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Background: Because dementia is an emerging problem in the world, biochemical markers of cerebrospinal fluid (CSF) and radio-isotopic analyses are helpful for diagnosing Alzheimer’s disease (AD). Although blood sample is more feasible and plausible than CSF or radiological biomarkers for screening potential AD, measurements of serum amyloid- β (Aβ), plasma tau, and serum antibodies for Aβ1 - 42 are not yet well established. Objective: We aimed to identify a new serum biomarker to detect mild cognitive impairment (MCI) and AD in comparison to cognitively healthy control by a new peptidome technology. Methods: With only 1.5μl of serum, we examined a new target plate “BLOTCHIP®” plus a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) to discriminate control (n = 100), MCI (n = 60), and AD (n = 99). In some subjects, cognitive Mini-Mental State Examination (MMSE) were compared to positron emission tomography (PET) with Pittsburgh compound B (PiB) and the serum probability of dementia (SPD). The mother proteins of candidate serum peptides were examined in autopsied AD brains. Results: Apart from Aβ or tau, the present study discovered a new diagnostic 4-peptides-set biomarker for discriminating control, MCI, and AD with 87% of sensitivity and 65% of specificity between control and AD (***p Conclusion: The present serum biomarker set provides a new, rapid, non-invasive, highly quantitative and low-cost clinical application for dementia screening, and also suggests an alternative pathomechanism of AD for neuroinflammation and neurovascular unit damage.

Due to the rapid increase in traffic accidents caused by the old populations of ages 65-74 and more than 75 in Japan, the renewal of driver's licenses has become more difficult following the revision of traffic laws in March 2017. As part of the driver's license clinic at Kurashiki Heisei Hospital, the present study investigated the status of voluntary license surrender in Okayama Prefecture of Japan. From March 2017 to December 2019, the number of voluntary surrenders increased from 5,434 to 10,284 cases, or at a rate of 0.42% to 0.80%, among license holders, with the old-old accounting for 68%-77% of voluntary surrenders. The major reasons for surrender were a decline in physical ability (25%-38%), a decline in driving needs (28%-60%), and family's suggestion (14%-17%). The increase in voluntary license surrender over these 3 years was common across all municipalities within Okayama Prefecture, but the surrender rate was closely correlated with the aged-society rate for both old populations of ages 65-74 and more than 75 (r = -0.5508, **p = 0.002 and r = -0.3086, p = 0.110, respectively). The driver's license clinic at Kurashiki Heisei Hospital received 110 visits during the 3-year period, in which MCI (mild cognitive impairment) accounted for 67% of voluntary surrenders (21.8%). The present study suggests that the increase in the rate of voluntary license surrender during the 3-year period was closely related to the aged-society rate in Okayama Prefecture, and that a driver's license clinic provides a detailed dementia status among license holders who have voluntarily surrendered their license.

Following the passage of a new traffic law in March 2017, an inquiry survey was performed for 202 patients (men 60.9%, women 39.1%) in a medical center for neurocognitive disorders in Japan. Half of the 108 patients who currently had a driver's license had experienced traffic problems, including nearly crashing accidentally, in the past, but only a few of the men were willing to return their driver's license to the government, regardless of age (

AIM: Most patients with dementia frequently encounter various problems in their daily lives. Those troubles embarrass both the patients and their families, and cause problems for society. However, there have been few scientific reports on the difficulties in the daily life of patients with dementia. Therefore, we tried to clarify the frequency and characteristics of troubles experienced by patients with dementia. METHODS: Seven medical centers treating dementia patients in Okayama Prefecture, Japan, participated in this survey. A total of 737 patients were placed in one of the three groups: a dementia group (n = 478), a mild cognitive impairment group (n = 199) and a control group (n = 60). The frequency of 13 difficulties was scored for each patient. RESULTS: Among normal participants, no person caused these problems once a year or more frequently. "Massive, recurrent buying" and "acts that risk causing a fire" were reported once a year or more for >10% of mild cognitive impairment patients. "Troubles with wealth management" and "troubles with money management" were the most frequent problems of dementia patients. CONCLUSIONS: Several problems are already sometimes encountered in patients with mild cognitive impairment. It would be useful to know which social difficulties are often seen in dementia patients in order to protect the safety of the patients. It is always difficult to balance respecting the autonomy of dementia patients and ensuring their safely.

