A cryogenic continuously rotating half-wave plate mechanism for the POLARBEAR-2b cosmic microwave background receiver

We present the design and laboratory evaluation of a cryogenic continuously rotating half-wave plate (CHWP) for the POLARBEAR-2b (PB-2b) cosmic microwave background receiver, the second installment of the Simons Array. PB-2b will observe at 5200 m elevation in the Atacama Desert of Chile in two frequency bands centered at 90 GHz and 150 GHz. In order to suppress atmospheric 1/f noise and mitigate systematic effects that arise when differencing orthogonal detectors, PB-2b modulates linear sky polarization using a CHWP rotating at 2 Hz. The CHWP has a 440 mm clear aperture diameter and is cooled to ≈50 K in the PB-2b receiver cryostat. It consists of a low-friction superconducting magnetic bearing and a low-torque synchronous electromagnetic motor, which together dissipate <2 W. During cooldown, a grip-and-release mechanism centers the rotor to <0.5 mm, and during continuous rotation, an incremental optical encoder measures the rotor angle with a noise level of 0.1 μrad/Hz. We discuss the experimental requirements for the PB-2b CHWP, the designs of its various subsystems, and the results of its evaluation in the laboratory. The presented CHWP has been deployed to Chile and is expected to see first light on PB-2b in 2020 or 2021.

Injectable Fluocinolone Acetonide Long-Acting Implant for Noninfectious Intermediate Uveitis, Posterior Uveitis, and Panuveitis: Two-Year Results

PURPOSE

To determine the effect of an injectable fluocinolone acetonide implant (FAi) in eyes with noninfectious intermediate uveitis, posterior uveitis, or panuveitis.

DESIGN

Noncomparative, interventional, dose-randomized, dose-masked, prospective, individual, investigator-sponsored investigational new drug study.

PARTICIPANTS

Eleven eyes of 11 participants with a history of recurrent noninfectious intermediate uveitis, posterior, or panuveitis.

METHODS

Participants were randomized to receive either a low- or a high-dose FAi. Eyes were observed on day 0 (day the implant was injected) and then at regular intervals through 2 years.

MAIN OUTCOME MEASURES

Ocular inflammation, visual acuity, anti-inflammatory medication use, and safety parameters before and after FAi implantation.

RESULTS

All participants were followed up for 2 years. At baseline, mean study eye visual acuity was 0.56 logarithm of the minimum angle of resolution (logMAR; standard deviation [SD], 0.43 logMAR). These values improved significantly to +0.25 logMAR (SD, 0.14 logMAR) and +0.17 logMAR (SD, 0.14 logMAR) at 12 and 24 months after implantation, respectively (P = 0.041 and P = 0.016, respectively). The average number of inflammation recurrences in the 12 months before implantation was 1.54 episodes per eye. None of the study eyes experienced a recurrence during the follow-up period. Of the 6 participants who continued receiving systemic medication after implantation, the dosage was reduced in 4 participants. Five of 11 eyes received an average of 1.6 posterior sub-Tenon triamcinolone acetonide (PSTA) injections in the 12 months preceding implantation. None required a PSTA injection after FAi implantation. The most common adverse event was intraocular pressure (IOP) rise. At baseline, 1 study eye (9%) required pressure-lowering drops; 2 additional study eyes (18%) required them during the follow-up period. Filtering procedures were performed in 2 of these eyes (18.1%). No FAi explantations were required, nor were any participants lost to follow-up during the investigation.

CONCLUSIONS

It is feasible to place a long-acting FAi in an outpatient setting, without prolonged adverse events attributed to the implant injection procedure. The FAi effectively controlled intraocular inflammation in all eyes in the study, and at the last follow-up, all implanted eyes demonstrated an improvement in visual acuity. Elevated IOP that occurred in 18% of FAi-implanted eyes was managed by standard means. The FAi implant is a promising approach for patients with noninfectious intermediate uveitis, posterior uveitis, or panuveitis who do not respond to, or are intolerant to, conventional therapy.

Intravitreous delivery of the corticosteroid fluocinolone acetonide attenuates retinal degeneration in S334ter-4 rats

PURPOSE

To study the neuroprotective properties of low-dose, sustained-release intravitreous fluocinolone acetonide (FA) in transgenic S334ter-4 rats.

METHODS

S334ter-4 rats aged 4 weeks were divided into four groups: 0.5 microg/d FA-loaded intravitreous drug delivery implant (IDDI); 0.2 microg/d FA-loaded IDDI; inactive IDDI; and unoperated controls. Electroretinography (ERG) was performed before surgery and every 2 weeks after surgery for 8 weeks. When the rats were 12 weeks of age, outer nuclear layer (ONL) and inner nuclear layer (INL) thicknesses were measured. Microglial cell counts were obtained from retinal wholemounts labeled for Iba-1.

RESULTS

At the end of the study, unoperated and inactive IDDI-implanted rats demonstrated 50% to 60% reductions in ERG amplitudes compared with those recorded at 4 weeks (P < 0.001 for both groups). FA 0.2-microg/d animals demonstrated 15% amplitude attenuation, while FA 0.5-microg/d animals showed 30% reduction. ONL thickness in FA 0.2-microg/d-treated eyes was 25.8% +/- 2.3% higher than in control group eyes (P < 0.001) and 30.0% +/- 2.1% higher than in inactive IDDI-implanted eyes (P < 0.001). In FA 0.5-microg/d-treated eyes, ONL thickness was 22.4% +/- 2.8% higher than in control group eyes (P < 0.001) and 22.3% +/- 3.7% higher than in inactive IDDI-implanted eyes (P < 0.01). No statistically significant difference was observed between the two control groups. No statistically significant difference between the two FA-treated groups was found. FA-treated groups demonstrated significantly fewer activated microglial cells than control groups.

