Vitamin D intoxication caused by ingestion of commercial cat food in three kittens

Two siblings, a 6-month-old sexually intact male weighing 2.5 kg (cat 1) and a sexually intact female (cat 2) British Shorthair cat weighing 2.3 kg, were examined because of a 3-week history of polyuria, lethargy and laboured breathing. One year previously, another sibling (cat 3) had been presented because of similar, yet more severe, clinical signs at the age of 5 months. Physical examination revealed lethargy, dehydration and polypnoea with slightly increased inspiratory effort. Diagnostic investigation revealed severe hypercalcaemia (cats 1-3), renal azotaemia (cats 1 and 3) and a radiologically generalised miliary interstitial pattern of the lungs (cats 1-3) attributable to hypervitaminosis D caused by ingestion of commercial cat food. Cat 3 was euthanased. Cats 1 and 2 were treated with isotonic saline solution (180 ml/kg IV daily), sucralfate (30 mg/kg PO q12h), terbutaline (only cat 1: 0.1 mg/kg SC q4h), furosemide (1.5 mg/kg IV q8h) and tapering doses of prednisolone. Cat 2 was normal on day 14. Cat 1 had stable renal disease and was followed up to day 672. The radiological generalised military interstitial pattern of the lungs had improved markedly. Excessive cholecalciferol-containing commercially available cat food poses a great hazard to cats. Supportive treatment may result in long-term survival and improvement of radiological pulmonary abnormalities

Vitamin D intoxication caused by ingestion of commercial cat food in three kittens

Two siblings, a 6-month-old sexually intact male weighing 2.5 kg (cat 1) and a sexually intact female (cat 2) British Shorthair cat weighing 2.3 kg, were examined because of a 3-week history of polyuria, lethargy and laboured breathing. One year previously, another sibling (cat 3) had been presented because of similar, yet more severe, clinical signs at the age of 5 months. Physical examination revealed lethargy, dehydration and polypnoea with slightly increased inspiratory effort. Diagnostic investigation revealed severe hypercalcaemia (cats 1-3), renal azotaemia (cats 1 and 3) and a radiologically generalised miliary interstitial pattern of the lungs (cats 1-3) attributable to hypervitaminosis D caused by ingestion of commercial cat food. Cat 3 was euthanased. Cats 1 and 2 were treated with isotonic saline solution (180 ml/kg IV daily), sucralfate (30 mg/kg PO q12h), terbutaline (only cat 1: 0.1 mg/kg SC q4h), furosemide (1.5 mg/kg IV q8h) and tapering doses of prednisolone. Cat 2 was normal on day 14. Cat 1 had stable renal disease and was followed up to day 672. The radiological generalised military interstitial pattern of the lungs had improved markedly. Excessive cholecalciferol-containing commercially available cat food poses a great hazard to cats. Supportive treatment may result in long-term survival and improvement of radiological pulmonary abnormalities

BRCA2 and RAD51 promote double-strand break formation and cell death in response to Gemcitabine

Replication inhibitors cause replication fork stalling and double-strand breaks (DSBs) that result from processing of stalled forks. During recovery from replication blocks, the homologous recombination (HR) factor RAD51 mediates fork restart and DSB repair. HR defects therefore sensitise cells to replication inhibitors, with clear implications for cancer therapy. Gemcitabine is a potent replication inhibitor used to treat cancers with mutations in HR genes such as BRCA2. Here we investigate why, paradoxically, mutations in HR genes protect cells from killing by Gemcitabine. Using DNA replication and -damage assays in mammalian cells, we show that even short Gemcitabine treatments cause persistent replication inhibition. BRCA2 and RAD51 are recruited to chromatin early after removal of the drug, actively inhibit replication fork progression and promote the formation of MUS81- and XPF-dependent DSBs that remain unrepaired. Our data suggest that HR intermediates formed at Gemcitabine-stalled forks are converted into DSBs and thus contribute to Gemcitabine-induced cell death, which could have implications for the treatment response of HR-deficient tumours

Clinicopathological Findings, Treatment and Outcome in 60 cats with Feline Gastrointestinal Eosinophilic Sclerosing Fibroplasia