There is a strong relationship between Alzheimer's disease (AD) and sleep problems, and a sleep condition is informative for evaluating the AD status. In the present study, we evaluated subjective sleep problems in AD and mild cognitive impairment (MCI) with self-check questionnaires and objective sleep problems with a convenient home-based portable device, WatchPAT. A total of 63 subjects with normal cognition (NC) (n = 22), MCI (n = 20), and AD (n = 21) were cross-sectionally investigated. AD patients showed a better self-check Pittsburgh sleep quality index (PSQI) score (*p 0.05) than NC and MCI patients. On the other hand, WatchPAT analysis showed a significantly reduced rapid eye movement (REM) sleep (*p 0.05) and increased light sleep in AD patients (*p 0.05) compared with NC subjects, and mildly reduced REM and increased light sleep in MCI subjects. The present study revealed a gap between the subjective self-check sleep questions and the objective WatchPAT analysis in AD patients. Thus, a home-based sleep study with WatchPAT is a useful tool to detect an objective sleep problem in AD and the risk of MCI conversion into AD.

Oxidative stress is part of the entire pathological process that underlies the development of Alzheimer's disease (AD), including the mild cognitive impairment (MCI) stage. Twendee X (TwX) is a supplement containing a strong antioxidative mix of eight antioxidants, which has been shown to have a clinical and therapeutic benefit in AD model mice. Here, we conducted a multicenter, randomized, double-blind, and placebo-controlled prospective interventional study to evaluate the efficacy of TwX in mitigating MCI. The primary outcomes were differences in Mini-Mental State Examination (MMSE) and Hasegawa Dementia Scale-revised (HDS-R) scores between baseline and six months for placebo and TwX groups. Seventy-eight subjects with MCI were randomized into placebo (n = 37) and TwX (n = 41) groups. MMSE scores at six months differed significantly between the TwX and placebo groups (p = 0.018), and HDS-R scores for the TwX group exhibited a significant improvement at six months relative to baseline (p = 0.025). The TwX group did not show any change in affective or activities of daily living scores at six months. The present study indicates that strong antioxidative supplement TwX is clinical beneficial for cognitive function in subjects with MCI.

Associations of sarcopenia and physical frailty in cognitive and affective (depression, apathy, and behavioral and psychological symptoms of dementia) functions of mild cognitive impairment (MCI) and Alzheimer’s disease (AD) were not fully evaluated previously, especially not for gender differences. 165 AD, 84 MCI, and 48 control participants (175 female, 122 male) were evaluated for cognitive, affective, activities of daily living (ADL), and physical functions associated with sarcopenia and physical frailty. In both sexes, cognitive and affective functions, ADL, and physical functions worsened in MCI and AD compared to control subjects. Physical dysfunctions, especially slow gait speed (3 m up and go test), were significantly associated with cognitive, affective, and ADL declines in participants (control subjects, MCI, and AD) of each gender, which were especially noticeable in females. The present study may be the first to suggest significant associations of sarcopenia and physical frailty with cognitive and affective functions of MCI and AD, especially in females.

The present study aimed to clarify the clinical characteristics of patients with dementia in an emergency clinic.We retrospectively examined patients with dementia who visited the emergency clinic at Kurashiki Heisei Hospital, Okayama, Japan. Among 16 764 patients who visited our emergency clinic in the 3 years from 2014 to 2017, we focused on 2574 (15.4%) patients with dementia.The mean age of patients with dementia was 84.9 ± 0.1 years, which was much older than the age of the total emergency patients (58.1 ± 0.2 years). The hospitalization rate was 54.9% for patients with dementia, which was more than double that of patients without dementia (23.3%; P 0.01), and was higher than that (44.3%) of patients who were aged ≥75 years without dementia. Infection (42.4%) and falls (20.9%) were the most common causes for emergency visits and hospitalization in the present study. Hospitalized patients with dementia spent a longer time in hospital for stroke (64.0 ± 5.3 days) and falls (51.9 ± 2.1 days) than those with infection, epilepsy, syncope, loss of consciousness, other causes (all P 0.01) or dehydration (P ≤ 0.05).Patients with dementia commonly attend our emergency clinic. These patients are older in age, have a higher hospitalization rate and have a longer hospitalization, especially due to stroke and falls, than patients without dementia. Geriatr Gerontol Int 2018; 18: 1383-1387.

