Systolic versus diastolic differences in cerebrovascular reactivity to hypercapnic and hypocapnic challenges.

INTRODUCTION: Cerebrovascular reactivity (CVR) describes the vasculature's response to vasoactive stimuli, where prior investigations relied solely on mean data, rather than exploring cardiac cycle differences. METHODS: Seventy-one participants (46 females and 25 males) from two locations underwent TCD measurements within the middle or posterior cerebral arteries (MCA, PCA). Females were tested in the early-follicular phase. The hypercapnia response was assessed using a rebreathing protocol (93% oxygen and 7% carbon dioxide) or dynamic end-tidal forcing as a cerebral blood velocity (CBv) change from 40 to 55-Torr. The hypocapnia response was quantified using a hyperventilation protocol as a CBv change from 40 to 25-Torr. Absolute and relative CVR slopes were compared across cardiac cycle phases, vessels, and biological sexes using analysis of covariance with Tukey post-hoc comparisons. RESULTS: No differences were found between hypercapnia methods used (p > 0.050). Absolute hypercapnic slopes were highest in systole (p < 0.001), with no cardiac cycle differences for absolute hypocapnia (p > 0.050). Relative slopes were largest in diastole and smallest in systole for both hypercapnia and hypocapnia (p < 0.001). Females exhibited greater absolute CVR responses (p < 0.050), while only the relative systolic hypercapnic response was different between sexes (p = 0.001). Absolute differences were present between the MCA and PCA (p < 0.001), which vanished when normalizing data to baseline values (p > 0.050). CONCLUSION: Cardiac cycle variations impact CVR responses, with females displaying greater absolute CVR in some cardiac phases during the follicular window. These findings are likely due to sex differences in endothelial receptors/signalling pathways. Future CVR studies should employ assessments across the cardiac cycle.

Genetic Risk Factors in Isolated Dystonia Escape Genome-Wide Association Studies.

BACKGROUND: Despite considerable heritability, previous smaller genome-wide association studies (GWASs) have not identified any robust genetic risk factors for isolated dystonia. OBJECTIVE: The objective of this study was to perform a large-scale GWAS in a well-characterized, multicenter sample of >6000 individuals to identify genetic risk factors for isolated dystonia. METHODS: Array-based GWASs were performed on autosomes for 4303 dystonia participants and 2362 healthy control subjects of European ancestry with subgroup analysis based on age at onset, affected body regions, and a newly developed clinical score. Another 736 individuals were used for validation. RESULTS: This GWAS identified no common genome-wide significant loci that could be replicated despite sufficient power to detect meaningful effects. Power analyses imply that the effects of individual variants are likely very small. CONCLUSIONS: Moderate single-nucleotide polymorphism-based heritability indicates that common variants do not contribute to isolated dystonia in this cohort. Sequence-based GWASs (eg, by whole-genome sequencing) might help to better understand the genetic basis. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Brief Resolved Unexplained Event: Evidence-Based and Family-Centered Management.

Brief resolved unexplained events (BRUEs) are frequently encountered in infants younger than 1 year. By definition, these events require the infant to be asymptomatic and at baseline at the time of presentation, with no significant abnormalities on examination and no discernible explanatory diagnosis. Research has shown that less than 5% of BRUE cases are attributable to serious underlying conditions, with no increased mortality risk and no increased risk of sudden infant death syndrome. Despite these findings, approximately 63% of patients with BRUEs are hospitalized and up to 82% undergo diagnostic tests, which predominantly result in false-positive findings. Such results may lead to unnecessarily prolonged hospital stays, additional tests or consultations, and increased parental anxiety. The management of a patient who has experienced a BRUE can be challenging for providers and parents alike. Although risk is known to be low in these infants, providers may be compelled to explain the event and provide reassurance. Caregivers oftentimes are concerned that the events may reoccur and be a harbinger of a missed diagnosis. Shared decision-making can be used to explain risk and the benefit of additional testing and hospitalization. This family-centered strategy can align care with the family's values, provide reassurance, and decrease decisional conflict.

Filling the gaps in the COVID-19 pandemic response: medical personnel in the US military health system.

