Myelin Pathology in Alzheimer's Disease: Potential Therapeutic Opportunities

Alzheimer's disease (AD) is an age-related neurodegenerative disease characterized by memory loss and cognitive decline. Despite significant efforts over several decades, our understanding of the pathophysiology of this disease is still incomplete. Myelin is a multi-layered membrane structure ensheathing neuronal axons, which is essential for the fast and effective propagation of action potentials along the axons. Recent studies highlight the critical involvement of myelin in memory consolidation and reveal its vulnerability in various pathological conditions. Notably, apart from the classic amyloid hypothesis, myelin degeneration has been proposed as another critical pathophysiological feature of AD, which could occur prior to the development of amyloid pathology. Here, we review recent works supporting the critical role of myelin in cognition and myelin pathology during AD progression, with a focus on the mechanisms underlying myelin degeneration in AD. We also discuss the complex intersections between myelin pathology and typical AD pathophysiology, as well as the therapeutic potential of pro-myelinating approaches for this disease. Overall, these findings implicate myelin degeneration as a critical contributor to AD-related cognitive deficits and support targeting myelin repair as a promising therapeutic strategy for AD.

Deep Learning and Machine Learning Algorithms for Retinal Image Analysis in Neurodegenerative Disease: Systematic Review of Datasets and Models

Purpose

Retinal images contain rich biomarker information for neurodegenerative disease. Recently, deep learning models have been used for automated neurodegenerative disease diagnosis and risk prediction using retinal images with good results.

Methods

In this review, we systematically report studies with datasets of retinal images from patients with neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, and others. We also review and characterize the models in the current literature which have been used for classification, regression, or segmentation problems using retinal images in patients with neurodegenerative diseases.

Results

Our review found several existing datasets and models with various imaging modalities primarily in patients with Alzheimer's disease, with most datasets on the order of tens to a few hundred images. We found limited data available for the other neurodegenerative diseases. Although cross-sectional imaging data for Alzheimer's disease is becoming more abundant, datasets with longitudinal imaging of any disease are lacking.

Conclusions

The use of bilateral and multimodal imaging together with metadata seems to improve model performance, thus multimodal bilateral image datasets with patient metadata are needed. We identified several deep learning tools that have been useful in this context including feature extraction algorithms specifically for retinal images, retinal image preprocessing techniques, transfer learning, feature fusion, and attention mapping. Importantly, we also consider the limitations common to these models in real-world clinical applications.

Translational Relevance

This systematic review evaluates the deep learning models and retinal features relevant in the evaluation of retinal images of patients with neurodegenerative disease.

Clinical impact of 11C-Pittsburgh compound-B positron emission tomography in addition to magnetic resonance imaging and single-photon emission computed tomography on diagnosis of mild cognitive impairment to Alzheimer's disease

This study aimed to evaluated the clinical impact of adding [11C] Pittsburgh compound-B (11C-PiB) PET for clinical diagnosis of mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia.Twenty six (mean age 78.5 ± 5.18 years, 21 females) AD (n = 7), amnestic MCI (n = 12), non-amnestic MCI (n = 3), vascular dementia, progressive supranuclear palsy (PSP) with frontotemporal dementia (FTD), FTD (n = 1 each), and normal (n = 1) patients underwent 11C-PiB-PET, MRI, and SPECT scanning. 11C-PiB-PET was compared with MRI and SPECT for clinical impact.11C-PiB-PET showed positivity in 6, 9, and 0 of the AD, amnestic MCI, and non-amnestic MCI patients, respectively, and 0 of those with another disease. Parahippocampal atrophy at VSASD was observed in 5 AD patients, 6 amnestic and PiB-positive MCI patients, 1 amnestic and PiB-negative MCI patient, and 1 vascular dementia patient. Parietal lobe hypoperfusion in SPECT findings was observed in 6, 4, and 2 of those, respectively, as well as 1 each of non-amnestic MCI, vascular dementia, and normal cases. Sensitivity/specificity/accuracy for selecting PiB-positive patients among the 15 MCI patients for 11C-PiB-PET were 100% (9/9)/100% (6/6)/100% (15/15), for VSRAD were 66.7% (6/9)/83.3% (5/6)/73.3% (11/15), and for SPECT were 44.4% (4/9)/50.0% (3/6)/46.7% (7/15), while those were 88.9% (8/9)/33.3% (2/6)/66.7% (10/15)/for combined VSRAD and SPECT. 11C-PiB-PET accuracy was significantly higher than that of SPECT.11PiB-PET alone may be useful for selecting patients who will progress from MCI to AD in the future, although follow-up study is necessary to clarify the outcome of MCI patients.

