Dexamethasone Implant Produces Better Outcomes than Oral Acetazolamide in Patients with Cystoid Macular Edema Secondary to Retinitis Pigmentosa.

Purpose: To compare the clinical outcome of intravitreal dexamethasone implant versus oral acetazolamide in patients with cystoid macular edema (CME) secondary to retinitis pigmentosa (RP). Design: Multicenter, prospective, propensity-score-matched, comparative study. Methods: Eyes with RP and CME were treated either with intravitreal dexamethasone implant or with oral acetazolamide (500 mg/day). Patients were evaluated monthly and followed up for 12 months. Primary outcome measures were changes in central retinal thickness and best corrected visual acuity (BCVA). Adverse events were recorded. Results: Propensity score matching resulted in 2 groups of 30 eyes each. All patients completed 12 months of follow-up. Mean central retinal thickness decreased from 535 µm at baseline to 208 µm at month 12 in the dexamethasone implant group and from 519 to 339 µm in the oral acetazolamide group (P < 0.001, Student's t-test). Mean BCVA average change from baseline during the study (area-under-the-curve approach) was -0.084 logarithm of the minimum angle of resolution (logMAR) (+4.2 letters) in the dexamethasone implant group and -0.032 (+1.6 letters) in the oral acetazolamide group (P < 0.05, Mann-Whitney U test). Patients in the dexamethasone implant group required on average 1.7 treatments during 1 year of therapy. Conclusions: In this study, intravitreal dexamethasone implant produced better anatomic and functional improvements over oral acetazolamide in patients affected by CME secondary to RP. Larger, randomized clinical trials with longer follow-up are warranted to confirm these data.

The effect of triamcinolone acetonide, sodium hyaluronate, and chondroitin sulfate on human endothelial cells: an in vitro study.

PURPOSE: To report the in vitro effect of triamcinolone acetonide (TA), sodium hyaluronate (SH), chondroitin sulfate (CS), and their combination on human endothelial cells. METHODS: The antiangiogenic proprieties of 2 formulations of TA (TA-1 and TA-2), 2 formulations of glycosaminoglycan-containing viscoelastic agents (V-1 and V-2), and the association of TA-1 and V-1 were investigated. Their effect on angiogenesis was tested using human endothelial cells cocultured with human fibroblasts and myoblasts. After fixation and staining for CD31, a colorimetric output was obtained. A BCIP/NBT-buffered substrate allowed image analysis of tubule formation. RESULTS: Both formulations of TA significantly reduced tubule formation as compared with controls (p<0.01). Moreover, the antiangiogenic effect of TA-1 was maintained when combined with V-1 (p<0.01). CONCLUSIONS: Triamcinolone acetonide alone or in combination with hyaluronate and chondroitin sulfate is able to significantly reduce human endothelial cell proliferation in an in vitro model.

Posterior juxtascleral infusion of modified triamcinolone acetonide formulation for refractory diabetic macular edema: one-year follow-up.

PURPOSE: To evaluate prospectively the efficacy and safety of posterior juxtascleral infusion of a new formulation of triamcinolone acetonide for refractory diffuse diabetic macular edema. METHODS: This was an interventional case series. Twenty-two consecutive eyes of 18 patients with refractory diffuse diabetic macular edema were included in the study. Each patient underwent a complete ophthalmic examination, including optical coherence tomography (OCT) and digital fluorescein angiography (FA). All patients received a suspension of 40 mg triamcinolone acetonide, 20 mg sodium chondroitin sulfate, and 15 mg sodium hyaluronate (1.5 mL), delivered posteriorly through a conjunctival and Tenon's incision. All patients completed the 1-year follow-up. RESULTS: On average, studied eyes received 1.5 treatments. Mean preoperative foveal thickness (+/-SD) and visual acuity (+/-SD) were 474.2 +/- 136.6 microm and 0.6 +/- 0.37 logarithm of the minimum angle of resolution (logMAR), respectively. The central foveal thickness was significantly reduced from baseline at every follow-up visit (P < 0.001). Mean (+/-SD) reductions in macular thickness were 136 +/- 108 microm at 1 week and 128 +/- 122 microm after 1 year of follow-up. Mean (+/-SD) improvement in visual acuity at 12 months was 0.15 +/- 0.21 logMAR (P = 0.008). Visual acuity improvement of one or more lines and three or more lines were observed in 14 (63.6%) and 6 (27.3%) eyes, respectively. Seven eyes (31.8%) required topical treatment due to a significant intraocular pressure increase. CONCLUSIONS: Posterior juxtascleral infusion of a new formulation of triamcinolone acetonide is an effective treatment for diffuse diabetic macular edema unresponsive to conventional grid laser photocoagulation. A randomized, larger study is warranted.