BACKGROUND: The COVID-19 pandemic was an unprecedented public health emergency that heavily affected the healthcare workforce. Although the Military Health System (MHS) has robust capabilities and was able to deploy medical staff to support civilian hospitals during the crisis, it too was adversely impacted by personnel issues. We aimed to identify and address gaps in understanding the impact of the COVID-19 pandemic on healthcare personnel in the MHS. METHODS: We conducted semi-structured key informant interviews with 28 MHS stakeholders, including policymakers, program managers, and healthcare providers. We recruited respondents using purposive and snowball sampling until we reached thematic saturation. Interviews were conducted virtually from December 2022 to March 2023 and coded by deductive thematic analysis using NVivo. RESULTS: Burnout and mental health concerns across the workforce increased during the pandemic, although some felt military culture facilitated resilience. Reduction in personnel was noted and slow hiring processes and noncompetitive wages hindered hiring, contributing to staffing shortages. Initial disruptions occurred in training and skills readiness, although these issues were reduced over time. Concerns remain about newer trainees' preparedness and teaching staff's availability in the MHS. CONCLUSION: This study uniquely assessed the impact of the COVID-19 pandemic response on the MHS healthcare workforce through in-depth key informant interviews. Multi-pronged strategies are needed to promote personnel well-being in complex healthcare systems like the MHS.

Identification of cysteine metabolism regulator (CymR)-derived pentapeptides as nanomolar inhibitors of Staphylococcus aureus O-acetyl-ʟ-serine sulfhydrylase (CysK).

The conditionally essential pathway of bacterial cysteine biosynthesis is gaining traction for the development of antibiotic adjuvants. Bacterial cysteine biosynthesis is generally facilitated by two enzymes possessing O-acetyl-ʟ-serine sulfhydrylase (OASS) activity, CysK and CysM. CysK enzymes can also form functional complexes with other proteins that regulate cysteine metabolism. In Staphylococcus aureus there exists a single OASS homologue, herein termed Sa CysK. Knockout of Sa CysK was found to increase sensitivity to oxidative stress, making it a relevant target for inhibitor development. Sa CysK forms two functional complexes via interaction with the preceding enzyme in the pathway serine acetyltransferase (CysE) or the transcriptional regulator of cysteine metabolism (CymR). These interactions occur through the insertion of a C-terminal peptide of CysE or CymR into the active site of Sa CysK, inhibiting OASS activity, and therefore represent an excellent starting point for developing Sa CysK inhibitors. Here we detail the characterization of CysE and CymR-derived C-terminal peptides as inhibitors of Sa CysK. First, interactions between CysE or CymR-derived C-terminal decapeptides and Sa CysK were assessed by X-ray crystallography. While both peptides occupied the active site of Sa CysK, the alternate sidechains of the CymR decapeptide formed more extensive interactions. Surface plasmon resonance binding assays and Sa CysK inhibition assays revealed that the CymR decapeptide bound to Sa CysK with nanomolar affinity (K D = 25 nM) and inhibited Sa CysK activity (IC 50 = 180 nM), making it a promising lead for the development of Sa CysK inhibitors. To understand the determinants of this high affinity interaction the structure-activity relationships of 16 rationally designed peptides were also investigated. This identified that the C-terminal pentapeptide of CymR alone facilitates the high affinity interaction with Sa CysK, and that subtle structural modification of the pentapeptide is possible without impacting potency. Ultimately, this work has identified CymR pentapeptides as a promising scaffold for the development of antibiotic adjuvants targeting Sa CysK. Author summary: There is increasing interest in the investigation of non-essential pathways including bacterial cysteine metabolism for developing antibiotic adjuvants. Within this pathway the O-acetyl-ʟ-serine sulfhydrylase (OASS) enzymes CysK and CysM have been a focus. As such, the OASS enzyme of Staphylococcus aureus , Sa CysK, gained our interest. Previous efforts to inhibit CysK enzymes have mimicked the interaction between CysK and the C-terminus of serine acetyltransferase (CysE) which occurs inside the CysK active site and inhibits OASS activity. CysE peptides have only moderate potency, typically binding with micromolar affinity. In S. aureus another complex forms between Sa CysK and a transcriptional regulator CymR, but the ability of CymR peptides to inhibit CysK enzymes has not been investigated. We noticed there is variation between the C-terminus of CysE and CymR, suggesting that CymR peptides make distinct interactions with Sa CysK and may be superior inhibitors. Here we characterized CysE and CymR peptides as Sa CysK inhibitors. We found CymR peptides make more extensive molecular interactions with Sa CysK and bind with higher affinity, being the most potent peptide inhibitors of a CysK enzyme to date. A CymR pentapeptide is the minimal length required for this potency and provides a promising scaffold for developing antibiotic adjuvants targeting Sa CysK.

