Structural Snapshots of Proteus vulgaris Tryptophan Indole-Lyase Reveal Insights into the Catalytic Mechanism.

Tryptophan indole lyase (TIL; [E.C. 4.1.99.1]) is a bacterial pyridoxal-5'-phosphate (PLP)-dependent enzyme that catalyzes reversible ß-elimination of indole from L-tryptophan. The mechanism of elimination of indole from L-tryptophan starts with the formation of an external aldimine of the substrate and PLP, followed by deprotonation of the α-CH of the substrate, forming a resonance-stabilized quinonoid intermediate. Proton transfer to C3 of the indole ring and carbon-carbon bond cleavage of the quinonoid intermediate provide indole and aminoacrylate bound to PLP, which then releases indole, followed by iminopyruvate. We have now determined the X-ray crystal structures of TIL complexes with (3S)-dioxindolyl-l-alanine, an inhibitor, and with substrates L-tryptophan, 7-aza-L-tryptophan, and S-ethyl-l-cysteine (SEC) in the presence of benzimidazole (BZI), an isostere of the product indole. These structures show a mixture of gem-diamine, external aldimine, quinonoid, and aminoacrylate intermediates, in both open and closed active site conformations. In the closed conformations of L-tryptophan, (3S)-dioxindolyl-l-alanine, and 7-aza-L-tryptophan complexes, hydrogen bonds form between Asp-133 with N1 of the ligand heterocyclic ring and NE2 of His-458 in the small domain of TIL. This hydrogen bond also forms in the BZI complex with the aminoacrylate intermediates formed from both L-tryptophan and SEC. The closed quinonoid complex of 7-aza-L-tryptophan shows that the azaindole ring in the closed conformation is bent out of plane of the Cß-C3 bond by about 40°, putting it in a geometry that leads toward the transition-state geometry. Thus, both conformational dynamics and substrate activation play critical roles in the reaction mechanism of the TIL.

Case-control study to identify the causative agents of ophthalmia and conjunctivitis in goats in Savannakhet province of Lao PDR.

Pinkeye is a highly contagious disease of goats with different aetiologies. Surveys in Lao PDR have identified eye lesions typical of pinkeye as a common condition, however, this has not been confirmed diagnostically, and the responsible pathogens have not been identified. A matched case-control study was implemented in 70 goat holdings from Savannakhet province, Lao PDR, to detect agents causing pinkeye and conduct phylogenetic analysis of the identified pathogens. Fifty eye swabs from goats with infected eyes (cases) and 50 paired samples from unaffected cohorts (controls) were collected from 25 holdings. Samples were tested using quantitative PCR assays targeting known pinkeye pathogens at the genus and species levels. The prevalence of pathogens in case and control goats was as follows: Mycoplasma conjunctivae (94% and 74% respectively, P = 0.006, OR = 5.5), Chlamydia pecorum (4%, 10%), Moraxella ovis (30%, 30%), Moraxella bovis (0%, 0%) and Moraxella bovoculi (0%, 0%). M. conjunctivae was present in a high proportion of goats in both groups revealing that Lao goats are carriers of M. conjunctivae. However, the mean log10 genome copy number/µL of DNA extract was significantly higher in case goats than control goats (P < 0.05). Thus, M. conjunctivae is likely the principal causative agent of pinkeye in Lao goats with carrier status converting to clinical infection following corneal damage or other causative factors. M. conjunctivae detected in samples from different goats and districts showed low genetic diversity. Identifying the causes of pinkeye in Lao goats will assist in designing appropriate treatment and control strategies.

A comparison of virtual versus in-person delivery of SafeCare on parent and implementation outcomes.