Background – Feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) presents as mass(es) associated with the gastrointestinal tract, mesentery, and abdominal lymph nodes.Hypothesis/Objectives – To report the clinicopathological findings, treatment, and outcome of cats with FGESF.Animals – Sixty client-owned cats diagnosed with FGESF. Methods – Retrospective review of medical records of cats with histopathologically confirmed FGESF. Results – The median age was 5.4 years (interquartile range [IQR] 3.3-8.9.); 30% were Domestic Shorthairs and 12% were Domestic Longhair cats, with the most prevalent pedigree breeds being Ragdolls (25%), Exotic Shorthair (10%) and Persian (8%) cats. The median duration of clinical signs was 90 days (IQR 17.5-247.0); the most common clinical signs were weight loss (60%), hyporexia/anorexia (55%), chronic vomiting (37%), lethargy (35%) and chronic diarrhea (27%). Masses were located in the small intestine (32%), stomach (27%), ileocolic junction (15%), colon (10%), lymph node (8%) and mesentery (8%) and 15% of cats had more than one mass. Eosinophilia was present in 50% and hypoalbuminemia in 28% of cats. The mass was removed surgically in 37% of cases. Most cats (98%) were treated with corticosteroids and 1 cat with antibiotics alone. The survival was not statistically different between cats treated with surgical resection and cats treated with medical therapy alone, 88% of the cats still alive at the time of writing. Conclusions and clinical importance – FGESF is an important differential diagnosis for abdominal masses in cats, and has a much better prognosis than previously reported. <br/

UV stalled replication forks restart by re-priming in human fibroblasts

Restarting stalled replication forks is vital to avoid fatal replication errors. Previously, it was demonstrated that hydroxyurea-stalled replication forks rescue replication either by an active restart mechanism or by new origin firing. To our surprise, using the DNA fibre assay, we only detect a slightly reduced fork speed on a UV-damaged template during the first hour after UV exposure, and no evidence for persistent replication fork arrest. Interestingly, no evidence for persistent UV-induced fork stalling was observed even in translesion synthesis defective, Polηmut cells. In contrast, using an assay to measure DNA molecule elongation at the fork, we observe that continuous DNA elongation is severely blocked by UV irradiation, particularly in UV-damaged Polηmut cells. In conclusion, our data suggest that UV-blocked replication forks restart effectively through re-priming past the lesion, leaving only a small gap opposite the lesion. This allows continuation of replication on damaged DNA. If left unfilled, the gaps may collapse into DNA double-strand breaks that are repaired by a recombination pathway, similar to the fate of replication forks collapsed after hydroxyurea treatment

Homologous recombination repairs secondary replication induced DNA double-strand breaks after ionizing radiation

Ionizing radiation (IR) produces direct two-ended DNA double-strand breaks (DSBs) primarily repaired by non-homologous end joining (NHEJ). It is, however, well established that homologous recombination (HR) is induced and required for repair of a subset of DSBs formed following IR. Here, we find that HR induced by IR is drastically reduced when post-DNA damage replication is inhibited in mammalian cells. Both IR-induced RAD51 foci and HR events in the hprt gene are reduced in the presence of replication polymerase inhibitor aphidicolin (APH). Interestingly, we also detect reduced IR-induced toxicity in HR deficient cells when inhibiting post-DNA damage replication. When studying DSB formation following IR exposure, we find that apart from the direct DSBs the treatment also triggers formation of secondary DSBs peaking at 7–9 h after exposure. These secondary DSBs are restricted to newly replicated DNA and abolished by inhibiting post-DNA damage replication. Further, we find that IR-induced RAD51 foci are decreased by APH only in cells replicating at the time of IR exposure, suggesting distinct differences between IR-induced HR in S- and G2-phases of the cell cycle. Altogether, our data indicate that secondary replication-associated DSBs formed following exposure to IR are major substrates for IR-induced HR repair

Regulators of cyclin-dependent kinases are crucial for maintaining genome integrity in S phase