FASTKD2 is associated with memory and hippocampal structure in older adults

Memory impairment is the cardinal early feature of Alzheimer's disease, a highly prevalent disorder whose causes remain only partially understood. To identify novel genetic predictors, we used an integrative genomics approach to perform the largest study to date of human memory (n=14 781). Using a genome-wide screen, we discovered a novel association of a polymorphism in the pro-apoptotic gene FASTKD2 (fas-activated serine/threonine kinase domains 2; rs7594645-G) with better memory performance and replicated this finding in independent samples. Consistent with a neuroprotective effect, rs7594645-G carriers exhibited increased hippocampal volume and gray matter density and decreased cerebrospinal fluid levels of apoptotic mediators. The MTOR (mechanistic target of rapamycin) gene and pathways related to endocytosis, cholinergic neurotransmission, epidermal growth factor receptor signaling and immune regulation, among others, also displayed association with memory. These findings nominate FASTKD2 as a target for modulating neurodegeneration and suggest potential mechanisms for therapies to combat memory loss in normal cognitive aging and dementia.

Geniposide decreases the level of Aβ1-42 in the hippocampus of streptozotocin-induced diabetic rats

Although cognitive dysfunction in diabetic patients has been explored extensively, diabetic complications of the central nervous system have not been studied. We have reported previously that geniposide has neurotrophic and neuroprotective activities with the activation of glucagons-like peptide 1 receptor, and regulates glucose-stimulated insulin secretion in vitro. But the role of geniposide on diabetic complications, especially on the neurodegenerative diseases, remains to be investigated. In this study, we investigated the effect of geniposide on the level of Aβ1-42 in the hippocampi of streptozotocin-induced diabetic rats and explored its possible mechanism. The results demonstrated that, accompanied with the improvement of insulin and blood glucose, treatment with geniposide decreased the Aβ1-42 level and improved the expression of insulin-degrading enzyme, which is the key degrading enzyme of Aβ peptide. The results of present study will help to understand the biochemical mechanisms of neuronal dysfunction and death in diabetes and to develop an efficient therapeutic strategy on Alzheimer's disease.

Recent advances in neuroimaging biomarkers in geriatric psychiatry

Neuroimaging, both structural and functional, serve as useful adjuncts to clinical assessment, and can provide objective, reliable means of assessing disease presence and process in the aging population. In the following review we briefly explain current imaging methodologies. Then, we analyze recent developments in developing neuroimaging biomarkers for two highly prevalent disorders in the elderly population- Alzheimer's disease (AD) and late-life depression (LLD). In AD, efforts are focused on early diagnosis through in vivo visualization of disease pathophysiology. In LLD, recent imaging evidence supports the role of white matter ischemic changes in the pathogenesis of depression in the elderly, the "vascular hypothesis." Finally, we discuss potential roles for neuroimaging biomarkers in geriatric psychiatry in the future.

Comparing the effects of different individualized music interventions for elderly individuals with severe dementia

BACKGROUND

Individuals with dementia often experience poor quality of life (QOL) due to behavioral and psychological symptoms of dementia (BPSD). Music therapy can reduce BPSD, but most studies have focused on patients with mild to moderate dementia. We hypothesized that music intervention would have beneficial effects compared with a no-music control condition, and that interactive music intervention would have stronger effects than passive music intervention.

METHODS

Thirty-nine individuals with severe Alzheimer's disease were randomly and blindly assigned to two music intervention groups (passive or interactive) and a no-music Control group. Music intervention involved individualized music. Short-term effects were evaluated via emotional response and stress levels measured with the autonomic nerve index and the Faces Scale. Long-term effects were evaluated by BPSD changes using the Behavioral Pathology in Alzheimer's Disease (BEHAVE-AD) Rating Scale.

RESULTS

Passive and interactive music interventions caused short-term parasympathetic dominance. Interactive intervention caused the greatest improvement in emotional state. Greater long-term reduction in BPSD was observed following interactive intervention, compared with passive music intervention and a no-music control condition.

CONCLUSION

Music intervention can reduce stress in individuals with severe dementia, with interactive interventions exhibiting the strongest beneficial effects. Since interactive music intervention can restore residual cognitive and emotional function, this approach may be useful for aiding severe dementia patients' relationships with others and improving QOL. The registration number of the trial and the name of the trial registry are UMIN000008801 and "Examination of Effective Nursing Intervention for Music Therapy for Severe Dementia Elderly Person" respectively.

