our numerical approach, the polymer is supposed to be blown in its molten state. Hence we have identified the mechanical behaviour of the polymer in its molten state through dynamical rheology experiments. A viscous Cross model has been proved to be relevant to the problem. Thermal dependence is assumed by an Arrhenius law. The process is simulated through a finite element code (POLYFLOW software) in the Ansys Workbench framework. Thickness measurements using image analysis of tomography data are performed and comparisons with the simulation results show good agreements.

  17. Results and analysis of the TMX electron-beam injection experiments

    SciTech Connect

    Poulsen, P.; Grubb, D.P.

    1980-08-01

    Electron beams (e-beams) were injected into the Tandem Mirror Experiment (TMX) plasma in order to investigate the effect on the ion cyclotron fluctuations of the plasma. The power level of the e-beams was comparable to that of the injected neutral beams. It was found that injection of the e-beams produced no significant effect on the ion cyclotron fluctuations, the measured plasma parameters, or the particle and power flow of the plasma. The increase in bulk electron temperature and the production of mirror-confined electrons found in previous experiments in which e-beams were injected into a mirror-confined plasma were not observed in this experiment. Analysis of the regions and frequencies of wave creation and absorption within the plasma shows that the plasma density and magnetic field profiles through the plasma strongly affect the resonances encountered by the waves. The steep axial density profiles produced by neutral-beam injection in the TMX experiment are not conducive to efficient coupling of the e-beam energy to the plasma.

  18. Corticosteroid versus placebo injection for plantar fasciitis: A meta-analysis of randomized controlled trials

    PubMed Central

    LI, ZONGHUAN; YU, AIXI; QI, BAIWEN; ZHAO, YONG; WANG, WEIYANG; LI, PING; DING, JUNHUI

    2015-01-01

    The aim of this meta-analysis was to determine the efficacy of corticosteroid versus placebo injection for the treatment of plantar fasciitis. Databases (Medline, Embase, the Cochrane Library and Google Scholar) and study references were searched for randomized controlled trials comparing corticosteroid with placebo injection for plantar fasciitis. Studies that met the inclusion criteria were selected for the analysis. The risk of bias tool was used for the methodological assessment. Outcomes including visual analogue score (VAS) and plantar fascia thickness (PFT) were extracted and pooled. Egger's test was used to detect publication bias. The evidence quality was assessed by the Grading of Recommendations Assessment, Development and Evaluation system. Statistical analysis was performed using RevMan 5.2. A total of four studies with 289 patients were included in the analysis. Compared with the placebo, corticosteroid injection provided better pain relief after one month [standardized mean difference (SMD), −0.32; 95% confidence interval (CI), −0.59--0.06); P=0.02). No difference was detected with respect to the VAS after two months (SMD, −0.04; 95% CI, −0.35–0.27; P=0.79) or three months (SMD, −0.42; 95% CI, −1.00–0.16; P=0.15) or to the PFT (MD, 0.70; 95% CI, −1.77–0.38; P=0.20), although a tendency of favoring corticosteroid injection was observed. No obvious publication bias was detected. In conclusion, corticosteroid injection may provide pain relief for a short period of time, but the efficacy may disappear with the progression of time. PMID:26136971

  19. [Treatment of wet AMD with less than 12 injections of Ranibizumab per year].

    PubMed

    Gerding, H

    2010-04-01

    Treatment of acute wet AMD with Ranibizumab effectively stabilizes and improves visual function on a long-term follow-up basis. At present, one of the most important topics of scientific discussion is whether the functional gain in these patients can be achieved and maintained with less than 12 intravitreal injections of Ranibizumab per year. The data available so far is reviewed in this analysis. The present status can be summarized as follows: 1) It seems evident that monthly injections during the first 12 months are functionally more effective than approaches with a reduced number of treatments; 2) the gain obtained during the first three months of Ranibizumab treatment is partially lost towards the end of the year under reduced treatment frequencies; 3) fixed regimens of quarterly injections do not provide any advantage compared to individually indicated re-injections; 4) a trend towards low functional efficacy can be recognised when less than 5 treatments per year are applied; 5) individual loading at the beginning of the treatment does not provide any advantages compared to a fixed loading regimen of 3 injections.

  20. Change in choroidal thickness after intravitreal aflibercept in pretreated and treatment-naive eyes for neovascular age-related macular degeneration

    PubMed Central

    Mazaraki, Kyriaki; Fassnacht-Riederle, Heidi; Blum, Robert; Becker, Matthias; Michels, Stephan

    2015-01-01

    Aim Evaluation of effects of intravitreal aflibercept therapy on choroidal thickness (CT) in neovascular age-related macular degeneration. Methods Retrospective cohort study evaluating the change in CT following a loading dose of three intravitreal aflibercept injections at 4 weeks interval. Pretreated and treatment-naive eyes as well as untreated fellow eyes were evaluated at five retinal locations (subfoveal, 300 and 2500 µm nasal and temporal to the fovea) using spectral domain optical coherence tomography prior to and 4 weeks after a loading dose of three intravitreal aflibercept injections. Results A total of 84 treated eyes (61 pretreated, 23 treatment naive) and 48 fellow eyes were enrolled into the study. Treatment-naive and pretreated eyes showed a significant reduction in CT at all retinal locations. The effect was more pronounced in treatment-naive eyes. In the pretreated group, the mean reduction in CT was greatest at 2500 µm temporal to the fovea at 10.7 µm compared with 22.4 at 300 µm nasal to the fovea in the treatment-naive group. Only the fellow eyes in the treatment-naive group showed a significant CT reduction 12 weeks after initiation of therapy to the partner eye. Conclusions Aflibercept induces a reduction in CT in treatment-naive and pretreated eyes with neovascular age-related macular degeneration. There is some evidence of a systemic effect of aflibercept reflected by CT reduction in untreated fellow eyes. PMID:25877895

  1. Role of implants in the treatment of diabetic macular edema: focus on the dexamethasone intravitreal implant

    PubMed Central

    Cebeci, Zafer; Kir, Nur

    2015-01-01

    Diabetic macular edema (DME) is the leading cause of sight-threatening complication in diabetic patients, and several treatment modalities have been developed and evaluated to treat this pathology. Intravitreal agents, such as anti-vascular endothelial growth factors (anti-VEGF) or corticosteroids, have become more popular in recent years and are widely used for treating DME. Sustained release drugs appear to be mentioned more often nowadays for extending the period of intravitreal activity, and corticosteroids play a key role in inhibiting the inflammatory process in DME. A potent corticosteroid, dexamethasone (Ozurdex®), in the form of an intravitreal implant, has been approved for various ocular etiologies among which DME is also one. This review evaluates the role of implants in the treatment of DME, mainly focusing on the dexamethasone intravitreal implant. PMID:26604809

  2. Efficacy of reduced dose of intravitreal triamcinolone acetonide in a case of active serpiginous choroiditis

    PubMed Central

    Ghose, Avirupa; Bhende, Promod S; Biswas, Jyotirmoy

    2016-01-01

    Active serpiginous choroiditis (SC) is a vision-threatening condition which requires intensive treatment using corticosteroids and/or immunosuppressives, especially if the lesions are involving or encroaching on the macula. Use of oral and intravenous high-dose steroids are contraindicated in uncontrolled diabetics. Intravitreal steroid delivers a localized dose in such situations. This case report highlights the efficacy of reduced dose of intravitreal triamcinolone acetonide (2 mg) in the treatment of active SC. PMID:27853021

  3. The Efficacy of Intravitreal Bevacizumab in Vitreous Hemorrhage of Diabetic Subjects

    PubMed Central

    Alagöz, Cengiz; Yıldırım, Yusuf; Kocamaz, Murat; Baz, Ökkeş; Çiçek, Uğur; Çelik, Burcu; Demirkale, Halil İbrahim; Yazıcı, Ahmet Taylan; Taşkapılı, Muhittin

    2016-01-01

    Objectives: To evaluate the efficacy of intravitreal bevacizumab (IVB) in the resolution of vitreous hemorrhage (VH) secondary to proliferative diabetic retinopathy (PDR). Materials and Methods: Seventy eyes of 70 patients (43 male, mean age 55.6±12.2 years) diagnosed with VH secondary to PDR were evaluated retrospectively. Demographic characteristics of the patients, baseline and final clinical results, and the interventions the patients were subject to were recorded. The patients who received IVB injections (group 1, n=29) were compared to those who did not receive injections (group 2, n=41) in terms of VH clearance time and surgery rates. Results: The mean follow-up time was 14.5±6.1 months in group 1 and 18.4±9.6 months in group 2 (p=0.185). The mean visual acuity was similar between the groups at baseline and at the last visit (for all p>0.05). Panretinal photocoagulation could be applied in 86% of subjects in group 1 and in 58% in group 2 2 within the first month (p=0.016). VH clearance time was not different between the groups (2.3±2.1 months in group 1 and 3.4±2.6 months in group 2, p=0.146). The number of subjects requiring surgery was 7 (24%) in group 1 and 20 (48.8%) in group 2 (p=0.048). Conclusion: IVB was found effective in cases with VH secondary to PDR in terms of reducing the need for surgery and increasing the rate of subjects to whom panretinal photocoagulation could be applied in the early period, although there was no impact on final visual acuity. PMID:28058164

  4. Trace determination of aqueous sulfite, sulfide, and methanethiol by fluorometric flow injection analysis

    SciTech Connect

    Dasgupta, P.K.; Yang, H.C.

    1986-11-01

    Preservation of sulfite, sulfide, and methanethiol in buffered formaldehyde and oxaldihydroxamic acid stabilizers has been studied. Flow injection analysis procedures that involve T mixing or membrane-based reagent introduction have been developed for the fast (24 samples/h) analysis of these anions based upon the reaction with N-acridinylmaleimide in a water-N,N-dimethylformamide medium to form a fluorescent product. Detection limits are 0.04, 0.60, and 0.80 ..mu..M, respectively, for the three sulfur species; differential analysis is possible.

  5. Long-term evaluation of dexamethasone intravitreal implant in vitrectomized and non-vitrectomized eyes with macular edema secondary to non-infectious uveitis

    PubMed Central

    Pelegrín, L; de la Maza, M S; Molins, B; Ríos, J; Adán, A

    2015-01-01

    Purpose To compare dexamethasone (DEX) intravitreal implant effect in non-vitrectomized (non-PPV) vs vitrectomized (PPV) eyes with macular edema (ME) secondary to non-infectious uveitis. Methods Medical records of patients with uveitic ME treated with DEX-intravitreal implant were reviewed. Main outcome measures were changes in central retinal thickness (CRT), best corrected visual acuity (BCVA), intraocular pressure (IOP), vitreous haze and adverse events. Statistical analysis was performed by Longitudinal Linear model using the General Estimating Equation methodology. Results Forty-two eyes of 32 patients were included. Median follow-up time was 18 months (interquartile range (IQR): 12–24). Median CRT showed its maximum decrease at the first month in non-PPV and PPV eyes without statistically significant differences between both groups (P=NS). Median Snellen BCVA, converted to logarithm (LogMAR), showed its maximum improvement at third month in both groups without statistically significant differences between them (P=NS). Median IOP was higher in non-PPV eyes than in PPV eyes from third (P=0.025) to 12th month (P=0.013). Vitreous haze score improved in both groups since first month and showed no differences (P=0.706). Reinjection was performed in 45.2% of eyes at a median time of 5 months IQR: (5–6). Ocular hypertension (47.6%) was the most common adverse event. Conclusions DEX-intravitreal implant for uveitic ME has similar long-term safety profile and good response measured in terms of CRT decrease, BCVA, and vitreous haze improvement in both groups. Non-PPV eyes following DEX-intravitreal implant showed higher IOP increase than PPV eyes, showing the need for close IOP monitoring. PMID:25998942

  6. Optimized and validated flow-injection spectrophotometric analysis of topiramate, piracetam and levetiracetam in pharmaceutical formulations.

    PubMed

    Hadad, Ghada M; Abdel-Salam, Randa A; Emara, Samy

    2011-12-01

    Application of a sensitive and rapid flow injection analysis (FIA) method for determination of topiramate, piracetam, and levetiracetam in pharmaceutical formulations has been investigated. The method is based on the reaction with ortho-phtalaldehyde and 2-mercaptoethanol in a basic buffer and measurement of absorbance at 295 nm under flow conditions. Variables affecting the determination such as sample injection volume, pH, ionic strength, reagent concentrations, flow rate of reagent and other FIA parameters were optimized to produce the most sensitive and reproducible results using a quarter-fraction factorial design, for five factors at two levels. Also, the method has been optimized and fully validated in terms of linearity and range, limit of detection and quantitation, precision, selectivity and accuracy. The method was successfully applied to the analysis of pharmaceutical preparations.

  7. Enzymatic Microreactors for the Determination of Ethanol by an Automatic Sequential Injection Analysis System

    NASA Astrophysics Data System (ADS)

    Alhadeff, Eliana M.; Salgado, Andrea M.; Cos, Oriol; Pereira, Nei; Valdman, Belkis; Valero, Francisco

    A sequential injection analysis system with two enzymatic microreactors for the determination of ethanol has been designed. Alcohol oxidase and horseradish peroxidase were separately immobilized on glass aminopropyl beads, and packed in 0.91-mL volume microreactors, working in line with the sequential injection analysis system. A stop flow of 120 s was selected for a linear ethanol range of 0.005-0.04 g/L±0.6% relative standard deviation with a throughput of seven analyses per hour. The system was applied to measure ethanol concentrations in samples of distilled and nondistilled alcoholic beverages, and of alcoholic fermentation with good performance and no significant difference compared with other analytical procedures (gas chromatography and high-performance liquid chromatography).

  8. Modeling and flow analysis of pure nylon polymer for injection molding process

    NASA Astrophysics Data System (ADS)

    Nuruzzaman, D. M.; Kusaseh, N.; Basri, S.; Oumer, A. N.; Hamedon, Z.

    2016-02-01

    In the production of complex plastic parts, injection molding is one of the most popular industrial processes. This paper addresses the modeling and analysis of the flow process of the nylon (polyamide) polymer for injection molding process. To determine the best molding conditions, a series of simulations are carried out using Autodesk Moldflow Insight software and the processing parameters are adjusted. This mold filling commercial software simulates the cavity filling pattern along with temperature and pressure distributions in the mold cavity. In the modeling, during the plastics flow inside the mold cavity, different flow parameters such as fill time, pressure, temperature, shear rate and warp at different locations in the cavity are analyzed. Overall, this Moldflow is able to perform a relatively sophisticated analysis of the flow process of pure nylon. Thus the prediction of the filling of a mold cavity is very important and it becomes useful before a nylon plastic part to be manufactured.

  9. Preliminary Failure Modes and Effects Analysis of the US Massive Gas Injection Disruption Mitigation System Design

    SciTech Connect

    Lee C. Cadwallader

    2013-10-01

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a candidate design for the ITER Disruption Mitigation System. This candidate is the Massive Gas Injection System that provides machine protection in a plasma disruption event. The FMEA was quantified with “generic” component failure rate data as well as some data calculated from operating facilities, and the failure events were ranked for their criticality to system operation.

  10. Characterization and optimization of low cost microfluidic thread based electroanalytical device for micro flow injection analysis.

    PubMed

    Agustini, Deonir; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

    2017-01-25

    The micro flow injection analysis (μFIA) is a powerful technique that uses the principles of traditional flow analysis in a microfluidic device and brings a number of improvements related to the consumption of reagents and samples, speed of analysis and portability. However, the complexity and cost of manufacturing processes, difficulty in integrating micropumps and the limited performance of systems employing passive pumps are challenges that must be overcome. Here, we present the characterization and optimization of a low cost device based on cotton threads as microfluidic channel to perform μFIA based on passive pumps with good analytical performance in a simple, easy and inexpensive way. The transport of solutions is made through cotton threads by capillary force facilitated by gravity. After studying and optimizing several features related to the device, were obtained a flow rate of 2.2 ± 0.1 μL s(-1), an analytical frequency of 208 injections per hour, a sample injection volume of 2.0 μL and a waste volume of approximately 40 μL per analysis. For chronoamperometric determination of naproxen, a detection limit of 0.29 μmol L(-1) was reached, with a relative standard deviation (RSD) of 1.69% between injections and a RSD of 3.79% with five different devices. Thus, based on the performance presented by proposed microfluidic device, it is possible to overcome some limitations of the μFIA systems based on passive pumps and allow expansion in the use of this technique.

  11. Proton and Helium Injection Into First Order Fermi Acceleration at Shocks: Hybrid Simulation and Analysis

    NASA Astrophysics Data System (ADS)

    Dudnikova, Galina; Malkov, Mikhail; Sagdeev, Roald; Liseykina, Tatjana; Hanusch, Adrian

    2016-10-01

    Elemental composition of galactic cosmic rays (CR) probably holds the key to their origin. Most likely, they are accelerated at collisionless shocks in supernova remnants, but the acceleration mechanism is not entirely understood. One complicated problem is ``injection'', a process whereby the shock selects a tiny fraction of particles to keep on crossing its front and gain more energy. Comparing the injection rates of particles with different mass to charge ratio is a powerful tool for studying this process. Recent advances in measurements of CR He/p ratio have provided particularly important new clues. We performed a series of hybrid simulations and analyzed a joint injection of protons and Helium, in conjunction with upstream waves they generate. The emphasis of this work is on the bootstrap aspects of injection manifested in particle confinement to the shock and, therefore, their continuing acceleration by the self-driven waves. The waves are initially generated by He and protons in separate spectral regions, and their interaction plays a crucial role in particle acceleration. The work is ongoing and new results will be reported along with their analysis and comparison with the latest data from the AMS-02 space-based spectrometer. Work supported Grant RFBR 16-01-00209, NASA ATP-program under Award NNX14AH36G, and by the US Department of Energy under Award No. DE-FG02-04ER54738.

  12. Rapid and non-destructive identification of water-injected beef samples using multispectral imaging analysis.

    PubMed

    Liu, Jinxia; Cao, Yue; Wang, Qiu; Pan, Wenjuan; Ma, Fei; Liu, Changhong; Chen, Wei; Yang, Jianbo; Zheng, Lei

    2016-01-01

    Water-injected beef has aroused public concern as a major food-safety issue in meat products. In the study, the potential of multispectral imaging analysis in the visible and near-infrared (405-970 nm) regions was evaluated for identifying water-injected beef. A multispectral vision system was used to acquire images of beef injected with up to 21% content of water, and partial least squares regression (PLSR) algorithm was employed to establish prediction model, leading to quantitative estimations of actual water increase with a correlation coefficient (r) of 0.923. Subsequently, an optimized model was achieved by integrating spectral data with feature information extracted from ordinary RGB data, yielding better predictions (r = 0.946). Moreover, the prediction equation was transferred to each pixel within the images for visualizing the distribution of actual water increase. These results demonstrate the capability of multispectral imaging technology as a rapid and non-destructive tool for the identification of water-injected beef.

  13. Analysis of cavity pressure and warpage of polyoxymethylene thin walled injection molded parts: Experiments and simulations

    NASA Astrophysics Data System (ADS)

    Guerrier, P.; Tosello, G.; Hattel, J. H.

    2015-05-01

    Process analysis and simulations on molding experiments of 3D thin shell parts have been conducted. Moldings were carried out with polyoxymethylene (POM). The moldings were performed with cavity pressure sensors in order to compare experimental process results with simulations. The warpage was characterized by measuring distances using a tactile coordinate measuring machine (CMM). Molding simulations have been executed taking into account actual processing conditions. Various aspects have been considered in the simulation: machine barrel geometry, injection speed profiles, cavity injection pressure, melt and mold temperatures, material rheological and pvT characterization. Factors investigated for comparisons were: injection pressure profile, short shots length, flow pattern, and warpage. A reliable molding experimental database was obtained, accurate simulations were conducted and a number of conclusions concerning improvements to simulation accuracy are presented regarding: pvT data, mesh, short shots, cavity pressure for process control validation as well as molding machine geometry modelling. Eventually, a methodology for improved molding simulations of cavity injection pressure, filling pattern and warpage was established.

  14. Whole Genome Analysis of Injectional Anthrax Identifies Two Disease Clusters Spanning More Than 13 Years

    PubMed Central

    Keim, Paul; Grunow, Roland; Vipond, Richard; Grass, Gregor; Hoffmaster, Alex; Birdsell, Dawn N.; Klee, Silke R.; Pullan, Steven; Antwerpen, Markus; Bayer, Brittany N.; Latham, Jennie; Wiggins, Kristin; Hepp, Crystal; Pearson, Talima; Brooks, Tim; Sahl, Jason; Wagner, David M.

    2015-01-01

    Government of Germany. This work was supported by funds from the German Ministry of Defense (Sonderforschungsprojekt 25Z1-S-431,214). Support for sequencing was also obtained from Illumina, Inc. These sources had no role in the data generation or interpretation, and had not role in the manuscript preparation. Panel 1: Research in Context Systematic Review We searched PubMed for any article published before Jun. 17, 2015, with the terms “Bacillus anthracis” and “heroin”, or “injectional anthrax”. Other than our previously published work (Price et al., 2012), we found no other relevant studies on elucidating the global phylogenetic relationships of B. anthracis strains associated with injectional anthrax caused by recreational heroin consumption of spore-contaminated drug. There were, however, publically available genome sequences of two strains involved (Price et al., 2012, Grunow et al., 2013) and the draft genome sequence of Bacillus anthracis UR-1, isolated from a German heroin user (Ruckert et al., 2012) with only limited information on the genotyping of closely related strains (Price et al., 2012, Grunow et al., 2013). Lay Person Interpretation Injectional anthrax has been plaguing heroin drug users across Europe for more than 10 years. In order to better understand this outbreak, we assessed genomic relationships of all available injectional anthrax strains from four countries spanning a > 12 year period. Very few differences were identified using genome-based analysis, but these differentiated the isolates into two distinct clusters. This strongly supports a hypothesis of at least two separate anthrax spore contamination events perhaps during the drug production processes. Identification of two events would not have been possible from standard epidemiological analysis. These comprehensive data will be invaluable for classifying future injectional anthrax isolates and for future geographic attribution. PMID:26870786

  15. Salvia miltiorrhiza injection on pulmonary heart disease: a systematic review and meta-analysis.

    PubMed

    Liu, Yu; Huang, Yuhong; Zhao, Caiyan; Qin, Xiude; Zhu, Qinghua; Chen, Sheng; Qu, Jinglai

    2014-01-01

    Cor pulmonale (pulmonary heart disease) is a chronic progressive complicated disease for which treatment needs to be sustained all the time, creating a great financial burden on individuals and society. In order to improve the life quality of cor pulmonale patients and decrease the dosage and quantity of the routine treatment, in China, TCM is often administered to patients with cor pulmonale. The results of many clinical trials have indicated that Salvia miltiorrhiza and complex Salvia miltiorrhiza injection may be an alternative medicine for cor pulmonale. With the purpose to prove whether Salvia miltiorrhiza and complex Salvia miltiorrhiza benefit the cor pulmonale patients, respectively, we carried out a systematic review to evaluate the efficacy and safety of Salvia miltiorrhiza and complex Salvia miltiorrhiza injection in cor pulmonale patients. Overall, 2,715 patients were identified from 35 randomized controlled trials. The meta-analysis used I(2) test for heterogeneity and chose random or fixed model according to heterogeneity of included studies. Clinical outcomes were evaluated by total effectiveness rate, partial pressure of oxygen ( PaO 2) and carbon dioxide ( PaCO 2), hemorheology, mPAP and adverse effects. Compared with routine medicine treatment alone, routine medicine treatment plus Salvia miltiorrhiza or complex Salvia miltiorrhiza injection showed better outcomes: A significantly higher clinical effectiveness rate ratio (p < 0.001), increase in PaO 2 (p < 0.001) and decrease in PaCO 2 (p < 0.001), improvement in hemorheology (p < 0.001), and alleviation in mPAP (p < 0.05). There is no obvious adverse effect reported. In summary, there are some evidences suggesting that Salvia miltiorrhiza or complex Salvia miltiorrhiza injection are active in cor pulmonale, however, the results were limited by the methodological flaws of the included studies. Long-term and high quality clinical trials are needed to provide more conclusive evidence for the future

  16. An intravitreal biodegradable sustained release naproxen and 5-fluorouracil system for the treatment of experimental post-traumatic proliferative vitreoretinopathy

    PubMed Central

    Cardillo, J A; Farah, M E; Mitre, J; Morales, P H; Costa, R A; Melo, L A S; Kuppermann, B; Jorge, R; Ashton, P

    2004-01-01

    Background/aims: To determine the potential of an intravitreal sustained release naproxen and 5-fluorouracil (NA/5-FU) codrug for the treatment of experimental proliferative vitreoretinopathy (PVR) in a model for trauma associated tractional retinal detachment (TRD). Methods: Sustained release pellets were prepared by covalently linking naproxen to 5-fluorouracil. Drug release was tested in vitro and toxic effects were evaluated by electroretinography and light microscopy. Traumatic PVR was induced in pigmented rabbits by performing a scleral laceration, followed by repair and intravitreal injection of 0.4 ml of autologous blood. Thirty six eyes were treated with a sustained release implant containing 1.5 mg NA/5-FU as a codrug and 36 control eyes were submitted to surgery alone. Eyes were evaluated for TRD by serial indirect ophthalmoscope examination at different time points followed by postmortem fundus evaluation of the enucleated eye Results: The NA/5-FU pellets were found to provide linear release of 5-FU and naproxen over the 30 day duration of the in vitro release test. Both the severity of PVR grade and the percentage of eyes with moderate or worse tractional detachment were significantly lower in eyes treated with the codrug pellet. There were no drug related toxic effects evident on histopathological or electroretinograph examination of eyes containing the NA/5-FU pellet. Conclusions: The results suggest that this NA/5-FU codrug device effectively inhibits the progression of PVR in a rabbit trauma model that closely resembles PVR in humans. Additional studies to add knowledge to these initial findings and to clarify the potential of the codrug device for the treatment of human PVR are warranted. PMID:15317716

  17. Determination of Hypochlorite in Bleaching Products with Flower Extracts to Demonstrate the Principles of Flow Injection Analysis

    ERIC Educational Resources Information Center

    Ramos, Luiz Antonio; Prieto, Katia Roberta; Carvalheiro, Eder Tadeu Gomes; Carvalheiro, Carla Cristina Schmitt

    2005-01-01

    The use of crude flower extracts to the principle of analytical chemistry automation, with the flow injection analysis (FIA) procedure developed to determine hypochlorite in household bleaching products was performed. The FIA comprises a group of techniques based on injection of a liquid sample into a moving, nonsegmented carrier stream of a…

  18. Microbial analysis of backflowed injection water from a nitrate-treated North Sea oil reservoir.

    PubMed

    Bødtker, Gunhild; Lysnes, Kristine; Torsvik, Terje; Bjørnestad, Eva Ø; Sunde, Egil

    2009-03-01

    Reservoir souring in offshore oil fields is caused by hydrogen sulphide (H(2)S) produced by sulphate-reducing bacteria (SRB), most often as a consequence of sea water injection. Biocide treatment is commonly used to inhibit SRB, but has now been replaced by nitrate treatment on several North Sea oil fields. At the Statfjord field, injection wells from one nitrate-treated reservoir and one biocide-treated reservoir were reversed (backflowed) and sampled for microbial analysis. The two reservoirs have similar properties and share the same pre-nitrate treatment history. A 16S rRNA gene-based community analysis (PCR-DGGE) combined with enrichment culture studies showed that, after 6 months of nitrate injection (0.25 mM NO(3) (-)), heterotrophic and chemolithotrophic nitrate-reducing bacteria (NRB) formed major populations in the nitrate-treated reservoir. The NRB community was able to utilize the same substrates as the SRB community. Compared to the biocide-treated reservoir, the microbial community in the nitrate-treated reservoir was more phylogenetically diverse and able to grow on a wider range of substrates. Enrichment culture studies showed that SRB were present in both reservoirs, but the nitrate-treated reservoir had the least diverse SRB community. Isolation and characterisation of one of the dominant populations observed during nitrate treatment (strain STF-07) showed that heterotrophic denitrifying bacteria affiliated to Terasakiella probably contributed significantly to the inhibition of SRB.