CONCLUSIONS

Chronic intravitreous infusion of FA preserves ONL cell morphology and ERG a- and b-wave amplitudes and reduces retinal neuroinflammation in S334ter rats. Based on these findings, the synthetic corticosteroid FA may promise a therapeutic role in patients with retinal degeneration.

"This villa life": town planning, suburbs and the "new social order" in early twentieth-century Sydney

In Australia, social reformers approached the new century and post-First World War reconstruction with the hope of establishing a "new social order" based on national efficiency and class harmony. This was to be delivered through the new science of town planning. The would-be reformers posited themselves as an intellectual vanguard which would provide leadership and assist in establishing an enlightened bureaucracy of professional public servants who would also lead the way to social betterment. Their project, however, had collapsed by the end of the war. Lacking collective political clout, the nascent planning professionals' influence declined as the political environment became more conservative in the 1920s. Reformist and radical features of town planning were stripped from suburban agendas. Suburbs, once held up as the cradle of the 'new social order', were to become places for quarantining class and reinvigorating liberalism.

Persons with acquired profound hearing loss (APHL): how do they and their families adapt to the challenge?

The study examined the impact of acquired profound hearing loss (APHL) on the relationship between the hearing impaired person and their normally hearing close family member, usually a partner, and identified the kinds of adjustment leading to maintenance or deterioration of the relationship. The participants were 25 people with APHL and 25 family members, interviewed separately in their own home. Analysis of the interview transcripts adopted a grounded theory methodology. The different levels of analysis were linked in terms of a core category based on the social construction of a committed relationship. The conceptual codes were grouped as: (a) aural impairments giving rise to the need for adjustment; (b) pragmatic adjustments to spoken communication and family activities; (c) managing the adjustments without negative consequences; (d) adjustments leading to negative interaction. The results suggest that APHL places considerable strain on relationships and increases their vulnerability to failure, consistent with previous research. They highlight the need for professional support and suggest that a systemic conceptual framework is needed that includes the public response to profound hearing impairment.

Town planning

From an accidental city without a plan, Sydney has become a city with many plans. Some would say too many, and there have been endless rounds of planning system reform since the 1980s. The central city and suburbs no longer grow ‘like topsy’ but with the greater metropolitan area still being propelled by market forces towards a population of seven million by the mid twenty-first century, there are new sets of pressures around both old (development versus environment, local-state tensions, congestion) and new (affordability, social polarisation, impacts of climate change) problems which inescapably challenge the first Australian city and the one most connected to the global economy.

Acquired profound hearing loss: mental health and other characteristics of a large sample

The study investigated the mental health and other characteristics of people with acquired profound hearing loss (APHL) and contrasted this group with acquired hearing loss (AHL) in general. A survey was completed over the internet by 95 adults and by 27 people who had attended a one-week course of rehabilitation. The latter group completed questionnaires of anxiety and depression, post-traumatic stress, and hearing handicap. The survey covered a wide range of factors associated with the history of hearing loss and evaluated previous contacts with professional services. The data from the two samples were very similar and were combined. The results indicated the existence of sudden and progressive onset groups, reliance on lip-reading, a severe effect of tinnitus, and some support for the conclusion that the psychosocial impact was greater in APHL than in AHL. A subgroup of APHL was severely distressed and handicapped. Respondents valued medical and audiological services but there was little evidence that previous counselling and support had been helpful. Recommendations for rehabilitation are briefly discussed.

Efficacy of Low-Release-Rate Fluocinolone Acetonide Intravitreal Implants to Treat Experimental Uveitis

OBJECTIVE

To determine the efficacy of 0.5-mg and 0.1-mg sustained-release fluocinolone acetonide intravitreal implants to inhibit ocular inflammation in a rabbit model of severe uveitis.

METHODS

The in vitro pharmacokinetic profile of both the 0.5-mg and 0.1-mg sustained-release fluocinolone intravitreal implants was determined during a 10-day period. A sustained-release fluocinolone acetonide intravitreal implant with a release rate of either 0.5 microg/d (n = 16) or 0.1 microg/d (n = 16) was implanted into the vitreous cavity of the right eye in albino rabbits after a subcutaneous injection of tuberculin antigen. Control animals (n = 14) received empty devices. Uveitis was induced with an intravitreal tuberculin antigen injection. A masked observer graded anterior chamber flare, anterior chamber cells, vitreous opacity, and inflammation on histologic sections.

RESULTS

In vitro, the drug was released from both devices in a linear manner. In vivo, treated eyes were significantly less inflamed than untreated eyes (P< or =.02). Inflammation was suppressed to a greater degree with the 0.5-microg/d implant compared with the 0.1-microg/d implant.

CONCLUSION

Sustained-release fluocinolone intravitreal implants suppress ocular inflammation in a rabbit model of severe uveitis.

CLINICAL RELEVANCE

The efficacy demonstrated with the 0.1-microg/d implant provides the rationale for future human studies with lower-release-rate implants than are currently used in noninfectious uveitis clinical trials.

Novel antiglaucoma prodrugs and codrugs of ethacrynic acid

The purpose of this study was to synthesize a novel prodrug of ethacrynic acid (ECA) with short chain polyethylene glycols (PEGs) and codrugs of ECA with the beta-adrenergic blocking agent atenolol (ATL) or timolol (TML) to overcome the adverse effects of ECA and to enhance its physicochemical properties.

Long-term follow-up results of a pilot trial of a fluocinolone acetonide implant to treat posterior uveitis

PURPOSE

To investigate the safety and efficacy of a fluocinolone acetonide intravitreal implant in the treatment of noninfectious posterior uveitis.

DESIGN

Noncomparative interventional case series, dose randomized, dose masked, prospective.

PARTICIPANTS

Thirty-six eyes of 32 patients with a history of recurrent noninfectious posterior uveitis.

