3T MRI Whole-Brain Microscopy Discrimination of Subcortical Anatomy, Part 2: Basal Forebrain.

BACKGROUND AND PURPOSE: The basal forebrain contains multiple structures of great interest to emerging functional neurosurgery applications, yet many neuroradiologists are unfamiliar with this neuroanatomy because it is not resolved with current clinical MR imaging. MATERIALS AND METHODS: We applied an optimized TSE T2 sequence to washed whole postmortem brain samples (n = 13) to demonstrate and characterize the detailed anatomy of the basal forebrain using a clinical 3T MR imaging scanner. We measured the size of selected internal myelinated pathways and measured subthalamic nucleus size, oblique orientation, and position relative to the intercommissural point. RESULTS: We identified most basal ganglia and diencephalon structures using serial axial, coronal, and sagittal planes relative to the intercommissural plane. Specific oblique image orientations demonstrated the positions and anatomic relationships for selected structures of interest to functional neurosurgery. We observed only 0.2- to 0.3-mm right-left differences in the anteroposterior and superoinferior length of the subthalamic nucleus (P = .084 and .047, respectively). Individual variability for the subthalamic nucleus was greatest for angulation within the sagittal plane (range, 15°-37°), transverse dimension (range, 2-6.7 mm), and most inferior border (range, 4-7 mm below the intercommissural plane). CONCLUSIONS: Direct identification of basal forebrain structures in multiple planes using the TSE T2 sequence makes this challenging neuroanatomy more accessible to practicing neuroradiologists. This protocol can be used to better define individual variations relevant to functional neurosurgical targeting and validate/complement advanced MR imaging methods being developed for direct visualization of these structures in living patients.

3T MRI Whole-Brain Microscopy Discrimination of Subcortical Anatomy, Part 1: Brain Stem.

BACKGROUND AND PURPOSE: The brain stem is compactly organized with life-sustaining sensorimotor and autonomic structures that can be affected by numerous pathologies but can be difficult to resolve on conventional MR imaging. MATERIALS AND METHODS: We applied an optimized TSE T2 sequence to washed postmortem brain samples to reveal exquisite and reproducible brain stem anatomic MR imaging contrast comparable with histologic atlases. This resource-efficient approach can be performed across multiple whole-brain samples with relatively short acquisition times (2 hours per imaging plane) using clinical 3T MR imaging systems. RESULTS: We identified most brain stem structures at 7 canonical axial levels. Multiplanar or oblique planes illustrate the 3D course and spatial relationships of major brain stem white matter pathways. Measurements of the relative position, course, and cross-sectional area of these pathways across multiple samples allow estimation of pathway location in other samples or clinical subjects. Possible structure-function asymmetries in these pathways will require further study-that is, the cross-sectional area of the left corticospinal tract in the midpons appeared 20% larger (n = 13 brains, P < .10). CONCLUSIONS: Compared with traditional atlases, multiplanar MR imaging contrast has advantages for learning and retaining brain stem anatomy for clinicians and trainees. Direct TSE MR imaging sequence discrimination of brain stem anatomy can help validate other MR imaging contrasts, such as diffusion tractography, or serve as a structural template for extracting quantitative MR imaging data in future postmortem investigations.

Impact of haemophilia with inhibitors on caregiver burden in the United States.

Inhibitor development complicates haemophilia treatment and may impact caregiver burden. Compare overall burden of caregivers of children with/without inhibitors in the United States using a novel disease-specific questionnaire and the previously validated CarerQol. An on-line questionnaire with six burden domains (i.e. emotional stress, personal sacrifice, financial burden, medical management, child's pain, and transportation) and three visual analogue scales (VAS) was developed based upon a targeted literature review and previous survey findings. The study sample consisted of caregivers of children with haemophilia. The total burden score was calculated by summing the six individual burden domain scores. Higher scores represented greater burden. Descriptive statistics was performed to examine the sample characteristics. The Wilcoxon rank-sum test was performed to compare burden by inhibitor status. All variables were considered significant at P < 0.001. A total of 310 caregivers completed the survey; 30 of them reported caring for a child with an inhibitor. A majority of caregivers of children with inhibitors were mothers (80.0%) and between 35 and 44 years of age (56.7%). Caregivers of children with inhibitors reported significantly higher median total burden scores (99.0 vs. 76.5, P < 0.0001) and median burden-VAS scores (5.5 vs. 3.0, P < 0.0001), as compared to those caring for children without inhibitors. A similar trend was seen across all the six burden domains, with greatest difference in the median burden scores observed in the 'personal sacrifice' (3.2 vs. 2.0) and 'transportation' (3.3 vs. 2.3) domains. Burden of caregivers should be considered when assessing the psychosocial aspects of managing patients with inhibitors.