Rate of body weight gain during early gestation in F0 beef heifers has effects that extend multigenerationally to the F2 fetuses.

Our aim was to investigate the effects of maternal (F0) body weight (BW) gain during the first 84 d of gestation on body composition, ovarian reserve, and hormonal and metabolic parameters of breeding-age F1 heifers, as well as the body weight and morphometry of F2 fetuses. The study also evaluated the effect of maternal body weight gain (F0) on the mRNA relative abundance of the small intestine of both F1 heifers and F2 fetuses. Crossbred Angus heifers (F0; n = 100) were managed to gain 0.20 kg/d (low gain [LG], n = 50) or 0.75 kg/d (moderate gain [MG], n = 50) for the first 84 d of gestation. Subsequently, F0 dams were managed on a common forage-based diet for the rest of gestation until the weaning of the F1 offspring. At 15 months of age a subset of F1 heifers was randomly selected for the current experiment (n = 8 LG and n = 8 MG). Heifers were bred via artificial insemination (AI; d 0), then harvested on d 84 of gestation. On d -10, 42, and 84, BW was recorded, and blood was collected and analyzed for concentrations of glucose, non-esterified fatty acids, progesterone, insulin, and insulin-like growth factor-1. Weight of F1 carcasses, organs, gravid uteri, and F2 fetuses and organs were recorded at harvest. Visible follicles were counted on F1 ovaries at harvest, and histology was used to count microscopic follicles. Liver and jejunal samples from F1 heifers were collected to measure tissue oxygen consumption and jejunal samples from F1 heifers and F2 fetuses were collected for mRNA relative abundance analysis. Body weight of F1 heifers from MG dams tended to be 12 kg greater (P = 0.06) than for F1 heifers from LG dams. Concentrations of glucose were greater (P = 0.03) in F1 heifers from the MG group, with no differences in other blood metabolites or follicular populations (P ≥ 0.16). Interestingly, mammary glands were heavier (P = 0.05) and placentas and body depth tended to be heavier and greater, respectively (P ≤ 0.10), for F2 fetuses from F0 LG heifers. Oxygen consumption in the liver and jejunum, as well as mRNA relative abundance in the jejunum of F1 heifers, were not affected by F0 rate of gain (P ≥ 0.16). However, the NDUFC1, SDHA, UQCR1, and PPARG genes were upregulated (P ≤ 0.05) in the jejunum of F2 fetuses from the LG group. In conclusion, BW gain of F0 heifers during early gestation exerts subtle effects on pre-breeding BW and blood metabolites in F1 offspring, with impacts present in F2 placenta, mammary gland, and intestine.

Lamina Cribrosa Microstructure in Nonhuman Primates With Naturally Occurring Peripapillary Retinal Nerve Fiber Layer Thinning.