METHODS

Patients were randomized to receive either a 0.59-mg or a 2.1-mg fluocinolone acetonide intravitreal implant. Patients were observed every 4 to 6 weeks for the first 3 months and then every 3 months thereafter.

MAIN OUTCOME MEASURES

Preoperative and postoperative ocular inflammation, visual acuity (VA), antiinflammatory medication use, and safety.

RESULTS

Mean follow-up duration was 683+/-461 days (range, 204-1817). Mean baseline visual acuity for the device-implanted eyes was +1.1 logarithm of the minimum angle of resolution (logMAR) units (20/250), which improved significantly to +0.81 logMAR units (20/125) at 30 months (P<0.05). Inflammation was effectively controlled over the follow-up period. The average number of recurrences in the 12 months before implantation was 2.5 episodes per eye. None of these eyes experienced a recurrence for the first 2 years after implantation. There was a reduction in systemic and local therapy use in the device-implanted eyes; of the patients who remained on systemic medication after implantation, dosage was reduced in 68%. The posterior sub-Tenon's capsule injection rate significantly decreased from a mean of 2.2 injections per eye per year to 0.07 injections per eye per year (P<0.0001) The most common adverse event was intraocular pressure (IOP) rise. At baseline, 11.0% of eyes used pressure-lowering agents, versus 56.1% over the follow-up period (P = 0.005). Filtering procedures were performed in 7 (19.4%) eyes. Four of the 8 phakic eyes, each of which had some level of cataract at device implantation, subsequently underwent cataract extraction. There were no device explantations or patients lost to follow-up during the investigation.

CONCLUSION

The fluocinolone acetonide intravitreal implant effectively controlled intraocular inflammation in the studied population. Elevated IOP and cataracts that occurred in fluocinolone device-implanted eyes were managed by standard means. The fluocinolone acetonide sustained drug delivery implant seems to be promising in patients with posterior uveitis who do not respond to or are intolerant to conventional treatment.

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

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.

Four zona pellucida glycoproteins are expressed in the human

BACKGROUND

The zona pellucida (ZP) is an extracellular glycoprotein matrix which surrounds all mammalian oocytes. Recent data have shown the presence of four human zona genes (ZP1, ZP2, ZP3 and ZPB). The aim of the study was to determine if all four ZP proteins are expressed and present in the human.

METHODS

cDNA derived from human oocytes were used to amplify by PCR the four ZP genes. In addition, isolated native human ZP were heat-solubilized, trypsin-digested and subjected to tandem mass spectrometry (MS/MS).

RESULTS

All four genes were expressed and the respective proteins present in the human ZP. Moreover, a bioinformatics approach showed that the mouse ZPB gene, although present, is likely to encode a non-functional protein.

CONCLUSIONS

Four ZP genes are expressed in human oocytes (ZP1, ZP2, ZP3 and ZPB) and preliminary data show that the four corresponding ZP proteins are present in the human ZP. Therefore, this is a fundamental difference with the mouse model

Examples of salt tectonics from West Africa: a comparative approach

Exploration experience gained in specific salt basins of West Africa may not be directly applicable to other salt basins along the entire passive margin. To conduct a comparative structural analysis, regional reflection seismic transects were constructed across the salt basins of Morocco, Senegal, Guinea-Bissau, Equatorial Guinea, Gabon and Angola.

Regional-scale similarities of the salt basins include the progressive complication of salt-related structures basinward, the change from an extensional domain on the shelf to a compressional domain on the slope and the presence of a toe-thrust front at the oceanward edge of the basins. Regional-scale differences are partly attributed to the relative stratigraphic position of the salt in relation to the rift history.

In the better-known post-rift salt basins of Equatorial Guinea, Gabon, Congo and Angola updip extension is represented by a broad rafted domain balanced by downdip contraction in the form of salt tongues, canopies and a toe-thrust zone. The efficiency of this gravity sliding/spreading across the whole margin is due to the more or less uniform original distribution of Aptian salt in the post-rift succession forming a continuous detachment level.

In contrast, the typically uneven original distribution of the Late Triassic and Early Jurassic syn-rift salt in Morocco, Mauritania, Senegal, The Gambia and Guinea-Bissau is due to basement highs separating rift half-grabens and creating a different structural pattern. Individual salt structures, such as pillows and diapirs, originated from isolated patches of the autochthonous salt. In the case of syn-rift salt, updip extension may not always be the ultimate driving force for the contractional salt-deformation downdip.

A phase I trial of continuously infused intratumoral bleomycin for the treatment of recurrent glioblastoma multiforme

Intratumoral (IT) chemotherapy has theoretical advantages in the treatment of brain tumors. The blood-brain barrier is not a factor in drug delivery, and large concentrations of drug can be instilled in the tumor with little systemic toxicity. Bleomycin has activity against gliomas and is a cell cycle selective agent whose efficacy should be enhanced by continuous infusion. We performed a phase I trial to test the feasibility of IT chemotherapy using a refillable, sustained release device, and to determine the maximum tolerable dose of IT bleomycin. The study was an open-ended dose escalation study. A modified Ommaya reservoir (containing a semipermeable membrane) was implanted with the delivery tube in the center of the tumor. Groups of three patients with recurrent glioblastoma multiforme were entered at progressively higher dose levels of bleomycin. The study closed when all patients at a given starting dose level developed toxicity. Nine patients received doses ranging from 5 to 34 U/wk; the median total cumulative dose was 195 U. No dose limiting systemic toxicity was detected. Neurologic toxicity occurred only at doses above 16 U/wk. We conclude that continuously infused IT bleomycin is well tolerated; the MTD (and recommended dose for a phase II efficacy trial) of IT bleomycin is 16 U/wk.