BACKGROUND: Evidence-based prevention services for child abuse and neglect (CAN), typically delivered via home visiting (HV), pivoted to virtual delivery in 2020 to continue family services while adhering to the COVID-19 public health guidelines. OBJECTIVE: The study aims are to compare parent and implementation outcomes for the HV program, SafeCare©, delivered virtually versus in-person, across a 2-year period. METHODS: Three data sources were used to examine parent program engagement and skill mastery, as well as provider fidelity. Sources included: 1) quantitative service data collected as part of routine SafeCare implementation (in-person families, n = 923; virtual families, n = 1978), 2) qualitative survey data collected from SafeCare providers (n = 212) and 3) focus group data with SafeCare Providers (n = 9). RESULTS: Service data were examined using mixed models due to the nesting of the data, with all analyses controlling for time. Qualitative data from the survey and focus groups were analyzed using thematic coding. Data were triangulated from the three sources to answer the primary research question. Findings suggest that virtual delivery of SafeCare holds promise, with parents who participated virtually completing more modules at a faster pace than in-person clients. SafeCare parents demonstrated positive programmatic outcomes regardless of whether they participated in the program virtually or in-person. Provider fidelity remained high in the transition to virtual delivery. However, technology-related logistical issues and provider self-efficacy related to virtual delivery presented challenges to program success. CONCLUSIONS: The study has multiple implications for the HV field about the viability of virtual service delivery. Further research is warranted with data collected directly from parents, and a more critical analysis of what works best for whom and when to further advance the field.

Longitudinal Impacts of Precision Greenness on Alzheimer's Disease.

BACKGROUND: The potential for greenness as a novel protective factor for Alzheimer's disease (AD) requires further exploration. OBJECTIVES: This study assesses prospectively and longitudinally the association between precision greenness - greenness measured at the micro-environmental level, defined as the Census block - and AD incidence. DESIGN: Older adults living in consistently high greenness Census blocks across 2011 and 2016 were compared to those living in consistently low greenness blocks on AD incidence during 2012-2016. SETTING: Miami-Dade County, Florida, USA. PARTICIPANTS: 230,738 U.S. Medicare beneficiaries. MEASUREMENTS: U.S. Centers for Medicare and Medicaid Services Chronic Condition Algorithm for AD based on ICD-9 codes, Normalized Difference Vegetation Index, age, sex, race/ethnicity, neighborhood income, and walkability. RESULTS: Older adults living in the consistently high greenness tertile, compared to those in the consistently low greenness tertile, had 16% lower odds of AD incidence (OR=0.84, 95% CI: 0.76-0.94, p=0.0014), adjusting for age, sex, race/ethnicity, and neighborhood income. Age, neighborhood income and walkability moderated greenness' relationship to odds of AD incidence, such that younger ages (65-74), lower-income, and non-car dependent neighborhoods may benefit most from high greenness. CONCLUSIONS: High greenness, compared to low greenness, is associated with lower 5-year AD incidence. Residents who are younger and/or who reside in lower-income, walkable neighborhoods may benefit the most from high greenness. These findings suggest that consistently high greenness at the Census block-level, may be associated with reduced odds of AD incidence at a population level.

Tibetans exhibit lower hemoglobin concentration and decreased heart response to hypoxia during poikilocapnia at intermediate altitude relative to Han Chinese.