Purpose: The lamina cribrosa (LC) is hypothesized to be the site of initial axonal damage in glaucoma with the circumpapillary retinal nerve fiber layer thickness (RNFL-T) widely used as a standard metric for quantifying the glaucomatous damage. The purpose of this study was to determine in vivo, 3-dimensional (3D) differences in the microstructure of the LC in eyes of nonhuman primates (NHPs) with naturally occurring glaucoma. Methods: Spectral-domain optical coherence tomography (OCT) scans (Leica, Chicago, IL, USA) of the optic nerve head were acquired from a colony of 50 adult rhesus monkeys suspected of having high prevalence of glaucoma. The RNFL-T was analyzed globally and in quadrants using a semi-automated segmentation software. From a set of 100 eyes, 18 eyes with the thinnest global RNFL-T were selected as the study group and 18 eyes with RNFL-T values around the 50th percentile were used as controls. A previously described automated segmentation algorithm was used for LC microstructure analysis. Parameters included beam thickness, pore diameter and their ratio (beam-to-pore ratio [BPR]), pore area and shape parameters, beam and pore volume, and connective tissue volume fraction (CTVF; beam volume/total volume). The LC microstructure was analyzed globally and in the following volumetric sectors: quadrants, central and peripheral lamina, and three depth slabs (anterior, middle, and posterior). Results: Although no significant difference was detected between groups for age, weight, or disc size, the study group had significantly thinner RNFL than the control group (P < 0.01). The study group had significantly smaller global and sectoral pore diameter and larger BPR compared with the control group. Across eyes, the global RNFL-T was associated positively with pore diameter globally. BPR and CTVF were significantly and negatively associated with the corresponding RNFL-T in the superior quadrant. Conclusions: Global and sectoral microstructural differences were detected when comparing thin and normal RNFL-T eyes. Whether these LC differences are the cause of RNFL damage or the result of remodeling of the LC requires further investigation. Translational Relevance: Our findings indicate structural alterations in the LC of NHP exhibiting natural thinning of the RNFL, a common characteristic of glaucomatous damage.

A single institution's surgical care model for pediatric burns with ≤ 10% body surface area involvement.

Small burn injuries are extremely prevalent in the pediatric population and continue to pose a challenge for clinicians. Despite their high incidence, a standardized algorithm for treating small burns does not currently exist, and care is often influenced by clinical judgement and resource availability. The aim of this study was to explore the utility of a two-stage grafting technique, involving allograft and autograft, for treating small burns (≤ 10% total body surface area) in pediatric patients. A retrospective review of patients aged 0-18 years who had a small burn and underwent a two-stage grafting procedure between 09-01-2018 and 09-01-2022 was conducted. One hundred and seventy-five patients with 220 wounds met the inclusion criteria for this study. The mean time from presentation to allograft surgery was 11.4 days (SD 5.2) followed by autograft surgery approximately one week later. Most patients were discharged within 24 hours following allograft surgery (87.4%) and autograft surgery (81.1%). Mean autograft take was 97.7% (SD 11.8) with only four patients experiencing significant graft loss requiring subsequent re-grafting. These positive outcomes demonstrate that the two-stage technique can be successfully utilized for treating smaller pediatric burns. Moreover, these findings help to address the significant knowledge gap regarding the optimal approach to treating small burn wounds. Further research is warranted to learn more about cosmetic outcomes following two-stage grafting and determine how it compares to other techniques for treating small burns.

Patients with dementia or frailty undergoing major limb amputation have poor outcomes.

OBJECTIVE: Major lower limb amputation is a disfiguring operation associated with impaired mobility and high near-term mortality. Informed decision-making regarding amputation requires outcomes data. Despite the co-occurrence of both chronic limb-threatening ischemia (CLTI) and Alzheimer's disease and related dementias (ADRD), there is sparse data on the outcomes of major limb amputation in this population and the impact of frailty. We sought to determine mortality, complications, readmissions, revisions, intensive interventions (eg, cardiopulmonary resuscitation), and other outcomes after amputation for CLTI in patients living with ADRD looking at the modifying effects of frailty. METHODS: We examined Medicare fee-for-service claims data from January 1, 2016, to December 31, 2020. Patients with CLTI undergoing amputation at or proximal to the ankle were included. Along with demographic information, dementia status, and comorbid conditions, we measured frailty using a claims-based frailty index. We dichotomized dementia and frailty (pre-frail/robust = "non-frail" vs moderate/severe frailty = "frail") to create four groups: non-frail/non-ADRD, frail/non-ADRD, non-frail/ADRD, and frail/ADRD. We used linear and logistic regression via generalized estimating equations in addition to performing selected outcomes analyses with death as a competing risk to understand the association between dementia status, frailty status, and 1-year mortality as our primary outcome in addition to the postoperative outcomes outlined above. RESULTS: Among 46,930 patients undergoing major limb amputation, 11,465 (24.4%) had ADRD and 24,790 (52.8%) had frailty. Overall, 55.9% of amputations were below-knee. Selected outcomes among frail/ADRD patients undergoing amputation (n = 10,153) were: 55.3% 1-year mortality 29.6% readmissions at 30 days, and 32.3% amputation revision/reoperation within 1 year. Of all four groups, those in the frail/ADRD had the worst outcomes only for 1-year mortality. CONCLUSIONS: First, patients with ADRD or moderate/severe frailty suffer an array of very poor outcomes after major limb amputation for CLTI, including high mortality, readmissions, revision, and risks of discharge to higher levels of care. Second, there is a complex relationship between outcome severity and ADRD/frailty status. Specifically, frailty is more often than ADRD associated with the poorest results for any given outcome. These data provide important outcomes data to help align decision-making with health care values and goals.

