The concentration of deoxyribonucleic acid in plasma from 73 patients with colorectal cancer and apparent clinical correlations

Background: Detection of cell-free plasma DNA has considerable potential as a tool for the diagnosis and assessment of the prognosis of many types of cancer. The aim of the present study was to quantify, by spectrophotometry, the cell-free DNA in plasma samples from patients with colorectal cancer at different stages of the disease and to attempt to correlate the resultant values with the clinical picture. Methods: We reviewed the medical reports of 73 patients, who had undergone resection of primary colorectal cancer. Samples of blood had been taken from each patient immediately prior to surgery. DNA was extracted from samples of plasma and quantified, by spectrophotometry, after a storage period of no longer than 2 years in 89% of the cases examined. Results: The mean(±S.D.) concentration of DNA in plasma samples was 108 ± 156 ng/μl. We found a statistically significant correlation between the concentration of DNA and the presence of metastases (mainly liver metastases). Conclusion: The detection and quantitation of cell-free DNA in plasma, using this simple technique, might be of clinical value for the surveillance of colon cancer patients and the detection of metastases.     

Polygenic risk scores and risk-stratified breast cancer screening: Familiarity and perspectives of health care professionals

PurposeHealth care professionals are expected to take on an active role in the implementation of risk-based cancer prevention strategies. This study aimed to explore health care professionals’ (1) self-reported familiarity with the concept of polygenic risk score (PRS), (2) perceived level of knowledge regarding risk-stratified breast cancer (BC) screening, and (3) preferences for continuing professional development.MethodsA cross-sectional survey was conducted using a bilingual—English/French—online questionnaire disseminated by health care professional associations across Canada between November 2020 and May 2021.ResultsA total of 593 professionals completed more than 2 items and 453 responded to all questions. A total of 432 (94%) participants were female, 103 (22%) were physicians, and 323 (70%) were nurses. Participants reported to be unfamiliar with (20%), very unfamiliar (32%) with, or did not know (41%) the concept of PRS. Most participants reported not having enough knowledge about risk-stratified BC screening (61%) and that they would require more training (77%). Online courses and webinar conferences were the preferred continuing professional development modalities.ConclusionThe study indicates that health care professionals are currently not familiar with the concept of PRS or a risk-stratified approach for BC screening. Online information and training seem to be an essential knowledge transfer modality.     

Biallelic loss-of-function variants in RABGAP1 cause a novel neurodevelopmental syndrome

PurposeRABGAP1 is a GTPase-activating protein implicated in a variety of cellular and molecular processes, including mitosis, cell migration, vesicular trafficking, and mTOR signaling. There are no known Mendelian diseases caused by variants in RABGAP1.MethodsThrough GeneMatcher, we identified 5 patients from 3 unrelated families with homozygous variants in the RABGAP1 gene found on exome sequencing. We established lymphoblastoid cells lines derived from an affected individual and her parents and performed RNA sequencing and functional studies. Rabgap1 knockout mice were generated and phenotyped.ResultsWe report 5 patients presenting with a common constellation of features, including global developmental delay/intellectual disability, microcephaly, bilateral sensorineural hearing loss, and seizures, as well as overlapping dysmorphic features. Neuroimaging revealed common features, including delayed myelination, white matter volume loss, ventriculomegaly, and thinning of the corpus callosum. Functional analysis of patient cells revealed downregulated mTOR signaling and abnormal localization of early endosomes and lysosomes. Rabgap1 knockout mice exhibited several features in common with the patient cohort, including microcephaly, thinning of the corpus callosum, and ventriculomegaly.ConclusionCollectively, our results provide evidence of a novel neurodevelopmental syndrome caused by biallelic loss-of-function variants in RABGAP1.     