Long-term effect on the equine eye of an intravitreal device used for sustained release of cyclosporine A

OBJECTIVE: To determine the long-term toxicity of an intravitreal device releasing continuous cyclosporinee A (CsA) in normal eyes of horses by evaluating clinical signs, electroretinography, and histopathology. Animals Studied Ten adult horses with normal ophthalmic examinations were used in this study Procedure(s) Four horses had one eye implanted with a CsA device, and six horses had the right eye implanted with a CsA-containing device (10 eyes with CsA in total) and the left eye (six eyes in total) with the device without drug (control). The implants were placed in the vitreous of the eyes through a sclerotomy 1 cm posterior to the limbus in the dorso-temporal quadrant of the eye. Scotopic electroretinograms were performed prior to implantation and at 1 week, and at 1, 3, 6, 9, and 12 months postimplantation. Two of the unilaterally implanted horses were euthanized at 1 weeks postimplantation, and two at 6 weeks postimplantation. Two of the bilaterally implanted horses were euthanized at 6 months, two at 9 months, and two at 12 months postimplantation. At euthanasia, the eyes were removed, aqueous and vitreous humor aspirated, and tissues fixed in 10% buffered formalin and processed for histopathology. CsA concentrations were measured by high pressure liquid chromatography in the aqueous and vitreous humors, and in peripheral blood. RESULTS: The devices were tolerated well in 14 of 16 eyes. There was minimal postoperative inflammation in most eyes, with a normal appearance within 7 days. In two eyes implanted with the CsA device, severe inflammation resulted in phthisis bulbi by 28 days. One of these eyes exhibited suspected bacterial endophthalmitis, and one had a sterile endophthalmitis and cataract presumably from trauma to the lens during implantation. In the other 14 eyes, no change was observed in the scotopic electroretinograms (ERG) from preoperative results, and no significant differences between the right (CsA) and left (control device) eyes were observed. CsA levels in the aqueous and vitreous humor, and peripheral blood were below the detection limit of the HPLC. Histologic findings revealed only a mild lymphoplasmacytic cellular infiltrate in the ciliary body and pars plana near the implantation site. CONCLUSIONS: The CsA devices were well tolerated with no long-term complications from the implants themselves. However, complications may occur from inadvertent implantation trauma or contamination during surgery. The long-term safety of the device may make it useful for delivery of CsA in the control of equine recurrent uveitis.

Pharmacokinetics of the fluocinolone/5-fluorouracil codrug in the gas-filled eye

PURPOSE

To determine the effect of intraocular gas tamponade on drug levels achieved with the intravitreal sustained-release fluocinolone (FL)/5-fluorouracil (5-FU) codrug pellet.

METHODS

After insertion of a 10-mg codrug pellet into the right eyes of 43 New Zealand white rabbits, perfluoropropane (0.4 mL of 100% C3F8) or a control sham was then injected into the midvitreous cavity. On postoperative days 2, 4, 7, 21, and 42, aqueous samples were collected, the rabbits were killed, and the right eyes were enucleated. The vitreous and remaining codrug pellet were then isolated. Pellet and intravitreal drug levels were determined by high-pressure liquid chromatography.

RESULTS

No measurable drug levels were detected in any of the aqueous samples. Maximal gas expansion occurred by day 4 and partial resorption was observed by days 14 to 21. Vitreous FL and 5-FU levels during C3F8 expansion (day 2) were statistically significantly higher in the gas-filled eyes. On postoperative days 4, 7, 21, and 42, there were no statistically significant differences between FL and 5-FU drug levels in eyes containing C3F8 as compared with control eyes. Pellet codrug, FL, and 5-FU levels over time were similar in gas-filled and control eyes.

CONCLUSIONS

Intraocular gas tamponade does not significantly affect the sustained intravitreal drug levels achieved with the FL/5-FU codrug. If clinically efficacious, the FL/5-FU codrug formulation does not need to be altered to treat proliferative vitreoretinopathy in the presence of intraocular gas.

Fluocinolone acetonide sustained drug delivery device to treat severe uveitis

PURPOSE

Uveitis is often a chronic disease requiring long-term medical therapy. In this report, we describe a pilot safety and efficacy trial of a novel sustained drug delivery system containing fluocinolone acetonide to treat patients with severe uveitis.

DESIGN

Prospective, noncomparative, interventional case series

PARTICIPANTS

Patients with severe uveitis.

METHODS

Sustained drug delivery devices designed to release fluocinolone acetonide for at least 2.5 years were implanted through the pars plana into the vitreous cavity of seven eyes of five patients. All patients had severe uveitis not well controlled with, or intolerant to, repeated periocular corticosteroid injections, systemic corticosteroids, nonsteroidal immunosuppressive agents, or a combination thereof at the time of device implantation. Before device implantation, patients underwent complete evaluation including history, ophthalmologic examination, fluorescein angiography, visual field testing, and electroretinography. After surgery, patients were reexamined at 1 week, 2 weeks, 4 weeks, and at 1- to 3-month intervals. Visual fields, electroretinograms, and fluorescein angiography were repeated at 3- to 6-month intervals.

MAIN OUTCOME MEASURES

Preoperative and postoperative visual acuity, ocular inflammation, anti-inflammatory medication use, and intraocular pressure.

RESULTS

Patients had a diagnosis of Behçet's syndrome (two eyes), or idiopathic panuveitis (five eyes, including two with necrotizing retinitis, two with progressive chorioretinitis, and one with iridocyclitis and intermediate uveitis). Patients were observed an average of 10 months (range, 5-19 months). All eyes had stabilized or improved visual acuity after device implantation, and four of seven eyes had an improvement of three lines or more. The mean initial visual acuity, measured by Snellen chart, was 20/207, and the mean final visual acuity was 20/57 (P = 0.02). After surgery, at the final visit, no eye had clinically detectable inflammation, and all seven eyes had a marked reduction in systemic, topical, and periocular anti-inflammatory medication use. Four eyes had increased intraocular pressure 6 weeks to 6 months after device implantation. Intraocular pressure has been controlled on topical medications. No patient experienced intraoperative complications.