  19. Reagents regeneration flow injection analysis (RRFIA) for spectrophotometric determination of methamphetamine coupled with solvent extraction.

    PubMed

    Teshima, Norio; Fukui, Nobukazu; Sakai, Tadao

    2005-12-15

    Methamphetamine (MPA), being a stimulant drug, reacts with tetrabromophenolphthalein ethyl ester (TBPEH) to form a red-violet ion associate, TBPEHMPA, in 1,2-dichloroethane (DCE) at pH 9. The maximum absorption wavelength was at 570nm. After measuring, yellow TBPEH with DCE could be regenerated by mixing with the buffer solution at pH 3. The regenerated TBPEH/DCE could be reused as an ion association reagent and extracting solvent. In addition, the reagent regeneration could be performed by the on-line flow injection system and the cyclic flow injection analysis system was demonstrated for the determination of MPA without consumption of ion association reagent and organic solvent. The calibration curve was linear in the range of 0.5-3.5x10(-5)M with good repeatability. The sample throughput was 20h(-1).

  20. Numerical analysis of experiments with gas injection into liquid metal coolant

    NASA Astrophysics Data System (ADS)

    Usov, E. V.; Lobanov, P. D.; Pribaturin, N. A.; Mosunova, N. A.; Chuhno, V. I.; Kutlimetov, A. E.

    2016-10-01

    Presented paper contains results of a numerical analysis of experiments with gas injection in water and liquid metal which have been performed at the Institute of Thermophysics Russian Academy of Science (IT RAS). Obtained experimental data are very important to predict processes that take place in the BREST-type reactor during the hypothetical accident with damage of the steam generator tubes, and may be used as a benchmark to validate thermo-hydraulic codes. Detailed description of models to simulate transport of gas phase in a vertical liquid column is presented in a current paper. Two-fluid model with closing relation for wall friction and interface friction coefficients was used to simulate processes which take place in a liquid during injection of gaseous phase. It has being shown that proposed models allow obtaining a good agreement between experimental data and calculation results.

  1. Development of batch injection analysis for electrochemical measurements of trace metal ions in ecotoxicological test media.

    PubMed

    Brett, C M; Morgado, J M

    2000-01-01

    Batch injection analysis with square-wave anodic stripping voltammetry has been developed as a powerful and rapid technique for obtaining data on the concentration of the fraction of labile metal ions present in media used in ecotoxicological tests. Microlitre samples of solution, without pretreatment, are injected directly over a detector electrode, the surface of which is protected by a thin Nafion polymer coating against irreversible adsorption by organic components. Examples are given showing the effect of adding vitamins and organic extract, singly and together, to the ASTM medium employed for tests using Daphnia magna and with lead and cadmium test ions. Such a methodology can be extended to other electroactive species present in these and similar media.

  2. Analytical solutions and moment analysis of chromatographic models for rectangular pulse injections.

    PubMed

    Qamar, Shamsul; Abbasi, Javeria N; Javeed, Shumaila; Shah, Munawar; Khan, Farman U; Seidel-Morgenstern, Andreas

    2013-11-08

    This work focuses on the analysis of two standard liquid chromatographic models, namely the lumped kinetic model and the equilibrium dispersive model. Analytical solutions, obtained by means of Laplace transformation, are derived for rectangular single solute concentration pulses of finite length and breakthrough curves injected under linear conditions. In order to analyze the solute transport behavior by means of the two models, the temporal moments up to fourth order are calculated from the Laplace-transformed solutions. The limiting cases of continuous injection and negligible mass transfer limitations are evaluated. For validation, the analytical solutions are compared with the numerical solutions of models using the discontinuous Galerkin finite element method. Results of different case studies are discussed for linear and nonlinear adsorption isotherms. The discontinuous Galerkin method is employed to obtain moments for both linear and nonlinear models numerically. Analytically and numerically determined concentration profiles and moments were found to be in good agreement.

  3. Sequential capillary electrophoresis analysis using optically gated sample injection and UV/vis detection.

    PubMed

    Liu, Xiaoxia; Tian, Miaomiao; Camara, Mohamed Amara; Guo, Liping; Yang, Li

    2015-10-01

    We present sequential CE analysis of amino acids and L-asparaginase-catalyzed enzyme reaction, by combing the on-line derivatization, optically gated (OG) injection and commercial-available UV-Vis detection. Various experimental conditions for sequential OG-UV/vis CE analysis were investigated and optimized by analyzing a standard mixture of amino acids. High reproducibility of the sequential CE analysis was demonstrated with RSD values (n = 20) of 2.23, 2.57, and 0.70% for peak heights, peak areas, and migration times, respectively, and the LOD of 5.0 μM (for asparagine) and 2.0 μM (for aspartic acid) were obtained. With the application of the OG-UV/vis CE analysis, sequential online CE enzyme assay of L-asparaginase-catalyzed enzyme reaction was carried out by automatically and continuously monitoring the substrate consumption and the product formation every 12 s from the beginning to the end of the reaction. The Michaelis constants for the reaction were obtained and were found to be in good agreement with the results of traditional off-line enzyme assays. The study demonstrated the feasibility and reliability of integrating the OG injection with UV/vis detection for sequential online CE analysis, which could be of potential value for online monitoring various chemical reaction and bioprocesses.

  4. Clinical evidence of intravitreal triamcinolone acetonide in the management of age-related macular degeneration.

    PubMed

    Becerra, E M; Morescalchi, F; Gandolfo, F; Danzi, P; Nascimbeni, G; Arcidiacono, B; Semeraro, F

    2011-02-01

    Triamcinolone acetonide (TA) is one of the first pharmacologic compounds evaluated for the treatment of choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). The most important effects of TA consist in the stabilisation of the blood-retinal barrier and the down-regulation of inflammation. TA also has anti-angiogenic and anti-fibrotic properties. The peculiar characteristic of being well tolerated by ocular tissues and the capability to remain active for many months after a single intravitreal injection, make this drug a safe and effective alternative. In the past decade, intravitreal injection of TA (IVTA) has emerged as a useful treatment of several ocular diseases such as uveitis, macular edema secondary to retinal vasculature disease, neovascularisation and vitreoretinopathy. In this paper, we review all the available evidence of its use in AMD as mono-therapy or in combination with other treatments, and we discuss which role TA will play in the treatment of AMD in the future. The first experiences with IVTA as monotherapy for the treatment of exudative AMD reported a positive outcome in transiently reducing the leakage from CNV. However, in the long-term follow-up, IVTA as monotherapy had no effect on the risk of severe visual acuity loss, despite a significant anti-angiogenic effect found 3 months after the treatment. Consequently, studies using the combination of IVTA and photodynamic therapy (PDT), which acts synergistically, were performed. They reported to improve vision and to reduce the number of re-treatments with PDT. A large number of publications confirmed the positive synergic role of combining TA and PDT (therapies) for the treatment of all types of CNV: classic or predominantly classic, occult or minimally classic and RAP (Retinal Angiomatous Proliferation) lesions. The advantages registered with the use of IVTA plus PDT compared to PDT alone were partially limited by the side effects, such as the rapid evolution

  5. REDUCTION OF AMYLOID-BETA LEVELS IN MOUSE EYE TISSUES BY INTRA-VITREALLY DELIVERED NEPRILYSIN

    PubMed Central

    Parthasarathy, Rajni; Chow, K. Martin; Derafshi, Zahra; Fautsch, Michael P.; Hetling, John R.; Rodgers, David W.; Hersh, Louis B.; Pepperberg, David R.

    2015-01-01

    Amyloid-beta (Aβ) is a group of aggregation-prone, 38- to 43-amino acid peptides generated in the eye and other organs. Numerous studies suggest that the excessive build-up of low-molecular-weight soluble oligomers of Aβ plays a role in the progression of Alzheimer’s disease and other brain degenerative diseases. Recent studies raise the hypothesis that excessive Aβ levels may contribute also to certain retinal degenerative diseases. These findings, together with evidence that a major portion of Aβ is released as monomer into the extracellular space, raise the possibility that a technology enabling the enzymatic break-down of monomeric Aβ in the living eye under physiological conditions could prove useful for research on ocular Aβ physiology and, perhaps ultimately, for therapeutic applications. Neprilysin (NEP), an endopeptidase known to cleave Aβ monomer into inactive products, is a membrane-associated protein. However, sNEP, a recombinant form of the NEP catalytic domain, is soluble in aqueous medium. With the aim of determining the Aβ-cleaving activity of exogenous sNEP in the microenvironment of the intact eye, we analyzed the effect of intra-vitreally delivered sNEP on ocular Aβ levels in mice that exhibit readily measurable, aqueous buffer-extractable Aβ40 and Aβ42, two principal forms of Aβ. Anesthetized 10-month wild-type (C57BL/6J) and 2–3-month 5XFAD transgenic mice received intra-vitreal injections of sNEP (0.004 – 10 μg) in one eye and were sacrificed at defined post-treatment times (30 min – 12 weeks). Eye tissues (combined lens, vitreous, retina, RPE and choroid) were homogenized in phosphate-buffered saline, and analyzed for Aβ40 and Aβ42 (ELISA) and for total protein (Bradford assay). The fellow, untreated eye of each mouse served as control, and concentrations of Aβ (pmol/g protein) in the treated eye were normalized to that of the untreated control eye. In C57BL/6J mice, as measured at 2 hr after sNEP treatment, increasing

  6. Flow Injection Mass Spectroscopic Fingerprinting and Multivariate Analysis for Differentiation of Three Panax Species

    PubMed Central

    Chen, Pei; Harnly, James M.; Harrington, Peter de B.

    2013-01-01

    This study describes the use of spectral fingerprints acquired by flow injection(FI)-MS and multivariate analysis to differentiate three Panax species: P. ginseng, P. quinquefolius, and P. notoginseng. Data were acquired using both high resolution and unit resolution MS, and were processed using principal component analysis (PCA), soft independent modeling of class analogy (SIMCA), partial least squares-discriminant analysis (PLS-DA), and a fuzzy rule-building expert system (FuRES). Both high and unit resolution MS allowed discrimination among the three Panax species. PLS-DA and FuRES provided classification with 100% accuracy while SIMCA provided classification accuracies of 77 and 88% by high- and low-resolution MS, respectively. The method does not quantify any of the sample components. With FI-MS, the analysis time was less than 2 min. PMID:21391484

  7. Involution patterns of retinopathy of prematurity after treatment with intravitreal bevacizumab: implications for follow-up

    PubMed Central

    Isaac, M; Tehrani, N; Mireskandari, K

    2016-01-01

    Purpose To describe involution patterns following monotherapy with intravitreal bevacizumab injection (IVB) for type 1 retinopathy of prematurity (ROP) in zone I or zone II posterior. Methods A retrospective chart review of infants treated with IVB from January 2010–April 2014. Infants with minimum of 82 weeks postmenstrual age at last follow-up were included. Primary outcome was timing of involution of type 1 ROP for the first 12 weeks post treatment. Secondary outcomes were development of any recurrence and structural outcome at last follow-up. Retinal examination records, fundus, and flourescein angiography images were reviewed. Results Twenty-eight eyes were included. Average follow-up post treatment was 33.9±9.7 months (range 21.4–61.9). Cumulative frequency of regression of plus disease was seen in 73.3, 86.7, and 100% of eyes by days 3, 5, and 8, respectively. Regression of both stage 3 and plus disease was observed in 29, 82, 88, and 100% by weeks 1, 2, 3, and 4, respectively. Within the first 3 months, 17/28 eyes developed recurrence to stage 1 or 2 after regression. None developed recurrence of plus disease. By the end of 3 months 18% of eyes vascularized into zone III. At a mean of 24±17.3 months, 39% of eyes were not vascularized into zone III as seen on flourescein angiography with scleral indentation. Conclusion Our experience suggests regression of plus disease and stage 3 are expected within the first 4 weeks after bevacizumab treatment. Recurrence may occur despite initial regression and requires careful follow-up. PMID:26869159

  8. Aqueous cytokine levels are associated with reduced macular thickness after intravitreal ranibizumab for diabetic macular edema

    PubMed Central

    Kato, Satoshi; Araki, Fumiyuki; Ueta, Takashi; Miyaji, Tempei; Yamaguchi, Takuhiro

    2017-01-01

    Purpose It is controversial whether the administration of anti-vascular endothelial growth factor drugs for diabetic macular edema (DME) affects intraocular inflammatory cytokines. In this study, we measured cytokine concentration in aqueous humor before and after intravitreal injection of ranibizumab (IVR). The aim was to determine changes in cytokine concentration and their effects on DME reduction. Methods Twelve patients (13 eyes) with DME received two IVR (0.5 mg) with a 1 month interval, and a total of 26 aqueous humor samples were obtained. Macular thickness was measured with an optical coherence tomography (OCT) using thickness-map mode with an Early Treatment Diabetic Retinopathy Study (ETDRS) 9-zone grid that was divided into two zones: a central circle with a diameter of 1 mm (zone1); and an outer circle with a diameter of 6 mm (zone2). Results The concentration of eotaxin-1 in aqueous humor samples decreased significantly after IVR. Baseline cytokine concentration was associated with IVR-induced DME reduction. In zone1, higher baseline concentration of interferon-induced protein (IP)-10, and in zone 2, higher baseline concentration of granulocyte-macrophage colony-stimulating factor, IP-10, and tumor necrosis factor (TNF) α; and lower baseline concentration of eotaxin-1, interleukin (IL)-5, and IL-8 were associated with improved DME. Cytokine changes were associated with IVR-induced DME reduction. In zone1, lower concentration of IP-10 compared to baseline or higher concentration of macrophage inflammatory protein (MIP) -α, and in zone 2, lower concentration of IL-5 compared to baseline, IL-8, and IP-10 or higher concentration of eotaxin-1 and MIP-1β were associated with improved DME. Conclusions These findings suggest that ranibizumab affects the concentration of cytokines in aqueous humor. Various cytokines contribute to a decrease in retinal thickness, both in the center of the macula and in a larger area of the retina. PMID:28346545

  9. Planning and Analysis of Fractured Rock Injection Tests in the Cerro Brillador Underground Laboratory, Northern Chile

    NASA Astrophysics Data System (ADS)

    Fairley, J. P., Jr.; Oyarzún L, R.; Villegas, G.

    2015-12-01

    Early theories of fluid migration in unsaturated fractured rock hypothesized that matrix suction would dominate flow up to the point of matrix saturation. However, experiments in underground laboratories such as the ESF (Yucca Mountain, NV) have demonstrated that liquid water can migrate significant distances through fractures in an unsaturated porous medium, suggesting limited interaction between fractures and unsaturated matrix blocks and potentially rapid transmission of recharge to the sat- urated zone. Determining the conditions under which this rapid recharge may take place is an important factor in understanding deep percolation processes in arid areas with thick unsaturated zones. As part of an on-going, Fondecyt-funded project (award 11150587) to study mountain block hydrological processes in arid regions, we are plan- ning a series of in-situ fracture flow injection tests in the Cerro Brillador/Mina Escuela, an underground laboratory and teaching facility belonging to the Universidad la Serena, Chile. Planning for the tests is based on an analytical model and curve-matching method, originally developed to evaluate data from injection tests at Yucca Mountain (Fairley, J.P., 2010, WRR 46:W08542), that uses a known rate of liquid injection to a fracture (for example, from a packed-off section of borehole) and the observed rate of seepage discharging from the fracture to estimate effective fracture aperture, matrix sorptivity, fracture/matrix flow partitioning, and the wetted fracture/matrix interac- tion area between the injection and recovery points. We briefly review the analytical approach and its application to test planning and analysis, and describe the proposed tests and their goals.

  10. An Analysis of Direct-injection spark-ignition (DISI) soot morphology

    SciTech Connect

    Barone, Teresa L; Storey, John Morse; Youngquist, Adam D; Szybist, James P

    2012-01-01

    We have characterized particle emissions produced by a 4-cylinder, 2.0 L DISI engine using transmission electron microscopy (TEM) and image analysis. Analyses of soot morphology provide insight to particle formation mechanisms and strategies for prevention. Particle emissions generated by two fueling strategies were investigated, early injection and injection modified for low particle number concentration emissions. A blend of 20% ethanol and 80% emissions certification gasoline was used for the study given the likelihood of increased ethanol content in widely available fuel. In total, about 200 particles and 3000 primary soot spherules were individually measured. For the fuel injection strategy which produced low particle number concentration emissions, we found a prevalence of single solid sub-25 nm particles and fractal-like aggregates. The modal diameter of single solid particles and aggregate primary particles was between 10 and 15 nm. Solid particles as small as 6 nm were present. Although nanoparticle aggregates had fractal-like morphology similar to diesel soot, the average primary particle diameter per aggregate had a much wider range that spanned from 7 to 60 nm. For the early fuel injection strategy, liquid droplets were prevalent, and the modal average primary particle diameter was between 20 and 25 nm. The presence of liquid droplets may have been the result of unburned fuel and/or lubricating oil originating from fuel impingement on the piston or cylinder wall; the larger modal aggregate primary particle diameter suggests greater fuel-rich zones in-cylinder than for the low particle number concentration point. However, both conditions produced aggregates with a wide range of primary particle diameters, which indicates heterogeneous fuel and air mixing.

  11. Factors Associated with Loss of Penicillin G Concentrations in Serum After Intramuscular Benzathine Penicillin G Injection: A Meta-analysis

    DTIC Science & Technology

    2012-07-01

    Naval Health Research Center Factors Associated With Loss of Penicillin G Concentrations in Serum After Intramuscular Benzathine Penicillin G... Serum After Intramuscular Benzathine Penicillin G Injection: A Meta-analysis 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Concentrations in  Serum  After Intramuscular Benzathine  Penicillin  G Injection:  A Meta-analysis Michael P. Broderick, PhD,* Christian J. Hansen, BS,* and Dennis

  12. Flow injection analysis-isotope ratio mass spectrometry for bulk carbon stable isotope analysis of alcoholic beverages.

    PubMed

    Jochmann, Maik A; Steinmann, Dirk; Stephan, Manuel; Schmidt, Torsten C

    2009-11-25

    A new method for bulk carbon isotope ratio determination of water-soluble samples is presented that is based on flow injection analysis-isotope ratio mass spectrometry (FIA-IRMS) using an LC IsoLink interface. Advantages of the method are that (i) only very small amounts of sample are required (2-5 microL of the sample for up to 200 possible injections), (ii) it avoids complex sample preparation procedures such as needed for EA-IRMS analysis (only sample dilution and injection,) and (iii) high throughput due to short analysis times is possible (approximately 15 min for five replicates). The method was first tested and evaluated as a fast screening method with industrially produced ethanol samples, and additionally the applicability was tested by the measurement of 81 alcoholic beverages, for example, whiskey, brandy, vodka, tequila, and others. The minimal sample concentration required for precise and reproducible measurements was around 50 microL L(-1) ethanol/water (1.71 mM carbon). The limit of repeatability was determined to be r=0.49%. FIA-IRMS represents a fast screening method for beverage authenticity control. Due to this, samples can be prescreened as a decisive criterion for more detailed investigations by HPLC-IRMS or multielement GC-IRMS measurements for a verification of adulteration.

  13. Flow injection analysis of mercury(II) in pharmaceuticals based on enzyme inhibition and biosensor detection.

    PubMed

    Bertocchi, P; Ciranni, E; Compagnone, D; Magearu, V; Palleschi, G; Pirvutoiu, S; Valvo, L

    1999-06-01

    An enzymatic amperometric procedure for measurement of mercury(II) in pharmaceuticals, based on the inhibition of invertase and on a glucose electrode was studied. Analytical parameters for measurements in batch and flow injection analysis (FIA) have been optimised. Mercury(II) was detected in the 10-60 ppb range with RSD < or =2%. A sample throughput of 6 h(-1) for batch and 15 h(-1) for FIA was obtained. The total mercury(II) from thimerosal (thiomersal, sodium ethylmercurithiosalicylate) in eye-drop samples was measured with the amperometric procedure after oxidative cleavage treatment. Results for both batch and FIA procedures correlated well with atomic absorbtion spectroscopy (AAS) data.

  14. Capillary gas chromatographic analysis of nerve agents using large volume injections.

    PubMed

    Degenhardt-Langelaan, C E; Kientz, C E

    1996-02-02

    The use of large volume injections has been studied for the verification of intact organophosphorus chemical warfare agents in water samples. As the use of ethyl acetate caused severe detection problems new potential solvents were evaluated. With the developed procedure, the nerve agents sarin, tabun, soman, DFP and VX can be determined in freshly prepared water samples at ppt levels. Except for the nerve agent tabun all other agents added to the water samples were still present after 8 days at 20-60% levels, if the pH of the water sample is adjusted to ca. 5 shortly after sampling and adjusted to pH 7 for analysis.

  15. Investigation of a chemiluminescent system for the determination of ammonia by flow-injection analysis

    SciTech Connect

    Kraus, P.R.; Crouch, S.R.

    1987-01-01

    A novel system for the determination of ammonia based on the chemiluminescent reaction between hypochlorite and luminol is presented. The technique of flow injection analysis was employed to automate the system. Ammonia reacts with hypochlorite to form monochloramine in basic solution which decreases the observed chemiluminescence intensity. Several interferents are identified, and the reasons why they interfere are discussed. The effects of interferents are minimized through the use of a double-tube dialyzer where the ammonia is diffused across the dialyzer membrane into a recipient stream of hydrochloric acid.

  16. Reservoir characterization based on tracer response and rank analysis of production and injection rates

    SciTech Connect

    Refunjol, B.T.; Lake, L.W.

    1997-08-01

    Quantification of the spatial distribution of properties is important for many reservoir-engineering applications. But, before applying any reservoir-characterization technique, the type of problem to be tackled and the information available should be analyzed. This is important because difficulties arise in reservoirs where production records are the only information for analysis. This paper presents the results of a practical technique to determine preferential flow trends in a reservoir. The technique is a combination of reservoir geology, tracer data, and Spearman rank correlation coefficient analysis. The Spearman analysis, in particular, will prove to be important because it appears to be insightful and uses injection/production data that are prevalent in circumstances where other data are nonexistent. The technique is applied to the North Buck Draw field, Campbell County, Wyoming. This work provides guidelines to assess information about reservoir continuity in interwell regions from widely available measurements of production and injection rates at existing wells. The information gained from the application of this technique can contribute to both the daily reservoir management and the future design, control, and interpretation of subsequent projects in the reservoir, without the need for additional data.

  17. Direct-injection chemiluminescence detector. Properties and potential applications in flow analysis.

    PubMed

    Koronkiewicz, Stanislawa; Kalinowski, Slawomir

    2015-02-01

    We present a novel chemiluminescence detector, with a cone-shaped detection chamber where the analytical reaction takes place. The sample and appropriate reagents are injected directly into the chamber in countercurrent using solenoid-operated pulse micro-pumps. The proposed detector allows for fast measurement of the chemiluminescence signal in stop-flow conditions from the moment of reagents mixing. To evaluate potential applications of the detector the Fenton-like reaction with a luminol-H2O2 system and several transition metal ions (Co(2+), Cu(2+), Cr(3+), Fe(3+)) as a catalyst were investigated. The results demonstrate suitability of the proposed detector for quantitative analysis and for investigations of reaction kinetics, particularly rapid reactions. A multi-pumping flow system was designed and optimized. The developed methodology demonstrated that the shape of the analytical signals strongly depends on the type and concentration of the metal ions. The application of the detector in quantitative analysis was assessed for determination of Fe(III). The direct-injection chemiluminescence detector allows for a sensitive and repeatable (R.S.D. 2%) determination. The intensity of chemiluminescence increased linearly in the range from about 0.5 to 10 mg L(-1) Fe(III) with the detection limit of 0.025 mg L(-1). The time of analysis depended mainly on reaction kinetics. It is possible to achieve the high sampling rate of 144 samples per hour.

  18. Portraying Persons Who Inject Drugs Recently Infected with Hepatitis C Accessing Antiviral Treatment: A Cluster Analysis

    PubMed Central

    Bamvita, Jean-Marie; Roy, Elise; Levesque, Annie; Bruneau, Julie

    2014-01-01

    Objectives. To empirically determine a categorization of people who inject drug (PWIDs) recently infected with hepatitis C virus (HCV), in order to identify profiles most likely associated with early HCV treatment uptake. Methods. The study population was composed of HIV-negative PWIDs with a documented recent HCV infection. Eligibility criteria included being 18 years old or over, and having injected drugs in the previous 6 months preceding the estimated date of HCV exposure. Participant classification was carried out using a TwoStep cluster analysis. Results. From September 2007 to December 2011, 76 participants were included in the study. 60 participants were eligible for HCV treatment. Twenty-one participants initiated HCV treatment. The cluster analysis yielded 4 classes: class 1: Lukewarm health seekers dismissing HCV treatment offer; class 2: multisubstance users willing to shake off the hell; class 3: PWIDs unlinked to health service use; class 4: health seeker PWIDs willing to reverse the fate. Conclusion. Profiles generated by our analysis suggest that prior health care utilization, a key element for treatment uptake, differs between older and younger PWIDs. Such profiles could inform the development of targeted strategies to improve health outcomes and reduce HCV infection among PWIDs. PMID:25349730

  19. Intravitreal injection of a chimeric phage endolysin Ply187 protects mice from Staphylococcus aureus endophthalmitis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives: The treatment of endophthalmitis is becoming very challenging due to the emergence of multidrug-resistant bacteria. Hence, the development of novel therapeutic alternatives for ocular use is essential. Here, we evaluated the therapeutic potential of Ply187AN-KSH3b, a chimeric phage endol...

  20. A simple and rapid method for purification of triamcinolone acetonide suspension for intravitreal injection.

    PubMed

    Hernaez-Ortega, Maria C; Soto-Pedre, Enrique

    2004-01-01

    Purification of triamcinolone acetonide suspension is important to avoid the potential toxic effects of the vehicle. The aim of this article is to describe a simple and rapid technique to remove the vehicle, instead of the long procedure described in the literature. Triamcinolone acetonide suspension was sedimented by density gradient centrifugation. In a few minutes, this new technique yielded a clear supernatant that was easily replaced by a nontoxic sterile solution. More prolonged procedures may not be convenient for unplanned treatments and may also contribute to a greater chance for contamination of the triamcinolone acetonide suspension.

  1. Pneumatic displacement and intra-vitreal bevacizumab in management of sub-retinal and sub-retinal pigment epithelial hemorrhage at macula in polypoidal choroidal vasculopathy (PCV): rationale and outcome.

    PubMed

    Nayak, Sameera; Padhi, Tapas Ranjan; Basu, Soumyava; Das, Taraprasad

    2015-01-01

    We report three cases of submacular haemorrhage due to polypoidal choroidal vasculopathy (PCV) treated with intravitreal bevacizumab and pneumatic displacement with perfluoropropane (C3F8) gas. The patients were between 45 to 55 years and presented with reduction of vision (20/400 to 20/80) within two weeks of onset of symptoms. The submacular (sub-retinal plus sub-retinal pigment epithelium [RPE]) hemorrhages was confirmed as PCV on indocyanine green angiography and optical coherence tomography in all of them. They were treated with intravitreal bevacizumab (1.25 mg/0.05 ml) and 0.3 ml of 100% C3F8 gas in the affected eye followed by prone positioning for two weeks. The vision and macular anatomy started improving within a week and continued up to three months. These cases demonstrate that pneumatic displacement combined with intravitreal anti-VEGF injection could be a promising option in patients with PCV and sub-macular blood, even when the blood is beneath the RPE.

