Use of in vitro human keratinocyte models to study the effect of cooling on chemotherapy drug-induced cytotoxicity

A highly distressing side-effect of cancer chemotherapy is chemotherapy-induced alopecia (CIA). Scalp cooling remains the only treatment for CIA, yet there is no experimental evidence to support the cytoprotective capacity of cooling. We have established a series of in vitro models for the culture of human keratinocytes under conditions where they adopt a basal, highly-proliferative phenotype thus resembling the rapidly-dividing sub-population of native hair-matrix keratinocytes. Using a panel of chemotherapy drugs routinely used clinically (docetaxel, doxorubicin and the active metabolite of cyclophosphamide 4-OH-CP), we demonstrate that although these drugs are highly-cytotoxic, cooling can markedly reduce or completely inhibit drug cytotoxicity, in agreement with clinical observations. By contrast, we show that cytotoxicity caused by specific combinatorial drug treatments cannot be adequately attenuated by cooling, supporting data showing that such treatments do not always respond well to cooling clinically. Importantly, we provide evidence that the choice of temperature may be critical in determining the efficacy of cooling in rescuing cells from drug-mediated toxicity. Therefore, despite their reductive nature, these in vitro models have provided experimental evidence for the clinically-reported cytoprotective role of cooling and represent useful tools for future studies on the molecular mechanisms of cooling-mediated cytoprotection

Henipavirus Neutralising Antibodies in an Isolated Island Population of African Fruit Bats

Isolated islands provide valuable opportunities to study the persistence of viruses in wildlife populations, including population size thresholds such as the critical community size. The straw-coloured fruit bat, Eidolon helvum, has been identified as a reservoir for henipaviruses (serological evidence) and Lagos bat virus (LBV; virus isolation and serological evidence) in continental Africa. Here, we sampled from a remote population of E. helvum annobonensis fruit bats on Annobón island in the Gulf of Guinea to investigate whether antibodies to these viruses also exist in this isolated subspecies. Henipavirus serological analyses (Luminex multiplexed binding and inhibition assays, virus neutralisation tests and western blots) and lyssavirus serological analyses (LBV: modified Fluorescent Antibody Virus Neutralisation test, LBV and Mokola virus: lentivirus pseudovirus neutralisation assay) were undertaken on 73 and 70 samples respectively. Given the isolation of fruit bats on Annobón and their lack of connectivity with other populations, it was expected that the population size on the island would be too small to allow persistence of viruses that are thought to cause acute and immunising infections. However, the presence of antibodies against henipaviruses was detected using the Luminex binding assay and confirmed using alternative assays. Neutralising antibodies to LBV were detected in one bat using both assays. We demonstrate clear evidence for exposure of multiple individuals to henipaviruses in this remote population of E. helvum annobonensis fruit bats on Annobón island. The situation is less clear for LBV. Seroprevalences to henipaviruses and LBV in Annobón are notably different to those in E. helvum in continental locations studied using the same sampling techniques and assays. Whilst cross-sectional serological studies in wildlife populations cannot provide details on viral dynamics within populations, valuable information on the presence or absence of viruses may be obtained and utilised for informing future studies

Modeling the transport of sucralose, an anthropogenic tracer, in an effluent dependent watershed with the Soil and Water Assessment Tool during an extreme drought.

Contaminants of emerging concern (CECs) in rapidly urbanizing watersheds represent an area of increasing attention. The Soil and Water Assessment Tool (SWAT), has been used for numerous water quality and quantity assessments, but CEC studies using SWAT are limited. Because the North Bosque watershed represents an ideal system to study historical and emerging water quality questions, I examined the capacity of SWAT to potentially model CECs using sucralose during an extreme drought, when the in-stream flows downstream from Stephenville, Texas, USA were dependent on effluent discharge. Modeling outputs throughout the watershed were compared to field observations of CECs (quantified by isotope dilution LC-MSMS) in surface water. Sucralose, an ideal effluent tracer, simulation outputs were similar at wastewater treatment plants but in-stream concentrations were lower than predicted potentially due to transport from surface water to groundwater, which is not accounted for by SWAT. This suggests that CECs may be entering the Trinity aquifer in a primary recharge area

The structural organisation of sperm head components of the wombat and koala (suborder: Vombatiformes): an enigma amongst marsupials

The sperm head structural organisation of the koala and hairy-nosed wombat, and the effects of varying concentrations of the ionic detergent, Triton X-100, on its component parts, were determined by electron microscopy. Although alike in form between the 2 species, the sperm nucleus of the former, but not the latter, had nuclear vacuoles and appeared to be more easily dispersed by the Triton X-100. The structure of the acrosome of the spermatozoon was similar between the 2 species and, in both, previously undescribed thin posterior and lateral segments were found to be present. It is suggested that this thin segment may facilitate sperm-zona and/or sperm-oolemma binding and fusion

Bevacizumab induced hypertension in gynecologic cancer: Does it resolve after completion of therapy?