C145 as a short-latency electrophysiological index of cognitive compensation in Alzheimer's disease

Brain plasticity and cognitive compensation in the elderly are of increasing interest, and Alzheimer's disease (AD) offers an opportunity to elucidate how the brain may overcome damage. We provide neurophysiological evidence of a short-latency event-related potential (ERP) component (C145) linked to stimulus relevancy that may reflect cognitive compensation in early-stage AD. Thirty-six subjects with early-stage, mild AD and 36 like-aged normal elderly (controls) had their EEG recorded while performing our Number-Letter task, a cognitive/perceptual paradigm that manipulates stimulus relevancies. ERP components, including C145, were extracted from ERPs using principal components analysis. C145 amplitudes and spatial distributions were compared among controls, AD subjects with high performance on the Number-Letter task, and AD subjects with low performance. Compared to AD subjects, control subjects showed enhanced C145 processing of visual stimuli in the occipital region where differential processing of relevant stimuli occurred. AD high performers recruited central brain areas in processing task relevancy. Controls and AD low performers did not show a significant task relevancy effect in these areas. We conclude that short-latency ERP components can detect electrophysiological differences in early-stage AD that reflect altered cognition. Differences in C145 amplitudes between AD and normal elderly groups regarding brain locations and types of task effects suggest compensatory mechanisms can occur in the AD brain to overcome loss of normal functionality, and this early compensation may have a profound effect on the cognitive efficiency of AD individuals.

Pilot data on telmisartan short-term effects on glucose metabolism in the olfactory tract in Alzheimer's disease

The possible effect of antihypertensive therapy on Alzheimer's disease (AD) has been studied, and angiotensin II receptor blockers (ARBs) have been suggested to exert an effect on cognitive decline. The purpose of this study is to clarify the functional effects of telmisartan, a long-acting ARB, on AD brain using prospective longitudinal (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) studies. For this purpose, brain glucose metabolism of four hypertensive patients with AD was examined with FDG-PET before and after administration of telmisartan. Studied subjects underwent three FDG-PET studies at intervals of 12 weeks. Antihypertensive treatment except for telmisartan was started after the first FDG-PET and continued for 24 weeks. Then 40-80 mg of telmisartan was added after the second FDG-PET and continued for 12 weeks.Glucose metabolism was significantly decreased during the first 12 weeks without telmisartan use at an area (-10, 21, -22, x, y, z; Z = 3.56) caudal to the left rectal gyrus and the olfactory sulcus corresponding to the left olfactory tract. In contrast, the introduction of telmisartan during the following 12 weeks preserved glucose metabolism at areas (5, 19, -20, x, y, z; Z = 3.09; 6, 19, -22, x, y, z; Z = 2.88) caudal to the bilateral rectal gyri and olfactory sulci corresponding to the bilateral olfactory tracts. No areas showed decreased glucose metabolism after the introduction of telmisartan. In AD, amyloid-β deposition is observed in the anterior olfactory nucleus (AON) of the olfactory tract. Glucose metabolism in AON may be progressively decreased and preserved by telmisartan.

Oxidative insults to neurons and synapse are prevented by aged garlic extract and S-allyl-L-cysteine treatment in the neuronal culture and APP-Tg mouse model

Alzheimer's disease (AD) is one of the most common forms of dementia in the elderly. In AD patients, β-amyloid peptide (Aβ) plaques and neurofibrillary tangles are common features observed in the CNS. Aβ deposition results in the production of reactive oxygen species (ROS) leading to the hyperphosphorylation of tau that are associated with neuronal damage. Cholinesterase inhibitors and a partial NMDA receptor antagonist (memantine) have been identified as potential treatment options for AD. However, clinical studies have found that these drugs fail to prevent the disease progression. From ancient times, garlic (Allium sativum) has been used to treat several diseases. By 'aging' of garlic, some adverse reactions of garlic can be eliminated. Recent findings suggest that 'aged garlic extract' (AGE) may be a therapeutic agent for AD because of its antioxidant and Aβ lowering properties. To date, the molecular properties of AGE have been sparsely studied in vitro or in vivo. The present study tested specific biochemical and molecular effects of AGE in neuronal and AD rodent models. Furthermore, we identified S-allyl-L-cysteine (SAC) as one of the most active chemicals responsible for the AGE-mediated effect(s). We observed significant neuroprotective and neurorescue properties of AGE and one of its ingredients, SAC, from ROS (H(2)O(2))-mediated insults to neuronal cells. Treatment of AGE and SAC were found to protect neuronal cells when they were independently co-treated with ROS. Furthermore, a novel neuropreservation effect of AGE was detected in that pre-treatment with AGE alone protected ∼ 80% neuronal cells from ROS-mediated damage. AGE was also found to preserve pre-synaptic protein synaptosomal associated protein of 25 kDa (SNAP25) from ROS-mediated insult. For example, treatment with 2% AGE containing diet and SAC (20 mg/kg of diet) independently increased (∼70%) levels of SNAP25 and synaptophysin in Alzheimer's amyloid precursor protein-transgenic mice, of which the latter was significantly decreased in AD. Taken together, the neuroprotective, including preservation of pre-synaptic proteins by AGE and SAC can be utilized in future drug development in AD.

