PURPOSE: Although the process by which intravitreal perfluorocarbon gas is absorbed is incompletely understood, it is known that considerable absorption of intravitreal perfluorocarbon gas occurs through the aqueous humor. The aim of the study was to evaluate experimentally the effect of topical aqueous humor suppressants on the intravitreal perfluorocarbon gas bubble duration. METHODS: After sulfur hexafluoride and perfluoropropane were injected intravitreally in ten rabbits, we measured the time of gas bubble disappearance in eyes treated with topical aqueous humor suppressants and in those not treated. RESULTS: The mean time(+/-SD) to disappearance of 0.4 cc of sulfur hexafluoride was 6.0+/-0.71 days, which was prolonged to 8.0+/-0.71 days with topical aqueous humor suppressants. The mean time(+/-SD) to disappearance of 0.2 cc perfluoropropane was 14.8+/-0.84 days, while it was prolonged to 22.0+/-1.58 days with topical aqueous humor suppressants. CONCLUSIONS: Sulfur hexafluoride and perfluoropropane intravitreal gas bubbles last longer in rabbit eyes treated with aqueous humor suppressants than in fellow control eyes.
Absorption ; Aqueous Humor* ; Rabbits* ; Sulfur Hexafluoride

We reviewed 71 cases of recurred retinal detachment after trans pars plana vitrectomy managed with fluid gas exchange with sulfur hexafluoride gas between January 1984 and April 1986 in order to identify the anatomic and functional success rate. The causes of vitrectomy were as follows: retinal detachment with peripheral retinal breaks(29 eyes) or giant dialysis(10 eyes) complicated by proliferative vitreoretinopathy, retinal detachment with no breaks(16 eyes), traction retinal detachments(6 eyes), and others(3 eyes). The anatomic and functional success rate was affected by the grade of proliferative vitreoretinopathy. In 71 cases performed fluid gas exchange with sulfur hexafluoride gas, anatomic success rate was 38%(27/71) and functional sucess rate was 22.5%(16/71).
Retinal Detachment* ; Retinaldehyde* ; Sulfur Hexafluoride ; Traction ; Vitrectomy ; Vitreoretinopathy, Proliferative

Surgical methods using retinotomy, intravitreal or subretinal tissue plasminogen activator(tPA) injection and so on have been introduced in diffuse subretinal hemorrahage involving submacular area. We present our experience of improvement of vision in an 50-year old woman with submacualr hemorrgage, treated with 0.6cc expanding sulfur hexafluoride gas(SF6) injetion intravitreally and face-dwon positioning resulting in the movement of subacular hemorrhage to the inferior direction and intravitreal space, and simple pars plana vitrectomy of breakthrough vitreous hemorrhage.
Female ; Hemorrhage* ; Humans ; Middle Aged ; Plasminogen ; Sulfur Hexafluoride ; Vitrectomy ; Vitreous Hemorrhage

To optimize the operating variables that affect the transfection of antisense oligodeoxyribonucleotide (AS-ODNs) by insonated gas-filled lipid microbubbles, SF6-filled microbubbles were prepared by sonication-lyophilization method. An AS-ODNs sequence and a breast cancer cell line SK-BR-3 were used to define the various operating variables determining the transfection efficiency of SF6-filled microbubbles. Three levels of mixing speed, different durations of mixing and various delay time before ultrasound were examined, separately. Transfection efficiency was detected by fluorescence microscopy. Transfection results with and without incubation of AS-ODNs and microbubbles before mixing cells were compared. From the results, there is no significant difference between the transinfection efficiency with or without incubation of AS-ODNs and microbubbles before mixing cells. AS-ODNs transfection efficiency showed an increasing trend with mixing speed and mixing duration, but there is a negative relationship with delay time before ultrasound. The optimum parameters for AS-ODNs transfection by SF6-filled microbubbles were found at a mixing speed of 40-50 r x min(-1) for 30-60 s with less than 60 s delay before ultrasound. For a successful transfection, long time of incubation with gene is essential for normal nonviral vectors such as liposomes or cationic lipid-polymer hybrids, because these vectors depend on endocytosis and membrane fusion to realize transfection. Unlike liposomes and cationic lipid-polymer hybrids, gas-filled lipid microbubbles depend on sonorporation effect to realize transfection. Therefore, the incubation of gene and microbubbles before mixing cells may not be necessary. Ultrasound-mediated AS-ODNs transfection enhanced by gas-filled lipid microbubbles represents an effective avenue for gene transfer.
Cell Line, Tumor ; Green Fluorescent Proteins ; Humans ; Microbubbles ; Oligodeoxyribonucleotides, Antisense ; genetics ; Sulfur Hexafluoride ; Transfection ; methods ; Ultrasonics

