Methodology for reliable and reproducible cryopreservation of human cervical tissue

BACKGROUND: In order to conduct laboratory studies on donated cervical tissue at suitable times an effective and reliable cryopreservation protocol for cervical tissue is required. METHODS: An active freezing approach was devised utilising 10% dimethyl sulfoxide in foetal bovine serum as a cryoprotective agent with a cooling rate of 1 °C/min to -50 °C then 10 °C/min to -120 °C; a related thawing protocol was also optimised which would allow for the bio-banking of cervical tissue. Viability of freshly harvested cervical tissue was compared to frozen-thawed samples utilising colorimetric MTT assay. In parallel, fresh and freeze-thawed samples were cultured and tested on days 1, 7 and 14 to determine whether bio-banking had detrimental effects on tissue viability over time. RESULTS: Repeat testing revealed that tissue viability between fresh and freeze-thawed wasand freeze-thawed samples was comparable at all four time points (days 0, 1, 7 and 14) with no apparent reductions of viability, thus demonstrating this method of cryopreserving cervical tissue is reliable and reproducible, without detrimental effects on live tissue culture. We believe this methodology creates the opportunity for bio-banking donated cervical tissues, which aids improved experimental design and reduces time pressures and wastage

ASPECT: A Survey to Assess Student Perspective of Engagement in an Active-Learning Classroom

This paper describes the development and validation of a survey to measure students? self-reported engagement during a wide variety of in-class active-learning exercises. The survey provides researchers and instructors alike with a tool to rapidly evaluate different active-learning strategies from the perspective of the learner

The spiral-locked letters of Elizabeth I and Mary, Queen of Scots

This article presents evidence about the use of the 'spiral lock', a highly secure letterlocking mechanism used by Elizabeth I, Mary, Queen of Scots, and other letter-writers in early modern Europe, to secure their correspondence shut. After explaining the concept of letterlocking, a centuries-old communication security technique, we demonstrate how the spiral lock worked, using photographs, vector drawings, and videos alongside textual descriptions, and show both how the lock was made and how to recognize it in an archive. The findings are set in multiple contexts: letterlocking as a new field of study; new digital humanities research in the life and letters of Mary, Queen of Scots; and a major exhibition at the British Library on the intersecting lives of the two queens

Reproductive outcomes in male childhood cancer survivors: a linked cancer-birth registry analysis

OBJECTIVE: Compare the risk of reproductive and infant outcomes between male childhood cancer survivors and a population-based comparison group. DESIGN: Retrospective cohort study. SETTING: 4 U.S. regions. PARTICIPANTS: Cancer registries identified males <20 years old diagnosed with cancer 1973-2000. Linked birth certificates identified first subsequent live offspring (n=470). Comparison subjects were identified from remaining birth certificates, frequency-matched on year and age at fatherhood, and race/ethnicity (n=4150). MAIN EXPOSURE: Cancer diagnosis prior to age 20. OUTCOME MEASURES: Pregnancy and infant outcomes identified from birth certificates. RESULTS: Compared with infants born to unaffected males, offspring of cancer survivors had a borderline risk of birth weight <2500 g (RR 1.43, 95% CI 0.99-2.05), with risk associated most strongly with younger age of cancer diagnosis and exposure to any chemotherapy (RR 1.96, 95% CI 1.22-3.17) or radiotherapy (RR 1.95, 95% CI 1.14-3.35). However, they were not at risk of being born prematurely, small for gestational age, having malformations or an altered male:female sex ratio. Overall, female partners of male survivors were not more likely to have maternal complications recorded on birth records versus the comparison group. However, preeclampsia was associated with some cancers, especially central nervous system tumors (RR 3.36, 95% CI 1.63-6.90). CONCLUSIONS: Most pregnancies resulting in live births among partners of male childhood cancer survivors were not at significantly greater risk of complications versus comparison subjects. The possibility of a paternal component affected by prior cancer history influencing predisposition towards some adverse perinatal outcomes merits further investigation

