Recurrence of a gonadal stromal cell tumor (Sertoli Leydig cell with heterologous elements) in a teenager

An unusual case of a moderately well-differentiated, encapsulated, Sertoli Leydig cell tumor with heterologous elements recurring 3 years after a conservative unilateral oophorectomy in a 15-year-old female is reported. This is the first case report of a metastatic Sertoli Leydig cell tumor with mucinous heterologous elements. A relative lack of uniformly accepted histological criteria of these tumors makes prognosis difficult to access. The optimal therapy for recurrent Sertoli Leydig cell tumor is unknown. Initial plans of management of this rare neoplasm, follow-up, and current concepts of treatment of recurrences will be discussed.

Role of IFN-gamma in lethal and nonlethal malaria in susceptible and resistant murine hosts

IFN-gamma plays an important role in host defense against microbial disease. Here, we studied the role of IFN-gamma in lethal and nonlethal murine malaria. Administration of recombinant murine IFN-gamma resulted in a dose-dependent protection of SW, BALB/cByJ, and CBA/J mice from the lethal variant of Plasmodium yoelii 17x (PyL) but had little effect on the course of the nonlethal variant of this parasite (PyNL). Administration of recombinant IFN-gamma also resulted in the activation of peritoneal macrophages for increased phagocytosis of malaria-infected erythrocytes and release of H2O2, as measured in vitro. The ability of spleen cells from infected mice to produce endogenous IFN-gamma and release H2O2 during the course of malaria was also studied. In BALB/cByJ mice, which are relatively susceptible to PyL and PyNL, there was an initial burst of IFN-gamma only in response to PyNL whereas in CBA/J mice, which are relatively resistant to these parasites, there was an initial burst of IFN-gamma in response to both PyL and PyNL. The kinetics of H2O2 release corresponded to that of IFN-gamma. In all infections, levels of IFN-gamma declined as parasitemia increased; however, nonlethal infections were characterized by a recovery of both IFN-gamma activity and H2O2 release as parasitemia declined. These data suggest that IFN-gamma may play an important role in modulating the course of malaria infections by activating macrophages for both intracellular and extracellular parasite destruction.

Abstract P5-14-04: Alleviate the pain in the system: Using process improvement and systems design tools to strive for a high quality breast healthcare system in the District of Columbia metro area

Background: Throughout the District of Columbia Metro Area, breast cancer mortality rates are higher than the national average due in part to limited service coordination and lack of access to breast health services along the continuum. The Primary Care Coalition of Montgomery County (PCC) and the Regional Primary Care Coalition (RPCC) are collaborating to improve the efficiency and effectiveness of breast cancer screening, referral, and follow-up so that jurisdictions and clinics in the DC metro area are better positioned to provide 100% low-income women residents with access to breast healthcare. The Regional Initiative builds upon the successes of the PCC Breast Healthcare Process Improvement Project.

Objectives: 1) Adopt the Primary Care-Based Model in three clinics in three other jurisdictions and implement process improvement approaches to show improvements in breast cancer screening, referral, and follow-up; and 2) Develop a cross-jurisdiction learning community to enhance spread throughout the Region.

Methods: The Regional Initiative employs a multi-tiered learning community framework to share data, address systems level barriers, and design new systems for the provision of high-quality care regardless of insurance status. Partners use the Model for Improvement to improve processes at the micro-system level and system design theory drives larger systems changes.

Results: Objective 1: The three adaptation sites represent Prince Georges County, Maryland, Washington, DC, and Fairfax Virginia. After a year of focused process improvement, partnership development, and data collection, initial analysis demonstrates: – All three clinics show increased screening rates approaching 65%, representing the 90th percentile performance in the Healthcare Effectiveness Data and Information Set (HEDIS) for Medicaid breast cancer screening.– At Greater Baden Medical Services in Prince Georges County, Maryland, cycle time between referral and mammography screening decreased from 48 to 27 days.– The Community Health Care Network, Fairfax County, Virginia, worked closely with one mammography provider to decrease the no-show rate for mammography appointments from 26% to 6%.– The Project Team developed a change package to share recommended interventions and successful strategies that have been tested and documented, and can be used by clinics certified as primary care medical homes or in the process of adopting those standards.

