Clinical compliance of donepezil in treating Alzheimer's disease in taiwan

BACKGROUND/RATIONALE

Adherence to cholinesterase inhibitor (ChEI) is associated with treatment effectiveness in the treatment of Alzheimer's disease (AD). We investigated the clinical adherence to donepezil in Taiwan.

METHODS

This was a retrospective study. Patients treated with donepezil were recruited from Kaohsiung Medical University Hospital and Kaohsiung Municipal Ta-Tung Hospital from February 2004 to April 2013. We analyzed their treatment duration in months.

RESULTS

A total of 273 patients were included in our analysis. Sixty-seven patients withdrew from donepezil treatment with mean treatment duration of 28.0 ± 25.9 months. Better initial scores on the Mini-Mental Status Examination (P = .007), Cognitive Abilities Screening Instrument (P = .003), and the Clinical Dementia Rating Scale (CDR) Sum of Boxes (P = .011) were positively associated with clinical adherence. The clinical adherent rate was higher in the CDR-0.5 group than in the CDR-2.0 group with significant difference.

CONCLUSION

Although there are some limitations in our study, these findings indicate that early intervention with ChEI in patients with AD should be emphasized and may lead to a better clinical adherence.

Characteristics of Alzheimer's disease among patients in Taiwan, Hong Kong, and Beijing

In order to obtain data from patients with Alzheimer's disease dementia and their informants in a uniform manner and to foster further research among the Chinese and other races, we have conducted an international study to recruit patients diagnosed with Alzheimer's disease (AD) from Taiwan, Hong Kong, and Beijing. The Uniform Data Set was translated into Chinese and administrated to AD patients and their informants. A total of 1,107 AD dementia patients were recruited, including 691 from Taiwan, 244 from Beijing, and 172 from Hong Kong. There were differences in the AD patients: gender (p = 0.099), education (p < 0.001), age (p < 0.001), and handedness (p = 0.007). For informants, age (p = 0.679), gender (p = 0.117), education (p < 0.001), and living together or not (p < 0.001) differed in the three samples. Although three areas across the Taiwan Strait are ethnic Chinese, the clinical picture for patients and informants are very different. Further study is needed to clarify the significance of clinical characteristics in Chinese societies.

Potential cognitive decline linked to angiotensin-converting enzyme gene but not hypertension: Evidence from cognitive event-related potentials

OBJECTIVES

The aims of the present study were to investigate the effect of hypertension and angiotensin-converting enzyme (ACE) genotypes on cognitive event-related potentials (ERPs), and whether the impact of ACE genotypes on P300 is related to the influence of hypertension.

METHODS

Using the Cognitive Abilities Screening Instrument (CASI), we recruited 97 mentally healthy middle-aged and older adults. Medical histories were collected, and blood pressure, ACE insertion/deletion polymorphisms and ERPs in an auditory oddball task were measured for all participants.

RESULTS

When the participants were stratified according to the presence or absence of hypertension, there were no differences in CASI score, percentage of ACE genotypes and ERPs. The subjects with the D/D homozygote displayed lower amplitude and longer latency of P300, although there were no differences in CASI score and the percentage of hypertension.

CONCLUSIONS

The subjects with the D/D genotype tended to have decreased amplitude and prolonged latency of P300 ERPs which reflected subtle cognitive impairment. There were no associations between hypertension, CASI score and P300 measurements.

SIGNIFICANCE

Using ERPs, potential cognitive decline was linked to ACE genotypes, independently of the effect of hypertension.

