Study of PT1 Peptide Analgesic and Anti-Inflammatory Activity on a Local Inflammation Model in Mice CD-1.

PT1 peptide isolated from the venom of spider Geolycosa sp. is a modulator of P2X3 receptors that play a role in the development of inflammation and the transmission of pain impulses. The anti-inflammatory and analgesic efficacy of the PT1 peptide was studied in a model of complete Freund's adjuvant-induced paw inflammation in CD-1 mice. The analgesic activity of PT1 peptide was maximum after intramuscular injection at a dose of 0.01 mg/kg, which surpassed the analgesic effect of diclofenac at a dose of 1 mg/kg. The anti-inflammatory activity was maximum after intramuscular injection at a dose of 0.0001 mg/kg; a decrease in paw thickness was observed as soon as 2 h after the administration of the PT1 peptide against the background of inflammation development. All tested doses of PT1 peptide showed high anti-inflammatory activity 4 and 24 h after administration. PT1 peptide at a dose of 0.01 mg/kg when injected intramuscularly simultaneously produced high anti-inflammatory and analgesic effects compared to other doses of the peptide. Increasing the dose of PT1 peptide led to a gradual decrease in its analgesic and anti-inflammatory activity; increasing the dose of intramuscular injection to 0.1 and 1 mg/kg is inappropriate.

Protein Kinase A Inhibitor Attenuates the Antinociceptive Effect of NMDA-Receptor Channel Antagonists in the Capsaicin Test in Mice.

Acute nociceptive pain in mice caused by subcutaneous (intraplantar) injection of TRPV1 ion channel agonist capsaicin (1.6 µg/mouse) and the effects of protein kinase A inhibitor H-89 (0.05 mg/mouse, intraplantar injection) and NMDA receptor channel antagonists MK-801 (7.5 and 15 µg/mouse, topical application) and hemantane (0.5 mg/mouse, topical application) on the pain were assessed. MK-801 and hemantane were found to reduce the duration of the pain response. H-89 did not significantly affect the pain in animals, but preliminary administration of this drug abolished the antinociceptive effect of MK-801 (7.5 µg/mouse) and weakens the effect of hemantane (0.5 mg/mouse).

Use of Adjuvant Compositions Based on Squalene Ensures Induction of Neutralizing Antibodies against SARS-CoV-2.

Squalene-based adjuvant compositions that can provide effective induction of specific humoral immune response have been developed. Recombinant receptor-binding domain (RBD) of surface S-protein of SARS-CoV-2 was used to evaluate the properties of the composition. Immunization of mice with the developed squalene-based compositions in combination with RBD allows obtaining high titers of specific antibodies: from 105 to 2×106. The blood sera from immunized mice exhibit neutralizing activity against SARS-CoV-2 Delta variant (B.1.617.2) with a titer up to 1:2000.

Analysis of the citation impact of Brazilian researchers in oral pathology and oral medicine over two decades.

BACKGROUND: Brazilian Oral Pathology (OP) and Oral Medicine (OM) have gained significant international recognition. However, no study has yet evaluated the impact of citations in scientific publications. Therefore, this study aimed to analyze the impact of citations from Brazilian researchers in OP and OM over the last two decades. MATERIAL AND METHODS: This was a cross-sectional study involving 50 researchers linked to postgraduate programs in OP/OM. Data collected from each professional's Lattes curriculum included gender, academic affiliation, the corporate category of the institution, and location. The number of papers published and citations received between 2004 to 2013 and 2014 to 2023 was also collected from the Web of Science database. RESULTS: Most researchers were male (56%) and from public institutions (90%), mainly in the Southeast region (60%). Over two decades, they collectively published 8,033 scientific articles, with significant growth (p<0.001) from to 2004-2013 to 2014-2023. While the average citations per researcher did not differ significantly between 2004-2013 and 2014-2023 (p=0.538), there was a notable 67.67% increase in citations in the last decade. CONCLUSIONS: Brazilian researchers in the areas of OP and OM have demonstrated a significant academic impact over the past two decades, with a marked increase in publications and citations over the last ten years. This highlights the contribution of Brazilians to the global scientific community in these areas.

Cardio- and Vasoprotective Effects of Quinacrine in an In Vivo Rat Model of Myocardial Ischemia/Reperfusion Injury.

