AMPA receptors mediate acetylcholine release from starburst amacrine cells in the rabbit retina

The light response of starburst amacrine cells is initiated by glutamate released from bipolar cells. To identify the receptors that mediate this response, we used a combination of anatomical and physiological techniques. An in vivo, rabbit eyecup was preloaded with [(3)H]-choline, and the [(3)H]-acetylcholine (ACh) released into the superfusate was monitored. A photopic, 3 Hz flashing light increased ACh release, and the selective AMPA receptor antagonist, GYKI 53655, blocked this light-evoked response. Nonselective AMPA/kainate agonists increased the release of ACh, but the specific kainate receptor agonist, SYM 2081, did not increase ACh release. Selective AMPA receptor antagonists, GYKI 53655 or GYKI 52466, also blocked the responses to agonists. We conclude that the predominant excitatory input to starburst amacrine cells is mediated by AMPA receptors. We also labeled lightly fixed rabbit retinas with antisera to choline acetyltransferase (ChAT), AMPA receptor subunits GluR1, GluR2/3, or GluR4, and kainate receptor subunits GluR6/7 and KA2. Labeled puncta were observed in the inner plexiform layer with each of these antisera to glutamate receptors, but only GluR2/3-IR puncta and GluR4-IR puncta were found on the ChAT-IR processes. The same was true of starburst cells injected intracellularly with Neurobiotin, and these AMPA receptor subunits were localized to two populations of puncta. The AMPA receptors are expected to desensitize rapidly, enhancing the sensitivity of starburst amacrine cells to moving or other rapidly changing stimuli.     

Peptidergic neurons of teleost retinas.

In retinas of teleost fish, neuropeptides typically have subtle, modulatory actions. The peptide effects typically have long latencies and durations, and, in some instances, they are known to be mediated by second messengers. Peptidergic neurons in teleost retinas have certain morphological features in common that are consistent with their function. Most peptidergic neurons are stratified amacrine cells with long, varicose processes; the processes of peptidergic centrifugal axons are also narrowly stratified and ramify extensively in the retina. The peptidergic amacrine cells are relatively infrequent, and, likewise, the centrifugal axons originate from a small number of perikarya in the brain. Cells that are so sparsely distributed and whose processes overlap so extensively are better-suited for modulation than for conveying detailed representations of visual space.     

Neutrino mass, proton decay, and neutron oscillations as crucial tests of unification models (A Review)

Several crucial tests of three popular unification models (of strong, electromagnetic, and weak interactions) are described. The models are SU(5) and SO(10) at the grand unification theory (GUT) level and SU(4)_C × SU(2)_L × SU(2)_R at the partial unification theory (PUT) level. The tests selected for discussion are the finiteness of the neutrino mass in the electron volt region, the decay of protons into antileptons in the range of 10^31± yr, and the detectability of neutron oscillations at all. The PUT group can also be tested by establishing the existence of four generations of quarks and leptons.     

Patient participation in physical therapy goal setting

BACKGROUND AND PURPOSE: An important part of treatment planning in physical therapy is effective goal setting. The Guide to Physical Therapist Practice recommends that therapists should identify the patient's goals and objectives during the initial examination in order to maximize outcomes. The purpose of this study was to examine whether therapists seek to involve patients in goal setting and, if so, what methods they use. Therapists' attitudes toward participation and patient satisfaction with the examination were also examined. SUBJECTS AND METHODS: Twenty-two physical therapists audiotaped the initial examination of 73 elderly patients (mean of 76.4 years of age, SD = 7.1, range = 65-94). The audiotaped examinations were then scored using the Participation Method Assessment Instrument (PMAI) to determine the frequency of attempts made by therapists to involve patients in goal setting. Therapists and patients completed surveys following the examinations. RESULTS: Therapists' use of participation methods during examinations ranged from a minimum of 1 to a maximum of 19 out of 21 possible items on the PMAI. The therapists stated that they believed that it is important to include patients in goal-setting activities and that outcomes will be improved if patients participate. Patients also indicated that participation is important to them. DISCUSSION AND CONCLUSION: In most cases, the therapists did not fully take advantage of the potential for patient participation in goal setting. Patient and therapist education is needed regarding methods for patient participation during initial goal-setting activities.     

Anesthetic management of juvenile nasopharyngeal angiofibroma resection

OBJECTIVE: To evaluate the anesthetic implications of the surgical resection of juvenile nasopharyngeal angiofibroma (JNA). DESIGN: Retrospective study. SETTING: University-affiliated community hospital. PARTICIPANTS: Ten patients undergoing resection of JNA. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data from the records of 10 patients undergoing resection of JNA were reviewed and analyzed with regard to demographics, history of the disease, characteristics of the tumor, surgical resection techniques, and anesthetic management. Patients were age 11 to 29 years. All had nasal obstruction as presenting symptom. There was no intracranial invasion. Eight tumors were resected via a lateral rhinotomy and 2 endoscopically (after embolization of the tumor's feeding vessels). Duration of surgery was 6 +/- 1 hours for rhinotomy and 6 and 6.5 hours for the 2 endoscopic resections. Anesthesia was induced in a rapid-sequence manner. Arterial and central venous catheters were placed in all patients. Mean arterial pressure was targeted to 55 to 65 mmHg by using increasing concentrations of isoflurane. The estimated blood loss was 4,800 +/- 1,600 mL and blood replacement was 3,200 +/- 1,400 mL in the first group. The 2 other patients lost 600 mL and 1,500 mL. Blood replacement in this group was 0 and 700 mL respectively. No mortality or major morbidity occurred. CONCLUSION: Resection of JNA should be considered a major procedure with many anesthetic challenges. Isoflurane may be employed to provide deliberate hypotension.     

Laser surgery for the treatment of glottic carcinomas

PURPOSE: The standard treatment for patients with early glottic carcinoma in Israel has been radiotherapy. In recent years, encouraging results with laryngo-microscopic carbon dioxide laser surgery as a treatment for early glottic carcinoma has changed our treatment strategy. We conducted a retrospective study to investigate the results of carbon dioxide laser excisional technique for early glottic carcinoma (T1, T2). MATERIALS AND METHODS: Twenty-six had squamous cell carcinoma (SCC), (21 patients with T1 and 5 patients with T2 lesions), 3 had carcinoma in situ, (CIS) and 3 had verrucous carcinoma (VC). RESULTS: All patients were free of disease after salvage treatment at the most recent follow-up. CONCLUSIONS: Careful patient selection with endoscopic staging and strict follow-up are essential to secure good results in the treatment of carbon dioxide laser for early laryngeal carcinoma.