Search results for "Eye"
showing 10 items of 2511 documents
Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink con…
2009
The relative power of the hippocampal theta-band ( approximately 6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative res…
Differentiation of Y79 cells induced by prolonged exposure to insulin
1997
Y79 human retinoblastoma cells are known to contain receptors for both insulin and insulin-like growth factors (IGFs), to produce these cytokines and release them in the culture medium. Previously we have demonstrated that IGFs and insulin stimulate Y79 cell proliferation through the involvement of type I IGF receptor and Insulin Receptor Substrate 1 (IRS-1). This paper studies the effect of prolonged exposure to insulin on Y79 cells. Cells grown for 10 days in the presence of insulin were reseeded and incubated once more with insulin. In the reseeded cells proliferation lowered and morphological changes appeared. After 10 days of reseeding, cells stopped proliferating and showed long ramif…
The effect of rewarding hypothalamic stimulation on behavioral and neural hippocampal responses during trace eyeblink conditioning in rabbit (Oryctol…
2005
Rabbits were trace-conditioned with a tone as a conditioned stimulus and an airpuff as an unconditioned stimulus. Electrical stimulation to the medial forebrain bundle in the lateral hypothalamus was delivered either before or after the tone-airpuff pair. The purpose of the present study was to test whether the effect of post-trial hypothalamic stimulation differed from the effect of pre-trial hypothalamic stimulation on trace conditioning in the same subjects. Additionally, hippocampal responses were measured during sessions to see if hypothalamic stimulation activated dopaminergic fibres and affected hippocampal cell functioning and thus learning. The results showed that behavioral nictit…
Deliberate Arterial Hypotension Does Not Reduce Intraocular Pressure in Pigs
1992
Among the accepted advantages of general anesthesia in ophthalmic surgery is improved control of intraocular pressure (IOP). Although standard textbooks advocate deliberate arterial hypotension to facilitate intraocular surgery by reducing IOP, scientific proof of such an effect is lacking. The authors investigated effects of induced arterial hypotension on IOP in an anesthetized porcine model. Forty-two piglets were anesthetized with piritramide, were placed in the prone position, and had the anterior chamber of one eye punctured with a small Teflon cannula to measure IOP. Six pigs were used in a pilot study to establish dose-response relationships for the hypotensive agents; 36 pigs were …
Time response of the vision binocularity by use of dynamic suppression of retinal images
1999
We present a novel technique for determination the stereopsis dynamic response, using as stimulus a random dot stereopair. Stereopsis can be evoked or depressed by continuous or flash illumination of the stimulus with simultaneous control of a special light scattering obstacle build in the visual path of one eye. The obstacle--a thin plate of electrooptical PLZT ceramics-- exposes (by applying of the voltage to semitransparent gold electrodes deposited on both surfaces of the plate) light scattering so blurring the retinal image, similar as for an eye with a cataract, depressing stereopsis. The random dot stereopair contains contours of images with a different stereodisparity. The PLZT plat…
Nemo regulates cell dynamics and represses the expression of miple, a midkine/pleiotrophin cytokine, during ommatidial rotation
2013
AbstractOmmatidial rotation is one of the most important events for correct patterning of the Drosophila eye. Although several signaling pathways are involved in this process, few genes have been shown to specifically affect it. One of them is nemo (nmo), which encodes a MAP-like protein kinase that regulates the rate of rotation throughout the entire process, and serves as a link between core planar cell polarity (PCP) factors and the E-cadherin–β-catenin complex. To determine more precisely the role of nmo in ommatidial rotation, live-imaging analyses in nmo mutant and wild-type early pupal eye discs were performed. We demonstrate that ommatidial rotation is not a continuous process, and …
Capecitabine and irinotecan with and without bevacizumab for advanced colorectal cancer patients
2009
AIM: To investigate the efficacy and safety of cape-citabine plus irinotecan ± bevacizumab in advanced or metastatic colorectal cancer patients. METHODS: Forty six patients with previously untreated, locally-advanced or metastatic colorectal cancer (mCRC) were recruited between 2001-2006 in a prospective open-label phase II trial, in German community-based outpatient clinics. Patients received a standard capecitabine plus irinotecan (CAPIRI) or CAPIRI plus bevacizumab (CAPIRI-BEV) regimen every 3 wk. Dose reductions were mandatory from the first cycle in cases of > grade 2 toxicity. The treatment choice of bevacizumab was at the discretion of the physician. The primary endpoints were respon…
A Long-Term Extension Study of Bevacizumab in Patients With Solid Tumors
2021
Abstract Background Bevacizumab has been studied in numerous clinical trials in multiple types of cancer; however, patients may receive bevacizumab over an extended period of time. This study assessed the long‐term safety and tolerability of bevacizumab among patients with solid tumors. Materials and Methods Patients enrolled in a Roche/Genentech‐sponsored trial who had derived benefit from bevacizumab therapy as monotherapy or in combination with anticancer drugs were eligible for continuation of bevacizumab in this long‐term extension (LTE) study. The primary endpoints were the incidence of adverse events (AEs) of Common Terminology Criteria for AEs (CTCAE) grade ≥3 related to bevacizumab…
First-Line XELOX plus bevacizumab followed by XELOX plus bevacizumab or single-agent bevacizumab as maintenance therapy in patients with metastatic c…
2012
Abstract Purpose. The aim of this phase III trial was to compare the efficacy and safety of bevacizumab alone with those of bevacizumab and capecitabine plus oxaliplatin (XELOX) as maintenance treatment following induction chemotherapy with XELOX plus bevacizumab in the first-line treatment of patients with metastatic colorectal cancer (mCRC). Patients and Methods. Patients were randomly assigned to receive six cycles of bevacizumab, capecitabine, and oxaliplatin every 3 weeks followed by XELOX plus bevacizumab or bevacizumab alone until progression. The primary endpoint was the progression-free survival (PFS) interval; secondary endpoints were the overall survival (OS) time, objective resp…
Polypoidal choroidal vasculopathy in pachychoroid: combined treatment with photodynamic therapy and aflibercept
2022
Abstract Introduction To evaluate the effects of combined therapy using intravitreal Aflibercept (IVA) and photodynamic therapy (PDT) on polypoidal choroidal vasculopathy related to pachychoroid disease (PPCV).Methods Patients with PPCV were treated with PDT combined with 3 IVA injections on a monthly basis, followed by pro re nata criteria. The 12-month follow-up consisted of multiple revaluations of visual acuity and SSOCT parameters of clinical activity.Results Nineteen eyes were included in the study; mean age was 65.5 years. Visual acuity improved after 12 months (0.35 ± 0.25 to 0.2 ± 0.20 logMAR, p = 0.005). Percentage of eyes with intraretinal and subretinal fluid reduced from baseli…