This study aimed to investigate the cardioprotective effect of quinacrine in an in vivo model of myocardial ischemia/reperfusion injury. A 30-min regional myocardial ischemia followed by a 2-h reperfusion was modeled in anesthetized Wistar rats. Starting at the last minute of ischemia and during the first 9 min of reperfusion the rats in the control (n=8) and experimental (n=9) groups were injected with 0.9% NaCl and quinacrine solution (5 mg/kg), respectively. The area at risk and infarct size were evaluated by "double staining" with Evans blue and triphenyltetrazolium chloride. To assess vascular permeability in the area at risk zone, indocyanine green (ICG) and thioflavin S (ThS) were injected intravenously at the 90th and 120th minutes of reperfusion, respectively, to assess the no-reflow zone. The images of ICG and ThS fluorescence in transverse sections of rat hearts were obtained using a FLUM multispectral fluorescence organoscope. HR tended to decrease by 13% after intravenous administration of quinacrine and then recovered within 50 min. Quinacrine reduced the size of the necrotic zone (p=0.01), vascular permeability in the necrosis region, and the no-reflow area (p=0.027); at the same time, the area at risk did not significantly differ between the groups. Intravenous administration of quinacrine at the beginning of reperfusion of the rat myocardium reduces no-reflow phenomenon and infarct size.

Distinct subcircuits within the mesolimbic dopamine system encode the salience and valence of social stimuli.

The mesolimbic dopamine (DA) system (MDS) is the canonical "reward" pathway that has been studied extensively in the context of the rewarding properties of sex, food, and drugs of abuse. In contrast, very little is known about the role of the MDS in the processing of the rewarding and aversive properties of social stimuli. Social interactions can be characterized by their salience (i.e., importance) and their rewarding or aversive properties (i.e., valence). Here, we test the novel hypothesis that projections from the medial ventral tegmental area (VTA) to the nucleus accumbens (NAc) core codes for the salience of social stimuli through the phasic release of DA in response to both rewarding and aversive social stimuli. In contrast, we hypothesize that projections from the lateral VTA to the NAc shell codes for the rewarding properties of social stimuli by increasing the tonic release of DA and the aversive properties of social stimuli by reducing the tonic release of DA. Using DA amperometry, which monitors DA signaling with a high degree of temporal and anatomical resolution, we measured DA signaling in the NAc core or shell while rewarding and aversive social interactions were taking place. These findings, as well as additional anatomical and functional studies, provide strong support for the proposed neural circuitry underlying the response of the MDS to social stimuli. Together, these data provide a novel conceptualization of how the functional and anatomical heterogeneity within the MDS detect and distinguish between social salience, social reward, and social aversion. Significance Statement: Social interactions of both positive and negative valence are highly salient stimuli that profoundly impact social behavior and social relationships. Although DA projections from the VTA to the NAc are involved in reward and aversion little is known about their role in the saliency and valence of social stimuli. Here, we report that DA projections from the mVTA to the NAc core signal the salience of social stimuli, whereas projections from the lVTA to the NAc shell signal valence of social stimuli. This work extends our current understanding of the role of DA in the MDS by characterizing its subcircuit connectivity and associated function in the processing of rewarding and aversive social stimuli.

The International Consensus for Early TB framework (ICE-TB): Implications from a low-incidence setting.

In recent years, there has been increasing recognition of the public health significance of the spectrum of TB disease presentation, and the existing classification systems of asymptomatic infection and symptomatic TB have been limited in terms of explanatory power. Accordingly, in 2022-2023, a new International Consensus framework for Early TB (ICE-TB) was developed, categorising the spectrum of TB infection and disease into five states based on the presence or absence of macroscopic pathology, host infectiousness, and symptoms and signs.We used the ICE-TB framework to re-analyse existing notification data for 2022 within a low-incidence setting to explore the potential utility and future challenges for its public health application.Existing notification data were sufficient to allow substantial reclassification of currently recognised active disease states, but did not systematically capture Mycobacterium tuberculosis infection or subclinical TB. Fifty percent of existing TB notifications would be classified as 'Clinical, infectious', with the potential need to consider further subclassification.Our exploration highlighted limitations in existing classification systems and diagnostic approaches and should encourage researchers and programmatic implementers to emphasise person-centred and programmatic needs in the development of new tools for TB management..

Prevalence of HIV-related stigma among people with HIV in Switzerland: addressing the elephant in the room.