Pregnancy outcomes in female childhood and adolescent cancer survivors: a linked cancer-birth registry analysis

Objective: To compare birth outcomes among childhood and adolescent female cancer survivors who subsequently bear children, relative to those of women without cancer history. Design: Retrospective cohort study. Setting: 4 U.S. regions. Participants: Cancer registries identified girls <20 years, diagnosed with cancer 1973-2000. Linked birth records identified first live births after diagnosis (n=1898). Comparison subjects were selected from birth records (n=14278). Cervical/genital tract cancer cases were analyzed separately. Main Exposure: Cancer diagnosis <20 years. Outcome Measures: Infant low birth weight, preterm delivery, sex ratio, malformations, mortality, delivery method; maternal diabetes, anemia, preeclampsia. Results: Childhood cancer survivors’ infants were more likely to be preterm (relative risk [RR] 1.54, 95% CI 1.30-1.83) and weigh <2500 g (RR 1.31, 95% CI 1.10-1.57). For cervical/genital cancer patients’ offspring, estimates were 1.33 (95% CI 1.13, 1.56), and 1.29 (95% CI 1.10-1.53), respectively. There were no increased risks of malformations, infant death, or altered sex ratio, suggesting no increased germ cell mutagenicity. In exploratory analysis, bone cancer survivors had an increased risk of diabetes (RR 4.92, 95% CI 1.60-15.13), and anemia was more common among brain tumor survivors (RR 3.05, 95% CI 1.16-7.98) and childhood cancer survivors with initial treatment of chemotherapy only (RR 2.45, 95% CI 1.16-5.17). Conclusions: Infants of female childhood and adolescent cancer patients were not at increased risk of malformations or death. Increased occurrence of preterm delivery and low birth weight suggest close monitoring is warranted. Increased diabetes and anemia among sub-groups have not been reported, suggesting areas for study

Can Observation Skills of Citizen Scientists Be Estimated Using Species Accumulation Curves?

Volunteers are increasingly being recruited into citizen science projects to collect observations for scientific studies. An additional goal of these projects is to engage and educate these volunteers. Thus, there are few barriers to participation resulting in volunteer observers with varying ability to complete the project’s tasks. To improve the quality of a citizen science project’s outcomes it would be useful to account for inter-observer variation, and to assess the rarely tested presumption that participating in a citizen science projects results in volunteers becoming better observers. Here we present a method for indexing observer variability based on the data routinely submitted by observers participating in the citizen science project eBird, a broad-scale monitoring project in which observers collect and submit lists of the bird species observed while birding. Our method for indexing observer variability uses species accumulation curves, lines that describe how the total number of species reported increase with increasing time spent in collecting observations. We find that differences in species accumulation curves among observers equates to higher rates of species accumulation, particularly for harder-to-identify species, and reveals increased species accumulation rates with continued participation. We suggest that these properties of our analysis provide a measure of observer skill, and that the potential to derive post-hoc data-derived measurements of participant ability should be more widely explored by analysts of data from citizen science projects. We see the potential for inferential results from analyses of citizen science data to be improved by accounting for observer skill

Francisella tularensis Transmission by Solid Organ Transplantation, 20171.

In July 2017, fever and sepsis developed in 3 recipients of solid organs (1 heart and 2 kidneys) from a common donor in the United States; 1 of the kidney recipients died. Tularemia was suspected only after blood cultures from the surviving kidney recipient grew Francisella species. The organ donor, a middle-aged man from the southwestern United States, had been hospitalized for acute alcohol withdrawal syndrome, pneumonia, and multiorgan failure. F. tularensis subsp. tularensis (clade A2) was cultured from archived spleen tissue from the donor and blood from both kidney recipients. Whole-genome multilocus sequence typing indicated that the isolated strains were indistinguishable. The heart recipient remained seronegative with negative blood cultures but had been receiving antimicrobial drugs for a medical device infection before transplant. Two lagomorph carcasses collected near the donor's residence were positive by PCR for F. tularensis subsp. tularensis (clade A2). This investigation documents F. tularensis transmission by solid organ transplantation