The transcription factor c-Myb regulates CD8+ T cell stemness and antitumor immunity.

Stem cells are maintained by transcriptional programs that promote self-renewal and repress differentiation. Here, we found that the transcription factor c-Myb was essential for generating and maintaining stem cells in the CD8+ T cell memory compartment. Following viral infection, CD8+ T cells lacking Myb underwent terminal differentiation and generated fewer stem cell-like central memory cells than did Myb-sufficient T cells. c-Myb acted both as a transcriptional activator of Tcf7 (which encodes the transcription factor Tcf1) to enhance memory development and as a repressor of Zeb2 (which encodes the transcription factor Zeb2) to hinder effector differentiation. Domain-mutagenesis experiments revealed that the transactivation domain of c-Myb was necessary for restraining differentiation, whereas its negative regulatory domain was critical for cell survival. Myb overexpression enhanced CD8+ T cell memory formation, polyfunctionality and recall responses that promoted curative antitumor immunity after adoptive transfer. These findings identify c-Myb as a pivotal regulator of CD8+ T cell stemness and highlight its therapeutic potential.

Challenging the Myth That the Sexually Abused Female Child Must Have Genital Injuries.

This article aims to define and describe female genital anatomy, the changes that occur in the genitalia during growth and puberty, and during sexual response and intercourse. It elaborates the reasons for normal genital examination findings in most female children who have been sexually abused and explains why the absence of findings of genital trauma should not be used to challenge the credibility of the child's history of sexual abuse.

Association of HIV Preexposure Prophylaxis With Incidence of Sexually Transmitted Infections Among Individuals at High Risk of HIV Infection.

Importance: Emerging evidence suggests that risk of bacterial sexually transmitted infections (STIs) increases among gay and bisexual men following initiation of HIV preexposure prophylaxis (PrEP). Objective: To describe STI incidence and behavioral risk factors among a cohort of predominantly gay and bisexual men who use PrEP, and to explore changes in STI incidence following PrEP commencement. Design, Setting, and Participants: The Pre-exposure Prophylaxis Expanded (PrEPX) Study, a multisite, open-label intervention study, was nested within the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance (ACCESS) clinic network. A total of 4275 participants were enrolled (July 26, 2016-April 1, 2018) in Victoria, Australia. Of these, 2981 enrolled at 5 ACCESS clinics (3 primary care, 1 sexual health, and 1 community-based HIV rapid testing service), had at least 1 follow-up visit, and were monitored until April 30, 2018. Exposures: Upon enrollment, participants received daily oral tenofovir disoproxil fumurate and emtricitabine for HIV PrEP, quarterly HIV and STI testing, and clinical monitoring. Main Outcomes and Measures: The primary outcome was incidence of chlamydia, gonorrhea, or syphilis. Incidence rates and hazard ratios describing behavioral risk factors of STI diagnosis were calculated. Incidence rate ratios (IRRs), adjusted for change in testing frequency, described changes in STI incidence from 1-year preenrollment to study follow-up among participants with preenrollment testing data (n = 1378). Results: Among the 2981 individuals (median age, 34 years [interquartile range, 28-42]), 98.5% identified as gay or bisexual males, 29% used PrEP prior to enrollment, 89 (3%) withdrew and were censored at date of withdrawal, leaving 2892 (97.0%) enrolled at final follow-up. During a mean follow-up of 1.1 years (3185.0 person-years), 2928 STIs were diagnosed among 1427 (48%) participants (1434 chlamydia, 1242 gonorrhea, 252 syphilis). STI incidence was 91.9 per 100 person-years, with 736 participants (25%) accounting for 2237 (76%) of all STIs. Among 2058 participants with complete data for multivariable analysis, younger age, greater partner number, and group sex were associated with greater STI risk, but condom use was not. Among 1378 participants with preenrollment testing data, STI incidence increased from 69.5 per 100 person-years prior to enrollment to 98.4 per 100 person-years during follow-up (IRR, 1.41 [95% CI, 1.29-1.56]). After adjusting for testing frequency, the increase in incidence from 1 year preenrollment to follow-up was significant for any STI (adjusted IRR, 1.12 [95% CI, 1.02-1.23]) and for chlamydia (adjusted IRR, 1.17 [95% CI, 1.04-1.33]). Conclusions and Relevance: Among gay and bisexual men using PrEP, STIs were highly concentrated among a subset, and receipt of PrEP after study enrollment was associated with an increased incidence of STIs compared with preenrollment. These findings highlight the importance of frequent STI testing among gay and bisexual men using PrEP.