Utilization of magnetic nanobeads for analyzing haptoglobin in human plasma as a marker of Alzheimer's disease by capillary electrophoretic immunoassay with laser-induced fluorescence detection

Alzheimer's disease (AD) is a neurodegenerative disorder resulting from an impaired cholinergic function with loss of cognitive activity in the brain. Haptoglobin is a useful biomarker for AD analysis. Compared to the conventional enzyme-linked immunosorbent assay for haptoglobin analysis, the proposed immunoassay procedure reduces sample analysis time by approximately 55 min. Therefore, immunoassay was coupled with capillary electrophoresis (CE) to determine haptoglobin concentrations indirectly by using magnetic nanobeads (MBs) as a support and laser-induced fluorescence detection. In human plasma sample, the haptoglobin was immobilized on the MBs and reacted with the purified anti-haptoglobin antibody. The optimum separation time for the analyte was shorter than 6 min at 25 °C with a fused-silica capillary column of 40.2 cm × 50 μm ID (effective length 30 cm) and a run buffer containing 25 mM phosphate (pH 8.0) with 0.01% poly(ethylene oxide) (PEO). When using Atto 495 NHS ester as an internal standard (IS) (250.0 ng mL(-1)), the linear range of the proposed method for indirect determination of haptoglobin was 0.2-3.0 mg mL(-1). The method was further used to monitor the course of AD in patients with behavioral and psychological symptoms of dementia (BPSD).

Effect of music intervention on the cognitive and depression status of senior apartment residents in Taiwan

OBJECTIVE

To identify the effect of music intervention on cognitive function and depression status of residents in senior citizen apartments based on the existing evidence regarding music therapy.

METHODS

An experimental study was conducted from November 2008 to December 2009. Sixty healthy senior apartment residents over 65 years of age were recruited and separated into two groups. According to their opinion, 41 took part in the music intervention group and 19 in the comparison group. The music intervention involved Buddhist hymns. The short-term effects were evaluated based on the measurement of cognitive function and depression level using the Mini-Mental State Examination (MMSE) and the Geriatric Depression Scale-short form (GDS-SF) at the baseline, 1 month, and 4 months.

RESULTS

The means of the initial and the 1-month MMSE and GDS-SF scores did not differ between the two groups. The 4-month MMSE score significantly declined compared with the initial level in the comparison group, whereas no significant change was observed in the experimental group. Moreover, the 4-month GDS-SF score significantly improved in both groups compared with the initial level.

CONCLUSION

Music intervention may postpone cognitive decline in healthy residents preferring Buddhist hymns in the senior citizen apartments in 4 months follow-up, and intense contact with participants may improve their mood status.

Adjunct effect of music therapy on cognition in Alzheimer's disease in Taiwan: a pilot study

PURPOSE

Music therapy (MT) reviews have found beneficial effects on behaviors and social interaction in Alzheimer's disease (AD) but inconsistent effects on cognition. The purpose of the study was to evaluate the adjunct effect of long-term and home-based MT in AD patients under pharmacological treatment.

PATIENTS AND METHODS

Mild AD cases (clinical dementia rating =0.5~1) were consecutively recruited and voluntarily separated into an MT group or control group (CG) for 6 months. Outcome assessments included Cognitive Abilities Screening Instrument (CASI), CASI-estimated mini-mental state examination, clinical dementia rating with sum of box scores, and neuropsychiatric inventory. The MT interventions were Mozart's Sonata (KV 448) and Pachelbel's Canon, listening with headphones for 30 minutes daily in the morning and before sleep, respectively.

RESULTS

Forty-one cases (MT versus CG number =20 versus 21) were analyzed. Adjusted differences of CASI-estimated mini-mental state examination and CASI after 6 months in the MT group were slightly less decreased than the CG without statistical significance. In further analysis of cognitive domains of CASI, the adjusted difference of abstraction domain in the MT group was significantly better than the CG.

CONCLUSION

Although there were no apparent additional benefits of this MT on the global cognition and daily functioning in mild AD patients, it confirms the adjunct cognition effect on the abstraction. This MT contributes to the supplementary treatment of AD.