OBJECTIVES: We aimed to determine the prevalence of HIV-related stigma among people with HIV (PWH) in Switzerland. DESIGN: A cross-sectional multicentre study nested within the Swiss HIV Cohort Study (SHCS). METHODS: We included adult PWH enrolled in the SHCS, attending follow-up between March 1st, 2020, and January 31st, 2021. Inability to speak English, French, German, or Italian was the only exclusion criterion. Participants were invited to complete a validated 12-item HIV-stigma questionnaire comprising four stigma subscales (negative self-image, personalised stigma, disclosure concerns, and concerns regarding public attitudes), plus two healthcare-related stigma items. Questionnaire responses were graded using a four-point Likert-type scale, higher scores indicating higher stigma. "Non-applicable", inferring HIV-status non-disclosure, was possible for personalised stigma; stigma scores from participants answering "non-applicable" to ≥1 items were analysed separately. Factors associated with HIV-stigma were identified through multivariable linear models. RESULTS: Of 9643 PWH with a SHCS visit, 5563 participated in the study: 26% were female, 13% Black and 37% heterosexual; median age was 53 years (interquartile range 44-59); 2067 participants (37%) gave ≥1 "non-applicable" responses. Disclosure concerns had the highest stigma scores and were reported by 4656/5563 (84%). HIV-stigma was reported across all demographic groups. However, being female, Black, and heterosexual were independently associated with higher scores. Higher education and longer follow-up duration were associated with lower scores. Healthcare-related stigma was reported in 37% of participants. CONCLUSIONS: HIV-stigma was prevalent across all demographic groups. The association with being female and Black suggests that HIV-stigma accentuates pre-existing gender and race inequalities.

Operating semiconductor quantum processors with hopping spins.

Qubits that can be efficiently controlled are essential for the development of scalable quantum hardware. Although resonant control is used to execute high-fidelity quantum gates, the scalability is challenged by the integration of high-frequency oscillating signals, qubit cross-talk, and heating. Here, we show that by engineering the hopping of spins between quantum dots with a site-dependent spin quantization axis, quantum control can be established with discrete signals. We demonstrate hopping-based quantum logic and obtain single-qubit gate fidelities of 99.97%, coherent shuttling fidelities of 99.992% per hop, and a two-qubit gate fidelity of 99.3%, corresponding to error rates that have been predicted to allow for quantum error correction. We also show that hopping spins constitute a tuning method by statistically mapping the coherence of a 10-quantum dot system. Our results show that dense quantum dot arrays with sparse occupation could be developed for efficient and high-connectivity qubit registers.

Co-administration of either curcumin or resveratrol with cisplatin treatment decreases hepatotoxicity in rats via anti-inflammatory and oxidative stress-apoptotic pathways.

Background: Cisplatin (CIS) is a broad-spectrum anticancer drug, with cytotoxic effects on either malignant or normal cells. We aimed to evaluate the hepatotoxicity in rats caused by CIS and its amelioration by the co-administration of either curcumin or resveratrol. Materials and Methods: Forty adult male rats divided into four equal groups: (control group): rats were given a saline solution (0.9%) once intraperitoneally, daily for the next 28 days; (cisplatin group): rats were given a daily oral dose of saline solution (0.9%) for 28 days after receiving a single dose of cisplatin (3.3 mg/kg) intraperitoneally for three successive days; (CIS plus curcumin/resveratrol groups): rats received the same previous dose of cisplatin (3.3 mg/kg) daily for three successive days followed by oral administration of either curcumin/resveratrol solution at a dose of (20 mg/kg) or (10 mg/kg) consequently daily for 28 days. Different laboratory tests (ALT, AST, ALP, bilirubin, oxidative stress markers) and light microscopic investigations were done. Results: Administration of CIS resulted in hepatotoxicity in the form of increased liver enzymes, oxidative stress markers; degenerative and apoptotic changes, the co-administration of CIS with either curcumin or resveratrol improved hepatotoxicity through improved microscopic structural changes, reduction in liver enzymes activity, decreased oxidative stress markers, improved degenerative, and apoptotic changes in liver tissues. Conclusion: Co-administration of either curcumin or resveratrol with cisplatin treatment could ameliorate hepatotoxicity caused by cisplatin in rats via anti-inflammatory and oxidative stress-apoptotic pathways.

Age Trajectories of the Structural Connectome in Child and Adolescent Offspring of Individuals With Bipolar Disorder or Schizophrenia.