Social cognition has recently been recognized as one of the essential cognitive domains. Some reports suggested that patients with Alzheimer's disease dementia (ADD) presented significant theory of mind deficits even in the mild condition. However, most previous studies included only small numbers of patients with ADD. The present study administered the first-order false belief (Sally-Anne) test to 116 consecutive patients with ADD from the outpatient units of the Memory Clinic and compared the characteristics of the two groups with correct and incorrect answers on the test. Then various clinical characteristics were evaluated. Only 37.1% of patients with ADD correctly answered the Sally-Anne test with the right explanation. Comparison between the two groups of correct and incorrect answers revealed a significant association between the frontal assessment battery score and the result of the Sally-Anne test in the multiple logistic regression analyses. Thus, patients with ADD presented a significant deficit in social cognition even in the mild condition. Frontal dysfunction was thought to be related to the deficits in mild ADD.

In addition to cognitive impairment, behavioral and psychological symptoms of dementia (BPSD) are another important aspect of most dementia patients. This study was designed for a new simple assessment of BPSD. We first employed a clinical survey for the local community with sending an inquiry letter to all members (n=129) of dementia caregiver society, and then attempted to create a new BPSD score for dementia with 10 BPSD items. This new simple BPSD score was compared to a standard-detailed BPSD score neuropsychiatric inventory (NPI) for a possible correlation (n=792) and a time to complete (n=136). Inter-rater reliability was examined comparing scores between main and second caregivers (n=70) for AD. Based on the clinical survey for local caregivers, a new BPSD score for dementia (ABS, Abe's BPSD score) was newly created, in which each BPSD item was allotted by an already-weighted score (maximum 1-9) based on the frequency and severity, and was finalized with taking temporal occurrences into account. ABS was filled by the main caregiver with a full score of 44, was well correlated with NPI (r=0.716, **p

Yokukansan (YKS), a traditional herbal medicine, has been used to treat behavioral and psychological symptoms of dementia (BPSD). The present study is the first double-blind, randomized, placebo-controlled trial to determine the efficacy and safety of YKS for the treatment of BPSD in Alzheimer's disease (AD).A total of 22 sites consisting of clinics, hospitals and nursing homes participated. A total of 145 patients with AD were randomized. Active YKS (7.5 g/day) and placebo were supplied to 75 and 70 participants, respectively. The primary outcome measure was the 4-week change in total score of the Neuropsychiatric Inventory Brief Questionnaire Form (NPI-Q), an instrument that evaluates BPSD. Secondary outcome measures included 12-week changes in NPI-Q scores, changes in NPI-Q subcategory scores and total scores of the Mini-Mental-State Examination.Four-week changes in NPI-Q total scores did not differ significantly between the treatment and placebo groups. There were also no significant differences between groups in 12-week changes in total NPI-Q scores, NPI-Q subcategory scores or total Mini-Mental-State Examination scores. However, a subgroup with fewer than 20 points on the Mini-Mental-State Examination at baseline showed a greater decrease in "agitation/aggression" score in the YKS group than in the placebo group (P = 0.007). No serious adverse effects were observed during the study.Our data did not reach statistical significance regarding the efficacy of YKS against BPSD; however, YKS improves some symptoms including "agitation/aggression" and "hallucinations" with low frequencies of adverse events. Geriatr Gerontol Int 2017; 17: 211-218.

Objectives – To investigate a possible implication of inflammatory processes in the development of dementia in cerebrovascular disease. Patients and methods – We examined the levels of interleukin-6 (IL-6) in the cerebrospinal fluid (CSF) of patients with Alzheimer's disease (AD) (n = 26), ischemic cerebrovascular disease without dementia (CVD) (n = 11), vascular dementia (VD) (n = 11), and other neurological disorders (n = 21) using sensitive enzyme-linked immunosorbent assay. Results – The CSF concentrations of IL-6 were significantly elevated in patients with VD compared with those of patients with AD or CVD. Conclusion – The CSF IL-6 levels are increased in patients with VD, suggesting that inflammatory mechanisms may be involved in the development of cognitive decline in some patients with cerebrovascular disease. CSF IL-6 may be a biological marker for dementia in cerebrovascular disease.