The optimal timing of forensic evidence collection following paediatric sexual assault.

BACKGROUND: Forensic evidence collection following sexual assault has an important medico-legal role. Despite the advent of DNA profiling, research into the optimisation of forensic biological specimen collection is limited. This has led to inconsistent and variable guidelines for forensic evidence collection. The guidelines in this jurisdiction (Victoria, Australia) recommends that specimens be collected up to 7 days following sexual assault in some circumstances. The aims of this study were to determine the optimal times post sexual assault for the collection of forensic biological evidence in paediatric cases (aged 0-17 years). METHODS: A retrospective review of paediatric sexual assault cases seen by the Victorian Forensic Paediatric Medical Service (VFPMS) between 1 January 2009, and 1 May 2016, was undertaken. Specimen site and collection times post assault were collated from VFPMS medico-legal reports and compared with the forensic evidence analysis results reported by the Victoria Police, Forensic Services Department. In addition, a survey of recommended forensic specimen collection times post assault in the different Australian jurisdictions was undertaken for comparison. RESULTS: Within the 6 year 5 month period studied there were 122 cases consisting of 562 different forensic specimens that were collected and analysed. 62 (51%) of cases produced one or more positive forensic result and, of the 562 specimens collected, 153 (27%) were positive for one or more of foreign DNA, spermatozoa, semen or saliva. Foreign DNA was more likely to be found if forensic specimens were collected during the first 24 h after the assault as compared with those collected at 25-48 h, (p < 0.005). Similarly, spermatozoa were identified more frequently on swabs collected at 0-24 h compared to 25-48 h (p < 0.002). Foreign DNA was not identified beyond 48 h post assault and spermatozoa were not identified beyond 36 h. Saliva and semen were not identified beyond 24 h. The youngest victims with positive forensic evidence were 2-3 years old. The survey of current forensic specimen collection practice in Australia shows that the guidelines for timing of forensic evidence collection in child sexual assault cases is highly variable between jurisdictions. CONCLUSIONS: Our results highlight the importance of collecting forensic specimens as a matter of urgency, regardless of age, within the first 48 h post assault. Although there is need for further research, the findings indicate a need for the re-evaluation of current guidelines for specimen collection in paediatric sexual assault cases.

A Phase I study of gemtuzumab ozogamicin (GO) in combination with busulfan and cyclophosphamide (Bu/Cy) and allogeneic stem cell transplantation in children with poor-risk CD33+ AML: a new targeted immunochemotherapy myeloablative conditioning (MAC) regimen.

Children with high-risk acute myelogenous leukemia (AML) (induction failure [IF], refractory relapse [RR], third complete remission [CR3]) have dismal outcomes. Over 80% of AML patients express CD33, a target of gemtuzumab ozogamicin (GO). GO is an active drug in childhood AML but has not been studied in a myeloablative conditioning regimen. We sought to determine the safety of GO in combination with busulfan/cyclophosphamide (Bu/Cy) conditioning before allogeneic hematopoietic stem cell transplantation (alloSCT). GO was administered on day -14 at doses of 3.0, 4.5, 6.0, and 7.5 mg/m(2), busulfan on days -7, -6, -5, -4 (12.8-16.0 mg/kg), and cyclophosphamide on days -3 and -2 (60 mg/kg/day). GVHD prophylaxis consisted of tacrolimus and mycophenolate mofetil. We enrolled 12 patients: 8 IF, 3 RR, 1 CR3; median age: 3 years (1-17); median follow-up: 1379 days (939-2305). Nine received umbilical cord blood (UCB), 2 matched unrelated donors (MUDs) and 1 HLA-matched sibling donor: 3 patients each at GO doses of 3.0, 4.5, 6.0, or 7.5 mg/m(2). No dose-limiting toxicities secondary to GO were observed. Day 100 treatment-related mortality (TRM) was 0%. Myeloid and platelet engraftment was observed in 92% and 75% of patients at median day 22 (12-40) and 42 (21-164), respectively. Median day +30 donor chimerism was 99% (85%-100%). The probability of grade II-IV acute graft-versus-host disease (aGVHD) was 42% and chronic GVHD (cGVHD) was 28%. One-year overall survival (OS) and event-free survival (EFS) was 50% (95% confidence interval [CI], 20.8-73.6). GO combined with Bu/Cy regimen followed by alloSCT is well tolerated in children with poor-risk AML. GO at 7.5 mg/m(2) in combination with Bu/Cy is currently being tested in a phase II study.