One-Carbon Metabolites Supplementation and Nutrient Restriction Alter the Fetal Liver Metabolomic Profile during Early Gestation in Beef Heifers.

Maternal nutrition is pivotal for proper fetal development, with one-carbon metabolites (OCM) playing a key role in fetal epigenetic programming through DNA and histone methylation. The study aimed to investigate the effects of nutrient restriction and OCM supplementation on fetal liver metabolomics in pregnant beef-heifers, focusing on metabolites and pathways associated with amino-acid, vitamin and cofactor, carbohydrate, and energy metabolism at day 63 of gestation. Thirty-one crossbred Angus heifers were artificially inseminated and allocated to four nutritional treatments in a 2 × 2 factorial arrangement of treatments, with the two factors being dietary intake/rate of gain (control-diet [CON]; 0.60 kg/day ADG, vs. restricted-diet [RES]; -0.23 kg/day ADG) and OCM supplementation (supplemented [+OCM] vs. not supplemented [-OCM]). The resulting treatment groups-CON-OCM, CON+OCM, RES-OCM, and RES+OCM were maintained for 63 days post-breeding. Following this period, fetal liver tissues were collected and subjected to metabolomic analysis using UPLC-tandem mass-spectrometry. We identified 288 metabolites, with the majority (n = 54) being significantly influenced by the main effect of gain (P ≤ 0.05). Moreover, RES showed decreased abundances of most metabolites in pathways such as lysine metabolism; leucine, isoleucine and valine metabolism; and tryptophan metabolism, compared to CON. Supplementation with OCM vs. no OCM supplementation, resulted in greater abundance of metabolites (P ≤ 0.05) affecting pathways associated with methionine, cysteine, S-adenosylmethionine and taurine metabolism; guanidino and acetamido metabolism; and nicotinate and nicotinamide metabolism. Notably, OCM supplementation with a moderate rate of gain increased the concentrations of ophthalmate, N-acetylglucosamine, and ascorbic-acid 3-sulfate, which are important for proper fetal development (P ≤ 0.05). Nutrient restriction reduced the majority of liver metabolites, while OCM supplementation increased a smaller number of metabolites. Thus, OCM supplementation may be protective of metabolite concentrations in key developmental pathways, which could potentially enhance fetal development under nutrient-restricted conditions.

SARS-CoV-2 seroprevalence in people living with HIV in South Sudan.

Objectives: The burden of SARS-CoV-2 infection in people living with HIV (PLHIV) in South Sudan is unknown. Methods: We conducted a cross-sectional seroprevalence survey of SARS-CoV-2 immunoglobulin (Ig) G antibodies and other diseases of public health importance (strongyloidiasis, toxoplasmosis) in PLHIV in South Sudan during April 1, 2020-April 30, 2022. We used a multiplex SARS-CoV-2 immunoassay to detect IgG antibodies targeting the SARS-CoV-2 spike, receptor binding domain, and nucelocapsid (N) proteins, and antigens for other pathogens (Strongyloides stercoralis and Toxoplasma gondii). Results: Among 3518 samples tested, seroprevalence of IgG antibodies to SARS-CoV-2 spike protein and receptor binding domain 591 and nucleocapsid ranged from 1.4% (95% confidence interval [CI]: 0.9-2.1%) in April-June 2020 to 53.3% (95% CI: 49.5-57.1%) in January-March 2022. The prevalence of S. stercoralis IgG ranged between 27.3% (95% CI: 23.4-31.5%) in October-December 2021 and 47.2% (95% CI: 37.8-56.8%) in July-September 2021, and, for T. gondii IgG, prevalence ranged from 15.5% (95% CI: 13.3-17.9%) in April-June 2020 to 36.2% (95% CI: 27.4-46.2%) July-September 2021. Conclusions: By early 2022, PLHIV in South Sudan had high rates of SARS-CoV-2 seropositivity. Surveillance of diseases of global health concern in PLHIV is crucial to estimate population-level exposure and inform public health responses.