Epidemiological studies have shown that elevated plasma homocysteine (Hcy) levels play an important role in the pathogenesis of Alzheimer's disease (AD). In spite of the evidence that a C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene elevates plasma Hcy levels, the impact of the C677T polymorphism on the development of AD is controversial. Here, we performed a genetic case-control study in a Japanese population to investigate whether three polymorphisms of the MTHFR gene, C677T (Ala222Val), A1298C (Glu429Ala), and A1793G (Arg594Gln), are associated with the development of late-onset AD (LOAD). In our study, the MTHFR gene had four major regional haplotypes: Haplotype A (677C-1298A-1793G), Haplotype B (677T-1298A-1793G), Haplotype C (677C-1298C-1793G), and Haplotype D (677C-1298C-1793A). The frequency of Haplotype C in LOAD was significantly lower than that in control group. Furthermore, the benefit conferred by the presence of at least one Haplotype C was stronger in LOAD patients who lacked the ApoE 4 allele (OR=0.293; 95% CI=0.115-0.744; P=0.010). The results indicate that Haplotype C of the MTHFR gene is protective against the development of LOAD.

Recent epidemiological studies have emphasized the impact of elevated blood homocysteine levels on the pathogenesis of Alzheimer’s disease (AD). In spite of a significant impact of a MTHFR C677T polymorphism on the blood homocysteine levels, the association between the C677T polymorphism and AD remains controversial. Therefore, other unidentified genetic factor(s) that regulate blood homocysteine levels may exist. Here, we have analyzed the 5′-upstream region of the MTHFR gene and examined AD patients (n = 223) and nondemented individuals (n = 323) for polymorphisms in the 5′-upstream region of the MTHFR gene. We identified two polymorphisms (–713G/A and –393C/A, upstream of the start codon). We found no significant relationship between AD and the 5′-upstream region polymorphisms of the MTHFR gene. Thus, our study does not reinforce the hypothesis of an independent involvement of the MTHFR gene upstream region polymorphisms in AD risk.

Alzheimer's disease (AD) is one of the most important diseases in aging society, and non-drug therapy might be an alternative therapeutic approach. Thus, we evaluated the add-on effect of cognitive rehabilitation on AD patients under donepezil treatment.We retrospectively analyzed 55 AD patients with a Mini-Mental State Examination score of 15-25, dividing them into two groups depending on whether they were receiving ambulatory cognitive rehabilitation (group D + R, n = 32) or not (group D, n = 23) in Kurashiki Heisei Hospital over 1 year. The present cognitive rehabilitation included physical therapy, occupational therapy and speech therapy for 1-2 h once or twice a week.Between group D and group D + R, there was no significant difference in baseline data, such as age, Mini-Mental State Examination score, periventricular hyperintensity on magnetic resonance imaging, deep white matter hyperintensity on magnetic resonance imaging or donepezil dose (4.1 mg/day). At 1 year later, however, the Mini-Mental State Examination score improved only in group D + R from 21.7 to 24.0 (**P 0.001), whereas that of group D remained at 21.5 with both groups of donepezil 5.0 mg/day.The combination of cognitive rehabilitation plus a choline esterase inhibitor donepezil showed a better effect for the cognitive function of AD patients than drug only therapy at 1 year.

We examined the expression of presenilin 1 (PS-1) mRNA in cultured skin fibroblasts taken from living patients with Alzheimer’s disease (AD) and human brains taken postmortem from AD patients by RT-PCR analysis. The donors of fibroblasts consisted of 28 cases with AD and 19 neurological patient without dementia (CTL). The brains came from 17 cases with AD and 23 cases with CTL. We found that PS-1 mRNA levels in skin fibroblasts of AD patients were significantly higher than those of CTL patients (p < 0.0001). Moreover, we found that PS-1 mRNA levels in human brains with AD were significantly higher than in those with CTL (p < 0.0001). These findings suggest that high levels of PS-1 mRNA in AD may play an important role in developing AD and that the examination of PS-1 mRNA in skin fibroblasts may be helpful for the diagnosis of AD.