Understanding the experience of caring for children with haemophilia: cross-sectional study of caregivers in the United States.

Congenital haemophilia is an inherited bleeding disorder typically diagnosed at birth or shortly thereafter. Haemophilia imposes a significant burden on patients and their caregivers. The aim of the study was to quantify the overall burden of haemophilia on caregivers in the USA using a novel disease-specific questionnaire and the previously validated CarerQol. Targeted literature review and a previous survey conducted by the authors was used to develop an online questionnaire with six burden domains of interest to caregivers (emotional stress, financial, sacrifice, medical management, child's pain and transportation) and several visual analogue scales (VAS). Content validity of the questionnaire was confirmed by three haemophilia caregivers. The study sample consisted of caregivers of children with haemophilia identified via a previously developed opt-in research database. Descriptive statistics were employed for demographic and clinical characteristics; a generalized linear model (GLM) was used to identify factors influencing caregiver burden. A total of 310 caregivers completed the survey (45.5% response rate). Most of the participating caregivers were mothers of a child with haemophilia (88%), between 35 and 44 years of age (48%), and with a college education or a postgraduate degree (63%). 'Child's pain' was identified as the most burdensome domain to caregivers (median score = 3.50 out of 5), followed by 'emotional stress' (2.67), 'financial' (2.40), 'transportation' (2.33), 'sacrifice' (2.17) and 'medical management' (2.00) domains. Although higher income exhibited a protective effect, episodes of bleeds, current presence of an inhibitor and lower caregiver productivity in the past month negatively affected caregiver burden per GLM results. Training and educational programs should potentially be developed to address caregiver burden.

Health-related quality of life in haemophilia patients with inhibitors and their caregivers.

Data on the health-related quality of life (HRQoL) of congenital haemophilia patients with inhibitors (CHwI) and their caregivers are limited. To understand the association between patient demo-graphics/clinical characteristics with HRQoL among CHwI patients and caregivers, a survey was developed to assess HRQoL with haemophilia-specific QoL questionnaires (HAEMO-QoL/HAEM-A-QoL). In the cross-sectional study, paper-pencil questionnaires were mailed to 261 US CHwI patients/caregivers in July 2010. Descriptive analyses were performed to characterize HRQoL by age and to identify drivers of impairment, from both patient/caregiver perspectives. HRQoL scores were transformed on a scale of 0-100, with higher scores indicating higher impairment in HRQoL. Ninety-seven respondents completed the HRQoL assessment. HRQoL impairment was higher in adult patients. In children ages 8-16 years, mean HAEMO-QoL total score was 33.8 (SD = 15.5), and 35.0 (SD = 16.1) in children ages 4-7 years; for adult patients the mean HAEM-A-QoL total score was 42.2 (SD = 14.8). Adults reported highest impairment in the 'sports/leisure' subscale (Mean = 62.5, SD = 18.7), whereas patients 8-16 years reported highest impairment in the 'physical health' subscale (Mean = 50.8, SD = 30.5).Caregivers of patients ages 4-7 years reported greatest impairment within the 'family' subscale (Mean = 55.6, SD = 19.4). Caregivers were ''considerably/very much'' bothered by their child's inhibitors and reported higher QoL impairment for their child than parents who were not bothered. Within ChwI patients, HRQoL impairments increased with age and existed across a range of physical/psychosocial domains. In addition, caregiver burden also affected the perceived HRQoL of paediatric CHwI patients. Additional research is considered necessary to further understand the support caregivers need while caring for children with CHwI.

Patient/caregiver perceived benefits and barriers to elective orthopedic surgery (EOS) in patients with congenital hemophilia with inhibitors.