A phase 1, multicenter study evaluating the safety and efficacy of KITE-585, an autologous anti-BCMA CAR T-cell therapy, in patients with relapsed/refractory multiple myeloma.

Despite advances in treatment, most patients with multiple myeloma (MM) will relapse, and long-term survival remains poor. B-cell maturation antigen (BCMA) is an ideal therapeutic target as it is expressed throughout the disease course with normal tissue expression limited to plasma and some B-cell lineages. This phase 1, multicenter, first-in-human study evaluated the safety and efficacy of KITE-585, an autologous anti-BCMA chimeric antigen receptor (CAR) T-cell therapy, in patients with relapsed/refractory MM (RRMM). Key eligibility criteria included measurable MM and progression, defined by the International Myeloma Working Group Consensus Criteria within 60 days of the last treatment. Patients underwent leukapheresis and subsequently received a 3-day conditioning therapy regimen (cyclophosphamide [300 mg/m2/day] and fludarabine [30 mg/m2/day]). Patients then received a flat dose of 3 × 107 to 1 × 109 KITE-585 CAR T cells in a 3+3 dose-escalation design. The primary endpoint was incidence of adverse events (AEs) defined as dose-limiting toxicities (DLTs). Key secondary and exploratory endpoints included efficacy outcomes, incidence of AEs, levels of KITE-585 in blood, serum cytokines, and incidence of anti-BCMA CAR antibodies. Seventeen patients were enrolled, and 14 received KITE-585 with a median follow-up of 12.0 months. The median age of patients was 56 years, 41.2% had an Eastern Cooperative Oncology Group performance status of 1, 92.9% had baseline BCMA expression on plasma cells, and median number of prior therapies was 5.5. No patients experienced a DLT, all patients experienced ≥ 1 grade ≥ 3 treatment-emergent AE (TEAE), and no grade 5 TEAEs were observed. There were no grade ≥ 3 events of cytokine release syndrome, neurologic events, or infections; all were grade 1 or 2, and each occurred in 21.4% of patients. Among all patients infused with KITE-585, 1 patient who received 3 × 107 anti-BCMA CAR T cells experienced a partial response. Median peak CAR T-cell expansion was low (0.98 cells/µL), as were median peak serum levels of CAR-associated cytokines, including interferon-γ (61.45 pg/mL) and interleukin-2 (0.9 pg/mL). KITE-585 demonstrated a manageable safety profile; however, the limited CAR T-cell expansion and associated lack of anti-tumor response in patients with RRMM treated with KITE-585 is consistent with the minimal CAR T-cell activity observed.

miR-155 harnesses Phf19 to potentiate cancer immunotherapy through epigenetic reprogramming of CD8+ T cell fate.

T cell senescence and exhaustion are major barriers to successful cancer immunotherapy. Here we show that miR-155 increases CD8+ T cell antitumor function by restraining T cell senescence and functional exhaustion through epigenetic silencing of drivers of terminal differentiation. miR-155 enhances Polycomb repressor complex 2 (PRC2) activity indirectly by promoting the expression of the PRC2-associated factor Phf19 through downregulation of the Akt inhibitor, Ship1. Phf19 orchestrates a transcriptional program extensively shared with miR-155 to restrain T cell senescence and sustain CD8+ T cell antitumor responses. These effects rely on Phf19 histone-binding capacity, which is critical for the recruitment of PRC2 to the target chromatin. These findings establish the miR-155-Phf19-PRC2 as a pivotal axis regulating CD8+ T cell differentiation, thereby paving new ways for potentiating cancer immunotherapy through epigenetic reprogramming of CD8+ T cell fate.

Test Dose Pharmacokinetics in Pediatric Patients Receiving Once-Daily IV Busulfan Conditioning for Hematopoietic Stem Cell Transplant: A Reliable Approach?