Mutational analysis of podocyte genes in children with sporadic steroid-resistant nephrotic syndrome

Recent studies have demonstrated that mutations in 4 podocyte genes, NPHS1, NPHS2, CD2AP, and WT1, are associated with the pathogenesis of steroid-resistant nephrotic syndrome (SRNS). Systematic investigation of all 4 genes for sporadic SRNS in China has not been performed. We examined 10 Chinese children with sporadic SRNS who showed no response to immunosuppressive agents and 20 SRNS controls who exhibited a response to prolonged steroid or immunosuppressive treatment and achieved complete remission. We analyzed mutations in the 4 podocyte genes, NPHS1, NPHS2, CD2AP, and WT1. Mutational analysis was performed using polymerase chain reaction and direct sequencing. Of the 10 SRNS children who showed no response to immunosuppressive agents, the compound heterozygous NPHS1 mutations 2677A>G (T893A) and *142T>C were identified in 1 patient, while a heterozygous mutation in WT1, 1180C>T (R394W), was found in another patient. Of the 20 SRNS children showing complete remission who responded to prolonged steroid therapy or immunosuppressive agents, 4 heterozygous NPHS1 mutations, 928G>A, IVS8+30C>T, IVS21+14G>A, and IVS25-23C>T, were identified in 4 patients and a heterozygous CD2AP mutation, IVS7-135G>A, was identified in 1 patient. Our results indicate the necessity of genetic examination for mutations in podocyte genes in Chinese SRNS children who show no response to immunosuppressive agents.

Comparison of activities of daily living impairments in Parkinson's disease patients as defined by the Pill Questionnaire and assessments by neurologists

OBJECTIVES

To compare the clinical judgment of experienced neurologists after interviewing Parkinson's disease (PD) patients and their caregivers with the use of the Pill Questionnaire to determine the presence of impairments on activities of daily living (ADL).

BACKGROUND

ADL impairment is a criterion for the diagnosis of dementia associated with PD. The Pill Questionnaire has been recommended as a screening tool to assess ADL impairment in PD patients, but its usefulness and validity have not been fully investigated.

METHODS

We recruited idiopathic PD patients from 12 hospitals in Taiwan, and the patients underwent clinical assessments, a neuropsychological test battery and the Unified Parkinson Disease Rating Scale evaluation. The Pill Questionnaire was administered by study assistants. Patient and caregiver interviews were performed by experienced neurologists who were blinded to the Pill Questionnaire results.

RESULTS

In total, 284 PD patients (mean age 71.8±9 years, mean education 8.7±5.3 years, mean disease duration 5.4±5.3 years) were recruited. 63 patients showed ADL impairment by the Pill Questionnaire, and 108 patients showed ADL impairment by neurologists' clinical interviews. κ Statistics showed moderate agreement between the two methods (κ=0.521, p<0.001). Of the 108 patients who were diagnosed with ADL impairment by neurologists, only 56 patients (51.9%) showed impairment according to the Pill Questionnaire. Most of the missed patients had milder cognitive impairment and lower motor disability.

CONCLUSIONS

A comprehensive interview is essential to determine the presence of ADL impairment in PD patients, especially in patients with early PD.

A formyl peptide receptor agonist suppresses inflammation and bone damage in arthritis

BACKGROUND AND PURPOSE

Annexin A1 (AnxA1) is an endogenous anti-inflammatory protein and agonist of the formyl peptide receptor 2 (FPR2). However, the potential for therapeutic FPR ligands to modify immune-mediated disease has been little explored. We investigated the effects of a synthetic FPR agonist on joint disease in the K/BxN model of rheumatoid arthritis (RA) and RA fibroblast-like synoviocytes (FLS).

EXPERIMENTAL APPROACH

Arthritis was induced by injection of K/BxN serum at day 0 and 2 in wild-type (WT) or AnxA1(-/-) mice and clinical and histopathological manifestations measured 8-11 days later. WT mice were given the FPR agonist compound 43 (Cpd43) (6 or 30 mg·kg(-1) i.p.) for 4 days. Effects of AnxA1 and Cpd43 on RANKL-induced osteoclastogenesis were assessed in RAW 264.7 cells and human RA FLS and macrophages.