Background: Offspring of parents with severe mental illness (e.g., bipolar disorder or schizophrenia) are at elevated risk of developing psychiatric illness owing to both genetic predisposition and increased burden of environmental stress. Emerging evidence indicates a disruption of brain network connectivity in young offspring of patients with bipolar disorder and schizophrenia, but the age trajectories of these brain networks in this high-familial-risk population remain to be elucidated. Methods: A total of 271 T1-weighted and diffusion-weighted scans were obtained from 174 offspring of at least 1 parent diagnosed with bipolar disorder (n = 74) or schizophrenia (n = 51) and offspring of parents without severe mental illness (n = 49). The age range was 8 to 23 years; 97 offspring underwent 2 scans. Anatomical brain networks were reconstructed into structural connectivity matrices. Network analysis was performed to investigate anatomical brain connectivity. Results: Offspring of parents with schizophrenia had differential trajectories of connectivity strength and clustering compared with offspring of parents with bipolar disorder and parents without severe mental illness, of global efficiency compared with offspring of parents without severe mental illness, and of local connectivity compared with offspring of parents with bipolar disorder. Conclusions: The findings of this study suggest that familial high risk of schizophrenia is related to deviations in age trajectories of global structural connectome properties and local connectivity strength.

In this article, we show that child and adolescent offspring of parents with schizophrenia had different patterns in the development of their brain's structural connections compared with offspring of parents with bipolar disorder and offspring of parents without these conditions. The findings of this long-term study indicate that having a family history of schizophrenia is associated with changes over time during adolescence in the overall organization of the brain's structural network.

Synthesis of novel fatty acid 3,4-dihydropyrimidin-2-(1H)-one and antitumoral activity against breast and gastric cancer cells.

Monastrol is the best-known small compound from the dihydropyrimidinones/thiones (DHPMs) heterocycle family, a cell-permeable molecule recognized as an inhibitor of mitotic kinesin Eg5, that is over-expressed in tumor cells and is a very promising target for the development of new drugs for cancer. The lipophilic properties of the DHPMs have been demonstrated to be of pivotal importance in the design of new molecules. This work describes the synthesis and antitumoral activity of novel C5-substituted fatty-DHPMs against breast and gastric cancer cell lines. The compounds were synthesized via Biginelli multicomponent reaction from oleyl ß-ketoester in good yields (40-72%) using a simple approach catalyzed by nontoxic and free-metal sulfamic acid. Among the compounds tested, the compound 10c, derived from 3-hydroxybenzaldehyde and urea, exhibited 77% cellular viability to normal cells (C2C12) and was selected to be evaluated against tumoral breast (MCF-7) and gastric (AGS) cell lines. The results obtained afforded an IC50 of breast cancer cells of 2.3 µM, qualifying the molecule as the most potent, and making it a promising compound for future experiments in vivo.

The Insulin Sensitizer KBP-336 Prevents Diabetes-Induced Cognitive decline in ZDF Rats.

BACKGROUND AND OBJECTIVES: Diabetes and especially insulin resistance are associated with an increased risk of developing cognitive dysfunction, making anti-diabetic drugs an interesting therapeutic option for the treatment of neurodegenerative disorders. Dual amylin and calcitonin receptor agonists (DACRAs) elicit beneficial effects on glycemic control and insulin sensitivity. However, whether DACRAs affect cognition is unknown. DESIGN AND INTERVENTION: Zucker Diabetic Fatty rats were treated with either the DACRA KBP-336 (4.5 nmol/kg Q3D), the amylin analog AM1213 (25 nmol/kg QD), or vehicle for 18 weeks. Further, the efficacy of a late KBP-336 intervention was evaluated by including a group starting treatment on day 30. Glucose control and tolerance were evaluated throughout the study and spatial learning and memory were evaluated by Morris Water Maze after 17 weeks of treatment. RESULTS: When evaluating spatial learning, rats receiving KBP-336 throughout the study performed significantly better than AM1213, vehicle, and late intervention KBP-336. Both KBP-336 and AM1213 treatments improved spatial memory compared to the vehicle. The overall performance in the cognitive tests was reflected in the treatment efficacy on glycemic control, where KBP-336 was superior to AM1213. CONCLUSION: In summary, the DACRA KBP-336 ameliorates diabetes-induced spatial learning and memory impairment in diabetic rats. Further, KBP-336 improves long-term glycemic control superior to the amylin analog AM1213. Taken together, KBP-336 is, due to its anti-diabetic and insulin-sensitizing properties, a promising candidate for the treatment of cognitive impairments.

Management of functional constipation-associated halitosis: a retrospective study.