Endophthalmitis Rates and Types of Treatments After Intraocular Procedures.

Importance: Long-term trend analyses of overall endophthalmitis rates and treatment patterns are scarce. It is also unknown if the deviation from the recommendations of the Endophthalmitis Vitrectomy Study toward decreased utilization of vitrectomy is associated with different vision outcomes. Objective: To determine whether the rate of endophthalmitis after intraocular procedures or the primary treatment (prompt vitrectomy vs tap and inject) for endophthalmitis has changed over the past 20 years. Design, Setting, and Participants: This cohort study examined data for cohorts created by querying for different intraocular procedures, including intravitreal injections and surgeries for cataract removal, glaucoma, retinal conditions, and corneal transplants from 2000 to 2022. The data source was a US administrative medical claims database comprising commercial and Medicare Advantage insurance plans. Any intraocular procedure with at least 6 months of data available before and 6 weeks after the procedure was eligible. Exclusion criteria consisted of any previous diagnosis of endophthalmitis or another intraocular procedure during the follow-up period. Main Outcome Measure: The main outcomes were rate of postprocedure endophthalmitis and relative rate of prompt vitrectomy (vs tap and inject) as the primary method of treatment. Results: Among 2 124 964 patients, the mean (SD) age was 71.4 (10.2) years; 1 230 320 were female and 894 414 male. Over 22 years, 5 827 809 intraocular procedures were analyzed with 4305 cases of endophthalmitis found for an overall endophthalmitis rate of 0.07%. The yearly rate of endophthalmitis varied but generally declined from a high of 7 cases per 3502 procedures (0.20%) in 2000 to a low of 163 cases per 332 159 procedures (0.05%) in 2022. The percentage of cases treated with prompt vitrectomy also varied but generally declined over time with a high of 17 of 35 (48.6%) in 2003 and a low of 60 of 515 (11.6%) in 2021. Multivariable analysis of the endophthalmitis incidence rate ratio (IRR) showed a per-year decrease of 2.7% (IRR, 0.97; 95% CI, 0.97-0.98; P < .001) over the study period. A similar analysis also showed that the incidence rate of prompt surgical treatment decreased by 3.8% per year throughout the study period (IRR, 0.96; 95% CI, 0.95-0.97; P < .001). Conclusions and Relevance: This study found that the incidence of endophthalmitis following intraocular procedures appears to have decreased substantially over the past 20 years while prompt vitrectomy is being used less frequently as primary treatment than in the past.

Does exercise modality and posture influence cerebrovascular and cardiovascular systems similarly?

Cerebral hemodynamics have been quantified during exercise via transcranial Doppler ultrasound, as it has high-sensitivity to movement artifacts and displays temporal superiority. Currently, limited research exists regarding how different exercise modalities and postural changes impact the cerebrovasculature across the cardiac cycle. Ten participants (4 females and 6 males) ages 20-29 completed three exercise tests (treadmill, supine, and upright cycling) to volitional fatigue. Physiological data collected included middle cerebral artery velocity (MCAv), blood pressure (BP), heart rate, and respiratory parameters. Normalized data were analyzed for variance and effect sizes were calculated to examine differences between physiological measures across the three exercise modalities. Systolic MCAv was greater during treadmill compared to supine and upright cycling (p < 0.001, (large) effect size), and greater during upright versus supine cycling (p < 0.017, (large)). Diastolic MCAv was lower during treadmill versus cycling exercise only at 60% maximal effort (p < 0.005, (moderate)) and no differences were observed between upright and supine cycling. No main effect was found for mean and diastolic BP (p > 0.05, (negligible)). Systolic BP was lower during treadmill versus supine cycling at 40% and 60% intensity (p < 0.05, (moderate-large)) and greater during supine versus upright at only 60% intensity (p < 0.003, (moderate)). The above differences were not explained by partial pressure of end-tidal carbon dioxide levels (main effect: p = 0.432). The current study demonstrates the cerebrovascular and cardiovascular systems respond heterogeneously to different exercise modalities and aspects of the cardiac cycle. As physiological data were largely similar between tests, differences associated with posture and modality are likely contributors.