KEY RESULTS

Treatment with Cpd43 before or after the onset of arthritis reduced clinical disease severity and attenuated synovial TNF-α and osteoclast-associated gene expression. Deletion of AnxA1 in mice exacerbated arthritis severity in the K/BxN model. In vitro, Cpd43 suppressed osteoclastogenesis and NFAT activity elicited by RANKL, and inhibited IL-6 secretion by mouse macrophages. In human RA joint-derived FLS and monocyte-derived macrophages, Cpd43 treatment inhibited IL-6 release, while blocking FPR2 or silencing AnxA1 increased this release.

CONCLUSIONS AND IMPLICATIONS

The FPR agonist Cpd43 reduced osteoclastogenesis and inflammation in a mouse model of RA and exhibited anti-inflammatory effects in relevant human cells. These data suggest that FPR ligands may represent novel therapeutic agents capable of ameliorating inflammation and bone damage in RA.

Effects of metabolic syndrome, apolipoprotein E, and CYP46 on cognition among Taiwanese Chinese

The combined effects of metabolic syndrome and the apolipoprotein E and CYP46 genotypes on the risk of cognitive decline has yet to be determined among Taiwanese Chinese. Two hundred and nine mentally healthy middle-aged and older adults were assessed for metabolic syndrome, cognitive function using the Cognitive Abilities Screening Instrument, Mini-Mental State Examination, ApoE, and CYP46 polymorphisms. There were no differences in cognitive performance, ApoE epsilon4 (ε4) carrier status, or CYP46 genotypes between participants with and those without metabolic syndrome. The ε4 carriers and participants with the AA allele of CYP46 had significantly lower mental manipulation score. Metabolic syndrome and ε4 had synergistic effects on cognitive decline. Therefore, the ε4 carriers and participants with the AA allele of CYP46 have decreased mental manipulation ability. The metabolic syndrome may play a role in subtle cognitive dysfunction in ε4 carriers among Taiwanese Chinese.

SHH-dependent knockout of HIF-1 alpha accelerates the degenerative process in mouse intervertebral disc

Hypoxia-inducible factor-1alpha (HIF-1 alpha) has been reported to have an important role in the metabolism and synthesis of extracellular matrix of the nucleus pulposus cells (NPCs) and was assumed to be involved in the process of intervertebral disc degeneration. The objective of this study was to investigate the role of HIF-1alpha in disc degeneration in vivo using a conditional HIF-1alpha knockout (KO) mouse model. ShhCre transgenic mice were mated with HIF-1 alpha fl/fl mice to generate conditional HIF-1alpha KO mice (HIF-1alpha fl/fl-ShhCre+). Three mice of each genotype (Wide-type and HIF-1alpha KO) at the age of 3 days, 6, and 12 weeks were sacrificed after genotyping. Five lumbar disc samples were harvested from each mouse, with a total of 45 disc samples for each genotype. In situ hybridization and immunohistochemical analysis were used to check the efficacy of HIF-1alpha knockout. Histological grading of the disc degeneration was performed according to the classification system proposed by Boos et al. Picro-sirius red staining, Safranine O/fast green staining and immunohistochemical study were used to evaluate the expression of aggrecan, type-II collagen and vascular endothelial growth factor (VEGF). Histologic analysis revealed more NPC deaths and signs of degeneration in HIF-1alpha KO mice and the degeneration scores of HIF-1alpha KO mice were significantly higher than those of the Wide-type mice at the age of 6 weeks and 12 weeks. There were less expressions of aggrecan, type-II collagen and VEGF in the intervertebral discs of HIF1-alpha KO mice than in those of wild-type mice. Taken together, the results of our study indicated that HIF-1alpha is a pivotal contributor to NPC survival and the homeotasis of extracellular matrix through the HIF-1alpha/VEGF signaling pathway, and plays an important role in the development of disc degeneration.

