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Neurotrophic factors are proteins with considerable potential in the treatment of central nervous system (CNS) diseases and traumatic injuries. However, a significant challenge to their clinical use is the difficulty associated with delivering these proteins to the CNS. Neurotrophic factors are hydrophilic, typically basic, monomeric or dimeric proteins, mostly in the size range of 5 to 30 kDa. Neurotrophic factors potently support the development, growth and survival of neurons, eliciting biological effects at concentrations in the nanomolar to femtomolar range. They are not orally bioavailable and the blood-brain and blood-cerebrospinal fluid barriers severely limit their ability to enter into and act on sites in the CNS following parenteral systemic routes of administration. Most neurotrophic factors have short in vivo half-lives and poor pharmacokinetic profiles. Their access to the CNS is restricted by rapid enzymatic inactivation, multiple clearance processes, potential immunogenicity and sequestration by binding proteins and other components of the blood and peripheral tissues. The development of targeted drug delivery strategies for neurotrophic factors will probably determine their clinical effectiveness for CNS conditions. Achieving significant CNS target site concentrations while limiting systemic exposure and distribution to peripheral sites of action will lessen unwanted pleiotropic effects and toxicity. Local introduction of neurotrophic factors into the CNS intraparenchymally by direct injection/infusion or by implantation of delivery vectors such as polymer matrices or genetically modified cells yields the highest degree of targeting, but is limited by diffusion restrictions and invasiveness. Delivery of neurotrophic factors into the cerebrospinal fluid (CSF) following intracerebroventricular or intrathecal administration is less invasive and allows access to a much wider area of the CNS through CSF circulation pathways. However, diffusional and cellular barriers to penetration into surrounding CNS tissue and significant clearance of CSF into the venous and lymphatic circulation are also limiting. Unconventional delivery strategies such as intranasal administration may offer some degree of CNS targeting with minimal invasiveness. This review presents a summary of the neurotrophic factors and their indications for CNS disorders, their physicochemical characteristics and the different approaches that have been attempted or suggested for their delivery to the CNS. Future directions for further research such as the potential for CNS disease treatment utilising combinations of neurotrophic factors, displacement strategies, small molecule mimetics, chimaeric molecules and gene therapy are also discussed. [ABSTRACT FROM AUTHOR]

The article presents a study examining trends in the intrametropolitan destination selectivity of movers over three postwar periods and by estimating their effects on the evolving suburbanization process. Trends in mover destination selectivity, as indicated by changes in movers' destination propensity rates, directly measure the changing attraction of city and suburb locations for whites and blacks of different social categories. Part of this analysis will compare mover destination propensity rate patterns for a set of the nation's oldest metropolitan areas across periods to determine change in the suburban selectivity of white and black movers in the post-1970 period. This research evaluates the validity of alternative scenarios for the post-1970 city-suburban redistribution of whites and blacks in large declining metropolitan areas. An extreme view suggests that their central cities are experiencing a revitalization fed by a greater ability to attract high status and career-oriented whites who value the amenities, proximity, and desirable residential housing that is now offered there. It also suggests a fundamental change in the intrametropolitan redistribution of blacks, indicating that they are now embarking on a suburbanization process that is reminiscent of white suburbanization several decades earlier.

Urban scholars and planners look to evidence of recent gains in the number of nontraditional households as a potential source of increase to the population sizes and tax bases of declining central cities. While it is now well established that substantial gains in the numbers of small, nontraditional households have occurred since the 1950s, it has not been demonstrated that: (a) these households are more likely to relocate in the city than traditional family households (husband-wife with children under 18); or (b) their cityward relocation patterns will significantly alter trends toward smaller city household populations. This paper addresses these questions by examining changes in city-suburb migration stream rates by household type over periods 1955-60, 1965-70 and 1970-75 for large metropolitan areas, and assesses their implications for potential changes in the aggregate sizes of city household populations. [ABSTRACT FROM AUTHOR]

Increased migration to the sunbelt and the metropolitan-nonmetropolitan "turnaround" represent departures from long-standing redistribution trends. Although these patterns have been examined from a number of perspectives, their consequences for individual metropolitan areas have not yet been brought to light. In the present study, stream-disaggregated data for the late 1950s and late 1960s are employed to assess the impact of recent migration on the sizes and compositions of white populations in thirty-one large metropolitan areas. Most large northern SMSAs have been experiencing the "new" migration patterns since the late 1950s. They have incurred net out-movements of whites to both metropolitan and nonmetropolitan areas. In their exchanges with nonmetropolitan areas, however, they have managed to retain greater numbers of college graduates and professional workers. Southern and western SMSAs did not sustain losses to nonmetropolitan areas during either period. They did appear to gain both total and high status population as a result of interregional metropolitan redistribution. [ABSTRACT FROM AUTHOR]