Optimized data preprocessing for multivariate analysis applied to 99mTc-ECD SPECT data sets of Alzheimer's patients and asymptomatic controls

Multivariate image analysis has shown potential for classification between Alzheimer's disease (AD) patients and healthy controls with a high-diagnostic performance. As image analysis of positron emission tomography (PET) and single photon emission computed tomography (SPECT) data critically depends on appropriate data preprocessing, the focus of this work is to investigate the impact of data preprocessing on the outcome of the analysis, and to identify an optimal data preprocessing method. In this work, technetium-99methylcysteinatedimer ((99m)Tc-ECD) SPECT data sets of 28 AD patients and 28 asymptomatic controls were used for the analysis. For a series of different data preprocessing methods, which includes methods for spatial normalization, smoothing, and intensity normalization, multivariate image analysis based on principal component analysis (PCA) and Fisher discriminant analysis (FDA) was applied. Bootstrap resampling was used to investigate the robustness of the analysis and the classification accuracy, depending on the data preprocessing method. Depending on the combination of preprocessing methods, significant differences regarding the classification accuracy were observed. For (99m)Tc-ECD SPECT data, the optimal data preprocessing method in terms of robustness and classification accuracy is based on affine registration, smoothing with a Gaussian of 12 mm full width half maximum, and intensity normalization based on the 25% brightest voxels within the whole-brain region.

Effects of acetylate hyperforin on the processing of amyloid precursor protein

Hyperforin (HF) is a phloroglucinol compound obtained from St. John's Wort (Hypericum perforatum). Recent studies have shown that Hyperforin can be used to improve psychopathologic symptoms of Alzheimer's disease but the mechanism is not clear. This may be partly due to the difficult in studying Hyperforin, since this chemical is unstable and is sensitive to light, oxygen, and heat. In this study, we explored the effects of acetylate hyperforin (ace-HF), a stable derivative of hyperforin, on the processing of amyloid precursor protein (APP). HEK293 cells transfected with pcDNA3.1APP695sw and SH-SY5Y cells were treated with ace-HF, followed by measuring the levels of APP and sAPPα. Twelve hours of treatment led to an increase in extracellular sAPPα, but APP mRNA and protein levels were unchanged. Further studies with α-secretase and a pan PKC inhibitor, Calphostin C, indicated that ace-HF's effect on extracellular sAPPα was closely related to PKC activities and α-secretase activities. Our findings suggest that ace-HF can modulate α-secretase-mediated APP processing via a PKC signaling pathway.

Isoprenoid quantitation in human brain tissue: a validated HPLC-fluorescence detection method for endogenous farnesyl- (FPP) and geranylgeranylpyrophosphate (GGPP)

Farnesyl- and geranylgeranylpyrophosphate (FPP and GGPP) are isoprenoid intermediates in the mevalonate pathway. They play a crucial role in cell survival, growth and differentiation due to their attachment (isoprenylation) to small GTPases (Ras, Rho, etc.). Isoprenoid formation seems to be tightly regulated within the mevalonate pathway and its perturbation has been linked to certain diseases (e.g., cancer, Alzheimer's disease), but tissue levels are unknown. It is therefore of the utmost importance to quantify these isoprenoids in diseased tissue or in tissue after drug administration. The current work describes an isolation procedure utilizing a combination of Extrelut(R) liquid/liquid and reversed-phase solid-phase extraction (SPE) for homogenized human frontal cortex tissue. In addition, after a careful validation of an HPLC-fluorescence method, this assay allowed the determination of nanomolar concentrations of endogenous FPP and GGPP levels (4.5 and 10.6 ng/mg protein, respectively) in human brain tissue. The method is selective, precise (<15% RSD), accurate (<15% relative error) and sensitive over a linear range of 10-400 ng/mL for FPP and 50-1000 ng/mL for GGPP according to the current FDA criteria for bioanalytical method validation. Overall, this new method introduces the ability to simultaneously quantify FPP and GGPP in human brain tissue, and is potentially applicable to several other tissues and species.