  2. Clinical utility of intravitreal fluocinolone acetonide (Iluvien®) implant in the management of patients with chronic diabetic macular edema: a review of the current literature

    PubMed Central

    Saedon, Habiba; Anand, Astha; Yang, Yit C

    2017-01-01

    The first-line therapy for patients with center-involving diabetic macular edema (DME) is with intravitreal anti-vascular endothelial growth factor (VEGF) agents, with or without adjunctive macular laser treatment. However, a significant proportion of patients have persistent and recurrent edema despite repeated anti-VEGF injections. The fluocinolone acetonide (FA) 190 μg intravitreal implant has been shown in pivotal clinical trials to be efficacious for the treatment of DME and has been approved in many countries for use in patients who have not responded to first-line therapy. In this report, we have collated the latest data from the increasing number of studies to illustrate the pattern of usage of the Iluvien FA implant for DME during the current anti-VEGF era. We have shown that there is now a wealth of published evidence from real-world studies to support the clinical utility of the FA implant in achieving further resolution of edema and improving visual acuity outcomes in this challenging group of patients. PMID:28392675

  3. Instability Analysis of a Low-Density Gas Jet Injected into a High-Density Gas

    NASA Technical Reports Server (NTRS)

    Lawson, Anthony Layiwola

    2001-01-01

    The objective of this study was to determine the effects of buoyancy on the absolute instability of low-density gas jets injected into high-density gas mediums. Most of the existing analyses of low-density gas jets injected into a high-density ambient have been carried out neglecting effects of gravity. In order to investigate the influence of gravity on the near-injector development of the flow, a linear temporal stability analysis and a spatio-temporal stability analysis of a low-density round jet injected into a high-density ambient gas were performed. The flow was assumed to be isothermal and locally parallel; viscous and diffusive effects were ignored. The variables were represented as the sum of the mean value and a normal-mode small disturbance. An ordinary differential equation governing the amplitude of the pressure disturbance was derived. The velocity and density profiles in the shear layer, and the Froude number (signifying the effects of gravity) were the three important parameters in this equation. Together with the boundary conditions, an eigenvalue problem was formulated. Assuming that the velocity and density profiles in the shear layer to be represented by hyperbolic tangent functions, the eigenvalue problem was solved for various values of Froude number. The temporal growth rates and the phase velocity of the disturbances were obtained. It was found that the presence of variable density within the shear layer resulted in an increase in the temporal amplification rate of the disturbances and an increase in the range of unstable frequencies, accompanied by a reduction in the phase velocities of the disturbances. Also, the temporal growth rates of the disturbances were increased as the Froude number was reduced (i.e. gravitational effects increased), indicating the destabilizing role played by gravity. The spatio-temporal stability analysis was performed to determine the nature of the absolute instability of the jet. The roles of the density ratio

  4. Flow injection analysis of picric acid explosive using a copper electrode as electrochemical detector.

    PubMed

    Junqueira, João R C; de Araujo, William R; Salles, Maiara O; Paixão, Thiago R L C

    2013-01-30

    A simple and fast electrochemical method for quantitative analysis of picric acid explosive (nitro-explosive) based on its electrochemical reduction at copper surfaces is reported. To achieve a higher sample throughput, the electrochemical sensor was adapted in a flow injection system. Under optimal experimental conditions, the peak current response increases linearly with picric acid concentration over the range of 20-300 μmol L(-1). The repeatability of the electrode response in the flow injection analysis (FIA) configuration was evaluated as 3% (n=10), and the detection limit of the method was estimated to be 6.0 μmol L(-1) (S/N=3). The sample throughput under optimised conditions was estimated to be 550 samples h(-1). Peroxide explosives like triacetone triperoxide (TATP) and hexamethylene triperoxide diamine (HMTD) were tested as potential interfering substances for the proposed method, and no significant interference by these explosives was noticed. The proposed method has interesting analytical parameters, environmental applications, and low cost compared with other electroanalytical methods that have been reported for the quantification of picric acid. Additionally, the possibility to develop an in situ device for the detection of picric acid using a disposable sensor was evaluated.

  5. Knee Viscosupplementation: Cost-Effectiveness Analysis between Stabilized Hyaluronic Acid in a Single Injection versus Five Injections of Standard Hyaluronic Acid.

    PubMed

    Estades-Rubio, Francisco J; Reyes-Martín, Alvaro; Morales-Marcos, Victor; García-Piriz, Mercedes; García-Vera, Juan J; Perán, Macarena; Marchal, Juan A; Montañez-Heredia, Elvira

    2017-03-17

    Given the wide difference in price per vial between various presentations of hyaluronic acid, this study seeks to compare the effectiveness and treatment cost of stabilized hyaluronic acid (NASHA) in a single injection with standard preparations of hyaluronic acid (HA) in five injections in osteoarthritis (OA) of the knee. Fifty-four patients with knee osteoarthritis (Kellgren-Lawrence Grade II and III) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score greater than 7, with a homogeneous distribution of age, sex, BMI, and duration of disease, were included in this study. Patients were randomized into two groups: Group I was treated with NASHA (Durolane(®)) and Group II with HA (Go-ON(®)). Patient's evolution was followed up at the 1st, 2nd, 4th, 8th, 12th, and 26th week after treatment. A statistically significant improvement in WOMAC score was observed for patients treated with NASHA versus those who received HA at Week 26. In addition, the need for analgesia was significantly reduced at Week 26 in the NASHA-treated group. Finally, the economic analysis showed an increased cost of overall treatment with HA injections. Our data support the use of the NASHA class of products in the treatment of knee OA.

  6. Knee Viscosupplementation: Cost-Effectiveness Analysis between Stabilized Hyaluronic Acid in a Single Injection versus Five Injections of Standard Hyaluronic Acid

    PubMed Central

    Estades-Rubio, Francisco J.; Reyes-Martín, Alvaro; Morales-Marcos, Victor; García-Piriz, Mercedes; García-Vera, Juan J.; Perán, Macarena; Marchal, Juan A.; Montañez-Heredia, Elvira

    2017-01-01

    Given the wide difference in price per vial between various presentations of hyaluronic acid, this study seeks to compare the effectiveness and treatment cost of stabilized hyaluronic acid (NASHA) in a single injection with standard preparations of hyaluronic acid (HA) in five injections in osteoarthritis (OA) of the knee. Fifty-four patients with knee osteoarthritis (Kellgren–Lawrence Grade II and III) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score greater than 7, with a homogeneous distribution of age, sex, BMI, and duration of disease, were included in this study. Patients were randomized into two groups: Group I was treated with NASHA (Durolane®) and Group II with HA (Go-ON®). Patient’s evolution was followed up at the 1st, 2nd, 4th, 8th, 12th, and 26th week after treatment. A statistically significant improvement in WOMAC score was observed for patients treated with NASHA versus those who received HA at Week 26. In addition, the need for analgesia was significantly reduced at Week 26 in the NASHA-treated group. Finally, the economic analysis showed an increased cost of overall treatment with HA injections. Our data support the use of the NASHA class of products in the treatment of knee OA. PMID:28304363

  7. Analysis of the injection process in direct injected natural gas engines. Part 1: Study of unconfined and in-cylinder plume behavior

    SciTech Connect

    Jennings, M.J.; Jeske, F.R. )

    1994-10-01

    A study of natural gas (NG) direct injection (DI) processes has been performed using multidimensional computational fluid dynamics analysis. The purpose was to improve the understanding of mixing in DI NG engines. Calculations of injection into a constant-volume chamber were performed to document unconfined plume behavior. A full three-dimensional calculation of injection into a medium heavy-duty diesel engine cylinder was also performed to study plume behavior in engine geometries. The structure of the NG plume is characterized by a core of unmixed fuel confined to the near-field of the jet. This core contains the bulk of the unmixed fuel and is mixed by the turbulence generated by the jet shear layer. The NG plume development in the engine is dominated by combustion chamber surface interactions. A Coanda effect causes plume attachment to the cylinder head, which has a detrimental impact on mixing. Unconfined plume calculations with different nozzle hole sizes demonstrate that smaller nozzle holes are more effective at mixing the fuel and air.

  8. Flow Injection Analysis of 5-(Hydroxymethyl)-2-furaldehyde in Honey by a Modified Winkler Method.

    PubMed

    Castoldi, Karine; Milani, Maria Izabel; Rossini, Eduardo L; Pezza, Leonardo; Pezza, Helena R

    2016-01-01

    One of the quality indicators for honey is 5-(hydroxymethyl)-2-furaldehyde (HMF), which is formed during the heating or aging of honey. The International Honey Commission recommends three methods for the determination of HMF in honey: the Winkler method, the White method, and determination by HPLC. The Winkler method uses the carcinogenic substance p-toluidine, which is not in accordance with the principles of Green Chemistry. The present work describes the determination of HMF in honey by flow injection analysis (FIA) using a modified Winkler method, replacing p-toluidine with p-aminobenzoic acid. The linear range was 1.00 to 40.0 mg L(-1), the limit of detection (LOD) was 0.43 mg L(-1), and the limit of quantification (LOQ) was 1.32 mg L(-1). The method is an efficient and environmentally friendly technique for the analysis of HMF in honey.

  9. Relativistic performance analysis of a high current density magnetron injection gun

    SciTech Connect

    Barnett, L. R.; Luhmann, N. C. Jr.; Chiu, C. C.; Chu, K. R.

    2009-09-15

    Electron beam quality is essential to the performance of millimeter-wave gyroamplifiers, particularly the gyrotron traveling-wave tube amplifier, which is extremely sensitive to the electron velocity spread and emission uniformity. As one moves up in power and frequency, the quality of the electron beam becomes even more critical. One aspect of the electron beam formation technology which has received relatively little attention has been the performance analysis of the electron beam itself. In this study, a 100 kV, 8 A magnetron injection gun with a calculated perpendicular-to-parallel velocity ratio of 1.4 and axial velocity spread of 3.5% has been designed, tested, and analyzed. It is shown that the equipment precision and a fully relativistic data analysis model afford sufficient resolution to allow a verification of the theoretical predictions as well as a quantitative inference to the surface roughness of the cathode used.

  10. Health-related quality of life, visual function and treatment satisfaction following intravitreal dexamethasone implant for diabetic macular edema

    PubMed Central

    Ramu, Jayashree; Chatziralli, Irini; Yang, Yit; Menon, Geeta; Bailey, Clare; Eckstein, Michael; Hykin, Phil; Sivaprasad, Sobha

    2017-01-01

    Purpose The aim of this study was to explore and describe quantitatively patient-reported outcome measures (PROMs), ie, health-related quality of life (QoL), visual function and treatment satisfaction, in patients with diabetic macular edema (DME) receiving two different regimens of Ozurdex (intravitreal dexamethasone implant). Methods In this multicenter, prospective study, 100 patients with center-involving refractory DME were randomized 1:1 to either five monthly fixed dosing or optical coherence tomography (OCT)-guided pro re nata (PRN) regimen of dexamethasone intravitreal implant therapy. The primary outcome was the difference between arms in change in PROMs and health-related QoL from baseline to 12 months, as measured by the Retinopathy-Dependent Quality of Life (RetDQoL) questionnaire, Visual Function Questionnaire-25 (VFQ-25) and Retinopathy Treatment Satisfaction Questionnaire (RetTSQ). Results There was no statistically significant difference in the RetDQoL score and VFQ-25 score at month 12 compared to those at baseline, whereas the total mean RetTSQ score increased significantly at the exit visit. The two treatment arms did not differ significantly regarding the change in PROMs and health-related QoL questionnaires. Logistic regression analysis showed that visual acuity (VA) of ≥55 letters, central foveal thickness <300 μm and macular volume <9.2 mm3 at the exit visit (month 12) predicted a higher change in RetTSQ. Conclusion This study showed that there is a statistically significant improvement in treatment satisfaction, as measured by RetTSQ, in patients with DME treated with dexamethasone intravitreal implant, independent of the dose regimen, namely, fixed or PRN. However, it should be noted that the clinically meaningful change could not be assessed accurately, since no thresholds for clinically meaningful change currently exist for the RetTSQ. On the other hand, there was no significant change in health-related QoL, as measured using VFQ-25

  11. Effect of endothelial progenitor cells derived from human umbilical cord blood on oxygen-induced retinopathy in mice by intravitreal transplantation

    PubMed Central

    Wang, Dan; Zhang, Bo; Shi, Hui; Yang, Wei; Bi, Ming-Chao; Song, Xiang-Fu; Zhang, Chen; Cheng, Jian-Hui; Hao, Ji-Long; Song, E

    2016-01-01

    AIM To investigate the effect of endothelial progenitor cells (EPCs) labeled by carboxy fluorescein diacetate succinimidyl ester (CFSE) on murine oxygen-induced retinopathy (OIR) by intravitreal transplantation. METHODS After isolated from human umbilical cord blood mononuclear cells, EPCs were cultivated and then labeled with CFSE in vitro. C57BL/6J mice were placed to 75% hyperoxia chamber from P7 to P12 to establish OIR model. At P12, OIR mice were intravitreally injected with 1 µL suspension contained 2×105 EPCs (EPCs group) or isometric phosphate buffered saline (PBS group). The contralateral eye of each mice received no injection (OIR group). Evans blue angiography and frozen section were examined to track the labeled cells in OIR group at P15 and P19. Using retina paraffin sections and adenosinediphos phatase staining at P12 and P19, the effect of EPCs on OIR mice was evaluated quantitatively and qualitatively. RESULTS The retinas from EPCs group with less non-perfusion area and fewer peripheral tufts were observed at P19, comparing with that from PBS or OIR group. The retinopathy in EPCs group receded earlier with less non-ganglion cells and neovascular nuclei, together with relatively regular distribution. The counts of the neovascular nuclei at P19 were reduced by 44% or 45%, compared with those of OIR group or PBS group respectively. Three days after EPCs injection, a large number of EPCs appeared in the vitreous cavity and adhered to the retinal surface. While at one week, the cells gathered between the internal plexiform layer and the inner limiting membrane, and some EPCs appeared in retinal vessels. CONCLUSION EPCs transplantation can participate in the reparative procedure of the neovascularization in OIR. PMID:27990359

  12. Early treatment of acute submacular haemorrhage secondary to wet AMD using intravitreal tissue plasminogen activator, C3F8, and an anti-VEGF agent.

    PubMed

    de Silva, S R; Bindra, M S

    2016-07-01

    PurposeAcute submacular haemorrhage secondary to wet age-related macular degeneration (AMD) has a poor prognosis for which there is currently no 'gold standard' treatment. We evaluated the efficacy of early treatment using intravitreal triple therapy of tissue plasminogen activator (tPA), expansile gas, and an anti-VEGF agent.MethodsThis retrospective case series included eight patients presenting with acute submacular haemorrhage involving the fovea. All patients received treatment with 50 μg (0.05 ml) tPA, 0.3 ml 100% perfluoropropane (C3F8), and an anti-VEGF agent (0.05 mg Ranibizumab or 1.25 mg Bevacizumab in 0.05 ml) administered via intravitreal injection. An anterior chamber paracentesis post injection or vitreous tap was performed before injection to prevent retinal vascular occlusion secondary to raised intra-ocular pressure. Outcomes assessed were visual acuity, change in macular morphology, and complications.ResultsPatients presented promptly with delay between symptom onset and clinic review being 1.9±0.6 days (mean±SD). Treatment was delivered quickly with interval from presentation to treatment being 1.1±1.2 days. Symptom onset to treatment was 3.0±1.0 days. Subfoveal haemorrhage was effectively displaced in all patients. LogMAR visual acuity improved from 1.67±0.47 at presentation to 0.63±0.33 at final follow-up (P<0.0001), a mean of 7.9±4.8 months after treatment. Central retinal thickness improved from 658.1±174.2 μm at presentation to 316.6±142.4 μm at final follow-up (P=0.0028).ConclusionsEarly treatment of submacular haemorrhage using intravitreal tPA, C3F8, and anti-VEGF was effective in significantly improving visual acuity in this series of patients who presented soon after symptom onset. Treatment was well tolerated in this group of elderly and potentially frail patients.

  13. Estimating maximum sustainable injection pressure duringgeological sequestration of CO2 using coupled fluid flow andgeomechanical fault-slip analysis

    SciTech Connect

    Rutqvist, J.; Birkholzer, J.; Cappa, F.; Tsang, C.-F.

    2006-10-17

    This paper demonstrates the use of coupled fluid flow andgeomechanical fault slip (fault reactivation) analysis to estimate themaximum sustainable injection pressure during geological sequestration ofCO2. Two numerical modeling approaches for analyzing faultslip areapplied, one using continuum stress-strain analysis and the other usingdiscrete fault analysis. The results of these two approaches to numericalfault-slip analyses are compared to the results of a more conventionalanalytical fault-slip analysis that assumes simplified reservoirgeometry. It is shown that the simplified analytical fault-slip analysismay lead to either overestimation or underestimation of the maximumsustainable injection pressure because it cannot resolve importantgeometrical factors associated with the injection induced spatialevolution of fluid pressure and stress. We conclude that a fully couplednumerical analysis can more accurately account for the spatial evolutionof both insitu stresses and fluid pressure, and therefore results in amore accurate estimation of the maximum sustainable CO2 injectionpressure.

  14. An unusual presentation of nonarteritic ischemic optic neuropathy with subretinal fluid treated with intravitreal bevacizumab

    PubMed Central

    Dave, Vivek Pravin; Pappuru, Rajeev R

    2016-01-01

    A 62-year-old hypertensive male presented with acute nonarteritic ischemic optic neuropathy (NAION) with contiguous macular edema and subretinal fluid in the right eye. Presenting vision was 20/1000. The patient was treated with intravitreal bevacizumab 1.25 mg/0.05 ml. At 1 month follow-up, the macular edema and the optic nerve head edema completely resolved with a good visual improvement up to 20/40. The visual improvement was maintained at the last follow-up 6 months postinjection. Intravitreal bevacizumab may be a good option for acute NAION especially in an unusual presentation with macular edema and subretinal fluid. PMID:26953030

  15. Improving treatment provision of Wet AMD with intravitreal ranibizumab.

    PubMed

    Ghazala, Fadi; Hovan, Marta; Mahmood, Sajjad

    2013-01-01

    Wet age-related macular degeneration (AMD) treatment using intravitreal ranibizumab needs to be started as soon as possible and treatment must be administered based on regular review to achieve the best results. In clinical practice this tight schedule is a challenge and methods of carrying out such timely treatment is the objective of this quality improvement work. A departmental audit was carried out on the service providing treatment for patients with wet AMD in 2009. This audit identified that the appointment system did not meet the ideal standards and subsequently wet AMD patients' visual outcome were poorer than the standard set in trials where the patients were seen and treated at predetermined intervals. In order to enhance the visual benefit of the administered therapy for our patients we thought it necessary to find ways to see and treat patients sooner as well as reduce time intervals between follow-up appointments. The quality improvement was carried out through redesigning the service in the macular treatment centre of Manchester Royal Eye Hospital. Three main strategies were implemented including: changes to the appointment system, expansion of the treatment facility and employment of additional staff. Following changes made, regular re-audits were used to analyse the effectiveness of the new strategies. The changes introduced have brought appointment standards to the level of Royal College of Ophthalmologists' recommendations. Consequently visual outcomes were approaching the standards set by landmark studies. The visual improvement of treated patients seen in the 2011 audit are comparable to other reports outside clinical trials in the UK. In order to enhance the efficacy of ranibizumab for wet AMD it is essential for treatment to be initiated as soon as possible and administered to patients at the recommended time intervals. The actions we have taken were effective in helping develop a service performing to higher standards.

  16. Flow, spray and combustion analysis by laser techniques in the combustion chamber of a direct-injection diesel engine

    NASA Astrophysics Data System (ADS)

    Hentschel, W.; Schindler, K.-P.

    1996-12-01

    The purpose of this paper is to show how the analysis of in -cylinder flow, fuel injection, and combustion by means of state-of-the-art optical techniques, as laser light-sheet, laser doppler anemometry and laser shadowgraphy, can help to support the understanding of the interaction of swirl flow development, spray formation, auto-ignition and combustion in near production-line direct-injection diesel engines and thus advances the development of engines with lower fuel consumption and emissions.

  17. Suprachoroidal delivery in a rabbit ex vivo eye model: influence of drug properties, regional differences in delivery, and comparison with intravitreal and intracameral routes

    PubMed Central

    Kadam, Rajendra S.; Williams, Jason; Tyagi, Puneet; Edelhauser, Henry F.

    2013-01-01

    Purpose First, to determine the influence of drug lipophilicity (using eight beta-blockers) and molecular weight (using 4 kDa and 40 kDa fluoroscein isothiocyanate [FITC]-dextrans) on suprachoroidal delivery to the posterior segment of the eye by using a rabbit ex vivo eye model. Second, to determine whether drug distribution differs between the dosed and undosed side of the eye following suprachoroidal delivery. Third, to compare the suprachoroidal delivery of sodium fluorescein (NaF) with the intracameral and intravitreal routes by using noninvasive fluorophotometry. Methods Using a small hypodermic 26G needle (3/8”) with a short bevel (250 µm), location of the suprachoroidal injection in an ex vivo New Zealand white rabbit eye model was confirmed with India ink. Ocular tissue distribution of NaF (25 µl of 1.5 µg/ml) at 37 °C was monitored noninvasively using the Fluorotron MasterTM at 0, 1, and 3 h following suprachoroidal, intravitreal, or intracameral injections in ex vivo rabbit eyes. For assessing the influence of lipophilicity and molecular size, 25 µl of a mixture of eight beta-blockers (250 µg/ml each) or FITC-dextran (4 kDa and 40 kDa, 30 mg/ml) was injected into the suprachoroidal space of excised rabbit eyes and incubated at 37 °C. Eyes were incubated for 1 and 3 h, and frozen at the end of incubation. Ocular tissues were isolated in frozen condition. Beta-blocker and FITC-dextran levels in excised ocular tissue were measured by liquid chromatography–tandem mass spectrometry and spectrofluorometry, respectively. Results Histological sections of India ink-injected albino rabbit eye showed the localization of dye as a black line in the suprachoroidal space. Suprachoroidal injection of NaF showed signal localization to the choroid and retina at 1 and 3 h post injection when compared with intravitreal and intracameral injections. Drug delivery to the vitreous after suprachoroidal injection decreased with an increase in solute lipophilicity

  18. Automated multiple flow-injection analysis in clinical chemistry: determination of total protein with Biuret reagent.

    PubMed

    Shideler, C E; Stewart, K K; Crump, J; Wills, M R; Savory, J; Renoe, B W

    1980-09-01

    We have examined the feasibility of the automated multiple flow-injection technique for application to clinical chemistry by adapting to this system the biuret method for the determination of total protein. Samples were discretely and rapidly introduced into a continuously flowing, nonsegmented reagent stream by means of an automatic sampler and high-pressure injection valve. Pumps operating at 1380-2070 kPa (200-300 psi) were utilized to introduce the biuret reagent and saline diluent into the system separately at flow rates of 72 and 47 microL/s, respectively. Use of 20-microL sample and a 3.0-s reaction-delay coil was adequately sensitive for analysis for total protein by this method. Samples were analyzed at a rate of 150/h with no detectable between-sample carryover. Within-run precision studies yielded relative standard deviations of 2.5% and less. Total protein values obtained by this method correlated well with those obtained by centrifugal analyzer and bubble-segmented continuous-flow biuret methods.

  19. Titration of strong and weak acids by sequential injection analysis technique.

    PubMed

    Maskula, S; Nyman, J; Ivaska, A

    2000-05-31

    A sequential injection analysis (SIA) titration method has been developed for acid-base titrations. Strong and weak acids in different concentration ranges have been titrated with a strong base. The method is based on sequential aspiration of an acidic sample zone and only one zone of the base into a carrier stream of distilled water. On their way to the detector, the sample and the reagent zones are partially mixed due to the dispersion and thereby the base is partially neutralised by the acid. The base zone contains the indicator. An LED-spectrophotometer is used as detector. It senses the colour of the unneutralised base and the signal is recorded as a typical SIA peak. The peak area of the unreacted base was found to be proportional to the logarithm of the acid concentration. Calibration curves with good linearity were obtained for a strong acid in the concentration ranges of 10(-4)-10(-2) and 0.1-3 M. Automatic sample dilution was implemented when sulphuric acid at concentration of 6-13 M was titrated. For a weak acid, i.e. acetic acid, a linear calibration curve was obtained in the range of 3x10(-4)-8x10(-2) M. By changing the volumes of the injected sample and the reagent, different acids as well as different concentration ranges of the acids can be titrated without any other adjustments in the SIA manifold or the titration protocol.

  20. Sexual and injection-related risks in Puerto Rican-born injection drug users living in New York City: A mixed-methods analysis

    PubMed Central

    2011-01-01

    Background These data were collected as part of the National HIV Behavioral Surveillance (NHBS) study. NHBS is a cross-sectional study to investigate HIV behavioral risks among core risk groups in 21 U.S. cities with the highest HIV/AIDS prevalence. This analysis examines data from the NHBS data collection cycle with IDU conducted in New York City in 2009. We explored how the recency of migration from Puerto Rico (PR) to New York City (NYC) impacts both syringe sharing and unprotected sex among injection drug users (IDU) currently living in NYC. Methods We used a mixed-methods approach to examine differences in risk between US-born IDU, PR IDU who migrated to NYC more than three years ago (non-recent migrants), and PR IDU who migrated in the last three years (recent migrants). Respondent-driven sampling (RDS) was used to recruit the sample (n = 514). In addition, qualitative individual and group interviews with recent PR migrants (n = 12) and community experts (n = 2) allowed for an in-depth exploration of the IDU migration process and the material and cultural factors behind continued risk behaviors in NYC. Results In multiple logistic regression controlling for confounding factors, recent migrants were significantly more likely to report unprotected sexual intercourse with casual or exchange partners (adjusted odds ratio [AOR]: 2.81; 95% confidence intervals [CI]: 1.37-5.76) and receptive syringe sharing (AOR = 2.44; 95% CI: 1.20-4.97) in the past year, compared to US-born IDU. HIV and HCV seroprevalence were highest among non-recent migrants. Qualitative results showed that risky injection practices are partly based on cultural norms acquired while injecting drugs in Puerto Rico. These same results also illustrate how homelessness influences risky sexual practices. Conclusions Poor material conditions (especially homelessness) may be key in triggering risky sexual practices. Cultural norms (ingrained while using drugs in PR) around injection drug use are

  1. Simultaneous determination of phosphate and silicate in waste water by sequential injection analysis.

    PubMed

    Mas-Torres, F; Munõz, A; Estela, J M; Cerdà, V

    1997-10-01

    A sequential injection analysis system for the simultaneous determination of phosphate and silicate in waste water is proposed. The method is based on the formation of yellow vanadomolybdophosphate and molybdosilicate, respectively, in addition to the use of large sample volumes. The mutual interference between both analytes was eliminated by selection of the appropriate acidity and by sample segmentation with oxalic acid. The calibration graph for phosphate and silicate is linear up to 12 mg l-1 P and 30 mg l-1 Si, respectively. The detection limits are 0.2 mg l-1 P and 0.9 mg l-1 Si. The method provides a throughput of 23 samples h-1 with a relative standard deviation < 1.4% for phosphate and < 4% for silicate. The method was found to be suitable for the determination of these species in waste water samples.

  2. Lightning strike simulation using coaxial line technique and 3D linear injection current analysis

    NASA Astrophysics Data System (ADS)

    Flourens, F.; Gauthier, D.; Serafin, D.

