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1.
Pediatr Res ; 91(4): 735-742, 2022 03.
Article in English | MEDLINE | ID: mdl-34997225

ABSTRACT

BACKGROUND: The lack of a consensus definition of neonatal sepsis and a core outcome set (COS) proves a substantial impediment to research that influences policy and practice relevant to key stakeholders, patients and parents. METHODS: A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In the included studies, the described outcomes were extracted in accordance with the provisions of the Core Outcome Measures in Effectiveness Trials (COMET) handbook and registered. RESULTS: Among 884 abstracts identified, 90 randomised controlled trials (RCTs) were included in this review. Only 30 manuscripts explicitly stated the primary and/or secondary outcomes. A total of 88 distinct outcomes were recorded across all 90 studies included. These were then assigned to seven different domains in line with the taxonomy for classification proposed by the COMET initiative. The most frequently reported outcome was survival with 74% (n = 67) of the studies reporting an outcome within this domain. CONCLUSIONS: This systematic review constitutes one of the initial phases in the protocol for developing a COS in neonatal sepsis. The paucity of standardised outcome reporting in neonatal sepsis hinders comparison and synthesis of data. The final phase will involve a Delphi Survey to generate a COS in neonatal sepsis by consensus recommendation. IMPACT: This systematic review identified a wide variation of outcomes reported among published RCTs on the management of neonatal sepsis. The paucity of standardised outcome reporting hinders comparison and synthesis of data and future meta-analyses with conclusive recommendations on the management of neonatal sepsis are unlikely. The final phase will involve a Delphi Survey to determine a COS by consensus recommendation with input from all relevant stakeholders.


Subject(s)
Neonatal Sepsis , Research Design , Delphi Technique , Humans , Infant, Newborn , Neonatal Sepsis/diagnosis , Neonatal Sepsis/therapy , Outcome Assessment, Health Care , Randomized Controlled Trials as Topic , Treatment Outcome
2.
J Hepatol ; 55(1): 96-102, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21354236

ABSTRACT

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is frequently a lethal disease and one of the few malignancies that is still increasing in incidence around the world. Better animal models are highly desired to investigate the molecular basis of HCC and to develop novel therapeutic strategies. Alpha-fetoprotein (Afp) gene is expressed in fetal liver, silenced soon after birth, and highly re-expressed in hepatocellular carcinomas (HCC). We aimed to take advantage of the dramatic re-expression of the Afp gene in HCC to develop a hepatocarcinogenesis reporter (HCR) mouse model for dual-modality, longitudinal in vivo imaging of liver tumor development, and progression. METHODS: Knock in mice were established by placing a thymidinekinase (tk)-luciferase (luc) reporter gene cassette under the transcriptional control of the endogenous Afp promoter. DEN, a liver carcinogen, was used to induce liver tumors, which was monitored by both luc-based bioluminescent (BL) and tk-based positron emission tomography (PET) imaging. RESULTS: The expression profile of luc was identical to that of the endogenous Afp gene during development. As early as 2 months after the exposure to DEN, BLI revealed multifocal signals in the liver, long before the appearance of histologically apparent neoplastic lesions. By 6 months, BL and PET dual imaging showed strong signals in malignant HCC. By serendipity, a strong BL signal was also detected in adult testes, a previously unknown site of Afp expression. CONCLUSIONS: The HCR model enables longitudinal monitoring of liver tumor development and progression, providing a powerful tool in developing chemoprevention and therapeutic strategies for HCC.


Subject(s)
Liver Neoplasms, Experimental/etiology , Luciferases/genetics , Thymidine Kinase/genetics , alpha-Fetoproteins/genetics , Animals , Diethylnitrosamine/toxicity , Disease Models, Animal , Disease Progression , Female , Gene Knock-In Techniques , Genes, Reporter , Humans , Liver Neoplasms, Experimental/diagnostic imaging , Liver Neoplasms, Experimental/genetics , Liver Neoplasms, Experimental/pathology , Luminescence , Male , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Mice, Transgenic , Positron-Emission Tomography , Precancerous Conditions/diagnostic imaging , Precancerous Conditions/etiology , Precancerous Conditions/genetics , Precancerous Conditions/pathology
3.
Mol Biol Cell ; 20(1): 114-23, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18987339