The features of functional constipation (FC)-associated halitosis were identified in the author's previous report. In this report, the author aimed to further investigate its treatment and efficacy. This retrospective study reviewed 100 FC patients, including 82 (82%) halitosis patients and 18 (18%) non-halitosis patients. They underwent the organoleptic test (OLT) to diagnose halitosis, and the organoleptic score (OLS) (0-5) was used to evaluated halitosis severity. The Cleveland Clinical Constipation Score (CCCS) (0-30) was used to evaluate FC severity. Patients were treated with the laxative polyethylene glycol electrolyte powder (PGEP) for four weeks. These tests were performed before and after treatment. The author found that, before treatment, the CCCS was 20.00 (18.00-23.00) for all patients, 21.00 (19.00-24.00) for halitosis patients, and 18.00 (17.00-18.25) for non-halitosis patients. A significant difference was observed between halitosis patients and non-halitosis patients (P< 0.001). The OLS for halitosis patients was 3.00 (3.00-4.00). A positive correlation (r= 0.814, 95% CI: 0.732-0.872,P< 0.001) was found between OLS and CCCS. A CCCS ⩾18 predicted over 50% probability of halitosis. After treatment, the CCCS significantly decreased to 11.50 (6.00-14.75) (P< 0.001), and OLS significantly decreased to 1.00 (0.00-2.00) (P< 0.001). A positive correlation (r= 0.770, 95% CI: 0.673-0.841,P< 0.001) persisted between OLS and CCCS. A pre-treatment CCCS ⩾21 predicted over 50% probability of post-treatment halitosis, while a post-treatment CCCS ⩾12 predicted over 50% probability of post-treatment halitosis. The author concludes that the severity of FC parallels the severity of FC-associated halitosis, and can predict the probability of halitosis. Laxative treatment with PGEP is effective in improving FC-associated halitosis.

Core socioDemographic data variables in ICU Trials (CoDe-IT): a protocol for generating core data variables using a Delphi consensus process.

INTRODUCTION: Sociodemographic variables influence health outcomes, either directly (ie, gender identity) or indirectly (eg, structural/systemic racism based on ethnoracial group). Identification of how sociodemographic variables can impact the health of critically ill adults is important to guide care and research design for this population. However, despite the growing recognition of the importance of collecting sociodemographic measures that influence health outcomes, insufficient and inconsistent data collection of sociodemographic variables persists in critical care studies. We aim to develop a set of core data variables (CoDaV) for social determinants of health specific to studies involving critically ill adults. METHODS AND ANALYSIS: We will conduct a scoping review to generate a list of possible sociodemographic measures to be used for round 1 of the modified Delphi processes. We will engage relevant knowledge users (previous intensive care unit patients and family members, critical care researchers, critical care clinicians and research co-ordinators) to participate in the modified Delphi consensus survey to identify the CoDaV. A final consensus meeting will be held with knowledge user representatives to discuss the final CoDaV, how each sociodemographic variable will be collected (eg, level of granularity) and how to disseminate the CoDaV for use in critical care studies. ETHICS AND DISSEMINATION: The University of Calgary conjoint health research ethics board has approved this study protocol (REB22-1648).

Distinctive clinical traits of lupus-related myocarditis: a multicentre retrospective study.

OBJECTIVES: Cardiovascular involvement in systemic lupus erythematosus (SLE) is frequent but little is known about possible distinctive traits of SLE-related myocarditis (myoSLE) in comparison to patients with SLE (onlySLE) or myocarditis alone (onlyMyo). METHODS: A retrospective analysis was performed comparing patients with myoSLE (n = 25) from three centres with consecutive patients with onlySLE (n = 279) and onlyMyo (n = 88). SLE patients were dichotomised by disease duration ≤1 vs >1 year into recent onlySLE/early myoSLE vs longstanding onlySLE/late myoSLE. Further stratification into disease duration of 1-5, 5-10 and >10 years was also performed. SLE disease activity index 2000 (SLEDAI-2K) was used to estimate disease activity. Myocarditis was diagnosed through biopsy or magnetic resonance. RESULTS: Women were significantly more frequent among myoSLE than among onlyMyo (72% vs 43%; p= 0.013). Compared with onlyMyo, myoSLE patients had a higher frequency of conduction abnormalities (22% vs 5%; p= 0.046) and presented with numerically higher frequencies of left ventricular function compromise (48% vs 30%), along with higher pro-brain natriuretic peptide levels. Inflammation markers were higher in myoSLE compared with onlyMyo and to patients with onlySLE with >10 years of disease duration. SLEDAI-2K was significantly higher in late myoSLE than in longstanding onlySLE. Antiphospholipid syndrome was more frequent in myoSLE than in onlySLE. Multivariate analysis showed an association among myoSLE, anti-beta-2-glycoprotein I antibodies (aB2GPI, p= 0.014) and a higher number of involved British Isles Lupus Assessment Group domains in patient history (p= 0.003). CONCLUSION: myoSLE has unique clinical traits compared with other forms of myocarditis and is associated with aB2GPI and a more severe SLE course.