    1989-09-01

    The GORFFD code for determining aircraft responses to either a lightning event or to simulated current injection is based on the finite-difference solution of Maxwell's equation, and allows the simulation of complex, 3D metallic and dielectric composite structures. A transfer method is used to analyze the EM environment associated with in-flight measurements. Attention is given to a linear-analysis numerical model in which the lightning channel is simulated as a thin wire that is driven by a current source. Surface E-fields and current mappings are produced for the Transall transport and Mirage fighter aircraft. An experimental method has been devised for verification of these lightning-strike simulations.

  3. Selective determination of chlorine dioxide using gas diffusion flow injection analysis

    SciTech Connect

    Hollowell, D.A.; Pacey, G.E.; Gordon, G.

    1985-12-01

    An automated absorbance technique for the determination of aqueous chlorine dioxide has been developed by utilizing gas diffusion flow injection analysis. A gas diffusion membrane is used to separate the donor (sampling) stream from the acceptor (detecting) stream. The absorbance of chlorine dioxide is monitored at 359 nm. The first method uses distilled water as the acceptor stream and gives a detection limit of 0.25 mg/L chlorine dioxide. This system is over 550 times more selective for chlorine dioxide than chlorine. To further minimize chlorine interference, oxalic acid is used in the acceptor stream. The detection limit for this system is 0.45 mg/L chlorine dioxide. This second system is over 5400 times more selective for chlorine dioxide than chlorine. Both methods show excellent selectivity for chlorine dioxide over iron and manganese compounds, as well as other oxychlorinated compounds such as chlorite and perchlorate ions. 18 references, 7 figures, 3 tables.

  4. Analysis of active components in Salvia miltiorrhiza injection based on vascular endothelial cell protection.

    PubMed

    Shen, Jie; Yang, Kai; Sun, Caihua; Zheng, Minxia

    2014-09-01

    Correlation analysis based on chromatograms and pharmacological activities is essential for understanding the effective components in complex herbal medicines. In this report, HPLC and measurement of antioxidant properties were used to describe the active ingredients of Salvia miltiorrhiza injection (SMI). HPLC results showed that tanshinol, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, protocatechuic acid and their metabolites in rat serum may contribute to the efficacy of SMI. Assessment of antioxidant properties indicated that differences in the composition of serum powder of SMI caused differences in vascular endothelial cell protection. When bivariate correlation was carried out it was found that salvianolic acid B, tanshinol and protocatechuic aldehyde were active components of SMI because they were correlated to antioxidant properties.

  5. Bienzymatic Biosensor for Rapid Detection of Aspartame by Flow Injection Analysis

    PubMed Central

    Radulescu, Maria-Cristina; Bucur, Bogdan; Bucur, Madalina-Petruta; Radu, Gabriel Lucian

    2014-01-01

    A rapid, simple and stable biosensor for aspartame detection was developed. Alcohol oxidase (AOX), carboxyl esterase (CaE) and bovine serum albumin (BSA) were immobilised with glutaraldehyde (GA) onto screen-printed electrodes modified with cobalt-phthalocyanine (CoPC). The biosensor response was fast. The sample throughput using a flow injection analysis (FIA) system was 40 h−1 with an RSD of 2.7%. The detection limits for both batch and FIA measurements were 0.1 μM for methanol and 0.2 μM for aspartame, respectively. The enzymatic biosensor was successfully applied for aspartame determination in different sample matrices/commercial products (liquid and solid samples) without any pre-treatment step prior to measurement. PMID:24412899

  6. Analysis of petroleum-contaminated water by GC/FID with direct aqueous injection

    SciTech Connect

    Potter, T.L.

    1996-11-01

    A direct aqueous injection capillary gas chromatography/flame ionization (GC/FID) procedure for the analysis of petroleum-contaminated water was developed and applied to seven water samples saturated with different petroleum products. Separation of C{sub 1} to C{sub 4} alcohols, C{sub 6} to C{sub 9} monoaromatics, MTBE, phenol, aniline, and other compounds, and the detection of BTEX compounds at concentrations at or below their maximum contaminant levels (MCLs) is reported. Among the test compounds analyzed, the only pair found to coelute were 1-butanol and benzene. A method for confirmation of alcohols and polar compounds in the presence of dissolved petroleum hydrocarbons was also evaluated. In this case, water samples were analyzed before and after purging. Polar compounds were found to be significant components of the water soluble fractions of commercial petroleum products.

  7. Modeling sorbent injection for mercury control in baghouse filters: I--model development and sensitivity analysis.

    PubMed

    Flora, Joseph R V; Hargis, Richard A; O'Dowd, William J; Pennline, Henry W; Vidic, Radisav D

    2003-04-01

    A two-stage mathematical model for Hg removal using powdered activated carbon injection upstream of a baghouse filter was developed, with the first stage accounting for removal in the ductwork and the second stage accounting for additional removal caused by the retention of carbon particles on the filter. The model shows that removal in the ductwork is minimal, and the additional carbon detention time from the entrapment of the carbon particles in the fabric filter enhances the Hg removal from the gas phase. A sensitivity analysis on the model shows that Hg removal is dependent on the isotherm parameters, the carbon pore radius and tortuosity, the C/Hg ratio, and the carbon particle radius.

  8. Bienzymatic biosensor for rapid detection of aspartame by flow injection analysis.

    PubMed

    Radulescu, Maria-Cristina; Bucur, Bogdan; Bucur, Madalina-Petruta; Radu, Gabriel Lucian

    2014-01-09

    A rapid, simple and stable biosensor for aspartame detection was developed. Alcohol oxidase (AOX), carboxyl esterase (CaE) and bovine serum albumin (BSA) were immobilised with glutaraldehyde (GA) onto screen-printed electrodes modified with cobalt-phthalocyanine (CoPC). The biosensor response was fast. The sample throughput using a flow injection analysis (FIA) system was 40 h⁻¹ with an RSD of 2.7%. The detection limits for both batch and FIA measurements were 0.1 µM for methanol and 0.2 µM for aspartame, respectively. The enzymatic biosensor was successfully applied for aspartame determination in different sample matrices/commercial products (liquid and solid samples) without any pre-treatment step prior to measurement.

  9. Determination of cyanide by a flow injection analysis-atomic absorption spectrometric method.

    PubMed

    López Gómez, A V; Martínez Calatayud, J

    1998-10-01

    A new flow injection analysis (FIA) procedure is proposed for the indirect atomic absorption spectrometric determination of cyanide. The FIA manifold is based on the insertion of the sample into a distilled water carrier, then the sample flows through a solid-phase reactor filled with silver iodide entrapped in polymeric resin beads. The calibration graph is linear over the range 0.2-6.0 mg l-1 of cyanide (correlation coefficient 0.9974), the detection limit is 0.1 mg l-1, the sample throughput is 193 h-1 and the RSD is 0.8%. The method is simple, quick and more selective than other published FIA procedures. The reproducibility obtained by using different solid-phase reactors and solutions is in the range 2.2-3.1% (RSD). The method was applied to the determination of cyanide in commercial samples such as pharmaceutical formulations and industrial electrolytic baths.

  10. Selective chlorine dioxide determination using gas-diffusion flow injection analysis with chemiluminescent detection

    SciTech Connect

    Hollowell, D.A.; Gord, J.R.; Gordon, G.; Pacey, G.E.

    1986-06-01

    An automated chemiluminescent technique has been developed utilizing the advantages of gas-diffusion flow injection analysis. A gas-diffusion membrane separates the donor (sampling) stream from the acceptor (detecting) stream and removes ionic interferences. A novel chemiluminescence flow-through detector cell is used to measure the concentration of chlorine dioxide as a function of the intensity of the chemiluminescence produced from its reaction with luminol. The chemiluminescent reagent merges with the analyte directly in front of the photomultiplier tube in order to maximize the sensitivity of the system. The detection limit for chlorine dioxide is approximately 5 ppb. The method is over 1500 times more selective for chlorine dioxide than for chlorine on a mole basis. This method eliminates interference from iron and manganese compounds, as well as other oxychlorinated compounds such as chlorite ion and chlorate ion.

  11. Analysis of flushing injection performance in a reciprocating plunger slurry pump

    SciTech Connect

    Not Available

    1984-01-01

    One of the major machinery problems encountered during operation of the Exxon Coal Liquefaction Pilot Plant was the relatively short life of the packing in the coal slurry reciprocating plunger pump. The cause of the short packing life was wear created by coal particles. Flushing oil was injected in the throat bushing on a portion of the plunger stroke to limit coal intrusion. To understand the effect of flush oil injection and the effect of the various pump design parameters on the flushing system, a mathematical model was developed by which the fluid dynamics of the throat bushing/plunger annulus could be analyzed. The transient equations of motion were solved numerically to yield the fluid velocity profile and the path of a given coal particle. The pressure gradient was evaluated iteratively from the imposed net flow rate condition which accounted for the flushing and leakage flow rates. Utilizing the model, a comparison was made between suction synchronized flushing and discharge synchronized flushing for various assumed leakage rates. The analysis showed that suction synchronized flushing was superior to discharge synchronized flushing. When the model was applied to ECLP's slurry pumps, it was found that for the pump with a throat bushing clearance length of 2.5 inches, the solids would enter the packing for practically any leakage rate. This was in good agreement with ECLP field experience. For the pump with a throat bushing clearance length of eight inches, the analysis indicated that at leakage rates as high as five gallons per hour solids would still not have entered the packing area. This was also in good agreement with ECLP field experience. Thus, it seems that the analytical model can be used in evaluating various design parameters as well as serving as a design tool for full scale slurry pumps.

  12. Quantum analysis and experimental investigation of the nondegenerate optical parametric oscillator with unequally injected signal and idler

    NASA Astrophysics Data System (ADS)

    Wang, Ning; Li, Yongmin

    2016-01-01

    We developed a quantum analysis of the nondegenerate optical parametric oscillator (NOPO) with unequally injected signal and idler. Both the steady-state output field and the two-mode quantum correlation spectrum are investigated under the condition of different injected idler-to-signal ratios (ISRs) and the relative phase between the pump and the injected seed. It is found that when the seed is injected through the output coupler, the NOPO allows for the robust generation of two-mode quantum entanglement even if the relative phase is free running and the ISR is as high as 0.7. At the specific relative phase of zero, a high degree of entanglement can exist across a whole range of ISRs. An experimental study of the NOPO with unequal seeds is presented, and the observed results verify the theoretical predictions.

  13. Polydrug use and HIV risk among people who inject heroin in Tijuana, Mexico: A Latent class analysis

    PubMed Central

    Meacham, M.C.; Rudolph, A.E.; Strathdee, S.A.; Rusch, M.L.; Brouwer, K.C.; Patterson, T.L.; Vera, A.; Rangel, G.; Roesch, S.C.

    2016-01-01

    Background Although most people who inject drugs (PWID) in Tijuana, Mexico, primarily inject heroin, injection and non-injection use of methamphetamine and cocaine is common. We examined patterns of polydrug use among heroin injectors to inform prevention and treatment of drug use and its health and social consequences. Methods Participants were PWID residing in Tijuana aged ≥ 18 years who reported heroin injection in the past 6 months and were recruited through respondent driven sampling (n=1025). Latent class analysis was conducted to assign individuals to classes on a probabilistic basis, using four indicators of past 6 month polydrug and polyroute use: cocaine injecting, cocaine smoking or snorting, methamphetamine injecting, methamphetamine smoking or snorting. Latent class membership was regressed onto covariates in a multinomial logistic regression. Results Latent class analyses testing 1, 2, 3, and 4 classes were fit, with the 3-class solution fitting best. Class 1 was defined by predominantly heroin use (50.2%, n=515); class 2 by methamphetamine and heroin use (43.7%, n=448), and class 3 by methamphetamine, cocaine, and heroin use (6.0%, n=62). Bivariate and multivariate analyses indicated a group of methamphetamine and cocaine users that exhibited higher risk sexual practices and lower heroin injecting frequency, and a group of methamphetamine users who were younger and more likely to be female. Conclusions Discrete subtypes of heroin PWID were identified based on methamphetamine and cocaine use patterns. These findings have identified subtypes of heroin injectors who require more tailored interventions to reduce the health and social harms of injecting drug use. PMID:26444185

  14. Analysis of Injection-Induced Micro-Earthquakes in a Geothermal Steam Reservoir, The Geysers Geothermal Field, California

    SciTech Connect

    Rutqvist, Jonny; Rutqvist, J.; Oldenburg, C.M.

    2008-05-15

    In this study we analyze relative contributions to the cause and mechanism of injection-induced micro-earthquakes (MEQs) at The Geysers geothermal field, California. We estimated the potential for inducing seismicity by coupled thermal-hydrological-mechanical analysis of the geothermal steam production and cold water injection to calculate changes in stress (in time and space) and investigated if those changes could induce a rock mechanical failure and associated MEQs. An important aspect of the analysis is the concept of a rock mass that is critically stressed for shear failure. This means that shear stress in the region is near the rock-mass frictional strength, and therefore very small perturbations of the stress field can trigger an MEQ. Our analysis shows that the most important cause for injection-induced MEQs at The Geysers is cooling and associated thermal-elastic shrinkage of the rock around the injected fluid that changes the stress state in such a way that mechanical failure and seismicity can be induced. Specifically, the cooling shrinkage results in unloading and associated loss of shear strength in critically shear-stressed fractures, which are then reactivated. Thus, our analysis shows that cooling-induced shear slip along fractures is the dominant mechanism of injection-induced MEQs at The Geysers.

  15. Perspective on the role of Ozurdex (dexamethasone intravitreal implant) in the management of diabetic macular oedema

    PubMed Central

    Mehta, Hemal; Gillies, Mark

    2015-01-01

    Diabetic macular oedema (DMO) is the most common cause of visual loss in the working age population. Intravitreal therapy has superseded macular laser as the first-line treatment for the management of centre-involving DMO in most patients. As well as the proven efficacy of intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents, phase II and III clinical trials of Ozurdex intravitreal dexamethasone implants for DMO have also demonstrated a mean increase in visual acuity and corresponding mean reduction in central macular thickness, particularly in pseudophakic eyes. Because of the risk of visual loss from cataract, glaucoma and intraocular infection with the use of intravitreal steroids, Ozurdex tends to be reserved for use in patients unresponsive to anti-VEGF therapy for centre-involving DMO. Situations where Ozurdex may be considered a first-line treatment option for eyes with centre-involving DMO include pseudophakia, impending cataract surgery, or in the context of a recent arterial thromboembolic event. Because of their stable pharmacokinetics, Ozurdex slow-release implants may also be considered in vitrectomized eyes. PMID:26336592

  16. Intravitreal Ampicillin Sodium for Antibiotic-Resistant Endophthalmitis: Streptococcus uberis First Human Intraocular Infection Report

    PubMed Central

    Velez-Montoya, Raul; Rascón-Vargas, Dulce; Mieler, William F.; Fromow-Guerra, Jans; Morales-Cantón, Virgilio

    2010-01-01

    Purpose. To describe the clinical characteristics, diagnosis, and treatment with intravitreal ampicillin sodium of a postoperative endophthalmitis case due to Streptococcus uberis; an environmental pathogen commonly seen in mastitis cases of lactating cows. Methods. Case Report. A 52-year-old, Hispanic diabetic patient who suddenly developed severe pain and severe loss of vision, following vitrectomy. Results. The patient was diagnosed with postoperative endophthalmitis secondary to a highly resistant strain of Streptococcus uberis that did not respond to intravitreal antibiotics. He was treated with an air-fluid interchange, anterior chamber washout, intravitreal ampicillin sodium (5 mg/0.1 mL), and silicon oil tamponade (5000 ck). The eye was anatomically stabilized, though there was no functional recovery. Conclusion. Streptococcus uberis is an uncommon pathogen to the human eye, which has unique features that help the strain in developing resistance to antibiotics. While treatment with intravitreal ampicillin is feasible, there are still concerns about its possible toxicity. PMID:20706679

  17. Risk of Tractional Retinal Detachment Following Intravitreal Bevacizumab Along with Subretinal Fluid Drainage and Cryotherapy for Stage 3B Coats’ Disease

    PubMed Central

    Bhat, Vishalakshi; D’Souza, Palmeera; Shah, Parag K.; Narendran, V.

    2016-01-01

    Purpose: To review the surgical outcomes of intravitreal bevacizumab (IVB) along with subretinal fluid drainage with cryotherapy in patients with stage 3B Coats’ disease. Materials and Methods: A retrospective study of seven cases of stage 3B Coats’ disease, who underwent subretinal fluid drainage with cryopexy, from May 2011 to March 2014. Five eyes received additional IVB at the end of surgery. Green laser therapy was performed on telangiectatic vessels postoperatively. Results: The mean age was 34 months (range, 10-84 months). Mean follow-up was 19 months. Six patients (85.7%) had an attached retina at final follow-up. Three out of four patients (75%) that received IVB developed tractional retinal detachments (TRDs). Two eyes that did not receive bevacizumab did not develop any traction. None progressed to neovascular glaucoma or phthisis bulbi. Conclusion: Simultaneous injection of bevacizumab along with subretinal drainage and cryotherapy for advanced Coats’ disease could not avoid TRD. PMID:27162454

  18. Emerging flow injection mass spectrometry methods for high-throughput quantitative analysis.

    PubMed

    Nanita, Sergio C; Kaldon, Laura G

    2016-01-01

    Where does flow injection analysis mass spectrometry (FIA-MS) stand relative to ambient mass spectrometry (MS) and chromatography-MS? Improvements in FIA-MS methods have resulted in fast-expanding uses of this technique. Key advantages of FIA-MS over chromatography-MS are fast analysis (typical run time <60 s) and method simplicity, and FIA-MS offers high-throughput without compromising sensitivity, precision and accuracy as much as ambient MS techniques. Consequently, FIA-MS is increasingly becoming recognized as a suitable technique for applications where quantitative screening of chemicals needs to be performed rapidly and reliably. The FIA-MS methods discussed herein have demonstrated quantitation of diverse analytes, including pharmaceuticals, pesticides, environmental contaminants, and endogenous compounds, at levels ranging from parts-per-billion (ppb) to parts-per-million (ppm) in very complex matrices (such as blood, urine, and a variety of foods of plant and animal origin), allowing successful applications of the technique in clinical diagnostics, metabolomics, environmental sciences, toxicology, and detection of adulterated/counterfeited goods. The recent boom in applications of FIA-MS for high-throughput quantitative analysis has been driven in part by (1) the continuous improvements in sensitivity and selectivity of MS instrumentation, (2) the introduction of novel sample preparation procedures compatible with standalone mass spectrometric analysis such as salting out assisted liquid-liquid extraction (SALLE) with volatile solutes and NH4(+) QuEChERS, and (3) the need to improve efficiency of laboratories to satisfy increasing analytical demand while lowering operational cost. The advantages and drawbacks of quantitative analysis by FIA-MS are discussed in comparison to chromatography-MS and ambient MS (e.g., DESI, LAESI, DART). Generally, FIA-MS sits 'in the middle' between ambient MS and chromatography-MS, offering a balance between analytical

  19. Design and in vitro assessment of L-lactic acid-based copolymers as prodrug and carrier for intravitreal sustained L-lactate release to reverse retinal arteriolar occlusions.

    PubMed

    Veurink, Marieke; Asmus, Lutz; Hennig, Maren; Kaufmann, Béatrice; Bagnewski, Lena; Heiligenhaus, Arnd; Mendrinos, Efstratios; Pournaras, Constantin J; Gurny, Robert; Möller, Michael

    2013-05-13

    Ophthalmic conditions in which the retinal vasculature is obstructed generally lead to vision loss. Administration of the vasodilator L-lactate might offer a treatment strategy by restoring the blood flow, but unfortunately its effect after single intravitreal injection is short-lived. This study describes a concept in which the sustained release of L-lactic acid from a biodegradable copolymer system is investigated. The 50:50 (n/n) copolymer system, composed of L-lactic acid and L,D-2-hydroxyoctanoic acid, is a viscous injectable that will form an intravitreal drug depot. Hydrolysis of the copolymer will automatically lead to the release of L-lactic acid, which will convert to L-lactate at physiological pH, thereby providing a carrier and pro-drug in one. In vitro and ex vivo release studies demonstrate an L-lactic acid release over several weeks. Biocompatibility of the co-polymer and its degradation products is shown on a human retinal pigment epithelial cell line and on ex vivo retinal tissues. A low molecular weight copolymer (1200 g/mol) with low polydispersity has promising properties with a constant release profile, good biocompatibility and injectability.

  20. Intravitreal Poly(L-lactide) Microparticles Sustain Retinal and Choroidal Delivery of TG-0054, a Hydrophilic Drug Intended for Neovascular Diseases

    PubMed Central

    Shelke, Namdev B; Kadam, Rajendra; Tyagi, Puneet; Rao, Vidhya R; Kompella, Uday B.

    2012-01-01

    While poorly soluble drugs such as corticosteroids sustain drug delivery in the vitreous humor by virtue of slow dissolution, macromolecules such as antibodies and their fragments sustain their levels due to their slow clearance. However, currently there are no approaches to sustain the delivery of well water soluble small molecule drugs in the vitreous. In this study we optimized a PLA microparticle formulation for sustained intravitreal delivery of TG-0054, a well water soluble anti-angiogenic drug that is of potential value in treating choroid neovascularization. After determining the influence of process parameters on particle size and drug loading, spherical microparticles syringeable through a 27 G needle, with a mean diameter of 7.6 μm, 10% w/w TG-0054 loading, sustained in vitro drug release for at least 6 months, and low residual organic solvent content (~ 1 ppb/mg) were prepared. Microparticles as well as drug solution were assessed for their in vivo drug delivery over 3 months following intravitreal injection in New Zealand white rabbits. Drug levels in the microparticle dosed eyes at 3 months were 43.7 ± 16.2, 243 ± 42.6, 62.8 ± 22.6 μg/g vitreous, retina, and choroid-RPE, respectively, and similar to levels at one month. Intravitreal injection of plain drug solution resulted in significantly lower amounts of drug in the dosed eye, with the levels being 0.8 ± 0.5, 2.7 ± 2.8, and 4.9± 4.2 μg/g in vitreous, retina, and choroid-RPE, respectively, at one month, with no detectable drug at three months. Although surface degradation was evident, microparticles maintained their spherical structure during the 6 months in vitro study and the 3 months in vivo study, with the vitreal particle retention at 1 and 3 months being 60% and 27%, respectively. Thus, PLA microparticles capable of sustaining retinal and choroidal delivery of TG-0054 for three to six months were developed. PMID:22888471

  1. The role of flow injection analysis within the framework of an automated laboratory

    PubMed Central

    Stockwell, Peter B.

    1990-01-01

    Flow Injection Analysis (FIA) was invented at roughly the same time by two quite dissimilar research groups [1,2]. FIA was patented by both groups in 1974; a year also marked by the publication of the first book on automatic chemical analysis [3]. This book was a major undertaking for its authors and it is hoped that it has added to the knowledge of those analysts attempting to automate their work or to increase the level of computerization/automation and thus reduce staffing commitments. This review discusses the role of FIA in laboratory automation, the advantages and disadvantages of the FIA approach, and the part it could play in future developments. It is important to stress at the outset that the FIA approach is all too often closely paralleled with convention al continuous flow analysis (CFA). This is a mistake for many reasons, none the least of which because of the considerable success of the CFA approach in contrast to the present lack of penetration in the commercial market-place of FIA instrumentation. PMID:18925262

  2. The Effects of Intravenous Dexmedetomidine Injections on IOP in General Anesthesia Intubation: A Meta-Analysis

    PubMed Central

    Zhu, Yu; Liu, Zhen

    2017-01-01

    Objective. The aim of this meta-analysis is to evaluate the effects of dexmedetomidine on intraocular pressure (IOP) in patients with general anesthesia administered via intubation. Methods. We searched randomized controlled trials (RCT) on the effects of intravenous injection of dexmedetomidine on IOP in patients with general anesthesia administered via intubation. Results. The meta-analysis study showed that (1) a statistically significant difference [WMD = −3.40 mmHg, 95% CI (−4.76, −2.04), P < 0.00001] was found between IOP of the two groups. (2) The IOP of the dexmedetomidine group that was administrated succinylcholine was lower than that of placebo group which was administrated succinylcholine [WMD = −4.13 mmHg, 95% CI (−6.01, −2.25), P < 0.0001]. (3) Compared with the IOP of patients in the placebo group, patients with intubation in the dexmedetomidine group maintained a lower IOP [WMD = −3.10 mmHg, 95% CI (−5.12, −1.07), P = 0.003]. However, for incidences of bradycardia, the use of dexmedetomidine was higher than that of the placebo [RR = 0.23, 95% CI (0.07, 0.76), P = 0.02]. Conclusion. This meta-analysis showed that, in many cases, dexmedetomidine can lower the IOP of patients with general anesthesia administered by intubation. PMID:28261613

  3. Application of quantum dots in clinical and alimentary fields using multicommutated flow injection analysis.

    PubMed

    Llorent-Martínez, E J; Molina-García, L; Kwiatkowski, R; Ruiz-Medina, A

    2013-05-15

    In recent years, the number of scientific papers regarding the use of quantum dots (QDs) has increased almost exponentially, especially emphasizing their use for new applications and describing new approaches. One of the future trends in the development of new methods of analysis is the use of automated methodologies. Among them, Multicommutated Flow Injection Analysis has been here selected in order to show its potentiality in pharmaceutical and food analysis. Using water-soluble CdTe QDs modified by mercaptopropionic acid, a flow system was developed for the determination of ascorbic acid. The system was based on the quenching effect produced by ascorbic acid on the fluorescence of QDs. Under the optimized conditions, the relationship between the fluorescence intensity of the QDs and ascorbic acid concentration was linear in the range of 12-250 μg mL(-1), obtaining a sample throughput of 68 determinations per hour. The proposed method was applied to the determination of ascorbic acid in pharmaceutical formulations, goji capsules and fruit juices. The results obtained were in good agreement with those showed by a reference method, so indicating the utility of the proposed method in the clinical and alimentary fields.

  4. Flow injection analysis as a tool for enhancing oceanographic nutrient measurements--a review.

    PubMed

    Worsfold, Paul J; Clough, Robert; Lohan, Maeve C; Monbet, Philippe; Ellis, Peter S; Quétel, Christophe R; Floor, Geerke H; McKelvie, Ian D

    2013-11-25

    Macronutrient elements (C, N and P) and micronutrient elements (Fe, Co, Cu, Zn and Mn) are widely measured in their various physico-chemical forms in open ocean, shelf sea, coastal and estuarine waters. These measurements help to elucidate the biogeochemical cycling of these elements in marine waters and highlight the ecological and socio-economic importance of the oceans. Due to the dynamic nature of marine waters in terms of chemical, biological and physical processes, it is advantageous to make these measurements in situ and in this regard flow injection analysis (FIA) provides a suitable shipboard platform. This review, therefore, discusses the role of FIA in the determination of macro- and micro-nutrient elements, with an emphasis on manifold design and detection strategies for the reliable shipboard determination of specific nutrient species. The application of various FIA manifolds to oceanographic nutrient determinations is discussed, with an emphasis on sensitivity, selectivity, high throughput analysis and suitability for underway analysis and depth profiles. Strategies for enhancing sensitivity and minimizing matrix effects, e.g. refractive index (schlieren) effects and the important role of uncertainty budgets in underpinning method validation and data quality are discussed in some detail.

  5. Development of a flow injection analysis method for the determination of acrylamide copolymers in oilfield brines

    SciTech Connect

    Taylor, K.C.; Burke, R.A.; Schramm, L.L.; Nasr-El-Din, H.A.

