26 research outputs found

    Early expansion of CD38+ICOS+ GC Tfh in draining lymph nodes during influenza vaccination immune response

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    T follicular helper (Tfh) cells provide critical help to B cells during the germinal center (GC) reaction to facilitate generation of protective humoral immunity. Accessing the human lymph node (LN) to study the commitment of CD4 T cells to GC Tfh cell differentiation during in vivo vaccine responses is difficult. We used ultrasound guided fine needle biopsy to monitor recall responses in axillary LNs to seasonal influenza vaccination in healthy volunteers. Specific expansion of GC cell subsets occurred exclusively within draining LNs five days postvaccination. Draining LN GC Tfh and precursor-Tfh cells express higher levels of CD38, ICOS, and Ki67, indicating they were significantly more activated, motile, and proliferating, compared to contralateral LN cells. These observations provide insight into the early expansion phase of the human Tfh lineage within LNs during a vaccine induced memory response and highlights early LN immune responses may not be reflected in the periphery

    Overcoming the mobility penalty introduced by dipole disorder in small-molecule HTM films

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    The importance of the hole-transport material (HTM) in perovskite solar cells (PSCs) is now very well-established, with state-of-the-art materials such as Spiro-OMeTAD attracting significant attention in the last decade. The high cost of such materials still limits the commercialisation of these HTMs. To tackle this, the amide linker has recently been introduced into HTM systems via EDOT-Amide-TPA, utilising condensation chemistry as a cheap and effective route to HTMs. EDOT-Amide-TPA is capable of a variety of intermolecular interactions such as dipole-dipole interactions and hydrogen bonding, both of which are beneficial for enhancing the film morphology and improving charge transport. However, the interplay between these different interactions is not trivial, and understanding how they affect each other is paramount to inform new HTM designs whilst minimising material waste. To date, studies investigating the combined effects of different intermolecular interactions within the HTL on the charge transport properties of these materials are lacking. Furthermore, dipole disorder within the film introduces a mobility ‘penalty’: mobility decreases with stronger overall dipole due to energetic disorder within the film, which hinders charge hopping. In this work, we investigate three amide-based HTM analogs with differing intermolecular interaction capabilities, and show that this penalty can be compensated by a preferentially increased dipole ordering, likely achieved through intermolecular hydrogen bonding. This effectively cancels out the dipole disorder while retaining the beneficial effects on the molecular packing. Our aim is that this work provides a good foundation for navigating the complex interplay between hydrogen bonding, dipole moments, conductivity, and film formation in small-molecule HTM

    Photodynamic therapy of subfoveal choroidal neovascularization: clinical and angiographic examples

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    BACKGROUND: Conventional photocoagulation of subfoveal choroidal neovascularization (CNV) is often accompanied by visual loss due to thermal damage to adjacent retinal structures. Photodynamic therapy (PDT) allows vascular occlusion by selective photochemical destruction of vascular endothelial cells only. In a pilot study we evaluated the use of PDT in CNV. METHODS: In a clinical phase I/II trial, patients with subfoveal CNV were treated with PDT. Benzoporphyrin derivative monoacid ring A (BPD) was used as sensitizer at a drug dose of 6 mg/m2 or 12 mg/m2. Irradiation was performed via a diode laser emitting at 690 nm coupled into a slit lamp. Safe and maximum tolerated light doses were defined by dose escalation from 25 to 150 J/cm2. Photodynamic effects were documented ophthalmoscopically and angiographically. RESULTS: Sixty-one patients received a single course of BPD-PDT. Preliminary results suggest no damage to retinal structures within the treated area clinically. Retinal perfusion was not altered, while CNV demonstrated immediate absence of fluorescein leakage in the majority of lesions subsequent to PDT. At optimized parameters (6 mg/m2 and 50 J/cm2) complete cessation of leakage from classic CNV occurred in 100% of cases at 1 week and in 50% at week 4. In 70-80% of classic CNV, leakage reappeared at week 12, but markedly less than before treatment. CONCLUSION: PDT allows temporary absence of leakage from CNV with preservation of visual acuity. The long-term prognosis of CNV secondary to age-related macular degeneration treated with repeated courses of PDT is being evaluated in a phase III trial

    Photodynamic therapy of subfoveal choroidal neovascularization: clinical and angiographic examples