CONCLUSIONS

A fluocinolone acetonide sustained drug delivery device is a promising new therapy for the treatment of severe uveitis. Intraocular pressure must be carefully monitored long after device implantation. Based on these data, a randomized study of a larger group of patients is warranted.

Effect of an intravitreal cyclosporine implant on experimental uveitis in horses

The purpose of this study was to determine the effects of an intravitreal device releasing cyclosporine A (CsA) on recurrent inflammatory episodes in experimental uveitis. Nine normal horses were immunized peripherally with H37RA-mTB antigen twice, and then received 25 microg of H37RA-mTB antigen intravitreally in the right eye and an equal volume of balanced salt solution intravitreally in the left eye. Two weeks later, the animals randomly received either a CsA or a polymer implant (without CsA) in both eyes 1 week following implantation of the devices, 25 microg of H37RA-mTB antigen was reinjected into the right eye of each animal. Clinical signs of ophthalmic inflammation were graded following injections and implantation. The animals from each group were euthanized at 3, 14, and 28 days following the second injection. Aqueous and vitreous humor protein concentrations were measured. The presence, number, and type (CD4, 5 and 8) of infiltrating inflammatory cells and amount of tissue destruction were determined. Total RNA was isolated and quantitative reverse transcriptase-polymerase chain reaction was performed for equine specific interleukin (IL) 2 and 4, interferon-gamma (IFN gamma) and beta-actin. In addition, aqueous and vitreous humor and peripheral blood were collected at the termination of the experiments and analyzed for CsA concentration by HPLC. Within 4h of the first intravitreal H37RA-mTB antigen injection, each animal developed epiphora, blepharospasm, mild corneal edema, aqueous flare, myosis, and vitreous opacity. The severity of signs peaked 48 to 72 h after injection and subsequently decreased back to normal within 14 days. Following the second injection, clinical signs in the eyes with the CsA device were less severe and significantly shorter in duration than signs with the polymer only implant eyes. Aqueous and vitreous humor protein levels, infiltrating cell numbers, total number of T-lymphocytes, and levels of IL-2 and IFN gamma-mRNA were significantly less in eyes with the CsA implant compared to eyes with the polymer only. CsA implants did not completely eliminate the development of a second ('recurrent') experimental inflammatory episode in these horses. However, the duration and severity of inflammation, cellular infiltration, tissue destruction, and pro-inflammatory cytokines RNA transcript levels were significantly less in those eyes implanted with the CsA device.

Safety and pharmacokinetics of an intraocular fluocinolone acetonide sustained delivery device

PURPOSE

To determine the safety and pharmacokinetics of an intraocular fluocinolone acetonide sustained drug delivery device.

METHODS

Nonbiodegradable drug delivery devices containing 2 or 15 mg of a synthetic corticosteroid, fluocinolone acetonide, were constructed. The long-term in vitro release rates of these devices were determined in protein-free buffer or buffer containing 50% plasma protein. Fifteen-milligram devices were also implanted into the vitreous cavities of rabbit eyes. Intravitreal drug levels, the amount of drug remaining in explanted devices, and the release rate of explanted devices were determined over a 1-year time period. Drug toxicity was assessed over this same time period by slit lamp examination, indirect ophthalmoscopy, electroretinography, and histologic examination.

RESULTS

The drug release rates for the 2-mg device, 1.9 +/- 0.25 microg/d, and for the 15-mg device, 2.2 +/- 0.6 microg/d, remained linear over the 6-month and 45-day testing period, respectively. The release rate increased by approximately 20% when devices were transferred from protein-free buffer to buffer that contained protein (P: < 0.0001). Vitreous levels remained fairly constant (0.10-0.21 microg/ml) over a 1-year period. No drug was present in the aqueous humor during this time period. Based on the device release rates, the predicted life span of the 2- and 15-mg devices are 2.7 and 18.6 years, respectively. There was no evidence of drug toxicity by clinical examination, electroretinography, or histologic examination.

CONCLUSIONS

It is feasible to construct a nontoxic fluocinolone acetonide drug delivery device that reproducibly releases fluocinolone acetonide in a linear manner over an extended period. These devices show great promise in the treatment of ocular diseases such as uveitis, which are often managed with chronic corticosteroid therapy.

Local immunosuppression prolongs survival of RPE xenografts labeled by retroviral gene transfer

PURPOSE

To determine whether local immunosuppression with Cyclosporin A can influence the survival of human fetal retinal pigment epithelium (RPE) xenografts in the rabbit's subretinal space.

METHODS

Cultured human fetal RPE cells were transduced with the gene for green fluorescent protein (GFP) using a lentiviral vector. The RPE was transplanted into the subretinal space of rabbits that received intravitreal cyclosporine either by weekly injections (0. 25-0.5 mg) or by slow release (approximately 2 microg/d) from a capsule sutured into the vitreal cavity after prior cryopexy. The transplanted RPE was followed by GFP fluorescence scanning laser ophthalmoscopy and by histology of the transplant site.

RESULTS

RPE xenografts in eyes receiving intravitreal cyclosporine survived longer (several months) than they did in control eyes without cyclosporine. Survival was as long with slow release capsules as it was with weekly intravitreal injections at much higher concentrations of cyclosporine.

CONCLUSIONS

Local immunosuppression of the eye with cyclosporine prolongs the survival of RPE xenografts in the subretinal space of rabbits, implying that rejection involves activated T lymphocytes. Local immunosuppression with slow release capsules is as effective as weekly injections at much higher concentrations.