    1995-11-01

    An automated method for the determination of acrylamide polymers by flow injection analysis (FIA) has been developed and optimized for routine use. The method has been extensively tested for interferences common in oilfield brines. Potential interferences were examined from Na{sup +}, Ca{sup 2+}, Cr{sup 3+}, Al{sup 3+}, Zr{sup 3+}, NH{sub 4}{sup +}, Cl{sup {minus}}, OH{sup {minus}}, CO{sub 3}{sup 2{minus}}, sample coloration, and commonly used surfactants. The analysis is specific for amides, and the sensitivity to concentration of amide groups in the polymer was shown to be constant as the degree of polymer hydrolysis was varied. The range of the method is 0.1 to 100 mg/L. Sample throughput is 30 samples/h with triplicate analysis. Relative standard deviations of 0.2% are readily obtained from standard solutions and 0.5% from complex samples (at 50 mg/L). The method is applicable to the determination of aqueous, acrylamide-based polymers in process streams, surface waters and oilfield brines.

  6. Numerical analysis of combustion characteristics of hybrid rocket motor with multi-section swirl injection

    NASA Astrophysics Data System (ADS)

    Li, Chengen; Cai, Guobiao; Tian, Hui

    2016-06-01

    This paper is aimed to analyse the combustion characteristics of hybrid rocket motor with multi-section swirl injection by simulating the combustion flow field. Numerical combustion flow field and combustion performance parameters are obtained through three-dimensional numerical simulations based on a steady numerical model proposed in this paper. The hybrid rocket motor adopts 98% hydrogen peroxide and polyethylene as the propellants. Multiple injection sections are set along the axis of the solid fuel grain, and the oxidizer enters the combustion chamber by means of tangential injection via the injector ports in the injection sections. Simulation results indicate that the combustion flow field structure of the hybrid rocket motor could be improved by multi-section swirl injection method. The transformation of the combustion flow field can greatly increase the fuel regression rate and the combustion efficiency. The average fuel regression rate of the motor with multi-section swirl injection is improved by 8.37 times compared with that of the motor with conventional head-end irrotational injection. The combustion efficiency is increased to 95.73%. Besides, the simulation results also indicate that (1) the additional injection sections can increase the fuel regression rate and the combustion efficiency; (2) the upstream offset of the injection sections reduces the combustion efficiency; and (3) the fuel regression rate and the combustion efficiency decrease with the reduction of the number of injector ports in each injection section.

  7. Single Event Analysis and Fault Injection Techniques Targeting Complex Designs Implemented in Xilinx-Virtex Family Field Programmable Gate Array (FPGA) Devices

    NASA Technical Reports Server (NTRS)

    Berg, Melanie D.; LaBel, Kenneth; Kim, Hak

    2014-01-01

    An informative session regarding SRAM FPGA basics. Presenting a framework for fault injection techniques applied to Xilinx Field Programmable Gate Arrays (FPGAs). Introduce an overlooked time component that illustrates fault injection is impractical for most real designs as a stand-alone characterization tool. Demonstrate procedures that benefit from fault injection error analysis.

  8. Evaluation of different preparation methods for a preservative free triamcinolone acetonide preparation for intravitreal administration: a validated stability indicating HPLC-method.

    PubMed

    Korodi, T; Lachmann, B; Kopelent-Frank, H

    2010-12-01

    Intravitreally applied triamcinolone acetonide (TA) is used to treat a variety of macular diseases. Commercially available products of TA are mainly intended for intramuscular application and contain benzyl alcohol (BA) as a bacteriostatic preservative. Since this agent damages ocular tissues, different methods such as filtration techniques and centrifugation are usually used to eliminate BA from commercial products (40 mg/mL TA, 9.9 mg/mL BA). In this study, we evaluated these methods in regard to their ability to eliminate benzyl alcohol and to guarantee standard doses of triamcinolone acetonide. A new formulation without BA (TA 40 mg/mL) was developped according to the following criteria: autoclavability, stability, and suitability for intravitreal use. For QA/QC evaluation a new rapid and simple HPLC procedure (C18 RP column, mobile phase consisting of methanol-water, 48:52, v/v) to quantify the respective compounds was developed and validated according to ICH guidelines. The HPLC method was proven to be selective, linear, precise and accurate. Analysis of preparations based on commercial products undergoing different filtration techniques showed variable results: TA concentrations of 22-80% of the declared amount were found, and BA content was not reduced to safe levels (up to 39% of initial content remained). Centrifugation methods decreased the concentration of the preservative adequately, however agglomerated TA crystals were observed, leading to irreproducible and deviating particle sizes that are potentially harmful with ocular use. The newly developed preservative free formulation (TA 40 mg/mL) delivered uniform doses of TA, revealed no drug loss during forced light exposure and was proven to be stable, sterile and bacterial endotoxin free after autoclaving and after storage for three months,. The new formulation may offer an alternative for the in-house production of intravitreally applicable TA preparations in hospital pharmacies and should enhance

  9. Highly potent VEGF-A-antagonistic DARPins as anti-angiogenic agents for topical and intravitreal applications.

    PubMed

    Stahl, Andreas; Stumpp, Michael T; Schlegel, Anja; Ekawardhani, Savira; Lehrling, Christina; Martin, Gottfried; Gulotti-Georgieva, Maya; Villemagne, Denis; Forrer, Patrik; Agostini, Hansjürgen T; Binz, H Kaspar

    2013-01-01

    The next-generation ophthalmic anti-VEGF therapeutics must aim at being superior to the currently available agents with regard to potency and improved drug delivery, while still being stable and safe to use at elevated concentrations. We show here the generation of a set of highly potent VEGF-A antagonistic DARPins (designed ankyrin repeat proteins) delivering these properties. DARPins with single-digit picomolar affinity to human VEGF-A were generated using ribosome display selections. Specific and potent human VEGF-A binding was confirmed by ELISA and endothelial cell sprouting assays. Cross-reactivity with VEGF-A of several species was confirmed by ELISA. Intravitreally injected DARPin penetrated into the retina and reduced fluorescein extravasation in a rabbit model of vascular leakage. In addition, topical DARPin application was found to diminish corneal neovascularization in a rabbit suture model, and to suppress laser-induced neovascularization in a rat model. Even at elevated doses, DARPins were safe to use. The fact that several DARPins are highly active in various assays illustrates the favorable class behavior of the selected binders. Anti-VEGF-A DARPins thus represent a novel class of highly potent and specific drug candidates for the treatment of neovascular eye diseases in both the posterior and the anterior eye chamber.

  10. Efficacy of Ligustrazine Injection as Adjunctive Therapy for Angina Pectoris: A Systematic Review and Meta-Analysis.

    PubMed

    Shao, Huikai; Zhao, Lingguo; Chen, Fuchao; Zeng, Shengbo; Liu, Shengquan; Li, Jiajia

    2015-11-29

    BACKGROUND In the past decades, a large number of randomized controlled trials (RCTs) on the efficacy of ligustrazine injection combined with conventional antianginal drugs for angina pectoris have been reported. However, these RCTs have not been evaluated in accordance with PRISMA systematic review standards. The aim of this study was to evaluate the efficacy of ligustrazine injection as adjunctive therapy for angina pectoris. MATERIAL AND METHODS The databases PubMed, Medline, Cochrane Library, Embase, Sino-Med, Wanfang Databases, Chinese Scientific Journal Database, Google Scholar, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and the Chinese Science Citation Database were searched for published RCTs. Meta-analysis was performed on the primary outcome measures, including the improvements of electrocardiography (ECG) and the reductions in angina symptoms. Sensitivity and subgroup analysis based on the M score (the refined Jadad scores) were also used to evaluate the effect of quality, sample size, and publication year of the included RCTs on the overall effect of ligustrazine injection. RESULTS Eleven RCTs involving 870 patients with angina pectoris were selected in this study. Compared with conventional antianginal drugs alone, ligustrazine injection combined with antianginal drugs significantly increased the efficacy in symptom improvement (odds ratio [OR], 3.59; 95% confidence interval [CI]: 2.39 to 5.40) and in ECG improvement (OR, 3.42; 95% CI: 2.33 to 5.01). Sensitivity and subgroup analysis also confirmed that ligustrazine injection had better effect in the treatment of angina pectoris as adjunctive therapy. CONCLUSIONS The 11 eligible RCTs indicated that ligustrazine injection as adjunctive therapy was more effective than antianginal drugs alone. However, due to the low quality of included RCTs, more rigorously designed RCTs were still needed to verify the effects of ligustrazine injection as adjunctive therapy for

  11. Evaluation of a direct injection nebulizer interface for flow injection analysis and high performance liquid chromatography with inductively coupled plasma-atomic emission spectroscopic detection

    SciTech Connect

    LaFreniere, K.E.

    1986-06-01

    A direct injection nebulizer (DIN) was designed, developed, and evaluated to determine its potential utilization as an effective interface for flow injection analysis (FIA) and high performance liquid chromatography (HPLC) coupled with inductively coupled plasma-atomic emission spectroscopic detection. The analytical figures of merit for the DIN when used as an interface for FIA-ICP-AES were found to be comparable to or better than those obtained with conventional pneumatic nebulization in terms of limits of detection (LODs), reproducibility, linearity, and interelement effects. Stable plasma operation was maintained for the DIN sample introduction of a variety of pure organic solvents, including acetonitrile, methanol, methylisobutylketone, and pyridine. The HPLC-DIN-ICP-AES facility was specifically applied for the speciation of inorganic and organometallic species contained in synthetic mixtures, vanilla extracts, and a variety of energy-related materials, such as shale oil process water, coal extracts, shale oil, crude oil, and an SRC II. Suggestions for future research are also considered. 227 refs., 44 figs., 15 tabs.

  12. Switching from risperidone long-acting injectable to paliperidone long-acting injectable or oral antipsychotics: analysis of a Medicaid claims database.

    PubMed

    Voss, Erica A; Ryan, Patrick B; Stang, Paul E; Hough, David; Alphs, Larry

    2015-05-01

    This report examines relapse risk following a switch from risperidone long-acting injectable (RLAI) to another long-acting injectable antipsychotic [paliperidone palmitate (PP)] versus a switch to oral antipsychotics (APs). Truven Health's MarketScan Multistate Medicaid Database compared relapses following switches from RLAI. New user cohorts for these two groups were created on the basis of first incidence of exposure to the 'switched to' drug. Groups were balanced using 1:1 propensity score matching. Time-to-event analysis assessed schizophrenia-related hospital/emergency department visits. A total of 188 patients switched from RLAI to PP, and 131 patients switched from RLAI to oral AP. Propensity score-matched cohort included 109 patients who switched to PP and 109 patients who switched to an oral AP. Patients who switched from RLAI to PP had fewer events (26 vs. 32), longer time to an event (mean 70 vs. 47 days), and lower risk of relapse (hazard ratio, 0.54; 95% confidence interval, 0.32-0.92; P=0.024) compared with those who switched from RLAI to oral AP. Switching from RLAI to PP may be associated with a lower risk for relapse and longer duration of therapy compared with switching to oral AP. Given the limitations of observational studies, these results should be confirmed by other prospective evaluations.

  13. High-resolution quantitative metabolome analysis of urine by automated flow injection NMR.

    PubMed

    Da Silva, Laeticia; Godejohann, Markus; Martin, François-Pierre J; Collino, Sebastiano; Bürkle, Alexander; Moreno-Villanueva, María; Bernhardt, Jürgen; Toussaint, Olivier; Grubeck-Loebenstein, Beatrix; Gonos, Efstathios S; Sikora, Ewa; Grune, Tilman; Breusing, Nicolle; Franceschi, Claudio; Hervonen, Antti; Spraul, Manfred; Moco, Sofia

    2013-06-18

    Metabolism is essential to understand human health. To characterize human metabolism, a high-resolution read-out of the metabolic status under various physiological conditions, either in health or disease, is needed. Metabolomics offers an unprecedented approach for generating system-specific biochemical definitions of a human phenotype through the capture of a variety of metabolites in a single measurement. The emergence of large cohorts in clinical studies increases the demand of technologies able to analyze a large number of measurements, in an automated fashion, in the most robust way. NMR is an established metabolomics tool for obtaining metabolic phenotypes. Here, we describe the analysis of NMR-based urinary profiles for metabolic studies, challenged to a large human study (3007 samples). This method includes the acquisition of nuclear Overhauser effect spectroscopy one-dimensional and J-resolved two-dimensional (J-Res-2D) (1)H NMR spectra obtained on a 600 MHz spectrometer, equipped with a 120 μL flow probe, coupled to a flow-injection analysis system, in full automation under the control of a sampler manager. Samples were acquired at a throughput of ~20 (or 40 when J-Res-2D is included) min/sample. The associated technical analysis error over the full series of analysis is 12%, which demonstrates the robustness of the method. With the aim to describe an overall metabolomics workflow, the quantification of 36 metabolites, mainly related to central carbon metabolism and gut microbial host cometabolism, was obtained, as well as multivariate data analysis of the full spectral profiles. The metabolic read-outs generated using our analytical workflow can therefore be considered for further pathway modeling and/or biological interpretation.

  14. High-Resolution Quantitative Metabolome Analysis of Urine by Automated Flow Injection NMR

    PubMed Central

    2013-01-01

    Metabolism is essential to understand human health. To characterize human metabolism, a high-resolution read-out of the metabolic status under various physiological conditions, either in health or disease, is needed. Metabolomics offers an unprecedented approach for generating system-specific biochemical definitions of a human phenotype through the capture of a variety of metabolites in a single measurement. The emergence of large cohorts in clinical studies increases the demand of technologies able to analyze a large number of measurements, in an automated fashion, in the most robust way. NMR is an established metabolomics tool for obtaining metabolic phenotypes. Here, we describe the analysis of NMR-based urinary profiles for metabolic studies, challenged to a large human study (3007 samples). This method includes the acquisition of nuclear Overhauser effect spectroscopy one-dimensional and J-resolved two-dimensional (J-Res-2D) 1H NMR spectra obtained on a 600 MHz spectrometer, equipped with a 120 μL flow probe, coupled to a flow-injection analysis system, in full automation under the control of a sampler manager. Samples were acquired at a throughput of ∼20 (or 40 when J-Res-2D is included) min/sample. The associated technical analysis error over the full series of analysis is 12%, which demonstrates the robustness of the method. With the aim to describe an overall metabolomics workflow, the quantification of 36 metabolites, mainly related to central carbon metabolism and gut microbial host cometabolism, was obtained, as well as multivariate data analysis of the full spectral profiles. The metabolic read-outs generated using our analytical workflow can therefore be considered for further pathway modeling and/or biological interpretation. PMID:23718684

  15. Flow injection analysis of nanomolar silicate using long pathlength absorbance spectroscopy.

    PubMed

    Ma, Jian; Byrne, Robert H

    2012-01-15

    Determination of silicate at low concentrations (i.e., nanomolar levels) is an important analytical objective for both marine science and the semiconductor industry. Here we report the use of flow injection analysis (FIA) in combination with long pathlength liquid core waveguide (LCW) spectrometry to achieve detection limits for dissolved silica on the order of 10nM. Sample throughput for the simple, automated analytical apparatus used in this work is 12h(-1) at low levels of dissolved silica; this rate can be increased by a factor of three for higher (micromolar) levels of dissolved silica. The analytical protocol is based on the reaction of silicate with ammonium molybdate to form a yellow silicomolybdate complex, which is subsequently reduced to silicomolybdenum blue by ascorbic acid. Optimization of the FIA procedure included consideration of the compositions and concentrations of reagents, volume of the injection loop, flow rate conditions, and lengths of mixing coils. The interference by phosphate was examined and eliminated through addition of oxalic acid. The dissolved silica detection limit of 7.2nM in pure water is consistent with the strictest standard for the semiconductor industry, and the 9.0nM detection limit for seawater shows that this analytical method is also suitable for oligotrophic ocean waters. The targeted analytical range of 10nM to 5μM can be easily extended to higher concentrations without altering the experimental hardware-i.e., by simply changing flow rates or selecting alternative analytical wavelengths. Compared to previously published LCW-based spectrophotometric methods, this analytical system exhibits improved sensitivity, reduced sample consumption, and higher sample throughput.

  16. Flow injection chemiluminescence analysis of phenolic compounds using the NCS-luminol system.

    PubMed

    Haghighi, Behzad; Dadashvand, Reza

    2006-03-01

    A flow injection system coupled with two simple and sensitive chemiluminescence (CL) methods is described for the determination of some phenolic compounds. The methods are based on the inhibition effects of the investigated phenols on the CL signal intensities of N-chlorosuccinimide-KI-luminol (NCS-KI-luminol) and NCS-luminol systems. The influences of the chemical and hydrodynamic parameters on the decrease in CL signal intensities of NCS-KI-luminol and NCS-luminol systems for hydroquinone, catechol, and resorcinol, serving as the model compounds of analyte, were studied in the flow injection mode of analysis. Under the selected conditions, the proposed CL systems were used for the determination of some phenolic compound and analytical characteristics of the systems including calibration equation, correlation coefficient, linear dynamic range, limit of detection, and sample throughput. The limits of detection for hydroquinone, catechol, and resorcinol were 0.002, 0.01, and 0.3 microM using the NCS-KI-luminol system; for the NCS-luminol system these were 0.01, 0.17, and 1.6 microM, respectively. The relative standard deviation for 10 repeated measurements of 0.04, 0.06, and 1 microM of hydroquinone, catechol, and resorcinol were 1.9, 1.4, and 2.0%, respectively, with the NCS-KI-luminol system; for 0.2, 0.5, and 4 microM of hydroquinone, catechol, and resorcinol these were 2.6, 2.2, and 3.7%, respectively, using the NCS-luminol system. The method was applied to the determination of catechol in known environmental water samples with a relative error of less than 6%. A possible reaction mechanism of the proposed CL system is discussed briefly.

  17. Intra-articular steroid injections for painful knees. Systematic review with meta-analysis.

    PubMed Central

    Godwin, Marshall; Dawes, Martin

    2004-01-01

    OBJECTIVE: Do intra-articular steroid injections relieve the pain of osteoarthritis (OA) of the knee? DATA SOURCES: MEDLINE, Cochrane, and Internet databases were searched for randomized controlled trials. STUDY SELECTION: Five randomized controlled trials involving 312 patients were found. SYNTHESIS: One week after injection, treated patients were less likely to have continuing pain and had significantly lower scores on a visual analogue scale (VAS) for pain. Three to 4 weeks after injection, treated patients still had significantly less pain, but their VAS scores were no longer significantly lower than scores in the control group. Six to 8 weeks after injection, neither pain reduction nor VAS scores were significantly different between groups. CONCLUSION: Intra-articular corticosteroid injection results in clinically and statistically significant reduction in osteoarthritic knee pain 1 week after injection. The beneficial effect could last for 3 to 4 weeks, but is unlikely to continue beyond that. PMID:15000335

  18. Hanford 100-N Area In Situ Apatite and Phosphate Emplacement by Groundwater and Jet Injection: Geochemical and Physical Core Analysis

    SciTech Connect

    Szecsody, James E.; Vermeul, Vincent R.; Fruchter, Jonathan S.; Williams, Mark D.; Rockhold, Mark L.; Qafoku, Nikolla; Phillips, Jerry L.

    2010-07-01

    The purpose of this study is to evaluate emplacement of phosphate into subsurface sediments in the Hanford Site 100-N Area by two different technologies: groundwater injection of a Ca-citrate-PO4 solution and water-jet injection of sodium phosphate and/or fish-bone apatite. In situ emplacement of phosphate and apatite adsorbs, then incorporates Sr-90 into the apatite structure by substitution for calcium. Overall, both technologies (groundwater injection of Ca-citrate-PO4) and water-jet injection of sodium phosphate/fish-bone apatite) delivered sufficient phosphate to subsur¬face sediments in the 100-N Area. Over years to decades, additional Sr-90 will incorporate into the apatite precipitate. Therefore, high pressure water jetting is a viable technology to emplace phosphate or apatite in shallow subsurface sediments difficult to emplace by Ca-citrate-PO4 groundwater injections, but further analysis is needed to quantify the relevant areal extent of phosphate deposition (in the 5- to 15-ft distance from injection points) and cause of the high deposition in finer grained sediments.

  19. [Analysis of nine narcotics in urine by microemulsion electrokinetic chromatography-field samplified sample injection].

    PubMed

    Zhang, Yu; Li, Qin; Lu, Minghua; Zhang, Lan; Chen, Guonan; Cai, Zongwei

    2011-08-01

    A simple, sensitive and reproducible method using microemulsion electrokinetic chromatography (MEEKC)-field amplified sample injection (FASI) was developed for the analysis of nine narcotics (morphine, codeine, naloxone, heroin, thebaine, cocaine, pethidine, fentanyl and methadone) in urine. In the MEEKC method, sodium dodecyl sulfate (SDS), 1-butanol and ethyl acetate were used as surfactant, co-surfactant and organic solvent, respectively. The effects of the acidity and concentration of borate buffer, SDS, 1-butanol and ethyl acetate contents were investigated. The optimum concentrations (by mass fraction) of microemulsion system were 0.6% SDS, 1.2% 1-butanol, 0.6% ethyl acetate and 97.6% 10 mmol/L Na2B4O7 buffer (pH 9.5). The applied voltage was 25 kV. FASI was coupled with the MEEKC method to increase the sensitivity. Under the optimum conditions, the nine narcotics were baseline separated within 15 min and the detection limits (S/N = 3) were in the range of 0.3 - 8.0 microg/L. The spiked recoveries in urine samples were between 79.4% and 119.9% with the intraday relative standard deviations (RSDs) less than 5.5%. The developed method has been successfully applied to the analysis of methadone in the samples from in vitro metabolism study.

  20. Ultra-sensitive Flow Injection Analysis (FIA) determination of calcium in ice cores at ppt level.

    PubMed

    Traversi, R; Becagli, S; Castellano, E; Maggi, V; Morganti, A; Severi, M; Udisti, R

    2007-07-02

    A Flow Injection Analysis (FIA) spectrofluorimetric method for calcium determination in ice cores was optimised in order to achieve better analytical performances which would make it suitable for reliable calcium measurements at ppt level. The method here optimised is based on the formation of a fluorescent compound between Ca and Quin-2 in buffered environment. A careful evaluation of operative parameters (reagent concentration, buffer composition and concentration, pH), influence of interfering species possibly present in real samples and potential favourable effect of surfactant addition was carried out. The obtained detection limit is around 15 ppt, which is one order of magnitude lower than the most sensitive Flow Analysis method for Ca determination currently available in literature and reproducibility is better than 4% for Ca concentrations of 0.2 ppb. The method was validated through measurements performed in parallel with Ion Chromatography on 200 samples from an alpine ice core (Lys Glacier) revealing an excellent fit between the two chemical series. Calcium stratigraphy in Lys ice core was discussed in terms of seasonal pattern and occurrence of Saharan dust events.

  1. Application of hot platinum microelectrodes for determination of flavonoids in flow injection analysis and capillary electrophoresis.

    PubMed

    Magnuszewska, Jolanta; Krogulec, Tadeusz

    2013-07-05

    The determination of quercetin and rutin by flow injection analysis (FIA) and capillary electrophoresis (CE) using electrochemical detection was described. These flavonoids were determined at normal (unheated) and hot platinum microelectrodes using cyclic voltammetry. When quercetin or rutin is reaching the platinum electrode, a change of the current in the region of the platinum oxide formation is observed. Integration of the current changes in this in this region creates analytical signals in the form of peaks. An increase of temperature to about 76°C in a small zone adjacent to the microelectrode causes an increase of the analytical signal by more than 6 times under FIA conditions. This method enables the use of hot microelectrodes as detectors in HPLC or CE. In CE the improvement of the analytical signal at hot microelectrodes is smaller than in FIA and increase only 1.3-3.4 times. Heated microelectrodes were used for analysis of the flavonoids in natural samples of the plant (extract of sea buckthorn) and a pharmaceutical preparation (Cerutin).

  2. Orbital Injection of the SEDSAT Satellite: Tethered Systems Dynamics and Flight Data Analysis

    NASA Technical Reports Server (NTRS)

    Lorenzini, Enrico C.; Gullahorn, Gordon E.; Cosmo, Mario L.; Ruiz, Manuel; Pelaez, Jesus

    1996-01-01

    This report deals with the following topics which are all related to the orbital injection of the SEDSAT satellite: Dynamics and Stability of Tether Oscillations after the First Cut. The dynamics of the tether after the first cut (i.e., without the Shuttle attached to it) is investigated. The tether oscillations with the free end are analyzed in order to assess the stability of the rectilinear configuration in between the two tether cuts; analysis of Unstable Modes. The unstable modes that appear for high libration angles are further investigated in order to determine their occurrences and the possible transition from bound librations to rotations; Orbital Release Strategies for SEDSAT. A parametric analysis of the orbital decay rate of the SEDSAT satellite after the two tether cuts has been carried out as a function of the following free parameters: libration amplitude at the end of deployment, deviation angle from LV at the first cut, and orbital anomaly at the second cut. The values of these parameters that provide a minimum orbital decay rate of the satellite (after the two cuts) have been computed; and Dynamics and Control of SEDSAT. The deployment control law has been modified to cope with the new ejection velocity of the satellite from the Shuttle cargo bay. New reference profiles have been derived as well as new control parameters. Timing errors at the satellite release as a function of the variations of the initial conditions and the tension model parameters have been estimated for the modified control law.

  3. Trace and ultratrace analysis methods for the determination of phosphorus by flow-injection techniques.

    PubMed

    Motomizu, Shoji; Li, Zhen-Hai

    2005-04-15

    Trace (< or =1 mg/l or 30 microM) and ultratrace (< or =1 microg/l or 30 nM) analysis methods for phosphorus determination by flow-injection analysis are reviewed. Most of the methods cited in this review are fundamentally based on the reaction of orthophosphate with molybdate to form heteropoly acids, such as molybdenum yellow and molybdenum blue, and some of the methods are based on the formation of such secondary reactions as ion associates and their aggregates with bulky cations, such as cationic dyes and quaternary ammonium ions. The heteropoly acids themselves can be measured by spectrophotometry, and the ion associate formed with a cationic dye, Malachite Green (MG), can be measured based on the coloration of MG. Light scattering detection methods can be used for measuring the aggregates of ion associates formed with bulky cations. Highly sensitive detection of phosphorus can be accomplished by fluorophotometry; Rhodamine B (RB) and its analogues react with molybdophosphate to form ion associates, which shows fluorescence quenching of RB: LOD is about 5 nM. The detection method based on the chemiluminescence of luminal oxidized with molybdophosphoric acids is probably the most sensitive of all the detection methods reported so far: LOD of the method is as low as 1nM. The LOD of the molybdenum blue method can be improved by using a liquid core waveguide: LOD is 0.5 nM.

  4. Visualization analysis of tiger-striped flow mark generation phenomena in injection molding

    NASA Astrophysics Data System (ADS)

    Owada, Shigeru; Yokoi, Hidetoshi

    2016-03-01

    The generation mechanism of tiger-striped flow marks of polypropylene (PP)/rubber/talc blends in injection molding was investigated by dynamic visualization analysis in a glass-inserted mold. The analysis revealed that the behavior of the melt flow front correlates with the flow mark generation. The cloudy part in the tiger-striped flow marks corresponded to the low transcription rate area of the melt diverging near the cavity wall, while the glossy part corresponded to the high transcription rate area of the melt converging toward the cavity wall side. The melt temperature at the high transcription rate area was slightly lower than that at the low transcription rate area. These phenomena resulted due to the difference in the temperature of the melt front that was caused by the asymmetric fountain flow. These results suggest the followings; At the moment when the melt is broken near the one side of cavity wall due to piling the extensional strains up to a certain level, the melt spurts out near the broken side. It results in generating asymmetric fountain flow temporarily to relax the extensional front surface, which moves toward the opposite side to form the high transcription area.

  5. Measurement and Analysis of ECH Power Injected Into DIII-D

    NASA Astrophysics Data System (ADS)

    Johnson, P. S.; Lohr, J.