We performed the intravitreal injection of air and pure perfluoropropane (C3F8) gas in the pigmented rabbits and observed the changes of gas levels by the ultrasonography. We also observed the changes of the intra-ocular gas levels by the ultrasonography and measured the intraocular pressures (lOPs) in 9 patients who had undergone vitrectomy and fluid-gas exchange with 20% sulfur hexafluoride (SF6) and 14% perfluoropropane (C3F8) gases. In the pigmented rabbits, the air was not expanded and completely absorbed within 2 days, and the C3F8 gas was expanded maximally at 3 to 7 days and completely absorbed after 3 weeks. Among nine human eyes treated with vitrectomy and fluid-gas exchange, the intraocular pressures were elevated above 25mmHg at 1 day after operation in 2 eyes, which were controlled with medical therapy. The lOPs were significantly correlated with the amount of the intraocular gases (r=0.3476, p<0.05). The assessment of intraocular gas level by ultrasonography seems to be easier and more objective method than others previously reported.
Absorption* ; Gases ; Humans ; Intraocular Pressure ; Intravitreal Injections ; Rabbits ; Sulfur Hexafluoride ; Ultrasonography ; Vitrectomy

PURPOSE: To report a case of chronic hypotony maculopathy caused by traumatic cyclodialysis cleft and treated with 20% sulfur hexafluoride (SF6) gas tamponade with cyclocryotherapy. CASE SUMMARY: A 39-year-old woman with a history of blunt trauma developed a unilateral chronic ocular hypotony in her left eye. She was treated with topical atropine sulphate 1% for 2 months. Three years later, she was referred to our clinic for evaluation and treatment of persistent hypotony. The intraocular pressure (IOP) was 4 mm Hg and the best corrected visual acuity was 0.4. B-scan echography revealed a choroidal effusion and fundus examination showed choroidal detachment and macular folds. Gonioscopy examination revealed cyclodialysis cleft from the direction of 7 o'clock to 11 o'clock. A single bubble of SF6 20% (0.4 cc) was injected into the vitreous cavity and transconjunctival cyclocryotherapy was performed under retrobulbar anesthesia. Six months later, the IOP was 12 mm Hg and the best corrected visual acuity was 1.0. B-scan echograpy and fundus examination showed the disappearance of the choroidal effusion. CONCLUSIONS: Gas tamponade with cyclocryotherapy may be useful in cases of cyclodialysis cleft that failed to respond to medical therapy.
Adult ; Anesthesia ; Atropine ; Choroid ; Eye ; Female ; Gonioscopy ; Humans ; Intraocular Pressure ; Ocular Hypotension ; Sulfur Hexafluoride ; Visual Acuity

Four cases of retinal detachment with macular hole and no posterior vitreoretinal connections were treated successfully by draining subretinal fluid externally, injecting sulfur hexafluoride gas into the vitreous cavity, and then keeping the patient in a prone position. And in all four cases, the retina remained attached during follow-up periods of 6 months or longer. This approach is simple, easy, and safe. Moreover, it brings good functional success because the macula is preserved. This approach must be the treatment of choice in retinal detachments with macular hole but without other breaks or vitreous adhesion.
Drainage* ; Follow-Up Studies ; Humans ; Prone Position ; Retina ; Retinal Detachment* ; Retinal Perforations* ; Retinaldehyde* ; Subretinal Fluid* ; Sulfur Hexafluoride

OBJECTIVETo observe the cell binding characteristics of SonoVue microbubbles targeting choriocarcinoma cells and provide evidence for clinical ultrasonic localization of the tumor utilizing the microbubbles.

METHODSThe targeted microbubbles were prepared by conjugating anti-HCG antibody with the SonoVue microbubbles and added in choriocarcinoma cells or endometrial stromal cells to compare the cell binding rate of the agents under optical microscope and with flow cytometry.

RESULTSFlow cytometry demonstrated a binding rate of 77.6% between the SonoVue microbubbles and anti-HCG antibody. Light microscopy showed that the total rosette formation rate of the choriocarcinoma cells exposed to the targeted microbubble bearing anti-HCG antibody reached (87.8-/+6.3)%, significantly higher than that of the endometrial stromal cells [(9.4-/+1.7)%, P<0.05]. The binding rate of the targeted microbubbles with the choriocarcinoma cells before and after PBS washing were (85.4-/+4.7)% and (83.1-/+3.8)% (P>0.05), respectively, suggesting strong stability of the binding. The binding rate was 81.0% according to the results of flow cytometry.