ABSTRACT

Disruption of replication can lead to loss of genome integrity and increase of cancer susceptibility in mammals. Thus, a replication impediment constitutes a formidable challenge to these organisms. Recent studies indicate that homologous recombination (HR) plays an important role in suppressing genome instability and promoting cell survival after exposure to various replication inhibitors, including a topoisomerase I inhibitor, camptothecin (CPT). Here, we report that the deletion of RecQ helicase Recql5 in mouse ES cells and embryonic fibroblast (MEF) cells resulted in a significant increase in CPT sensitivity and a profound reduction in DNA replication after the treatment with CPT, but not other DNA-damaging agents. This CPT-induced cell death is replication dependent and occurs primarily after the cells had exited the first cell cycle after CPT treatment. Furthermore, we show that Recql5 functions nonredundantly with Rad51, a key factor for HR to protect mouse ES cells from CPT-induced cytotoxicity. These new findings strongly suggest that Recql5 plays an important role in maintaining active DNA replication to prevent the collapse of replication forks and the accumulation of DSBs in order to preserve genome integrity and to prevent cell death after replication stress as a result of topoisomerase I poisoning.


Subject(s)
Camptothecin/pharmacology , Cell Survival/drug effects , DNA Replication , Embryonic Stem Cells , Enzyme Inhibitors/pharmacology , Fibroblasts , RecQ Helicases/metabolism , Animals , Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/physiology , Cell Survival/physiology , Cells, Cultured , DNA Replication/drug effects , Embryonic Stem Cells/cytology , Embryonic Stem Cells/drug effects , Embryonic Stem Cells/physiology , Fibroblasts/cytology , Fibroblasts/drug effects , Fibroblasts/physiology , Humans , Mice , Rad51 Recombinase/metabolism , RecQ Helicases/genetics
4.
Blood ; 111(3): 1274-81, 2008 Feb 01.
Article in English | MEDLINE | ID: mdl-18000168

ABSTRACT

High-molecular-weight kininogen (HK) plays an important role in the assembly of the plasma kallikrein-kinin system. While the human genome contains a single copy of the kininogen gene, 3 copies exist in the rat (1 encoding K-kininogen and 2 encoding T-kininogen). Here, we confirm that the mouse genome contains 2 homologous kininogen genes, mKng1 and mKng2, and demonstrate that these genes are expressed in a tissue-specific manner. To determine the roles of these genes in murine development and physiology, we disrupted mKng1, which is expressed primarily in the liver. mKng1(-/-) mice were viable, but lacked plasma HK and low-molecular-weight kininogen (LK), as well as DeltamHK-D5, a novel kininogen isoform that lacks kininogen domain 5. Moreover, despite normal tail vein bleeding times, mKng1(-/-) mice displayed a significantly prolonged time to carotid artery occlusion following Rose Bengal administration and laser-induced arterial injury. These results suggest that a single gene, mKng1, is responsible for production of plasma kininogen, and that plasma HK contributes to induced arterial thrombosis in mice.


Subject(s)
Kininogens/metabolism , Plasma/metabolism , Thrombosis/metabolism , Amino Acid Sequence , Animals , Base Sequence , Bradykinin/blood , Gene Deletion , Genetic Vectors/genetics , Homozygote , Kininogens/chemistry , Kininogens/deficiency , Kininogens/genetics , Mice , Mice, Knockout , Molecular Sequence Data , RNA, Messenger/genetics , Sequence Alignment , Thrombosis/genetics , Time Factors
5.
Genes Dev ; 21(23): 3073-84, 2007 Dec 01.
Article in English | MEDLINE | ID: mdl-18003859

ABSTRACT

Members of the RecQ helicase family play critical roles in genome maintenance. There are five RecQ homologs in mammals, and defects in three of these (BLM, WRN, and RECQL4) give rise to cancer predisposition syndromes in humans. RECQL and RECQL5 have not been associated with a human disease. Here we show that deletion of Recql5 in mice results in cancer susceptibility. Recql5-deficient cells exhibit elevated frequencies of spontaneous DNA double-strand breaks and homologous recombination (HR) as scored using a reporter that harbors a direct repeat, and are prone to gross chromosomal rearrangements in response to replication stress. To understand how RECQL5 regulates HR, we use purified proteins to demonstrate that human RECQL5 binds the Rad51 recombinase and inhibits Rad51-mediated D-loop formation. By biochemical means and electron microscopy, we show that RECQL5 displaces Rad51 from single-stranded DNA (ssDNA) in a reaction that requires ATP hydrolysis and RPA. Together, our results identify RECQL5 as an important tumor suppressor that may act by preventing inappropriate HR events via Rad51 presynaptic filament disruption.