    2007-11-01

    The 6 ECH waveguides at DIII-D are on the order of 100 meters in length with up to 16 miter bends. Accurate measurement of the ratio of generated-to-transmitted power gives the transmission line efficiency directly and is essential for analysis of experiments. The power generated by the gyrotrons is measured calorimetrically for each pulse, but direct measurements of the injected power have relied on analysis of modulated plasma heating, which can overlook significant power where plasma volumes are large and ECH driven temperature fluctuations are small. High power tests of efficiencies of individual components have been difficult due to mutual interaction of components, sensitivity of power monitors to polarization, and the generally high efficiency of the components. We report a direct measurement of the efficiencies of complete transmission lines, using a high power dummy load placed at the end of each DIII-D waveguide. Experimental results will be compared to previous measurements and to theoretical calculations of the performance of the components and waveguide lines.

  6. Flow Injection Analysis and Liquid Chromatography for Multifunctional Chemical Analysis (MCA) Systems

    ERIC Educational Resources Information Center

    Mayo, Ana V.; Loegel, Thomas N.; Bretz, Stacey Lowery; Danielson, Neil D.

    2013-01-01

    The large class sizes of first-year chemistry labs makes it challenging to provide students with hands-on access to instrumentation because the number of students typically far exceeds the number of research-grade instruments available to collect data. Multifunctional chemical analysis (MCA) systems provide a viable alternative for large-scale…

  7. Preliminary analysis of the use of electrical resistance tomography for injectate tracking at the Geysers geothermal field

    SciTech Connect

    Creed, Bob; Daily, Bill

    1996-01-24

    Current geochemical and geophysical injectate tracking methods are useful reservoir management techniques but do not track injectate movement quick enough to maximize injection efficiency or avoid negative impacts on nearby steam production wells. A preliminary analysis indicates that two dimensional electrical resistance tomography (ERT) may be useful for imaging plume movement resulting from Geysers/Lake County Effluent Pipeline injectate in near real time. ERT models comparing an injection plume resistivity of 50 Ohm-m with background resistivities of 10, 100 (typical Geysers greywacke), and 500 Ohm-m (typical Geysers felsite) indicate that liquid plumes can be imaged at depths of 6,000 feet to 8,000 feet or greater for resistivity contrasts of 2 to 1 or greater. Further refinement of the ERT model could be accomplished with more data on porosity in the vicinity of the borehole, resistivity measurements, and reservoir engineering estimates of plume temperature and saturation. Based on the results of this analysis and previous successes in using ERT to map shallow subsurface steam and water movement in porous media it is likely, but not certain, that ERT will prove to be an additional reservoir management tool to be used in conjunction with additional geochemical, geophysical, and reservoir engineering techniques. A field scale test at The Geysers is required to verify the utility of ERT for injectate tracking. The goal of this paper is to stimulate discussion among geothermal researchers regarding use of the ERT technique for injectate tracking at The Geysers and get some input on the appropriateness and utility of the assumptions used.

  8. Hyphenation of sequential- and flow injection analysis with FTIR-spectroscopy for chemical analysis in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Lendl, B.; Schindler, R.; Kellner, R.

    1998-06-01

    A survey of the principles of sequential (SIA)-and flow injection analysis (FIA) systems with FTIR spectroscopic detection is presented to introduce these hyphenations as powerful techniques for performing chemical analysis in aqueous solution. The strength of FIA/SIA-FTIR systems lies in the possibility to perform highly reproducible and automated sample manipulations such as sample clean-up and/or chemical reactions prior to spectrum acquisition. It is shown that the hyphenation of FIA/SIA systems with an FTIR spectrometer enhances the problem solving capabilities of the FTIR spectrometer as also parameters which can not be measured directly (e.g. enzyme activities) can be determined. On the other hand application of FTIR spectroscopic detection in FIA or SIA is also of advantage as it allows to shorten conventional analysis procedures (e.g. sucrose or phosphate analysis) or to establish and apply a multivariate calibration model for simultaneous determinations (e.g. glucose, fructose and sucrose analysis). In addition to these examples two recent instrumental developments in miniaturized FIA/SIA-FTIR systems, a μ-Flow through cell based on IR fiber optics and a micromachined SI-enzyme reactor are presented in this paper.

  9. Probabilistic Seismic Hazard Analysis of Injection-Induced Seismicity Utilizing Physics-Based Simulation

    NASA Astrophysics Data System (ADS)

    Johnson, S.; Foxall, W.; Savy, J. B.; Hutchings, L. J.

    2012-12-01

    Risk associated with induced seismicity is a significant factor in the design, permitting and operation of enhanced geothermal, geological CO2 sequestration, wastewater disposal, and other fluid injection projects. The conventional probabilistic seismic hazard analysis (PSHA) approach provides a framework for estimation of induced seismicity hazard but requires adaptation to address the particular occurrence characteristics of induced earthquakes and to estimation of the ground motions they generate. The assumption often made in conventional PSHA of Poissonian earthquake occurrence in both space and time is clearly violated by seismicity induced by an evolving pore pressure field. Our project focuses on analyzing hazard at the pre-injection design and permitting stage, before an induced earthquake catalog can be recorded. In order to accommodate the commensurate lack of pre-existing data, we have adopted a numerical physics-based approach to synthesizing and estimating earthquake frequency-magnitude distributions. Induced earthquake sequences are generated using the program RSQSIM (Dieterich and Richards-Dinger, PAGEOPH, 2010) augmented to simulate pressure-induced shear failure on faults and fractures embedded in a 3D geological structure under steady-state tectonic shear loading. The model uses available site-specific data on rock properties and in-situ stress, and generic values of frictional properties appropriate to the shallow reservoir depths at which induced events usually occur. The space- and time-evolving pore pressure field is coupled into the simulation from a multi-phase flow model. In addition to potentially damaging ground motions, induced seismicity poses a risk of perceived nuisance in nearby communities caused by relatively frequent, low magnitude earthquakes. Including these shallow local earthquakes in the hazard analysis requires extending the magnitude range considered to as low as M2 and the frequency band to include the short

  10. Analysis: desirable attributes of insulin injection pens that drive patient preference and compliance.

    PubMed

    Zahn, Jeffrey D

    2011-09-01

    Insulin pens are used by approximately half of worldwide insulin users. Insulin pens have made insulin injections easier compared to traditional vial and syringe injections. In an article in this issue of Journal of Diabetes Science and Technology, Dr. Asakura discusses several important design parameters, which are considered during refillable insulin-injection pen design. Ease of cartridge replacement, insulin-dose setting dial use, injection, and prominence of audible clicks can all affect overall dose accuracy and user friendliness of insulin pens in patients suffering from diabetes and related comorbidities. These parameters, along with patient introduction from prescribing physicians and level of training provided, drives patient pen selection and injection-regimen compliance to control their blood sugar.

  11. The comparison of flow injection analysis and quartz chemical sensors for the determination of hydrazine

    SciTech Connect

    Smith, K.J.

    1992-01-01

    Due to the wide variety of its uses, hydrazine is present in many different work environments. Hydrazine is a suspect human carcinogen and poses a potential health risk if a person is exposed to hydrazine. The levels of hydrazine in the work environment must be monitored to avert potential health risks. Two different methods are investigated as possible monitors for hydrazine in a work environment. The primary goal of this research is to compare a flow injection analysis (FIA) method and a quartz chemical sensor for the determination of hydrazine vapor at sub ppm levels. The first study involves a comparison of FIA methods for direct hydrazine determination in the liquid phase. This study demonstrates the optimum conditions for the types of chemistry being investigated. This information is carried forward to a second study involving a comparison of gas diffusion FIA methods for hydrazine analysis. A third study develops and defines important principles in reverse dual phase gas diffusion FIA. A method for determining carbon dioxide is used to demonstrate these principles. A fourth study applies the information about the chemistry of hydrazine from the second study to the reverse dual phase gas diffusion FIA system developed for carbon dioxide. A fifth study demonstrates the applicability of quartz chemical sensors for hydrazine analysis. This study involves both surface acoustic wave devices (SAWs) and quartz crystal microbalances (QCMs). A summary follows these different studies which compares the success of each method. The criteria of evaluation are reviewed. New developments resulting from this research are presented. A final addendum includes work done on the automation of a method for free chlorine determination.

  12. Cabazitaxel Injection

    MedlinePlus

    ... injection is used along with prednisone to treat prostate cancer (cancer of a male reproductive organ) that has ... cabazitaxel injection is usually used in men with prostate cancer. If used by pregnant women, cabazitaxel injection can ...

  13. Fondaparinux Injection

    MedlinePlus

    ... fondaparinux injection.Talk to your doctor about the risk of using fondaparinux injection. ... Fondaparinux injection is used to prevent deep vein thrombosis (DVT; a blood ... Xa inhibitors. It works by decreasing the clotting ability of the blood.

  14. Morphine Injection

    MedlinePlus

    Morphine injection is used to relieve moderate to severe pain. Morphine is in a class of medications called opiate ( ... Morphine injection comes as a solution (liquid) to inject intramuscularly (into a muscle) or intravenously (into a ...

  15. Dexamethasone Injection

    MedlinePlus

    Dexamethasone injection is used to treat severe allergic reactions. It is used in the management of certain types of ... gastrointestinal disease, and certain types of arthritis. Dexamethasone injection is also used for diagnostic testing. Dexamethasone injection ...

  16. Romidepsin Injection

    MedlinePlus

    Romidepsin injection is used to treat cutaneous T-cell lymphoma (CTCL; a group of cancers of the immune system ... one other medication given by mouth or by injection. Romidepsin injection is in a class of medications ...

  17. Ondansetron Injection

    MedlinePlus

    Zofran® Injection ... Ondansetron injection is used to prevent nausea and vomiting caused by cancer chemotherapy and surgery. Ondansetron is in a ... medications: or any of the ingredients in ondansetron injection. Ask your pharmacist for a list of the ...

  18. The electrochemiluminescence of luminol on titania nanotubes functionalised indium tin oxide glass for flow injection analysis.

    PubMed

    Zhao, Qun; Xiao, Changbin; Tu, Yifeng

    2015-10-01

    The titania nanotubes (TiNTs) had been immobilised onto the indium tin oxide (ITO) coated glass to intensify the electrochemiluminescence (ECL) of luminol. The morphology, structure and properties such as specific surface area and transmittance of synthesised TiNTs were characterised. The results indicated that the TiNTs was several hundred nanometres in length with the diameter of 20 nm. In flow injection analysis (FIA) mode, the TiNTs dramatically enhanced the ECL emission of luminol for about 25 multiple, meanwhile decreased the requirement of buffer pH and exciting potential. The ECL emission of luminol on functionalised ITO electrode has sensitive response toward hydrogen peroxide, and extraordinarily responsive toward the antioxidant. Under the optimal conditions, the ECL emission exhibited a linear response within the concentration range from 0.1 mg L(-1) to 30 mg L(-1) and an absolute detection limit of 1.65×10(-10) g of resveratrol. The gross antioxidant activity of blueberry and kiwi were determined with satisfactory recoveries.

  19. Deferiprone, a non-toxic reagent for determination of iron in samples via sequential injection analysis

    NASA Astrophysics Data System (ADS)

    Pragourpun, Kraivinee; Sakee, Uthai; Fernandez, Carlos; Kruanetr, Senee

    2015-05-01

    We present for the first time the use of deferiprone as a non-toxic complexing agent for the determination of iron by sequential injection analysis in pharmaceuticals and food samples. The method was based on the reaction of Fe(III) and deferiprone in phosphate buffer at pH 7.5 to give a Fe(III)-deferiprone complex, which showed a maximum absorption at 460 nm. Under the optimum conditions, the linearity range for iron determination was found over the range of 0.05-3.0 μg mL-1 with a correlation coefficient (r2) of 0.9993. The limit of detection and limit of quantitation were 0.032 μg mL-1 and 0.055 μg mL-1, respectively. The relative standard deviation (%RSD) of the method was less than 5.0% (n = 11), and the percentage recovery was found in the range of 96.0-104.0%. The proposed method was satisfactorily applied for the determination of Fe(III) in pharmaceuticals, water and food samples with a sampling rate of 60 h-1.

  20. The determination of trace lead in Chinese medicinal herbs by flow injection analysis in polyethyleneglycol medium

    NASA Astrophysics Data System (ADS)

    Gong, Aiqin; Zhu, Xiashi; Huang, Xiaoyan; Zhang, Yaqin

    2008-01-01

    In this work, a new flow injection analysis (FIA) for the determination of Pb 2+ in Chinese medicinal herbs was developed. In the buffer solution of borax-NaOH (pH 10.5), Pb 2+ reacted with 2-[(5-bromo-2-pyridyl)-azo]-5-(diethyl-amino)phenol (5-Br-PADAP) to form a complex. The experimental results showed that the sensitivity was enhanced in the presence of polyethyleneglycol-800 (PG-800). The main factors affecting the determination were investigated in detail. Under the optimum conditions, the linear range and detection limit is 0.0-0.3 μg/mL and 1.5 ng/mL (correlation coefficient r = 0.9996), respectively. The linear regression equation is A = -0.005 + 0.60 c (μg/mL). The sample throughout is 10 h -1. Foreign substrates effects were also investigated. The proposed method has been successfully applied to the determination of lead in reference material, goldthread and lepidium seed.

  1. Determination of propafenone hydrochloride by flow-injection analysis coupled with resonance light scattering detection.

    PubMed

    Hu, Xiaoli; Xu, Dongpo; Liu, Shaopu; Liu, Zhongfang; Liu, Sa

    2009-01-01

    A simple, sensitive and rapid flow injection analysis (FIA) method with resonance light scattering (RLS) was described for the determination of propafenone (PPF). The method was based on the ion-association reaction of 12-tungstophosphoric acid (TP) with propafenone. In pH 1.0 acidic medium, TP reacted with PPF to form an ion-associate complex, which resulted in a significant enhancement of RLS intensity. The maximum scattering peak was located at 340 nm, the RLS intensity was proportional to the concentration of PPF in the range 0.003-9.0 microg/mL, and the detection limit (3sigma) of 1.0 ng/mL was obtained at a sampling rate of 60 samples/h. The feasible reaction conditions and FIA parameters for the system were optimized. The method proposed in this paper shows satisfactory reproducibility with a relative standard deviation (RSD) of 2.1% for 10 successive determinations of 2.0 microg/mL PPF. The present method had been successfully applied to the determination of PPF in serum samples and pharmaceutical samples. The results obtained were in agreement with the method used in the Chinese Pharmacopoeia.

  2. Flow injection analysis of nitrate and nitrite in commercial baby foods.

    PubMed

    Chetty, Adrian A; Prasad, Surendra

    2016-04-15

    Commercial baby foods are an easy alternative to home-made meals especially for working parents in a nuclear family therefore it is imperative to determine the nitrate and nitrite content in commercially available baby foods varieties marketed in Fiji. A total of 108 baby food samples were analyzed for nitrate and nitrite using our standardized flow injection analysis (FIA) technique with colorimetric detection technique employing sulfanilamide and N-(1-naphthyl)ethylenediamine dihydrochloride as color reagents where the samples throughput was 38 h(-1). The commercial baby food varieties chosen comprised of vegetables, cereals, fruits and milk. The study shows that the nitrate content of the baby foods studied ranges from 2.10 to 220.67 mg kg(-1) whereas the nitrite content ranges from 0.44 to 3.67 mg kg(-1). Typical recoveries of spiked nitrate residues ranged from 92% to 106%. The study shows that the average nitrate content of commercially available baby foods in Fiji descends below the maximum level proposed by the European Union Legislation.

  3. Determination of Trace Nickel in Natural Water by Flow Injection Analysis with Cetrimonium Bromide as Sensitizer

    NASA Astrophysics Data System (ADS)

    Zhao, Z. X.; Zhang, C. X.; Li, N.; Zhang, X. S.

    2015-11-01

    2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) is a highly sensitive chromogenic reagent that can react with most of the transition and alkaline earth metals. The Ni(II)-5-Br-PADAP complex is more stable than other metal-5-Br-PADAP complexes. In the presence of seignette salt, ethylenediaminetetraacetic acid (EDTA) can decompose most of the 5-Br-PADAP complexes with metals except for iron, cobalt, and nickel. Cetrimonium bromide (CTMAB) as a sensitizer for the color reaction forms a ternary complex with nickel and 5-Br-PADAP with maximum absorption wavelength at 561 nm. CTMAB can significantly improve the sensitivity and selectivity of nickel determination, as well as the stability and solubility of compounds. In this study, the determination of trace nickel in natural water samples was performed by flow injection analysis. The calibration lines were established in the range of 0-200 μg/l of nickel (n ≥ 3), and the limit of detection was 0.093 μg/l. The relative standard deviation was 2.55% for the determination of 25 μg/l nickel (n ≥ 20). The recoveries of this method ranged from 91.0 to 101% for environmental water samples. A large amount of aluminum, calcium, cadmium, copper, bicarbonate, magnesium, zinc, and iron, except for cobalt, did not interfere with the determination of nickel.

  4. Paper-based analytical device for electrochemical flow-injection analysis of glucose in urine.

    PubMed

    Lankelma, Jan; Nie, Zhihong; Carrilho, Emanuel; Whitesides, George M

    2012-05-01

    This article describes a new design for a paper-based electrochemical system for flow-injection analysis. Capillary wicking facilitates a gravity-driven flow of buffer solution continuously through paper and nitrocellulose, from a buffer reservoir at one end of the device to a sink at the other. A difference in height between the reservoir and the sink leads to a continuous and constant flow. The nitrocellulose lies horizontally on a working electrode, which consists of a thin platinum layer deposited on a solid support. The counter and reference electrodes are strategically positioned upstream in the buffer reservoir. A simple pipetting device was developed for reliable application of (sub)microliter volumes of sample without the need of commercial micropipets; this device did not damage the nitrocellulose membrane. Demonstration of the system for the determination of the concentration of glucose in urine resulted in a noninvasive, quantitative assay that could be used for diagnosis and monitoring of diabetes. This method does not require disposable test strips, with enzyme and electrodes, that are thrown away after each measurement. Because of its low cost, this system could be used in medical environments that are resource-limited.

  5. Experiments and analysis of drainage displacement processes relevant to carbon dioxide injection.

    PubMed

    Aryana, Saman A; Kovscek, Anthony R

    2012-12-01

    The motivation for this work is a dramatically improved understanding of the fluid mechanics of drainage processes with applications such as CO_{2} storage in saline aquifers and water-alternating-gas injection as an enhanced oil recovery method. In this paper we present in situ distributions of wetting and nonwetting fluids obtained during core-scale two-phase immiscible drainage experiments. The ratio of the viscosity of the resident fluid to that of the invading fluid varies across a range of 0.43 to 150. Saturation distributions observed during dynamic displacement experiments are surprisingly smooth and do not display only one or a few dominant fingers, contrary to the indications of the current literature. The analysis of the saturation distribution using the fractal dimensions of the dynamic three-dimensional saturation distributions suggests that the constitutive relationships for porous media, namely, the relative permeability functions, are history dependent. Accordingly, it is suggested that the nonlinear, unstable flow regime is the regime where efforts to improve physical understanding must be focused.

  6. Microfluidic Flow Injection Analysis with Thermal Lens Microscopic Detection for Determination of NGAL

    NASA Astrophysics Data System (ADS)

    Radovanović, Tatjana; Liu, Mingqiang; Likar, Polona; Klemenc, Matjaž; Franko, Mladen

    2015-06-01

    A combined microfluidic flow injection analysis-thermal lens microscopy (FIA-TLM) system was applied for determination of neutrophil gelatinase-associated lipocalin (NGAL)—a biomarker of acute kidney injury. NGAL was determined following a commercial ELISA assay and transfer of the resulting solution into the FIA-TLM system with a 100 m deep microchannel. At an excitation power of 100 mW, the FIA-TLM provided about seven times lower limits of detection (1.5 pg as compared to a conventional ELISA test, and a sample throughput of six samples per minute, which compares favorably with sample throughput of the microtiter plate reader, which reads 96 wells in about 30 min. Comparison of results for NGAL in plasma samples from healthy individuals and for NGAL dynamics in patients undergoing coronary angiography measured with transmission mode spectrometry on a microtiter plate reader and with FIA-TLM showed good agreement. In addition to improved LOD, the high sensitivity of FIA-TLM offers possibilities of a further reduction of the total reaction time of the NGAL ELISA test by sacrificing some of the sensitivity while reducing the duration of individual incubation steps.

  7. Irreversible and reversible reactive chromatography: analytical solutions and moment analysis for rectangular pulse injections.

    PubMed

    Bibi, Sameena; Qamar, Shamsul; Seidel-Morgenstern, Andreas

    2015-03-13

    This work is concerned with the analysis of models for linear reactive chromatography describing irreversible A→B and reversible A↔B reactions. In contrast to previously published results rectangular reactant pulses are injected into initially empty or pre-equilibrated columns assuming both Dirichlet and Danckwerts boundary conditions. The models consist of two partial differential equations, accounting for convection, longitudinal dispersion and first order chemical reactions. Due to the effect of involved mechanisms on solute transport, analytical and numerical solutions of the models could be helpful to understand, design and optimize chromatographic reactors. The Laplace transformation is applied to solve the model equations analytically for linear adsorption isotherms. Statistical temporal moments are derived from solutions in the Laplace domain. Analytical results are compared with numerical predictions generated using a high-resolution finite volume scheme for two sets of boundary conditions. Several case studies are carried out to analyze reactive liquid chromatographic processes for a wide range of mass transfer and reaction kinetics. Good agreements in the results validate the correctness of the analytical solutions and accuracy of the proposed numerical algorithm.

  8. Successive determination of urinary bilirubin and creatinine employing simultaneous injection effective mixing flow analysis.

    PubMed

    Ponhong, Kraingkrai; Teshima, Norio; Grudpan, Kate; Vichapong, Jitlada; Motomizu, Shoji; Sakai, Tadao

    2015-02-01

    A novel four-channel simultaneous injection effective mixing flow analysis (SIEMA) system has been assembled for successive determination of bilirubin and creatinine in urinary samples. The chemical variables and physical parameters in the flow system were optimized for the enhancement of successive analytical performances. The interferences from urine matrices on the determination of bilirubin and creatinine were eliminated to dilute urine samples. The calibration graphs with the optimum conditions were achieved to be in 0.024-5.0 mg L(-1) for bilirubin and 2-100 mg L(-1) for creatinine. The relative standard deviations (RSDs) at 3 mg L(-1) of bilirubin and at 50 mg L(-1) of creatinine for 11 runs were 1.5 and 1.0%, respectively. The limits of detections (3σ of blank) for bilirubin and creatinine were 7 µg L(-1) and 0.6 mg L(-1), respectively. The sample throughput for stepwise detection was 22 h(-1). The proposed method was applied to the successive determination of bilirubin and creatinine in urine samples.

  9. Numerical analysis for the multi-phase flow of pulverized coal injection inside blast furnace tuyere

    SciTech Connect

    Chen, C.W.

    2005-09-01

    The pulverized coal injection (PCI) system was modified from single lance injection into double lance injection at No. 3 Blast Furnace of CSC. It is beneficial to reduce the cost of coke. However, the injected coal was found very close to the inner wall of the tuyere during the operation, such as to cause the possibility of erosion for the tuyere. In this study a three-dimensional mathematical model has been developed based on a computational fluid dynamics software PHOENICS to simulate the fluid flow phenomena inside blast furnace tuyere. The model was capable of handling steady-state, three-dimensional multi-phase flow of pulverized coal injection. The model was applied to simulate the flow patterns of the injection coal inside the tuyere with two kinds of lance design for the PCI system. The distribution of injection coal was simulated such as to estimate the possibility of erosion for the tuyere. The calculated results agreed with the operating experience of CSC plant and the optimum design of double lance was suggested. The model was also applied to simulate the oxygen concentration distribution with these different oxygen enrichments for the coal/oxygen lance system. The calculated results agreed with the experimental measurement. These test results demonstrate that the model is both reasonably reliable and efficient.

  10. The Effect of Different Dosing Schedules of Intravitreal Sirolimus, a Mammalian Target of Rapamycin (mTOR) Inhibitor, in the Treatment of Non-Infectious Uveitis (An American Ophthalmological Society Thesis)

    PubMed Central

    Nguyen, Quan Dong; Sadiq, Mohammad Ali; Soliman, Mohamed Kamel; Agarwal, Aniruddha; Do, Diana V.; Sepah, Yasir J.

    2016-01-01

    Purpose: To determine if two different doses of intravitreal sirolimus, an mTOR inhibitor, can decrease inflammation and is safe in eyes with non-infectious posterior, intermediate, or panuveitis in the Sirolimus as a Therapeutic Approach UVEitis: Protocol-2 (SAVE-2) Study. Methods: SAVE-2 is a prospective randomized, phase II, open-label interventional clinical trial conducted at 4 clinical centers in the United States. Eligible subjects were randomized into one of two treatments. Group 1 received 440µg of intravitreal sirolimus in study eyes on days 0, 30, 60, 90, 120, and 150; group 2 received 880µg of intravitreal sirolimus on days 0, 60, and 120. Fellow eyes were also eligible to receive sirolimus (of opposite dose to that of study eye). Primary endpoint of the study was at month 6 (M6). Results: 24 subjects have been randomized in SAVE-2 and are included in the analysis. Vitreous haze decreased by ≥2 steps in 63.6% and 50% of patients in groups 1 and 2, respectively at M6 (p=0.695). Mean change in best-corrected visual acuity for subjects was +3.66 and −2.91 ETDRS letters in group 1 and 2, respectively. Among subjects with macular edema at baseline (n=13), the mean change in foveal thickness was −89.42µm in group 1 and +81.5µm in group 2 at M6. Conclusions: Both low and high doses of intravitreal sirolimus were found to decrease vitreous haze in eyes with non-infectious uveitis. Low dose (440µg) sirolimus administered monthly may be more efficacious in reducing uveitic macular edema than high dose (880µg) administered every 2 months. PMID:27630374

  11. Basin-scale Modeling of Geological Carbon Sequestration: Model Complexity, Injection Scenario and Sensitivity Analysis

    NASA Astrophysics Data System (ADS)

    Huang, X.; Bandilla, K.; Celia, M. A.; Bachu, S.

    2013-12-01

    Geological carbon sequestration can significantly contribute to climate-change mitigation only if it is deployed at a very large scale. This means that injection scenarios must occur, and be analyzed, at the basin scale. Various mathematical models of different complexity may be used to assess the fate of injected CO2 and/or resident brine. These models span the range from multi-dimensional, multi-phase numerical simulators to simple single-phase analytical solutions. In this study, we consider a range of models, all based on vertically-integrated governing equations, to predict the basin-scale pressure response to specific injection scenarios. The Canadian section of the Basal Aquifer is used as a test site to compare the different modeling approaches. The model domain covers an area of approximately 811,000 km2, and the total injection rate is 63 Mt/yr, corresponding to 9 locations where large point sources have been identified. Predicted areas of critical pressure exceedance are used as a comparison metric among the different modeling approaches. Comparison of the results shows that single-phase numerical models may be good enough to predict the pressure response over a large aquifer; however, a simple superposition of semi-analytical or analytical solutions is not sufficiently accurate because spatial variability of formation properties plays an important role in the problem, and these variations are not captured properly with simple superposition. We consider two different injection scenarios: injection at the source locations and injection at locations with more suitable aquifer properties. Results indicate that in formations with significant spatial variability of properties, strong variations in injectivity among the different source locations can be expected, leading to the need to transport the captured CO2 to suitable injection locations, thereby necessitating development of a pipeline network. We also consider the sensitivity of porosity and

  12. Stability Analysis of High-Speed Boundary-Layer Flow with Gas Injection (Briefing Charts)

    DTIC Science & Technology

    2014-06-01

    to improve the injector performance • Shaping of injector – Conical shapes – Cylindrical shape • Suction-blowing of zero mass injection • Conclusions...16Distribution A: Approved for Public Release; Distribution Unlimited Injector of conical shape 5-deg half-angle sharp cone with the injector having the slope...pressure for conical injectors (injection rate 13.5 g/s) =1 =3 Baseline (=0) Injection region 18Distribution A: Approved for Public Release

  13. Flow regime analysis for fluid injection into a confined aquifer: implications for CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Guo, B.; Zheng, Z.; Celia, M. A.; Stone, H.