Aptameric GT oligomers need to be complexed to ethoxylated polyethylenimine as pre-paired duplexes to efficiently exert their cytotoxic activity in human lymphoblastic cancer cells.

The aptameric oligonucleotides GT were found to exert a selective, specific and dose-dependent cell growth inhibition effect on a variety of human cancer cells by recognising specific nuclear proteins and among these in particular an isoform of the eukaryotic elongation factor 1A1 (EEF1A1). The potential development of these aptameric oligomers needs that they retain serum and intracellular stabilities. Polycations are safe non-viral carriers of the nucleic acids. We demonstrated that a weakly basic polycation, the ethoxylated polyethylenimine (EPEI), can efficiently deliver cytotoxic GT oligomers when they were complexed as partial pre-paired duplex. In this way, nuclease-resistance of the oligomer was markedly improved and the administration of the duplex complexed with EPEI to lymphoblastic cancer cells caused a specific cytotoxic effect at concentrations lower than that of naked GT. However, the cytotoxic activity of the oligomer-EPEI complex resulted strictly related to the GC content and Tm of the duplex region. The single-stranded GT and the duplex with high GC content and Tm, although complexed with EPEI failed to exert cytotoxicity. Overall results indicated that aptameric oligomers complexed with polycations can be efficiently delivered into the cells and display the desired biological effect designing a balanced partial duplex whose stability can allow oligomer release from the polycation under the physiological cellular conditions.

Diurnal changes of tonic nociceptive responses in mice: evidence for a proalgesic role of melatonin.

Diurnal variations in tonic pain reactions have been described in mice tested in Spring, but the underlying mechanisms are still unknown. We tested the potential role of melatonin, a key hormone in the control of neuro-endocrine circadian rhythms. The experiments were performed in male CBA/J mice housed under controlled temperature, humidity, and light (12/12 dark/light cycle) conditions, during the Light (7-10a.m.) or Dark (7-10p.m.) phases of the diurnal cycle. In a first group of experiments, animals were either pretreated with i.p. saline (controls) or with the melatonin receptor antagonist, luzindole (30 mg/kg), before the s.c. injection of a dilute formalin solution into a hindpaw. In control animals, pain-related behavioral reactions (licking and flinching) were higher in the evening (Dark) than in the morning (Light), both during the first (0-10 min) and the second (11-55 min) phase of the response to s.c. formalin. In animals pre-treated with luzindole, no diurnal changes occurred, pain reactions in the Dark being similar to those of the Light Control group. In a second group of experiments, artificial pinealectomy, obtained by exposing animals to continuous light for 48 h, also reduced pain reactions in the evening to levels comparable to those in the morning. Receptor autoradiography showed lower binding availability at spinal cord level in mice sacrificed during the Dark, as expected from the circadian pattern of melatonin secretion. A further significant decrease of melatonin receptor binding was induced by noxious stimulation. These results suggest a proalgesic role of endogenous melatonin in tonic pain.

Ultrastructural morphology of adrenal chromaffin cells indicative of a process of piecemeal degranulation.

Chromaffin cells of the mouse adrenal medulla were found by transmission electron microscopy (TEM) to exhibit ultrastructural changes suggestive of piecemeal degranulation (PMD), a unique model of cell secretion characterized by the slow release of granule materials without granules opening to the cell exterior. The expression of PMD was recognized in both adrenaline- and noradrenaline-containing cells. Ultrastructural changes included specific granule and cytoplasmic morphologies. In adrenaline-releasing cells the granule content was loosely packed or condensed, and surrounded by a clear halo. In noradrenaline-storing cells, the granule material appeared asymmetrically arranged and exhibited characteristic "semilunar" electron-dense domains within the granule chambers. Notably, altered granules did not fuse with each other or with the plasma membrane, and were intermingled with normal, resting granules. Large, empty cytoplasmic containers or vacuoles filled with partially dissolved matrices were frequently observed. In addition, both adrenaline- and noradrenaline-storing cells presented a rich supply of membrane-bound, smooth vesicles (50-200 nm diameter) that were either free in the cytoplasm or attached to granules. The finding of ultrastructural features characteristic of PMD in adrenal chromaffin cells suggests that such a secretory model may be an alternative secretory pathway to regulated exocytosis. Moreover, these results support the hypothesis that PMD may be a general degranulation pattern in cells involved in paracrine-endocrine secretion.

Tonic pain response in mice: effects of sex, season and time of day.