Curcuminoids inhibit the angiogenic response stimulated by fibroblast growth factor-2, including expression of matrix metalloproteinase gelatinase B

We have studied mechanisms controlling activation of the gelatinase B gene (matrix metalloproteinase-9) by fibroblast growth factor-2 (FGF-2) during angiogenesis, and the effects of the natural product curcuminoids on this process. Using a transgenic mouse (line 3445) harboring a gelatinase B promoter/lacZ fusion gene, we demonstrate FGF-2 stimulation of reporter gene expression in endothelial cells of invading neocapillaries in the corneal micropocket assay. Using cultured corneal cells, we show that FGF-2 stimulates DNA binding activity of transcription factor AP-1 but not NF-kappaB and that AP-1 stimulation is inhibited by curcuminoids. We further show that induction of gelatinase B transcriptional promoter activity in response to FGF-2 is dependent on AP-1 but not NF-kappaB response elements and that promoter activity is also inhibited by curcuminoids. In rabbit corneas, the angiogenic response induced by implantation of an FGF-2 pellet is inhibited by the co-implantation of a curcuminoid pellet, and this correlates with inhibition of endogenous gelatinase B expression induced by FGF-2. Angiostatic efficacy in the cornea is also observed when curcuminoids are provided to mice in the diet. Our findings provide evidence that curcuminoids target the FGF-2 angiogenic signaling pathway and inhibit expression of gelatinase B in the angiogenic process.

Slow-release 5-fluorouracil and triamcinolone reduces subglottic stenosis in a rabbit model

A previous pilot study suggested that a sustained-release conjugate that provided a slow release of 5-fluorouracil and triamcinolone acetonide injected into the tracheal and paratracheal tissues of rabbits at the time of subglottic surgery reduced the formation of subglottic stenosis. Our study was undertaken to confirm the effect. Ten milligrams of the compound suspended in hyaluronic acid was injected at the time of injury via a laryngofissure approach. The results showed that the control group had a mean stenosis of 52%, whereas the treated group had a mean stenosis of 32%. There was a significant difference between the treated and untreated groups (p = .003). It is hoped that this co-drug ultimately can be used in humans to reduce stenosis formation after laryngotracheal surgery and in other forms of otorhinolaryngological surgery.

The identity status of African Americans in middle adolescence: a reexamination of Watson and Protinsky (1991)

In contrast to earlier research, Watson and Protinsky (1991) found that African American students did not experience identity foreclosure to a greater extent than did their Caucasian peers. Watson and Protinsky, however, examined only ideological identity. The purpose of the present study was to extend this line of research by examining identity development in the interpersonal domain as well as the ideological domain. Forty-eight African American students completed a revised version of the Extended Objective Measure of Ego Identity Status (EOM-EIS II). Supporting the conclusions of Watson and Protinsky, the results showed that few of the African American students were foreclosed. Instead, most of the students were in moratorium; that is, they were engaged in the identity-exploration process. Results for the interpersonal domain were similar to those for the ideological domain.

Does slow-release 5-fluorouracil and triamcinolone reduce subglottic stenosis?

The surgical management of subglottic stenosis may be complicated by reformation of strictures. A slow-release combination of 5-fluorouracil, which has an antiproliferative effect on fibroblasts, and the corticosteroid triamcinolone acetonide has been used experimentally to control scar production in ophthalmic operations. This study was performed to determine if this material also can be used to reduce formation of subglottic stenosis. Subglottic stenosis was induced in rabbits by means of injury to the subglottic mucosa and submucosa. A suspension of the compound at a concentration of 2.5 mg/ml or 12.5 mg/ml was injected into the adjacent soft tissues. A control group of rabbits received the same volume of the suspension fluid but no compound. Two rabbits from each group were killed 1, 2, and 12 weeks postoperatively. No stenosis was seen at 1 or 2 weeks, but at 12 weeks the rate of formation of subglottic stenosis was decreased to a mean of 15.20% in the experimental groups compared with 47.37% in the control group. There were no indications of local or systemic toxicity. The promising results from this preliminary study suggest that use of this compound may reduce restenosis among patients treated surgically for subglottic stenosis. Further studies are being conducted.

An intravitreal sustained-release triamcinolone and 5-fluorouracil codrug in the treatment of experimental proliferative vitreoretinopathy

OBJECTIVE

To determine the efficacy and pharmacokinetics of an intravitreal sustained-release triamcinolone acetonide and 5-fluorouracil (TA/5-FU) codrug in the treatment of experimental proliferative vitreoretinopathy (PVR).

METHODS

The therapeutic efficacy of the TA/5-FU codrug was determined in a rabbit model that simulates human PVR. Intravitreal levels of triamcinolone and 5-fluorouracil were measured at different time points and drug release in vitro was tested. Toxic effects were evaluatedby electroretinograpy, clinical examination, and light microscopy.

RESULTS

Both the severity of PVR grade and the percentage of eyes with moderate or worse tractional detachment were significantly less in eyes treated with the codrug. The therapeutic effect of the intravitreal codrug was paralleled by sustained intravitreal levels of triamcinolone and 5-fluorouracil. There were no drug-related toxic effects evident on clinical or histopathologic examination of eyes containing the TA/5-FU codrug.

CONCLUSIONS

The intravitreal sustained-release TA/5-FU codrug effectively inhibits the progression of PVR in a rabbit model that closely resembles PVR in humans. The TA/5-FU codrug may simultaneously target different components of the wound-healing response.

Intravitreal sustained-release cyclosporine in the treatment of experimental uveitis

OBJECTIVE

Uveitis often is a chronic disease requiring long-term medical therapy. Despite treatment, the disease may be difficult to control and may produce serious, vision-threatening ocular complications. In this study, the authors determined whether an intravitreal cyclosporine-sustained delivery device was effective in the treatment of ocular inflammation in a rabbit model of uveitis.