OBJECTIVE: Congenital hemophilia patients with inhibitors are at greater risk for developing arthropathy and orthopedic complications compared to those without inhibitors. Elective orthopedic surgeries (EOS) may be an option for these patients and may provide long-term cost savings due to reduced bleed frequency. However, patient motivations and goals for undergoing or delaying such surgeries are not well understood. A US-based patient/caregiver survey was designed to describe inhibitor patient experiences and outcomes following EOS and to develop a comprehensive understanding of patient preferences for EOS, which are lacking in the literature. METHODS: The paper-pencil questionnaire was mailed to 261 US inhibitor patients/caregivers and included history and timing of EOS, quality-of-life (QoL) and potential benefits of and barriers to receiving EOS. Univariate/bivariate descriptive analyses were performed to characterize those with/without a history of EOS. RESULTS: For 103 subjects who responded, the mean age was 20.9 years. Approximately 25% (n = 26) of respondents underwent EOS, most commonly on the knee (21, 81%); 73.1% of surgery recipients reported the surgery improved or greatly improved their QoL based on single-item response. The highest ranked perceived benefits were less pain, fewer bleeds, and improved mobility. However, the leading concerns reported were lack of improved mobility (62.2%), fear of uncontrolled bleeding (61.3%), and surgical complications, such as blood clot (60.0%). LIMITATIONS: The study consisted of a small sample size, primarily due to the difficulty in trying to reach inhibitor patients or their caregivers, thereby restricting inferential and stratification analysis. CONCLUSIONS: QoL improved for most inhibitor patients who reported having EOS. For those considering surgery, there is optimism about the potential benefits, but realistic concerns associated with bleed control and post-op complications.

Assessment of chemokine receptor function on monocytes in whole blood: In vitro and ex vivo evaluations of a CCR2 antagonist.

Inhibition of monocyte and macrophage function by targeting chemokine receptors represents an attractive strategy for therapeutic intervention in inflammatory diseases. We describe an assay to assess chemokine receptor function on whole blood monocytes by measuring chemokine stimulated change in cell shape as measured by flow cytometry. The relative potential of the chemokine receptors CCR1, CCR2, CCR5, CX(3)CR1, and CXCR4 to activate monocytes in whole blood was evaluated and compared. Analysis of MCP-1 response for monocytes in blood from numerous donors revealed that the assay method had excellent intra-donor reproducibility and sensitivity. Further, the utility of this assay to determine target engagement by chemokine receptor antagonists was demonstrated using a CCR2 antagonist in rhesus monkeys. Blockade of CCR2 on whole blood monocytes was demonstrated ex vivo on blood samples collected from rhesus monkeys administered a small molecule CCR2 antagonist (MK-0812). Using a delayed-type hypersensitivity reaction to elicit monocyte recruitment to the skin of rhesus monkeys, we also evaluated the ability of MK-0812 to block monocyte migration in vivo. Blockade of CCR2 stimulation of whole blood monocytes was correlated with the inhibition of monocyte recruitment to the skin, validating the potential to use this approach in the evaluation of dose selection for chemokine receptor antagonists clinically.

High titers of mucosal and systemic anti-PrP antibodies abrogate oral prion infection in mucosal-vaccinated mice.

Significant outbreaks of prion disease linked to oral exposure of the prion agent have occurred in animal and human populations. These disorders are associated with a conformational change of a normal protein, PrP(C) (C for cellular), to a toxic and infectious form, PrP(Sc) (Sc for scrapie). None of the prionoses currently have an effective treatment. Some forms of prion disease are thought to be spread by oral ingestion of PrP(Sc), such as chronic wasting disease and variant Creutzfeldt-Jakob disease. Attempts to obtain an active immunization in wild-type animals have been hampered by auto-tolerance to PrP and potential toxicity. Previously, we demonstrated that it is possible to overcome tolerance and obtain a specific anti-PrP antibody response by oral inoculation of the PrP protein expressed in an attenuated Salmonella vector. This past study showed that 30% of vaccinated animals were free of disease more than 350 days post-challenge. In the current study we have both optimized the vaccination protocol and divided the vaccinated mice into low and high immune responder groups prior to oral challenge with PrP(Sc) scrapie strain 139A. These methodological refinements led to a significantly improved therapeutic response. 100% of mice with a high mucosal anti-PrP titer immunoglobulin (Ig) A and a high systemic IgG titer, prior to challenge, remained without symptoms of PrP infection at 400 days (log-rank test P<0.0001 versus sham controls). The brains from these surviving clinically asymptomatic mice were free of PrP(Sc) infection by Western blot and histological examination. These promising findings suggest that effective mucosal vaccination is a feasible and useful method for overcoming tolerance to PrP and preventing prion infection via an oral route.

