Farmers’ attitudes about farming and the environment: A survey of conventional and organic farmers

Farmers have been characterized as people whose ties to the land have given them a deep awareness of natural cycles, appreciation for natural beauty and sense of responsibility as stewards. At the same time, their relationship to the land has been characterized as more utilitarian than that of others who are less directly dependent on its bounty. This paper explores this tension by comparing the attitudes and beliefs of a group of conventional farmers to those of a group of organic farmers. It was found that while both groups reject the idea that a farmer’s role is to conquer nature, organic farmers were significantly more supportive of the notion that humans should live in harmony with nature. Organic farmers also reported a greater awareness of and appreciation for nature in their relationship with the land. Both groups view independence as a main benefit of farming and a lack of financial reward as its main drawback. Overall, conventional farmers report more stress in their lives although they also view themselves in a caretaker role for the land more than do the organic farmers. In contrast, organic farmers report more satisfaction with their lives, a greater concern for living ethically, and a stronger perception of community. Finally, both groups are willing to have their rights limited (organic farmers somewhat more so) but they do not trust the government to do so.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83671/1/Sullivan,_S.,_E._McCann,_R._De_Young_&_D._Erickson_(1996)._Farmers_attitudes_about_farming_and_the_environment,_JAEE,_9,_123-143.pd

Preservation of Retina Ganglion Cell Function by Morphine in a Chronic Ocular-Hypertensive Rat Model

PURPOSE. The current study examined if opioid-receptoractivation by morphine can improve retinal function and retinal ganglion cell (RGC) integrity in a chronic glaucoma rat model. METHODS. IOP was raised in Brown Norway rats by injecting hypertonic saline into the limbal venous system. Rats were treated daily with 1 mg/kg morphine for 28 days at 24-hour intervals; animals were examined for changes in IOP by a TonoLab tonometer. Pattern-ERG (PERG) was obtained in response to contrast-reversal of patterned visual stimuli. RGCs were visualized by fluorogold retrograde-labeling. Changes in the expression pattern of TNF-a and caspases were measured by Western blotting. RESULTS. A significant IOP elevation was seen as early as 7 days, and maintained for up to 8 weeks, after surgery. PERG amplitudes were significantly reduced in ocular-hypertensive eyes (15.84 6 0.74 lvolts) when compared with normal eyes (19 6 0.86 lvolts). PERG deficits in hypertensive eyes were reversed by morphine treatment (18.23 6 0.78 lvolts; P < 0.05). In untreated rats, a 24% reduction in labeled RGCs was measured in the hypertensive eye compared with the normal eye. This reduction in RGC labeling was significantly ameliorated in the presence of morphine. In retinal samples, TNF-a, caspase-8, and caspase-3 expressions were significantly upregulated in ocular hypertensive eyes, but completely inhibited in the morphine-treated animals. CONCLUSIONS. These data provide evidence that activation of opioid receptors can provide significant improvement in PERG and RGC integrity against glaucomatous injury. Mechanistic data provide clues that activation of one or more opioid receptors can reduce glaucomatous-injury via suppression of TNF-a and caspase activation. (Invest Ophthalmol Vis Sci

Suppression of Acid Sphingomyelinase Protects the Retina from Ischemic Injury

Citation: Fan J, Wu BX, Crosson CE. Suppression of acid sphingomyelinase protects the retina from ischemic injury. Invest Ophthalmol Vis Sci. 2016;57:4476-4484. DOI:10.1167/ iovs.16-19717 PURPOSE. Acid sphingomyelinase (ASMase) catalyzes the hydrolysis of sphingomyelin to ceramide and mediates multiple responses involved in inflammatory and apoptotic signaling. However, the role ASMase plays in ischemic retinal injury has not been investigated. The purpose of this study was to investigate how reduced ASMase expression impacts retinal ischemic injury. METHODS. Changes in ceramide levels and ASMase activity were determined by high performance liquid chromatography-tandem mass spectrometry analysis and ASMase activity. Retinal function and morphology were assessed by electroretinography (ERG) and morphometric analyses. Levels of TNF-a were determined by ELISA. Activation of p38 MAP kinase was assessed by Western blot analysis. RESULTS. In wild-type mice, ischemia produced a significant increase in retinal ASMase activity and ceramide levels. These increases were associated with functional deficits as measured by ERG analysis and significant structural degeneration in most retinal layers. In ASMase þ/À mice, retinal ischemia did not significantly alter ASMase activity, and the rise in ceramide levels were significantly reduced compared to levels in retinas from wild-type mice. In ASMase þ/À mice, functional and morphometric analyses of ischemic eyes revealed significantly less retinal degeneration than in injured retinas from wild-type mice. The ischemia-induced increase in retinal TNF-a levels was suppressed by the administration of the ASMase inhibitor desipramine, or by reducing ASMase expression. CONCLUSIONS. Our results demonstrate that reducing ASMase expression provides partial protection from ischemic injury. Hence, the production of ceramide and subsequent mediators plays a role in the development of ischemic retinal injury. Modulating ASMase may present new opportunities for adjunctive therapies when treating retinal ischemic disorders

Histone Deacetylase Inhibition Restores Retinal Pigment Epithelium Function in Hyperglycemia.