Background: High-altitude populations exhibit distinct cellular, respiratory, and cardiovascular phenotypes, some of which provide adaptive advantages to hypoxic conditions compared to populations with sea-level ancestry. Studies performed in populations with a history of high-altitude residence, such as Tibetans, support the idea that many of these phenotypes may be shaped by genomic features that have been positively selected for throughout generations. We hypothesize that such traits observed in Tibetans at high altitude also occur in Tibetans living at intermediate altitude, even in the absence of severe sustained hypoxia. Methodology: We studied individuals of high-altitude ancestry (Tibetans, n = 17 females; n = 12 males) and sea-level ancestry (Han Chinese, n = 6 females; n = 10 males), both who had been living at ∼1300 m (∼4327 ft) for at least 18 months. We measured hemoglobin concentration ([Hb]), hypoxic ventilatory response (HVR), and hypoxic heart rate response (HHRR) with end-tidal CO2 (PetCO2) held constant (isocapnia) or allowed to decrease with hypoxic hyperventilation (poikilocapnia). We also quantified the contribution of CO2 on ventilation and heart rate by calculating the differences of isocapnic versus poikilocapnic hypoxic conditions (Δ V˙I/ΔPetCO2 and ΔHR/ΔPetCO2, respectively). Results: Male Tibetans had lower [Hb] compared to Han Chinese males (p < 0.05), consistent with reports for individuals from these populations living at high altitude and sea level. Measurements of ventilation (resting ventilation, HVR, and PetCO2) were similar for both groups. Heart rate responses to hypoxia were similar in both groups during isocapnia; however, HHRR in poikilocapnia was reduced in the Tibetan group (p < 0.03), and the heart rate response to CO2 in hypoxia was lower in Tibetans relative to Han Chinese (p < 0.01). Conclusion: These results suggest that Tibetans living at intermediate altitude have blunted cardiac responses in the context of hypoxia. Hence, only some of the phenotypes observed in Tibetans living at high altitude are observed in Tibetans living at intermediate altitude. Whereas blunted cardiac responses to hypoxia is revealed at intermediate altitudes, manifestation of other physiological adaptations to high altitude may require exposure to more severe levels of hypoxia.

A pilot study to assess the feasibility and uptake of MindDEC, a mindfulness-based self-management course for type 2 diabetes.

OBJECTIVE: The study aimed to investigate the feasibility of a remote mindfulness based self-management intervention for individuals with type 2 diabetes. It is important to further our understanding of how to improve self-management to improve health outcomes and low levels of uptake to self-management courses. METHOD: 29 participants with type 2 diabetes were recruited from the University Hospital Coventry and Warwickshire NHS trust. Three groups of participants engaged with a remote mindfulness based self-management intervention, which were delivered sequentially. After each intervention was complete, patient feedback was retrieved and implemented into the following intervention. The quantitative analysis comprised of descriptive statistics, independent sample t-test, paired sample t-test and multiple regression analysis. A qualitative analysis was also conducted through reflexive thematic analysis (RTA) to understand participant's perspective on the intervention. RESULTS: There was a total of 17 who attended the course (59 %) and a total drop out of 12 participants over the three courses (41 %). The qualitative findings reported three main themes: (1) Eating to manage my emotions rather than my diabetes (2) Implementing mindfulness has helped me manage my emotions (3) Medication rather than self-management behaviours control my diabetes. The focus group feedback included participants' appreciation of the community aspect of the intervention and their perception that the current course was more interactive compared to previous interventions. In addition, participants highlighted the importance of offering the course at an earlier stage of diagnosis to provide further support at the beginning of their diabetes journey. No significant findings were reported for the independent sample t-test, paired sample t-test and multiple regression analysis. CONCLUSION: The qualitative findings suggested that the course was beneficial, especially in demonstrating how mindfulness could aid self-management for individuals living with type 2 diabetes. Further funding and trials are warranted to improve the quality of technology used and to assess impact on diabetes control and mental health.

Exploring management and outcomes of elderly patients with glioblastoma using data from two randomised trials (GEINO1401/EX-TEM).