Is vaccination against transmissible spongiform encephalopathy feasible?

Prion diseases are a unique category of illness, affecting both animals and humans, where the underlying pathogenesis is related to a conformation change of the cellular form of a normal, self-protein called a prion protein (PrP(c) [C for cellular]) to a pathological and infectious conformation known as scrapie form (PrPsc [Sc for scrapie]). Currently, all prion diseases are without effective treatment and are universally fatal. The emergence of bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease has highlighted the need to develop possible therapies. In Alzheimer's disease (AD), which has similarities to prion diseases, both passive and active immunisation have been shown to be highly effective at preventing disease and cognitive deficits in model animals. In a human trial of active vaccination in AD, despite indications of cognitive benefits in patients with an adequate humoral response, 6% of patients developed significant complications related to excessive cell-mediated immunity. This experience highlights that immunotherapies designed to be directed against a self-antigen have to finely balance an effective humoral immune response with potential autoimmune toxicity. Many prion diseases have the gut as a portal of infectious agent entry. This makes mucosal immunisation a potentially very attractive method to partially or completely prevent prion entry across the gut barrier and to also produce a modulated immune response that is unlikely to be associated with any toxicity. The authors' recent results using an attenuated Salmonella vaccine strain expressing the prion protein show that mucosal vaccination can partially protect against prion infection from a peripheral source, suggesting the feasibility of this approach.

Mucosal vaccination delays or prevents prion infection via an oral route.

In recent years major outbreaks of prion disease linked to oral exposure of the prion agent have occurred in animal and human populations. These disorders are associated with a conformational change of a normal protein, PrP(C) (prion protein cellular), to a toxic and infectious form, PrP(Sc) (prion protein scrapie). None of the prionoses currently have an effective treatment. A limited number of active immunization approaches have been shown to slightly prolong the incubation period of prion infection. Active immunization in wild-type animals is hampered by auto-tolerance to PrP and potential toxicity. Here we report that mucosal vaccination with an attenuated Salmonella vaccine strain expressing the mouse PrP, is effective at overcoming tolerance to PrP and leads to a significant delay or prevention of prion disease in mice later exposed orally to the 139A scrapie strain. This mucosal vaccine induced gut anti-PrP immunoglobulin (Ig)A and systemic anti-PrP IgG. No toxicity was evident with this vaccination approach. This promising finding suggests that mucosal vaccination may be a useful method for overcoming tolerance to PrP and preventing prion infection among animal and potentially human populations at risk.

Therapeutics and prion disease: can immunisation or drugs be effective?

Prion diseases are of considerable importance because of the threat of a variant form of Creutzfeldt Jakob disease that has emerged in recent years. Pre-clinical diagnosis of prion diseases still remains poor and effective therapies also do not exist at present. This review examines research on possible therapeutic strategies that might have potential benefits if applied before neurodegeneration has occurred.

Apolipoprotein E isoform-specific regulation of dendritic spine morphology in apolipoprotein E transgenic mice and Alzheimer's disease patients.

Dendritic spines are postsynaptic sites of excitatory input in the mammalian nervous system. Apolipoprotein (apo) E participates in the transport of plasma lipids and in the redistribution of lipids among cells. A role for apoE is implicated in regeneration of synaptic circuitry after neural injury. The apoE4 allele is a major risk factor for late-onset familial and sporadic Alzheimer's disease (AD) and is associated with a poor outcome after brain injury. ApoE isoforms are suggested to have differential effects on neuronal repair mechanisms. In vitro studies have demonstrated the neurotrophic properties of apoE3 on neurite outgrowth. We have investigated the influence of apoE genotype on neuronal cell dendritic spine density in mice and in human postmortem tissue. In order to compare the morphology of neurons developing under different apoE conditions, gene gun labeling studies of dendritic spines of dentate gyrus (DG) granule cells of the hippocampus were carried out in wild-type (WT), human apoE3, human apoE4 expressing transgenic mice and apoE knockout (KO) mice; the same dendritic spine parameters were also assessed in human postmortem DG from individuals with and without the apoE4 gene. Quantitative analysis of dendritic spine length, morphology, and number was carried out on these mice at 3 weeks, 1 and 2 years of age. Human apoE3 and WT mice had a higher density of dendritic spines than human E4 and apoE KO mice in the 1 and 2 year age groups (P<0.0001), while at 3 weeks there were no differences between the groups. These age dependent differences in the effects of apoE isoforms on neuronal integrity may relate to the increased risk of dementia in aged individuals with the apoE4 allele. Significantly in human brain, apoE4 dose correlated inversely with dendritic spine density of DG neurons cell in the hippocampus of both AD (P=0.0008) and aged normal controls (P=0.0015). Our findings provide one potential explanation for the increased cognitive decline seen in aged and AD patients expressing apoE4.