Objective 2: The Cross-Jurisdiction Learning Collaborative brings representatives from each jurisdiction together to share breast health measures, success stories, and plan/discuss process improvement activities from a regional perspective. Participants include over 50 breast health providers from around the region: – 17 safety-net clinics– 11 hospital and/or mammography providers– All County and/or State National Breast and Cervical Cancer Early Detection Programs in the Region

Next Steps: Spread learnings regionally and nationally to foster collaboration, replicate the PCC Primary Care-Based Model using the change package, and further improve breast health outcomes for the safety-net population.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-14-04.

Knowledge of cystic fibrosis in patients and their parents

A standardized questionnaire was used to assess knowledge about cystic fibrosis in 28 patients with cystic fibrosis (aged 10 to 21 years) and in the parents of 25 of these patients. Knowledge of disease pathophysiology and treatment was generally comprehensive and detailed; knowledge of the genetics was fair. However, there were conspicuous deficits in the awareness of reproductive risks and of male sterility. Significant predictors of patient knowledge were patient age, sex, and educational level and parental age. Predictors of parent knowledge were Shwachman score, socioeconomic status, and sex of responding parent. Patients rely heavily on parents for information about cystic fibrosis. More than one third of both patients and parents sought more information about the disease and its implications.

Homing gene drives can transfer rapidly between Anopheles gambiae strains with minimal carryover of flanking sequences

CRISPR-Cas9 homing gene drives are designed to induce a targeted double-stranded DNA break at a wild type allele ('recipient'), which, when repaired by the host cell, is converted to the drive allele from the homologous ('donor') chromosome. Germline localisation of this process leads to super-Mendelian inheritance of the drive and the rapid spread of linked traits, offering a novel strategy for population control through the deliberate release of drive individuals. During the homology-based DNA repair, additional segments of the recipient chromosome may convert to match the donor, potentially impacting carrier fitness and strategy success. Using Anopheles gambiae strains with variations around the drive target site, here we assess the extent and nature of chromosomal conversion. We show both homing and meiotic drive contribute as mechanisms of inheritance bias. Additionally, over 80% of homing events resolve within 50 bp of the chromosomal break, enabling rapid gene drive transfer into locally-adapted genetic backgrounds.

Principles behind practice. 4. Natural history

The busy clinician is confronted daily with a wide range of decisions about patient diagnosis and management. The sharpness and scepticism to constantly ask fundamental questions about the natural history of a patient's disease is a talent that a few lucky individuals have. For the rest of us, it is an acquired skill which must be developed and maintained. We suggest the following questions to guide the clinician in taking account of the natural history of disease in everyday clinical practice. How strong is the evidence that the putative consequence of this illness is or is not attributable to some external factor? Can I be sure that this exposure (drug, surgery, social or behavioural therapy, toxic or environmental agent) does not have a long latency and that subsequent development of illness will not ensue? What do I know from long-term prospective studies about the life history of this disease? Does lead time explain the apparent benefit of this diagnostic test or other screening procedure? Does the evidence of the natural history of this disease specifically relate to the characteristics of my patient--age, sex, set of prognostic factors, selected or unselected referral? Is there good evidence from at least one good randomised controlled trial with a "no treatment" control group that this intervention is efficacious (and not hazardous)?

Targeted genomic surveillance of insecticide resistance in African malaria vectors

The emergence of insecticide resistance is threatening the efforts of malaria control programmes, which rely heavily on a limited arsenal of insecticidal tools, such as insecticide-treated bed nets. Importantly, genomic surveillance of malaria vectors can provide critical, policy-relevant insights into the presence and evolution of insecticide resistance, allowing us to maintain and extend the shelf life of these interventions. Yet the complex genetic architecture of resistance, combined with resource constraints in malaria-endemic settings, have thus far precluded the widespread use of genomics in routine surveillance. Meanwhile, stakeholders in sub-Saharan Africa are moving towards locally driven, decentralised generation of genomic data, underscoring the need for standardised and robust genomics workflows. To address this need, we demonstrate an approach to targeted genomic surveillance in Anopheles gambiae s.l with Illumina sequencing. We target 90 genomic loci in the Anopheles gambiae s.l genome, including 55 resistance-associated mutations and 35 ancestry informative markers. This protocol is coupled with advanced, automated software for accurate and reproducible variant analysis. We are able to elucidate population structure and ancestry in our cohorts and accurately identify most species in the An. gambiae species complex. We report frequencies of variants at insecticide-resistance loci and explore the continued evolution of the pyrethroid target site, the Voltage-gated sodium channel. Applying the platform to a recently established colony of field-caught resistant mosquitoes (Siaya, Kenya), we identified seven independent resistance-associated variants contributing to reduced efficacy of insecticide-treated nets in East Africa. Additionally, we leverage a machine learning algorithm (XGBoost) to demonstrate the possibility of predicting bioassay mortality using genotypes alone. This achieved very high accuracy (73%), demonstrating the potential of targeted genomics to predictively monitor insecticide resistance. Together these tools provide a practical, scalable solution for resistance monitoring while advancing the goal of building local genomic surveillance capacity in sub-Saharan Africa.