Fast quantification of S-adenosyl-L-methionine in dietary health products utilizing reversed-phase high-performance liquid chromatography: teaching an old method new tricks

S-adenosyl-L-methionine is a ubiquitous methyl donor in living bodies. It is known to participate in several physiological processes including homocysteine metabolism and glutathione synthesis regulation, and cellular antioxidant mechanism. S-adenosyl-L-methionine containing dietary supplements has been prescribed recently for the treatment of depression, arthritis, and liver diseases with encouraging results. The development of an efficient analytical protocol for S-adenosyl-L-methionine containing dietary supplements is crucial for maintaining product quality and consumer health. In this study, the S-adenosyl-L-methionine content of several yeast products and commercial healthy food product samples was quantitatively analyzed utilizing HPLC. The chromatographic separation was achieved on a reversed-phase column and 2 % acetonitrile with a 98 % ammonium-acetate mobile phase under pH 4.5, with a flow rate of 1.0 mL/min. The wavelength used for detection with the UV detector was 254 nm. The total analysis time was short and the target compound showed a well-defined peak. The correlation coefficient of the regression curve showed good linearity and sensitivity with r = 0.999. All experiments were replicated five times and the relative standard deviations as well as the relative error values were all less than 3 %. Moreover, the achieved precision and accuracy values were high with 97.4-100.9 % recovery. Qualitative determination of S-adenosyl-L-methionine in the tested products was achieved using NMR and LC-MS techniques. The developed protocol is robust, fast, and suitable for the quality control analysis of yeast and commercial S-adenosyl-L-methionine products.

Registration of Alzheimer's disease in Taiwan: patient and informant

BACKGROUND

To obtain updated data of patients with Alzheimer's disease (AD) and their informants in Taiwan with the aim of fostering and supporting collaborative research.

METHODS

In total, 691 patients with the diagnosis of AD were recruited at 6 sites in Taiwan. The Uniform Data Set (UDS; form A) was administrated.

RESULTS

The mean age of the patients with AD was 79.3 ± 7.7 years and the mean age of informants was 57.5 ± 13.7 years. In all, 69% of the informants lived with patients and 77% of patients lived with spouse, partner, or children; 11% had 1 sibling with dementia, 1.8% had 2 siblings with dementia, and 0.5% had 3 or more siblings with dementia.

CONCLUSION

We have reported the updated status of AD in Taiwan through a UDS that will foster future collaboration among countries using UDS. The updated information of patients with AD and their informants will direct the future care of AD in Taiwan.

Seropositivity of HPV 16 E6 and E7 and the risk of oral cancer

OBJECTIVES

The objective of the study was to determine the prevalence of HPV seropositivity among patients with oral squamous cell carcinoma (OSCC) and healthy individuals and to correlate the association between HPV 16 seropositivity and risk of OSCC.

MATERIALS AND METHODS

HPV 16 E6 and E7 plasmids were constructed for the production of recombinant protein, which was used as the antigen in ELISA. HPV ELISA was performed on serum samples from 50 healthy individuals and 50 patients with OSCC.

RESULTS

Using the HPV ELISA, 30% (OR = 2.25, 95% CI = 0.85-5.93) and 18% (OR = 1.61, 95% CI = 0.53-4.92) of patients with oral cancer were found to be HPV 16 E6 and E7 seropositive, respectively. Significant association was found between HPV 16 seropositivity and increased risk of OSCC in men, but not in male subjects. A similar trend was observed in non-betel quid chewers.

CONCLUSIONS

Potential associations between HPV 16 E6/E7 seropositivity and oral cancer were revealed in men and non-betel quid chewer subjects, suggesting a possible etiological role of HPV 16 in subgroup of patients with OSCC in Malaysia.