组蛋白H3K9甲基修饰酶在2周、4周和6周龄小鼠肝脏中的表达

目的 探讨不同周龄小鼠肝脏组蛋白H3K9甲基转移酶(KMT)和去甲基化酶(KDM)的表达.方法 取2周、4周和6周龄BALB/c雄性小鼠肝脏组织,分别提取总mRNA和蛋白质,应用实时定量反转录-聚合酶链式反应(RT-qPCR)确定几种H3K9甲基转移酶和去甲基化酶的表达差异,使用Western blotting 检测两...     

Associations of hematological and biochemical markers with intracranial atherosclerotic stenosis in stroke-free populations: A systematic review and meta-analysis of observational studies

Background and aimsIntracranial atherosclerotic stenosis (ICAS) is an important cause of ischemic stroke and transient ischemic attack. We aimed to synthesize relevant evidence on the associations of hematological and biochemical markers with ICAS in stroke-free populations.Methods and resultsWe searched MEDLINE and EMBASE for articles reporting associations of hematological and biochemical markers with ICAS presence in stroke-free populations. Weighted mean difference (WMD) and 95% confidence interval (CI) for each biomarker were pooled using fixed- or random-effects models. Among 32 studies included in the systematic review, 23 studies (48,326 subjects) with 22 biomarkers were meta-analyzed. Compared with subjects without ICAS, those with ICAS had significantly higher white blood cell (4118 subjects, WMD 0.28 per 10⁹/L, 95% CI 0.01–0.56), neutrophil (4326 subjects, WMD 0.24 per 10⁹/L, 0.10–0.38), neutrophil/lymphocyte ratio (4326 subjects, WMD 0.16, 0.07–0.26), low-density lipoprotein (28,606 subjects, WMD 0.12 mmol/L, 0.05–0.19), non-high-density lipoprotein (3671 subjects, WMD 0.17 mmol/L, 0.08–0.25), C-reactive protein (CRP; 5355 subjects, WMD 0.06 mg/dL, 0.04–0.07), high-sensitivity CRP (9383 subjects, WMD 0.07 mg/dL, 0.01–0.13), uric acid (5966 subjects, WMD 17.91 μmol/L, 11.16–24.66), creatinine (5731 subjects, WMD 4.03 μmol/L, 0.77–7.29), and homocysteine (7053 subjects, WMD 2.25 μmol/L, 1.02–3.48), but lower lymphocyte (4326 subjects, WMD ?0.12 per 10⁹/L, ?0.19–?0.04). Sensitivity analyses showed similar results.ConclusionsSeveral hematological and biochemical markers easily accessible were associated with ICAS presence in stroke-free populations. This can facilitate early identification of subjects at a high risk of ICAS, who may benefit from ICAS screening and prevention.Prospero registration numberCRD42021247990.     

New role of LRP5, associated with nonsyndromic autosomal‐recessive hereditary hearing loss

Human hearing loss is a common neurosensory disorder about which many basic research and clinically relevant questions are unresolved. At least 50% of hearing loss are due to a genetic etiology. Although hundreds of genes have been reported, there are still hundreds of related deafness genes to be found. Clinical, genetic, and functional investigations were performed to identify the causative mutation in a distinctive Chinese family with postlingual nonsyndromic sensorineural hearing loss. Whole‐exome sequencing (WES) identified lipoprotein receptor‐related protein 5 (LRP5), a member of the low‐density lipoprotein receptor family, as the causative gene in this family. In the zebrafish model, lrp5 downregulation using morpholinos led to significant abnormalities in zebrafish inner ear and lateral line neuromasts and contributed, to some extent, to disabilities in hearing and balance. Rescue experiments showed that LRP5 mutation is associated with hearing loss. Knocking down lrp5 in zebrafish results in reduced expression of several genes linked to Wnt signaling pathway and decreased cell proliferation when compared with those in wild‐type zebrafish. In conclusion, the LRP5 mutation influences cell proliferation through the Wnt signaling pathway, thereby reducing the number of supporting cells and hair cells and leading to nonsyndromic hearing loss in this Chinese family.