We carried out two separate epidemiological studies on long-term changes, 10 years apart, on the prevalence rate of dementia in the elderly by the same method for the same area in Japan. We also performed a genetic study of patients with dementia of the Alzheimer type (DAT) based on the epidemiological studies. The number of patients with dementia was much larger in 1990 than in 1980. Especially, the number of mildly demented patients was significantly larger in 1990 than in 1980. The 35 patients with DAT did not show any mutations of amyloid-β protein precursor, presenilin 1 and presenilin 2 genes. The frequency of apolipoprotein E (apo E) σ4 allele in DAT was significantly higher than that in control subjects (p < 0.005). This study suggests that the frequency of DAT may increase by aging of the population in the future and we confirm the close association between apoE σ4 allele and DAT in a community-based study in Japan.

Background: About 20% of familial amyotrophic lateral sclerosis (ALS) is caused by mutations in SOD1 and is typically transmitted as an autosomal dominant trait. However, due to reduced mutation penetrance, the disease may present in a recessive or sporadic manner. Objective: To determine the factors responsible for the low penetrance of the SOD1 mutation. Methods: Twelve members of a Canadian ALS family of Filipino origin were recruited for the study. SOD1 was sequenced in the proband. SOD1 expression was assessed by real-time-PCR and immunoblotting. Results: The proband was a homozygous carrier of a novel 6 bp deletion in exon 2 (ΔG27/P28), the pathologic significance of which was confirmed by immunohistochemistry. Eight living family members are heterozygotes and remain unaffected at ages ranging between 48 and 85 years. Haplotype analysis showed that the deletion is a single founder mutation likely common in the Cagayan province (Philippines). The low penetrance of the mutation is explained by the fact that it enhances the naturally occurring alternative splicing of exon 2 of the SOD1 mRNA, leading to reduced transcription of the mutant allele. Indeed, Western blot analysis demonstrated the low level of SOD1 protein in carriers of the ΔG27/P28 compared to wild-type individuals or a carrier of the A4V SOD1 mutation. Conclusion: The enhanced splicing of exon 2 acts as a natural knock-down of the mutant SOD1 allele in the Filipino amyotrophic lateral sclerosis (ALS) family. There is a need for careful investigation of splicing isoforms of SOD1 and other ALS genes as factors influencing the severity of disease.

Background/Aims: Alzheimer’s disease (AD) is a well-known type of dementia. However, it remains difficult to identify AD in the early stage and to distinguish it from other dementing disorders. We examined glycoproteins in cerebrospinal fluid (CSF) as potential biological markers of AD. Methods: CSF samples were collected from AD, other dementia and nondemented patients. Glycoproteins in CSF were detected by lectin blotting using wheat germ agglutinin (WGA), and sugar chain analysis was performed by isoelectric focusing. Results: In Alzheimer’s CSF, several glycoproteins had lower WGA-binding activities, one of which was sufficiently sensitive and specific to distinguish AD from nondemented controls and other dementias. Further analysis identified this glycosylated protein as transferrin, and altered sugar chain composition of transferrin isoforms was observed despite normal protein levels in CSF. Conclusion: The decreased WGA-binding activity of transferrin in AD is probably due to altered glycosylation of transferrin molecules. Transferrin glycosylation is thus a potential biological marker for AD diagnosis, and changes in this glycosylation may play an important role in the pathophysiology of AD.

Here we report the relationship between age at onset, clinical course and genotype in a family with combined LRRK2 G2019S and Parkin exon 2 deletions. In the combined mutation carriers the age at onset and clinical course was highly variable and not always younger than in the carriers of LRRK2 G2019S mutations alone.

