Population-based screening in a municipality after a primary school outbreak of the SARSCoV-2 Alpha variant, the Netherlands, December 2020–February 2021

An outbreak of SARS-CoV-2 Alpha variant (Pango lineage B.1.1.7) was detected at a primary school (School X) in Lansingerland, the Netherlands, in December 2020. The outbreak was studied retrospectively, and population-based screening was used to assess the extent of virus circulation and decelerate transmission. Cases were SARS-CoV-2 laboratory confirmed and were residents of Lansingerland (November 16(th) 2020 until February 22(th) 2021), or had an epidemiological link with School X or neighbouring schools. The SARS-CoV-2 variant was determined using variant PCR or whole genome sequencing. A questionnaire primarily assessed clinical symptoms. A total of 77 Alpha variant cases were found with an epidemiological link to School X, 16 Alpha variant cases linked to the neighbouring schools, and 146 Alpha variant cases among residents of Lansingerland without a link to the schools. The mean number of self-reported symptoms was not significantly different among Alpha variant infected individuals compared to non-Alpha infected individuals. The secondary attack rate (SAR) among Alpha variant exposed individuals in households was 52% higher compared to non-Alpha variant exposed individuals (p = 0.010), with the mean household age, and mean number of children and adults per household as confounders. Sequence analysis of 60 Alpha variant sequences obtained from cases confirmed virus transmission between School X and neighbouring schools, and showed that multiple introductions of the Alpha variant had already taken place in Lansingerland at the time of the study. The alpha variant caused a large outbreak at both locations of School X, and subsequently spread to neighbouring schools, and households. Population-based screening (together with other public health measures) nearly stopped transmission of the outbreak strain, but did not prevent variant replacement in the Lansingerland municipality

Betulinic acid delivered in liposomes reduces growth of human lung and colon cancers in mice without causing systemic toxicity

Betulinic acid (BetA) is a plant-derived pentacyclic triterpenoid with potent anticancer capacity that targets the mitochondrial pathway of apoptosis. BetA has a broad efficacy in vitro against prevalent cancer types, including lung, colorectal, prostate, cervix and breast cancer, melanomas, neuroblastomas, and leukemias. The cytotoxic effects of the compound against healthy cells are minimal, rendering BetA a promising potential anticancer drug. However, because of the weak hydrosolubility of BetA, it has been difficult to study its efficacy in vivo and a pharmaceutical formulation is not yet available. We report the development of a liposome formulation of BetA and show its successful application in mice. Large liposomes, assembled without cholesterol to reduce their rigidity, efficiently incorporated BetA. Nude mice xenografted with human colon and lung cancer tumors were treated intravenously with the BetA-containing liposomes. Tumor growth was reduced to more than 50% compared with the control treatment, leading to an enhanced survival of the mice. Oral administration of the liposomal formulation of BetA also slowed tumor growth. Any signs of systemic toxicity caused by BetA treatment were absent. Thus, liposomes are an efficient formulation vehicle for BetA, enabling its preclinical development as a nontoxic compound for the treatment of cancers. Anti-Cancer Drugs 22: 223-233 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkin

The microtubule plus-end-tracking protein CLIP-170 associates with the spermatid manchette and is essential for spermatogenesis.

CLIP-170 is a microtubule "plus-end-tracking protein" implicated in the control of microtubule dynamics, dynactin localization, and the linking of endosomes to microtubules. To investigate the function of mouse CLIP-170, we generated CLIP-170 knockout and GFP-CLIP-170 knock-in alleles. Residual CLIP-170 is detected in lungs and embryos of homozygous CLIP-170 knockout mice, but not in other tissues and cell types, indicating that we have generated a hypomorphic mutant. Homozygous CLIP-170 knockout mice are viable and appear normal. However, male knockout mice are subfertile and produce sperm with abnormal heads. Using the knock-in mice, we followed GFP-CLIP-170 expression and behavior in dissected, live testis tubules. We detect plus-end-tracking GFP-CLIP-170 in spermatogonia. As spermatogenesis proceeds, GFP-CLIP-170 expression increases and the fusion protein strongly marks syncytia of differentiated spermatogonia and early prophase spermatocytes. Subsequently GFP-CLIP-170 levels drop, but during spermiogenesis (post-meiotic development), GFP-CLIP-170 accumulates again and is present on spermatid manchettes and centrosomes. Bleaching studies show that, as spermatogenesis progresses, GFP-CLIP-170 converts from a mobile plus-end-tracking protein to a relatively immobile protein. We propose that CLIP-170 has a structural function in the male germline, in particular in spermatid differentiation and sperm head shaping