METHODS

New Zealand White rabbits were immunized subcutaneously with Mycobacterium tuberculosis H37Ra antigen. Fourteen days later, sustained-release cyclosporine devices were implanted into the vitreous cavity of the right eye of experimental rabbits. Control animals received sham devices. Seven days after device implantation, rabbits were challenged with an intravitreal injection of tuberculin antigen. To simulate chronic inflammation with exacerbations, some animals were rechallenged with intravitreal antigen on day 21 after device implantation. Inflammation was assessed clinically by a masked observer who graded anterior chamber cells, flare, corneal neovascularization, iris congestion, and vitreous opacity daily until day 7 and on day 13 after the initial intravitreous challenge, and on days 1 and 2 after the rechallenge. Retinal function was evaluated by electroretinography. Animals were killed 3, 6, 8, and 14 days after the initial intravitreal challenge and on the second day after rechallenge for aqueous leukocyte count, protein measurement, and histologic examination. The number of aqueous and peripheral blood proliferating lymphocytes and the subset of CD4+ T cells were determined by flow cytometry. High-performance liquid chromatography was used to measure cyclosporine A levels in vitreous and peripheral blood. Light microscopy was used to evaluate the eyes histopathologically.

RESULTS

By clinical criteria, treated eyes had significantly less inflammation than untreated eyes. The number of aqueous cells and protein concentration determined quantitatively paralleled the clinical assessment of anterior chamber cells and flare. The electroretinography B-wave was depressed significantly in untreated eyes compared with that of treated eyes (P < 0.02). Histopathologic examination results showed marked inflammation and tissue disorganization in untreated eyes, whereas cyclosporine-treated eyes had preserved architecture and greatly reduced inflammatory cells. Intravitreal cyclosporine remained at therapeutic levels for at least 6 months after intravitreal device implantation, whereas blood levels were low to nondetectable.

CONCLUSIONS

The intravitreal cyclosporine A device effectively suppresses ocular inflammation in a rabbit model of uveitis. This device may be useful in the treatment of patients with severe chronic uveitis who are intolerant to currently available therapies.

Ganciclovir implant exchange. Timing, surgical procedure, and complications

BACKGROUND

The ganciclovir implant is effective for the treatment of cytomegalovirus (CMV) retinitis. The device eventually runs out of drug, however, and must be replaced. We report our experience with exchanging ganciclovir implants during the course of a randomized clinical trial.

METHODS

During our study, patients with newly diagnosed peripheral CMV retinitis were treated with a ganciclovir implant. The implant was scheduled for exchange at 32 weeks. It was exchanged earlier if progression of CMV retinitis occurred. Patient examinations and standard fundus photography were performed at 2-week intervals after the exchange procedure.

RESULTS

Twenty-six exchange procedures were performed. Twenty-two eyes in 15 patients received a second implant and 4 eyes in 4 patients later received a third implant. Cytomegalovirus retinitis was rendered or maintained inactive in 22 of 23 cases with more than 1 month of follow-up after the second or third implants. Complications after the second implant procedure included transient vitreous hemorrhage in 5 eyes, postoperative inflammation in 1 eye, and retinal detachment in 1 eye. Median visual acuity returned to 20/25 by 28 days and to 20/20 by 42 days. Complications after the third implant procedure included dense vitreous hemorrhage in 3 of 4 eyes. Median survival time after a second implant procedure was 89 days.

CONCLUSIONS

The initial ganciclovir implant exchange procedure is well tolerated with continued long-term control of CMV retinitis. Multiple reentries through the same wound may be associated with an increased risk for vitreous hemorrhage.

Intravitreal sustained release corticosteroid-5-fluoruracil conjugate in the treatment of experimental proliferative vitreoretinopathy

PURPOSE

Proliferative vitreoretinopathy (PVR) remains the most common cause of failed retinal detachment (RD) surgery. The authors compared the effectiveness of two intraocular sustained-release codrugs in suppressing PVR in a rabbit model a surgically implantable pellet releasing 5-fluorouracil (FU) and dexamethasone (DX) for 1 week and an injectable intravitreal sustained-release suspension releasing 5-FU and triamcinolone acetonide for 1 month.

METHODS

Sustained-release devices and suspensions were prepared to deliver equimolar quantities of corticosteroid and 5-FU. In group 1, devices were implanted surgically into the vitreous of the right eye of 10 New Zealand White rabbits. Ten control rabbits received surgical implantation of the suture only. In group 2, drug suspension was injected into the vitreous of the right eye of 10 New Zealand White rabbits. Ten control rabbits received injection of the vehicle only. One day later, each rabbit was injected intravitreally with 250,000 homologous rabbit dermal fibroblasts. Severity of PVR was graded clinically by two masked observers on days 3, 7, 10, 14, 21, and 28.

RESULTS

In group 1, clinical severity of PVR was less in the experimental group than in the control group at all time points, this was only statistically significant on day 10 (P = 0.04). Six eyes developed moderate to severe tractional RD or bullous RD in the control group by day 10 compared with none in the experimental group (P = 0.01). In group 2, the median clinical grading of eyes in the experimental group was significantly less than that in the control group at all time points through day 21 (P < or = 0.01).

CONCLUSIONS

Both the intravitreal sustained-release dexamethasone-5-FU device and the triamcinolone-5-FU suspension effectively inhibit the progression of PVR in a rabbit model. Simultaneous delivery of 5-FU and corticosteroid may target different components of the wound-healing process in this disease.