In diabetic individuals, macular edema is a major cause of vision loss. This condition is refractory to insulin therapy and has been attributed to metabolic memory. The retinal pigment epithelium (RPE) is central to maintaining fluid balance in the retina, and this function is compromised by the activation of advanced glycation end-product receptors (RAGE). Here we provide evidence that acute administration of the RAGE agonist, glycated-albumin (gAlb) or vascular endothelial growth factor (VEGF), increased histone deacetylase (HDAC) activity in RPE cells. The administration of the class I/II HDAC inhibitor, trichostatin-A (TSA), suppressed gAlb-induced reductions in RPE transepithelial resistance (in vitro) and fluid transport (in vivo). Systemic TSA also restored normal RPE fluid transport in rats with subchronic hyperglycemia. Both gAlb and VEGF increased HDAC activity and reduced acetyl-α-tubulin levels. Tubastatin-A, a relatively specific antagonist of HDAC6, inhibited gAlb-induced changes in RPE cell resistance. These data are consistent with the idea that RPE dysfunction following exposure to gAlb, VEGF, or hyperglycemia is associated with increased HDAC6 activity and decreased acetyl-α-tubulin. Therefore, we propose inhibiting HDAC6 in the RPE as a potential therapy for preserving normal fluid homeostasis in the hyperglycemic retina

Photodynamic Therapy with Verteporfin in a Rabbit Model of Corneal Neovascularization

PURPOSE. To determine the efficacy of photodynamic therapy (PDT) with verteporfin (Visudyne; Novartis AG, Basel, Switzerland) for treatment of corneal neovascularization in a rabbit eye model. METHODS. Corneal neovascularization was induced in Dutch belted rabbits by placing an intrastromal silk suture near the limbus. Verteporfin was administered by intravenous injection at a dose of 1.5 mg/kg, and the pharmacokinetics of verteporfin distribution in the anterior segment or PDT-induced (laser energy levels 17, 50, and 150 J/cm 2 ) regression of corneal blood vessels were then determined. To assess PDT-induced toxicity of the anterior segment, corneal and iris/ciliary body histology, and IOP were evaluated after PDT. RESULTS. Verteporfin accumulation in vascularized regions of the cornea and the iris/ciliary body tissue were time dependent and maximum levels achieved at 60 minutes after injection. In rabbits, PDT of corneal vessels using laser energy of 17 or 50 J/cm 2 resulted in 30% to 50% regression of corneal neovascularization; however, in these animals, a rapid regrowth of new blood vessels occurred between 3 and 5 days. In the rabbits receiving PDT using laser energies of 150 J/cm 2 , the mean vessel regression was 56%. During the nine days of the laser therapy follow-up period, no vessel regrowth was observed in these rabbits. Histologic examination of the anterior segment after PDT (150 J/cm 2 ) showed localized degeneration of the corneal blood vessels without observable change in other anterior segment structures. CONCLUSIONS. These results provide evidence that PDT can produce significant regression of neovascular corneal vessels with no observable toxicity to the anterior segments. However, the optimal laser energy necessary to induce long-term regression (150 J/cm 2 ) was three times that used to treat choroidal neovascularization. (Invest Ophthalmol Vis Sci. 2003;44: 2954 -2958) DOI:10.1167/iovs.02-0572 C orneal neovascularization affects an estimated 1.4 million Americans and is a major cause of blindness worldwide. 1 Several corneal disorders including infections, chemical burns, immunologic diseases, degenerative disorders, and prior trauma can induce corneal neovascularization. In the United States, the most frequently associated etiology is long-time contact lens wear, especially that of soft hydrogel lenses. The primary treatment for actively proliferating corneal vessels is topical corticosteroids. 2 However, in corneas where vessels have been established for an extended period, corticosteroid treatment is often ineffective. Recently, angiogenic inhibitors have also been used to treat corneal neovascularization. 3,4 Photodynamic treatment (PDT) offers another potential treatment for corneal neovascularization. In PDT, systemically administered porphyrin derivatives accumulate in proliferating endothelial cells. Laser energy is then used to activate the porphyrin derivates 2,5-9 liberating cytotoxic oxygen free radicals. The ensuing cytotoxic response results in occlusion of neovascular vessels. Photodynamic treatment using verteporfin (Visudyne; Novartis AG, Basel, Switzerland), a benzoporphyrin derivative monoacid ring A, has been recently approved for the treatment of subfoveal choroidal neovascularization. -12 The purpose of this study was to evaluate the efficacy of the FDA-approved verteporfin formulation and dose and laser treatment for corneal neovascularization. These studies examined the pharmacokinetic characteristics of verteporfin in the anterior segment of rabbit eyes with corneal neovascularization, the PDT-induced toxicity of adjacent ocular structures (e.g., the corneal endothelium and iris/ciliary body), and the optimal laser parameters for treatment of corneal neovascularization. Our results demonstrate that significant amounts of verteporfin can be found in vascularized areas of the cornea as early as 15 minutes after drug injection and that PDT is efficacious in producing and maintaining regression of corneal blood vessels up to 9 days after PDT. However, the optimal laser energy necessary to induce long-term regression (150 J/cm 2 ) was three times that used to treat choroidal neovascularization. MATERIALS AND METHODS Dutch-belted rabbits, weighing 1.5 to 2 kg were maintained in a standard 12-hour light-dark cycle with free access to food and water. Corneal neovascularization was induced using a modified technique described by Schmidt-Erfurth et al. To determine the area of corneal neovascularization, slit-lamp photographs in a standardized magnification were taken on days 1, 4, 7