Mapping the antigenicity of copper-treated cellular prion protein with the scrapie isoform.

When recombinant and cellular prion protein (PrP(C)) binds copper, it acquires properties resembling the scrapie isoform (PrP(Sc)), namely protease resistance, detergent insolubility and increased beta sheet content. However, whether the conformations of PrP(C) induced by copper and PrP(Sc) are similar has not been studied in great detail. Here, we use a panel of seven monoclonal antibodies to decipher the epitopes on full-length mouse PrP(C) that are affected by exogenous copper, and to compare the antigenicity of the copper-treated full-length PrP(C) with the full-length PrP(Sc) present in scrapie-infected mouse brains. In the presence of copper, we found that epitopes along residues 115-130 and 153-165 become more accessible on PrP(C). These regions correspond to the two beta sheet strands in recombinant PrP and they were proposed to be important for prion conversion. However, when we compared the antibody-binding patterns between full-length PrP(C) with full-length PrP(Sc) and between copper-treated full-length PrP(C) with full-length PrP(Sc), antibody binding to residues 143-155 and 175-185 was consistently increased on PrP(Sc). Collectively, our results suggest that copper-treated full-length PrP(C) does not resemble full-length PrP(Sc), despite acquiring PrP(Sc)-like properties. In addition, since each full-length protein reacts distinctively to some of the antibodies, this binding pattern could discriminate between PrP(C) and PrP(Sc).

The Drosophila kinesin-I associated protein YETI binds both kinesin subunits.

The microtubule-based motor kinesin-I is essential for the intracellular transport of membrane-bound organelles in the Drosophila nervous system and female germ line. A number of studies have demonstrated that kinesin-I binds to its intracellular cargos through protein-protein interactions between the kinesin tail domain and proteins on the cargo surface. To identify proteins that mediate or regulate kinesin-cargo interactions, we have performed yeast two-hybrid screens of a Drosophila embryonic cDNA library, using the tetratricopeptide repeats of the kinesin light chain and amino acids 675-975 of the kinesin heavy chain as baits. One of the proteins we have identified is YETI. Interestingly, YETI has the unique ability to bind specifically to both subunits of the kinesin tail domain. An epitope-tagged YETI fusion protein, when expressed in Drosophila S2 cultured cells, binds to kinesin-I in copurification assays, suggesting that YETI-kinesin-I interactions are context-independent. Immunostaining of cultured cells expressing YETI shows that YETI accumulates in the nucleus and cytosol. YETI is evolutionarily conserved, and its yeast homolog (AOR1) may have a role in regulating cytoskeletal dynamics or intracellular transport. Collectively, these results demonstrate that YETI interacts with both kinesin subunits of the kinesin tail domain, and is potentially involved in kinesin-dependent transport pathways.

Longitudinal cerebrospinal fluid tau load increases in mild cognitive impairment.

Cross-sectional cerebrospinal fluid (CSF) levels of tau and amyloid (A) beta (beta) are of diagnostic importance for Alzheimer's disease (AD) and mild cognitive impairment (MCI). However, most longitudinal studies of tau fail to demonstrate progression. Because predominantly brain-derived proteins such as tau, have higher ventricle to lumbar ratios, we hypothesized that adjusting for the ventricular enlargement of AD would correct for the dilution of tau, and improve detection of longitudinal change. Abeta which is not exclusively brain derived, shows a ratio <1, and no benefit was expected from adjustment. In a 1 year longitudinal study of eight MCI and ten controls, we examined CSF levels of hyperphosphorylated (P) tau231, Abeta40, and Abeta42. In cross-section, MCI patients showed elevated Ptau231 and Abeta40 levels, and greater ventricular volumes. Longitudinally, only after adjusting for the ventricular volume and only for Ptau231, were increases seen in MCI. Further studies are warranted on mechanisms of tau clearance and on using imaging to interpret CSF studies.