The aim of the study was to identify chromosomal regions that may harbor putative genetic variants influencing age at onset in familial late-onset Alzheimer's disease (LOAD). Data from a genome-wide scan that included genotyping of APOE were analyzed in 1,161 individuals from 209 families of Caribbean Hispanic ancestry with a mean age at onset of 73.3 years multiply affected by LOAD. Two-point and multipoint analyses were conducted using variance component methods using 376 microsatellite markers with an average intermarker distance of 9.3 cM. Family-based test of association was also conducted for the same set of markers. Age at onset of symptoms among affected individuals was used as the quantitative trait. Our results showed that the presence of APOE-epsilon4 lowered the age at onset by 3 years. Several candidate loci were identified. Using linkage analysis strategy, the highest logarithm of odds (LOD) scores were obtained using a conservative definition of LOAD at 5q15 (LOD = 3.1), 17q25.1 (LOD = 2.94), 14q32.12 (LOD = 2.36), and 7q36.3 (LOD = 2.29) in a model that adjusted for APOE-epsilon4 and other covariates. Both linkage and family-based association identified 17p13 as a candidate region. Family-based association analysis showed markers at 12q13 (p = 0.00002), 13q33 (p = 0.00043), and 14q23 (p = 0.00046) to be significantly associated with age at onset. The current study supports the hypothesis that there are additional genetic loci that could influence age at onset of late onset Alzheimer's disease. The novel loci at 5q15, 17q25.1, 13q33, and 17p13 and the previously reported loci at 7q36.3, 12q13, 14q23, and 14q32 need further investigation.

Background: Frontotemporal dementia (FTD) in several 17q21-linked families was recently explained by truncating mutations in the progranulin gene ( GRN ). Objective: To determine the frequency of GRN mutations in a cohort of Caucasian patients with FTD without mutations in known FTD genes. Methods: GRN was sequenced in a series of 78 independent FTD patients including 23 familial subjects. A different Calabrian dataset (109 normal control subjects and 96 FTD patients) was used to establish the frequency of the GRN mutation. Results: A novel truncating GRN mutation (c.1145insA) was detected in a proband of an extended consanguineous Calabrian kindred. Segregation analysis of 70 family members revealed 19 heterozygous mutation carriers including 9 patients affected by FTD. The absence of homozygous carriers in a highly consanguineous kindred may indicate that the loss of both GRN alleles might lead to embryonic lethality. An extremely variable age at onset in the mutation carriers (more than five decades apart) is not explained by APOE genotypes or the H1/H2 MAPT haplotypes. Intriguingly, the mutation was excluded in four FTD patients belonging to branches with an autosomal dominant mode of inheritance of FTD, suggesting that another novel FTD gene accounts for the disease in the phenocopies. It is difficult to clinically distinguish phenocopies from GRN mutation carriers, except that language in mutation carriers was more severely compromised. Conclusion: The current results imply further genetic heterogeneity of frontotemporal dementia, as we detected only one GRN -linked family (about 1%). The value of discovering large kindred includes the possibility of a longitudinal study of GRN mutation carriers.

Objectives To identify novel candidate regions for late-onset Alzheimer disease (LOAD) and to confirm linkage in previously identified chromosomal regions. Design Family-based linkage analysis. Setting Probands with familial LOAD identified in clinics in the Dominican Republic, Puerto Rico, and the United States. Patients We conducted a genome scan in 1161 members primarily clinically diagnosed as having LOAD; these members were from 209 families of Caribbean Hispanic ancestry. Main Outcome Measures We analyzed 376 microsatellite markers with an average intermarker distance of 9.3 centimorgan. We conducted linkage analysis using possible and probable LOAD, and we performed affecteds-only 2-point linkage analyses assuming either an autosomal dominant or a recessive model. Subsequently, we conducted a multipoint affected sibling pair linkage analysis. Results Two-point parametric linkage analysis identified a locus at 3q28 with a genomewide empirical P value of .03 (logarithm of odds [LOD], 3.09) in a dominant model for probable and possible LOAD. Other regions suggestive of linkage included 2p25.3 (LOD, 1.77), 7p21.1 (LOD, 1.82), and 9q32 (LOD, 1.94). Under a recessive model, we also identified loci at 5p15.33 (LOD, 1.86), 12q24.21 (LOD, 2.43), 14q22.3 (LOD, 2.53), and 14q23.1 (LOD, 2.16) as suggestive for linkage. Restricted to probable LOAD, many of these loci continued to meet criteria suggestive for linkage, as did loci at 2p25.3 (LOD, 2.72), 3q28 (LOD, 2.28), 6p21.31 (LOD, 2.19), and 7p21.1 (LOD, 2.05). APOE conditional analysis indicated that the observed linkage at 3q28 was independent of the APOE e4 allele. Multipoint nonparametric affected sibling pair linkage analysis provided confirmation of suggestive linkage for most, but not all, loci. Conclusions Seven loci with LOD scores greater than 2.0 were identified among multiple affected Caribbean Hispanic families with LOAD. The highest LOD score was found at chromosome 3q28. At least 2 other independent studies have observed support for significant linkage at chromosome 3q28, highlighting this region as a locus for further genetic exploration.

