Fully automated and highly specific plasma ß-amyloid immunoassays predict ß-amyloid status defined by amyloid positron emission tomography with high accuracy.

BACKGROUND: Clinicians, researchers, and patients alike would greatly benefit from more accessible and inexpensive biomarkers for neural ß-amyloid (Aß). We aimed to assess the performance of fully automated plasma Aß immunoassays, which correlate significantly with immunoprecipitation mass spectrometry assays, in predicting brain Aß status as determined by visual read assessment of amyloid positron emission tomography (PET). METHODS: The plasma Aß42/Aß40 ratio was measured using a fully automated immunoassay platform (HISCL series) in two clinical studies (discovery and validation studies). The discovery and validation sample sets were retrospectively and randomly selected from participants with early Alzheimer's disease (AD) identified during screening for the elenbecestat Phase 3 program. RESULTS: We included 197 participants in the discovery study (mean [SD] age 71.1 [8.5] years; 112 females) and 200 in the validation study (age 70.8 [7.9] years; 99 females). The plasma Aß42/Aß40 ratio predicted amyloid PET visual read status with areas under the receiver operating characteristic curves of 0.941 (95% confidence interval [CI] 0.910-0.973) and 0.868 (95% CI 0.816-0.920) in the discovery and validation studies, respectively. In the discovery study, a cutoff value of 0.102 was determined based on maximizing the Youden Index, and the sensitivity and specificity were calculated to be 96.0% (95% CI 90.1-98.9%) and 83.5% (95% CI 74.6-90.3%), respectively. Using the same cutoff value, the sensitivity and specificity in the validation study were calculated to be 88.0% (95% CI 80.0-93.6%) and 72.0% (95% CI 62.1-80.5%), respectively. CONCLUSIONS: The plasma Aß42/Aß40 ratio measured using the HISCL series achieved high accuracy in predicting amyloid PET status. Since our blood-based immunoassay system is less invasive and more accessible than amyloid PET and cerebrospinal fluid testing, it may contribute to the diagnosis of AD in routine clinical practice.

Enhancement of Gene Knockdown on CD22-Expressing Cells by Chemically Modified Glycan Ligand-siRNA Conjugates.

Extrahepatic targeted delivery of oligonucleotides, such as small interfering RNA (siRNA) and antisense oligonucleotides (ASOs), is an attractive technology for the development of nucleic acid-based medicines. To target CD22-expressing B cells, several drug platforms have shown promise, including antibodies, antibody-drug conjugates, and nanoparticles, but to date CD22-targeted delivery of oligonucleotide therapeutics has not been reported. Here we report the uptake and enhancement of siRNA gene expression knockdown in CD22-expressing B cells using a chemically stabilized and modified CD22 glycan ligand-conjugated siRNA. This finding has the potential to broaden the use of siRNA technology, opening up novel therapeutic opportunities, and presents an innovative approach for targeted delivery of siRNAs to B cell lymphomas.

Fully automated chemiluminescence enzyme immunoassays showing high correlation with immunoprecipitation mass spectrometry assays for ß-amyloid (1-40) and (1-42) in plasma samples.

Blood based ß-amyloid (Aß) assays that can predict amyloid positivity in the brain are in high demand. Current studies that utilize immunoprecipitation mass spectrometry assay (IP-MS), which has high specificity for measuring analytes, have revealed that precise plasma Aß assays have the potential to detect amyloid positivity in the brain. In this study, we developed plasma Aß40 and Aß42 immunoassays using a fully automated immunoassay platform that is used in routine clinical practice. Our assays showed high sensitivity (limit of quantification: 2.46 pg/mL [Aß40] and 0.16 pg/mL [Aß42]) and high reproducibility within-run (coefficients of variation [CVs]: <3.7% [Aß40] and <2.0% [Aß42]) and within-laboratory (CVs: <4.6% [Aß40] and <5.3% [Aß42]). The interference from plasma components was less than 10%, and the cross-reactivity with various lengths of Aß peptides was less than 0.5%. In addition, we found a significant correlation between the IP-MS method and our immunoassay (correlation coefficients of Pearson's r: 0.91 [Aß40] and 0.82 [Aß42]). Our new method to quantify plasma Aß40 and Aß42 provides clinicians and patients with a way to continuously monitor disease progression.

Repeated collection of conjoined oocytes from a patient with polycystic ovary syndrome, resulting in one successful live birth from frozen thawed blastocyst transfer: a case report.

Few cases have been reported in which the aspiration of a single follicle led to the recovery of two conjoined oocytes surrounded by a single zona pellucida. This report describes a successful embryo transfer with subsequent live birth derived from conjoined oocytes, and a later pair of conjoined oocytes in the same patient. After oocyte retrieval from a patient with polycystic ovary syndrome, two pairs of conjoined oocytes were collected. One oocyte was fertilized using in vitro fertilization (IVF) and developed to the blastocyst stage. This blastocyst was cryopreserved and later transferred to the uterus after separating the unfertilized conjoined oocyte. A successful pregnancy and healthy live birth was achieved. Two years later, the patient returned for a second IVF; one pair of conjoined oocytes was detected. One of the pair was fertilized and developed to a blastocyst, but was not transferred. We demonstrate that selective fertilization of a mature oocyte from conjoined oocytes by IVF can lead to the development of a blastocyst and subsequent pregnancy and live birth. To our knowledge, this is the second case report of successful live birth from conjoined oocytes. It may be the first case of repeated fertile conjoined oocytes from the same patient.

Chemical zona pellucida thinning with acidified Tyrode's solution: comparison between partial and circumferential techniques.

PURPOSE: To compare effectiveness of two different chemical zona thinning techniques. METHOD: We studied 163 patients who had experienced IVF or ICSI failures in two or more cycles. Patients were assigned to one of three groups: zona intact (n=72), partial thinning (n=59), or circumferential thinning (n=73). Before transfer, the zonae pellucidae of embryos were thinned partially or circumferentially using acidified Tyrode's solution. RESULTS: Implantation rates were 8.9% in the intact zona group, 17.6% in the partial thinning group, and 11.9% in the circumferential thinning group: respective clinical pregnancy rates were 16.7% (12/72), 32.2% (19/59), and 27.4% (20/73). Both rates were significantly higher in the partial thinning group than the intact zona group. For circumferential thinning versus zona intact groups, differences fell short of significance. CONCLUSIONS: Following embryo transfer failure, partial thinning would be recommended over circumferential thinning for successful assisted hatching.

Assisted hatching using a 1.48-µm diode laser: Evaluation of zona opening and zona thinning techniques in human embryos.

Aim: We assessed the effectiveness of assisted hatching using a 1.48-µm diode laser in human embryos, comparing zona opening and zona thinning techniques. Methods: A total of 56 day 3 embryos were assigned randomly to a zona opening group, a zona thinning group, or a control group. We then carried out assisted hatching using the OCTAX Laser Shot system (MTG Medical Technology, Altdorf, Germany) in the first two groups. In the zona opening group, the inner membrane of the zona pellucida was broken to create a full-thickness opening. In the zona thinning group, the inner membrane of the zona pellucida was not breached. After the laser procedure, embryos were cultured to the hatched blastocyst stage. Results: Blastocyst development rates did not differ significantly between the three groups. In the zona opening group, blastocysts were significantly more likely to hatch than those in the control group (P ≤ 0.05) and no arrested hatching of blastocysts was observed. Conclusions: Assisted hatching using a 1.48-µm diode laser in the zona opening technique increases the likelihood of blastocyst hatching in human embryos and does not adversely effect subsequent embryo development. (Reprod Med Biol 2006; 5: 221-226).