Risk factors for bloodstream infections due to carbapenem-resistant Enterobacterales: a nested case-control-control study.

BACKGROUND: Carbapenem-resistant Enterobacterales (CRE) bloodstream infections (BSIs) are a major threat to patients. To date, data on risk factors have been limited, with low internal and external validity. In this multicentre study, risk factors for CRE BSI were determined by comparison with two control groups: patients with carbapenem-susceptible Enterobacterales (CSE) BSI, and patients without Enterobacterales infection (uninfected patients). METHODS: A multicentre, case-control-control study was nested in a European prospective cohort study on CRE (EURECA). CRE BSI:CSE BSI matching was 1:1, CRE BSI:Uninfected patients matching was 1:3, based on hospital, ward and length of stay. Conditional logistic regression was applied. RESULTS: From March 2016 to November 2018, 73 CRE BSIs, 73 CSE BSIs and 219 uninfected patients were included from 18 European hospitals. For CRE versus CSE BSI, previous CRE colonization/infection [incidence rate ratio (IRR) 7.32; 95% CI 1.65-32.38) increased the risk. For CRE versus uninfected controls, independent risk factors included: older age (IRR 1.03; 95% CI 1.01-1.06), patient referral (long-term care facility: IRR 7.19; 95% CI 1.51-34.24; acute care hospital: IRR 5.26; 95% CI 1.61-17.11), previous colonization/infection with other MDR organisms (MDROs) (IRR 9.71; 95% CI 2.33-40.56), haemodialysis (IRR 8.59; 95% CI 1.82-40.53), invasive procedures (IRR 5.66; 95% CI 2.11-15.16), and ß-lactam/ß-lactamase inhibitor combinations (IRR 3.92; 95% CI 1.68-9.13) or third/fourth generation cephalosporin (IRR 2.75; 95% CI 1.06-7.11) exposure within 3 months before enrolment. CONCLUSIONS: Evidence of previous CRE colonization/infection was a major risk factor for carbapenem resistance among Enterobacterales BSI. Compared with uninfected patients, evidence of previous MDRO colonization/infection and healthcare exposure were important risk factors for CRE BSI. Targeted screening, infection prevention and antimicrobial stewardship should focus on these high-risk patients.

Day-to-day reliability of basal heart rate and short-term and ultra short-term heart rate variability assessment by the Equivital eq02+ LifeMonitor in US Army soldiers.

INTRODUCTION: The present study determined the (1) day-to-day reliability of basal heart rate (HR) and HR variability (HRV) measured by the Equivital eq02+ LifeMonitor and (2) agreement of ultra short-term HRV compared with short-term HRV. METHODS: Twenty-three active-duty US Army Soldiers (5 females, 18 males) completed two experimental visits separated by >48 hours with restrictions consistent with basal monitoring (eg, exercise, dietary), with measurements after supine rest at minutes 20-21 (ultra short-term) and minutes 20-25 (short-term). HRV was assessed as the SD of R-R intervals (SDNN) and the square root of the mean squared differences between consecutive R-R intervals (RMSSD). RESULTS: The day-to-day reliability (intraclass correlation coefficient (ICC)) using linear-mixed model approach was good for HR (0.849, 95% CI: 0.689 to 0.933) and RMSSD (ICC: 0.823, 95% CI: 0.623 to 0.920). SDNN had moderate day-to-day reliability with greater variation (ICC: 0.689, 95% CI: 0.428 to 0.858). The reliability of RMSSD was slightly improved when considering the effect of respiration (ICC: 0.821, 95% CI: 0.672 to 0.944). There was no bias for HR measured for 1 min versus 5 min (p=0.511). For 1 min measurements versus 5 min, there was a very modest mean bias of -4 ms for SDNN and -1 ms for RMSSD (p≤0.023). CONCLUSION: When preceded by a 20 min stabilisation period using restrictions consistent with basal monitoring and measuring respiration, military personnel can rely on the eq02+ for basal HR and RMSSD monitoring but should be more cautious using SDNN. These data also support using ultra short-term measurements when following these procedures.