Global cDNA amplification combined with real-time RT-PCR: accurate quantification of multiple human potassium channel genes at the single cell level

We have developed a sensitive quantitative RT-PCR procedure suitable for the analysis of small samples, including single cells, and have used it to measure levels of potassium channel mRNAs in a panel of human tissues and small numbers of cells grown in culture. The method involves an initial global amplification of cDNA derived from all added polyadenylated mRNA followed by quantitative RT-PCR of individual genes using specific primers. In order to facilitate rapid and accurate processing of samples, we have adapted the approach to allow use of TaqMan real-time quantitative PCR. We demonstrate that the approach represents a major improvement over existing conventional and real-time quantitative PCR approaches, since it can be applied to samples equivalent to a single cell, is able to accurately measure expression levels equivalent to less than 1/100th copy/cell (one specific cDNA molecule present amongst 10(8) total cDNA molecules). Furthermore, since the initial step involves a global amplification of all expressed genes, a permanent cDNA archive is generated from each sample, which can be regenerated indefinitely for further expression analysis.

Role of a children's hospital safety centre in injury control

Over the past 13 years, child safety centres have been established at several Australian Children's hospitals. In a short time, they have developed an important role in community injury control programmes. These centres provide an efficient conduit for transferring up-to-date injury surveillance and prevention information to families, industry, health and education professionals, and government. The activities of the Child Safety Centre at the Royal Children's Hospital in Melbourne are described, together with ways in which a degree of self-funding can be achieved.

Measuring the Impact of Genetic Heterogeneity and Chromosomal Inversions on the Efficacy of CRISPR-Cas9 Gene Drives in Different Strains of Anopheles gambiae

The human malaria vector Anopheles gambiae is becoming increasingly resistant to insecticides, spurring the development of genetic control strategies. CRISPR-Cas9 gene drives can modify a population by creating double-stranded breaks at highly specific targets, triggering copying of the gene drive into the cut site ("homing"), ensuring its inheritance. The DNA repair mechanism responsible requires homology between the donor and recipient chromosomes, presenting challenges for the invasion of laboratory-developed gene drives into wild populations of target species An. gambiae species complex, which show high levels of genome variation. Two gene drives (vas2-5958 and zpg-7280) were introduced into three An. gambiae strains collected across Africa with 5.3-6.6% variation around the target sites, and the effect of this variation on homing was measured. Gene drive homing across different karyotypes of the 2La chromosomal inversion was also assessed. No decrease in gene drive homing was seen despite target site heterology, demonstrating the applicability of gene drives to wild populations.

CRISPR-Mediated Cassette Exchange (CriMCE): A Method to Introduce and Isolate Precise Marker-Less Edits

The introduction of small unmarked edits to the genome of insects is essential to study the molecular underpinnings of important biological traits, such as resistance to insecticides and genetic control strategies. Advances in CRISPR genome engineering have made this possible, but prohibitively laborious for most laboratories due to low rates of editing and the lack of a selectable marker. To facilitate the generation and isolation of precise marker-less edits we have developed a two-step method based on CRISPR-mediated cassette exchange (CriMCE) of a marked placeholder for a variant of interest. This strategy can be used to introduce a wider range of potential edits compared with previous approaches while consolidating the workflow. We present proof-of-principle that CriMCE is a powerful tool by engineering three single nucleotide polymorphism variants into the genome of Anopheles gambiae, with 5-41 × higher rates of editing than homology-directed repair or prime editing.

Growth of the genital primordium as a marker to describe a time course for the heterogonic larval development in Strongyloides stercoralis

A time course for the heterogonic development of Strongyloides stercoralis is described and a method for distinguishing the early larval stages of this nematode is proposed. The number of cells in the developing gonad were counted at various time intervals of incubation, along with the percentage of larvae in molt at each interval. The time course of growth of the gonad follows a pattern comparable to that reported for body length in an idealized general nematode. A model for the heterogonic development of S. stercoralis is proposed, which, although similar to other nematode developmental models, is stage specific for S. stercoralis, allowing the otherwise morphologically similar rhabditiform stages (L1, L2) to be distinguished.