Therapeutics in Alzheimer's and prion diseases.

There is increasing recognition that numerous neurodegenerative conditions have the same underlying pathogenetic mechanism, namely a change in protein conformation, where the beta-sheet content is increased. In Alzheimer's disease, amyloid deposition in the form of neuritic plaques and congophilic angiopathy is driven by the conversion of normal soluble amyloid-beta peptide (sA beta) to A beta plaques; while in the prionoses the critical event is the conversion of normal prion protein, PrP(C), to the disease-associated form, PrP(Sc). This common theme in the pathogenesis of these disorders and the extracellular localization of the accumulating abnormal protein make them highly amenable to therapeutic approaches based on experimental manipulation of protein conformation and clearance. A number of different approaches under current development include drugs which affect the processing of the precursor proteins drugs the clearance of the amyloidogenic protein, and which inhibit or prevent the conformation change and immunological approaches. Particularly interesting are compounds termed 'beta-sheet breakers' that directly target the abnormal conformational change both for A beta- and PrP(Sc)-related deposits. In addition, immune system activation can serve as beta-sheet breakers and/or to increase the clearance of the disease-associated proteins. These conformation-based approaches appear to hold the best promise for therapies for this devastating group of disorders.

Therapeutic effects of astrocytes expressing both tyrosine hydroxylase and brain-derived neurotrophic factor on a rat model of Parkinson's disease.

Tyrosine hydroxylase (TH) and brain-derived neurotrophic factor (BDNF), expressed in normal astrocytes, were used in combination for the treatment of Parkinson's disease (PD) symptoms in a rat model. Normal neonatal rat astrocytes were co-transfected with a vector expressing BDNF (AAVBDNF) and a retroviral vector expressing TH (termed TH-BDNF-DA(+) cells), and then implanted into the striatum of PD rats induced by 6-hydroxydopamine. TH-BDNF-DA(+) cells compensated for a severe insufficiency of endogenous dopaminergic neurons in the PD rats, resulting in a significant improvement of PD symptoms. The decrease in the rotational rate of PD rats implanted with TH-BDNF-DA(+) cells was more marked than that in PD rats implanted with normal astrocytes expressing either TH or BDNF alone (termed TH(+) and BDNF(+) cells, P<0.01 and 0.001, respectively), and suggested a synergistic effect between TH and BDNF. In contrast, the rotational rate was not altered from the baseline in PD rats without treatment or implanted with parental rat astrocytes alone (P>0.05). BDNF protected the dopaminergic neurons from apoptosis induced by 6-hydroxydopamine, and significantly increased the long-term survival of TH-positive cells in the striatum. Our data indicate that the combined use of TH and BDNF has a synergistic therapeutic effect, and is more efficient for the treatment of PD than a single gene therapy using either TH or BDNF alone.

Vascular fibrosis and calcification in the hippocampus in aging, Alzheimer disease, and Down syndrome.