The plasmin system is involved in the degradation of Abeta peptides, the accumulation of which in brain is a hallmark of Alzheimer's disease (AD). In a North European case-control AD dataset we studied 14 common variations in the PLG, PAI-1, PLAT and PLI genes encoding components of the plasmin system. Among the four polymorphisms in the PLAT, PAI-1 and PLI genes showing nominally significant evidence for an association with AD (allele p-value=0.01-0.00003) the strongest association was detected for the deletion allele in the Alu-repeat region of the PLAT gene. However, none of these positive results were confirmed in follow-up studies using an independent Canadian case-control cohort and two familial AD datasets of North European and Caribbean Hispanic origin. Thus, the current survey does not support the notion that common polymorphisms in the plasmin genes influence the development of AD.

We tried to examine if there is a particular distribution pattern of lipoprotein(a) [Lp(a)] phenotypes specific for patients with vascular dementia (VD). Fourteen cases of VD (9 males and 5 females), 18 cases of dementia of the Alzheimer type (DAT)(7 males and 11 females), 29 cases of cerebrovascular disease (CVD) in the chronic phase (18 males and 11 females) and 47 healthy individuals as controls (25 males and 22 females) were examined for serum Lp(a). Serum concentrations and phenotypes of Lp(a) were assessed by ELISA and a test kit for the Lp(a) phenotype, respectively. Serum concentrations of Lp(a) were significantly higher in patients with VD (p < 0.05) as well as patients with CVD (p < 0.01) compared with those in healthy individuals. Serum concentrations of Lp(a) did not significantly differ between patients with DAT and healthy individuals. The incidences of Lp(a) phenotypes containing relatively low-molecular-weight apolipoprotein(a) isoforms were significantly higher in patients with CVD in the chronic phase (p < 0.05) or those with VD (p < 0.01) compared with those in healthy individuals. Distribution patterns of Lp(a) phenotypes did not differ between patients with DAT and healthy individuals. Thus, high serum levels of Lp(a) could be considered a clinical hallmark to distinguish VD from DAT. Abnormally high serum levels of Lp(a) in patients with CVD and VD seemed to be due to specific increases in low-molecular-weight apolipoprotein(a) isoforms in Lp(a).

Expression of presenilin-1 (PS-1) mRNA in an alternative splicing at the 3' end of exon 3 was examined in brain tissue, lymphocytes and cultured skin fibroblasts using the RT- polymerase chain reaction (RT-PCR) method. We quantified the relative ratios of the densities of the long form of PS-1 mRNA, which contains a sequence encoding four amino acids (VRSQ, denoted as VRSQ+) to the short form, which lacks the VRSQ sequence (VRSQ-). The brain tissue of subjects with sporadic Alzheimer's disease (AD) had reduced levels of the VRSQ+ form of the PS-1 mRNA compared to a control group. No significant differences appeared in peripheral tissues, such as lymphocytes or cultured skin fibroblasts in AD with control subjects. Changes in the alternative splicing of exon 3 may be specific to the brain and may play an important role in the pathogenesis of sporadic AD.

The heat shock protein 70 (HSP70) gene is located in chromosome 14, it is now considered as a molecular ''chaperone'' and a cell-protective agent. It may be closely related to the pathogenesis of dementia of the Alzheimer type (DAT). To examine the relationship between HSP70 and DAT, HSP70 mRNA expression levels in mononuclear blood cells (MBCs) from patients with DAT were measured by Northern blotting. We found no significant correlation between HSP70 mRNA levels and aging. We found that HSP70 mRNA levels in MBCs from patients with DAT were significantly lower than those from patients with vascular dementia and nondemented controls. These findings suggest that the lower levels of constitutive HSP70 mRNA in DAT play an important role in developing DAT and that the measurement of HSP70 mRNA may be useful for the diagnosis of DAT.