Effects of dietary restriction and one-carbon metabolite supplementation during the first 63 days of gestation on the maternal gut, vaginal, and blood microbiota in cattle.

BACKGROUND: Maternal diet quality and quantity have significant impacts on both maternal and fetal health and development. The composition and function of the maternal gut microbiome is also significantly influenced by diet; however, little is known about the impact of gestational nutrient restriction on the bovine maternal microbiome during early gestation, which is a critical stage for maternal microbiome-mediated fetal programming to take place. The objective of the present study was to evaluate the impacts of diet restriction and one-carbon metabolite (OCM) supplementation during early gestation on maternal ruminal, vaginal, and blood microbiota in cattle. Thirty-three beef heifers (approx. 14 months old) were used in a 2 × 2 factorial experiment with main factors of target gain (control [CON]; targeted 0.45 kg/d gain vs restricted [RES]; targeted - 0.23 kg/d gain), and OCM supplementation (+ OCM vs - OCM; n = 8/treatment; except n = 9 for RES-OCM). Heifers were individually fed, starting treatment at breeding (d 0) and concluding at d 63 of gestation. Ruminal fluid and vaginal swabs were collected on d - 2, d 35, and d 63 (at necropsy) and whole blood was collected on d 63 (necropsy). Bacterial microbiota was assessed using 16S rRNA gene (V3-V4) sequencing. RESULTS: Overall ruminal microbiota structure was affected by gain, OCM, time, and their interactions. The RES heifers had greater microbial richness (observed ASVs) but neither Shannon nor Inverse Simpson diversity was significantly influenced by gain or OCM supplementation; however, on d 63, 34 bacterial genera showed differential abundance in the ruminal fluid, with 25 genera enriched in RES heifers as compared to CON heifers. In addition, the overall interaction network structure of the ruminal microbiota changed due to diet restriction. The vaginal microbiota community structure was influenced by gain and time. Overall microbial richness and diversity of the vaginal microbiota steadily increased as pregnancy progressed. The vaginal ecological network structure was distinctive between RES and CON heifers with genera-genera interactions being intensified in RES heifers. A relatively diverse bacterial community was detected in blood samples, and the composition of the blood microbiota differed from that of ruminal and vaginal microbiota. CONCLUSION: Restricted dietary intake during early gestation induced significant alterations in the ruminal microbiota which also extended to the vaginal microbiota. The composition of these two microbial communities was largely unaffected by OCM supplementation. Blood associated microbiota was largely distinctive from the ruminal and vaginal microbiota.

Generative artificial intelligence as a source of breast cancer information for patients: Proceed with caution.

BACKGROUND: This study evaluated the accuracy, clinical concordance, and readability of the chatbot interface generative pretrained transformer (ChatGPT) 3.5 as a source of breast cancer information for patients. METHODS: Twenty questions that patients are likely to ask ChatGPT were identified by breast cancer advocates. These were posed to ChatGPT 3.5 in July 2023 and were repeated three times. Responses were graded in two domains: accuracy (4-point Likert scale, 4 = worst) and clinical concordance (information is clinically similar to physician response; 5-point Likert scale, 5 = not similar at all). The concordance of responses with repetition was estimated using intraclass correlation coefficient (ICC) of word counts. Response readability was calculated using the Flesch Kincaid readability scale. References were requested and verified. RESULTS: The overall average accuracy was 1.88 (range 1.0-3.0; 95% confidence interval [CI], 1.42-1.94), and clinical concordance was 2.79 (range 1.0-5.0; 95% CI, 1.94-3.64). The average word count was 310 words per response (range, 146-441 words per response) with high concordance (ICC, 0.75; 95% CI, 0.59-0.91; p < .001). The average readability was poor at 37.9 (range, 18.0-60.5) with high concordance (ICC, 0.73; 95% CI, 0.57-0.90; p < .001). There was a weak correlation between ease of readability and better clinical concordance (-0.15; p = .025). Accuracy did not correlate with readability (0.05; p = .079). The average number of references was 1.97 (range, 1-4; total, 119). ChatGPT cited peer-reviewed articles only once and often referenced nonexistent websites (41%). CONCLUSIONS: Because ChatGPT 3.5 responses were incorrect 24% of the time and did not provide real references 41% of the time, patients should be cautioned about using ChatGPT for medical information.