Maintenance of genome integrity is of critical importance to cells. To identify key regulators of genomic integrity, we screened a human cell line with a kinome small interfering RNA library. WEE1, a major regulator of mitotic entry, and CHK1 were among the genes identified. Both kinases are important negative regulators of CDK1 and -2. Strikingly, WEE1 depletion rapidly induced DNA damage in S phase in newly replicated DNA, which was accompanied by a marked increase in single-stranded DNA. This DNA damage is dependent on CDK1 and -2 as well as the replication proteins MCM2 and CDT1 but not CDC25A. Conversely, DNA damage after CHK1 inhibition is highly dependent on CDC25A. Furthermore, the inferior proliferation of CHK1-depleted cells is improved substantially by codepletion of CDC25A. We conclude that the mitotic kinase WEE1 and CHK1 jointly maintain balanced cellular control of Cdk activity during normal DNA replication, which is crucial to prevent the generation of harmful DNA lesions during replication

MTH1 inhibitor TH588 disturbs mitotic progression and induces mitosis-dependent accumulation of genomic 8-oxodG

Reactive oxygen species (ROS) oxidize nucleotide triphosphate pools (e.g., 8-oxodGTP), which may kill cells if incorporated into DNA. Whether cancers avoid poisoning from oxidized nucleotides by preventing incorporation via the oxidized purine diphosphatase MTH1 remains under debate. Also, little is known about DNA polymerases incorporating oxidized nucleotides in cells or how oxidized nucleotides in DNA become toxic. Here we show that replacement of one of the main DNA replicases in human cells, DNA polymerase delta (Pol δ), with an error-prone variant allows increased 8-oxodG accumulation into DNA following treatment with TH588, a dual MTH1 inhibitor (MTH1i) and microtubule targeting agent. The resulting elevated genomic 8-oxodG correlated with increased cytotoxicity of TH588. Interestingly, no substantial perturbation of replication fork progression was observed, but rather mitotic progression was impaired and mitotic DNA synthesis triggered. Reducing mitotic arrest by reversin treatment prevented accumulation of genomic 8-oxodG and reduced cytotoxicity of TH588, in line with the notion that mitotic arrest is required for ROS buildup and oxidation of the nucleotide pool. Furthermore, delayed mitosis and increased mitotic cell death was observed following TH588 treatment in cells expressing the error-prone but not wild type Pol δ variant, which is not observed following treatments with anti-mitotic agents. Collectively, these results link accumulation of genomic oxidized nucleotides with disturbed mitotic progression

Impact of vibrationally resolved H2 on particle balance in Eirene simulations

| openaire: EC/H2020/633053/EU//EUROfusion Funding Information: The authors would like to thank Professor U. Fantz and Professor D. Reiter for valuable discussions enabling this work. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under grant agreement number 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. This work was supported by the Academy of Finland under grant no. 13330050. Publisher Copyright: © 2022 The Authors. Contributions to Plasma Physics published by Wiley-VCH GmbH.To evaluate the impact of transport of metastable, vibrationally excited states of the hydrogen molecule in dense and cold plasmas each vibrational state must be simulated as an individual species. Eirene neutral gas simulations of a one-dimensional flux-tube using a metastable-resolved model indicate a 30–50% decrease in the effective dissociation rate compared to simulations using a metastable-unresolved setup, which consider a single molecular species. Zero-dimensional Eirene simulations omitting transport effects predict a 25–65% decrease in the effective dissociation rate due to differences between the metastable-unresolved AMJUEL and the metastable-resolved H2VIBR rates available in Eirene. The exclusion of molecular hydrogen depletion via electronically excited states and vibrational transitions (Formula presented.) from the metastable-resolved rates reduce the effective dissociation rate. By accounting for the difference caused by the different collisional-radiative treatment of the metastable-resolved rates compared to the metastable-unresolved rates, transport effects are expected to be relevant under detached divertor conditions. It is, however, not possible to individually assess the role of the collisional-radiative processes and transport on the effective dissociation rate using the currently available atomic and molecular rates for the metastable-resolved and metastable-unresolved Eirene setups.Peer reviewe