Axon regeneration in goldfish and rat retinal ganglion cells: differential responsiveness to carbohydrates and cAMP.

Mammalian retinal ganglion cells (RGCs) do not normally regenerate their axons through an injured optic nerve, but can be stimulated to do so by activating macrophages intraocularly. In a cell culture model of this phenomenon, we found that a small molecule that is constitutively present in the vitreous, acting in concert with macrophage-derived proteins, stimulates mature rat RGCs to regenerate their axons if intracellular cAMP is elevated. In lower vertebrates, RGCs regenerate their axons spontaneously in vivo, and in culture, the most potent axon-promoting factor for these cells is a molecule that resembles the small vitreous-derived growth factor from the rat.

Perseveration in schizophrenia: failure to generate a plan and relationship with the psychomotor poverty subsyndrome.

Although perseveration in the Wisconsin Card Sorting Test (WCST) has been studied extensively in schizophrenia, the underlying cognitive dysfunctions are not yet clear. In schizophrenia, perseveration has been found to relate to frontal and striatal abnormalities. Therefore, both a failure to generate a plan as seen in patients with frontal abnormalities, or a failure to execute a plan as observed in Parkinson patients, who suffer primarily from striatal abnormalities, could explain perseveration in schizophrenia.

Inosine induces axonal rewiring and improves behavioral outcome after stroke.

Cerebral infarct (stroke) often causes devastating and irreversible losses of function, in part because of the brain's limited capacity for anatomical reorganization. The purine nucleoside inosine has previously been shown to induce neurons to express a set of growth-associated proteins and to extend axons in culture and in vivo. We show here that in adult rats with unilateral cortical infarcts, inosine stimulated neurons on the undamaged side of the brain to extend new projections to denervated areas of the midbrain and spinal cord.

Analysis of 2beta-carbomethoxy-3beta-(4-fluorophenyl)-N-(3-iodo-E-allyl)nortropane in rat plasma. II. Pharmacokinetic profile in male and female Sprague-Dawley rats evaluated by capillary electrophoresis.

This paper describes a pharmacokinetic study performed in Sprague-Dawley rats after i.v. administration of a single 6-mg/kg dose of 2beta-carbomethoxy-3beta-(4-fluorophenyl)-N-(3-iodo-E-allyl)nortropane (Altropane).

The role of medial prefrontal cortical dopamine in spontaneous flexibility in the rat.

In rat studies, both lesions in the medial prefrontal cortex (mPFC) and alterations of the level of mPFC dopamine (DA) have been found to induce disturbances in behavioural flexibility, as measured with switching tasks. It is not clear whether mPFC DA is also involved in spontaneous flexibility. Therefore, the aim of the present study was to investigate the role of mPFC DA in spontaneous flexibility.

Quantitative measurements of medical images for pharmaceutical clinical trials: comparison between on-site and off-site assessments.

Objective: In pharmaceutical clinical trials, quantitative measurements on medical images are often conducted to confirm drug efficacy. This study aims to compare the quantitative image analysis performance of an off-site core laboratory with the performance of investigators from multiple clinical sites.

Materials And Methods: In a phase I clinical trial, 25 healthy subjects underwent dynamic brain single-photon emission computed tomography (SPECT) scintigraphy with 123I-Altropane, a cocaine analogue with high affinity and selectivity for dopamine transporter sites in the striatum.

Set-maintenance and set-shifting problems in schizophrenic subtypes: relationship to dysfunctions of the fronto-striatal loops.

Research with patients suffering from Parkinson's disease and frontal lobe lesions has shown that disturbances in the fronto-striatal loops in the brain can cause perseveration. Perseveration is a core symptom of schizophrenia, yet the cause is not known. For schizophrenic patients disorders of many parts of the fronto-striatal loops are found, for example disturbances of the prefrontal cortex and the striatum.

Perseveration in schizophrenic patients: a neuropsychological approach for research.

Perseveration is a core symptom of schizophrenia, the cause, however, is unknown. It has been shown that for people with frontal lobe lesions, perseveration can be explained with a set-maintenance problem. Perseveration in Parkinson's disease can be explained with problems shifting from one set to another without cues (set-shifting).

Amiprilose hydrochloride for the treatment of rheumatoid arthritis.

The intent of this study was to compare, in a monotherapy framework, an optimal dose of the synthetic hexose sugar, amiprilose hydrochloride (HCl), to a placebo in the treatment of rheumatoid arthritis. In this double-blind, randomized, multi-center study, patients first underwent a washout period from disease-modifying antirheumatic drugs. Those who subsequently met flare criteria within 14 days of discontinuing previously stable doses of nonsteroidal anti-inflammatory drugs were randomized to amiprilose HCl (103 patients) or a placebo (115 patients) for the subsequent 20 weeks.