Physiologic modulation of natural killer cell activity as an index of Alzheimer's disease progression

Patients with Alzheimer's disease (AD) are characterized by an altered sensitivity to cortisol-mediated modulation of circulating lymphocytes. Longitudinal studies are needed to address the clinical applicability of these abnormalities as prognostic factors. Therefore, we designed a longitudinal study to address the clinical applicability of physiologic modulation of Natural Killer (NK) cell activity as a prognostic factor in AD. NK activity was assessed as baseline measurement and in response to modulation by cortisol at 10(-6)M. To verify the immunophysiological integrity of the NK cell population, we tested augmentation of NK cytotoxicity by human recombinant interleukin (IL)-2 (100 IU/ml) as control. The response to modulation by cortisol or by IL-2 was significantly greater in patients with AD. Based on change in the Mini-Mental State score at entry and at 18 months, patients with AD could be assigned to a "fast progression" (Delta > 2 points) or to a "slow progression" group (Delta Collapse

Key Words

• alzheimer's disease (ad)
• natural killer (nk) cells
• nk cytotoxic activity
• cortisol
• interleukin (il)-2
• psychoimmunology

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Affiliation(s)

Paolo Prolo Division of Oral Biology & Medicine, UCLA School of Dentistry, Los Angeles, CA 90095-1668, USA.
Francesco Chiappelli
Alberto Angeli
Andrea Dovio
Paola Perotti
Marisa Pautasso
Maria Luisa Sartori
Laura Saba
Stefano Mussino
Thomas Fraccalini
Fausto Fantó
Cristina Mocellini
Maria Gabriella Rosso
Enzo Grasso

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Extrapyramidal symptoms and signs in Alzheimer's disease: prevalence and correlation with the first symptom

OBJECTIVES

To determine the prevalence and clinical correlates of extrapyramidal signs (EPS) in outpatients with probable Alzheimer's disease (AD); to examine the appearance of EPS in association with the first symptom that led the patient or family to ask for medical help; to examine the association of the prevalence of EPS with gender, age at onset of the disease, duration of the disease, severity of dementia, functional disability, and potential use of neuroleptics; and to address the issue of the possible role of EPS as a predictive factor for the clinical course of the disease.

PATIENTS AND METHODS

We examined 126 patients meeting NINCDS-ADRDA* criteria for probable AD and 29 healthy, nondementia controls of comparable age and gender. Thirteen of the patients taking neuroleptics at the time of the examination were excluded from the main study group and formed a separate subgroup of AD/neuroleptics-positive. Twenty-eight of the AD/neuroleptics-free patients were re-examined during an 18-month period in order to determine the possible role of EPS as a predictive factor of the clinical course of the disease.

RESULTS

Only 8 percent of the AD/neuroleptics-free patients were free of EPS, while the corresponding percentage in the control group was 61.5 percent. The most common types of EPS presented in the patient group were hypomimia ([facial mask] 60 percent), difficulty in talking (53.66 percent), bradykinesia (51.4 percent), postural instability (47.33 percent), abnormal gait (34.66), and rigidity (26 percent), respectively. No significant differences were found when examining for the presence of resting tremor, other tremors, dystonias, and dyskinesias. With regard to the presence of EPS and the first symptom, no significant difference was found among patients whose first complaint was memory disorder (probable AD) and patients with other symptoms. When examining the association between the prevalence of EPS and gender or age at onset of the disease, no special correlation was detected. However, such a correlation was found between the prevalence of EPS and duration of the disease, as indicated by the fact that EPS appear in 78.9 percent of the patients with a duration of illness less than two years, but in 97 percent of the patients with a corresponding duration of two years or more. The mean duration of the disease in patients appearing with EPS is found to be 2.68 +/- 1.98 years. The presence of EPS increases proportionally with the progression of the disease and cognitive and functional decline. Patients with poor results in the MMSE (score of less than 11) appear to present EPS at a greater percentage than those with better performance on the examination (MMSE scores greater than 11). With regard to the association between EPS and functional ability in AD, it seems that the presence of EPS imposes difficulties in daily activities, as seen by the fact that patients with EPS have lower FRSSD scores (mean +/- SD: 14.87 +/- 10.53) than patients without EPS (5 +/- 2.58). After controlling for duration of the disease, the use of neuroleptics is found to influence the appearance of EPS in patients with AD. Almost all of the patients AD/neuroleptics-positive patients presented EPS (100 percent), while 92 percent of the AD/neuroleptics-free patients manifested such symptoms. Finally, we re-evaluated 28 patients, who were part of the initial AD/neuroleptics-free group, in order to determine whether the appearance of EPS could have prognostic value for the clinical course of the disease. Patients who presented EPS at initial examination appeared to deteriorate faster, mainly cognitively, but also functionally. The mean decrease in MMSE scores in patients with EPS was found to be 2.65 +/- 3.46; while in patients without EPS at initial visit, MMSE scores were 0.63 +/- 3.88. The functional decline seems to be less influenced by the presence of EPS. The corresponding mean decrease in FRSSD scores of the two groups was 2.1 +/- 5.55 and 1.8 +/- 2.1, respectively.