Hypertension (HTN) induced by bevacizumab is a side effect that is often thought to resolve after treatment. However, there are currently no reports on rates of resolution. We assess the incidence and timing of the resolution of bevacizumab induced HTN. We evaluated all patients treated with bevacizumab for gynecologic malignancies at a single institution from 2012 through 2014. HTN was retrospectively diagnosed and staged by CTCAE v4.0 criteria. Resolution of HTN was defined as ≥2 values return to baseline blood pressure and/or discontinuation/decrease of blood pressure medications. We identified 104 patients; 35 were excluded due to receiving bevacizumab at time of analysis. Grade 2 or higher induced HTN was identified in 34/69 (49.3%) patients, of which 26/69 (37.7%) had grade 2 HTN and 8/69 (11.6%) had grade 3/4 HTN. Onset of HTN occurred at a median of 67 (14–791) days. Resolution of HTN occurred in 28/34 (82.4%) patients with a median time to resolution of 87 (3–236) days. BMI, history of HTN, blood pressure medications, prior bevacizumab treatment, number of bevacizumab cycles, CA-125 and albumin at initiation of treatment were not independent risk factors associated with developing HTN in multivariate analysis. Median PFS for those with HTN was 12.5 (1.9–45.8) months vs 11.0 (2.1–44.7) for those without (p = 0.17). Hypertension induced by bevacizumab resolved in 82% of patients in a median of 87 days. There were no identifiable risk factors associated with induced HTN and HTN was not a biomarker for improved prognosis in our cohort

Temporal deposition and spatial distribution of cytoskeletal proteins in the sperm head of an Australian rodent

The Australian murine rodent, the plains mouse (Pseudomys australis), possesses a highly complex sperm head, in which there are, in addition to an apical hook, two ventral processes that extend from its upper concave surface. The present study set out to determine the temporal deposition and distribution of the proteins within these structures during late spermiogenesis by light and electron microscopy using various antibodies to bull and laboratory rat sperm-head cytoskeletal proteins. The findings show that there are two phases of protein deposition. In the first phase, perinuclear theca proteins are deposited at the base of the ventral processes around the acrosomal extensions of the developing spermatids. In the second phase, as the ventral processes expand, actin and then perforatorial proteins are laid down during which time the processes become progressively more bilaterally flattened. These various proteins are moulded together to give rise to the two very large cytoskeletal structures that extend from the upper concave surface of the sperm head. They may be involved in binding the spermatozoon to the outer surface of the zona pellucida and/or in aiding the spermatozoon in zona penetration at the time of fertilisation.William G. Breed, Dina Idriss, Christopher M. Leigh and Richard J. Ok

Glc7/Protein Phosphatase 1 Regulatory Subunits Can Oppose the Ipl1/Aurora Protein Kinase by Redistributing Glc7

Faithful chromosome segregation depends on the opposing activities of the budding yeast Glc7/PP1 protein phosphatase and Ipl1/Aurora protein kinase. We explored the relationship between Glc7 and Ipl1 and found that the phosphorylation of the Ipl1 substrate, Dam1, was altered by decreased Glc7 activity, whereas Ipl1 levels, localization, and kinase activity were not. These data strongly suggest that Glc7 ensures accurate chromosome segregation by dephosphorylating Ipl1 targets rather than regulating the Ipl1 kinase. To identify potential Glc7 and Ipl1 substrates, we isolated ipl1-321 dosage suppressors. Seven genes (SDS22, BUD14, GIP3, GIP4, SOL1, SOL2, and PEX31) encode newly identified ipl1 dosage suppressors, and all 10 suppressors encode proteins that physically interact with Glc7. The overexpression of the Gip3 and Gip4 suppressors altered Glc7 localization, indicating they are previously unidentified Glc7 regulatory subunits. In addition, the overexpression of Gip3 and Gip4 from the galactose promoter restored Dam1 phosphorylation in ipl1-321 mutant cells and caused wild-type cells to arrest in metaphase with unsegregated chromosomes, suggesting that Gip3 and Gip4 overexpression impairs Glc7's mitotic functions. We therefore propose that the overexpression of Glc7 regulatory subunits can titrate Glc7 away from relevant Ipl1 targets and thereby suppress ipl1-321 cells by restoring the balance of phosphatase/kinase activity