Aeromedical Decision Making for Military Aircrew with Graves’ Disease

BACKGROUND: Graves’ Disease (GD) is a common cause of hyperthyroidism. Although definitive treatment with radioactive iodine (RAI) is preferred for military aircrew, there are cultural and individual differences in receptivity toward RAI, and clinical guidelines that recommend antithyroid drugs (ATD) as the first line therapy. We examined a case series of Republic of Singapore Air Force (RSAF) aviators with GD treated with ATD and the impact of their condition on aeromedical disposition.CASE SERIES: All RSAF aircrew diagnosed with GD and treated with ATD over a 15-yr period were retrospectively identified and analyzed to determine the impact on their fitness for flying duties. The mean age of the 13 aircrew was 33 ± 7.1 yr (range, 25–47 yr), with 11 (84.6%) being males. There were 10 (76.9%) who had ATD as the only treatment while 3 (23.1%) were initially treated with ATD but subsequently underwent RAI or surgery. Of the 10 treated with only ATD, 3 (30.0%) were returned to restricted flying, 6 (60.0%) were returned to unrestricted flying, and 1 (10.0%) is still undergoing ATD titration. There were 10 (76.9%) aircrew who were returned to some form of flying duties while on low doses of ATD.DISCUSSION: This case series suggests that ATD is a viable treatment modality in the aeromedical management of military aviators with GD and it is possible to return military aircrew on a stable maintenance dose of ATD to flying duties. A framework is proposed to support the aeromedical decision-making process for military aircrew in the treatment of GD.Loh EH-T, Soh FW, See B, Tan BBC. Aeromedical decision making for military aircrew with Graves’ disease. Aerosp Med Hum Perform. 2021; 92(12):980–986.

DEGREE OF INVASION OF HORSES PARASCARIS EQUORUM UNDER DIFFERENT CONDITIONS OF CONTENT

The significant dependence on the invasion of Parascaris equorum horses with different maintenance technologies was studied. Methods of helminthocoprooscopy revealed the spread of parascaridosis of horses kept in stable and herd conditions in the Pobeda farm in the Cheremshansky district of the Republic of Tatarstan. The high invasion of animals with herd and stable housing is apparently associated with a large contamination of horse stalls, stables, care items and the surrounding area with parascaride eggs. The maximum parasiticidal infection of horses was established with stable maintenance. As a result of the studies, it was found that the maximum extent of invasion (EI) of horses in the examined farm with stable technology of keeping was 42.8 % and herd content was 37.5 %. The intensity of invasion (II) by parascarides varied from 23.7±3.4 to 77.3±5.6 ind. eggs in 1 g of feces, depending on the technology of maintenance.

Investigating the Potential Impact of Dosing Tolerance to Facilitate Use of Nplate Self-Administration in Adult Patients with ITP

