Novel polymorphisms of the amyloid precursor protein (APP) gene in Chinese/Taiwanese patients with Alzheimer’s disease

We aimed to determine if the amyloid precursor protein (APP) gene polymorphism is present in Chinese/Taiwanese patients with Alzheimer’s disease (AD). This is a 3-year prospective assessment of the genotypes of the APP gene among Chinese/Taiwanese patients with AD. The sample consisted of 50 AD patients and 50 unaffected controls. Participants were recruited from the practices of the authors. Controls were comprised of 45 unrelated healthy subjects and 5 unaffected family members of AD patients. Data were collected in a university-based research unit of a tertiary medical center. Sequencing of the APP gene from exon 15 to exon 18 was performed on the peripheral blood of the patients and the unaffected controls after their informed consent was obtained. Among 50 AD subjects, 11 (7 men, 4 women) had APP gene polymorphisms. Mean age of onset was 72 years (range 65–82 years). Polymorphism of APP gene with A to C substitution at nucleotide position (nt) 284490 (A284490C) was found in 8 AD patients, at nt 284493 (A284493C) in 5, T284497C in 3 patients, and T284500C in 1 patient. These single nucleotide substitutions of the APP gene corresponded to the amino acid substitutions I718L, L720S, and V710G. These polymorphisms were not found in the unaffected controls. The mutations were confirmed by StyI restriction enzyme digestion assay using the subclone from polymerase chain reaction (PCR) products of the mutated APP gene. Thus, APP gene polymorphisms at codon 718 (I > L), 720 (L > S), and 710 (V > G) can be found in certain Chinese/Taiwanese patients with Alzheimer’s disease.     

Cross-species comparison of in vivo PK/PD relationships for second-generation antisense oligonucleotides targeting apolipoprotein B-100

The in vivo pharmacokinetics/pharmacodynamics of 2′-O-(2-methoxyethyl) (2′-MOE) modified antisense oligonucleotides (ASOs), targeting apolipoprotein B-100 (apoB-100), were characterized in multiple species. The species-specific apoB antisense inhibitors demonstrated target apoB mRNA reduction in a drug concentration and time-dependent fashion in mice, monkeys, and humans. Consistent with the concentration-dependent decreases in liver apoB mRNA, reductions in serum apoB, and LDL-C, and total cholesterol were concurrently observed in animal models and humans. Additionally, the long duration of effect after cessation of dosing correlated well with the elimination half-life of 2′-MOE modified apoB ASOs studied in mice (t_1/2 ≅ 20 days) and humans (t_1/2 ≅ 30 days) following parental administrations. The plasma concentrations of ISIS 301012, observed in the terminal elimination phase of both mice and monkeys were in equilibrium with liver. The partition ratios between liver and plasma were similar, approximately 6000:1, across species, and thus provide a surrogate for tissue exposure in humans. Using an inhibitory E_max model, the ASO liver EC_50s were 101 ± 32, 119 ± 15, and 300 ± 191 μg/g of ASO in high-fat-fed (HF) mice, transgenic mice containing the human apoB transgene, and monkeys, respectively. The estimated liver EC₅₀ in man, extrapolated from trough plasma exposure, was 81 ± 122 μg/g. Therefore, extraordinary consistency of the exposure-response relationship for the apoB antisense inhibitor was observed across species, including human. The cross-species PK/PD relationships provide confidence in the use of pharmacology animal models to predict human dosing for second-generation ASOs targeting the liver.     

Pro-inflammatory cytokines modulate glial apolipoprotein E secretion

Alzheimer's disease (AD) is a neurological disorder characterized by plaques and an elevated immune response. Specifically, increased expression of interleukin (IL)-1 and tumour necrosis factor (TNF)-alpha, has been observed in AD cerebrospinal fluid and temporal brain tissue. Both of these immunomodulators were shown to carry genetic variants that increase the risk of developing AD. Studies have also established the apolipoprotein E (apoE) gene to be a risk factor for AD with epsilon4 carriers having been found to show lower levels of brain apoE. In the present study, treatment of primary rat mixed glial cell cultures with IL-1beta induced a significant increase in extracellular apoE protein. In contrast, treatment primary rat astrocyte and mixed glial cell cultures with TNF-alpha significantly reduced extracellular apoE protein levels. These results are consistent with the notion that elevated cytokine expression directly modulates immunosuppression and indirectly apoE-mediated neuronal remodeling.     

Detection of persistent high risk human papillomavirus infections with hybrid capture II and SPF10/LiPA.

BACKGROUND: HPV infection in young women is common. However only a certain number of HPV genotypes are oncogenic. It is necessary for high risk HPV infection to persist at the cervix for a considerable time before oncogenesis occurs. OBJECTIVES: To look for persistence of high risk HPV in women attending a colposcopy clinic. Two DNA detection methods were used and the results compared to determine the rates of persistent, resolved and acquired infections over a 6-month period. HPV genotyping was used to determine type specific persistence. STUDY DESIGN: One hundred and thirty-eight women were tested for HPV infection when attending the colposcopy clinic at UCLH and then tested again at a subsequent visit approximately 6 months later. HPV DNA was detected by the Digene HC II assay using the high risk probes only and by PCR with the SPF10 primer set. All SPF10 PCR-positive samples were then specifically genotyped by a Line Probe Assay (LiPA) [Kleter et al. 1999. J. Clin. Microbiol. 1999;37:2508]. RESULTS: At entry of the study high risk HPV was detected in 43% of the samples by Digene HC II and in 60% of the samples by SPF10/LiPA. Thirty-eight (28%) of the women had a true persistent infection with the same high risk HPV genotype over a median period of 6.3 months. Nine (7%) women resolved one HR HPV infection after their first colposcopy visit, but obtained a different high risk HPV infection by the time they were tested at their second visit as identified by LiPA. Thirty-seven (27%) of the 138 women had mixed HPV infections, representing 45% of all those infected. CONCLUSIONS: The SPF10/LiPA assay detected more high risk infections than the Digene HC II assay. The Digene HC II assay was unable to distinguish between persistent infections with the same high risk genotype and those where the genotype had changed between visits.     

The patients’ perspective: Results of a survey assessing knowledge about and attitudes toward depression in PD

We report results of a survey assessing patients’ knowledge about and attitudes towards depression in Parkinson’s disease (PD). 345 patients from 8 tertiary care centers responded (43% response rate). Overall, patients were relatively knowledgeable about depression and its occurrence in PD. However, many patients believed that depression is a normal reaction to the illness. While many respondents would be reluctant to initiate a discussion of depression during a clinical evaluation, most would feel comfortable talking about depression with their physician if he or she asked them questions about their mood. Based on the results of this survey, we recommend the following approach for physicians: (1) inform PD patients that, although a frequent occurrence, depression need not be accepted as a “normal reaction” to PD; and (2) routinely inquire about depressive symptoms rather than waiting for the patient to spontaneously report them.