Seasonal and diurnal variations in tonic pain reactions were examined in female and male CBA/J mice maintained in a 12/12 dark/light cycle, at controlled temperature and humidity conditions. Animals were injected into the dorsum of one hindpaw with a dilute (20 microl, 1%) formalin solution. Pain-related behaviors were quantified as the time spent licking the injected paw and the number of flinching episodes. The experiments were performed during the first part of the light phase (Light: from 7 to 10 a.m.) or during the first part of the dark phase of the diurnal cycle (Dark: from 7 to 10 p.m.), in two different periods of the year: Spring (March-June) and Winter (November-January). Considering all data, females showed a slightly enhanced licking response, as well as an increase in the time spent in self-grooming, in comparison with males. In Spring, the licking and flinching responses were higher during the Dark phase than during the Light phase. This held for both sexes and for both phases of the behavioral response to formalin injection. By contrast, no significant diurnal variation in pain reactions was found in Winter. These seasonal and diurnal differences were not due to nonspecific changes in motor behavior, inasmuch as locomotor activity and self-grooming showed a different pattern: during the second phase after formalin, self-grooming was higher in the Light period in the experiments performed in Spring, whereas locomotor activity showed no significant seasonal changes. These results show that the behavioral reactions to prolonged noxious input, integrated both at spinal and supraspinal sites, undergo similar seasonal and diurnal variations in both sexes, strengthening the importance of chronobiological factors in the modulation of nociception.

Increase in therapeutic index of doxorubicin and vinblastine by aptameric oligonucleotide in human T lymphoblastic drug-sensitive and multidrug-resistant cells.

Aptameric GT oligomers are a new class of potential anticancer molecules that inhibit the growth of human cancer cell lines by binding to specific nuclear proteins. We demonstrated that an aptameric GT oligonucleotide increased the therapeutic index of doxorubicin and vinblastine in T lymphoblastic drug-sensitive and multidrug-resistant (MDR) cells. The doxorubicin ID50 decreased 6.5-fold by coadministration of 1 microM GT to CCRF-CEM cells and by 24-fold by coadministration of 0.75 microM GT to CEM-VLB300 cells. In CEM-VLB300 cells, the vinblastine ID50 decreased 11-fold by coadministration of 0.5 microM GT. Control CT sequence did not potentiate the drugs in either CCRF-CEM or CEM-VLB300 cells. The ability of GT to bind to specific nuclear proteins in cancer cells related to the increase in the therapeutic index of doxorubicin and vinblastine. No cooperation was detected by the administration of GT oligomer together with doxorubicin to rat differentiated thyroid FRTL-5 cells and to normal human lymphocytes. These cells did not show binding of GT to the specific nuclear proteins, and they were not sensitive to the cytotoxic action of the GT sequence. Drug potentiation by GT not involving normal human lymphocytes might be exploited to develop a more selective treatment of drug-sensitive and MDR tumors.

Seasonal dependency of the effects of rotational stress and cyclophosphamide in mice bearing lewis lung carcinoma.

The antitumor effects of cyclophosphamide were previously shown to be markedly reduced by the application of restraint stress in mice bearing Lewis lung carcinoma. The aim of this work was to determine the effects of rotational stress on the antitumor action of cyclophosphamide in the same animal-tumor system. Since the effects of rotational stress on metastasis were found to display a circannual rhythm, with a maximum in summer and a minimum in winter, the experiments were performed in June and February. Groups of 10 young female mice were kept under low stress housing conditions, with a 12-12 h light/dark cycle, starting 2 weeks before and during each experiment. Rotational stress caused an increase of metastasis volume to 361% of nonstressed controls in June and a decrease to 32.4% in February. In both seasons, the treatment with cyclophosphamide (240 mg/kg/day for 6 days) caused the absence of detectable metastasis at sacrifice in all mice; its combination with rotational stress caused the presence of metastases in similar proportions (6/10 and 10/10 for June vs February, respectively). The survival time of control mice was approximately twice as long in February as in June and was not appreciably modified by rotational stress; cyclophosphamide was similarly active in both seasons (4/10 and 6/10 long-term survivors for June vs February, respectively), and the number of long-term survivors was reduced to 0/10 in both seasons by rotational stress. The survival of the different experimental groups inversely correlated with the number of metastases as determined at sacrifice at the end of treatment and also with the number of CD3(+) and CD4(+) splenic T-lymphocyte subsets. These results do not appear to depend on the disruption of the circadian organization of the mice by rotational stress or by seasonal differences in cyclophosphamide activity. On the other hand, they can be interpreted assuming that cyclophosphamide reduces tumor metastasis and that T-lymphocyte-mediated immune responses of the host, amenable to modulation by stress and displaying seasonal differences uncoupled from circadian rhythms, further contribute to the tumor inhibitory effects of the drug. The observed differences in tumor metastasis caused by rotational stress and survival time in two different seasons, and the marked attenuation of cyclophosphamide antitumor action by rotational stress, appear of interest for their experimental and clinical implications.