Background and Objective: Romiplostim, is a TPO agonist approved for the treatment for adult ITP. It follows a weight-based and platelet response-guided dose titration algorithm to maintain patients' platelet counts (PC) between 50 and 200x10 9/L, after which a maintenance dose is administered once weekly to keep platelet counts within the target range. While self-administration of romiplostim maintenance dose has been approved in EU for adult patients, in the US romiplostim is only approved for weekly administration by a healthcare provider (HCP) using an 0.01 mL graduation syringe to ensure dosing accuracy; a dose tolerance margin of romiplostim has never been investigated before. The following work explores the impact of dosing tolerance on PC to assess the feasibility of romiplostim self-administration in adult ITP patients. Methods: The analysis was based on a previously developed pharmacodynamic model of romiplostim in ITP patients (Perez-Ruixo et al, 2012, Gibiansky et al, 2021). Previous romiplostim clinical studies in patients with ITP were leveraged to develop an updated model of 475 ITP patients (>50 kg, weekly romiplostim total dose > 100 µg and between 1 and 10 µg/kg stable maintenance dose for at least 1 month, self-administration) and assess potential differences in PC between ITP patients who qualify for self-administration and the general adult ITP population. Comparison of observed and model predicted PC and romiplostim dose over time confirmed the adequacy of the model to assess the impact of varying dose tolerances on PC that may occur with self-administration. Under the proposed guidelines for romiplostim self-administration eligibility, an adult patient would self-administer up to 4 weekly stable maintenance doses of romiplostim between two platelet measurements 1 month apart. To evaluate the impact on PC over 1 month when patients self-administered all four weekly doses versus patients receiving the same prescribed dose by a healthcare provider, three dosing scenarios were considered: (1) exact titrated dose (no dose deviation), (2) titrated dose plus 0.03 mL or 15 µg of romiplostim, and (3) titrated dose minus 0.03 mL or 15 µg of romiplostim. To further characterize the number of ITP patients with clinically meaningful platelet deviations, the predicted number of virtual patients with a PC below 30 x10 9/L or above 400 x10 9/L were also summarized for each simulated scenario. Lastly, the simulated population was divided into four groups based on the magnitude of their prescribed dose and used to evaluate whether the prescribed romiplostim dose influences platelet excursion rates following the investigated dose scenarios. Results: Simulations suggest that 4 successive weekly doses of ± 0.03 mL (or ± 15 µg) the prescribed romiplostim dose is unlikely to cause a significant change in platelet excursion rates relative to continuous administration of the exact prescribed dose. No meaningful increase (0.1 - 0.4%) was observed in the predicted excursion rates across these thresholds for either the under- or overdosing scenarios (Figure 1). This results also show that while there is a slight trend between the magnitude of the prescribed dose and the fraction of subjects that experience a platelet excursion, it does not result in a meaningful increase (<4%) in platelet excursions in any of the evaluated subgroups. Specifically, we observed minimal changes in the fraction of patients with a platelet excursion outside the potentially clinically meaningful thresholds across all simulated dose groups and dosing scenarios (Table 1). The results from this analysis suggest that possible dosing variance expected from the self-administration of romiplostim by an eligible lay person (± 0.03 mL or 15 μg) with monthly PC evaluation will not lead to a significant increase in the rate of platelet count excursions for patients who achieve a stable romiplostim dose and meet the proposed eligibility criteria. Figure 1 Figure 1. Disclosures Serrano Castillo: Amgen: Current Employment, Current equity holder in publicly-traded company. Saad: Amgen: Current Employment, Current equity holder in publicly-traded company. Wang: Amgen Inc: Current Employment, Current equity holder in publicly-traded company. Zhang: Amgen: Current Employment, Current equity holder in publicly-traded company. Chow: Amgen: Current Employment, Current equity holder in publicly-traded company. Doshi: Amgen: Current equity holder in publicly-traded company; Amgen: Current Employment.

EVALUATION OF TONGUE FORCE USING PIEZOELECTRIC SENSOR IN TONGUE THRUSTING PATIENTS

Tooth position and the form of the dental arch are subject to constant pressure from the circum-oral muscles and the tongue. Stable maintenance of the position of the teeth and the form of the dental arch is thought to depend on the balance of these pressures. Literature regarding the association of tongue force and the malocclusion remains controversial. Hence the present study aimed to measure the tongue force among the tongue thrusting patients using piezoelectric sensor and to compare with the control group. The results of the present study showed that there was no statistical significant difference between the two groups. This could be because of small sample size, which leads for future scope to increase in the sample size.

A Novel UC Exclusion Diet and Antibiotics for Treatment of Mild to Moderate Pediatric Ulcerative Colitis: A Prospective Open-Label Pilot Study

Background: As the microbiome plays an important role in instigating inflammation in ulcerative colitis (UC), strategies targeting the microbiome may offer an alternative therapeutic approach. The goal of the pilot trial was to evaluate the potential efficacy and feasibility of a novel UC exclusion diet (UCED) for clinical remission, as well as the potential of sequential antibiotics for diet-refractory patients to achieve remission without steroids. Methods: This was a prospective, single-arm, multicenter, open-label pilot study in patients aged 8–19, with pediatric UC activity index (PUCAI) scores >10 on stable maintenance therapy. Patients failing to enter remission (PUCAI < 10) on the diet could receive a 14-day course of amoxycillin, metronidazole and doxycycline (AMD), and were re-assessed on day 21. The primary endpoint was intention-to-treat (ITT) remission at week 6, with UCED as the only intervention. Results: Twenty-four UCED treatment courses were given to 23 eligible children (mean age: 15.3 ± 2.9 years). The median PUCAI decreased from 35 (30–40) at baseline to 12.5 (5–30) at week 6 (p = 0.001). Clinical remission with UCED alone was achieved in 9/24 (37.5%). The median fecal calprotectin declined from 818 (630.0–1880.0) μg/g at baseline to 592.0 (140.7–1555.0) μg/g at week 6 (p > 0.05). Eight patients received treatment with antibiotics after failing on the diet; 4/8 (50.0%) subsequently entered remission 3 weeks later. Conclusion: The UCED appears to be effective and feasible for the induction of remission in children with mild to moderate UC. The sequential use of UCED followed by antibiotic therapy needs to be evaluated as a microbiome-targeted, steroid-sparing strategy.