The informant AD8 is superior to participant AD8 in detecting cognitive impairment in a memory clinic setting

The informant AD8 has good discriminatory indices in detecting questionable dementia. However, studies on participant AD8 yielded inconsistent results. This study aims to investigate the discriminatory ability of the AD8 in detecting cognitive impairment at a memory clinic by comparing the informant AD8, participant AD8, Montreal Cognitive Assessment (MoCA), and Mini-Mental State Examination (MMSE). The AD8 was administered to 280 participant-informant dyads. The MoCA and MMSE were administered to all participants, who subsequently received a comprehensive clinical and neuropsychological assessment leading to a consensus diagnosis and a Clinical Dementia Rating (CDR). Area under the receiver operating characteristic curve (ROC) analysis was used to compare the discriminatory ability of AD8, MoCA, and MMSE. Participants were Chinese (83.6%) females (54.3%) with a mean age and education of 73.4 ± 8.6 years and 6.2 ± 5.6 years, respectively. The discriminant validity of the informant AD8 was significantly superior to the participant AD8 in detecting cognitive impairment (CDR ≥ 0.5) {Area Under Curve (AUC) [95% confidence interval (CI)]: 0.96 (0.93-0.98) versus 0.66 (0.58-0.74), p < 0.01}. Furthermore, the informant AD8 was equivalent to MoCA and MMSE in detecting cognitive impairment {AUC [95% CI]: MoCA [0.98 (0.96-0.99)]; MMSE [0.95 (0.93-0.98)]}. The informant AD8 (≥2) had very good sensitivity and specificity, while the participant AD8 (≥2) had suboptimal sensitivity and specificity in detecting cognitive impairment (sensitivity 0.93 versus 0.59; specificity 0.87 versus 0.65; 91.8% versus 60% correctly classified). The informant AD8 is superior to the participant AD8, and equivalent to the MMSE and MoCA in screening for cognitive impairment in memory clinic patients.

Wilms' tumor suppressor gene mutations in girls with sporadic isolated steroid-resistant nephrotic syndrome

Mutations in the Wilms' tumor suppressor gene (WT1) can lead to syndromic forms of steroid-resistant nephrotic syndrome (SRNS) such as Denys-Drash or Frasier syndrome and can cause isolated SRNS. A mutation within WT1 is a frequent cause of sporadic isolated SRNS in girls. In a worldwide cohort of girls, the rate of occurrence was 10.8%. Previous reports have indicated that in Chinese girls, the detection rate of WT1 mutations is 16.7% for early onset isolated nephrotic syndrome. The detection rate of WT1 mutations in Chinese girls with sporadic isolated SRNS is unknown. We examined WT1 mutations in 14 Chinese girls with sporadic isolated SRNS using polymerase chain reaction and direct sequencing and studied a control group of 38 boys with sporadic isolated SRNS. We identified a WT1 mutation in 1 of 14 (7.1% detection rate) Chinese girls with sporadic isolated SRNS. No mutations occurred in WT1 in the remaining 13 girls or the control group. Our investigation supports the necessity of genetic examination for mutations in WT1 in girls with sporadic isolated SRNS.

Serum high-density lipoprotein cholesterol and progression to arterial stiffness in middle-aged and elderly Chinese

BACKGROUND AND AIMS

Low high-density lipoprotein cholesterol (HDL-c) is a risk factor for cardiovascular disease. Brachial-ankle pulse wave velocity (baPWV) is an indicator of arterial stiffness, which is recognized as a predictor of cardiovascular disease. The aim of this study was to investigate the association between HDL-c and baPWV among middle-aged and elderly Chinese.

METHODS

A total number of 1133 Chinese (430 men, 703 women) aged from 50 to 90 years old were recruited from Shanghai downtown district. The baPWV and major cardiovascular risk factors of the participants were measured.

RESULTS

Serum HDL-c was negatively correlated with baPWV (r = -0.143, P < 0.001) after adjustment for age and gender. Multivariate linear regression analysis demonstrated that age (P < 0.001), systolic blood pressure (P < 0.001), HDL-c (P < 0.001), smoking (P = 0.001), BMI (P = 0.002), fasting plasma glucose (P = 0.004), and white blood cell (P = 0.005) were independently associated with baPWV. After multiple adjustments, participants in the highest quartile of HDL-c had an odds ratio of 0.442 (95% CI 0.268-0.729) for developing high arterial stiffness compared with participants in the lowest quartile. The association remained significant after further adjustment for major cardiovascular risk factors.