Radiation-induced tumors of the temporal bone.

Objective: To discuss a rare but devastating complication following radiotherapy to the head and neck: radiation-induced malignancies of the temporal bone.

Study Design: A retrospective case review comprising five patients with radiation-induced tumors involving the temporal bone.

Setting: A tertiary referral center.

Catecholamine-secreting paragangliomas at the skull base.

Paragangliomas (glomus tumors) comprise 15% of all neoplasms at the skull base. Despite extensive growth, these tumors usually do not secrete active biogenic substances into the circulation in sufficient quantities to produce symptoms. When they do secrete large amounts of catecholamines, they will cause symptoms that mimic a pheochromocytoma.

Analysis of chromosome 22 deletions in neurofibromatosis type 2-related tumors.

The neurofibromatosis type 2 (NF2) gene has been hypothesized to be a recessive tumor suppressor, with mutations at the same locus on chromosome 22 that lead to NF2 also leading to sporadic tumors of the types seen in NF2. Flanking markers for this gene have previously been defined as D22S1 centromeric and D22S28 telomeric. Identification of subregions of this interval that are consistently rearranged in the NF2-related tumors would aid in better defining the disease locus.

Epidemiology, pathogenesis, and genetics of acoustic tumors.

This article reviews the epidemiology of both unilateral and bilateral (NF-2) acoustic tumors. The growth rate of acoustic tumors is examined from a clinical, radiographic, and laboratory perspective. The anatomic, histologic, and biochemical considerations as well as the influences of sex hormones on acoustic tumor formation are reviewed.

Neutrophil CR3 expression and specific granule exocytosis are controlled by different signal transduction pathways.

Neutrophils express receptors (CR3) for the complement fragment C3bi. CR3 expression can be increased by exposure of the cells to chemotactic factors such as FMLP or to the calcium ionophore A23187. It has been suggested that CR3 moieties are stored in the membrane bounding either the secondary or the tertiary (gelatinase containing) granules.

Facial nerve grafting.

The techniques of facial nerve grafting have undergone several adjustments and refinements within the last 20 years. Those techniques that have stood the test of time are discussed, and new approaches to facial nerve grafting in the temporal bone are explored.

Gadolinium-DTPA enhanced magnetic resonance imaging in acoustic neuroma diagnosis and management.

Gadolinium-DTPA (Gd-DTPA) is a paramagnetic contrast agent that increases the intensity of acoustic neuromas (AN) on T1-weighted magnetic resonance imaging (MRI) scans. Over a 9-month period we have reviewed Gd-DTPA-enhanced MRI scans on 32 consecutive cases (35 tumors) involving the internal auditory canal (IAC) and cerebellopontine angle (CPA). The majority of patients (84%) were imaged on latest generation 1.

Stimulation of rat hepatocyte fibronectin production by monocyte-conditioned medium is due to interleukin 6.

In this report, conditioned media from LPS-stimulated monocytes increased rat hepatocyte production of fibronectin (Fn) in a dose-dependent manner. Preincubation of the conditioned media with anti-IL-6, but not with anti-IL-1 alpha, anti-IL-1 beta, or anti-TNF, completely neutralized the Fn-stimulating activity. 10-100 pg/ml of rIL-6 was sufficient to increase Fn production.

Coagulation increases neutrophil CR1 and CR3 expression: primary role for platelet-derived growth factor.

Neutrophil receptors for C3b(CR1) and C3bi(CR3) mediate a number of functions important for infection control and tissue repair, such as adherence, aggregation, orientation in chemotactic gradients, and phagocytosis of opsonized particles. We studied the effect of the coagulation of whole blood on the induction of neutrophil complement receptor (CR) expression in vitro. Neutrophils incubated in serum for 1 hour at 37 degrees C increased the expression of CR1 3.

Neutrophil CR3 induction by platelet supernatants is due to platelet-derived growth factor.

Recently, serum was shown to contain a factor that increased expression of the complement receptor CR3 on neutrophil membranes. This factor was localized to platelet granules and was released during coagulation. This study was undertaken to identify this factor in platelet granules.

Induction of hepatocyte synthesis of fibronectin by a non-interleukin-1 monokine.

Plasma fibronectin concentrations initially decrease and then markedly increase following injury and during inflammation. Although hepatocytes are known to be the major source of plasma fibronectin, the stimulus controlling its production is not known. The present study investigated the role of interleukin-1 (Il-1) and LPS-induced monocyte supernatants in stimulating hepatocyte fibronectin synthesis in vitro.