PURPOSE: The impact of age on optimal management of glioblastoma remains unclear. A recent combined analysis of two randomised trials, GEINO14-01 and EX-TEM, found no benefit from extending post-radiation temozolomide in newly diagnosed glioblastoma. Here, we explore the impact of age. METHODS: Relevant intergroup statistics were used to identify differences in tumour, treatment and outcome characteristics based on age with elderly patients (EP) defined as age 65 years and over. Survival was estimated using the Kaplan Meier method. RESULTS: Of the combined 205 patients, 57 (28%) were EP. Of these, 95% were ECOG 0-1 and 65% underwent macroscopic resection compared with 97% and 61% of younger patients (YP) respectively. There were numerically less MGMT-methylated (56% vs. 63%, p = 0.4) and IDH-mutated (4% vs. 13%, p = 0.1) tumours in EP vs. YP. Following surgery, EP were more likely to receive short course chemoradiation (17.5% vs. 6%, p = 0.017). At recurrence, EP tended to receive or best supportive care (28.3% vs. 15.4%, p = 0.09) or non-surgical options (96.2% vs. 84.6%, p = 0.06), but were less likely to receive bevacizumab (23.1% vs. 49.5%, p < 0.01). Median PFS was similar at 9.3months in EP and 8.5months in YP, with similar median OS at 20months. CONCLUSION: In this trial population of predominantly fit EP, survival was similar to YP despite a proportion receiving less aggressive therapy at diagnosis and recurrence. Advancing age does not appear to be an adverse prognostic factor for glioblastoma when patients are fit for treatment, and a less aggressive approach in selected patients may not compromise outcomes.

Risk characterization of N-nitrosodimethylamine in pharmaceuticals.

Since 2018, N-nitrosodimethylamine (NDMA) has been a reported contaminant in numerous pharmaceutical products. To guide the pharmaceutical industry, FDA identified an acceptable intake (AI) of 96 ng/day NDMA. The approach assumed a linear extrapolation from the Carcinogenic Potency Database (CPDB) harmonic-mean TD50 identified in chronic studies in rats. Although NDMA has been thought to act as a mutagenic carcinogen in experimental animals, it has not been classified as a known human carcinogen by any regulatory agency. Humans are exposed to high daily exogenous and endogenous doses of NDMA. Due to the likelihood of a threshold dose for NDMA-related tumors in animals, we believe that there is ample scientific basis to utilize the threshold-based benchmark dose or point-of-departure (POD) approach when estimating a Permissible Daily Exposure limit (PDE) for NDMA. We estimated that 29,000 ng/kg/day was an appropriate POD for calculating a PDE. Assuming an average bodyweight of 50 kg, we expect that human exposures to NDMA at doses below 5800 ng/day in pharmaceuticals would not result in an increased risk of liver cancer, and that there is little, if any, risk for any other type of cancer, when accounting for the mode-of-action in humans.

Can a mock medication-taking learning activity enable pharmacy students to experience the range of barriers and facilitators to medication adherence? An analysis informed by the Theoretical Domains Framework and COM-B model.

Background: Pharmacy professionals are well-placed to provide medication adherence support to patients. The Capability, Opportunity, Motivation-Behaviour (COM-B) and Theoretical Domains Framework (TDF) are two complementary models previously applied to medication-taking behaviour. Understanding the patient-specific barriers and facilitators to adherence using psychological frameworks from the early stages of pharmacy education enables the design and delivery of effective interventions. Objectives: To examine whether a novel 'mock medicine' learning activity enabled students to experience the range of barriers and facilitators to medication adherence using the COM-B and TDF. Methods: A mock medicine activity was conducted with students at pharmacy schools in three universities in the UK, Norway, and Australia over one week. Percentage adherence was calculated for five dosing regimens; theoretical framework analysis was applied to map reflective statements from student logs to COM-B and TDF. Results: A total of 349 students (52.6%) returned completed logs, with high overall mean adherence (83.5%, range 0-100%). Analysis of the 277 (79.4%) students who provided reflective statements included barriers and facilitators that mapped onto one (9%), two (29%) or all three (62%) of the COM-B components and all fourteen TDF domains (overall mean = 4.04; Uni 1 = 3.72; Uni 2 = 4.50; Uni 3 = 4.38; range 1-8). Most frequently mapped domains were 'Environmental context and resources' (n = 199; 72%), 'Skills' (n = 186; 67%), 'Memory, attention and decision-making' (184; 66%) and 'Beliefs about capabilities' (n = 175; 63%). Conclusions: This is the first study to utilise both COM-B and TDF to analyse a proxy measure of medication adherence in pharmacy education. Data mapping demonstrated that students experienced similar issues to patients when prescribed a short course of medication. Importantly, all the factors influencing medication-taking reported by students were captured by these two psychological frameworks. Future educational strategies will involve students in the mapping exercise to gain hands-on experience of using these psychological constructs in practice.