A long-term multicentre assessment of the safety and tolerability of calcitriol ointment in the treatment of chronic plaque psoriasis

Calcitriol (1 alpha,25-dihydroxyvitamin D3), applied topically in an ointment base, has been shown to be effective in the treatment of chronic plaque psoriasis. This open study was designed to assess the safety and tolerability of 3 micrograms/g calcitriol ointment applied twice daily over treatment periods of up to 78 weeks. In the 253 evaluable patients with chronic plaque psoriasis no clinically relevant changes were observed in the baseline/end-point analyses of mean serum levels of total calcium, albumin-adjusted total calcium, phosphorus and creatinine, and plasma calcitriol levels. Mean values of 24-h urinary calcium, phosphorus, creatinine and hydroxyproline excretions, creatinine clearance and mean urinary calcium/creatinine ratio also did not show clinically relevant changes in the baseline/end-point analyses. The treatment was well tolerated, with no serious adverse events occurring during the course of the study. Eight patients withdrew from the study due to adverse events which, although not serious, were thought to be treatment-related: in seven patients skin irritation reactions and in one case a transient asymptomatic slight hypercalcaemia was observed. In addition, assessments of global severity, global improvement and Psoriasis Area and Severity Index scores confirmed the therapeutic efficacy of twice daily 3 micrograms/g calcitriol ointment demonstrated in an earlier controlled study. In conclusion, this study demonstrated that twice daily application of 3 micrograms/g calcitriol ointment is safe and well-tolerated in the treatment of chronic plaque psoriasis.

Sustained-release subconjunctival 5-fluorouracil

BACKGROUND AND OBJECTIVES

The purpose of this research was to obtain preliminary safety and efficacy data on a novel sustained-release 5-fluorouracil (5-FU) implant in high-risk glaucoma surgical patients.

PATIENTS AND METHODS

The implants were placed subconjunctivally in four patients undergoing high-risk trabeculectomy. The patients have been observed for approximately 2.5 years.

RESULTS

In three of the four patients intraocular pressure was controlled at less than 21 mm Hg, with stabilization of the visual field. One patient had early failure. No untoward events were linked to the placement of the implant.

CONCLUSION

Sustained-release systems for subconjunctival 5-FU may be useful in filter maintenance.

An intravitreal device providing sustained release of cyclosporine and dexamethasone

PURPOSE

A device that releases cyclosporine and dexamethasone into the eye for extended periods of time might be beneficial in diseases such as proliferative vitreoretinopathy and uveitis. In this study we examine the pharmacokinetics and toxicity of cyclosporine and dexamethasone combined in an intravitreal sustained-release device and the toxicity of a similar device containing only dexamethasone in rabbits.

METHODS

Rabbits were divided into three groups for (1) evaluation of the drug tissue levels and device release kinetics following implantation of a device containing 100 micrograms of cyclosporine labeled with 2 microCi of 3H-cyclosporine and 2 mg of dexamethasone; (2) evaluation of the toxicity of this intravitreal device; and (3) evaluation of the toxicity of a similar device containing 2 mg of dexamethasone only. Cyclosporine was measured using a scintillation counter and dexamethasone was measured by high pressure liquid chromatography (HPLC). Toxicity was evaluated by electroretinography, clinical examination, and light microscopy.

RESULTS

Vitreous concentrations of cyclosporine (+/- standard deviation) averaged 0.06 (+/- 0.02) microgram/ml over 10 weeks. The average dexamethasone concentration over the 10 week period was 2.9 (+/- 0.9) micrograms/ml. Devices containing cyclosporine and dexamethasone released each drug at rates similar to devices containing cyclosporine or dexamethasone alone. Devices containing both cyclosporine and dexamethasone caused reversible depressions in the b-wave amplitude of photopic and scotopic electroretinograms (ERG's). There was no evidence of toxicity associated with the devices containing dexamethasone only. There was no drug-related toxicity evident on clinical or histopathologic examination of eyes with devices containing the combination of cyclosporine and dexamethasone or dexamethasone alone.

CONCLUSIONS

We conclude that the device maintains potentially therapeutic levels of both cyclosporine and dexamethasone in the vitreous. Reversible electroretinographic abnormalities are attributable to cyclosporine. A sustained-release device containing cyclosporine and dexamethasone may be useful for reducing inflammation in diseases such as proliferative vitreoretinopathy and uveitis.

Evaluation of a delivery system providing long-term release of cyclosporine

OBJECTIVES

To examine the clearance of cyclosporine after intravitreal injection and to assess the kinetics and toxic effects of an intravitreal device that provides sustained delivery of cyclosporine.

METHODS

Rabbits were divided into two groups to evaluate (1) the elimination kinetics after 1-microgram and 10-microgram intravitreal injections of cyclosporine and (2) the levels produced after implantation of a device that contained cyclosporine over 6 months. The toxic effects of the intravitreal device over 6 months were assessed in rabbits and cynomolgus monkeys.

RESULTS

After the 10-microgram injection, the half-life was longer (10.8 hours vs. 4.2 hours) and the distribution volume was smaller (1.7 mL vs 3.2 mL) than after the 1-microgram injection. This difference can be attributed to saturable partitioning of the drug. The device resulted in a vitreous concentration of approximately 500 ng/mL throughout the study period. In the rabbit it resulted in reversible lens opacification and decreased b-wave amplitude. This toxic effect was not detected in the monkey.

CONCLUSIONS

The device produces sustained intravitreal levels of cyclosporine. Although it was associated with reversible toxic effects in the rabbit, it was well tolerated in primates. Sustained-release implants are a promising new treatment for chronic uveitis.

Sustained release intravitreal dexamethasone

Sustained intravitreal levels of dexamethasone may be useful in the treatment of proliferative vitreoretinopathy (PVR). The preparation and evaluation of an implantable system for intravitreal sustained release of dexamethasone is described. Pellets of dexamethasone were coated in biocompatible, nonerodible polymers and the release rate tested in vitro. Devices were then implanted in the rabbit vitreous and the in vivo release rate and corresponding steady state vitreous concentration determined. Toxicity was also evaluated by histopathology and electrographic examination. Devices released dexamethasone at approximately 1 ug/hr in vitro and 1.5 ug/hr in vivo. When implanted into the vitreous intravitreal concentrations of approximately 2.5 +/- 1.2 ug/hr were maintained for over 3 months. Devices were well tolerated with no evidence of inflammation or retinal abnormalities.