    2015-12-01

    Carbon dioxide injection into a confined saline aquifer may be modeled as an axisymmetric two-phase flow problem. Assuming the two fluids segregate in the vertical direction due to strong buoyancy, and neglecting capillary pressure and miscibility, the lubrication approximation leads to a nonlinear advection-diffusion equation that describes the evolution of the sharp fluid-fluid interface. The flow behaviors in the system are controlled by two dimensionless groups: M, the viscosity ratio of the displaced fluid relative to injected fluid, and Γ , the gravity number, which represents the relative importance of buoyancy and fluid injection. Four different analytical solutions can be derived as the asymptotic approximations, representing specific values of the parameter pairs. The four solutions correspond to: (1) Γ << 1, M <1; (2) Γ << 1, M =1; (3) Γ << 1, M >1; and (4) Γ >> 1, any M values. The first two of these solutions are new, while the third corresponds to the solution of Nordbotten and Celia (2006) for confined injections and the fourth corresponds to the solution of (Lyle et al., 2005) for gravity currents in an unconfined aquifer. Overall, the various axisymmetric flows can be summarized in a Γ-M regime diagram with five distinct dynamic behaviors including the four asymptotic regimes and an intermediate regime (Fig. 1). Data from a number of CO2 injection sites around the world can be used to compute the two dimensionless groups Γ and M associated with each injection. When plotted on the regime diagram, these values show the flow behavior for each injection and how the values vary from site to site. For all the CO2 injections, M is always larger than 1, while Γ can range from 0.01 up to 100. The pairs of (Γ, M) with lower Γ values correspond to solution (3), while the ones with higher Γ values can move up to the intermediate regime and the flow regime for solution (4). The higher values of Γ correspond to pilot-scale injections with low

  14. Direct injection isocratic high-performance liquid chromatographic analysis of mitomycin C in plasma.

    PubMed

    Song, D; Au, J L

    1996-02-09

    A direct injection high-performance liquid chromatography method is described for the determination of mitomycin C (MMC) in human plasma. The stationary phase consisted of hydrophilic and hydrophobic functional groups covalently bound to silicone-coated silica beads (CAPCELL PAK MF Ph-1, 150x4.6 mm I.D., 5 microns). A mobile phase using 100% water gave a better separation of MMC from endogenous interferences as compared to a mobile phase with 12.5% acetonitrile and 2.5 mM phosphate buffer (pH 6.9). Using water as the eluent (1 ml/min) and UV detection at 365 nm, MMC was found to elute at 5.0 min with a peak width of 0.3 min, whereas endogenous interferences eluted before 3 min. Total assay time per sample was 6 min. Internal standard was not required because the recovery of MMC was nearly complete, about 90% from 20 to 5000 ng/ml. The standard curve was linear from 20 to 5000 ng/ml in plasma, and the intra-and inter-day variation was between 3 to 6%. The lower detection limit was 5 ng/ml with a 25 microliters sample, which represents a two- to four-fold improvement over the 10 ng/ml detection limit by previous methods using liquid-liquid extraction and comparable sample size. The simplicity of this method, i.e., no sample extraction, no internal standard, 100% aqueous mobile phase, isocratic elution and short analysis time (6 min/sample), makes it suitable for large scale routine sample analysis, whereas its small sample volume requirement and high sensitivity are useful for pharmacokinetic studies in small animals where limited sample is available.

  15. Analysis of Anaphylactic Shock Caused by 17 Types of Traditional Chinese Medicine Injections Used to Treat Cardiovascular and Cerebrovascular Diseases

    PubMed Central

    Guo, Yu-Jiao; Wang, De-Wang; Meng, Ling; Wang, Yong-Qing

    2015-01-01

    Several reports describing anaphylactic shock following treatment of cardiovascular and cerebrovascular diseases with Chinese herbal injections were described. Our analysis of these reports showed that anaphylactic shock caused by traditional Chinese medicine (TCM) injections for the treatment of cardiovascular and cerebrovascular diseases is common but also sometimes fatal. Therefore, we proposed the following four suggestions for improving the clinical safety of delivering Chinese herbal injections and reducing the occurrence of allergic shock. First, patients with cardiovascular and cerebrovascular diseases are at high risk, so they should only be given TCM injections after a doctor's diagnosis and approval. Second, people in allergic groups can suffer anaphylactic shock, so vigilance is important in the treatment of all age groups, although even more caution should be exercised when treating children or elderly people. In fact, TCM injections may not be appropriate for those age groups, so that they should be carefully considered before treatment. Third, no significant gender differences have been noted in patients with anaphylactic shock, so all patients should be carefully monitored, irrespective of gender. Fourth, the timeframe in which different drugs cause anaphylactic shock varies; thus, patients should be observed as long as possible. PMID:26000291

  16. Short-Term Cessation of Sex Work and Injection Drug Use: Evidence from a Recurrent Event Survival Analysis

    PubMed Central

    Gaines, Tommi L.; Urada, Lianne; Martinez, Gustavo; Goldenberg, Shira M.; Rangel, Gudelia; Reed, Elizabeth; Patterson, Thomas L.; Strathdee, Steffanie A.

    2015-01-01

    Objective This study quantitatively examined the prevalence and correlates of short-term sex work cessation among female sex workers who inject drugs (FSW-IDUs) and determined whether injection drug use was independently associated with cessation. Methods We used data from FSW-IDUs (n=467) enrolled into an intervention designed to increase condom use and decrease sharing of injection equipment but was not designed to promote sex work cessation. We applied a survival analysis that accounted for quit-re-entry patterns of sex work over 1-year stratified by city, Tijuana and Ciudad Juarez, Mexico. Results Overall, 55% of participants stopped sex work at least once during follow-up. Controlling for other characteristics and intervention assignment, injection drug use was inversely associated with short-term sex work cessation in both cities. In Ciudad Juarez, women receiving drug treatment during follow-up had a 2-fold increase in the hazard of stopping sex work. In both cities, income from sources other than sex work, police interactions and healthcare access were independently and significantly associated with shorter-term cessation. Conclusions Short-term sex work cessation was significantly affected by injection drug use. Expanded drug treatment and counseling coupled with supportive services such as relapse prevention, job training, and provision of alternate employment opportunities may promote longer-term cessation among women motivated to leave the sex industry. PMID:25644589

  17. Flow Rates Measurement and Uncertainty Analysis in Multiple-Zone Water-Injection Wells from Fluid Temperature Profiles

    PubMed Central

    Reges, José E. O.; Salazar, A. O.; Maitelli, Carla W. S. P.; Carvalho, Lucas G.; Britto, Ursula J. B.

    2016-01-01

    This work is a contribution to the development of flow sensors in the oil and gas industry. It presents a methodology to measure the flow rates into multiple-zone water-injection wells from fluid temperature profiles and estimate the measurement uncertainty. First, a method to iteratively calculate the zonal flow rates using the Ramey (exponential) model was described. Next, this model was linearized to perform an uncertainty analysis. Then, a computer program to calculate the injected flow rates from experimental temperature profiles was developed. In the experimental part, a fluid temperature profile from a dual-zone water-injection well located in the Northeast Brazilian region was collected. Thus, calculated and measured flow rates were compared. The results proved that linearization error is negligible for practical purposes and the relative uncertainty increases as the flow rate decreases. The calculated values from both the Ramey and linear models were very close to the measured flow rates, presenting a difference of only 4.58 m³/d and 2.38 m³/d, respectively. Finally, the measurement uncertainties from the Ramey and linear models were equal to 1.22% and 1.40% (for injection zone 1); 10.47% and 9.88% (for injection zone 2). Therefore, the methodology was successfully validated and all objectives of this work were achieved. PMID:27420068

  18. Simulation of Reclaimed-Water Injection and Pumping Scenarios and Particle-Tracking Analysis near Mount Pleasant, South Carolina

    USGS Publications Warehouse

    Petkewich, Matthew D.; Campbell, Bruce G.

    2009-01-01

    The effect of injecting reclaimed water into the Middendorf aquifer beneath Mount Pleasant, South Carolina, was simulated using a groundwater-flow model of the Coastal Plain Physiographic Province of South Carolina and parts of Georgia and North Carolina. Reclaimed water, also known as recycled water, is wastewater or stormwater that has been treated to an appropriate level so that the water can be reused. The scenarios were simulated to evaluate potential changes in groundwater flow and groundwater-level conditions caused by injecting reclaimed water into the Middendorf aquifer. Simulations included a Base Case and two injection scenarios. Maximum pumping rates were simulated as 6.65, 8.50, and 10.5 million gallons per day for the Base Case, Scenario 1, and Scenario 2, respectively. The Base Case simulation represents a non-injection estimate of the year 2050 groundwater levels for comparison purposes for the two injection scenarios. For Scenarios 1 and 2, the simulated injection of reclaimed water at 3 million gallons per day begins in 2012 and continues through 2050. The flow paths and time of travel for the injected reclaimed water were simulated using particle-tracking analysis. The simulations indicated a general decline of groundwater altitudes in the Middendorf aquifer in the Mount Pleasant, South Carolina, area between 2004 and 2050 for the Base Case and two injection scenarios. For the Base Case, groundwater altitudes generally declined about 90 feet from the 2004 groundwater levels. For Scenarios 1 and 2, although groundwater altitudes initially increased in the Mount Pleasant area because of the simulated injection, these higher groundwater levels declined as Mount Pleasant Waterworks pumping increased over time. When compared to the Base Case simulation, 2050 groundwater altitudes for Scenario 1 are between 15 feet lower to 23 feet higher for production wells, between 41 and 77 feet higher for the injection wells, and between 9 and 23 feet higher for

  19. Analysis of D pellet injection experiments in the W7-AS Stellarator

    SciTech Connect

    Lyon, J.F.; Baylor, L.R.; Baldzuhn, J.; Fiedler, S.; Hirsch, M.; Kuehner, G.; Weller, A.

    1997-07-01

    A centrifugal injector was used to inject deuterium pellets (with 3--5 x 10{sup 19} atoms) at approx. equal 600 m/s into current-less, nearly shear-less plasmas in the Wendelstein 7-AS (W7-AS) stellarator. The D pellet was injected horizontally at a location where the non-circular and non-axisymmetric plasma cross section is nearly triangular. Visible-light TV pictures usually showed the pellet as a single ablating mass in the plasma, although the pellet occasionally broke in two or splintered into a cloud of small particles. The density evolution following pellet injection and the effect of pellet injection on energy confinement and fluctuations are discussed.

  20. High-throughput chemical residue analysis by fast extraction and dilution flow injection mass spectrometry.

    PubMed

    Nanita, Sergio C

    2011-01-21

    Fast extraction and dilution flow injection mass spectrometry (FED-FI-MS) is presented as a technique to increase throughput in quantitative multiresidue screening in complex matrices, while meeting current analytical method quality requirements.

  1. Theoretical and experimental analysis of injection seeding a Q-switched alexandrite laser

    NASA Technical Reports Server (NTRS)

    Prasad, C. R.; Lee, H. S.; Glesne, T. R.; Monosmith, B.; Schwemmer, G. K.

    1991-01-01

    Injection seeding is a method for achieving linewidths of less than 500 MHz in the output of broadband, tunable, solid state lasers. Dye lasers, CW and pulsed diode lasers, and other solid state lasers have been used as injection seeders. By optimizing the fundamental laser parameters of pump energy, Q-switched pulse build-up time, injection seed power and mode matching, one can achieve significant improvements in the spectral purity of the Q-switched output. These parameters are incorporated into a simple model for analyzing spectral purity and pulse build-up processes in a Q-switched, injection-seeded laser. Experiments to optimize the relevant parameters of an alexandrite laser show good agreement.

  2. Current smoking is associated with a poor visual acuity improvement after intravitreal ranibizumab therapy in patients with exudative age-related macular degeneration.

    PubMed

    Lee, Sangmoon; Song, Su Jeong; Yu, Hyeong Gon

    2013-05-01

    In this study, the risk factors that may influence visual improvement after intravitreal ranibizumab (IVR) treatment for exudative age-related macular degeneration (AMD) were examined. From 2008 to 2012, 420 patients (448 eyes) with exudative AMD were prospectively registered at Seoul National University Hospital. From this group of patients, 125 eyes were included in this study. All patients were treated with 3 consecutive IVR injections. The visual acuity (VA) was evaluated at baseline and 1 month after the third ranibizumab injection. To evaluate the risk factors associated with VA improvement after IVR, patient demographic data and systemic risk factors were analyzed. Patients were divided into a poor VA improvement group and a good VA improvement group, with reference to the median visual improvement in all eyes. Among 125 eyes, 66 eyes (52.8%) were included in the responder group and 59 eyes (47.2%) in the non-responder group. The median VA improvement after 3 monthly ranibizumab injections was -0.05 logMAR. Multivariate analyses revealed that current smoking (adjusted OR, 7.540; 95% CI, 1.732-32.823) was independently associated with poor VA improvement after IVR treatment for exudative AMD. In conclusion, cigarette smoking is an independent risk factor for lower VA gains with IVR treatment for exudative AMD.

  3. A clinical study to evaluate the efficacy of intravitreal Anti-VEGF therapy in treating macular edema due to retinal venous occlusions

    PubMed Central

    Kumar, Poninder; Banarji, Ajay; Patyal, Sagarika; Gurunadh, V.S.; Ahluwalia, T.S.; Oli, Avadesh; Moulick, P.S.; Makker, Anuradha

    2013-01-01

    Background A non-randomized, interventional study was carried out various types of retinal venous occlusions with significant macular edema who required an Anti-VEGF injection. Method One hundred and one consecutive patients diagnosed as a case of CRVO/HCRVO/BRVO were enrolled in the study provided they had significant macular edema. Atleast three intra-vitreal injections of Anti-VEGFs were given and both the pre and post injections BCVA and CMT on OCT were observed and analyzed. Results 87 patients (86.14%) showed a significant improvement of vision of atleast two lines on the Snellen's and mean BCVA improved from log MAR +1.084 to log MAR +0.455. CMT on OCT showed reduction in thickness after Anti-VEGF therapy in 99 patients out of 101 and mean CMT decreased from 586.30 μ at baseline to 329.50 μ. Both of these findings were statistically very significant. Conclusions Anti-VEGF therapy had a marked improvement in BCVA along with a dramatic reduction in CMT in the vast majority of RVOs patients with no serious ocular or systemic side effects. PMID:24600120

  4. Off-design analysis of a gas turbine powerplant augmented by steam injection using various fuels

    NASA Technical Reports Server (NTRS)

    Stochl, R. J.

    1980-01-01

    Results are compared using coal derived low and intermediate heating valve fuel gases and a conventional distillate. The results indicate that steam injection provides substantial increases in both power and efficiency within the available compressor surge margin. The results also indicate that these performance gains are relatively insensitive as to the type of fuel. Also, in a cogeneration application, steam injection could provide some degree of flexibility by varying the split between power and process steam.

  5. Analysis of the response of the Raft River monitor wells to the 1979 injection tests

    SciTech Connect

    Spencer, S.G.; Callan, D.M.

    1980-09-01

    The geothermal resource for the Department of Energy's (DOE) Raft River Geothermal 5 MWe Power Project is located in a closed ground water basin in southcentral Idaho. Chemical analyses indicate the existence of natural communication along fractures between the geothermal reservoir and the shallower aquifers developed for irrigation. Much of the ground water that is presently used for irrigation is of poor quality. Injection of geothermal fluids at intermediate depths may increase communication between the reservoir and the aquifer, resulting in further degradation of shallow ground water quality over time. Seven monitor wells, ranging in depth from 150 m to 400 m, were drilled to evaluate the potential for this degradation. Monitoring of these wells during two 21-day injection tests at the Raft River Geothermal Injection Well-6 (RRGI-6) indicates two types of response in the shallow aquifer system. First, the water level in Monitor Well-4 (MW-4) increased an average of 0.4 m/week during injection, indicating direct fracture connection between the injection zone and the aquifer penetrated by MW-4. Second, water levels in MW-5, MW-6, and MW-7 showed a step function decrease which coincided with the period of the injection tests. Analyses indicate that this response may be caused by elastic deformation in the aquifer matrix.

  6. Spectral Domain OCT Documented Resolution of Pseudophakic Cystoid Macular Edema after Intravitreal Triamcinolone

    PubMed Central

    Murthy, Ravi K; Chalam, Kakarla V.

    2010-01-01

    Cystoid macular edema (CME) is an important cause of visual loss after cataract surgery. Treatment is usually with topical anti-inflammatory agents, with anti-vascular endothelial growth factor agents and steroids used intravitreally in resistant cases. Even though time-domain Stratus OCT can quantify the macular thickness, it cannot prognosticate visual outcomes due to the poor resolution of images, especially the outer segment-inner segment junction. Spectral-domain OCT (SD-OCT) by its ability to acquire large number of images in a short span of time provides high resolution cross-sectional images of the retina, which not only highlights the underlying pathological changes, but in addition can prognosticate visual recovery. We describe pre and post SD-OCT features of a case of refractory CME who was treated with intravitreal triamcinolone actetonide. PMID:23861610

  7. Analysis of Tests of Subsurface Injection, Storage, and Recovery of Freshwater in Lancaster, Antelope Valley, California

    USGS Publications Warehouse

    Phillips, Steven P.; Carlson, Carl S.; Metzger, Loren F.; Howle, James F.; Galloway, Devin L.; Sneed, Michelle; Ikehara, Marti E.; Hudnut, Kenneth W.; King, Nancy E.

    2003-01-01

    Ground-water levels in Lancaster, California, declined more than 200 feet during the 20th century, resulting in reduced ground-water supplies and more than 6 feet of land subsidence. Facing continuing population growth, water managers are seeking solutions to these problems. Injection of imported, treated fresh water into the aquifer system when it is most available and least expensive, for later use during high-demand periods, is being evaluated as part of a management solution. The U.S. Geological Survey, in cooperation with the Los Angeles County Department of Public Works and the Antelope Valley-East Kern Water Agency, monitored a pilot injection program, analyzed the hydraulic and subsidence-related effects of injection, and developed a simulation/optimization model to help evaluate the effectiveness of using existing and proposed wells in an injection program for halting the decline of ground-water levels and avoiding future land subsidence while meeting increasing ground-water demand. A variety of methods were used to measure aquifer-system response to injection. Water levels were measured continuously in nested (multi-depth) piezometers and monitoring wells and periodically in other wells that were within several miles of the injection site. Microgravity surveys were done to estimate changes in the elevation of the water table in the absence of wells and to estimate specific yield. Aquifer-system deformation was measured directly and continuously using a dual borehole extensometer and indirectly using continuous Global Positioning System (GPS), first-order spirit leveling, and an array of tiltmeters. The injected water and extracted water were sampled periodically and analyzed for constituents, including chloride and trihalomethanes. Measured injection rates of about 750 gallons per minute (gal/min) per well at the injection site during a 5-month period showed that injection at or above the average extraction rates at that site (about 800 gal/min) was

  8. Ibandronate Injection

    MedlinePlus

    Boniva® Injection ... Ibandronate injection is used to treat osteoporosis (a condition in which the bones become thin and weak and break ... Ibandronate injection comes as a solution (liquid) to be injected into a vein by a doctor or nurse in ...

  9. Leuprolide Injection

    MedlinePlus

    Leuprolide injection comes as a long-acting suspension (Lupron) that is injected intramuscularly (into a muscle) by a doctor or nurse in a medical ... Depot-4 month, Lupron Depot-6 Month). Leuprolide injection also comes as a long-acting suspension (Eligard) that is injected subcutaneously (just under ...

  10. An eighteen-month follow-up study on the effects of Intravitreal Dexamethasone Implant in diabetic macular edema refractory to anti-VEGF therapy

    PubMed Central

    Pacella, Fernanda; Romano, Maria Rosaria; Turchetti, Paolo; Tarquini, Giovanna; Carnovale, Anna; Mollicone, Antonella; Mastromatteo, Alessandra; Pacella, Elena

    2016-01-01

    AIM To evaluate the long-term efficacy and safety of dexamethasone implants in subjects affected by diabetic macular edema (DME) resistant to anti-vascular endothelial growth factor (VEGF) therapy. METHODS Thirty-two DME patients were enrolled. A 700 microgram slow release Intravitreal Dexamethasone Implant (Ozurdex®) was placed in the vitreous cavity. All patients were followed for 18mo. Best-corrected visual acuity (BCVA) measured with Early Treatment Diabetic Retinopathy Study (ETDRS) and central macular thickness (CMT) exams were carried out at baseline (T0) and after 1 (T1), 3 (T3), 4 (T4), 6 (T6), 9 (T9), 12 (T12), 15 (T15), and 18mo (T18) post injection. RESULTS Repeated measures ANOVA showed an effect of treatment on ETDRS (P<0.0001). Post hoc analyses revealed that ETDRS values were significantly increased at T1, T3, T4, T9, and T15 (P<0.001) as compared to baseline value (T0). At T6, T12, and T18, ETDRS values were still statistically higher than baseline (P<0.001 vs T0). However, at these time points, we observed a trend to return to baseline conditions. ANOVA also showed an effect of treatment (P<0.0001). CMT decreased significantly at T1, T3, T4, T9, and T15 (P<0.001). At T6 (P<0.01), T12 and T18 (P<0.001) CMT was also significantly lower than T0 although a trend to return to the baseline conditions was also observed. CONCLUSION Our findings demonstrate that Intravitreal Dexamethasone Implant is a good option to improve BCVA and CMT in DME patients resistant to anti-VEGF therapy. Our data also show that the use of drugs administered directly into the vitreous allows achieving appropriate and long-lasting concentration at the site of disease without systemic side effects. PMID:27803859

  11. Economic analysis of condensers for water recovery in steam injected gas turbines

    SciTech Connect

    De Paepe, M.; Huvenne, P.; Dick, E.

    1998-07-01

    Steam injection cycles are interesting for small power ranges because of the high efficiency and the relatively low investment costs. A big disadvantage is the consumption of water by the cycle. Water recovery is seldom realized in industrial practice. In this paper an analysis of the technical and economical possibilities of water recovery by condensation of water out of the exhaust gases is made. Three gas turbines are considered : the Kawasaki M1A-13CC (2.3 MWe), the Allison 501KH (6.8 MWe) and the General Electric LM1600 (17 MWe). For every gas turbine two types of condensers are designed. In the water cooled condenser finned tubes are used to cool the exhaust gases, flowing at the outside of the tubes. The water itself flows at the inside of the tubes and is cooled by a water to air cooler. In the air cooled condenser the exhaust gases flow at the inside of the tubes and the cooling air at the outside. The investment costs of the condensers is compared to the costs of the total installation. The investment costs are relatively smaller if the produced power goes up. The water cooled condenser with water to air cooler is cheaper than the air cooled condenser. Using a condenser results in higher exploitation costs due to the fans and pumps. It is shown that the air cooled condenser has lower exploitation costs than the water cooled one. Pay back time of the total installation does not significantly vary compared to the installation without recovery. Water prices are determined for which water recovery is profitable. For the water cooled condenser the turning point lies at 2.2 Euro/m; for the air cooled condenser this is 0.6 Euro/m.

  12. Metagenomic Analysis Indicates Epsilonproteobacteria as a Potential Cause of Microbial Corrosion in Pipelines Injected with Bisulfite.

    PubMed

    An, Dongshan; Dong, Xiaoli; An, Annie; Park, Hyung S; Strous, Marc; Voordouw, Gerrit

    2016-01-01

    Sodium bisulfite (SBS) is used as an oxygen scavenger to decrease corrosion in pipelines transporting brackish subsurface water used in the production of bitumen by steam-assisted gravity drainage. Sequencing 16S rRNA gene amplicons has indicated that SBS addition increased the fraction of the sulfate-reducing bacteria (SRB) Desulfomicrobium, as well as of Desulfocapsa, which can also grow by disproportionating sulfite into sulfide, sulfur, and sulfate. SRB use cathodic H2, formed by reduction of aqueous protons at the iron surface, or use low potential electrons from iron and aqueous protons directly for sulfate reduction. In order to reveal the effects of SBS treatment in more detail, metagenomic analysis was performed with pipe-associated solids (PAS) scraped from a pipe section upstream (PAS-616P) and downstream (PAS-821TP) of the SBS injection point. A major SBS-induced change in microbial community composition and in affiliated hynL genes for the large subunit of [NiFe] hydrogenase was the appearance of sulfur-metabolizing Epsilonproteobacteria of the genera Sulfuricurvum and Sulfurovum. These are chemolithotrophs, which oxidize sulfide or sulfur with O2 or reduce sulfur with H2. Because O2 was absent, this class likely catalyzed reduction of sulfur (S(0)) originating from the metabolism of bisulfite with cathodic H2 (or low potential electrons and aqueous protons) originating from the corrosion of steel (Fe(0)). Overall this accelerates reaction of of S(0) and Fe(0) to form FeS, making this class a potentially powerful contributor to microbial corrosion. The PAS-821TP metagenome also had increased fractions of Deltaproteobacteria including the SRB Desulfomicrobium and Desulfocapsa. Altogether, SBS increased the fraction of hydrogen-utilizing Delta- and Epsilonproteobacteria in brackish-water-transporting pipelines, potentially stimulating anaerobic pipeline corrosion if dosed in excess of the intended oxygen scavenger function.

  13. Metagenomic Analysis Indicates Epsilonproteobacteria as a Potential Cause of Microbial Corrosion in Pipelines Injected with Bisulfite

    PubMed Central

    An, Dongshan; Dong, Xiaoli; An, Annie; Park, Hyung S.; Strous, Marc; Voordouw, Gerrit

    2016-01-01

    Sodium bisulfite (SBS) is used as an oxygen scavenger to decrease corrosion in pipelines transporting brackish subsurface water used in the production of bitumen by steam-assisted gravity drainage. Sequencing 16S rRNA gene amplicons has indicated that SBS addition increased the fraction of the sulfate-reducing bacteria (SRB) Desulfomicrobium, as well as of Desulfocapsa, which can also grow by disproportionating sulfite into sulfide, sulfur, and sulfate. SRB use cathodic H2, formed by reduction of aqueous protons at the iron surface, or use low potential electrons from iron and aqueous protons directly for sulfate reduction. In order to reveal the effects of SBS treatment in more detail, metagenomic analysis was performed with pipe-associated solids (PAS) scraped from a pipe section upstream (PAS-616P) and downstream (PAS-821TP) of the SBS injection point. A major SBS-induced change in microbial community composition and in affiliated hynL genes for the large subunit of [NiFe] hydrogenase was the appearance of sulfur-metabolizing Epsilonproteobacteria of the genera Sulfuricurvum and Sulfurovum. These are chemolithotrophs, which oxidize sulfide or sulfur with O2 or reduce sulfur with H2. Because O2 was absent, this class likely catalyzed reduction of sulfur (S0) originating from the metabolism of bisulfite with cathodic H2 (or low potential electrons and aqueous protons) originating from the corrosion of steel (Fe0). Overall this accelerates reaction of of S0 and Fe0 to form FeS, making this class a potentially powerful contributor to microbial corrosion. The PAS-821TP metagenome also had increased fractions of Deltaproteobacteria including the SRB Desulfomicrobium and Desulfocapsa. Altogether, SBS increased the fraction of hydrogen-utilizing Delta- and Epsilonproteobacteria in brackish-water-transporting pipelines, potentially stimulating anaerobic pipeline corrosion if dosed in excess of the intended oxygen scavenger function. PMID:26858705

  14. Analysis of gas turbine engines using water and oxygen injection to achieve high Mach numbers and high thrust

    NASA Technical Reports Server (NTRS)

    Henneberry, Hugh M.; Snyder, Christopher A.