Plasmidome of Listeria spp.—The repA-Family Business

Bacteria of the genus Listeria (phylum Firmicutes) include both human and animal pathogens, as well as saprophytic strains. A common component of Listeria spp. genomes are plasmids, i.e., extrachromosomal replicons that contribute to gene flux in bacteria. This study provides an in-depth insight into the structure, diversity and evolution of plasmids occurring in Listeria strains inhabiting various environments under different anthropogenic pressures. Apart from the components of the conserved plasmid backbone (providing replication, stable maintenance and conjugational transfer functions), these replicons contain numerous adaptive genes possibly involved in: (i) resistance to antibiotics, heavy metals, metalloids and sanitizers, and (ii) responses to heat, oxidative, acid and high salinity stressors. Their genomes are also enriched by numerous transposable elements, which have influenced the plasmid architecture. The plasmidome of Listeria is dominated by a group of related replicons encoding the RepA replication initiation protein. Detailed comparative analyses provide valuable data on the level of conservation of these replicons and their role in shaping the structure of the Listeria pangenome, as well as their relationship to plasmids of other genera of Firmicutes, which demonstrates the range and direction of flow of genetic information in this important group of bacteria.

Sexual morph specialisation in a trioecious nematode balances opposing selective forces.

The coexistence of different mating strategies, whereby a species can reproduce both by selfing and outcrossing, is an evolutionary enigma that has long intrigued biologists (Darwin, 1877). Theory predicts only two stable mating states : outcrossing with strong inbreeding depression or selfing with weak inbreeding depression. As these two mating strategies are subject to opposing selective forces, mixed breeding systems are thought to be a rare transitory state, yet they have been found to persist even after multiple speciation events. We hypothesise that if each mating strategy plays a distinctive role during the species life history, opposing selective pressures could be balanced, permitting the stable co-existence of selfing and outcrossing sexual morphs. In this scenario, we would expect each sexual morph to be specialised in their respective roles. Here we show, using a combination of behavioural, physiological and gene expression studies, that the selfing (hermaphrodite) and outcrossing (female) sexual morphs of the trioecious nematode Auanema freiburgensis have distinct adaptations optimised for their different roles during the life cycle. A. freiburgensis hermaphrodites are produced under stressful conditions, are specialised for dispersal to new habitat patches and exhibit metabolic and intestinal changes that enable them to meet the energetic cost of dispersal and reproduction. In contrast, A. freiburgensis females are produced in favourable conditions, facilitate rapid population growth and compensate for the lack of reproductive assurance by reallocating resources from intestinal development to robust mate-finding behaviour. The specialisation of each mating system for their role in the life cycle could balance opposing selective forces allowing the stable maintenance of both outcrossing and selfing mating systems in A. freiburgensis.

The selfish yeast plasmid utilizes the condensin complex and condensed chromatin for faithful partitioning

Equipartitioning by chromosome association and copy number correction by DNA amplification are at the heart of the evolutionary success of the selfish yeast 2-micron plasmid. The present analysis reveals frequent plasmid presence near telomeres (TELs) and centromeres (CENs) in mitotic cells, with a preference towards the former. Inactivation of Cdc14 causes plasmid missegregation, which is correlated to the non-disjunction of TELs (and of rDNA) under this condition. Induced missegregation of chromosome XII, one of the largest yeast chromosomes which harbors the rDNA array and is highly dependent on the condensin complex for proper disjunction, increases 2-micron plasmid missegregation. This is not the case when chromosome III, one of the smallest chromosomes, is forced to missegregate. Plasmid stability decreases when the condensin subunit Brn1 is inactivated. Brn1 is recruited to the plasmid partitioning locus (STB) with the assistance of the plasmid-coded partitioning proteins Rep1 and Rep2. Furthermore, in a dihybrid assay, Brn1 interacts with Rep1-Rep2. Taken together, these findings support a role for condensin and/or condensed chromatin in 2-micron plasmid propagation. They suggest that condensed chromosome loci are among favored sites utilized by the plasmid for its chromosome-associated segregation. By homing to condensed/quiescent chromosome locales, and not over-perturbing genome homeostasis, the plasmid may minimize fitness conflicts with its host. Analogous persistence strategies may be utilized by other extrachromosomal selfish genomes, for example, episomes of mammalian viruses that hitchhike on host chromosomes for their stable maintenance.