Dynamic PET reveals compartmentalized brain and lung tissue antibiotic exposures of tuberculosis drugs.

Tuberculosis (TB) remains a leading cause of death, but antibiotic treatments for tuberculous meningitis, the deadliest form of TB, are based on those developed for pulmonary TB and not optimized for brain penetration. Here, we perform first-in-human dynamic 18F-pretomanid positron emission tomography (PET) in eight human subjects to visualize 18F-pretomanid biodistribution as concentration-time exposures in multiple compartments (NCT05609552), demonstrating preferential brain versus lung tissue partitioning. Preferential, antibiotic-specific partitioning into brain or lung tissues of several antibiotics, active against multidrug resistant (MDR) Mycobacterium tuberculosis strains, are confirmed in experimentally-infected mice and rabbits, using dynamic PET with chemically identical antibiotic radioanalogs, and postmortem mass spectrometry measurements. PET-facilitated pharmacokinetic modeling predicts human dosing necessary to attain therapeutic brain exposures. These data are used to design optimized, pretomanid-based regimens which are evaluated at human equipotent dosing in a mouse model of TB meningitis, demonstrating excellent bactericidal activity without an increase in intracerebral inflammation or brain injury. Importantly, several antibiotic regimens demonstrate discordant activities in brain and lung tissues in the same animal, correlating with tissue antibiotic exposures. These data provide a mechanistic basis for the compartmentalized activities of antibiotic regimens, with important implications for developing treatments for meningitis and other infections in compartments with unique antibiotic penetration.

High Prevalence of Artifacts in Optical Coherence Tomography With Adequate Signal Strength.

Purpose: This study aims to investigate the prevalence of artifacts in optical coherence tomography (OCT) images with acceptable signal strength and evaluate the performance of supervised deep learning models in improving OCT image quality assessment. Methods: We conducted a retrospective study on 4555 OCT images from 546 patients, with each image having an acceptable signal strength (≥6). A comprehensive analysis of prevalent OCT artifacts was performed, and five pretrained convolutional neural network models were trained and tested to infer images based on quality. Results: Our results showed a high prevalence of artifacts in OCT images with acceptable signal strength. Approximately 21% of images were labeled as nonacceptable quality. The EfficientNetV2 model demonstrated superior performance in classifying OCT image quality, achieving an area under the receiver operating characteristic curve of 0.950 ± 0.007 and an area under the precision recall curve of 0.985 ± 0.002. Conclusions: The findings highlight the limitations of relying solely on signal strength for OCT image quality assessment and the potential of deep learning models in accurately classifying image quality. Translational Relevance: Application of the deep learning-based OCT image quality assessment models may improve the OCT image data quality for both clinical applications and research.

Supporting the nation in crisis: the military health system's role in enhancing public health capacity through public-private partnerships.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic caused significant global disruptions to the healthcare system, which was forced to make rapid changes in healthcare delivery. The pandemic necessitated closer collaboration between the US civilian healthcare sector and the military health system (MHS), resulting in new and strengthened partnerships that can ultimately benefit public health and healthcare for the nation. In this study, we sought to understand the full range of partnerships in which the MHS engaged with the civilian sector during the COVID-19 pandemic and to elicit lessons for the future. METHODS: We conducted key informant interviews with MHS policymakers and advisers, program managers and providers who were affiliated with the MHS from March 2020 through December 2022. Key themes were derived using thematic analysis and open coding methods. RESULTS: We conducted 28 interviews between December 2022 and March 2023. During the pandemic, the MHS collaborated with federal and local healthcare authorities and private sector entities through endeavours such as Operation Warp Speed. Lessons and recommendations for future pandemics were also identified, including investment in biosurveillance systems and integration of behavioural and social sciences. CONCLUSIONS: The MHS rapidly established and fostered key partnerships with the public and private sectors during the COVID-19 pandemic. The pandemic experience showed that while the MHS is a useful resource for the nation, it also benefits from partnering with a variety of organizations, agencies and private companies. Continuing to develop these partnerships will be crucial for coordinated, effective responses to future pandemics.