    1993-01-01

    An analysis of gas turbine engines using water and oxygen injection to enhance performance by increasing Mach number capability and by increasing thrust is described. The liquids are injected, either separately or together, into the subsonic diffuser ahead of the engine compressor. A turbojet engine and a mixed-flow turbofan engine (MFTF) are examined, and in pursuit of maximum thrust, both engines are fitted with afterburners. The results indicate that water injection alone can extend the performance envelope of both engine types by one and one-half Mach numbers at which point water-air ratios reach 17 or 18 percent and liquid specific impulse is reduced to some 390 to 470 seconds, a level about equal to the impulse of a high energy rocket engine. The envelope can be further extended, but only with increasing sacrifices in liquid specific impulse. Oxygen-airflow ratios as high as 15 percent were investigated for increasing thrust. Using 15 percent oxygen in combination with water injection at high supersonic Mach numbers resulted in thrust augmentation as high as 76 percent without any significant decrease in liquid specific impulse. The stoichiometric afterburner exit temperature increased with increasing oxygen flow, reaching 4822 deg R in the turbojet engine at a Mach number of 3.5. At the transonic Mach number of 0.95 where no water injection is needed, an oxygen-air ratio of 15 percent increased thrust by some 55 percent in both engines, along with a decrease in liquid specific impulse of 62 percent. Afterburner temperature was approximately 4700 deg R at this high thrust condition. Water and/or oxygen injection are simple and straightforward strategies to improve engine performance and they will add little to engine weight. However, if large Mach number and thrust increases are required, liquid flows become significant, so that operation at these conditions will necessarily be of short duration.

  15. Experimental and numerical analysis of the temperature distribution of injection molded products using protruding microprobes.

    PubMed

    Liu, Shih-Jung; Ho, Chia-Wei

    2011-05-01

    Injection molding has been one of the most important polymer processing methods for manufacturing plastic parts. In the process, the temperature is an important parameter that influences process features such as cycle times, crystallization rates, degree of crystallinity, melt flow properties, and molded product qualities. This study aims to, experimentally and numerically, examine the three-dimensional temperature distribution along the melt flow path of injection molded parts. A special experimental set-up, which includes an injection mold equipped with protruding microprobes for guiding embedded thermocouples, was designed and built to measure the temperature field along the flow path, i.e., inside the runner and the cavity, of injection molded products. The experimental results suggested that the disturbance induced by the probes remained negligible and precise temperature profiles could be measured at various positions inside the cavity. A significant increase of melt temperature was found to result from the viscous dissipation of the polymeric materials in the runner. Additionally, a commercially available code was employed to simulate and predict the temperature variation in injection molded parts. It was shown that the numerical simulation predicted better the temperature distributions inside the cavity than those along the runner.

  16. Experimental and numerical analysis of the temperature distribution of injection molded products using protruding microprobes

    NASA Astrophysics Data System (ADS)

    Liu, Shih-Jung; Ho, Chia-Wei

    2011-05-01

    Injection molding has been one of the most important polymer processing methods for manufacturing plastic parts. In the process, the temperature is an important parameter that influences process features such as cycle times, crystallization rates, degree of crystallinity, melt flow properties, and molded product qualities. This study aims to, experimentally and numerically, examine the three-dimensional temperature distribution along the melt flow path of injection molded parts. A special experimental set-up, which includes an injection mold equipped with protruding microprobes for guiding embedded thermocouples, was designed and built to measure the temperature field along the flow path, i.e., inside the runner and the cavity, of injection molded products. The experimental results suggested that the disturbance induced by the probes remained negligible and precise temperature profiles could be measured at various positions inside the cavity. A significant increase of melt temperature was found to result from the viscous dissipation of the polymeric materials in the runner. Additionally, a commercially available code was employed to simulate and predict the temperature variation in injection molded parts. It was shown that the numerical simulation predicted better the temperature distributions inside the cavity than those along the runner.

  17. Analysis of linear and cyclic oligomers in polyamide-6 without sample preparation by liquid chromatography using the sandwich injection method. I. Injection procedure and column stability.

    PubMed

    Mengerink, Y; Peters, R; Kerkhoff, M; Hellenbrand, J; Omloo, H; Andrien, J; Vestjens, M; van der Wal, S

    2000-04-21

    We report a method for reliable routine polymer sample introduction with minimal bias, a separation method of the first six linear and cyclic oligomers by liquid chromatography, quantification using group equivalents and long term method performance. Injecting a polymer sample in a mobile phase containing an aqueous non-solvent often results in blocked systems as the polymer precipitates in the connecting capillaries. In this first part we focus on a new injection technique, in which the dissolved polyamide is placed between two zones of formic acid, preventing the polymer to precipitate before it reaches the column. Development of this sandwich injection method makes direct injection of the polymer into an aqueous acetonitrile gradient feasible. The oligomeric polyamide recovery of this technique, extraction, dissolution/precipitation and direct injection on a hexafluoro-isopropanol (HFIP) gradient were compared. With the sandwich injection method the polymer remains on the column, slowly changing the stationary phase. The influence of this on resolution and retention was studied. Column stability allows sixty injections before cleaning or replacing the column is necessary.

  18. An apparatus for the determination of volatile analytes by stopped-flow injection analysis using an integrated fiber optic detector.

    PubMed

    Baxter, P J; Růzicka, J; Christian, G D; Olson, D C

    1994-03-01

    A new method for the analysis of volatile analytes using a stopped-flow injection system originating from either a gas or liquid phase has been developed. It uses an integrated fiber optic detector which also serves as a reactor. This system combines the advantages of gas diffusion and stopped-flow, making the overall assay very sensitive. Both gas streams and aqueous solutions containing ammonia were analyzed. The limits of detection are 40 ppb for gas phase analysis and 1.0 ppm for aqueous phase analysis.

  19. Quantum analysis of the nondegenerate optical parametric oscillator with injected signal

    SciTech Connect

    Coutinho dos Santos, B.; Dechoum, K.; Khoury, A.Z.; Silva, L.F. da; Olsen, M.K.

    2005-09-15

    In this paper we study the nondegenerate optical parametric oscillator with injected signal, both analytically and numerically. We develop a perturbation approach which allows us to find approximate analytical solutions, starting from the full equations of motion in the positive-P representation. We demonstrate the regimes of validity of our approximations via comparison with the full stochastic results. We find that, with reasonably low levels of injected signal, the system allows for demonstrations of quantum entanglement and the Einstein-Podolsky-Rosen paradox. In contrast to the normal optical parametric oscillator operating below threshold, these features are demonstrated with relatively intense fields.

  20. Determination of five sesquiterpenoids in Xingnaojing injection by quantitative analysis of multiple components with a single marker.

    PubMed

    Pan, Weidong; Yang, Lixin; Feng, Weihong; Lin, Limei; Li, Chun; Liu, Weiwei; Gan, Guofeng; Fan, Junhong; Zou, Jigao; Wang, Zhimin; Pan, Haifeng

    2015-10-01

    A quantitative analysis of multiple components with a single-marker method was established for the simultaneous determination of five sesqutiterpenoids in Xingnaojing injection. This method was established with Xingnaojing injection determined by high-performance liquid chromatography coupled with diode array detection. The durability and system suitability of the established method were evaluated, and the reliable relative correction factors were obtained with curdione selected as an internal reference. The contents of the five components in all Xingnaojing injections were determined by external standard method and the contents of curcumenone, curcumenol, curzerenone, and germacrone were also calculated with the obtained relative correction factors. Then, relative error was investigated to estimate the difference of the two methods. As a result, the established new method possesses good adaptability, and there is no significant difference between the two methods, except for the content of curzerenone in eight samples. To put the established method into practice, the limits of quantitation of the established method of the five components were proposed and defined. Thus, the developed methodology can also be utilized to the quality evaluation of Xingnaojing injection, in spite of the difference found in the content of curzerenone between the external standard method and the newly established method.

  1. The Effectiveness of Corticosteroid Injection for De Quervain’s Stenosing Tenosynovitis (DQST): A Systematic Review and Meta-Analysis

    PubMed Central

    Rowland, Patrick; Phelan, Nigel; Gardiner, Sean; Linton, Kenneth N; Galvin, Rose

    2015-01-01

    De Quervain’s stenosing tenosynovitis (DQST) treatments include corticosteroid injection around the tendon sheath; however there is some ambiguity concerning the efficacy of this treatment. The aim of this systematic review and meta-analysis is to examine the totality of evidence relating to the use of corticosteroid injection in DQST when compared to placebo or other active treatments. A systematic literature search was conducted in July 2014. Only randomized control trials (RCTs) were included. Outcome measures included impairment, activity limitation and participation restriction. Five RCTs were identified with 165 patients, 88 in the treatment group and 77 in the control group. Patients who received corticosteroid injection (n=142) had a higher rate of resolution of symptoms [RR 2.59, 95% CI: 1.25 to 5.37, p=0.05, I2=62%]. This group reported greater pain relief as assessed by Visual Analogue Scale (VAS) at first assessment [mean difference -2.51, 95% CI: -3.11 to -1.90, p=0.0003, I2=65%] and demonstrated a statistically significant improvement in function (n=78) as measured by the DASH score and Dutch AIMS-HFF score [SMD -0.83, 95% CI: -1.54 to -0.12, p=0.02, I2=48]. This review confirms that corticosteroid injection results in a statistically significant increase in resolution of symptoms, pain relief and increased function in the treatment of DQST. PMID:26587059

  2. The Effectiveness of Corticosteroid Injection for De Quervain's Stenosing Tenosynovitis (DQST): A Systematic Review and Meta-Analysis.

    PubMed

    Rowland, Patrick; Phelan, Nigel; Gardiner, Sean; Linton, Kenneth N; Galvin, Rose

    2015-01-01

    De Quervain's stenosing tenosynovitis (DQST) treatments include corticosteroid injection around the tendon sheath; however there is some ambiguity concerning the efficacy of this treatment. The aim of this systematic review and meta-analysis is to examine the totality of evidence relating to the use of corticosteroid injection in DQST when compared to placebo or other active treatments. A systematic literature search was conducted in July 2014. Only randomized control trials (RCTs) were included. Outcome measures included impairment, activity limitation and participation restriction. Five RCTs were identified with 165 patients, 88 in the treatment group and 77 in the control group.Patients who received corticosteroid injection (n=142) had a higher rate of resolution of symptoms [RR 2.59, 95% CI: 1.25 to 5.37, p=0.05, I2=62%]. This group reported greater pain relief as assessed by Visual Analogue Scale (VAS) at first assessment [mean difference -2.51, 95% CI: -3.11 to -1.90, p=0.0003, I2=65%] and demonstrated a statistically significant improvement in function (n=78) as measured by the DASH score and Dutch AIMS-HFF score [SMD -0.83, 95% CI: -1.54 to -0.12, p=0.02, I2=48]. This review confirms that corticosteroid injection results in a statistically significant increase in resolution of symptoms, pain relief and increased function in the treatment of DQST.

  3. Analysis of clinical records of dental patients attending Jordan University Hospital: Documentation of drug prescriptions and local anesthetic injections

    PubMed Central

    Dar-Odeh, Najla; Ryalat, Soukaina; Shayyab, Mohammad; Abu-Hammad, Osama

    2008-01-01

    Objectives: The aim of this study was to analyze clinical records of dental patients attending the Dental Department at the University of Jordan Hospital: a teaching hospital in Jordan. Analysis aimed at determining whether dental specialists properly documented the drug prescriptions and local anesthetic injections given to their patients. Methods: Dental records of the Dental Department at the Jordan University Hospital were reviewed during the period from April 3rd until April 26th 2007 along with the issued prescriptions during that period. Results: A total of 1000 records were reviewed with a total of 53 prescriptions issued during that period. Thirty records documented the prescription by stating the category of the prescribed drug. Only 13 records stated the generic or the trade names of the prescribed drugs. Of these, 5 records contained the full elements of a prescription. As for local anesthetic injections, the term “LA used” was found in 22 records while the names and quantities of the local anesthetics used were documented in only 13 records. Only 5 records documented the full elements of a local anesthetic injection. Conclusion: The essential data of drug prescriptions and local anesthetic injections were poorly documented by the investigated group of dental specialists. It is recommended that the administration of the hospital and the dental department implement clear and firm guidelines for dental practitioners in particular to do the required documentation procedure. PMID:19209291

  4. Polymerase chain reaction-capillary electrophoresis genetic analysis microdevice with in-line affinity capture sample injection.

    PubMed

    Thaitrong, Numrin; Toriello, Nicholas M; Del Bueno, Nadia; Mathies, Richard A

    2009-02-15

    An integrated polymerase chain reaction (PCR)-capillary electrophoresis (CE) microdevice with an efficient in-line affinity-based injector has been developed for genetic analysis. Double stranded DNA PCR amplicons generated in an integrated 250 nL PCR reactor are captured, purified, and preconcentrated by an oligonucleotide probe immobilized in an in situ polymerized gel matrix followed by thermal release and injection into the CE-separation channel. This in-column injector employs a photopolymerized oligonucleotide-modified acrylamide capture gel to eliminate band broadening and increase the injection efficiency to 100%. The on-chip generated PCR amplicons processed on this microdevice exhibit a 3-5 fold increase in signal intensities and improved resolution compared to our previous T-shaped injector. Multiplex analysis of 191-bp amplicons from Escherichia coli O157 and 256-bp amplicons from E. coli K12 is achieved with a 6-fold increase in resolution. These advances are exploited to successfully detect E. coli O157 in a 500-fold higher background of E. coli K12. This microdevice with in-line affinity capture gel injection provides an improved platform for low-volume, high sensitivity, fully integrated genetic analysis.

  5. Intravitreal Bevacizumab Versus Ranibizumab for Treatment of Neovascular Age-Related Macular Degeneration: Findings from a Cochrane Systematic Review

    PubMed Central

    Solomon, Sharon D.; Lindsley, Kristina B.; Krzystolik, Magdalena G.; Vedula, Satyanarayana S.; Hawkins, Barbara S.

    2015-01-01

    Topic To summarize the relative effects of bevacizumab (Avastin®, Genentech, Inc.) and ranibizumab (Lucentis®, Genentech, Inc.), using findings from a Cochrane Eyes and Vision Group systematic review . Clinical relevance Neovascular age-related macular degeneration (NVAMD) is the most common cause of uncorrectable vision loss in the elderly in developed countries. Bevacizumab and ranibizumab are the most frequently-used anti-VEGF agents injected intravitreally to treat NVAMD Methods We included only randomized controlled trials (RCTs) in which the two anti-VEGF agents had been compared directly. The primary outcome was 1-year gain in best-corrected visual acuity (BCVA) of 15 or more logMAR letters. We followed Cochrane methods for trial selection, data extraction, and data analyses. Relative effects of bevacizumab versus ranibizumab are presented as estimated risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs). Results We identified 6 eligible RCTs with 2809 participants. The proportion of eyes that gained 15 or more letters of BCVA by 1 year was similar for the two agents when the same regimens were compared: RR=0.90, 95% CI: 0.73 to 1.11. The mean change in BCVA from baseline also was similar: MD=−0.5 letter; 95% CI: −1.6 to +0.6. Other BCVA and quality-of-life outcomes were similar for the two agents. One-year treatment cost with ranibizumab was 5.1 and 25.5 times the cost for bevacizumab in the two largest trials. Ocular adverse events were uncommon (<1%); rates were similar for the two agents. Conclusions We found no important difference in effectiveness or safety between bevacizumab and ranibizumab for NVAMD treatment but a large cost difference. PMID:26477843

  6. Analysis of gemcitabine liposome injection by HPLC with evaporative light scattering detection.

    PubMed

    Zhou, Qinmei; Liu, Liucheng; Zhang, Dengshan; Fan, XingFeng

    2012-12-01

    Gemcitabine liposome injection (i.e., stealth liposomes) has facilitated the targeting of gemcitabine for cancer treatment. We systemically reviewed liposome-based drug-delivery systems, which can improve pharmacokinetics, reduce side effects, and potentially increase tumor uptake, for pancreatic cancer therapy. A novel liposomal formulation, which allows for higher tumor-targeting efficiencies and can be used in current clinical trials to treat this challenging disease, has gained great popularity and attention. In this work, a simple, rapid high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of N-(carbonyl-methoxypolyethylene glycol 2000)-1, 2-distearoyl-sn-glycero-3-phosphoethanolamine sodium salt and neutral colipids cholesterol and hydrogenated soy phosphatidylcholine or distearoyl phosphatidylcholine. Because of the poor ultraviolet absorbance of the lipids, evaporative light-scattering detection (ELSD) was used to monitor the separation. The separation was carried out on a YMC-Pack column (YMC Co., Ltd., Kyoto, Japan). Lipids were eluted using binary linear gradients starting from a mixture of 80% A and 20% B to 100% B in 10 minutes, followed by a 6-minute plateau at 100% B, where A is chloroform/isopropyl alcohol/diethylamine/trifluoroacetic acid (TFA) (50:50:0.01:0.0025) and B is chloroform/isopropyl alcohol/H₂O/diethylamine/TFA (41:50:9:0.01:0.0025). The mobile phase composition was then changed back to initial solvent mixture in 1 minute, and the column was equilibrated for 13 minutes before every subsequent run. Then, 0.025% (v/v) TFA was added into the mobile phase to enhance the retaining of the stealth lipids. This newly developed method enabled direct analysis of liposomes without solvent lipid extraction and was validated to be linear, precise, accurate, specific, and sensitive. The method has been successfully employed in a wide range of lipid-based formulation screening, process development, and

  7. Evaluation of Direct Aqueous Injection Method for Analysis of Chloroform in Drinking Water

    ERIC Educational Resources Information Center

    Pfaender, Frederic K.; And Others

    1978-01-01

    A direct aqueous injection (DAI) technique was compared with the purge method for chloroform measurement in drinking water. The DAI method gave consistently higher values for chloroform than the purge method. The results indicated the need for caution in the interpretation of chloroform and other trihalomethane values generated by DAI. (Author/MA)

  8. Determination of Nitrogen by Flow Injection Analysis in Environmental and Wastewaters

    SciTech Connect

    Straw, K.A.

    1999-03-01

    In summary, three generations of Lachat FIA systems have been used in the laboratory over a period of 13 yrs, running, in addition to the 4 N methods, Cr{sup +6}, SiO{sub 2}, Fluoride by ISE. Overall flow injection systems have been versatile and reliable and a good choice in the lab for analyzing a wide variety of samples quickly.

  9. Analysis of high gradient magnetic field effects on distribution of nanoparticles injected into pulsatile blood stream

    NASA Astrophysics Data System (ADS)

    Reza Habibi, Mohammad; Ghassemi, Majid; Hossien Hamedi, Mohammad

    2012-04-01

    Magnetic nanoparticles are widely used in a wide range of applications including data storage materials, pharmaceutical industries as magnetic separation tools, anti-cancer drug carriers and micro valve applications. The purpose of the current study is to investigate the effect of a non-uniform magnetic field on bio-fluid (blood) with magnetic nanoparticles. The effect of particles as well as mass fraction on flow field and volume concentration is investigated. The governing non-linear differential equations, concentration and Navier-stokes are coupled with the magnetic field. To solve these equations, a finite volume based code is developed and utilized. A real pulsatile velocity is utilized as inlet boundary condition. This velocity is extracted from an actual experimental data. Three percent nanoparticles volume concentration, as drug carrier, is steadily injected in an unsteady, pulsatile and non-Newtonian flow. A power law model is considered for the blood viscosity. The results show that during the systole section of the heartbeat when the blood velocity increases, the magnetic nanoparticles near the magnetic source are washed away. This is due to the sudden increase of the hydrodynamic force, which overcomes the magnetic force. The probability of vein blockage increases when the blood velocity reduces during the diastole time. As nanoparticles velocity injection decreases (longer injection time) the wall shear stress (especially near the injection area) decreases and the retention time of the magnetic nanoparticles in the blood flow increases.

  10. Golimumab Injection

    MedlinePlus

    ... body and causes pain, swelling, and damage) including: rheumatoid arthritis (condition in which the body attacks its own ... doctor.If golimumab injection is used to treat rheumatoid arthritis, it may also be injected intravenously (into a ...

  11. Adalimumab Injection

    MedlinePlus

    ... causes pain, swelling, and damage) including the following: rheumatoid arthritis (a condition in which the body attacks its ... If you are using adalimumab injection to treat rheumatoid arthritis, your doctor may tell you to inject the ...

  12. Aripiprazole Injection

    MedlinePlus

    ... aripiprazole injection and aripiprazole extended-release injection developed gambling problems or other intense urges or behaviors that ... even if you do not realize that your gambling or any other intense urges or unusual behaviors ...

  13. Teduglutide Injection

    MedlinePlus

    ... mix and inject it.Teduglutide comes as a kit containing vials of teduglutide powder for injection, prefilled syringes containing diluent (liquid to be mixed with teduglutide powder), needles to attach to the diluent syringe, dosing syringes ...

  14. Degarelix Injection

    MedlinePlus

    Degarelix injection is used to treat advanced prostate cancer (cancer that begins in the prostate [a male reproductive gland]). Degarelix injection is in a class of medications called gonadotropin-releasing hormone (GnRH) ...

  15. Cyclosporine Injection

    MedlinePlus

    ... injection is used with other medications to prevent transplant rejection (attack of the transplanted organ by the ... people who have received kidney, liver, and heart transplants. Cyclosporine injection should only be used to treat ...

  16. Colistimethate Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria. Colistimethate injection is in a class of medications called antibiotics. It works by killing bacteria.Antibiotics such as colistimethate injection will not work ...

  17. Chloramphenicol Injection

    MedlinePlus

    ... treat certain types of serious infections caused by bacteria when other antibiotics cannot be used. Chloramphenicol injection ... antibiotics. It works by stopping the growth of bacteria..Antibiotics such as chloramphenicol injection will not work ...

  18. Estrogen Injection

    MedlinePlus

    ... forms of estrogen injection are used to treat hot flushes (hot flashes; sudden strong feelings of heat and sweating) ... If you are using estrogen injection to treat hot flushes, your symptoms should improve within 1 to ...

  19. Medroxyprogesterone Injection

    MedlinePlus

    ... Medroxyprogesterone injection is a very effective method of birth control but does not prevent the spread of human ... you have been using a different method of birth control and are switching to medroxyprogesterone injection, your doctor ...

  20. Etanercept Injection

    MedlinePlus

    ... areas causing pain and joint damage), chronic plaque psoriasis (a skin disease in which red, scaly patches ... etanercept injection is used to treat chronic plaque psoriasis, it may be injected twice a week during ...

  1. Levoleucovorin Injection

    MedlinePlus

    Levoleucovorin injection is used to prevent harmful effects of methotrexate (Rheumatrex, Trexall) when methotrexate is used to to treat certain types of cancer. Levoleucovorin injection is also used to treat people ...

  2. Leucovorin Injection

    MedlinePlus

    Leucovorin injection is used to prevent harmful effects of methotrexate (Rheumatrex, Trexall; cancer chemotherapy medication) when methotrexate is used to to treat certain types of cancer. Leucovorin injection is used to ...

  3. Teniposide Injection

    MedlinePlus

    ... in men. You should not become pregnant or breast-feed while you are receiving teniposide injection. If you or your partner become pregnant while receiving teniposide injection, call your doctor. Teniposide may harm the fetus.

  4. Ipilimumab Injection

    MedlinePlus

    ... are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while receiving ipilimumab injection, call your doctor. Ipilimumab injection may cause your baby to be born too early or to die before birth.

  5. Pralatrexate Injection

    MedlinePlus

    Pralatrexate injection is used to treat peripheral T-cell lymphoma (PTCL; a form of cancer that begins in a ... come back after treatment with other medications. Pralatrexate injection has not been shown to help people who ...

  6. Cyanocobalamin Injection

    MedlinePlus

    Cyanocobalamin injection is used to treat and prevent a lack of vitamin B12 that may be caused by any ... organs) and permanent damage to the nerves. Cyanocobalamin injection also may be given as a test to ...

  7. Paclitaxel Injection

    MedlinePlus

    Paclitaxel injection manufactured with human albumin is used to treat breast cancer that has not improved or that has come back after treatment with other medications. Paclitaxel injection manufactured with polyoxyethylated castor oil is used to ...

  8. Diphenhydramine Injection

    MedlinePlus

    Diphenhydramine injection is used to treat allergic reactions, especially for people who are unable to take diphenhydramine by mouth. ... is used also to treat motion sickness. Diphenhydramine injection is also used alone or along with other ...

  9. Peramivir Injection

    MedlinePlus

    Peramivir injection is used to treat some types of influenza infection ('flu') in people who have had symptoms of ... flu for no longer than 2 days. Peramivir injection is in a class of medications called neuraminidase ...

  10. Cefotetan Injection

    MedlinePlus

    Cefotetan injection is used to treat infections of the lungs, skin, bones, joints, stomach area, blood, female reproductive organs, and urinary tract. Cefotetan injection is also used before surgery to prevent infections. ...

  11. Mipomersen Injection

    MedlinePlus

    Mipomersen injection is used to decrease levels of cholesterol and other fatty substances in the blood in people who ... that removes LDL from the blood), but mipomersen injection should not be used along with this treatment. ...

  12. Romiplostim Injection

    MedlinePlus

    Romiplostim injection is used to increase the number of platelets (cells that help the blood to clot) in order ... low number of platelets in the blood). Romiplostim injection should only be used in people who cannot ...

  13. Hydrocortisone Injection

    MedlinePlus

    Hydrocortisone injection is used to treat symptoms of low corticosteroid levels (lack of certain substances that are usually produced ... also used to treat severe allergic reactions. Hydrocortisone injection is used in the management of multiple sclerosis ( ...

  14. Palivizumab Injection

    MedlinePlus

    Palivizumab injection is used to help prevent respiratory syncytial virus (RSV; common virus that can cause serious lung infections) ... or have certain heart or lung diseases. Palivizumab injection is not used to treat the symptoms of ...

  15. Naltrexone Injection

    MedlinePlus

    Naltrexone injection is used along with counseling and social support to help people who have stopped drinking large amounts of alcohol to avoid drinking again. Naltrexone injection is also used along with counseling and social ...

  16. Tesamorelin Injection

    MedlinePlus

    Tesamorelin injection is used to decrease the amount of extra fat in the stomach area in adults with human ... fat in certain areas of the body). Tesamorelin injection is not used to help with weight loss. ...

  17. Testosterone Injection

    MedlinePlus

    ... and testosterone pellet (Testopel) are forms of testosterone injection used to treat symptoms of low testosterone in ... are low before you begin to use testosterone injection. Testosterone enanthate (Delatestryl) and testosterone pellet (Testopel) are ...

  18. Tigecycline Injection

    MedlinePlus

    Tigecycline injection used to treat certain serious infections including community acquired pneumonia (a lung infection that developed in a ... area between the chest and the waist). Tigecycline injection should not be used to treat pneumonia that ...

  19. Eculizumab Injection

    MedlinePlus

    Eculizumab injection is used to treat paroxysmal nocturnal hemoglobinuria (PNH: a type of anemia in which too many red ... oxygen to all parts of the body). Eculizumab injection is also used to treat atypical hemolytic uremic ...

  20. Pembrolizumab Injection

    MedlinePlus

    Pembrolizumab injection is used to treat melanoma (a type of skin cancer) that cannot be treated with surgery or ... spread to other parts of the body. Pembrolizumab injection is also used to treat a certain type ...

  1. Methylprednisolone Injection

    MedlinePlus

    ... allergic reactions. Methylprednisolone injection is used in the management of multiple sclerosis (a disease in which the ... laboratory test, tell your doctor and the laboratory personnel that you are using methylprednisolone injection.If you ...

  2. Obinutuzumab Injection

    MedlinePlus

    Obinutuzumab injection is used