Intravenous (IV) busulfan test dose pharmacokinetics (PK) has been shown to accurately predict once-daily dose requirements and improve outcomes in adult transplant patients, but there are limited data to support this approach in children. Test doses of busulfan ∼0.8 mg/kg were infused over 2 to 3 hours, followed by serial sampling to 4-6 hours postinfusion in pediatric hematopoietic stem cell transplant recipients (n = 5). Once-daily busulfan doses were calculated based on a myelosuppressive area under the concentration-time curve (AUC) target of ∼3700 to 4000 µmol·min/L and assumed dose-proportionality to the test dose. PK analysis was then repeated at full daily doses within 6-8 days of test dose administration. Plasma PK samples collected under test and full-dose conditions were analyzed using validated commercial assays and noncompartmental methods. In 4 out of 5 patients, PK estimates after once-daily IV busulfan administration differed in comparison to test dose estimates (AUC range -38.2% to +49.7%, clearance range -34.3% to +61.8%). Patients 1, 2, and 3 required increases in remaining daily busulfan doses to achieve AUC targets, and no adjustment was required in patient 4. Patient 5's AUC was 49.7% higher than expected, and he subsequently developed fatal sinusoidal obstruction syndrome. In our experience with pediatric patients, test dose PK failed to reliably predict daily dosing requirements with large discrepancies from predicted AUC targets. This article highlights the necessity for therapeutic drug monitoring of IV busulfan and inadvisability of relying solely on test-dose busulfan PK in pediatric patients. Furthermore, clinicians should consider strategies to expedite dose adjustments in real time.

Does the forensic physician have a role beyond injury documentation and specimen collection in Australia? A personal view.

Clinical forensic medicine (CFM), as a single discipline, encompasses a number of areas of medico-legal practice including injury interpretation, management of sexual and physical assault cases (both adult and child; alleged victim and offender), mental health issues, traffic medicine, custodial medicine and toxicology. The cases are usually alive but in some jurisdictions the forensic practitioner also engages in death investigation with some undertaking autopsies. During the last 20-30 years, the discipline has fragmented with areas being hived off to other medical specialist disciplines and, importantly, to nurses. Any user of forensic services wants the best value for money particularly when under financial pressure. To this end, governments have sought savings through privitisation of services and/or the utilisation of less qualified personnel to undertake some or all of the tasks. This places CFM at a crossroads. To ensure survival, the discipline needs to reconsider its direction and performance, convince stakeholders of its relevance and importance, and lift its profile within the legal, academic and medical world. It will need to think outside the square, place greater emphasis on the 'clinical' and relinquish those activities that are better undertaken by less expensive and qualified personnel. The establishment of meaningful research and academic centres are essential. The loss of and/or failure to grow CFM will result in the loss of a skills base and the subsequent potential for the miscarriages of justice.

Evaluation of forensic medical history taking from the child in cases of child physical and sexual abuse and neglect.

BACKGROUND: Suspected child physical abuse, sexual abuse and neglect are not uncommon presentations. As part of the assessment of these cases, a forensic medical history may be taken. This forensic history is used not only to determine the steps necessary to address the child's wellbeing but also to direct the forensic examination. Currently, there is no clear consensus on whether or not a forensic medical history should consistently be considered an integral element within the paediatric forensic evaluation. This study examines the value derived by the medical practitioner taking a forensic medical history rather than relying on hearsay evidence when a child presents for an assessment. METHODS: A retrospective review of paediatric cases seen by the Victorian Forensic Paediatric Medical Service (VFPMS) between 2014 and 2015 was undertaken. 274 forensic case reports were reviewed and the data was entered into an Excel spread sheet and analysed using chi squared tests within STATA®. RESULTS: With increasing age of the child, a forensic medical history is significantly more likely to be taken. Additional information is made available to the medical practitioner what would otherwise have been provided if the medical practitioner relied only on the interview conducted by the police. Discrepancies observed between the official third parties (police or child protection) report of what a child has said and what the child says to the medical practitioner decrease with age, as do discrepancies observed between the child's version of events and a third party's (eg. parents, caregivers, friends) version of events. CONCLUSIONS: The study showed that by taking a forensic medical history from the child additional information can be obtained. Further, that there is a value in the examining medical practitioner taking a forensic medical history from children in cases of child physical and sexual abuse and neglect.

"Binkie flutter," an apparently voluntary behavior of infants, possibly related to vibratory jaw movements in dogs: report of 4 cases.

Four cases of apparently voluntary rapid vibratory pacifier movements occurring in normal, unstressed infants up to 1 year of age and captured on video are presented. I speculate on the possible relationship of the movements to similar vibratory jaw movements in dogs, in which species they may represent a neuromuscular mechanism for rapid feedback control.