Subject(s)
Neoplasms, Experimental/prevention & control , Rad51 Recombinase/metabolism , RecQ Helicases/metabolism , Recombination, Genetic , Adenosine Triphosphate/metabolism , Animals , Cell Line , DNA Breaks, Double-Stranded , Genomic Instability , Histones/metabolism , Humans , Hydrolysis , Loss of Heterozygosity , Mice , Mice, Inbred C57BL , Mice, Knockout , Models, Biological , Mutation , Neoplasms, Experimental/genetics , Neoplasms, Experimental/metabolism , Rad51 Recombinase/genetics , RecQ Helicases/deficiency , RecQ Helicases/genetics , Recombinant Proteins/genetics , Recombinant Proteins/metabolism
6.
Mol Cell Biol ; 25(9): 3431-42, 2005 May.
Article in English | MEDLINE | ID: mdl-15831450

ABSTRACT

In eukaryotes, crossovers in mitotic cells can have deleterious consequences and therefore must be suppressed. Mutations in BLM give rise to Bloom syndrome, a disease that is characterized by an elevated rate of crossovers and increased cancer susceptibility. However, simple eukaryotes such as Saccharomyces cerevisiae have multiple pathways for suppressing crossovers, suggesting that mammals also have multiple pathways for controlling crossovers in their mitotic cells. We show here that in mouse embryonic stem (ES) cells, mutations in either the Bloom syndrome homologue (Blm) or the Recql5 genes result in a significant increase in the frequency of sister chromatid exchange (SCE), whereas deleting both Blm and Recql5 lead to an even higher frequency of SCE. These data indicate that Blm and Recql5 have nonredundant roles in suppressing crossovers in mouse ES cells. Furthermore, we show that mouse embryonic fibroblasts derived from Recql5 knockout mice also exhibit a significantly increased frequency of SCE compared with the corresponding wild-type control. Thus, this study identifies a previously unknown Recql5-dependent, Blm-independent pathway for suppressing crossovers during mitosis in mice.


Subject(s)
Adenosine Triphosphatases/physiology , Bloom Syndrome/genetics , Crossing Over, Genetic/genetics , DNA Helicases/physiology , Sister Chromatid Exchange/genetics , Adenosine Triphosphatases/genetics , Animals , Crossing Over, Genetic/physiology , Crossing Over, Genetic/radiation effects , DNA Helicases/genetics , Fibroblasts/radiation effects , Gamma Rays , Gene Deletion , Gene Silencing , Gene Targeting , Mice , Mice, Knockout , Mitosis/genetics , Mitosis/physiology , Mitosis/radiation effects , RecQ Helicases , Sister Chromatid Exchange/physiology , Stem Cells/radiation effects
7.
Hum Mol Genet ; 14(6): 813-25, 2005 Mar 15.
Article in English | MEDLINE | ID: mdl-15703196

ABSTRACT

Type II Rothmund-Thomson syndrome (Type II RTS) is a rare autosomal recessive genetic disorder characterized by a congenital skin rash, birth defects of the skeleton, genomic instability and cancer predisposition. It is caused by mutations in the RECQL4 gene and thus represents one of the three cancer-prone genetic diseases that are caused by mutations in a RecQ helicase-encoding gene. Genomic instability has been suspected as a major underlying cause of this disease, and analyses of Type II RTS patient-derived cells demonstrate unusually high frequencies of chromosomal aberrations, suggesting the involvement of chromosomal instability. However, the nature of the instability induced by RECQL4 mutations has not been clearly defined. We created a viable Recql4 mutant mouse model. These mice exhibit a distinctive skin abnormality, birth defects of the skeletal system, genomic instability and increased cancer susceptibility in a sensitized genetic background. Thus, they provide a useful model for studying Type II RTS. In addition, we demonstrate that cells from these mutant mice have high frequencies of premature centromere separation and aneuploidy. Thus, our observations provide evidence for a previously unsuspected role for Recql4 in sister-chromatid cohesion, and suggest that the chromosomal instability may be the underlying cause of cancer predisposition and birth defects in these mutant mice.


Subject(s)
Adenosine Triphosphatases/metabolism , Aneuploidy , Chromatids/metabolism , DNA Helicases/metabolism , Mutation , Rothmund-Thomson Syndrome/metabolism , Adenosine Triphosphatases/genetics , Animals , Chromatids/genetics , Chromosomal Instability/genetics , DNA Helicases/genetics , Disease Models, Animal , Genetic Predisposition to Disease , Humans , Mice , Mice, Mutant Strains , Neoplasms/genetics , Neoplasms/metabolism , RecQ Helicases , Rothmund-Thomson Syndrome/genetics
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