This paper introduces an analytic framework that can be used to assess the relationships between individual movement differentials and place characteristics, on the one hand, and aggregate mobility levels and city-suburb population change (in size or composition), on the other. Application of this framework using census data for individual metropolitan areas allows the analyst to decompose population changes due to net migration into contributing mobility streams and their component rates which are subject to unique community and individual influences. The paper provides both theoretical and empirical rationale for the framework, illustrates its use with 1970 census data, and discusses its implications for empirical research on city-suburb population redistribution. [ABSTRACT FROM AUTHOR]

New-onset epileptic seizures occur in patients with Alzheimer's disease (AD), but the nature and underlying reasons for these seizures are unclear. We identified new-onset, nonsymptomatic seizures in 77 (17%) of 446 patients with uncomplicated, definite AD on autopsy. Among these seizure patients, 69 had generalized tonic-clonic seizures, and 55 had less than three total seizures. The seizure patients had a younger age of dementia onset than did the remaining AD patients; however, at seizure onset, they averaged 6.8 years into their AD and had advanced dementia. When further compared to 77 AD controls, matched for age of onset and duration, the seizure patients did not differ on medical illnesses, amount of medications, and degree of focal neuropathology. We conclude that a few unprovoked generalized seizures frequently occur late in the course of AD, and that AD patients with a younger age of dementia onset are particularly susceptible to seizures. [ABSTRACT FROM PUBLISHER]

In the absence of pathognomonic clinical features, the clinical diagnosis of Alzheimer's disease (AD) remains one of exclusion of other dementias. We investigated the clinical diagnoses among 394 neuropathologically confirmed AD cases in a dementia brain bank. Most patients were correctly diagnosed as AD (348 or 88%). Among the misdiagnosed patients, AD was mistaken for a primary depressive disorder in 14, multi-infarct dementia in 13, Parkinson's disease in nine, and alcoholic dementia in four. The number of misdiagnosed AD patients did not differ between physician specialties but was greater among AD patients with agitation, depression, paranoia, or delusions. This retrospective study suggests that the diagnostic sensitivity for AD is high among a cross-section of practicing physicians and that an important factor in mistaking AD for another illness is unfamiliarity with the potential psychiatric symptoms of AD. (J Geriatr Psychiatry Neurol 1991;4:26-29). [ABSTRACT FROM PUBLISHER]

Chronic Creutzfeldt-Jakob disease, presenting in later life, may be difficult to distinguish from other dementing illnesses. Patients with this disease may lack the characteristic myoclonus and electroencephalographic complexes. We report four patients with a slowly progressive dementia who were misdiagnosed during life and had a spongiform encephalopathy at autopsy. All four patients had early extrapyramidal rigidity, primitive reflexes, and other neurologic signs. The presence of these neurologic findings early in the course of a dementia suggests that clinicians should consider chronic Creutzfeldt-Jakob disease, evaluate the patient with electroencephalographic studies, and emphasize universal tissue precautions. [ABSTRACT FROM PUBLISHER]

Accumulation of metal and the accompanying increase in oxidative stress and inflammation plays an important role in neurodegenerative disease. Deferoxamine (DFO) is a metal chelator found to be beneficial in several animal models of neurodegenerative disease and insult including Alzheimer's disease, Parkinson's disease, stroke, and subarachnoid hemorrhage. In this study, we determine whether intranasally (IN) administered DFO is beneficial in the intracerebroventricular streptozotocin (ICV STZ) rat model of sporadic Alzheimer's disease, which is different from previous models in that it exhibits dysregulation of insulin metabolism as well as oxidative stress and inflammation. Surgical induction of the model included ICV injections of either STZ or citrate buffer (sham in rats), which were treated IN with either saline or DFO (n=10-15/group). Treatment started either before or after injection of STZ to induce the model, and continued throughout the study. IN treatment continued three times per week for three weeks before behavior tests started followed by eventual euthanasia with tissue collection. Spatial memory tests with the Morris water maze showed that STZ rats treated with IN DFO both before and after model induction had significantly shorter escape latencies. Pre-treatment with IN DFO also significantly decreased footslips on the tapered balance beam test. Brain tissue analyses showed DFO treatment decreased oxidation as measured by oxyblot and increased insulin receptor expression. These results further support the potential of IN DFO for use as a treatment for Alzheimer's disease, and show benefit in a non-amyloid/tau rodent model., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Deferoxamine (DFO) has shown therapeutic promise for the treatment of Parkinson׳s disease (PD) as it has reduced both behavioral and biochemical deficits when injected into the brain of rodent models of PD. Intranasally administered DFO targets the brain directly but non-invasively and has been effective in animal models of stroke and Alzheimer׳s disease. In this study we sought to determine whether intranasal (IN) DFO could be neuroprotective for PD in a rat model. PD was induced with a unilateral injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle, while sham surgery rats received saline injections. Rats were pre-treated three times with either IN DFO or saline (starting 4 days before 6-OHDA), and post-treated twice/wk for one month before behavioral tests. In the apomorphine-induced rotational test, IN DFO significantly decreased the number of contralateral turns after injection of apomorphine HCl (p<0.05). Also, IN DFO significantly decreased limb asymmetry in the rearing tube as measured with contralateral limb touches (p<0.05). The IN DFO treatment yielded a trend towards decreased contralateral foot-slips on the tapered balance beam, though the difference was not significant. Finally, IN DFO-treated rats had increased preservation of tyrosine hydroxylase immunoreactive neurons in the substantia nigra (p<0.05). These results confirm that DFO is beneficial in a 6-OHDA model and demonstrate improvement in motor deficits and dopaminergic neuronal survival with non-invasive intranasal delivery, making this an attractive potential treatment for PD., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disorder in which motor neurons may be targeted by oxidative and nitrergic stress without sufficient compensation by intrinsic support mechanisms. In this work, we addressed two key tenets of this hypothesis for the pathogenesis of ALS. Using superoxide dismutase (SOD) 1G93A mice, we studied the impact of reduction of nitrergic stress within the CNS with the use of a broad spectrum nitric oxide synthase (NOS) inhibitor, NG-nitro-l-arginine methyl ester. A separate cohort of SOD1G93A mice received direct insulin neurotrophic support, ligating receptors expressed upon motor neurons, to attempt protection against neuronal and functional motor dropout. For direct access, we used a novel form of intranasal delivery that provides peak concentration levels in the CNS within 1 h of delivery without systemic side effects at doses which previously rescued retrograde loss of motor axons after axotomy. To identify even minor impacts of these interventions on the outcome, we utilized an intensive program of serial behavioral and electrophysiological testing weekly, combined with endpoint quantitative morphometry and molecular analysis. This intensive evaluation enhanced our knowledge of the time course in SOD1G93A mice and impact of the SOD1G93A mutation upon motor neurons and their function. Neither intervention had even minimal impact upon slowing progression of disease in SOD1G93A mice. Our data argue against significant roles for nitrergic stress in promoting motor neuron loss and the importance of alternative neurotrophic support mechanisms that might support motor neurons and prevent disease progression in SOD1G93A mice.