A day care program and evaluation of animal-assisted therapy (AAT) for the elderly with senile dementia

We conducted a survey to clarify the evaluation methods of animal-assisted therapy (AAT) for the elderly with senile dementia in an adult day care center. AAT was implemented for a total of six biweekly sessions. The AAT group consisted of seven subjects and the control group numbered 20 subjects. In a comparison between Mini-Mental State Exam (MMSE) scores at baseline and those measured three months later, the average MMSE score before AAT (baseline) was 11.43 (+/- 9.00), and three months later it was 12.29(+/- 9.69). In the AAT group, the average score on Nishimura's Activities of Daily Living (N-ADL) at baseline was 28.43(+/- 14.00), and after ATT it was 29.57(+/- 14.47). In the AAT group, the average baseline score on behavioral pathology of Alzheimer's disease (Behave-AD) was 11.14(+/- 4.85), and three months after AAT it was 7.29(+/- 7.11) (p < 0.05). In the control group, the average baseline score was 5.45(+/- 3.27) and three months later it was 5.63(+/- 3.59). The evaluation of salivary CgA, as a mental stress index, showed a decreasing tendency in the AAT group. Our findings demonstrate the usefulness of using several methods for evaluation of the changes in patients given AAT.

Interaction between apolipoprotein-E and angiotensin-converting enzyme genotype in Alzheimer's disease

Both apolipoprotein-E (apo-E) epsilon 4 allele and angiotensin-converting enzyme (ACE) deletion (D) polymorphism have been associated with a high risk for coronary heart disease. Increased frequency of the epsilon 4 allele has also been reported in patients with late-onset of familial and sporadic Alzheimer's disease (AD). The primary aim of this study is to examine the possible relationship between the ACE gene polymorphism and AD. The second aim of this study is to explore the relation of the ACE and apo-E genotypes with AD. Polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and agarose gel electrophoresis techniques were used to determine the apo-E and ACE genotypes. The frequencies of ACE D and ACE insertion (I) allele among AD patients and controls were 55.7 percent versus 44.2 percent and 51.7 versus 48.2 percent, respectively. Apo-E allele frequencies in the AD group for epsilon 2, epsilon 3 and epsilon 4 were, 1.7 percent, 96.5 percent, and 1.7 percent, respectively. The apo-E allele frequencies of healthy groups for epsilon 2, epsilon 3 and epsilon 4 were 1 percent, 56 percent, and 1.7 percent, respectively. In conclusion ACE D and apo epsilon 4 allele were found to be more frequent in patients with Alzheimer's disease than in the control group.

Comparing the well-being of post-caregivers and noncaregivers

Researchers who study family caregiving have begun to recognize the need to broaden the realm of inquiry to include the exploration of the positive aspects of caregiving as well as conceptualizing caregiving on a continuum from the pre-caregiving phase through the post-caregiving phase. Additionally, researchers are urged to use control groups in research. This study complements the current trends by examining the positive aspects of caregiving among former caregivers. Specifically, the well-being of post-caregivers is compared to that of noncaregivers. Bivariate analyses examine the factors that are significantly different between former caregivers and noncaregivers. Results show that former caregivers have higher well-being than noncaregivers. In the multivariate model, only one subscale of well-being (basic needs) is different between the two groups. Implications of this research are discussed.