CONCLUSIONThe targeted microbubbles as a contrast agent can efficiently bind to the choriocarcinoma cells in vitro with a stability sufficient to resist the blood flow.

Choriocarcinoma ; pathology ; Contrast Media ; metabolism ; Female ; Humans ; Microbubbles ; Phospholipids ; metabolism ; Pregnancy ; Sulfur Hexafluoride ; metabolism ; Uterine Neoplasms ; metabolism

OBJECTIVETo evaluate the clinical performance of an innovative contrast-enhanced ultrasound (CEUS) technique in characterization of focal liver lesions (FLL).

METHODSCEUS was performed in 505 patients with FLLs. A sulfur hexafluoride-filled microbubble ultrasound contrast agent and a continuous real-time imaging technique of contrast pulse sequencing were used. The observation items included initial nodule enhancement time, enhancement level and pattern, and dynamic evolution of enhancement along with the CEUS phases.

RESULTSThere were similar findings for both malignant and benign FLLs in initial enhancement time and enhancement level on CEUS. The dynamic evolution of enhancement along with enhancement phase was the most significant parameter for characterization of FLLs. Most malignant lesions showed enhancement at arterial phase and hypo-enhancing at late phase, whereas the benign lesions presented enhancement at arterial phase and persistent hyper- or iso-enhancing until late phase. Using these characteristics as a diagnostic criteria, the sensitivity, specificity, positive predicative value, negative predicative value and accuracy of CEUS in identifying malignant FLLs were 95.7% (313/327), 86.0% (153/178), 92.6% (313/338), 91.6% (153/167) and 92.3% (466/505), respectively.

CONCLUSIONSCharacterization of FLLs by using the innovative CEUS technique is recommendable due to its safety, facility and high accuracy.

Adult ; Aged ; Aged, 80 and over ; Diagnosis, Differential ; Female ; Humans ; Liver Diseases ; diagnostic imaging ; Male ; Middle Aged ; Sulfur Hexafluoride ; Ultrasonography ; methods

PURPOSE: The purpose of this study is to establish the methodology regarding synthesis of ultrasound contrast agent imaging, and to evaluate the characteristics of the synthesized ultrasound contrast agents, including size or degradation interval and image quality. MATERIALS AND METHODS: The ultrasound contrast agent, composed of liposome and SF6, was synthesized from the mixture solution of 21 micromol DPPC (1, 2-Dihexadecanoyl-sn-glycero-3-phosphocholine, C40H80NO8P), 9 micromol cholesterol, 1.9 micromol of DCP(Dihexadecylphosphate, [CH3(CH2)15O]2P(O)OH), and chloroform. After evaporation in a warm water bath and drying during a period of 12-24 hours, the contrast agent was synthesized by the sonication process by addition of buffer and SF6 gas. The size of the contrast agent was controlled by use of either extruder or sonication methods. After synthesis of contrast agents, analysis of the size distribution of the bubbles was performed using dynamic light scattering measurement methods. The degradation curve was also evaluated by changes in the number of contrast agents via light microscopy immediate, 12 hours, 24 hours, 36 hours, 48 hours, 60 hours, 72 hours, and 84 hours after synthesis. For evaluation of the role as an US contrast agent, the echogenicity of the synthesized microbubble was compared with commercially available microbubbles (SonoVue, Bracco, Milan, Italy) using a clinical ultrasound machine and phantom. RESULTS: The contrast agents were synthesized successfully using an evaporation-drying-sonication method. The majority of bubbles showed a mean size of 154.2 nanometers, and they showed marked degradation 24 hours after synthesis. ANOVA test revealed a significant difference among SonoVue, synthesized contrast agent, and saline (p < 0.001). Although no significant difference was observed between SonoVue and the synthesized contrast agent, difference in echogenicity was observed between synthesized contrast agent and saline (p < 0.01). CONCLUSION: We could synthesize ultrasound contrast agents using an evaporation-drying-sonication method. On the basis of these results, many prospective types of research, such as anticancer drug delivery, gene delivery, including siRNA or microRNA, targeted molecular imaging, and targeted therapy can be performed.
Baths ; Chloroform ; Cholesterol ; Contrast Media ; Light ; Liposomes ; Microbubbles ; MicroRNAs ; Microscopy ; Molecular Imaging ; Phospholipids ; RNA, Small Interfering ; Sonication ; Sulfur Hexafluoride ; Water