We determined the nervous system targeting of interferon-beta1b (IFN-beta1b), a 20 kDa protein used to treat the relapsing-remitting form of multiple sclerosis, following intranasal administration in anesthetized, adult cynomolgus monkeys. Five animals received an intranasal bolus of [(125)I]-labeled IFN-beta1b, applied bilaterally to the upper nasal passages. Serial blood samples were collected for 45 min, after which the animals were euthanized by transcardial perfusion-fixation. High resolution phosphor imaging of tissue sections and gamma counting of microdissected tissue were used to obtain the distribution and concentration profiles of [(125)I]-IFN-beta1b in central and peripheral tissues. Intranasal administration resulted in rapid, widespread targeting of nervous tissue. The olfactory bulbs and trigeminal nerve exhibited [(125)I]-IFN-beta1b levels significantly greater than in peripheral organs and at least one order of magnitude higher than any other nervous tissue area sampled. The basal ganglia exhibited highest [(125)I]-IFN-beta1b levels among CNS regions other than the olfactory bulbs. Preferential IFN-beta1b distribution to the primate basal ganglia is a new finding of possible clinical importance. Our study suggests both IFN-beta and IFN-alpha, which share the same receptor, may be bound with relatively high affinity in these structures, possibly offering new insight into a neurovegetative syndrome induced by IFN-alpha therapy and suspected to involve altered dopamine neurotransmission in the basal ganglia. Most importantly, our results suggest intranasally applied macromolecules may bypass the blood-brain barrier and rapidly enter the primate CNS along olfactory- and trigeminal-associated extracellular pathways, as shown previously in the rat. This is the first study to finely detail the central distribution of a labeled protein after intranasal administration in non-human primates.

Raising insulin acutely in the periphery and in brain improves verbal memory. Intranasal insulin administration, which raises insulin acutely in the CNS without raising plasma insulin levels, provides an opportunity to determine whether these effects are mediated by central insulin or peripheral processes. Based on prior research with intravenous insulin, we predicted that the treatment response would differ between subjects with (epsilon4+) and without (epsilon4-) the APOE-epsilon4 allele. On separate mornings, 26 memory-impaired subjects (13 with early Alzheimer's disease and 13 with amnestic mild cognitive impairment) and 35 normal controls each underwent three intranasal treatment conditions consisting of saline (placebo) or insulin (20 or 40 IU). Cognition was tested 15 min post-treatment, and blood was acquired at baseline and 45 min after treatment. Intranasal insulin treatment did not change plasma insulin or glucose levels. Insulin treatment facilitated recall on two measures of verbal memory in memory-impaired epsilon4- adults. These effects were stronger for memory-impaired epsilon4- subjects than for memory-impaired epsilon4+ subjects and normal adults. Unexpectedly, memory-impaired epsilon4+ subjects showed poorer recall following insulin administration on one test of memory. These findings suggest that intranasal insulin administration may have therapeutic benefit without the risk of peripheral hypoglycemia and provide further evidence for apolipoprotein E (APOE) related differences in insulin metabolism.