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    BACKGROUND: Conventional photocoagulation of subfoveal choroidal neovascularization (CNV) is often accompanied by visual loss due to thermal damage to adjacent retinal structures. Photodynamic therapy (PDT) allows vascular occlusion by selective photochemical destruction of vascular endothelial cells only. In a pilot study we evaluated the use of PDT in CNV. METHODS: In a clinical phase I/II trial, patients with subfoveal CNV were treated with PDT. Benzoporphyrin derivative monoacid ring A (BPD) was used as sensitizer at a drug dose of 6 mg/m2 or 12 mg/m2. Irradiation was performed via a diode laser emitting at 690 nm coupled into a slit lamp. Safe and maximum tolerated light doses were defined by dose escalation from 25 to 150 J/cm2. Photodynamic effects were documented ophthalmoscopically and angiographically. RESULTS: Sixty-one patients received a single course of BPD-PDT. Preliminary results suggest no damage to retinal structures within the treated area clinically. Retinal perfusion was not altered, while CNV demonstrated immediate absence of fluorescein leakage in the majority of lesions subsequent to PDT. At optimized parameters (6 mg/m2 and 50 J/cm2) complete cessation of leakage from classic CNV occurred in 100% of cases at 1 week and in 50% at week 4. In 70-80% of classic CNV, leakage reappeared at week 12, but markedly less than before treatment. CONCLUSION: PDT allows temporary absence of leakage from CNV with preservation of visual acuity. The long-term prognosis of CNV secondary to age-related macular degeneration treated with repeated courses of PDT is being evaluated in a phase III trial

    Photodynamic therapy with verteporfin for choroidal neovascularization caused by age-related macular degeneration: results of a single treatment in a phase 1 and 2 study

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    OBJECTIVE: To evaluate the safety and short-term visual and fluorescein angiographic effects of a single photodynamic therapy treatment with verteporfin with the use of different dosage regimens in patients with choroidal neovascularization (CNV) from age-related macular degeneration. DESIGN: Nonrandomized, multicenter, open-label, clinical trial using 5 dosage regimens. SETTING: Four ophthalmic centers in North America and Europe providing retinal care. PARTICIPANTS: Patients with subfoveal CNV caused by age-related macular degeneration. METHODS: Standardized protocol refraction, visual acuity testing, ophthalmic examination, color photographs, and fluorescein angiograms were used to evaluate the effects of a single treatment of photodynamic therapy with verteporfin. Follow-up was planned through 3 months in 97 patients and for less than 3 months in 31 other patients. RESULTS: The mean visual acuity change (and range of change) from baseline at the follow-up examination at week 12 after a single treatment with regimens 1 through 5 was -0.2 (-3 to +2), -0.9 (-9 to +5), -1.6 (-9 to +2), +0.4 (-8 to +7), and +0.1 (-8 to +9) lines, respectively. Only the highest light dose (150 J/cm2) in regimens 2 and 3, which produced angiographic nonperfusion of neurosensory retinal vessels, caused marked vision loss. Some cessation of fluorescein leakage from CNV was achieved without loss of vision when the light dose used was less than 150 J/cm2. Systemic adverse events were rare. Cessation of fluorescein leakage from CNV was noted in all regimens by 1 week after photodynamic therapy. Fluorescein leakage from at least a portion of the CNV reappeared by 4 to 12 weeks after treatment in almost all cases. Progression of classic CNV beyond the area of CNV identified before treatment was noted in 42 (51%) of the 83 eyes with classic CNV followed up for 3 months after a single treatment. Eyes in which the area of any CNV leakage at 12 weeks was less than at baseline had a significantly better visual acuity outcome (+0.8 line) than eyes in which CNV leakage progressed (-0.8 line). CONCLUSIONS: Photodynamic therapy with verteporfin achieved short-term cessation of fluorescein leakage from CNV without loss of vision or growth of classic CNV in some patients with age-related macular degeneration. Except for nonperfusion of neurosensory retinal vessels at a light dose of 150 J/cm2, no other adverse events were of concern. Randomized clinical trials to investigate whether this new modality can preserve vision in patients with CNV secondary to age-related macular degeneration are justified

    Photodynamic therapy with verteporfin for choroidal neovascularization caused by age-related macular degeneration: results of retreatments in a phase 1 and 2 study