A combined analysis of two prospective randomised studies exploring the impact of extended post-radiation temozolomide on survival outcomes in newly diagnosed glioblastoma.

PURPOSE: The optimal duration of post-radiation temozolomide in newly diagnosed glioblastoma remains unclear, with no published phase III randomised trials. Standard-of-care stipulates 6 months. However, in routine care, it is often extended to 12 months, despite lacking robust supporting data. METHODS: GEINO14-01 (Spain) and EX-TEM (Australia) studies enrolled glioblastoma patients without progression at the end of 6 months post-radiation temozolomide. Participants were randomised 1:1 to six additional months of temozolomide or observation. Primary endpoint was 6-month progression free survival from date of randomisation (6mPFS). Secondary endpoints included overall survival (OS) and toxicity. 204 patients were required to detect an improvement in 6mPFS from 50 to 60% (80% power). Neither study recruited sufficient patients. We performed a combined analysis of individual patient data. RESULTS: 205 patients were recruited: 159 in GEINO14-01 (2014-2018) and 46 in EX-TEM (2019-2022). Median follow-up was 20.0 and 14.5 months. Baseline characteristics were balanced. There was no significant improvement in 6mPFS (57.2% vs 64.0%, OR0.75, p = 0.4), nor across any subgroups, including MGMT methylated; PFS (HR0.92, p = 0.59, median 7.8 vs 9.7 months); or OS (HR1.03, p = 0.87, median 20.1 vs 19.4 months). During treatment extension, 64% experienced any grade adverse event, mainly fatigue and gastrointestinal (both 54%). Only a minority required treatment changes: 4.5% dose delay, 7.5% dose reduction, 1.5% temozolomide discontinuation. CONCLUSION: For glioblastoma patients, extending post-radiation temozolomide from 6 to 12 months is well tolerated but does not improve 6mPFS. We could not identify any subset that benefitted from extended treatment. Six months should remain standard-of-care.

Enzootic calcinosis in Toggenburg goats in New Zealand.

CASE HISTORY: Necropsies on Toggenburg goats culled from a small farm in the Manawatu district of New Zealand, performed at Massey University (Palmerston North, NZ) over a period of 29 years (1991-2019), revealed soft tissue mineralisation, particularly of cardiovascular tissues. The farm spans 10 acres and runs between 15 and 30 Toggenburg goats. The goats are predominantly on pasture comprising a variety of types. PATHOLOGICAL FINDINGS: Necropsies were performed on all adult goats (n = 45) that died or were euthanised. Histopathology was performed on 42 goats (93%), of which 33 (73%) included sufficient tissues diagnostically relevant to soft tissue mineralisation. The most significant gross findings were in various arteries, with the aorta most commonly affected, followed by the heart and lungs. The aortic intima showed prominent, multifocal to coalescing, raised, wrinkled, white plaques. Microscopically there were multiphasic lesions of mineralisation, chondroid, and osseous metaplasia in the elastic arteries, aorta, heart and lungs. A lumbar vertebra from one goat had prominent, basophilic, fibrillar, tangled matrix lining Haversian canals and lamellae. LABORATORY FINDINGS: Blood samples were collected from 15 adult goats in the affected herd and from 10 adult Toggenburg goats from an unaffected herd. Samples were collected by jugular venipuncture at 2-month intervals for 12 months (April 2018-March 2019). Concentrations of calcium, phosphorus, 25-hydroxyvitamin D2 and D3 (25OHD2, 25OHD3) in serum were analysed. The concentration of total 25OHD in serum was 34.2 (95% CI = 18.9-49.4) nmol/L (p < 0.001) higher in goats from the affected herd than in goats from the unaffected herd. Serum 25OHD2 concentration was 46.2 (95% CI = 39.2-53.2) nmol/L higher (p < 0.001) in goats from the affected herd compared to the unaffected herd. Serum Ca concentrations in affected goats were 0.101 (95% CI = 0.005-0.196) mmol/L higher (p = 0.039) than unaffected goats, but remained within the reference range. There was no evidence of a difference in serum 25OHD3 and P concentration between the herds. VEGETATION SURVEY: All paddocks on the property were surveyed every 2 months along evenly spaced line transects, and then further traversed perpendicularly to form a grid. No known calcinogenic species were identified. Known plant sources of vitamin D identified on the farm included mushrooms (species not defined), Dactylis glomerata, lichen, pine pollen, and algae. DIAGNOSIS: Soft tissue mineralisation and enzootic calcinosis. CLINICAL RELEVANCE: Veterinarians are alerted to the possibility of either enzootic calcinosis in goats and the potential occurrence of calcinogenic plants in New Zealand; or chronic vitamin D toxicosis of non-plant origin.