Study of the hippocampal formation of 82 subjects, including 25 control subjects from 33 to 83 years of age, 34 subjects with Alzheimer disease (AD) from 65 to 89 years of age, and 23 subjects with Down syndrome (DS) from 33 to 72 years of age, revealed hippocampal vasculopathy with fibrosis and calcification (VFC) in 40% of control, 59% of AD, and 4% of DS subjects. VFC starts in the precapillaries/capillaries in the molecular layer of the dentate gyrus (DG) and expands to the granule cell and polymorphic cell layer of the DG, and to the stratum lacunosum/molecular in the CA1 sector. Vasculopathy spreads from the tail to the body and, in a few cases, to the head of the hippocampal formation. Light and electron microscopy reveal thickening of the vascular wall with fibrosis, calcification, and enforcement of the astrocyte interface with vessels with anchorage densities associated with hemidesmosome-like structures. In moderately and severely affected cases, fragmentation and removal of calcified and occluded vessels result in local reduction of vascular network. In two AD subjects, severe vascular calcification extending from the tail to the head of the hippocampal formation was associated with loss of almost all neurons in the CA1 sector and in the subiculum proper, corresponding to hippocampal sclerosis. The topography of affected vessels and the patterns of neuronal loss reflect the middle hippocampal artery distribution with its precapillary/capillary network. The similar prevalence of vasculopathy in the AD group and in the age-matched control group, and the presence of hippocampal VFC in only one subject in the DS cohort, 96% of which is affected by Alzheimer-type pathology, oppose the link between AD and this form of vasculopathy. However, severe VFC affects the pattern of AD pathology locally by deletion of neurofibrillary degeneration and beta-amyloidosis in the CA1 sector, subiculum proper, and the molecular layer of the dentate gyrus. Hippocampal VFC appears to be a form of vascular pathology with a unique predilection for the middle hippocampal artery and corresponding capillary network, which results in patchy neuronal loss in moderately affected subjects and in almost total neuronal loss in the area of impaired blood supply in severely affected subjects. These observations suggest an etiologic link between hippocampal VFC and hippocampal sclerosis.

Melatonin reverses the profibrillogenic activity of apolipoprotein E4 on the Alzheimer amyloid Abeta peptide.

Inheritance of apoE4 is a strong risk factor for the development of late-onset sporadic Alzheimer's disease (AD). Several lines of evidence suggest that apoE4 binds to the Alzheimer Abeta protein and, under certain experimental conditions, promotes formation of beta-sheet structures and amyloid fibrils. Deposition of amyloid fibrils is a critical step in the development of AD. We report here that addition of melatonin to Abeta in the presence of apoE resulted in a potent isoform-specific inhibition of fibril formation, the extent of which was far greater than that of the inhibition produced by melatonin alone. This effect was structure-dependent and unrelated to the antioxidant properties of melatonin, since it could be reproduced neither with the structurally related indole N-acetyl-5-hydroxytryptamine nor with the antioxidants ascorbate, alpha-tocophenol, and PBN. The enhanced inhibitory effects of melatonin and apoE were lost when bovine serum albumin was substituted for apoE. In addition, Abeta in combination with apoE was highly neurotoxic (apoE4 > apoE3) to neuronal cells in culture, and this activity was also prevented by melatonin. These findings suggest that reductions in brain melatonin, which occur during aging, may contribute to a proamyloidogenic microenvironment in the aging brain.

[Familial Alzheimer's disease connected with mutation in presenilin gene 1 (P117L)]. / Rodzinna choroba Alzheimera zwiazana z mutacja w genie preseniliny 1 (P117L).

We describe a Polish family with Alzheimer's disease in some of its members. Two sisters were observed and examined--also neuropathologically in the Institute of Psychiatry and Neurology in Warsaw. The disease onset was in our patients at 32 and 33 years. The first symptoms were memory loss and disorientation. Later on myoclonus and extrapyramidal stiffness were noted in both cases. Neurovisualizing examinations performed in both sisters showed diffuse brain atrophy. The symptoms increased rapidly and in short time (several months) the patients became mute and bedbound. They died at age 35 and 37 years. We were informed that the father of the patients suffered from very similar illness and died at age of 37 years and their older brother had the some symptoms and died at the age of 28 years. Post-mortem brain examination disclosed in the both hospitalized cases diffuse atrophy of the cerebral hemispheres, particularly severe in the temporal lobes. Microscopically senile plaques of various types were found in the cortex. The density of the plaques was very high but Alzheimer's fibrillary degeneration was found occasionally only. The amyloid burden in cortex of the examined brains, estimated as the measure of parenchymal amyloidosis beta, was two to six-fold higher in most areas compared with changes in sporadic AD and Down-syndrome cases. DNA was isolated from blood and tissue of both cases and from blood of their 8 children as well. In both patients mutation in presenilin 1 (PS1) gene of Prol 117 Leu was found and it was discovered that 4 persons of their progeniture were carriers of this mutation. The described mutation causes one of the earliest so far reported onset and death in FAD kindreds. Presenilin isolated from both cases and transfected into cultures of murine neuroblastoma and human kidneys provoked production of beta amyloid with increased A-beta 42/40 ratio.