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    OBJECTIVES: To evaluate safety and short-term visual acuity and fluorescein angiographic effects of photodynamic therapy (PDT) after retreatments with verteporfin for choroidal neovascularization (CNV) in age-related macular degeneration (AMD) that demonstrated fluorescein leakage after at least 1 course of PDT. DESIGN: Nonrandomized, multicenter, open-label phase 1 and 2 clinical trial using 2 different retreatment dosage regimens. SETTING: Four ophthalmic centers in Europe and North America providing retinal care. METHODS: Standardized protocol refraction, visual acuity testing, ophthalmic examinations, color photographs, and fluorescein angiograms were used to evaluate the results of multiple PDT treatments. Two regimens (regimens 2 and 4) for treatment and retreatment were chosen from 5 used in a single-treatment study. Both regimens used a verteporfin dose of 6 mg/m2 infused for 10 minutes. However, regimen 2 used a light dose of 100 J/cm2 applied 20 minutes after the start of the verteporfin infusion, whereas regimen 4 used a light dose of 50, 75, or 100 J/cm2 applied 15 minutes after infusion commenced. Posttreatment evaluations were planned in 31 participants up to 3 months after up to 2 retreatments given at 2- or 4-week intervals after initial PDT treatment. Similar posttreatment evaluations were planned after retreatments in 5 additional participants who were reenrolled some time more than 12 weeks after an initial PDT treatment. RESULTS: The average visual acuity change for the 31 participants who had retreatment within 2 to 4 weeks after the initial treatment and a follow-up examination 16 to 20 weeks after the initial treatment was 0.2 lines (range, -4 to 4 lines) in regimen 2 and -1.0 line (range, -5 to 3 lines) in regimen 4. Similar outcomes were noted in the 5 reenrolled participants. Cessation of fluorescein leakage from classic CNV for at least 1 to 4 weeks could be achieved without loss of visual acuity after at least 2 treatments in 2 (6.5%) of 31 patients. Similar to single-treatment effects, the disappearance of leakage was documented regularly at 1 week after each retreatment. Fluorescein leakage reappeared by 4 to 12 weeks after a retreatment in almost all cases. However, compared with baseline, leakage activity appeared to be reduced after multiple PDT courses. For the 31 patients who had follow-up for 3 months after the last retreatment and had received retreatment 2 to 4 weeks after the initial treatment, progression of CNV beyond the area identified before the retreatment was noted in 10 (48%) of the 21 eyes with classic CNV in regimen 2 and 9 (90%) of 10 eyes in regimen 4. The rate and severity of ocular or systemic adverse events were not increased by multiple applications. CONCLUSIONS: Multiple applications of PDT with verteporfin achieve repetitive, short-term cessation of fluorescein leakage from CNV secondary to AMD, without loss of visual acuity. This strategy can be used in randomized clinical trials investigating the efficacy of verteporfin in PDT for recurrent fluorescein dye leakage from persistent or recurrent CNV, following an initial or subsequent PDT treatment, with maintenance of visual acuity. Retreatments may achieve progressive cessation of leakage and prevent further growth of CNV and subsequent visual loss

    A preliminary study of photodynamic therapy using verteporfin for choroidal neovascularization in pathologic myopia, ocular histoplasmosis syndrome, angioid streaks, and idiopathic causes

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    Objective: To evaluate short-term safety and the effects on visual acuity and fluorescein angiography of single or multiple sessions of photodynamic therapy with verteporfin for choroidal neovascularization (CNV) not related to age-related macular degeneration (AMD), including pathologic myopia, the ocular histoplasmosis syndrome, angioid streaks, and idiopathic causes. Design: A nonrandomized, multicenter, open-label, dose-escalation phase 1 and 2 clinical trial. Setting: Four ophthalmic centers in Europe and North America providing retinal care. Participants: Thirteen patients with subfoveal CNV due to pathologic myopia, the ocular histoplasmosis syndrome, angioid streaks, or idiopathic causes. Methods: Standardized protocol refraction, visual acuity testing, ophthalmic examinations, color photographs, and fluorescein angiograms were used to evaluate the results of photodynamic therapy treatments with verteporfin. Follow-up ranged from 12 weeks for patients who were treated once to 43 weeks for patients who were treated up to 4 times. Results: Verteporfin therapy was well tolerated in patients with CNV not related to AMD. No deterioration in visual acuity was observed; most patients gained at least 1 line of vision. Reduction in the size of leakage area from classic CNV was noted in all patients as early as 1 week after verteporfin therapy, with complete absence of leakage from classic CNV in almost half of the patients. Improvement in visual acuity after verteporfin therapy was greatest (+6, +8, and +9 lines) in 3 patients with relatively poor initial visual acuity (between 20/200 and 20/800). Up to 4 treatments were found to have short-term safety even with retreatment intervals as short as 4 weeks. Conclusions: Treatment of CNV not related to AMD with verteporfin therapy achieves short-term cessation of fluorescein leakage from CNV in a small number of patients without loss of vision. Further randomized clinical trials including a larger number of patients are under way to confirm whether verteporfin therapy is beneficial for subfoveal CNV not related to AMD
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