CONCLUSION

HDL-c has an independent protective effect on arterial stiffness in middle-aged and elderly Chinese. Early detection of HDL-c level is important in high risk populations with arterial stiffness. Increasing HDL-c level may be an attractive therapeutic target for the prevention of arterial function and subsequent disease.

Supercurrent modulated by magnetization in a composite topological superconductor junction

We report a theoretical study of the supercurrent flowing in a composite topological superconductor (TS) junction, where a magnetized quantum dot is considered in between the two TS leads. Based on the tight-binding model and the Keldysh Green's function method, we found that the magnetization (m) in the dot can significantly modify the current-phase relationship, and a nonzero supercurrent flows at zero superconducting phase gradient when m has a component perpendicular to both the external magnetic field h and the pseudomagnetic field Bsoc from the spin-orbit coupling. The induced zero-phase supercurrent can be modulated substantially by both the magnitude and the direction of m, and takes its maximum value at the critical magnetic field of the topological phase transition. Our findings might provide an experimentally simple and accessible scheme for the detection of Majorana fermions.

Functional regulation of Alu element of human angiotensin-converting enzyme gene in neuron cells

The angiotensin-converting enzyme (ACE) insertion/deletion (I/D) genotype and its protein activity have been widely implicated to be associated with Alzheimer's disease (AD). However, whether the insertion sequence, Alu element, in intron 16 of the human ACE gene plays a functional role remains uncertain. To investigate the influence of the I/D polymorphism on ACE promoter, we recombined the I and D form fragments with the human ACE promoter sequence before the reporter gene in pSEAP-Basic2 vector. The effect of the Alu element on regulating the transcriptional activity of ACE promoter was examined using transient transfection in SH-SY5Y cells. We found that the I form fragment upregulated the transcriptional activity of ACE promoter by approximately 70% but that the D form fragment did not. Our study first reveals that Alu sequence in human ACE gene possesses a regulatory function on the ACE promoter activity in neuron. This novel finding bridges the gap between the association of ACE I/D genotype with AD, and suggests that Alu sequence is not merely a "junk" DNA in human ACE gene.

Chromosomal Mapping and QTL Analysis of Resistance to Downy Mildew in Cucumis sativus

Downy mildew of cucumber (Cucumis sativus), caused by Pseudoperonospora cubensis, is a major foliar disease worldwide. The cucumber inbred lines K8 (resistant to downy mildew) and K18 (susceptible) were used to study the inheritance of resistance to downy mildew. Chromosomal mapping of the resistance genes was completed to provide a theoretical basis for the resistance mechanisms and for marker assisted selection (MAS). Inoculation was used to test the level of resistance to P. cubensis in the F₂ and F_2:3 families derived from the cross K8 × K18. Simple sequence repeat (SSR) analysis, combined with bulked segregation analysis (BSA), was done with the DNA of F₂ plants using 2,360 pairs of SSR primers. JoinMap Version 3.0 and MapInspect were used to construct SSR linkages and to verify the relationships between these SSR linkages and cucumber chromosomes. Quantitative trait locus (QTL) analysis of downy mildew resistance was done using MapQTL Version 4.0. Inheritance of resistance to downy mildew in K8 was quantitative. Five QTLs for resistance to downy mildew were detected: dm1.1, dm5.1, dm5.2, dm5.3, and dm6.1. The loci of dm1.1 and dm6.1 were on chromosomes 1 and 6, respectively. The loci of dm5.1, dm5.2, and dm5.3 were on chromosome 5, and were linked. Six linked SSR markers for these five QTLs were identified: SSR31116, SSR20705, SSR00772, SSR11012, SSR16882, and SSR16110. Six and four nucleotide binding site (NBS)-type resistance gene analogs (RGAs) were predicted in the region of dm5.2 and dm5.3, respectively. These results will be of benefit for fine-mapping the major QTLs for downy mildew resistance, and for MAS in cucumber.