Controlled Frustration Release on the Kagome Lattice by Uniaxial-Strain Tuning.

It is predicted that strongly interacting spins on a frustrated lattice may lead to a quantum disordered ground state or even form a quantum spin liquid with exotic low-energy excitations. However, a controlled tuning of the frustration strength, separating its effects from those of disorder and other factors, is pending. Here, we perform comprehensive ^{1}H NMR measurements on Y_{3}Cu_{9}(OH)_{19}Cl_{8} single crystals revealing an unusual Q[over →]=(1/3×1/3) antiferromagnetic state below T_{N}=2.2 K. By applying in situ uniaxial stress, we break the symmetry of this disorder-free, frustrated kagome system in a controlled manner yielding a linear increase of T_{N} with strain, in line with theoretical predictions for a distorted kagome lattice. In-plane strain of ≈1% triggers a sizable enhancement ΔT_{N}/T_{N}≈10% due to a release of frustration, demonstrating its pivotal role for magnetic order.

Genome Wide Conditional Mouse Knockout Resources.

The International Knockout Mouse Consortium (IKMC) developed high throughput gene trapping and gene targeting pipelines that produced mostly conditional mutations of more than 18,500 genes in C57BL/6N mouse embryonic stem (ES) cells which have been archived and are freely available to the research community as a frozen resource. From this unprecedented resource more than 6,000 mutant mouse strains have been produced by the IKMC and mostly the International Mouse Phenotyping Consortium (IMPC). In addition, a cre-driver resource was established including 250 inducible cre-driver mouse strains in a C57BL/6 background. Complementing the cre-driver resource, a collection of comprising 27 cre-driver rAAVs has also been produced. The resources can be easily accessed at the IKMC/IMPC web portal (www.mousephenotype.org). The IKMC/IMPC resource is a standardized reference library of mouse models with defined genetic backgrounds that enables the analysis of gene-disease associations in mice of different genetic makeup and should therefore have a major impact on biomedical research.

Manejo ambulatorio de niños con bronconeumonía / Ambulatory management of children with bronchopneumonia

Se tratan 50 niños eutróficos entre 2 y 12 años de edad portadores de bronconeumonía, en forma ambulatoria y con terapia oral (amoxilina y eritromicina por 10 días). Estos pacientes fueron controlados clínicamente a los 2 , 7 y 15 días de evolución de tratamiento y con Rx. tórax de control a los 15 días de terapia. Se obtiene una excelente remisión de la sintomatología, signología clínica y radiológica en el 98% de los pacientes. Esto sugiere que el tratamiento ambulatorio es una buena alternativa para un adecuado manejo de este tipo de pacientes